Photon counting with a FDIRC Cherenkov prototype readout by SiPM arrays

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2017-02, Vol.845, p.447-451
• Main Authors: Marrocchesi, P.S., Bagliesi, M.G., Basti, A., Bigongiari, G., Bonechi, S., Brogi, P., Checchia, C., Collazuol, G., Maestro, P., Morsani, F., Piemonte, C., Stolzi, F., Suh, J.E, Sulaj, A.
• Format: Article
• Language: English
• Subjects: Cherenkov detectors; FDIRC; Particle identification; Silicon photomultiplier
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2016.05.069

A prototype of a Focused Internal Reflection Cherenkov, equipped with 16 arrays of NUV-SiPM, was tested at CERN SPS in March 2015 with beams of relativistic ions at 13, 19 and 30GeV/n obtained from fragmentation of an Ar primary beam. The detector, designed to identify cosmic nuclei, features a Fused Silica radiator bar optically connected to a cylindrical mirror of the same material and an imaging focal plane of dimensions ∼4cm×3cm covered with a total of 1024 SiPM photosensors. Thanks to the outstanding performance of the SiPM arrays, the detector could be operated in photon counting mode as a fully digital device. The Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z2 as a function of the atomic number Z of the beam particle. In this paper, we report on the characterization and test of the SiPM arrays and the performance of the Cherenkov prototype for the charge identification of the beam particles.