Influence of capsule support tent on ICF DD gas implosion performance is investigated with a two-dimensional radiation diffusion hydrodynamic code LARED-S. It shows that the support tent reduces significantly the neutron yield with a YOC (yield over clean) of 55.2%. The main degradation mechanism is that the capsule shell produces high-amplitude high-density spikes, penetrating deep into the central DD gas. It increases greatly power loss due to electron conduction on the CH/DD interface, leading to the rapid reduction of DD reaction rate and final neutron yield. Compared with one-dimensional ideal implosion simulation result, bang-time of the two-dimensional tent simulation is apparently earlier, and perturbations introduced by the capsule support tent reduce the central pressure and internal energy of DD gas, which is converted from the shell implosion kinetic energy.

We perform 2D ignition capsule implosion simulation by a 2D multi-group radiation diffusion hydrodynamic code LARED-S which simultaneously simulates radiation drive asymmetry and outer surface roughness. Implosion flow field shows large-amplitude spikes and bubbles as well as a significant low-mode shell areal density asymmetry. Amplitudes of modes generated by mode coupling are in good agreement with analytic mode coupling equation until perturbation amplitude of fundamental mode L24 is greater than nonlinear saturation amplitude. In deceleration phase, perturbation growth is in strong nonlinear phase, and strong mode coupling effects broaden mode distribution. High-density spikes are bent by vortex flow. Mode coupling degrades greatly implosion performance, leading to ignition failure. Further simulations of mode coupling between low-mode drive asymmetry and capsule surface roughness is critical for understanding influences of hydrodynamic instabilities on ignition capsule implosion.

We introduce an ignition hohlraum 2D-simulation design method with 2D code.A design sequence,in which X-rays drive tempetature is tuned before P² asymmetry,is put forward.Details in designing laser power is studied.It indicates that control of P² asymmetry during trough pulse limits the maximum of filling gas density and expansion of capsule ablator can be restrained by longer drive pulse.An ignition hohlraum 2D-simulation design is given.