Studies of hot electron production and its behavior

Thesis--University of Tsukuba, D.Sc.(B), no. 264, 1985. 7. 3

Disruption simulations for JT-60SA design and construction

Disruption simulations with DINA code are performed for JT-60SA design. The simulation results have been applied for the design of many components, not only for the vacuum vessel and in-vessel components, but also for peripheral components. For instance, for the design of in-vessel coils, stabilizing plate and magnetic sensors, EM force induced by halo current and eddy current at disruption were calculated. For design of poloidal field (PF) coils, the power supply of PF coils and refrigerator system for super conducting coils, eddy current of PF coils and AC loss of superconducting coils were evaluated

Completion of Tokamak Assembly and the Status of Integrated Commissioning for JT-60SA

日欧の幅広いアプローチ活動で建設を進めたJT-60SA装置は、各機器の技術仕様、組立精度を満たした上で2020年の3月に完成した。本発表では、組立技術開発・組立結果・統合コミッショニングの進展について報告する。4th Asia Pacific Conference on Plasma Physic

Design and manufacturing of thermal shield for JT-60SA

The thermal shield (TS) of JT-60SA which is a superconducting tokamak, is installed to reduce radiation heat load from a vacuum vessel (VV), a cryostat vessel and ports at ambient temperature to superconducting coils at 4 K. The TS is double walled structure with He cooling pipe at 80 K, and is divided electrically in toroidal direction and poloidal direction to suppress eddy currents flowing through the TS during disruption. The TS is required to be installed in a narrow space which is between the VV, the ports, and the superconducting coils. Manufacturing and assembly accuracy of the TS are required to ensure the sufficient space for the relative displacement caused by thermal displacement and seismic load. Customization of mechanical joints in the divided section of the TS is effective process for keeping the required accuracy. Assembly of 340 ° sector of the vacuum vessel thermal shield has been completed

Status of the JT-60SA project: An overview on fabrication, assembly and future exploitation

JT-60SA is a superconducting tokamak developed under the Satellite Tokamak Programme of the BroaderApproach Agreement between EU and Japan, and the Japanese national programme. It is designed tooperate in the break-even conditions for long pulse duration (typically 100 s), with a maximum plasmacurrent of 5.5 MA. Its scientific aim is to contribute at early realization of fusion energy, in support tothe ITER project and also to future DEMO devices by addressing key engineering and physical issues foradvanced plasma operation.The JT-60SA Project has shown steady progress in the last years: from the design of the main compo-nents, started in 2007 in a close collaboration between EU and Japan, continuing through the assembly inthe torus hall, started in January 2013 with the delivery of the first large European component, the Cryo-stat Base. Since then big milestones have been achieved, like the complete winding and pre-installationof the three lower Equilibrium Field (EF) coils, the welding of a 340◦of the Vacuum Vessel sectors, andthe completion of most of the Toroidal Field (TF) Coils.Outside the tokamak hall, large auxiliary plant like the Cryogenic System (CS) and the Quench ProtectionCircuits (QPC) have been fully installed and commissioned, while the Switching Network Units (SNU) andTF and EF coils Power Supplies (SCMPS) are completing installation on site. Other components such asCryostat Vessel, Thermal Shields, In Vessel Components and so forth are being manufactured and beingdelivered to Naka site for installation and commissioning.This paper gives technical progress on fabrication, installation and assembly of tokamak componentsand ancillary systems, as well as progress of JT-60SA Research Plan being developed jointly by EU andJapanese fusion communities

Manufacturing of the JT-60SA cryostat vessel body cylindrical section

tThe JT-60SA cryostat is a large vacuum vessel made up of 304 stainless steel which encloses the tokamakproviding the vacuum environment to reduce thermal loads on the components at cryogenic temper-ature. It must withstand the external atmospheric pressure during normal operation and the internaloverpressure in case of an accident. Due to functional purposes, the cryostat has been divided in threelarge assemblies: the Cryostat Base (CB), the Cryostat Vessel Body Cylindrical Section (CVBCS) and theTop Lid. The CB was manufactured in Spain and assembled in-situ in 2013, while the CVBC is currentlyunder manufacturing also by a Spanish company and it is expected to be delivered in Naka next year2017. This paper gives an overview of the manufacturing process and present status of the CVBCS. Themanufacturing includes the assembly and testing at the manufacturer workshop as well as the packagingof the component. The reference code being used for the manufacturing is ASME 2007 Section VIII Div.2