Special Colloquium

Dr. Emmanuel d'Humières, University of Bordeaux – France, University of Nevada, Reno – USA

"New perspectives in laboratory astrophysics using high intensity lasers"

10:00am, RLM 11.204

Abstract: The development of high intensity laser facilities has allowed to make tremendous progress in laser electron acceleration, laser ion acceleration and high-energy radiation generation. A new trend is to use these facilities for laboratory astrophysics studies in order to explore regimes that cannot be reached on high-energy long pulse duration facilities. In this presentation, several examples of recent laboratory astrophysics studies using high intensity lasers will be reviewed. First, two studies both experimental and theoretical on magnetized plasmas generated by high intensity (> 1018 W/cm2) lasers will be presented. The coupling of terawattclass lasers along with efficient magnetic pulsers generating fields up to 20 T, now allows to study physics related to collisionless shocks in supernovae remnants (SNRs), at the stage of the interaction with an ambient magnetized interstellar medium. In order to reach even higher magnetic fields, we have shown that by adjusting target geometry and laser pulse parameters it is possible to generate spontaneous high amplitude (Gigagauss) magnetic fields, which possess confined spatial structure and exist much longer than the pulse duration time. We have also prepared two types of experiments on forthcoming ultra high intensity (> 1022 W/cm2) laser facilities, like Apollon and ELI, now under construction in Europe. The linear Breit-Wheeler (BW) pair creation process (γ+γ to e++e-), is the lowest threshold process in photon-photon interaction, controlling the energy release in Gamma Ray Bursts and Active Galactic Nuclei. The linear BW process has never been clearly observed in laboratory with important probability of matter creation. Using MeV photon sources a new experimental set-up based on numerical simulations with QED effects is proposed to achieve more than 104 BW pairs per shot. Finally, we have also assessed the capability of exawatt lasers to generate relativistic pair plasmas prone to collective phenomena of astrophysical interest.