Radiative heating of B, Al and Ni thin foils at 15-25 eV temperatures

Several thin foils have been heated by X-ray radiation emitted by a small g old cavity irradiated with the LULI facility Nd glass laser. The foils were heated to moderate temperatures (10-25 eV) in conditions near local thermo dynamic equilibrium. Measurements of the absorption of K alpha transitions of aluminum, of the K-shell transitions of boron, and of the n = 2-3 and 4 transitions of nickel are reported. A 5000 l/mm transmission grating spectr ograph recorded the boron data, and a flat thallium hydrogen phthalate (TlA P) crystal was used for aluminum and nickel absorption measurements. The ni ckel and aluminum spectra indicate a higher temperature (22-25 eV) than the boron case (14 eV), explained by a difference in the absorption spectra of these elements, In the Ni case the measured 2p-3d spin-orbit-split absorpt ion structures compared well with theoretical spectra obtained with the SCO superconfiguration code using the spin orbit split transition arrays forma lism (SOSA). The heating of the foils as calculated with radiative hydrodyn amic simulations is very similar to the experimental data. (C) 2000 Elsevie r Science Ltd. All rights reserved.