Energy-preserving coupling of explicit particle-in-cell with Monte Carlo collisions.

Vay, Jean-Luc; Angus, Justin Ray; Shapoval, Olga; Lehe, Rémi; Grote, David; Huebl, Axel · Phys Rev E · 2025

basic_science · Level V

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Abstract

The particle-in-cell (PIC) and Monte Carlo collisions (MCC) methods are workhorses of many numerical simulations of physical systems. Recently, it was pointed out that, while the two methods can be exactly-or nearly-energy-conserving independently, combining the two leads to anomalous numerical heating. This paper reviews the standard explicit PIC-MCC algorithm, elucidates the origins of the anomalous numerical heating, and explains how to couple the two methods such that the anomalous numerical heating is avoided.