Three-dimensional nonlinear simulation of the spheromak tilt instability

Summary for only given, as follows. A spheromak is a force-free spherical plasma configuration that uses only internally generated magnetic fields to contain the plasma. It is known from linear theory that slightly prolate spheromaks are unstable to an m=1 mode tilt. Experimentally oblate spheromaks have also demonstrated a tilt instability. We are using our nonlinear 3D code to investigate this unstable mode as a function of the geometry (of the cylindrical flux conserver). The code is a parallel Riemann solver for the resistive and viscous MHD. We compare the results with those of linear codes and with experimental data.