PT Journal AU ATLAS Tile Calorimeter Community (Abdallah, Jea Castillo Gimenez, V Costelo, J Ferrer, A Fullana, E Gonzalez, V Higon-Rodriguez, E Poveda, J Ruiz, A Salvachua, B Sanchis, E Solans, C Torres, J Valero, A Valls Ferrer, JA TI The optical instrumentation of the ATLAS Tile Calorimeter SO Journal of Instrumentation JI J. Instrum. PY 2013 BP P01005 - 21pp VL 8 DI 10.1088/1748-0221/8/01/P01005 LA English DE Calorimeters; Calorimeter methods; Scintillators; scintillation and light emission processes (solid; gas and liquid scintillators) AB The Tile Calorimeter, covering the central region of the ATLAS experiment up to pseudorapidities of +/-1.7, is a sampling device built with scintillating tiles that alternate with iron plates. The light is collected in wave-length shifting (WLS) fibers and is read out with photomultipliers. In the characteristic geometry of this calorimeter the tiles lie in planes perpendicular to the beams, resulting in a very simple and modular mechanical and optical layout. This paper focuses on the procedures applied in the optical instrumentation of the calorimeter, which involved the assembly of about 460,000 scintillator tiles and 550,000 WLS fibers. The outcome is a hadronic calorimeter that meets the ATLAS performance requirements, as shown in this paper. ER