Tokamak discharge simulation coupling free-boundary equilibrium and plasma model with application to JT-60SA

Ostuni, Valeria; Artaud, Jean-François; Giruzzi, G.; Joffrin, E.; Heumann, Holger; Urano, H.

doi:10.1088/1741-4326/abcdb7

Cited by 6 publications

(4 citation statements)

References 22 publications

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“…A complementary approach has been used by developing a new simulator that combines the free-boundary equilibrium code FEEQS and the fast integrated modelling code METIS. Simulations of a full H-mode discharge (scenario 2) have been performed, including plasma profiles, and are consistent with limits of the EF coils and the CSs [39]. Another example of FEEQS-METIS simulation is given in figure 24, for the hybrid scenario (scenario 4-2).…”

Section: Plasma Prediction and Scenario Development For Iter And Demomentioning

confidence: 85%

Completion of JT-60SA construction and contribution to ITER

et al. 2022

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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.

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Section: Plasma Prediction and Scenario Development For Iter And Demomentioning

confidence: 85%

Completion of JT-60SA construction and contribution to ITER

et al. 2022

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“…In preparation of this goal, predictive modelling of the current ramp-up is being performed. This was first analysed with a fast integrated tokamak modelling tool (METIS+FEEQS) in [6]. A similar current ramp-up in fully predictive way was simulated using the JINTRAC suite of codes [7].…”

Section: Introductionmentioning

confidence: 99%

ECRF stray radiation studies in preparation of the operations of JT-60SA

et al. 2023

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JT-60SA tokamak is equipped with an ECRF system since the beginning of its operational phase. Starting from two gyrotrons units during the Integrated Commissioning, applicable for core heating, assisted breakdown and assisted Wall Conditioning, the system capabilities will be progressively extended from the Initial Research phase for wider applications. The development of the full current plasma H mode scenario 2 (inductive, type I ELM, Ip=5.5 MA, BT=2.25 T, q95=3) is among the first scientific objectives of the research program. In preparation of this, predictive modelling of the current ramp-up in scaled versions of scenario 2 is being done, based on parameters previously published. In this scenario the ECRF power is injected from an early phase of the discharge. Such modelling provides the kinetic profiles giving the opportunity to estimate the expected amount of EC stray radiation during the ramp-up phase when the EC power absorption might be less than 100% and consequently the potential risk of damage of the in-vessel components is higher.

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“…The inherent flexibility of JT-60SA enables the exploration of diverse scenarios, including pulsed and inductive standard H-modes resembling the ITER baseline scenario, advanced inductive configurations with high-β and low magnetic shear akin to the ITER hybrid scenario, and fully non-inductive, steady-state advanced scenarios that hold potential for extrapolation to a steady-state demonstration fusion power plant [6,[10][11][12][13]. The NBI actuator plays a critical role in all scenarios, leading to a substantial fraction of fast ions and notable fast ion beta values.…”

Section: Introductionmentioning

confidence: 99%

Predictive modeling of Alfvén eigenmode stability in inductive scenarios in JT-60SA

Coelho,

Vincenzi,

Vallar

et al. 2023

Front. Phys.

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The JT-60SA device offers unique conditions before ITER for the study of the interaction of energetic particles with plasma waves. With similar dimensions to JET, e.g., a major radius but with a slightly more elongated plasma volume, JT-60SA is used as a high-power device where additional heating power (including 10 MW of the 500 keV Neutral Beam Injection) of up to 41 MW and the potential for high non-inductive plasma current operation pave the path for numerous challenges in physics on MHD stability, in particular, when considering the effects of energetic particles. Several operational scenarios with ITER and DEMO-relevant plasma regimes, in terms of non-dimensional plasma parameters, are anticipated. In this work, the stability of Alfvén eigenmodes (AEs) in variants of two of the most relevant operational scenarios with single null is analyzed: a full Ip inductive scenario at high density (1.1 × 1020 m−3 on-axis electron density) and 5.48MA/2.05T toroidal plasma current and magnetic field, and an advanced (hybrid) scenario with an ion energy transport barrier (ITB) and 3.5MA/2.28T toroidal plasma current and magnetic field. The workflow included the CRONOS code to establish the scenario, the ASCOT code to calculate the slowing-down energetic particle distributions for a positive/negative ion source-based neutral beam, and the MISHKA/CASTOR-K suite to calculate the MHD spectra of AEs and the associated drive/damping contributions from the NBI energetic ions, as well as the thermal ion landau damping. The systematic analysis, over a large Fourier space of the toroidal mode number/mode frequency, provides evidence that although a significant fraction of supra-Alfvénic particles stemming from the negative ion source-based neutral beam (500 keV) can, in some cases, drive to AEs in both scenarios, it is not enough to overcome the thermal ion landau damping. In addition, the advanced scenario with ITB is shown to be stable against AEs localized in the vicinity of the barrier as well, offering good prospects of sustainability of the plasma performance and of ITB. Finally, some sensitivity scan results are shown on the influence of fast ion density and q-profile on the AE mode spectra and stability.

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Tokamak discharge simulation coupling free-boundary equilibrium and plasma model with application to JT-60SA

Cited by 6 publications

References 22 publications

Completion of JT-60SA construction and contribution to ITER

Completion of JT-60SA construction and contribution to ITER

ECRF stray radiation studies in preparation of the operations of JT-60SA

Predictive modeling of Alfvén eigenmode stability in inductive scenarios in JT-60SA

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