Charged Particle Detection with NUV-Sensitive SiPM in a Beam of Relativistic Ions

Particle detector prototypes equipped with Silicon Photomultipliers designed to be sensitive in the near-ultraviolet wavelength region (NUV-SiPM) were tested in a beam of relativistic ions with electric charge Z in the range 1 ≤ Z ≤ 28, at energies 13 and 30 GeV/amu at CERN SPS. Two different prototypes of charged particle detectors were tested. The first one was a scintillating fiber hodoscope with individual fibers optically coupled to single SiPM devices. The second one consisted of an array of discrete SiPM sensors that were directly exposed to the ion beam to study their capability to trigger an avalanche in response to the ionization generated inside the silicon device. In this paper, we first report the results of the characterization and dedicated tests of the NUV-SiPM sensors that were carried out in our laboratory under controlled conditions; then, we discuss the analysis of the beam test data and the performance of both prototypes.