We show that a magnetic shock whose initial density and/or magnetic perturbation exceeds the Hugoniot limit may lead to substantial and rapid energy release in low $\beta$ plasmas (such as occur in the magnetospheres of neutron stars). We illustrate this effect for a fast Magnetohydrodynamic perturbation, as well as for large density perturbations which can be naturally created in low $\beta$ plasmas. Using the Riemann solution and simulations, we show that slow modes of finite magnitudes and Alfvénic perturbations can generate strong density perturbations. These perturbations develop into shocks, resulting in efficient energy release.

• Received 3 May 2001

DOI:https://doi.org/10.1103/PhysRevE.65.035401