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User name jroche
Log entry time 06:11:46 on October 13, 2010
Entry number 334594
Followups:
keyword=Scintillator timing (S2 only in the trigger)Run 7207 was taken with S2 only in the trigger. I am suprised by the timing distirbutions we are getting in S2 tdcs. It looks to me that the time of the hits in S2 varies if a S1 scintillator is hit at the same time or not. Looks odd to me.
More details:
The plots show the timing distribution for all events (red) and for the events for which a S1 scintillator is hit. Each plots show the 12 pmts with pmt 0 being on teh top left, pmt 1 on the top rigth, etc. The first figure is for the right pmts while figure 2 is for the left pmts. Typical cuts for the red spectra is: D.evtype=="D.evtype==1&&L.s2.nlthit==1&L.s2.rt[x]*L.s2.lt[x]>0&&L.cer.asum_c>200"; For the black spectra, the cuts are: D.evtype==1&&L.s2.nlthit==1&&L.s1.nlthit==1&&L.s2.rt[x]*L.s2.lt[x]>0&&L.cer.asum_c>200"; where x is a number from 0 to 11. A typical separation between the black and red peak is 350 channel (=8.75 ns). Also note that the double black peaks in pmts 5 and 10 correspond to two different scintillator 1 being hit. ie: for S2[5], the first peak correpsond to s1[1] being hit and the second peak to s1[2] being hit. The difference between the 2 peaks is ! 150 channels (~3.75 ns).
A copy of this log entry has been emailed to: hyde@jlab.org
Figure 1
Figure 2
