Scientists generate strongest-ever controllable magnetic field bringing us closer to nuclear fusion

Physicists from the University of Tokyo claim to have generated the strongest controllable magnetic field ever produced and sustained it for longer than any previous field of a similar strength. This research could lead to powerful investigative tools for material scientists and may have applications in fusion power generation.

Fusion power is thought to be the most promising way to provide clean energy for future generations. “One way to produce fusion power is to confine plasma – a sea of charged particles – in a large ring called a tokamak in order to extract energy from it,” explained Professor Shojiro Takeyama. “This requires a strong magnetic field in the order of thousands of teslas for a duration of several microseconds. This is tantalisingly similar to what our device can produce.”

At 1200 teslas, Prof Takeyama’s field dwarfs almost any artificial magnetic field ever recorded; however, it’s not the strongest overall. In 2001, physicists in Russia produced a field of 2800 teslas, but their method blew up their equipment and the uncontrollable field could not be tamed. Lasers can also create powerful magnetic fields, but in experiments they only last a matter of nanoseconds.

The magnetic field created by Takeyama’s team lasted thousands of times longer, around 100 microseconds. It's possible to create longer-lasting fields, but these are only in the region of hundreds of teslas.

“With magnetic fields above 1000 Teslas, you open up some interesting possibilities,” prof Takeyama added that as well as helping with fusion power generation research. “You can observe the motion of electrons outside the material environments they are normally within. So we can study them in a whole new light and explore new kinds of electronic devices.”