The "Hour-glass" energy diverter (Crowbar)

In prior studies, the most successful infinite range energy diverter designed for protection of microwave devices was a fixed-space multiple-gap array with sequential firing of the gaps. The structure was fairly complicated and required individual capacitors from each electrode to ground. A new type of array, which in appearance has the shape of an hour-glass, has been developed. It eliminates the heed for the high-voltage capacitors, is simpler to construct, and provides excellent high-voltage shielding. The energy requirements for triggering are about one joule. Firing time from zero voltage to the maximum voltage used in the tests was less than 0.5 microsecond. Data on an "Hour-Glass" array with several variations of interelectrode capacitance using both positive and negative triggers have been obtained. The effect of sharpening gaps in the trigger circuit on firing reliability will be discussed.