Expansion of a radially symmetric blast shell into a uniformly magnetized plasma

M. E. Dieckmann , Q. Moreno , D. Doria , L. Romagnani , G. Sarri , D. Folini (1) , R. Walder (1) , A. Bret , E. d'Humières , M. Borghesi

1 CRAL - Centre de Recherche Astrophysique de Lyon

The expansion of a thermal pressure-driven radial blast shell into a dilute ambient plasma is examined with two-dimensional PIC simulations. The purpose is to determine if laminar shocks form in a collisionless plasma which resemble their magnetohydrodynamic counterparts. The ambient plasma is composed of electrons with the temperature of 2 keV and cool fully ionized nitrogen ions. It is permeated by a spatially uniform magnetic field. A forward shock forms between the shocked ambient medium and the pristine ambient medium, which changes from an ion acoustic one through a slow magnetosonic one to a fast magnetosonic shock with increasing shock propagation angles relative to the magnetic field. The slow magnetosonic shock that propagates obliquely to the magnetic field changes into a tangential discontinuity for a perpendicular propagation direction, which is in line with the magnetohydrodynamic model. The expulsion of the magnetic field by the expanding blast shell triggers an electron-cyclotron drift instability.

Mots clés: Physics - Plasma Physics

Domaines: Planète et Univers [physics]

M. E. Dieckmann, Q. Moreno, D. Doria, L. Romagnani, G. Sarri, et al.. Expansion of a radially symmetric blast shell into a uniformly magnetized plasma. Physics of Plasmas, 2018, 25, ⟨10.1063/1.5024851⟩. ⟨insu-03711227⟩