arXiv:2603.02299v1 Announce Type: new
Abstract: We take issue with the conclusions in the recent publication by Savard et al. In the study, the authors implement a fully nonlinear charge- and energy-conserving implicit particle-in-cell method (ECC-IPIC), and use it to study the impact of particle number in the quality of the ECC-IPIC solutions for several problems, including an ion acoustic shockwave (IASW) problem and several sheath problems in bounded plasmas. From the study, the authors concluded that “to reproduce highly resolved convergent solutions, a higher amount of particles per cell need to be used in the implicit scheme for both periodic and bounded simulations when the cell size exceeds the Debye length.” We demonstrate that, according to our analysis for the IASW test, this conclusion does not survive independent scrutiny. We have identified several diagnostics procedural issues that are at the root of their conclusion, which when fixed dramatically change the outcome of the study.