We are developing a Monte Carlo Collision (MCC) model in VORPAL, a three-dimensional particle-in-Cell (PIC) plasma simulation code that will self-consistently model various types of electron impact collisions with a neutral gas (or) a combination of gas mixtures. The MCC model will include elastic (such as elastic scattering, and large-angle elastic scattering), inelastic (such as excitation, and ionization) and Bremsstrahlung collisions. A null collision technique is used for handling the electron impact collisions. The collision cross sections data are based on the Evaluated Electron Data Library (EEDL) dataset, which we obtained from the International Atomic Energy Agency Nuclear Data Services (IAEA NDS). The EEDL library contains collision cross sections and generation data for electrons and photons for atoms with Z = 1 – 100 for incident electron energies from 10 eV (or threshold) to 100 GeV. Additionally, we will enable the elastic scattering cross section data available for low incident electron energies (below 10 eV) from known measurements, so that the MCC model can be applied for studying the low temperature plasma problems. Users also have the option of specifying a user-defined model of the cross section. We will show simulation results for gases and parameters relevant to the plasma processes involved in the breakdown of metallic structures occurring in high-gradient RF cavity experiments.

  

*The work of Tech-X personnel is funded by the U. S. Department of Energy under Small Business Innovation Research (SBIR) Contract No. DE-FG02-07ER84833.