Optimization by Marker Removal for δ ƒ Particle Simulations
Authors: Wenjun Deng and Guo-Yong Fu
Abstract:
A marker removal optimization technique is developed for δ ƒ particle simulations
to optimize the marker distribution so as to save markers and computing
time. The technique can be directly applied to single-mode linear
simulations. For multi-mode or nonlinear simulations, the technique can still
be directly applied if there is one most unstable mode that dominates the
simulation and δ ƒ does not change too much in nonlinear stage, otherwise
special care is needed, which is discussed in detail in this paper. The technique
effectiveness, e.g., marker saving factor, depends on how localized δ ƒ
is. In this paper, the technique is first demonstrated in a simple 2D bumpon-
tail simulation, and then generalized to 5D gyrokinetic simulations. The
technique saves markers by factors of 4 and 19 in our nonlinear 2D bump-ontail
and 5D toroidal Alfven eigenmode (TAE) simulations, respectively. The
technique can be used for phase space of arbitrary dimension, as long as the
equilibrium motion constants can be found. The technique is not limited to
particle-in-cell (PIC) simulations but could be applied to other approaches marker
particle simulations such as particle-in-wavelet (PIW) and treecode simulations.
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Submitted to: Computer Physics Communications (June 2013)
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Download PPPL-4941 (pdf 5.7 MB 40 pp)
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