414 / 2019-02-28 21:32:21

Linear stability of impulsively accelerated density interface in ideal two-fluid plasma

Richtmyer-Meshkov instability; two-fluid plasma; linear stability

全体主题 > Interface Instabilities at Extremes

Inertial confinement fusion (ICF) is a promising method for the generation of fusion energy. By imploding the target to very high densities, it is expected that the fusion reactions occur and the fuel is confined by its own inertia. A key bottleneck towards the achieving goal of ICF is hydrodynamic instabilities, such as Richtmyer–Meshkov instability (RMI) which occurs when a perturbed density interface is impulsively accelerated. Due to the high temperature and high energy-density scenario in ICF, it is expected the materials to be in a plasma state, and thus could be influenced by a magnetic field. Baksh et al. [2] performed a linear analysis of the RMI in the context of single-fluid MHD in cylindrical geometry. They employed the method developed by Samtaney [1] to compute the numerical solution of the linearized system of equations. It was concluded that the RMI was suppressed due to the transport of vorticity away from the interface by Alfvén fronts. Presently, we investigate the linear stability of impulsively accelerated density interface in ideal two-fluid plasma (TFP) [3]. In the TFP model, ions and electrons evolve as two different fluids governed by Euler equations, and are coupled to the full Maxwell’s equations. In this model, two non-dimensional length scales arise: Debye length rD and the Larmor radius rL. The system of equations is written in a general form as in Eq. (1). For linear analysis, we split the solution into the base flow and perturbations . Then the linear stability is numerically studied as an initial-value-problem by solving Eq. (2) and (3) simultaneously. We examine the effects of perturbation wavenumber and impulsive acceleration strength on RMI, as well as the parametric variation on Debye length rD and the Larmor radius rL, and examine the suppression mechanisms in the TFP model.