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Proceedings Paper

Negative Ions From Alkali Hydrides As A Source For H[sup]-[/sup] Beams
Author(s): S. K. Srivastava
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Paper Abstract

One of the methods of neutralization of a negatively charged particle beam is to photo-detach the extra electron on the particle by a laser beam. At high beam energies this method is more efficient than the charge exchange technique used for a positively charged particle beam. Therefore, development efforts have been in progress in the field of negatively charged particle beams. Among several techniques which are used for the production of negative ion beams the technique of surface conversion of molecules into negative ion fragments has been least explored. Two recent experiments where dissociation of a molecule gave rise to negative ions enhanced our interest in the study of negative ion production by surface conversion. First one was conducted by Palmer who observed that when a beam of LiH was made to impinge upon a heated tungsten surface (heated between 600K and 1000K) H- was produced. They attributed this to surface chemi-ionization. The second was reported by Wang et al. They found that thermal SF6 molecules decomposed into various negative ion fragments upon impact with room temperature alkali surfaces and, thus, these surfaces became copious sources of negative ions. Therefore, we undertook the study of H- formation by LiH. In the following the experimental arrangement is described and the results are presented.

Paper Details

Date Published: 25 July 1989
PDF: 5 pages
Proc. SPIE 1061, Microwave and Particle Beam Sources and Directed Energy Concepts, (25 July 1989); doi: 10.1117/12.951847
Show Author Affiliations
S. K. Srivastava, California Institute of Technology (United States)

Published in SPIE Proceedings Vol. 1061:
Microwave and Particle Beam Sources and Directed Energy Concepts
Howard E. Brandt, Editor(s)

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