Two-Dimensional Vlasov Simulation of Raman Scattering and Plasma Beatwave Acceleration on Parallel Computers

Abstract

A two-dimensional relativistic Vlasov model for a multi-computer environment was developed to address the particle acceleration process in phase space, including situations relevant to forward Raman scattering (FRS) and plasma beatwave acceleration (PBWA). Attention was focused on its accuracy, stability, efficiency properties, and implementation facilities on massively parallel computers. The two-dimensional Vlasov code has been adapted to optimally use the particular parallel architecture of the T3D or T3E computer (both processor's specifications and node-to-node communications). Results obtained on a 64-node Cray T3D clearly show the details of particle acceleration in phase space, including very low density regions where particles-in-cell (PIC) codes simply run out of calculation particles. On the other hand optimization obtained on the T3D architecture leads to a CPU time of 9.5 μs per time step, per particle, per processor indicating that one processor on the Cray C94 computer is equivalent to 20 processors on the T3D computer. Finally, we note that the Vlasov code is able to achieve high parallel efficiency with scalability of order 2.