【作者】 冯哲；

【导师】 张小章；

【作者基本信息】 清华大学 ， 核科学与技术， 2011， 博士

【摘要】 强流ECR (Electron Cyclotron Resonance)离子源作为加速器系统的前端注入设备，其核心部件的设计是影响其工作性能以及产生束流品质的关键。ECR离子源具有结构紧凑，可产生高密度等离子体，性能稳定，可重复性好等优点。然而，由于其系统组成的特点，各个核心部件的性能都会影响产生束流的品质，尽管研究者们对于离子源的调试已经做过很多有借鉴意义的工作，但对影响其关键性能的主要因素和相关理论还不能做出令人信服的解释，因此我们需要在进行离子源的设计中，试图对能反映束流品质的关键部件和离子源中的等离子体参数进行正确的描述和理解。这种基于等离子体诊断来研究束流性能的方法也是目前国内外强流ECR离子源设计与研究领域所欠缺和需要的。为解决这一问题，本文以ECR质子源为研究对象，对ECR氢等离子体进行了发射光谱诊断和碰撞辐射模型研究。借助实验检验，优化了ECR质子源核心部件的设计，研究了束流引出以及传输特性。其创新之处体现在：一、将发射光谱诊断方法应用到ECR质子源中对ECR氢等离子体Blamer系氢原子的发射光谱进行诊断，依托辐射碰撞模型对氢等离子体的电子密度和温度进行计算，比较了连续和脉冲微波源工作模式下的氢等离子体密度随微波源参数的变化，工程上首次指出一个脉宽内激发态氢原子发射光谱随时间的变化规律，在时间尺度上对束流的脉冲化结果及脉冲微波源的设计提供了参考。二、在束流引出时，利用等离子体发射光谱诊断的方法有效地将不同微波功率下等离子体密度与束流强度的变化规律联系起来，并找到质子源引出束流的最佳气压值范围并探究其成因，提高了质子源的工作效率。三、初步研究了束流引出状态下不同引出电压及抑制电压对等离子体发射光谱的影响，以及束流引出时其对等离子体参量的影响，丰富了离子源关于束流引出的物理内容，对进一步提高束流强度和离子源工作的稳定性具有指导意义。本文还通过建造一套结构紧凑的质子源和低能输运段系统并对其核心参数进行理论计算和实验比较，系统地分析了系统关键部件的设计方法，优化其核心参数。利用发射光谱诊断方法，得到ECR氢等离子体参数随质子源核心部件和实验参数的变化规律，为提高ECR质子源的工作性能提供了参考。更多还原

【Abstract】 As the front-end accelerator system injection device, the design of high-currentECR ion source plays an important role in the performance of the whole system.Especially the design of its core components is the key to affect their work performanceand extracted beam quality. Being a beam production equipment, ECR ion source has acompact structure that can produce high density plasma with stable performance andgood repeatability. However, for the ECR ion source system compositioncharacteristics, each core components’ performance will affect the quality of producedbeam. Although researchers have done lots of works on the souce experiments, theconvincing explanation of the main factors and relative theories about affecting thesource performance are still not given. For this reason, we need to have a correctdescription and understanding about the key components that relate to the beam qualityand the ion source plasma parameters during the design of the ion source. This researchmethod about the performance of the beam based on plasma diagnostics is right whatwe lack in the research field of high-current ECR ion source design and experiment athome and abroad.In this paper the ECR hydrogen plasma produced in the ECR proton source isinvestigated by using the emission spectra diagnostics tools based on the collisionalradiative model. By comparing their results, the design of the key components of ECRproton source, the beam extraction and transmission characteristics are optimized. Theinnovation is reflected as follows:1. The use of emission spectroscopy diagnostics on ECR proton source to measure theECR hydrogen plasma emission spectra, especially the blamer lines of hydrogenatomic emission spectrometry varies with the experimental conditions. Caculatingthe plasma parameters like electron density and electron temperature by using asimple collision radiation model of the hydrogen plasma. Besides, we comprare theECR hydrogen plasma parameters in cw mode to which in pulse mode ofmicrowave generator, we point out the vatiation of hydogen plasma emissionspectra intensity along with time in one duration of microwave signal for the firsttime from an engineering view, providing an effective reference to the pulse beam extraction and the design of microwave generator parameters in the time scale.2. This diagnostic method effectively connects the plasma parameters with beamcurrent intensity in the condition of different microwave power, providing andexplaining an important reference of the optimum pressure range during the beamextraction, as a result, the efficiency of the ion source is improved.3. The emission spectra of ECR hydrogen plasma varation with the extracted andsuppressed voltage along with the influence of beam to plasma parameters duringthe beam extraction are preliminary investigated with the aim of shedding light onthe mechanism for beam extraction, it is instructive for futher improving the beamintensity and the stability of the ion source.We manufact a new compact ECR proton source and LEBT (Low Energy beamtransport) system, the design method of the key components for this system arediscussed systematically using theoretical simulation and experimental comparison onthe core parameters, thus optimizing their key parameters. By using the emissionspectroscopy method, relations are obtained between ECR hydrogen plasma parametersand key components of the proton source as well as different experimental parameters,and thus influences the intensity of beam extraction.更多还原