Initial wall conditioning for the TMX-U fusion experiment
The introduction of impurities and hydrogen from the walls and liners of the TMX-U device can have a deleterious effect on the plasma. The area of these surfaces is large (approx.10/sup 7/ cm/sup 2/) and has a complicated shape, so cleaning is difficult. Techniques that have been used to condition these walls include (1) initial solvent cleaning; (2) baking; (3) glow discharge cleaning; (4) gettering; and (5) plasma clean up. Several diagnostic techniques, including UV and visible spectroscopy and residual gas analysis, have been used to evaluate the effectiveness of the conditioning procedures. A series of experiments was performed to optimize the glow discharge in the TMX-U geometry; during approximately 80 h of glow discharge cleaning, low-Z impurities were removed. Gettering along with pumping with liquid-nitrogen-cooled liners and cryopumps resulted in base pressures approx.10/sup -8/ Torr. This paper describes these procedures and their importance in the formation of initial plasmas in TMX-U.
- Research Organization:
- Lawrence Livermore National Laboratory, University of California, Livermore, California 94550
- OSTI ID:
- 5768649
- Journal Information:
- J. Vac. Sci. Technol., A; (United States), Vol. 1:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LINERS
BAKING
GETTERING
IMPURITIES
SURFACE CLEANING
TMX DEVICES
WALLS
CRYOPUMPS
GAS ANALYSIS
GLOW DISCHARGES
PLASMA
PLASMA DIAGNOSTICS
ULTRAHIGH VACUUM
ULTRAVIOLET SPECTRA
VISIBLE SPECTRA
CLEANING
ELECTRIC DISCHARGES
EQUIPMENT
HEATING
LABORATORY EQUIPMENT
MAGNETIC MIRRORS
OPEN PLASMA DEVICES
PUMPS
SPECTRA
SURFACE FINISHING
TANDEM MIRRORS
THERMONUCLEAR DEVICES
VACUUM PUMPS
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