Numerical Simulations of Forced Coalescence of Magnetic Islands Generated by a Tearing Mode Instability

抄録

The coalescence instability so far has been analyzed for the Finn-Kaw model in which parallel currents in neighboring islands tend to attract each other. The current distribution of magnetic islands resulting from the compressible tearing mode, however, is opposite to that of the Finn-Kaw model. It was found by simulations that the coalescence instability does not take place for magnetic islands generated by a tearing mode instability. An apparent coalescence is induced by an external force, but it appears to reflect the growth of the linear tearing mode instability with the wavelength longer than the original one.