The assembly comprises two coils: a toroidal-field magnet that acts as a magnetic cage, and a central solenoid that serves as the igniter.

The results, achieved by researchers with the Institute of Plasma Physics, Chinese Academy of Sciences, clear a major engineering hurdle on the path to confining a plasma hotter than the sun’s core, state news agency Xinhua reported on Saturday.

The project – the Comprehensive Research Facility for Fusion Technology – aims to create a miniature sun at over 100 million degrees Celsius (over 180 million Fahrenheit) and trap it inside a doughnut-shaped metal cage to generate electricity.

The magnetic cage, known as the CRAFT toroidal field coil, is a core component of the reactor.

It uses a strong magnetic field to prevent the container of the miniature sun from melting as the plasma inside reaches hundreds of millions of degrees.