Axisymmetric predictions for mitigated and vertically unstable disruptions in ITER with runaway electrons

Abstract

We present two-dimensional global simulations of mitigated and vertically unstable disruptions in ITER in the presence of runaway electrons. An elongated plasma in free-boundary equilibrium is subjected to an artificial thermal quench and current-profile flattening, followed by one or more massive material injections and RE avalanche. Scenarios of major disruptions as well as upward and downward vertical displacement events are considered. Results provide important insights into the effects of runaway electron formation, post thermal quench current-profile, injection quantities and timings, and impurity flushout on the overall evolution of disruption and the plasma vertical motion thereof. Interplay between the various effects offers scope for potentially beneficial runaway electron mitigation scenarios.