Performance analysis of the muon chambers of the ATLAS experiment at - PowerPoint PPT Presentation

Performance analysis of the muon chambers of the ATLAS experiment at the LHC collider Marco Vanadia – Sapienza, University of Rome

The LHC Collider 1 ➔ pp collider ➔ High √s ➔ goal 14 TeV (7+7) ➔ High Luminosity ➔ goal L=10 34 cm -2 s -1 ➔ collisions every 25 ns, requires complex trigger ➔ 6 experiments ➔ SM studies ➔ Search for Higgs Boson ➔ SUSY ➔ Exotic processes ➔ ... Performance analysis of the muon chambers Marco Vanadia 01/02/2010 of the ATLAS experiment at the LHC collider

The ATLAS detector 2 ➔ Inner Detector ➔ Pixel ➔ Strip ➔ Transition Radiation Tracker ➔ EM Calorimeter ➔ Ar+Pb accordion ➔ Hadronic Calorimeter ➔ Scintillator + WLS Barrel ➔ Ar+Pb accordion Endcap ➔ Muon Spectrometer ➔ Works in toroidal B field ➔ Air core magnets Performance analysis of the muon chambers Marco Vanadia 01/02/2010 of the ATLAS experiment at the LHC collider

ATLAS muon spectrometer chambers 3 1 – 6 m MDT RPC Tracking η Trigger Tracking η Tracking Φ 0 . 5 – 2 m CSC TGC Tracking η Trigger Tracking Φ Tracking η Tracking Φ Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

ATLAS MDT chambers 4 1-2 Multilayers Drift Tubes 3-4 Layers Radius = 15 mm Readout: Ar/CO 2 - 93/7 - 3bar mezzanine cards Anodic wire 3080V (ASD, ADC, TDC) Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Calibration model 5 Track reconstruction: Needs r(t) relation, t 0 and t MAX per tube Input: ➔ ADC Spectrum ➔ TDC Spectrum ➔ Second coordinate (from TGC, RPC) Requires high statistics: Output: ➔ TDC spectrum constants Dedicated data stream from ➔ Mean charge per channel q 0 trigger L2 with only muon ➔ σ(r) fragments of the events ➔ r(t) relation Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Data Quality at Calibration Centres 6 Evaluation on muon Analysis on ADC, TDC, DQ Flags spectrometer status and Occupancies, Efficiencies... behaviour Calibration Data Quality analysis DQ Flags Stream Local Calibration DB Calibration analysis DCS Calibration constants Tier2: Michigan, Munich, Rome Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

Search for dead MDT channels 7 Search for dead (inefficient) channels using tubes hits occupancies MONITORING FLAG RECONSTRUCTION Existing ATLAS software → ➔ DEA ( T. Baroncelli) → ➔ GnaMon ( P. Fleischmann) Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

Search for dead MDT channels 8 Statistical based Calculate mean search: Poisson distribution Measure λ Mean = λ Find tubes that Stddev = √λ are dead with a fixed CL Main issues So we use ➔ Noisy channels MED & MAD ➔ Many dead channels MED(λ) ≈ λ + 1/3 ➔ Big fluctuactions MAD(λ) ≈ 0.68 λ 1/2 (cosmic only?) Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

Search for dead MDT channels 9 Strategy ➔ Check sequence in order to find what is the problem (HV, Gas, Wire...) ➔ Check only if histogram has enough statistics ➔ Produce a list of dead chambers, MLs, layers, mezzanines, tubes ➔ Flag chamber status Conclusions Fraction of chambers ➔ Test on cosmic rays data: OK ➔ Improvement in efficiency and reliability ➔ Low statistics requested for the analysis ➔ Now fully inserted in Tier2 software Events Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

Search for dead MDT channels 10 Example of dead channels analysis output Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Reconstruction performance analysis 11 NEW DQ Analysis: Offline reconstruction: ➔ Segment residuals Hit ➔ Track analysis Pattern ➔ Basic monitoring histograms Segments ➔ Residuals analysis Tracks Segment residual Fit of distribution: analysis: Gaussian + tails (MS, uncorrelated hits) Double Gaussian Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Segment analysis 12 Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Segment analysis 13 BML1A05 mm Study of the distribution in function of r drift mm BML1A09 mm mm mm Comparison p(Kolm)=3.4*10 -11 p(Kolm)=0.065 with K=0.021 K=0.080 reference OR Systematic errors Kolmogorov test mm mm Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

MDT Track analysis 14 Track analysis: ➔ Inserted in Tier2 software during my thesis ➔ First of all, introduced basic monitoring histograms ➔ Replicated residual analysis performed for segments on tracks Performance analysis of the muon chambers Performance analysis of the muon chambers Marco Vanadia 01/02/2010 01/02/2010 of the ATLAS experiment at the LHC collider of the ATLAS experiment at the LHC collider

Conclusions 15 New DQ Analysis: Technical work performed: ➔ Dead ➔ Rewritten channels analysis fully many of Muon DQ inserted and tested in Tier2 software software packages (Athena ➔ Track analysis inserted in Tier2 framework) ➔ Fixed bugs in DQ analysis of BEE, → software ( Daniele Capriotti) ➔ Segment and track analysis code BOG, BOF, BIR chambers ➔ DQ tree and histograms layout inserted in the software, needs ➔ Software for automatic feedback as a further investigation with collision data pdf presentation from DQ Dead Chambers 0.0% Detector status results: Low Stat Chambers 2.3% ➔ Cosmic data test with my software showed a detector in health, ready for Objects Deads Total Deads collision data taking ML 0.28% 0.28% ➔ Here I show results obtained on run Layer 0.10% 0.38% 131576 26/9/2009, -1 milion events Mezzanines 0.07% 0.33% Tubes 0.12% 0.52% Performance analysis of the muon chambers Marco Vanadia 01/02/2010 of the ATLAS experiment at the LHC collider