Public Liquid-Argon Calorimeter Plots for 2008 Cosmic Data

Remark

The paper on LAr Readiness summarizes the LAr results on 2008 data. If you want more plots on specific analyses, go to the other sections below...

The LAr Readiness Paper

All the information can be found here.

abstract : The ATLAS liquid argon calorimeter has been operating continuously since August 2006. At this time, only part of the calorimeter was readout, but since the beginning of 2008, all calorimeter cells have been connected to the ATLAS readout system in preparation for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance, electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter response along η (averaged over φ) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative muons have been used to cross-check the Monte Carlo simulation. The performance results obtained using the ATLAS readout, data acquisition, and reconstruction software indicate that the liquid argon calorimeter is well-prepared for collisions at the dawn of the LHC era.

The Drift Time Paper

All the information can be found here.

Main results :

Drift Time vs eta in the Middle Layer EM	Drift time vs eta eps
The drift times of electrons in the cells of the second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.7% in the endcaps. This leads to an estimated contribution to the constant term of (0.29 +0.05/−0.04) % in the barrel and (0.54 +0.06/−0.04) % in the endcaps.	Drift time uniformity in barrel layer 2 eps Drift time uniformity in endcap layer 2 eps
Drift Velocity vs eta in the Middle Layer EM , at 88.5 K and for an electric field of 1kV/mm, is found to be 4.61 ± 0.07 mm/μs.	Drift velocity vs eta eps

More Plots from Cosmic Muons Analyses with 2008 data

• Uniformity (Ref: internal communication ATL-COM-LARG-2009-052)

dE/(rho dx)	dE/(rho dx) eps

• Timing measurements using cosmic muons (Ref: internal communication ATL-COM-LARG-2009-048)

Timing resolution of the front and middle layers	gif (front) pdf eps gif (middle) pdf eps

Link to 2008 Proton Beam Analyses

Click here!

-- CarolineCollard - 15-Jul-2010

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