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

none76noneGiruzzi, G.; Joffrin, E.; Garcia, J.; Douai, D.; Artaud, J. -F.; Pégourié, B.; Maget, P.; Kamada, Y.; Yoshida, M.; Ide, S.; Hayashi, N.; Matsunaga, G.; Nakano, T.; Shinohara, K.; Sakurai, S.; Suzuki, T.; Urano, H.; Enoeda, M.; Kubo, H.; Kamiya, K.; Takechi, M.; Miyata, Y.; Isayama, A.; Kobayashi, T.; Moriyama, S.; Shimizu, K.; Hoshino, K.; Kawashima, H.; Bierwage, A.; Mcdonald, D.; Sozzi, C.; Figini, L.; Nowak, S.; Moro, A.; Platania, P.; Ricci, D.; Granucci, G.; Bolzonella, T.; Bettini, P.; Innocente, P.; Terranova, D.; Pigatto, L.; Villone, F.; Pironti, A.; Mastrostefano, S.; De Tommasi, G.; Mattei, M.; Mele, A.; Orsitto, F.; Dunai, D.; Szepesi, T.; Barbato, E.; Vitale, V.; Romanelli, M.; Garzotti, L.; Boboc, A.; Saarelma, S.; Wischmeier, M.; Lauber, P.; Lang, P.; Neu, R.; Day, C.; Gleason-Gonzalez, C.; Scannapiego, M.; Zagorski, R.; Galazaka, K.; Stepniewski, W.; Cruz, N.; De La Luna, E.; Farcia-Munoz, M.; Vega, J.; Clement-Lorenzo, S.; Sartori, F.; Coda, S.; Goodman, T.; Soare, S.Giruzzi, Gerardo; Joffrin, E.; Garcia, J.; Douai, D.; Artaud, J. F.; Pégourié, B.; Maget, P.; Kamada, Y.; Yoshida, M.; Ide, S.; Hayashi, N.; Matsunaga, G.; Nakano, T.; Shinohara, K.; Sakurai, S.; Suzuki, T.; Urano, H.; Enoeda, M.; Kubo, Hiroshi; Kamiya, K.; Takechi, M.; Miyata, Y.; Isayama, A.; Kobayashi, T.; Moriyama, S.; Shimizu, K.; Hoshino, K.; Kawashima, H.; Bierwage, A.; Mcdonald, D.; Sozzi, C.; Figini, L.; Nowak, S.; Moro, A.; Platania, P.; Ricci, Daniele; Granucci, G.; Bolzonella, Tommaso; Bettini, P.; Innocente, P.; Terranova, David; Pigatto, Leonardo; Villone, F.; Pironti, Alfredo; Mastrostefano, S.; De Tommasi, G.; Mattei, M.; Mele, Adriano; Orsitto, F.; Dunai, D.; Szepesi, T.; Barbato, E.; Vitale, V.; Romanelli, M.; Garzotti, L.; Boboc, A.; Saarelma, S.; Wischmeier, M.; Lauber, P.; Lang, P.; Neu, R.; Day, C.; Gleason Gonzalez, C.; Scannapiego, M.; Zagorski, R.; Galazaka, K.; Stepniewski, W.; Cruz, N.; De La Luna, E.; Farcia Munoz, M.; Vega, J.; Clement Lorenzo, S.; Sartori, F.; Coda, S.; Goodman, T.; Soare, S

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-), 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

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 2020 and is expected to give substantial contributions to both ITER and DEMO scenario optimisation. A broad set of preparation activities for an efficient start of the experiments on JT-60SA is being carried out, involving 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 most significant results of the main activities undertaken are presented and summarised

Completion of JT-60SA construction and contribution to ITER

Construction of the JT-60SA tokamak was completed on schedule in March 2020. Manufacture and assembly of all the main tokamak components satisfied technical requirements, including dimensional accuracy and functional performances. Development of the plasma heating systems and diagnostics have also progressed, including the demonstration of the favourable electron cyclotron range of frequency (ECRF) transmission at multiple frequencies and the achievement of long sustainment of a high-energy intense negative ion beam. Development of all the tokamak operation control systems has been completed, together with an improved plasma equilibrium control scheme suitable for superconducting tokamaks including ITER. For preparation of the tokamak operation, plasma discharge scenarios have been established using this advanced equilibrium controller. Individual commissioning of the cryogenic system and the power supply system confirmed that these systems satisfy design requirements including operational schemes contributing directly to ITER, such as active control of heat load fluctuation of the cryoplant, which is essential for dynamic operation in superconducting tokamaks. The integrated commissioning (IC) is started by vacuum pumping of the vacuum vessel and cryostat, and then moved to cool-down of the tokamak and coil excitation tests. Transition to the super-conducting state was confirmed for all the TF, EF and CS coils. The TF coil current successfully reached 25.7 kA, which is the nominal operating current of the TF coil. For this nominal toroidal field of 2.25 T, ECRF was applied and an ECRF plasma was created. The IC was, however, suspended by an incident of over current of one of the superconducting equilibrium field coil and He leakage caused by insufficient voltage holding capability at a terminal joint of the coil. The unique importance of JT-60SA for H-mode and high-β steady-state plasma research has been confirmed using advanced integrated modellings. These experiences of assembly, IC and plasma operation of JT-60SA contribute to ITER risk mitigation and efficient implementation of ITER operation

Analysis of ELM stability with extended MHD models in JET, JT-60U and future JT-60SA tokamak plasmas

The stability with respect to a peelingballooning mode (PBM) was investigated numerically with extended MHD simulation codes in JET, JT-60U and future JT-60SA plasmas. The MINERVA-DI code was used to analyze the linear stability, including the effects of rotation and ion diamagnetic drift (w∗i), in JET-ILW and JT-60SA plasmas, and the JOREK code was used to simulate nonlinear dynamics with rotation, viscosity and resistivity in JT-60U plasmas. It was validated quantitatively that the ELM trigger condition in JET-ILW plasmas can be reasonably explained by taking into account both the rotation and w∗i effects in the numerical analysis. When deuterium poloidal rotation is evaluated based on neoclassical theory, an increase in the effective charge of plasma destabilizes the PBM because of an acceleration of rotation and a decrease in w∗i. The difference in the amount of ELM energy loss in JT-60U plasmas rotating in opposite directions was reproduced qualitatively with JOREK. By comparing the ELM affected areas with linear eigenfunctions, it was confirmed that the difference in the linear stability property, due not to the rotation direction but to the plasma density profile, is thought to be responsible for changing the ELM energy loss just after the ELM crash. A predictive study to determine the pedestal profiles in JT-60SA was performed by updating the EPED1 model to include the rotation and w∗i effects in the PBM stability analysis. It was shown that the plasma rotation predicted with the neoclassical toroidal viscosity degrades the pedestal performance by about 10% by destabilizing the PBM, but the pressure pedestal height will be high enough to achieve the target parameters required for the ITER-like shape inductive scenario in JT-60SA