Pub Date : 2026-05-01Epub 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":"2026-05-01","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 : 2026-05-01Epub Date: 2026-01-22DOI: 10.1016/j.nima.2026.171308
C. Arcaro , J. Altet , X. Aragonès , E. Barajas , J.A. Barrio , J. Buces , L. Burmistrov , E. Charbon , R. de Menezes , F. Di Pierro , L. Giangrande , S. Gómez , M. Heller , D. Hoffmann , R. Isocrate , I. Jorge , A. Lòpez , R. Manera , D. Marín , F. Marini , L.Á. Tejedor Álvarez
An international collaboration is developing the advanced camera (AdvCam), the next-generation camera for Imaging Atmospheric Cherenkov Telescopes (IACTs), designed specifically for the Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array Observatory (CTAO), which feature a segmented mirror with a diameter of 23 m and a focal length of 28 m. AdvCam incorporates cutting-edge Silicon photomultipliers and a fully digital readout system, setting new standards for performance and efficiency.
The AdvCam will feature four times more channels than the existing PMT-based camera installed at LST-1. Covering the same field of view, this upgraded camera design enables finer image resolution and significantly improves the angular precision and background noise rejection. To cope with the increase in number of channels, many technological challenges are being tackled, from low-power and high-speed integrated chip design to real-time data processing on hardware accelerators.
This technological leap will lower the energy threshold by allowing telescopes to operate at a lower minimum signal level and providing brighter images with higher signal-to-noise ratio. The increase in effective area, angular resolution and energy resolution of this new-generation of IACTs will enhance CTAO’s sensitivity, unlocking new potential for gamma-ray astronomy. In this work, we present the performance of the AdvCam’s core building blocks and its innovative architecture capable of enabling unprecedented triggering capabilities. We also showcase the latest performance results based on Monte Carlo simulations that have been tuned to reflect the latest stages of the on-going technological developments, highlighting the transformative capabilities of this next-generation IACT camera.
{"title":"The AdvCam project: Designing the future cameras for the Large-Sized Telescopes of the Cherenkov Telescope Array Observatory","authors":"C. Arcaro , J. Altet , X. Aragonès , E. Barajas , J.A. Barrio , J. Buces , L. Burmistrov , E. Charbon , R. de Menezes , F. Di Pierro , L. Giangrande , S. Gómez , M. Heller , D. Hoffmann , R. Isocrate , I. Jorge , A. Lòpez , R. Manera , D. Marín , F. Marini , L.Á. Tejedor Álvarez","doi":"10.1016/j.nima.2026.171308","DOIUrl":"10.1016/j.nima.2026.171308","url":null,"abstract":"<div><div>An international collaboration is developing the advanced camera (AdvCam), the next-generation camera for Imaging Atmospheric Cherenkov Telescopes (IACTs), designed specifically for the Large-Sized Telescopes (LSTs) of the Cherenkov Telescope Array Observatory (CTAO), which feature a segmented mirror with a diameter of 23 m and a focal length of 28 m. AdvCam incorporates cutting-edge Silicon photomultipliers and a fully digital readout system, setting new standards for performance and efficiency.</div><div>The AdvCam will feature four times more channels than the existing PMT-based camera installed at LST-1. Covering the same field of view, this upgraded camera design enables finer image resolution and significantly improves the angular precision and background noise rejection. To cope with the increase in number of channels, many technological challenges are being tackled, from low-power and high-speed integrated chip design to real-time data processing on hardware accelerators.</div><div>This technological leap will lower the energy threshold by allowing telescopes to operate at a lower minimum signal level and providing brighter images with higher signal-to-noise ratio. The increase in effective area, angular resolution and energy resolution of this new-generation of IACTs will enhance CTAO’s sensitivity, unlocking new potential for gamma-ray astronomy. In this work, we present the performance of the AdvCam’s core building blocks and its innovative architecture capable of enabling unprecedented triggering capabilities. We also showcase the latest performance results based on Monte Carlo simulations that have been tuned to reflect the latest stages of the on-going technological developments, highlighting the transformative capabilities of this next-generation IACT camera.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171308"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078179","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 : 2026-05-01Epub Date: 2026-01-24DOI: 10.1016/j.nima.2026.171315
H.Y. Wu , Z.H. Li , M. Venaruzzo , L. Colombini , D.W. Luo , H. Hua , S. Nishimura , A. Abba , Y. Venturini , C. Tintori , M. Bianchini
Modern nuclear-physics experiments increasingly demand user-programmable triggering and real-time digital pulse processing under high channel density and high counting rates, where closed or fixed vendor firmware often becomes the limiting factor. We present a general-purpose digital data acquisition platform built around an open-FPGA firmware framework that enables users to develop and deploy custom trigger and pulse-processing algorithms on commercial waveform digitizers, while preserving a unified system-level control and monitoring workflow.
The system combines digitizers covering 125 MS/s–1 GS/s with a programmable logic module for crate-level coincidence/validation triggers, providing a hierarchical trigger architecture that supports both per-channel discrimination and external multi-board coincidences. Leveraging the open-FPGA approach, we implement and validate representative real-time algorithms, including (i) a five-segment summation energy filter designed to improve pile-up resilience at high rates, and (ii) pulse-shape-discrimination processing. A multi-threaded C++ software framework with a Qt-based GUI integrates configuration, high-throughput readout, real-time monitoring, and online analysis.
Performance evaluations demonstrate excellent energy resolution, stability at high count rates, and effective pulse share discrimination. The proposed framework provides a flexible and reproducible path to algorithm-driven DAQ customization for a wide range of detector systems.
{"title":"The upgrade of the general-purpose digital data acquisition system (GDDAQ)","authors":"H.Y. Wu , Z.H. Li , M. Venaruzzo , L. Colombini , D.W. Luo , H. Hua , S. Nishimura , A. Abba , Y. Venturini , C. Tintori , M. Bianchini","doi":"10.1016/j.nima.2026.171315","DOIUrl":"10.1016/j.nima.2026.171315","url":null,"abstract":"<div><div>Modern nuclear-physics experiments increasingly demand user-programmable triggering and real-time digital pulse processing under high channel density and high counting rates, where closed or fixed vendor firmware often becomes the limiting factor. We present a general-purpose digital data acquisition platform built around an open-FPGA firmware framework that enables users to develop and deploy custom trigger and pulse-processing algorithms on commercial waveform digitizers, while preserving a unified system-level control and monitoring workflow.</div><div>The system combines digitizers covering 125 MS/s–1 GS/s with a programmable logic module for crate-level coincidence/validation triggers, providing a hierarchical trigger architecture that supports both per-channel discrimination and external multi-board coincidences. Leveraging the open-FPGA approach, we implement and validate representative real-time algorithms, including (i) a five-segment summation energy filter designed to improve pile-up resilience at high rates, and (ii) pulse-shape-discrimination processing. A multi-threaded C++ software framework with a Qt-based GUI integrates configuration, high-throughput readout, real-time monitoring, and online analysis.</div><div>Performance evaluations demonstrate excellent energy resolution, stability at high count rates, and effective pulse share discrimination. The proposed framework provides a flexible and reproducible path to algorithm-driven DAQ customization for a wide range of detector systems.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171315"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078180","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 : 2026-05-01Epub Date: 2026-01-15DOI: 10.1016/j.nima.2026.171294
Huiliang Hou , Yuefeng Huang , Hongzhong Ying , Lei He , Jiaxin Li , Zhimin Dai
When the detection area increases and the number of SiPMs grows, accurate event localization becomes increasingly critical. This paper proposes a new event localization method for large-area silicon photomultiplier (SiPM) array readout, overcoming the limitations of conventional pulse localization approaches, which rely on amplitude ratios between pulses. Due to the resistor network, signals from SiPMs at different locations undergo distortions. We proposed a simplified model, a tri-exponential model to explain these distortions and leveraged it to design a pulse-shape discrimination (PSD) algorithm that extracts 12 position-dependent features from each signal. These features are then classified using a machine learning approach to generate a model capable of accurately determining the interaction position. The new method achieves over 95% accuracy in identifying interaction positions within an 8 × 8 detector array.
{"title":"Multi-parameter digital waveform feature extraction method for event position localization","authors":"Huiliang Hou , Yuefeng Huang , Hongzhong Ying , Lei He , Jiaxin Li , Zhimin Dai","doi":"10.1016/j.nima.2026.171294","DOIUrl":"10.1016/j.nima.2026.171294","url":null,"abstract":"<div><div>When the detection area increases and the number of SiPMs grows, accurate event localization becomes increasingly critical. This paper proposes a new event localization method for large-area silicon photomultiplier (SiPM) array readout, overcoming the limitations of conventional pulse localization approaches, which rely on amplitude ratios between pulses. Due to the resistor network, signals from SiPMs at different locations undergo distortions. We proposed a simplified model, a tri-exponential model to explain these distortions and leveraged it to design a pulse-shape discrimination (PSD) algorithm that extracts 12 position-dependent features from each signal. These features are then classified using a machine learning approach to generate a model capable of accurately determining the interaction position. The new method achieves over 95% accuracy in identifying interaction positions within an 8 × 8 detector array.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171294"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024227","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 : 2026-05-01Epub Date: 2025-12-13DOI: 10.1016/j.nima.2025.171233
Filippo Falezza, Jack Bishop, Tzany Kokalova, Carl Wheldon, Stuart Pirrie, Max Conroy, Neil Curtis
This article details a comprehensive Geant4 simulation based on an analytical approach to the PrimaryGenerator class. Rather than simulating the interaction of decay with through the in-built Geant4 physics list, this simulation uses the differential cross sections of the reaction to directly produce neutrons and ions while simultaneously increasing computational efficiency. The advantage of this is the ability to generate Doppler broadened 4.4 MeV and 3.2 MeV rays from decay and hence the verification of the excited states ratio per neutron emission. Each stage of the simulation has been verified against commonly accepted results, including the mass distribution of the fission fragments. The features of the emerging neutron spectrum have been compared to commonly accepted data, confirming the validity of the simulation. The source term and the simulation template are made publicly available in conjunction with this article. Although not extensively verified, the neutron source has also been implemented, making it a straightforward framework for implementing further sources.
{"title":"Simulation and analysis of an AmBe source","authors":"Filippo Falezza, Jack Bishop, Tzany Kokalova, Carl Wheldon, Stuart Pirrie, Max Conroy, Neil Curtis","doi":"10.1016/j.nima.2025.171233","DOIUrl":"10.1016/j.nima.2025.171233","url":null,"abstract":"<div><div>This article details a comprehensive Geant4 simulation based on an analytical approach to the <span>PrimaryGenerator</span> class. Rather than simulating the interaction of <span><math><mrow><msup><mrow></mrow><mrow><mn>241</mn></mrow></msup><mtext>Am</mtext></mrow></math></span> <span><math><mi>α</mi></math></span> decay with <span><math><mrow><msup><mrow></mrow><mrow><mn>9</mn></mrow></msup><mtext>Be</mtext></mrow></math></span> through the in-built Geant4 physics list, this simulation uses the differential cross sections of the <span><math><mrow><msup><mrow></mrow><mrow><mn>9</mn></mrow></msup><mtext>Be</mtext><msup><mrow><mrow><mo>(</mo><mi>α</mi><mo>,</mo><mi>n</mi><mo>)</mo></mrow></mrow><mrow><mn>12</mn></mrow></msup><mtext>C</mtext></mrow></math></span> reaction to directly produce neutrons and <span><math><mrow><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup><mtext>C</mtext></mrow></math></span> ions while simultaneously increasing computational efficiency. The advantage of this is the ability to generate Doppler broadened 4.4 MeV and 3.2 MeV <span><math><mi>γ</mi></math></span> rays from <span><math><mrow><msup><mrow></mrow><mrow><mn>12</mn></mrow></msup><mtext>C</mtext></mrow></math></span> decay and hence the verification of the excited states ratio per neutron emission. Each stage of the simulation has been verified against commonly accepted results, including the mass distribution of the <span><math><mrow><msup><mrow></mrow><mrow><mn>241</mn></mrow></msup><mtext>Am</mtext></mrow></math></span> fission fragments. The features of the emerging neutron spectrum have been compared to commonly accepted data, confirming the validity of the simulation. The source term and the simulation template are made publicly available in conjunction with this article. Although not extensively verified, the <span><math><mrow><msup><mrow></mrow><mrow><mn>239</mn></mrow></msup><mtext>PuBe</mtext></mrow></math></span> neutron source has also been implemented, making it a straightforward framework for implementing further sources.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171233"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024229","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 : 2026-05-01Epub Date: 2026-01-23DOI: 10.1016/j.nima.2026.171309
Guodong Jiang , Yuan He , Longbo Shi , Kean Jin , Zhengrong Wu , Liepeng Sun , Chao Pan , Guirong Huang , Feng Qiu
This study investigates the feasibility of two-phase immersion cooling (2PIC) for 162.5 MHz LDMOS solid-state RF power amplifiers (SSPAs) in accelerator applications, addressing the challenges of high heat flux. Through the establishment of an electro-thermal coupling model and integration of isothermal RF experiments with immersion cooling tests, this work systematically compares the thermal management performance and RF characteristics of 2PIC against traditional water-cooled plates. Results show that under high input power (>−8 dBm), 2PIC reduces junction temperature by 35 °C and total thermal resistance by 53 % compared to water-cooled plates, while maintaining a 7.2 %–18 % increase in output power, an efficiency improvement of ∼5 % compared with water-cooled plates, and harmonic suppression better than −33 dBc. Optimization of coolant temperature and fill ratio further validates 2PIC's advantage in balancing phase-change heat transfer and RF stability. This research provides critical technical support for thermal management of next-generation accelerator SSPAs, confirming that 2PIC can simultaneously meet the dual requirements of high-power density heat dissipation and RF performance retention.
{"title":"Feasibility study of two-phase immersion cooling in accelerator solid-state RF power amplifiers","authors":"Guodong Jiang , Yuan He , Longbo Shi , Kean Jin , Zhengrong Wu , Liepeng Sun , Chao Pan , Guirong Huang , Feng Qiu","doi":"10.1016/j.nima.2026.171309","DOIUrl":"10.1016/j.nima.2026.171309","url":null,"abstract":"<div><div>This study investigates the feasibility of two-phase immersion cooling (2PIC) for 162.5 MHz LDMOS solid-state RF power amplifiers (SSPAs) in accelerator applications, addressing the challenges of high heat flux. Through the establishment of an electro-thermal coupling model and integration of isothermal RF experiments with immersion cooling tests, this work systematically compares the thermal management performance and RF characteristics of 2PIC against traditional water-cooled plates. Results show that under high input power (>−8 dBm), 2PIC reduces junction temperature by 35 °C and total thermal resistance by 53 % compared to water-cooled plates, while maintaining a 7.2 %–18 % increase in output power, an efficiency improvement of ∼5 % compared with water-cooled plates, and harmonic suppression better than −33 dBc. Optimization of coolant temperature and fill ratio further validates 2PIC's advantage in balancing phase-change heat transfer and RF stability. This research provides critical technical support for thermal management of next-generation accelerator SSPAs, confirming that 2PIC can simultaneously meet the dual requirements of high-power density heat dissipation and RF performance retention.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171309"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024151","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 : 2026-05-01Epub Date: 2026-01-14DOI: 10.1016/j.nima.2026.171281
R. Mondal Saha , K. Banerjee , N. Gayathri , Saif Ahmad Khan , S. Dalal , R. Shil , P. Pant , S.R. Singh , T. Bar , K.S. Golda
Lithium, being an alkali metal, is highly susceptible to oxidation, making the target preparation particularly challenging. To overcome this limitation, various lithium compounds-lithium carbonate (LiCO), lithium fluoride (LiF), and lithium hydroxide monohydrate (HLiO) were employed for target fabrication using sedimentation and vapour deposition technique. The stability of these compound-based targets was compared with that of metallic lithium target by evaluating their longevity upon exposure to the atmosphere. Morphological and elemental analyses were performed on the fabricated targets and the raw powder materials to examine structural changes and purity variations during fabrication. These targets were subsequently irradiated with proton beams to study the resulting neutron energy spectra. Furthermore, Monte Carlo simulations were carried out to estimate the spatial and energy distributions of proton beams transmitted through the different targets. The results indicate that lithium compounds with higher densities lead to greater energy and spatial broadening of the transmitted beams. Analysis also indicates a critical density of 2.2 g/cm, beyond which further increases in spatial and energy spread become minimal.
{"title":"Challenges and methods in fabricating solid lithium-compound targets","authors":"R. Mondal Saha , K. Banerjee , N. Gayathri , Saif Ahmad Khan , S. Dalal , R. Shil , P. Pant , S.R. Singh , T. Bar , K.S. Golda","doi":"10.1016/j.nima.2026.171281","DOIUrl":"10.1016/j.nima.2026.171281","url":null,"abstract":"<div><div>Lithium, being an alkali metal, is highly susceptible to oxidation, making the target preparation particularly challenging. To overcome this limitation, various lithium compounds-lithium carbonate (Li<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>CO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>), lithium fluoride (LiF), and lithium hydroxide monohydrate (H<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>LiO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>) were employed for target fabrication using sedimentation and vapour deposition technique. The stability of these compound-based targets was compared with that of metallic lithium target by evaluating their longevity upon exposure to the atmosphere. Morphological and elemental analyses were performed on the fabricated targets and the raw powder materials to examine structural changes and purity variations during fabrication. These targets were subsequently irradiated with proton beams to study the resulting neutron energy spectra. Furthermore, Monte Carlo simulations were carried out to estimate the spatial and energy distributions of proton beams transmitted through the different targets. The results indicate that lithium compounds with higher densities lead to greater energy and spatial broadening of the transmitted beams. Analysis also indicates a critical density of <span><math><mo>≈</mo></math></span>2.2 g/cm<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span>, beyond which further increases in spatial and energy spread become minimal.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171281"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024153","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 : 2026-05-01Epub Date: 2026-01-14DOI: 10.1016/j.nima.2026.171295
B. Davids , N.E. Esker , J. Jaeyoung , Y.K. Kim , K. Pak , M. Williams
The mean transmission efficiency of the EMMA recoil mass spectrometer at TRIUMF has been measured with 6 different angular apertures at 17 kinetic energy/charge deviations with respect to the central, reference trajectory. Measurements performed using a 148Gd source installed at the target position of the spectrometer are compared to ion-optical calculations and Monte Carlo simulations. The transmission efficiency as a function of angle and kinetic energy/charge is described empirically using piecewise Gaussian functions whose parameters are fit to the data.
{"title":"Transmission efficiency of the recoil mass spectrometer EMMA at TRIUMF","authors":"B. Davids , N.E. Esker , J. Jaeyoung , Y.K. Kim , K. Pak , M. Williams","doi":"10.1016/j.nima.2026.171295","DOIUrl":"10.1016/j.nima.2026.171295","url":null,"abstract":"<div><div>The mean transmission efficiency of the EMMA recoil mass spectrometer at TRIUMF has been measured with 6 different angular apertures at 17 kinetic energy/charge deviations with respect to the central, reference trajectory. Measurements performed using a <sup>148</sup>Gd <span><math><mi>α</mi></math></span> source installed at the target position of the spectrometer are compared to ion-optical calculations and Monte Carlo simulations. The transmission efficiency as a function of angle and kinetic energy/charge is described empirically using piecewise Gaussian functions whose parameters are fit to the data.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171295"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024233","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 : 2026-05-01Epub Date: 2026-01-17DOI: 10.1016/j.nima.2026.171298
B. Kreider , I. Cox , R. Grzywacz , J.M. Allmond , A. Augustyn , N. Braukman , P. Brionnet , A. Esmaylzadeh , J. Fischer , N. Fukuda , G. Garcia De Lorenzo , S. Go , S. Hanai , D. Hoskins , N. Imai , T.T. King , N. Kitamura , K. Kolos , A. Korgul , C. Mazzocchi , R. Yokoyama
In recent experiments, inorganic scintillators have been used to study the decays of exotic nuclei, providing an alternative to silicon detectors and enabling measurements that were previously impossible. However, proper use of these materials requires us to understand and quantify the scintillation process, specifically in response to very heavy nuclei. In this work, we show a simplified method based on the models of Birks (1951) and Meyer and Murray (1962) to parametrize the light output of inorganic scintillators in response to beams of energetic heavy ions over a broad range of energies. We test the accuracy of our parametrization approach by calculating light output and quenching factors for various ions and comparing them with experimental data from Lutetium Yttrium Orthosilicate (LYSO:Ce), a common inorganic scintillator. The Meyer–Murray model suggests that, for sufficiently heavy ions at high energies, the majority of the light output is associated with the creation of delta electrons, which are induced by the passage of the beam through the material. These delta electrons dramatically impact the response of detection systems when subject to ions with velocities typical of beams in modern fragmentation facilities. To illustrate this, we also present a qualitative estimate of the effects of delta rays on overall light output using the Birks–Meyer–Murray parametrization. The approach presented herein will serve as a basic framework for further, more rigorous studies of scintillator response to heavy ions. This work is a crucial first step in planning future experiments where energetic exotic nuclei are interacting with scintillator detectors.
{"title":"A method for estimating light quenching in inorganic scintillator detectors for radioactive ion beam experiments","authors":"B. Kreider , I. Cox , R. Grzywacz , J.M. Allmond , A. Augustyn , N. Braukman , P. Brionnet , A. Esmaylzadeh , J. Fischer , N. Fukuda , G. Garcia De Lorenzo , S. Go , S. Hanai , D. Hoskins , N. Imai , T.T. King , N. Kitamura , K. Kolos , A. Korgul , C. Mazzocchi , R. Yokoyama","doi":"10.1016/j.nima.2026.171298","DOIUrl":"10.1016/j.nima.2026.171298","url":null,"abstract":"<div><div>In recent experiments, inorganic scintillators have been used to study the decays of exotic nuclei, providing an alternative to silicon detectors and enabling measurements that were previously impossible. However, proper use of these materials requires us to understand and quantify the scintillation process, specifically in response to very heavy nuclei. In this work, we show a simplified method based on the models of Birks (1951) and Meyer and Murray (1962) to parametrize the light output of inorganic scintillators in response to beams of energetic heavy ions over a broad range of energies. We test the accuracy of our parametrization approach by calculating light output and quenching factors for various ions and comparing them with experimental data from Lutetium Yttrium Orthosilicate (LYSO:Ce), a common inorganic scintillator. The Meyer–Murray model suggests that, for sufficiently heavy ions at high energies, the majority of the light output is associated with the creation of delta electrons, which are induced by the passage of the beam through the material. These delta electrons dramatically impact the response of detection systems when subject to ions with velocities typical of beams in modern fragmentation facilities. To illustrate this, we also present a qualitative estimate of the effects of delta rays on overall light output using the Birks–Meyer–Murray parametrization. The approach presented herein will serve as a basic framework for further, more rigorous studies of scintillator response to heavy ions. This work is a crucial first step in planning future experiments where energetic exotic nuclei are interacting with scintillator detectors.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171298"},"PeriodicalIF":1.4,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024228","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 : 2026-05-01Epub 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":"2026-05-01","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}
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