シートプラズマによる大電流H-, D-イオン源の研究 (II)
1984 年 27 巻 7 号 p. 610-616
詳細
1984 年 27 巻 7 号 p. 610-616
A development to large area H- or D- ion source is tried by using three extraction electrodes : The first electrode bias voltage is set near the wall potential (floating), the second electrode is set near 13 % of main extraction voltage and the third electrode is the main acceleration electrode. An ion current of 13 mA (3.3 mA/cm2) for H- or 11 mA (2.8 mA/cm2) for D- at 3 keV is extracted from 9 apertures of 6 mmφ in 4 cm2 outside of the sheet plasma (14 cm wide and 1.0 cm thick) under a pressure of 7.7×10-4 Torr H2 or D2 gas and a week magnetic field 50 gauss. Then, it is noted that the corresponding electron current is suppressed below 1/10 of the H- or D- ion current.
