Department of Li/sup /minus// and H/sup /minus// ion sources
Sources of Li/sup /minus// and H/sup /minus// ions are needed for diagnostic neutral beam and for current drive in fusion plasmas. Previous efforts to generate Li/sup /minus// beams have focused on electron capture in a gas or production on a low work function surface in a plasma. Volume production of Li/sup /minus// by dissociative attachment of optically pumped lithium molecules has also been studied. This thesis presents the first experimental results for volume production of a Li/sup /minus// ion beam from a plasma discharge. A theoretical model for volume production of Li/sup /minus// ions and separate model for Li/sub 2/ production in the lithium discharge are developed to explain the experimental results. The model is in good agreement with the experiment and shows favorable parameter scalings for further improvement of the Li/sup /minus// ion source. A /sup 6/Li/degree/ diagnostic neutral beam based on this ion source is proposed for measurement of magnetic pitch angle in the International Thermonuclear Experimental Reactor (ITER). Previous efforts in developing H/sup /minus// ion sources have concentrated on volume production in a plasma discharge. Experiments to improve the H/sup /minus// current density from a magnetically filtered multicusp ion source by seeding the discharge with cesium or barium have been conducted. A substantial (> factor of five) increase in H/sup /minus// output is achieved for both cesium and barium addition. Further experiments with barium have shown that the increase is due to H/sup /minus// production on the anode walls. The experiments with cesium are consistent with this formation mechanism. These results show that this new type of 'converterless' surface production H/sup /minus// source provides greatly improved performance when compared to a volume H/sup /minus// source. 92 refs., 47 figs.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6138995
- Report Number(s):
- LBL-26618; ON: DE89009975
- Resource Relation:
- Other Information: Thesis (Ph.D.). Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ION SOURCES
DESIGN
BARIUM
CESIUM
CURRENT DENSITY
ELECTRON CAPTURE
HYDROGEN IONS
LITHIUM IONS
NEUTRAL ATOM BEAM INJECTION
PLASMA DIAGNOSTICS
THERMONUCLEAR REACTORS
USES
ALKALI METALS
ALKALINE EARTH METALS
BEAM INJECTION
CAPTURE
CHARGED PARTICLES
ELEMENTS
IONS
METALS
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