Residual gases in an extreme-high vacuum (XHV) system are measured at each pumping step. On the basis of the analysis, the pumping capacity of each vacuum pump is estimated. As a result, it is found that, in the case of a liquid N2-cooled shroud, the titanium-sublimation pump has a high capacity for evacuating of Ch4 and Ar as well as H2 gas, and a pumping system which consists of two turbo molecular pumps and a rotary pump has a pumping capacity for almost all gases in the region of ultra high vacuum, but loses the capacity for H2 gas in the XHV region.
|Number of pages||7|
|Journal||Denshi Gijutsu Sogo Kenkyusho Iho/Bulletin of the Electrotechnical Laboratory|
|Publication status||Published - 1993 Jan 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering