Imaging of Pressure-Dependent High-Power Microwave Surface Flashover

Open-shutter and intensified charge-coupled device images of high-power microwave breakdown were taken in an effort to characterize the pressure dependence of plasma development. These images were taken with a Nikon D200 and Andor iStar DH734-25U-03, respectively. With the pressures increasing from 200 mtorr to 155 torr, the plasma changes from a diffuse discharge encompassing a large volume to a multichannel structure following the electric field lines.