Strip-like plasma drift in a magnetized RF discharge

摘要

A strip-like structure has been observed in a low-pressure radio frequency (RF) induced plasma, where a magnetic field perpendicular to the plasma flow is introduced in order to filter out the electrons. This structure forms for a broad set of parameters in different gases. It seems to result from an E × B drift due to the capacitive coupling of the antenna to the grounded chamber walls. Measurements indicate that the strip acts as a path for the electrons to cross the magnetic field. This strip formation can be avoided by introducing a Faraday shield between the antenna and the discharge tube. The electrostatic field between the antenna and the Faraday shield will be localized and the coupling of the plasma will be essentially inductive.