Test beam results of the fiber-sampling dual-readout calorimeter

The dual-readout calorimetric technique reconstructs the event-by-event electromagnetic fraction of the hadronic shower through the simultaneous measurement of scintillating (S) and Cherenkov (C) light produced by the shower development. The new generation of prototypes, based on Silicon Photomultipliers (SiPMs) readout, adds unprecedented granularity to the well-known high-energy resolution. A highly granular prototype (10×10×100cm3), designed to fully contain electromagnetic showers, was recently built and qualified on beam. It consists of 9 modules, each made of 320 brass capillaries equipped with both scintillating and clear fibers. All the fibers of the central module are coupled with SiPMs, while the PMTs are used for the others. Furthermore, the new FERS-System, designed by Caen to exploit the CITIROC1A ASICs performances, is at the core of the SiPM readout. The recent test beam at DESY allowed us to qualify the readout system and define a procedure to calibrate the SiPM response from ADC to ph-e in a wide dynamic range. We measured the number of ph-e per GeV for scintillating and Cherenkov light together with the calorimetric performances in the energy range of 1–6 GeV. This work reports the system qualification and the test beam results regarding SiPM calibration.