Formative time-lag studies with high-frequency discharges

Experiments with discharges between non-uniform electrodes at frequencies in the region of 1 to 15 Mc/s are described. It was found that, above a certain critical frequency, the discharge was able to cross the gap completely, whereas the discharge at direct current or 50 c/s with the same electrodes would take the form of a localized corona envelope. By using pulse techniques, it was possible to measure the formative time-lags for h.f. discharges, using concentric-cylinder and parallelwire electrodes. A lowering of the breakdown voltage of some 13% was observed to take place above the critical frequency. A tentative qualitative explanation is proposed of some of the observed results.