Thermal quench runaway electron generation and post current quench runaway deconfinement characteristics

摘要

The significant loop voltages induced during rapid-shutdowns and disruptions of tokamaks can generate runaway electrons which then may damage machine components. We present results from a new spatially distributed scintillator array designed for observing the spatial distribution òf x-rays emitted by runaway deconfinement and also for rough energy resolution. Using this array we describe multiple phases of runaway electron deconfinement with various generation and deconfinement mechanisms governing the evolution throughout. To explain the early presence of runaway electrons before current quench loop voltages could accelerate them, we also discuss analysis of internal loop voltages which reveals a previously neglected early loop voltage not captured by poloidally averaged external measurements.