ADVANCEDOPTICALSYSTEMSFOR ULTRAHIGHENERGY COSMICRAYS DETECTION

ABSTRACT A new advanced optical system is proposed andanalysedinthisworkwiththepurposetoimprovethephotons collection efficiency of Multi-Anode-PhotoMultipliers(MAPMT)detector s,whichwillbeused to cover large focal surface of instrumentsdedicated to the Ult ra High Energy Cosmic Rays(UHECRs, above 10 19 eV) and Ultra High EnergyNeutrino(UHEN)detection.Theemploymentoftheadv ancedopticalsystemallowstofocusallphotonsinsidethesensitiveareaofdetectorsandtoimprovethesignal-to-noise ratios in the wavelength range ofinterest (300-400nm), thus coupling ima ging andfilteringcapability.Filterisreali sedwithamultilayercoatingtoreachhightransparencyinUVrangeandwith a sh arp cut-off outside. In this work theapplicationsondifferentseriesofPMTshavebeenstudiedandresultsofsimulationsareshown.Firstprototypeshavebeenrealised.Finally,thispaperproposesanotherclassofadapter stobe optically coupled on each pixel of MAP MTdetector selected, consisting of non-imagingconcentratorsa sWinstoncones. Key words : Photo-detecto r; Photo-multiplier; Lightcollector;Lens;Opticaladapter;Filter