Approved Combined Inner Detector Plots

Introduction

The Inner Detector commissioning and performance plots below are approved to be shown by ATLAS speakers at conferences and similar events.

Figures

Detector alignment

Residual distribution in x, integrated over all hits-on-tracks in the pixel barrel for the nominal geometry and the preliminary aligned geometry. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A double Gaus fit is performed but only the mean and sigma of the narrower Gaussian are shown.
Approved_PixBarResX.eps
Residual distribution in y, integrated over all hits-on-tracks in the pixel barrel for the nominal geometry and the preliminary aligned geometry. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local y coordinate, which is the non-precision coordinate. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A single Gaussian fit is performed.
Approved_PixBarResY.eps
Residual distribution in x, integrated over all hits-on-tracks in the SCT barrel for the nominal geometry and the preliminary aligned geometry. The residual is defined as the measured hit position minus the expected hit position from the track extrapolation. Shown is the projection onto the local x coordinate, which is the precision coordinate. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A single Gaussian fit is performed.
Approved_SCTBarResX.eps
TRT residual for combined tracks before and after TRT alignment. The alignment includes a global alignment with respect to the Pixel and SCT, as well as an internal module level alignment.

Description: The plot show TRT residual distribution from cosmic data with the solenoid on (run 91900). Tracks are required to have pT >2 GeV, event phase between 5 and 30 ns, >= 45 TRT hits, >= 2 Pixel hits, >= 9 SCT hits, and no endcap hits. A single Gaussian fit to the core of the distribution (+/- 0.3 mm) is done, and the mean and sigma of the fit are reported. The distribution is made in athena release 15 (-tag=15.0.0) and using ID alignment tags InDet_Cosmics_2008_03 and TRT_Cosmics_2008_06.

TRTBarrelResidualCombinedTracks.eps
Cosmic tracks crossing the entire ID leave hits in both the upper and lower halves of the ID. These tracks can be split near the interaction point and fit separately, resulting in two collision-like tracks that can then be compared. The plots shows the difference in the d0 track parameter between the two split tracks. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). Tracks also are required to have a hit in the Pixel B layer, 3 Pixel hits and in total 7 Silicon hits. The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A single Gaussian fit is performed.
Cosmic tracks crossing the entire ID leave hits in both the upper and lower halves of the ID. These tracks can be split near the interaction point and fit separately, resulting in two collision-like tracks that can then be compared. The plots shows the difference in the z0 track parameter between the two split tracks. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). Tracks also are required to have a hit in the Pixel B layer, 3 Pixel hits and in total 7 Silicon hits. The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A single Gaussian fit is performed.
Approved_DeltaZ0.eps
Cosmic tracks crossing the entire ID leave hits in both the upper and lower halves of the ID. These tracks can be split near the interaction point and fit separately, resulting in two collision-like tracks that can then be compared. The plots shows the difference in the Q/pT track parameter between the two split tracks. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). Tracks also are required to have a hit in the Pixel B layer, 3 Pixel hits and in total 7 Silicon hits. The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A single Gaus fit is performed.
Approved_DeltaQoPT.eps
Cosmic tracks crossing the entire ID leave hits in both the upper and lower halves of the ID. These tracks can be split near the interaction point and fit separately, resulting in two collision-like tracks that can then be compared. The plots shows the difference in the phi track parameter between the two split tracks. Tracks are selected to have pT > 2 GeV, |d0|<50mm, |z0|<400mm (in other words they are required to go through the pixel L0). Tracks also are required to have a hit in the Pixel B layer, 3 Pixel hits and in total 7 Silicon hits. The distribution is shown for 5 cosmic runs: 91885, 91888, 91890, 91891, 91900, all have solenoid on - corresponding to ~25% of all the solenoid-on data taken in Sep/Oct 2008. New Tracking is used (in 14.5.2.1). A double Gaussian fit is performed but only the mean and sigma of the narrower Gaus are shown.
Approved_DeltaPhi.eps

ID track parameter resolutions

Cosmics muons traverse the whole Inner Detector and thus leave hits in the upper and lower parts of the detector. By dividing the track to its upper and lower half according to the value of the y coordinate of hits on track and refitting both hit collections, two collision-like tracks originating from the same cosmic muon are obtained. After alignment, track parameter resolutions are studied by comparing the difference (residual) of the track parameters at the perigee point. Since both tracks have an associated error, the quoted resolution is the RMS of the residual distribution of the particular track parameter divided by square root 2. The track parameter resolutions are studied dependant on variables like the pT or the d0 of the tracks. Shifted mean values of the residual distributions can be a sign of systematic detector deformations. The following distributions show data from runs 91885,91888,91890,91891 and 91900 taken in 2008. The tracks have been refitted using Athena release 15.0.0.7 (Tier0).

The following cuts have ben applied per track (if not stated otherwise):

• nPixelHits in the barrel >=2
• nSCTHits in the barrel >=6
• nTRTHits in the barrel >=25
• |d0| < 40mm
• pT >= 1 GeV

Additionally only events with an event phase between 5 and 30 ns are accepted to ensure proper timing of the sub-detectors. The plots show comparisons of tracks using the full Inner Detector (silicon and TRT detectors, closed triangles), only the silicon sub-detecors (open triangles) together with tracks from cosmic simulation using the full Inner Detector (stars). The requirement of at least 25 TRT hits is dropped for silicon only tracks. However, the cut on the event phase is retained to ensure proper timing and the comparability of the analyzed sets of tracks. There is no cut on the event phase for simulation events since the jitter in cosmic trigger timing is not simulated.

Transverse impact parameter resolution as a function of pT. In the low pT region, the resolution is dominated by multiple scattering effects. At higher values, the resolution is flat. Taking into account the TRT information improves the resolution. The difference to the MC curve indicates the remaining mislaignment.
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Transverse impact parameter resolution as a function of d0 itself. For this plot the d0 cut is released to 120 mm and the minum number of Pixel hits is set to one. In general the resolution for full ID tracks is better. The resolution is better in the central d0 region due to more Pixel layers crossed and less spread clusters in the Pixel detector. Dips are seen if the d0 of the tracks equal the radii of the pixel layers (indicated by dashed lines). Since the d0 is in these cases very close to a hit on a Pixel layer, the extrapolation to the perigee point is very small and the resolution improves. The MC distributions confirms the observed behaviour.
eps figure
Mean of the transverse impact parameter distribution as a function of pT. The expected value of the mean is 0 as confirmed by the MC distribution. In data a shift is seen for full ID and silicon only tracks. The shift increases with higher pT.
eps figure
Mean of the transverse impact parameter distribution as a function of d0 itself. For this plot the d0 cut is released to 120 mm and the minum number of Pixel hits is set to one. The expected value of the mean is 0 as confirmed by the MC distribution. In data a shift is seen for full ID and silicon only tracks. The shift is biggest in the central d0 region.
eps figure
Relative momentum resolution as a function of pT. The relative momentum resolution increases with higher pT due to stiffer tracks and a more difficult measurement of the sagitta. Including information from the TRT extends the lever arm and helps improving the resolution especially at high pT values. The difference to the MC curve indicates the remaining misalignment.
eps figure
Mean of the relative momentum distribution as a function of pT. The expected value of the mean is 0 as confirmed by the MC distribution. In data a shift is seen for full ID and silicon only tracks. The shift increases with higher pT.
eps figure
Resolution of the azimuthal angle as a function of pT. In the low pT region, the resolution is dominated by multiple scattering effects. At higher values, the resolution is flat. Taking into account the TRT information improves the resolution. The difference to the MC curve indicates the remaining mislaignment.
eps figure
Resolution of the polar angle as a function of eta. The resolution of the polar angle theta improves at larger eta due to broader pixel clusters that allow a more precise position measurement. Since the TRT effectively does not measure the z coordinate in the barrel region, the resolutions are equal for silicon only and full ID tracks. The difference to the MC curve indicates the remaining misalignment.
eps figure

Distributions from cosmic ray tracks

Warning: Cosmic ray spectra including comparisons with MC which appeared before on this page are not approved for external use at this stage. The MC does not model some details of the special cosmic trigger configuration and timing. It includes the two main access shafts, but not the two lift shafts. Until these effects are taken into account, the MC-data comparison is not useful.

Cosmic muons crossing the entire ATLAS detector leave hits in the Inner Detector (ID) and so tracks can be reconstructed. Two different tracking algorithms are in use for the reconstruction: the CTB (Cosmics and Test Beam) tracking and the New Tracking. The results below show the performance of the CTB.

Tracks are characterized by 5 parameters. These are defined in a reference point, the perigee, which is the point of closest approach to the z/beam axis. d0 is the signed distance to the z-axis, z0 is the z-coordinate of the perigee, phi0 is the angle in the x-y plane at the perigee, theta0 is the angle with the z-axis and q/p is the charge of the cosmic muon divided by its momentum.

In the next plots, the parameters of these cosmic muon tracks (reconstructed with CTB tracking and release 14.5.0.5, AtlasProduction) from the ATLAS combined cosmic run 91890 (Autumn 2008) are shown. Both toroid and solenoid were on during this run.

For the theta0 and z0 distributions, tracks are required to have Silicon hits (since these parameters are not measured by the TRT barrel).

Cosmic spectra (d0 distribution) as seen in run 91890.
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Cosmic spectra (z0 distribution) as seen in run 91890.
eps figure
Cosmic spectra (phi0 distribution) as seen in run 91890.
eps figure
Cosmic spectra (theta0 distribution) as seen in run 91890.
eps figure
Cosmic spectra (QoverP distribution) as seen in run 91890.
eps figure

Cosmic ray track statistics

Collected track statistics in autumn 2008:
 field off field on total All tracks 4940000 2670000 7610000 SCT hit 1150000 880000 2030000 Pixel hit 230000 190000 420000

pdf figure

Event displays

Inner detector event display for event 757427 of the cosmic run 90270 with field ON.
Inner detector event display for event 62340 of the cosmic run 90731 (no Solenoid). Showing hits on track for both TRT endcaps, as well as SCT and pixel barrel and endcap hits.

Beam Conditions Monitor (BCM) timing distributions

During the combined Inner Detector running in November 2008, out of 50 million triggers, over 100 events with signals in the BCM were observed. The BCM reads out 31 consecutive bunch crossings for each trigger, and the initial timing calibration from measured cable and fibre lengths puts the signal around bin 19. The timing distribution is narrower for events triggered by the TRT than for events triggered by the RPC muon chambers.

BCM timing distribution for RPC triggered events
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BCM timing distribution for TRT triggered events
eps figure

Comparison of NewTracking and CTBTracking

Comparison of NewTracking versus CTB Tracking for real data from the IDCosmic stream of run 91885 (field ON) reconstructed in the first reprocessing in December 2008. (These are technical plots, comparing the results of two different tracking algorithms).

The following cuts have ben applied:

• 2*nPixelHits+nSCTHits>=8
• number of TRT hits >=40
• pT >= 5 GeV

Distribution of pt for NewTracking and CTB Tracking.
eps figure
Distribution of q/p for NewTracking and CTB Tracking.
eps figure
Number of Hits (nPixel+nSCT+nTRT) on the track.
eps figure
Distribution of d0 for NewTracking and CTB Tracking.
eps figure
Distribution of phi0 for NewTracking and CTB Tracking.
eps figure
Distribution of z0 for NewTracking and CTB Tracking.
eps figure
Distribution of η for NewTracking and CTB Tracking. The double-peak structure at η ≈ -0.4 und η ≈ 0.3 is due to the construction shafts through which the ATLAS detector was lowered into the cavern.

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Figure description ... figure

Responsible: PippaWells
Last reviewed by: Never reviewed

Topic attachments
I Attachment History Action Size Date Who Comment
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png SCTResX_NewT_D0Z0cut.png r2 r1 manage 31.8 K 2008-12-11 - 19:13 TobiasGolling SCT x residuals
eps mean_delta_QoverP_vs_pT.eps r2 r1 manage 11.3 K 2009-06-16 - 15:46 ManuelKayl
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eps Approved_DeltaD0.eps r1 manage 32.0 K 2009-03-05 - 14:19 TobiasGolling Delta D0 from cosmic tracks broken down in 2 legs
png Approved_DeltaD0.png r1 manage 30.6 K 2009-03-05 - 14:19 TobiasGolling Delta D0 from cosmic tracks broken down in 2 legs
eps Approved_DeltaPhi.eps r1 manage 49.1 K 2009-03-05 - 14:20 TobiasGolling Delta Phi from cosmic tracks broken down in 2 legs
png Approved_DeltaPhi.png r1 manage 31.4 K 2009-03-05 - 14:21 TobiasGolling Delta Phi from cosmic tracks broken down in 2 legs
eps Approved_DeltaQoPT.eps r1 manage 17.6 K 2009-03-05 - 14:21 TobiasGolling Delta QopT from cosmic tracks broken down in 2 legs
png Approved_DeltaQoPT.png r1 manage 29.8 K 2009-03-05 - 14:21 TobiasGolling Delta QopT from cosmic tracks broken down in 2 legs
eps Approved_DeltaZ0.eps r1 manage 26.0 K 2009-03-05 - 14:21 TobiasGolling Delta Z0 from cosmic tracks broken down in 2 legs
png Approved_DeltaZ0.png r1 manage 32.7 K 2009-03-05 - 14:22 TobiasGolling Delta Z0 from cosmic tracks broken down in 2 legs
eps Approved_PixBarResX.eps r1 manage 28.5 K 2009-03-05 - 14:22 TobiasGolling Pixel x residuals
png Approved_PixBarResX.png r1 manage 32.8 K 2009-03-05 - 14:23 TobiasGolling Pixel x residuals
eps Approved_PixBarResY.eps r1 manage 38.8 K 2009-03-05 - 14:23 TobiasGolling Pixel y residuals
png Approved_PixBarResY.png r1 manage 39.7 K 2009-03-05 - 14:23 TobiasGolling Pixel y residuals
eps Approved_SCTBarResX.eps r1 manage 27.5 K 2009-03-05 - 14:24 TobiasGolling SCT x residuals
png Approved_SCTBarResX.png r1 manage 31.5 K 2009-03-05 - 14:24 TobiasGolling SCT x residuals
gif Atlas_ID_Loops_ON_cy_2008.gif r1 manage 20.9 K 2009-03-09 - 14:19 SaverioDAuria Number of ID Cooling Loops ON as a function of time
gif IDCosmic08_statistics.gif r1 manage 60.4 K 2009-02-13 - 09:33 ChristianSchmitt
pdf IDCosmic08_statistics.pdf r1 manage 18.0 K 2009-02-13 - 09:33 ChristianSchmitt
eps TRTBarrelResidualCombinedTracks.eps r1 manage 43.3 K 2009-04-14 - 14:49 ChristianSchmitt
png TRTBarrelResidualCombinedTracks.png r1 manage 24.6 K 2009-04-14 - 14:49 ChristianSchmitt
eps bcm_rpc.eps r1 manage 10.5 K 2009-06-18 - 11:34 PippaWells BCM timing for RPC triggers
png bcm_rpc.png r1 manage 76.7 K 2009-06-18 - 11:33 PippaWells BCM timing for RPC triggers
eps bcm_trt.eps r1 manage 10.6 K 2009-06-18 - 11:35 PippaWells BCM timing for TRT triggers
png bcm_trt.png r1 manage 76.3 K 2009-06-18 - 11:34 PippaWells BCM timing for TRT triggers
eps delta_QoverP_vs_pT.eps r1 manage 10.2 K 2009-06-16 - 15:30 ManuelKayl
png delta_QoverP_vs_pT.png r1 manage 13.2 K 2009-06-16 - 15:30 ManuelKayl
eps delta_d0_vs_d0.eps r1 manage 15.4 K 2009-06-16 - 15:14 ManuelKayl
png delta_d0_vs_d0.png r1 manage 19.8 K 2009-06-16 - 15:34 ManuelKayl
eps delta_d0_vs_pT.eps r1 manage 11.8 K 2009-06-16 - 15:13 ManuelKayl
png delta_d0_vs_pT.png r1 manage 15.4 K 2009-06-16 - 15:13 ManuelKayl
eps delta_phi0_vs_pT.eps r1 manage 11.0 K 2009-06-16 - 15:30 ManuelKayl
png delta_phi0_vs_pT.png r1 manage 14.1 K 2009-06-16 - 15:30 ManuelKayl
eps delta_theta_vs_eta.eps r1 manage 11.3 K 2009-06-16 - 15:31 ManuelKayl
png delta_theta_vs_eta.png r1 manage 12.5 K 2009-06-16 - 15:31 ManuelKayl
eps mean_delta_d0_vs_d0.eps r1 manage 15.6 K 2009-06-16 - 15:32 ManuelKayl
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eps mean_delta_d0_vs_pT.eps r1 manage 11.7 K 2009-06-16 - 15:33 ManuelKayl
png mean_delta_d0_vs_pT.png r1 manage 14.8 K 2009-06-16 - 15:33 ManuelKayl
eps trackpar_QoverP.eps r1 manage 12.9 K 2009-03-09 - 14:16 PippaWells
png trackpar_QoverP.png r1 manage 8.1 K 2009-03-09 - 14:15 PippaWells
eps trackpar_d0.eps r1 manage 11.3 K 2009-03-09 - 14:18 PippaWells
png trackpar_d0.png r1 manage 7.8 K 2009-03-09 - 14:18 PippaWells
eps trackpar_eta.eps r1 manage 9.5 K 2009-03-09 - 14:17 PippaWells
png trackpar_eta.png r1 manage 6.1 K 2009-03-09 - 14:17 PippaWells
eps trackpar_phi0.eps r1 manage 12.5 K 2009-03-09 - 14:17 PippaWells
png trackpar_phi0.png r1 manage 8.3 K 2009-03-09 - 14:17 PippaWells
eps trackpar_theta0.eps r1 manage 10.4 K 2009-03-09 - 14:15 PippaWells
png trackpar_theta0.png r1 manage 6.9 K 2009-03-09 - 14:14 PippaWells
eps trackpar_z0.eps r1 manage 12.3 K 2009-03-09 - 14:14 PippaWells
png trackpar_z0.png r1 manage 8.5 K 2009-03-09 - 14:13 PippaWells
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Topic revision: r27 - 2009-06-19 - PippaWells

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