Summary of results from the TEXTOR helium self-pumping experiment
Helium removal experiments were conducted in TEXTOR with a small helium self-pumping module located in a modified ALT-I limiter head. The module contained two heated nickel alloy trapping plates, a nickel deposition filament array, a Langmuir probe, flux probe, and thermocouples. The experiment examined plasma helium removal via trapping of helium ions in the deposited nickel surfaces. Such helium removal was successfully observed, with about 10 % of the helium in a 10 % He/D plasma being removed in a 1 s period. The module was found to be compatible with overall tokamak operation with essentially no sputtered nickel entering the core plasma. The temperature rise on the ion-exposed inner trapping plate during a plasma shot was consistent with a local sheath potential of about 3kT(e). Helium atom concentrations in the deposited nickel were consistent with the observed helium removal.
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 196-198 (1992) pp. 664-669
Record Number: 199310268 / Last updated on: 1994-11-29
Original language: en
Available languages: en