Numerical Modelling of Collisionless Perpendicular Shocks

D. G ́OMEZ , C. BERTUCCI , P. DMITRUK , L. MORALES

Conferencia; COLAGE XI - Eleventh Latin American Conference on Space Geophysics; 2018

Due to the low plasma density, collisionless shocks are ubiquitous in space physics.Examples of this are the bow shocks formed by the solar wind in front of the planets or the ter-mination shock at the heliospheric boundary. The one-fluid magnetohydrodynamic frameworkprovides an adequate description of the large scale structures of the upstream and downstreamplasmas, but fails at describing the internal structure of these collisionless shocks.A more comprehensive study of the inner and outer features of collisionless shocks would requirethe use of kinetic theory. Nonetheless, in the present contribution we show that a completetwo-fluid model that includes the role of both ions and electrons, can properly capture some ofthe features observed in real shocks. For the specific case of perpendicular shocks,i.e.those forwhich the magnetic field is perpendicular to the shock normal, we numerically solve the one-dimensional two-fluid MHD equations to describe the generation of shocks and their spatialstructure across the shock. Our preliminary numerical results show that finite amplitude fast-magnetosonic waves eventually evolve into stationary fast-magnetosonic shocks with a rampthickness of the order of a few electron inertial lengths. Also, the parallel and perpendicu-lar components of the self-consistent electric field are derived, and their role in acceleratingparticles is discussed