Sub-GeV Dark Matter Detection with Electron Recoils in Carbon Nanotubes

Directional detection of Dark Matter particles (DM) in the MeV mass range could be accomplished by studying electron recoils in large arrays of parallel carbon nanotubes. In a scattering process with a lattice electron, a DM particle might transfer sufficient energy to eject it from the nanotube surface. An external electric field is added to drive the electron from the open ends of the array to the detection region. The anisotropic response of this detection scheme, as a function of the orientation of the target with respect to the DM wind, is calculated, and it is concluded that no direct measurement of the electron ejection angle is needed to explore significant regions of the light DM exclusion plot. A compact sensor, in which the cathode element is substituted with a dense array of parallel carbon nanotubes, could serve as the basic detection unit.Comment: 8 pages, 4 figures; updated and improved version to appear in Phys. Lett.

The CO2 system in the Mediterranean Sea: a basin wide perspective.

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Planning and designing an integrated management of coastal hypoxia in the Emila Romagna region water (Northern Adriatic Sea)

Abstract The design of an integrated monitoring network useful for the early-warning, the management and mitigation of both the environmental and socio-economic costs of hypoxia/anoxia events in the Northern Adriatic coastal zone, south of the mouth of the Po river, is described in the contribute. It has been developed within the EMMA research project (Environmental Management through Monitoring and Modelling of Anoxia; LIFE04ENV/IT/0479) (2004-2007). Over the past few decades, hypoxia events have recurrently affected the coastal zone of Emilia Romagna Region (Italy). Data collected by the C.Z. lying in the Province of Rimini, because of its economic importance, are presented. The area is subjected to intense anthropogenic pressure due to its high population (416 000 equivalent inhabitants) with tourist seasonal peaks of up to 973 110 equivalent inhabitants (in summer time), to industrial and agricultural activity, to maritime traffic and nutrient river discharges (about 600 tons y-1 of nitrogen and 300 tons y-1 of phosphorus, in 2002). Hypoxia and anoxia have a negative effect on the quality of bathing waters as well as on fishing and mussel farming, which are important activities for the economy of the area. The planning of the monitoring network has been carried out by analyzing the scientific knowledge on hypoxia in the local area; its integration with other existing monitoring activities, available facilities and data resources was considered in order to optimize cost effectiveness of the network

Integrated Management of Coastal Hypoxia in the Northern Adriatic Sea: the Case Study of the Province of Rimini.

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DISSOLVED CARBON DIOXIDE, NUTRIENTS AND OXYGEN IN THE ADRIATIC SEA. A REGIONAL OBSERVING EFFORT

Abstract The Adriatic Sea can be strongly affected by changes in climate and weather, it can play an important role in biological productivity and air-sea CO 2 fluxes,

Start of SPIDER operation towards ITER neutral beams

Heating Neutral Beam (HNB) Injectors will constitute the main plasma heating and current drive tool both in ITER and JT60-SA, which are the next major experimental steps for demonstrating nuclear fusion as viable energy source. In ITER, in order to achieve the required thermonuclear fusion power gain Q=10 for short pulse operation and Q=5 for long pulse operation (up to 3600s), two HNB injectors will be needed [1], each delivering a total power of about 16.5 MW into the magnetically-confined plasma, by means of neutral hydrogen or deuterium particles having a specific energy of about 1 MeV. Since only negatively charged particles can be efficiently neutralized at such energy, the ITER HNB injectors [2] will be based on negative ions, generated by caesium-catalysed surface conversion of atoms in a radio-frequency driven plasma source. A negative deuterium ion current of more than 40 A will be extracted, accelerated and focused in a multi-aperture, multi-stage electrostatic accelerator, having 1280 apertures (~ 14 mm diam.) and 5 acceleration stages (~200 kV each) [3]. After passing through a narrow gas-cell neutralizer, the residual ions will be deflected and discarded, whereas the neutralized particles will continue their trajectory through a duct into the tokamak vessels to deliver the required heating power to the ITER plasma for a pulse duration of about 3600 s. Although the operating principles and the implementation of the most critical parts of the injector have been tested in different experiments, the ITER NBI requirements have never been simultaneously attained. In order to reduce the risks and to optimize the design and operating procedures of the HNB for ITER, a dedicated Neutral Beam Test Facility (NBTF) [4] has been promoted by the ITER Organization with the contribution of the European Union\u2019s Joint Undertaking for ITER and of the Italian Government, with the participation of the Japanese and Indian Domestic Agencies (JADA and INDA) and of several European laboratories, such as IPP-Garching, KIT-Karlsruhe, CCFE-Culham, CEA-Cadarache. The NBTF, nicknamed PRIMA, has been set up at Consorzio RFX in Padova, Italy [5]. The planned experiments will verify continuous HNB operation for one hour, under stringent requirements for beam divergence (< 7 mrad) and aiming (within 2 mrad). To study and optimise HNB performances, the NBTF includes two experiments: MITICA, full-scale NBI prototype with 1 MeV particle energy and SPIDER, with 100 keV particle energy and 40 A current, aiming at testing and optimizing the full-scale ion source. SPIDER will focus on source uniformity, negative ion current density and beam optics. In June 2018 the experimental operation of SPIDER has started