用于自由电子激光装置的丝扫描束流横向截面测量系统原型机

基于丝扫描系统的束流横向截面测量为半阻拦式的测量方法,相比于截面靶测量对束流影响较小。上海高重复频率硬X射线自由电子激光装置(SHINE)束团截面在线测量系统计划采用丝扫描技术实现,为此设计研制了由丝靶探头、机械运动机构、束损探测器、电子学系统构成的丝扫描束流横向截面测量系统原型机。本文介绍了该原型机的工作原理、具体设计及在丝扫描探头上游安装腔式束流位置测量(CBPM)系统进行束流中心位置和束团电荷量精确补偿的优化方案。为精确评估该样机系统性能,在上海软X射线自由电子激光(SXFEL)中相邻位置布局了丝扫描探头和YAG靶截面探头,通过同时测量并对比同样束流截面的方法,对丝扫描系统原型机性能进行了束流实验评估。束流实验结果表明,在束团电荷量500 pC、电子能量0.84 GeV的条件下,丝扫描技术可用于电子束团的在线半阻拦式截面测量,测量不确定度好于30μm,测量结果与SXFEL装置标配的YAG靶截面靶测量系统结果一致。     

基于光学渡越辐射方法的实时电子能谱测量系统

针对加速器技术发展和应用对能谱测量精度、速度要求的不断提高,提出基于光学渡越辐射方法和实时能谱测量方案,给出了该方案的初步解决方法,并对各个实现细节给与描述,最终给出在中国科学院高能物理研究所自由电子激光（BFEL）实验室所得的阶段性实验结果。在现有实验条件下,所得OTR光宽20mm,与理论计算值相吻合。     

SFEL束流偏转传输系统的设计

上海宽波段自由激光用户装置正在中国科学院上海原子核研究所ＦＥＬ实验室设计建造。这里介绍了两个典型偏转系统的设计考虑，并讨论了设计结果。     

上海深紫外自由电子激光束流截面诊断系统

上海深紫外光自由电子激光(SDUV-FEL)束流截面诊断系统设计与实现是基于工业以太网的方案,具有良好的通用性和扩展性.该系统包含了图像采集、气动控制和电动控制三大子系统,采用了虚拟仪器技术完成设备的驱动和测量软件的开发.本文介绍了该系统的组成结构和软硬件设计,并展示了在SDUV-FEL装置上的实验结果.目前该系统已成为上海深紫外自由电子激光最主要的诊断手段和数据获取方式,并已成功应用到激光系统的测量控制中.     

腔式束流位置探测器的设计与实验研究

束流位置探测器对自由电子激光装置的研制和运行具有重要的意义。其中,腔式束流位置探测器(腔式BPM)又以其高精度、高分辨率的特点而得到广泛的应用。本文对应用于上海深紫外自由电子激光装置上的腔式BPM进行了理论分析、模拟计算和BPM腔的测量等方面的研究。     

上海自由电子激光工程地基振动测试研究

上海自由电子激光(SFEL)工程是国家重大科技基础设施建设项目,束流稳定性的好坏是影响SFEL性能的关键指标,而地基振动是影响束流稳定性的重要因素之一.本文对SFEL工程的地基振动进行了长达450 m、24 h连续测试;对不同位置、不同时刻、不同频段、不同方向的结果进行了详细地分析,并与国外光源的地基振动结果进行了比较,为SFEL工程的建设准备了比较详细的地基振动资料.     

上海软X射线自由电子激光腔式束流位置测量系统

上海软X射线自由电子激光装置（Shanghai Soft X-ray Free Electron Laser, SXFEL）需1个分辨率达到亚μm量级的束流位置测量系统,并采用基于束流准直的方法实现波荡器段电子束与光子束的紧密重合。为此设计研制了1个由C波段腔式探头、单路混频至低中频的射频前端以及自主研发的专用数字信号束流位置处理器（digital beam position monitor processor, DBPM）构成的腔式束流位置测量（cavity beam position monitor, CBPM）系统。本文对系统的设计、软硬件结构、系统搭建进行了介绍,并基于漂移段搭建的3个紧邻的CBPM阵列完成了在线系统性能评估。束流实验结果表明,在束团电荷量为500 pC、系统动态范围在±800 μm的条件下,位置分辨率可达880 nm,这也是国内首次研制成功可在线运行的具有亚μm位置分辨率的CBPM系统。此外,采用CBPM的相位腔进行相对束团电荷量、束团到达时间的测量,其性能评估结果也均优于SXFEL设计要求。     

基于ARM的嵌入式Linux网络数据传输性能分析

大型高能物理实验数据采集系统普遍采用多级触发结构,各级间用网络将数据发送到更高级别的系统。以太网技术多作为触发数据传输的媒介。为提高系统传输效率,找到系统数据传输的优化方法,本文基于ARM平台,从数据流角度阐述了Linux2.4内核网络数据的接收过程,并结合测得的内核内部数据分析了网络性能变化的具体原因,给出优化系统性能的方向。     

基于图像获取技术的发射度测量方法研究

介绍了HIRFL上利用荧光靶图像获取装置构成多孔屏束流发射度测量系统，对测量数据的处理、光斑面积、周长和束流发射度的计算方法做了重点介绍，该系统具有可靠性好、测量直观、界面友好等优点。     

基于ARM9与FPGA的工业CT数据传输系统的接口设计

以samsung公司的ARM9系列处理器S3C2410和altera公司的cyclone系列FPGA为平台，详细介绍了S3C2410芯片通过AHB总线与FPGA进行硬件连接技术和基于QuartusⅡ环境下AHB总线控制时序的实现方法以及ARM-Linux平台下的AHB总线驱动程序的开发。设计结果实现了工业CT数据传输系统稳定快速地传输数据，此设计方案充分发挥了ARM和FPGA的各自优势，对其他双核接口设计开发有很好的指导作用。     

On the comparison of three methods of assessing beam quality for broad beam in vitro cell irradiation

The interaction of charged particles with living matter has recently attracted increasing interest in the field of biomedical applications such as hadron therapy, radioprotection and space radiation biology. Particle accelerators are particularly useful in this area.In vitro radiobiological studies with a broad beam configuration require beam homogeneity. The goal is to produce a dose distribution given to a cell population that is as close to uniform as possible.In this paper, we compare the results of three devices used to assess the beam quality for broad beam irradiation: a passivated implanted planar silicon (PIPS) particle detector, a position-sensitive solid state detector, which is camera-like, and a solid state nuclear track detector (CR39).The first device is a PIPS detector of 300 μm nominal depletion depth and an entrance window with a thickness of about 500 Å. It is collimated with a 0.5 mm aperture and mounted in air on an XY moving table as close as possible to the exit window of the beam line.The second device is a CMOS position-sensitive detector (technological process 0.6 μm AMS CUA), 112 × 112 pixels, with 153 × 153 μm² pixel size. It allows the user to rapidly obtain dose uniformity over a surface of 1 × 1 cm². During uniformity and dose rate assessment it is placed in air at the PIPS location.For both detectors, beam profile was obtained for various proton fluxes (from ∼5 × 10⁴ to 10⁶ particles cm⁻² s⁻¹). Preliminary tests were made with CR39 using 4 MeV He⁺⁺ ions.Results are analysed using Poisson distribution and cell hit probability.     

A real-time beam loss monitoring system for storage ring of SSRF

In this paper we report the real-time beam loss monitoring (BLM) system at the storage ring of SSRF.The BLM-XS detectors and Ethernet data acquisition system are used in this system.Some applications and experiments of the BLM system are also presented.The BLM system provides dynamic information of beam loss for the storage ring,and is helpful to ensure the facility commissioning,investigate the problems of machine,optimize the machine parameters and further increase the beam lifetime.     

电子枪束流截面测量系统

电子枪束流截面测量系统采用单片机控制步进电机驱动测试丝在束流下快速扫描,同时完成束流的数据采集,通过Matlab实现立体图的输出,从而判断电子枪的工作情况。用此系统在5mA束流下进行了测试,得到了束斑直径(13-14mm)和截面束流密度矩阵。     

Computer investigation of ion beam optics for a Freeman type ion source system

The present work investigates the computer analysis of the ion beam properties produced by a Freeman type system. The extraction for such system is composed of four electrodes that permit to keep a fixed output energy by means of two accelerating gaps and one decelerating gap. The latter allows reducing the beam divergence angle. The combination of the acceleration/deceleration sections provides to keep a low beam emittance at the source outlet. The simulation of single charged argon ion trajectories for a plasma concave of curvature 4 mm was first studied with and without space charge effect using acceleration/deceleration extraction system with the aid of the SIMION computer program. The voltage applied to the accelerating electrode was optimized to accomplish the suitable ion trajectories without hitting the extraction electrode. Then, two additional studies were performed: the influence of the acceleration voltage and extraction voltage on the beam emittance and beam diameter; and the effect of the extraction gap width (distance between the plasma emission surface and the acceleration electrode) on the shape of the ion beam envelope and the position of the ion beam waist. Last, the influence of the space charge on the ion beam envelope was also investigated.     

基于AT89C55单片机的3B3光束线狭缝控制系统

介绍了北京同步辐射装置3B3光束线精密可调狭缝控制系统,重点讨论了运用步进电机电细分技术以及采取的可靠性技术措施,分析了系统的先进性、可靠性以及智能化特点。     

EAST中性束注入器稳态偏转磁铁的参数设计与估算研究

中性束注入器偏转磁铁是剥离束流中剩余离子的关键设备,它与剩余离子吞食器等内部部件构成了中性束注入器的束偏转系统。束偏转系统的性能对中性束注入器束流的品质及其束传输效率发挥着重要作用。本文根据EAST(Experimental Advanced Superconducting Tokamak,EAST)中性束注入器对束偏转系统的要求,对其偏转磁铁各性能参数进行了估算。为中性束注入器设计了一台用以剩余离子180°偏转的偏转磁铁。该偏转磁铁采用H型二极电磁铁结构;其磁极端面设计为138cm×47cm的圆角矩形结构;其线圈设计为每侧2饼,每饼2层,每层8根的串联结构,导线选用外方内圆空心铜导体,以满足偏转磁铁稳态运行的需要。该设计的偏转磁铁在370 A励磁电流条件下,可提供80keV氘离子束偏转所需的磁场。实验测试结果显示:500 A励磁电流稳态运行条件下,偏转磁铁线圈冷却水温升约21.5℃,该设计结构的偏转磁铁满足EAST中性束注入器满参数稳态运行和未来运行参数逐步提高的需要。     

Electrical and thermo-mechanical analysis of beam recovery system for megawatt power gyrotron

The paper presents the electrical and thermo-mechanical design of single stage beam recovery system for 120 GHz, 1 MW gyrotron. The electrical study shows that the cylindrical shape single stage beam recovery system enhances the efficiency by 66.26%. The maximum power deposited to collector in depressed collector operation is 0.48 MW for electronic efficiency, 30% and 1.44 MW for DC electron beam. The thermo-mechanical analysis has been performed to evaluate the water cooling system. The cooling system has capability of accommodating a peak wall loading, 0.9 kW/cm² at flow rate of 1500 l/min for safe operating time, 60 ms. Further, a high voltage analysis is also carried out to appraise the electric field distribution in the collector.     

Design and development of a synchronized operation control system for Thomson scattering diagnostic on J-TEXT

A Thomson scattering diagnostic system is under construction at the Joint Texas Experimental Tokamak (J-TEXT).A 1064 nm Nd:YAG laser with 50 Hz repetition rate is used as the laser source.We have used a software for careful and precise control of the laser through serial communication.A time sequence operating system has been developed to synchronize the laser control and data acquisition system with the central control system (CSS).The system operates commands from the CSS of J-TEXT and generates triggers for the laser and data acquisition system in the proper sequence.It also measures an asynchronous time value that is needed for accurate time stamping.All functions are served by a field-programmable gate array development platform that is suitable for high-speed data and signal processing applications.Several embedded peripherals,including Ethernet and USB 2.0,provide communication with the CSS and the server.     

Measurement of beam power and profile for DNB on HT-7 tokamak

In normal experimental operation, a diagnostic neutral beam (DNB) can produce 6 A of extracted beam current in hydrogen at an energy of 49 keV with a pulse length of 100 ms. Hydrogen and deuterium beams can be produced as well. The diagnostic neutral beam has been added to the diagnostic set so that charge-exchange recombination spectroscopy (CXRS) can be used to acquire ion temperature and rotation. The beam power and beam profile distribution of the DNB injection can be obtained with a thermocouple probe measurement system on the HT-7 superconducting tokamak. The thermocouple probe measurement system with 13 thermocouples crossly distributed on the probe plate was used to measure the temperature rise of each coppery target, so the profile distribution of the ion/neutral beam was obtained by calculation. In this paper, the structure of the probe plate on the DNB for HT-7 tokamak and some measurement results are presented.     

重离子束均匀度的测定及治癌束流成形的模拟试验

采用５０μｍ厚聚碳酸酯薄膜，利用核径迹测技术测得φ４０ｍｍ的２５ＭｅＶ／ｕ＾４０Ａｒ＾１４＋离子束的均匀度在散焦情况下为３２．７％，在Ｄ“散焦＋样品旋转”情况下为５２．４％。还采用多层聚碳酸酯薄膜组件作为肿瘤块等效材料，进行了重离子束治癌束流成形模拟试验。