Title :
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
fDate :
10/1/1993 12:00:00 AM
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;
Journal_Title :
Plasma Science, IEEE Transactions on
