ABSTRACT
We present a one dimensional model of radio frequency (RF) power absorption in electron cyclotron resonance (ECR) ion sources based on a modified cold plasma dielectric description. The absorption is modeled by an imaginary collision frequency (damping coefficient) whose value is related to physical parameters such as magnetic field and its spatial derivative, electron temperature, and RF frequency and power. Properties and scaling laws of ECR power absorption are discussed within this model. Numerical benchmarking against a more accurate kinetic plasma code shows very good agreement.
ABSTRACT
FAR-TECH, Inc., has developed a particle-in-cell Monte Carlo code (EBIS-PIC) to model ion motions in an electron beam ion source (EBIS). First, a steady state electron beam is simulated by the PBGUNS code (see http://far-tech.com/pbguns/index.html). Then, the injected primary ions and the ions from the background neutral gas are tracked in the trapping region using Monte Carlo method. Atomic collisions and Coulomb collisions are included in the EBIS-PIC model. The space charge potential is updated by solving the Poisson equation each time step. The preliminary simulation results are presented and compared with BNL electron beam test stand (EBTS) fast trapping experiments.
