Log entry time 11:16:15 on February 26, 2011

Entry number 348775

This entry is a followup to: 348709

 Times to get from target to point at which EDTM is injected

 Proton into BigBite:

    0.875     0.450     0.404     0.300 GeV/c
  -----------------------------------------------
    0.682     0.432     0.395     0.304   Beta 
  -----------------------------------------------
     17.1      27        29.5      38.3   TOF (3.5 m to E-plane)
    226       226       226       226     Signal cable from PMT
    -----     ---       -----     -----
    243 ns    253 ns    256 ns    264 ns

 Electron into L-HRS: (1.0 to 3.6 GeV/c)

   87   TOF (26 m to s2m)
   60   Signal cable from PMT
  ---
  147 ns


 Time difference between proton and electron signals to EDTM
 injection point:

    0.875     0.450     0.404     0.300 GeV/c
  -----------------------------------------------
B-L = 96 ns    106 ns    109 ns    117 ns

The edtm configuration for this is set to 

./edtmsetup 0 92 232  

The T6 coincidence is formed with an overlap between T3 and the E-plane
singles trigger (formerly T6).  The electron (T3) was chosen to carry
the T6 time.  For this trigger setup, the scripts t1_delay and t3_delay
are not used.  Instead I used old fashioned cable delay and a LeCroy
dual gate generator model 222.  

I took a copy of T3 and E-plane singles that were relatively undelayed
from where they originate at the weldment.  The timing difference at
this point has the E-plane trigger generation 136 ns before the T3 
trigger reaches the weldment and is massaged.  I used the LeCroy 222 to
delay a copy of T6 by 140 ns.  I then delayed the un-delayed copy of T3
by 66 ns to form T6 coincidence.  T3 comes inside the E-plane window
about 50 ns after the E-plane trigger opens.

All these numbers are based on the slowest proton in BigBite 
(300 MeV/c).  The time difference between slowest and fastest proton in
BigBite is only 21 ns.  Hence between 300 MeV/c and 875 MeV/c the 
E-plane trigger window will slip forward by 21 ns preserving the 
coincidence time setup for all BigBite momenta.

At the point the coincidence is formed, the E-plane trigger width is
set to about 140 ns (coincidence window).  The delayed T3 copy is set
to be about 50-60 ns wide.

Not that it matters for the N-Delta settings, but T5 comes before T6 at
the Trigger supervisor by 18 ns.  However a real T5 does not exist for
the BigBite elastic (e,e'p) settings.