Time-resolved characterization of the formation of a collisionless shock
H. Ahmed, M. E. Dieckmann, L. Romagnani, D. Doria, G. Sarri, M. Cerchez, E. Ianni, I. Kourakis, A. L. Giesecke, M. Notley, R. Prasad, K. Quinn, O. Willi, and M. Borghesi
Accepted
We report on the temporally and spatially resolved detection of the precursory stages that lead to the formation of an unmagnetized, supercritical collision-less shock in a laser-driven laboratory experiment. The measured evolution of the electrostatic potential associated with the shock unveils the transition from a current free double layer into a symmetric shock structure, stabilized by ion reflection at the shock front. Supported by a matching Particle-In-Cell simulation and theoretical considerations, we suggest that this process is analogeous to ion reflection at supercritical collisionless shocks in supernova remnants.