Revealing crossed-beam energy transfer as the origin of asymmetric backscattering in hohlraums

Le résumé fourni par la source

Backscattering due to laser plasma instabilities (LPIs) presents a risk in the laser-driven inertial confinement fusion. Generally, it is assumed that the backscattering of laser beams in the same cone is identical in hohlraum physics studies. In the experiments performed at SG-100kJ laser facility, we find that the backscattering of laser beams in the same cone are quite different. Our investigation reveals the main reason for this phenomenon is that the laser beams in the same cone obtain different power from their neighbor beams via crossed-beam energy transfer (CBET) depending on their polarizations. The dependence of multi-beam CBET on laser polarization arrangement is confirmed in a specially designed experiment. These findings are crucial for understanding the backscattering, CBET, energy deficit and the azimuthal drive asymmetry in cylindrical hohlraums. Laser plasma instabilities are the main factors contributing to degradation of hohlraum performance in inertial confinement fusion experiments. Here, the authors show asymmetric backscattering within the same laser cone at the SG-100kJ laser facility, unveiling the role of crossed-beam energy transfer and laser polarization.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.