Particle simulation of ion extraction from plasma by a radio frequency resonance method

Abstract

The mechanism of ion extraction from plasma by rf resonance has been studied by one-dimensional particle simulation. The plasma-sheath resonance under the weak magnetic field occurs at the theoretically predicted frequency in the simulation and it has durability. In the rf period at the resonance, the large electric field penetrates into the plasma and the electrons move collectively due to a polarization drift and E×B drift. Two processes are proposed for the ion extraction mechanism. In the first, the rectified electron current in the resonance causes the plasma potential to be higher. Consequently, ions are extracted to a pair of parallel plate electrodes, which sandwich the plasma. In the second, the time-averaged electric field in the plasma region causes ions to accelerate to both electrodes. This means that the restriction of the plasma shielding effect is overcome by the time-averaged electric field.