Abstract Details
Abstracts
Author: Guangye Chen
Requested Type: Consider for Invited
Submitted: 2023-03-24 09:51:28
Co-authors: L. Chacon, O. Koshkarov, L. F. Ricketson
Contact Info:
Los Alamos National Laboratory
P.O. Box 1663
Los Alamos, NM 87544
USA
Abstract Text:
We introduce a new multidimensional electrostatic particle-in-cell (PIC) algorithm that enables our previous electrostatic fully implicit PIC algorithm [1] to use very large timesteps compared to particle gyro-period without loss of accuracy. The algorithm employs a new asymptotic-preserving (AP) particle-push scheme [2]. In the large-timestep limit, the integrator preserves all particle drifts (including grad(B) drifts), while recovering the fully resolved orbit for small timesteps. The integrator works for arbitrary magnetic fields and can be implemented very efficiently [3]. The resulting AP PIC algorithm can be shown to conserve global energy and local charge exactly [4]. We will demonstrate these properties numerically with several strongly magnetized examples (e.g., diocotron instability, lower-hybrid/modified two-stream instability, drift instability, etc.), including some with non-uniform magnetic fields. We will show orders of magnitude wall-clock-time speedups vs the standard fully implicit electrostatic PIC algorithm without sacrificing solution quality [4].
[1] G. Chen, L. Chacón, and D. C. Barnes. "An energy-and charge-conserving, implicit, electrostatic particle-in-cell algorithm." J. Comp. Phys. 230.18 (2011): 7018-7036.
[2] L. F. Ricketson, and L. Chacón. "An energy-conserving and asymptotic-preserving charged-particle orbit implicit time integrator for arbitrary electromagnetic fields." J. Comp. Phys. 418 (2020): 109639.
[3] O. Koshkarov, L. Chacón, G. Chen, and L. Ricketson. "Fast nonlinear iterative solver for an implicit, energy-conserving, asymptotic-preserving charged-particle orbit integrator", J. Comp. Phys. 459 (2022): 111146
[4] G. Chen, and L. Chacón, “An implicit, conservative and asymptotic-preserving electrostatic particle-in-cell algorithm for arbitrarily magnetized plasmas in uniform magnetic fields” arXiv:2205.09187 (2022)
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