二次离子质谱在HL－1托卡马克研究中的应用

APPLICATION OF SIMS IN HL-1 TOKAMAK EXPERIMENT

应用ＬＡＳ－２０００二次离子质谱表面分析系统作了如下测量：（１）测出ＨＬ－１装置的总出气量以及其主要出气组分的出气量百分比和出气峰值温度等参数；（２）对等离子体－表面相互作用进行了ＳＩＭＳ／蒙特卡洛互补分析，测出等离子体边界层中氢气量径向特征长度和氢粒子注入硅片的特征深度，估算出氢通量平均动力温度；（３）对硅收集探针的ＳＩＭＳ／ＡＥＳ分析表明，ＨＬ－１等离子体删削层中主要杂质组分为Ｏ、Ｃ、Ｎｉ、Ｍｏ和Ｃｒ，同时给出原子密度相对百分比；在ＨＬ－１装置中用原位蒸钛来吸氧、碳杂质，从而提高了等离子体纯度和品质；（４）定期检测表明，装置的器壁表面污染呈减弱趋势，这说明ＨＬ－１真空系统的设计研制及运行维护技术措施等是合适的。

The main experimental fruits obtained with a LAS-2000 SIMS system are the following: (1)As the first wall sample being heated , the total outgassing amount, the component percentage and the temperature refer to the outgassing peak were measured. (2)SIMS/Monte-Carlo complemental analysis was carried out to an array of silicon collectors attached on the movable limiter. A radial decay length of the hydrogen flux and characteristic depth of the implanted hydrogen flux were measured. An average dynamic temperature T of 55eV was estimated. (3)SIMS/AES analysis for the silicon collector revealed that main impurity components in the scrape-off layer were O, C, Ni, Mo and Cr. The light impuruies of C and O were the dominant. It led to the use of Ti-gettering to improve the plasma purity and performance. (4)Regular SIMS analysis showed that the surface contamination of the discharge vessel decreased from time to time, qualified by three times of regular SIMS analysis of collectors on the wall during 9 years operation of HL-1 tokamak since 1984. Thus it proved the fitness of the design, the fabrication, the operation and the maintenance technology of the HL-1 vacuum system.