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- 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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| 2. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 6. |
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- 2018
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Forskningsöversikt (refereegranskat)
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| 10. |
- Eriksson, Benjamin, 1992-
(författare)
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The evolution of TOFu : Developing and utilizing neutron time-of-flight spectrometry of deuterium and tritium fusion plasmas at JET
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Considerable effort has been invested in attempting to generate electricity from the energy released in controlled thermonuclear fusion reactions, with a European fusion research roadmap stretching beyond 2050. Our current endeavors may culminate in a virtually inexhaustible, low-carbon energy source for future generations. Experimental reactors such as the Joint European Torus (JET) and the International Thermonuclear Experimental Reactor (ITER) are stepping stones on the road to demonstrating the viability of fusion energy. Using various diagnostics and simulations, information on the plasma conditions in such experimental reactors can be obtained.In this thesis, the neutron time-of-flight spectrometer TOFOR at JET is used to study the neutron emission spectrum from the JET machine to determine different fusion plasma parameters. The first part of the thesis describes the efforts to upgrade the data acquisition (DAQ) system of TOFOR with a new, fully digital system: TOFu. Data reduction techniques are developed for the new DAQ system, and are shown to increase the signal-to-background ratio significantly. The instrumental response function is improved using the new system by measuring the energy-dependent time resolution and energy thresholds and applying them to the response function. Data analysis routines are developed to generate time-of-flight spectra from the data acquired by the 37 TOFOR sub-detectors.In the second part of the thesis, the data acquired by the new DAQ system is used to perform various physics studies of JET plasmas. We demonstrate the possibility of measuring the fuel ion temperature for Ohmic discharges of pure deuterium plasmas, with a precision that was unattainable with the former DAQ system. Furthermore, during the time of my doctoral studies, two deuterium-tritium experimental campaigns (DTE2 and DTE3) were conducted at JET. In order to contribute to the analysis of these experiments, we developed methods to measure the tritium fuel concentration in the fusion plasma using TOFOR. Also, experiments with pure tritium plasmas gave us the unique opportunity to measure the neutron emission spectrum from the T + T4He + 2n reaction during which we made the first observation in a magnetically confined plasma of the intermediate resonant reaction T + T5He + n.The analysis methods and experimental techniques developed in this thesis may be used in future neutron spectrometry systems, e.g., at ITER where there are plans to build a high-resolution neutron spectrometer (HRNS) consisting of several detection systems, one of which is a TOFOR-like time-of-flight spectrometer.
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