  The Transition Radiation Detector (TRD) for the ALICE experiment at the Large
Hadron Collider (LHC) identifies electrons in p+p and in the challenging high
multiplicity environment of heavy-ion collisions and provides fast online
tracking for the ALICE Level1 trigger. The TRD is designed to have excellent
position resolution and pion rejection capability. Presently, six of the 18 TRD
supermodules are installed in the ALICE central barrel. In 2008, four
supermodules were installed and commissioning of the detector using cosmic ray
tracks was successfully performed. We briefly describe the design of the
detector and report on the performance and current understanding of the
detector based on these data.
