In this paper, we present a review of the experiment devoted to the study of the pion photoproduction on a tensor-polarized deuteron target performed with the use of the VEPP-3 electron beam in 2013. The connection between the electro- and photoreactions on the deuteron is described. The methods for analyzing the experimental statistics and estimating the inseparable background with the use of the GEANT4 package and the GENBOS photoreaction generator are presented.
{"title":"Pion photoproduction on a deuteron at the VEPP-3 electron beam","authors":"Yu.M. Cherepennikov , E.M. Darwish , A.I. Fix , V.V. Gauzshtein , M.I. Levchuk , A. Yu Loginov , D.M. Nikolenko , I.A. Rachek , Yu.V. Shestakov , M.V. Shevelev , D.K. Toporkov , A.V. Yurchenko , S.A. Zevakov","doi":"10.1016/j.nima.2025.170316","DOIUrl":"10.1016/j.nima.2025.170316","url":null,"abstract":"<div><div>In this paper, we present a review of the experiment devoted to the study of the pion photoproduction on a tensor-polarized deuteron target performed with the use of the VEPP-3 electron beam in 2013. The connection between the electro- and photoreactions on the deuteron is described. The methods for analyzing the experimental statistics and estimating the inseparable background with the use of the GEANT4 package and the GENBOS photoreaction generator are presented.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1074 ","pages":"Article 170316"},"PeriodicalIF":1.5,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429891","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 : 2025-02-11DOI: 10.1016/j.nima.2025.170314
Dmitrii V. Gavrilenko , Alexander P. Potylitsyn , Alexey A. Tishchenko
In this paper, an approach is proposed to take into account the influence of the finite Rayleigh length of a laser beam on the number of scattered photons in the process of inverse Compton scattering. The method is based on the calculation of the overlap integral between the particle distribution density functions in electron and photon beams, taking into account the change in their sizes and in a total cross section during the collision. It is shown that this effect can have a significant impact on the total number of scattered photons, reducing it. It occurs even at the Rayleigh lengths exceeding the dimensions of the interaction region. We estimated the effect for the parameters of LUXE facility and found it to be very weak. At the same time, for Gauss-Laguerre beams, in which due to the superoscillation effect the Rayleigh length seems to be able to reach very small values, we predict that the effect of the finite Rayleigh length in Compton backscattering will be very distinct, reaching about 20% or more.
{"title":"Finite Rayleigh length in Compton backscattering","authors":"Dmitrii V. Gavrilenko , Alexander P. Potylitsyn , Alexey A. Tishchenko","doi":"10.1016/j.nima.2025.170314","DOIUrl":"10.1016/j.nima.2025.170314","url":null,"abstract":"<div><div>In this paper, an approach is proposed to take into account the influence of the finite Rayleigh length of a laser beam on the number of scattered photons in the process of inverse Compton scattering. The method is based on the calculation of the overlap integral between the particle distribution density functions in electron and photon beams, taking into account the change in their sizes and in a total cross section during the collision. It is shown that this effect can have a significant impact on the total number of scattered photons, reducing it. It occurs even at the Rayleigh lengths exceeding the dimensions of the interaction region. We estimated the effect for the parameters of LUXE facility and found it to be very weak. At the same time, for Gauss-Laguerre beams, in which due to the superoscillation effect the Rayleigh length seems to be able to reach very small values, we predict that the effect of the finite Rayleigh length in Compton backscattering will be very distinct, reaching about 20% or more.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170314"},"PeriodicalIF":1.5,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421645","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 : 2025-02-11DOI: 10.1016/j.nima.2025.170280
Chongchong Du , Jiuqing Wang , Sheng Wang , Daheng Ji , Saike Tian , Xiaoyu Li
The diffraction-limited storage rings (DLSRs) can provide an electron beam emittance below 100 , approaching the hard X-rays diffraction limit with better transverse coherence and higher brightness compared to the current light sources, to the synchrotron light users. A round beam with equal horizontal and vertical emittances can effectively mitigate intra-beam scattering effects and increase the Touschek lifetime, however a horizontally elongated flat beam is preferable for some beamline applications with brighter photon beam. Depending on the specific requirement on the experiment, some users prefer high brightness with flat beam while others prefer high horizontal coherence with round beam. To address the limitation of being able to provide only one type of operation mode as either round beam or flat beam, this paper proposes two approaches for the simultaneous operation of both modes with several bunches in flat beam and the other in round beam, namely the flat beam generation in round-beam mode and the round beam generation in flat-beam mode. As an example to demonstrate its feasibility, the lattice design, dynamic aperture, and numerical simulations of these two approaches on the latest lattice of the High Energy Photon Source (HEPS) storage ring, are presented.
{"title":"Studies of simultaneous operation both round beam and flat beam in a diffraction-limited storage ring","authors":"Chongchong Du , Jiuqing Wang , Sheng Wang , Daheng Ji , Saike Tian , Xiaoyu Li","doi":"10.1016/j.nima.2025.170280","DOIUrl":"10.1016/j.nima.2025.170280","url":null,"abstract":"<div><div>The diffraction-limited storage rings (DLSRs) can provide an electron beam emittance below 100 <span><math><mrow><mtext>pm</mtext><mo>⋅</mo><mtext>rad</mtext></mrow></math></span>, approaching the hard X-rays diffraction limit with better transverse coherence and higher brightness compared to the current light sources, to the synchrotron light users. A round beam with equal horizontal and vertical emittances can effectively mitigate intra-beam scattering effects and increase the Touschek lifetime, however a horizontally elongated flat beam is preferable for some beamline applications with brighter photon beam. Depending on the specific requirement on the experiment, some users prefer high brightness with flat beam while others prefer high horizontal coherence with round beam. To address the limitation of being able to provide only one type of operation mode as either round beam or flat beam, this paper proposes two approaches for the simultaneous operation of both modes with several bunches in flat beam and the other in round beam, namely the flat beam generation in round-beam mode and the round beam generation in flat-beam mode. As an example to demonstrate its feasibility, the lattice design, dynamic aperture, and numerical simulations of these two approaches on the latest lattice of the High Energy Photon Source (HEPS) storage ring, are presented.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170280"},"PeriodicalIF":1.5,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428120","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 : 2025-02-11DOI: 10.1016/j.nima.2025.170301
Gong Ruizhe , Shi Lei , Sun Jitao , Wang Qian , Yin Chongxian , Liu Ming
The rapid advancement of free-electron laser (FEL) technology to its fourth generation introduces significant challenges in data acquisition and alignment due to high repetition frequency beams reaching up to 1 MHz (Huang et al., 2021). Traditional software-based synchronization methods, such as Network Time Protocol (NTP), fail to provide the required timestamp accuracy under these conditions. Furthermore, the White Rabbit system, though has many advanced factors, also has limitations such as relatively high hardware requirements and inflexible master clock frequency, making it suboptimal for FEL projects.
This paper presents a novel hardware timestamp scheme based on an event timing system, widely used in large scientific facilities, which simplifies wiring complexity and reduces hardware demands at the receiver end. This scheme has been successfully implemented on the DC GUN equipment at Dalian, China, and tested under 1 MHz beam current conditions. The results demonstrate that the proposed solution can provide stable and accurate timestamps with a precision of up to 10 ns.
Our scheme's compatibility with existing event timing systems ensures ease of integration and modification, facilitating enhanced data accuracy and utilization in applications such as fast track feedback and AI-driven auto-beam tuning. This design promises significant improvements in the precision and efficiency of data alignment in high-frequency beam environments.
自由电子激光器（FEL）技术迅速发展到第四代，由于重复频率高达 1 MHz（Huang 等人，2021 年），给数据采集和对准带来了巨大挑战。传统的基于软件的同步方法，如网络时间协议（NTP），在这些条件下无法提供所需的时间戳精度。此外，"白兔 "系统虽然有许多先进因素，但也存在硬件要求相对较高、主时钟频率不灵活等局限性，使其成为 FEL 项目的次优选择。本文介绍了一种基于事件定时系统的新型硬件时间戳方案，该方案广泛应用于大型科学设施，简化了布线复杂性，降低了接收端的硬件要求。该方案已在中国大连的 DC GUN 设备上成功实施，并在 1 MHz 束流条件下进行了测试。我们的方案与现有的事件授时系统兼容，确保了集成和修改的简便性，有利于提高数据的准确性，并在快速轨道反馈和人工智能驱动的自动波束调谐等应用中加以利用。这种设计有望显著提高高频波束环境中数据对准的精度和效率。
{"title":"Preliminary experiment study of hardware time stamp method based on event timing system","authors":"Gong Ruizhe , Shi Lei , Sun Jitao , Wang Qian , Yin Chongxian , Liu Ming","doi":"10.1016/j.nima.2025.170301","DOIUrl":"10.1016/j.nima.2025.170301","url":null,"abstract":"<div><div>The rapid advancement of free-electron laser (FEL) technology to its fourth generation introduces significant challenges in data acquisition and alignment due to high repetition frequency beams reaching up to 1 MHz (Huang et al., 2021). Traditional software-based synchronization methods, such as Network Time Protocol (NTP), fail to provide the required timestamp accuracy under these conditions. Furthermore, the White Rabbit system, though has many advanced factors, also has limitations such as relatively high hardware requirements and inflexible master clock frequency, making it suboptimal for FEL projects.</div><div>This paper presents a novel hardware timestamp scheme based on an event timing system, widely used in large scientific facilities, which simplifies wiring complexity and reduces hardware demands at the receiver end. This scheme has been successfully implemented on the DC GUN equipment at Dalian, China, and tested under 1 MHz beam current conditions. The results demonstrate that the proposed solution can provide stable and accurate timestamps with a precision of up to 10 ns.</div><div>Our scheme's compatibility with existing event timing systems ensures ease of integration and modification, facilitating enhanced data accuracy and utilization in applications such as fast track feedback and AI-driven auto-beam tuning. This design promises significant improvements in the precision and efficiency of data alignment in high-frequency beam environments.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1074 ","pages":"Article 170301"},"PeriodicalIF":1.5,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-10DOI: 10.1016/j.nima.2025.170286
Dóra Erzsébet Veres , Massimo Giovannozzi , Giuliano Franchetti
Recent developments in accelerator physics and nonlinear beam dynamics have broadened the range of techniques for manipulating charged-particle beams. The effective use of adiabatic trapping and beam transport in resonance islands within the CERN Proton Synchrotron has been the basis for multiturn extraction. Moreover, the effective deployment of bent crystals in the CERN Large Hadron Collider has improved the efficiency of the collimation system and within the CERN Super Proton Synchrotron, it has significantly minimised losses at the extraction septum during slow extraction. We discuss the potential synergy of using resonance islands and bent crystals together to create a novel approach for slow extraction in circular hadron accelerators.
{"title":"An innovative method for slow extraction in circular hadron accelerators with resonance islands and bent crystals","authors":"Dóra Erzsébet Veres , Massimo Giovannozzi , Giuliano Franchetti","doi":"10.1016/j.nima.2025.170286","DOIUrl":"10.1016/j.nima.2025.170286","url":null,"abstract":"<div><div>Recent developments in accelerator physics and nonlinear beam dynamics have broadened the range of techniques for manipulating charged-particle beams. The effective use of adiabatic trapping and beam transport in resonance islands within the CERN Proton Synchrotron has been the basis for multiturn extraction. Moreover, the effective deployment of bent crystals in the CERN Large Hadron Collider has improved the efficiency of the collimation system and within the CERN Super Proton Synchrotron, it has significantly minimised losses at the extraction septum during slow extraction. We discuss the potential synergy of using resonance islands and bent crystals together to create a novel approach for slow extraction in circular hadron accelerators.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170286"},"PeriodicalIF":1.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-10DOI: 10.1016/j.nima.2025.170285
C.L. Stewart , B.L. Goldblum , R.G. Abbott , L. Appleby , B.J. Borghetti , V. Hollingshead , J.H. Whetzel
Real-time reactor power monitoring is critical for a variety of nuclear applications, spanning safety, security, operations, and maintenance. While machine learning methods have shown promise in monitoring reactor power levels, there is limited research on their efficacy in label-starved environments. The goal of this work is to assess the feasibility of classifying nuclear reactor power level using multisource data in scenarios with limited labels. Data were collected using low-resolution multisensors at four nuclear reactor facilities: two large research reactors and two TRIGA reactors. Within each pair, one reactor dataset served as the source and the other as the target in a transfer learning paradigm. Twenty-three supervised models were trained on labeled sequences of magnetic field and acceleration data from each of the target sites. Self-learning and transfer learning methods were applied to the top performing models to assess their classification performance with increasing amounts of labeled data. While reactor power level classification was achieved with a Matthews Correlation Coefficient of up to 0.739 ± 0.003 and 0.622 ± 0.009 with only 400 sequences per power state for the large research reactor and TRIGA target sites, respectively, self-learning and transfer learning leveraging source site data did not improve target classification performance. These findings suggest that alternative methods, such as higher sensitivity sensors, digital twins, or the use of physics-informed models, are required to enable high-performance classification in machine learning approaches to reactor monitoring with a dearth of target ground truth.
{"title":"Machine learning for reactor power monitoring with limited labeled data","authors":"C.L. Stewart , B.L. Goldblum , R.G. Abbott , L. Appleby , B.J. Borghetti , V. Hollingshead , J.H. Whetzel","doi":"10.1016/j.nima.2025.170285","DOIUrl":"10.1016/j.nima.2025.170285","url":null,"abstract":"<div><div>Real-time reactor power monitoring is critical for a variety of nuclear applications, spanning safety, security, operations, and maintenance. While machine learning methods have shown promise in monitoring reactor power levels, there is limited research on their efficacy in label-starved environments. The goal of this work is to assess the feasibility of classifying nuclear reactor power level using multisource data in scenarios with limited labels. Data were collected using low-resolution multisensors at four nuclear reactor facilities: two large research reactors and two TRIGA reactors. Within each pair, one reactor dataset served as the source and the other as the target in a transfer learning paradigm. Twenty-three supervised models were trained on labeled sequences of magnetic field and acceleration data from each of the target sites. Self-learning and transfer learning methods were applied to the top performing models to assess their classification performance with increasing amounts of labeled data. While reactor power level classification was achieved with a Matthews Correlation Coefficient of up to 0.739 ± 0.003 and 0.622 ± 0.009 with only 400 sequences per power state for the large research reactor and TRIGA target sites, respectively, self-learning and transfer learning leveraging source site data did not improve target classification performance. These findings suggest that alternative methods, such as higher sensitivity sensors, digital twins, or the use of physics-informed models, are required to enable high-performance classification in machine learning approaches to reactor monitoring with a dearth of target ground truth.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170285"},"PeriodicalIF":1.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-10DOI: 10.1016/j.nima.2025.170288
R. Mondal Saha , K. Banerjee , A. Chakraborty , N. Gayathri , Satya Samiran Nayak , Souvik Jana , G.R. Umapathy , R. Shil , Anirban Basak , S. Bhattacharyya , Satyajit Hazra , Saif Ahmad Khan
Natural and isotopically enriched selenium targets with a typical thickness of 6.8 mg/cm were prepared using only 20 mg of powder, which was deposited on a Mylar backing through sedimentation process. The surface morphology of these targets was examined using scanning electron microscopy, while elemental analysis was conducted through -ray photoelectron spectroscopy, energy-dispersive -ray spectroscopy and -ray diffraction technique. These analyses confirmed that the selenium retained its crystalline structure, with no elemental impurities other than carbon and oxygen. The presence of carbon and oxygen was mainly due to the polyvinyl alcohol used during fabrication. The thickness of the targets was measured via -ray attenuation using a Germanium-based Low-Energy Photon Spectrometer. These targets were subsequently employed in ion-beam-induced -ray spectroscopic measurements to investigate the nuclear level structure of Br. Even after five days of continuous beam exposure, the condition of the targets remained unchanged. X-ray diffraction analysis of the irradiated targets showed no significant changes in microstrain and crystallite size.
{"title":"Preparation of selenium target using sedimentation method for in-beam γ-ray spectroscopic measurement","authors":"R. Mondal Saha , K. Banerjee , A. Chakraborty , N. Gayathri , Satya Samiran Nayak , Souvik Jana , G.R. Umapathy , R. Shil , Anirban Basak , S. Bhattacharyya , Satyajit Hazra , Saif Ahmad Khan","doi":"10.1016/j.nima.2025.170288","DOIUrl":"10.1016/j.nima.2025.170288","url":null,"abstract":"<div><div>Natural and isotopically enriched selenium targets with a typical thickness of 6.8 mg/cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> were prepared using only 20 mg of powder, which was deposited on a Mylar backing through sedimentation process. The surface morphology of these targets was examined using scanning electron microscopy, while elemental analysis was conducted through <span><math><mi>X</mi></math></span>-ray photoelectron spectroscopy, energy-dispersive <span><math><mi>X</mi></math></span>-ray spectroscopy and <span><math><mi>X</mi></math></span>-ray diffraction technique. These analyses confirmed that the selenium retained its crystalline structure, with no elemental impurities other than carbon and oxygen. The presence of carbon and oxygen was mainly due to the polyvinyl alcohol used during fabrication. The thickness of the targets was measured via <span><math><mi>X</mi></math></span>-ray attenuation using a Germanium-based Low-Energy Photon Spectrometer. These targets were subsequently employed in ion-beam-induced <span><math><mi>γ</mi></math></span>-ray spectroscopic measurements to investigate the nuclear level structure of <span><math><msup><mrow></mrow><mrow><mn>81</mn><mo>,</mo><mn>82</mn></mrow></msup></math></span>Br. Even after five days of continuous beam exposure, the condition of the targets remained unchanged. X-ray diffraction analysis of the irradiated targets showed no significant changes in microstrain and crystallite size.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1074 ","pages":"Article 170288"},"PeriodicalIF":1.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419355","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 : 2025-02-09DOI: 10.1016/j.nima.2025.170269
Yan Wang , Kun Jiang , Kaifeng Shen , Cheng Li , Zebo Tang , Wangmei Zha
Accurate gain calibration of photomultiplier tubes is crucial because their fundamental function is to detect photon counts under low-light conditions. Traditional photomultiplier tube calibration methods require assumptions about the single photoelectron response in the charge spectrum, which are then used to construct the complete photomultiplier tube response function. However, discrepancies between these assumptions and actual single photoelectron responses can introduce calibration bias. This paper presents a novel method utilizing a joint analysis of charge and amplitude spectra. This approach enables precise calibration of the photomultiplier tube gain and provides an authentic single photoelectron response.
{"title":"High-precision calibration of gain and characterization of single-photoelectron response in photomultiplier tubes","authors":"Yan Wang , Kun Jiang , Kaifeng Shen , Cheng Li , Zebo Tang , Wangmei Zha","doi":"10.1016/j.nima.2025.170269","DOIUrl":"10.1016/j.nima.2025.170269","url":null,"abstract":"<div><div>Accurate gain calibration of photomultiplier tubes is crucial because their fundamental function is to detect photon counts under low-light conditions. Traditional photomultiplier tube calibration methods require assumptions about the single photoelectron response in the charge spectrum, which are then used to construct the complete photomultiplier tube response function. However, discrepancies between these assumptions and actual single photoelectron responses can introduce calibration bias. This paper presents a novel method utilizing a joint analysis of charge and amplitude spectra. This approach enables precise calibration of the photomultiplier tube gain and provides an authentic single photoelectron response.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170269"},"PeriodicalIF":1.5,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372223","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 : 2025-02-08DOI: 10.1016/j.nima.2025.170307
Jianming Zhang , Zhiwei Li , Jie Pang , Dikun Yang , Zhentao Yang , Zhongchang Chen , Guihua Long , Peng Du , Liping Huang , Tiantian Song , Kaidi Li , Menglin Cui , Feng Bao , Fang Liu , Yanhui Wang , Dongxiang Liu , Xiaoping Ouyang , Ran Han
Detecting the geological structure of the overburden above subway tunnels is crucial for the safe operation of the subway. Cosmic-ray muon, due to their strong penetration capabilities, offer a non-invasive method to probe underground structures. This study leverages muon absorption imaging technology to map the geological density variations of the overburden between Shenzhen Metro's Apollo South and Yuanshan Stations. A muon detector measured muon flux at 22 points within the tunnel, which, combined with preliminary geophysical drilling data, allowed for the estimation of average densities using the differential evolution global optimization algorithm. The results show that muon flux variations corresponded well with changes in marble content within the soil, reflecting density increases from 2.08 g/cm³ to 2.27 g/cm³ between measurement points 1 to 13, and decreases to 2.03 g/cm³ at points 14 and beyond due to river erosion effects. This study confirms the efficacy of muon absorption imaging in identifying density anomalies in tunnel overburden. By integrating prior geological information, the differential evolution algorithm enhances the precision and efficiency of stratification analysis. This novel approach offers significant potential for mitigating geological hazards and ensuring subway safety, with broader applications in other underground infrastructure and continuous monitoring systems. The findings could influence future standards in subway construction and operation, highlighting the importance of innovative methods in geological assessment and infrastructure safety.
{"title":"Muon absorption imaging for the density structure of metro tunnel overburden","authors":"Jianming Zhang , Zhiwei Li , Jie Pang , Dikun Yang , Zhentao Yang , Zhongchang Chen , Guihua Long , Peng Du , Liping Huang , Tiantian Song , Kaidi Li , Menglin Cui , Feng Bao , Fang Liu , Yanhui Wang , Dongxiang Liu , Xiaoping Ouyang , Ran Han","doi":"10.1016/j.nima.2025.170307","DOIUrl":"10.1016/j.nima.2025.170307","url":null,"abstract":"<div><div>Detecting the geological structure of the overburden above subway tunnels is crucial for the safe operation of the subway. Cosmic-ray muon, due to their strong penetration capabilities, offer a non-invasive method to probe underground structures. This study leverages muon absorption imaging technology to map the geological density variations of the overburden between Shenzhen Metro's Apollo South and Yuanshan Stations. A muon detector measured muon flux at 22 points within the tunnel, which, combined with preliminary geophysical drilling data, allowed for the estimation of average densities using the differential evolution global optimization algorithm. The results show that muon flux variations corresponded well with changes in marble content within the soil, reflecting density increases from 2.08 g/cm³ to 2.27 g/cm³ between measurement points 1 to 13, and decreases to 2.03 g/cm³ at points 14 and beyond due to river erosion effects. This study confirms the efficacy of muon absorption imaging in identifying density anomalies in tunnel overburden. By integrating prior geological information, the differential evolution algorithm enhances the precision and efficiency of stratification analysis. This novel approach offers significant potential for mitigating geological hazards and ensuring subway safety, with broader applications in other underground infrastructure and continuous monitoring systems. The findings could influence future standards in subway construction and operation, highlighting the importance of innovative methods in geological assessment and infrastructure safety.</div></div>","PeriodicalId":19359,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment","volume":"1073 ","pages":"Article 170307"},"PeriodicalIF":1.5,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143394661","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 : 2025-02-07DOI: 10.1016/j.nima.2025.170283
S. Weatherly , C. Jing , E. Wisniewski , D. Doran , J. Power , B. Freemire , T. Abe , T. Higo , D. Satoh
A Dielectric Disk Accelerator (DDA) is a metallic accelerating structure loaded with dielectric disks to increase coupling between cells, thus producing a high group velocity, while still maintaining a high shunt impedance. This is crucial for achieving high efficiency, high gradient acceleration in the short rf pulse acceleration regime. Recent research of these structures has produced traveling wave structures that are powered by very short (9 ns), very high power (400 MW) RF pulses using two beam acceleration at the Argonne Wakefield Accelerator Complex. In testing, these structures have withstood more than 320 MW of power and produced accelerating gradients of over 100 MV/m. A new standing wave DDA structure is being fabricated for testing on the Nextef2 test stand at KEK that will be powered by a more conventional, klystron power source. Simulation results of this structure show that at 50 MW of input power, the DDA produces a 457 MV/m gradient. It also has a large shunt impedance of 160 M/m and an r/Q of 21.6 k/m. Cold testing of this structure was conducted this summer showing a good match with the excited field but a significantly lower matching at the working frequency.
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