First results from the NEMO Phase 1 experiment

TL;DR

The NEMO Phase-1 experiment successfully operated a prototype detector at 2000 m depth, reconstructing muon tracks and analyzing environmental parameters, demonstrating the feasibility of underwater neutrino detection.

Contribution

First operational results of the NEMO Phase-1 prototype, including sensor positioning, environmental analysis, and muon track reconstruction at great depth.

Findings

High-accuracy optical sensor positioning achieved

Environmental parameters characterized

Muon angular distributions measured and compared with simulations

Abstract

The NEMO prototype detector, called "NEMO Phase-1", has been successfully operated at 2000 m depth from December 2006 to May 2007. The apparatus comprises a \emph{Junction Box} and a \emph{Mini-Tower} hosting 16 optical sensors. Preliminary results are presented. Positions of the optical sensors in the Mini-Tower were reconstructed through the acoustic positioning system with high level accuracy. Environmental parameters were analyzed. From data corresponding to a livetime of 11.3 hours, atmospheric muon tracks have been reconstructed and their angular distributions were measured and compared with Monte Carlo simulations.