INVESTIGATION OF THE EXTRACTED H- CURRENT IN A CONTINUOUSLY PULSED-VOLUME NEGATIVE-ION SOURCE

被引:6
作者
HEEREN, RMA [1 ]
MELLON, KN [1 ]
HOPKINS, MB [1 ]
CIRIC, D [1 ]
KLEYN, AW [1 ]
机构
[1] DUBLIN CITY UNIV,DEPT PHYS,DUBLIN 9,IRELAND
来源
EUROPHYSICS LETTERS | 1992年 / 17卷 / 6BIS期
关键词
ION SOURCES; POSITIVE NEGATIVE AND POLARIZED; ELEMENTARY PROCESSES IN PLASMA;
D O I
10.1209/0295-5075/17/6/005
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
We have observed a significant increase in average extracted negative-ion current <I-> when pulsing the discharge current of a small, high-power density volume negative-ion source at low pressures. Compared to a DC-operated discharge, <I-> is increased by 35% at a pressure of 0.38 Pa. This result is explained with a simple model which shows that the enhancement of <I-> at low pressures can be attributed to an increased production of negative ions through dissociative attachment, as a result of the colder electrons in the postdischarge. The temporal behaviour of the extracted negative-ion current in this small, high-power density source is markedly different than the negative-ion current of a larger low-power density source.
引用
收藏
页码:503 / 508
页数:6
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