The Transition Radiation Detector (picture at right) is a component of the
which studies the
Quark Gluon Plasma (QGP)
produced in nucleus-nucleus collisions at CERN's
Large Hadron Collider (LHC).
The LHC started colliding proton beams in 2009; the first collisions of lead nuclei took place in Nov. 2010.
Read more about the LHC experiments
The TRD of ALICE is composed of 540 detectors, arranged in 18 sectors in
azimuth, each of 5 stacks in longitudinal direction, with 6 layers per stack.
The diameter of the TRD cylinder is about 7 m and the length also 7 m.
It has more than 1 million channels of readout, each sampling the signal
in 20 time bins. The active gas is a xenon-CO2 mixture.