Optimum plasma grid bias for a negative hydrogen ion source operation with Cs

Journal Article · Mon Feb 15 04:00:00 EST 2016 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4935007· OSTI ID:22482952

Bacal, Marthe ^[1]; Sasao, Mamiko ^[2]; Wada, Motoi ^[3]; McAdams, Roy ^[4]

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1. UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France)
2. R&D Promotion Organization, Doshisha University, Kamigyoku, Kyoto 602-8580 (Japan)
3. School of Science and Engineering, Doshisha University, Kyotonabe, Kyoto 610-0321 (Japan)
4. CCFE, Culham Science Center, Abingdon, Oxfordshire 0X14 3DB (United Kingdom)

The functions of a biased plasma grid of a negative hydrogen (H{sup −}) ion source for both pure volume and Cs seeded operations are reexamined. Proper control of the plasma grid bias in pure volume sources yields: enhancement of the extracted negative ion current, reduction of the co-extracted electron current, flattening of the spatial distribution of plasma potential across the filter magnetic field, change in recycling from hydrogen atomic/molecular ions to atomic/molecular neutrals, and enhanced concentration of H{sup −} ions near the plasma grid. These functions are maintained in the sources seeded with Cs with additional direct emission of negative ions under positive ion and neutral hydrogen bombardment onto the plasma electrode.

• OSTI ID: 22482952
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 87; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
74 ATOMIC AND MOLECULAR PHYSICS
CURRENTS
GRIDS
HYDROGEN IONS 1 MINUS
MOLECULAR IONS
PLASMA
PLASMA POTENTIAL
SPATIAL DISTRIBUTION