Particle-in-Cell Code for GPU Systems

Particle simulation in the field of nuclear fusion is a well-established technique which has spawned dozens of codes around the world through years (e.g. BIT1, VPIC, VSIM, OSIRIS, REMP, EPOCH, SMILEI, FBPIC, GENE, WARP, PEPC) with varying degrees of specialization for different physics areas and accessibility. Particle-in-cell (PIC) codes simulate numerous plasma phenomena on HPC systems. Today, flagship supercomputers feature GPUs per compute node to achieve unprecedented computing power at high power efficiency. PIC codes require new algorithm design and implementation for exploiting such accelerated platforms. In this work, we design and optimize simple PIC code called SIMPIC, to run on a general GPU compute node. First we provide a fully GPU SIMPIC code and show that the run time is 50 % reduced than in CPU. This code in future will be used as a test example for modifying the other more complex PIC codes from CPU to GPU.