Signatures of the Bohm and sheath velocities in minority-light-ion energy distributions

Abstract
The energy distributions of light minority ions impinging on the walls of a radio frequency plasma are obtained numerically by integrating trajectories in a self-consistent electric field. The distributions are found to contain features which can be directly related to the Bohm and sheath velocities. The genesis of these features is considered and a comparison is made to experimentally determined distributions in a mixture of argon and 8% helium.