This paper summarises the mechanical construction and installation of the Tile Calorimeter for the ATLAS experiment at the Large Hadron Collider in CERN, Switzerland. The Tile Calorimeter is a sampling calorimeter using scintillator as the sensitive detector and steel as the absorber and covers the central region of the ATLAS experiment up to pseudorapidities ±1.7. The mechanical construction of the Tile Calorimeter occurred over a period of about 10 years beginning in 1995 with the completion of the Technical Design Report and ending in 2006 with the installation of the final module in the ATLAS cavern. During this period approximately 2600 metric tons of steel were transformed into a laminated structure to form the absorber of the sampling calorimeter. Following instrumentation and testing, which is described elsewhere, the modules were installed in the ATLAS cavern with a remarkable accuracy for a structure of this size and weight. KEYWORDS: Detector design and construction technologies and materials; Calorimeters JINST 8 T11001Contents 1 Introduction 1 2 Design overview 2 3 Submodule construction 9 4 Module production 12 4.1 Module construction 13 4.2 Girder ring insertion 15 4.3 Installation of fiducial marks 15 5 Calorimeter installation 16

The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300 GeV at an incident angle of about 11 is well-described by the expression =E = 46:5 6:0 = p E + 1 : 2 0 : 3 3:2 0:4 GeV=E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied.

A new combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 10 to 300 GeV at an incident S. Akhmadaliev et al. / Nuclear Instruments and Methods in Physics Research A 449 (2000) 461}477 463In the collider reference system, which has been adopted here, the z-axis indicates the LHC beam line, the x-and y-axis the horizontal and the vertical directions, while and are the azimuthal and polar angle, respectively. The pseudorapidity is de"ned as "!ln(tan( /2)).angle of about 123 is well described by the expression /E"((41.9$1.6)%/(E#(1.8$0.1)%)(1.8$0.1)/E, where E is in GeV. The response to electrons and muons was evaluated. Shower pro"les, shower leakage and the angular resolution of hadronic showers were also studied. Results are compared with those from the previous beam test.

A study of high energy muons traversing the ATLAS hadron Tile calorimeter in the barrel region in the energy range between 10 and 300 GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (10 34 cm 2 sec 1 ). The photoelectron statistics eect in the muon shape response is shown. The e/mip ratio is found to be0:81 0:03; the e/ ratio is in the range 0.91 -0.97.The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event b y e v ent basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution.3

The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter presents a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV. a detailed picture of transverse shower behaviour is obtained. The underlying radial energy densities for the four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrisation has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeters design. (C) 2000 Elsevier Science B.V. All rights reserved