Diagnostical Applications in Phase-0 and at FAIR

Intense uranium ion beams that will be available after commissioning of the new synchrotron SIS100 in Darmstadt will be used for volumetric heating of any type of material and generation of extreme states of matter with Mbar pressures and some eV of temperature. Investigation of their EOS is one of the main goals of the plasma physics program at FAIR. Diagnostic of such extreme states of matter demands development of new diagnostic methods and instruments, which are capable to operate in an environment with a high level of radiation damage. The precise knowledge of the energy density distribution of the U-beam on the target is a very important input parameter for numerical simulations of the hydrodynamic response of the target on deposited energy. Simulations are crucial during the planning of experiments and for the interpretation of obtained experimental data. To investigate the energy density distribution, we propose to use the target and heavy ion beam X-ray fluorescence for imaging of the target expansion and mapping of the heavy ion beam distribution in the interaction region with a high spatial resolution of at least 100 μm. First pilot experiments on measurements and characterisation of the heavy ion and target fluorescence using pinholes, X-ray CdTe-diodes and dispersive systems have been carried out in 2016 and 2019 at the UNILAC Z6 experimental area in collaboration with the Plasma Physics Group of GSI, Darmstadt, the Institute for Optics and Quantumelectronics of the Friedrich-Schiller_University, Jena and the Institute for Theoretical and Experimental Physics, Moscow. The obtained results can be scaled to high heavy ion energies available at SIS18 and SIS100. Development of laser based intense and well directed beams of MeV electrons and gamma-rays for backlighting states of matter with high areal density is of great importance. If the laser parameters cannot be changed, one can optimise the properties of the secondary laser sources using modified structured targets of near critical density. Simulations demonstrate that interaction of the relativistic laser pulse (〖10〗^19 W/〖cm〗^2) with a near critical plasma layer (〖10〗^21 1/〖cm〗^3) leads to effective generation of highly energetic electrons (>10-20 MeV) carrying a charge that at least 2 orders of magnitude exceeds prediction by ponderomotive scaling for the incident laser amplitude. Electrons accelerated from the target with l = 500 µm have the highest energies and the highest charge (ca. 25 nC for electrons with energies higher than 30 MeV). A significant increase of the electron number at tens of MeV energy makes such type of laser-based electron source very prospective for diagnostic of high areal density HED states. First pilot experiments on the characterisation of MeV electron beams generated due to interaction of the PHELIX-laser pulse with low density CHO-foams in 2017 and 2019 were carried out. Experiments and simulations were performed with following collaborators: Plasma Physics Group of GSI, Darmstadt. Lebedev Physical Institute, the Institute for Theoretical and Experimental Physics and Joint Institute for High Temperatures, Moscow. The obtained results are very promising and demonstrate a good agreement between experiment and theory.