Pub Date : 2026-01-01DOI: 10.1016/j.nima.2025.171274
Xingcan Li , Hua Cai , Shubin Chen , Kun Ge , Zhehao Hua , Hao He , Jifeng Han , Peng Hu , Jinsheng Jia , Weichang Li , Sen Qian , Wang Qiao , Xusheng Qiao , Jing Ren , Xinyuan Sun , Zexuan Sui , Gao Tang , Jingping Tang , Dong Yang , Huiping Yuan , Jinlong Zhu
A novel Hadron Calorimeter (HCAL) design scheme utilizing glass scintillators to replace plastic scintillators in the analog read-out option has been proposed. To satisfy the performance indicators of Glass Scintillator Hadron Calorimeter (GSHCAL), batch testing and screening of the properties of glass scintillators are imperative. Large-size glass scintillators were batch-fabricated via the melt-quenching method, and their properties were rapidly tested and analyzed using a PMT-based test system. Over 50 % of the samples comply with the specified performance indicators. The light output (LO) of the glasses is effectively sustained above 1000 ph/MeV, while the decay time is controlled below 500 ns. This study provides an effective approach for the batch testing of large-size glass scintillators and contributes significantly to the development of GSHCAL.
{"title":"Batch testing results of GFO glass scintillators for GSHCAL","authors":"Xingcan Li , Hua Cai , Shubin Chen , Kun Ge , Zhehao Hua , Hao He , Jifeng Han , Peng Hu , Jinsheng Jia , Weichang Li , Sen Qian , Wang Qiao , Xusheng Qiao , Jing Ren , Xinyuan Sun , Zexuan Sui , Gao Tang , Jingping Tang , Dong Yang , Huiping Yuan , Jinlong Zhu","doi":"10.1016/j.nima.2025.171274","DOIUrl":"10.1016/j.nima.2025.171274","url":null,"abstract":"<div><div>A novel Hadron Calorimeter (HCAL) design scheme utilizing glass scintillators to replace plastic scintillators in the analog read-out option has been proposed. To satisfy the performance indicators of Glass Scintillator Hadron Calorimeter (GSHCAL), batch testing and screening of the properties of glass scintillators are imperative. Large-size glass scintillators were batch-fabricated via the melt-quenching method, and their properties were rapidly tested and analyzed using a PMT-based test system. Over 50 % of the samples comply with the specified performance indicators. The light output (LO) of the glasses is effectively sustained above 1000 ph/MeV, while the decay time is controlled below 500 ns. This study provides an effective approach for the batch testing of large-size glass scintillators and contributes significantly to the development of GSHCAL.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171274"},"PeriodicalIF":1.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929143","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}
Over the past several decades, external-beam radiotherapy has advanced significantly owing to sophisticated treatment-planning techniques and image-guided delivery. Nevertheless, the dose actually delivered to patients can deviate from that prescribed because of treatment-planning inaccuracies, delivery errors, and setup uncertainties. Consequently, in vivo dosimetry, a quality assurance technique that directly measures the dose delivered to patients, has been recommended internationally. In this study, we evaluated the response of a small spherical diode dosimeter (SSDD) to X-rays as a novel alternative to conventional in vivo dosimeters. The sensitive volume consists of a 1.2-mm-diameter spherical silicon junction, comprising a p-type core surrounded by an n-type layer on all sides except the bottom, forming a spherical p–n junction. Aluminum (n-side, top) and silver (p-side, bottom) electrodes are aligned along the central axis of the sphere. The SSDD (diameter = 1.7 mm) is sufficiently small for body insertion and enables real-time delivered dose measurements via the collected ionization charge. Radiation-induced response degradation was found to be linear and could be readily corrected through pre- and post-irradiation calibration. The percent depth dose (PDD) measured using the SSDD closely matched that obtained with a Farmer-type ionization chamber, reproducing the reference PDD within 2.5 % at all depths except at the nominal surface. Angular dependence evaluation revealed alternating regions of higher and lower sensitivity at steps of ∼90° for all dosimeters. Although an angular dependence was observed, its magnitude was small (≤3 %). These findings indicate that the SSDD is a suitable in vivo dosimeter for therapeutic X-ray beams.
{"title":"Fundamental X-ray characterization of a small spherical diode dosimeter for in-vivo dosimetry","authors":"Masaya Watanabe , Ren Abukawa , Shinnosuke Matsumoto","doi":"10.1016/j.nima.2025.171272","DOIUrl":"10.1016/j.nima.2025.171272","url":null,"abstract":"<div><div>Over the past several decades, external-beam radiotherapy has advanced significantly owing to sophisticated treatment-planning techniques and image-guided delivery. Nevertheless, the dose actually delivered to patients can deviate from that prescribed because of treatment-planning inaccuracies, delivery errors, and setup uncertainties. Consequently, in vivo dosimetry, a quality assurance technique that directly measures the dose delivered to patients, has been recommended internationally. In this study, we evaluated the response of a small spherical diode dosimeter (SSDD) to X-rays as a novel alternative to conventional in vivo dosimeters. The sensitive volume consists of a 1.2-mm-diameter spherical silicon junction, comprising a p-type core surrounded by an n-type layer on all sides except the bottom, forming a spherical p–n junction. Aluminum (n-side, top) and silver (p-side, bottom) electrodes are aligned along the central axis of the sphere. The SSDD (diameter = 1.7 mm) is sufficiently small for body insertion and enables real-time delivered dose measurements via the collected ionization charge. Radiation-induced response degradation was found to be linear and could be readily corrected through pre- and post-irradiation calibration. The percent depth dose (PDD) measured using the SSDD closely matched that obtained with a Farmer-type ionization chamber, reproducing the reference PDD within 2.5 % at all depths except at the nominal surface. Angular dependence evaluation revealed alternating regions of higher and lower sensitivity at steps of ∼90° for all dosimeters. Although an angular dependence was observed, its magnitude was small (≤3 %). These findings indicate that the SSDD is a suitable in vivo dosimeter for therapeutic X-ray 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 171272"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929144","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 : 2025-12-31DOI: 10.1016/j.nima.2025.171254
A. Spatafora , D. Carbone , L. La Fauci , G.A. Brischetto , D. Calvo , F. Cappuzzello , M. Cavallaro , A. Crnjac , K. Ivanković Nizić , M. Jakšić , D. Torresi , S. Tudisco , NUMEN collaboration
Large area, p–n junction, silicon carbide (SiC) detectors will be used to construct the new particle identification system of the focal plane detector of the MAGNEX magnetic spectrometer foreseeing the NUMEN experimental campaigns. The present work aims to the characterization of these devices in terms of the charge collection efficiency (CCE) both in the inner areas and along the perimeter. Ion beam induced charge technique with a proton microprobe is used for obtaining a 3D characterization of the CCE of the SiC detectors. The technique allows to draw the CCE profile with accuracy as low as along the surface area and to explore a possible dependence on the depth of the detectors by exploring a range of proton incident energies from 1.26 to 3.92 MeV. In the inner area a good uniformity in the signal collection is found, whereas an anomalous behavior is observed in two of the four edges. The present results suggest the necessity to improve the wafer cutting techniques together with a recast of the edge structures.
{"title":"Proton microbeam studies of charge collection efficiency in large area silicon carbide detectors","authors":"A. Spatafora , D. Carbone , L. La Fauci , G.A. Brischetto , D. Calvo , F. Cappuzzello , M. Cavallaro , A. Crnjac , K. Ivanković Nizić , M. Jakšić , D. Torresi , S. Tudisco , NUMEN collaboration","doi":"10.1016/j.nima.2025.171254","DOIUrl":"10.1016/j.nima.2025.171254","url":null,"abstract":"<div><div>Large area, p–n junction, silicon carbide (SiC) detectors will be used to construct the new particle identification system of the focal plane detector of the MAGNEX magnetic spectrometer foreseeing the NUMEN experimental campaigns. The present work aims to the characterization of these devices in terms of the charge collection efficiency (CCE) both in the inner areas and along the perimeter. Ion beam induced charge technique with a proton microprobe is used for obtaining a 3D characterization of the CCE of the SiC detectors. The technique allows to draw the CCE profile with accuracy as low as <span><math><mrow><mn>10</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> along the surface area and to explore a possible dependence on the depth of the detectors by exploring a range of proton incident energies from 1.26 to 3.92 MeV. In the inner area a good uniformity in the signal collection is found, whereas an anomalous behavior is observed in two of the four edges. The present results suggest the necessity to improve the wafer cutting techniques together with a recast of the edge structures.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171254"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883494","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 : 2025-12-31DOI: 10.1016/j.nima.2025.171268
J.M. Mejía Camacho , J.C. Cabanillas Noris , I. León Monzón , G. Herrera Corral
This paper proposes a methodology to predict the possible change of the power supply voltage levels over time for the photomultiplier tubes (PMT) used in scintillator plastic detectors located in High Energy Physics (HEP) experiments. Setting the appropriate voltage levels of a PMT becomes crucial to ensure an accurate reading of charge values during particle collisions. However, determining optimal voltage levels is labor-intensive and time-consuming. To minimize this challenge, we propose a set of steps utilizing an artificial Neural Network (NN) trained using the data taken by the ALICE Diffractive detector (AD) during RUN-2 of the Large Hadron Collider (LHC). The methodology involves rigorous data processing to identify and mitigate atypical data, followed by training the NN model using the data of the AD PMTs, such as charge readings, voltage applied, current consumption, and time of use. The resulting trained NN model demonstrates high accuracy in predicting voltage levels. The potential impact of this research is significant, offering a streamlined method to define PMT voltage levels, saving substantial time and effort, and contributing to obtaining accurate data-taking for later analysis in the study of physics. Moreover, this approach sets the start for future advancements in particle physics research by enabling efficient methodologies to define the voltage levels of PTMs for other ALICE detectors, ultimately contributing to enhanced data precision and analysis in future LHC runs.
{"title":"Neural network-based predicting model of power supply voltage for a scintillator plastic detector in high energy physics","authors":"J.M. Mejía Camacho , J.C. Cabanillas Noris , I. León Monzón , G. Herrera Corral","doi":"10.1016/j.nima.2025.171268","DOIUrl":"10.1016/j.nima.2025.171268","url":null,"abstract":"<div><div>This paper proposes a methodology to predict the possible change of the power supply voltage levels over time for the photomultiplier tubes (PMT) used in scintillator plastic detectors located in High Energy Physics (HEP) experiments. Setting the appropriate voltage levels of a PMT becomes crucial to ensure an accurate reading of charge values during particle collisions. However, determining optimal voltage levels is labor-intensive and time-consuming. To minimize this challenge, we propose a set of steps utilizing an artificial Neural Network (NN) trained using the data taken by the ALICE Diffractive detector (AD) during RUN-2 of the Large Hadron Collider (LHC). The methodology involves rigorous data processing to identify and mitigate atypical data, followed by training the NN model using the data of the AD PMTs, such as charge readings, voltage applied, current consumption, and time of use. The resulting trained NN model demonstrates high accuracy in predicting voltage levels. The potential impact of this research is significant, offering a streamlined method to define PMT voltage levels, saving substantial time and effort, and contributing to obtaining accurate data-taking for later analysis in the study of physics. Moreover, this approach sets the start for future advancements in particle physics research by enabling efficient methodologies to define the voltage levels of PTMs for other ALICE detectors, ultimately contributing to enhanced data precision and analysis in future LHC runs.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171268"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883487","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 : 2025-12-31DOI: 10.1016/j.nima.2025.171251
D. Ramos , X. Ledoux , L. Audouin , G. Fremont , P. Gangnant , J.C. Foy , C. Le Naour , M. Maloubier
A new experimental setup has been installed at the Time-Of-Flight area of the Neutrons For Science facility (NFS) at GANIL/SPIRAL2 for neutron beam monitoring. This setup consists of an array of Position-Sensitive Parallel-Plate Avalanche Counters (PS-PPACs) that detects both fission fragments in coincidence from secondary neutron-induced fission reactions in several U targets. The neutron energy is determined on an event-by-event basis using the Time-of-Flight method, and the reaction point within the U targets is reconstructed, enabling the measurement of the neutron beam flux and beam profile. The high transparency of the setup allows it to operate in parallel with other experiments running at NFS, thus providing an in-beam monitor of the neutron intensity. In this work, we report on the characteristics of this new setup, its operating principle, and the first results obtained using the high-intensity white-spectrum neutron beam at NFS. This beam is produced via reactions between a primary 40-MeV deuteron beam, accelerated in the SPIRAL2 LINAC, and a 8 mm-thick rotating beryllium converter target.
{"title":"A new beam monitor at NFS/SPIRAL2 based on position-sensitive PPACs detecting fission fragments from 238U(n,f)","authors":"D. Ramos , X. Ledoux , L. Audouin , G. Fremont , P. Gangnant , J.C. Foy , C. Le Naour , M. Maloubier","doi":"10.1016/j.nima.2025.171251","DOIUrl":"10.1016/j.nima.2025.171251","url":null,"abstract":"<div><div>A new experimental setup has been installed at the Time-Of-Flight area of the Neutrons For Science facility (NFS) at GANIL/SPIRAL2 for neutron beam monitoring. This setup consists of an array of Position-Sensitive Parallel-Plate Avalanche Counters (PS-PPACs) that detects both fission fragments in coincidence from secondary neutron-induced fission reactions in several <span><math><msup><mrow></mrow><mrow><mn>238</mn></mrow></msup></math></span>U targets. The neutron energy is determined on an event-by-event basis using the Time-of-Flight method, and the reaction point within the U targets is reconstructed, enabling the measurement of the neutron beam flux and beam profile. The high transparency of the setup allows it to operate in parallel with other experiments running at NFS, thus providing an in-beam monitor of the neutron intensity. In this work, we report on the characteristics of this new setup, its operating principle, and the first results obtained using the high-intensity white-spectrum neutron beam at NFS. This beam is produced via reactions between a primary 40-MeV deuteron beam, accelerated in the SPIRAL2 LINAC, and a 8 mm-thick rotating beryllium converter target.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171251"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883493","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 : 2025-12-31DOI: 10.1016/j.nima.2025.171256
Fengbo Gu , Junhui Liao , Jiangfeng Zhou , Meiyuanan Ma , Zhuo Liang , Guangpeng An , Zhaohua Peng , Jian Zheng , Lifeng Zhang , Lei Zhang , Yuanning Gao , Fabio Acerbi , Andrea Ficorella , Alberto Gola , Laura Parellada Monreal
Five FBK “NUV-HD-Cryo” SiPMs have been characterized at 7 K and 10 K, with 405 nm and 530 nm LED light, respectively. The dark count rate (DCR) was measured to be 1 Hz for the 100 mm-size SiPMs, or 0.01 Hz/mm, which is 7 orders lower than the DCR at room temperature (RT). Given the very low DCR at these cryogenic temperatures, we measured the SiPMs’ I–V curves with such a method: illuminated the SiPMs with weak light, which differs from the conventional measurements at RT. Then, we measured the photo-detection efficiency (PDE), after-pulse (AP), and cross-talk probabilities (CT) with a bias voltage ranging from overvoltage (OV) 5 to 11 V. At the OV interval (5 to 11 V), the PDE was between 20%–45%, and the AP and CT were both between 5% and 20%. With an OV higher than 10 V, the PDE would be 40%, and the AP and CT are 20%. Combining all of the measurements, we are confident that the SiPMs can be equipped as the photosensors on liquid helium detectors, including but not limited to the time projection chambers, which we have proposed in hunting for low-mass dark matter directly and beyond.
{"title":"Characterization of FBK NUV-HD-Cryo SiPMs near LHe temperature","authors":"Fengbo Gu , Junhui Liao , Jiangfeng Zhou , Meiyuanan Ma , Zhuo Liang , Guangpeng An , Zhaohua Peng , Jian Zheng , Lifeng Zhang , Lei Zhang , Yuanning Gao , Fabio Acerbi , Andrea Ficorella , Alberto Gola , Laura Parellada Monreal","doi":"10.1016/j.nima.2025.171256","DOIUrl":"10.1016/j.nima.2025.171256","url":null,"abstract":"<div><div>Five FBK “NUV-HD-Cryo” SiPMs have been characterized at 7 K and 10 K, with 405 nm and 530 nm LED light, respectively. The dark count rate (DCR) was measured to be <span><math><mo>∼</mo></math></span>1 Hz for the <span><math><mo>∼</mo></math></span>100 mm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>-size SiPMs, or 0.01 Hz/mm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span>, which is <span><math><mo>∼</mo></math></span>7 orders lower than the DCR at room temperature (RT). Given the very low DCR at these cryogenic temperatures, we measured the SiPMs’ I–V curves with such a method: illuminated the SiPMs with weak light, which differs from the conventional measurements at RT. Then, we measured the photo-detection efficiency (PDE), after-pulse (AP), and cross-talk probabilities (CT) with a bias voltage ranging from overvoltage (OV) 5 to 11 V. At the OV interval (5 to 11 V), the PDE was between 20%–45%, and the AP and CT were both between <span><math><mo>∼</mo></math></span>5% and <span><math><mo>∼</mo></math></span>20%. With an OV higher than 10 V, the PDE would be <span><math><mo>≥</mo></math></span> 40%, and the AP and CT are <span><math><mo>∼</mo></math></span>20%. Combining all of the measurements, we are confident that the SiPMs can be equipped as the photosensors on liquid helium detectors, including but not limited to the time projection chambers, which we have proposed in hunting for low-mass dark matter directly and beyond.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171256"},"PeriodicalIF":1.4,"publicationDate":"2025-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883483","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 : 2025-12-30DOI: 10.1016/j.nima.2025.171264
Pengfei Zhou , Zhirong Zeng , Zheng He , Xiao Wang , Li Lin , Ming Tang , Arsen Goukassov , Fangwei Wang , Tianjiao Liang , Erxi Feng
Designing neutron guide systems for single-crystal time-of-flight spectrometers requires balancing neutron flux, divergence, and compatibility with polarization optics. We present an automated optimization framework that integrates Monte Carlo simulations, Bayesian optimization, and a back-tracing method to systematically explore guide geometries under realistic engineering constraints. Applied to the Elastic Diffuse Spectrometer at the China Spallation Neutron Source, the framework evaluated four candidate designs to maximize flux while meeting divergence limits imposed by polarization and resolution requirements. Among the Bayesian-optimized configurations, the straight–elliptic guide offered the best overall balance of flux, divergence, and polarization performance.
{"title":"Bayesian optimization of combined ballistic neutron guides for the Elastic Diffuse Scattering spectrometer at CSNS","authors":"Pengfei Zhou , Zhirong Zeng , Zheng He , Xiao Wang , Li Lin , Ming Tang , Arsen Goukassov , Fangwei Wang , Tianjiao Liang , Erxi Feng","doi":"10.1016/j.nima.2025.171264","DOIUrl":"10.1016/j.nima.2025.171264","url":null,"abstract":"<div><div>Designing neutron guide systems for single-crystal time-of-flight spectrometers requires balancing neutron flux, divergence, and compatibility with polarization optics. We present an automated optimization framework that integrates Monte Carlo simulations, Bayesian optimization, and a back-tracing method to systematically explore guide geometries under realistic engineering constraints. Applied to the Elastic Diffuse Spectrometer at the China Spallation Neutron Source, the framework evaluated four candidate designs to maximize flux while meeting divergence limits imposed by polarization and resolution requirements. Among the Bayesian-optimized configurations, the straight–elliptic guide offered the best overall balance of flux, divergence, and polarization performance.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171264"},"PeriodicalIF":1.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924697","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}
Measurements have been made of the decay heat generated within the new-style tantalum-clad ten-plate tungsten target for the First Target Station (TS-1) of the ISIS Spallation Neutron Source. The new-style target incorporates less tantalum than the old-style target, and the decay heat is correspondingly less. Measured values of decay heat agree well with values obtained from Monte Carlo calculations.
{"title":"Measurement of decay heat in ISIS new-style TS-1 target","authors":"D.J.S. Findlay, G.P. Škoro, J.P. Chapman, J.D. Moor, S.D. Gallimore","doi":"10.1016/j.nima.2025.171263","DOIUrl":"10.1016/j.nima.2025.171263","url":null,"abstract":"<div><div>Measurements have been made of the decay heat generated within the new-style tantalum-clad ten-plate tungsten target for the First Target Station (TS-1) of the ISIS Spallation Neutron Source. The new-style target incorporates less tantalum than the old-style target, and the decay heat is correspondingly less. Measured values of decay heat agree well with values obtained from Monte Carlo calculations.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171263"},"PeriodicalIF":1.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929218","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 : 2025-12-30DOI: 10.1016/j.nima.2025.171259
S. Terui , T. Ishibashi , M. Shirai , X. Jin , M. Yao , K. Shibata , T. Abe , N. Akita , A. Natochii , Q. Liu
Currently, SuperKEKB faces the challenge of sudden beam loss (SBL), which occurs with almost no prior warning, and the causes of SBL are not yet fully understood. A damaged collimator has a reduced ability to suppress beam background noise (BG) compared to an undamaged collimator. When BG suppression decreases, operation must be stopped and the collimator jaw replaced. Therefore, a robust collimator head material is required. In this study, we investigated the material properties of copper-carbide graphite (CuGr) as a candidate collimator head material for SuperKEKB and future electron/positron colliders in terms of its electrical conductivity in the high-frequency region, secondary electron yield, outgassing rate owing to photon-stimulated desorption, and amount of dust generated by the ultrasonic cleaning of CuGr. The results were compared with the simulation results of the beam background with CuGr. According to the study findings, CuGr can be effectively used as the collimator head material. Its use in SuperKEKB and future ring colliders is expected to contribute to stable accelerator operation.
{"title":"Investigation of new collimator head material candidates for SuperKEKB and future electron/positron colliders","authors":"S. Terui , T. Ishibashi , M. Shirai , X. Jin , M. Yao , K. Shibata , T. Abe , N. Akita , A. Natochii , Q. Liu","doi":"10.1016/j.nima.2025.171259","DOIUrl":"10.1016/j.nima.2025.171259","url":null,"abstract":"<div><div>Currently, SuperKEKB faces the challenge of sudden beam loss (SBL), which occurs with almost no prior warning, and the causes of SBL are not yet fully understood. A damaged collimator has a reduced ability to suppress beam background noise (BG) compared to an undamaged collimator. When BG suppression decreases, operation must be stopped and the collimator jaw replaced. Therefore, a robust collimator head material is required. In this study, we investigated the material properties of copper-carbide graphite (CuGr) as a candidate collimator head material for SuperKEKB and future electron/positron colliders in terms of its electrical conductivity in the high-frequency region, secondary electron yield, outgassing rate owing to photon-stimulated desorption, and amount of dust generated by the ultrasonic cleaning of CuGr. The results were compared with the simulation results of the beam background with CuGr. According to the study findings, CuGr can be effectively used as the collimator head material. Its use in SuperKEKB and future ring colliders is expected to contribute to stable accelerator operation.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1084 ","pages":"Article 171259"},"PeriodicalIF":1.4,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883481","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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