Study of the aberrations of the IMP heavy ion microbeam irradiation system

A high energy heavy ion microbeam irradiation system is constructed at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS). A quadrupole focusing system, in combination with a series of slits, has been designed here. The IMP microbeam system is described in detail. The intrinsic and parasitic aberrations associated with the magnets are simulated. The ion beam optics of this microbeam system is investigated systematically. Then the optimized initial beam parameters are given for high spatial resolution and high hitting rates.     

碳离子治疗系统研发转化介绍

碳离子束因其倒转的深度剂量分布和高的相对生物学效应,具有对正常组织损伤小、副作用低等优势,是目前实体肿瘤治疗最先进的放疗用射线。2019 年9 月29 日,由中国科学院近代物理所及其控股公司兰州科近泰基新技术有限责任公司研制的碳离子治疗系统获批第三类医疗器械产品注册,用于恶性实体肿瘤的治疗,填补了高端医疗器械碳离子治疗系统国产化空白,对于提升我国肿瘤诊疗手段和水平具有重大意义。     

兰州重离子加速器冷却储存环kicker磁铁设计

 介绍了兰州重离子加速器冷却储存环（HIRFL-CSR）CSRm引出kicker磁铁的物理设计、参数计算以及结构设计和加工。为了减小电感,使上升时间达到要求,CSRm引出kicker磁铁采用分布式的传输线方案,同时将无感电容与磁铁并联以满足匹配的问题。磁铁用单匝线圈和铁氧体铁芯来降低电感、减少涡流损耗,并采取两台电源成对供电、导体一端共地的结构形式消除杂散电感和轴向场,这种方式不但消除了过桥的不利影响,而且可通过调节导体间距离方便的调节磁场均匀区宽度和磁铁电感。完成设计后磁铁电感小于1 μH,在140 mm范围内磁场均匀度好于±0. 5%,最高磁场达到0.038 T,最大峰值激磁电流约为2.5 kA。     

HIRFL-CSR commissioning in 2006 and 2007

HIRFL-CSR, a new heavy ion cooler-storage-ring system at IMP, had been in commissioning since the beginning of 2006. In the two years of 2006 and 2007 the CSR commissioning was finished, including the stripping injection (STI), electron-cooling with hollow electron beam, C-beam stacking with the combination of STI and e-cooling, the wide energy-range synchrotron ramping from 7 MeV/u to 1000 MeV/u by changing the RF harmonic-number at mid-energy, the multiple multi-turn injection (MMI), the beam accumulation with MMI and e-cooling for heavy-ion beams of Ar, Kr and Xe, the fast extraction from CSRm and single-turn injection to CSRe, beam stacking in CSRe and the RIBs mass-spectrometer test with the isochronous mode in CSRe by using the time-of-flight method.     

Design of the IMP microbeam irradiation system for 100 MeV/u heavy ions

A state-of-the-art high energy heavy ion microbeam irradiation system is constructed at the Institute of Modern Physics of the Chinese Academy of Sciences. This microbeam system operates in both full current intensity mode and single ion mode. It delivers a predefined number of ions to pre-selected targets for research in biology and material science. The characteristic of this microbeam system is high energy and vertical irradiation. A quadrupole focusing system, in combination with a series of slits, has been designed to optimize the spatial resolution. A symmetrically achromatic system leads the beam downwards and serves simultaneously as an energy analyzer. A high gradient quadrupole triplet finally focuses a C^6＋ ion beam to 1 μm in the vacuum chamber within the energy range from 10 MeV/u to 100 MeV/u. In this paper, the IMP microbeam system is described in detail. A systematic investigation of the ion beam optics of this microbeam system is presented together with the associated aberrations. Comparison is made between the IMP microbeam system and the other existing systems to further discuss the performance of this microbeam. Then the optimized initial beam parameters are given for high resolution and high hitting efficiency. At last, the experiment platform is briefly introduced.     

Commissioning of electron cooling in CSRm

A new generation electron cooler has started operation in the heavy ion synchrotron CSRm which is used to increase the intensity of heavy ions. Transverse cooling of the ion beam after horizontal multi-turn injection allows beam accumulation at the injection energy. After optimization of the accumulation process an intensity increase in a synchrotron pulse by more than one order of magnitude has been achieved. In given accumulation time interval of 10 seconds, 108 particles have been accumulated and accelerated to the final energy. The momentum spread after accumulation and acceleration in the 10-4 range has been demonstrated in six species of ion beams. Primary measurements of accumulation process varying with electron energy, electron beam current, electron beam profile, expansion factor and injection interval have been performed. The lifetimes of ion beams in the presence of electron beams were roughly measured with the help of DCCT signal.     

HIAF-BRing电源样机模块故障联锁保护系统设计与实现

强流重离子加速器装置（HIAF）的增强器（BRing）二极铁电源样机采用多模块串并联的全储能快循环脉冲电源实现方案,电源功率达到MW级。由于电源规模庞大和功率巨大,为了在运行中迅速保护电源设备,设计并实现了一套双冗余的基于可编程逻辑控制器（PLC）、模块故障联锁板和现场可编程门阵列（FPGA）的模块故障联锁保护系统,利用硬件和软件同时对电源功率单元模块实施故障检测、故障传递和故障保护。设计完成后分别从电源联锁环路的响应时间、核心控制板故障引发电源环路联锁的总时间和设备故障响应等三个方面进行测试,测试结果表明,在电源发生故障时,模块故障联锁保护系统满足电源样机对实时性和可靠性的要求,达到设计目标。     

微束辐照装置及其在生物和材料领域中的应用

自从20世纪50年代开始利用微束辐照生物活细胞以来,由于微束独特的辐照特征, 其在生物学、 材料学、 生物医学、航空航天科学、环境科学、地质学、微加工等领域得到了广泛的应用。 在前人大量研究的基础上, 对微束装置及其应用进行总结概括。 展望了微束的发展趋势并简单介绍中国科学院近代物理研究所正在兴建的中高能重离子微束辐照装置。 Collimated proton microbeam has been used to irradiate the biological living cells since 1850s. Due to its unique characteristic in irradiation, microbeam has been extensively applied to many research fields,such as biology, material science, biomedicine,aeronautics and stronautics, environmental science, geology,micromachining and so on. Based on the much research of predecessors, the microbeam facilities and their corresponding applications are summarized in this paper. At last,prospects on the development trend of microbeam are made, and the intermediate energy and high energy heavy ion microbeam irradiation facility being constructed at the Institute of Modern Physics of Chinese Academy of Sciences is briefly introduced.     

基于悬浮拓扑的加速器脉冲电源设计

随着加速器技术的发展,重离子加速器脉冲电源工作频率逐步提高,电流上升速率逐步提升。脉冲电源磁铁负载具有阻感特性,其在电流波形上升段将吸收大量的无功,会对电网产生周期性强冲击;同时,快电流上升速率下的高精度要求,对电源设计提出了新的挑战。论文设计了一种基于电容储能的悬浮型H桥级联拓扑,利用电源自身储能电容和负载电感进行无功交互,实现了无功能量的内部循环,以减小对其对电网冲击;同时采用H桥级联多电平结合移相倍频控制,以保证电源快动态响应下的高精度需求。样机实验结果验证了电源拓扑和控制原理的可行性,为加速器快电流上升速率脉冲电源提供了一种新的解决方案。     

HIAF-BRing快循环全储能脉冲电源高低压切换控制及其切换点平滑算法

应用于强流重离子加速器装置增强环（HIAF-BRing）的快循环全储能脉冲电源需要在极宽的输出电压范围内保持极高的控制精度,为此电源采用了高压功率单元和低压功率单元串联的拓扑方式,在低压段采用低压功率单元,电压升高之后切换到高压功率单元,通过高低压切换控制来实现电流全阶段的高精度输出。但是在样机实测中发现存在切换点的振荡问题,导致切换点处的输出电流绝对误差无法满足指标要求。本文提出了一种切换点平滑控制算法来平滑处理切换点占空比,给出了仿真结果,并且在HIAF-BRing快循环全储能脉冲电源样机上面实际验证了高低压切换控制方法及其切换点平滑控制算法的有效性。实验结果表明：100 A注入平台的输出电流绝对误差由±500 mA降至±50 mA, 100 A注入平台的切换点处输出电流绝对误差由±1.16 A降至±120 mA,100 A注入平台输出精度较低的问题得以解决。