ELFIE - X-ray time-resolved spectroscopy of thin foil plasmas produced by a short pulse laser at moderate intensity (S. Bastiani-Ceccotti)
In this experiment, we propose the study of the radiative properties of a homogeneous plasma, characterized by non-spectroscopic diagnostics in order to determine its hydrodynamic parameters. The objective is to have an accurate description of the hydrodynamic conditions of the plasma simultaneously with the spectral measurements. This allows minimizing the number of free parameters in the kinetic atomic codes, improving their reliability. We will use the sub-ps laser beam of the ELFIE facility at moderate intensity (~ 1016 W/cm2). In this kind of interaction, hot electron production and hydrodynamic expansion during the laser pulse duration are negligible leading to a fairly homogeneous plasma.
We will irradiate Al and KBr dot targets with one of the two 350 fs beams of the ELFIE facility (frequency doubled), stretched to 5 ps. The time-resolved plasma X-ray emission will be recorded by a KAP conical crystal. The spectral range (1650-2200 eV) will cover the Al Lya - Heß line emission and Ne-like 2p-3d and 2s-3p Br emissions. As hydrodynamic diagnostics, we plan to implement a Mach-Zehnder 3w interferometer using the probe beam. The interferograms will be simultaneously recorded on a streak camera, to record the time evolution of the density along an axis, and on a CCD camera, to record the 2D mapping of the density. Finally, a “triple-pinhole” camera will permit to monitor the absence of suprathermal electrons, thus ensuring the proper interaction we aim to obtain. The hydrodynamic diagnostics should permit to constrain some hydrocodes (MULTi, DUED,…), which will be then post-processed with the atomic kinetic code SPECT3D. The measurements will also be used to compare calculations issue from other atomic physics codes (PPP, SCRAM).
ELFIE - S38-41/2018