The 23rd Academic Exchange Seminar Between Shanghai Jiao Tong University and Osaka University
Dong Wu
(Shanghai Jiaotong University)
ABSTRACT
The head-on collision of high density plasma jets is of key importance for inertial confinement fusion double-cone ignition (DCI) scheme. To overcome the simulation limitations that appear in the fluid description, in this paper, we propose a new simulation method for large-scale high density plasmas with an ingenious kinetic-ion and kinetic/hydrodynamic-electron treatment. This method takes advantages of modern particle-in-cell simulation techniques and binary Monte Carlo collisions, which include both long-range collective electromagnetic fields and short-range particle-particle interactions. Especially, in this method, the restrictions of simulation grid size and time step, that appear in a fully kinetic description, can be eliminated. Furthermore, the collisional coupling and state-dependent coefficients, that are usually approximately used in a fluid description, are no longer needed. The correctness and robustness of the new simulation method are verified, by comparing with fully kinetic simulations at small scales and pure hydrodynamic simulations at large scale. Following the conceptual design of DCI scheme, the colliding of two plasma jets with initial density of 100 g/cc and counter-propagating velocity at 300 km/s is investigated by using this new simulation method. Quantitative values, including density increment, pre-heated plasma temperature, and conversion ratio from colliding kinetic energy to thermal energy, are obtained in this investigation: density increment is 3, plasma heating is 400 eV and conversion ratio is 88.2%. These values might serve as a reference for the future detailed studies.