In situ deposition of boron layer by electron cyclotron resonance discharges for wall conditioning
- Nagoya Univ. (Japan); and others
Plasma-assisted coating of boron thin films on inner surfaces of nuclear fusion devices, referred to as boronization, has been applied to many machines since its development in a laboratory device and the first performance in TEXTOR. Tile boronization is the most promising method of wall conditioning for particle controls in fusion experiments, in view of strong oxygen gettering (impurity control) and low hydrogen recycling (fuel control). To date, decomposition of boron hydride such as diborane (B{sub 2}H{sub 6}) and decaborane (B{sub 10}H{sub 14}) has been accomplished by dc glow discharges without magnetic fields which can boronize a large vessel as uniformly as possible. In a next generation fusion device such as ITER, however, a hot core plasma should be sustained quasi-steadily in a strong magnetic field provided by super-conducting magnets. Thus, a new boronization technique will be needed which enables in situ boron deposition using a fusion plasma itself without interrupting magnetic fields. In this paper, we report a fundamental experiment on boronization using a magnetized plasma, i.e., an electron-cyclotron-resonance (ECR) microwave discharge. The spatial distributions of boron films suggest that boron containing ions (B{sub m}H{sub n}{sup +}) are easily transported far away along the magnetic field lines, thus making boron deposition in a wide area of fusion machine.
- OSTI ID:
- 212952
- Report Number(s):
- CONF-950749-; TRN: 96:010102
- Resource Relation:
- Conference: 22. international conference on phenomena in ionized gases, Hoboken, NJ (United States), 31 Jul - 4 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of XXII International conference on phenomena in ionized gases. Contributed papers 4; Becker, K.H.; Carr, W.E.; Kunhardt, E.E. [eds.]; PB: 256 p.
- Country of Publication:
- United States
- Language:
- English
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