382 / 2019-02-28 16:17:52

Marshak wave: Propagation of Radiation and Thermal Fronts in a Plasma

Marshak wave,self-consistent solutions,heat transport

全体主题 > Fundamental Physics at Extremes

Isochoric heating of the matter is of great importance for measuring equation of states and creating of extremes states characterized by high temperature and high pressure. Isochoric heating in a dense materials is achieved by propagation of fast heat wave where energy is transported by either radiation of electrons. Propagation of a heat wave in a homogeneous material takes place of a self-consistent wave where the position of the wave front and time are related by a power law. A radiation heat wave has been described in a seminal paper by Marshak [1]. He obtained analytical self-solutions for homogeneous medium assuming a constant density, exponential time dependence of the temperature at the boundary and power dependence of the radiation transport coefficient on the temperature.
In this talk, we extend the Marshak’s solution to several cases of practical interest in high energy density physics. First, we deduced the all possible self-similar solutions for the radiation transport for the temperature or the radiation flux at the boundary exhibiting a power or exponential dependence on the time. The shape of the heat wave and explicit time-dependent scaling formulas are obtained. Second, we considered the heat wave mediated by electron heat conduction and obtained the shape of a self-consistent solutions for the cases where the temperature or heat flux are given at the boundary as power or exponential functions of time. We also considered the self-consistent solution for the electron heat wave in a solid material supported by a laser irradiation of a constant intensity for the case where the laser absorption coefficient is a power function of the plasma temperature.
Finally, we will discuss a possibility of construction of self-similar solutions for the heat wave in the case of nonlocal energy transport. Such solutions can be of interest for extreme cases of high energy loads and/or high temperatures.