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User name D. Parno
Log entry time 21:45:23 on March 14, 2009
Entry number 266148
This entry is a followup to: 266124
keyword=BB Shower Sum TDC Signal Changes with F1 Reference StructureAt Brad's request, I looked into whether the BB timing signals depended on the structure in the F1 signal differences that arose around Run 2107.
Fig. 1 shows that there is some such dependence in Run 2158. I generated the three colored histograms using cuts on the F1 signal difference (DBB.f1s8ref0[0] - DBB.f1s5ref0[0]), dividing that difference into three ranges. Fig. 2 shows that F1 signal difference plot for reference.
In Fig. 1, the red histogram shows BB.sum.RT when (DBB.f1s8ref0[0] - DBB.f1s5ref0[0]) < -2000. This corresponds to the dominant structure, on the left of the histogram in Fig. 2.
The blue histogram shows BB.sum.RT when -2000 < (DBB.f1s8ref0[0] - DBB.f1s5ref0[0]) < -1800. This corresponds to the central peak in Fig. 2, which is at the same location as the single peak in Run 2106 (which seems to have been the last "good run" in this regard).
The green histogram shows BB.sum.RT when (DBB.f1s8ref0[0] - DBB.f1s5ref0[0]) > -1800. This corresponds to the structure on the right of Fig. 2.
There are a few clear differences in structure:
- The peak of the red histogram is wider on the left than that of the blue histogram.
- In all three histograms, there are secondary peaks in the background around -500. These peaks coincide for the red and the green, but not for the blue.
- The green histogram shows a shoulder at more negative values that is not present in either of the others.
- The background in the red histogram does not have the same amplitude on
either side of the primary peak, as the others do.
A copy of this log entry has been emailed to: brads
Figure 1
Figure 2
