Validation of the current decay model in the initial phase of current quench in high β_p disruptive discharges of JT-60U

摘要

The precise prediction of plasma current decay time, T, is important in order to estimate the electromagnetic forces acting on vacuum vessel and in-vessel components during the tokamak disruption. The so-called LIR model often used to predict the current decay time in ITER [1] is based on a simple series circuit considering the plasma resistance R_p and inductance L_p, which are constant in time. In the "LIR model", the current decay time represents with τ_(L/r) = L_p/R_p. If the plasma resistivity is defined by Spitzer resistivity [2], the current decay time is mainly determined by the electron temperature T_e and effective charge Z_(eff). However, the systematic research of the relationship between the current decay time during disruption and the measurement value of L_p and R_p has rarely been done until now.