[Halld-online] number of samples for pulse integral and pulse pedestal

[Richard Jones]

Hello David, Sean,

You have probably seen that I have checked in the first iteration of our
online monitoring plugin for the TAGM.

On a related issue, are we supposed to tell you how many samples we want to
have in the fadc for computing the pulse integral and the pulse pedestal? I
see in the rawevent plugin that a default of 55 samples is being used.
Perhaps this is just a placeholder, but that is clearly too long for the
TAGM pulses. I can send you some raw pulse waveforms for reference if you
like, but our rise time (10/90) is 1.5 samples (on the scope it is faster,
but I think the FADC receiver amplifier is shaping it with a bandwidth
limiter) and the fall time is 8 samples, so 12 samples (50ns) is about
right for the pulse integral if you want to capture the entire pulse. At
high rates we should probably consider reducing it to more like 8 to reduce
pile-up effects. For the pulse pedestal I should think that 3-4 samples
would be ok.

-Richard J.
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