Spatial Behavior of the Plasma Potential in a Magnetized Radio-Frequency Discharge from Emissive Probe Data

抄録

The spatial profiles of the plasma potential at the crest and the trough phases of the oscillating radio-frequency field in an inductively coupled plasma, in uniform magnetic field, were obtained from the first derivative of the time-averaged current–voltage characteristics of an axially movable emissive probe. On this basis the axial profile of the time-averaged plasma potential was evaluated, it confirming the existence of an electric double layer inside the plasma source. The oscillation amplitude of the plasma potential was obtained as well, it being a measure of the axial component of the excited magnetic field amplitude. Moreover, the oscillation amplitude profile shows a high sensitivity to the presence of the double layer inside the plasma, it having a pronounced maximum at the location of the above space charge structure.