A hadronic tile calorimeter for the TESLA detector

Concept and design of a granular iron-scintillator sandwich calorimeter for the TESLA detector are shortly described and some recent R&D results for the light yield in the calorimeter tiles are discussed in view of further improvements. New types of sensitive semiconductor photodetectors with significant gain and insensitivity to the strong magnetic field are studied, some features and performance are discussed. A first prototype calorimeter assembled from ∼250 scintillator tiles is prepared for tests with cosmic muons and electrons (0.5–7 GeV) at DESY. These studies are needed to optimize construction and set up of a further 1 m3 prototype with ∼4000 calorimeter cells for measurements in hadronic beams (1–50 GeV) in 2005/2006 and serve for test and improvement of the simulation tools for energy-flow measurements in jets and optimization of the mass reconstruction of multi-jet final states.