Nanosecond pulser thyratrons

The fundamental feasibility of using thyratrons for 1 ns turn-on of certain millimeter wave devices has been demonstrated, in that a voltage rise rate of 6kv/ns has been achieved across a pure approximately 60 pF load. Use of ferrite bead saturable reactors enabled this to be accomplished at a thyratron pressure compatible with both reliable voltage holdoff and sufficiently short recovery time for a 20 kHz prr. The thyratron used was a 3-inch diameter HY-3013 modified for low inductance and designated HY-3013L. In particular this result shows that HY-3013L will meet the recently reduced EIO triggering requirements (< or approx. 3 kv), even though the ratio of load voltage to thyratron voltage will decrease to only 0.5-1.0 when the pulse width is reduced to 4 ns FWHM. (The exact value of this ratio will depend on the type of circuit employed). Operation at higher voltages will require a several-fold decrease in thyratron recovery time. Substantial reduction in thyratron jitter is also needed, and a reduction in the power required to trigger the thyratron would be desirable. Thyratrons based on the HY-3013L, but modified to achieve these goals, are being designed.