Enhancement of DIII-D neutral beam system for higher performance

Conference · Tue Sep 01 04:00:00 EDT 1992

OSTI ID:7192525

Hong, R; Colleraine, A P; Kellman, D H; Kim, J; Luxon, J L; Nerem, A; Phillips, J; Wight, J

The DIII-D tokamak employs eight neutral beam systems for plasma heating and current drive experiments. These positive ion source neutral beam systems have gone through several improvements in operational technique and in system hardware since the start of conditioning of the first long pulse ion source in December 1986. These improvements have led to the routine operation in deuterium at beam power levels of 20 MW. The improvements in operational technique include filament power supply operating mode, accelerator grid voltage holding capability, mid changes in grid potential gradients. The hardware improvements include installation of arc notching, arc discharge density regulation, and control of neutralizer gas puffing. Each of these improvements are discussed in this paper. Successful testing and operation of the ion source at 93 kV deuterium beam energy, well above the design value of 80 kV, also led to the possibility of enhancing system capability to 28 MW power level, nearly twice the original design value. Upgrading of the beam system to 60 second pulse duration at the currently achieved power level is under consideration. Studies have shown that this pulse length extension can be achieved with improvements in beamline heat handling components and auxiliary systems, especially the power supply system. The drift duct (the section between neutral beam beamline and tokamak) upgrade and protection for the long pulse duration present the greatest challenges, and are crucial to achieving long pulse beam injection into the tokamak plasma.

• Research Organization: General Atomics, San Diego, CA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-89ER51114
• OSTI ID: 7192525
• Report Number(s): GA-A-21034; CONF-920930--6; ON: DE93000878
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700460* -- Fusion Technology-- Heating & Fueling Systems
BEAM INJECTION
BEAM INJECTION HEATING
CLOSED PLASMA DEVICES
DOUBLET-3 DEVICE
Fu
Fuels-- (1992)
HEATING
ION SOURCES
MODIFICATIONS
NEUTRAL ATOM BEAM INJECTION
NON-INDUCTIVE CURRENT DRIVE
PERFORMANCE
PLASMA HEATING
THERMONUCLEAR DEVICES
TOKAMAK DEVICES