Measurement of the negative hydrogen ions temperature by using an omegatron mass analyzer in the sheet plasma
Abstract
The production mechanisms of negative ions in hydrogen plasma are not easily understood because of the complex phenomena of atomic and molecular reactions. A mainstream measurement of H- is a laser photodetachment technique. We had measured negative ions using a laser photodetachment technique. Consequently, under a secondary hydrogen gas supply entering into the plasma, the H- is distributed in the periphery of the sheet plasma. In addition, it has been reported that the negative hydrogen ions transport velocity evaluated by the relaxation time of optically released electron current. Nevertheless, this technique a laser photodetachment cannot be used as a mass analyzer. In this paper, we have measured the temperature of the negative hydrogen ions TH- by using an omegatron mass analyzer in the sheet plasma. The TH- is determined by measuring the collection ion currents IH- as a function of the ion repeller voltage VG2 by using an omegatron mass analyzer. From the fitting an exponential region of the measured I-V characteristics curve, TH- is around 1.40 eV at the gas pressure of 0.23 Pa in the periphery region of the sheet plasma.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- September 2015
- Bibcode:
- 2015APS..GECGT1072T