Sener participates in the recently inaugurated JT-60SA, the world’s largest experimental nuclear fusion reactor

At a recent ceremony, the European Commissioner for Energy, Kadri Simson, together with Japan’s Minister for Educaton, Culture, Sports, Science and Technology, Masahito Moriyama, and Japan’s Minister of State for Science and Technology Policy, Sanae Takaichi, were joined by senior politicians, representatives from industry, and the research community, to inaugurate the JT-60SA facility, a result from the Broader Approach Agreement between the European Union and Japan.

JT-60SA is the world’s largest experimental device for the study of thermonuclear reaction in a fully ionised hydrogen/deuterium plasma confined in a Tokamak configuration. Works for the device started in 2007 and were completed in 2020 with the end of assembly. Since then, a series of technical improvements were carried out, with first plasma operations towards the end of 2023. The overall cost of the project for the phase of construction, is estimated to be in the range of 560 million EUR in today’s values, shared between Europe and Japan. The project is considered a fine example of science diplomacy and has been praised for the spirit of collaboration, its efficient management, and exemplary execution.

Sener was contracted by Fusion for Energy (F4E) for the design, construction, validation, and delivery of the pellet centrifuge accelerator for JT-60SA. The project is being developed with support from Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT). This collaboration leverages the valuable expertise of the Max Planck Institute for Plasma Physics in the creation of previous generations of centrifuges in order to modernize and advance the concept towards a tool with multi-actuation capabilities.

The JT-60SA pellet Launching System (PLS) serves the purpose of delivering various hydrogen pellets – mm-sized solid bodies – to the plasma. This system creates hydrogen pellets and accelerate them up to 600 m/s and it is composed by a set of hydrogen extruders and a centrifuge accelerator. This is a 5-meters vacuum system designed to receive pellets from up to three different sources at a total rate up to 80 Hz and accelerate them to achieve speeds between 100 and 600 m/s using a centrifugal arm rotating at a frequency of 20 to 120 Hz. Since it is designated for varying tasks, arriving pellets will be different in size and potentially as well in their consistence.

The centrifuge accelerator has been designed to withstand 132 Gy, which has challenged the selection of the electronic critical components and sensors. The rotating arm and its driving mechanisms, which is one of the central parts of the centrifuge has been designed to maintain rotational accuracies of less than 1% with extremely low vibrations.

To facilitate monitoring of the acceleration process, the system is equipped with three high speed imaging diagnostic systems (20,000 fps cameras with pulsed laser flashes at 100,000 Hz) distributed along the pellet path. These have been designed to capture pellets at their maximum speed of 600 m/s, without trigger.