CHINA is on course to finish building an “artificial sun” before the end of the year, local media reports. The incredible structure will be capable of reaching 100million degrees Celcius – six times hotter than the centre of our Sun.
Scientists hope that the “artificial sun” will help harness the power of nuclear fusion. This would bring humanity a step closer to creating “unlimited clean energy”, by mimicking reactions that naturally occur inside the Sun proper.
The “artificial sun” was first announced by Chinese researchers last November, but the project has just hit an important milestone. Chinese media reports that early trials have allowed researchers to create stunningly high temperatures.
Researchers are using a device called a “tokamak”, which uses a powerful magnetic field to trap hot plasma. Our Sun hits temperatures of around 15million degrees Celcius at its core. But the plasma from China’s artificial sun has reached an electron temperature of 100million degrees Celcius – and an ion temperature of 50million degrees Celcius.
Ions are what “generate energy in the device”, Duan Xuru, an official at the China National Nuclear Corporation, told Science and Technology Daily, the official newspaper of China’s Ministry of Science and Technology. So the plan is to now bring the ion temperature up to 100million degrees too. Ion temperature is usually lower than electron temperature, so this may be difficult.
The device, Duan said, needs to be tweaked to hit the goal. As well as high pressure, nuclear fusion requires extremely high temperatures – which the artificial sun could provide.
Nuclear Fusion – what is it?
Here’s what you need to know…
- Nuclear fusion is a process where two light nuclei (parts of an atom) are used to create a single “heavy” nucleus
- This “nuclear reaction” releases huge amounts of energy
- That’s because the “heavy” nucleus is not as heavy as the mass of the two “light” nuclei combined
- This “lost mass” can then be changed into huge amounts of energy
- Fusion is a common occurrence inside stars, like the Sun at the centre of our own galaxy
- This is how the Sun is able to provide so much heat and light
- But kickstarting a nuclear fusion reaction on Earth is difficult
- The goal is to start a nuclear reaction that releases more energy that you needed to start the reaction
- The problem is that both nuclei have positive charges, and repel each other
- To stop this, you need to make them hit each other at very high speeds – requiring high pressure and temperature
- If scientists can develop a low-energy way of making this happen, they could generate enormous (and potentially “unlimited”) amounts of clean energy
If successful, China will be able to provide a major helping hand to ITER, the International Thermonuclear Experimental Reactor. It’s a major project involving scientists from 35 countries that aims to “new energy” sources using nuclear fusion. If nuclear fusion can be harnessed using a low-energy method, it could allow for the creation of “unlimited” clean energy.