Figures 1 to 6 are coloured versions of Figures 10.32, 10.33, 10.35, 10.36, 10.37, 10.38 published in the ATLAS detector paper
Fig. 1: For muons with pT = 100 GeV, expected fractional momentum resolution as a function of the pseudrapidity for stand-alone and combined reconstruction. The degradation in the region with 1.1 < |n| < 1.7 is due to the absence of the middle muon stations in the barrel/end-cap transition region for the initial data-taking, to the low bending power of the magnetic field in the transition region between the barrel and end-cap toroids and to the material of the coils of the end-cap toroids. |
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Fig. 2: For muons with pT = 100 GeV, expected fractional momentum resolution as a function of the azimuth for stand-alone and combined reconstruction. The resolution is degraded at 240° and 300° , due to the additional material introduced by the feet which support the barrel part of the detector. |
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Fig. 3: Expected stand-alone and combined fractional momentum resolution as a function of the transverse momentum for single muons with |n| < 1.1. |
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Fig. 4: Expected stand-alone and combined fractional momentum resolution as a function of the transverse momentum for single muons with |n| > 1.7. |
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Fig. 5: Efficiency for reconstructing muons with pT = 100 GeV as a function of |n|. The results are shown for stand-alone reconstruction, combined reconstruction and for the combination of these with the segment tags. |
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Fig. 6: Efficiency for reconstructing muons as a function of the transverse momentum . The results are shown for stand-alone reconstruction, combined reconstruction and for the combination of these with the segment tags. |
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Fig. 7: The plot shows the measured sagitta, in the precision plane, for cosmics taken without magnetic field in the middle barrel chamber BML2C03 of muon spectrometer. For a properly aligned tower the mean value of the sagitta is expected to be inside required 30 microns level. The three plots show the sagitta distribution for three different geometries : the red distribution is obtained using nominal geometry, the blue one using the optical alignment system based geometry and the green one is obtained after alignment with straight tracks ( for further details please contact potrap@mppmuNOSPAMPLEASE.mpg.de). |
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Fig. 8: The plot shows "track" sagittas calculated from segments in the
stations EI-EM-EO before and after applying alignment corrections
determined by the optical alignment system of the endcaps. We do not
actually use any of the tracking algorithms, instead we define as a
"track" a triplet of segments that have passed our selection cuts. The
sagitta is then calculated in the usual way as the distance in the
precision coordinate of the EM segment from the line joining the EI-EO
segments.
The "nominal chamber positions" histogram reflects the positioning
accuracy that we have reached in the endcaps - typically 5mm rms in
all coordinates for the chambers within a wheel, but up to 25mm
displacements of entire wheels along ATLAS-Z. The EM station is
displaced significantly along ATLAS-Z on the A-side, but not on the
C-side, which is the main contribution to the difference between sides
A and C.
The "after alignment corrections" histogram should, for the optical
alignment to be ok, be centered at zero and have a width that can be
explained by effects other than random chamber misalignment. We
observe a mean value of -48 +/- 54mu, thus compatible with zero, and a
width of 1.5mm, compatible with the expected multiple-scattering width
(as a benchmark, for 40GeV muons at theta=30 degrees the expected
width from a single-muon simulation is 1.4mm).
We conclude that, with the statistics available at this moment, we see
no indication of the optical alignment being not ok within the claimed
accuracy of 45-50mu. |
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Fig. 9: The plot shows the difference in angle (in the precision coordinate)
of the three segments of a "track" from the line joining the EI and EO
segments. Each "track" = segment triplet contributes three entries to
the histogram. We cut at +/-10mrad in this plot in order to remove
background from wrong segment combinations (this also discards
very-low momentum muons).
Segment positions (being some sort of average over all the hits in a
chamber) are much less affected by calibration (t0 and r(t) function)
than segment angles (being some sort of difference between hits), and
thus the width of this distribution, even after alignment corrections,
is significantly larger than expected from simulation (for 40GeV muons
at theta=30 degrees the expected width is around 0.5mrad). |
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Fig. 10:
Resolution plot temporarily removed |
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Fig. 11: The plot shows the global occupancy of MDT multilayers over the full detector divided in INNER, MIDDLE, and OUTER layer of chambers |
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Fig. 12: The plot shows the Residuals for MDT chambers after applying T0 refit on cosmic muons, the residuals have been fitted with a double gaussian and the narrower one is 105 micron wide. |
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Fig. 13: The plot shows the hit profile and the efficiency for an MDT barrel sector, both from the hit profile and the efficiency plot the presence of a dead wire is visible. |
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Fig. 14:
Segment efficiency per MDT chamber for cosmics.
Efficiency is determined using Muon Spectrometer tracks with segments in
two or more station layers (Inner/Middle/Outer). By selecting one layer,
for example the Inner layer, and requiring a track with segments in the
Middle and Outer layers that crosses the Inner layer, the number of missed
segments in the Inner layer and the corresponding efficiency is determined.
Note that the segment (here in the Inner Layer) is not required to lie on the track.
For the extrapolation an ideal cilinder without chamber cut outs is used.
This means that in the feet region and the RIBs small inefficiencies are expected
due to the limited chamber coverage.
Results are for Mdt chambers after acceptance and minimum number of events cuts
BI BO station |eta| = 2-4 and EI |eta| = 1-2, EO EM and BM no cuts,
one chamber was removed. Results after these cuts for 322 Barrel and 339 Endcap chambers.
Average segment efficiency
Barrel Inner 98.7 %
Barrel Middle 99.2 %
Barrel Outer 99.6 %
Endcap Inner 99.2 %
Endcap Middle 99.8 %
Endcap Outer 99.9 %
Total average segment efficiency 99.5 ± 0.5 %
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Fig. 15: Plot shows segment efficiency for station eta vs phi, for the Barrel Middle
MDT chambers (BM). The method is described in caption of Fig 14. The RIB structure can be observed. |
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Fig. 16: Segment Efficiency for Endcap Middle Chambers as Fig 15. One chamber that is off can be observed.
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Fig. 17: Status of the coverage for the Low Pt trigger in the Barrel for a cosmic run taken in September 2009. |
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Fig. 18: Cosmics muon map reconstructed by off-line RPC standalone muon monitoring projected on surface (y=81m).The tracking is based on RPC space points, which are defined by orthogonal RPC cluster hits. The pattern recognition is seeded by a straight line defined by two space points belonging to the two Middle planes.
Space points not part of any previous track and inside a predefined distance from the straight line are associated to the pattern. Patterns with points in at least 3 out of 4 layers in Middle planes are retained and a linear interpolation is performed in the two orthogonal views. |
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Fig. 19: Spatial correlation between MDT tubes and RPC eta hits with cosmic data.The picture shows the scatter plot between MDT tubes z coordinate and RPC eta hits z coordinate of the same chamber along sector 7 for the Middle chamber.
There is no clean-up cuts but an ADC cut > 50 on MDT Front-end response to reject MDT random hits.
The blue squares are due to uncorrelated hits and show the station geometrical boundary along the z-axis. |
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Fig. 20: Time alignment inside Low Pt trigger towers in phi view with cosmic data.The plot shows the distribution of the relative time between RPC layers of Low Pt non-bending view coincidence matrix delivering one and only one hardware trigger in the event.
The time is relative to the layer nearest to the IP. |
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Fig. 21: RPC distribution of single channel noise counting rate per unit area measured with random triggers. The noise is referred to the front-end channel and is calculated by the total number of hits divided by the total number of random triggers and the readout window (200 ns) normalized by the equivalent strip surface.
The definition of the equivalent strip surface takes into account the wire-or and the logical-or in phi view. |
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Fig. 22: Distribution of RPC hits per event with RPC cosmic trigger (not filled area) and with random trigger (black filled area).
The distributions correspond to the RPC detector occupancy due to cosmics and uncorrelated noise. |
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Fig. 23: RPC spatial correlation between trigger strip number and confirm strip number in phi view for a programmed trigger road in cosmics data. The trigger strip corresponds to the Pivot plane strip which caused the trigger to fire for the given threshold. The confirm strip corresponds to the Low Pt plane of
the triggered chamber. It is possible to see the trigger road projective pattern by the deviation of the data points from the dashed line.
Strip number 0 corresponds to the center of the geometrical sector.
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Fig. 24: TGC hits distribution in x-y plane for A side on run 91060. Hit positions are calculated from coincidence of wire eta hits and strip phi hits. Only bottom sectors (sector 8~12) are used for triggerring (eps file also found with the same name) |
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Fig. 25: TGC hits distribution in x-y plane for C side on run 91060(upper) and 91803(lower). Hit positions are calculated from coincidence of wire eta hits and strip phi hits. Only bottom sectors (sector 8~12) are used for triggerring (eps file also found with the same name) |
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Fig. 26: TGC trigger readout distribution (or latency) for TGC triggered events on run 91060. Three bunch crossing (BC) data, previous, current and next BC, are read out. More than 99% of events are in current BC. This means that we are reading the data in pipeline with correct latency. (This does not mean that trigger timing btw TGC and other subtrigger is aligned. ) Rest of less than 1% events are, we guess, due to cosmic showers. (eps file also found with the same name) |
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Fig. 27: Number of TGC hits per event for TGC stream (which contains RPC triggerred events. About 20% of events are RPC triggerred since RPC sector logic got crazy and sent the events to TGC stream...) on run 91060.. Both wire and strip hits in current BC are counted. Mean value of 53 hits is much smaller than number of channels 300 thousand events. This proves cleaness of TGC chambers. (eps file also found with the same name) |
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Fig. 28: removed (2009.05.21 : M.I) |
Fig. 29: removed (2009.05.21 : M.I) |
Fig. 30: Correlation btw MDT tube hits in middle station and TGC track interpolated to MDT middle station for A side on run 91060. TGC tracks are reconstructed with wire hits and required at least 3 station hits. Clear correlation is seen. Vertical lines are due to noisy MDT tube while horizontal lines are due to noisy TGC wires. (eps file also found with the same name) |
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Fig. 31: Correlation btw MDT tube hits in middle station and TGC track interpolated to MDT middle station for C side on run 91060. TGC tracks are reconstructed with wire hits and required at least 3 station hits. Clear correlation is seen. Vertical lines are due to noisy MDT tube while horizontal lines are due to noisy TGC wires. (eps file also found with the same name) |
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Fig. 32: The plot shows TGC layer efficiency as a function of applied High-Voltage. The event sample (= denominator of eff.) is selected based on the MDT track-segment and corresponding 3-wire hit channels for the case of TGC2 / TGC3 (2-wire hit channels for the case of TGC1) , and the efficiency of the last 4th (3rd) layer is evaluated. |
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Fig. 33: TGC Frontend readout timing (or latency) for TGC triggered events on run 91060. Three bunch crossing (BC) data, previous, current and next BC, are read out. More than 98% of events are in current BC. This means that we are reading the data in pipeline with correct latency. (This does not mean that readout timing btw TGC and other subtrigger is aligned. ) Rest of less than 1% events are, we guess, due to cosmic showers. (eps file also found with the same name) |
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Fig. 34: (a) TGC efficiency map for layer 5, T7 chamber. The horizontal axis is the strip channel and the vertical axis is the wire channel. (b) Efficiency projection to the strip channels. The blue bands show the strip channels which contains the wire support structure in its channel (dead region). Observed efficiency drops are consistent with the location of wire support location. |
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Fig. 35: TGC wire efficiency vs high voltage (for active region). Circle mark shows the combined run result in 2008, while square mark shows the beam test results in 2003. The difference of altitude (80m) is taken into account. Both results are consistent within 1%. |
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Fig. 36: The distributions of TGC wire efficiency for individual chamber at different high voltage values, 2650, 2750, 2800 and 2850V |
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Fig. 37: Muon trajectories triggered by the TGC with PT1(black), PT4(red) and PT5(blue).As the PT threshold becomes larger, directional characteristics for the interaction point become sharper. |
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Fig. 38: The distribution of the angle difference (Δθ) between the measured track segment of MDT EM and the infinite momentum line. Each color corresponds to the PT1(black), PT4(red) and PT5(blue) issued by TGC. As the PT threshold becomes larger, the distribution of Δθ get narrower |
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Fig. 39: TGC total trigger rate on 10th, September. Spike structure seems to be consistent with the 40s interval of the beam injection. |
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Fig. 40: TGC total trigger rate for the cosmic ray muons. 24 sectors are included.The trigger rate of PT1(black), PT4(red) and PT5(green) are shown. |
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Fig. 41: An rt-relation derrived from cosmic data. |
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Fig. 42: Resolution and systematic mean deviation of the t0-fit: From a large sample of cosmic data, a drift time spectrum with high statistics was filled. This was used as an probability desity to create random drift times. A large amount of spectra were filled using these hits, and t0-fits were performed. The width and mean of the distribution of the fitted t0 is shown vs the fit statistics. |
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Fig. 43: A residual distribution from cosmic data: Shown is the mean value and the width of the residual distribution. |
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Fig. 44a: A rt-relation from a run with toroid off was applied to a run with toroid on. The resulting residual distribution is shown. |
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Fig. 44b: A rt-relation from a run with toroid off was applied to a run with toroid on. Here a b-field correctino was applied ot the drift times. The resulting residual distribution is shown. |
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Fig. 45: Precision of the gas-monitor rt vs the assumed temperature for the temperature correction. |
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Fig. 46: Maximum drift times trends, measured by the Gas Monitor, of MDT Supply and Return gas lines from May-October 2009 |
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Fig. 47: Means of Hit Residuals for 951 Chambers in Run 91060 using Gas Monitor Universal RT |
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Fig. 48: Hit Residuals (narrow sigma of double gaussian fit) for 951 Chambers in Run 91060 using Gas Monitor Universal RT |
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Fig. 49: Example of Hit Residuals with double gaussian fit for Chamber EIL4A05 in Run 91060 |
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Fig. 50: Example of Hit Residuals vs signed drift radius for Chamber EIL4A05 in Run 91060 |
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Fig. 51: Hit Residuals vs drift radius on Chamber BML2A05 (at 24.7 C) using Universal RT with and without Temperature correction. |
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Fig. 52: Theta at perigee for cosmic events (run 91060) and beam halo events (run 87863), without any cuts, reconstructed by Muonboy. Secondary peaks in Beam distribution are due to the projection of MBTS trigger stations. Distributions are normalized. |
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Fig. 53(a): Transverse momentum resolution evaluated with the top bottom method as a function of pT for large sectors as measured with the MOORE algorithm. The fitted curve is a phenomenological description of the stand-alone momentum resolution; it is the quadratic sum of an energy loss fluctuation term p0/pT, a multiple scattering term p1, and a spectrometer resolution term p2*pT. |
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Fig. 53(b): Transverse momentum resolution evaluated with the top bottom method as a function of pT for small sectors as measured with the MOORE algorithm. The fitted curve is a phenomenological description of the stand-alone momentum resolution; it is the quadratic sum of an energy loss fluctuation term p0/pT, a multiple scattering term p1, and a spectrometer resolution term p2*pT. |
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Fig. 53(c): Transverse momentum resolution evaluated with the top bottom method as a function of pT for large sectors as measured with the Muonboy algorithm. The fitted curve is a phenomenological description of the stand-alone momentum resolution; it is the quadratic sum of an energy loss fluctuation term p0/pT, a multiple scattering term p1, and a spectrometer resolution term p2*pT. |
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Fig. 53(d): Transverse momentum resolution evaluated with the top bottom method as a function of pT for small sectors as measured with the Muonboy algorithm. The fitted curve is a phenomenological description of the stand-alone momentum resolution; it is the quadratic sum of an energy loss fluctuation term p0/pT, a multiple scattering term p1, and a spectrometer resolution term p2*pT. |
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Fig. 53(e): The same plot like 53(c), but for Monte-Carlo data. |
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Fig. 53(f): The same plot like 53(d), but for Monte-Carlo data. |
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Fig. 54: MDT hit residuals for tubes excluded in the segment fit but expected to be crossed by the muon as a function of the distance of the track from the wire. Small residuals are associated with efficient hits. The triangular region is populated by early hits coming from delta-electrons.
Missing hits are assigned to residuals equal to 15.5 mm. |
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Fig. 55: Tube efficiency as a function of the drift distance averaged over all tubes of the chamber BML2A03. Reported are the hardware efficiency, as well as tracking efficiencies for hit residuals smaller than 3, 5, 10 times the estimated residual standard deviation. |
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Fig. 56: MDT single-tube 5 sigma tracking efficiencies for the chamber BML2A07. The right plot shows an expanded view in the region where two disconnected tubes were found with tracking efficiency consistent with zero. |
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Fig. 57: MDT tube 5 sigma tracking efficiencies for for about 80 thousand barrel channels. About 0.2% of the channels are not functional and have an efficiency compatible with zero. |
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Fig. 58: TGC timing with Beam Halo events: The trigger delivered by the TGC system on Beam Halo events are correctly synchronized with the ATLAS trigger. In the plot it is shown the BCID (Bunch crossing identifier) which is the same as the one delivered by the ATLAS trigger. |
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Fig. 59: Relative difference in synchronization for all the TGC trigger channel. This measurement has been done using a Test Pulse Signal by which the latency of each single trigger channel has been measured. The relative synchronization of about 20K channels is at the level of 2.5 ns. |
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Fig. 60: Mean values of the apparent sagittas of straight muon tracks in the top sectors of the barrel muon spectrometer. The muon chambers at have index 1, the chambers at the out ends of the barrel at have index 6.. |
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Fig. 61: RPC cluster size for the horizontal sectors of the barrel muon spectrometer. A dependency on sector angular position with respect to the vertical cosmics is visible by comparison with the distribution in vertical sectors (see fig. 62). No runs with uniform HV at the nominal voltage of 9600 Volts was available, therefore a run taken at 9400 V was chosen. |
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Fig. 62: RPC cluster size for the vertical sectors of the barrel muon spectrometer. A dependency on sector angular position with respect to the vertical cosmics is visible by comparison with the distribution in horizontal sectors (see fig. 61). No runs with uniform HV at the nominal voltage of 9600 Volts was available, therefore a run taken at 9400 V was chosen. |
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Fig. 63: RPC cluster size as a function of HV for a single sector obtained with the RPC StandAlone algorithm, included in the ATLAS Muon Monitoring code. The data are cosmics taken with magnetic field on. The front-end discrimination threshold was set at the standard value of Vth =1000 mV.
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Fig. 64: RPC average cluster size as a function of the sector number.
A dependency on sector angular position with respect to the vertical cosmics is clearly visible.
For muons coming from the interaction point a flat behaviour is expected with a mean value close to the minimum of the present plot. Eta (Blue) and Phi (Red) panels are shown separately. Phi panels show a slightly higher cluster size than eta panels as expected from detector construction; an additional PET sheet is inserted in between the gas volume and the eta readout panel.
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Fig. 65: RPC detection efficiency as a function of HV for two readout panels (eta/phi) faced to the same gas volume. The efficiency is obtained using the RPC StandAlone tracking algorithm included in the ATLAS Muon Monitoring code. The data are cosmics taken with magnetic field on. The front-end discrimination threshold was set at the standard value of Vth =1000 mV.
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Fig. 66: RPC efficiency as a function of HV for a single gas volume, obtained with the RPC StandAlone tracking algorithm, included in the ATLAS Muon Monitoring code. The data are cosmics taken with magnetic field on. The front-end discrimination threshold was set at the standard value of Vth =1000 mV.
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Fig. 67: RPC pivot plane response for a splash event coming from ATLAS side A (right side of the plot).The black areas are due to the toroid legs in sector 12 and 14, to the toroid ribs along the even sectors and to the crack for the services at eta=0. The few white holes are due to detector regions not operated during the splash.
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Fig. 68: RPC pivot plane response for a splash event coming from ATLAS side C (left side of the plot).The black areas are due to the toroid legs in sector 12 and 14, to the toroid ribs along the even sectors and to the crack for the services at eta=0. The few white holes are due to detector regions not operated during the splash.
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Fig. 69: RPC number of gaps over charge threshold (set at about 100 hits/m^2) vs time. The instantaneous gap current is read at a sample rate of 1kHz via ADC boards (DCS standard) and if a programmed threshold is passed the charge peak is recorded by the DCS. Two group of events coming from beam splashes at the 2 sides of ATLAS are visible.
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Fig. 70: RPC map for the charge released by a single splash event (from side A) on the detector gaps, expressed in terms of hits/m^2 (ADC threshold equivalent to ~400 hits/m^2). Eta and Phi coordinates are given in terms of Muon Station sector and position in eta. The fractional values are given by the gap position within the station. The three layers of chambers (Low_Pt, Pivot and High_Pt) at increasing distance from the beam axis are shown separately.
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Fig. 71: RPC cluster size distribution for two threshold values with chambers HV at 9000 V.
It depends only slightly on threshold as expected. Each entry of the histogram is a read-out panel. The histograms are normalized to unit area. Higher threshold values correspond to effective looser threshold.
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Fig. 72: RPC cluster size distribution for two high voltage values with front-end discriminator threshold at the nominal value of 1000 mV. The dependence on high voltage at a fixed threshold is as expected. Each entry of the histogram is a read-out panel. The histograms are normalized to unit area. Data from a 2009 cosmic run.
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Fig. 73: RPC spatial resolution for the eta panels of the BM chambers at the nominal HV of 9600 V. The spatial resolution is obtained with a Gaussian fit of the residual distribution for clusters of size 1 (blue) and 2 (red) and it is normalized to the strip pitch (~30 mm) of the corresponding read-out panel.
A residual is defined as the position of the RPC cluster with respect to the track extrapolation on the RPC read-out panel.
Each entry of the histogram is a read-out panel. The histograms are normalized to unit area
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Fig. 74: RPC efficiency vs sector for BO read-out panels at 9600 V (red) and sector 4-5-6 at 9400 V (grey) with a mean hit time greater than 25 ns.
The blue distribution is for BO read-out panels at 9600 V with a mean hit time less than 25 ns (hits out of the read-out window). Each entry of the histogram is a read-out panel with a front-end discrimination threshold at the nominal value of 1000 mV. Data are from a cosmic run taken in November 2009 with magnetic field on. No correction to high voltage for pressure and temperature is applied. Only read-out panels traversed at least by 100 muon tracks are considered.
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Fig. 75: RPC efficiency vs cluster size for BO chambers with HV=9600V and a threshold of 1000 mV. Each histogram entry is a read-out panel. Data from a cosmic run taken in November 2009 with magnetic field on. No correction to high voltage for pressure and temperature are applied. Only read-out panels traversed at least by 100 muon tracks are considered.
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Fig. 76: RPC mean of residuals distribution for eta panel vs sector.
Some sectors are missing due to low statistics (vertical sectors). It gives a feedback on the misalignment of RPC read-out panels with respect to MDT chambers up to fractions of mm (thanks to MDTs high tracking precision). Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 77: RPC mean panel cluster size for BM chambers of all sectors at 9600 V and a threshold of 1000 mV. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel. Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 78: RPC mean panel cluster size for BM chambers of all sectors at 9600 V and a threshold of 1000 mV selecting only ETA read-out panels. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel.Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 79: RPC mean panel cluster size for BM chambers of all sectors at 9600 V and a threshold of 1000 mV selecting only PHI read-out panels. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel.Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 80: RPC mean panel cluster size for BO chambers of all sectors at 9600 V and a threshold of 1000 mV. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel.Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 81: RPC mean panel cluster size for BO chambers of all sectors at 9600 V and a threshold of 1000 mV selecting only ETA read-out panels. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel.Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 82: RPC mean panel cluster size for BO chambers of all sectors at 9600 V and a threshold of 1000 mV selecting only PHI read-out panels. Event selection: 1 or 2 MDT muon tracks. Each entry of the histogram is a read-out panel.Data from a cosmic run taken in November 2009 with magnetic field on.
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Fig. 83(a): Sagitta resolution in the Large Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 83(b): Sagitta resolution in the Small Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 84: Sagitta resolution in the Small Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 85: Sagitta resolution in the Small Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 86: Sagitta resolution in the Small Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 87: Sagitta resolution in the Small Barrel Sectors of the Muon Spectrometer as a function of muon momentum.
Cosmic muons from special commissioning runs with toroid=OFF/solenoid=ON used (Fall 2009). Muon momentum is taken from Inner Detector measurements. Data is fitted by the function containing multiple scattering term K1 and intrinsic resolution term K0. |
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Fig. 88:Efficiency as a function of Eta for Stand alone tracks from Cosmics for the Moore reconstruction program . |
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Fig. 89: Efficiency as a function of Eta for Stand alone tracks from Cosmics for the Muonboy reconstruction program. |
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Fig. 90: Momentum resolution as a function of transverse momentum for the Barrel Small Chambers measured with Cosmics (red points) and with single muons from collisions (blue points). |
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Fig. 91: Endcap sagitta distribution from 2009 cosmics. Shown is the distribution for the two endcaps in the EI-EM-EO region, before (black-hashed) and after (yellow) applying optical alignment corrections. The black curve is a fit of a double-Gaussian distributions with four parameters; the mean values of the two single Gaussians are set to the same value, and they are normalized to the same area. The mean values are -15 +/- 19 mu for the sum of both endcaps (as shown on the plot), -28 +/- 22 mu for side A, and -11 +/- 38 mu for side C (both not shown here). The width of the distribution is dominated by multiple scattering, and indicates that the typical momentum of the cosmic muons in this plot is around 100 GeV. |
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Fig. 92: Mean values of sagitta distributions for individual sectors, plotted versus the sector number. To produce this plot, histograms like the one in Fig. 91 were created for each sector and fitted with a double-Gaussian function. The red-hashed sectors 16/01/02 and 08/09/10 are so poorly illuminated by cosmics that no meaningful results can be obtained. The straight black line is the "fit" of a 0-th order polynomial with its only free parameter fixed at zero; the chi2/ndf of the fit is thus a measure of how well the individual sector mean values are compatible with a common mean at zero. The errors of the mean values are statistical only, and they are significantly larger than the intrinsic accuracy of the optical alignment, in other words: this analysis is currently statistics-limited. |
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