【作者】 沙杉；

【导师】 陈熙萌； 赵红卫；

【作者基本信息】 兰州大学 ， 粒子物理与原子核物理， 2013， 博士

【摘要】 本论文对中国科学院近代物理研究所的激光离子源进行了全面系统的研究,建成了两条激光源的实验束流线：1#束流线和2#束流线。1#束流线主要用来研究激光离子源自身技术；2#束流线主要用来研究激光离子源结合RFQ进行的离子加速。在论文中,对于激光离子源方面的设计包括：激光光路的设计、靶室设计、束流诊断系统设计、控制系统设计和准直系统设计等。在靶室和激光光路设计中,对各种设计思路进行了阐述,对比了不同设计方案的优缺点；在束流诊断部分,自行设计了2#束流线上的静电偏转板,在设计中采用了OPERA软件来计算边缘电场的影响,并通过模拟得到了其电极的“有效长度”,经过实验验证符合设计要求。在控制系统部分,自行设计了用于靶运动控制的三维电机运动控制系统,该控制系统中的机械运动控制部分选用伺服电机和滑轨传动的方式,并使用Labview软件自行设计开发了自动控制软件；设计了激光离子源和RFQ加速器的同步控制系统,保障激光离子源产生的等离子体同步注入到RFQ进行加速。自行设计了一套用于激光离子源准直的方法,该方法使用K&E水准仪和激光墨线仪与“拉丝法”来共同完成,最终可以将激光焦点位置置于束流线的中心轴线上,便于进行测量和调试。利用自行建造的激光离子源实验装置,获得了使用不同固体靶材情况下的总束流强度和电荷态分布：在实验中得到了13.65mA的C离子束(最高电荷态为C6+)、12.27mA的Al离子束(最高电荷态为Al12+)、7.87mA的Ti离子束(最高电荷态为Ti16+)、7.81mA的Ni离子束(最高电荷态为Ni19+)、3.06mA的Ag离子束(最高电荷态为Ag20+)、2.08mA的Ta离子束(最高电荷态为Ta13+)、0.5mA的Pb离子束(最高电荷态为Pb10+)。进行了激光离子源稳定性测试,在近千次的持续打靶测试中,记录了峰值时间、峰值流强、半高宽(FWHM)和总电量的变化,研究表明其稳定性达到设计和实验要求。在激光离子源结合RFQ研究中,使用自行设计的同步系统成功地将激光离子源与RFQ进行了同步加速,在RFQ后得到了～16mA的加速C离子束流,从而验证了自行设计的同步控制系统的正确性,并且通过改变RFQ腔体加载的功率,得到了优化的RFQ工作点在190kW。更多还原

【Abstract】 The comprehensive researches of Laser Ion Source (LIS) were carried out at the Institute of Modern Physics, Chinese Academic of Sciences. The two beam lines of the LIS were built, named No.1#and No.2#. The scientific purpose of No.1#beam line is deeply investigated the own techniques of LIS, another beam line is learned for the directly plasma injection scheme which straightforward connect the LIS with RFQ accelerator, the accelerated ion beam have achieved from the RFQ accelerator.The design works of LIS were included:laser optical path, experimental target chamber, beam diagnostics equipment, automation control system and collimating method of LIS, et al. In the design works of both the laser target chamber and optical path, the three different ideas were compared, these pros and cons of different project were shown completely. A self-design EIA (Electrostatic Ion Analyzer) was employed to analyze the ion beam charge states that were produced from the laser ion source at No.2#beam line. According to the experimental setup, a new EIA was designed that was used on No.2#beam line by us, the electromagnetic simulation software OPERA was employed, based on the simulated result, the "effective length" of EIA was calculated. These designs were verified by the experiment measurements that were satisfied to our expected. For the convenient purpose, a3-D manipulator were designed that can control the target during the experiment in the vacuum, the movement of those control items adopts actuating motors and precise sliders, the control software was developed by Labview. The synchronous system acts as an important role between LIS and RFQ, which was guaranteed the efficiency of injection laser plasma to the RFQ cavity, this principle layout of synchronous system was originally designed by us. Due to the laser focal spot size is very tiny, a new precise method of alignment was produced, the method includes:a K&E cubic precision optical level, cross-line laser and "string alignment method". Eventually, the laser focal spot on the target can put on the axis of the entire beam line easily.Due to the established beam line, the results of the charge states and total beam current of various target materials was achieved:the typical laser plasma experiment result was shown as follows:the carbon ion beam current (the maximum charge state was C6+) was13.65mA, the Al ion beam (the maximum charge state was Al12+) current was12.27mA, the Ti ion beam current (the maximum charge state was Ti16+) was7.87mA, the Ni ion beam current (the maximum charge state was Ni19+) was7.81mA, the Ag ion beam current (the maximum charge state was Ag20+) was3.06mA, the Ta ion beam current (the maximum charge state was Ta13+) was2.08mA, the lead ion beam current (the maximum charge state was Pb10+) was0.5mA. Moreover, the stability of LIS was measured that use the carbon target, the experimental counts of the last shots about one thousand. The peak time, peak current, FWHM and electric quantity were recorded. The analyzed results of these record parameters demonstrated the requirements of design and experimental goal was achieved.The experimental research aspect of LIS and RFQ, it was successfully that the synchronized accelerated ion beam was captured using self-designed synchronization system, the total current of accelerated ion beam was about16mA, that was clearly evidence to prove the validity of the synchronization system of LIS and RFQ. According to changing the different input power of the RFQ cavity, the optimized "working point" of the RFQ was190kW that was demonstrated by the accelerated ion beam experimental results.更多还原