A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E−2 spectrum from two large areas, spanning 50° above and below the Galactic centre (the “Fermi bubbles”). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles with the future multi-km3 neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the results indicate that neutrinos from the bubbles could be discovered in about one year of operation, for a neutrino spectrum with a cutoff at 100TeV and a detector with about 6km3 of instrumented volume. The effect of a possible lower cutoff is also considered.

Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average for angles up to 45° with respect to the perpendicular. Ray-tracing calculations could reproduce the measurements, allowing to estimate an increase in the overall photocathode sensitivity, integrated over all angles of incidence, by 27% (for a single PMT). Prototype DOMs, being built by the KM3NeT consortium, will be equipped with these expansion cones.

The long optical base transmissometer (LAMS—Long Arm Marine Spectrophotometer) constructed in 2008 by NESTOR group is described. The data of the recent water transparency measurements in the NESTOR site and in the Capo Passero site in the wavelength range 378–522nm are presented

A long optical base line spectrophotometer designed to measure light transmission in deep sea waters is described. The variable optical path length allows measurements without the need for absolute or external calibration. The spectrophotometer uses eight groups of uncollimated light sources emitting in the range 370–530nm and was deployed at various depths at two locations in the Ionian Sea that are candidate sites for a future underwater neutrino telescope. Light transmission spectra at the two locations are presented and compared.

Today’s greatest challenge in accelerator-based neutrino physics is to measure the mixing angle θ13 which is known to be much smaller than the solar mixing angle θ12 and the atmospheric mixing angle θ23. A non-zero value of the angle θ13 is a prerequisite for observing CP violation in neutrino mixing. In this paper, we discuss a deep-sea neutrino experiment with 1.5 Mt fiducial target mass in the Gulf of Taranto with the prime objective of measuring θ13. The detector is exposed to the CERN neutrino beam to Gran Sasso in off-axis geometry. Monochromatic muon neutrinos of ≈ 800 MeV energy are the dominant beam component. Neutrinos are detected through quasi-elastic, charged-current reactions in sea water; electrons and muons are detected in a large-surface, ring-imaging Cherenkov detector. The profile of the seabed in the Gulf of Taranto allows for a moveable experiment at variable distances from CERN, starting at 1100 km. From the oscillatory pattern of the disappearance of muon neutrinos, the experiment will measure sin2θ23 and especially Δm2 23 with high precision. The appearance of electron neutrinos will be observed with a sensitivity to P(νμ→νe) as small as 0.0035 (90% CL) and sin2θ13 as small as 0.0019 (90% CL; for a CP phase angle δ=0° and for normal neutrino mass hierarchy).

LAERTIS, designed to collect environmental data from the deep-sea, is operated since 1999 and has been deployed several time at 4000m depth at the NESTOR site. Power and data were transferred through a 30-km electro-optical cable to the Shore Station. In this report, we describe briefly the LAERTIS instrumentation and present typical data that were collected successfully during those deployment demonstrating the importance of a deep-sea station permanently connected to shore.

Today’s greatest challenge in accelerator-based neutrino physics is to measure the mixing angle θ13 which is known to be much smaller than the solar mixing angle θ12 and the atmospheric mixing angle θ23. A non-zero value of the angle θ13 is a prerequisite for observing CP violation in neutrino mixing. In this paper, we discuss a deep-sea neutrino experiment with 1.5 Mt fiducial target mass in the Gulf of Taranto with the prime objective of measuring θ13. The detector is exposed to the CERN neutrino beam to Gran Sasso in off-axis geometry. Monochromatic muon-neutrinos of ≈ 800 MeV energy are the dominant beam component. Neutrinos are detected through quasi-elastic, charged-current reactions in sea water; electrons and muons are detected in a large-surface, ring-imaging Cherenkov detector. The profile of the seabed in the Gulf of Taranto allows for a moveable experiment at variable distances from CERN, starting at 1100 km. From the oscillatory pattern of the disappearance of muon-neutrinos, the experiment will measure sin θ23 and especially ∆m23 with high precision. The appearance of electron-neutrinos will be observed with a sensitivity to P (νμ → νe) as small as 0.0035 (90% CL) and sin θ13 as small as 0.0019 (90% CL; for a CP phase angle δ = 0◦ and for normal neutrino mass hierarchy). Submitted to European Physical Journal C 1) CERN, Geneva, Switzerland 2) Joint Institute for Nuclear Research, Dubna, Russia 3) Dipartimento di Fisica, Università degli Studi di Bologna and INFN, Bologna, Italy 4) Institut de Physique Corpusculaire, Collège de France, Paris, France

NESTOR Collaboration has deployed one NESTOR module of the deep-sea neutrino telescope at a depth of 4000m, 14km off the southwest coast of Greece. The deployment site provides excellent environmental data. Power and data were transferred through a 30km electro-optical cable to the shore laboratory. In this report, we describe briefly the detector and the well-defined procedure for recovery and deployment of a detector attached to the electro-optical cable and we depict the deployment of several towers and complementary independent strings acoustically connected to the towers.

The key component of NESTOR, the deep-sea Cherenkov neutrino telescope, built in the Mediterranean, NW of Greece, is the optical module. The NESTOR Optical Module employs a PhotoMultiplier Tube (PMT) in a transparent glass pressure housing. The Hamamatsu PMT R8055-01, 13in. photomultiplier was selected for NESTOR to replace the old 15′′ Hamamatsu PMTs (R2018-03). Extensive tests have been made on the sensitivity, uniformity, time resolution and noise rates of 162 R8055-01 13in. PMTs

A module of the NESTOR underwater neutrino telescope, was deployed, in March 2003, at a depth of 3800m in order to test the overall detector performance and particularly that of the data acquisition systems. A prolonged period of running under stable operating conditions made it possible to measure the cosmic ray muon flux, I0cosa(θ).

NESTOR is a deep-sea neutrino telescope that is under construction in the Ionian Sea off the coast of Greece at a depth of about 4000m. This paper briefly reviews the detector structure and deployment techniques before describing in detail the calibration and engineering run of a test detector carried out in 2003. The detector was operated for more than 1 month and data was continuously transmitted to shore via an electro-optical cable laid on the sea floor. The performance of the detector is discussed and analysis of the data obtained shows that the measured cosmic ray muon flux is in good agreement with previous measurements and with phenomenological cosmic ray models.

NESTOR is a deep-sea neutrino telescope that is currently under construction in the Ionian Sea, off the coast of Pylos, Southwestern Greece, at a depth of approximately 4000 m. We outline briefly the layout of the telescope and summarize the present status of the project. The results of a one month continuous operation of a test unit using our standard detector modules is discussed. Data of the cosmic ray muon flux acquired with the help of an electro-optical cable during this period is presented. The data are in good agreement with earlier experiments at comparable, depth. In addition we discuss our results of bioluminescence measurements and other site and technical aspects.

A module of the NESTOR underwater neutrino telescope was deployed at a depth of 3800 m in order to test the overall detector performance and particularly that of the data acquisition systems. A prolonged period of running under stable operating conditions made it possible to measure the cosmic ray muon flux, I-0 (.) cos(alpha)(theta), as a function of the zenith angle theta. Measured values of index alpha and the vertical intensity I-0(Graphics)are in good agreement with previous measurements and phenomenological predictions. (c) 2005 Elsevier B.V. All rights reserved.

An underwater neutrino experiment has been proposed which provides precise measurements of the neutrino mixing parameters θ23 and Δm232 and permits an increase of sensitivity for the small angle θ13 by more than one order of magnitude. A Cherenkov detector of about 1.5Mt active mass, deployed in the Gulf of Taranto, utilizes the CNGS beam in off-axis configuration which represents an essentially mono-energetic source of muon neutrinos. A unique feature of the experiment is the possibility to move the detector and therefore exploit different baselines around 1200km where the oscillation pattern is fully developed. The conceptual detector design consists of O(30,000) large area and acceptance photosensors arranged in a matrix of ∼300×300m2 size. Hybrid photon detectors are considered as promising candidates as they provide clean signal characteristics and uniform collection efficiency. We discuss the design and expected performance of a large spherical HPD with 380mm diameter, which is housed in a high-pressure glass container. A scaled prototype HPD of 208mm diameter is currently under development using the existing CERN HPD facility.

NESTOR is a submarine high-energy muon and neutrino telescope, now under construction for deployment in the Mediterranean close to Greek shores. The first floor of the NESTOR with 12 optical modules had been deployed successfully in March 2003 together with electronics system. All systems and the associated environmental monitoring units are operating properly and data are being recorded. The status of the NESTOR project is presented. We outline briefly the construction of deepwater neutrino telescope, properties of the NESTOR site, infrastructure of the project, the deployment of the first floor and its current operation. First data are presented and plans for next steps are summarized.

The first so-called floor with 12 detector modules of the NESTOR deep sea high energy muon and neutrino telescope had been deployed successfully this March (2003) together with its electronics system. Since that data the system and the associated environmental monitoring units are operating properly and data pp. 1377–1380 c ©2003 by Universal Academy Press, Inc.

NESTOR is a deep-sea water Cherenkov neutrino detector now under construction for deployment in the Mediterranean off Greece. Its key component is an optical module employing a photomultiplier tube with a 15 in. hemispherical photocathode in a transparent glass pressure housing. Extensive tests have been made on the sensitivity, uniformity, time resolution, noise rates and mechanical properties of the module: several test deployments have been made at sea.

The CNGS design has been approved with two muon detector stations, separated by 67 metres of rock. During the recent discussions on cost reduction, it has been suggested that a possible saving would be to postpone equipping the second muon detector station. The importance of the second array of muon detectors, in particular at the start-up of CNGS, is being described in this note. It is argued that both muon detector stations must be operational from the beginning of CNGS operation. Geneva, Switzerland 5 December 2002

Simulations of the CNGS neutrino beam from CERN to the Gran Sasso Laboratory (LNGS) assume that the proton beam and all secondary beam elements are perfectly aligned on an axis between the two laboratories. This study examines the effects on the neutrino flux at Gran Sasso of deviations from the axis of the primary proton beam and misalignment of secondary beam elements. It also examines how such deviation or misalignment can be detected at monitors placed along the secondary beam line at CERN and at Gran Sasso. Calculations are based on the CNGS neutrino beam, optimized for appearance experiments as described in the Addendum to the Conceptual Technical Design Report of CNGS. It is shown that the number of neutrino charged current events predicted at Gran Sasso is insensitive to all but the most extreme misalignments.