Abstract:

The structure and operating procedure of the vacuum performance of in-vessel viewing system (IVVS) are introduced. The outgassing rate materials used for IVVS ware tested to evaluate if the system vacuum properties meet EAST vacuum environment requirements. The ultimate pressure provided by the tank for IVVS is 3.37×10^-3Pa under effective pumping speed of 1064L•s^–1. Analyses and optimization was made to improve the system vacuum properties, and finally the ultimate pressure is declined to a certain range of 1×10^-4Pa under the same pumping speed by replacing lower outgassing rate materials, bake-processing of IVVS and more optimized structure. After optimization, the vacuum performance of the system is obviously improved that can meet the requirements of vacuum environment accepted by EAST. Furthermore, the ultimate pressure can be still promoted by adding a set of cryopump to the vacuum pumping system in the tank.

Key words: In-vessel viewing system, Vacuum performance, Material outgassing rate, EAST

摘要：

介绍了EAST真空室内巡视系统(IVVS)系统对EAST真空室第一壁进行巡检操作的工作原理，并基于系统部分材料出气率测试对其真空性能进行了分析。获得了在有效抽速为1064L•s^–1的条件下，IVVS系统试验样机所采用的真空容器的极限真空度为3.37×10^–3Pa。为优化IVVS真空性能，结合材料放气率试验，将部分材料更换为放气率低的材料，对系统进行烘烤处理，并对其中的相关结构提出了优化方案。优化后系统的真空性能有明显提高，在同等抽速条件下的极限真空度在1×10^–4Pa范围内，能够满足EAST接受的真空环境要求。此外，抽气机组增添低温泵可以更进一步提高系统的真空性能。

关键词: 真空室内巡视系统, 真空性能, 材料出气率, EAST装置