First-wall cleaning and isotope control studies by D(2) ICRF conditioning in Tore Supra with a permanent magnetic field
The use of a permanent magnetic field in superconducting magnetic fusion devices impedes conditioning by glow discharges as actually applied in most pulsed machines. An alternative has been studied in Tore Supra for this purpose with a 3.8 T permanent field: a discharge produced by ion cyclotron range of frequency (ICRF) wave injection. Helium ICRF discharge conditioning (ICRF-DC) has already been shown to desaturate the deuterium-loaded carbon first wall efficiently. How D(2) ICRF-DC can be applied to clean the wall or change its hydrogen isotopic ratio is described. This is achieved by pumping wall-desorbed molecules induced by particle bombardment from the ICRF plasma. The conditioning efficiency is optimized as a function to two input parameters: the gas pressure and the applied power. A plasma characterization is also given as a function of these parameters and a global model has been used to compare the experimental results and to interpret the main processes to which the neutral and charged species are subjected.
Bibliographic Reference: Article: Plasma Phyics and Controlled Fusion, Vol. 39 (1997), pp. 1083-1099
Record Number: 199711339 / Last updated on: 1997-10-16
Original language: en
Available languages: en