Operation of thyratrons at very high peak currents

The authors present results of experiments carried out to ascertain the maximum current carrying capabilities of single gap hydrogen thyratrons of types CX1573 C and CX1574 C. The 3 in diameter CX1573 C has switched 65 kA for 10⁵ shots and the 4.5 in diameter CX1574 C has run at the circuit-limited maximum current of 80 kA for 2×10⁵ shots. The mechanism of operation at the very high levels is an initial normal glow discharge transferring to an arc discharge. In the CX1573 C this mechanism is considered to operate above 30 kA, and in the CX1574 C above 60 kA. Neither tube showed significant changes in measured switching characteristics during these tests. These current levels are many times greater than the normal modulator ratings of these thyratrons, which are production tubes widely used today in high current laser circuits. The tests described here demonstrate the ability of thyratrons to cope with the high Coulomb ratings normally associated with spark gaps, coupled with the major advantage of reliable triggering