Chinese scientists hail ‘important step’ towards nuclear fusion from ‘artificial sun’
- Researchers working on the HL-2M reactor in Sichuan say they have generated enough power to meet two key requirements for a working reactor
- The technology could provide a long-term solution to the world’s energy needs by generating power without producing nuclear waste
It generated a plasma current of more than 1 million amperes, or 1 mega-amp, the official Science and Technology Daily reported – a current strong enough to meet some of the key conditions needed to produce a working reactor.
Fusion, the same process that has kept the sun burning for the past 5 billion years, is regarded as the ultimate solution to humanity’s energy needs because, unlike today’s uranium-fuelled nuclear power plants, a fusion reactor would produce no radioactive waste.
Zhong Wulu, the deputy director of the Institute of Fusion Science at the Southwestern Institute of Physics, told the newspaper: “This breakthrough marks an important step towards fusion ignition in China’s nuclear fusion research.”
He said the experimental HL-2M reactor in Chengdu, the capital of Sichuan province, was closer to the threshold needed for a reaction to become self-sustaining – operating without the need for an external power source.
Generating 1 mega-amp of power is also an important step because it meets two key conditions for a working reactor: meeting the required density for the atomic collision that produces the reaction and providing enough time for the reaction to occur.
The third condition needed is having a high enough temperature of at least 100 million degrees Celsius (180 million Fahrenheit).
The HL-2M device has already reached this target, by generating a temperature of 150 million degrees Celsius, 10 times hotter than the sun, for more than 10 seconds.
The experimental reactor is China’s largest advanced tokamak device – a type of reactor that uses a powerful magnetic field to produce reactions – according to China National Nuclear Corporation, which oversees the project.
“The large vacuum container in our tokamak device is filled with gas. We ionise the gas into plasma, then use a strong magnetic field to levitate the charged particles in the vacuum container,” Zhong told Science and Technology Daily.
The device is designed to replicate the way the sun produces energy by fusing two types of hydrogen atoms together in a process that releases an enormous amount of energy.
In theory, hydrogen from seawater could be used, providing a clean energy source from a near-limitless supply.
The challenge in recreating the process on Earth is keeping it under control so that the reactor does not explode.
The hot gas formed by fusing atoms burns or melts everything it touches, while the nuclear reaction generates a large amount of high-speed particles that could damage buildings or human tissue if not properly contained.
China aims to build an industrial prototype fusion reactor by 2035 and bring the technology into large-scale commercial use by 2050.
It has built experimental devices in other parts of the country, including the Experimental Advanced Superconducting Tokamak in the southeastern province of Anhui.
Scientists in other countries are also pursuing the same goal, including the team working on the International Thermonuclear Experimental Reactor in France. When completed, that reactor will run with a current of 15 mega-amps – far stronger than the current produced by existing facilities.