Influence of two simultaneous driven currents on multiple tearing modes in tokamak plasmas

Abstract

The influence of two driven currents simultaneously and respectively imposed on the m/n = 2/1 and 3/2 resistive tearing modes in tokamak plasmas is researched by using a three-dimensional toroidal magnetohydrodynamic code CLT. The simulation results show that using two suitable driven currents can better suppress multiple tearing modes than using only one of the two driven currents. When the two suitable driven currents are simultaneously imposed on both the m/n = 2/1 and 3/2 modes, respectively, the two modes may be well suppressed. If only one of the driven currents is imposed on the m/n = 2/1 mode, then the m/n = 2/1 mode may be well suppressed but the m/n = 3/2 mode may be not. Conversely, if only the other of the two driven currents is imposed on the m/n = 3/2 mode, both the two modes may be not suppressed. Moreover, it should be noted that the parameters of using two driven currents to suppress multiple tearing modes must be appropriate; otherwise, some new modes (such as m/n = 5/3 mode) may be excited and grown due to the interaction among the driven currents and multiple modes.