Flashover of vacuum interfaces with many stages and large transit times

Methods are developed to calculate the effective breakdown levels and reliabilities of vacuum interfaces with many stages and (where applicable) large transit times. The method assumes that a breakdown equation like that of J.C. Martin describes the flashover of individual stages. The NIKE and Saturn tubes are used to illustrate the results. Uncertainties in the single insulator breakdown equation are discussed, as are the implications of experience with Saturn and the AIRIX injector.