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Title: Charged particle flows in the beam extraction region of a negative ion source for NBI

Experiments by a four-pin probe and photodetachment technique were carried out to investigate the charged particle flows in the beam extraction region of a negative hydrogen ion source for neutral beam injector. Electron and positive ion flows were obtained from the polar distribution of the probe saturation current. Negative hydrogen ion flow velocity and temperature were obtained by comparing the recovery times of the photodetachment signals at opposite probe tips. Electron and positive ions flows are dominated by crossed field drift and ambipolar diffusion. Negative hydrogen ion temperature is evaluated to be 0.12 eV.
Authors:
 [1] ; ; ; ; ; ;  [1] ;  [2] ; ; ;  [3]
  1. SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)
  2. (Japan)
  3. National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)
Publication Date:
OSTI Identifier:
22482925
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; AMBIPOLAR DIFFUSION; ANIONS; BEAMS; CATIONS; CROSSED FIELDS; HYDROGEN IONS; PROBES; SIGNALS