Speaker
Description
The FINESSE program at the European Spallation Source (ESS) in Lund, Sweden, is a high-precision experimental project designed to search for physics beyond the Standard Model. It aims at neutron-to-antineutron ($n\to\bar{n}$) and neutron-to-sterile/mirror-neutron oscillations ($n\to n'$), corresponding to baryon number violations of $\Delta B = 2$ and $\Delta B = 1$, respectively. Moreover, a searches for axion-like particles (components of dark matter) and neutron electric dipole moment are foreseen as well. To detect these rare processes and week phenomena, the experiment needs an extremely low-background environment. To suppress the cosmic-ray muons, which are the major background source, a high-efficiency, multi-layer Cosmic-Ray Veto (CRV) detector is being developed at IFJ PAN, Kraków.
This work presents the optional designs of the CRV, Geant4-based Monte Carlo simulations and its performance evaluation. Employed are plastic scintillator modules with light collection by means of wavelength-shifting (WLS) fibers and Silicon Photomultipliers (SiPMs). Detailed Geant4 simulations were performed to model particle interactions, scintillation light transport and its efficient detection for various detector geometries. Overall detection efficiency, timing resolution and spatial resolution of CRV is discussed. Reported will be also the current status of prototype construction and testing, signal processing and future implementation strategies for the full-scale detector system.