100 MeV质子回旋加速器二期辐照效应管道设计

针对中国原子能科学研究院100 MeV质子回旋加速器上的单粒子效应辐照装置进行了二期管道设计,采用八极磁铁校正法对束流进行了扩束及均匀化,最终在靶上得到了一个30 cm×30 cm、均匀性好于92%的均匀分布的束斑,满足了单粒子效应实验的需求。为降低靶站处的束流能散及中子本底,采用两级降能的方案,在偏转磁铁前放置1个降能片,将能量分为100 MeV和40 MeV两档,并分别针对这两个能量点进行方案设计,束流利用率均在42%以上。公差分析结果表明,四极磁铁对靶上束斑均匀性的影响大于八极磁铁,安装过程中应优先保证四极磁铁的安装公差。     

束流均匀化聚焦六级磁铁设计

<正>加速器输出束流功率分布不均匀,束流密度大将使钛窗、束流靶容器或被辐照物品损坏,因此电子束辐照需将束流进行扩束均匀化处理。束斑内部束流密度分布虽然不均匀但整体上为对称分布,所以要实现束流均匀化需使用奇对称场。目前能产生奇对称场的八极磁铁和十二极磁铁已用于束流均匀化研究。八极磁铁进行束流均匀化时在束流边缘束流密度过高,对于低流强的应用场景可利用准直器将束流边缘密度过     

100 MeV回旋加速器实现双向同时引出质子束流

正中国原子能科学研究院研制的100 MeV强流质子回旋加速器(CYCIAE-100)引出的质子能量范围为75～100 MeV、质子束流的最高流强为200μA。CYCIAE-100在南北对称的两个方向各安装了一套剥离靶引出系统,引出方式为双向剥离引出。2014年,完成了第一套北向剥离靶系统的安装调试,首次获得100 MeV引出质子束流。2015年,完成了第二套剥离靶系统的安装调试。目前,CYCIAE-100在两个方向均可连续引出75～100 MeV的质子束流,并且完成了单粒子效应和中子物理等许多实验任务。2017年,工程部技术人员经过反复尝试和实验,CYCIAE-100成     

HLS脉冲八极磁铁注入方案设计与研究

脉冲多极磁铁注入方法是近年来储存环上新兴的一种束流注入方案,具有注入元件少和对储存束流扰动小等优点。本文研究了在合肥光源(Hefei Light Source,HLS)上储存环采用单块脉冲八极磁铁实现束流注入的设计方案。通过物理过程推导和计算,在储存环上选择合适的八极磁铁的安装位置,初步确定相应的磁铁参数。对注入过程进行跟踪模拟,结果验证了注入束流的存活效率较高,对于储存束流的扰动比脉冲四极磁铁和脉冲六极磁铁注入方法更小,证明了在HLS上采用单块脉冲八极磁铁完成注入过程是可行的。     

高电荷态重离子束流产生技术的研究

为了提高北京HI-13串列加速器束流的硅中射程和LET值,本文开展了高电荷态束流引出技术及pA级弱束流诊断技术研究。采用电刚度和磁刚度模拟技术,配合pA级弱束流束斑观测和束流强度监测技术,获得能量360 MeV、峰总比80%的¹⁹⁷Au离子束流,其在Si中的表面LET为86.1 MeV•cm²•mg^-1、射程为30.1 μm,满足单粒子效应（SEE）实验的要求,拓展了北京HI-13串列加速器上单粒子效应实验所用离子的能量和LET值范围。     

BPL 750 keV束流输运线上四极磁铁的设计

一、引言自从北京质子直线加速器的10 MeV段1982年底出束以来,于1985年已将其能量扩展到35 MeV,脉冲流强达到70 mA,作为从高压倍加器至质子直线加速器之间的750 keV束流输运线,经历了10 MeV和35 MeV两个阶段的调试和运行。它有效地将质子束流从高压倍加器输运到直线加速器,传输效率达到设计指标。本文介绍安装在这一束流输运线上的四极磁铁的设计、磁场测量结果及实际运行情况。     

100 MeV回旋加速器能量测量设备的安装调试

正为了测量100 MeV回旋加速器实际输出质子束流的能量,回旋加速器研究设计中心采用了Physikalisch-Technische Werkst tten(PTW)公司生产的水体模剂量测量系统(以下简称水箱)测量质子束流在水中的深度剂量曲线,确定布拉格峰位置。测量采用的是100 MeV回旋加速器南向单粒子效应束流线和单粒子效应实验台架。该束流线是一条水平方向固定的束流线,因此输出的质子束流为水平方向固定束。水箱的侧面有一个入射窗,入射窗处安装1个参考探测器。束流线与     

300MeV/A H_2~+可变能量超导回旋加速器束流引出物理设计研究

针对单粒子效应测试对质子束能量的要求,中国原子能科学研究院设计了一台300 MeV/A H_2~+超导回旋加速器,该加速器使用超导线圈实现主磁铁小型化,剥离引出H_2~+离子获得可变能量的质子束。通过调节剥离点位置和分析剥离后质子的轨迹与束流包络,对该加速器引出过程的束流动力学进行了研究,完成了引出过程的物理设计。结果表明,此台加速器可在205~240 MeV、265~300 MeV内连续变能量引出质子,在更低能量范围内有单能量点引出质子的能力。     

一个用于束流脉宽压缩的Mobley型宽窗磁铁

本文描述的Mobley型宽窗磁铁是安装在我所2.5MeV质子静电加速器中,为获取1ns脉冲束装置的一个关键设备。在加速器电压为1.5～2.3MeV、粒子能散度0.5％左右时,对H~ 和D~ 束可分别将10～15ns脉冲束压缩或0.9～1.1ns和1.3～1.5ns,靶上最佳束斑3×4mm~2。     

中国原子能科学研究院100 MeV质子单粒子效应辐照装置试验能力研究

为检验中国原子能科学研究院100 MeV质子回旋加速器（CY CIAE-100）建立的单粒子效应（SEE）辐照装置的试验能力和数据测量的准确性和可靠性，利用欧洲航天局（ESA）研制的SEU监测器进行了校核试验。试验中选取多个不同能量点对SEU监测器进行辐照获取了相应的单粒子翻转（SEU）截面，同时对束流的均匀性进行了检验。SEU监测器SEU截面测试结果与其在国外其他加速器，如瑞士PSI、比利时LIF等所获得的数据基本一致。校核试验验证了中国原子能科学研究院100 MeV质子回旋加速器SEE试验能力以及数据测量的准确性。     

复旦大学单粒子微束研制进展

建设了一基于复旦大学2×3 MV串列加速器的单粒子微束装置。离子束经分析磁铁30°水平偏转传输后再经90°偏转磁铁竖直上行至辐照终端,以内径1.5 μm的毛细玻璃管微准直器获取离子微束。采用薄膜闪烁体结合光电倍增管的探测结构对微束离子进行精确探测和计数,并以高压静电偏转开关快速关断束流以实现对离子数目的精确控制。目前实验已获得在质子能量为3 MeV时,能散（能量分布曲线中半高宽FWHM）<60 keV、束分辨<2.2 μm、定量照射精度>95%的质子微束。本文对复旦大学单粒子微束的束流管道设计、微束获取、束开关及单粒子探测等核心环节的研制进展进行介绍。     

中国散裂中子源快周期同步加速器磁铁电源系统的研究

目前正在进行可行性研究的中国散裂中子源的主体结构是1台强流质子同步加速器。该加速器的一期目标为注入能量70MeV、引出能量1.6GeV、束流功率100kW、循环工作频率25Hz。文章阐述系统总体结构的设计原则以及二极磁铁（B）和四极磁铁（Q）磁场的跟踪误差要求。     

Nonlinear processes of probe formation of a beam with inhomogeneous phase density at nuclear microprobe

The work describes nonlinear processes of probe formation on the target with allowance for an inhomogeneous density of ion distribution in phase space in the object collimator plane taken from experimental data. The chromatic aberrations, intrinsic aberrations of the 3rd order and parasitic aberrations caused by sextupole and octupole components of the magnetic quadrupole lens field have been taken into account in the object-target phase coordinate transformation. The criterion of obtaining the optimal resolution was defined as the minimum spot size (FWHM) for a fixed ratio I_FWHM/I₀ of beam current in this spot to the total beam current. The conditions for which the initial density of ion distribution in phase space is matched with the ion-optical characteristics of the probe-forming system were considered. The influence of axial brightness and parasitic sextupole and octupole field components on the beam current distribution at the target has been determined.     

The external beam microprobe facility in Florence: Set-up and performance

An external beam microprobe facility, based on a quadrupole doublet supplied by Oxford Microbeam Ltd, has been installed on a new beamline at the 3 MV single-ended Van de Graaff accelerator in Florence. The goal was to obtain a beam with a spot size on target of 10–20 μm and a current in the order of at least 1 nA, in order to allow PIXE, PIGE and RBS elemental analysis in air or in a helium atmosphere. The beam was extracted from the vacuum lines through a 0.1 μm thick Si₃N₄ window to minimise lateral straggling. The design goals have been successfully achieved; the measurements of the beam spot characteristics in vacuum as well as in air and in helium atmosphere, are here reported.     

Study of intensity suppression in a gantry beamline for SC200 proton therapy system

ABSTRACT

For proton therapy, a beam intensity of 0.4 nA to 4 nA is typically used with a beam transmission factor of 10. However, because of energy degrading, emittance matching, and energy spread selecting, the ratio of beamline transmission (I_Max/I_Min) for our SC200 proton therapy facility (200 MeV/500 nA) should be far more than 10. Therefore, a novel intensity suppression scheme, based on the installation of two new collimators placed symmetrically with respect to the gantry coupling point, is proposed and verified. First, the feasibility of delivering a beam with variable size at the gantry isocenter is demonstrated. The beam delivery method uses waist-to-waist imaging optics, a symmetric beam method, and the principle of beam line inversion. The relationship between energy and isocenter beam size (in air) is then verified using an empirical formula and a Monte Carlo method. The intensity suppression and subsequent optimization of the gantry beam optics were accomplished through simulations. The results indicate that increases in the entrance beam radius at a specific collimator results in significant changes in the beam optics and intensity behind the collimator. This passive scheme, which produces intentional losses at the gantry coupling point, is demonstrated to be viable.     

A beam optics study of the biomedical beam line at a proton therapy facility

A biomedical beam line has been designed for the experimental area of a proton therapy facility to deliver mm to sub-mm size beams in the energy range of 20-50 MeV using the TRANSPORT/TURTLE beam optics codes and a newly-written program. The proton therapy facility is equipped with a 230 MeV fixed-energy cyclotron and an energy selection system based on a degrader and slits, so that beam currents available for therapy decrease at lower energies in the therapeutic beam energy range of 70-230 MeV. The new beam line system is composed of an energy-degrader, two slits, and three quadrupole magnets. The minimum beam sizes achievable at the focal point are estimated for the two energies of 50 and 20 MeV. The focused FWHM beam size is approximately 0.3 mm with an expected beam current of 20 pA when the beam energy is reduced to 50 MeV from 100 MeV, and roughly 0.8 mm with a current of 10 pA for a 20 MeV beam.     

CYCIAE-30医用回旋加速器束流输运系统升级改造

在中国原子能科学研究院CYCIAE－30医用回旋加速器现有的束流输运系统的基础上，根据气体靶生产新品种医用同位素的技术要求，用TRACE－3D对束流输运系统的升级改造方案进行设计，包括束流线的总体布局和光学设计。根据束流光学设计的结果，〖JP3〗设计了新增束流线的磁四极透镜和偏转磁铁。     

Rearranging a nanoprobe: Line foci,grid shadow patterns and performance tests

After a major modification of the target chamber at the Leipzig high energy ion nanoprobe the probe forming lens system, consisting of two separated quadrupole doublets, had been carefully realigned. This was done by adjusting the line foci position of each individual quadrupole on the centre position defined by the unfocused beam. Using a high magnification microscope the alignment process is very effective and precise. The lens system could be precisely realigned except an intrinsic rotational misalignment which is essentially reduced by a correction lens.Grid shadow patterns have been taken and analysed in order to assess the characteristics of the system. The dominant aberrations are spherical with an additional parasitic octupole.The grid shadow method is also very useful to determine the best position of the aperture diaphragms which minimizes the influence of the aberrations onto the beam spot size.The rearrangement allowed larger aperture diaphragms for higher beam currents at a moderate increase in beam spot sizes. Performance tests yielded proton microbeam currents and half-widths of 4.5 nA at 1.5 μm, 8.3 nA at 1.5 μm and 17.2 nA at 2 μm. For high resolution work the expected beam spots around 0.3 μm at 100 pA were not achieved. The reason is very likely interference on the beam scanner, correlated in x- and y-direction, which results from the insufficiently rectified power supply voltage of the transconductance amplifier.     

北京同步辐射装置X光光刻束线监测系统

本文介绍了安装在北京同步辐射装置（BSRF）3B1束线上的自制同步辐射光束在线监测系统，对光束垂直位置，光斑均匀性及光刻曝光量（同步光积分光强）实现了在线监控，给出了实时在线测试结果。     

100 MeV紧凑型回旋加速器主磁铁的三维磁场有限元分析技术

100 MeV紧凑型回旋加速器主磁铁的几何结构十分复杂,但为了形成加速器束流动力学所要求的磁场分布,本文对初步设计的磁铁进行必要的简化。综合采用各种适当的三维有限元网格剖分技术,对该磁铁的磁场进行数值分析,计算精度满足加速器物理设计的要求。