Generation of negative hydrogen ions in low-voltage cesium-hydrogen discharge

Conference · Mon Oct 05 00:00:00 EDT 1992 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:6934953

Baksht, F G; Djuzhev, G A; Elizarov, L I; Ivanov, V G; Kostin, A A; Shkolnik, S M ^[1]

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1. A. F. Ioffe Physical-Technical Institute, St. Petersburg, 194021 (Russian Federation)

Theory of low-voltage (LV) Cs--H[sub 2] discharge is presented. LV arc plasma is created in consequence of ionization of small Cs amount (N[sub Cs]/N[sub H[sub 2]][approx lt]10[sup [minus]2]), hydrogen being non ionized and slightly dissociated. In dense LV plasma the cathode beam relaxation and thermal electron heating occur because of pair Coulomb collisions between beam and plasma electrons. The volume H[sup [minus]] generation occurs because of dissociation attachment of heated thermal electrons to vibrationally excited H[sub 2] molecules. It is shown theoretically that high H[sup [minus]] concentration (N[sub H][minus][approx gt]10[sup 13] cm[sup [minus]3]) may be achieved in dense plasma of LV Cs--H[sub 2] discharge. The high rate of H[sup [minus]] generation is explained by optimum value of thermal electron temperature (T[sub e][approx gt]1 eV), high electron concentration (n[similar to]10[sup 14] cm[sup [minus]3]) and high hydrogen pressure (P[sub H[sub 2]][approx gt]1 Torr), that causes rapid v-v pumping of vibrationally excited H[sub 2] levels. Results of the first experimental investigation of LV Cs--H[sub 2] discharge are presented. It is shown that LV discharge exists at comparatively small anode voltage (U[sub a][approx gt]1 V) and sufficiently high electron temperature and concentration. Preliminary comparison between theoretical and experimental data is fulfilled. Experimental plasma parameters agree satisfactory with theoretical ones.

• OSTI ID: 6934953
• Report Number(s): CONF-921145--
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (United States), Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Vol. 287:1; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

661220* -- Particle Beam Production & Handling
664300 -- Atomic & Molecular Physics-- Collision Phenomena-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ANIONS
CESIUM
CHARGED PARTICLES
COLLISIONS
DATA
DISSOCIATION
ELECTRON COLLISIONS
ELECTRON DENSITY
ELECTRON TEMPERATURE
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
INFORMATION
ION DENSITY
ION SOURCES
IONS
METALS
MOLECULE COLLISIONS
NUMERICAL DATA
THEORETICAL DATA
Ta
Targets-- (1992-)