PSD14: International Conference on Position Sensitive Detectors

31 Aug 2026, 18:00 → 4 Sept 2026, 22:00 Europe/London

Mile End Campus: Graduate Centre Foyer and Peston Lecture Theatre (Queen Mary University of London, London, UK)

The conference will feature the latest developments in position sensitive radiation detectors from leading researchers around the world, and across a wide range of scientific disciplines. The conference has a strong multidisciplinary emphasis, and encourages cross-fertilisation and transfer of ideas between researchers working in many fields. In person participation is important. The PSD conference takes place every 3 years, with the first edition held in September 1986.

All sessions are plenary, starting with an overview presentation by a keynote speaker and then the research presentations on that topic.

 

Registration and call for abstracts are now closed. 

Registration includes one place at conference dinner on Wednesday 2 September, and refreshments throughout the 4 days of the conference. Accomodation booked separately at £76/night (see instructions on registration page).

 

The conference will cover a broad range of application areas, including:

• X-ray and gamma-ray imaging applications
• Detector systems for particle and nuclear physics experiments
• Instrumentation for synchrotrons and advanced light sources
• Detectors for neutron science facilities
• Imaging and sensing for life sciences and medical applications
• Space and planetary science detector systems
• Astrophysics and astroparticle detection applications
• Security, environmental, and monitoring applications
• Detectors operating in high-radiation and extreme conditions
• Applications in condensed matter and materials research
• Fast timing and high-rate measurement applications
• Emerging applications of novel and quantum detectors
• Advances in pixel detectors and integration technology
• Gas-based detection detector systems

Thanks to our Sponsors!

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For more info see sponsors tab at left!

Monday 31 August

18:00 Informal Pub/Dinner Meetup - The Cherry - 359 Mile End Road

No booking needed, not a formal or organised event. If you're in town, feel free to drop in and meet a few of the conference organisers.

Tuesday 1 September

10:00 Registration and Coffee

12:00 Lunch

Opening Session

Convener: Seth Zenz (Queen Mary University of London)

1 Introduction and Logistics

Speaker: Seth Zenz (Queen Mary University of London)

PSD14 Intro.pdf

PSD14 Intro.pptx

2 Welcome to Queen Mary University of London

Speaker: Adrian Bevan (Queen Mary University of London (GB))

2026-09-01-PSD.pdf

Detectors for Light Sources and Neutron Facilities: Detectors for Light Sources and Neutron Facilities 1

Convener: Seth Zenz (Queen Mary University of London)

3 Organic and inorganic neutron detector developments

We present novel thermal and fast neutron detector technologies that have been created at QMUL in collaboration with our industrial partners, AWE and Micron Semiconductor Ltd. These technologies enable the creation of large area thermal and fast neutron detector solutions using organic and inorganic semiconductors. We have demonstrated the ability to detect neutrons over the range of energies from 0.025eV to 16.5MeV with organic semiconductor technology. Our inorganic semiconductor technology enables us to detect fast neutrons with a low photon background contamination, as well as having an enriched boron coating that enables the measurement of thermal neutrons. Simulation has played an important role in the design of these technologies, and also in helping us establish the QMUL Neutron facility. Signals from the organic and inorganic sensors can be acquired and analysed to disambiguate between the fast and thermal neutron components in the data.

Copyright 2026 UK Ministry of Defence © Crown Owned Copyright 2026/AWE

Speaker: Adrian Bevan (Queen Mary University of London (GB))

PSD14_Bevan_NeutronDetectors.pdf

Advances in Pixel Detectors & Integration Technologies: Advances in Pixel Detectors And Integration Technologies 0

Convener: Seth Zenz (Queen Mary University of London)

4 Lessons learned from the ATLAS Pixel Detector operation at LHC in Phase-1

After more than 15 years of operation, the ATLAS Pixel Detector will take its final data this June before being replaced with a new all-silicon detector (ITk) during LHC Long Shutdown 3. Its original part, consisting in 3 layers of planar pixel sensor was continuously operating well since the start of LHC collisions in 2008, while its innermost layer, the Insertable B Layer (IBL) at about 3 cm from the beam line, was installed in 2015 before the start of LHC Run2 and consisted of both planar and 3D pixel sensors.
The Pixel detector successfully collected data during LHC runs 1-3, under conditions that exceeded the original specifications by a large factor. Over the years, the Pixel Detector faced a number of technical and operational challenges, particularly in terms of radiation damage, occupancy, and trigger rate. This talk will describe the main issues encountered and the solutions that were found to ensure highest data quality and smooth operation throughout the lifetime of the detector. The lessons learned from the ATLAS Pixel Detector can provide valuable guidance for the design and operation of future experiments.

Speaker: Chris Scheulen (Universite de Geneve (CH))

C_Scheulen_PSD14.pdf

14:20 Coffee

Life Sciences and Consensed Matter: Life Sciences and Condensed Matter

Convener: Dr Paul Miyagawa (University of London (GB))

5 An Imaging and Spectroscopy Detector for High-Energy, High-Rate Gamma-Ray Measurements during Proton Therapy

Prompt-gamma imaging has the potential to reduce range uncertainties in medical proton therapy by detecting prompt-gamma rays emitted during treatment. Within the REALPATH project, we are developing a novel prompt-gamma imaging camera based on an array of 512 LYSO scintillator pixels (6 mm × 6 mm × 30 mm each) coupled to SiPMs and read out by a custom electronics platform incorporating the SITH (Spectroscopy Imaging Timing Hadrontherapy) ASIC. To accommodate the high fluence delivered by modern medical proton accelerators, the detector is designed to cope with rates of up to 1 Mcps per pixel across all 512 pixels. At the same time, good spectroscopic performance at high energies, in the range of 3 MeV to 6 MeV, is important for effective neutron background rejection and prompt-gamma emission analysis. In this contribution, we present the experimental characterization of the first 64-pixel detector module together with the first proton range measurements in a PMMA phantom at CNAO (Centro Nazionale di Adroterapia Oncologica) in Pavia, Italy. Detector characterization was carried out using $^{137}$Cs and $^{241}$Am-Be radioactive sources, enabling performance studies at count rates exceeding 1 Mcps per pixel and at gamma-ray energies up to 4.4 MeV from the $^{241}$Am-Be source. Using these measurements, we investigated the effect of light sharing between neighboring pixels within each 4x4 SiPM array and developed a correction method that significantly improves the detector's spectroscopic performance. The measurements demonstrate a low dead time of 412 ns per event and an excellent energy resolution of 4.8% FWHM at the 4.44 MeV full-energy peak. These characteristics make the detector a promising candidate not only for prompt-gamma imaging but also for other applications requiring position-sensitive, high-rate gamma-ray spectroscopy.

Speaker: Korbinian Urban (Department of Electronics, Information and Bioengineering (DEIB), Politecnico di Milano, Milan, Italy and National Institute for Nuclear Physics (INFN), Milan Section, Milan, Italy)

2026_09_01_psd14_kurban_realpath.pdf

6 Leveraging photon counting technology for single-mask x-ray phase contrast micro-CT

X-ray Phase Contrast (XPC) micro-CT enables imaging weakly attenuating samples that are challenging to image with conventional micro-CT. Our group focuses on mask-based XPC, using a highly attenuating mask upstream of the sample to shape the x-ray beam into beamlets. Attenuation and refraction by the sample then cause an intensity reduction and directional shift of the beamlets, respectively.

To detect these effects, a detector with sufficiently small pixels to resolve and “track” the beamlets can be employed; however, this can be impractical due to limitations in matrix size leading to small fields-of-view with high-resolution detectors. With larger-pixel detectors (e.g., common flat panels), tracking the beamlets requires a second mask creating an array of well-defined edges in front of the pixels; however, two exposures with different mask-detector alignments are required to quantitatively extract attenuation and refraction. Photon counting detectors offer reasonably large fields of view (e.g., 77.1 by 38.4 mm$^{2}$) while providing sharp transitions between pixels, removing the need for the second mask and allowing to quantitatively extract attenuation and refraction from a single exposure.

This talk will introduce a single-mask XPC system incorporating a photon counting detector (DECTRIS EIGER2 R 500K) and discuss how its properties can be exploited to improve image quality: on top of the absence of dark noise, ensuring ideal signal-to-noise, the lack of inter-pixel noise correlation enables self-supervised image denoising via Noise2Noise-style approaches. We also illustrate the system’s performance through an application in developmental biology, showing high-contrast images of mouse fetuses that reveal soft-tissue structures inaccessible with conventional micro-CT.

Speaker: KHUSHAL SHAH (University College London)

PSD14_Khush.pptx

7 New time-of-flight ion imaging system based on LGADs

Time-of-flight ion computed tomography (ToF-iCT) is a promising imaging technique for ion beam therapy, offering the potential to enhance dose conformity and range accuracy through the direct reconstruction of patient stopping power distributions. In this contribution, we present a ToF-iCT demonstrator that has been tested using a medical ion beam. This places demanding requirements on the imaging system, particularly with regard to rate capability, spatial and timing performance, and the material budget. The demonstrator is based on twelve single-sided strip low-gain avalanche diodes (LGADs) in an orthogonal arrangement, which enable single-particle tracking and energy estimation through time-of-flight measurements. We will report on recent developments and research activities, present imaging results from an ongoing imaging campaign, including in vivo imaging of live mice, and outline a use case for range verification with mixed beams, together with the results of the first experiments.

Speaker: Harald Handerkas (TU Wien/Austrian Academy of Sciences)

PSD14_New_time-of-flight_ion_imaging_system_based_on_LGADs.pdf

Technology developments in gas, X-ray and gamma detectors: Technology Developments in Gas, X-Ray, and Gamma Ray Detectors 1

Convener: Dr Paul Miyagawa (University of London (GB))

8 u-Rwell in cylindrical TPC for nuclear astrophysics

TRIUMF Annular Chamber for Tracking and Identification of Charged Particles (TACTIC) is a cylindrical Active Target Time Projection Chamber (TPC) designed to study alpha-induced charged-particle reactions of astrophysical importance at the relevant energies. The reaction cross section measurements rely on the tracking and identification of the reaction products by means of differential energy loss in the gaseous detection volume. In order to detect the reaction products over a wide range of energies (tens of keV to a few MeV), the novel μ-RWELL (micro-Resistive WELL) detectors are used in TACTIC as the gas multiplication stage. An unique central cathode cage configuration enables the detector to accommodate higher beam intensities (in the order of 107 pps) compared to other active target detectors. This specific feature, combined with a high detection efficiency, allows the measurements of low cross sections (in the order of μb) utilising radioactive ion beams in the astrophysically important energy regions of interest. The thick target technique enables the excitation function over the energy region of interest to be measured simultaneously with one beam energy, resulting in a time-efficient measurement.

We evaluate the performance of large-area μ-RWELL detectors in both planar and cylindrical geometries across various gas mixtures. Key parameters including gas gain and energy resolution achievable are investigated using alpha and 55Fe X-ray sources. Particular emphasis is placed on the characterisation of μ-RWELL in helium-based gas mixtures, motivated by the use of helium as the most common target gas in Active-Target detectors for studying alpha-induced nuclear reactions.

Furthermore, we demonstrate sub-keV energy detection capability and an energy resolution of 9%, highlighting the sensitivity to low-ionising charged particles for ion beam experiments. Finally, we report the successful in-beam experiments with TACTIC at TRIUMF, demonstrating for the first time the implementation of μ-RWELL detectors in a curved geometry for such applications.

Speaker: Lara Malpas (University of York)

9 Positive ion-initiated secondary avalanches in a gas time projection chamber with an intensified camera readout

Micropatterned gas Time Projection Chambers (TPCs) are of interest for rare event physics where 3D reconstruction of low-energy recoil tracks has the potential to provide unique sensitivity to various searches, such as Dark Matter [1]. Camera based readouts for gas TPCs are gaining popularity to measure low-energy tracks for low cost per channel, high resolution and isolation of the readout from the sensitive gas volume.

We have recently developed a gas TPC called CYGNUS-n. This talk will discuss initial performance test of CYGNUS-n and the analysis methods. I will also report on measurements taken to explore the effect of the back flow of positive ions through the avalanche stage composed of two thin gas electron multipliers (GEMs), in low pressure CF4. Secondary avalanches caused by the back flowing positive ions on the first GEM stage were studied, along with the conditions which maximised these secondary avalanches. Upto 18$\%$ additional measurable light yield from secondary avalanches was observed. By fast gating the camera intensifier, we have confirmed the secondary avalanches are spatially correlated with the initial track, with additional expected broadening due to the inter-GEM diffusion. We have quantified spatial resolution of the initial, secondary and combined avalanches as measured by the camera. These results suggest principles for tuning the operational parameters of multi-GEM gain stages, and can be used to optimise the trade-off between measured light intensity and track broadening when using camera-based optical readouts for gas detectors.

References
[1] Vahsen, S.E., O’Hare, C.A.J., Lynch, W.A., Spooner, N.J.C., Baracchini, E., Barbeau,
P., Battat, J.B.R., Crow, B., Deaconu, C., Eldridge, C. and Ezeribe, A.C., 2020. CYGNUS: Feasibility of a nuclear recoil observatory with directional sensitivity to dark matter and neutri-nos.arXiv preprint arXiv:2008.12587.

Speaker: Victoria Bashu (The Australian National University)

VUB_PSD14_IBF_Study_CYGNUS_N.pptx

17:00 Welcome Drink

Wednesday 2 September

Detectors for Light Sources and Neutron Facilities: Detectors for Light Sources and Neutron Facilities 2

Convener: Aled Horner (Queen Mary, University of London)

10 A Compact SiPM-Based Neutron Anger Camera with Sub-Millimeter Spatial Resolution and Time-of-Flight Imaging Capability

Position-sensitive neutron detectors combining spatial, temporal, and spectroscopic capabilities are increasingly demanded for neutron scattering instruments and time-of-flight (ToF) beamlines. We report on a compact neutron Anger camera designed as a proof-of-concept for large-area scintillation-based imaging systems.

The detector employs a 1 mm thick GS20 lithium glass scintillator coupled to a 6 mm boron-free quartz light spreader, with reflective coatings to maximize light collection. Scintillation photons are detected by a custom SiPM matrix of 192 Hamamatsu devices arranged in a 16 × 12 configuration, each with a 6 × 6 mm² active area and 6.1 mm pitch, yielding a 12 × 8 cm² active area. Readout is handled by three FERS acquisition modules performing event-by-event digitization and timestamping via optical links to a central concentrator.

Event localization relies on a center-of-mass algorithm applied to the SiPM light distribution, enabling sub-pixel interpolation into a virtual 320 × 240 pixel image space. Detector characterization was performed with a deuterium-tritium neutron source. Edge-spread function analysis on sharp-edge and slit-mask phantoms yielded an effective spatial resolution of ~0.3 mm, well below the physical SiPM pitch, confirming the Anger reconstruction effectiveness. Images show good linearity and uniformity across the full active area.

Preliminary timing measurements demonstrate a resolution of ~1 ns, enabling ToF-based energy-resolved neutron imaging from pulsed sources. The system supports both integrated and frame-based acquisition modes with online reconstruction.

These results establish SiPM-based Anger cameras as a scalable architecture for high-resolution, spectrally resolved neutron imaging in next-generation instrumentation.

Speaker: Yuri Venturini (CAEN)

PSD14_2026_Venturini_NeutronAngerCamera.pdf

11 Characterization of inverse LGAD in soft X-ray energy range.

At PSI, we are developing inverse Low-Gain Avalanche Diode (iLGAD) sensors in collaboration with Fondazione Bruno Kessler (FBK) to extend the application of hybrid detectors to the soft X-ray range. iLGAD features an internal gain layer, which enables a significant increase in the signal-to-noise ratio (SNR) for soft X-ray detection. To account for the shallow absorption depth of low-energy photons, we implemented a thin entrance window (TEW) in the iLGAD to enhance its quantum efficiency (QE).

In this presentation, we will report on the QE measurements of the latest TEW batch, which exceed 85% at 250 eV—comparable to state-of-the-art soft X-ray detectors. Beyond QE, we will also present recent beam-test results obtained at the MAX IV synchrotron using soft X-rays from 390 eV to 2500 eV. The iLGAD was bump-bonded to the MÖNCH [1] charge-integrating readout chip, featuring a pixel size of 25 μm. The results demonstrate that single-photon detection can be achieved at 400 eV with an SNR > 5.

Furthermore, a reduction in signal amplitude was observed at the Si K-edge (1839 eV). To investigate this, a grazing incidence beam test was performed at ESRF using a focused beam to map the gain at various photon absorption depths. The analysis reveals that the gain for photons absorbed immediately after the gain layer is lower than for deeper absorption. At the Si K-edge, the X-ray attenuation length drops sharply from 14 μm to 1 μm, shifting the majority of photon absorption into this lower-gain region and explaining the observed amplitude drop. These experimental findings show good agreement with dynamic gain simulations using TCAD.

[1] M. Ramilli, et al 2017 JINST 12 C01071

Speaker: Shuqi Li

PSD_2026.pdf

12 HEXITEC$_{\textrm{MHz}}$ – a 1 MHz continuous frame rate spectroscopic X-ray imaging detector system

The upgrade of photon light sources to diffraction-limited storage rings, alongside the demands of techniques such as Hyperspectral X-ray Tomography, requires spectroscopic X-ray imaging detectors capable of operating at significantly higher photon fluxes than previous generations permitted. HEXITEC$_{\textrm{MHz}}$, developed at STFC, is the latest generation of the HEXITEC spectroscopic X-ray imaging detector family. Coupled to HF-CdZnTe sensor material and achieving a 1 MHz continuous frame rate, HEXITEC$_{\textrm{MHz}}$ delivers high-resolution spectroscopy across 2–200 keV at fluxes exceeding 10⁶ ph s⁻¹ mm⁻², representing a greater than hundred-fold improvement on the 9.1 kHz frame rate of the original HEXITEC system. Sensor characterisation measurements have demonstrated an energy resolution of 1.2 keV FWHM at fluxes of 10⁶ ph s⁻¹ mm⁻², confirming that high spectroscopic performance is maintained under high-flux conditions [1, 2].

HEXITEC$_{\textrm{MHz}}$ is designed as a compact, deployable instrument with a camera head footprint of ~6 cm × 6 cm × 30 cm, requiring only a 12 V supply and a small chiller unit for operation, with data transmitted via fibre optic. Maintaining the 250 μm pixel pitch of the original ASIC, the system achieves its 1 MHz frame rate through an integrating front-end architecture, in-pixel digitisation, and high-speed serialisers. This paper presents the full HEXITEC$_{\textrm{MHz}}$ camera system, covering the ASIC pixel architecture, in-FPGA data correction and compression algorithms, DAQ control software and firmware, and hardware- and software-triggered acquisition modes.

Working with Pacific Northwest National Laboratory, a series of measurements using a 160 keVp W X-ray source validated HEXITEC$_{\textrm{MHz}}$ across several experiments. Spectroscopic radiography of Au, Pt, and Au+Pt samples confirmed the system's ability to differentiate elements separated by only one atomic number. The system's suitability for time-resolved studies was further demonstrated through dynamic spectroscopic radiography of ion drift of critical materials in solution within a magnetic field, achieving a temporal resolution of 100 ms. Combined Radiography, Energy and Angular Diffraction Imaging (READI) was also demonstrated on powder samples. These results highlight the 100 ms dynamic imaging capability in particular as a distinctive strength, positioning HEXITEC$_{\textrm{MHz}}$ as a versatile platform for high-flux spectroscopic X-ray imaging across a broad range of scientific applications.

[1] M.C Veale et al., Preliminary characterisation of the HEXITEC$_{\textrm{MHz}}$ spectroscopic X-ray imaging detector, J. Inst. 18 (2023) P07048 doi:10.1088/1748-0221/18/07/P07048.

[2] B. Cline et al., Characterisation of HEXITEC$_{\textrm{MHz}}$ - A 1 MHz continuous frame rate spectroscopic X-ray imaging detector system, Nuc. Inst. Meth. A. 1057 (2023) 168718 doi:10.1016/j.nima.2023.168718.

Speaker: Ben Cline

10:00 Coffee

Astrophysics, Space, and Extreme Environments: Astrophysics, Space, and Extreme Environments 1

Convener: David Hall

13 Introduction to Detectors for Astrophysics, Space and Extreme Environments

Speaker: David Hall

Detectors for Astrophysics, Space, and Extreme Environments (v1.1).pdf

14 Testing CMOS image sensors for future space telescope missions

Future space telescope missions require state-of-the-art, high-resolution detectors that can measure light with a wide range of wavelengths. CMOS image sensors are being considered as detector technologies for such telescopes, with Teledyne e2v’s CIS300 family being a prime candidate. Missions such as ARRAKIHS and CASTOR, which aim to study dark matter and galaxy formation, have chosen the CIS300 as its main detector. Other missions considering the CIS300 include NASA’s Habitable Worlds Observatory, which aims to study earth-like planets.

The CIS300 is a large area CMOS image sensor that can detect light with wavelengths from UV to near-IR, suitable for various astronomical applications. Its large area and three-side-buttable package allow for tessellation, with minimal dead space, into a large focal plane. It can withstand the harsh conditions in space, as it can operate in a wide range of temperatures and has radiation-hard versions. It can operate in rolling shutter or global shutter (with optional digital double sampling) modes, a staircase mode, and a high dynamic range mode. It has multiple gains at the pixel level and at the preamplifier level, which can be set independently. Optimisation of the gains and modes of operations can give readout noise below 2 e− rms, which can be used with long integration times to capture dim objects.

The various settings and modes of operation of the CIS300 require thorough testing, characterisation, and optimisation. A dedicated setup has been developed to perform a suite of standard electro-optical tests including dark current, readout noise, linearity, and quantum efficiency. Testing of the CIS300 is underway, enabling the detector technologies necessary for future space telescope missions.

Speaker: Anabel Romero Hernandez (Open University)

PSD14_2026_aromero.pdf

15 Insights into CCD trap defects from in-orbit trap pumping on the Euclid VIS instrument.

The VIS instrument onboard the Euclid space telescope (which launched in 2023) is the first in-orbit instrument to include trap pumping as part of its calibration routines to assist with the correction of image distortions due to charge transfer inefficiency (CTI) caused by charge trap defects. Trap pumping is a method to identify individual charge trap defects in a CCD, allowing the sub-pixel location and emission time constant to be determined.
This work presents a further study of this trap pumping data focusing on how the trap defects created by the radiation environment of Euclid compare to the pre-launch testing and predictions. It also explores the unexplored behaviour found of some individual trap defects when observed over a long period of time.

Speaker: Toby Wallage (Open University)

Tobyw_PSD14_talk_presentation.pptx

16 Performance evaluation of the AstroPix v3 and v4 HV-CMOS Sensors: Results from the DESY II Testbeam

AstroPix is a novel monolithic High-Voltage CMOS (HV-CMOS) active pixel sensor designed for use in medium-range gamma-ray observatories like AMEGO-X. To meet mission requirements, the sensor must demonstrate low power consumption (< 1.5 mW/cm2) and deliver a required dynamic range between 25 and 700 keV with an energy resolution below 10% at 122 keV. The third sensor version features a pixel matrix of 35x35 pixels with a 500 um pitch, and is a first full-scale chip. A coordinate readout scheme is implemented by connecting pixels via logical OR lines along both rows and columns. This provides independent row and column signals which are matched to pinpoint the event location. Version four contains a smaller pixel matrix of 13x16 pixels and features a per-pixel readout, which will be the standard for all subsequent versions. To maximize the probability of photon detection, full depletion of the sensor is critical. We are evaluating the performance of the devices, including charged particle detection efficiency, spatial resolution, and depletion depth, in a dedicated testbeam environment at the DESY II Testbeam Facility. Utilizing a reference tracking telescope, we can precisely evaluate the device-under-test performance by direct data comparison under controlled conditions. This talk will present the integration and performance validation of the AstroPix v3 and v4 sensors within the beam telescopes, along with first experimental results from the recent beamtimes.

Speaker: Elizaveta Sitnikova (Deutsches Elektronen-Synchrotron (DE))

Astropix_PSD14.pdf

17 A compact Radiation Monitor for the LISA experiment

The Laser Interferometer Space Antenna (LISA) will be the first space-based gravitational-wave observatory sensitive in the 0.1 mHz-1 Hz band. Background radiation can limit LISA sensitivity at the lower frequencies. To monitor and characterize this environment, a compact Radiation Monitor (RM) has been developed for the LISA mission. The RM is designed to measure the integral cosmic-ray proton flux with a statistical precision of about 1% in approximately one hour, while satisfying strict constraints on mass, volume, and power consumption. The detector is based on plastic scintillators read out by silicon photomultipliers, combined with tungsten absorbers and copper shielding to reject low-energy protons. Signal processing is performed using a low-power ASIC, custom developed for space applications. An FPGA controls the ASIC, the trigger logic and processes the digitized data. The flux and energy information is obtained from the coincidence counts for the four scintillators. We evaluated the performance of the RM, assessed through Monte Carlo simulations and dedicated experiments performed with a proton beam at TRIUMF (up to 480 MeV) and 160 GeV/c muons at SPS (CERN). We will present results of the detector acceptance, angular response and discuss the capabilities for spectrum and direction reconstruction.

Speaker: Roberta Pillera (Universita e INFN, Bari (IT))

12:00 Lunch

Posters: Posters and Exibitions

Convener: Seth Zenz (Queen Mary University of London)

18 Process development to assemble MAPS into detector-modules for the R3B Target Recoil Si-Tracker

The R3B Target Recoil Tracker (TRT) is a silicon-based detector system being developed for the Facility for Antiproton and Ion Research (FAIR) accelerator complex in Darmstadt (DE). The TRT is designed to measure recoil particles produced in a fixed target by relativistic radioactive beams, enabling precise reconstruction of reaction kinematics and contributing to the study of exotic nuclei and nucleosynthesis processes. The detector consists of two cylindrical layers of 50um thin ALPIDE sensors (Monolithic Active Pixel Sensors, MAPS) positioned around a hydrogen fixed target within a vacuum chamber. Each detector module incorporates one aluminium flexible printed circuit (FPC), precision glue deposition, and 9 ALPIDE chips. The module material budget is minimised (~0.16%X/X0) to reduce multiple scattering, which would otherwise degrade track reconstruction.
TRT module production requires 60 detector-grade modules, including spares. The modules will be assembled in the UK and shipped to FAIR.
Multiple prototype generations were produced, progressing from low-readiness mock-up assemblies to high-readiness modules using production-grade components and fully functional chips. The precision alignment systems, including the ALICIA assembly machine, significantly improved placement accuracy and assembly consistency.
This poster outlines results and lessons learnt of the medium readiness prototyping campaign. The work focused on establishing a reliable and repeatable assembly process for the detector modules, including optimisation of cleaning procedures, vacuum handling systems, alignment tooling, and glue application techniques. Results demonstrate the importance of iterative prototyping, tooling refinement, and precision assembly techniques to target a consistent high yield production.

Speaker: Konrad Sutowski (STFC)

19 The Multitube detector for the CSPEC cold shopper spectrometer: construction, validation and performance measurements

3He-based gaseous neutron detectors have demonstrated adaptability across a wide range of applications, from elementary particle physics to neutron imaging. Depending on experimental requirements, detector volumes range from a few centiliters to several hundred liters. This work presents the development of a 3-meter-high two-dimensional Multitube detector designed for the Cold Chopper Spectrometer (CSPEC) at the European Spallation Source (ESS). The detector design builds on the expertise of the Neutron Detector Service (SDN) at the Institut Laue-Langevin (ILL) in constructing meter-scale position-sensitive detectors with spatial resolutions of a few centimeters. Following the completion of the first Multitube module, measurements performed at the CT2 beamline at the ILL demonstrated the expected detector performance while validating the production process for the remaining twelve modules.

Speaker: William Saenz (ILL)

20 Inner Tracking System 2 (ITS2) - Data Quality Control and Calibration

Svetlana Kushpil for the ALICE Collaboration

The Inner Tracking System (ITS2) of the ALICE experiment at the CERN
Large Hadron Collider is based on a Monolithic Active Pixel Sensor technology.
Installed during the Long Shutdown 2 (LS2), it has been operating in LHC
Run 3 and successfully collected data from pp, Pb–Pb, O–O, Ne–Ne collisions.
The ITS2 consists of seven concentric layers of ALPIDE monolithic active pixel
sensors produced in the TowerJazz 180 nm CMOS process, covering a total sen-
sitive area of about 10 m2. The sensor features a pixel pitch of 27 μm × 29
μm and a position resolution of about 5 μm. The very low material budget,
amounting to 0.36% X0/layer for the three innermost layers and 1.10% X0/layer
for the outer layers, in combination with the small radial distance of only 23
mm from the beam, leads to an excellent impact parameter resolution at low
transverse momentum, which is crucial to reconstruct low transverse momen-
tum heavy-flavor particles in the heavy-ion collision environment. To ensure
stable operations and maintain high data quality, the synchronous monitoring
of the detector operating parameters and the asynchronous reconstruction of the
collected data are performed through the data Quality Control system (QC).
Regular calibration procedures are carried out to determine the charge thresh-
olds and identify noisy channels of the detector. This contribution gives an
overview of the operational procedures required to maintain an optimal data
quality, along with results obtained from calibrations and the QC system. The
monitoring for fake-hit rate, front-end electronics status, data integrity, clus-
ter and track distributions, threshold and noise calibrations will be presented,
together with the detector performance achieved in different collision systems
during LHC Run 3.

Speaker: Svetlana Kushpil (Czech Academy of Sciences (CZ))

21 Early Performance Results of the CMS Phase-2 Tracker Cosmic Test Stand

The High-Luminosity LHC (HL-LHC) will operate with up to 200 simultaneous proton–proton interactions per bunch crossing, requiring upgraded detector readout, triggering, and data acquisition systems. The Phase-2 CMS Outer Tracker introduces new detector modules and a trigger architecture designed to contribute to online trigger decisions within 12.5 $\mu$s. Demonstrating the performance and operational behaviour of this system prior to HL-LHC data taking is an important step toward operational readiness.

A CMS Tracker Phase-2 Cosmic Rack setup has been assembled, consisting of a vertical array of Outer Tracker ladders, each instrumented with twelve Outer Tracker modules. The system is integrated using a readout and processing architecture based on ATCA electronics and prerequisite firmware and software. The rack is operated with cosmic-ray muons, with the ability for self-triggering in addition to the provision of an independent trigger based on scintillator tiles instrumented with photomultiplier tubes.

This setup enables end-to-end integration tests of the trigger and DAQ chain, and provides a platform for developing and validating commissioning procedures. It also supports studies of detector synchronisation, backend system performance, online control, and offline reconstruction. First performance results from the system are presented.

Speaker: Andrew Mastronikolis (Imperial College (GB))

22 Installation and performance of Jungfrau detectors at Diamond Light Source

The Jungfrau family of detectors has been developed by the Paul Scherrer Institute (PSI), Switzerland. These are state of the art pixel detectors, using integrating front-end electronics and adaptive gain, to deliver a very large dynamic range. This type of architecture, developed for FELs, will be increasingly used at upgraded synchrotron light sources. Jungfrau detectors are based on 0.5 Mpixel modules, which are then tiled to cover larger areas. Challenges associated with the architecture include the need to record and subtract dark images, and very high data rates before saving to disk in a compressed format.
At Diamond Light Source, UK, a 1 Mpixel Jungfrau (Jungfrau-1M) has been evaluated, using a laboratory X-ray machine and on the macromolecular crystallography beamline, I24. A nonlinearity was seen around the switching points, which has also been commented on by other authors. The performance of the detector with known protein samples was nevertheless very good.
Following the initial work with the JF-1M, a 9 Mpixel Jungfrau (JF-9M) was installed on Beamline I24. This was challenging in terms of networking and data rates, the provision of a cooling system for of the detector and safety interlocking.
We describe the challenges of installing and using the Jungfrau detectors and the solutions chosen, including the use of a QuantaGrid S74G-2U server for data acquisition. This is based on the NVIDIA Grace Hopper superchip and allows background subtraction and application of gain coefficients on the fly.
We present performance measurements of the detectors, from laboratory work and on the Beamline, and experimental results from protein samples.

Speaker: Dr John Matheson (Diamond Light Source)

JF_Poster_v9.pdf

23 Prototype Design and Characterization of HouYi, a Burst-mode Charge- Integration Readout Chip for High-Z Pixel Detector

HEPS (High Energy Photon Source) is the first fourth-generation light source in China, featuring high-energy, high-luminosity X-rays. Since more than half of its end stations generate photon energies above 25 keV, high-Z detectors are essential. Additionally, advanced experiments such as X-ray Photon Correlation Spectroscopy (XPCS) and ultrafast dynamics studies necessitate detectors with high frame rates. To meet the demand for a high-speed, high-Z pixel detector at HEPS, a readout ASIC named HouYi has been developed

HouYi is a charge-integration readout chip operating in burst mode, designed for compatibility with electron-collecting sensors like CZT and CdTe. It features a pixel pitch of 150 μm × 150 μm, with an array size of 64 × 64 in the engineering run. The burst frequency is adjustable from 1 MHz to 4.7 MHz. To achieve both single-photon sensitivity and a high dynamic range, the chip incorporates a two-stage adaptive gain front-end circuit. Following charge integration, signals are stored in a 32-cell analog memory array, enabling successive sampling of 32 frames. The corresponding gain settings are also stored in analog form by converting a 2-bit digital gain signal into analog voltage levels. Finally, signals are read out via four differential drivers during the intervals between photon bunches.

HouYiV01S is the first small-scale prototype, containing a 32 × 32-pixel array with full functionality. Performance tests confirm its proper operation. The chip can integrate, store, and read out 32 pulses at frame rates up to 4.7 MHz. At a photon energy of 30 keV, the signal-to-noise ratio of the preamp exceeds 5, indicating the capability for single-photon resolution. The transfer characteristics of the dynamic range is approximately 4300 photons at 30 keV. The overall nonlinearity of the signal chain is below 4 %.

Speaker: Wei Wei

24 Verifying the 3D energy deposition profile of an MeV proton bunch using a liquid scintillator in an ion-acoustic experiment.

The ion-acoustic effect generates images of the ion-dose distribution
from the ultrasound produced when an energetic, fast pulse of ionizing
particles interact in an appropriate medium. We recorded the light excited in a liquid scintillator as a cross-check of the waves simultaneously
recorded using ultrasonic sensors.
In earlier work we used ANSYS ZEMAX in non-nequential ray-tracing
mode to simulate the optical image, from two orthogonal directions, that
would be recorded in our phantom filled with UltimaGoldXR liquid scintillator. Our ultrasonic characterisation of UltimaGoldXR (acoustic attenuation coefficient at 22 ◦C was $$ 0.19f^{1.75} $$
, where f is frequency in range 1.5 to 3.5 MHz. The
speed of sound was 1479 m/s) demonstrated that it was an appropriate
medium in which to generate and detect an ion-acoustic signal and we
used the LION beamline at the Centre for Advanced Laser Applications,
Garching to generate proton beams with nominal peak energies from 10
to 20 MeV.
Here we compare measurements made of the deposited energy as a
function of depth, estimated by Monte Carlo modelling of particle transport starting with entry dose measured 5 cm before entry into the phantom
using radiochromic film stacks, with a ZEMAX simulation that includes
absorption and scattering from black anodized surfaces, black Kapton and
a realistic model of the optical system including coatings on the lenses. We
evaluate the correlation between the two different methods of determining
the three-dimensional energy profile. This work updates our previous simulation which assumed an ideal beam from the accelerator and we discuss
the challenges of measuring and simulating the complexities of the real
3D beam profile within the liquid scintillator.

Speakers: Calvin Dyson, Calvin Dyson, Calvin Dyson

PSDConf_IonAcoustic_Poster.pdf

25 Investigation of a Novel Segmented Point-Contact BEGe Detector.

The Segmented Inverted Coaxial Germanium (SIGMA) detector is a p-type, large-volume High Purity Germanium (HPGe) detector developed for gamma-ray tracking and imaging. Highly segmented germanium detectors are well-suited to a wide range of applications, including spectroscopic gamma-ray imaging for nuclear decommissioning and deployment in portable detector arrays at international accelerator facilities for nuclear structure and astrophysics studies. However, analysing multi-interaction events, where an incident photon deposits energy at multiple spatial locations, becomes complex, as a combination of different events produces induced image charges that are similar and hard to distinguish without intrinsic azimuthal information.

In this work, a simplified, next-generation SIGMA-like design is proposed to reduce technical risk, improve manufacturability, and preserve high-precision performance. As a proof-of-concept, a novel Segmented Point-contact (SPOT) Broad Energy Germanium (BEGe) detector has been designed and evaluated via simulation. The AGATA Detector Library (ADL) was used to model the detector’s electric and weighting potentials and to generate charge signals via charge-transport simulations. A signal database, or basis, covering the detector volume was produced, with electronic noise and preamplifier response incorporated to produce realistic charge signals.
The detector sensitivity, defined by differences in the charge signal shape across the detector volume, was quantified for SPOT and compared to a conventional BEGe detector. The position resolution of SPOT is assessed using signal-comparison Pulse-Shape Analysis (PSA), in which a χ² minimisation algorithm determines the gamma-ray interaction point by matching experimental signals to the simulated basis. These results show that SPOT has improved azimuthal resolution through segmentation and highlight its potential as a simpler alternative for high-resolution gamma-ray tracking applications.

Speaker: Emily Richardson

26 A 20-Gbps PAM4 pre-amplifier for optical receivers in high-energy physics experiments using 55-nm CMOS

Optical data transmission is essential for on-detector readout electronics in large particle physics experiments. Multi-level pulse amplitude modulation (PAM4) can increase the single-channel data rate without altering the analog bandwidth, thereby reducing the number of data transmission channels and the material budget. In 55-nm CMOS, a 20-Gbps transmitter has been designed for front-end detector data transmission, necessitating a custom optical receiver at the corresponding speed for the backend electronics. This work presents a 20-Gbps PAM4 pre-amplifier for such an optical receiver, fabricated in the same process. The initial prototype design mainly consists of a photodiode (PD) bias circuit, a transimpedance amplifier (TIA), a variable gain amplifier (VGA), a continuous-time linear equalizer (EQ), a DC offset cancellation (DCOC) circuit and a test output driver. The bias circuit uses active inductors to provide an appropriate reverse bias voltage for the PD, achieving high optical efficiency while also outputting differential current to the TIA. The TIA uses a pseudo-differential modified regulated cascode structure to break the gain-bandwidth product limitation. The VGA employs a tunable source degeneration structure to maintain output linearity. The EQ compensates for high-frequency loss while reducing low-frequency gain to balance noise and bandwidth. The output driver and DCOC circuit improve driving capability and eliminate DC offset. Post-simulation results show that the initial design achieves 20-Gbps PAM-4 eye diagrams with a transimpedance gain of 62 dBΩ and consumes 45 mW from a 1.2V supply. More detailed designs and test results will be reported.

Speakers: Xiongbo Yan (Institute of High Energy Physics), hangqi chen (nanjing university)

27 First evaluation of ColorPix-3 ASIC

In this contribution, we present the first characterization measurements of the ColorPix-3 ASIC integrated with the UniCorn readout interface. ColorPix-3 features a 32 × 32 pixel matrix with a pixel pitch of 70 μm and is designed for high-resolution, position-sensitive, and energy-resolved X-ray imaging. A 2 mm-thick CZT sensor layer is bump-bonded to the ASIC and serves as the detection medium, providing significantly higher X-ray and gamma-ray detection efficiency than conventional silicon-based sensors.

The ASIC records data in the form of hit counts across ten configurable energy thresholds. Due to device-to-device variations, several DAC parameters must be optimized prior to operation. We describe the complete calibration and equalization procedure, including threshold scans, pixel offset compensation, and energy-threshold calibration, followed by measurements performed under X-ray irradiation.

The experimental results confirm the intended functionality of the chip and demonstrate key detector characteristics, including charge-sharing effects between neighboring pixels. Finally, we discuss implications and the following applications.

Speakers: Jan Broulim (Czech Technical University in Prague (CZ)), Karolina Lavickova (Czech Technical University in Prague (CZ))

PSD_CP_3.pdf

28 A 6-ps Event-Driven Circular-Interpolation Time-to-Digital Converter in 55-nm CMOS

The time-to-digital converter (TDC) is an essential instrument for achieving picosecond-level time resolution and finds widespread application in fields such as high-energy physics and time-of-flight positron emission tomography (TOF-PET). In this work, a TDC core, referred to as xpcTDC, is developed based on a circular-interpolation scheme. The TDC consists of four functional blocks: a controller, a pseudo-differential ring oscillator with quantizers, an encoder and event builder, and two serializers. It supports operation at three selectable reference clock frequencies—160 MHz, 80 MHz, and 40 MHz—each offering a distinct average event rate. Notably, at 160 MHz, a maximum event rate of 66 MHz is attained. The ring oscillator has 15 pseudo-differential delay cells of 30-ps cell delay, and uses a 5-stage resistive interpolation, thereby achieving a time resolution of approximately 6 ps. By carefully designing the resistance values, a uniform distribution of the interpolated delays is ensured. Following quantization of the TDC measurement results, the critical bubble issue is addressed in the encoder. The design is capable of accurately resolving bubbles with a depth of less than 10, a capability that has been verified through simulation. The two encoders provide the flexibility to selectively output either the encoded results alone or both the pre-encoded and encoded data in a synchronized manner. Finally, the chip was submitted for tape-out in April and is expected to begin testing in August, with experimental results anticipated thereafter.

Speakers: Xiaoting Li (IHEP), 蒋辉 jianghui (The Institute of High Energy Physics)

29 A novel sub-10ps event-driven TDC utilizing pulse-interleaved architecture

Future high-energy physics experiments and highly-granulated silicon detectors impose stringent requirements on readout electronics regarding power consumption, footprint, and timing precision. This report presents LATRICi, a pulse-interleaved time-to-digital converter (TDC) implemented in a 55nm CMOS process. As an evolution of the initial LATRIC0 prototype, which utilized an event-driven ring oscillator architecture with a 31-ps resolution, the proposed design optimizes delay cells to mitigate process mismatch, achieving a simulated average unit delay (Td) of 22.5 ps. To enhance timing precision, LATRICi integrates a latch-pulse-interleaved module. This circuit generates three interpolated sub-signals for time-over-threshold (TOT) and clock-period calibration (CAL) measurements. The interleaving strategy exploits the delay difference between a NAND gate in the ring oscillator delay line and a voltage-controlled inverter. Regulated by a delay-locked loop, the time interval between the sub-signals is maintained at one-third of the unit delay (Td/3). This architecture improves the final timing resolution to 7.5 ps, representing a three-fold enhancement over the previous version. Post-layout simulations indicate a stable bin size distribution, with differential non-linearity (DNL) and integral non-linearity (INL) confined within ±0.5 LSB and -0.6 to +0.2 LSB, respectively. At a 100-MHz event rate, the TDC core consumes 2 mW per channel and occupies an area of 419 × 134 µm². The ASIC has been taped out, and its specifications indicate applicability for large-scale, multi-channel readout systems in high-luminosity colliders.

Speaker: 黄文豪 huangwenhao

30 Novel Readout Architectures for RPC Detectors with Reduced Channel Count: The TOMAR and CREW Approaches

Resistive Plate Chambers (RPCs) are widely used detectors in high-energy physics and related fields. Front-end electronics is driving cost in large-scale RPC systems. This contribution presents a comparative study of two novel readout strategies for the reduction of front-end electronics (FEE) channel count while preserving adequate spatial resolution and timing performance: TOMAR (TOMograohia Aplicada com RPCs / Applied Muon Tomography with RPCs) and CREW (Corner Readout Experiment Wiola).
TOMAR achieves excellent spatial resolution (sub millimeter) by employing a large number of thin readout strips. To reduce electronics costs, signals from these strips are connected in parallel groups to reduce the number of electronic channels needed. An aditional electrode equipped with thick strips desentagle the ambigutiy created by the parallel conection and provides timing. As a result timing and position resolution are preserved but significantly lowering the detector instrumentation cost and complexity.
CREW employs a different approach: a single continuous readout plate instrumented at only four corners. Timing information is recorded at each corner, and the hit position is reconstructed from differences in signal arrival times, achieving precision comparable to classical strip readout (a few millimiters). This geometry reduces the channel count to just four channels per readout cell while retaining full two-dimensional position sensitivity.
Both methods are evaluated in terms of spatial resolution, timing performance, and practical implementation considerations.

Speaker: Lidia Lappo (Warsaw University of Technology)

31 Optimization of X-ray Radiography Instrument and CT Reconstruction for Electric Wheelchair Lithium-Ion Battery Module

Lithium-ion batteries (LIBs) are used to power electric wheelchairs owing to their high energy density and long lifespan. LIB modules for wheelchairs consist of densely packed cells, and non-destructive testing is required to detect internal defects. This study aims to suggest the proper instrument configuration and CT reconstruction method for LIB module-level inspection which remains challenging due to scatter radiation and artifacts.
Monte Carlo simulations were performed with Geant4 to optimize radiography instrument and CT reconstruction workflow. A 3×3 cylindrical 18650 LIB module with 0.18 mm cracks in each cell was modeled with a CsI(Tl) detector. The instrument was optimized by varying X-ray energy, filtration material and thickness, detector pixel size, and magnification. For reconstruction workflow optimization, preprocessing, reconstruction, and postprocessing methods were compared. Feldkamp-Davis-Kress (FDK) reconstruction was used as the baseline. Image quality and defect detectability were quantified using signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and detectability index (d′).
The optimized instrument configuration was 150 keV X-ray energy, 1.6 mm Sn filtration, 85 μm detector pixel size, and 2.1 magnification. Raw projections, OS-SART, and Gaussian smoothing ahcieved the highest reconstruction performance. Compared with FDK, SNR, CNR, and d′ increased by 233%, 119%, and 117%, respectively. These results indicate that instrument and reconstruction optimization can improve defect detectability in compact LIB modules.

ACKNOWLEDGEMENT
This work was supported by the Nuclear Safety Research Program through the Korea Foundation Of Nuclear Safety (KoFONS) using financial resources granted by the Nuclear Safety and Security Commission (NSSC) of the Republic of Korea (RS-2021-KN050310).

Speaker: Ms Donghee Kim (Yonsei University)

32 Upgrade of the Belle II vertex detector with depleted monolithic CMOS active pixel sensors

The Belle II experiment currently records data at the SuperKEKB $e^+e^-$
collider, which holds the world luminosity record of $5.2\times10^{34}$
$\textrm{cm}^{-2}\textrm{s}^{-1}$ and plans to push up to
$6\times10^{35}\textrm{cm}^{-2}\textrm{s}^{-1}$, after an upgrade
of its interaction region. To cope with the increased backgrounds, a new
fully pixelated vertex detector is under design. Its 5 layers will be
instrumented with the same DMAPS, OBELIX, designed in the Tower 180 nm
technology, and recently submitted for fabrication.
The OBELIX pixel matrix is inhereted from the TJ-Monopix2 sensor,
whose characterization has focused on its performance after irradiation
with integrated fluences up to the expected $5\times10^{14}\textrm{MeV} \textrm{n}_\textrm{eq}\textrm{cm}^{-2}$. The new
sensor features a 33 µm pitch with a 7-bit Time-Over-Threshold
digitization. The new read-out architecture has been designed to support
triggered operation and additional features needed for improving
time-stamping and contributing to Belle II track triggering. The
specifications require the detector to sustain a maximum average hit
rate of 120 $\textrm{MHz}\textrm{cm}^{-2}$, while keeping an
overall material budget lower than 3\% X0. A light
mechanical structure is foreseen, with two different approaches.
The ladders of the 2 innermost layers are cut out directly from the
processed wafers and connected with a post-process redistributed metal
layer. Passive cooling using a thin layer of high-conductance material
(TPG) beneath the sensors and connected to actively cooled blocks has
been chosen. The post-irradiation performance of TPG was recently
validated. The 3 outermost layers, instead, are composed of staggered
ladders, realized with a light carbon fibre structure supporting a
liquid-cooled plate in contact with the sensors connected to a flex
printed cable. This contribution will review the status of the
development of the sensor and the detection modules.

Speaker: Adrian Bevan (Queen Mary University of London (GB))

BelleII_Upgrade.pdf

33 Neutron spectroscopy with nitrogen-filled spherical proportional counters

Neutron spectroscopy is an invaluable tool for a wide range of scientific and industrial applications, including underground dark matter searches. Neutron-induced backgrounds originating from cosmic-ray muons and cavern radioactivity can mimic the expected dark matter signal and therefore constitute a major source of background in rare-event experiments. However, current neutron detection techniques suffer from several limitations, making precise measurements particularly challenging. A promising approach to neutron spectroscopy is the use of a nitrogen-filled Spherical Proportional Counter (SPC), exploiting the $^{14}N(n,α) ^{11}B$ and $^{14}N(n,p)^{14}C$ reactions. Measurements with mono-energetic neutrons were performed for the first time at the 5.5 MV Tandem accelerator of the National Centre for Scientific Research “Demokritos”, Athens, using a 30 cm in diameter nitrogen-filled spherical proportional counter equipped with an 11-anode ACHINOS multi-anode sensor with individual anode read-out. The detector response at an operating pressure of 1 bar to mono-energetic neutrons of $E_n$ = 0.75, 1.0, 1.425, 1.79, 1.80, 2.22, 2.517 and 2.75 MeV produced via the $^{7}Li(p, n)^{7}Be$ reaction will be presented and compared with the results of a dedicated simulation framework.

Speaker: Isabella Oceano

34 Real-Time FPGA Tracking and Vertex Reconstruction for the MUonE Silicon Tracking System

High-rate position-sensitive silicon trackers increasingly require real-time reconstruction close to the detector readout in order to reduce data volumes before storage. The MUonE experiment is a proposed fixed-target experiment at the CERN M2 beamline designed to independently measure the hadronic leading-order corrections to the muon anomalous magnetic moment ($g-2$). It consists of a high-intensity 160 GeV muon beam impinging on a sequence of thin targets instrumented with a high-granularity silicon tracking system and accompanied by a calorimeter. We present a real-time FPGA reconstruction chain for high-rate silicon tracking, demonstrated in the context of elastic muon-electron scattering events in MUonE at a 40 MHz input rate. Low-latency vertex reconstruction is required for the MUonE experiment to reduce the final design data rate from $\mathcal{O}(1 \ \mathrm{TB/s})$ to a manageable level for storage and offline analysis. The vertex reconstruction algorithm employs a hardware-oriented minimization method. The full reconstruction chain is implemented in C++ and synthesized to RTL using High-Level Synthesis (HLS). We demonstrate a live test on a physical FPGA using real detector data, and show agreement with the software vertex reconstruction within the detector resolution. We present latency, FPGA resource-utilization, and reconstruction-performance studies showing that the track-fitting block meets the MUonE real-time processing requirements, while the vertex reconstruction block is progressing toward the same target.

Speaker: Benjamin Lawrence-Sanderson (Northwestern University (US))

35 The ATLAS High-Granularity Timing Detector for the HL-LHC: project status and results

The HGTD is a novel detector introduced by ATLAS to augment the new all silicon Inner Tracker (ITk) in the pseudorapidity range from 2.4 to 4.0, adding the capability to measure charged-particle trajectories in time as well as space. Two double-sided layers of silicon sensors will provide precision timing information for charged particles with a resolution as good as 30 ps per track to help assign each particle to the correct vertex, recovering the ATLAS reconstruction performance at HL-LHC, enhancing the experiment’s pile-up rejection and providing bunch-by-bunch luminosity measurements. Readout cells have a size of 1.3 mm x 1.3 mm, leading to a highly granular detector with ~3.7 million channels. Low-Gain Avalanche Detectors (LGAD) technology has been chosen as it provides enough gain to reach the large signal over noise ratio needed. The requirements and overall specifications of the HGTD will be presented as well as the technical design and the project status. The R&D efforts on the detector components and construction, supported by laboratory and test beam results, will also be presented.

Speaker: Theodoros Manoussos

36 Quality Control of Hybrid Pixel Modules for the CMS Inner Tracker Upgrade at the HL-LHC

The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) will push the performance of tracking detectors to unprecedented levels, with instantaneous luminosities reaching up to $7.5 \times 10^{34}\,\mathrm{cm}^{-2}\,\mathrm{s}^{-1}$. To operate under these extreme conditions, the CMS experiment will replace its current tracking system during Long Shutdown~3 with a new Inner Tracker (IT) designed to sustain high radiation levels, accommodate increased particle fluxes, and support high-rate data readout.

At the core of the IT are hybrid pixel modules combining n-in-p silicon sensors with a pixel pitch of $25 \times 100\,\mu\mathrm{m}^2$ and a $65\,$nm CMOS readout ASIC developed by the RD53 collaboration, interconnected via bump bonding. The assembly is mounted on a high-density interconnect (HDI), which distributes power and signals, and is wire-bonded to the readout chip. The Phase-2 IT comprises three subsystems and extends the tracking coverage to $|\eta| = 4$. In the innermost barrel layers, where radiation levels are highest, single-chip modules equipped with 3D silicon sensors will be employed, while the outer barrel layers and endcaps will use dual-chip and quad-chip modules. To minimise the material budget and power losses, the modules operate within a serial powering scheme. As the project transitions from preproduction to large-scale production, ensuring uniform performance and long-term reliability across thousands of modules becomes a central challenge.

To address this, a comprehensive Quality Control (QC) program has been developed and deployed across production sites. The QC procedures cover all stages of module qualification, including electrical characterisation, verification of powering and readout functionality, threshold tuning, and detailed assessment of pixel response uniformity and noise performance. Dedicated tests are also implemented to evaluate the integrity of the sensor--ASIC interconnection and to identify defective channels that could degrade position resolution.

Stress tests and irradiation campaigns are used to validate module performance under conditions representative of the detector lifetime. This contribution presents the QC strategy for the CMS IT pixel modules, highlighting the test methodology, automation, and grading criteria used during production to ensure that only fully compliant modules are integrated into the final detector. First results from pre-production and early production modules are discussed, demonstrating the robustness of the QC workflow and its role in preserving the tracking performance required for HL-LHC operation.

Speaker: Christina Giallombardo (University of Zurich (CH))

37 Beam-Test Validation of a Real-Scale SiPM-Based Photodetector Prototype for the ePIC dRICH

The dual-radiator Ring Imaging Cherenkov detector (dRICH) of the ePIC experiment at the future Electron–Ion Collider will provide charged-hadron particle identification in the hadron-going region over a broad momentum range. Cherenkov photons will be detected by a large-area, position-sensitive silicon photomultiplier photodetector plane covering about 3 m², with 3 × 3 mm² pixels and more than 300,000 readout channels. This represents the first large-scale application of SiPMs for single-photon detection in a high-energy physics RICH detector.

We report on the development and beam-test validation of a real-scale dRICH prototype corresponding to one sector of the full detector. The prototype instruments an active photodetection area of about 15 × 15 cm², corresponding to more than 2,000 channels, while preserving the final detector granularity and the relevant optical layout, including the dual aerogel–gas radiator configuration and the off-axis focusing geometry. The photodetector is based on compact photodetection units, each integrating 256 SiPM pixels, local cooling, and fast front-end TDC electronics. The system is read out through a complete chain based on the ALCOR ASIC, allowing validation under realistic operating conditions.

A dedicated CERN beam-test campaign in 2026, at the SPS and PS, is being used to assess the detector response under complementary beam conditions. Key observables include the number of detected photoelectrons, single-photon Cherenkov-angle resolution, timing performance, and stability of the readout chain. These measurements provide essential input for the optimisation of the final ePIC dRICH photodetector system and demonstrate the potential of granular SiPM-based imaging sensors for future high-rate particle-identification detectors.

Speaker: Roberto Preghenella (INFN, Bologna (IT))

38 Assessment of Low Gain Avalanche Detector Response for High-Dose-Rate Proton Beam Monitoring in LhARA

The Hybrid Laser Accelerator for Radiobiological Applications (LhARA) is designed as an innovative, flexible, and low-cost facility dedicated to the systematic study of the radiobiological effects of particle beam therapy. Capable of delivering instantaneous dose rates that not only reach but also surpass the conventional “FLASH” regime with ultra-high dose rate.
However, monitoring such intense, rapid-pulse beams requires radiation-resistant detection technologies. This work presents a comprehensive simulation study evaluating the response of a special type of low-gain avalanche detector (LGAD) to the LhARA proton beamline.
We present the results of our Monte Carlo simulation combined with a Technology Computer-Aided Design simulation of the irradiation of the LGAD detector with ultra-high dose rate, the simulation results indicate the potential feasibility of using LGAD technology for dosimetry in the environment of the LhARA beamline. This study establishes an essential foundation for future experimental validation and optimization of next-generation beam monitoring instrumentation.

Speaker: FATIMA ZAHRA RIMCHI (Faculty of Sciences, Mohammed First University, Oujda, Morocco)

FatimaZahraRimchi -Poster- PSD14.pdf

39 Track Reconstruction in Spherical Proportional Counters

The spherical proportional counter (SPC) is a versatile gaseous detector with a variety of physics applications from fast neutron spectroscopy to rare events searches such as the direct detection of dark matter. The electric field established by the spherical geometry of the detector grants typical single-anode SPCs sensitivity to the radial position of ionising events via the drift of primary electrons in the gas. The development of the ACHINOS multi-anode sensor, with individual anode read-out, improves on this by giving the detector additional sensitivity to the angular position of these events, determined by which anodes receive signal. This enables the 3D reconstruction of event initial positions, particularly for point-like interactions such as nuclear or electron recoils. Extending this further, timing differences between anode signals can give the SPC sensitivity to the direction of ionising particles in track-like events, including ionisation trails by cosmic muons, allowing potential for full track reconstruction. In this work we present the latest developments in SPC track reconstruction algorithms in the 11- and 60-anode ACHINOS configurations, employing machine learning techniques such as neural networks, trained on the multi-anode read-out signals of simulated muon events. The reconstruction of cosmic muon data is also discussed.

Speaker: Robert James Ward (Hamburg University (DE))

PSD14_TrackReco_PosterA0_v6.pdf

40 Design and construction of the segmented plastic scintillator SiPM-readout anti-coincidence detector for ADAPT

The Antarctic Demonstrator for the Advanced Particle-astrophysics Telescope (ADAPT) is a NASA suborbital mission for a high-altitude balloon flight over Antarctica, which is anticipated to fly in the 2026-27 season. ADAPT validates key technologies for the future space-based APT, which aims for an order of magnitude improvement in MeV-TeV gamma-ray sensitivity. This presentation details the Design and Construction of the ADAPT Anti-Coincidence Detector (ACD). The ACD is critical for achieving high-efficiency charged particle veto, selecting gamma-ray candidate events from the overwhelming cosmic-ray background. The detector uses segmented plastic scintillator tiles read out by Silicon Photomultipliers (SiPMs). We will detail the fabrication process and present early performance metrics, including light yield measurements, validating the ACD as a high-performance pathfinder for the full APT mission.

Speaker: Nicola Mazziotta (Universita e INFN, Bari (IT))

41 Low-pressure position resolution studies in planar and cylindrical geometries with the novel 𝛍-RWELL MPGD

The novel 𝛍-RWELL MPGD is a proven high-gain, spark-resistant, single-amplification stage providing versatility in its applications within nuclear astrophysics, medical physics, and nuclear security industries. In this study, the 𝛍-RWELL is tested for its position resolution in a cylindrical active-target time projection chamber, TACTIC (TRIUMF Annular Chamber for Tracking and Identification of Charged particles), and the planar Test Chamber. TACTIC provides full angular coverage and the ability to constrain differential energy loss properties for charged particle-induced reactions whilst simultaneously scanning reaction vertices at different energies. This is the first application of the 𝛍-RWELL in a cylindrical geometry for these purposes.
A 241Am alpha source was used in gas pressures as low as 250mbar in a mixture of 90:10 Ar:CO₂. The following studies evaluated reconstructing the source position in TACTIC and the Test Chamber, where emphasis has been placed on low-pressure environments for increased centre-of-mass energy resolution. Early-stage results of this work detail the positional resolution of source reconstruction and the effects of changing gas pressure in multiple geometries for improved charged particle track reconstruction.

Speaker: Lara Malpas (University of York)

42 Identification and reconstruction of multi-pixel events for improved spectroscopic imaging with HEXITEC

Charge sharing deteriorates the spatial and spectral performance of spectroscopic imaging systems which exploit the small-pixel effect, such as HEXITEC. As charge sharing may be produced by multiple non-exclusive physical processes, a diverse range of charge carrier behaviours exist within charge sharing events – with each multipixel event containing process-specific spatial and spectral distortions. The performance of generalised methods of charge sharing correction are therefore limited by their one-size-fits-all approach. Traditional, generalised charge sharing correction results in either significant sensitivity loss when using Charge Sharing Discrimination (CSD), or significant energy and spatial resolution loss when using Charge Sharing Addition (CSA). These limitations represent a key barrier preventing high-performance spectroscopic imaging within low flux applications.

Shape analysis of multipixel events exploits event-shape-specific energy information to infer the charge carrier behaviour and interaction process most-likely to be responsible for a given multipixel event. This allows existing process-specific methods for spectral and spatial reconstruction to be applied only to events, or portions of multipixel events, which require correction.

Event shape analysis was carried out at 141 keV. This indicated >99.6% of events resulted from 10 event shapes. The most-likely charge carrier behaviours for each high-likelihood event shape was determined. Current methods for spectral and spatial reconstruction were adapted for effective application within HEXITEC data. Event-shape-specific charge sharing correction was carried out for 2-pixel events, producing process-specific images which were combined to create a final reconstructed image. This new approach to charge sharing correction achieved significant sensitivity improvements when compared to CSD (17.3M vs 8.7M total image counts), reduced energy resolution loss in comparison to CSA (0.7% vs 1.2% at 141 keV) and improved spatial resolution when compared to either CSD or CSA (500 μm vs 580 μm FWHM).

Speaker: Andrew Farnworth (Loughborough University)

43 Phase-2 upgrade of the CMS Outer Tracker: challenges and lessons from silicon strip module production

In view of the High-Luminosity upgrade of the Large Hadron Collider, the silicon tracker of the Compact Muon Solenoid detector will be fully replaced within the Phase-2 upgrade to cope with luminosities increased by about an order of magnitude compared to LHC design luminosity, and up to 200 simultaneous interactions per bunch crossing. In addition, the new tracker will provide tracking information to the Level-1 trigger, allowing early selection of interesting events and reducing the data rate from 40 MHz to about 750 kHz. The upgraded Outer Tracker will consist of more than 13,000 silicon modules with fine spatial granularity, assembled in several centers worldwide. Module production has been ongoing for over a year, marking the transition from prototyping to large-scale production. During this period, a range of challenges has been encountered, including issues related to component choices, production processes, and external constraints. Some have already been successfully addressed, while others are being actively worked on by dedicated task forces. This talk will present practical lessons learned from large-scale production, including how challenges were handled and how processes were adapted.

Speaker: Inna Makarenko (Vrije Universiteit Brussel (BE))

PSD14_Sep2026_poster_Makarenko_v1.pdf

44 Thermal Modelling Studies of the ATLAS ITk Strip Barrel Staves Using ANSYS

Speaker: Ali Awais (Queen Mary University of London)

Abstarct_AliAwais.pdf

ITk_Ansys_thermal_simulations_ Poster_V1.1.pdf

45 Comparative 3D TCAD Analysis of Active-Edge Planar Pixel Sensors for HL-LHC Applications

To meet the stringent requirements of the High Luminosity LHC (HL-LHC) upgrade, the ATLAS inner tracker (ITk) requires silicon sensors with exceptional radiation hardness and maximized geometrical efficiency. Active edge technology is essential to minimize inactive peripheral areas; however, accurately predicting their behavior under extreme radiation remains a challenge. This work presents a novel 3D TCAD simulation framework developed with Silvaco™ to perform a comprehensive comparative analysis of various active edge n-on-p planar pixel sensor structures. Unlike conventional 2D modeling, these advanced 3D simulations provide a precise evaluation of the localized electric field distributions and charge transport mechanisms at the sensor boundaries. The methodology incorporates a refined three-level trap model for p-type FZ silicon, calibrated with experimental doping profiles from Secondary Ion Mass Spectrometry (SIMS). The radiation-induced degradation is investigated for fluences exceeding $2 \times 10^{16} \text{ n}_{eq}/\text{cm}^2$, pushing the study into the high-radiation regime expected for future tracker layers. Key results focus on the impact of different edge geometries on breakdown voltage stability, leakage current evolution, and Charge Collection Efficiency (CCE). The 3D analysis reveals critical insights into charge loss mechanisms and field enhancements that are often underestimated in 2D models. By comparing multiple design iterations, this study identifies the most robust active edge configurations for high-fluence environments, providing crucial guidelines for the optimization of next-generation planar pixel sensors in high-energy physics experiments.

Speaker: Djemouai DJAMAI (Laboratory of Engineering and Sciences of Advanced Materials (ISMA))

46 Characterization and Application of the First Prototype of HEROC: An Analog Readout ASIC for Position-Sensitive Helium-3 Tube Neutron Detectors

The China Spallation Neutron Source (CSNS) is undergoing an upgrade to CSNS-II, targeting an increase in proton beam power to 500 kW. This upgrade imposes stringent requirements on neutron detector readout electronics, including operation under vacuum conditions, higher counting rates, improved spatial resolution, and reduced power consumption. Conventional discrete-component front-end electronics suffer from high power dissipation and limited performance, making them unsuitable for these applications.

To address these challenges, we have developed a prototype application-specific integrated circuit (ASIC), named HEROC (HElium-3 ReadOut Circuits), for position-sensitive Helium-3 tube neutron detectors. Each channel integrates a charge-sensitive amplifier, pole-zero cancellation, shaping amplifier, and output buffer, providing a compact and low-power analog front-end solution. The fabricated 8-channel ASIC demonstrates an input dynamic range from 10 fC to 1.5 pC and supports counting rates up to 500 kHz. Electrical measurements show an equivalent noise charge of 1130 electrons at 15 pF, with power consumption below 9.9 mW per channel, corresponding to an approximate 90% reduction compared to the discrete-component front-end electronics used in CSNS-I.

The ASIC was validated through vacuum and neutron beam tests. Stable operation was achieved under vacuum with negligible temperature increase. Beam tests at CSNS produced clear charge spectra and time-of-flight distributions, and an optimal position resolution of 6 mm was obtained. The system demonstrated stable operation at counting rates up to 125 kHz during beam measurements. The results indicate that the HEROC ASIC is a promising solution for low-power, vacuum-compatible neutron detector readout in CSNS-II spectrometers. The ASIC-based detector readout system has already been successfully deployed and is operating stably at the first CSNS-II beamline, the Neutron Technology Development Beamline. It is planned for further implementation in additional CSNS-II spectrometers.

Speaker: Jiayi REN

47 High Precision 3D Time Projection Chamber R&D for Future Circular e+e- Collider

The Circular Electron Positron Collider Technical Design Report (TDR), as a Higgs and high luminosity Z factory, has been released 2025 at Institute of High Energy Physics, CAS in China. The baseline design of a detector concept consists of a large 3D tracking system, which is a high precision (about 100μm) spatial resolution Time Projection Chamber (TPC) detector as the main track embedded in a 3.0T solenoid field, especially for the accelerator operating at High luminosity Tera-Z. TPC requires the longitudinal time resolution <100ns) and the physics goals require PID resolution (<3%).
In this talk, we will present the feasibility and progress of the high-precision TPC technology for the Circular Electron Positron Collider (CEPC), even at low-luminosity Tera-Z operation. The fundamental parameters such as spatial resolution, PID with good separation power using cluster counting, and drift velocity were studied through simulation and measurement using a TPC prototype with 500 mm drift length. Compared with pad readout in simulation, the high-granularity readout TPC option (hundred-micrometer level) achieves
better spatial resolution for single electrons, balanced against power consumption, with very high detection efficiency, excellent tracking, and good PID performance (less than 3σ). In addition, we will report on the ongoing R&D of TPC readout modules based on the TEPIX chip, which represents a key step towards integrated, low power front end electronics for future TPC systems. We will review these results and summarize the next steps towards TPC R&D for tracker detectors in future e+e- colliders.

Speaker: Huirong Qi (Institute of High Energy Physics, CAS)

48 The NA62 Gigatracker and 4D track reconstruction

The GigaTracKer is a hybrid silicon pixel detector of the fixed-target experiment NA62 at the CERN SPS that aims to precisely measure the branching ratio of the very rare $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ decay. The detector was designed to provide measurements of the momentum, direction, and time of beam particles arriving at a rate of 750 MHz. The tracking system consists of four stations installed in vacuum ($\sim10^{-6}$ mbar), $60.8 \times 27\ \text{mm}^2$ each, with a total material budget of less than $2\%$ X$_0$. Each station is cooled with a microchannel cooling plate used for the first time in a high-energy physics experiment. The beam particles are tracked in four dimensions using time-stamping pixels ($300\times300\ \mu \text{m}^{2}$) with a single-hit time resolution of 115 ps. This performance must be maintained despite the beam irradiation that amounts to $4.5 \times 10^{14}$ 1 MeV neutron equivalent yearly fluence (integrated over a data taking period of 200 days). The detector has been fully operational since 2016. We describe the GigaTracKer design, performance, and developed 4D track reconstruction algorithms.

Speaker: Elizabeth Sarah Long (Charles University (CZ))

GTKPoster2026.pdf

49 Characterisation of Fully Depleted CMOS Monolithic Active Pixel Sensors for X-ray Imaging Applications

Fully depleted CMOS monolithic active pixel sensors represent a promising technology for compact, low-power and high-resolution X-ray imaging systems, with potential applications in space instrumentation and medical imaging. In this work, we present the characterisation of ARCADIA CMOS pixel sensors developed in a 110 nm CMOS imaging technology, with emphasis on their electrical, readout and X-ray detection performance.

The investigated devices are based on a high-resistivity n-type active substrate and are designed to allow depletion from the backside through a dedicated backside implant. Measurements were performed on ARCADIA MD3 sensor assemblies using laboratory X-ray sources and a dedicated DAQ system based on front-end electronics and FPGA readout. The study includes sensor biasing, leakage current measurements, threshold optimisation, hit-map studies, cluster analysis and X-ray response measurements using characteristic X-ray lines.

The results show stable sensor operation under reverse bias, low-power readout performance and clear X-ray detection capability. Two-dimensional hit maps and cluster observables are used to evaluate the spatial response and charge-sharing behaviour of the sensor. The measurements provide useful input for the optimisation of thick fully depleted CMOS sensors and their possible use in advanced X-ray imaging techniques, including applications where high spatial resolution, low material budget and scalable monolithic integration are required.

Preferred contribution type: Poster
Relevant track: Advances in Pixel Detectors & Integration Technologies

Speaker: Mr Sami Ullah Khan (University of Padua & INFN Turin)

50 Development of a Multiplexed Readout Method for Scintillator Detectors at CSNS

To support cutting-edge research, including high-resolution structural analysis and high-precision stress-strain measurements, the general-purpose powder diffractometer (GPPD) at the China Spallation Neutron Source (CSNS) is in urgent need of an upgrade, with the performance enhancement of scintillator neutron detectors as the core technical strategy. Expanding the effective detection coverage of scintillator detectors and optimizing the detector unit structure can better meet the comprehensive requirements of advanced neutron scattering experiments for detection systems. Correspondingly, the detector upgrade imposes stringent demands on the associated readout electronics, such as higher integration density, improved position resolution, and enhanced large-scale channel processing capability. A dedicated application-specific integrated circuit (ASIC) tailored to the new scintillator detector has been developed, and a multiplexed readout method based on the “ASIC + multiplexer” architecture is proposed and systematically investigated. A compact, highly integrated, and large-scale readout electronics system is realized without sacrificing position resolution. Meanwhile, to adapt to the Apache-Kafka data stream processing platform of CSNS, the back-end electronics are implemented using system-on-chip field-programmable gate array technology, enabling direct communication with the Kafka platform. Neutron beam experiments integrated with the new scintillator detector demonstrate that the system achieves high-quality two-dimensional neutron imaging under 8:1 channel multiplexing, with a neutron detection efficiency exceeding 45% at 2 Å. The overall performance of the system meets the high-precision measurement requirements of the upgraded GPPD spectrometer.

Speaker: Li Yu

51 Embedding thermal management in hybrid pixel detectors that operate HPGe sensors with room-T ASICs.

A new and unproven technology is being explored to potentially enable and radically change the use of HPGe sensors with existing room temperature ASICs in hybrid pixel detectors. The goal is to control high temperature gradients (~130 C) over a short distance (100’s μm) between HPGe sensors and ASICs. A micro-thermal divider translates the physics requirements set by the Fourier’s Law of heat conduction, into an engineered solution exploiting the capabilities offered by micro-fabrication and micro-machining processes, and by micro-electronics interconnection techniques.

Hybrid pixel-detectors have proven to be a very powerful technology for X-ray detection by combining direct photon detection and small pixel size, with the flexibility to match the same readout chip to the optimal sensor material for the application. High-Z sensors different than silicon are required to achieve high quantum efficiency for X-rays above 20 keV. However, many high-Z materials such as GaAs, CdTe and CdZnTe often suffer from unfavourable material properties or nonuniformities. Remarkably, HPGe crystals provide a unique combination of favourable crystal properties and material purity that translates into a high and uniform detection efficiency, as well as an excellent energy resolution over a large area (wafer dia. 90mm). The deployment of HPGe sensors in hybrid pixel detectors is currently limited by the cryogenic requirements of the sensors, representing a barrier to wider adoption.

Prototypes were manufactured with an embedded micro-thermal divider to evaluate the effects on electrical performance and mechanical stability. Results from the latest batch of prototypes will be presented and next steps outlined.

Speaker: Konrad Sutowski (STFC)

52 Radiation damage effects on the intra-pixel timing performance in planar silicon sensors

Fast and radiation-hard silicon timing detectors with tracking functionality are becoming increasingly important for future generation experiments. We present the intra-pixel timing performance of irradiated planar silicon sensors and compare with previous results obtained with non-irradiated devices. Detailed intra-pixel maps reveal structured non-uniformities in the intra-pixel timing performance, which are discussed in the context of the pixel electrode weighting field and radiation damage mechanisms. This study was conducted using 200 $\mu$m n-on-p planar silicon pixel sensors bonded to the TDCpix ASIC, originally developed for the NA62 GigaTracKer. The hybrids were irradiated at the University of Birmingham MC40 cyclotron to fluences of $5\times10^{13}$ and $1\times10^{14}$ 1 MeV n.eq / cm$^2$. The devices were studied using the TimePix4 telescope, located on the H8 beamline at the CERN Super Proton Synchrotron. The TimePix4 telescope provided reconstructed tracks with a spatial resolution of $\mathcal{O}$(10 $\mu$m) at the hybrid position. This made it possible to study the timing performance inside the large 300 $\mu$m pixels as a function of the in-pixel coordinates. The association of TimePix4 tracks with TDCpix hits was provided by hardware level synchronization and a custom space-time alignment algorithm.

Speaker: Ceyhan Sam (University of Birmingham (GB))

CeyhanSam_PSD14_Poster_A0.pdf

53 Results from Investigating the Tolerance of LGADs to High-Dose X-Ray Radiation

Low-gain avalanche detectors (LGADs) have strong potential as next-generation sensors and imagers in photon science, especially for soft X-ray beamlines at synchrotron light sources. Their intrinsic gain provides higher signal-to-noise ratios when compared to traditional planar sensors, enabling direct detection of soft X-rays which would otherwise not be possible with hybrid imagers. While not currently widely used in photon science, LGADs are already being exploited in high-energy particle physics for their precise time resolution, in the timing layers of both the ATLAS and CMS detector upgrades.

In this poster, we present results from investigations of the damage caused by high-intensity photon beams to these devices. The investigations involved the irradiation of pad LGADs with flat-field and micro-focused X-rays. The evolution of current-voltage characteristics was measured, alongside how operational leakage and photo currents changed over a range of flat-field doses. These were generated by a tungsten-anode X-ray tube, and ranged from several hundred kilorad to several hundred megarad (SiO₂). The same characteristics were monitored during tests at Diamond Light Source^®, in which devices were exposed to an 8 keV micro-focused beam of order five square microns in area.

The results show strong promise for the survivability of LGADs in high-photon-intensity environments such as synchrotron light sources. We discuss how LGAD designs can be improved to maintain performance and reduce radiation-induced effects. Future work, already beginning, will involve exposing these devices to even higher X-ray doses, as well as making more accurate measurements of their gain and measuring the variation between different sensor designs.

Speaker: Mr Samuel Wood (University of Oxford)

54 Future Detector Materials for X-ray Photon Science Applications

The STFC Technology Department’s Detector Development Group have been developing detectors for X-ray photon science for over two decades. The group have developed a broad range of camera systems during this time that have included silicon-based imagers like the Large Pixel Detector (LPD) for the European XFEL [1] as well as hundreds of modules of our HEXITEC spectroscopic imaging detectors that make use of compound semiconductor materials like cadmium zinc telluride (CdZnTe) [2]. As photon light sources enter a new generation of diffraction-limited storage rings and MHz continuous repetition rate XFELs, the need for detector materials that can operate at higher photon fluxes and energies has never been greater.

This paper will present an overview of the groups work on the characterisation of different detector materials and their performance under these challenging conditions. This will include the most recent results from high-flux capable CdZnTe material produced by Redlen Technologies bonded to our next generation detector systems HEXITEC-MHz [3] and XIDYN [4] operating at photon fluxes in excess of 10$^{6}$ photons s$^{-1}$ mm$^{2}$. In addition, results will be shown from a new generation of perovskite radiation detector materials. The performance of melt grown CsPbBr$_{3}$ and solution grown FAPbBr$_{3}$ will be compared to that of CdZnTe under high flux synchrotron radiation.

REFERENCES

[1] M. C. Veale et al., Characterisation of the high dynamic range Large Pixel Detector (LPD) and its use at X-ray free electron laser sources, JINST 12 (2017) P12003 doi:10.1088/1748-0221/12/12/P12003

[2] M. C. Veale et al., HEXITEC: A High-Energy X-ray Spectroscopic Imaging Detector for Synchrotron Applications, Sync. Rad. News 31 (2018) 28 doi:10.1080/08940886.2018.1528431

[3] B. Cline et al., Characterisation of HEXITECMHz - A 1 MHz continuous frame rate spectroscopic X-ray imaging detector system, Nuc. Inst. Meth. A. 1057 (2023) 168718 doi:10.1016/j.nima.2023.168718

[4] S. Knowles et al., DynamiX: A prototype high-framerate, high-dynamic-range hard X-ray detector for 4th generation synchrotrons, iWoRID 2025 https://www.technology.stfc.ac.uk/Pages/News-Conferences-and-Publications/Conferences-Visits-and-Events/IWoRID-2025/DynamiX-iWorid25-Knowles.pdf

Speaker: Dr Matthew Veale (UKRI Science & Technology Facilities Council)

55 WLS Fiber Localization via DBSCAN Clustering of Dark Count Rate Spatial Excess in a CMOS SPAD Array

We present a background-referenced method for localizing the spatial response associated with a wavelength-shifting (WLS) fiber using hierarchical DBSCAN clustering, without imposing a predefined fiber position.

The methodology was evaluated using experimental data acquired from a detector setup combining a WLS fiber embedded in a shielded scintillator bar, a pixelated photosensor, FPGA-based acquisition, and an independent hodoscope-based validation chain. A no-fiber background map is used as a pixel-wise instrumental baseline, while the fiber-coupled measurements are analyzed after background subtraction to identify the resulting spatial excess response. The datasets analyzed in this work were acquired under ambient laboratory conditions, without active temperature control.

The background-subtracted spatial excess map is processed in physical detector coordinates using the pixel pitch as the spatial metric. A hierarchical DBSCAN pipeline first identifies local microclusters and subsequently merges their centroids into larger superclusters. A parameter scan is used to identify configurations in which the reconstructed response remains spatially stable before independent structures merge artificially. The final localization is obtained by maximizing the spatial support enclosed within the physical fiber radius, yielding a reconstructed response centroid at (3.082 mm, 0.645 mm), corresponding to approximately (93.67, 8.83) in sensor column-row coordinates.

The reconstructed point is interpreted as the centroid of the measured spatial response rather than the geometrical center of the fiber, and the response footprint is not directly identified with the physical fiber diameter. An independent hodoscope-based acquisition provides temporal information on photon arrival and an additional cross-check of the reconstructed fiber-response position.

These results demonstrate that background subtraction combined with hierarchical spatial clustering can recover a localized WLS-fiber-associated response under non-uniform detector background conditions without imposing an external fiber position. The approach is detector-architecture agnostic and can be applied more broadly to pixelated photodetector systems where spatially varying background complicates direct localization.

Speaker: Fernanda Zapata Bascuñán (National University of San Martín (UNSAM))

56 Testing of Analogue Pixel Test Structures for the ALICE 3 Inner Tracker

A major upgrade of the ALICE experiment is foreseen for Run 5 of the LHC. The new retractable Vertex Detector (VD) is a crucial component of the upgraded experiment and will achieve an unprecedented pointing resolution owing to its close proximity to the interaction point, with three layers installed inside the beam pipe, in combination with a low material budget. Monolithic Active Pixel Sensors (MAPS) are ideally suited, yet require significant research and development to meet the combined requirements in position and time resolution as well as radiation hardness, all while limiting the power consumption. In addition, the desired position resolution of 2.5 µm, that is achievable with a pixel pitch of 10 µm, requires an unprecedented integration density.

To this end, small pitch analogue prototypes are characterised in view of their charge collection properties, in order to pave the way towards a pixel chip targeting the requirements of the ALICE 3 VD. A second variant of the pixel chip is adapted to the needs of the outer tracker layers (barrel and forward disks) surrounding the VD up to a radius of 80 cm.

In this contribution, the pixel chip requirements and design concepts for the VD and outer layers will be presented. Particular focus will be given to the characterisation of prototypes to validate the required technological steps towards ALICE 3, including laboratory measurements and test beam campaigns.

Speaker: Alessandro Sturniolo (University of Liverpool (GB))

ASturniolo_ALICE3-IT-APTS_characterisation_v4.pdf

57 A dual-mode clocking circuit for serial data links in particle physics experiments

In applications such as particle physics experiments, synchrotron radiation facilities, space exploration, and medical imaging, high-speed serial links are essential for data transmission between front-end and back-end systems. The development of high-performance clock data recovery (CDR) and phase-locked loop (PLL) circuits represents a key focus in the design of such systems. The proposed CEPC common front-end electronics requires a high-speed SerDes ASIC, capable of supporting an uplink data rate of 11.09 Gbps and a downlink data rate of 2.77 Gbps. This paper presents a dual-mode clocking circuit operating in either CDR or PLL mode. Both modes share a common voltage-controlled LC-tank oscillator covering two sub-bands, with a tuning range from 4.89 GHz to 5.96 GHz across all process, voltage, and temperature (PVT) variations. Mode switching is achieved by enabling the corresponding phase detector, charge pump, and low-pass filter. In PLL mode, the circuit receives a 43.33-MHz reference clock and synthesizes a 5.55-GHz output. In CDR mode, it accepts half-rate serial data at 2.77 Gbps and recovers both the data and synchronized clock signals (5.55 and 2.77 GHz). The generated clocks are distributed to the SerDes, clock dividers, and output drivers. The clocking circuit integrates 16 channels of clock dividers and multiplexers, with 9 channels brought out due to I/O constraints. Each channel offers seven selectable frequencies. The simulated core power consumption is approximately 38 mW. Fabricated in a 55-nm CMOS technology, the circuit is scheduled for testing in August, with detailed design and measurement results to be reported subsequently.

Speaker: Xiaoting Li (IHEP)

58 Backside-Processed MAPS for Low-Energy Spectroscopy

Monolithic Active Pixel Sensors (MAPS) have demonstrated excellent performance in the field of high-energy physics, especially with improved timing performance with respect to standard CMOS imaging sensor. Their application to low-energy spectroscopy seems promising, however, requires dedicated sensor optimization in order to minimize the inactive entrance layer and enhance charge collection efficiency. This work presents the characterization of a Monolithic Imager sensor developed in a modified TowerJazz 0.18 µm CMOS imaging process and optimized for low-energy particle and photon detection.

The back side of the sensor was post-processed with ion implantation and laser annealing by IBS [1]. This treatment enables the formation of an ultra-thin entrance window, significantly improving sensitivity to low-energy particles.

Sensor characterization was performed using a low-noise readout system to study the noise and energy resolution. Measurements with the 55Fe source show a clear separation between characteristic lines and demonstrate the suitability of the sensor for spectroscopic applications. Additional measurements results obtained with a tritium source prove that the sensor can detect very low-energy beta particles.

The results confirm the effectiveness of the backside processing approach and highlight the potential of MAPS technology for applications requiring direct detection of low-energy radiation, including environmental monitoring, radioprotection, and scientific instrumentation.

[1] Laser activation of Ultra Shallow Junctions (USJ) doped by Plasma Immersion Ion Implantation (PIII), Applied Surface Science 255 (2009) 5647–5650

Speaker: Gaël Chevrier (IPHC CNRS)

59 Dose-efficient edge-illumination X-ray phase-contrast imaging with EIGER photon-counting detection

Edge illumination X-ray phase-contrast imaging (EI-XPCI) can allow dose reductions at constant image SNR, with great prospective benefit to biomedical applications. Photon counting detectors offer a route to this by providing a Poissonian response while eliminating read-out noise with appropriate energy thresholds, unlike energy integrating detectors where additive dark noise becomes increasingly important at low fluence.

We investigated this detector advantage for propagation distance optimisation. In a double mask EI-XPCI system, the object-detector distance was increased with fixed geometrical magnification, so changes in retrieved contrast were dominated by propagation sensitivity rather than beamlet widths or projected sample size. Concurrently, the source-object distance increases, reducing the dose. Measurements were performed with an EIGER 500K Hybrid Photon Counting detector for several refractive and scattering samples, compared with simulations. Additional flux-variance measurements were acquired with EIGER count-rate correction to test whether detector nonlinearity or correction artefacts contribute to observed noise response.

Mean flux followed an inverse-square dependence with distance. The refraction signal stayed constant with distance whereas dark-field decreased. Temporal variance increased with distance more than expected from the flux reduction, so the expected constant SNR dose reduction was not fully realised at larger distances. Flux-variance analysis showed that detector response remained Poissonian with and without count-rate correction, indicating that excess variance originates from the wider EI-XPCI system rather than from intrinsic detector statistics. These results identify photon counting detection as a promising route for dose efficient EI-XPCI, while highlighting the system stability requirements needed to exploit it quantitatively.

Speaker: Alexander Duncalf (University College London)

60 Solid State and Diamond Detectors for Medium to Low Energy (< 5 keV) Electrons

For ultra-large constellation missions (greater than 1,000 spacecraft) to be feasible, each instrument on each spacecraft must be compact, low-cost, easy to manufacture, and require minimal resources. For low-energy plasma instruments, these constraints apply to both the plasma spectrometer and the particle detector. The ideal particle detector operates at low-voltage, is light-blind, and has an energy detection threshold of tens of eV. Here we present results from tests of an eight-pixel, silicon strip detector and a single pixel, solar-blind, diamond detector. The solid state detector successfully detected electrons down 4 keV and the diamond detector also had a detection threshold of 4 keV. The solid-state detector was a commercially available, 500 m thick, Canberra PF-8CT-13*18 detector with a dead layer less than 50 nm thick. The diamond detector was a three-layer, diamond detector manufactured by Advent Diamond with an Aluminum coating. As expected, with a bandgap of 5.45 eV, the diamond detector was insensitive to ambient light. Custom-built, charge sensitive pulse shaping circuitry was used for both detectors with slight component value differences implemented for biasing and detector capacitance compensation. Here we present measurements of the detector response versus electron beam energy and beam current.

Speaker: Gregory Lusk (West Virginia University)

61 Prototyping the ALICE 3 bRICH: a compact SiPM-based PID system with tracking and timing capabilities

The ALICE Collaboration is proposing a completely new apparatus, ALICE 3, to investigate the properties of the quark--gluon plasma in heavy-ion collisions during LHC Run 5. A key PID subsystem in the barrel region will be a proximity-focusing Ring-Imaging Cherenkov detector (bRICH). It will cover a radial region of 36 cm, using aerogel ($n = 1.03$) as radiator and silicon photomultipliers (SiPMs) as photon sensors. The detector is designed to ensure efficient e/$\pi$, $\pi$/K and K/p separation for momenta up to 2, 10 and 16 GeV/$c$, respectively. Filling the proximity gap with a CO$_2$-based gas mixture ($n = 1.0006$) allows the further extension of electron PID up to 4 GeV/$c$ through Cherenkov threshold-based pion discrimination to access unprecedented dielectron-related observables. The challenging requirement of preserving the target single-photon performance with SiPMs exposed to fluences corresponding to NIEL levels above $10^{11}$ 1-MeV n$_{\mathrm{eq}}$/cm$^2$ led to the design of a dedicated module concept based on radiation-hard components. The module concept is based on the DENEB front-end ASIC, targeting a single-photon time resolution of 100 ps. It also integrates two-phase microchannel CO$_2$ cooling of the SiPMs down to $-40^\circ$C, together with an annealing system capable of heating them above $70^\circ$C. In addition, we demonstrate that smaller SiPMs coupled to light concentrators made of fused silica can reduce the active area and the overall dark count rate (DCR), while preserving the same effective area, number of channels and spatial resolution, and improving the time resolution. Various small-scale prototypes were successfully tested in beam-test campaigns at the CERN-PS T9 and T10 beam lines. The measurements validated both the bRICH layout and the expected performance in terms of timing, photon yield, angular resolution, and the resulting separation power. They also demonstrated the stability of the reconstruction performance under the increasing DCR conditions expected during ALICE 3 operation. In this contribution, the bRICH concept, the latest detector R&D results, and the main beam-test results will be presented.

Speaker: Nicola Nicassio (Universita e INFN, Bari (IT))

Poster_PSD14_2026.pdf

62 A Single-Ended Multiplexed DOI-Capable PET Detector with 4-to-1 Crystal-to-Pixel Coupling and Edge-Effect Mitigation: An Optical Simulation Study

Current positron emission tomography (PET) systems use a high number of readout channels to support high spatial resolution, incurring high cost and complexity. Introducing multiplexed light-sharing readouts reduces the number of necessary channels. However, they suffer from edge effects due to differences in light sharing architecture at the scintillator matrix edge compared to the center, diminishing their spatial resolution and signal-to-noise ratio (SNR). We have developed a single-ended readout depth of interaction (DOI) enabled PET detector with 4-to-1 multiplexing mitigating edge effects. The matrix is coupled to light guides and a silicon photomultiplier (SiPM) array on opposing ends. Multiplexed single-ended readout was achieved by coupling adjacent crystal pairs at the matrix center and distant pairs at the matrix edge. Sharing the scintillation light between exactly two different SiPM pixels enables DOI determination, while pairing distant crystals at matrix edges mitigates edge effects. DOI capability was evaluated using optical simulations. The number of photons incident on the two pixels for a range of DOI was recorded. The number of photons incident on the interaction crystal pixel is always higher than on the connected crystal pixel enabling unambiguous determination of the interaction crystal. The ratio of the number of photons incident on the interaction pixel over the coupled pixel increases exponentially with DOI. Crucially, this property is retained for the edge crystals. The ratio values for both edge and center pairs span three orders of magnitude allowing the presented detector architecture to achieve favorable DOI capability across the entire scintillator matrix.

Speaker: Ms Gabriela Jazvac (Institute for Medical Research and Occupational Health)

63 Design and Test Results of the SIPAC: A Prototype SiPM Readout ASIC for CEPC Calorimeters

The Circular Electron Positron Collider (CEPC) is proposed for Higgs boson studies and will employ Silicon Photomultipliers (SiPMs) extensively in calorimeter detectors. This work presents SIPAC, a dedicated SiPM readout ASIC for calorimeters, implemented in a 55-nm CMOS process. To accommodate the relatively slow SiPM signals after crystal conversion, a voltage amplifier is adopted as the front-end architecture. Considering the strong influence of electronic noise on timing and energy resolution, dedicated shaping circuits are designed for parallel energy and timing measurements.

The energy path incorporates a slow shaper with two-stage low-pass filtering, achieving a signal-to-noise ratio (SNR) of 17, while the timing path employs a fast shaper with band-pass filtering. The shaped signals are digitized by a shared SAR ADC and a hybrid TDC, respectively. The TDC combines coarse counting with delay-line-based fine interpolation for time-of-arrival measurement. AC coupling is implemented to isolate the DAC used for SiPM gain adjustment.

Post-layout simulations show that, within an input dynamic range of 1.28 pC to 3.84 nC, the nonlinearity errors are 0.4% and 0.3% for the high-gain and low-gain paths, respectively, while the SAR ADC achieves 10-bit ENOB. A four-channel prototype was fabricated in October 2025 and returned in February 2026. Standalone measurements demonstrate a dynamic range of 3000, integral nonlinearity better than 2% and 1.2% for the high-gain and low-gain channels, respectively, an SNR of 17.65 for minimum-ionizing-particle signals, and a TDC resolution of 102 ps. The results will also be presented in this poster.

Speaker: 邓云起 dengyq (Central China Normal University，Institute of High Energy Physics)

64 Development of an Organic Semiconductor based Fast Neutron Camera

Alternatives to He3 gas based neutron detectors have long been sought after following increasing shortages in the last decades. While some technologies exist, organic electronics have seen widespread scientific interest use due to their tunability, scalability and cost-effectiveness. This project builds on these paradigms to present an organic semiconductor based fast neutron camera, with potential later sensitisation to thermal neutrons. This can serve a multitude of applications including nuclear security and safeguarding, fundamental particle physics, reactor monitoring and medical physics.

The design uses PNDI(2OD)2T as the organic polymer and much of the initial testing was conducted using an Am-241 370kBq alpha source. This allows for safe and ease of use while providing illustrative results given the fast neutron detection mechanism involves an intermediate alpha particle. Some preliminary neutron tests using our in-house AmBe-based irradiation facility [1] will follow soon.

Supplementary to previous initial testing and validation [2], I present the expansion of this technology exploring different electrode designs, moving towards PCB substrates for electrical integration, as well as preliminary signal amplification. We also present some results for radiation tolerance studies at the SCK-CEN BRIGITTE facility in Mol, Belgium featuring a primarily 1 MeV gamma Co-60 source, operated with help from colleagues at the Austrian Academy of Sciences, to demonstrate device operation up to a total irradiated dose of up to 0.92MGy.

Once materials, design, characterisation and amplification are finalised for a single pixel, a multipixel array can be explored for imaging. This would be paired with several field tests to build a database with characteristic responses given different materials and applications.

[1] A. J. Bevan and I. Dawson. Characterisation and monte carlo validation of a compact AmBe neutron irradiation facility providing fast and thermal neutron fields for detector development, 2026.

[2] Aled Horner et al., Direct neutron detectors based on carborane containing conjugated polymers, 2025

Speaker: Divij Gupta (Queen Mary University of London)

65 Fast luminosity detector based on the radiation hardness LGAD technology for SuperKEKB

To provide precicely bunch-to-bunch luminosity measurement of SuperKEKB, the fast luminosity detector should have less than 4 ns signal width and be radiaitonharded. At SuperKEKB, this has been demonstrated using CVD diamond detectors at 4m from the IP. LGADs (Low Gain Avalanche Diode) have recently been installed at SuperKEKB and tested as a potential alternative with the Lumibelle2 collaboration. This sensor has a much faster rise time and shorter signal width on the order of a nanosecond, which is more suitable for the fast bunch-to-bunch luminosity measurement. The areas of the LGAD detector is 3.9mm x 7.5mm and 7.5 mm x 7.5mm are operated in a single-channel parallel-readout scheme.The detector was characterized on the bench with a 90Sr 𝛽source under different bias voltages, and front-end coupling/shaping capacitance settings. The signal amplitude, baseline noise, pulse width,
and timing-related waveform properties were evaluated. Laboratory tests show that the LGAD
readout chain provides clearly distinguishable signal amplitudes, low baseline noise, and pulse
widths below the nominal 4 ns bunch spacing of SuperKEKB. After installation in the LER
and HER regions of SuperKEKB, beam data recorded during operation show that the precision of the LGAD
could be ~2% and provide much higher counting rates than the current diamond channels.These results indicate that the LGAD-based detector can provide a stronger and statistically more precise signal for fast luminosity monitoring.

Speaker: Yunyun Fan (Chinese Academy of Sciences (CN))

66 In silico comparison of scintillator based photon counting detectors with the semiconductor gold standard.

Motivation: Spectral photon counting CT (SPCCT) is widely accepted as a major medical advancement, bringing the potential for quantitative molecular imaging at higher speeds than conventional approaches. Realising this potential is currently limited by the cost and spectral performance of the semiconductors used for the sensor material, e.g. CdTe. Recently, interest has grown around scintillators as an alternative, as whilst they lack the high intrinsic energy resolution of CdTe, they do not suffer from the extensive low energy tailing seen in small pixelated semiconductor detectors. As SPCCT uses broad energy bins, it is not immediately clear whether a higher spectral resolution (semiconductors)or less low energy tailing (scintillators) is more important for quantitative SPCCT applications. Here we use detailed simulations to answer this question.
Methodology: This work uses PC-SIM (Photon Counting Spectral Imaging Model), a new, modular tool for detailed simulations of SPCCT image processing chains. We combine this with Monte Carlo simulations performed in GATE to compare scintillators and semiconductors under a range of imaging conditions.
Results: Comparisons of spectral performance between scintillator and semiconductor based SPCCT systems will be used to identify any conditions under which scintillator performance can compete with the current gold standard of semiconductor based detectors. This presentation will also serve as an introduction to PC-SIM, outlining its design philosophy and its editable modules which allow users to rapidly model the impact of their ideas on a realistic SPCCT system

Speaker: Oliver Pickford Scienti (Institute of Cancer Research)

67 Development of a Monolithically Integrated SPAD Detector and TIA Readout Circuit in a 55-nm CMOS Process

This paper presents a monolithically integrated single-photon avalanche diode (SPAD) detector and its transimpedance amplifier (TIA) readout circuit, designed and fabricated in a SMIC 55 nm CMOS process. Two different SPAD structures are designed: a shallow-junction avalanche region structure (Structure I) and a deep-junction avalanche region structure (Structure II). Detectors of both structures are implemented in three configurations: single pixels, 3×3 arrays, and 5×10 arrays. The readout section integrates a TIA circuit with three adjustable gain levels. The feedback resistance can be set to 500 Ω, 3 kΩ, and 12 kΩ to accommodate varying gain requirements in different testing environments. The chip has completed fabrication and preliminary functional testing. Static I-V test results indicate that both structures exhibit SPAD avalanche breakdown characteristics, with the leakage current showing an increasing trend under illumination. The current evaluation focuses on the photon response of the 5×10 array of Structure I. When illuminated by a pulsed laser with a 625-nm wavelength, a 4-MHz frequency, and a 5-ns pulse width, the results show that the photon avalanche pulses amplified by the TIA synchronize with the external TTL trigger signal. These test data verify the physical feasibility of monolithically integrating SPAD arrays and TIA circuits at the 55 nm process node. This demonstrates the chip's capability to detect pulsed photon signals, providing a device foundation and data reference for the development of 4D tracking and photoelectric detection systems.

Speaker: 黄文豪 huangwenhao

68 Study of p-type magnetic Czochralski silicon diodes with SPA- and TPA-TCT

Radiation hardness is a vital property of sensors used in high-energy physics experiments. Significant effort has been made to develop particle detectors for the harsh radiation environments of the Large Hadron Collider (LHC) and the High-Luminosity Large Hadron Collider (HL-LHC). One suitable candidate material, silicon grown with the magnetic Czochralski method, possesses a high intrinsic oxygen concentration enabling it to withstand higher radiation fluences. The aggregation of oxygen atoms leads to the formation of electrically active defects, known as thermal donors, which can be used for bulk compensation, thereby lowering the depletion voltage and adjusting the bulk resistivity. In our work, we study p-type magnetic Czochralski silicon diode sensors with thermal donors. Thermal donor formation was achieved by sintering the silicon at temperatures of 410℃ and 430℃. We evaluated the sensors using a variety of methods, including the current-voltage (IV) and capacitance-voltage (CV) characterization, as well as single-photon absorption (SPA) and two-photon absorption (TPA) transient current techniques (TCT). We analyzed the sensors' electrical behavior and SPA-TCT response to 660 nm red and 1060 nm infrared laser pulses injected into the sensors' top and edge. Additionally, a 1550 nm TPA-TCT setup was used to probe the diode bulk beneath the optical window via top injection. By analyzing the obtained waveforms from the SPA and TPA signals, we characterize the movement of charge carriers in the bulk at different bias voltages. We also touch on the specifics of the amplification and readout chains, comparing signals from current-sensitive and charge-sensitive amplifiers to analyze the transients.

Speaker: Henry Hiltunen (LUT University)

69 Flexible Organic Semiconductor Alpha Particle Sensors for Pipeline Inspection in the Nuclear Industry

Nuclear decommissioning demands a complete understanding of the radiological hazard present, which is often achieved through the combination of in-situ detection and the complementary radiochemistry. Current challenges with in-situ detection arise from the various functions present at nuclear installations. These place constraints on the detector geometry, precision, chemical and environmental resistance of the characterisation technology employed, frequently requiring tailored solutions. We investigate organic (polymer, oligomer, and small molecule) semiconductors deposited on flexible substrates as a conformal and tuneable solution to this challenge. Organic semiconductors in general have made headway in consumer electronics, such as OLED displays in mobile phones, as well as IR photodiodes, and flexible photovoltaics. In the last 20 years, organic semiconductors have been investigated as cheaper alternatives (compared to their inorganic counterparts) in the field of radiation detection, with all radiation types being reported in the literature with end-goal applications in medical dosimetry, nuclear security, and high energy physics. We aim to fabricate
flexible alpha particle sensors to be used for in-situ characterisation of buried structures (pipelines) and scaffolding present on Nuclear Decommissioning Authority (NDA) sites. Characterisation in this context includes: 1. Contamination location. 2. Radioactivity. 3. Radioisotope identification. Investigations into the alpha detection capabilities of these diode-style organic sensors are undertaken in laboratory conditions utilising 241-Am sources, with an initial interest in understanding the detection capabilities of the sensor element alone, with respect to minimum detectable activity and sensitivity to particle energy. The end goal of this project will be to combine our sensors with an eversion robot and perform in-situ characterisation at an NDA site.

Speaker: Albanik Gashi (Queen Mary University of London)

70 Extreme phase sensitivity at high X-ray energies

X-ray Phase Contrast Imaging (XPCI) is a non-destructive imaging technique that enables imaging of weakly absorbing materials by exploiting the phase shifts introduced by the sample. One of the limitations of XPCI methods is the energy range at which they are operated, mostly below 50 keV. To image high-Z and thicker materials for industrial testing or security applications, it is essential to use high-energy X-rays due to their penetration power. However, operating at higher energies introduces challenges such as inefficiency of optical elements, decreased detector efficiency, and reduced refraction angles, which most XPCI methods measure due to their proportionality to phase shifts.

As the refraction angle scales as $\frac{1}{E^2}$, recovering sufficient signal at high energies requires optimising the experimental parameters such as increasing propagation distance between sample and detector. Increasing propagation distance requires a small focal spot to maintain low source blurring, which typically reduces flux and leads to long exposure times. Liquid Metal Jet (LMJ) sources address this by delivering an order of magnitude higher flux at high energies.

The choice of detector is critical as well. Photon counting detectors such as EIGER implement hybrid photon counting (HPC), detecting individual photons per pixel with zero readout noise and at high count rates [1]. At high energies, having low noise is essential to capture the weak phase contrast signal as all the sources of noise besides inherent Poisson noise are eliminated from the imaging process. Furthermore, CdTe sensors provide quantum efficiency above 60% up to 100 keV [2], making them well suited for high-energy applications. On the other hand, HPC detectors suffer from charge sharing, which affects the energy and spatial resolution of the detector [3]. The effect of charge sharing depends on the energy of the impinging photons, leading to loss of counts at low energies and double counting at high energies.

In this work, we present an experimental and theoretical study comparing the effects of propagation distance and energy on the contrast-to-noise ratio (CNR) and sensitivity of retrieved refraction profiles from an Edge Illumination (EI) setup, a non-interferometric XPCI method that uses highly attenuating masks to create sensitivity to phase effects [4]. We also analyse energy-binned refraction signals to evaluate detector performance across energy regimes and the energy dependence of the measured signal. Finally, by analysing the retrieved signals at various energy thresholds and comparing these with theoretical models, we assess the impact of charge sharing on the EI signal and explore potential correction strategies. Our results show that both CNR and sensitivity vary with propagation distance and energy as expected. The sensitivity of energy binned refraction signals reveals consistent detector behaviour across various energy bins, indicating that the decrease in the CNR is governed by the expected $\frac{1}{E^2}$, scaling of the refraction signal rather than detector performance degradation.

References
[1] Donath T, Trampari S, Wagner L, Jørgensen MRV, Gjørup FH, Checchia S, et al. Enhancing high-energy powder X-ray diffraction applications using a PILATUS4 CdTe detector. Journal of Synchrotron Radiation. 2025 Feb;32(Pt 2):378–384.
[2] Donath T, Sˇiˇsak Jung D, Burian M, Radicci V, Zambon P, Fitch AN, et al. EIGER2 hybrid-photon-counting X-ray detectors for advanced synchrotron diffraction experiments. Journal of Synchrotron Radiation. 2023 Jul;30(4):723–738.
[3] Fardin L, Giaccaglia C, Busca P, Bravin A. Characterization of a CdTe single-photon-counting detector for biomedical imaging applications. Physica Medica. 2023 Apr;108:102571.
[4] Olivo A, Arfelli F, Cantatore G, Longo R, Menk RH, Pani S, et al. An innovative digital imaging set-up allowing a low-dose approach to phase contrast applications in the medical field. Medical Physics. 2001 Aug;28(8):1610–1619.

Speaker: Ecem Erin Erin (PhD Student)

Emerging Technologies: Emerging Technologies 1

Convener: Heli Hietala

71 4H-SiC LGADs: fabrication-stability optimisation using TCAD simulations

The wide-bandgap semiconductor 4H-SiC offers radiation hardness, thermal stability and a high critical field, making it an attractive fast-timing detector material that can operate without cooling in harsh environments. To compensate for its low charge generation, the low-gain avalanche diode (LGAD) concept provides internal amplification, but device performance hinges on a narrow gain-layer implant whose batch-to-batch variability currently limits reproducibility.
We present TCAD work on 4H-SiC LGADs developed within the CAPADS programme together with onsemi, building on three generations of single-pad prototypes and extending toward segmented devices. A trustworthy device model was established by matching simulated and measured capacitance-voltage curves through the epitaxial concentration, epitaxial thickness and gain-layer dose, since the standard SiC TCAD models and low-concentration SIMS are insufficient on their own; this revealed significant gaps between nominal and effective fabrication parameters. With the calibrated model, two instabilities were identified: a strong sensitivity of gain to the gain-layer nitrogen dose, and aluminium dopant channelling that produces a parasitic secondary junction below the gain layer, highly dependent on implantation tilt. A change of implantation tilt from 0° to 5° is proposed to suppress the channelling tail and stabilise the gain, and verification wafers were fabricated and characterised. Building on this single-pad understanding, we report the first fabricated and characterised segmented 4H-SiC LGADs: strip detectors with 80 µm pitch and pixel arrays with 55 and 110 µm pitch, using inter-channel isolation strategies including geometric separation and oxide-filled trenches. Together these results advance both the reproducibility and the spatial segmentation of 4H-SiC LGADs.

Speaker: Tobias Vasiljev (FNSPE CTU in Prague)

PSD14_4hsiclgads_vasiljev.pdf

PSD14_4hsiclgads_vasiljev.pptx

PSD14_4hsiclgads_vasiljev.pptx

72 SiPMs in direct detection of charged particles for timing: applications and in-SiPM and in-SPAD performance using MIPs

Silicon PhotoMultipliers (SiPMs) are increasingly recognized as detectors of choice for a wide range of applications due to their high photon detection efficiency, compactness, low cost and insensitivity to magnetic fields. This work demonstrates their capability to directly detect charged particles with excellent time resolution by leveraging Cherenkov radiation generated within the detector’s standard protective layer, eliminating the need for an external radiator and enabling a simple and compact detection concept.
Measurements with FBK's standard SiPMs featuring different protective layer thicknesses achieve near 100$\%$ detection efficiency, significantly exceeding the nominal geometrical fill factor. A time resolution below 20 ps, including sensor and electronic contributions, is consistently observed across devices with different active areas (1×1 mm$^2$, 3×3 mm$^2$) and microcell pitches (20, 40 $\mu$m).
Radiation tolerance studies on 1×1 mm$^2$ SiPMs show no significant degradation in time resolution up to fluences of 10$^{10}$ 1 MeV n$_\textit{eq}$ cm$^{-2}$. While radiation exposure increases the dark count rate, optimized signal thresholds can mitigate this effect, with negligible loss in detection efficiency.
Using a tracking system and charged particles, recent measurements of SiPMs without protective layers deepen the understanding of the detection mechanism and characterize detection efficiency and time resolution. Specifically, partially processed prototypes of a novel Back Side Illuminated SiPM, designed for improved performances by FBK in collaboration with INFN, exhibit promising uniform performance.
The results highlight SiPMs with standard layer as simple, versatile detectors for both photons and charged particles, combining excellent timing, high efficiency, radiation tolerance and noise rejection. Possible applications span various domains where Time Of Flight (TOF) information is important, such as High-Energy Physics (HEP) or space measurements.

Speaker: Bianca Sabiu (Universita e INFN, Bologna (IT))

SABIU_PSD_26.pdf

73 Towards a Superconducting Luminometer for FCC-ee: Device Physics, Detector Response, and Beam Performance

Superconducting nano-wire single-photon detectors (SNSPDs) combine sub-eV sensitivity with intrinsic timing capabilities approaching the picosecond scale, making them compelling candidates for a new generation of high-energy physics detectors. Extending the exceptional single-photon performance of SNSPDs to relativistic charged particles enables high precision luminometry applications for future colliders, such as the Future Circular Collider (FCC), where a $10^{−4}$ precision level is envisaged.

In this presentation we investigate the interaction of charged particles with superconducting nano-wires using NbTiN, NbN and $MgB_{2}$ SNSPD devices. Detector performance is evaluated using laboratory $^{90}Sr$ source and 160 GeV pion beams at the CERN SPS within a EUDET-type MIMOSA-26 beam telescope providing ∼5 μm tracking resolution. Detection efficiency, spatial response, and timing characteristics of the devices are probed as a function of nano-wire geometry, bias conditions, and superconducting material properties.

To interpret microscopic detection mechanisms, measurements are complemented with a comprehensive simulation framework, linking charged-particle energy deposition to superconducting dynamics and electronic signal formation. Energy deposition is modeled within GEANT4 by implementing a custom extension of the Photo Absorption Ionization (PAI) model below the 10 eV Sandia tables limit using a Drude–Lorentz approximation. This approach explores the crucial low-energy excitation spectrum, relevant to the 800 meV effective threshold of tested geometries. The subsequent evolution of the superconducting condensate and transient resistive hot-spot formation are studied through time-dependent Ginzburg-Landau simulations, while SPICE-based circuit modeling generates expected pulse formation and readout behavior.

Together, these results provide direct insight into the coupling of ionizing radiation to superconducting nano-wires and establish the physical foundations for SNSPD-based charged-particle detectors with ultrafast timing capabilities. Ongoing production efforts and upcoming beam campaigns represent an important step toward fully superconducting tracking and luminometry systems for next-generation collider experiments.

Speaker: Dr Vagelis Gkougkousis (University of Zurich)

PSD14_Gkougkousis.pdf

74 Design and Performance of Fast Analog Pixel Test Structures for the ALICE ITS3 Upgrade

The ALICE ITS3 upgrade represents a major step forward in silicon tracking, employing the commercial 65 nm CMOS imaging technology (TPSCo) to develop ultra-thin monolithic active pixel sensors (MAPS) for high-energy physics applications. The target performance includes spatial resolution below 5 μm, an extremely low material budget (0.09% $X_0$ per layer), and a radiation tolerance up to 4×10$^{12}$ 1 MeV n$_{eq}$ cm$^{−2}$ for ALICE ITS3 detector.
Within the R&D framework, several pixel test structures have been designed and fabricated to explore both sensor geometries and front-end architectures. In particular, analog pixel test structures (APTS) featuring a fast operational amplifier (-OA) as output buffer have been developed to investigate the charge collection dynamics and the intrinsic timing performance of the sensor. Measurements performed with charge particle beam demonstrated a time resolution of 63 ps, combined with a charge collection efficiency above 99% and a spatial resolution better than 3 μm, with a stable performance up to 1×10$^{14}$ 1 MeV n$_{eq}$ cm$^{−2}$.
Building on these results, a second engineering run (ER2) introduced three novel APTS-OA variants targeting improved detector performance and radiation robustness. The new designs aim at enhancing the lateral electric field through sensor doping optimization, reducing the input capacitance from 2 fF to 600 aF. This upgrade will improve the signal-to-noise ratio, increasing radiation hardness while preserving fast charge collection. In addition, the front-end architecture has been optimized for small pixel pitches (10 μm), compatible with future ultra-high granularity tracking detectors.
This contribution presents the results obtained during a dedicated test beam campaign, with particular focus on charge collection properties and their impact on timing performance. A direct comparison among the ER2 variants and the baseline APTS-OA structure developed during the first TPSCo 65 nm technology validation phase will be discussed, highlighting the effect of sensor optimization on charge sharing, signal formation, and time resolution.

Speaker: Umberto Savino (Universita e INFN Torino (IT))

PSD14_Savino.pdf

75 A novel LGAD design with continuous gain layer: MARTHA

MARTHA (Monolithic Array of Reach-Through Avalanche Diodes) is a novel LGAD concept developed for future high-granularity timing detectors requiring simultaneous precision timing and high spatial resolution, as envisioned for next-generation collider experiments such as FCC-ee.
By introducing an additional low-doped n-layer between the n+ contact and the gain layer, the electric field distribution is sufficiently reduced to allow sensor pixelation without segmentation of the gain layer itself. As a consequence, MARTHA provides a true 100% fill-factor architecture while preserving intrinsic gain properties.
The MARTHA concept is currently in the proof-of-principle phase. So far, eight wafers featuring three different gain-layer implementations have been designed and produced by the Halbleiterlabor der Max-Planck-Gesellschaft (HLL-MPG) on 450 μm thick substrates. The initial substrate
thickness was chosen to address requirements from photon-science applications; future productions will optimize the implant design to be produced on thinner wafers, to achieve timing performance competitive with high-energy physics applications.
First characterization studies have been performed using Transient Current Technique (TCT) measurements and particle-beam tests. The voltage dependence of the gain and spread across the wafer of the three MARTHA variants was investigated using a 1060 nm infrared laser system.
Stable gains in the range 20-80 are obtained, which are larger than for typical LGAD (G∼10-20).
In addition, the timing performance of dedicated diode structures was studied during a beam campaign at the DESY II test beam facility. A timing resolution of 281 ps, after jitter subtraction, was obtained, in agreement with expectations for LGAD sensors of this thickness. Furthermore, strip sensors with a pitch of 100 μm were investigated using a dedicated readout system at the DESY II test beam facility with 5 GeV electron beams, to determine the MIP detection efficiency in the inter-strip region. These measurements provide a first validation of the MARTHA concept for highly segmented detector geometries.
This contribution presents the MARTHA sensor concept together with the first experimental characterization results from laboratory and test-beam measurements.

Speaker: Esther Constanze Wais (Hamburg University (DE))

PSD_Strips_Final.pdf

76 Proceedings Information

Speaker: Paul Sellin

PSD14 Frontiers FAQ.pdf

PSD Frontiers intro.pdf

PSD Frontiers intro.pptx

Publication of Proceedings - PSD14

16:00 Coffee, Posters, Exhibitions 2

18:30 Conference Dinner

Thursday 3 September

Emerging Technologies: Emerging Technologies 2

Convener: Aled Horner (Queen Mary, University of London)

77 Self-Quenching 3D Trench Detectors: Geometry-Driven Gain and Fast Timing

This study investigates a novel, ultra-thin 3D silicon detector featuring submicron columnar electrodes fabricated via an advanced 8-inch CMOS process at the IME-CAS. With an active thickness of 30 μm and a column diameter of only 0.5 μm, the architecture generates high localized electric fields that enable intrinsic charge multiplication without the requirement for dedicated gain layers (e.g., as in LGADs). The sensors were characterized using Two-Photon and Three-Photon Absorption Transient Current Techniques (2PA-TCT and 3PA), allowing for high-resolution, position-resolved mapping of charge collection, gain, and timing across the device volume. In non-irradiated devices, clear evidence of impact-ionization-driven gain was observed at bias voltages above full depletion, reaching values of 7.5 at 60 V (near breakdown) with a relatively uniform lateral distribution.
Key Findings:
• Spatial Gain Profile: Charge multiplication exhibits a pronounced depth dependence, peaking at the tip of the central electrode where the electric field is most intense.
• Radiation Tolerance: Following irradiation to a fluence of 5e15 neq/cm2, a gain of 5 was still achievable at room temperature. Further testing at -20C demonstrated increased maxima. bias and enhanced gain performance.
• Self-Stabilization Mechanism: Notably, the electrode tip, traditionally the primary site for premature breakdown for 3D column devices, exhibits a "self-quenching" behavior. This stabilization is driven by field-focusing and subsequent screening of the external field, a phenomenon absent in the thicker columnar geometries used in current ATLAS and CMS 3D pixel upgrades.
These results suggest that geometry-driven gain in submicron 3D detectors offers a robust path toward radiation-hard, fast-timing sensors with inherent breakdown protection.

Speaker: Prof. Gordana Lastovicka Medin (University of Montenegro (ME))

PSD14 - GordanaMedin_2026.pdf

PSD14 - GordanaMedin_2026.pptx

78 Development and Characterization of TESs and JESs for Ultra-Sensitive Low-Energy Radiation Detection

Among the main challenges in modern fundamental physics, low-energy phenomena related to dark matter searches, cosmic microwave background (CMB), and gravitational-wave astronomy require ultra-sensitive detectors. Transition Edge Sensors (TESs) and Josephson Escape Sensors (JESs) [Phys. Rev. Applied 14, 2020] are promising candidates for the development of single-photon calorimeters and ultra-sensitive bolometers operating from the infrared to the THz regime. TESs currently achieve noise-equivalent power (NEP) of the order of $10^{-19}$ $W/\sqrt{Hz}$ and energy resolution of a few meV. Within the STEEP project of INFN, we aim to develop bolometers with $NEP\simeq 10^{-20}$ $W/\sqrt{Hz}$ and calorimeters with energy resolution $\delta E \simeq 400$ $\mu$eV, improving current performance by approximately one order of magnitude.

To optimise the detectors’ performance, which share a common structure, each component is studied separately. A gold shunt resistor is developed and characterised through temperature-dependent resistivity measurements to ensure stable electrothermal feedback. The electrodes require large-gap superconductors to minimise resistance and thermal leaks. Niobium electrodes were investigated, allowing operation over a wider temperature range, but fabrication challenges led to the selection of aluminium for the final device. The active region consists of a 15 nm Al / 12 nm Cu bilayer, with $T_c \simeq$ $400 mK$. The superconducting properties and their dependence on the dimensions, bias current, and temperature were studied via 4-terminal cryogenic measurements. Decrease of the width revealed a crossover from two-dimensional to one-dimensional behaviour, described by the 2D BKT and 1D Ivanchenko–Zil'berman models, respectively, while preliminary results indicate a NEP of $10^{-18}$ $W/\sqrt{Hz}$ in TES configuration and approaching $10^{-24}$ $W/\sqrt{Hz}$ in JES configuration. These results establish the material and device parameters required for the future implementation of frequency-domain multiplexed TES/JES focal-plane arrays.

Speaker: Anastasia Kotsovolou (University of Pisa and INFN Pisa)

PSD14_Kotsovolou.pdf

09:45 Coffee, Poster, Exhibitions 3

Applications in Particle Physics: Applications in Particle Physics 1

Convener: Dr Richard Bates (University of Glasgow (GB))

79 Applications of Position Sensitive Detectors in Particle Physics and Pixel Detectors

Speaker: Francisca Munoz Sanchez (The University of Manchester (GB))

PSD_ParticlePhysics_fmunoz_3Sept2026.pdf

80 ATLAS Inner Tracker Upgrade for High-Luminosity LHC

The ATLAS experiment is currently preparing for an upgrade of the Inner Tracking for High-Luminosity LHC operation, scheduled to start in 2030. The radiation damage at the maximum integrated luminosity of 4000/fb implies integrated hadron fluencies over 2x1016neq/cm2 and tracking in a very dense environment call for a replacement of the existing Inner Detector. An all-silicon Inner Tracker (ITk) is proposed with a pixel detector surrounded by a strip detector. After an extensive prototyping phase, all the institutes involved in the ITk are currently in pre-production or production mode. In this contribution we present the design of the ITk Detector and its expected performance. An overview of the current status of the various detector components, both pixel, strip and the other common items, focusing on the preparation for production, with its more challenging aspects, will be summarized. The talk will focus on key challenges overcome and lessons learned during the production.

Speaker: Francisca Munoz Sanchez (The University of Manchester (GB))

ATLAS-ITK-Overview_PSD14_fmunoz.pdf

81 Pushing TOF Timing to the Limit with Cherenkov Light and SiPM Arrays

In the framework of the ECFA‑DRD4 project, we have developed high‑precision Time‑of‑Flight (TOF) detectors based on thin, high‑refractive‑index Cherenkov radiators read out by arrays of silicon photomultipliers (SiPMs). The concept exploits the prompt nature of Cherenkov emission to achieve ultimate system‑level time resolution.

The main factors affecting the timing performance were investigated through comprehensive Monte Carlo simulations, whose predictions were subsequently validated with experimental beam‑test data. Prototype detectors equipped with Hamamatsu SiPM arrays and various window materials—including fused silica and MgF₂—were tested at the CERN PS T10 beam line using "off-the-shelf" readout electronics. A time resolution better than 30 ps was achieved at single SiPM pixel level with 100% charged‑particle detection efficiency. The measured time resolution shows the expected improvement with the number of fired SiPM channels, scaling approximately as (1/\sqrt{N_{\text{SiPM}}}) within experimental uncertainties.

These results demonstrate that a TOF detector based on thin fused‑silica radiators coupled to SiPM arrays represents a significant advancement for next‑generation particle‑identification systems targeting higher momenta and will be essential for pile‑up mitigation and 4D tracking in future high‑luminosity collider environments.

Future directions for further improving the already promising results achieved will also be discussed.

Speaker: Nicola Nicassio (Universita e INFN, Bari (IT))

Presentazione_PSD14.pdf

82 ALICE 3 Inner Tracker: Design and Developments

ALICE 3 is pursued as the next-generation heavy-ion detector aiming to fully exploit the LHC with different collision systems in Run 5. A key component of the detector is the Vertex Detector, designed to provide a pointing resolution of 10 μm at $p_T$ = 200 MeV/c. It will be surrounded by tracking layers and disks to cover a pseudorapidity range of $|\eta| \leq$ 2.5. It will exploit CMOS silicon pixel sensors produced. The three innermost layers of the Vertex Detector will be installed in a secondary vacuum within the beam pipe, with a material budget as low as 0.1% $X_0$ per layer and sensors having a spatial resolution of 2.5 μm. Its retractable design allows the innermost layer to be placed 0.5 cm from the interaction point, posing critical challenges in terms of particle hit rates, bandwidth, and radiation load. The tracking layers target a spatial resolution of 10 μm and their design focuses on the large-area coverage based on a modular and scalable production, while targeting a material budget of 1% $X_0$ per layer to achieve the required momentum resolution. This presentation discusses the design considerations for the ALICE 3 Inner Tracker, reviews the performance studies and presents the R&D activities.

Speaker: Kshitij Agarwal (Universita e INFN Trieste (IT))

20260903_Agarwal_PSDv3_w-bkp.pdf

12:20 Lunch

Technology developments in gas, X-ray and gamma detectors: Technology developments in gas, X-ray and gamma detectors 2

Convener: Paul Sellin

83 Development of Thin, Thermally Stable n-type Junctions for Segmented HPGe Detectors via Pulsed Laser Melting

High-purity germanium (HPGe) detectors represent the state of the art in gamma-ray spectroscopy, where position-sensitive capabilities play a crucial role in improving spatial resolution and event reconstruction. The performance of segmented HPGe detectors, however, is still constrained by lithium-diffused n⁺ contacts, which introduce thick inactive layers, limit fine segmentation, and exhibit poor thermal stability during annealing cycles.
A novel technology for the fabrication of thin, thermally stable, and highly segmentable n-type junctions for lithium-free HPGe detectors is presented. The approach combines magnetron sputtering of dopant precursors with Pulsed Laser Melting (PLM), enabling the formation of ultra-shallow junctions with sharp interfaces ideally suited for position-sensitive applications.
The technology has been successfully extended from small-scale devices to large-area, segmented, and thick detectors. Owing to the extremely shallow nature of the junctions, a comprehensive optimization of surface preparation, contamination control, segmentation strategies, and surface passivation has been required.
The resulting detectors exhibit excellent thermal stability under annealing conditions, high inter-segment resistance, and reliable operation at bias voltages exceeding the depletion voltage, ensuring efficient charge collection. These characteristics enable accurate signal localization and support pulse shape analysis techniques.
Overall, PLM-based junctions represent a promising route toward next-generation position-sensitive HPGe detectors, with significant potential impact on nuclear spectroscopy and radiation detection applications.

Speaker: Walter Raniero (INFN-LNL)

Walter_Raniero_PSD_2026.pdf

84 Beam test results of the pixel-readout beam-particle monitor for the CSR external-target experiment

The Cooler Storage Ring External-Target Experiment (CEE) requires a high-precision Beam-Particle Monitor (BPM) to track individual heavy-ion beam particles. Reliable detection of lighter ions, such as Carbon, at particle rates up to 1 MHz is essential for precise primary vertex reconstruction and beam diagnostics.
The BPM employs a dual micro-Time Projection Chamber (micro-TPC) architecture operating at atmospheric pressure. It utilizes custom-designed Topmetal-CEEv2 monolithic pixel charge sensors and double-layer Gas Electron Multiplier (GEM) amplification. To evaluate the detector's baseline capabilities, a beam test was conducted using Carbon ions in the absence of a magnetic field. The system utilized an asynchronous, data-driven zero-suppression readout to efficiently record spatial and temporal track coordinates.
The Carbon ion beam test successfully validated the BPM’s high-precision tracking capabilities. Residual analysis demonstrated single-row transverse spatial resolutions of better than 50 µm and arrival time resolutions of approximately 15 ns. By correlating track segments between the orthogonal micro-TPCs, the system achieved an absolute incident time ($t_0$) reconstruction precision of better than 100 ns. Furthermore, the development of offline reconstruction algorithms and calibration procedures, including event reconstruction under non-uniform magnetic fields, space-charge effect corrections, online energy calibration, and pixel time-walk corrections, will also be presented.

Speaker: Hulin Wang (Central China Normal University)

PSD14_BeamMonitor_Hulin_v2.pdf

85 FasXcam: a monolithic active pixel sensor for fast, energy-resolved soft X-ray imaging

Direct-detection, energy-resolved X-ray imaging at high frame rates and low dead time is challenging for conventional detectors, which typically trade spatial resolution, speed and per-photon spectral information against one another. We present FasXcam, a monolithic active pixel sensor (MAPS) for energy-resolved soft X-ray imaging developed by the CAPADS group as a successor to the X-CHIP and SpacePix detector families.
Fabricated in a 180 nm SOI CMOS process, it integrates the full signal chain on-substrate from charge collection through digitisation and high-speed serial readout. The device comprises two electrically independent chiplets forming a 64 × 64 matrix of 60 µm pixels (≈14.7 mm² active area). Each pixel contains a charge-sensitive amplifier, a peak-detector-hold stage and a discriminator; signals are digitised by column-parallel asynchronous SAR ADCs (8-bit effective, one converter serving two columns) and streamed over high-speed LVDS links. Global- and rolling-shutter readout are supported, the latter reducing dead time to two rows and reaching ≈15,500 frames/s at a ≈300 MHz system clock. On-chip charge injection, a temperature sensor and external ADC test paths enable in-situ characterisation.
We report the first full functional verification of the chip. Pixel noise maps show homogeneous response without structural defects, and per-pixel charge-injection scans define the nonlinear charge-to-ADC transfer used for energy calibration. Spectra acquired with ⁵⁵Fe and ²³⁸Pu resolve the characteristic lines at 5.9/6.4 keV and 13.6/17.1 keV; Gaussian fits yield ≈0.33 keV FWHM at 5.9 keV and confirm near-linear response up to ≈20 keV after nonlinearity correction, validating the architecture for fast, spectroscopic X-ray imaging.

Speaker: Marek Tunkl (FNSPE CTU in Prague)

CAPADS_PSD_FasXcam.pdf

86 Embedding Position Sensitivity in the Detector with ANNA: an Analog Neural Network ASIC

Neural networks (NNs) are promising solutions for achieving fast and efficient reconstruction of the position of interaction in detectors, usually combining accuracy with ultra-low power operation. In scintillator-based PET and SPECT gamma cameras, embedding NN processing early in the acquisition chain can simplify the system design, reducing throughput, power consumption and scanner cost. NNs are mostly implemented in PCs, GUIs and FPGAs. In this work, we report the development of an Analog Neural Network ASIC (ANNA), which exploits the analog nature of detector signals and implements on-chip a NN without prior digitalization of signals. ANNA features a fully analog charge domain processing architecture enabling the implementation of configurable feedforward fully connected analog NN. Each neuron consists of an efficient multiplication and summing unit. The maximum supported complexity is 70 analog inputs with 5 weighted layers, up to 32 neurons per layer, and 32 analog outputs. Weights are quantized over 63 analog levels, with programmable non-linear activation functions. Preliminary measurements performed on the ASIC validate the correct operation of the proposed architecture and demonstrate the feasibility of fully analog gamma-ray position reconstruction on monolithic scintillators. Thanks to its programmability, ANNA employment is not limited to emission tomography, but can be tailored to other scenarios in processing signals of ”intelligent” detectors in fundamental and applied physics. We will discuss, in particular, the perspective of application of ANNA to reconstruct particle interaction in resistive LGADs (Low Gain Avalanche Diodes) towards the development of new compact and low-power high-energy physics trackers.

Speaker: Carlo Fiorini (Politecnico di Milano - INFN Milano)

Fiorini PSD2026 3.0.pdf

Fiorini PSD2026 3.0.pptx

87 Development of high efficiency and high resolution thick-GEM detectors for muography application

We present the development of Thick Gaseous Electron Multiplier (THGEM) detectors designed for cosmic muon radiography. As a robust variant of Micro-Pattern Gaseous Detectors (MPGDs), THGEMs can offer excellent position resolution, durability and portability, making them highly effective in muography application. To serve as effective tracking detectors in muography, these devices must offer sub-millimeter position resolution, long-term stability, and high muon detection efficiency. Several prototypes of dimensions 4 cm $\times$ 4 cm and 10 cm $\times$ 10 cm were designed at SINP, and manufactured using standard PCB drilling and etching technology on double-clad, insulating materials at the local industries, and then tested in both single and double-stage configuration. In double-stage operation, lesser discharge rate and higher gains were achieved. To further enhance stability and suppress discharges, a dedicated post-fabrication treatment involving surface polishing, ultrasonic cleaning and conditioning was implemented. A maximum gain of approximately $7\times 10^3$ and $3.3\times 10^4$ in single and double-stage respectively could be achieved using Ar-CO2 (90:10) gas mixture while the maximum muon detection efficiency was found to be 99% and 99.5%. The position resolution of the prototype equipped with a readout plane consisting parallel strips of width of 350 μm and pitch of 450 μm was studied using a high precision 3-axis positioning system. It was used to scan the detector response by irradiating with an Fe55 source with 2 mm collimator. Event positions were reconstructed from strip charges using the Centre-of-Gravity method, yielding a best spatial resolution of 30 μm in both configurations. Furthermore, the impact of operating voltage and alternatively gain, on position resolution of both the configurations was evaluated for Ar-CO2 (90:10) and Ar-isobutane (95:5) gas mixtures. Experimental results were validated through Garfield++ simulations.

Speakers: Prof. Nayana Majumdar (Saha Institute of Nuclear Physics), Mr Saikat Ghosh (Saha Institute of Nuclear Physics)

PSD14_slides_2026.pdf

PSD14_slides.pdf

PSD14_slides.pptx

15:00 Coffee

88 Poster Prize Announcement

Speaker: Seth Zenz (Queen Mary University of London)

PSD14-PrizesAnnouncements-Thu3Sep2026.pdf

PSD14-PrizesAnnouncements-Thu3Sep2026.pptx

Applications in security, environmental imaging and nuclear physics

Convener: Dr David Smith (Brunel University London)

89 Commissioning of the Gas Ionizing Reactions Array for Fission Fragments Experiments (GIRAFFE) at FRIB

A large-area detector system has been developed for measuring coincident fission fragments in experiments with reaccelerated rare isotope beams. The system consists of two 30 x 40 cm2 position-sensitive detectors based on the Multi-Mesh Thick Gas Electron Multipliers (MM-THGEM) and one 10 x 10 cm2 position-sensitive Multi-Wire Proportional Counter (MWPC). All detectors are operated in low pressure isobutane and are equipped with delay-line readout for precise x and y coordinate reconstruction. Additionally, the double Time-of-Flight (ToF) method is employed to reconstruct the mass and angle of the binary reaction products. The MWPC in-beam transmission detector, located before a reaction target, is used as the start timing signal for the ToF measurement, with the MM-THGEM detectors providing the stop timing signal. The 1 ns ToF resolution and 1 mm position resolution ensure a mass reconstruction of 3 a.m.u. for the binary fragments.
The full system has been successfully commissioned with a stable 16O beam elastically scattered on 208Pb and 197Au targets and has begun operations in measuring fission fragments formed in the 34Si + 232Th reaction at the ReA6 reaccelerated facility of the Facility for Rare Isotope Beams (FRIB). I will report on the design and performance of the individual detectors and of the overall system.

Acknowledgement: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics and user resources of the Facility for Rare Isotope Beams (FRIB) Operations, which is a DOE Office of Science User Facility under Award Number DE-SC0023633. This project is also supported by the U.S. Department of Energy (DOE) under Award Number DE-SC0021938 and by Australian Research Council Grant DE230100197. The authors acknowledge the facilities, and the scientific and technical assistance provided by Heavy Ion Accelerators (HIA). HIA is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy (NCRIS) program.

Speaker: Iulia Maria Harca (Facility for Rare Isotope Beams)

HARCA_PSD14_2026.pdf

90 Run 3 experience with the ALICE ITS2: operation, performance and lessons learned

The ALICE experiment underwent major upgrades during the LHC Long Shutdown 2 (2019–2022), including the installation of the new Inner Tracking System, ITS2. The detector consists of seven layers based on ALPIDE CMOS Monolithic Active Pixel Sensors, comprising 12.5 billion pixels over an active area of about 10 m² and providing an intrinsic spatial resolution of about 5 µm. With its high granularity, low material budget of 0.36% X₀ per layer in the innermost layers, and the first detection layer placed at a radius of 23 mm from the interaction point, ITS2 was designed to improve tracking efficiency and impact-parameter resolution, particularly at low transverse momentum.

ITS2 has been operated throughout LHC Run 3 across a range of collision systems, including proton–proton, Pb–Pb and short special runs with lighter ions. This contribution will present a Run 3 overview of detector operation, calibration strategy, data-quality monitoring and tracking performance. Particular attention will be given to long-term detector stability, operational procedures, beam background mitigation, and the experience gained in maintaining a large-area MAPS-based tracking detector under routine LHC running conditions. The presentation will also summarise the main Run 3 lessons, providing input for the future ALICE ITS3 upgrade and next-generation silicon tracking systems, including detector concepts for ALICE 3.

Speaker: Jian Liu (University of Liverpool (GB))

ITS2_Jian_Liu.pptx

Friday 4 September

Astrophysics, Space, and Extreme Environments: Astrophysics, Space, and Extreme Environments 2

Convener: Jason Gow (Open University)

91 Design and Beam-Test Performance of a Highly Compact Si-W Electromagnetic Calorimeter

Highly compact and granular electromagnetic calorimeters are required for precision measurements in luminometers at future Higgs factories and for the determination of positron multiplicity and energy spectra in the laser–electron scattering experiment LUXE, which probes strong-field QED. In luminometer applications, where Bhabha scattering serves as the reference process, a compact calorimeter with a small Molière radius enables a precise definition of the fiducial volume, reduces the required space, and improves the separation of high-energy electromagnetic showers from low-energy background. In laser–electron scattering, the wide range of positron multiplicity makes a compact calorimeter suitable for both counting and energy measurement. A sandwich-type calorimeter has been designed and partially constructed, consisting of tungsten absorber plates interleaved with thin silicon sensor planes in 1.2 mm gaps. Each sensor plane comprises a 90x90 mm² silicon pad sensor segmented into a 16× 16 matrix, flexible Kapton PCBs, and a carbon-fiber support, with a total thickness of less than 1 mm. The readout system employs 32 channel FLAME ASICs with charge integrating analogue front-end electronics and 10-bit ADCs. A prototype equipped with up to 11 detector planes was tested with 1 - 6 GeV electron beams at the DESY-II synchrotron. Preliminary results on the energy, position, and angular resolution, the Molière radius, and the longitudinal shower development are presented. The current status of the prototype development and the performance expected from simulations will also be discussed.

Speaker: Dr Veta Ghenescu (Institute of Space Science subsidiary of INFLPR (RO))

520b155f-47fc-421e-99e2-8541206e6cd1.pdf

92 On the road to extreme radiation hardness with the innovative batch of FBK nLGADs

Good spatial and timing resolution in tracking systems for future High-Energy Physics experiments requires a good understanding of the mechanisms that cause sensor performance degradation under extreme irradiation.

A batch of p-in-n Low-Gain Avalanche Diode (LGADs) has been manufactured by the Fondazione Bruno Kessler (FBK), with a highly doped signal multiplication layer formed using n-type dopants (nLGADs) within a 55 µm-thick substrate. A novel design with a p++ ohmic contact and n+ gain implant accounting for the activation and diffusion of the gain layer dopants. The nLGAD batch features fourteen such wafers, varying by doping concentration, type of dopant (phosphorus or arsenic), diffusion, and implantation depth. The donor removal mechanism responsible for gain degradation due to irradiation is studied for nominal dopant concentrations of ~10$^{16}$ atoms/cm$^{2}$. This is investigated by irradiating subsets of the nLGAD devices with neutrons up to fluences of 1$\times$10$^{15}$ n$_{\rm{1~MeV~eq}}$ cm$^{-2}$ at the Jozef Stefan Institute in Ljubljana.

Key results from the characterisation of these sensors include donor removal rates performed in the Torino laboratory, and timing performances both before and after irradiation using a plethora of ionising sources such as the 4 GeV/c electron beam at the DESY Test Beam Facility, the CERN SPS proton and pion beam, measurements with a $^{90}$Sr β source, and a ~ 5 keV X-ray source. These will also be supported by gain studies with 1060 nm IR, 404 nm blue, and 375 nm UV laser measurements with an SPA-TCT setup, and charge carrier information extracted in a TPA-TCT apparatus.

Alongside previous studies on the acceptor removal rate in the eXFlu batch of n-in-p LGADs, the results provide insight into the p+-n+ compensated LGAD designs of the CompleX1 batch of sensors. The design, simulations, and preliminary results of the CompleX1 batch will also be presented in the context of radiation tolerance on the path to refining pixel sensors optimised for operation at fluences up to ~1$\times$10$^{16}$ n$_{\rm{1~MeV~eq}}$ cm$^{-2}$ and beyond.

Speaker: Robert Stephen White (Universita e INFN Torino (IT))

PSD14_NLGAD_RWhite.pdf

93 Systematic Study of Proton- and Neutron-Induced Radiation Damage in 4H-SiC PIN Diodes

4H silicon carbide (4H-SiC) is a wide-bandgap semiconductor with compelling properties for radiation-hard particle detectors, including high breakdown fields, excellent thermal stability, and low leakage currents even after irradiation. These characteristics make it a promising candidate for next-generation detectors in extreme environments like future hadron colliders, medical ion accelerators, and fusion reactors. However, the microscopic evolution of radiation damage in 4H-SiC remains poorly understood: inconsistencies of defect parameters in the literature limit the reliability of device simulations needed to design optimized detectors.

To address this, we present a comprehensive, comparative irradiation study of 4H-SiC PIN diodes. Diodes were irradiated with 24 GeV protons (5e12 to 5e15 p/cm²) and neutrons (1e13 to 1e18 neq​/cm²) and characterized before and after irradiation via current–voltage (IV), capacitance–voltage (CV), and UV-laser-based charge collection efficiency (CCE) measurements in forward and reverse bias.

Our results confirm the established picture in the high-fluence regime characterized by negligible increases in leakage current level, a loss of rectification, and voltage-independent capacitance. Crucially, the low-fluence regime reveals a complex transition driven by competing defect-mediated mechanisms, shifting from generation-dominated leakage to carrier removal and compensation, bridging the gap between the pristine and the trap-dominated regime. The results also provide well-resolved, quantitative observables for the verification of defect models. They inform TCAD simulation models currently under development, designed to capture the physics of radiation-induced defects in 4H-SiC PIN structures and aiming to establish a basis for simulation-driven detector optimisation.

Speaker: Sebastian Onder (Austrian Academy of Sciences (AT))

PSD14_Onder.pdf

PSD14_Onder.pdf

PSD14_Onder.pptx

10:00 Coffee

Advances in Pixel Detectors & Integration Technologies: Advances in Pixel Detectors & Integration Technologies 1

Convener: Ali Awais (Queen Mary University of London)

94 The ePIC Silicon Vertex Tracker for the Electron-Ion Collider

The Electron-Proton/Ion Collider (ePIC) Collaboration is preparing the first experiment at the Electron-Ion Collider, a future high-luminosity collider at Brookhaven National Laboratory dedicated to electron-proton and electron-ion collisions. To support the ePIC QCD programme, the ePIC Silicon Vertex Tracker is required to provide precise charged-particle tracking and vertexing close to the interaction point and over a broad acceptance, while meeting stringent requirements on detector granularity, material budget and operational stability.

The Silicon Vertex Tracker is based on Monolithic Active Pixel Sensors arranged in barrel and forward/backward disk layers. The detector is being developed as a large-area, low-mass, low-power pixel system, with ongoing work on sensors and readout, lightweight mechanical structures, cooling, services, and system-level design and prototyping. This contribution will provide an overview of the detector concept, key design choices and current development status.

Speaker: Jian Liu (University of Liverpool (GB))

SVT_Jian_Liu.pdf

95 OCTOPUS: A MAPS demonstrator for future Lepton Collider Vertex detectors

Vertex detectors for future experiments, e.g., at a possible FCC-ee, will require an unprecedented spatial resolution below 3 µm, a time resolution in the order of 5 ns, a hit-rate capability approaching 100 MHz/cm², and an extremely low material budget only achievable by sensors thinned to 50 µm, and limiting the power consumption below 50 mW/cm².
The OCTOPUS project aims to develop a Monolithic Active Pixel Sensor (MAPS) to meet all these requirements in a staged approach, currently targeting a 65nm CMOS imaging process. The project combines TCAD and Allpix Squared simulations, ASIC development, data acquisition, and beam-test characterization within a common design framework.
An intermediate objective is the realization of a high-resolution MAPS sensor with relaxed timing and power constraints for beam telescope applications for detector characterization at test beams.
Current R&D activities focus on optimized sensor layouts, including the NCross concept to improve charge sharing at pixel pitches of around 20 µm. In parallel, dedicated ASIC architectures are under development, featuring compact low-power in-pixel front-ends, asynchronous matrix readout based on Asynchronous Priority Arbiter (APA) schemes, and end-of-column time stamping with 5 ns precision. The project will also assess and evaluate technology prototypes, including a proof-of-concept demonstrator for an APA-based readout architecture.
This contribution presents the current status and plans for OCTOPUS, including simulation results for sensor design optimization, the design of a first prototype ASIC, and evaluation results from demonstrators using the Caribou DAQ system.

Speaker: Thomas Bergauer (Austrian Academy of Sciences (AT))

2026-09-02-Bergauer-OCTOPUS_presented.pdf

96 Design and construction of the Inner Tracker for the CMS Upgrade at HL-LHC

The CMS Inner Tracker (IT) is a key component of the Phase-2 upgrade of the CMS detector, designed to operate under the extreme radiation conditions of the High-Luminosity LHC, while maintaining and extending current tracking performance. The new system, featuring increased granularity, enhanced radiation tolerance, extended geometrical coverage, and higher readout rates capability, will replace the existing pixel detector, ensuring precise vertex reconstruction in the dense HL-LHC environment. This contribution presents an overview of the Inner Tracker, including its layout, detector concept, and key technological advancements. The stringent requirements imposed by the HL-LHC have driven developments in silicon sensor technologies, front-end electronics, cooling systems, low-material-budget mechanics, and powering schemes; the adopted solutions are presented, with emphasis on the overall design strategy. The current status of the project is discussed, with a focus on ongoing production of pixel modules, including assembly procedures and quality assurance protocols, supported by results from extensive testing campaigns. Progress in large-scale integration and detector construction is also discussed, addressing the challenges of assembling modules with lightweight mechanical structures while integrating cooling and powering. The contribution aims to provide a global overview of the system, assessing the readiness of the detector for installation and commissioning at the HL-LHC.

Speakers: Giulio Bardelli (CERN), Inna Makarenko (Vrije Universiteit Brussel (BE))

PSD14_CMSIT_Bardelli.pdf

97 Announcements

12:00 Lunch

Applications in Particle Physics: Applications in Particle Physics 2

Convener: Dr Richard Bates (University of Glasgow (GB))

98 PICMIC: An Ultra Precise 4D Detection Concept”

The PICosecond subMICron (PICMIC) is a new detection concept that intends to simultaneously exploit the remarkable intrinsic spatial and time precision of the MicroChannel Plate (MCP) detectors. PICMIC is based itself on two new concepts. The first is similar in principle to the one used in the GPS and allows, with a limited number of electronic channels, to obtain a precise measurement of the arrival time of particles crossing the MCP. The second, conceived to measure the position of these particles, uses tiny pixels that are interconnected in an original way. The new scheme leads to an excellent granularity without suffering from the usual ambiguity encountered in the strip-based readout systems. The new system is operated with a smaller number of electronic channels with respect to a pixel-based readout one.

Both the spatial and the time measurement systems were individually tested and validated before to be assembled in a first prototype. The prototype equipped with an alpha source allowed the validation of the whole concept. We present in this seminar the PICMIC concept, the realization of the measurement systems as well as the first results obtained with the prototype. Our preliminary results show a spatial resolution of 15 µm and a time resolution of around 20 ps. In addition, We will discuss the development of a new generation of MCP we call NanoChannel Plate (NCP) which intends to improve the time and spatial resolution by at least one order of magnitude. Such a new device could be fully exploited thanks to the PICMIC concept.

Speaker: Imad Laktineh (Centre National de la Recherche Scientifique (FR))

PICMIC-PSD.pdf

PICMIC-PSD.pptx

99 Sub-mm tracking in tonne-scale detectors using SPAD arrays

High-resolution scintillator detectors achieve precise particle tracking through fine segmentation down to a few hundred micrometres. However, this granularity adds detector complexity that can make scaling to large volumes problematic. Moreover, traditional photosensor systems would lead to prohibitively many readout channels, further increasing complexity and cost.

As a solution, we propose a paradigm shift: applying 3D imaging techniques to particle interactions in an unsegmented monolithic volume of organic scintillator, enabling high-resolution tracking. This is achieved by combining plenoptic imaging with a Single-Photon Avalanche Diode (SPAD) array imaging sensor.

We report the operation and performance of the first SPAD-based plenoptic camera for particle tracking, built around the SwissSPAD2 sensor [Dieminger et al., Nat. Commun. 2026, doi:10.1038/s41467-026-70918-x]. We discuss both analytical and artificial-intelligence-driven reconstruction algorithms for event imaging. Results are presented from a controlled two-photon-absorption setup, which produces localised, point-like light emission within the scintillator, simulating particle energy depositions. Sub-mm lateral and sub-cm depth resolutions were achieved.

A simulation case study on accelerator neutrino detection demonstrates the unique potential of this approach, achieving full event reconstruction with $\sim$250~$\mu$m spatial resolution in tonne-scale detectors. The custom SPAD array required to realise this is currently under development [Kaneyasu et al., arXiv:2511.16684] and we present its design and initial test results.

This work sets the path forward for new detection systems for high-precision particle tracking in dense active volumes, with applications ranging from neutrino detection to calorimetry.

Speaker: Till Conrad Dieminger (ETH Zurich (CH))

TD_PSD14_SHORT.pdf

100 Performance Characterisation and Radiation Hardness of Commercially Available NUV-MT SiPMs

Silicon Photomultipliers (SiPMs) exhibit several desirable characteristics, including single-photon sensitivity, high intrinsic gain, and compact design. This has led to their increasingly widespread adoption in particle and astroparticle physics experiments, as well as a variety of other applications. More recently, SiPMs based on the NUV-MT technology have demonstrated improved photodetection efficiency along with reduced dark count rate and crosstalk compared to earlier designs. The performance of commercially available SiPMs based on the NUV-MT technology is characterised and presented in terms of breakdown voltage, gain, dark count rate, after pulsing probability, and optical crosstalk across a range of temperatures and operating voltages. The performance of different noise characterisation methodologies will also be discussed. Furthermore, the radiation hardness of these SiPMs is investigated following irradiations in a monoenergetic neutron beam and subsequent thermal annealing, with results presented on the effects on SiPM dark count rates.

Speaker: Dr Zoe Balmforth (University of Hamburg)

psd14_ZB.pdf

101 Status of the Mu3e Detector Construction

The Mu3e detector is under construction at the Paul Scherrer Institute. It aims to set a limit on the observation of the SM forbidden lepton flavour violating mu->e+e-e- decay. As an integral part of its design, it incorporates a state-of-the-art depleted monolithic pixel sensor tracking system, comprising an inner vertexing barrel and outer tracking system. These detectors achieve a 0.1% X/Xo radiation length and incorporate aggressively thinned silicon, SPTab bonded Al/kapton readout flexible circuits and 25um composite mechanical supports.
The contribution will explore the physics motivation of the design of the pixel system, and discuss the unusual material constrains this-places on the detector, particularly the reconstruction of the momentum of low energy electrons. We will report on the technical challenges that have been overcome in the final prototyping stages, and the move into full detector module serial production and installation. Specifically, we will explore the design difficulties in the close integration of the mechanical and electrical components, the choice of the electrical interconnect technology, the issues involved in quality control testing of 6,000 70um thick Mupix11 monolithic silicon pixel sensors, the late change to a composite material for supports, and the further development towards functionally engineered composite meta-materials. We will discuss how the technology developments and lessons learned are applicable to future low mass tracking systems. Finally, we will also look forward and discuss plans for the initial commissioning and data taking period at the end of 2026 and the initial Phase1 physics running in 2027.

Speaker: Richard Plackett (University of Oxford (GB))

Plackett_20260901_PSD_Mu3e Experiement v2.pdf

Plackett_20260901_PSD_Mu3e Experiement v2.pptx

Advances in Pixel Detectors & Integration Technologies: Applications in Pixel Detectors & Integration Technologies 2

Convener: Dr Richard Bates (University of Glasgow (GB))

102 A Fully Digital Approach to Sub-Micron Resolution Particle Detection: The Particam Concept

Silicon sensors are the common position sensitive technology in particle physics and related applications. Despite decades of progress, silicon sensors have not kept pace with the miniaturisation achieved by the broader semiconductor industry, limitations that conventional analogue approaches have been unable to overcome. Key problems are the low dynamic range implied by the reduced operating voltage and the relatively large transistor footprint required by analogue front-end circuits, which prevents silicon pixel detectors from maintaining pace with the miniaturisation achieved by the broader semiconductor industry.

Particam addresses this challenge through a fully digital architecture that exploits Single Event Upsets (SEUs) in circuits inspired by digital memory cells as the detection mechanism, rather than suppressing them like in conventional design approach. Reducing each pixel to a memory cell-like circuit with very few transistors, pixel pitches of a few microns become achievable, yielding sub-micron resolution even if operated in binary mode. Moreover, this approach also offers very substantial advantages in reducing power consumption.

A proof-of-principle demonstrator has been produced in the UMC 65 nm process, featuring pixel variants with pitches ranging from 2 um to 6.5 um. Pulse and alpha particle measurements confirm the circuits operate as intended. Laser measurements have been performed to characterise the charge collection properties of the device, with results demonstrating its potential as a high-resolution laser sensor. Results from this prototype are presented, together with plans for further development and potential applications.

Speaker: Enoch Ejopu (University of Liverpool (GB))

Enoch_Ejopu_PS14_Slides.pdf

103 Assembly of hybrid detector modules for advanced medical imaging

Advances in medical imaging require utilizing reliable and pioneering radiation detector technology. At STFC, in collaboration with US-based company MH3D Inc, we are helping to develop their world's first pre-clinical scanner, the Alpha-SPECT$^{TM}$ Mini. This scanner can select, measure and visualise the distribution of radionuclides during TAT (Targeted Alpha Therapy), a selective form of cancer treatment that is currently undergoing clinical trials.
The detector modules for the Alpha-SPECT$^{TM}$ Mini are fully assembled and radiation tested at STFC before integrating to the scanner. STFC has previously assembled radiation detectors with pitch as small as 55µm[1][2]. The hybrid detector module consists of a HEXITEC Application Specific Integrated Circuit read-out chip (ASIC)[3] and a compound semiconductor Cadmium Zinc Telluride (CZT) sensor for detecting gamma rays. The assembly process of the module starts with triple gold ball studding of the ASIC. The average height of the triple studs are ~40µm. For minimizing failure rates, first the ASICs are wire bonded to a PCB and then subjected to a Voltage pulse test before assembling on to a sensor. Afterwards, the tested module is assembled to a 6mm thick CZT printed uniformly with thixotropic silver epoxy on a pitch of 500µm and assembled on to the wirebonded ASIC using precise flip-chip technology, capable of placing a chip to an accuracy of 0.5µm. Finally, the assembled hybrid module is tested using Americium-241 and Cobalt-57 radiation sources. The tested full module has a spectroscopic energy resolution of 2keV full width half maximum (FWHM) measured at 60keV and a bond yield of 99.9%. STFC Technology department's detector integration facility has developed and implemented an advanced and improved assemble process that has now a capability of assembling hundreds of modules with high yield.

[1] Veale, Matthew Charles, et al. "Characterization of the uniformity of high-flux CdZnTe material." Sensors 20.10 (2020): 2747.

[2] Schneider, Andreas, et al. "Single Die Process Using Shadow Masks for a 55µm Fine Pitch Array of 4µm-Tall Indium Bumps Across an Entire Chip." 2024 IEEE 10th Electronics System-Integration Technology Conference (ESTC). IEEE, 2024.

[3] Jones, Laurence, et al. “HEXITEC ASIC - a pixellated readout chip for CZT detectors,” Nucl. Inst. Meth. Phys. Res. A: Accelerators, Spectrometers, Detectors and Associated Equipment vol. 604 issue 1-2, pp. 34-37, June 2009.

Speaker: Dr Aswathi Koorikkat (Rutherford Appleton Laboratory (RAL), UKRI-Science and Technology, Facilities Council (STFC), Didcot, UK)

Akoorikkat_talk.pdf

Akoorikkat_talk.pptx

104 Final Announcements

Speaker: Seth Zenz (Queen Mary University of London)

PSD14-FinalAnnouncements.pdf

PSD14-FinalAnnouncements.pptx

15:01 Coffee Break