Absorption measurements of radiatively heated multi-layered Al/Ni foils

Mixtures of light and mid-Z elements have been used to measure the absorption of the mid-Z element Ni, the temperature is inferred from the K-shell absorption of the light element Al. Here we test this method by comparing the temperatures deduced from Al K-alpha transitions and nickel L-shell absorption spectra in Al/Ni multilayers and bilayers. The ionisation state is obtained by comparison of the Al and Ni spectra with calculations assuming local thermodynamic equilibrium. The temperatures obtained from the experiment are compared with hydrodynamic simulations predictions. Simulation code results show that the density differs by a factor of 2 in the two elements. This has to be taken into account in the determination of the temperature. (C) 2001 Elsevier Science Ltd. All rights reserved.