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| 2. |
- Joffrin, E., et al.
(författare)
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Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
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| 3. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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| 5. |
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| 6. |
- Kehoe, Laura, et al.
(författare)
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Make EU trade with Brazil sustainable
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Bozakov, Zdravko, et al.
(författare)
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Deliverable D2.1 - First Version of Low-Level Core Transport System
- 2016
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Rapport (refereegranskat)abstract
- This document presents the first version of the low-level Core Transport System in NEAT, to be used for development of a reference implementation of the NEAT System. The design of this core transport system takes into consideration the Transport Services and the API defined in Task 1.3 and in close coordination with the overall architecture (Task 1.2). To realise the basic Transport Services provided by the API, a set of low-level transport functionalities has to be provided by the NEAT core transport system. These functionalities take the formof several building blocks, or NEAT Components, each representing an associated implementation activity. Some of the components are needed to ensure the basic operation of the NEAT System—e.g., a NEAT Flow Endpoint, a callback-based NEAT API Framework, the NEAT Logic and the functionality to Connect to a name. Some other components are needed to ensure connectivity usingMiddlebox Traversal techniques (e.g., TURN), discovery of path support for different transport protocols using Happy Eyeballs mechanisms, offering end-to end Security (e.g., (D)TLS over transport), gather statistics for the users or system administrators, and the ability to apply different policies in order to influence the decision-making process of the transport system. This document describes each of these building blocks and related design choices.
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| 8. |
- Fairhurst, Gorry, et al.
(författare)
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Deliverable D1.1 - NEAT Architecture
- 2016
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Rapport (refereegranskat)abstract
- Ossification of the Internet transport-layer architecture is a significant barrier to innovation of the Internet. Such innovation is desirable for many reasons. Current applications often need to implement their own mechanisms to receive the transport service they need, but many do not have the breadth of adapting to all possible network characteristics. An updated transport architecture can do much to make the Internet more flexible and extensible. New ground-breaking services often require different or updated transport protocols, could benefit from better signalling between application and network, or desire a more flexible choice of which network path is used for which traffic. This document therefore proposes a new transport architecture. Such architecture lowers the barrier to service innovation by proposing a “transport system”, the NEAT System, that can leverage the rich set of available transport protocols. It paves the way for an architectural change of the Internet where new transport-layer services can seamlessly be integrated and quickly made available, minimising deployment difficulties, and allowing Internet innovators to take advantage of them wherever possible. The document provides a survey of the state-of-the-art to identify the architectural obstacles to, and opportunities for, evolution of the transport layer. It also details a set of general requirements for a new transport architecture. This new architecture is motivated by a set of use-cases, followed by a description of the NEAT architecture for a transport system, designed to permit applications to select appropriate transports based on their needs and the available transport services.
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| 9. |
- Jones, Geraint H., et al.
(författare)
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The Comet Interceptor Mission
- 2024
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Ingår i: Space Science Reviews. - : Springer Nature. - 0038-6308 .- 1572-9672. ; 220:1
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Tidskriftsartikel (refereegranskat)abstract
- Here we describe the novel, multi-point Comet Interceptor mission. It is dedicated to the exploration of a little-processed long-period comet, possibly entering the inner Solar System for the first time, or to encounter an interstellar object originating at another star. The objectives of the mission are to address the following questions: What are the surface composition, shape, morphology, and structure of the target object? What is the composition of the gas and dust in the coma, its connection to the nucleus, and the nature of its interaction with the solar wind? The mission was proposed to the European Space Agency in 2018, and formally adopted by the agency in June 2022, for launch in 2029 together with the Ariel mission. Comet Interceptor will take advantage of the opportunity presented by ESA’s F-Class call for fast, flexible, low-cost missions to which it was proposed. The call required a launch to a halo orbit around the Sun-Earth L2 point. The mission can take advantage of this placement to wait for the discovery of a suitable comet reachable with its minimum Δ V capability of 600 ms − 1 . Comet Interceptor will be unique in encountering and studying, at a nominal closest approach distance of 1000 km, a comet that represents a near-pristine sample of material from the formation of the Solar System. It will also add a capability that no previous cometary mission has had, which is to deploy two sub-probes – B1, provided by the Japanese space agency, JAXA, and B2 – that will follow different trajectories through the coma. While the main probe passes at a nominal 1000 km distance, probes B1 and B2 will follow different chords through the coma at distances of 850 km and 400 km, respectively. The result will be unique, simultaneous, spatially resolved information of the 3-dimensional properties of the target comet and its interaction with the space environment. We present the mission’s science background leading to these objectives, as well as an overview of the scientific instruments, mission design, and schedule.
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| 10. |
- Khademi, Naeem, et al.
(författare)
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Deliverable D2.2 - Core Transport System, with both Low-level and High-level Components
- 2017
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Rapport (refereegranskat)abstract
- This document presents the core transport system in NEAT, as used for development of thereference implementation of the NEAT System. The document describes the componentsnecessary to realise the basic Transport Services provided by the NEAT User API, with thedescription of a set of NEAT building blocks and their related design choices. The designof this core transport system takes into consideration the Transport Services and the API(defined in Task 1.3) and in close coordination with the overall architecture (Task 1.2).To realise the Transport Services provided by the API, a set of transport functionalitieshas to be provided by the NEAT Core Transport System. These functionalities take the formof several building blocks, or NEAT Components, each representing an associated implementationactivity. Some of the components are needed to ensure the basic operation ofthe NEAT System—e.g., a NEAT Flow Endpoint, a callback-based NEAT API Framework, theNEAT Logic and the functionality to Connect to a name. Additional components are neededfor: (a) ensuring connectivity, by means of mechanisms for discovery of path support fordifferent protocols; (b) supporting end-to-end security; (c) the ability to apply differentpolicies to influence the decision-making process of the transport system; (d) providingother important functionalities (e.g., a user-space SCTP stack, or gathering statistics forusers or system administrators).This document updates Deliverable D2.1; in particular, the descriptions of NEAT componentspresented here correspond to the implementation status at the time of writing,and as such they replace those in D2.1.
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