Piston driven collisionless shock experiments, using a pulsed power wire array platform on MAGPIE*

Collisionless shocks are frequently inferred in astrophysical systems where abrupt structural transitions occur over scales much shorter than mean Coulomb collisions, instead relying on instabilities seeded by wave particle interactions to provide dissipation.

Here we present the development and data from a laboratory platform to study collisionless shocks using a 1.4 MA pulsed power driver (MAGPIE, Imperial College London). The setup utilizes two side-by-side inverse wire arrays to produce counter-streaming, super-magnetosonic flows of plasma ablated from metal wires. One ("over-massed") wire array produces a steady flow of ablated background plasma. The second exploding wire array launches a piston-like current loop into this plasma with significant velocity and self-generated magnetic field, to allow the reflection of oncoming particles.

The dynamics of the interaction are captured using multi-frame, self-emission imaging (optical & XUV) and a suite of laser based diagnostics (interferometry, Thomson scattering, Faraday rotation imaging) allows the parameters and structure of the interactions to be measured.