Silicon Tracking Calorimeter for Antimatter Search in Space: First Experimental Results From a Prototype

This report presents the preliminary results of the performances of a prototype of a silicon tungsten calorimeter, which has been conceived as a high-granularity tracking calorimeter for cosmic ray studies. The calorimeter contains 20 XY sampling planes interleaved with 19 showering material planes (W, 0. 5 X₀ = 1. 75 mm). One sensitive plane is obtained two silicon strip detectors (Si-D) (60 x 60) mm² divided in 16 strips 3. 6 mm wide. The strips of the two detectors are perpendicular to each other in order to provide the transverse distributions in both coordinates at each sampling. The basic characteristics of the design and the first experimental results obtained at a test beam at CERN PS for 2, 4 and 6 GeV electrons and pions are reported. The main results here presented are: the response of the calorimeter to the electron energies, the transverse shower profiles at different calorimeter depths as well as the patterns of the electron induced electromagnetic shower and those of the interating and non interating pions. The angular resolution has been measured for electron showers at 4 GeV. The calorimeter performances and the adopted design criteria are also considered for possible applications to preshower detectors.