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Welcome to the rfEDIPIC wiki. These pages will provide an overview of the Radio Frequency EDIPIC (rfEDIPIC) code: basics of 1-D pic, simulation capabilities, control and input files, and diagnostics.

The rfEDIPIC code is a fork of Princeton University's EDIPIC code available here. EDIPIC was created by Dmytro Sydorenko while at the University of Saskatchewan and has since been used by Igor Kaganovich's group at PPPL.

One Dimensional Particle in Cell

rfEDIPIC is a 1-D particle in cell (PIC) code coupled with a Monte Carlo collision algorithm which allows for kinetic simulation of low temperature processing plasmas. To maintain efficiency, EDIPIC simulates a one dimensional slice of a reactor, illustrated below.

With this configuration, each simulation particle represents a "charge sheet" evolving in the plasma. Each particle retains three velocity space coordinates throughout the simulation which allows for determination of the full 3-D distribution function.

Simulation particles interact with one another through long range Coulomb forces mediated by the electromagnetic field. This field is calculated at grid points (or equivalently, plasma nodes) spaced apart by cell size $\Delta x$ and interpolated onto particles from their nearest-neighbor grid points. To solve for fields, EDIPIC employs the electrostatic approximation, whereby the plasma current (and resulting induced magnetic field) is assumed to be negligible. The electric field (a result of external boundary conditions and the particle charge "shaped" onto neighboring grid points, as illustrated below), $E$, is solved for at each node using Poisson's equation.

To advance the simulation in time, particles are advanced through time steps $\Delta t$ between calculations of the electric field. In EDIPIC's jargon, particles are advanced over ther $k^{th}$ time step through a "pre-push" and "final push" in a three step process:

1. the pre-push advances particles with $E^{(k-1)}$ to their "streaming positions"
2. charge is interpolated to grid points and Poisson's equation is solved to find $E^{(k)}$
3. the final push advances particles with the field $E^{(k)}$.

If Monte Carlo collisions are specified with the background gas or wall collisions occur, these would be resolved in a 4th step following the above process.