| Abstract | The primary objectives of the KM3NeT Design Study are the development of a cost-effective design for a cubic-kilometre sized deep-sea infrastructure housing a neutrino telescope with unprecedented physics sensitivity and providing long-term access for deep-sea research, the evaluation of procedures for the assembly and construction of the infrastructure and the preparation of models for its operation and maintenance.
General conditions: The combination of the relatively low flux of high energy cosmic neutrinos and their weak interaction with matter implies the need for a very massive detector (1012 kg, i.e. a cubic kilometre of water). The solution pursued is to instrument a large volume of deep-sea water with a three-dimensional array of photo-sensors (photomultiplier tubes, PMTs) detecting the Cerenkov light produced by charged particles emerging from neutrino interactions in the water or sea bed. In order to suppress daylight and background from muons produced in cosmic ray interactions in the Earth's atmosphere, the telescope must be operated at depths of several kilometres. In seawater, irreducible background light is emitted by decays of 40K nuclei and by bioactivity, and environmental processes such as sedimentation or bio-fouling affect the long-term performance of the KM3NeT infrastructure.
Design goals: The technical design targets at an overall cost below 200Me per cubic kilometre of instrumented sea water; a gure which represents an improvement of cost per unit volume of more than two from the present generation of underwater neutrino detectors. The goal of the Design Study is to prepare the framework allowing for the construction of the KM3NeT neutrino telescope in time to take data concurrently with the IceCube neutrino telescope in the Southern Hemisphere. The KM3NeT infrastructure is foreseen to have an operational lifetime of at least 10 years without significant reduction in sensitivity due to environmental processes.
Involvement of HCMR (WP5 and WP9)
Specific objectives of WP5 and WP9: (1) Assess existing water, oceanographic, biological and geological data from candidate sites:
All information available about optical and biological water properties, sea bottom surveys, environmental properties and geo-hazards at the three sites (Capo Passero, Toulon, Pylos) is collected and categorised. As a result of this preliminary study the experimental activities needed to complete the set of measurements are identified. (2) Perform missing measurements: on water, oceanographic, biological and geological properties of candidate sites. (3) Science reviews of candidate sites: The first step in the second objective is to prepare reports for each of the three candidate sites describing: Bathymetry, underlying geology, sedimentation regime, the sediment interface, water circulation, wave propagation, biological productivity regime, biodiversity, human impacts, resource issues and hazards. The reports conclude with an assessment of the main science issues to be addressed, e.g. seismcity, slope stability, tsunamis, flow, temperature, biological productivity and sedimentation. (4) Contribution to the design of the benthic observatory platform(s) and participation in the data acquisition. |
