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Nuclear Science and Techniques 2024年第1期35卷 45-58页

作者： Yi-Xing Lu wen-cheng fang Yu-Sen Guo Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800China University of Chinese Academy of Sciences Beijing 101408China Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204China Shanghai Key Laboratory of Cryogenics&Superconducting RF Technology Shanghai 201800China ShanghaiTech University Shanghai 201210China

Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator *** RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this *** RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary *** develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a *** aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance,fabrication procedure,and feasibility of the tuning ***,a new tuning algorithm based on the response matrix and least-squares method is developed,which yields favorable results based on the prototype,i.e.,the errors of the dipole and quadrupole components reduced to a low level after several tuning *** from the conceptual design and techniques obtained from the prototype,the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step.

关键词： Compact proton injector RFQ IH-DTL High gradient Tuning

Design and preliminary test of the LLRF in C band high-gradient test facility for SXFEL

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Nuclear Science and Techniques 2020年第10期31卷 43-54页

作者： cheng-cheng Xiao Jun-Qiang Zhang Jian-Hao Tan wen-cheng fang Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

This paper describes the design and preliminary test of the low-level radio frequency(LLRF)part of the C band high-gradient test facility for the Shanghai Soft X-ray Free-Electron Laser(SXFEL)-Linear Accelerator(LINAC).Before installation,the accelerating structures should be tested and *** the conditioning process,breakdown detection is needed to protect the accelerating structures and klystron from *** PCI extensions for instrumentation-based LLRF system and auto-conditioning algorithm are designed and applied in the LLRF part of the C band high-gradient test *** C band accelerating structures and 1 pulse compressor have completed conditioning and were installed in the SXFEL-LINAC.

关键词： Accelerating structure High gradient C band Breakdown LLRF Conditioning

Design,fabrication,and cold test of an S-band high-gradient accelerating structure for compact proton therapy facility

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Nuclear Science and Techniques 2021年第4期32卷 38-48页

作者： Yu Zhang wen-cheng fang Xiao-Xia Huang Jian-Hao Tan cheng Wang Chao-Peng Wang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China ShanghaiTech University Shanghai 201210China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

An S-band high-gradient accelerating structure is designed for a proton therapy linear accelerator(linac)to accommodate the new development of compact,singleroom facilities and ultra-high dose rate(FLASH)*** optimize the design,an efficient optimization scheme is applied to improve the simulation *** S-band accelerating structure with 2856 MHz is designed with a low beta of 0.38,which is a difficult structure to achieve for a linac accelerating proton particles from 70 to 250 MeV,as a high gradient up to 50 MV/m is required.A special design involving a dual-feed coupler eliminates the dipole field *** paper presents all the details pertaining to the design,fabrication,and cold test results of the S-band high-gradient accelerating structure.

关键词： S-band High gradient Accelerating structure Compact Single-room facility Dual-feed coupler Cold test

Design optimization and cold RF test of a 2.6-cell cryogenic RF gun

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Nuclear Science and Techniques 2021年第9期32卷 84-93页

作者： cheng Wang Jian-Hao Tan Xiao-Xia Huang Yi-Xing Lu Lin Wang wen-cheng fang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China

To further improve the performance of acceler-ators,the first cryogenic normal-conducting RF gun in China was designed and *** a new and attractive trend,this optimized cryogenic RF gun can generate a low-emittance beam with a short-driven laser pulse because of its promising high gradient on the *** this paper,optimization of the RF design and beam dynamics,including suppression of the peak RF field and elimination of the multipole mode,is *** addi-tion,the emittance growth caused by the alignment devi-ation and RF jitter is *** the gun was manufactured,a cold test was conducted at both room temperature and cryogenic *** room tempera-ture,the field distribution was obtained by the bead pull *** cryogenic conditions,the RF properties,such as the coupling coefficient and quality factor,varied with *** test results agreed with the *** the cryogenic test,vibration measurements were *** vibration isolation,a maximum vibration of 50 lm was *** cold test results are the basis of the following high-power test.

关键词： Photoinjector Cryogenic structure C-band Cold test

Study and design of cryogenic accelerating structure and RF optimization of single cell for SXFEL energy upgrading

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Radiation Detection Technology and Methods 2022年第3期6卷 367-374页

作者： Zi-He Gao cheng Wang wen-cheng fang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

Purpose Recent researches of RF gun operated at cryogenic temperature have many advantages to serve as the technology to realize the future light *** order to further improve the accelerating gradient of accelerators,the cryogenic acceleration structure is ***/methodology/approach The cryogenic accelerating structure is studied by numerical analysis and *** In this paper,the low-temperature characteristics of the material are analyzedﬁrstly,and then the preliminary design scheme of the cavity is proposed according to the analysis ***,the prototype with RF coupler is designed and optimized systemically,and the modiﬁed Poynting vector distribution is ***,the high-power test based on existed setup is also ***/value The study of the cryogenic structure in this paper is helpful for improving the accelerating gradient and developing compact accelerators.

关键词： Cryogenic structure C-band Copper Residual resistance ratio(RRR) RF breakdown

Static superconducting gantry‑based proton CT combined with X‑ray CT as prior image for FLASH proton therapy

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Nuclear Science and Techniques 2023年第1期34卷 125-135页

作者： Yu‑Qing Yang wen‑cheng fang Xiao‑Xia Huang Jian‑Hao Tan cheng Wang Chao‑Peng Wang Zhen‑Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

Proton FLASH therapy with an ultra-high dose rate is in urgent need of more accurate treatment plan system(TPS)to promote the development of proton computed tomography(CT)without intrinsic error compared with the transformation from X-ray *** paper presents an imaging mode of proton CT based on static superconducting gantry different from the conventional rotational *** beam energy for proton CT is fixed at 350 MeV,which is boosted by a compact proton linac from 230 MeV,and then delivered by the gantry to scan the patient’s body for proton *** study demonstrates that the static superconducting gantry-based proton CT is effective in clinical *** particular,the imaging mode,which combines the relative stopping power(RSP)map from X-ray CT as prior knowledge,can produce much a higher accuracy RSP map for TPSs and positioning and achieve ultra-fast image for real-time image-guided *** paper presents the conceptual design of a boosting linac,static superconducting gantry and proton CT imaging *** feasibility of energy enhancement is verified by simulation,and results from Geant4 simulations and reconstruction algorithms are presented,including the simulation verification of the advantage of the imaging mode.

关键词： Proton therapy Proton CT FLASH treatment Real-time image-guided radiotherapy

Radio frequency conditioning of an S-band accelerating structure prototype for compact proton therapy facility

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Nuclear Science and Techniques 2021年第6期32卷 94-107页

作者： Yu Zhang wen-cheng fang Xiao-Xia Huang Jian-Hao Tan Shao-Peng Zhong cheng-cheng Xiao Jun-Qiang Zhang cheng Wang Yu-Qing Yang Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Tech University Shanghai 201210China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The development of a high-gradient accelerating structure is underway to construct a compact proton linear accelerator for cancer *** experiments and numerous studies are being conducted to develop compact linear accelerators for proton *** of the electromagnetic and mechanical design has been performed to simplify the manufacturing process and reduce costs.A novel high-gradient structure with a low relativistic proton velocity(β),v/c=0.38,was designed,fabricated,and tested at high *** first full-scale prototype was also successfully tested with high radio frequency(RF)power,a repetition rate of 50 Hz,and pulse length of 3μs to reach a high-gradient of 46 MV/m using a 50 MW S-band klystron power supply obtained from the Shanghai Soft X-ray Free Electron Laser *** is the first high-power test in China,which is in line with the expected experimental *** study presents preliminary high-power testing of S-band standing wave accelerating structures with 11 *** work aims to verify the feasibility of using a high-gradient RF accelerating structure in compact proton therapy *** cold test of the prototype cavity was completed in *** of the high-power RF test setup,the process of RF conditioning,and the high-power results are described.

关键词： S-band Standing wave(SW) High-gradient Accelerating structure RF conditioning

A new imaging mode based on X-ray CT as prior image and sparsely sampled projections for rapid clinical proton CT

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Nuclear Science and Techniques 2023年第8期34卷 64-74页

作者： Yu-Qing Yang wen-cheng fang Xiao-Xia Huang Qiang Du Ming Li Jian Zheng Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Key Laboratory of Cryogenics and Superconducting RF Technology ShanghaiChina Suzhou Institute of Biomedical Engineering and Technology Chinese Academy of Sciences SuzhouChina

Proton computed tomography(CT)has a distinct practical significance in clinical *** eliminates 3–5%errors caused by the transformation of Hounsfield unit(HU)to relative stopping power(RSP)values when using X-ray CT for positioning and treatment planning systems(TPSs).Following the development of FLASH proton therapy,there are increased requirements for accurate and rapid positioning in ***,a new rapid proton CT imaging mode is proposed based on sparsely sampled *** proton beam was boosted to 350 MeV by a compact proton linear accelerator(LINAC).In this study,the comparisons of the proton scattering with the energy of 350 MeV and 230 MeV are conducted based on GEANT4 *** the sparsely sampled information associated with beam acquisitions at 12 angles is not enough for reconstruction,X-ray CT is used as a prior *** RSP map generated by converting the X-ray CT was constructed based on Monte Carlo *** the estimation of the most likely path(MLP),the prior image-constrained compressed sensing(PICCS)algorithm is used to reconstruct images from two different phantoms using sparse proton projections of 350 MeV parallel proton *** results show that it is feasible to realize the proton image reconstruction with the rapid proton CT imaging proposed in this *** can produce RSP maps with much higher accuracy for TPSs and fast positioning to achieve ultra-fast imaging for real-time image-guided radiotherapy(IGRT)in clinical proton therapy applications.

关键词： Proton CT Real-time image guidance Image reconstruction Proton therapy

Performance of an electron linear accelerator for the first photoneutron source in China

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Nuclear Science and Techniques 2019年第4期30卷 1-7页

作者： Xuan Li Jun-Qiang Zhang Guo-Qiang Lin wen-cheng fang Qiang Gu Meng Zhang Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai Synchrotron Radiation Facility Chinese Academy of Sciences University of Chinese Academy of Sciences

A compact 15.0-MeV, 1.5-kW electron linear accelerator(LINAC) was successfully constructed to provide an electron beam for the first photoneutron source at the Shanghai Institute of Applied Physics, Shanghai,China. This LINAC consists of five main parts: a thermal cathode grid-controlled electron gun, a pre-buncher, a variable-phase-velocity buncher, a light-speed accelerating structure, and a high-power transportation beamline. A digital feedforward radio frequency compensator is adopted to reduce the energy spread caused by the transient beam loading effect. Furthermore, a real-time electron gun emission feedback algorithm is used to keep the beam stable. After months of efforts, all the beam parameters successfully met the requirements of the facility. In this paper, the beam commissioning process and performance of the LINAC are presented.

关键词： Electron linear accelerator High-power transportation beamline Digital feedforward radio frequency compensation Real-time electron gun emission feedback algorithm Transmission efficiency

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中国消化内镜医生的操作相关肌肉骨骼损伤

临床消化病杂志 2024年第2期36卷 114-119页

作者：秦越唐雅婷巩尧瑶程文芳南京医科大学第一附属医院&江苏省人民医院消化内科江苏南京210029

[目的]调查中国内镜医师的内镜操作相关肌肉骨骼损伤(MSD)的患病率、常见损伤部位和危险因素,并提出预防措施。[方法]通过在线调查收集来自中国8个省份各级医院的193名内镜医师的基本资料、工作量参数、MSD相关信息,以及受访者对内镜设... 详细信息

[目的]调查中国内镜医师的内镜操作相关肌肉骨骼损伤(MSD)的患病率、常见损伤部位和危险因素,并提出预防措施。[方法]通过在线调查收集来自中国8个省份各级医院的193名内镜医师的基本资料、工作量参数、MSD相关信息,以及受访者对内镜设计或预防损伤的要求,应用单因素和多因素Logistic回归分析确定与损伤相关的危险因素。[结果]参与调查的内镜医生的内镜操作相关损伤患病率为87.6%。最常见的症状部位是左手拇指、腰部和颈部。多因素Logistic回归分析表明,与损伤相关的独立危险因素是操作肠镜[优势比(OR)=3.229;95%CI,1.065~9.787;P=0.038]和每周工作时间(OR=1.192;95%CI,1.007~1.411;P=0.041)。[结论]中国消化内镜医师的操作相关MSD的患病率较高,操作肠镜和每周工作时间是2个独立危险因素。个人预防措施、合理的排班以及内镜设计的人体工程学优化有助于改善内镜工作相关的损伤。

关键词：肌肉骨骼损伤消化内镜内镜医师肠镜