Construction of the Forward Endcap Calorimeter of the PANDA Experiment at FAIR

Abstract

PANDA is the main hadron physics addressing experiment of the future FAIR (Facility for Antiproton and Ion Research) center at Darmstadt, Germany. Located at the HESR antiproton storage ring the PANDA detector is optimized for physics of the weak and strong interactions in the charm sector: Search for new and exotic states of matter, precise determination of quantum numbers, masses and widths of hadronic resonances and deeper insights into the structure of hadrons. The detector consists of a target spectrometer built around the interaction region, where antiprotons carrying momenta of 1.5-15 GeV/c collide with a fixed hydrogen target, and a forward spectrometer. Its design is based on compactness and cost saving while achieving high resolution, rate capability and physics selectivity. In the PANDA target spectrometer the electromagnetic calorimeter is composed of three subdetectors based on lead tungstate crystals operated at −25° C. A barrel structure built from 11360 crystals will be closed in up- and downstream direction by two endcaps containing 524 and 3856 crystals, respectively. After intense beam test phases with a 200 crystal forward endcap prototype the required performance was shown to be met and the design finished. The upstream located forward endcap is currently under construction. Besides the overall mechanical design and cooling concept the 16-crystal submodules series manufacturing and quality assurance measures are presented.