Massively parallel particle-in-cell simulation of advanced
particle accelerator concepts.*
D.L. Bruhwiler, J.R. Cary, D.A. Dimitrov, P. Messmer and C. Nieter
W. Mori, V. Decyk, F. Tsung, M. Zhou and C. Huang
E. Esarey and C.G.R. Geddes
T. Katsouleas, S. Deng and A. Ghalam
The quest to understand the fundamental nature of matter requires ever
higher energy particle collisions, which in turn leads to ever larger and
more expensive accelerator facilities. Advanced concepts for electron and
positron acceleration are required to reduce the cost and increase the
performance of next-generation accelerators. Plasma-based accelerators
can sustain electron plasma waves with phase velocities close to the speed
of light c and longitudinal electric fields on the order of the
nonrelativistic wave breaking field, E_0 = c m_e omega_p / e, where
omega_p = (4 pi n_e e^2 / m_e)^1/2 is the plasma frequency at an electron
density n_e . For n_e=10^18 cm^-3, E_0 = 100 GV/m. Massively parallel
particle-in-cell (PIC) simulations are required to simulate both
laser-driven (LWFA)  and beam-driven (PWFA)  concepts, in order to
support on-going experiments and to explore new ideas. We summarize
recent successes in the use of parallel PIC codes VORPAL , OSIRIS 
and QuickPIC  to validate computations with experimental data, to
benchmark codes with independent implementations and to benchmark reduced
PIC algorithms. Code performance and representative algorithms are
discussed in the context of past work and future challenges.
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*This work is supported by the SciDAC project -- "Advanced Computing for
21st Century Accelerator Science & Technology," an initiative of the U.S.
Department of Energy, under Contract No. DE-FC02-01ER41178. This work is
further supported by the U.S. Department of Energy, under Contract No.'s
DE-FG03-95ER40926 and DE-AC03-76SF00098. This work used resources of the
National Energy Research Scientific Computing Center.