Study of astrophysical collisionless shocks in the laboratory

High Mach number astrophysical plasmas can create collisionless shocks via plasma instabilities and turbulence that are responsible for magnetic field generations and cosmic ray acceleration. With the advent of high-power lasers, laboratory experiments with high-Mach number, collisionless plasma flows can provide critical information to help understand the mechanisms of shock formation by plasma instabilities and self-generated magnetic fields. A series of experiments were conducted on Omega and the National Ignition Facility to observe: the filamentary Weibel instability that seeds microscale magnetic fields [1, 2]; collisionless shock formation (seen by an abrupt ~4x increase in density and ~6x increase in temperature); and electron acceleration distributions that deviated from the thermal distributions [3]. In addition to the case of collisionless shock formation under unmagnetized initial condition, shock formation under magnetized environment is also being studied. Experimental results along with theoretical interpretations aided by particle-in-cell simulations will be discussed.



[1] H.-S. Park et al., HEDP 8, 38 (2012)

[2] C. Huntington et al., Nature Physics 11, 173 (2015)

[3] F. Fiuza et al., Nature Physics, 16, 916 (2020)