| Here are some plots from a quick analysis I did of the dec. 2003 PrimEx luminosity test data. The main purposes here are 1.) to try and identify major problems with the data and 2.) to try and ensure the database and analysis software are working properly. |
| Here's a discussion of some of the more major problems with the test data. |
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Triggers For the runs I looked at (TAC runs with TAC "collimator" in), The trigger configuration was more or less the same with the primary source of events coming from the MOR trigger. There were also so prescaled TAC triggers, and the always present Clock trigger. |
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TAC Timing The TDC spectra are still one of the big mysteries of this data set. The plot shown here is discussed in the problems page. One possibility for the above plot was that it due mainly to the low, 35mV threshold if it was somehow very noisy. Here is a 2D plot showing the TDC spectra as a function of TDC threshold. You can see the noise does seem to lessen with threshold, but only slightly. Note that the 35mV timing is shifted because it came from the first level linear fan-out. The 45mV, 55mV, and 65mV thresholds were from a second linear fan-out. The cabling paths were different which causes the descrepancy. Here's the projections of the above plot onto the X axis. This just shows that relatively few events are lost from the "real" peaks due to the TAC thresholds. The secondary peaks seem to be more sensitive to it. The root file with the 2D histogram (2nd plot up from here) can be found here. The macro used to produce the 1D plot from the 2D histo can be found here |
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Tagger Timing This plot from run 1530 shows the difference (in TDC counts) between the TAC and the individual T-counters. I don't understand the structure beyond 350 on the x-axis. The band at about 300, though, is just what we would expect. This plot shows the same data as above, only the values have been converted to ns and shifted into alignment using Eric Clinton's calibration constants. Here's one last plot showing that the tagger calibration has aligned the E and T counters nicely. This plot is of the E-T timing difference after calibration. |
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TAC ADC This plot shows the correlation between TAC ADC(x-axis) and Tagger T-counter (y-axis). Eugene Pasyuk pointed out that the gate timing must have been very close since T-counter #9 (one he knew was slightly out of time with the others) was not integrating the same fraction of the signal that events triggered by other T-counters were (hence the shift). |
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Tagging Ratios I hesitate to even put these up since I believe a lot can probably be done to clean them up. Nevertheless, here they are: This first one is from the 100pA runs 1529,1530, and 1532 (combined). It represents the tagging ratio as a function of T-counter. Events in this (and the next plot) used the following cuts:
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