FILAMENTATION, DEFLECTION, SCATTER, AND CROSSED BEAM ENERGY TRANSFER IN HIGH TEMPERATURE HOHLRAUMS

摘要

High temperature hohlraums are reduced-scale targets shot at high power. The creation of such hot environments is crucial to material science studies under extreme conditions. A key ingredient in creating hot environments is to successfully couple the laser energy into the target. Maximum coupling is limited in high temperature hohlraums by laser-plasma interactions that occur outside the target (the target fills up on the time scale of the laser pulse). High temperature hohlraums shot at the Omega laser at the Laboratory for Laser Energetics (Rochester, NY) show reduced energy coupling. Comparison between experiments and radiation-hydrodynamic simulations show that as much as 40% of the incident energy is unaccounted for in the smaller targets. Laser-plasma interaction in such targets occur in a regime of high intensity, high density, and high electron temperature where novel saturation mechanisms such as Brillouin re-scatter of Raman forward scatter have been predicted to exist. The interplay between filamentation/deflection and laser scatter is simulated and analyzed in this regime.