Measuring Method and Confirmation of H- (D-) Ion Current by Sheet Plasma 1

摘要

It is very difficult to separate an electron current from H- and D- ion current under volume production, because both electrons and H- or D- ions are extracted from a discharge plasma in H2 or D2 gas. However, H- or D- ion current by volume production in the sheet plasma can be easily separated from electron current by using the weak magnetic field applied to the sheet plasma itself. Then, if the H- or D- ion current is compared with positive ion (mainly H+3 or D+3) current which is extracted by changing sign of the acceleration voltage from plus (for H- or D- ion) to minus, the H- or D- ion current can be confirmed more exactly.