Characterization of a scintillating fibers read by MPPC detectors trigger prototype for the AMADEUS experiment

摘要

Multi-Pixel Photon Counters (MPPC) consist of hundreds of micro siliconAvalanche PhotoDiodes (APD) working in Geiger mode. The high gain and the lownoise, typical of these devices, together with their good performance inmagnetic field, make them ideal readout detectors for scintillating fibers astrigger detectors in particle and nuclear physics experiments like AMADEUS,where such detectors are planned to be used to trigger on charged kaon pairs.In order to investigate the detection efficiency of such a system, a prototypesetup consisting of 32, 1 mm diameter scintillating fibers, arranged in twodouble layers of 16 fibers each, and read out by 64 MPPCs with an ad-hoc builtreadout electronics, was tested at the piM-1 line of the Paul ScherrerInstitute (PSI) in Villigen, Switzerland. The detection efficiency and thetrigger capability were measured on a beam containing protons, electrons, muonsand pions with a momentum of 440 MeV/c. The measured average efficiency forprotons for a double layer of scintillating fibers (96.9 +/-1.2%) represents aguarantee of the good performance of this system as a trigger for the AMADEUSexperiment.