Study of the sensitivity of a quadrupole mass analyzer and a Bayard Alpert gauge with changes in temperature and gas composition

Abstract

The quadrupole mass analyzer (QMA) and the Bayard Alpert (BA) gauge are used widely in Tokamaks (fusion devices) to study the composition of residual gases and to measure the total pressure inside the vacuum chambers of these devices. The partial pressure analysis of the spectra provides useful information about the sources of impurities or leaks in these chambers. Cryostat chamber of SST-1 Tokamak encloses cold masses like liquid nitrogen panels and liquid helium cooled coils. A QMA or a BA gauge mounted on the cryostat chamber is therefore subjected to gases at low temperatures. An experiment was performed to study the behaviour of these gauges under these conditions. The results will be presented in this paper.