An assessment of the lifetime of Faraday shield elements

Author

Caughman, J. B o, II ; Ruzic, D.N. ; Hoffman, D.J. ; Langley, R.A. ; Lewis, M.B. ; Ryan, P.M.

Author_Institution

Illinois Univ., Urbana, IL, USA

fYear

1989

fDate

2-6 Oct 1989

Firstpage

921

Abstract

The interaction of plasma with RF fields from an ion cyclotron range of frequencies (ICRF) antenna has been studied to estimate the amount of Faraday shield erosion expected in normal ICRF heating (ICRH) operation. Plasma parameters and ion energies have been measured in the near field of an antenna and used in a model to estimate the erosion rate of the Faraday shield surface. Experiments were conducted on the RF Test Facility (RFTF), a magnetic mirror device at Oak Ridge National Laboratory (ORNL), using a single-strap resonant loop antenna with a two-tier Faraday shield. Plasma parameters and ion energies have been correlated with the antenna current and used in a computational model of the plasma sheath to predict the amount of erosion expected from the Faraday shield elements exposed to plasma. Predictions of light-ion sputtering of candidate Faraday shield materials are presented

Keywords

fusion reactor materials; fusion reactor safety; plasma diagnostics; plasma sheaths; shielding; sputtering; Faraday shield elements; ICRF heating; RF Test Facility; RF fields; antenna current; erosion rate; ion energies; lifetime; light-ion sputtering; magnetic mirror; near field; plasma parameters; plasma sheath; single-strap resonant loop antenna; Antenna measurements; Cyclotrons; Frequency estimation; Heating; Magnetic resonance; Plasma devices; Plasma materials processing; Plasma measurements; Plasma sheaths; Radio frequency;

fLanguage

English

Publisher

ieee

Conference_Titel

Fusion Engineering, 1989. Proceedings., IEEE Thirteenth Symposium on

Conference_Location

Knoxville, TN

Type

conf

DOI

10.1109/FUSION.1989.102368

Filename

102368