OPACITY MEASUREMENTS OF A RADIATIVELY HEATED BORON SAMPLE

A preliminary measurement of the opacity of a thin boron foil radiativ ely heated at moderate temperatures (5-20 eV) in conditions near local -thermodynamic-equilibrium (LTE) are reported. The opacity of a 0.37 m u m thick boron sample has been measured in the K-shell range (40-60 A ngstrom) using a 5000 1 mm(-1) transmission grating. The sample is hea ted by the X-rays emitted at the rear side of two laser-irradiated 0.1 mu m thick: gold foils. Ab-initio atomic structure calculations are u sed to fit the experimental spectrum and deduce the ionization charge distribution. Using a non-LTE kinetic code, the heated sample temperat ure and density ranges are determined. The plasma conditions are predi cted with a radiative hydrodynamic code and compared with experimental data. This preliminary analysis shows that the numerical tools are re ady for the analysis of future experiments which will be performed wit h cleaner experimental conditions. (C) 1997 Published by Elsevier Scie nce Ltd. All rights reserved.