I ran the Prometheus this afternoon, however the x-ray gun still was unstable. The new problem was the high voltage could not be applied to the rail gap. The filament switch was turn off after running several mintues, then I found the fuse was broken. I measured the Primary voltages, the north bank looked well, but there was no signal from south side.
I changed the fuse and the one 27 Ohm resistor for Thyratron at South bank.