Viktor K. Decyk

OSIRIS: A Three-Dimensional, Fully Relativistic Particle in Cell Code for Modeling Plasma Based Accelerators

We describe OSIRIS, a three-dimensional, relativistic, massively parallel, object oriented particle-in-cell code for modeling plasma based accelerators. Developed in Fortran 90, the code runs on multiple platforms (Cray T3E, IBM SP, Mac clusters) and can be easily ported to new ones. Details on the codes capabilities are given. We discuss the object-oriented design of the code, the encapsulation of system dependent code and the parallelization of the algorithms involved. We also discuss the implementation of communications as a boundary condition problem and other key characteristics of the code, such as the moving window, open-space and thermal bath boundaries, arbitrary domain decomposition, 2D (cartesian and cylindric) and 3D simulation modes, electron sub-cycling, energy conservation and particle and field diagnostics. Finally results from three-dimensional simulations of particle and laser wakefield accelerators are presented, in connection with the data analysis and visualization infrastructure developed to post-process the scalar and vector results from PIC simulations.

QuickPIC: a parallelized quasi-static PIC code for modeling plasma wakefield acceleration

There has been much recent interest in plasma wakefield acceleration. This is partly due to the possibility of using it as an energy doubler, i.e., an afterburner, stage at the end of an existing linear collider such as SLC. The process in this scheme is highly nonlinear and therefore particle models are required to study it. Furthermore, the key physics involves fully three-dimensional effects. Unfortunately, even on the largest computers it is still not possible to model a full energy doubler stage using existing codes such as OSIRIS. Fortunately however, for these cases the drive beam evolves on a much longer time scale than the plasma frequency. In these cases the beam appears static or frozen for long periods of time. Under these conditions one can make the quasi-static or frozen field approximation. We have recently developed a skeleton version of a parallelized quasi-static PIC code for modeling particle beam drivers. This code combines all the best features from WAKE and the work of D.H. Whittum (1997); and it is fully parallelized. We describe the basic equations and the algorithm. We will also present preliminary results, which include benchmarking it against our fully explicit code OSIRIS.