Plasma packet propagation in microchannels

Summary form only given. The temporal and spatial evolution of low temperature plasma packets has been examined in microchannels fabricated in nanoporous alumina (Al₂O₃). Patterned by conventional photolithographic techniques, microchannels having width of 200 ~ 250 μm and depth of 110 ~ 120 μm were etched and various channel arrangements (such as spirals, intersecting sinusoids, and “switchyard” geometries) have been tested successfully. Plasma propagation is monitored by a gated, intensified CCD detector that views the channels through a planar ITO electrode. Experiments with Ne at 500 Torr reveal plasma packets that propagate within the channels at velocities as large as several tens of km-s^-1. The fundamental processes responsible for this behavior, as well as potential applications of specific microchannel array geometries, will be discussed.