Study of plasma X-rays

The radiation created by the interaction of a subpicosecond laser with a solid target quickly appeared as a single source of X-photons with a duration in the range of one to ten picoseconds. Potential applications included the possibility to probe “nanosecond” plasma over a period of time almost negligible compared to that plasma’s hydrodynamic evolution. More specifically, opacity measurement experiments requiers such auxiliary sources, because they allow a measurement of the absorption of a material with a fixed hydrodynamic.

To do this, it seems necessary to characterize and to understand the emissive behaviour of plasmas creatde by the interaction between an ultra-short and an ultra-intense laser and a solid target or a thin sheet. This long-standing work on X-sources will continue on the APOLLON facility.
In addition to the source characterization (spectrum, emission, duration), understanding and simulation of this plasmas are essential for the définition of future experiments. From this point of view, it should be noted that the need to validate hydrodynamic codes (in the picosecond regime) as well as HETL atomic physics codes is more necessary than ever.

An interesting aspect of these experiments is the non-stationary aspect of the atomic physic. Experiments on the study of X-rays absorption or emission from a plasma produced by the interaction of an ultra-short pulse will be a research focus of the APOLLON facility.