Edge plasma conditions and plasma-surface interactions in Extrap T1
Abstract
The T1 device is a toroidal machine with {R}/{a} = {0.5 m}/{0.06 m} and stainless steel wall. It has been used to study high current density reversed field pinch plasmas. The edge plasma has been extensively investigated with double and triple Langmuir probes, heat flux probes and passive probes. Discharges with 40-90 kA plasma current is characterized by an edge density ne( a) ≈ 10 19m -3, Te( a) ≈ 10 eV and a high asymmetric parallel heat flux. A drift perpendicular to the magnetic field can be inferred from Langmuir probe measurements and passive probes and appears to be largely diamagnetic. Edge ion temperatures Ti ≥ 100 eV are inferred from the saturation behaviour of hydrogen ions implanted in passive probes, from the high qi∥ and from the inferred sputtering rate of metals.
- Publication:
-
Journal of Nuclear Materials
- Pub Date:
- April 1995
- DOI:
- 10.1016/0022-3115(94)00571-0
- Bibcode:
- 1995JNuM..220..712B