Particle-in-Cell Simulations of a Hollow Cathode Experiment for Molecular Spectroscopy of Metal-Containing Plasmas Using the hPIC2 Code

Understanding the sputtering yields of metals is important in fireball chemistry studies, but fireball chemistry studies have largely used Laser Induced Breakdown Spectroscopy, a short repeatable event for which its repeatability is limited by ablation of the surface. Thus, it would be desirable to have a steady source to analyze metals and metal-oxides with, the hollow cathode (HC) system allows steady state analysis of metals and metal-oxides in a steady state. Previous work by Glumac [Kautz et al. 2021] has shown interesting results in controlling the amount of metal released into the plasma in their hollow cathode system. The current study aims to constrain the uncertainty on the atomic metal released into the plasma and the amount of metal in the plasma by simulating the HC system using the hPIC2 code [Meredith et al., CPC 283, 2023]. The following question will then be answered: For the HC system can we control the metal release to the point that we can constrain the rate coefficient of molecular formation from the measured concentration of molecular species as a function of time?