The BaF2 photon spectrometer TAPS

The detector system TAPS (Two-Three-Arm Photon Spectrometer) has been designed and installed to study high-energy photons as well as neutral mesons produced in relativistic heavy-ion reactions. The spectrometer will consist of up to 384 individual BaF₂ modules packed in arrays of 64 scintillators. Each spectrometer arm, which carries two detector blocks, can be moved around the target location independently. The design concept, the specifications of the individual scintillator, and results from test on subarrays performed with monochromatic photons and charged particles are presented. Initial experiments have been performed exploiting heavy-ion beams up to a projectile energy of 1 GeV/u. The commissioning of the apparatus and the first experiments have shown that the envisaged performance has been fully achieved