Quality control of new deep-sea neutrino detector EU-funded researchers are providing invaluable technical support of a new deep-sea neutrino detector, including evaluation of response characteristics of detector elements as well as software for data monitoring and analyses. Digital Economy © Thinkstock For thousands of years, man has studied the night sky, observing the visible light emitted by stars in an attempt to understand the Universe. As technology improved, new observational windows were opened enabling investigation of invisible portions of the electromagnetic spectrum leading to the discovery of intriguing new phenomena. Rather than focus on photons, many scientists are now investigating another elementary particle, the neutrino. However, its very small mass, electrical neutrality and minimal reactivity with matter make its detection difficult. To increase the probability of interaction and thus detection of high-energy neutrinos (HENs), scientists rely on tremendous amounts of matter with which to interact. Since these huge amounts of matter would propose technical and economical difficulties, scientists have turned to nature, using huge bodies of water or blocks of ice as detector material. European researchers working on the ‘High-energy cosmic neutrinos astronomy using a Mediterranean undersea telescope’ (Neutel-APC) project sought to contribute to the HEN detection effort via technical support of a new prototype undersea neutrino telescope (ANTARES, or Astronomy with a Neutrino Telescope and Abyss Environmental Research) deployed 2.5 kilometres deep in the Mediterranean off the shores of France. Researchers developed a ‘black box’ test bench mimicking deep sea illumination in order to measure and optimise the response of the telescope’s detector elements with unprecedented precision. In addition, they developed a software tool integrated with the ANTARES database to monitor external conditions and status of the detector as well as produce quality ‘flags’ indicating the suitability of certain data sets for specific analyses. Scientists also developed a novel multi-messenger analysis method, combining searches for sources of HENs with searches for gravitational wave (GW) sources. The joint research activity is expected to provide new and valuable insight into the conditions of cosmic emissions from common astrophysical sources. Overall, technological optimisations and data monitoring and analysis tools developed by the Neutel-APC project team should facilitate effective use of the cubic-kilometre–sized detector in the Mediterranean under the ANTARES project and enhanced detection of HENs leading to improved understanding of the nature and origin of the Universe.