3D MHD Simulation Study on Pressure-Driven Instability of Spheromak in a Flux Conserver

抄録

A full resistive 3D MHD simulation code is developed to examine the pressure-driven instability of a high-beta spheromak in a flux conserver. It is found that the time evolution of the pressure-driven mode can adequately be investigated by the developed 3D code. Simulations are made for three different beta values. Results have shown that a low-n ballooning mode (m=1, n=3) is most strongly excited for all beta values. Extrapolation of these results suggests that the beta limit for this mode is about 5%. With the development of the instability, magnetic surfaces are observed to be destroyed considerably.