Minutes 060609

Notes for item 2, tagger and trigger timing, etc:

1.  We should install He bags;  need official request to H-B for this and other beamline components
    incl. radiator thickness, collimator size, etc.
2.  Tagger trigger timing (thanks to Eugene Pasyuk):
  20 ns      transit time in PMT's
  50 ns      cable to CFD
  10-15 ns   internal CFD
  5 ns       cable to L-R coincidence module
  5 ns       internal coincidence module
  10 ns      cable to Master OR module
  20 ns      internal Master OR
  80 ns      cable to forward carriage
3.  Photon flight time to alcove approx 100 ns
4.  Tagger uses LeCroy 1877 multi-hit and CAEN pipelined TDC's, both run in common-stop mode
5.  CAEN V792 ADC (BCAL readout) is slowest and sets front-end busy time.  May skip busy and just 
    use front-end-busy-timer in TS, as V792 has fixed digitization time of approx 7 microsec.