The Device

JT-60SA is an experimental device based on the tokamak concept, in which a hot gas is confined in a torus-shaped vessel using a magnetic field. The gas will be heated to over 100 million degrees, typically for 100 seconds every hour.

In JT-60SA the plasma fuel will be hydrogen or deuterium. Deuterium mimics well the behaviour of a reacting deuterium-tritium plasma in a real power reactor or ITER, without generating large amounts of heat or neutrons. The reaction produces some neutrons directly, plus reactions with tritium, a by-product of one branch of the DD reaction. JT-60SA thus slowly can become radioactive in use, and remote handling of systems near the plasma must be planned.


Based on the objectives of JT-60SA, a conceptual design for the device was prepared in 2005, describing the components and operating parameters. This was improved in 2008, and an Integrated Design Report was produced at the end of 2008 that was then used as the basis for procurement, allowing detailed specifications to be subsequently developed by the EU and JA Home Teams prior to procurement.


JT-60SA is financed jointly by Europe and Japan, with equal contributions under the Broader Approach agreement. Read more >>


The research plan during operation has been established in collaboration between Japanese and European scientists. Read more >>


The JT-60SA design was updated at the end of 2008 and reported in the Integrated Design Report. Read more >>

Main Features

The JT-60SA tokamak consists of the magnets and vacuum vessel. The vessel houses components dedicated to vessel protection, plasma impurity control, plasma position control and fuelling, vacuum pumping and cooling. Diagnostics and heating systems utilise the vessel ports. A cryostat and thermal shield surround the tokamak and protect the superconducting magnets operating at ~4K from heat inleak from the environment and hotter structures. Services are provided for water coolingcryogenicspower supplies, the control system, as well as heating, ventilation and air conditioning of the building. The JT-60SA tokamak is located in the building previously occupied by the JT-60U tokamak, which involved disassembly and recommissioning of some equipment before assembly of the JT-60SA tokamak. Additional safety features have also been added.