Neutrino astrophysics offers new perspectives on the Universe investigation: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if ...not exclusive) information about the cosmos with respect to photons. While the small interaction cross section of neutrinos allows them to come from the core of astrophysical objects, it is also a drawback, as their detection requires a large target mass. This is why it is convenient to put huge cosmic neutrino detectors in natural locations, like deep underwater or under-ice sites. In order to supply for such extremely hostile environmental conditions, new frontier technologies are under development. The aim of this work is to review the motivations for high-energy neutrino astrophysics, the present status of experimental results and the technologies used in underwater/ice Cherenkov experiments, with a special focus on the efforts for the construction of a km
3
-scale detector in the Mediterranean Sea.
Status of the DOM electronics Real, D.; Calvo, D.; van Beveren, V. ...
Journal of instrumentation,
10/2021, Letnik:
16, Številka:
10
Journal Article
Recenzirano
Abstract
The KM3NeT collaboration has already produced electronics to assemble more than one thousand digital optical modules, which have started to be deployed at the bottom of the Mediterranean ...Sea. An upgrade of the electronics is currently underway, expecting to have a revision of it by end of 2021. Here we describe the main improvements added to the digital optical module electronics, including the new high reliability transceiver in the central logic board and the increased efficiency in the power board.
Abstract
The KM3NeT collaboration is building a deep-sea neutrino observatory in the Mediterranean Sea equipped with thousands of glass spheres, hosting the so-called digital optical modules, with an ...instrumented volume of several cubic kilometers. Reliability of the components used in the construction of the detectors is of extreme importance as the deployed detection units, each one composed of 18 digital optical modules, will not be accessible for any kind of maintenance and the detector should be functional for a period longer than 10 years. This work presents the different reliability methods used in KM3NeT to assess and improve the reliability of the electronics housed in the Digital Optical Modules of KM3NeT.
Abstract
The KM3NeT collaboration has already produced more than one thousand acquisition boards, used for building two deep-sea neutrino detectors at the bottom of the Mediterranean Sea, with the ...aim of instrumenting a volume of several cubic kilometers with light sensors to detect the Cherenkov radiation produced in neutrino interactions. The so-called digital optical modules, house the PMTs and the acquisition and control electronics of the module, the central logic board, which includes a Xilinx FPGA and embedded soft processor. The present work presents the architecture and functionalities of the software embedded in the soft processor of the central logic board.
Abstract
A testbench has been set up at the INFN Sezione di Bologna to optimise key elements of the KM3NeT data acquisition system. A complete framework has been built to simulate a full detection ...unit and test the optical network, time synchronisation, and on-shore computing resources. A fundamental tool in the test-setup is a customized electronic board: “the OctoPAES”.
Based on an Altera MAX10 CPLD, it is designed to emulate in a realistic way the optical and acoustic signals recorded by the underwater detectors. This allows us to test, in extreme conditions, the acquisition system and validate its performance with realistic data. If properly configured, the optical data provided by the OctoPAES can be combined to emulate the signals of a through-going muon or other calibration events. In this contribution the OctoPAES boards and some of their use cases at the testbench are presented.
The KM3NeT collaboration is currently building two deep sea neutrino telescopes at the bottom of the Mediterranean sea. The acquisition electronics for the first phase of the telescopes has been ...produced and several Detection Units have already been deployed. For subsequent phases, an improved version of the acquisition electronics has been designed with the goal of reducing the power consumption and improving the long term reliability of the boards. The control software suite, named Control Unit, is also being upgraded, in particular to overcome hardware failures. In this article, we present the last versions of the Central Logic Board and its associated Power Board, together with the evolution of the Control Unit.
KM3NeT-Italy is an INFN project that will develop the central part of a submarine cubic-kilometer neutrino telescope in the Ionian Sea, at about 80 km from the Sicilian coast (Italy). It will use ...hundreds of distributed optical modules to measure the Cherenkov light emitted by high-energy muons, whose signal-to-noise ratio is quite disfavoured. In this contribution the Trigger and Data Acquisition System (TriDAS) developed for the KM3NeT-Italy detector is presented. The "all data to shore" approach is adopted to reduce the complexity of the submarine detector: at the shore station the TriDAS collects, processes and filters all the data coming from the detector, storing triggered events to a permanent storage for subsequent analysis. Due to the large optical background in the sea from 40K decays and bioluminescence, the throughput from the sea can range up to 30 Gbps. This puts strong constraints on the performances of the TriDAS processes and the related network infrastructure.
Abstract
The KM3NeT collaboration is currently deploying the first detection units of a neutrino observatory in the Mediterranean Sea, which, once completed, will be equipped with thousands of ...so-called digital optical modules. In addition to the detection units KM3NeT has designed an independent calibration unit, housing a set of calibration instruments, including e.g. an acoustic beacon and a laser beacon. The calibration unit and the embedded software developed to operate it are presented here.
KM3NeT-Italia is an INFN project supported with Italian PON fundings for building the core of the Italian node of the KM3NeT neutrino telescope. The detector, made of 700 10′′ Optical Modules (OMs) ...lodged along 8 vertical structures called towers, will be deployed starting from fall 2015 at the KM3NeT-Italy site, about 80 km off Capo Passero, Italy, 3500 m deep. The all data to shore approach is used to reduce the complexity of the submarine detector, demanding for an on-line trigger integrated in the data acquisition system running in the shore station, called TriDAS. Due to the large optical background in the sea from 40K decays and bioluminescence, the throughput from the underwater detector can range up to 30 Gbps. This puts strong constraints on the design and performances of the TriDAS and of the related network infrastructure. In this contribution the technology behind the implementation of the TriDAS infrastructure is reviewed, focusing on the relationship between the various components and their performances. The modular design of the TriDAS, which allows for its scalability up to a larger detector than the 8-tower configuration is also discussed.
Since the early days of experimental particle physics photomultipliers (PMTs) have played an important role in the detector design. Thanks to their capability of fast photon counting, PMTs are ...extensively used in the new-generation of astroparticle physics experiments, such as air, ice and water Cherenkov detectors. Small size PMTs (< or = 3 inches diameter) show little sensitivity to the Earth magnetic field, small transit time, stable transit time spread; the price per photocathode area is less comparing to the one for the large area PMTs, typically used so far in such applications. Together with developments and reduced price of multichannel electronics, the use of PMTs of 3-inches or smaller diameter is a promising option even for nowadays large volume detectors. In this paper we report on the design and performance of a new instrument for mass characterisation of PMTs (from 1 inch to 3 inches size), capable to calibrate hundreds of PMTs per day and provide measurements of dark counts, signal amplitude, late-, delayed-, pre- and after-pulses, transit time and transit time spread.
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