Modeling Tools

The Low-Temperature Plasma Particle-in-Cell (LTP-PIC) code is a kinetic plasma simulation tool designed from the ground up for scalability and portability on modern supercomputing architectures. Performance is achieved via multi-level parallelism using MPI, OpenMP and with algorithms designed to take advantage of modern vector registers and memory hierarchies. On heterogeneous machines (CPU + GPU) the portable OpenACC standard is employed to take advantage of GPU accelerators. The code is fully three-dimensional, and designed for modeling low temperature plasmas and devices with a specific focus placed on performance of the Poisson solver (on both CPU and GPU) as well as Monte-Carlo algorithms for collisions and plasma surface interactions. Applications of LTP-PIC include the study of anomalous transport in low-temperature ExB devices (Hall thrusters, Penning discharge), as well as industry relevant plasmas such as capacitive and inductively coupled discharges. The code is currently being updated to include solvers for low-frequency electromagnetic phenomena and improved chemistry models.

The EDIPIC suite, comprising EDIPIC 1D and EDIPIC 2D, offers sophisticated simulation tools for low-temperature plasma research. Developed by Dr. Dmytro Sydorenko, EDIPIC 1D uses a direct implicit particle-in-cell (PIC) approach, while EDIPIC 2D employs an explicit PIC method for two-dimensional simulations in cylindrical and Cartesian geometries. Both tools support advanced features like plasma-surface interactions, with collision processes modeled via Monte Carlo and Langevin methods. Written in Fortran 90 and optimized with MPI for up to 400 CPU cores, EDIPIC boasts extensive diagnostics for in-depth plasma analysis. Available on GitHub, these open-source tools have been validated through international benchmarks and contribute significantly to both academic and industrial plasma studies, including RF capacitive discharges, DC discharges, and Hall thrusters, with contributions from Drs. Alexander Khrabrov and Willca Villafana.

Dr. Mikhail Mokrov has developed a 2D axisymmetric fluid code for the modelling of non-equilibrium plasma in microwave-driven, resonant cavity diamond growth reactors. The code is designed to predict flux species impinging on the diamond surface, including the simulation of co-dopant chemical reactions and predicting the effect of process control changes, such as the introduction of pulsed plasma modes, different sample holder shapes and gas injection. In its preliminary form representing the internal geometry of PPPL Seki 6370 diagnostics-focused diamond reactor, the code incorporates the following modules: electromagnetic module based on eigenmode calculation by solving Helmholtz equation in a resonance cavity; non-equilibrium plasma module solving drift-diffusion equations for electrons and ions (several ionic species are supposed to be present and quasi-neutrality is assumed); reactions-diffusion chemical kinetics equations for multi-component neutral gas mixture; and  compressible Navier-Stokes equations in the gravity field. Key future improvements will include time-dependent electromagnetic simulations and computational fluid dynamics for real geometry of the chemical vapor deposition reactors.