Influence of ponderomotive force for inductive plasma sources

The authors present a model for the effect of the ponderomotive potential that is generated at the edge of inductively driven plasma sources by the RF magnetic field. The model solves the continuity equation together with the momentum equations for ions and for electrons that includes the ponderomotive force on the electrons. For the case of a linearly varying ponderomotive potential in an edge region, the authors obtain an analytic 1-D solution for a range of collisionality following the work of Self and Ewald. This allows straightforward assessment of the influence of the ponderomotive force for producing a more uniform density profile and reducing plasma losses. The authors go on to consider the effects in 2-D by using the fluid code FEMR that calculates the self-consistent wave fields in the Darwin approximation. A comparison is made between simulations that include the RF magnetic field in the electron momentum equation to generate the ponderomotive force and simulations that suppress the RF magnetic field but add a ponderomotive potential term for the electrons