A method of direct corona imaging on a dielectric transparency

The standard scheme of Kirlian photography is modified to have water on top of a thin mylar dielectric layer, underneath which the object is placed. Water serves both as an electrode and as a constant-temperature heat reservoir. HV is applied between object and water to create sustained corona discharges. Experiments showed that, under an AC or pulsating-current excitation over a duration of minutes, a permanent optical image becomes retained on the mylar surface, which is then usable for projection or for direct viewing with slanted lighting. Direct current approaches were found inefficient to produce the same results. A thermo-plastic theory is hypothesized to account for the observations