Characterization of the AEgIS scintillating fiber detector FACT for antihydrogen detection

The Antimatter Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) at the Antiproton Decelerator at CERN has the goal to produce antihydrogen atoms (H ̄) at low temperatures based on positronium charge exchange. In order to detect the production of antihydrogen the products of its annihilation will be tracked by a barrel-shaped scintillating fiber detector. This master thesis deals with the characterization and preparation of this Fast Annihilation Cryogenic Tracking (FACT) detector to be ready for the first production of antihydrogen within the AEgIS apparatus this year. The thesis particularly focuses on the performance of the Multi Pixel Photon Counters (MPPCs) used in FACT to read out scintillating fibers in view of an accu- rate calibration of the detector. The properties of the silicon photomultipliers including a detailed analysis of their gain, their photon detection efficiency (PDE), the afterpulse probability and the overall level of dark count noise are explored at various operating parameters. The results regarding the Hamamatsu Photonics S10362-11-100C MPPC that is dominantly used in FACT are presented. From this analysis general guidelines are derived to optimize the detection efficiency for antihydrogen annihilations. This thesis also aims to document the current implementation of the detector that will be used to measure antihydrogen this year.