I have a jitter issue with a ReTOF mass spectrometer I'm working with. I assume that it cannot come from a trigger issue since the PCI card that collects the signal from the multi channel plate has the same trigger as the HV repeller/accelerator plates with a fast rise time of 2-3 ns. The jitter can be as much as 20 ns. The HV is supplied by a NHQ 216L power supply that is connected to a Behlke GHTS 60 switch box at 10 Hz and I notice that the LCD on the HV supply also jitters below the set value (3480-3500 V). This only happens if the voltage is above 1800 V or so and the trigger to the switch box is on. If I turn off the trigger to the switch box then the LCD on the PS shows a stable voltage at 3500 V. Below 1800 V, the voltage fluctuation is minimized as well as the signal jitter. So it makes sense to me that the jitter is actually a change in flight times due to unstable voltage conditions at the extraction region of the TOF. I've tried using multiple power supplies and switch boxes and I get the same result. Can this be an impedance issue with the cables between the HV supply and the switch box? How would you troubleshoot this?
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