Experimental study of semi-relativistic quasi-perpendicular shock formation

Laboratory studies of microphysics with strong magnetization and relativistic flow velocities may provide insight into extreme astrophysical phenomena. This work studied an asymmetric interaction on the OMEGA EP laser system, by focusing a long pulse laser to ~10¹⁴ W/cm² at a small separation from a relativistic intensity >10¹⁹ W/cm² short pulse laser on a CH foil. A modification of the quasi-static magnetic fields of the long-pulse generated plasma plume is observed in target-normal proton radiographs. Forward modeling shows that this modification is evidence for magnetized shock formation. A 3D OSIRIS particle-in-cell simulation shows that the strong self-generated magnetic fields of the short-pulse plasma drape around the long-pulse plasma plume, forming an unstable contact discontinuity from which a shock is driven.