Testbeam studies of production modules of the ATLAS Tile Calorimeter

Abstract

We report test beam studies of 11% of the production ATLAS Tile Calorimeter modules. The modules were equipped with production front-end electronics and all the calibration systems planned for the final detector. The studies used muon, electron and hadron beams ranging in energy from 3 to 350 GeV. Two independent studies showed that the light yield of the calorimeter was similar to 70 pe/GeV, exceeding the design goal by 40%. Electron beams provided a calibration of the modules at the electromagnetic energy scale. Over 200 calorimeter cells the variation of the response was 2.4%. The linearity with energy was also measured. Muon beams provided an intercalibration of the response of all calorimeter cells. The response to muons entering in the ATLAS projective geometry showed an RMS variation of 2.5% for 91 measurements over a range of rapidities and modules. The mean response to hadrons of fixed energy had an RMS variation of 1.4% for the modules and projective angles studied. The response to hadrons normalized to incident beam energy showed an 8% increase between 10 and 350 GeV, fully consistent with expectations for a noncompensating calorimeter. The measured energy resolution for hadrons of sigma/E = 52.9%/root E circle plus 5.7% was also consistent with expectations. Other auxiliary studies were made of saturation recovery of the readout system, the time resolution of the calorimeter and the performance of the trigger signals from the calorimeter. (C) 2009 Elsevier B.V. All rights reserved

Study of the response of the ATLAS central calorimeter to pions of energies from 3 to 9GeV

“…A total of 10 5 events were simulated for each experimental point. 13 The distribution of the variable E raw obtained with simulated data is shown in Fig. 9 for beam energies 3, 5, 7 and 9 GeV, and simulation can be quantified using the quantities…”

“…This feature can be exploited to reject some of the high-energy halo muons. The time difference Dt between the time of the reconstructed signal shape in each cell of TileCal (t pulse ) [13] and the trigger time (t trigger ) was computed. Fig.…”

“…In TileCal, the fit filter method [13] was used to determine the cell energy. The electromagnetic scale of the reconstructed cell energy was obtained using electron beams incident at the center of each cell with an angle of 201 [13].…”

“…The electromagnetic scale of the reconstructed cell energy was obtained using electron beams incident at the center of each cell with an angle of 201 [13].…”

Readiness of the ATLAS Tile Calorimeter for LHC collisions

“…3, with the amplitude being one of the parameters of the fit [10]. To determine the values of the gains for each channel, dedicated CIS calibration runs are taken frequently, in which a scan is performed over the full range of charges for both gains.…”