Experimental study of KrF-laser<i>–</i>high-<i>Z</i>-plasma interaction dominated by radiation transport

Abstract

An experimental study is presented of heating of gold plasma by a Raman-compressed KrF laser (2-ns full width at half maximum, \ensuremath{\lambda}=268 nm) in the intensity range of 5\ifmmode\times\else\texttimes\fi{}${10}^{11}$--2\ifmmode\times\else\texttimes\fi{}${10}^{13}$ W/${\mathrm{cm}}^{2}$. Measurements of electron temperature and its scaling with laser intensity, angular distribution of plasma energy and ion blowoff velocity, and keV x-ray emission are performed and compared with those for an aluminum plasma heated under the same experimental conditions. Strikingly different characteristics observed in the high-Z gold plasma are discussed in terms of radiation loss and radiative energy transport.