Improvement of deuterium emission by St 172 NEG pump in a sealed off vacuum device

Abstract

Zirconium based alloys are proved to be a good material for hydrogen storage as well as a vacuum pump. A non evaporable getter pump based on St 172 was tested for deuterium storage capacity in a sealed off vacuum device. The vacuum in the range of ultra high vacuum was maintained by the getter pump by gettering. Initial vacuum was created by a turbo molecular pumping system. After activation of the getter, test chamber was charged at 1 bar and 3 bar deuterium pressure for 24 h in two different experimental campaigns. After charging with deuterium, the chamber was pumped to ultimate vacuum and isolated from the TMP. The partial pressure of deuterium for different temperature of the getter was measured in sealed condition. Higher charging pressure improves the partial pressure of deuterium during desorption cycle. The experimental details and the results are presented in this article.