‘Artificial sun’ reaches 100 million degrees Celsius

The Experimental Advanced Superconducting Tokamak (East) is an experimental fusion reactor built at the Institute of Plasma Physics in Hefei, China, on behalf of the Chinese Academy of Sciences. The tokamak is the first such device in the world to use certain types of superconducting magnets and has been built for a fraction of the cost of comparable devices elsewhere in the world.

This device is an advanced version of the Soviet-designed tokamak: a device which applies an extremely powerful magnetic field to confine hot doughnut-shaped plasma (a charged, gaseous state of matter) and prevent it from touching its container. Tokamaks are considered our best hope for the design and construction of nuclear fusion reactors, which - by blasting together particles to form larger particles under astronomical heat and pressure - could release colossal amounts of energy. This is the same process that keeps stars ‘burning’. 

Sustaining nuclear fusion could provide an essentially unlimited source of clean energy, with physicists and engineers having worked towards practical nuclear fusion for decades, using magnetic fields to stabilise hot doughnuts of plasma. However, sustaining such extreme heat and pressure is extremely challenging, causing physicists to often joke that nuclear fusion is “always 50 years away”.

This week, the institute behind the East announced that the device had reached a milestone temperature of 100 million degrees Celsius and heating power of 100Mw. This temperature was sustained for 10 seconds. This is more than six times hotter than the core of the Sun, which sizzles at approximately 15 million degrees Celsius.

This achievement is so significant because 100 million Celsius is the estimated minimum temperature which physicists believe to be necessary to achieve self-sustaining nuclear fusion on Earth.