Abstract:
The ALICE Time Projection Chamber (TPC) was upgraded with a Gas Electron Multiplier (GEM)-based amplification system and continuous readout for Run 3 of the LHC. After the first successful Pb-Pb data taking in 2023, the TPC took several measurements by injecting the meta-stable radioactive isotope Kr-83m into the gas volume in order to calibrate the gain of each pad. In addition to the nominal settings used for physics data taking, several other combinations of electric fields in the quadruple-GEM stack were tested.
The recorded data was used to extract the pad-by-pad gain maps for the calibration of the TPC. In addition, the MC methods provided by the ALICE O2 toolkit were used to simulate the decays of Kr-83m in the ALICE TPC.
This talk will present the comparison between the results for the different field settings as well as compare the results of the simulation with the data measured by the ALICE TPC.
Supported by BMBF.