User name R. Michaels
Log entry time 15:48:35 on November26,2000
Entry number 52527
Over the Thanksgiving break, the following changes were made to
the R-arm trigger. Note, the L-arm was left untouched.
1. Some timing adjustments to make PMT signals line up.
2. Discriminator inputs re-arranged so that S1 goes into channels
1-6 and S2 into 9-14. (Previously it had been 1-12 but now we
skip 7,8). This facilitates the new definition of T1. Note, this implies
a change to detmap.config for R-arm scintillators.
3. New definition of T1 trigger: The L+R results of paddles
1-6 on S1 are first OR'd. These emerge from a rear NIM output
of the 4516 unit used to make L+R. Similarly for S2. Then we
form (S1-OR).AND.(S2-OR). Timing adjusted to be the same
as the former S-Ray. It was 65 nsec faster than former S-Ray.
4. The T2 definition: Ignore S-ray. If new T1 is present, make no T2,
but if T1 is absent, form T2 from 2/3 of S1,S2, and Cerenkov. This is
similar to before, where T2 is exclusive of T1, but the new definition of
T1 takes the place of S-ray. The S-ray (result of 1st MLU) still exists and
is cabled up, but it is ignored, except in one respect: It goes to the scaler
channel 17 (starting from 0) in the normalization scaler. It should not be
much different from T1 rate. In principle we could also keep a prescaled
sample of T1 and S-ray to compare.
That's it for now. I should be finished with trigger tests by Tuesday night.
Meanwhile, the L-arm trigger and DAQ should be usually available.