Deuterium Pellet Injection into Plasmas of the Fontenay-aux-Roses Tokamak TFR: Photographic and Spectroscopic Measurements of the Ablation Zone

Abstract

The trajectories of D2-pellets injected into TFR-plasmas were photographed under an oblique of approximately 45 degrees relative to the plane of injection. Bright and dark zones extending in toroidal direction were observed. These striations showed an inclination relative to the direction of the toroidal magnetic field and are likely to indicate the poloidal magnetic-field strength. Direct time-integrated spectroscopic measurements on a single striation yields an average electron density of 1017 cm-3 and temperatures ranging from T = 1.6 eV in the immediate vicinity of the ablation zone to approximately 20 eV in a distance of 1.5 to 2 cm from the ablation centre.