Plastic Scintillators and WLS Optical Fibers in Particle Physics - Characterization of Scintillators for the Future Circular Collider as a Function of Their Dimensions and Aging of WLS Optical Fibers

Abstract

The calorimeters which will operate in experiments at the hadronic Future Circular Collider—FCC-hh—will be one of the key pieces for the complete exploration of collisions between hadrons. This is because the increasing of energy in proton collisions will require detectors that can work in environments under severe radiation, with high-energy rates, presenting a high resolution and low granularity. In this context, the choice of the hadronic calorimeter of the FCC-hh, the Hadronic Barrel (HB) and the extended barrel (HEB), will be inspired by the ATLAS Tile Calorimeter (TileCal). The HB will have 10 layers, with scintillating tiles that will be separated through a reflective material (e.g., Tyvek) and read by wavelength shifting fibers (WLS) of 1 mm in diameter connected to silicon photomultipliers (SiPMs). Our study focuses on the comparison of the luminous signal intensity in the tile in the first layer of the HB and the tile in the last layer of HB, taking into account the dimensions of the tile. A study on the optimization of the signal uniformity was made, by adding a light-absorbing black strip to the tile, and results were compared with similar experiments performed at CERN. The procedure was performed in the Tilemeter, in the Laboratory of Optics and Scintillating Materials (LOMaC) of the Laboratory of Instrumentation and Experimental Particle Physics, in Lisboa.