User name R. Michaels
Log entry time 16:49:20 on November 4,2000
Entry number 51476
keyword=re: deadtime calculation bugs (recoverable)
Regarding the deadtime oddities, I noticed three things:
1) The datastream contains enough info to compute the
deadtime correctly, so problems noted are recoverable;
2) The ``datamon'' software was looking at the wrong scaler
channels, because we rearranged things. Oops. I fixed it.
3) I believe the runend.tcl script does not take into account
the fact that for every T5 there is a T1 and a T3 in scalers.
Doing this by hand I get approximate deadtimes of
1062....375 Hz.....3 %
1063....1660 Hz....16 %
Keep in mind, deadtime only scales with rate if
the triggers are random; the above two runs had
large prescale factors to adjust the rate of T4, which
then looks a bit like a pulser. I'll let Mark Jones fix
runend.tcl (assuming I'm correct that its needs fixing).
I guess it wasn't noticed before because usually
singles prescale factors are big.