Simulation and design study of cryogenic cone shell target for Fast Ignition Realization Experiment project

In the fast ignition (FI) scheme, at first, high-density fuel core plasma is assembled by implosion laser, and is then heated by petawatt laser to achieve a fusion burning condition. The formation of high-density fuel core plasma is one of the key issues for FI. A typical target for FI is a shell fitted with a reentrant gold cone to make a pass for heating laser. The ablated plasma of gold cone interferes with the implosion dynamics, which is quite different from that of the conventional central-hot-spot approach. Therefore, the dynamics of a nonspherical implosion must be controlled to assemble high density and high areal density. Numerical simulations are performed to study radiation hydrodynamics of cone-guided implosions. In the results, the effect of the cone on implosion dynamics is clarified. The cone surface is irradiated by the radiation and ablated plasma affects the imploding shell. Coating on the cone, which tamps the gold plasma, is effective to improve the implosion performance, although the result does not satisfy the condition of core plasma for the first stage of the Fast Ignition Realization Experiment [K. Mima et al., Proceedings of the IAEA Fusion Energy Conference, Lyon, 2002 (IAEA, Vienna, 2002), Paper No. IAEA-CN-94/IF/03].