Pub Date : 2026-01-09DOI: 10.1016/j.nima.2026.171283
Hanqiu Jiang , Jiajun Zhong , Changlong Chen , Junrong Zhang , Rong Du
Data reduction plays a critical role in the commissioning of the time-of-flight Small-angle Neutron Scattering (SANS) instrument at the China Spallation Neutron Source (CSNS). While the generalized SANS data reduction protocols and software have been well-established, the specific data architecture and the diverse user community of this instrument create unique need for a tailored data reduction system.
A novel software package sansRZ, also as an integral component of the RZera project, has been developed for the CSNS SANS instrument. The fundamental calculation algorithms are adopted from the robust, community-validated Mantid framework. A modular, Python based extension was built around this core to provide rapid data handling, self-diagnostic capability and better graphical user interface (GUI). An data validation module and the comprehensive logging capabilities have been developed within the Python structure to help users identify potential data issues early in the data reduction process. This article presents an overview of the software architecture as well as the main features and capabilities of the software.
{"title":"sansRZ: A python-based data reduction tool for the time-of-flight SANS instrument at CSNS","authors":"Hanqiu Jiang , Jiajun Zhong , Changlong Chen , Junrong Zhang , Rong Du","doi":"10.1016/j.nima.2026.171283","DOIUrl":"10.1016/j.nima.2026.171283","url":null,"abstract":"<div><div>Data reduction plays a critical role in the commissioning of the time-of-flight Small-angle Neutron Scattering (SANS) instrument at the China Spallation Neutron Source (CSNS). While the generalized SANS data reduction protocols and software have been well-established, the specific data architecture and the diverse user community of this instrument create unique need for a tailored data reduction system.</div><div>A novel software package <strong>sansRZ</strong>, also as an integral component of the <strong>RZera</strong> project, has been developed for the CSNS SANS instrument. The fundamental calculation algorithms are adopted from the robust, community-validated Mantid framework. A modular, Python based extension was built around this core to provide rapid data handling, self-diagnostic capability and better graphical user interface (GUI). An data validation module and the comprehensive logging capabilities have been developed within the Python structure to help users identify potential data issues early in the data reduction process. This article presents an overview of the software architecture as well as the main features and capabilities of the software.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171283"},"PeriodicalIF":1.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980300","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}
Superconducting linear accelerators in Accelerator-Driven Subcritical Systems (ADS) demand very high availability, as unplanned beam trips can endanger the spallation target and reactor. To address reliability and protection needs at the China Initiative Accelerator-Driven Subcritical System (CiADS) facility, we design and validate a System-on-Chip (SoC)-based dual-redundant master controller for magnet power supplies. The controller integrates: (i) an FPGA-resident finite-state-machine (FSM) fast-protection core for superconducting and normal-conducting magnets; (ii) a dual-master hot-standby mechanism; (iii) N+1 current-sharing with module-failure compensation; and (iv) a triggered fault-snapshot pipeline with EPICS integration. Experiments on the HIAF-iLinac testbed show failover of 500 ± 20 ms, seamless switchover with no output disturbance, <30 % CAN-bus utilization, and fault snapshots that match oscilloscope captures. These results indicate that the SoC-based controller meets CiADS protection and redundancy requirements while improving determinism, maintainability, and long-term reliability over conventional PLC/PC architectures, providing a reusable reference design for future megawatt-scale ADS facilities.
{"title":"Functional design and implementation of the CiADS power supply master controller based on System-on-Chip","authors":"Wenqi Lyu , Yuan He , Ximeng Chen , QingQing Linghu , Zhongzu Zhou , Zhijun Wang , Jiang Zhao , Detai Zhou , Zongheng Xue","doi":"10.1016/j.nima.2026.171276","DOIUrl":"10.1016/j.nima.2026.171276","url":null,"abstract":"<div><div>Superconducting linear accelerators in Accelerator-Driven Subcritical Systems (ADS) demand very high availability, as unplanned beam trips can endanger the spallation target and reactor. To address reliability and protection needs at the China Initiative Accelerator-Driven Subcritical System (CiADS) facility, we design and validate a System-on-Chip (SoC)-based dual-redundant master controller for magnet power supplies. The controller integrates: (i) an FPGA-resident finite-state-machine (FSM) fast-protection core for superconducting and normal-conducting magnets; (ii) a dual-master hot-standby mechanism; (iii) <em>N</em>+1 current-sharing with module-failure compensation; and (iv) a triggered fault-snapshot pipeline with EPICS integration. Experiments on the HIAF-iLinac testbed show failover of 500 ± 20 ms, seamless switchover with no output disturbance, <30 % CAN-bus utilization, and fault snapshots that match oscilloscope captures. These results indicate that the SoC-based controller meets CiADS protection and redundancy requirements while improving determinism, maintainability, and long-term reliability over conventional PLC/PC architectures, providing a reusable reference design for future megawatt-scale ADS facilities.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171276"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980299","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 : 2026-01-08DOI: 10.1016/j.nima.2026.171280
Marcus A.P. Miljak , Pramod Koshy , Joel N. O'Dwyer
Scientists working with XRD have limited tools to model intricacies in XRD experiments. Conventional Bragg-Brentano style powder diffractometers have robust in-built software which allow users to simulate powder XRD diffractograms. However, these programs can only account for so many modifications to powder XRD experiments. Thus, there is no all-encompassing software that allows a user to simulate a powder XRD diffractogram from an arbitrary experimental geometry, while also being able to account for all necessary X-ray physics and crystallographic information.
A modification to Geant4 Penelope Rayleigh scattering model has been performed that allows a user to simulate physically accurate coherent elastic scattering (Bragg scattering) from a powdered crystal material. This will enable scientists to simulate XRD experiments, with any geometry, as long as it can be constructed in Geant4 while also accounting for all necessary physics.
To showcase the modification, two Bragg-Brentano style diffractometers (Empyrean I and MiniFlex) have been constructed in Geant4 and were used to produce a simulated diffractogram. The simulations were undertaken with custom generated scattering form factors that account for inherent diffraction peak broadening. These results are compared to experimentally obtained diffractograms, with the analysis revealing a good match. Thus, this showcases the potential for the model to be used in different diverse XRD experiment simulations.
{"title":"Powder X-ray diffraction implementation in Geant4","authors":"Marcus A.P. Miljak , Pramod Koshy , Joel N. O'Dwyer","doi":"10.1016/j.nima.2026.171280","DOIUrl":"10.1016/j.nima.2026.171280","url":null,"abstract":"<div><div>Scientists working with XRD have limited tools to model intricacies in XRD experiments. Conventional Bragg-Brentano style powder diffractometers have robust in-built software which allow users to simulate powder XRD diffractograms. However, these programs can only account for so many modifications to powder XRD experiments. Thus, there is no all-encompassing software that allows a user to simulate a powder XRD diffractogram from an arbitrary experimental geometry, while also being able to account for all necessary X-ray physics and crystallographic information.</div><div>A modification to Geant4 Penelope Rayleigh scattering model has been performed that allows a user to simulate physically accurate coherent elastic scattering (Bragg scattering) from a powdered crystal material. This will enable scientists to simulate XRD experiments, with any geometry, as long as it can be constructed in Geant4 while also accounting for all necessary physics.</div><div>To showcase the modification, two Bragg-Brentano style diffractometers (Empyrean I and MiniFlex) have been constructed in Geant4 and were used to produce a simulated diffractogram. The simulations were undertaken with custom generated scattering form factors that account for inherent diffraction peak broadening. These results are compared to experimentally obtained diffractograms, with the analysis revealing a good match. Thus, this showcases the potential for the model to be used in different diverse XRD experiment simulations.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171280"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980301","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 : 2026-01-08DOI: 10.1016/j.nima.2026.171278
Xuanqi Zhang , Yulan Li , Zhi Zhang , Yang Tian , Zhijun Chi , Hao Ding , Hongze Zhang , Jin Lin , Yingchao Du , Chuanxiang Tang
The Very Compact Inverse Compton Scattering Gamma-ray Source (VIGAS) is a gamma-ray facility under construction at Tsinghua University. It has the ability to produce more than quasi-monoenergetic gamma photons per pulse within 10 ps. Due to ultra-short pulse length, conventional detectors and methods cannot directly measure the energy spectrum of the VIGAS. In this study, we employ the Compton scattering method to reduce the photon flux and collect the scattered photons in a specific direction using high-purity germanium (HPGe) detectors. The central energy and energy spread of the incident gamma rays can be determined by analyzing the spectrum of the scattered photons. To correct for the Doppler broadening effect during the Compton scattering process, the error transfer formula method is developed. Monte Carlo simulations show that the energy spectrum of the VIGAS can be reconstructed accurately by error transfer formula method, with a central energy accuracy better than 0.1% and energy spread accuracy better than 3%. A proof-of-principle experiment conducted at the Shanghai Laser Electron Gamma Source (SLEGS) validates the feasibility of the Compton scattering-based reconstruction method for energy spectrum measurements.
{"title":"A Compton scattering-based energy spectrum measurement method for high flux gamma-ray of VIGAS facility","authors":"Xuanqi Zhang , Yulan Li , Zhi Zhang , Yang Tian , Zhijun Chi , Hao Ding , Hongze Zhang , Jin Lin , Yingchao Du , Chuanxiang Tang","doi":"10.1016/j.nima.2026.171278","DOIUrl":"10.1016/j.nima.2026.171278","url":null,"abstract":"<div><div>The Very Compact Inverse Compton Scattering Gamma-ray Source (VIGAS) is a gamma-ray facility under construction at Tsinghua University. It has the ability to produce more than <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math></span> quasi-monoenergetic gamma photons per pulse within 10 ps. Due to ultra-short pulse length, conventional detectors and methods cannot directly measure the energy spectrum of the VIGAS. In this study, we employ the Compton scattering method to reduce the photon flux and collect the scattered photons in a specific direction using high-purity germanium (HPGe) detectors. The central energy and energy spread of the incident gamma rays can be determined by analyzing the spectrum of the scattered photons. To correct for the Doppler broadening effect during the Compton scattering process, the error transfer formula method is developed. Monte Carlo simulations show that the energy spectrum of the VIGAS can be reconstructed accurately by error transfer formula method, with a central energy accuracy better than 0.1% and energy spread accuracy better than 3%. A proof-of-principle experiment conducted at the Shanghai Laser Electron Gamma Source (SLEGS) validates the feasibility of the Compton scattering-based reconstruction method for energy spectrum measurements.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171278"},"PeriodicalIF":1.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929141","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 : 2026-01-07DOI: 10.1016/j.nima.2025.171245
H. Eick , E. Aktan , P. Brand , T. Burg , M. Cerchez , C. Mannweiler , S. Vestrick , O. Willi , A. Khoukaz
Precise knowledge of cluster-jet target beam properties like the cluster size and speed is essential for the planning, execution, and analysis of hadron physics and high-power laser experiments. Here, we present results of size distributions obtained from shadowgraphy measurements of hydrogen clusters at a state-of-the-art cluster-jet target generator. The cluster-jets were generated by expanding cryogenic hydrogen in a de Laval nozzle at various stagnation conditions in the liquid state. Near the nozzle exit, cluster sizes are found to be well below 10 m and little dependence of the cluster diameter on stagnation conditions is observed. The investigated size distributions as well as the abundance allow the estimation of the granularity of the cluster beam at possible interaction points for experiments with electron, hadron, or laser beams.
{"title":"Determination of hydrogen cluster size distributions of a cluster-jet target using shadowgraphy","authors":"H. Eick , E. Aktan , P. Brand , T. Burg , M. Cerchez , C. Mannweiler , S. Vestrick , O. Willi , A. Khoukaz","doi":"10.1016/j.nima.2025.171245","DOIUrl":"10.1016/j.nima.2025.171245","url":null,"abstract":"<div><div>Precise knowledge of cluster-jet target beam properties like the cluster size and speed is essential for the planning, execution, and analysis of hadron physics and high-power laser experiments. Here, we present results of size distributions obtained from shadowgraphy measurements of hydrogen clusters at a state-of-the-art cluster-jet target generator. The cluster-jets were generated by expanding cryogenic hydrogen in a de Laval nozzle at various stagnation conditions in the liquid state. Near the nozzle exit, cluster sizes are found to be well below 10 <span><math><mi>μ</mi></math></span>m and little dependence of the cluster diameter on stagnation conditions is observed. The investigated size distributions as well as the abundance allow the estimation of the granularity of the cluster beam at possible interaction points for experiments with electron, hadron, or laser beams.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171245"},"PeriodicalIF":1.4,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929142","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 : 2026-01-06DOI: 10.1016/j.nima.2025.171270
Wei Tian, Donglian Xu
{"title":"Corrigendum to “A camera system for real-time optical calibration of water-based neutrino telescopes” [Nucl. Instrum. Meth. A 1076 (2025) 170489]","authors":"Wei Tian, Donglian Xu","doi":"10.1016/j.nima.2025.171270","DOIUrl":"10.1016/j.nima.2025.171270","url":null,"abstract":"","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171270"},"PeriodicalIF":1.4,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929145","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 : 2026-01-05DOI: 10.1016/j.nima.2026.171275
S. Dalal , K. Banerjee , G. Mukerjee , T.K. Rana , P. Roy , S. Manna , S. Roy , R. Shil , S.R. Singh , P. Pant , S. Adhikary , S. Kundu , T.K. Ghosh , A. Sen , R. Pandey , B. Layek , S. Sadhukhan , S. Dawn
The -ray spectroscopy of light mass nuclei Li, Be, 11B, and C is demonstrated using a deuterated liquid scintillator detector EJ315 of dimension 2. The measured pulse height distribution, which gives the Compton continuum, was unfolded using a response matrix prepared with Geant4 simulation. This approach provides full energy information of the incident -rays which was verified using various standard sources. A comparison of unfolded -ray spectra with those measured using the CeBr detector of same dimension was found to be in agreement.
{"title":"Gamma-ray spectroscopy using deuterated liquid scintillator EJ315 detector","authors":"S. Dalal , K. Banerjee , G. Mukerjee , T.K. Rana , P. Roy , S. Manna , S. Roy , R. Shil , S.R. Singh , P. Pant , S. Adhikary , S. Kundu , T.K. Ghosh , A. Sen , R. Pandey , B. Layek , S. Sadhukhan , S. Dawn","doi":"10.1016/j.nima.2026.171275","DOIUrl":"10.1016/j.nima.2026.171275","url":null,"abstract":"<div><div>The <span><math><mi>γ</mi></math></span>-ray spectroscopy of light mass nuclei <span><math><msup><mrow></mrow><mrow><mn>7</mn></mrow></msup></math></span>Li, <span><math><msup><mrow></mrow><mrow><mn>7</mn><mo>,</mo><mn>8</mn></mrow></msup></math></span>Be, <sup>11</sup>B, and <span><math><msup><mrow></mrow><mrow><mn>11</mn><mo>,</mo><mn>12</mn></mrow></msup></math></span>C is demonstrated using a deuterated liquid scintillator detector EJ315 of dimension 2<span><math><mrow><msup><mrow></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup><mo>×</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup></mrow></math></span>. The measured pulse height distribution, which gives the Compton continuum, was unfolded using a response matrix prepared with Geant4 simulation. This approach provides full energy information of the incident <span><math><mi>γ</mi></math></span>-rays which was verified using various standard sources. A comparison of unfolded <span><math><mi>γ</mi></math></span>-ray spectra with those measured using the CeBr<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> detector of same dimension was found to be in agreement.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171275"},"PeriodicalIF":1.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924698","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 : 2026-01-05DOI: 10.1016/j.nima.2025.171269
H. Ramm , P. Simon , P. Alexaki , C. Arran , R. Bingham , A. Goillot , J.T. Gudmundsson , J.W.D. Halliday , B. Lloyd , E.E. Los , V. Stergiou , S. Zhang , G. Gregori , N. Charitonidis
A robust and flexible architecture capable of providing real-time analysis on diagnostic data is of crucial importance to physics experiments. In this paper, we present such an online framework, used in June 2025 as part of the HRMT-68 experiment, performed at the HiRadMat facility at CERN, using the Super Proton Synchrotron (SPS) beam line. HRMT-68 was a fixed-target laboratory astrophysics experiment aiming to identify plasma instabilities generated by a relativistic electron–positron beam during traversal of an argon plasma. This framework was essential for experimental data acquisition and analysis, and can be adapted for a broad range of similar-scale experiments with a variety of experimental diagnostics, even those without a standard direct network communication interface. The developed framework’s customizable design enabled us to rapidly observe and extract emergent features from a diverse range of diagnostic data. Simultaneously, its modularity allowed for a quick introduction of new diagnostic devices and the modification of our analysis as features of interest were identified. As a result, we were able to effectively diagnose equipment malfunction, and infer the beam’s response to varying bunch duration, beam intensity, and the plasma state without resorting to offline analysis, at which time adjustment or improvement would have been impossible. We present the features of this agile framework, whose codebase we have made publicly available so that it may be adapted for future experiments with minimal modification.
{"title":"An online data analysis framework for small-scale physics experiments","authors":"H. Ramm , P. Simon , P. Alexaki , C. Arran , R. Bingham , A. Goillot , J.T. Gudmundsson , J.W.D. Halliday , B. Lloyd , E.E. Los , V. Stergiou , S. Zhang , G. Gregori , N. Charitonidis","doi":"10.1016/j.nima.2025.171269","DOIUrl":"10.1016/j.nima.2025.171269","url":null,"abstract":"<div><div>A robust and flexible architecture capable of providing real-time analysis on diagnostic data is of crucial importance to physics experiments. In this paper, we present such an online framework, used in June 2025 as part of the HRMT-68 experiment, performed at the HiRadMat facility at CERN, using the Super Proton Synchrotron (SPS) beam line. HRMT-68 was a fixed-target laboratory astrophysics experiment aiming to identify plasma instabilities generated by a relativistic electron–positron beam during traversal of an argon plasma. This framework was essential for experimental data acquisition and analysis, and can be adapted for a broad range of similar-scale experiments with a variety of experimental diagnostics, even those without a standard direct network communication interface. The developed framework’s customizable design enabled us to rapidly observe and extract emergent features from a diverse range of diagnostic data. Simultaneously, its modularity allowed for a quick introduction of new diagnostic devices and the modification of our analysis as features of interest were identified. As a result, we were able to effectively diagnose equipment malfunction, and infer the beam’s response to varying bunch duration, beam intensity, and the plasma state without resorting to offline analysis, at which time adjustment or improvement would have been impossible. We present the features of this agile framework, whose codebase we have made publicly available so that it may be adapted for future experiments with minimal modification.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171269"},"PeriodicalIF":1.4,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145898015","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 : 2026-01-02DOI: 10.1016/j.nima.2025.171271
J. Va'vra
Persistent photon and single-electron emissions - in the form of “electron trains” and localized “hot spots” - have been observed in multiple dual-phase liquid xenon (LXe) time projection chambers (TPCs), often persisting long after ionizing events. We show that these phenomena are naturally explained by photon-triggered single-electron emission from resistive mixed-oxide films on stainless-steel (SS304 or s.s.) wires, which behave as leaky capacitors with long RC time constants at LXe temperature. Positive ions landing on these oxides can further enhance local fields and drive Malter-like electron emission. We outline the materials physics (Cr2O3/Cr2O3-x/Cr(OH)3 mosaics), quantify expected time scales (∼1 s under illumination), and demonstrate how small damaged regions with enhanced QE can produce persistent hot spots.
{"title":"Electron emissions and hot spots in dual-phase LXe TPCs","authors":"J. Va'vra","doi":"10.1016/j.nima.2025.171271","DOIUrl":"10.1016/j.nima.2025.171271","url":null,"abstract":"<div><div>Persistent photon and single-electron emissions - in the form of “electron trains” and localized “hot spots” - have been observed in multiple dual-phase liquid xenon (LXe) time projection chambers (TPCs), often persisting long after ionizing events. We show that these phenomena are naturally explained by photon-triggered single-electron emission from resistive mixed-oxide films on stainless-steel (SS304 or s.s.) wires, which behave as leaky capacitors with long RC time constants at LXe temperature. Positive ions landing on these oxides can further enhance local fields and drive Malter-like electron emission. We outline the materials physics (Cr<sub>2</sub>O<sub>3</sub>/Cr<sub>2</sub>O<sub>3-x</sub>/Cr(OH)<sub>3</sub> mosaics), quantify expected time scales (∼1 s under illumination), and demonstrate how small damaged regions with enhanced QE can produce persistent hot spots.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171271"},"PeriodicalIF":1.4,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924694","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 : 2026-01-02DOI: 10.1016/j.nima.2025.171273
J. Peña-Rodríguez, J. Förtsch, C. Pauly, K.-H. Kampert
The quantitative measurement of energy deposits in particle detectors, particularly in calorimeters, is usually accomplished with the help of Analog-to-Digital converters (ADCs) due to their precision, wide measurement range, and good linearity. However, drawbacks such as power consumption, data volume, and bandwidth limit their use in the next generation of high-energy physics experiments. Time-over-threshold (ToT) systems offer simplicity, low power consumption, ease of integration, and a wide bandwidth, but they lack precision, linearity, and dynamic range. In this work, we propose a shaper circuit that improves the weaknesses of ToT systems without sacrificing performance. The shaper contains a fast diode that discharges a capacitor with a constant current, thereby linearizing the trailing edge of the input signal. The three tested capacitances (47 pF, 100 pF, and 330 pF) probed the linearization concept with R-squared values between the linear model and the data around 0.99. The shaper precision and resolution improve by increasing the capacitance, but also the dead time. The shaper bandwidth was 150 MHz for 47 pF. We simulated and implemented the shaper concept in the readout system of the Ring Imaging Cherenkov detector of the Compressed Baryonic Matter experiment at FAIR.
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