The scaling of radiation trapping effects in ICF implosion experiments with anticipated increases in the diver energy of proposed laser facilities

We apply the Marshak model of radiation-driven thermal waves in conjunction with hydroscaling analysis of ICF implosions to guide the design of radiation trapping demonstration experiments that can be scaled from the OMEGA laser facility to experiments on its proposed successor facility where much higher driver energies are anticipated. An opaque internal pusher layer is a standard component of the “volume-burn” approach to ICF ignition, acting as a “radiation trap” to reduce hot-spot cooling prior to ignition. The effectiveness of radiation trapping behind a diverging radiation thermal wave is characterized by a Marshak wave model that readily shows how this effectiveness varies over broad ranges of hot-spot scale and conditions and the shell composition, which is further evaluated by 1-D radiation-hydrodynamic simulation. This material is based upon work supported by the Department of Energy [National Nuclear Security Administration] University of Rochester “National Inertial Confinement Fusion Program” under Award Number DE-NA0004144.