summary about strange timing concern

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User name R. Michaels

Log entry time 07:45:40 on July 8,2010

Entry number 330770

This entry is a followup to: 330740

keyword=summary about strange timing concern

Regarding the concern about double-peaks on L-HRS.

My shift partner said he recalled these were rare episodes,
but I think they persisted most of the shift. If it's a module
failure it's not clear which.

For example, a flakey RT module could cause jumps in the TDC stop
but the ADC gate is independent of this. A flakey gate generator
could cause jumps in the ADC gate but the TDC stops are independent.
If L-S2m were double-pulsing this should affect gates on R-HRS
for T4, but it does not. It's a puzzle !

I am concerned that a fraction (perhaps up to 50%) of the data are
bad for those runs, since shifted ADCs mean you lose PID on L-HRS.

If the double-peaks can be observed in a cosmics run, then it can
be diagnosed with a scope. Someone should look.