TgDelta Calibration

Problem:

When looking at the results of TgDelta calibration I observed some strange behavior. I got feeling that deuteron results were not consistant with proton results. Why?

Precisely extract all elastic events (H,D)

I have applied additional cuts on left-arm to precisely select elastic deuteron and proton events:

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Compare elastic events in FP for different q (i.e. momenta):

I selected H and D elastic events at same q, and checked how these events appear in the focal plane. Because of different energy losses of p and d in spectrometer, they do not lie at the same position in the focal plane. Need to correct for these difference, before able to do my final tgDelta calibration.

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Energy-Loss Calculation:

I have corrected my energy-loss simulation. In the previous version I integrated inly losses in in E- and dE-planes. Now I integrate also losses in the target, air and target enclosure. Using new information that I got while staying at JLab, I have also changed thicknesses of various materials. Simulation works better now:

Some information about position and thickness of the target enclosure foils: TargetFoils.pdf

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New elastic events comparison in FP for different q (i.e. momenta):

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#2413: 2GeV D-elastic:

#3151: 2GeV D-elastic:

#3608: 3GeV D-elastic:

#3265: 2GeV H-elastic:

Problematic 1GeV H-run (#1518):

Results using only energy-losses-corrected elastic H,D runs:

The elastic data, that we have collected during experiment, can be used only for the calibration of the upper part of the momentum region (p>0.45GeV/c). There is no useful data for the lower momentum region (p < 0.45GeV/c):

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Proton PTP data:

For the calibration of the lower momentum region I am using QE data, where I consider only events from well defined points (P.T.P). To determine the momentum of particles at these points, I use my energy-loss simulation. In the previous calibration my cuts in dE/E plane were too wide. This caused instabilities in my calibration. This mistake is clearly visible, when I plot FpTh vs. FpX plot: