User name V. Sulkosky
Log entry time 19:21:08 on November 6,2007
Entry number 212914
keyword=Left Gas Cerenkov PositioningWhile investigating the signal from PMT #10 on the LHRS gas Cerenkov,
Bogdan suggested to cut on the mirror position. Figure 1 shows a
plot of the track x and y coordinate as reconstructed in the plane of
the Cerenkov detector. I have color-coded the plot to emphasize the
contributions from the different mirrors.
There is little acceptance for PMT #1 and #2, which are at the bottom
of the plot. PMT #10 is located at the top right (purple points).
This plot also indicates that the Cerenkov may not be centered in the
detector frame, since the right side of the detector has almost
a factor of two extension in y compared to the left side.
During the access tomorrow, I will check the alignment of the detector.
Figure 2 shows the pedestal subtracted ADC spectra for PMT #6 after
placing a cut on the track x and y positions (blue points near the
"Left Side" label).
FIGURE 1
FIGURE 2
