422 / 2019-02-28 23:26:15

Numerical study of the impact of plasma viscosity on exploding pusher implosion processes

Inertial confinement fusion; Implosion; Plasma vicosity

全体主题 > Laser and Particle Beam Fusion

Here a Lagrangian radiation hydrodynamic code (MUILTI1D) is extended with inclusion of plasma ion viscosity and ion thermal conduction, which have included flux-limited electron thermal transport with a flux limiter, multigroup radiative transport, inverse bremsstrahlung absorption and equations of state tables taken from SESAME data. Using the hydrodynamic simulations, the impact of plasma viscosity on exploding pusher implosion processes is investigated. For the implosion processes, the ratio of ion-ion mean free path to the shell radius may become large, classical formulas of ion viscosity and thermal conductivity break down. To save them in our hydrodynamic simulations, the limited flux model is adopted. Then, the typical D3He gas-filled exploding-pusher inertial confinement fusion (ICF) implosions at the Omega Laser Facility are simulated and examined. It is confirmed in our simulation that the ion viscosity can mitigates a temperature spike at the center of shock convergence in a one-dimensional spherical geometry, which is mainly due to the viscous diffusion of velocity in the momentum equation and fluid velocity will smooth during the shock convergence. The different ion viscosity flux limiter (vfl) are used in our simulations in comparison to other published simulated data and experimental ones. It is shown that the value of vfl has a significant impact on the burn profile shape for the low density gas-fill implosions. For this phenomenon, viscous dissipation in the energy equation is found to play a crucial role. During the shock convergence processes, viscous heating can prominently increase the ion temperature near shock surface and trigger fusion