Simulations of the Kink Instability of Flux Ropes in the WVU PHASMA Experiment

Magnetic flux ropes are columns of plasma with axial and azimuthal magnetic fields. The kink instability of a magnetic flux rope is a fundamental process observed in many laboratory, astrophysical, and space plasmas such as pinches, relativistic jets, and eruptive phenomena in the solar corona. Here, we present results from the 3D magnetohydrodynamics code F3D of a flux rope motivated by the West Virginia University PHAse Space MApping (PHASMA) experiment. The evolution of an m=1 kink instability as a function of flux rope axial current, axial magnetic field, and boundary conditions (line-tied and non-line-tied) is investigated and compared to laboratory observations. The experiments show evidence of the excitation of an Alfvenic mode that develops after the m=1 kink nonlinearly saturates. The simulation results are compared to laboratory measurements of kink mode frequency, Alfvenic mode frequency, and kink threshold current.