Observation of ion-ion correlation effects on emissivity and opacity of hot ultra-dense low Z plasmas

The transmission function and the resulting emissivity and opacity of bound -bound transitions in hot ultra-dense, low Z (aluminum or fluorine) plasmas are investigated in this paper. It is shown that the treatment of both the area-normalized line profiles and the absorption oscillator strengths invo lved are crucial. Taking account, self-consistently, of all the interaction s inside a radiating transient molecule, as proposed in the dicenter code I DEFIX, we computed the photo-excitation cross-sections, the emissivities, t he opacities, and then compare the results with those from standard codes. We emphasize the strong dependence of the above quantities with the ionic c orrelations. A first experiment, devoted to measure opacities and emissivit ies of hot and ultra-dense aluminum plasmas, has been designed. The interpr etation of the results shows the adaptability of the dicenter model for the se extreme conditions. (C) 2001 Elsevier Science Ltd. All rights reserved.