NuSec Detection Science Workshop 2026

Wednesday 11 Feb 2026, 09:00 → 17:00 Europe/London

National Physical Laboratory

Paul Sellin (University of Surrey)

NuSec Technical Workshop 2026

The NuSec Detection Science Workshop 2026 takes place at National Physical Laboratory on Wednesday 11 February 2026.  This one day in-person meeting is aimed at all researchers working on detection science for nuclear security applications. 

The technical scope of the workshop will cover all detection science topics relevant to NTRnet, with a particular focus on the following areas:

• new detectors for nuclear security applications, including perovskites, new scintillators, and neutron detectors.
• detection systems, instrumentation, and field trials relevant to nuclear security.
• 'Big data' networks and AI/machine learning algorithms, with updates from the recent SIGMA data challenge.

The program will include a mixture of invited talks from senior researchers, and presentations from PhD students and early career researchers. 

To register your attendance at the NuSec workshop please submit your registration details using the Workshop Registration page. There is no charge to register for the NuSec workshop. We regret that we are not able to offer online attendance for this workshop. 

The workshop is run by the NTR-Net doctoral training network, and we will present the latest news and funding opportunities from NTRnet.  

09:00 Registration and Coffee

Session 1: Detector Development

Convener: Chris Allwork

1 Detector development at the University of Surrey

The detection of neutrons with a variety of energies has impact that spans the realms of fundamental and applied physics. At the University of Surrey, we undertake research into both novel detector materials and the application of more established materials for neutron detection, with a focus on scintillator detectors.

A summary of recent work performed by the group will be presented, with a focus on inorganic materials and their response to neutrons, as well as how results can be improved using novel analysis techniques. Research will be presented based on work performed in-house, using the University of Surrey’s radiation laboratories, as well as work done at the National Physical Laboratory’s neutron facility.

Speaker: Joey O'Neill (University of Birmingham)

NuSec 2026 Joey Talk.pdf

2 The Development of Hard X-ray Imaging Detectors at STFC

This presentation will give an overview of current work at the STFC Detector Development Group to produce a new generation of X-ray imaging detectors for hard X-rays (5 - 600keV) utilising modern compound semiconductor sensor materials such as HF-CdZnTe for photon science applications.

These developments include HEXITEC-MHz, a new generation of our High Energy X-ray Imaging Technology that now operates at a continuous 1 million frames per second. With 80 x 80 pixels on a 250$\mu$m pitch, this high frame rate now enables the capture of high resolution (FWHM ~ 1keV) per pixel spectroscopy at photon fluxes of up to 10$^{8}$ photons s$^{-1}$ mm$^{2}$. $^{[1]}$ Recent experiments alongside Pacific Northwestern National Laboratory (USA) have used the system to demonstrate different imaging modalities including dynamic spectroscopic imaging of ion drift in a solution under a magnetic field with a 250ms temporal resolution and simultaneous spectroscopic radiography, energy dispersive and angular dispersive X-ray diffraction of powder samples.

An update on on the XIDyn project, a collaborative X-ray detector development between STFC, ESRF, Diamond Lightsource, University of Heidelberg, and EuXFEL, will also be given $^{[2]}$. The full XIDyn ASIC which will be delivered by summer 2026 consists of 144 x 192 pixels on a 110$\mu$m pitch and operates at continuous frame rates of >100kHz. Using a novel charge cancellation and digitisation design, the detector is capable of capturing images at photon fluxes of up to 10$^{12}$ photons s$^{-1}$ mm$^{-2}$. Results from the current test chip will be used to illustrate the capabilities of the technology.

References

[1] M.C. Veale et al 2023 JINST 18 P07048
[2] https://www.technology.stfc.ac.uk/Pages/News-Conferences-and-Publications/Conferences-Visits-and-Events/SRI2024/SRI2024-Presentations.aspx

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

3 Long-Term High-Voltage Bias Stability and Degradation Pathways in Perovskite Single-Photon Counting Radiation Detectors

Current existing semiconductor radiation detection technologies, such as Cadmium Telluride (CdTe), Cadmium Zinc Telluride (CZT), High-purity Germanium (HpGe) and Silicon (Si), suffer from several limitations. These include high production costs, the need for cryogenic cooling (for HpGe), and insufficient stopping power in materials composed of low-atomic-number elements (such as Si). These challenges have motivated the radiation detection community to investigate novel materials that offer lower production costs, the ability to operate at room temperature, and high stopping power for semiconductor radiation detection technologies.
Perovskite Single Crystals (PSCs) have emerged as a promising candidate for direct radiation detection in photon-counting mode due to their excellent optoelectronic properties, low defect density, and high mobility-lifetime products (µͳ). Despite these advantages, ion migration in PSCs poses a significant obstacle for the stable long-term operation of these devices. Under high electric fields, ion migration accelerates the electrochemical reactions at the metal/perovskite interface, leading to device degradation. This remains a significant barrier to the commercialisation of PSC-based radiation detectors.
In this work, hybrid PSCs (FAPbBr3) are grown from solution using a low-cost, low-temperature method called inverse temperature crystallisation (ITC). These PSCs are polished to achieve smooth, mirror-like surfaces, and metal electrodes, such as Bi and Au, are deposited by thermal evaporation. Both single-pad and guard-ring device architectures are fabricated. These detectors exhibit excellent charge-transport properties, including high hole mobilities of 190 cm^2 V^(-1) s^(-1) and a high hole µͳ of 2.7 x 10 ^(-3) cm^2 V^(-1). Importantly, guard ring devices demonstrate an order of magnitude reduction of dark current – from 29 nA cm^(-2) in single pad detectors to 2.9 nA cm^(-2) in guard ring devices, highlighting the importance of electrode engineering on suppressing the leakage currents of these devices.
Long-term dark current measurements were conducted for both device types, and X-ray photoelectron spectroscopy (XPS) was performed to characterise the chemical composition and bonding environment of the crystal's surface and bulk following extended device biasing. Additionally, the implementation of charge-blocking layers via atomic-layer deposition (ALD) is explored as a strategy to mitigate ion migration toward the anode metal electrode. Finally, long-term single-photon-counting radiation-detection measurements are performed using 241Am 5.49 MeV α-particles, 59.5 keV γ-rays, and 137Cs 662 keV γ-rays to investigate the device's long-term operation under constant radiation exposure.

Speaker: Mr Jayana Jayarathne (University of Surrey)

4 Using a HPGe-PIPSBox detector system to compare the noble gases produced by fission from U-235 and Cm-248

Noble gases are chemically unreactive and therefore the easiest fission fragments to extract from fissioned samples. Krypton and xenon isotopes are relatively highly produced making them good candidates for measurement. Sitting in different mass peaks, their ratio can also be used to differentiate between fission sources. Using a beta-gamma system to measure the extracted gases improve signal-to-noise and thus sensitivity to these radiogases. The poster presents data from Cm-248 and U-235 sources.

Speaker: Ms Sifa Poulton (National Physical Laboratory)

5 Bismuth-loaded Plastic Scintillator for Nuclear Security Applications

In recent years a great deal of research has been devoted to the development of so-called spectroscopic plastic scintillator. The addition of high-Z materials increases the stopping power and photopeak efficiency of plastic scintillator albeit generally with a reduction in light yield. Common elements used for this development include tin (Z=50) and lead (Z=82), and such metal-loaded plastics are currently available commercially. Here we present characterisation of two new materials developed at Lawrence Livermore National Laboratory which make use of bismuth (Z=83) to enhance the effective atomic number of the scintillator.

Bi-PVT shows promise as a potential drop-in replacement for existing metal-loaded plastic systems. In particular, Bi-PVT is being investigated as a radiation portal monitor upgrade material, and we will present results of its implementation within a commercial dosimeter. Conversely, the novel material BLIP (Bismuth-Loaded Iridium Fluor Plastic) can achieve far higher loadings of metal before light reduction becomes detrimental to the performance of the scintillator. BLIP has been shown to surpass NaI(Tl) in the metric of counts per unit mass, suggesting deployment scenarios where weight becomes a major factor – aerial or backpack-mounted radiation detection equipment.

UK Ministry of Defence © Crown owned copyright 2025/AWE

Speaker: Matt Taggart (AWE Nuclear Security Technologies)

6 Clear and Bright X-Ray Imaging with Nanophotonic Scintillators

Lens-based imaging detectors such as those typically used for MeV X-ray imaging and synchrotron-based imaging suffer greatly from poor collection efficiency, typically recording only ~1% of light emitted by the scintillator. However, spatially periodic, sub-wavelength photonic structures provide a means to modify the emission, transport and outcoupling of photons in a crystal. Nanoscale patterns applied to scintillators have been shown to generate significant enhancement in the intensity of the detected signal.
Here, we present investigation of a range of nanophotonic structures made using different technologies, targeting improvements in lens-based imaging detectors. We present a range of results including synchrotron and lab-based measurements of signal enhancement in excess of 300%, as compared to unpatterned scintillators. In contrast to the blurring effects which would be expected when recording images using scintillators with randomly roughened surfaces, we have found that the highly ordered surface nanophotonic patterns do not necessarily produce a drop in spatial resolution, allowing for high-quality X-ray imaging.
In addition, we present the results of synchrotron experiments carried out using a microbeam X-ray and a partially patterned scintillator, including a remote outcoupling experiment which demonstrates how a small-area pattern emits light more readily than the surrounding scintillator even when the pattern itself is not directly illuminated. These experiments have provided greater understanding of the transport and outcoupling of light in these materials, further elucidating the mechanism of scintillation enhancement and guiding further development.

Speaker: Dr Isabel Braddock (Science and Technology Facilities Council)

11:00 Coffee Break

Session 2: Field Trials and Measurements

Convener: Steven Bell (NPL)

7 Seeing Beta Clearly: Diamond Spectrometers for In-Situ Nuclear Characterisation

Speaker: Neil Fox (University of Bristol)

8 Rapid Modelling of Novel Nuclear Scenarios for Response Guidance and Training

Within the nuclear security landscape, threats can exist within a variety of challenging environments. Developing the most appropriate procedure for a chaotic scenario can be difficult without having an appropriate model to work with, and uncertainty in the expected activity and shielding of a radioactive source can lead to sub-optimal containment and unnecessarily high irradiation.

Whilst several advancements have been made in the field of nuclear instrumentation to aid in the localisation of radioactive sources, these localisations are typically constrained to surfaces which fail to account for self-shielding effects and provide accurate dose estimates. In order to fully quantify the activity and the accurately estimate dose more intensive modelling is required which comes with significant time requirements.

Within this work we demonstrate the use of a novel frontend interface for the modelling of challenging radioactive environments. NuClearVision provides an intuitive frontend to MCNP, GEANT4 and OpenMC with a unified GUI capable of producing industry standard simulations from scratch with minimal user input in a shortened timeframe. Our software fully handles the geometric initialisation, transforms, variance reduction and material assignments automatically through transcription layers, allowing for the end user to quickly make representative simulations of their scenario for a variety of applications. Support for LIDAR point clouds and CAD models allows for accurate modelling of complex objects, whilst macrobodies are available for approximations. The results of these simulations feed into a full-scale digital twin of the scenario, allowing for complex path planning, dosimetry and training within a virtual reality simulation.

Speaker: Fraser Holloway (The University of Liverpool)

9 Remote characterisation of buried and spatially distributed radioactive sources using full-spectrum analysis

Remote identification of buried or spatially distributed radioactive material is difficult because surface measurements mix natural background with any anthropogenic contribution. Activity may lie on the ground surface or be buried beneath sediment, and these geometries impose different attenuation and scattering effects that distort spectra. Burial depth suppresses photopeaks, hardens the spectrum and reduces count rate, making shielded activity appear indistinguishable from genuinely low activity. This distinction matters operationally, as concealed sources or vertically migrating legacy discharges can present signatures similar to benign material unless depth effects are accounted for. Effective remote sensing therefore requires analytical methods able to interpret these spectral modifications, attribute them to source depth or distribution and convert measurements into reliable dose and activity estimates for environmental and emergency-response applications.

This work presents a scenario specific full spectrum analysis (FSA) approach for extracting information on buried or distributed sources from remotely acquired gamma spectra using uncrewed aerial vehicles (UAVs). FSA treats the measured spectrum as a non-negative combination of Monte Carlo generated unit spectra that represent isotopes of interest (U-238, Th-232, K-40, Cs-137 and others) under different physical source geometries that can be modelled to best explain the physical environment. By exploiting the full spectral shape rather than relying solely on photopeaks, FSA captures the influence of scattering, attenuation and depth effects that distort spectra from buried or mixed sources. This enables a more accurate activity estimation and qualitative discrimination between surface bound and subsurface contributions in scenarios where conventional region-of-interest or window-based methods lack the ability to separate overlapping isotopic components.

The methodology is demonstrated using UAV collected gamma spectrometry data across the River Esk estuary at Ravenglass in Cumbria. A salt-marsh environment containing naturally occurring K, U and Th within the sediment alongside well-documented anthropogenic contaminants from historical Sellafield discharges, including Cs-137, Am-241, Sr-90 and plutonium isotopes. Two UAV survey campaigns have been conducted over two years, using first a 37 cm³ CsI detector and later a larger 237 cm³. A Monte-Carlo-based ambient dose equivalent H*(10) pipeline yielded a maximum dose rate across the surveyed marshland of 0.092 µSv h⁻¹. This is in close agreement with recent Sellafield Ltd. and RIFE (Radioactivity in Food and the Environment ) ground-sample studies of the same location, which report a maximum dose of 0.098 µSv h⁻¹. Application of FSA to the same dataset provided spatial activity (Bq) estimates for NORM isotopes and successfully identified Cs-137 in regions consistent with documented deposition patterns. The approach enabled clear spatial discrimination between NORM and Cs-137 and produced isotope-specific activity maps that could be directly compared with the dose distribution. The highest dose regions were geospatially coincident with the areas of greatest Cs-137 activity, while NORM contributions were laterally homogeneous across the wider marsh. This combined interpretation provides surveyors and responders with clearer situational understanding, supporting defensible risk assessment and targeted remediation.

Speaker: Ewan Woodbridge (University of Bristol)

10 Single Particle Uranium Analysis by Triple Quadrupole Time of Flight Mass Spectrometry for Nuclear Forensics

The International Atomic Energy Association’s (IAEA) Network of Analytical Labs (NWAL) performs particle analyses from swipe samples for the monitoring of nuclear facilities and the radioactive material with two major focuses: detection of uranium bearing particles, and confirmation of declared enrichment.
Currently this analysis is carried out by large geometry secondary ion mass spectrometry (LG-SIMS) or fission track thermal ion mass spectrometry (FT-TIMS). Analysis using these instruments is both expensive and time consuming. In addition, FT-TIMS requires access to neutrons for irradiation, a site-specific requirement that heavily limits its availability. The number of samples needing analysis by NWAL is increasing rapidly, heavily taxing their resources. A faster analytical method is necessary to keep up with the growing number of samples.
The Penn State REACTR lab has acquired a Nu Vitesse inductively-coupled-plasma time-of-flight mass spectrometer (ICP-TOF-MS) with a triple quadrupole addition. The Nu Vitesse time of flight system has a very fast spectral acquisition speed which allows it to differentiate suspended particles from solution. Combined with an Image Geo 193 laser ablation system, this instrument is capable of performing spatially resolved isotopic and chemical analysis of solid samples. Both functions are of particular interest for testing IAEA swipes, and warrant investigation.
With the fast spectral acquisition capability of the ICP-TOF-MS and the laser ablation capability this system provides two possible approaches to analyzing uranium particles on IAEA swipes. The first approach involves pulling particles off the cotton swipe to create a suspension which can be analyzed directly by the machine. The second approach involves using the laser ablation system to map and ablate individual particles and collect their individual make up with the detector. Both methods provide the ability to measure the individual chemical and isotopic make up of particles, information that is useful for detecting anthropogenic sources of uranium.
The Nu Vitesse system should offer an improvement to speed and cost relative to the current systems used by NWAL. In addition, The time-of-flight mass spectrometer provides the ability to corelate particle composition with uranium isotopic abundance.

Speaker: Michael Romero (Pennsylvania State University)

11 Optimizing Lanthanide Accelerator Mass Spectrometry for its use in Nuclear Data Production

Accelerator Mass Spectrometry (AMS) is traditionally applied to radiocarbon dating, and cosmogenic nuclides but has the capability of analyzing lanthanides [1], [2]. Lanthanides prove difficult to measure via AMS due to their inherent contamination with each other and the isobar suppression limits of the system. This study aims to develop a sensitive technique for measuring lanthanides via Accelerator Mass Spectrometry at the SUERC AMS Laboratory. AMS measurements of lanthanide reaction products from neutron and charge particle reactions will provide nuclear data that is of interest to the nuclear data community, that is currently unmeasurable by standard decay spectroscopy [3]. The method development includes ion source characterisation, radiochemistry, accelerator optimization and detector development for the rare earth elements (REE).

The initial exploration determined baseline low energy mass scans for all REE in oxide form. The optimal starting material was determined by collecting mass scans of varying REE starting samples. The counterions (oxide, fluoride), mixtures of calcium fluoride, metal binders (niobium, silver) and cathode material (aluminum and copper) were altered to determine the effect on the current output. The general trend showed that samples performed better when in an oxide:niobium, 1:2 ratio in an aluminum cathode. All data is applied to a machine learning algorithm that predicts ion current, starting sample and ranks feature importance for the model.

The 5 MV tandem accelerator was used to explore high energy mass scans of the top five performing REE from the low energy system. This provided insight on the length of irradiation needed, ion efficiency, and the purity required to get a well resolved ratio of reaction products and therefore relative cross section measurement at the final detector. High energy data will be used alongside gas stopping simulations to determine the expected energy deposits in the final detector along with any changes that need to be made to the detector.

[1] L. K. Fifield, “Accelerator mass spectrometry and its applications,” Reports on Progress in Physics, vol. 62, p. 1223, Aug 1999.
[2] R. Middleton, A Negative-Ion Cookbook. Department of Physics, University of Pennsylvania, 1989.
[3] T. Wright, S. Bennett, S. Heinitz, U. Koester, R. Mills, T. Soldner, P. Steier, A. Wallner, and T. Wieninger, “Measurement of the 13c(n,γ) thermal cross section via neutron irradiation and AMS,” The European Physical Journal A, vol. 55, 11 2019

UK Ministry of Defence until owned copyright 2025/AWE

Speaker: Victoria Johnson (University of Glasgow/SUERC)

NuSec 2026_VJ.pptx

Lunch and Posters

12 Characterisation of a planar opaque LiquidO detector with cosmic-ray muons

LiquidO is an innovative scintillator-based radiation detector concept whose core principle is the self-segmentation of the detector volume via stochastic light confinement in an opaque medium. Light produced in the scintillator is confined near its creation point thanks to the short scattering length of the material, and efficiently collected by a lattice of wavelength-shifting optical fibres routed to silicon photomultipliers.

In this work, the focus is on evaluating the performance of a 256-fibres planar LiquidO detector. The prototype consists of eight layers of fibres arranged in two perpendicular directions with a 5-millimetre pitch, each fibre read out at both ends. The active volume contains 1.5 litres of a wax-based opaque scintillator, characterised by a sub-millimetre scattering length. When traversed by cosmic-ray muons, the stochastic confinement of scintillation light produces the characteristic LiquidO “light cylinder,” enabling clear event identification and reconstruction of the muon track position and direction.

A previous 3-cm cube LiquidO prototype demonstrated sub-millimetre position resolution in one dimension, achieved with fibres instrumented along a single direction. The detector presented here extends these studies to three dimensions, enabling an investigation of the imaging capabilities of the LiquidO technology at larger detection volumes.

The results obtained with this larger prototype represent an important step toward applying LiquidO in a range of contexts, including nuclear-reactor monitoring, cosmic-ray imaging, non-proliferation imaging, and astrophysical explorations, and contribute to the wider development efforts of the LiquidO consortium.

Speaker: Nicolò Tuccori (University of Sussex)

13 A TENA Based Interrogation Setup for the Detection of SNM Utilising He4 Scintillation Detectors

This work presents initial steps toward assessing the feasibility of using high-pressure helium-4 (He-4) scintillation detectors in an active-interrogation system utilising the Threshold Energy Neutron Analysis (TENA) technique for the detection of special nuclear materials (SNMs). The proposed setup consists of a deuterium–deuterium (DD) based Inertial Electrostatic Confinement (IECF) fusor as the interrogation source, arrays of Arktis S670 He-4 detectors, and the detection of neutrons with energies higher than the probing source (~2.45 MeV), which serves as a robust indicator of the presence of SNM. These detectors offer strong potential for this detection scheme due to their exceptional gamma rejection (~10⁻⁷), fast timing resolution (tens of nanoseconds), and their ability to provide information on neutron energy spectra through recoil-energy deposition.

Speaker: Edward Martin (University of Bristol)

14 Accelerated Ageing Through Thermal Cycling of Optical Coupling Samples to Investigate Performance Degradation in Detectors

Thermal cycling is used to accelerate the ageing process through an exaggerated version of the diurnal temperature variations that a detector or material may experience, during use or storage, over the lifetime of a detector. This is done in order to understand the potential causes of performance degradation or required frequency for recalibration. For this investigation, samples of the Eljen EJ550 optical grease were thermally cycled between +5 and +75°C in an environmental chamber, with the relative humidity set to the minimum at each stage in the cycle such that the only degradation would be as a result of migration of material or thermal cycling. Four sets of samples were created with different preparation methods, volumes and substrates utilised in the preparation of optical grease samples, consisting of 0.02g between microscope slides, 2ml petri dish, and 1 and 2 inch diameter discs in petri slides. A total of 15 samples per set were created that were divided into three subsets: Cyclical, Duration and Room samples.
The transmission for all samples was measured using a spectrophotometer for a wavelength range of 300 to 700nm in order to cover the emission range of EJ200 scintillators. Identical samples with air as opposed to grease were utilised for baseline/zero corrections performed for the spectrophotometer, meaning all transmission values are relative to air. Cyclical samples were recharacterised at the end of each year equivalent cycle, Duration and Room were only recharacterised after the final cycle as controls for the removal from the chamber and the passage of real time respectively. Samples were cycled to equivalent of a maximum 20 years, with an additional set of “no bubble” samples introduced at the start of the 11th year equivalent cycle in order to determine the impact of the presence of air bubbles on the transmission. To aid understanding of the migration of material in real time, additional samples were created and positioned above a web camera set to capture images at regular intervals. The 1 inch petri slide samples displayed the greatest average variation in percentage transmission across the range 400-500nm, with a drop of 20% between pre and post-20 year characterisation (28% percentage difference), while the 2 inch petri slide samples showed an average 10% decrease in percentage transmission (15% percentage difference). Microscope slides and petri dish samples displayed a 2.6% average transmission decrease (3% percentage difference) and 3.9% average transmission increase (4.7% percentage difference) respectively.

Speaker: Dr Kerri Loughney

NuSec_Poster_KL_ZS-2026.pdf

15 Machine Learning Classification of Silica Glass Jewellery Beads for Thermoluminescence Dosimetry

For personal radiological health monitoring, thermoluminescence dosimetry (TLD) provides a method to estimate the absorbed dose for an individual over a specified time interval. A dosimeter captures and traps ionised electrons, which, when heated, release the trapped electrons via electron-hole recombination, through an emission of light called a glow curve. For TLD, the material’s composition, features and the readout heating parameters affect the glow curves’ characteristics, which should be proportional to absorbed dose. While trapped, the electrons can be released early due to tunnelling, material defects, and early thermal excitation, thereby compromising an accurate measurement of absorbed dose. With an ever-growing nuclear industry, new dosimetry materials and efficient analysis techniques remain an active research field.

The research presented explores the application of machine learning (ML) for advanced glow curve classification, specifically advancing past work into the use of micro silica glass jewellery beads as retrospective body and extremity TL dosimeters. A seed training dataset containing 1016 glow curves is formed of 348 LiF:Mg,Ti TLD-100 chips, 333 LiF:Mg,Cu,P TLD-100H chips and 335 silica beads with varying colours and sizes, alongside varying isotopes, doses and various heating parameters. This is injected into two ML frameworks: a random forest classifier (RFC) and a convolutional neural network (CNN). To further enhance this analysis, four sub-datasets were created, amplified using data augmentation techniques to 10,160 and 101,600 on raw and Gaussian-filter smoothed glow curves. All model variants were tested to classify the sample names and colour, with all the RFC-variants producing accuracy, precision, recall and F1 scores > 0.9 and the 1D CNN-variants outputting accuracies of > 0.86 with precision, recall and F1 scores > 0.8 for sample names and mixed scores for colour. The adoption of image classification is supported for accurate sample colour classification, enhanced further within a multi-modal framework in ensuing development.

Future work aims to elucidate the relationship between the underlying material physics, physical kinematics and glow curve mathematical modelling using deconvolution. An ML model is envisaged to inform these complex kinematic parameters faster, more accurately and efficiently than current processes, exposing the hidden luminescence elements of a material under irradiation for the use of TLD. Providing an enhanced analysis of the glow curve structure and a precise calculation of absorbed dose for individual health monitoring within the nuclear sector.

Speaker: Mr Lukasz Tomaszewski (University of Surrey)

16 Simulating Multi Pixel Detectors for Advanced Radiation Monitoring

This study examined the influence of multi-pixel detector (MPD) geometry on performance in environmental radiation monitoring, with emphasis on geometric configuration, angular response, and spectral quality. Geant4 simulations were used to model both cubic and non-cubic detector arrays, which were evaluated through metrics including hit distribution, angular sensitivity, and energy uniformity. The results indicated that regular cubic arrays offered the most reliable balance of angular coverage and manufacturability, whereas non-cubic geometries introduced added complexity. Experimental validation was conducted using four CsI detectors (37 cm3), and tested with Cs-137 and Co-60 sources at multiple positions. Overall, the findings demonstrate that detector geometry influences both localisation and isotope identification capability.

Speaker: Lauren Hengeveld (University of Bristol)

Simulating Multi Pixel Detectors for Advanced Radiation Monitoring.pdf

17 Characterisation of Perovskite Thin Films using Single Source Vacuum Deposition (SSVD) for Ionising Radiation Application

Metal halide perovskite thin-films are among the promising class of materials with significant potential for large-area radiation detectors. While solution-based processing is common, it presents challenges in achieving uniform, thick films. This study explores single-source vacuum deposition (SSVD) as an alternative and simplified method by utilising a single precursor to enhance control over film composition and uniformity of lead halide perovskite films. Using an in-house deposition system, formamidinium lead bromide (FAPbBr3 ) films were deposited on glass substrates at varying deposition rates. Also, 2D perovskite thin film fabricated using SSVD is reported.The results from thin films were systematically characterised to evaluate their structural, compositional, optical, and radiation scintillation response. Film thickness and roughness were measured with a profilometer and morphology and composition were analysed using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). Additionally, the optical properties were assessed using photoluminescence (PL) and the X-ray response was evaluated through radioluminescence (RL) measurements. The study successfully produced films with a maximum thickness of 11.0 ± 4.0 µm and an average roughness of 0.3 ± 0.2 µm. SEM analysis revealed grain sizes from 0.3 µm to 3 µm, dependent on deposition conditions. EDS and PL analyses confirmed the successful deposition of the FAPbBr3 perovskite phase. The films demonstrated a linear response to radiation, with a notable limit of detection (LoD) of 110 nGy/s, showing potential for radiation detection applications. This work enhances the understanding of the SSVD process for perovskite thin films and motivates further exploration towards a scalable, high-quality radiation detector for nuclear security and medical radiation field.

Speaker: Muzzamer Zahid (University of Surrey)

Muzzamer Zahid_poster Nusec 2026.pdf

18 Development of a High-Resolution Alpha Spectrometer (HRAS) Detector System

Measurements by alpha spectrometry are required for a number of applications, including: nuclear forensics, nuclear decommissioning, environmental monitoring, nuclear medicine, and refining nuclear data. Low-resolution alpha spectrometer systems are widespread, but often the resolution is too poor to accurately determine activities of sources or identify contaminants in an unknown sample. High-resolution alpha spectrometry can resolve these issues. However, whilst it is possible to purchase high-resolution Passivated Implanted Planar Silicon (PIPS) detectors, suitable detector chambers are not commercially available. The Joint Research Centre (JRC), Geel, and The Centre for Energy, Environmental and Technological Research (CIEMAT), Madrid, are known to have developed custom detector systems suitable for making high-resolution measurements. This work describes the work done to build the new HRAS system at NPL, which will be used to develop accurate and precise alpha-particle emission intensity data for medical and forensic relevant radionuclides. This will contribute to the national challenge of developing confidence in the data being used in pre-clinical and clinical studies for cancer treatment and nuclear forensics.

Speaker: Frankie Falksohn (NPL)

19 Optimisation of compact radiation sources for NTR applications

Radiation sources have been shown to have many applications in nuclear threat reduction (NTR), including radiography (whether in ports or ‘in the field’) and nuclear scattering (either polarised or unpolarised gamma rays for identification of isotope specific content).

Laser wakefield acceleration (LWFA) is a mechanism by which electrons may be accelerated over much shorter distances than conventional accelerators - often by around three orders of magnitude. With the field of LWFA there are novel routes to generating x-ray sources including betatron (electrons synchrotron radiating in the accelerator) and inverse Compton scattering (ICS), but colliding the electron beam with a laser pulse after the acceleration phase. While both of these techniques have been used to generate radiation sources, thus far no optimisation has been conducted for applications in nuclear threat reduction.

Here we present a preliminary study on how the parameters of the wakefield accelerator might be tuned in order to optimise the technology for one or other of the radiation generation mechanisms. Particle-in-cell (PIC) simulation results are shown which indicate that novel laser focusing geometries could better condition the electron beams for ICS generation, and how moving to plasma density regimes far higher than is routine in LWFA may result in stronger betatron emission suitable for NTR applications.

Speaker: Christopher Murphy (School of Physics, Engineering and Technology, University of York)

20 Fabrication and Optical Characterisation 2D Perovskite Scintillators

Two-dimensional (2D) hybrid perovskite materials have emerged as promising candidates for next-generation scintillators due to their high light yields, fast radiative recombination and low-temperature solution-processability [1]. The aim of this study is to develop a bright, efficient radiation detector using different fabrication processes such as doping and pellet pressing for nuclear forensic applications. In this work, we report the fabrication and characterisation of the 2D perovskite n-butylammonium lead bromide (BA2PbBr4) using several techniques.
BA2PbBr4 belongs to the Ruddlesden-Popper group of 2D perovskites, where inorganic layers are separated by butylammonium cations. This structure results in strong excitonic emission and enhanced resistance to environmental degradation. High-quality BA2PbBr4 crystals are grown using a slow-cooling method, yielding large 1cmx1cm sized crystals up to 1mm thick. Dopants such as Manganese can be incorporated into the initial solution. Dopants allow desirable properties to be selected such as emission wavelengths, lifetimes and crystal structure. For practical handling and scintillation measurements, the as-grown crystals can be ground into a fine powder and compressed into pellets using a hydraulic press. This process enables uniform sizes and thicknesses of material.
BA2PbBr4 single crystals and pellets show a higher light yield compared to LYSO. BA2PbBr4 also shows a strong response to gamma radiation. A further advantage of BA2PbBr4 is its uniquely short lifetime under 5ns compared to LYSO at 40ns and other commercial scintillators in the millisecond range [2]. Traditional scintillator materials also often suffer from high fabrication costs and limited tunability. These 2D perovskites therefore serve as a promising candidate for the next generation of scintillators for radiation detection.

Speaker: Amy Dickinson (University of Surrey)

NuFor 2025 Poster - Amy Dickinson.pdf

21 What’s in the Box? X-ray and EM Hybrid Image Reconstruction

Identifying materials within sealed containers is of interest to the UK’s continuing stewardship of nuclear material. Radiological methods can be used to specifically identify nuclear material but are susceptible to self shielding where the material of interest attenuates its own specific signals creating the risk of misleading results. The Alternative Signatures group in the Nuclear Threat Reduction/Nuclear Security department of the Atomic Weapons Establishment (AWE) is interested in investigating alternative methods for the specific, safe and simple identification of nuclear material even when the typical signatures of the materials may be unavailable.

X-ray imaging is commonly used to image concealed objects but x-rays are attenuated in proportion to density which reduces the available contrast when attempting to discriminate high density materials. Magnetic induction spectroscopy (MIS) explores the interaction of magnetic fields with conductive material. A magnetic induction spectrum is sensitive to the location and geometry of conductive material around a magnetic field source and receiver.

Hybrid tomography involves the fusion of two distinct imaging methods to yield a novel imaging method that combines the benefits of both. The aim of this project will be to develop a novel method for fusing the data obtained by x-ray imaging and MIS of objects relevant to AWE’s mission.

Speaker: Thomas Anderson-Olson (University of Manchester)

NuSec.pdf

Session 3: Machine Learning and Algorithm Development

Convener: Paul Sellin

22 Community insights on establishing a centre for AI in applied nuclear physics

In October 2025 a one-day community workshop was convened to explore the vision, scope, and feasibility of establishing a Centre for AI in Applied Nuclear Physics, with relevance to both civil and defence domains. The event brought together researchers, industry partners, and government stakeholders for a series of interactive sessions, keynote presentations, and a community poster forum.

This submission will report the key findings and themes that emerged from the workshop. These include community priorities for shared infrastructure, opportunities for coordinated development of open datasets, and identified needs in education and career pathways. Consensus views will be summarised alongside noted areas of divergence, and practical considerations raised regarding the Centre’s proposed structure, remit, and long-term sustainability. This feedback aims to ensure transparency, maintain momentum, and invite further input from the nuclear community.

Speaker: Caroline Shenton-Taylor (University of Surrey)

23 Innovation in neutron and gamma sensor technology and AI-enhanced analysis for security applications

Global geo-political and economic instabilities and uncertainties mean that our security services are under increasing pressure to respond to suspected and genuine incidents under time pressures and with limited resources. These conditions impose challenges on the equipment used and the underpinning technologies, in order to ensure ease of use, robustness under increasingly under environmental conditions, detection sensitivity and technical reliability with respect to false alarms, detection reliability and cost-effectiveness.
Mirion serves many customers in the security and nuclear material safeguards services, supplying products in many countries, and in support of many facets of the industries. This includes working extensively with users, regulators, and laboratories engaged in the accreditation of the technology and products. It also requires careful maintenance of the underlying technology portfolio.
Key technologies underpinning security applications are usually based on remote detection of characteristic radiation signatures. This ensures ease of access for operators while minimising direct exposure to potentially hazardous items. Normally, this means that gamma spectroscopy or gross gamma counting (dose rate), or neutron measurements (either dose rate or neutron counting in Totals or Coincidence modes) are suitable for use with inspection probes. In order to deal with varied requirements for deployment, delivery of these detectors through either Unattended Automated Vehicles (UAVs), backpacks, crawlers, or quadruped robots or similar, are often considered.
In Mirion, our teams work extensively with customers to conduct field trials, ensuring user interfaces, ergonomics, detector responsiveness and serviceability, are all matched to user requirements. As part of our technology program, we work with many national laboratories and universities to ensure that maximum advantage is taken of existing technology, thus minimising development time and costs to convert into field products, whilst actively supporting and developing skills development through the universities through for example PhD programs. In this paper we present examples of such work with reference to previous case studies. Examples include exploration into emerging detector technologies such as perovskites, diamond detectors and Si carbides, and aligning technological features and performance characteristics, for example relative neutron and gamma sensitivity, to the application - driven field conditions, for example with respect to temperature and radiation hardness of components. Our work also includes constant appraisal of neutron detection technology and we give examples of lessons learned from field-proven installations involving neutron detectors operating in harsh environmental conditions for example waste management, and where this experience can carry over to in-field applications such as safeguards, security and emergency response inspections.
We give an industry perspective on the issues surrounding data management, from experience serving many fields. We describe how software integration tools can streamline data collection and make it more universally accessible to different customer teams. Increasingly, Artificial Intelligence techniques are becoming studied more widely. Again we give an industry perspective with reference to our developments aimed at accelerating and automating spectral analysis in ways that allow complex patterns of characteristic features to be recognised, whilst addressing issues of user confidence and validation.

Speaker: Patrick Chard (Mirion Technologies (Canberra UK) Ltd)

24 Evaluating Object Detection Neural Networks for Landmine Detection: Training and Performance Analysis with Synthetic and Real-World Data

Reliable UXO detection remains one of the most persistent sensing challenges due to the diversity of threats and the variability of real-world environments. This study explores the use of synthetic data to train object detection models for landmine detection. The YOLOV8n model trained on n=1000 real images achieved a mAP@50 of 0.983, a precision of 0.966 and a recall of 0.961. The best synthetic model, starting from YOLOv8n, used n=10,000 images with a 90:10 UE:CPL split, yielding a mAP@50 score of 0.936, a precision of 0.912, and a recall of 0.880. These findings indicate that comparable model performance can be achieved with entirely synthetic data, with a greatly reduced lead time due to automated data generation and bounding box labelling. Varying setup conditions for CPL models also found that matching the pixel size in training images to that of the final data yielded the most robust models. These experiments further demonstrated that earlier CPL research, showing that patch-level realism alone was sufficient in low-noise environments, remains valid even when extended to more cluttered and stochastic background conditions.

Speaker: Mr Seb Pereira (University of Bristol)

25 SIGMA data threat injection methodology

The methodology for generation of the SIGMA hybrid datasets is described from identification of candidate regions where threats can be injected, through template generation to subsampling into background data. The proposed format for data is also discussed, comments welcome

Speaker: Rafael Hunt-Stokes

26 SIGMA Hybrid data overview

Over the last two years, a number of datasets have been made available to the UK academic community from ~100 SIGMA detectors deployed in London during 2017-2018.  These datasets contain real threats and background, however, lack ground truth makes detailed analysis of detection probability and ID challenging.  A new dataset with injected threats (known isotope, activity, speed) into regions of real background data  is described for the NaI SIGMA detectors at a top level.

Speaker: Philip Martin

Session 4 - Discussion

27 Closing Remarks

Speaker: Thomas Scott (University of Bristol)