Low-voltage discharge in cesium-hydrogen mixture as a source of negative hydrogen ions

Author

Baksht, F.G. ; Djuzhev, Georgy A. ; Elizarov, L.I. ; Ivanov, Vasily G. ; Kostin, Anatoly A. ; Shkolnik, Sergey M.

Author_Institution

A.F. Ioffe Phys.-Tech. Inst., Polytech., St. Petersburg, Russia

Volume

21

Issue

5

fYear

1993

fDate

10/1/1993 12:00:00 AM

Firstpage

552

Lastpage

559

Abstract

It is shown theoretically that a low-voltage Cs-H₂ discharge can be utilized as a volume-plasma negative hydrogen ion source with very high H^- concentration (≲10¹³ cm^-3) in plasma. The volume H^- generation occurs because of dissociation attachment of heated thermal electrons to vibrationally excited H₂ molecules. The high rate of H^- generation is explained by high electron concentration (~10¹⁴ cm^-3), high hydrogen pressure (≳1 torr) and optimum value of thermal electron temperature (≳1 eV) in plasma. It causes rapid pumping of vibrationally excited H₂ levels and high rate of dissociative attachment. Electron vibration kinetics in the discharge is considered, and H^- concentration is calculated. The optimum discharge parameters for H^- generation are determined. Experimental investigation of the discharge has been performed. It is shown that theoretical and experimental plasma parameters are very close to one another

Keywords

caesium; discharges (electric); electron attachment; hydrogen; hydrogen ions; ion sources; molecular electron impact dissociation; negative ions; plasma collision processes; plasma probes; 1 eV; 1 torr; Cs-H₂; H₂; H^-; dissociation attachment; electron vibration kinetics; heated thermal electrons; ion source; low-voltage discharge; optimum discharge parameters; pumping; vibrationally excited molecules; Electrodes; Electrons; Fault location; Fusion power generation; Hydrogen; Ion sources; Plasma accelerators; Plasma materials processing; Plasma sources; Plasma temperature;

fLanguage

English

Journal_Title

Plasma Science, IEEE Transactions on

Publisher

ieee

ISSN

0093-3813

Type

jour

DOI

10.1109/27.249642

Filename

249642