Tagger trigger timing

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Below is tagger trigger timing information I got from Eugene Pasyuk. Note that cables are trimmed so the sum of all delays is the same for all T-counters. This is calculated using existing cables.

25 ns
electron flight time tagger radiator to farthest T-counter
20 ns
internal T-counter PMT
50 ns
cable to CFD
15 ns
internal CFD
5 ns
cable to L-R coincidence logic module
5 ns
internal L-R coincidence logic module
10 ns
cable to Master Or module
20 ns
internal MOR
80 ns
cable to forward carriage
150 ns
cable to BCAL Trigger Supervisor
45 ns
internal Trigger Supervisor
50 ns
ADC gate generation, cables to ADC crate, ADC internal
325 + 150 ns
total delay

Note that the photon flight time from the radiator to the BCAL detector is 115 ns, and that the RadPhi setup has 300 ns delay cables (straight, or 100+200 using a patch panel).

Thus using existing cables the trigger delay is 325+150=475 ns minus the flight time 115 ns gives 360 ns, longer than the 300 ns ADC delay cables.

See Overall tagger timing for further discussion.