Deep sea tests of a prototype of the KM3NeT digital optical module

The first prototype of a photo-detection unit of the future KM3NeT neutrino telescope has been deployed in the deepwaters of the Mediterranean Sea. This digital optical module has a novel design with a very large photocathode area segmented by the use of 31 three inch photomultiplier tubes. It has been integrated in the ANTARES detector for in-situ testing and validation. This paper reports on the first months of data taking and rate measurements. The analysis results highlight the capabilities of the new module design in terms of background suppression and signal recognition. The directionality of the optical module enables the recognition of multiple Cherenkov photons from the same (40)Kdecay and the localisation of bioluminescent activity in the neighbourhood. The single unit can cleanly identify atmospheric muons and provide sensitivity to the muon arrival directions

The LOFT mission concept: a status update

The Large Observatory For x-ray Timing (LOFT) is a mission concept which was proposed to ESA as M3 and M4 candidate in the framework of the Cosmic Vision 2015-2025 program. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument and the uniquely large field of view of its wide field monitor, LOFT will be able to study the behaviour of matter in extreme conditions such as the strong gravitational field in the innermost regions close to black holes and neutron stars and the supra-nuclear densities in the interiors of neutron stars. The science payload is based on a Large Area Detector (LAD, >8m2 effective area, 2-30 keV, 240 eV spectral resolution, 1 degree collimated field of view) and a Wide Field Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g., GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the current technical and programmatic status of the mission

The Large Observatory for x-ray timing

The Large Observatory For x-ray Timing (LOFT) was studied within ESA M3 Cosmic Vision framework and participated in the final down-selection for a launch slot in 2022-2024. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument, LOFT will study the behaviour of matter under extreme conditions, such as the strong gravitational field in the innermost regions of accretion flows close to black holes and neutron stars, and the supra-nuclear densities in the interior of neutron stars. The science payload is based on a Large Area Detector (LAD, 10 m2 effective area, 2-30 keV, 240 eV spectral resolution, 1° collimated field of view) and a WideField Monitor (WFM, 2-50 keV, 4 steradian field of view, 1 arcmin source location accuracy, 300 eV spectral resolution). The WFM is equipped with an on-board system for bright events (e.g. GRB) localization. The trigger time and position of these events are broadcast to the ground within 30 s from discovery. In this paper we present the status of the mission at the end of its Phase A study

\ensuremath{\gamma}-ray spectroscopy of low-lying yrast and non-yrast states in neutron-rich 94,95,96Kr^{94,95,96}\mathrm{Kr}

International audienceWe report on γ-ray spectroscopy of low-lying excited states in the neutron-rich Kr94,95,96 isotopes measured as part of the “Shell Evolution And Search for Two-plus energies At RIBF” (SEASTAR) campaign at the RIKEN Radioactive Isotope Beam Factory. Excited yrast and non-yrast states were observed, and half-lives extracted via geant4 simulations. In Kr94,96 candidates for the 31− state were identified. For Kr95, the prompt SEASTAR data were combined with delayed spectroscopic data measured with the EURICA array to observe transitions on top of the known (7/2)+ isomer at a level energy of 195.5(3) keV. The comparison of the new experimental results with five-dimensional collective Hamiltonian (5DCH) and mapped interacting boson model (IBM) calculations, both using the Gogny D1M interaction, could suggest oblate-prolate shape coexistence already in Kr96

Operational Experience With the Readout System of the MINOS Vertex Tracker

International audienceThe magic numbers off stability (MINOS) vertex tracker is a compact instrument built for in-beam spectroscopy of exotic nuclei. Its main component is a ~30-cm-long hollow cylinder shape time projection chamber (TPC) surrounding a liquid hydrogen target. The anode of the TPC is read out by a Micromegas detector segmented in 18 concentric rings of 2 mm × 2 mm pads totaling 3604 channels. A dedicated system based on the AFTER and AGET chips was designed to read out this TPC, and the required software to configure, monitor, and acquire data was developed. After a construction period of two years and the validation in a test beam, four nuclear physics experiments exploiting MINOS have successfully been conducted at RIKEN, Japan. We describe the prominent aspects of the readout system of MINOS and we report on lessons learned during the three years of exploitation

Ranking port cities with high exposure and vulnerability to climate extremes: exposure estimates

This global screening study makes a first estimate of the exposure of the world’s large port cities to coastal flooding due to storm surge and damage due to high winds. This assessment also investigates how climate change is likely to impact each port city’s exposure to coastal flooding by the 2070s, alongside subsidence and population growth and urbanisation. The analysis demonstrates that a large number of people are already exposed to coastal flooding in large port cities. Across all cities, about 40 million people (0.6% of the global population or roughly 1 in 10 of the total port city population in the cities considered here) are exposed to a 1 in 100 year coastal flood event. When assets are considered, the distribution becomes more heavily weighted towards developed countries, as the wealth of the cities becomes important. The total value of assets exposed in 2005 is across all cities considered here is estimated to be US$3,000 billion; corresponding to around 5$35,000 billion by the 2070s; more than ten times current levels and rising to roughly 9% of projected global GDP in this period. On a global-scale, for both types of exposure, population growth, socio-economic growth and urbanization are the most important drivers of the overall increase in exposure. Climate change and subsidence significantly exacerbate this effect although the relative importance of these factors varies by location. The policy implications of this report are clear: the benefits of climate change policies - both global mitigation and local adaptation at the city-scale - are potentially great

Greffes de cornée automatisées par laser femtoseconde optimisé et système de contrôle aberrométrique

International audienceNous présentons un premier bilan du projet Greco qui vise la conception et la réalisation d'un dispositif innovateur de chirurgie oculaire par laser à impulsions ultrarapides optimisé pour la greffe de cornée

Patterns of gravity induced aggregate migration during casting of fluid concretes

In this paper, aggregate migration patterns during fluid concrete castings are studied through experiments, dimensionless approach and numerical modeling. The experimental results obtained on two beams show that gravity induced migration is primarily affecting the coarsest aggregates resulting in a decrease of coarse aggregates volume fraction with the horizontal distance from the pouring point and in a puzzling vertical multi-layer structure. The origin of this multi layer structure is discussed and analyzed with the help of numerical simulations of free surface flow. Our results suggest that it finds its origin in the non Newtonian nature of fresh concrete and that increasing casting rate shall decrease the magnitude of gravity induced particle migration. (C) 2012 Elsevier Ltd. All rights reserved

Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei

7 pags., 4 figs.Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250 MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.We thank the RIBF and BigRIPS teams for providing a stable beam and optimum settings over the two experimental campaigns. A. F. acknowledges support from the DFG under Grant No. SFB1245. M. G.-R. acknowledges support from the Alexander von Humboldt foundation. A. O. thanks the European Research Council for its support through ERC Grant No. MINOS-258567, the JSPS Japanese Society for the Promotion of Science for the long-term fellowship L-13520, the German DFG for its support from the SFB Grant No. 1245, and the Alexander von Humboldt Foundation for its support. K. Mo. acknowledges support from German BMBF Grant No. 05P15PKFNA. M. L. C., M. L., and V. W. acknowledge support from German BMBF Grants No. 05P15RDFN1, and No. 05P19RDFN1, as well as DFG Grant No. SFB 1245. L. X. C. and B. D. L. are supported by the Vietnam MOST through Physics Development Program Grant No. Ð TÐ LCN.25/18 and acknowledge the Radioactive Isotope Physics Laboratory of the RIKEN Nishina Center for supporting their stay during the experiment. A. J. and V. V. acknowledge support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2- P. U.K. participants acknowledge support from the Science and Technology Facilities Council (STFC). Collaborators from I. M. P. were supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences. R. T. was supported by the JSPS Grant-in-Aid for JSPS Research Fellows JP14J08718. Zs. D., Z. K., and Zs. V. acknowledge the support from Projects No. OTKA K128947 and No. GINOP-2.3.3-15-2016-00034. C. Santamaria acknowledges support by the IPA program at the RIKEN Nishina Center