User name R. Michaels
Log entry time 05:28:39 on April 1,2000
Entry number 37626
This entry is a followup to: 37517
keyword=trigger deadtime studyWe have done a series of runs changing the rate
to try to measure the trigger deadtime. Since the trigger
deadtime is of order 100 nsec while the scaler deadtime
is 10 nsec, I would expect to see a drop in the ratio of
trigger rate to raw S2 rate. The S2-R (sum) rate is
relevant for deadtime, since S2-R strobes MLU.
(Note, we stayed at the higher rate points only a few
minutes, the VDCs drew 15 microamps at worst).
Run with Carbon target. Open collimator.
CODA ....Beam.........T1.......Strobe....S2-3-R......ratio...........Predicted
Run.........Current......kHz........kHz......(typ S2)......T1/Strobe...deadtime(roughly)
3115...........4.5.........45.69.......68.21.......20.86.......0.6698.........0.68%
3116...........4.5.........45.63.......68.34.......20.83.......0.6677.........0.68%
3117..........10.2.......104.50.....156.75......47.80.......0.6667.........1.57%
3118..........19.5.......201.06.....305.61......93.38.......0.6579.........3.06%
3119...........1.0..........10.61.....16.82.........4.97........0.6310.........0.17%
3120..........15..........154.40....233.14......71.04.......0.6623.........2.33%
3121..........18..........183.87....279.16......85.00.......0.6587..........2.79%
3122..........3.2...........34.53....52.22........15.73......0.6612...........0.5%
3123...........2.............22.02.....33.61.......10.11......0.6552...........0.3%
3124..........22.8........231.10...352.07......107.18....0.6564...........3.52%
3125..........8.0...........82.45....123.42......37.52......0.6680............1.23%
Below is a plot. A drop at high rates suggests deadtime.
I am not sure what causes drop at low rates.
FIGURE 1
