Visible emission contours for neon plasmas in silicon microcavity discharge devices: pressure dependence of spatially resolved fluorescence above the anode plane

Images of the Ne plasma plume residing above the microcavity of a Si inverted square pyramid microdischarge device have been obtained with an optical telescope and a charged-coupled device camera. Viewing the discharge along the device surface show the plume to be approximately hemispherical with a bright core having a width (at the surface) of /spl sim/140 /spl mu/m for p/sub Ne/=300 torr. The dependence of the plume contour on pressure is in qualitative agreement with recent computational results (Kushner, 2004).