GPU-accelerated 3D time-domain simulation of vacuum electron devices

We present results of 3D time-domain simulations of vacuum electron devices performed on high-performance GPU hardware using a new simulation code, NEPTUNE. Electromagnetic field evolution using two techniques is compared. First a GPU implementation of the finite-difference time-domain (FDTD) method is shown to give a 20x reduction in execution time compared to an equivalent CPU code. Second, we demonstrate an implicit, complex-envelope ADI-FDTD algorithm on the GPU, achieving a further 5x reduction in execution time to give a combined rf simulation performance gain over 100x compared to conventional CPU FDTD solvers. A particle beam interaction model also running on the GPU is under development with the goal to achieve self-consistent 3D large-signal simulation.