Changing Heater and Reservoir Voltages for TWIN Thyratron

I adjusted the heater voltage and reservoir voltage. These voltages were set at 10.06 VAC(Heater) and 8.04 VAC (Reservoir) respectively. In the beginning, I turn on the system after 10 or 15 minutes warming up, the TWIN ran at 5 Hz for 1 second, then the repetition rate changed to 1 Hz, after 2 or 3 shoots, there was no operation anymore. I increased the V_H to 10.71 VAC, V_R to 8.35 VAC the TWIN did not run. When I increased the V_R up to 8.77 VAC, the TWIN was interlocked as soon as I turn on.

I have to shut down the TWIN system. Several minutes later, I turn on the system and warmed up, set the V_H 11.38 VAC, V_R 8.40 VAC, the repetition rate 5Hz. This time the TWIN ran normally, then I increased the repetition rate to 6Hz, everything was ok! Then turn off the system, set the repetition rate up to 8 Hz, the TWIN was not running, after a few seconds, it ran at low rate then up to 8 Hz. After the system ran for a couple minutes, I turn it off again and increased the repetition rate up to 10Hz, this time the TWIN ran normally after 1 minute. However, when I decreased the rate down to 5 Hz, the TWIN was dead again.

I have to shut down the TWIN again and left it not run for a couple of minutes. Then I set up the V_H 11.35VAC, V_R 8.35VAC, the TWIN has been run well for about 30 minutes. Then the TWIN excimer became unstable, there were one miss fire after 10 shoots (@repetition rate 10Hz). I switched off the TWIN and waited for several minutes, then turn it on, but just run 1 minutes, the TWIN became unstable either at 5Hz or 10Hz.

I found the TWIN excimer was sensitive to the reservoir voltages, when V_R under 8.35 VAC, the TWIN could be run; when the reservoir value up to 8.35 VAC, the power supply would be interlocked. I don't know why.