Mainz 2012 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 11: Instrumentation

HK 11.3: Talk

Monday, March 19, 2012, 17:15–17:30, P 2

Gain Calibration of the ALICE TRD using the Decay of 83mKr as an Electron Source — •Johannes Stiller — Physikalisches Institut, Heidelberg, Deutschland

For an early calibration of the ALICE Transition Radiation Detector (TRD) on the level of individual readout pads, a dedicated calibration run with a Krypton source was carried out. We recorded 2.28 billion decays of metastable 83mKr in the 646k readout-pads of the 10 TRD super modules presently installed in the ALICE experiment at CERN. In our analysis the gain uniformity within each chamber as well as the energy resolution of all installed chambers were obtained. These results are crucial for good online particle identification and triggering. In an iterative analysis step, the gain calibration results in a gain uniformity of better than 2 %. A comparison between our results and corresponding findings from earlier measurements during chamber construction was performed and good agreement was found. The gain factors are now available for download to the front-end electronics and online calibration and analysis.