The Spatial and Temporal Evolution of the Glow in an RF Discharge

The temporal and spatial evolution of the glow in a 1.0- and 2.6-MHz radio-frequency (RF) excited discharge has been photographed with a high-speed framing camera. Evidence is presented showing electrons with a ballistic behavior in the body of the glow and a time delay between the maximum optical intensity of the glow and the maximum RF voltage. The effect of the dc self-bias on the glow is also shown. The implications of these observations on the dynamics of the ion motion in the plasma are discussed.