This page is meant to document histograms in the standard Brunel output that are useful for detector alignment monitoring. For now, just add for the most important histograms a path in the root file.


  • /Velo/VeloTrackMonitor/m_prof_res_XX= shows the profile histogram of the residual versus the azimuthal angle for each sensor XX.
  • the script (in Quality/MoniGUI/python) fits each histogram by a sinusoidal to evaluate the misalignment of each sensor. Two overview histograms summarize the misalignment results: the first histogram the results for the sensor with a misalignment above a warning threshold and the second histogram shows the significance of the misalignment for all the sensor.


  • /Track/TTTrackMonitor/Ttrack/XXX/unbiasedResSector (XXX = TTaX, TTaU, TTbV, TTbX) shoes the unbiased residual versus sector. This plot is produced in fullDetail mode


  • /Track/ITTrackMonitor/Ttrack/XXX/unbiasedResSector (XXX = ASide, CSide, Top, Bottom, Mixed) shoes the unbiased residual versus sector. This plot is produced in fullDetail mode


  • /OT/OTTrackMonitor/respullvsmodule shows the average residual versus the module number in the OT.


  • /Muon/MuonAlignmentMonitor/ directory contains several useful histograms. The container used to fill the histograms is the MuonPID one. x_vs_y = 2D distribution of the associated Long track tx_vs_ty = 2D distribution of the slopes of the associated Long track chi2_match = match chisquare of the Muon segment to the Long track prof_resX_Y profile histograms of residuals between the Long track and the Muon track states @closest state to M1 -- X=(Dx, Dy, Dtx, Dty ) vs Y=(x,y,tx,ty) residX_YSide_station_Z (X=x,y; Y=a,c; Z=1,2,3,4,5) unbiased residuals of the Long track extrapolation and the associated Muon tile positions


  • /RICH/RichAlignMoniR1/dThetavphiRecAll & RICH/RichAlignMoniR2/dThetavphiRecAll show the distribution of Cherenkov angle with ring angle globally for RICH1 and RICH2. Sinusoidal deviations are expected with misalignment w.r.t. Tracking. For an aligned RICH, the amplitudes of these deviations will be <1 mrad.

Presenter page to be finalised. Guide for DQ Shifters



-- WouterHulsbergen - 09-Oct-2009

This topic: LHCb > WebHome > LHCbComputing > LHCbDetectorAlignment > AlignmentMonitoring
Topic revision: r6 - 2009-11-13 - unknown
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