Operation of the EGA Electron Gun at High Gas Pressure
Cirri, M. Bianconi, F Cordero, A. Bicci, M. Dobrowolny, ; C. Bonifazi ; et al. ; - ASI Sponsor
Mar - 1992
DOI: 10.1007/BF02507614
ISSN : 0390-5551 ;
journal : Il Nuovo Cimento

Volume : 15 C ; Issue : 2
type: Article Journal

Abstract
This paper presents experimental results on the effects of increasing gas pressure on electron gun operations. The electron gun used is the gun EGA which has been developed for the TSS-1 mission. Various gases have been used with pressures in the range from 10−6 to a few times 10−3 mbar. The measurements, taken in a vacuum chamber, show a steady increase in the slope of theI–V characteristics of the gun when the pressure is increased, as a consequence of ionization phenomena induced by the electron beam. Further measurements have been taken of the overall current on a target at some distance from the gun itself. An attempt is also made at a theoretical calculation of the effects observed, based on simplified models.

keywords : Physics of the ionosphere