A novel preionization technique which uses a surface corona discharge to produce preionization electrons for the controlled low jitter breakdown of a main corona‐gap preionizer is described. The pre‐preionization scheme has been used to reliably preionize a long optical pulse (450 ns full width at half‐maximum) XeCl laser. The laser excitation circuit is a new version of the overshoot mode of magnetic‐spiker sustainer excitation specifically designed to be simple, reliable, and capable of high repetition rate operation. ©1994 American Institute of Physics.