1,721,851 research outputs found
DTT Divertor Tokamak Test facility. Interim Design Report. Summary
Full text linkLa proposta di progetto DTT, Divertor Tokamak Test facility, rappresenta una proposta innovativa e completa nella roadmap verso l’implementazione dell’energia da fusione termonucleare. Il progetto coinvolge un centinaio di ricercatori provenienti da università e laboratori italiani e stranieri. Approvato dalle autorità italiane, il progetto potrà beneficiare di finanziamenti governativi e regionali e di un ampio sostegno europeo, ottenuto nell’ambito del Piano europeo per gli investimenti in infrastrutture. La pubblicazione intende fornire i dati chiave aggiornati del complesso e articolato progetto
Technological review of the HRP manufacturing process R&D activity
No full textENEA and Ansaldo Nucleare S.p.A. have been deeply involved in the European International Thermonuclear Experimental Reactor (ITER) R&D activities for the manufacturing of high heat flux plasma-facing components (HHFC), and in particular for the inner vertical target (IVT) of the ITER divertor. This component has to be manufactured by using both armour and structural materials whose properties are defined by ITER. Their physical properties prevent the use of standard joining techniques. The reference armour materials are tungsten and carbon/carbon fibre composite (CFC). The cooling pipe is made of copper alloy (CuCrZr-IG). During the last years ENEA and Ansaldo have jointly manufactured several actively cooled monoblock mock-ups and prototypical components of different length, geometry and materials, by using innovative processes: HRP (hot radial pressing) and PBC (pre-brazed casting). The history of the technical issues solved during the R&D phase and the improvements implemented to the assembling tools and equipments are reviewed in the paper together with the testing results. The optimization of the processes started from the successful manufacturing of both W and CFC armoured small scale mockups thermal fatigue tested in the worst ITER operating condition (20 MW/m2) through the achievement of record performances obtained from a monoblock medium scale mockup. On the base of these results ENEA-ANSALDO participated to the European programme for the qualification of the manufacturing technology to be used for the procurement of the ITER divertor IVT, according to the F4E specifications. A divertor inner vertical target prototype (400 mm total length) with three plasma facing component units, was successfully tested at ITER relevant thermal heat fluxes. Now, ANSALDO and ENEA are ready to face the challenge of the ITER inner vertical target production, transferring to an industrial production line the experience gained in the development, optimization and qualification of the PBC and HRP processes. © 2013 Elsevier B.V. All rights reserved
Mechanical and electrical properties of cryo-worked Cu
No full textFor manufacturing the magnets of fusion machines pure copper of both high mechanical resistance and electrical conductivity is required. Though high purity copper guarantees high electrical conductivity, its mechanical properties may be not suitable for the applications in tokamaks. In this view, a new procedure developed for obtaining high purity copper with excellent mechanical strength is described in this work. Samples of oxygen free copper (OFC) have been worked by pressing in liquid nitrogen (77 K). It has been verified that the mechanical properties of the worked metal are strongly dependent on the strain rate. Very low strain rates permitted to attain values of tensile yield strength (550 MPa) significantly higher than those obtained by traditional cold-working at room temperature (450 MPa). The electrical conductivity of the cryo-worked Cu decreases with the tensile yield strength even though the hardest samples of tensile yield strength of 550 MPa exhibit still acceptable values of conductivity (about 94 % IACS at room temperature). © 2013 Springer Science+Business Media New York
The DTT proposal. A tokamak facility to address exhaust challenges for DEMO: Introduction and executive summary
No full textAs indicated in the European Fusion Roadmap, the main objective of the Divertor Tokamak Test facility (DTT) is to explore alternative power exhaust solutions for DEMO so as to mitigate the risk that the conventional divertor based on detached conditions to be tested on the ITER device cannot be extrapolated to a fusion reactor. The issues to be investigated by DTT include:. •demonstrate a heat exhaust system capable of withstanding the large load of DEMO in case of inadequate radiated power fraction;•close the gaps in the exhaust area that cannot be addressed by present devices;•demonstrate that the possible (alternative or complementary) solutions (e.g., advanced divertor configurations or liquid metals) can be integrated in a DEMO device. In this paper, we describe a proposal for such a DTT, presented by ENEA in collaboration with a European team of scientists. The selection of the DTT parameters (a major radius of 2.15. m, an aspect ratio of about 3, an elongation of 1.6-1.8, a toroidal field of 6. T, and a flat top of about 100. s) has been made according to the following specifications:. •edge conditions as close as possible to DEMO in terms of dimensionless parameters;•flexibility to test a wide set of divertor concepts and techniques;•compatibility with bulk plasma performance.•an upper bound of 500M€ for the investment costs. This paper illustrates this DTT proposal showing how the basic machine parameters and concept have been selected so as to make a significant step toward the accomplishment of the power exhaust mission
Commentary: Biochemical Markers for Diagnosis and Follow-up of Aortic Diseases: An Endless Search for the Holy Grail
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Feasibility study of an intense D-T fusion source: "The new sorgentina"
No full textThe international community agrees on the importance to build a large facility devoted to test and validate materials to be used in harsh neutron environments. Such a facility, proposed by ENEA, reconsiders a previous study known as "Sorgentina" but takes into account new technological development so far attained. The "New Sorgentina" Fusion Source (NSFS) project is based upon an intense D-T 14 MeV neutron source achievable with T and D ion beams impinging on 2 m radius rotating targets. NSFS produces about 1 × 1013 n cm-2 s-1 over about 50 cm 3. Larger volumes of lower neutron flux will be available (e.g. for TBM experiments) as well as collimated channels to study some features of the ITER neutron camera. The NSFS facility will overcome problems related to the ion source and accelerating system, by means of an upgraded version of the JET-PINI ion beams. NSFS has to be intended as an European facility that may be realized in a few years, once provided a preliminary technological program devoted to the operation of the ion source in continuous mode, target heat loading/removal, target and tritium handling, inventory as well as site licensing. In this contribution, the main characteristics of NSFS project will be presented. © 2014 Elsevier B.V
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
DTT Divertor Tokamak Test facility. Interim Design Report. A milestone along the roadmap to the realisation of fusion energy
No full textDTT (Divertor Tokamak Test facility) è una pietra miliare nel programma scientifico internazionale finalizzato a dimostrare – nella seconda metà di questo secolo – la convenienza dell’uso commerciale della fusione termonucleare controllata. DTT è un tokamak ideato e progettato in Italia con un ampio respiro internazionale. La costruzione sarà realizzata nel sito ENEA di Frascati, con il supporto di fondi in gran parte nazionali, integrati da EUROfusion e da canali europei di incentivazione agli investimenti innovativi. Il gruppo di progetto include oltre 180 ricercatori di alto profilo internazionale appartenenti a ENEA, CREATE, CNR, INFN, RFX e varie università. Il volume, dal titolo DTT Interim Design Report (“Green Book” dal colore della copertina), descrive sinteticamente lo stato del progetto, la pianificazione delle attività future e la sua struttura del team. Il report vuole anche promuovere una approfondita discussione internazionale e sollecitare un’ampia collaborazione sul progetto DTT
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