Arc-backs in ignitrons in series

Theory based on the random occurrence of arc-backs indicates that the arc-back rate of ignitrons in series should be very low compared with the arc-back rate of the individual ignitron operating alone on its share of the voltage. To check these ideas, experiments were carried out with high-current ignitrons (350 amperes average per anode) operating in series with voltages balanced and unbalanced, and individually. The results of these tests are given and discussed.