Deep sea tests of a prototype of the KM3NeT digital optical module (original) (raw)
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The prototype detection unit of the KM3NeT detector
The European Physical Journal C, 2016
A prototype detection unit of the KM3NeT deepsea 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 The research leading to these results has received funding from the European Community Sixth Framework Programme under Contract 011937 and the Seventh Framework Programme under Grant Agreement 212525.
The KM3NeT multi-PMT optical module
Journal of Instrumentation
The optical module of the KM3NeT neutrino telescope is an innovative multi-faceted large area photodetection module. It contains 31 three-inch photomultiplier tubes in a single 0.44 m diameter pressure-resistant glass sphere. The module is a sensory device also comprising calibration instruments and electronics for power, readout and data acquisition. It is capped with a breakout-box with electronics for connection to an electro-optical cable for power and long-distance communication to the onshore control station. The design of the module was qualified for the first time in the deep sea in 2013. Since then, the technology has been further improved to meet requirements of scalability, cost-effectiveness and high reliability. The module features a sub-nanosecond timing accuracy and a dynamic range allowing the measurement of a single photon up to a cascade of thousands of photons, suited for the measurement of the Cherenkov radiation induced in water by secondary particles from inter...
A new multianodic large area photomultiplier to be used in underwater neutrino detectors
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2009
In this article we describe the properties of a new 10-in. hemispherical photomultiplier manufactured by Hamamatsu. The prototype has a segmented photocathode and four independent amplification stages. The photomultiplier is one of the main components of a newly designed direction-sensitive optical module to be employed in large-scale underwater neutrino telescopes. The R&D activity has been co-funded by the INFN and the KM3NeT Consortium. The prototype performance fully meets with the design specifications.
Transmission of light in deep sea water at the site of the A ntares neutrino telescope
Astroparticle Physics, 2005
The ANTARES neutrino telescope is a large photomultiplier array designed to detect neutrino-induced upward-going muons by their Cherenkov radiation. Understanding the absorption and scattering of light in the deep Mediterranean is fundamental to optimising the design and performance of the detector. This paper presents measurements of blue and UV light transmission at the ANTARES site taken between 1997 and 2000. The derived values for the scattering length and the angular distribution of particulate scattering were found to be highly correlated, and results are therefore presented in terms of an absorption length λ abs and an effective scattering length λ eff sct . The values for blue (UV) light are found to be λ abs ≃ 60(26) m, λ eff sct ≃ 265(122) m, with significant (∼15%) time variability. Finally, the results of ANTARES simulations showing the effect of these water properties on the anticipated performance of the detector are presented.
Dependence of atmospheric muon flux on seawater depth measured with the first KM3NeT detection units
The European Physical Journal C, 2020
KM3NeT is a research infrastructure located in the Mediterranean Sea, that will consist of two deep-sea Cherenkov neutrino detectors. With one detector (ARCA), the KM3NeT Collaboration aims at identifying and studying TeV–PeV astrophysical neutrino sources. With the other detector (ORCA), the neutrino mass ordering will be determined by studying GeV-scale atmospheric neutrino oscillations. The first KM3NeT detection units were deployed at the Italian and French sites between 2015 and 2017. In this paper, a description of the detector is presented, together with a summary of the procedures used to calibrate the detector in-situ. Finally, the measurement of the atmospheric muon flux between 2232–3386 m seawater depth is obtained.
The new CLBv4 for the KM3NeT Neutrino Telescope
EPJ Web of Conferences, 2019
The KM3NeT collaboration aims at the construction of a deepsea neutrino observatory in the Mediterranean Sea equipped with thousands of glass spheres, the so-called Digital Optical Modules, each of which contains 31 photomultipliers of small photocathode area. These devices will be used for the detection of the Cherenkov light induced by charged particles produced by the interaction of neutrinos with matter inside or in the vicinity of the KM3NeT detector. The signal acquired by each photomultiplier is sent to a Time to Digital Converter which is part of a Central Logic Board. The Time to Digital Converter resolution is 1 ns and the White Rabbit technology is used to guarantee time synchronization between the optical modules. Due to the large volume to be instrumented by KM3NeT, a cost reduction of the different systems is important so different versions of the Central Logic Board have been designed. The newest version was designed also to also reduce the phase noise in the main clo...
Characterisation of the Hamamatsu photomultipliers for the KM3NeT Neutrino Telescope
Journal of Instrumentation, 2018
View the article online for updates and enhancements. Related content Qualification tests of the R11410-21 photomultiplier tubes for the XENON1T detector P. Barrow, L. Baudis, D. Cichon et al.-The optical modules of the phase-2 of the NEMO project S Aiello, E Leonora, F Ameli et al.-Expansion cone for the 3-inch PMTs of the KM3NeT optical modules The KM3NeT collaboration-Recent citations STRAW (STRings for Absorption length in Water): pathfinder for a neutrino telescope in the deep Pacific Ocean M. Boehmer et al
EPJ Web of Conferences, 2016
The KM3NeT-Italia underwater neutrino detection unit, the tower, consists of 14 floors. Each floor supports 6 Optical Modules containing front-end electronics needed to digitize the PMT signal, format and transmit the data and 2 hydrophones that reconstruct in real-time the position of Optical Modules, for a maximum tower throughput of more than 600 MB/s. All floor data are collected by the Floor Control Module (FCM) board and transmitted by optical bidirectional virtual point-to-point connections to the onshore laboratory, each FCM needing an onshore counterpart as communication endpoint. In this contribution we present NaNet 3 , an onshore readout board based on Altera Stratix V GX FPGA able to manage multiple FCM data channels with a capability of 800 Mbps each. The design is a NaNet customization for the KM3NeT-Italia experiment, adding support in its I/O interface for a synchronous link protocol with deterministic latency at physical level and for a Time Division Multiplexing protocol at data level.