Advances in the physics studies for the JT-60SA tokamak exploitation and research plan

JT-60SA, the largest tokamak that will operate before ITER, has been designed and built jointly by Japan and Europe, and is due to start operation in 2020. Its main missions are to support ITER exploitation and to contribute to the demonstration fusion reactor machine and scenario design. Peculiar properties of JT-60SA are its capability to produce long-pulse, high-ß, and highly shaped plasmas. The preparation of the JT-60SA Research Plan, plasma scenarios, and exploitation are producing physics results that are not only relevant to future JT-60SA experiments, but often constitute original contributions to plasma physics and fusion research. Results of this kind are presented in this paper, in particular in the areas of fast ion physics, high-beta plasma properties and control, and non-linear edge localised mode stability studies.Postprint (published version

Advances in the physics studies for the JT-60SA tokamak exploitation and research plan

JT-60SA, the largest tokamak that will operate before ITER, has been designed and built jointly by Japan and Europe, and is due to start operation in 2020. Its main missions are to support ITER exploitation and to contribute to the demonstration fusion reactor machine and scenario design. Peculiar properties of JT-60SA are its capability to produce long-pulse, high-β, and highly shaped plasmas. The preparation of the JT-60SA Research Plan, plasma scenarios, and exploitation are producing physics results that are not only relevant to future JT-60SA experiments, but often constitute original contributions to plasma physics and fusion research. Results of this kind are presented in this paper, in particular in the areas of fast ion physics, highbeta plasma properties and control, and non-linear edge localised mode stability studies.EURATOM 63305

Plasma physics and control studies planned in JT-60SA for ITER and DEMO operations and risk mitigation

Alarge superconducting machine, JT-60SA has been constructed to provide major contributions to the ITER program and DEMO design. For the success of the ITER project and fusion reactor, understanding and development of plasma controllability in ITER and DEMO relevant higher beta regimes are essential. JT-60SA has focused the program on the plasma controllability for scenario development and risk mitigation in ITER as well as on investigating DEMO relevant regimes. This paper summarizes the high research priorities and strategy for the JT-60SA project. Recent works on simulation studies to prepare the plasma physics and control experiments are presented, such as plasma breakdown and equilibrium controls, hybrid and steady-state scenario development, and risk mitigation techniques. Contributions of JT-60SA to ITER and DEMOhave been clarified through those studies.Peer ReviewedArticle escrit per 127 autors/autores: M Yoshida, G Giruzzi, N Aiba, J F Artaud, J Ayllon-Guerola, L Balbinot, OBeeke, E Belonohy, P Bettini, W Bin, A Bierwage, T Bolzonella, M Bonotto, CBoulbe, J Buermans, M Chernyshova, S Coda, R Coelho, S Davis, C Day, GDeTommasi, M Dibon, A Ejiri, G Falchetto, A Fassina, B Faugeras, L Figini, M Fukumoto, S Futatani, K Galazka, J Garcia, M Garcia-Muñoz, L Garzotti, L Giacomelli, L Giudicotti, S Hall, N Hayashi, C Hoa, M Honda, K Hoshino, M Iafrati, A Iantchenko, S Ide, S Iio, R Imazawa, S Inoue, A Isayama, E Joffrin, K Kamiya, Y Ko, M Kobayashi, T Kobayashi, G Kocsis, A Kovacsik, T Kurki-Suonio, B Lacroix, P Lang, Ph Lauber, A Louzguiti, E de la Luna, G Marchiori, M Mattei, A Matsuyama, S Mazzi, A Mele, F Michel, Y Miyata, J Morales, P Moreau, A Moro, T Nakano, M Nakata, E Narita, R Neu, S Nicollet, M Nocente, S Nowak, F P Orsitto, V Ostuni, Y Ohtani, N Oyama, R Pasqualotto, B Pégourié, E Perelli, L Pigatto, C Piccinni, A Pironti, P Platania, B Ploeckl, D Ricci, P Roussel, G Rubino, R Sano, K Särkimäki, K Shinohara, S Soare, C Sozzi, S Sumida, T Suzuki, Y Suzuki, T Szabolics, T Szepesi, Y Takase, M Takech, N Tamura, K Tanaka, H Tanaka, M Tardocchi, A Terakado, H Tojo, T Tokuzawa, A Torre, N Tsujii, H Tsutsui, Y Ueda, H Urano, M Valisa, M Vallar, J Vega, F Villone, T Wakatsuki, T Wauters, M Wischmeier, S Yamoto, L ZaniPostprint (published version

First principles fluid modelling of magnetic island stabilization by ECCD

International audienceTearing modes are MHD instabilities that reduce the performances of fusion devices. They can however be controlled and suppressed using Electron Cyclotron Current Drive (ECCD) as demonstrated in various tokamaks. In this work, simulations of islands stabilization by ECCD-driven current have been carried out using the toroidal nonlinear 3D full MHD code XTOR-2F, in which a current-source term modeling the ECCD has been implemented. The efficiency parameter is computed and its variations with respect to source width and location are computed. The influence of parameters such as current intensity, source width and position with respect to the island is evaluated and compared to the Modified Rutherford Equation. We retrieve a good agreement between the simulations and the analytical predictions concerning the variations of control efficiency with source width and position. We also show that the 3D nature of the current source term can lead to the onset of an island if the source term is precisely applied on a rational surface. We report the observation of a flip phenomenon in which the O-and X-Points of the island rapidly switch their position in order for the island to take advantage of the current drive to grow

Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW and comparison with JET-C

The electron temperature and density pedestals tend to vary in their relative radial positions, as observed in DIII-D (Beurskens et al 2011 Phys. Plasmas 18 056120) and ASDEX Upgrade (Dunne et al 2017 Plasma Phys. Control. Fusion 59 14017). This so-called relative shift has an impact on the pedestal magnetohydrodynamic (MHD) stability and hence on the pedestal height (Osborne et al 2015 Nucl. Fusion 55 063018). The present work studies the effect of the relative shift on pedestal stability of JET ITER-like wall (JET-ILW) baseline low triangularity (\u3b4) unseeded plasmas, and similar JET-C discharges. As shown in this paper, the increase of the pedestal relative shift is correlated with the reduction of the normalized pressure gradient, therefore playing a strong role in pedestal stability. Furthermore, JET-ILW tends to have a larger relative shift compared to JET carbon wall (JET-C), suggesting a possible role of the plasma facing materials in affecting the density profile location. Experimental results are then compared with stability analysis performed in terms of the peeling-ballooning model and with pedestal predictive model EUROPED (Saarelma et al 2017 Plasma Phys. Control. Fusion). Stability analysis is consistent with the experimental findings, showing an improvement of the pedestal stability, when the relative shift is reduced. This has been ascribed mainly to the increase of the edge bootstrap current, and to minor effects related to the increase of the pedestal pressure gradient and narrowing of the pedestal pressure width. Pedestal predictive model EUROPED shows a qualitative agreement with experiment, especially for low values of the relative shift

Physics and operation oriented activities in preparation of the JT-60SA tokamak exploitation

The JT-60SA tokamak, being built under the Broader Approach agreement jointly by Europe and Japan, is due to start operation in 2019 and is expected to give substantial contributions to both ITER and DEMO scenario optimization. A broad set of preparation activities for an efficient start of the experiments on JT-60SA is being carried out, involving the elaboration of the Research Plan, advanced modelling in various domains, feasibility and conception studies of diagnostics and other sub-systems in connection with the priorities of the scientific programme, development and validation of operation tools. The logic and coherence of this approach, as well as the main activities undertaken are presented and summarized

Plasma physics and control studies planned in JT-60SA for ITER and DEMO operations and risk mitigation

A large superconducting machine, JT-60SA has been constructed to provide major contributions to the ITER programme and DEMO design. For the success of the ITER project and fusion reactor, understanding and development of plasma controllability in ITER and DEMO relevant higher beta regimes are essential. JT-60SA has focused the program on the plasma controllability for scenario development and risk mitigation in ITER as well as on investigating DEMO relevant regimes. This paper summarizes the high research priorities and strategy for the JT-60SA project. Recent works on simulation studies to prepare the plasma physics and control experiments are presented, such as plasma breakdown and equilibrium controls, hybrid and steady-state scenario development, and risk mitigation techniques. Contributions of JT-60SA to ITER and DEMO have been clarified through those studies

Proceedings of the 12th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Heating

xvii, 592 p. : ill. ; 24 cm. + 1 CD-ROM (4 3/4 in.