F. Fiuza (SIMES extra seminar)

Date(s) - Apr 9 2013
12:00 AM - 12:30 PM

Shasta Room, Bldg 40, Room 361


Studying astrophysically relevant current instabilities and collisionless shocks in the laboratory

F. Fiuza

Lawrence Livermore National Laboratory

Collisionless shocks are pervasive in space and astrophysical plasmas and are known to be efficient particle accelerators; however, the microphysics underlying shock formation and particle acceleration is not yet fully understood. The fast progress in laser technology is bringing the study of near-relativistic collisionless shocks into the realm of laboratory plasmas.

We use multi-dimensional particle-in-cell simulations to explore the laboratory conditions associated with intense laser-plasma interactions that allow for the study of the physics of current instabilities, collisionless shocks, and particle acceleration.

It is shown that when an ultraintense laser interacts with an overcritical plasma, relativistic flows are generated and drive a cold return current.

The counterstreaming flows are Weibel/current-filamentation unstable, leading to the generation of a Weibel-instability-mediated shock, with properties similar to the ones associated with astrophysical scenarios.

We will discuss the possibility of studying the spatio-temporal properties of current instabilities and the formation of Weibel-instability-mediated collisionless shocks based on this setup using the current and future laser systems at the Matter in Extreme Conditions (MEC) end station at SLAC together with the LCLS beam. The unique combination of a multi-TW to PW short-pulse drive laser with an ultrashort x-ray probe pulse is shown to provide ideal conditions to unveil the physics behind cosmic accelerators in laboratory.