Fundamental experiments on evaporation of cesium in ion sources

U Fantz; R Gutser; C Wimmer

doi:10.1063/1.3258428

Fundamental experiments on evaporation of cesium in ion sources

Rev Sci Instrum. 2010 Feb;81(2):02B102. doi: 10.1063/1.3258428.

Authors

U Fantz¹, R Gutser, C Wimmer

Affiliation

¹ Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching, Germany. fantz@ipp.mpg.de

PMID: 20192409
DOI: 10.1063/1.3258428

Abstract

Basic experiments are carried out to study the cesium evaporation and desorption from surfaces at different temperatures in an environment, which is very close to the conditions of negative hydrogen ion sources for fusion applications: in a vacuum base pressure of 10(-5) mbar and in a hydrogen plasma in the Pa-range. Several diagnostic techniques such as emission and absorption spectroscopy, a surface ionization detector, and a quartz-microbalance have been utilized to determine the cesium densities, evaporation and desorption rates. The work function of a cesiated surface measured by the photoelectric effect degrades with increasing plasma-off time. Impurities and cesium compounds are detected by a residual mass analyzer.