Time-resolved imaging of a silicon micro-cavity discharge array

Time-resolved imaging of an array of silicon based micro-cavity discharge devices, operating in helium at 700 Torr, is presented. The array is shown to ignite four times per cycle, with the brightest emission corresponding to a distinct current peak in the negative phase of the applied sinusoidal voltage. The cavities do not ignite simultaneously and the instantaneous intensity across the array is non-uniform. Before the brightest emission peak is reached, optical imaging shows some of the cavities to be ignited. During the emission peak, neighboring cavities are successively ignited, resulting in two emission regions which propagate across the array with wavefront velocities of 3 and 6 km/s.