Initial boronization of the DIII-D tokamak
A system has been installed to deposit a thin film of elemental boron to the walls of the D3-D tokamak, in order to reduce the influx of impurities during plasma discharges. Subsequently new regimes of substantially tokamak energy confinement were obtained. The deposition of the boron layer is achieved during a glow-discharge session using a helium-diborane age mixture and a film of {approx}100 nm is deposited. The boronization system includes special storage and handling precautions for the diborane, a delivery and metering system for the glow-discharge, modifications to the tokamak's residual gas analyzer system, and a dedicated system for handling and neutralizing the exhaust gas from the tokamak. Tokamak discharges with similar parameters before and after boronization are used to characterize the effects of the boron film. Nickel has been reduced by a factor of 30, while impurities such as oxygen and carbon are reduced fivefold. A system of pulsing the flow discharge has been developed in order to improve the uniformity of the film applied.
- Research Organization:
- General Atomics, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-89ER51114
- OSTI ID:
- 5994750
- Report Number(s):
- GA-A-20750; CONF-911132-9; ON: DE92004457
- Resource Relation:
- Conference: 38. national symposium of the American Vacuum Society, Seattle, WA (United States), 11-15 Nov 1991
- Country of Publication:
- United States
- Language:
- English
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A system to deposit boron films (boronization) in the DIII-D tokamak
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Related Subjects
FIRST WALL
SURFACE COATING
BORON
DOUBLET-3 DEVICE
LAYERS
PRESSURE VESSELS
THIN FILMS
CLOSED PLASMA DEVICES
CONTAINERS
DEPOSITION
ELEMENTS
FILMS
SEMIMETALS
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTOR WALLS
TOKAMAK DEVICES
700420* - Fusion Technology- Plasma-Facing Components- (1992-)