スフェロマク緩和現象の三次元シミュレーション

抄録

Relaxation processes toward the lower energy states in spheromak configurations were studied by means of three dimensional magnetohydrodynamic simulations. For the initial conditions, two cases of equilibrium states were given and the temporal evolutions of the instabilities were investigated in the nonlinear regime. In the first case, which has a high q-profile (1.7 at the magnetic axis), the poloidal flux amplification was observed through the development of a m=1, n=1 mode. This process can be explained by the Kadomtsev internal disruption model. In the second case, which has a low q-profile (0.12 at the magnetic axis), magnetic flux conversion from the poloidal to the toloidal direction toward the Taylor minimum energy state was observed through the development of a m=1, n=4 kink mode. It is expected that this process is related to the self-reversal mechanism in a reversed field pinch.