Suppression of Runaway Electron Current During a Discharge Disruption in an ITER-Scale Tokamak of Using an Injected Collector

This paper presents the results of numerical simulations of the time evolution of plasma current and the suppression of the runaway electron current in an ITER-scale tokamak during the disruption of the tokamak discharge by means of injection of tungsten collectors capturing the runaway electrons (RE). A zero-dimensional approach was used while solving a system of two differential equations for both plasma and RE currents. The RE losses on the tungsten collector during its flight through the plasma at the discharge current quench stage were taken into account. Requirements were formulated for the selection of collector injection parameters ensuring the safe operation of the tokamak. The simulation results show that the most promising scenario is the simultaneous injection of three 80-gram tungsten collectors at a speed of 250 m/s immediately after the thermal quench stage.