The article presents the results of the work involving an experimental monitor designed to measure the neutron yield of pulsed neutron sources using the activation method. Indium is used as an activation material. The procedure for developing and manufacturing the device is described, including the justification of the moderator design and the configuration of secondary radiation counters, obtained using the Geant4 tools.
The results of the experiments on registering the pulsed neutron radiation with the energies of 2.5 and 14 MeV in the range of neutron yields from 4∙104 to 4∙1011 neutrons per pulse at 15–150 cm distances between the source and the front surface of the device are presented. The influence of the main factors contributing to the uncertainty of the measurement results is considered.
A method of pulse counting is described when the counters operate under excessive ultimate count rate. The method consists in the waiting for the activity to decrease to a critical level with subsequent backward extrapolation to the initial moment of time. This algorithm allows measuring the outputs of intense pulsed neutron sources, despite the limitations on the count rate of the detectors used.
{"title":"Neutron yield monitor for pulsed radiation sources","authors":"A.P. Denisenko , E.V. Ryabeva , R.F. Ibragimov , M. Yu Mishin , YuV. Mikhailov , V.P. Tarasov","doi":"10.1016/j.nima.2026.171314","DOIUrl":"10.1016/j.nima.2026.171314","url":null,"abstract":"<div><div>The article presents the results of the work involving an experimental monitor designed to measure the neutron yield of pulsed neutron sources using the activation method. Indium is used as an activation material. The procedure for developing and manufacturing the device is described, including the justification of the moderator design and the configuration of secondary radiation counters, obtained using the Geant4 tools.</div><div>The results of the experiments on registering the pulsed neutron radiation with the energies of 2.5 and 14 MeV in the range of neutron yields from 4∙10<sup>4</sup> to 4∙10<sup>11</sup> neutrons per pulse at 15–150 cm distances between the source and the front surface of the device are presented. The influence of the main factors contributing to the uncertainty of the measurement results is considered.</div><div>A method of pulse counting is described when the counters operate under excessive ultimate count rate. The method consists in the waiting for the activity to decrease to a critical level with subsequent backward extrapolation to the initial moment of time. This algorithm allows measuring the outputs of intense pulsed neutron sources, despite the limitations on the count rate of the detectors used.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171314"},"PeriodicalIF":1.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078187","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 : 2026-01-24DOI: 10.1016/j.nima.2026.171316
D. Shatilov
The original article Zhang et al. (2025) can be logically divided into two parts: (1) the selection of main parameters for monochromatization and (2) interaction region optics design; the comment pertains only to the first part. The authors of Zhang et al. (2025) state that “The purpose of this paper is to report on the development of realistic IR optics designs for monochromatization at the FCC-ee”. However, the proposed parameters do not seem very realistic and raise many questions; due to space limitations, we will only consider the most important ones.
原文章Zhang et al.（2025）在逻辑上可以分为两个部分：(1)单色化主要参数的选择和(2)相互作用区光学设计；评论只涉及第一部分。Zhang等人（2025）的作者指出，“本文的目的是报告FCC-ee单色化实际红外光学设计的发展”。然而，所提出的参数似乎不太现实，并提出了许多问题；由于篇幅限制，我们将只考虑最重要的。
{"title":"Comment on “Monochromatization interaction region optics design for direct s-channel Higgs production at FCC-ee”","authors":"D. Shatilov","doi":"10.1016/j.nima.2026.171316","DOIUrl":"10.1016/j.nima.2026.171316","url":null,"abstract":"<div><div>The original article Zhang et al. (2025) can be logically divided into two parts: (1) the selection of main parameters for monochromatization and (2) interaction region optics design; the comment pertains only to the first part. The authors of Zhang et al. (2025) state that “The purpose of this paper is to report on the development of realistic IR optics designs for monochromatization at the FCC-ee”. However, the proposed parameters do not seem very realistic and raise many questions; due to space limitations, we will only consider the most important ones.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1086 ","pages":"Article 171316"},"PeriodicalIF":1.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081861","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 : 2026-01-24DOI: 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":"2026-01-24","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 : 2026-01-23DOI: 10.1016/j.nima.2026.171297
Omar Abdelrahman , Gianluca Aglieri Rinella , Luca Aglietta , Giacomo Alocco , Matias Antonelli , Roberto Baccomi , Francesco Barile , Pascal Becht , Franco Benotto , Stefania Maria Beolè , Marcello Borri , Daniela Bortoletto , Naseem Bouchhar , Giuseppe Eugenio Bruno , Matthew Daniel Buckland , Szymon Bugiel , Paolo Camerini , Francesca Carnesecchi , Marielle Chartier , Domenico Colella , Alessandra Zingaretti
This paper presents the characterisation and testing of the first wafer-scale monolithic stitched sensor (MOSS) prototype developed for the ALICE ITS3 upgrade that is to be installed during the LHC Long Shutdown 3 (2026–2030). The MOSS chip design is driven by the truly cylindrical detector geometry that imposes that each layer is built out of two wafer-sized, bent silicon chips. The stitching technique is employed to fabricate sensors with dimensions of 1.4 cm 25.9 cm, thinned to 50 m. The chip architecture, the in-pixel front-end, the laboratory and in-beam characterisation, the susceptibility to single-event effects, and the series testing are discussed. The testing campaign validates the design of a wafer-scale stitched sensor and the performance of the pixel matrix to be within the ITS3 requirements. The MOSS chip demonstrates the feasibility of the ITS3 detector concept and provides insights for further optimisation and development.
本文介绍了为ALICE ITS3升级开发的第一个晶圆级单片缝合传感器（MOSS）原型的特性和测试，该原型将在大型强子对撞机长停堆3（2026-2030）期间安装。MOSS芯片的设计是由真正的圆柱形探测器几何结构驱动的，它要求每层都由两个晶圆大小的弯曲硅芯片组成。采用拼接技术制备了尺寸为1.4 cm × 25.9 cm、厚度为50 μm的传感器。讨论了芯片结构、像素内前端、实验室和光束内特性、单事件效应敏感性和系列测试。测试活动验证了晶圆级缝合传感器的设计和像素矩阵的性能符合ITS3的要求。MOSS芯片证明了ITS3探测器概念的可行性，并为进一步优化和开发提供了见解。
{"title":"Characterisation of the first wafer-scale prototype for the ALICE ITS3 upgrade: The monolithic stitched sensor (MOSS)","authors":"Omar Abdelrahman , Gianluca Aglieri Rinella , Luca Aglietta , Giacomo Alocco , Matias Antonelli , Roberto Baccomi , Francesco Barile , Pascal Becht , Franco Benotto , Stefania Maria Beolè , Marcello Borri , Daniela Bortoletto , Naseem Bouchhar , Giuseppe Eugenio Bruno , Matthew Daniel Buckland , Szymon Bugiel , Paolo Camerini , Francesca Carnesecchi , Marielle Chartier , Domenico Colella , Alessandra Zingaretti","doi":"10.1016/j.nima.2026.171297","DOIUrl":"10.1016/j.nima.2026.171297","url":null,"abstract":"<div><div>This paper presents the characterisation and testing of the first wafer-scale monolithic stitched sensor (MOSS) prototype developed for the ALICE ITS3 upgrade that is to be installed during the LHC Long Shutdown 3 (2026–2030). The MOSS chip design is driven by the truly cylindrical detector geometry that imposes that each layer is built out of two wafer-sized, bent silicon chips. The stitching technique is employed to fabricate sensors with dimensions of 1.4 cm <span><math><mo>×</mo></math></span> 25.9 cm, thinned to 50 <span><math><mi>μ</mi></math></span>m. The chip architecture, the in-pixel front-end, the laboratory and in-beam characterisation, the susceptibility to single-event effects, and the series testing are discussed. The testing campaign validates the design of a wafer-scale stitched sensor and the performance of the pixel matrix to be within the ITS3 requirements. The MOSS chip demonstrates the feasibility of the ITS3 detector concept and provides insights for further optimisation and development.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1086 ","pages":"Article 171297"},"PeriodicalIF":1.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081863","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 : 2026-01-23DOI: 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":"2026-01-23","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 : 2026-01-22DOI: 10.1016/j.nima.2026.171299
F.G. Mo , Q. Tang , C. Guo , C.G. Yang , JUNO Collaboration
The Jiangmen Underground Neutrino Observatory (JUNO) is the state-of-the-art neutrino physics experiment located in South China. With 20 ktons of ultra-pure Liquid Scintillator, JUNO aims to achieve groundbreaking measurements, including the determination of the Neutrino Mass Ordering and a precise measurement of three neutrino oscillation parameters with sub-percent precision. The central detector is immersed in a Water Cherenkov Detector (WCD), which contains 40 ktons of ultrapure water and 2400 microchannel plate photomultipliers, serving dual purposes of radioactive background suppression from surrounding rock and cosmic muon tagging. The inner surface of the water pool’s wall is covered by 5 mm HDPE to prevent the rock emanating radon from diffusing into the water. Tyvek reflectors cover both the HDPE surface and the stainless lattice steel structure to enhance the light collection efficiency. A 100 t/h ultra-pure water system, which could reduce radon to mBq/m level and radium to Bq/m level, maintains high water quality and ensures optimal detector performance. A magnetic shielding system effectively mitigates geomagnetic field effects on PMT operation. The WCD demonstrates exceptional cosmic muon detection efficiency, exceeding 99% while suppressing muon-induced fast neutron backgrounds to 0.1 events per day. This paper will provide an overview of the design and current status of JUNO’s Water Cherenkov detector.
{"title":"JUNO’s Water Cherenkov Detector","authors":"F.G. Mo , Q. Tang , C. Guo , C.G. Yang , JUNO Collaboration","doi":"10.1016/j.nima.2026.171299","DOIUrl":"10.1016/j.nima.2026.171299","url":null,"abstract":"<div><div>The Jiangmen Underground Neutrino Observatory (JUNO) is the state-of-the-art neutrino physics experiment located in South China. With 20 ktons of ultra-pure Liquid Scintillator, JUNO aims to achieve groundbreaking measurements, including the determination of the Neutrino Mass Ordering and a precise measurement of three neutrino oscillation parameters with sub-percent precision. The central detector is immersed in a Water Cherenkov Detector (WCD), which contains 40 ktons of ultrapure water and 2400 microchannel plate photomultipliers, serving dual purposes of radioactive background suppression from surrounding rock and cosmic muon tagging. The inner surface of the water pool’s wall is covered by 5 mm HDPE to prevent the rock emanating radon from diffusing into the water. Tyvek reflectors cover both the HDPE surface and the stainless lattice steel structure to enhance the light collection efficiency. A 100 t/h ultra-pure water system, which could reduce radon to mBq/m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> level and radium to <span><math><mi>μ</mi></math></span>Bq/m<span><math><msup><mrow></mrow><mrow><mn>3</mn></mrow></msup></math></span> level, maintains high water quality and ensures optimal detector performance. A magnetic shielding system effectively mitigates geomagnetic field effects on PMT operation. The WCD demonstrates exceptional cosmic muon detection efficiency, exceeding 99% while suppressing muon-induced fast neutron backgrounds to <span><math><mo>∼</mo></math></span>0.1 events per day. This paper will provide an overview of the design and current status of JUNO’s Water Cherenkov detector.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171299"},"PeriodicalIF":1.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078189","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 : 2026-01-22DOI: 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":"2026-01-22","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}
Radiofrequency quadrupole (RFQ) linear accelerators with variable aperture cell parameters offer an effective means of accelerating high-intensity ion beams exceeding 100 mA and have been implemented in various RFQ designs. However, in a four-rod RFQ, the use of dielectric perturbation methods to measure the voltage distribution behind the rod electrodes is not applicable when implementing variable aperture geometries, because changes in the rod shape influence the electric field at the location of the perturbation element. Therefore, it was necessary to design the rod profile for each cell such that the electric field distribution behind the rods remains unaffected by changes in the aperture. In this study, we present a method to adjust the voltage distribution by modifying the geometry of the rod electrodes according to each cell's aperture parameters. This design approach enables the integration of variable aperture cells into a four-rod RFQ linac, significantly enhancing the achievable beam current. To ensure uniform capacitance and maintain a constant rod-electrode voltage despite variations in the average aperture radius, we developed a systematic method for shaping the rod electrodes. This method was refined using two-dimensional (2D) and three-dimensional (3D) electromagnetic field simulations to optimize the electrode cross-sectional profiles. The fabricated rod electrodes were then installed in a four-rod RFQ, and the electric field distribution was measured using the perturbation method and tuned by adjusting the base plates. As a result, the measured variation of ±1.1 % confirms that this design methodology can produce a sufficiently uniform voltage distribution for high-current beam acceleration. These results demonstrate the practical feasibility of a variable-aperture four-rod RFQ linac.
{"title":"Design and fabrication of a four-rod radio frequency quadrupole with a variable aperture","authors":"Shota Ikeda , Shunsuke Ikeda , Takeshi Kanesue , Toshiro Sakabe , Antonino Cannavo , Masahiro Okamura , Kazumasa Takahashi , Chuan Zhang , Masashi Masuoka , Horana Gamage Madhawa","doi":"10.1016/j.nima.2026.171303","DOIUrl":"10.1016/j.nima.2026.171303","url":null,"abstract":"<div><div>Radiofrequency quadrupole (RFQ) linear accelerators with variable aperture cell parameters offer an effective means of accelerating high-intensity ion beams exceeding 100 mA and have been implemented in various RFQ designs. However, in a four-rod RFQ, the use of dielectric perturbation methods to measure the voltage distribution behind the rod electrodes is not applicable when implementing variable aperture geometries, because changes in the rod shape influence the electric field at the location of the perturbation element. Therefore, it was necessary to design the rod profile for each cell such that the electric field distribution behind the rods remains unaffected by changes in the aperture. In this study, we present a method to adjust the voltage distribution by modifying the geometry of the rod electrodes according to each cell's aperture parameters. This design approach enables the integration of variable aperture cells into a four-rod RFQ linac, significantly enhancing the achievable beam current. To ensure uniform capacitance and maintain a constant rod-electrode voltage despite variations in the average aperture radius, we developed a systematic method for shaping the rod electrodes. This method was refined using two-dimensional (2D) and three-dimensional (3D) electromagnetic field simulations to optimize the electrode cross-sectional profiles. The fabricated rod electrodes were then installed in a four-rod RFQ, and the electric field distribution was measured using the perturbation method and tuned by adjusting the base plates. As a result, the measured variation of ±1.1 % confirms that this design methodology can produce a sufficiently uniform voltage distribution for high-current beam acceleration. These results demonstrate the practical feasibility of a variable-aperture four-rod RFQ linac.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171303"},"PeriodicalIF":1.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024150","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}
Dy3+-doped Lu2.5Y0.5(Al2.5Ga2.5)O12 (LuYAGG:Dy3+) single crystals were successfully grown by the optical floating-zone technique, and their structural, optical, and scintillation properties were systematically investigated as a function of Dy3+ concentration (0.5–10 mol%). X-ray diffraction confirmed that all compositions crystallized in a single-phase cubic garnet structure with high crystalline and without secondary phases. Optical transmittance spectra showed excellent transparency (∼80 %) and distinct Dy3+ absorption features corresponding to 4f–4f transitions and an O2− → Dy3+ charge-transfer band in the UV region. Photoluminescence and excitation spectra revealed two characteristic emissions at ∼484 nm (4F9/2 → 6H15/2) and ∼580 nm (4F9/2 → 6H13/2), with the strongest emission observed at moderate Dy3+ concentrations. The decrease in PL intensity, quantum yield, and decay in lifetime at higher dopant levels confirmed concentration quenching via cross-relaxation and self-absorption. Normalized radioluminescence spectra under X-ray excitation exhibited identical Dy3+ emission bands across all samples, indicating consistent emission mechanisms independent of doping level. However, pulse-height and light-yield measurements identified the 2 mol% Dy3+ crystal as exhibiting the most efficient scintillation response (∼6000 ph/MeV, ∼73 % of Bi4Ge3O12), consistent with optimal energy transfer and minimized non-radiative losses. The millisecond-scale scintillation decay reflected 4f–4f transitions typical of Dy3+, suggesting its suitability for applications prioritizing high stability and sensitivity over fast timing, such as radiation dosimetry and low-count-rate γ-ray detection.
{"title":"Growth and characterization of Dy3+-Doped LuYAGG single crystal scintillators prepared by floating-zone method","authors":"Prapon Lertloypanyachai , Prom Kantuptim , Toshiaki Kunikata , Yusuke Endo , Sunisa Jitsoonthonchaiyakul , Weerapong Chewpraditkul , Takumi Kato , Daisuke Nakauchi , Noriaki Kawaguchi , Kenichi Watanabe , Takayuki Yanagida","doi":"10.1016/j.nima.2026.171307","DOIUrl":"10.1016/j.nima.2026.171307","url":null,"abstract":"<div><div>Dy<sup>3+</sup>-doped Lu<sub>2.5</sub>Y<sub>0.5</sub>(Al<sub>2.5</sub>Ga<sub>2.5</sub>)O<sub>12</sub> (LuYAGG:Dy<sup>3+</sup>) single crystals were successfully grown by the optical floating-zone technique, and their structural, optical, and scintillation properties were systematically investigated as a function of Dy<sup>3+</sup> concentration (0.5–10 mol%). X-ray diffraction confirmed that all compositions crystallized in a single-phase cubic garnet structure with high crystalline and without secondary phases. Optical transmittance spectra showed excellent transparency (∼80 %) and distinct Dy<sup>3+</sup> absorption features corresponding to 4f–4f transitions and an O<sup>2−</sup> → Dy<sup>3+</sup> charge-transfer band in the UV region. Photoluminescence and excitation spectra revealed two characteristic emissions at ∼484 nm (<sup>4</sup>F<sub>9/2</sub> → <sup>6</sup>H<sub>15/2</sub>) and ∼580 nm (<sup>4</sup>F<sub>9/2</sub> → <sup>6</sup>H<sub>13/2</sub>), with the strongest emission observed at moderate Dy<sup>3+</sup> concentrations. The decrease in PL intensity, quantum yield, and decay in lifetime at higher dopant levels confirmed concentration quenching via cross-relaxation and self-absorption. Normalized radioluminescence spectra under X-ray excitation exhibited identical Dy<sup>3+</sup> emission bands across all samples, indicating consistent emission mechanisms independent of doping level. However, pulse-height and light-yield measurements identified the 2 mol% Dy<sup>3+</sup> crystal as exhibiting the most efficient scintillation response (∼6000 ph/MeV, ∼73 % of Bi<sub>4</sub>Ge<sub>3</sub>O<sub>12</sub>), consistent with optimal energy transfer and minimized non-radiative losses. The millisecond-scale scintillation decay reflected 4f–4f transitions typical of Dy<sup>3+</sup>, suggesting its suitability for applications prioritizing high stability and sensitivity over fast timing, such as radiation dosimetry and low-count-rate γ-ray detection.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171307"},"PeriodicalIF":1.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024226","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 : 2026-01-21DOI: 10.1016/j.nima.2026.171306
Andrea Serpolla , Andrii Tykhonov , Paul Coppin , Manbing Li , Andrii Kotenko , Enzo Putti-Garcia , Hugo Valentin Boutin , Mikhail Stolpovskiy , Jennifer Maria Frieden , Chiara Perrina , Xin Wu
The Dark MAtter Particle Explorer (DAMPE) instrument is a space-borne cosmic-ray detector, capable of measuring ion fluxes up to 500 TeV/n. This energy scale is made accessible through its calorimeter, which is the deepest currently operating in orbit. Saturation of the calorimeter readout channels starts occurring above 100 TeV of incident energy, and can significantly affect the primary energy reconstruction. Different techniques – analytical and machine-learning based – were developed to tackle this issue, focusing on the recovery of single-bar deposits, up to several hundreds of TeV. In this work, a new machine-learning technique is presented, which benefits from a unique model to correct the total deposited energy in DAMPE calorimeter. The described method is able to generalise its corrections for different ions and extend the maximum detectable incident energy to the PeV scale. This work is a continuation of the results presented in Stolpovskiyet al. (2022).
{"title":"Machine-learning correction for the calorimeter saturation of cosmic-ray ions with the Dark Matter Particle Explorer: Towards the PeV scale","authors":"Andrea Serpolla , Andrii Tykhonov , Paul Coppin , Manbing Li , Andrii Kotenko , Enzo Putti-Garcia , Hugo Valentin Boutin , Mikhail Stolpovskiy , Jennifer Maria Frieden , Chiara Perrina , Xin Wu","doi":"10.1016/j.nima.2026.171306","DOIUrl":"10.1016/j.nima.2026.171306","url":null,"abstract":"<div><div>The Dark MAtter Particle Explorer (DAMPE) instrument is a space-borne cosmic-ray detector, capable of measuring ion fluxes up to <span><math><mo>∼</mo></math></span>500 TeV/n. This energy scale is made accessible through its calorimeter, which is the deepest currently operating in orbit. Saturation of the calorimeter readout channels starts occurring above <span><math><mo>∼</mo></math></span>100 TeV of incident energy, and can significantly affect the primary energy reconstruction. Different techniques – analytical and machine-learning based – were developed to tackle this issue, focusing on the recovery of single-bar deposits, up to several hundreds of TeV. In this work, a new machine-learning technique is presented, which benefits from a unique model to correct the total deposited energy in DAMPE calorimeter. The described method is able to generalise its corrections for different ions and extend the maximum detectable incident energy to the PeV scale. This work is a continuation of the results presented in Stolpovskiyet al. (2022).</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1085 ","pages":"Article 171306"},"PeriodicalIF":1.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024232","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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