@article{OPUS4-16515,
  title     = {The prototype detection unit of the KM3NeT detector},
  series = {The European Physical Journal C},
  volume    = {76},
  journal   = {The European Physical Journal C},
  number    = {54},
  organization    = {KM3NeT Collaboration},
  doi       = {10.1140/epjc/s10052-015-3868-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165159},
  year      = {2016},
  abstract  = {A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore the Italian coast. KM3NeT in its final configuration will contain several hundreds of detection units. Each detection unit is a mechanical structure anchored to the sea floor, held vertical by a submerged buoy and supporting optical modules for the detection of Cherenkov light emitted by charged secondary particles emerging from neutrino interactions. This prototype string implements three optical modules with 31 photomultiplier tubes each. These optical modules were developed by the KM3NeT Collaboration to enhance the detection capability of neutrino interactions. The prototype detection unit was operated since its deployment in May 2014 until its decommissioning in July 2015. Reconstruction of the particle trajectories from the data requires a nanosecond accuracy in the time calibration. A procedure for relative time calibration of the photomultiplier tubes contained in each optical module is described. This procedure is based on the measured coincidences produced in the sea by the 40K background light and can easily be expanded to a detector with several thousands of optical modules. The time offsets between the different optical modules are obtained using LED nanobeacons mounted inside them. A set of data corresponding to 600 h of livetime was analysed. The results show good agreement with Monte Carlo simulations of the expected optical background and the signal from atmospheric muons. An almost background-free sample of muons was selected by filtering the time correlated signals on all the three optical modules. The zenith angle of the selected muons was reconstructed with a precision of about 3∘.},
  language  = {en}
}
@article{OPUS4-22781,
  title     = {Long-term monitoring of the ANTARES optical module efficiencies using \(^{40}\)K decays in sea water},
  series = {European Physical Journal C},
  volume    = {78},
  journal   = {European Physical Journal C},
  organization    = {The ANTARES Collaboration},
  doi       = {10.1140/epjc/s10052-018-6132-2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227815},
  pages     = {1-8},
  year      = {2018},
  abstract  = {Cherenkov light induced by radioactive decay products is one of the major sources of background light for deep-sea neutrino telescopes such as ANTARES. These decays are at the same time a powerful calibration source. Using data collected by the ANTARES neutrino telescope from mid 2008 to 2017, the time evolution of the photon detection efficiency of optical modules is studied. A modest loss of only 20\% in 9 years is observed. The relative time calibration between adjacent modules is derived as well.},
  language  = {en}
}