Choose timezone
Your profile timezone:
VIEnna Workshop on Simulations 2024
→
Europe/Vienna
Lecture room: Seminar room 1
Campus Akademie (Österreichische Akademie der Wissenschaften)
Bäckerstrasse 13
A-1010 Vienna
Austria
Description
The VIEnna Workshop on Simulations 2024 (VIEWS24) aims to give an overview of the current state and challenges of low energy, particle background simulations with Geant4 for rare events searches. The workshop will be combined with a school so that new members of our community can familiarized themselves with Geant4 before participating in the workshop.
On the workshop we aim for an open exchange of our experiences with Geant4 simulation at low energies (i.e. roughly below 10 keV, going down to eV-scale), to discuss the challenges we encounter, and to share solutions we found, e.g. tuned Geant4 settings or Geant4 extension by dedicated program code. Hence, we welcome contributions from any kind of rare event searches, any kind of detector type or target material, and regardless of the actual background source. Beyond the simulation process itself, we are also interested in its “inputs”: models of the relevant physics processes and there applicability limits and measurements of low energy process as reference data. If there is common interest of the participants, we plan to write a common whitepaper to summarize the outcome of this workshop.
To summarize, the topics of the workshop are:
- Geant4 simulation of low energy (<10 keV) backgrounds for rare event searches
- Any rare event: Dark Matter, Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) experiments, etc.
- Any kind of detector type: semiconductors, scintillators, cryogenic calorimeters, etc.
- Any kind of target material: Si, Ge, CaWO4, etc.
- Any kind of particle background source: radioactive contaminations, atmospheric neutrons at shallow sites, muon-induced background at deep underground sites, etc.
- Challenges at low energies, e.g.
- Unidentified backgrounds
- Scarce experimental references data to calibrate the simulation to
- Breakdown of physics models developed for higher energies
- Growing impact of solid state effects
- Solutions to the challenges, e.g.
- Improved models for low energy processes
- Measurement campaigns for experimental reference data
- Tuned or extended code to improve Geant4 low energies
- Alternative simulation codes dedicated to low energies
Local Organizing Committee:
- Valentyna Mokina (chair)
- Brigitte De Monte (secretary)
- Samir Banik
- Jens Burkhart
- Holger Kluck *
* first expressed the idea of the workshop without the school and was a main contributor to the creation of the name "VIEWS".
VIEWS24
-
-
1
Registration
-
Geant4 Beginner course
-
2
Welcome and logisticsSpeakers: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy), Dr Valentyna Mokina (HEPHY)
- 3
-
4
Hands-on
-
2
-
11:00
Coffee break
-
Geant4 Beginner course
- 5
-
6
Introduction to Geant4 and MC methodSpeaker: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy)
-
7
Q&ASpeaker: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy)
-
13:00
Lunch
-
Geant4 Beginner course
-
8
Installation of Geant4 and application buildSpeaker: Pablo Cirrone
-
9
Task0
-
8
-
16:00
Coffee break
-
Geant4 Beginner course
-
10
Task0 (continuation)
-
11
UI InterfacesSpeaker: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy)
-
10
-
18:00
Welcome reception
Campus Akademie (Österreichische Akademie der Wissenschaften)
Bäckerstrasse 13
-
1
-
-
Geant4 Beginner course
- 12
-
13
Task1
-
10:30
Coffee break
-
Geant4 Beginner course
-
14
Task1 (continuation)
-
14
-
13:00
Lunch
-
Geant4 Beginner course
- 15
-
16
Task2
-
16:00
Coffee break
-
Geant4 Beginner course
-
17
Physics - part 1Speaker: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy)
-
18
Task3a
-
17
-
19:00
School dinner
Location: „Stöckl im Park“, Prinz Eugen Straße 25, 1030 Vienna
-
-
-
Geant4 Beginner course
- 19
-
20
Task3
-
10:30
Coffee break
-
Geant4 Beginner course
-
21
Task3 (continuation)
-
21
-
13:00
Lunch
-
Geant4 Beginner course
-
22
Interaction with kernel - part 1Speaker: Luciano Pandola (INFN Laboratori Nazionali del Sud, Italy)
-
23
Task4
-
22
-
16:00
Coffee break
-
Geant4 Beginner course
-
24
Task4 (continuation)
-
24
-
-
-
Geant4 Beginner course
- 25
-
26
Task4 (continuation)
-
10:30
Coffee break
-
Geant4 Beginner course
-
27
Task4 (continuation)
- 28
-
29
Closing
-
27
-
13:00
Lunch
-
30
Registration for workshop
-
WorkshopConvener: Dr Valentyna Mokina (HEPHY)
- 31
-
32
Optimization of the COSINUS experiment for background reduction using Monte Carlo simulations
COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) is a direct detection dark matter experiment, whose goal is to perform a model-independent cross-check of the longstanding DAMA/LIBRA claim. The experiment uses NaI crystals as scintillating calorimeters which allow for the detection of both light and phonon signals, giving event-by-event particle discrimination. COSINUS is currently being constructed at the Laboratori Nazionali del Gran Sasso, in Italy. In this low background, underground facility, the detectors are located in a dilution refrigerator at the centre of a 7x7 m cylindrical water tank, which acts as both a passive and active shield. This talk will present the results of the detailed Monte Carlo simulations that optimized the geometry of the shielding in order to minimize dark matter like background events. Additionally, this talk will also discuss future modeling of the intrinsic radioactive background based on extensive material screening processes.
Speaker: Dr Matthew Stukel (SNOLAB) -
33
Background modeling for the COSINE-100 dark matter experiment
COSINE-100 is a dark matter search experiment with an array of NaI(Tl) crystals, aiming to confirm the annual modulation that DAMA/LIBRA claims to have detected. It is crucial to reduce the energy threshold, which will not only validate the DAMA/LIBRA experiment but also increase the sensitivity of COSINE-100 for detecting low-mass dark matter. Therefore, it is essential to have a precise and quantitative understanding of the backgrounds. We build a background model for the COSINE-100 experiment, conducting background simulations using the Geant4 toolkit. In this presentation, we will discuss the background modeling for COSINE-100.
Speaker: Eun Ju Jeon (Center for Underground Physics, IBS) -
34
Geant4 based simulations of backgrounds in the CRESST experiment
The Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) experiment employs scintillating crystals at extremely low temperatures ($\mathcal{O}$(10 mK)) to search for nuclear recoils from hypothetical dark matter (DM) particles. CRESST has achieved thresholds below 100 eV with a wide range of target materials including CaWO$_4$, LiAlO$_2$, Al$_2$O$_3$, and Si. However, the ability to discriminate between potential DM signals and electromagnetic background is insufficient at these energies. A detailed electromagnetic background model was developed for CRESST and is being continuously adapted to CRESST's current inventory of detector modules. Our approach involves employing ImpCRESST, a Geant4-based simulation tool, to model background interactions and applying a high-dimensional Bayesian likelihood fit of spectral templates generated from the simulation to the measured spectrum. The fit returns the activities of various background sources considered in the simulation. In this talk, we will present the current status of CRESST's background model, including insights from ImpCRESST, and discuss our plans for enhancing the model.
Speaker: Dr Samir Banik (Technische Universität Wien, Atominstitut) -
35
Geant4 usage for AMoRE
AMoRE is an experiment searching for neutrinoless double beta (0nbb) decay using Mo-100 isotopes in molybdate crystal scintillators operated at mK temperatures. It aims to improve an upper limit on the half-life of 0nbb decay, and its sensitivity increases linearly with the experiment exposure if the zero background level in the region of interest (ROI) is achieved. Therefore, it is crucial to understand the backgrounds, and we use the Geant4 toolkit to assess them. In this presentation, we will discuss how Geant4 is used for AMoRE.
Speaker: Eun Ju Jeon (Center for Underground Physics, IBS)
-
16:00
Coffee break
-
WorkshopConvener: Dr Matthew Stukel (Gran Sasso Science Institute)
-
36
The SuperCDMS Simulation Framework
The SuperCDMS experiment is a second-generation dark matter search under
construction at the SNOLAB underground facility in Sudbury, Ontario. The
experiment will consist of twenty-four ~1 kg crystals of germanium or silicon, with readout for time-resolved phonon energy and ionization signals. Estimating the experimental sensitivity, which involves determining the effects of a multitude of background sources and modeling the response of the detectors to both signal and background interactions, requires a strong and comprehensive simulation framework.
In this report, we will present an overview of the SuperCDMS experiment and its simulation framework, with a focus on the design and performance of the main features of the simulation: a flexible and customizable set of geometry, physics and radiation source models; a detailed detector response simulation based on Geant4 and the G4CMP library; and a "fast parameterized" model of the detector response to support high-statistics simulations. The use of Geant4's importance biasing to evaluate the effectiveness of shielding will be presented separately.Speaker: Michael Kelsey (Texas A&M University (US)) -
37
Background simulation and control schemes in the CDEX-50 experiment
The CDEX program pursues the direct detection of light dark matter with germanium detectors since 2009 at the China Jinping Underground Laboratory (CJPL). Several searches related to WIMP dark matter have been carried out based on the CDEX-1 and CDEX-10 experiments. An upgraded dark matter experiment of the CDEX-50 is proposed and on-going together with the R&D programs on the key low radioactivity technologies, which aims to search for dark matter using a 50-kg germanium detector array. The CDEX-50 background simulation and background control schemes will be described and discussed.
Speaker: Junzheng Wang -
38
Background simulations for the BULLKID-DM experiment
BULLKID-DM is an experiment designed to search for direct interactions of dark matter particles with mass around 1 $GeV/c^2$ or below. The experiment employs cubic silicon particle absorbers, each weighing 0.34 grams, sensed by cryogenic kinetic inductance detectors. A prototype detector comprising 60 absorbers has been successfully operated on the surface. Analysis of a single 0.34 g absorber, with surrounding absorbers serving as a veto, has demonstrated remarkable capabilities for background rejection, owing to its segmented structure.
This talk will introduce a Monte Carlo model developed to characterize background contributions from environmental gammas, neutrons, and muons. Understanding background contributions is crucial for the upcoming phase of the experiment, wherein a larger ~0.5 kg detector will be deployed deep underground at the Gran Sasso laboratory.Speaker: Eric Vazquez-Jauregui -
39
Geant4 simulations for CEvNS searches at nuclear power plants - the CONUS and CONUS+ experiments
The CONUS experiment (COherent elastic NeUtrino nucleus Scattering) aimed to detect coherent elastic neutrino-nucleus scattering (CEvNS) of reactor antineutrinos on germanium nuclei by measuring their recoil after such an interaction. It operated from 2017 to 2022 at 17m distance from the 3.9 GWth core of the Brokdorf nuclear power
plant (Germany). The experiment employed four 1 kg point-contact high-purity germanium (HPGe) detectors and was able to measure the current best limit for CEvNS at reactor site.In the CONUS experiment Geant4 simulations were used extensively to optimise the shield setup of the experiment and to fully characterise the measured background. This talk will present some of the results of these simulations as well as some of the challenges that were faced due to the unique location of a low background experiment at a nuclear power plant. Additionally, the next chapter of CONUS, the CONUS+ experiment in Leibstadt, Switzerland, will be introduced. Just like for its predecessor, Geant4 simulations again play a prominent role in the planning and the data analysis of this new experiment and their contributions will be presented here.
Speaker: Nicola Ackermann
-
36
-
-
-
WorkshopConvener: Paola Ferrario (Donostia International Physics Center (DIPC) (ES))
-
40
Projected Backgrounds Simulation in the RELICS Experiment
The REactor neutrino LIquid xenon Coherent Scattering experiment (RELICS), leveraging liquid xenon time projection chamber (LXeTPC) technology, aims to investigate the CE$\nu$NS process by detecting antineutrinos interacting with xenon nuclei. This study details the design and optimization of the RELICS detector and shield to achieve an optimal signal to background ratio. Backgrounds from the Cosmic Muons, radioactivity of detector and shield materials are all considered in the simulation package developed based on GEANT4. Background mitigation through active Xenon veto and multiple scatters within the LXeTPC are applied to the simulated datasets. Within a fiducial mass of 32 kg, the single scatter electronic recoil (ER) background is estimated to be (22.7$\pm$0.2)$\times 10^{-3} \rm (kg \cdot day \cdot keV)^{-1}$ in ER equivalent energy region of [0, 100] keV, dominated by gammas from the detector materials. The nuclear recoil (NR) background is (1.54$\pm$0.08)$\times 10^{-2} \rm (kg \cdot day)^{-1}$ in NR equivalent energy region of [0.1, 1] keV, dominated by cosmic Muon-induced neutrons. The expected CE$\nu$NS event rate is two orders of magnitude higher than the background level estimated above, enabling RELICS a high discovery potential of CE$\nu$NS signals from reactor neutrinos.
Speaker: Kaihang Li -
41
The effect of contamination on the S1 triplet component in DarkSide-50 dark matter experiment
The DarkSide-50 (DS-50) experiment aims at the direct detection of the Weakly-Interacting Massive Particles (WIMP). Studies have been conducted in both high-mass (>10 GeV/c2) and low-mass (<10 GeV/c2) ranges for WIMPs in DS-50. It is a dual-phase liquid argon time projection chamber (LAr TPC) where Dark Matter (DM), which constitutes five-sixth of all matter in the universe, is expected to interact with the argon nucleus resulting in nuclear recoils.
In the DS-50 low-mass search, the analysis on the low-energy background observed an excess amount of signals around a few extracted ionized electrons, referred to as Spurious Electrons (SEs), during a period when the inline gas purifier was bypassed for a few days. The cause of these SEs, hence, may be related to the impurities in the LAr. A faster reduction in the SE rate was observed once the getter was re-installed, implying a rapid removal of impurities in the gas phase. It has been observed in the literature that the presence of contamination in LAr can quench the scintillation signal (S1) in LAr. One of the primary suspects for these contaminants is nitrogen since it is highly volatile compared to the other impurities in TPC. To investigate the presence of the suspected nitrogen in LAr, the suppression of the observed lifetime of the scintillation signal has been examined using real data from DS-50. The scintillation photons are emitted from two excimer states: the long-lived triplet state (~1.5 µs) and short-lived singlet state (~6 ns). The impurities with concentrations at the order of ppm can lead to a reduction in the observed lifetime of the triplet component. This impurity-analysis would help understand the SE process, consequently improving the sensitivity of low-mass DM searches in future experiments.Speaker: Clea Sunny (AstroCeNT, CAMK PAN) -
42
Simulations of the LUX-ZEPLIN (LZ) experiment using Geant4
Liquid noble gas detectors, such as LZ, continue to demonstrate world leading sensitivity to WIMP dark matter for masses above a few GeV. Here an overview of the LZ simulation framework is provided including custom physics lists employed for low energy tracks and deposits, modifications to better model Xe and Gd processes, and external parametric models of scintillation and ionisation responses. The highly shielded design of these detectors, including the self-shielding from the dense target medium, leads to difficulty in probing the central detector volume using basic Monte Carlo techniques, with most interactions confined to the shielding or target perimeter. This problem is expected to be more pronounced in the much larger LXe detector proposed by the XLZD consortium.
Speaker: Albert Baker (King's College London) -
43
Monte Carlo simulations for bubble chambers
The PICO collaboration has developed an active programme of dark matter detectors using bubble chambers filled with fluorocarbon fluids as targets. These detectors operated deep underground at SNOLAB, have an excellent capability to reject backgrounds owing to their insensitivity to electron recoil backgrounds.
This talk will present the Monte Carlo model used to estimate the background contributions and assess detector response and calibration using radioactive sources. Detailed results will be provided for the expected backgrounds in the operational PICO-40L detector and the forthcoming ton-scale detector, PICO-500.Speaker: Eric Vazquez-Jauregui -
44
Monte Carlo simulations for a low energy antiproton-nucleus annihilation study
The antiproton-nucleus ($\bar{p}A$) annihilation is one of the main processes in antimatter studies, as antiparticles are mostly detected through their annihilation. Despite its significance, the process itself is not well established and the lack of models for low energies complicates the simulation of detectors for the experiments conducted at CERN's Antiproton Decelerator.
Previous measurements of charged particles resulting from $\bar{p}A$ annihilations have shown that the FLUKA model exhibits the closest agreement with experimental data, while the Geant4 FTFP model shows significant discrepancies both on the multiplicities of minimum ionising particles (MIPs) and heavily ionising particles (HIPs). Both models were developed for high energy application and have not been extensively validated for sub-keV energies.
In addition, the Geant4 FTFP model predicts that at 250 eV energies a substantial fraction of antiprotons will not annihilate, but scatter off the target foil. The FLUKA model completely lacks the capability to simulate this process at energies below 1 keV.
For this reason a systematic study of $\bar{p}A$ annihilations at 250 eV on a variety of thin target foils is being set up at the ASACUSA facility. This experiment will provide data on MIP and HIP multiplicities, as well as the ratio of annihilating to reflected antiprotons. Such data will enable a study of the possible final state interactions triggered by the primary annihilation mesons, as well as their branching ratios. The results will be implemented for assessment of simulation models such as the Liège Intranuclear Cascade model, and their potential tuning.Speaker: Viktoria Kraxberger (Austrian Academy of Sciences (AT)) -
45
A GEANT4-based simulation of cosmic rays background and secondary beams analysis for nuBDX-mini experiment
This work represents a comparison of experimental cosmic radiation data obtained at the laboratory of the INFN Genova section and GEMC simulations. GEMC is an interface to the GEANT4 library developed and used at Jefferson Lab. The cosmic radiation was measured by an inorganic scintillating detector (Caesium Iodide Thallium-doped crystal) 6x6x32 cm in size. The detector is surrounded by an active plastic veto, which allows it to track events and put them in coincidence with the crystal. The simulations were normalized to the daily expected number of events, and a realistic geometry was implemented. This work is also useful to optimize the shielding design aimed to be used with the nuBDX-MINI detector that will be deployed at Jefferson Lab (USA). nuBDX is the electron beam-dump experiment aimed to measure coherent elastic neutrino nucleon scattering (CEvNS) using neutrinos produced by the interaction of an intense 11 GeV energy electron beam with the experimental Hall-A dump in a fixed target experiment. nuBDX-MINI is a prototype of the final detector made by a CsI crystal surrounded by an active plastic scintillator veto.
The nuBDX setup is unique since neutrino flux produced in electron-dump interaction has the maximum in the decay-at-rest (DAR) energy spectrum in the 1-100 MeV range, optimal to access CEvNS. On the other hand, the low energy of incoming neutrino and the small recoil induced by the coherent nucleus scattering require low-threshold (10-200 keV) target detectors to detect low nuclear recoils.
The optimum way to shield the low-threshold detector from a neutron background was considered. Based on the calculations, the most functional composition and shape of neutron radiation protection were determined. A shielding consisting of several layers, including a thick layer of lead and water was deployed. An active veto surrounding the crystal provides further rejection capability. Lead foil covering the scintillator to shield from gamma radiation produced in the external lead layer by primary neutron flux was also added.Speaker: Tetiana Nagorna (Istituto Nazionale di Fisica Nucleare)
-
40
-
11:00
Coffee break
-
WorkshopConvener: Eun Ju Jeon (Center for Underground Physics, IBS)
-
46
JUNO detector simulation based on customized Geant4 physics list
Jiangmen Underground Neutrino Observatory (JUNO) is designed to determine the neutrino mass ordering and precisely measure neutrino oscillation parameters. The JUNO central detector is the largest liquid scintillator detector which contains 20 kton liquid scintillator, surrounded by more than 17000 20-inch photon multiplier tubes (PMTs) and 25600 3-inch PMTs. The JUNO detector simulation has been developed based on Geant4 with customized Geant4 physics list, the costomized processes include G4Cerenkov, G4Scintillation,G4OpBoundaryProcess, G4EmLivermorePhysics, G4RadioactiveDecayPhysics, and G4HadronPhysicsQGSP_BERT_HP. Some of them have already been included in latest Geant4 releases, but some are not.
Speaker: Ziyan Deng -
47
Geant4 simulations for the NEXT experiment and applications
NEXT is an experiment searching for neutrinoless double beta decay with high-pressure gaseous xenon enriched in the Xe-136 isotope. It is situated in the Canfranc Underground Laboratory, in the Spanish Pyrenees.
Neutrinoless double beta decay represents an extremely rare hypothetical mode of beta decay. Its confirmation would provide critical insights into the nature of neutrinos, demonstrating that neutrinos are Majorana particles, meaning that the neutrino is its own antiparticle.
An accurate modelling of both the expected signal and the background affecting the detector is essential in all rare event searches. To address this, the NEXT Collaboration has developed the NEXUS software, built upon the Geant4 toolkit. This software incorporates the specific geometry of the NEXT detectors, enabling simulations of the interaction of both radiogenic and cosmogenic backgrounds with xenon, as well as of xenon nuclear decay.
In this talk I will describe the NEXUS software and discuss the challenges of the simulation, which include the computational effort required by the propagation of a large amount of photons, the precise modelling of the optical properties of materials or the vertex generation.
I will also mention the application of Geant4 to a spin-off project of the NEXT experiment, called PETALO, which employs liquid xenon for Positron Emission Tomography technology.Speaker: Paola Ferrario (Donostia International Physics Center (DIPC) (ES)) -
48
The search for neutrinoless double beta decay using the nEXO experiment: Simulation needs and challenges
The nEXO experiment aims to explore beyond standard model physics in the neutrino sector, particularly through the search for neutrinoless double beta decay (0vBB) of Xenon-136. This decay, if observed, is a lepton-number violating process and would shed light on the fundamental properties of neutrinos. nEXO will employ a 5-tonne xenon target enriched to 90% of the 2vBB isotope, Xenon-136, and utilizes a liquid xenon time projection chamber (TPC) detector design. The nEXO experiment will probe 0vBB half-lives up to 10^28 years, 2 orders of magnitude past the current experimental limits.
nEXO employs a thorough radiopurity screening campaign, with multi-mode screening for all forms of radiogenic backgrounds. Combining these screening measurements with simulations of full decay chains for the measured uranium and thorium of all detector materials, we can estimate the background contributions to our expected signal. To this end, efficient simulation methods are crucial due to the low efficiency of external background simulations, low levels of radioactive contamination, and the 10-year lifetime of the experiment. To further optimize simulation time, nEXO GEANT4 simulations use light-maps to produce the expected photodetector response for energy depositions within the TPC. This light-map is built using the GPU accelerated photon transport simulation framework, Chroma. The role of Chroma in nEXO simulations and plans, including direct GEANT4 integration will be discussed, alongside the current challenges, and strategies that are being explored for GEANT4 simulations.
Speaker: David Gallacher -
49
Optical Simulations in the LEGEND-1000 Outer Argon Shielding
The LEGEND (Large Enriched Germanium Experiment for Neutrinoless Double-beta decay) project searches for neutrinoless double-beta decay in $^{76}$Ge, aiming to operate at the ton-scale in its second phase (LEGEND-1000). The first phase, LEGEND-200, uses a light detection system to detect energetic events in the liquid argon shielding surrounding the $^{76}$Ge crystals, taking advantage of argon’s natural scintillation. The current baseline design of LEGEND-1000 has an inner liquid argon volume (comprised of “underground argon”) with light detection instrumentation, and an outer liquid argon volume (comprised of “atmospheric argon”). This work investigates the possibility of adding light detection instrumentation to the outer liquid argon, for the purpose of identifying additional types of background signals, which can then be vetoed. This work includes two sets of Geant4-based simulations: one to model cosmic muon-induced neutron capture in the liquid argon of LEGEND-1000, and another to model scintillation light production and propagation. Inspired by a similar tool applied in GERDA and LEGEND-200, a three-dimensional optical map has been constructed from the scintillation simulations. This map has been built in a generalized fashion and can be applied to any well-defined set of light detection instrumentation placed along the neutron moderator of LEGEND-1000, allowing the same map to be used for multiple configurations. This work discusses the simulation production flow and the building of the optical map. It will also discuss the post-processing to apply the optical map to a LEGEND-1000 simulation data set, as well as showcase a set of plots for data analysis and optimization of the instrumentation.
Speaker: Clay Barton
-
46
-
12:50
Lunch
-
WorkshopConvener: Prof. Ziyan Deng
-
50
G4CMP: Condensed Matter Physics Simulation Using the Geant4 Toolkit
G4CMP simulates phonon and charge transport in cryogenic semiconductor crystals using the Geant4 toolkit. The transport code is capable of simulating the propagation of acoustic phonons as well as electron and hole charge carriers. Processes for anisotropic phonon propagation, oblique charge-carrier propagation, and phonon emission by accelerated charge carriers are included. The simulation reproduces theoretical predictions and experimental observations such as phonon caustics, heat-pulse propagation times, and mean charge-carrier drift velocities. In addition to presenting the physics and features supported by G4CMP, this report outlines example applications from the dark matter and quantum information science communities. These communities are applying G4CMP to model and design devices for which the energy transported by phonons and charge carriers is germane to the performance of superconducting instruments and circuits placed on silicon and germanium substrates.
Speaker: Michael Kelsey (Texas A&M University (US)) -
51
eV-Scale Modelling of Low-Energy Backgrounds in Superconducting Tunnel Junctions utilizing GEANT4 and G4CMP
The BeEST experiment searches for physics beyond the standard model (BSM) in the neutrino sector by utilizing the electron capture (EC) decay of 7Be. The 7Be is embedded in superconducting tunnel junction (STJ) sensors such that the low-energy (eV-scale) radiation is detected with high energy resolution and efficiency. Modelling of low-energy backgrounds is crucial to understanding potential beyond standard model (BSM) physics, including low-energy phonon and quasiparticle generation within the superconductors. In this talk, current modelling of these features and corresponding challenges for the BeEST experiment will be discussed with aims towards gaining feedback from the GEANT4 expert community.
The BeEST experiment is funded in part by the Gordon and Betty Moore Foundation (10.37807/GBMF11571), the DOE-SC Office of Nuclear Physics under Award Numbers DE-SC0021245 and DE-FG02-93ER40789, and the LLNL Laboratory Directed Research and Development program through Grants No. 19-FS-027 and No. 20-LW-006. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. The theoretical work was performed as part of the European Metrology Programme for Innovation and Research (EMPIR) Projects No. 17FUN02 MetroMMC and No. 20FUN09 PrimA-LTD. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52- 07NA27344.
Speaker: Caitlyn Stone-whitehead (Colorado School of Mines) -
52
ELOISE – Measured electronic stopping power in CaWO$_4$ and Al$_2$O$_3$ at sub-keV in comparison with Geant4 simulation
CaWO$_4$ and Al$_2$O$_3$ are well-known target materials for experiments searching for rare events like CE$\nu$NS with NUCLEUS or hypothetical dark matter-nucleus scattering with CRESST. Pushing the detection threshold down to sub-keV energies, experiments are in need for verified and reliable simulations of radioactive background components at sub-keV energies, e.g. based on the widely used Geant4 toolkit.
The ELOISE project aims to tackle this issue for electromagnetic particle interactions in both materials. We are currently in the process of evaluating Geant4’s accuracy by comparing benchmark simulations with data from extended literature research and dedicated measurements. As sub-keV data on the electronic stopping power is rare or totally missing, ELOISE conducted dedicated Electron Energy Loss Spectroscopy (EELS) on CaWO$_4$ and Al$_2$O$_3$ to obtain their optical energy loss function. From this, we deduced preliminary electronic stopping powers and tentatively compare them with Geant4 simulations of electron energy loss in both materials.
In this contribution, I will briefly describe the problem and outline the scope of ELOISE. Afterwards, I will report the results of ELOISE’s reference measurements and the obtained stopping powers. Finally, I will discuss our preliminary comparison with Geant4 simulations of CaWO$_4$ and Al$_2$O$_3$ at sub-keV energies.Speaker: Dr Holger Kluck (Institute of High Energy Physics (HEPHY) of the Austrian Academy of Sciences) -
53
The DELight simulation framework
The low energy threshold necessary for the search of nucleus scattering from sub-GeV/c$^2$ light dark matter (LDM) can be achieved nowadays by solid state detectors, with the disadvantage of limited scalability. The DELight experiment plans to overcome this limit by deploying a target of superfluid helium-4 instrumented with magnetic microcalorimeters, recovering the scalability of noble liquid experiments, while reaching low energy thresholds typical of cryogenic semiconductors thanks to its quasiparticle channel. In addition, the light nuclear mass of helium makes it an ideal candidate for LDM searches, allowing DELight to probe masses down to 100 MeV/c$^2$ already during its first phase which will deploy a target of about 1 kg.
As DELight is in its design phase, detailed simulations are of key importance. The current design geometry is implemented in GEANT4, which allows for the propagation and tracking of radiogenic and cosmic background radiation, returning the energy deposition in the sensitive volume. The same framework is also used to simulate the propagation of the different signal quanta from interactions in the helium: photons, excimers, and quasiparticles. In particular, the nature of quasiparticles in superfluid helium-4 renders existing frameworks for their propagation in condensed matter unsuitable. The relative partitioning of the signal into the multiple channels is calculated from measured and calculated cross sections, both for electronic and nuclear recoils.
This talk will focus on the discussion of the simulation framework and the first results towards the optimization and understanding of DELight.
Speaker: Francesco Toschi (Karlsruhe Institute of Technology) -
54
Geant4 simulations of surface contaminations and roughness and their influence on low energy background spectra
CRESST is an experiment for the direct detection of dark matter, situated at Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It is capable of detecting nuclear recoils down to 10 eV with an impressive sensitivity in the sub-GeV mass region. This is achieved by using cryogenic scintillation crystals as target materials. However, in this low energy region it can be challenging to distinguish between dark matter interactions and electromagnetic background. Various background components are considered via simulations with ImpCRESST, a Geant4 based simulation code, which is continuously adapted to the setup of CRESST. At the current state default Geant4 and therefor the CRESST background model only considers a flat detector surface, but surface roughness in combination with surface contamination is of particular interest. Because of nuclides decaying inside the crystal in the vicinity of the surface, it is possible that only a share of the energy is placed inside the detector. As a result, higher energy events can leak into the lower energy range and may affect the simulated background. This contribution presents a newly developed extension of ImpCRESST for simulation of surface contamination with radiogenic elements in combination with a simulated surface roughness of the detector. The implementation of the particle generator, the ”actual” rough surface and different development obstacles and insights are discussed and first results using this module in ImpCRESST are shown.
Speaker: Christoph Gruner
-
50
-
16:00
Coffee break
-
WorkshopConvener: Dr Samir Banik (Technische Universität Wien, Atominstitut)
-
55
Geant4 simulations applied to analysis of the Po-210 and Pb-210 content in the components of the DarkSide-20k dark matter detector
The DarkSide-20k (DS-20k) experiment is located in the Gran Sasso underground laboratory in Italy. Its main goal is to search for direct interactions of cold dark matter particles with argon nuclei. The detector is based on a two-phase time projection chamber (TPC) and because the expected signal from dark matter is very low, a strong background suppression is needed in order to maximize the detectors sensitivity. As a consequence there are strong requirements for the construction components/material with respect to contamination with radioactive isotopes.
In searches for dark matter one of the most important background sources are neutrons, especially those produced in the (alpha, n) reactions. It is impossible to distinguish between the signal coming from dark matter particles and that induced by neutrons. Alpha particles can be produced in the Po-210 (daughter of the long-lived Pb-210) decays. In my research Po-210 content in samples to be used in the DS detector, is determined by application of alpha spectrometry. A large-surface, low-background alpha spectrometer XIA UltraLo-1800 was used. Registered spectra contain contributions from the bulk and from the surface Po-210 contamination. Monte Carlo simulations are crucial to deconvolute these contributions and to obtain the surface and bulk Po-210 activity concentrations. The alpha-spectrometer and the samples geometry were implemented in the Geant4 package including appropriate physical processes. A few millions of the Po-210 decays were generated from the samples’ bulk (entire volume) and surface (a few nanometers of the layer). The combined spectra from the simulations were fitted to real data by the χ2 method due to the deconvolute the bulk and surface activity. The obtained values are compared to the DarkSide requirements.Speaker: Milena Czubak -
56
The Geant4-based simulation program for the PandaX experiments
PandaX is an experiment that aims to search for dark matter, neutrinoless double beta decay, and other rare processes using a liquid xenon time projection chamber. A good understanding of the energy deposition processes in the detector holds great importance to the experiment. To address this, BambooMC, a Geant4-based Monte Carlo simulation program, has been developed. In this presentation, the design and functionalities of BambooMC will be introduced, along with an innovative simulation acceleration scheme where a biasing technique is employed. The sensitive region of the detector is simulated in a layered fashion, with an amplified number of events in each layer. With this technique, the simulation speed is enhanced by approximately three orders of magnitude.
Speaker: Tao Li (Sun Yat-sen University) -
57
GEANT4 simulations based results and studies in the CUPID-Mo and CUPID experiments
The CUPID experiment is a next-generation bolometric 0νββ experiment that will be installed at LNGS in the CUORE cryostat. CUPID will search for the 0νββ of 100Mo with 1596 Li2MoO4 scintillating crystals. It will take advantage of the CUORE infrastructure and the recent development of scintillating crystals through the CUPID-0 and CUPID-Mo demonstrators. The CUPID-Mo demonstrator was located in the Laboratoire Souterrain de Modane (France) and studied the 0νββ of 100Mo with an array of 20 enriched Li2100MoO4 bolometers and 20 Ge light detectors. The experiment took
data from spring 2019 to summer 2020 and, at that time, set a leading limit on the half life of 0νββ decay of 100Mo (T1/2 > 1.8 x 1024 yr at 90% C.L.) with a total exposure of 2.71 kg.yr. In this talk, I will present the GEANT4 Monte-Carlo simulations that we developed with a detailed geometry of the set-up and the detector response that was applied. These Monte-Carlo simulations were used as input for the construction of a background model that was based on a global simultaneous fit of CUPID-Mo data using a Bayesian approach. This resulted in a measurement of the crystal contamination and demonstrated that CUPID-Mo achieved one of the lowest background index for a bolometric experiment. This also allowed us to measure with the best precision ever the 2νββ of 100Mo. In this talk, I will also present the GEANT4 simulations developed for the CUPID experiment and the projected backgrounds based on the knowledge from CUORE and CUPID-Mo experiments. In particular, I will also present a geometry-based biasing that we are currently implementing to simulate backgrounds that are CPU time-consuming, like the environmental background or contaminations in the radiation shields.Speaker: Léonard IMBERT (CNRS / IJCLab / Université Paris-Saclay / France) -
58
Application of GEANT4's Importance Biasing in radiogenic background simulations
Experiments which aim to measure extremely rare events such as the direct detection of dark matter or coherent elastic neutrino-nucleus scattering are in need of low-background environments to be able to observe a potential signal and distinguish it from the present background. Furthermore, it is crucial to understand the background composition of the measured energy spectra to explore new regions of interest with statistical methods such as a profile likelihood approach.
In order to reach these goals, such experiments are located in underground laboratories and their detectors are surrounded by several layers of shielding material to protect them from external radiation.
Typically, a shield is composed of $\mathcal{O}(10)$ cm of lead to absorb $\gamma$-rays and thick layers of polyethylene to thermalize and absorb neutrons. Consequently, the corresponding Monte Carlo simulations based on GEANT4 require a huge amount of primary particles to be propagated through the experiment's geometry to achieve sufficient statistics inside the detectors. Nevertheless, the simulated energy spectra in the detectors lack in statistics which propagates into large uncertainties in the background composition.GEANT4 offers a mechanism called Importance Biasing which can increase the amount of detector hits by orders of magnitude for the same number of primary events. This is achieved by intentionally duplicating particles which propagate into the direction of the detectors while aborting particle tracks that travel away from the detectors.
This talk will present the challenges of implementing Importance Biasing in the GEANT4 application developed by the SuperCDMS collaboration and will discuss the achieved efficiency boost of the respective background simulations.Speaker: Birgit Zatschler (LPSC Grenoble)
-
55
-
19:00
Workshop dinner
Location: "Stadtwirt", Untere Viaduktgasse 45, 1030 Vienna
-
-
-
WorkshopConvener: Dr Valentyna Mokina (HEPHY)
-
59
Deep Generative Models for Calorimeter Simulations
Deep generative models (DGMs) have had a huge impact on our society in the past year. Known to many via chatbots such as ChatGPT and LLama, or image generators like Dall-E and midjourney, they have shown impressive performance on various text- and image-based tasks.
I will present an overview of current deep generative models and their application to particle physics and especially detector simulation. Adopted to detector simulation and calorimeter showers, DGMs promise samples that are nearly indistinguishable from GEANT4, at 4-5 orders of magnitude smaller generation times. I will also discuss lessons learned from the "Fast Calorimeter Simulation Challenge 2022".Speaker: Dr Claudius Krause (HEPHY Vienna (ÖAW)) -
60
Simulation of low energy events for DAMIC-M
DAMIC-M (Dark Matter in CCDs at Modane) is a near-future experiment aiming to search for low-mass dark matter particles through their interactions with silicon atoms in the bulk of charge-coupled devices (CCDs). DAMIC-M will feature a detector mass of about 1 kg, employing 208 (1.5k x 6k) skipper CCDs. Skipper amplifiers will enable DAMIC-M CCDs to achieve a sub-electron readout noise, thereby allowing to extend the experimental energy threshold to the eV-scale. Strengthened by these characteristics, DAMIC-M will reach unprecedented sensitivities to dark matter candidates of the so-called hidden sector, while continuing the search for low mass WIMPs.
DAMIC-M largely relies on Geant4 simulations for the background estimation and calibration to nuclear recoils.
Detailed measurements with skipper CCDs have been conducted to characterize the spectrum of Compton scattered electrons, a predominant source of background at low energy. Notably, Geant4 fails to faithfully reproduce the experimental data in the low energy regime (<0.3 keV). In light of this limitation, alternative simulation codes have been evaluated. Ab-initio calculations have proven capable of accurately representing the observed data when appropriately tuned.
A measurement of the nuclear recoil ionization efficiency down to <20 eV electron equivalent has also been made using a photo-neutron source. GEANT4 and MCNP simulations were key in the analysis, with both yielding similar results in the energy range of interest.In this talk we compare DAMIC-M calibration measurements with Geant4 results, providing insight into the challenges inherent in the simulation of low-energy phenomena.
Speaker: Claudia DE DOMINICIS (CNRS, LPNHE) -
61
GEANT4 simulations within the ANAIS-112 experiment data analysis procedures
ANAIS is a direct dark matter detection experiment whose goal is to confirm or refute in a model independent way the positive annual modulation signal reported by DAMA/LIBRA. ANAIS-112, consisting of 112.5 kg of NaI(Tl) scintillators, is taking data at the Canfranc Underground Laboratory in Spain since August 2017. Results corresponding to the analysis of three years of data show no modulation and are incompatible with DAMA/LIBRA. A 3-year data reanalysis based on a new filtering protocol improves both the selection efficiency and the background of the experiment, thus enabling a first direct test of DAMA/LIBRA at three sigma level. However, testing this signal relies on the knowledge of the scintillation quenching factors (QF) for the conversion of nuclear recoil energy depositions with respect to the same energy deposited by electrons. Previous measurements of the QF in NaI(Tl) show a large dispersion, which introduces a systematic uncertainty in the comparison between different experiments using NaI(Tl). Consequently, in order to fully understand the response of the ANAIS-112 detectors to nuclear recoils, a specific neutron calibration program is being developed. This program combines two different approaches: on the one hand, QF measurements across several NaI(Tl) crystals similar to those used in ANAIS-112 were carried out in a monoenergetic neutron beam; on the other hand, the study presented here aims at the evaluation of the QF by exposing directly the large ANAIS-112 crystals to neutrons from 252Cf sources. Comparison between these onsite calibrations and detailed GEANT4 simulations allows testing different QF models. Some results will be discussed. In addition, the GEANT4 model of the full ANAIS-112 experiment is currently under revision and upgrading. Present status will be reported in this talk, focusing in particular in the optical simulations of the ANAIS-112 detectors, which allow to produce synthetic signals that can be used for training machine-learning procedures for noise discrimination.
Speaker: Mrs Tamara Pardo Yanguas (CAPA, University of Zaragoza, Spain) -
62
Simulation of Low-energy Calibration using Geant4 in Search of Reactor Neutrino Coherent Scattering
REactor neutrino LIquid xenon Coherent Scattering experiment (RELICS) employs the liquid xenon time projection chamber (LXeTPC) technique for the search of neutrino coherent scattering off xenon nuclei (CE$\nu$NS) caused by $\sim$MeV neutrinos emitted from nuclear reactor.Such CE$\nu$NS interactions result in deposit energies of approximately $\sim$keV or sub-keV in LXe, demanding calibrations within the relevant energy ranges.To achieve this, $^{137}$Cs and $^{60}$Co sources will be utilized to calibrate $\gamma$ and $\beta$-induced electronic recoils, while $^{241}$AmBe and a Deuteron-Deuteron (DD) neutron generator will be employed for calibration of CE$\nu$NS.This presentation will focus on simulations of RELICS detector's response using various calibration sources, employing a GEANT4-based toolkit. Notably, it will provide detailed information on the design and simulation of the calibration process for CE$\nu$NS signals with energies ranging from approximately 0.1 to 1.0 keV, by selecting neutron double scatters originating from a collimated DD generator.
Speaker: Jiachen Yu -
63
Accurate simulations for the CRAB project: from thermal neutron production to low energy nuclear recoils induced by thermal neutron capture
L. Thulliez(1) for the CRAB collaboration
(1) IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, FranceThe detection of the coherent elastic neutrino-nucleus scattering (CEνNS) at reactors or of hypothetical light dark matter (DM) particles will allow to test new physics beyond the standard model. In both cases their direct detection will lead to sub-keV nuclear recoils. This requires low energy thresholds of few 10 eV along with energy resolutions of few eV, which are currently achieved by cryogenic detector operated at mK temperatures. Understanding the response of these detectors at a sub-keV energy scale is therefore crucial but remains a challenge. Recently the CRAB collaboration has proposed [1] to calibrate the cryo-detectors with pure nuclear recoils induced by thermal neutron radiative captures, perfectly mimicking the CEνNS or DM signals.
We will discuss the first measurement performed with a CaWO4 cryogenic detector of the NUCLEUS experiment [3] exposed to a low flux of thermal neutrons produced by a commercial 252Cf source. The measured recoil spectrum shows a nuclear recoil peak at around 112 eV (182W(n,γ)183W) with a 3σ significance and evidence at the 6σ level of the nuclear recoil spectrum, in very good agreement with FIFRELIN-GEANT4 simulations [4]. This talk will emphasis the software developments that have been performed leading to such a good agreement. These mainly concern the modeling of the 252Cf source with FIFRELIN, the neutron slowing-down in GEANT4 that has been recently improved [5] and the accurate computation of the nuclear recoil induced by thermal neutron capture thanks to FIFRELIN.
Then we will present the interplay between the timing of nuclear de-excitations and atom recoils in matter, which has recently been investigated in coupling the FIFRELIN and IRADINA (binary collision approximation) codes. We will discuss how these timing effects can significantly impact the spectrum of nuclear recoils, especially for germanium and silicone detectors [7], and so the calibration. The simulation results for the main crystal materials used in CEνNS and DM communities, that are available online [8] along with a Geant4 interface [9], will be presented.
A series of high precision measurements is in preparation at the TRIGA Mark-II reactor in Vienna where the gammas escaping the cryo-detector will be tagged in addition to the nuclear recoil. This will allow to get more calibration peaks to test the linearity of the detector response, the quenching factors and also to set constraints on nuclear models and solid state physics.[1] L. Thulliez, D. Lhuillier et al., Calibration of nuclear recoils at the 100 eV scale using neutron capture, JINST, 16, 7 (2021)
[2] O. Litaize, O. Serot, and L. Berge. Fission modelling with FIFRELIN. Eur. Phys. J. A, 51(12):177 2015.
[3] R. Strauss et al., Gram-scale cryogenic calorimeters for rare-event searches, Phys. Rev. D 96, 022009 (2017)
[4] CRAB collaboration, NUCLEUS collaboration, H. Abele et al., Observation of a nuclear recoil peak at the 100 eV scale induced by neutron capture, Phys. Rev. Lett. 130, 211802 (2023) arXiv:2211.03631 [nucl-ex] (2022)
[5] L. Thulliez, C. Jouanne, E. Dumonteil, Improvement of Geant4 Neutron-HP package: From methodology to evaluated nuclear data library, Nuclear Inst. and Methods in Physics Research, A 1027 (2022) 166187
[6] C. Borschel and C. Ronning. Ion beam irradiation of nanostructures – A 3D Monte Carlo simulation code. Nucl. Instrum. Meth. Phys. Res. B: Beam Interactions with Materials and Atoms, 269(19):2133–2138, 2011
[7] CRAB collaboration, G. Soum-Sidikov et al., Study of collision and γ-cascade times following neutron-capture processes in cryogenic detectors, Phys. Rev. D 108, 072009 (2023) arXiv:2305.10139 [physics.ins-det] (2023)
[8] G. Soum-Sidikov, L. Thulliez, O. Litaize, A. Chalil, J.-P. Crocombette, and D. Lhuillier, Fifradina dataset for radiative thermal neutron-capture processes in cryogenic detectors (CRAB), 10.5281/zenodo.7936552, 2023.
[9] L. Thulliez, H. Kluck et A. Bonhomme, Fifrelin4Geant4, (2023) DOI:10.5281/zenodo.7933381 , http://gitlab.com/lthullie/fifrelin4geant4Speaker: Loic Thulliez (IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France) -
64
The accuracy of gamma cascades for thermal neutron capture on gadolinium in Geant4
Due to its extremely high absorption cross-section for thermal neutrons, gadolinium is widely used for passive shielding, neutron tagging, or even medical applications. A neutron capture on gadolinium is followed by an $\sim$8 MeV gamma de-excitation cascade, which is usually easily detectable. In order to perform accurate Monte Carlo simulations for these purposes, the complex gamma cascades need to be well-known. In this talk, the de-excitation chains implemented in Geant4 v11.0.3 are compared to the accurate calculations done by Peter Grabmayr (1) in MAURINA as part of R&D for LEGEND.
(1) Grabmayr, P. Gamma cascades in gadolinium isotopes. Eur. Phys. J. C 83, 444 (2023).
Speaker: Eric Esch
-
59
-
11:00
Coffee break
-
WorkshopConvener: Dr Samir Banik (Technische Universität Wien, Atominstitut)
-
65
Improving Geant4's Neutron Physics for Modeling of Cosmogenic Isotope Production in LEGEND
The in-situ production of long-lived radioactive isotopes by cosmic muons can constitute a significant background in the search for rare events deep underground unless appropriate mitigation strategies are applied [1,2]. The delayed decay of $^{77(m)}$Ge is the primary cosmogenic contributor for the $^{76}$Ge-based neutrinoless double-beta decay experiment LEGEND. This talk presents the Geant4 simulation used to investigate the production mechanism of $^{77(m)}$Ge via the capture of muon-induced neutrons for this experiment. We studied the physics relevant to production and improved Geant4's neutron physics based on recent measurements and models [3,4]. Furthermore, we used the simulation output to identify a production event and how it can be used for background rejection.
[1] C. Wiesinger et al., Eur. Phys. J. C (2018) 78: 597
[2] M. Neuberger et al., PoS TAUP2023 (2024) 278
[3] A. Gawlik-Ramięga et al. (n_TOF Collaboration) Phys. Rev. C 104, 044610
[4] P. Grabmayr, submitted to EPJASpeaker: Mr Moritz Neuberger (Physik-Department E15, Technische Universität München, Germany) -
66
G4DS Package for the DarkSide-20k Experiment
DarkSide-20k will be a 50 tonne dual-phase LAr TPC for direct DM search, currently under construction at Hall C of LNGS. The simulation of backgrounds relies on a Geant4-based software package, G4DS, which was extensively developed in the context of the DarkSide-50 and is being used for all DarkSide-20k simulations as well as for several related experiments. G4DS provides a description of the response of argon to nuclear and electron recoils, as well as a simulation of the TPC optics tuned on DarkSide-50 data. We will discuss the status of the simulation and the latest developments for the modelling of neutron captures in Gd-PMMA that has been selected as a main construction material of the TPC. We will discuss, in addition, neutron propagation and cosmogenic backgrounds for DarkSide-20k.
Speaker: Devidutta Gahan (INFN-Cagliari) -
67
REST-for-Physics framework for Geant4 simulations and data analysis
The REST-for-Physics (Rare Event Searches Toolkit for Physics) framework is a ROOT based open-source software to process the data from detector physics experiments. Its main features include the traceability of code and data to ensure reproducible results, potential scalability and reusability. The framework provides common event data structures for experimental and MonteCarlo simulated events, where common event processes may operate on both. The Geant4 simulated events can be launched directly through the builtin restG4 package that interfaces with the REST-for-Physics Geant4 library. REST-for-Physics is actively maintained and it is already consolidated in Rare Event Searches experiments using gaseous Time Projection Chambers such as PandaX-III, TREX-DM and BabyIAXO.
Speaker: Álvaro Ezquerro Sastre (Universidad de Zaragoza) -
68
Geant4.jl: Particle Transportation in Julia
The Julia programming language, renowned for its speed and ease of development, has emerged as a powerful tool for scientific computing and numerical simulations. In this paper, we introduce Geant4.jl, a Julia package that offers bindings for the Geant4 toolkit. Geant4, a widely utilised framework in high-energy physics, nuclear physics, medical physics, and space science, is characterised by its extensive library comprising thousands of C++ classes and intricate design. Our primary objective in developing Geant4.jl is to provide a user-friendly interface tailored specifically for simulation application developers. This interface not only enhances usability but also ensures optimal computational performance, leveraging features such as multi-threading. We underscore the substantial advantages offered by this streamlined toolkit, particularly when compared to the intricacies of the C++ interface, which occasional users often contend with when developing customised simulations.
Speaker: Pere Mato Vila (CERN) -
69
Background model studies for IAXO using the REST-for-Physics framework
The International AXion Observatory (IAXO) is an axion helioscope that will look for axions and axion-like-particles produced in the Sun. BabyIAXO is an intermediate stage to be hosted in DESY (Germany) which will already probe previously untapped regions of the parameter space. The baseline detection technology for IAXO are the microbulk Micromegas detectors, capable of achieving the ultra-low background conditions necessary to detect the soft X-rays produced in the conversion of the axion into photons via the Primakoff effect.
Given the stringent demands for background rejection, a detailed background model is required. Extensive Geant4 simulations have been performed in order to characterize contributions such as from detector components (contamination, cosmogenic activation) and ambient radiation or cosmic ray-induced background - a notable challenge due to detector operation at surface level.
These Geant4 simulations have been performed using the REST-for-Physics framework, which provides an interface to Geant4 as well as an analysis pipeline which enables the production of experimental-like data which has been key in the development of the background model and design of the detector and veto systems.
Speakers: Luis Antonio Obis Aparicio (CAPA - University of Zaragoza), Luis Antonio Obis Aparicio (University of Zaragoza / CAPA) -
70
SummarySpeakers: Eric Vazquez-Jauregui, Eric Vazquez-Jauregui (SNOLAB)
-
71
ClosingSpeaker: Dr Valentyna Mokina (HEPHY)
-
65
-
