Mitigating Laser Imprint in ICF Implosions Using the Electromagnetic Pulse from a High-Intensity Laser

Nonuniformities in the laser direct drive inertial confinement fusion due to laser speckle and beam-to-beam intensity variations can seed hydrodynamic instabilities such as the Richtmyer–Meshkov (R-M) and Rayleigh–Taylor (R-T). Techniques to mitigate the laser imprint often utilize a low-density plasma surrounding the target to increase the conduction zone length and ablation velocity, reducing instability growth rate. To establish this plasma, most configurations propose complex targets using foams or pre-expanded high Z layers. However, in this talk we propose and demonstrate the ability of the electromagnetic pulse from a short-pulse high-intensity laser incident on the target’s supporting structure to establish a low-density plasma. This effect can be used to mitigate laser imprint using well established capabilities already available at ICF laser facilities.

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.