Simulations of Directly-Driven Cone-in-Shell Implosions

In fast ignition a short-pulse high intensity laser is used to generate relativistic electrons that subsequently deposit their energy into the compressed fuel to initiate a propagating burn wave. A high-density cone is often inserted into the capsule to allow a clear path for the ignition laser to the compressed fuel. The presence of the cone alters the dynamics in two ways from a spherically symmetric implosion. First, x-ray preheat can be absorbed by the cone causing the cone material to expand ahead of the imploding fuel leading to mixing of the high-Z cone material into the fuel. Second, the stagnation of the fuel near the cone can launch a jet into the cone increasing the transport distance of the short-pulse generated relativistic electrons. This paper reports on HYDRA simulations of directly driven OMEGA-scale plastic capsule implosions.