Effects of bias potential upon H{sup -} density near a plasma grid of a negative ion source
- Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)
A molybdenum plasma grid was installed in a 30-cm-long 16-cm-diam 16-pole magnetic multicusp ion source to simulate the effect of a plasma electrode bias of a negative ion source. Effects caused by the bias voltage applied to the electrode upon the plasma parameters, the density of negative hydrogen ions (H{sup -}), and the drift velocity of plasma perturbed by the photodetachment of H{sup -} were investigated with the direct current laser photodetachment method. The electron density at the distance of 0.5 cm from the plasma grid decreased from 8x10{sup 10} to 4x10{sup 10} cm{sup -3} by increasing the grid bias from 0 to +4 V, while the H{sup -} density increased from 8x10{sup 8} to 4.5x10{sup 9} cm{sup -3}. The drift velocity of plasma perturbation was changed by a factor of 3 corresponding with the gradient of the plasma potential near the electrode.
- OSTI ID:
- 20778998
- Journal Information:
- Review of Scientific Instruments, Vol. 77, Issue 3; Conference: 11. international conference on ion sources, Caen (France), 12-16 Sep 2005; Other Information: DOI: 10.1063/1.2165573; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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