Nonequilibrium Conditions in a Shock Front

Recent measurements\footnote{ J. E. Miller \textit{et al}., ``Equation-of-State Measurements in Ta$_{2}$O$_{5}$ Aerogel,'' submitted to the Proceedings of AIP.} on shock waves propagating in Ta$_{2}$O$_{5}$ foams showed that the shock temperature did not rise with rising pressure. An explanation is that the electrons are not in equilibrium with the ions and their temperature rise lags behind the rapidly moving shock front. Results of hydrodynamic simulations that predict such behavior and provide calculations of optical transport that explain the observations are presented. Experimental methods that could be used to further diagnose this phenomenon will be discussed. This work was supported by U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460.