NEVOD as a test facility for future neutrino telescopes

A.A Petrukhin,S.S Khokhlov,C Spiering

doi:10.1051/epjconf/201920707006

Abstract

The possibility to calibrate the new optical modules mDOM of the IceCube-Upgrade neutrino telescope inside the tank of Cherenkov water detector NEVOD is discussed. Methods to calibrate optical modules are presented. The spatial lattice of the detector NEVOD and deployed outside of the water tank calibration telescope system and coordinate-tracking detector DECOR allow calibrating the response of mDOM with respect to the Cherenkov light from muons, muon bundles and cascades with known trajectories.

Highlights

The basic characteristics of water – a large angle of Cherenkov light emission and good transparency for light propagation – make it possible to construct neutrino telescopes (NT) of very large dimensions with a relatively small number of photomultipliers (PMTs) which are housed in optical modules (OMs)
The detecting system is formed by a spatial lattice of quasi-spherical modules (QSMs), each of them including six PMTs with flat cathodes oriented along the coordinate axes
We have developed two methods to calibrate test optical modules in NEVOD

Summary

Introduction

The basic characteristics of water – a large angle of Cherenkov light emission and good transparency for light propagation – make it possible to construct neutrino telescopes (NT) of very large dimensions with a relatively small number of photomultipliers (PMTs) which are housed in optical modules (OMs). An optimal operation of a NT would call for isotropic module sensitivity over a 4π solid angle, such a module must consist of several differently oriented PMTs. The idea of a quasi-spherical module was proposed for the first time in 1979 at the 16th International Cosmic Rays Conference (ICRC) [1]. The idea of a quasi-spherical module was proposed for the first time in 1979 at the 16th International Cosmic Rays Conference (ICRC) [1] Later it was realized as a quasi-spherical module with six PMTs, the basic element of the Cherenkov water detector NEVOD [2]. First generation underwater neutrino detectors made no (or nearly no) use of the idea of quasi-spherical modules: the IceCube OM houses just one PMT, NT200 in Lake Baikal operated two -oriented OMs in coincidence, each with one PMT, and ANTARES has three single-PMT OMs which cover the full azimuth but look essentially downward. NEVOD is presently worldwide the only setup which meets these requirements

Experimental complex NEVOD

Methods to calibrate optical modules with NEVOD

Calibration of quasi-spherical module

Calibration of mDOM of IceCube-Upgrade in NEVOD

Findings

Conclusion