Magnetized bow shocks in radiatively cooled collisional plasma flows

We investigate magnetized bow shock formation in strongly radiatively cooled collisional plasma flows using the 3D resistive MHD code GORGON. We simulate bow shocks from the interaction of supersonic, super-Alfvénic plasma, generated during the ablation phase of an inverse z-pinch array, with dielectric blunt obstacles. Mass ablation from the wire array produces radially diverging, highly collisional (λ_ii<<a), β∼0.1 upstream flows with frozen-in magnetic flux (Re_m>>1). Obstacles mimic B-dot probes and are aligned to measure the advected azimuthal magnetic field. Bow shock shape is modified by flux pile-up at the probe; so opening angle and stand-off distance vary with the angle between the shock and the magnetic field – thus, these shocks exhibit a 3D structure. We investigate the effect of probe size and strong radiative cooling on shock structure and the post-shock magnetic field measured by the probe.

Numerical results are benchmarked against experiments performed at the MAGPIE facility (1.4MA, 250ns), and are used to predict bow shock structure at the Z Pulsed Power facility (Sandia National Labs; 30MA, 300ns), for the MARZ (Magnetically Ablated Reconnection on Z) Z fundamental science program.