Performance and calibration studies for run 420.
- CERN 18
- S420, bar with 3-layer spherical lens
- protons @ 7 GeV/c
- geometrical reconstruction
- delta t selection with s = 0.5 ns
Geant visualization of two extreme positions. z=250 mm:
![](/~rdzhigad/data/prt/zscan/r420_250.png)
z=850 mm:
![](/~rdzhigad/data/prt/zscan/r420_850.png)
Position calibration for the lens by scanning x-step (steps definitions) Show/Hide
![](/~rdzhigad/data/prt/zscan/join_scan_x_420/spr.png)
![](/~rdzhigad/data/prt/zscan/join_scan_x_420/sep.png)
For y-step:
![](/~rdzhigad/data/prt/zscan/join_scan_y_420/spr.png)
![](/~rdzhigad/data/prt/zscan/join_scan_y_420/sep.png)
=>lens's steps: [65,18.5] mm
Azhimuthal scan for z = 650 mm Show/Hide
![](/~rdzhigad/data/prt/zscan/phi_scan/spr.png)
![](/~rdzhigad/data/prt/zscan/phi_scan/sep.png)
Time difference cut scan (for bugged version) Show/Hide
![](/~rdzhigad/data/prt/zscan/tr_scan/nph.png)
![](/~rdzhigad/data/prt/zscan/tr_scan/spr.png)
![](/~rdzhigad/data/prt/zscan/tr_scan/sep.png)
Chromatic correction Show/Hide
before correction (beam data z = 850 mm):
![](/~rdzhigad/data/prt/zscan/chrom/chrom.png)
![](/~rdzhigad/data/prt/zscan/chrom/chroml.png)
after correction:
![](/~rdzhigad/data/prt/zscan/chrom/chrom_corr.png)
![](/~rdzhigad/data/prt/zscan/chrom/chroml_corr.png)
performance conparision:
![](/~rdzhigad/data/prt/zscan/join_scan_420_oc/nph.png)
![](/~rdzhigad/data/prt/zscan/join_scan_420_oc/spr.png)
![](/~rdzhigad/data/prt/zscan/join_scan_420_oc/sep.png)
Performance plots after all corrections (0.5 ns time constant cut) Show/Hide
![](/~rdzhigad/data/prt/zscan/join_scan_420/nph.png)
![](/~rdzhigad/data/prt/zscan/join_scan_420/spr.png)
![](/~rdzhigad/data/prt/zscan/join_scan_420/sep.png)
Simulation with Ideal path in EV Show/Hide
![](/~rdzhigad/data/prt/zscan/ideal/tangle_i.png)
![](/~rdzhigad/data/prt/zscan/ideal/time_diff_i.png)
all pathes:
![](/~rdzhigad/data/prt/zscan/ideal/tangle.png)
![](/~rdzhigad/data/prt/zscan/ideal/time_diff.png)
Direct vs. reflected photon yield Show/Hide
0.5 ns time constant cut:
![](/~rdzhigad/data/prt/zscan/join_scan_420_dirref_0.5/nph.png)
1.5 ns time constant cut:
![](/~rdzhigad/data/prt/zscan/join_scan_420_dirref_1.5/nph.png)
comparision with simulation without transport efficiency (1.5 ns):
![](/~rdzhigad/data/prt/zscan/nph_1.5.png)