Study of Burgers-like turbulence driven by resistive instabilities in a flux tube

We present results from a study of the nonlinear dynamics of kink-like resistive instabilities in a flux tube in reduced MHD. Simulations were performed using the pseudo-spectral code Viriato, in which a screw pinch equilibrium with a low safety factor (q) on axis was initialized. Due to having q < 1 throughout much of the system, the equilibrium is linearly unstable to a variety of poloidal and toroidal (m and n) resistive modes at the q = m/n rational surfaces, which we confirm via linear analysis. For certain initial perturbations of m=1, high n modes we find that the nonlinear coupling of multiple linearly unstable modes drives turbulence in the system via the excitation of larger m and n tearing modes. This turbulence can be characterized by the formation of current sheets, resulting in a Burgers-like turbulent spectrum with a magnetic energy power law E_M ~ k^-2 and a kinetic energy power law E_K ~ k^-1. These results may have implications for the study of astrophysical jets as well as tearing mode turbulence in reversed field pinches.