Study of discharge quenching in the T-10 tokamak by injecting high-Z impurity pellets

The problem of the fast quenching of a discharge in tokamaks by injecting high- Z impurity pellets is considered. Results are presented from experiments in the T-10 tokamak, in which a substantial decrease (up to 70%) in the thermal plasma energy was observed. A one-dimensional transport code is developed to describe tokamak-discharge quenching. The code is used to simulate the experiments on quenching the T-10 discharge. It is shown that the injection of a high- Z pellet into the T-10 plasma changes the transport coefficients as compared to their steady-state values derived from the energy balance or scalings.