• The Central Solenoid, a crucial component of the ITER fusion reactor, has been completed and is being installed in France.
• The solenoid is a powerful superconducting magnet system designed to contain superheated plasma for nuclear fusion, potentially generating 500 MW of energy from 50 MW input.
• ITER, a collaboration of 35 countries, aims to demonstrate nuclear fusion as a viable and sustainable energy source, though challenges regarding costs and timelines exist.

The International Thermonuclear Experimental Reactor (ITER) is making progress in its ambitious attempt to harness nuclear fusion, the energy source of the sun. A key component, the Central Solenoid, a powerful superconducting magnet system, has been completed and is being installed in Saint-Paul-lez-Durance, France. This magnet, designed and built in the United States, will serve as the "magnetic heart" of the reactor, containing superheated plasma at temperatures ten times hotter than the sun's core. ITER is a collaborative effort involving 35 countries, aiming to prove that fusion energy can be a commercially viable and essentially limitless power source.

• What: The completion and installation of the Central Solenoid, a powerful superconducting magnet system that will serve as the "magnetic heart" of the ITER fusion reactor.
• Who: ITER (International Thermonuclear Experimental Reactor), a collaboration involving 35 countries including the US, Europe, China, Russia, Korea, Japan, and India. Key personnel include Pietro Barabaschi, ITER’s Director-General, and David Vandergriff, an engineer at Oak Ridge National Laboratory.
• When: The Central Solenoid was completed and is being installed as of May 2025. ITER aims to achieve its goals in the coming years.
• Where: Saint-Paul-lez-Durance, southern France, where the ITER reactor is being assembled.

The completion of the Central Solenoid represents a significant milestone for ITER and the pursuit of nuclear fusion as a viable energy source. ITER's success could revolutionize energy production, providing a clean and virtually limitless alternative to fossil fuels. However, the project faces challenges including escalating costs and technological hurdles. While private companies are also pursuing fusion energy, ITER remains a crucial large-scale experiment. The project's international collaboration also underscores the potential for scientific cooperation despite geopolitical tensions.

"With ITER, we show that a sustainable energy future and a peaceful path forward are possible."

"The key isn’t just the magnet—it’s its skeleton."

The ITER project, now featuring its completed Central Solenoid, is steadily advancing the demonstration of nuclear fusion's viability. Despite existing delays and technical challenges, international partners remain committed, and the project continues to evolve, improving processes and solving technical problems. The potential of fusion energy to revolutionize the energy sector is immense, promising a sustainable, abundant, and secure energy source for millennia to come. Fusion offers significant advantages, including no carbon emissions, reduced long-lived radioactive waste compared to nuclear fission, and inherent safety features that prevent Fukushima-type accidents. As ITER progresses, its results will significantly impact nuclear physics research, offering a pathway to energy independence and a cleaner, more sustainable future. The ongoing assembly and future operation of ITER represent a critical step in mastering the power of the stars and realizing a new era of energy production, one that could positively contribute to resource availability, reduced carbon emissions, and the challenges of fission waste disposal.