RADIATIVE SHOCKS IN LOW PRESSURE GASES

摘要

In this paper, two points are presented. The first one is related to the elaboration of a new theoretical approach and, in the second one, we present the results we have obtained from our latest experiments concerning the radiative shock. In the paper dated 2000 (Bouquet et al.), a fully analytical theory of the radiative shock has been developed. However, some microscopic phenomena were not taken into account in our modeling. In this communication, we present a new theory in which the ionization rates Z_1 and Z_2 (Z_2 ≠ Z_1) in the precursor and in the shocked material, respectively, are included. The way this effect alters the value of the critical value of the shock speed, Drad , above which radiation phenomena prevail over thermal ones, is derived. In the second part, numerical simulations are presented. Results obtained from various numerical codes in 1D and 2D geometries are shown and comparisons are given. The dependence of the structure of the precursor upon several parameters is exhibited. (Results coming from the latest French experiments at LULI are presented in another communication at this meeting (Leygnac et al.)).