Progress of the JT-60SA project

Abstract

The JT-60SA project was initiated in June 2007 under the framework of the Broader Approach Agreement and Japanese National Fusion Programme for an early realization of fusion energy by conducting supportive and complementary work for the ITER project towards supporting the basis for DEMO. With the project now in an advanced implementation stage, the early defined approach for its implementation has proven to be successful and hence continues to be employed. This is underpinned by the very close collaboration between QST in Japan, F4E in Europe, and all other European stakeholders: the EU Voluntary Contributors and EUROfusion. As of September 2018, the closure of the torus has been accomplished. All TF coils have been manufactured, tested at full current and cryogenic temperature demonstrating a consistent temperature margin, and assembled. All manufacturing of equilibrium field coils was completed by the middle of August 2016. Three central solenoid (CS) modules were completed by March 2017 while manufacturing of the last CS module has recently been completed. The manufacture and delivery of all 26 high temperature superconductor current leads was completed in November 2017. All large power systems, including the switching network units and super conducting magnet power supplies, have also been manufactured, delivered and with few residual commissioning activities still ongoing in Naka. With the cryostat base already in place since 2013, the cryostat vessel body cylindrical section has been manufactured, preassembled, measured and delivered to Naka. The full scope of the cryoplant, manufacturing and commissioning, is now successfully completed. The final assembly phase has therefore started together with the gradual execution of integrated commissioning leading to the completion of the assembly in March 2020 and a first plasma in September 2020. The efficient start-up and scientific exploitation of JT-60SA by the large international team is a challenging enterprise, which will be similar to, and provide important input to, the ITER start-up phase. To optimize this phase, a broad set of coordinated activities have been carried out over recent years by a joint Japanese-EU JT-60SA research unit, fully integrated in the integrated project team and liaising with the broader Japanese and EU fusion physics community. The paper will provide an overview of the progress of the manufacturing and assembly of the JT-60SA machine towards first plasma, and progress in preparing for the next phases of JT-60SA following this milestone.

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

“…The tokamak JT-60SA [10] was chosen as a first application to test the coupled codes. JT-60SA will support the ITER experimental program realizing stable steady-state operations and it will provide key information for the design of DEMO scenarios that should be operated in a higher normalized beta regime.…”

A New Lumped Approach for the Simulation of the Magnetron Injection Gun for MegaWatt-Class EU Gyrotrons

“…In the framework of nuclear fusion research, a worldwide aggressive research program is addressing the main issues concerning the operation of magnetic-confinement devices, i.e., tokamaks [1], such as ITER (International Thermonuclear Experimental Reactor) [2], under construction in France or JT-60SA [3], under commissioning in Japan, and stellarators [4], such the Weldenstein 7X [5], under operation in Germany. For both kinds of configurations, for present and future machines, the plasma inside the vacuum chamber needs to be heated up to temperatures of 100-200 MK, which requires dedicated heating technologies.…”

“…Electron emission and subsequent cooling effect modeled through the Richardson-Dushman equation, which applies only to the zone M4 and isdefined according to Equation (3).…”

Numerical Analysis of the Convective Heat Transfer Coefficient Enhancement of a Pyro-Breaker Utilized in Superconducting Fusion Facilities

“…The current of magnet power supply of CFETR will reach the level of 100 kA [1,2]. In the quench protection system (QPS), a pyro-breaker is used as a backup protection switch to ensure the safety of the superconducting fusion device [3][4][5][6]. As the pyro-breaker is connected in series in the main circuit, the current in the pyro-breaker will reach 100 kA in a steady state.…”