The key to understanding Supersonic Radiative Marshak waves using Simple Models and Advanced Simulations*

Radiative heat (Marshak) waves play important roles in many high energy density physics phenomena, for example in inertial confinement fusion (ICF) and in astrophysical and laboratory plasmas. In recent decades, several experiments of supersonic Marshak waves propagating through low-density foams were reported,  for example in [1-4]. The theoretical understanding of these complicated systems is still incomplete. We analyzed different experiments, carried out in different experimental set ups. In this work we integrate several methods that analyze the experiments. First, we show a simple analytic model that grasps the main physical effects [5]. Nevertheless, we use heavy exact 2D IMC and S_N hydro-dynamic simulations, for more accurate results in every experiment. Although the experiments were carried out in extremely different circumstances, we show they share a lot in common. Finally, we show a new approximation [6], yields very similar results to the exact.

[1]J. Massen, et al., PRE 50, 4130 (1994).

[2]C.A. Back, et al., Phys. Plas. 7, 2126 (2000).

[3]C.A. Back, et al.,  PRL. 847, 274 (2000).

[4]A.S. Moore, et al., JQSRT, 159, 19 (2015).

[5]A. P. Cohen, et al., JCTT, accepted (2018).

[6]A. P. Cohen et al., arXiv:1802.01128 (2018).