Optimum plasma grid bias for a negative hydrogen ion source operation with Cs
- UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France)
- R&D Promotion Organization, Doshisha University, Kamigyoku, Kyoto 602-8580 (Japan)
- School of Science and Engineering, Doshisha University, Kyotonabe, Kyoto 610-0321 (Japan)
- 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, Vol. 87, Issue 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characteristics of plasma grid bias in large-scaled negative ion source
Enhancement of pure volume negative ion production using a grid bias method or a magnetic filter method