INCREASE IN ROSSELAND MEAN OPACITY FOR INERTIAL FUSION HOHLRAUM WALLS

The Rosseland mean opacity of hohlraum gold walls can be increased by filling in the low absorption gaps in the gold spectrum with one or mo re additional elements. Using our opacity code STA, we investigated va rious mixtures. A combination of gold and copper, or nickel, is equiva lent or better than the previously proposed gold and gadolinium mixtur e, and is much easier to fabricate. Other more elaborate mixtures yiel d even higher opacities. Our simulations are in good agreement with ex periment. At the temperatures and densities of interest, non-local-the rmodynamic-equilibrium corrections are minor, of order 10%, and not si gnificant in view of the experimental accuracy.