Advanced optical systems for ultra high energy cosmic rays detection
Authors: Gambicorti L., Pace E., Mazzinghi P.
Autors Affiliation: Dep. of Astronomy and Space Science, Florence University, Largo E. Fermi, 2, Firenze, 50125, Italy; CNR-INOA National Institute of Applied Optics, Largo E. Fermi, 6, Firenze, 50125, Italy
Abstract: A new advanced optical system is proposed and analysed in this work with the purpose to improve the photons collection efficiency of Multi-AnodePhotoMultipliers (MAPMT) detectors, which will be used to cover large focal surface of instruments dedicated to the Ultra High Energy Cosmic Rays (UHECRs, above 1019eV) and Ultra High Energy Neutrino (UHEN) detection. The employment of the advanced optical system allows to focus all photons inside the sensitive area of detectors and to improve the signal-to-noise ratios in the wavelength range of interest (300-400nm), thus coupling imaging and filtering capability. Filter is realised with a multilayer coating to reach high transparency in UV range and with a sharp cut-off outside. In this work the applications on different series of PMTs have been studied and results of simulations are shown. First prototypes have been realised. Finally, this paper proposes another class of adapters to be optically coupled on each pixel of MAPMT detector selected, consisting of non-imaging concentrators as Winston cones.
KeyWords: Cosmology; Lenses; Light; Optical systems; Photomultipliers; Photons; Signal to noise ratio, Collection efficiency; Filter; High transparency; Light collector; Multi-layer-coating; Optical adapters; Ultra high-energy cosmic rays; Ultra-high energy neutrinos, Cosmic raysDOI: 10.1117/12.2308137