Bonn 2010 – wissenschaftliches Programm
HK 36.8: Poster
Mittwoch, 17. März 2010, 14:00–16:00, HG Aula
Calibration of the ALICE Transition-Radiation Detector with Krypton-83m — •Mustapha Al Helwi — Physikalisches-Institut, University of Heidelberg, Germany
The Transition-Radiation Detector (TRD) of ALICE at the LHC is designed for electron identification, charged particle tracking and providing a fast trigger. The TRD consists of 18 super-modules with 540 readout drift chambers filled with Xe gas. The large active area of roughly 700 m2 is covered by about 1.2 million readout channels. The traversing charged particle ionizes the gas along its path and electrons drift in a uniform field of 700V/cm over 3 cm before being amplified. In order to guarantee a high quality of the collected data a uniform gain is essential. The gain contains both gas and electronics response which may vary throughout the detector. The isotope 83Kr, which was distributed homogeneously during a dedicated calibration run in the TRD volume by the gas circulation system, was used to investigate channel by channel variations. We discuss the calibration procedure and first results obtained for the seven TRD super modules installed in ALICE.