Development of plasma diagnostics in support of PETAL on LMJ laser facility. First preliminary PETAL experiments

The PETAPhys project, performed under of the auspice of the “cluster of excellence” LAPHIA of the University of Bordeaux, has provided a support to the commissioning phase of the PETAL laser operation. It was complementary to the Equipex project PETAL+, which delivers the major diagnostic equipment. Within the PETAPhys project, we have developed two simple and robust diagnostics The first diagnostic (Twist) is the optical imaging of the PETAL beam focal spot in the spectral range of the second and third harmonic radiation emitted from the target. The second diagnostic (CRACC X) is a hard X-ray spectrometer consisting in a stack of imaging plates (IP) and filters. The Petal+ Equipex (funded by the French National Agency for Research, and coordinated by the Bordeaux University) has provided three spectrometry diagnostics for the characterization of the particles generated by PETAL experiments: - SEPAGE, an inserted diagnostic, composed of two Thomson parabola. - SPECTIX, an inserted diagnostic, composed of two Braggs crystals with high resolving power. - SESAME, an electron and proton spectrometer based on a magnetic dipole at two different angles. At the end of 2017, the first shots on target of the PETAL laser were performed on the LMJ facility. Laser energy ranged from 100 J to 450 J and pulse duration from 600 fs to 11 ps. These experiments aimed at the qualification of the plasma diagnostics and estimation of emission of X-rays, protons, electrons from targets irradiated with PETAL. All dedicated PETAL diagnostics were activated and successfully validated. Preliminary data, with a focus on PETAPhys/PETAL+ diagnostics results, will be discussed.