Collisionless ion-electron energy exchange in magnetized astrophysical shocks
ORAL
Abstract
Magnetized collisionless shocks are ubiquitous in the universe, and energy partition in these shocks has long been an open question. Independent thermalization would predict a largely uneven energy partition because of the large ion-electron mass ratio, contradicting astronomical observations. Our kinetic simulations of low Mach number magnetized collisionless shocks show a significant energy exchange between ions and electrons in the downstream of the shocks, which implies a collisionless electron heating mechanism. A multi-fluid model indicates a resonance between electron whistler and ion magnetohydrodynamic waves may provide new mechanisms that account for the energy transfer from ions to electrons.
*This material is based upon work supported by the Department of Energy [National Nuclear Security Administration] University of Rochester “National Inertial Confinement Fusion Program” under Award No. DE-NA0004144, the Department of Energy under Award Nos. DE-SC0020431 and DE-SC0024566, and the resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory. The authors thank the UCLA-IST OSIRIS consortium for the use of OSIRIS.
–
Publication:Y. Zhang et al., "Kinetic Study of Shock Formation and Particle Acceleration in Laser-Driven Quasi-Parallel Magnetized Collisionless Shocks," accepted, Physics of Plasmas. Y. Zhang et al., "Collisionless ion-electron energy exchange in magnetized shocks," in preparation.
