TRACER Transition Radiation Array for Cosmic Energetic Radiation

TRACER has been calibrated in December 1999 and January 2000 at a Fermilab test beam. Wilson Hall

Muons and electrons with energies between 3 and 227 GeV from a secondary beam in the "Meson Area" have been used for the calibration. FNAL map

Several detectors in the beamline allow to identify particles for the calibration. Two plastic scintillation counters (beam paddle) up and down stream of TRACER identify the beam. The downstream beam paddle forms in coincidence with the TRACER scintillators (T1 and T2) the main trigger. Electrons are identified by two Cerenkov counters (Cer1, Cer2) and a shower counter. The latter, consisting of 3 scintillation counters (SC1, SC2, and SC3) and two layers of Tungsten (2 radiation lengths per layer). A scintillation counter behind a shielding concrete and iron beam stop detects muons. Two multi wire proportional chambers (TR1, TR2) have been used in order to test new radiator material to develop new transition radiation detectors.

TRACER in the beam line. The last pice of beam pipe serves as Cerenkov counter. The head of the Cerenkov counter is visible in front of the TRACER instrument.

TRACER has been rotated for the calibration by 90 degrees relative to the flight orientation.