Pub Date : 2025-12-18DOI: 10.1016/j.nima.2025.171231
Dmytro Minchenko, Juan Pablo Yañez, Aksel Hallin
We present a study of the impact of scattering on the emission of Cherenkov radiation, explore the limitations of the simulation tools currently in use in particle and nuclear physics, and propose a method for overcoming these limitations. We start with a derivation of the Cherenkov power spectrum and its angular profile, accounting for interference of the radiation emitted, in contrast with commonly used tools that assume perfect coherence. We then study the impact that the path of electrons through a medium has on the angular profile of Cherenkov light. Finally, we devise a model that can incorporate these effects into Geant4 and tune it to explain calibration data from the water-phase of SNO+. We find that the tuned model significantly improves the agreement between data and simulation, so we provide it for its wider use.
{"title":"Simulating the impact of scattering on the angular distribution of Cherenkov radiation","authors":"Dmytro Minchenko, Juan Pablo Yañez, Aksel Hallin","doi":"10.1016/j.nima.2025.171231","DOIUrl":"10.1016/j.nima.2025.171231","url":null,"abstract":"<div><div>We present a study of the impact of scattering on the emission of Cherenkov radiation, explore the limitations of the simulation tools currently in use in particle and nuclear physics, and propose a method for overcoming these limitations. We start with a derivation of the Cherenkov power spectrum and its angular profile, accounting for interference of the radiation emitted, in contrast with commonly used tools that assume perfect coherence. We then study the impact that the path of electrons through a medium has on the angular profile of Cherenkov light. Finally, we devise a model that can incorporate these effects into Geant4 and tune it to explain calibration data from the water-phase of SNO+. We find that the tuned model significantly improves the agreement between data and simulation, so we provide it for its wider use.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171231"},"PeriodicalIF":1.4,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cadmium telluride (CdTe) has been widely used for room-temperature radiation detectors, for which low dark current under high bias is a primary requirement. Building upon our previous report on Cu-electrode detectors, this study expands the investigation to silver (Ag) to verify the universality of a reversible electrical aging process and to propose a consistent electrical model governing this phenomenon. We demonstrate that applying a high reverse bias for an extended period suppresses the dark current in Ag–CdTe detectors, as well as in Cu–CdTe detectors, to a level comparable to that of conventional Schottky-type detectors. Crucially, this effect is reversible: the suppressed dark current can be restored to a high-current state by applying thermal stress (baking at 85 °C) and subsequently suppressed again by reapplying the aging process. This consistent reversibility across different Group 11 metals indicates that the dominant mechanism is not irreversible bulk diffusion but a modification of properties intrinsic to the CdTe interface. Based on these findings, we propose that the observed electrical behaviors, including the dark current suppression and the transient forward current, can be consistently explained by a model based on Fermi-level pinning.
{"title":"Reversible dark current suppression in p-type CdTe detectors with Cu and Ag electrodes through electrical aging","authors":"Katsuyuki Takagi , Toshiyuki Takagi , Akifumi Koike , Hiroki Kase , Toru Aoki , Hidenori Mimura","doi":"10.1016/j.nima.2025.171236","DOIUrl":"10.1016/j.nima.2025.171236","url":null,"abstract":"<div><div>Cadmium telluride (CdTe) has been widely used for room-temperature radiation detectors, for which low dark current under high bias is a primary requirement. Building upon our previous report on Cu-electrode detectors, this study expands the investigation to silver (Ag) to verify the universality of a reversible electrical aging process and to propose a consistent electrical model governing this phenomenon. We demonstrate that applying a high reverse bias for an extended period suppresses the dark current in Ag–CdTe detectors, as well as in Cu–CdTe detectors, to a level comparable to that of conventional Schottky-type detectors. Crucially, this effect is reversible: the suppressed dark current can be restored to a high-current state by applying thermal stress (baking at 85 °C) and subsequently suppressed again by reapplying the aging process. This consistent reversibility across different Group 11 metals indicates that the dominant mechanism is not irreversible bulk diffusion but a modification of properties intrinsic to the CdTe interface. Based on these findings, we propose that the observed electrical behaviors, including the dark current suppression and the transient forward current, can be consistently explained by a model based on Fermi-level pinning.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171236"},"PeriodicalIF":1.4,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An in-beam PET scanner has been developed within the PETITION (PET for InTensive care units and Innovative protON therapy) collaboration to exploit the full potential of proton therapy by enabling either real-time range verification of proton beams or daily biological adaptation of treatment plans based on PET imaging acquired in treatment position before delivery. To optimize the design, the performance of various scanner geometries was first investigated using Monte Carlo simulations in GATE (v8.2), assessing sensitivity and spatial resolution with a 1 MBq 22Na point source and evaluating image reconstruction using a uniform 1 MBq activity-filled water cylinder and a proton-irradiated head phantom. Based on these studies, a novel C-shaped scanner was developed and simulations were compared with the experimental performance. The prototype achieved a peak simulated sensitivity of 2.9%, with measured sensitivity of 2.1%. Spatial resolution was 2.0 mm FWHM tangentially and axially, and 3.5–4.0 mm radially, showing good agreement between simulations and measurements. Multi-angle acquisition and reconstruction improved image quality, reducing artefacts and enhancing similarity to reference scans in the water cylinder study. Activity distributions from the proton-irradiated head phantom showed alignment with expected activation profiles, demonstrating reliable reconstruction of clinically relevant signals. These findings confirm the feasibility of an open-ring PET scanner for proton therapy with performance comparable to clinical PET systems while uniquely enabling in-treatment position imaging and online beam range verification. Therefore, it supports novel approaches for adaptive and biologically guided proton therapy.
{"title":"Simulation and experimental characterization of in-beam PETITION PET scanner for proton therapy","authors":"Shubhangi Makkar , Marina Béguin , Noemi Bührer , Günther Dissertori , Judith Flock , Cristian Fuentes , Keegan McNamara , Christian Ritzer , Antony Lomax , Carla Winterhalter","doi":"10.1016/j.nima.2025.171230","DOIUrl":"10.1016/j.nima.2025.171230","url":null,"abstract":"<div><div>An in-beam PET scanner has been developed within the PETITION (PET for InTensive care units and Innovative protON therapy) collaboration to exploit the full potential of proton therapy by enabling either real-time range verification of proton beams or daily biological adaptation of treatment plans based on PET imaging acquired in treatment position before delivery. To optimize the design, the performance of various scanner geometries was first investigated using Monte Carlo simulations in GATE (v8.2), assessing sensitivity and spatial resolution with a 1 MBq <sup>22</sup>Na point source and evaluating image reconstruction using a uniform 1 MBq activity-filled water cylinder and a proton-irradiated head phantom. Based on these studies, a novel C-shaped scanner was developed and simulations were compared with the experimental performance. The prototype achieved a peak simulated sensitivity of 2.9%, with measured sensitivity of 2.1%. Spatial resolution was 2.0 mm FWHM tangentially and axially, and 3.5–4.0 mm radially, showing good agreement between simulations and measurements. Multi-angle acquisition and reconstruction improved image quality, reducing artefacts and enhancing similarity to reference scans in the water cylinder study. Activity distributions from the proton-irradiated head phantom showed alignment with expected activation profiles, demonstrating reliable reconstruction of clinically relevant signals. These findings confirm the feasibility of an open-ring PET scanner for proton therapy with performance comparable to clinical PET systems while uniquely enabling in-treatment position imaging and online beam range verification. Therefore, it supports novel approaches for adaptive and biologically guided proton therapy.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171230"},"PeriodicalIF":1.4,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.nima.2025.171229
P.-A. Söderström , D.L. Balabanski , M. Cuciuc , D.M. Filipescu , I. Gheorghe , A. Kuşoğlu , C. Matei , D.A. Testov , S. Aogaki , H.T. Aslani , L. Capponi , D. Choudhury , G. Ciocan , T. Glodariu , M. Krzysiek , V. Lelasseux , R. Roy , R.F. Andrei , M. Brezeanu , R. Corbu , G.V. Turturică
Here we present the thermal neutron counter from the ELI Gamma Above Neutron Threshold setup at the Extreme Light Infrastructure – Nuclear Physics. We describe the mechanical design of the setup, the properties of the He gas counters, and the hardware data-acquisition electronics and software digital signal processing. The performance of the complete detector array is demonstrated via Geant4 and MCNP simulations, and measurements with typical neutron sources. The analysis procedure for experimental measurements are outlined with a in-beam test experiment with an beam to measure the cross-section branching ratios.
{"title":"ELIGANT-TN — ELI Gamma above neutron threshold: The thermal neutron setup","authors":"P.-A. Söderström , D.L. Balabanski , M. Cuciuc , D.M. Filipescu , I. Gheorghe , A. Kuşoğlu , C. Matei , D.A. Testov , S. Aogaki , H.T. Aslani , L. Capponi , D. Choudhury , G. Ciocan , T. Glodariu , M. Krzysiek , V. Lelasseux , R. Roy , R.F. Andrei , M. Brezeanu , R. Corbu , G.V. Turturică","doi":"10.1016/j.nima.2025.171229","DOIUrl":"10.1016/j.nima.2025.171229","url":null,"abstract":"<div><div>Here we present the thermal neutron counter from the ELI Gamma Above Neutron Threshold setup at the Extreme Light Infrastructure – Nuclear Physics. We describe the mechanical design of the setup, the properties of the <span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span>He gas counters, and the hardware data-acquisition electronics and software digital signal processing. The performance of the complete detector array is demonstrated via Geant4 and MCNP simulations, and measurements with typical neutron sources. The analysis procedure for experimental measurements are outlined with a in-beam test experiment with an <span><math><mi>α</mi></math></span> beam to measure the <span><math><mrow><msup><mrow></mrow><mrow><mn>13</mn></mrow></msup><mi>C</mi><msup><mrow><mrow><mo>(</mo><mi>α</mi><mo>,</mo><msub><mrow><mi>n</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>)</mo></mrow></mrow><mrow><mn>16</mn></mrow></msup><mi>O</mi></mrow></math></span> cross-section branching ratios.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171229"},"PeriodicalIF":1.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171228
I. Rouzi , H. Sekkat , R. Sebihi , A. Nourreddine
Accurate dose calculation is essential in high-dose-rate (HDR) brachytherapy and Monte Carlo (MC) simulation has become a key tool for validating treatment planning system (TPS) algorithms. This study aims to evaluate the egs_brachy application of the EGSnrc code for HDR brachytherapy by comparing its dosimetric results with those of the Oncentra Brachy TPS and independent radiochromic film measurements. Six scenarios, including controlled single- and multi-dwell configurations as well as a clinical endometrial brachytherapy geometry, were simulated using a detailed model of the 192Ir Flexisource. Simulations were performed in a 30 × 30 × 30 cm3 water phantom using 108 particle histories. Dose distributions were compared against TPS calculations based on the TG-43 formalism and experimental verification was performed using calibrated EBT3 films analyzed after 48 h of stabilization. Evaluation metrics included point-dose differences, isodose overlays and a gamma analysis with 3 %/3 mm criteria. Across all configurations, egs_brachy demonstrated promising agreement with TPS results, with relative differences typically below 5 %, and reproduced the expected effects of dwell-time modulation. Gamma analysis showed concordance between MC simulations and film measurements, with γ ≤ 1 for all clinically relevant regions. These findings confirm that egs_brachy provides accurate and reliable dose calculations for HDR brachytherapy and is a robust platform for validating and improving TPS-based dose computations.
{"title":"Validation of Monte Carlo-based egs_brachy simulations for HDR brachytherapy: A comparative study with Oncentra TPS and radiochromic film measurements","authors":"I. Rouzi , H. Sekkat , R. Sebihi , A. Nourreddine","doi":"10.1016/j.nima.2025.171228","DOIUrl":"10.1016/j.nima.2025.171228","url":null,"abstract":"<div><div>Accurate dose calculation is essential in high-dose-rate (HDR) brachytherapy and Monte Carlo (MC) simulation has become a key tool for validating treatment planning system (TPS) algorithms. This study aims to evaluate the egs_brachy application of the EGSnrc code for HDR brachytherapy by comparing its dosimetric results with those of the Oncentra Brachy TPS and independent radiochromic film measurements. Six scenarios, including controlled single- and multi-dwell configurations as well as a clinical endometrial brachytherapy geometry, were simulated using a detailed model of the <sup>192</sup>Ir Flexisource. Simulations were performed in a 30 × 30 × 30 cm<sup>3</sup> water phantom using 10<sup>8</sup> particle histories. Dose distributions were compared against TPS calculations based on the TG-43 formalism and experimental verification was performed using calibrated EBT3 films analyzed after 48 h of stabilization. Evaluation metrics included point-dose differences, isodose overlays and a gamma analysis with 3 %/3 mm criteria. Across all configurations, egs_brachy demonstrated promising agreement with TPS results, with relative differences typically below 5 %, and reproduced the expected effects of dwell-time modulation. Gamma analysis showed concordance between MC simulations and film measurements, with γ ≤ 1 for all clinically relevant regions. These findings confirm that egs_brachy provides accurate and reliable dose calculations for HDR brachytherapy and is a robust platform for validating and improving TPS-based dose computations.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171228"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171227
X. Xie , A. Bergamaschi, M. Brückner, M. Carulla, R. Dinapoli, S. Ebner, K. Ferjaoui, E. Fröjdh, V. Gautam, D. Greiffenberg, S. Hasanaj, J. Heymes, V. Hinger, M. Hürst, V. Kedych, T. King, S. Li, C. Lopez-Cuenca, A. Mazzoleni, D. Mezza, J. Zhang
The MÖNCH hybrid pixel detector, with a 25 m pixel pitch and fast charge-integrating readout, has demonstrated subpixel resolution capabilities, i.e., particle localization precision below the pixel pitch by exploiting the analog charge readout, for X-ray imaging and deep learning-based electron localization in electron microscopy. Fully exploiting this potential requires extensive calibration to ensure both linearity and uniformity of the pixel response, which is challenging for detectors with a large dynamic range. To overcome the limitations of conventional calibration methods, we developed an accurate and efficient correction method to achieve pixel-wise gain and nonlinearity calibration based on the backside pulsing technique. A three-dimensional lookup table, indexed by pixel X and Y coordinates and value in analog-to-digital units (ADU), was generated for all pixels across the full dynamic range, mapping the pixel response to a calibrated linear energy scale.
Compared with conventional linear calibration, the proposed method yields negligible deviations between the calibrated and nominal energies for photons and electrons. The improvement in energy resolution ranges from 4% to 22% for 15–25 keV photons and from 12% to 21% for 60–200 keV electrons. Deep learning-based electron localization demonstrates a 4% improvement in spatial resolution when using the proposed calibration method. This approach further enables rapid diagnosis of the cause of bad pixels and estimation of bump-bonding yield.
{"title":"Improved pixel-wise calibration for charge-integrating hybrid pixel detectors with performance validation","authors":"X. Xie , A. Bergamaschi, M. Brückner, M. Carulla, R. Dinapoli, S. Ebner, K. Ferjaoui, E. Fröjdh, V. Gautam, D. Greiffenberg, S. Hasanaj, J. Heymes, V. Hinger, M. Hürst, V. Kedych, T. King, S. Li, C. Lopez-Cuenca, A. Mazzoleni, D. Mezza, J. Zhang","doi":"10.1016/j.nima.2025.171227","DOIUrl":"10.1016/j.nima.2025.171227","url":null,"abstract":"<div><div>The MÖNCH hybrid pixel detector, with a 25 <span><math><mi>μ</mi></math></span>m pixel pitch and fast charge-integrating readout, has demonstrated subpixel resolution capabilities, i.e., particle localization precision below the pixel pitch by exploiting the analog charge readout, for X-ray imaging and deep learning-based electron localization in electron microscopy. Fully exploiting this potential requires extensive calibration to ensure both linearity and uniformity of the pixel response, which is challenging for detectors with a large dynamic range. To overcome the limitations of conventional calibration methods, we developed an accurate and efficient correction method to achieve pixel-wise gain and nonlinearity calibration based on the backside pulsing technique. A three-dimensional lookup table, indexed by pixel X and Y coordinates and value in analog-to-digital units (ADU), was generated for all pixels across the full dynamic range, mapping the pixel response to a calibrated linear energy scale.</div><div>Compared with conventional linear calibration, the proposed method yields negligible deviations between the calibrated and nominal energies for photons and electrons. The improvement in energy resolution ranges from 4% to 22% for 15–25 keV photons and from 12% to 21% for 60–200 keV electrons. Deep learning-based electron localization demonstrates a 4% improvement in spatial resolution when using the proposed calibration method. This approach further enables rapid diagnosis of the cause of bad pixels and estimation of bump-bonding yield.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171227"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171226
Julia Saleh-Natur , Ehud Behar , Omer Reich , Shlomit Tarem , Zvika Tarem , Alexander Vdovin , Amir Feigenboim , Liron Avioz , Aleksei Klimov , Sharon Mitrani , Solomon Margolin , Avner Kaidar , Hovhannes Agalarian , Roi Rahin , Alon Osovizky , Eran Vax , Max Ghelman
-ray bursts (GRBs) are the most energetic messengers of core-collapse supernovae and mergers of neutron stars. Although GRB detection has become commonplace, its accurate and timely localization remains challenging as non-focusing soft -ray detectors retain no directional information. GALI is a new instrument for localizing GRBs, based on the mutual occultation of hundreds of scintillators. The GALI concept is scalable and can fit on a small satellite. Here, we present an operational model of liter with 362 scintillators that localizes an 241Am laboratory source to accuracy. We compare these results with simulations, which include proper sky background, predicting a GRB localization accuracy of in space. We demonstrate with GALI results how Poisson statistics can be used to estimate localization uncertainty confidence areas on the sky.
{"title":"GALI — A GAmma-ray burst Localizing Instrument","authors":"Julia Saleh-Natur , Ehud Behar , Omer Reich , Shlomit Tarem , Zvika Tarem , Alexander Vdovin , Amir Feigenboim , Liron Avioz , Aleksei Klimov , Sharon Mitrani , Solomon Margolin , Avner Kaidar , Hovhannes Agalarian , Roi Rahin , Alon Osovizky , Eran Vax , Max Ghelman","doi":"10.1016/j.nima.2025.171226","DOIUrl":"10.1016/j.nima.2025.171226","url":null,"abstract":"<div><div><span><math><mi>γ</mi></math></span>-ray bursts (GRBs) are the most energetic messengers of core-collapse supernovae and mergers of neutron stars. Although GRB detection has become commonplace, its accurate and timely localization remains challenging as non-focusing soft <span><math><mi>γ</mi></math></span>-ray detectors retain no directional information. GALI is a new instrument for localizing GRBs, based on the mutual occultation of hundreds of scintillators. The GALI concept is scalable and can fit on a small satellite. Here, we present an operational model of <span><math><mrow><mo>∼</mo><mn>1</mn></mrow></math></span> <!--> <!-->liter with 362 scintillators that localizes an <sup>241</sup>Am laboratory source to <span><math><mrow><mo>∼</mo><mn>1</mn><mo>°</mo></mrow></math></span> accuracy. We compare these results with simulations, which include proper sky background, predicting a GRB localization accuracy of <span><math><mrow><mo>∼</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo>−</mo><msup><mrow><mn>3</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> in space. We demonstrate with GALI results how Poisson statistics can be used to estimate localization uncertainty confidence areas on the sky.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171226"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171225
Gibae Nam , Jongbeom Kim , Mookyoung Yoo , Minhyeok Son , Manhyuk Choi , Inju Yu , Hajun Bin , Euiyoung Lee , Dahyun Jin , Hyoungho Ko
This paper presents a CMOS readout application-specific integrated circuit (ASIC) employing a pseudo resistor (PR) robust to process–voltage–temperature (PVT) variations for radiation detectors, ensuring stable reset operation and improved noise performance. Conventional reset techniques often suffer from nonlinear characteristics and high sensitivity to PVT variations, resulting in inconsistent discharge behavior and degraded noise performance. To address these challenges, the proposed circuit integrates a robust PR structure that employs a dedicated bias voltage generator to maintain consistent resistance across PVT variations. The readout signal path includes a charge-sensitive amplifier (CSA), a CR–RC2 pulse shaper with pole-zero cancellation (PZC), and a discriminator, supporting both time and amplitude measurements from silicon detector signals. Targeting gamma rays at 30.8 keV and 81 keV from a Ba-133 radioactive check source, the system achieves an equivalent noise charge (ENC) of 169 e− + 4.1 e−/pF. With a detector capacitance of 3 pF, the ASIC achieves an ENC of approximately 180 e−, corresponding to an energy resolution of 1.5 keV (full-width at half-maximum, FWHM) at 30.8 keV, equivalent to 4.9 %. Fabricated in a 0.18-μm CMOS process, the chip occupies an area of 2.45 mm × 2.45 mm and demonstrates low-noise performance suitable for compact and low-capacitance radiation detection systems.
{"title":"A CMOS readout ASIC with a PVT-variation-robust pseudo resistor for radiation detectors","authors":"Gibae Nam , Jongbeom Kim , Mookyoung Yoo , Minhyeok Son , Manhyuk Choi , Inju Yu , Hajun Bin , Euiyoung Lee , Dahyun Jin , Hyoungho Ko","doi":"10.1016/j.nima.2025.171225","DOIUrl":"10.1016/j.nima.2025.171225","url":null,"abstract":"<div><div>This paper presents a CMOS readout application-specific integrated circuit (ASIC) employing a pseudo resistor (PR) robust to process–voltage–temperature (PVT) variations for radiation detectors, ensuring stable reset operation and improved noise performance. Conventional reset techniques often suffer from nonlinear characteristics and high sensitivity to PVT variations, resulting in inconsistent discharge behavior and degraded noise performance. To address these challenges, the proposed circuit integrates a robust PR structure that employs a dedicated bias voltage generator to maintain consistent resistance across PVT variations. The readout signal path includes a charge-sensitive amplifier (CSA), a CR–RC<sup>2</sup> pulse shaper with pole-zero cancellation (PZC), and a discriminator, supporting both time and amplitude measurements from silicon detector signals. Targeting gamma rays at 30.8 keV and 81 keV from a Ba-133 radioactive check source, the system achieves an equivalent noise charge (ENC) of 169 e<sup>−</sup> + 4.1 e<sup>−</sup>/pF. With a detector capacitance of 3 pF, the ASIC achieves an ENC of approximately 180 e<sup>−</sup>, corresponding to an energy resolution of 1.5 keV (full-width at half-maximum, FWHM) at 30.8 keV, equivalent to 4.9 %. Fabricated in a 0.18-μm CMOS process, the chip occupies an area of 2.45 mm × 2.45 mm and demonstrates low-noise performance suitable for compact and low-capacitance radiation detection systems.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171225"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171217
S.A. Gillespie , D. Weisshaar , A. Gade
We report on the upgrade of the electronics and data acquisition (DAQ) of the high-efficiency CAESium-iodide scintillator ARray (CAESAR) at the Facility for Rare Isotope Beams (FRIB). With the on-going capability ramp-up of FRIB, CAESAR is expected to continue to be an in-demand -ray spectrometer owing to its high detection efficiency, compactness, and modularity, enabling easy integration with additional detection and DAQ systems. Within this context, the CAESAR electronics and DAQ were upgraded to remove obsolete modules, enhance the ease of integration with external instruments, and optimize the DAQ live time. We present the comprehensive results from offline (-ray sources) and online (in-beam experiment) commissioning, characterizing the performance of CAESAR’s new electronics and DAQ.
{"title":"Upgrade of the CAESium-iodide scintillator ARray (CAESAR) electronics and data acquisition system for optimized performance at FRIB","authors":"S.A. Gillespie , D. Weisshaar , A. Gade","doi":"10.1016/j.nima.2025.171217","DOIUrl":"10.1016/j.nima.2025.171217","url":null,"abstract":"<div><div>We report on the upgrade of the electronics and data acquisition (DAQ) of the high-efficiency CAESium-iodide scintillator ARray (CAESAR) at the Facility for Rare Isotope Beams (FRIB). With the on-going capability ramp-up of FRIB, CAESAR is expected to continue to be an in-demand <span><math><mi>γ</mi></math></span>-ray spectrometer owing to its high detection efficiency, compactness, and modularity, enabling easy integration with additional detection and DAQ systems. Within this context, the CAESAR electronics and DAQ were upgraded to remove obsolete modules, enhance the ease of integration with external instruments, and optimize the DAQ live time. We present the comprehensive results from offline (<span><math><mi>γ</mi></math></span>-ray sources) and online (in-beam experiment) commissioning, characterizing the performance of CAESAR’s new electronics and DAQ.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171217"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.nima.2025.171223
Caryanne R. Wilson , Oskar Searfus , Valentin Fondement , Colton Graham , Xianfei Wen , Shaun D. Clarke , Sara A. Pozzi , Igor Jovanovic
Measurement of the fast neutron production rate in deuterium–tritium (D–T) fusion reactions is important for applications such as active interrogation, fusion diagnostics, and borehole logging. Such measurements are typically performed by neutron activation analysis of metal foils, especially copper. Copper foil activation analysis requires efficiency and energy calibrations of the detector used to measure the foil, and it relies on the detection of 511 keV gamma rays, which are prominent in the active background when neutrons are being produced. Alternatives, such as Br produced by inelastic neutron scattering on 79Br, are limited by short half-life, low-energy gamma emission, and inability to selectively measure D–T neutrons. This work describes a novel alternative approach to measure 10 MeV neutron fields based on self-activation analysis of a LaBr:Ce detector. The activity of 78Br, the activation product of the 79Br(n,2n)78Br reaction, is used to determine the neutron flux and infer the neutron production rate. We experimentally demonstrate the method with a cylindrical LaBr:Ce crystal with a diameter and height of 3.81 cm that was placed at an 18 cm distance from the neutron production point, at a 90° angle with respect to the deuteron beam in a D–T neutron generator. Operating voltage and current of the generator were adjusted to evaluate the technique’s performance over a nominal generator output range of approximately n/s. The neutron output obtained from LaBr:Ce activation agrees to within three standard deviations of the output obtained using copper activation. The self-activation technique can be conveniently employed in a variety of applications to simplify measurements of fast neutrons produced in D–T fusion reactions.
{"title":"LaBr3: Ce self-activation analysis for measuring fast neutron fields","authors":"Caryanne R. Wilson , Oskar Searfus , Valentin Fondement , Colton Graham , Xianfei Wen , Shaun D. Clarke , Sara A. Pozzi , Igor Jovanovic","doi":"10.1016/j.nima.2025.171223","DOIUrl":"10.1016/j.nima.2025.171223","url":null,"abstract":"<div><div>Measurement of the fast neutron production rate in deuterium–tritium (D–T) fusion reactions is important for applications such as active interrogation, fusion diagnostics, and borehole logging. Such measurements are typically performed by neutron activation analysis of metal foils, especially copper. Copper foil activation analysis requires efficiency and energy calibrations of the detector used to measure the foil, and it relies on the detection of 511 keV gamma rays, which are prominent in the active background when neutrons are being produced. Alternatives, such as <span><math><msup><mrow></mrow><mrow><mn>79</mn><mi>m</mi></mrow></msup></math></span>Br produced by inelastic neutron scattering on <sup>79</sup>Br, are limited by short half-life, low-energy gamma emission, and inability to selectively measure D–T neutrons. This work describes a novel alternative approach to measure <span><math><mo>≳</mo></math></span>10 MeV neutron fields based on self-activation analysis of a LaBr<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>:Ce detector. The activity of <sup>78</sup>Br, the activation product of the <sup>79</sup>Br(n,2n)<sup>78</sup>Br reaction, is used to determine the neutron flux and infer the neutron production rate. We experimentally demonstrate the method with a cylindrical LaBr<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>:Ce crystal with a diameter and height of 3.81 cm that was placed at an <span><math><mo>∼</mo></math></span>18 cm distance from the neutron production point, at a 90° angle with respect to the deuteron beam in a D–T neutron generator. Operating voltage and current of the generator were adjusted to evaluate the technique’s performance over a nominal generator output range of approximately <span><math><mrow><mrow><mo>(</mo><mn>1</mn><mo>−</mo><mn>9</mn><mo>)</mo></mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>7</mn></mrow></msup></mrow></math></span> n/s. The neutron output obtained from LaBr<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>:Ce activation agrees to within three standard deviations of the output obtained using copper activation. The self-activation technique can be conveniently employed in a variety of applications to simplify measurements of fast neutrons produced in D–T fusion reactions.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171223"},"PeriodicalIF":1.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145786625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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