The TRD is an important subsystem of the ALICE experiment at the
LHC at CERN. Segmented into 18 super modules, each consisting of 30
readout drift chambers filled with Xe-CO2 [85-15], the ALICE TRD is
designed to be an effective tool in terms of separation of electrons and pi-
ons, reconstruction of tracks of charged particles and fast trigger capabilities.
Each readout chamber consists of a radiator and a multi-wire proportional
chamber, which is segmented into either 16x144 or 12x144 readout pads, giv-
ing a total number of 1,118,952 pads. For an early and effective calibration at
the level of individual pads, which is crucial for a good particle identification,
a dedicated calibration run with a Krypton source has been carried out. We
have recorded 2.1 billion decays of metastable 83mKr in the 10 super modules
presently installed. We present an overview of the obtained results in terms
of gain uniformity over chambers and energy resolution. The obtained gain
factors can be used in the front-end electronics, an important ingredient for
the TRD trigger.