Particle-in-cell/Monte-Carlo simulation of plasma and neutral gas flow for the inner coating of PET bottles by plasma-based ion implantation.: N2 gas plasma

Plasma behavior inside of a PET bottle together with the gas flow has been analyzed under plasma-based ion implantation (PBII) conditions. The software "PEGASUS" with the cylindrical coordinate system was used for the simulation. PEGASUS uses the particle-in-cell (PIC) method for the movement of charged particles in the electromagnetic field and the Monte Carlo method for collisions of ions, electrons, and neutrals in the plasma in a low-pressure gas. The gas flow is analyzed by the Monte Carlo method. It gives spatial distributions of densities, velocities, fluxes, temperatures and pressures of each neutral species. The plasma simulation was coupled with the gas flow simulation, and the plasma behavior in the flowing N-2 gas was analyzed. The gas pressure was 10 and 50 Pa; a positive pulse voltage (maximum voltage = 500 V) was applied to the center rod from where the gas flows. Time evolutions of spatial distributions of the potential and the densities of ions, electrons and radicals in the coating system were obtained together with the flux of ions and electrons on the target surface.