A $\delta f$ PIC method with Forward-Backward Lagrangian reconstructions

TL;DR

This paper introduces a $f$ particle simulation method utilizing Forward-Backward Lagrangian reconstructions to accurately model plasma density evolutions, especially in regimes with significant deviations from initial states.

Contribution

The paper presents a novel $f$ PIC method with FBL-based density remapping, enhancing simulation accuracy for dynamic plasma profiles.

Findings

Successfully applied to two-stream instability simulations

Demonstrates robustness in handling large density deviations

Validates qualitative properties of the method

Abstract

In this work we describe a $\delta f$ particle simulation method where the bulk density is periodically remapped on a coarse spline grid using a Forward-Backward Lagrangian (FBL) approach. This method is designed to handle plasma regimes where the densities strongly deviate from their initial state and may evolve into general profiles. We describe the method in the case of an electrostatic particle-in-cell scheme and validate its qualitative properties using a classical two-stream instability subject to a uniform oscillating drive.