非拦截式束流剖面探测器-IPM与BIF

发布时间：2018-05-11 21:46

本文选题：束流剖面测量 + 非拦截式束流诊断　；参考：《中国科学技术大学》2017年博士论文

【摘要】：束流剖面测量作为加速器束流诊断系统的一个重要组成部分,对加速器物理的空间电荷效应、束流横向冷却等研究具有重要意义。同时在加速器正常运行中,束流剖面的准确测量对加速器不同位置的束流横向匹配、束流尺寸控制、机器参数优化等也至关重要。束流剖面测量按对束流的阻挡程度又可以分为拦截式与非拦截式两种测量手段,相对于传统拦截式的剖面诊断工具,非拦截式测量方式可以从容应对强流剖面测量,还可以实现剖面实时监测。其中,剩余气体电离(Ionization Profile Monitor)与气体诱导荧光(Beam Induced Fluorescence)探测器作为国际上常用的非拦截式剖面诊断设备,非常适合于质子及重离子类型同步加速器和强流传输线的剖面测量应用。国内关于IPM与BIF探测器的研究起步较晚,两种探测器在国内加速器设施的剖面诊断中均未实现应用。为了配合兰州重离子加速器(HIRFL)束流诊断系统的改造升级,应对即将到来的中国加速器驱动嬗变研究装置(CIADS)与强流重离子加速器设施(HIAF)的强流剖面测量需求,本课题关于两种非拦截式IPM与BIF束流剖面探测器的研制是极其迫切与必要的。非拦截式IPM与BIF束流剖面探测器都是基于束流带电粒子与剩余气体的电离与激发理论。IPM探测器利用束流粒子与真空管道内剩余气体分子的电离作用,以电离产物的离子-电子对作为测量信号,在探测器内置静电场框架产生的均匀静电场引导与加速下,信号粒子到达微通道板进行倍增放大,放大后的电子由静电场继续引导至磷光屏-相机构成的光学系统,或者阳极-电子学系统进行获取。气体诱导荧光BIF探测器是利用束流粒子使稀有气体分子电离或激发,气体分子在随后的退激发回到基态过程中辐射的可见光波段光子作为测量信号,微弱荧光信号通过图像增强组件进行一系列光子转换及增强过程,最后透过观察窗被外置相机进行光学获取。两种非拦截式剖面探测器基于共同的束流粒子与剩余气体相互作用机制,测量信号载体又略有不同各具特色,两者共同在强流剖面测量应用中发挥着重要价值。论文介绍了国际上IPM与BIF探测器的研究背景、发展历程和应用现状,分析了两种探测器的基本原理、工作流程以及影响因素,如静电场非均匀性,空间电荷效应,杂散电子干扰等。论文的重点是对IPM与BIF探测器的设计制造、束流实验和改良优化等内容进行详细介绍。经过大量理论调研与工程实践,IPM与BIF探测器均成功完成了模拟设计和离线测试,并在HIRFL不同区域进行了束流实验。BIF探测器是应加速器驱动次临界嬗变系统(ADS)直线注入器Ⅱ的强流剖面测量需求而研制,探测器研制完成后在TR2超重实验终端进行了剖面测量实验,实验研究了不同工作气压下探测器的剖面测量结果,并加装滤光片进行了氦气退激光谱研究。实验中通过与单丝剖面扫描结果对比验证了BIF探测器具有较好的准确性与可靠性,且空间分辨率达到115 μm,可以满足ADS以及未来CIADS强流剖面测量的应用需求。IPM探测器是应HIRFL-CSR的实时非拦截式剖面测量需求而研制,探测器建成之后在SSC-Linac进行了束流实验,其测量结果与单丝扫描剖面测量吻合极好,实验中还通过更改不同的电压设置,研究了静电场均匀性对IPM探测器的测量影响。目前IPM探测器经过静电场分压方式改良后已经安装应用于CSRm,并成功实现对束流剖面的实时监测,其空间分辨率高达55 μm,可以满足CSRm电子冷却后极冷、极小发射度束流的剖面测量需求。论文的最后还提出了一种全新紧凑型结构的IPM探测器设计,该设计利用一套IPM探测器能够实现束流横向水平与垂直两个方向的剖面测量功能,从而很大节省剖面测量的空间与经费,对于未来CIADS超导直线这类空间紧缺型加速器的剖面诊断具有重大实用价值。
[Abstract]:As an important part of the accelerator beam diagnosis system, beam profile measurement is of great significance to the study of the space charge effect of accelerator physics, beam transverse cooling and so on. At the same time, the accurate measurement of the beam profile in the normal operation of the accelerator has the transverse matching of the beam flow in the accelerator position, the beam size control, and the machine. The parameter optimization is also essential. The beam profile measurement can be divided into two kinds of interceptor and non interceptor measure. Compared with the traditional interceptor profile diagnosis tool, the non interceptor measurement method can deal with the strong current profile, and can also realize the real-time monitoring of the section. Ionization Profile Monitor and gas induced fluorescence (Beam Induced Fluorescence) detectors are widely used as non interceptor section diagnostic equipment in the world. It is very suitable for the profile measurement applications of proton and heavy ion type synchrotron and strong current transmission line. The domestic research on IPM and BIF detector started late, two kinds of exploration. In order to match the upgrading of the Lanzhou heavy ion accelerator (HIRFL) beam diagnostic system, we should meet the needs of the forthcoming China accelerator driven transmutation research device (CIADS) and the strong current heavy ion accelerator facility (HIAF), the two species of this project, in order to meet the needs of the strong current profile measurement of the forthcoming Chinese accelerator drive transmutation device (CIADS) and the strong current heavy ion accelerator facility (HIAF). The development of the non interceptor IPM and the BIF beam profile detector is extremely urgent and necessary. Both the non interceptor IPM and the BIF beam profile detector are based on the ionization and excitation theory of the beam charged particles and the remaining gases, the ionization of the beam particles and the residual gas in the vacuum pipeline, and the ions of the ionization products. The electron pair is used as a measuring signal. Under the guidance and acceleration of the uniform electrostatic field produced by the built-in electrostatic field frame of the detector, the signal particles reach the microchannel plate multiplier and magnify. The amplified electrons continue to be guided by the electrostatic field to the optical system composed of the phosphor camera or the anode electronics system. The gas induced fluorescence BIF is obtained. The detector uses the beam particles to ionize or excite the rare gas molecules. The gas molecules are radiated in the visible light band as the measurement signal during the subsequent return to the ground state, and the weak fluorescence signals are converted and enhanced through the image enhancement component. Finally, the observation window is carried out by an external camera. Optical acquisition. Two kinds of non interceptor section detectors are based on the interaction mechanism of the common beam particle and the residual gas, and the signal carrier is slightly different. Both of them play an important role in the application of the strong current profile measurement. The paper introduces the research background, the development process and the application of the IPM and BIF detectors in the world. The basic principles, work flow and influencing factors of the two kinds of detectors, such as static electric field inhomogeneity, space charge effect, and stray electronic interference, are analyzed. The emphasis is on the design and manufacture of IPM and BIF detectors, beam experiment and improvement and optimization. After a large number of theoretical research and engineering practice, IPM and BI The F detector successfully completed the simulation design and off-line testing, and carried out the beam experiment in different regions of the HIRFL. The.BIF detector was developed by the accelerator driven subcritical transmutation system (ADS) linear injector II. After the development of the detector, a section measurement experiment was carried out at the TR2 overweight experimental terminal. The results of the profile measurement of the detector at different working pressure are studied and the helium gas regression spectrum is studied with a filter. The experiment shows that the BIF detector has good accuracy and reliability, and the spatial resolution reaches 115 mu m, which can satisfy the ADS and the future CIADS strong current profile measurement. The.IPM detector is developed for the real-time non intercepting profile measurement requirement of HIRFL-CSR. After the detector is built, the beam experiment is carried out in SSC-Linac. The measurement results are in good agreement with the monofilament scanning profile measurement. In the experiment, different voltage settings are changed, and the measurement of the uniformity of the electrostatic field to the IPM detector is also studied. At present, the IPM detector has been installed and applied to CSRm after the improvement of the electrostatic field partial pressure, and has successfully realized the real-time monitoring of the beam profile. Its spatial resolution is up to 55 u m, which can meet the requirements of the CSRm electron cooling after cooling and the minimum emission beam profile measurement. Finally, a new compact junction is also proposed. The design of IPM detector is designed. This design uses a set of IPM detectors to realize the cross section horizontal and vertical two direction profile measurement functions, thus greatly saving the space and funds of the profile measurement, and is of great practical value for the future section diagnosis of the space tight accelerator like CIADS superconducting straight line.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TL507

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