Plots of RPC performance G. Cattani, University of Rome “Tor Vergata” & INFN Roma 2 on behalf of ATLAS Muon Collaboration

Cluster size distribution for chambers at 9000 V for two threshold values. 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 NB: higher threshold values correspond to effective looser threashold 00

01 Cluster size distribution for different high voltages at a threshold 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 cosmics 2009 run

02 Spatial resolution for BM chambers at 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 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

Efficiency vs sector for BO read-out panels at 9600 V (red) and sector 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 threshold of 1000 mV Data from a cosmics November 2009 run with magnetic field on No correction to high voltage for pressure and temperature Only read-out panels traversed at least by 100 muon tracks are considered 03

Efficiency vs cluster size for BO chambers at 9600 V and a threshold of 1000 mV Each entry of the histogram is a read-out panel Data from a cosmics November 2009 run with magnetic field on No correction to high voltage for pressure and temperature Only read-out panels traversed at least by 100 muon tracks are considered 04 extrapolate d

05 Mean of residual distribution vs sector for ETA panels 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 cosmics November 2009 run with magnetic field on

06 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 cosmics November 2009 run with magnetic field on

07 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 cosmics November 2009 run with magnetic field on

08 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 cosmics November 2009 run with magnetic field on

09 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 cosmics November 2009 run with magnetic field on

10 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 cosmics November 2009 run with magnetic field on

11 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 cosmics November 2009 run with magnetic field on