Comparative Benchmark of XPDP1 and VSim Simulations for Helium and Argon Capacitively Coupled Plasma Discharges*

Particle-in-cell (PIC) simulations coupled with Monte Carlo collisions (MCC) have shown to be an important tool in plasma physics for understanding the intricate details of capacitively coupled plasma (CCP) discharges. We have demonstrated previously that the PIC-MCC simulation tool XPDP1 code employing LXCat cross sections can give consistent results in low-temperature helium CCP discharges with the VSim simulation package. Based on the success of this benchmark, the present research continues the effort to study argon CCP discharges and provides an in-depth comparison of the XPDP1 and VSim codes for argon chemistry. Compared to the helium cases, argon CCP discharges exhibit a set of difficulties, such as a more complicated route to stability and high sensitivity to simulation parameters such as the macro-particle number and mesh size used. Aligned with the helium discharges, we have replaced the functional cross-sectional data in the original XPDP1 code with the more comprehensive LXCat database to model argon CCP discharges more realistically, demonstrating the consistency between the two codes while providing the comparison in computing efficiency. The main contribution of this work is to verify the implementation of importing the LXCat cross-section data into XPDP1 is successful and necessary for CCP discharges with different chemical species. In addition, the VSim code has been verified and can be used for higher-dimensional CCP simulations using parallel computation. Comprehensive argon CCP discharge simulations and benchmark results will be presented, emphasizing specific aspects including plasma density, core hours, mesh number, number of macro-particles in the model, etc. This benchmark highlights the importance of employing the LXCat database in PIC-MCC simulations of plasma discharges.