Analysis of symmetrization process of density perturbations after deuterium pellet injection in T-10

Fast evolution of an electron density perturbation in the time interval between pellet ablation and density toroidal symmetrization is an important issue of pellet fuelling. The studies of the toroidal velocity of density perturbations created by pellets were carried out on TFTR, JET, JT-60 and T-10 using neutron or SXR emission and interferometer data. Both triangle and self-similar profiles of density perturbation with the constant and varying front speed of order of ion-sonic velocity os= √Te/mi were used for the process description. The main purpose of this paper was to obtain additional information on density cloud evolution in the case of fast formation of density perturbation by deuterium pellet using high spatial and temporal resolution SXR-technique along with interferometer measurements. (author) 5 refs., 4 figs