[Halld-pid-upgrade] Cluster Counting and DAQ

[Matthew Shepherd]

Hi Lubomir,

After thinking about it more, I don't think I phrased my question in the clearest way regarding the DAQ and cluster counting.

You showed that you need to count ionization clusters that arrive over a period of something 10 - 12 microseconds after the primary track.

I think our trigger typically arrives 2-3 microseconds after the event.  For all subsystems this means they must look back into their buffer some fixed time and readout the event.  (In many subsystems the trigger can't arrive much later or else the data is lost.)

For the cluster counting scheme this means that you need retrieve data from 2-3 microseconds before the trigger and up to 10 microseconds after the trigger.  I don't understand the intricacies of the electronics or trigger, but does the fact that you won't have completely recorded an event until almost 10 microseconds after the trigger is sent to the crates cause a problem?  (Presumably in that 10 microseconds there is a decent probability that another trigger will arrive as well.)

Maybe there is not a problem, but this seems to be a readout scheme that is somehow fundamentally different from other subsystems.

Matt

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Matthew Shepherd, Associate Professor
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