Achievement and improvement of the JT-60U negative ion source for JT-60 Super Advanced (invited)

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3279398· OSTI ID:22053867

Kojima, A; Hanada, M; Tanaka, Y; Inoue, T; Watanabe, K; Taniguchi, M; Kashiwagi, M; Umeda, N; Tobari, H ^[1]; Grisham, L R ^[2]

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1. Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)
2. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

Developments of the large negative ion source have been progressed in the high-energy, high-power, and long-pulse neutral beam injector for JT-60 Super Advanced. Countermeasures have been studied and tested for critical issues of grid heat load and voltage holding capability. As for the heat load of the acceleration grids, direct interception of D{sup -} ions was reduced by adjusting the beamlet steering. As a result, the heat load was reduced below an allowable level for long-pulse injections. As for the voltage holding capability, local electric field was mitigated by tuning gap lengths between large-area acceleration grids in the accelerator. As a result, the voltage holding capability was improved up to the rated value of 500 kV. To investigate the voltage holding capability during beam acceleration, the beam acceleration test is ongoing with new extended gap.

• OSTI ID: 22053867
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 2; Conference: ICIS 2009: 13. international conference on ion sources, Gatlinburg, TN (United States), 20-25 Sep 2009; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATORS
ANIONS
BEAM INJECTION
DEUTERIUM IONS
ELECTRIC FIELDS
ELECTRIC POTENTIAL
HEATING LOAD
JT-60 TOKAMAK
JT-60U TOKAMAK
TUNING