Direct-drive Inertial Confinement Fusion Ignition Simulation Study

Demonstration of Inertial Confinement Fusion (ICF) ignition is currently in the central ignition manner. The hydrodynamic instability violates implosion, compression, ignition and burn, and imposes the stringent restricts on the requirement of drive symmetry and target fabrication. It is the critical issue for reducing laser energy and expense for the ignition facility. Based on the simplified physical model and the sphere and cylinder version of LARED-S code, this work developed the ignition code for ICF ignition study, performed 1D and 2D simulations of direct-drive ignition target, deepened the understanding of relative physical processes.The code work was included in programming of thermonuclear reaction and α-particle heating and techniques used in 1D and 2D ignition simulations. The 1D simulation result agreed well with the self-similarity solution of α-particle heat conduction. The simulation work was carried out in study of direct-drive implosion and ignition. Firstly, 1D direct-drive implosion and ignition was simulated according to the designs of the direct-drive all-DT ignition target of the LLE in University of Rochester for National Ignition facility (NIF). The comprehensive understanding was obtained for 1D ignition physics, and the 1D result agreed well with the most parameters of the NIF design. Secondly, the marginal ignition and the effect of α-particle heating to ignition were investigated and the results show: α-particle heating plays a central role for ignition in the marginal ignition case, ignition primarily depends on the enlarged of the hot-spot arising from the ablation of electron and α-particle conductions to the cold DT material for the less driven energy, but the required ρR for ignition is achieved after the maximum compression, therefore fusion gain reduces largely, even ignition fails, due to slow increase of temperature and quick drop of the cold DT density because of fluid expansion outside. Thirdly, 2D simulation study of the hydrodynamic instability was performed during the...