Scientists from the Chinese Academy of Sciences set a new milestone on Friday in humanity's quest to achieve clean and limitless energy. They managed to get the Experimental Advanced Superconducting Tokamak (EAST) device, designed to replicate the same nuclear fusion process that takes place in the sun, to run at 120 million degrees Celsius for 101 seconds, setting a new record. EAST also achieved a peak temperature of 160 million degrees Celsius for 20 seconds. The experiment was carried out at the Institute of Plasma Physics in Hefei.
Nuclear fusion is one scientific feat that continues to elude humanity. The process results in the production of huge amounts of energy without any wastage and is widely seen as one of the key technologies that could pave the path towards a society fuelled entirely on sustainable energy.
For nuclear fusion to take place, extreme heat and pressure are applied to hydrogen atoms. Under these conditions, nuclei of deuterium and tritium – components of the hydrogen atom – fuse together to produce a helium nucleus, a neutron, and vast amounts of energy that can, potentially, be harnessed. As per some estimates, deuterium from a single litre of seawater can produce energy equivalent to 300 litres of gasoline through a nuclear fusion reaction.
Nuclear fusion, it is worth noting, also differs from nuclear fission which involves splitting the nucleus of a heavy atom into two or more lighter atom nuclei – a process that creates much larger amounts of nuclear waste and is relatively more dangerous.
The overarching purpose of the EAST fusion reactor is to act like an 'artificial sun,' effectively turning into a perpetual source of energy as far as mankind is concerned. Fuel is first heated to temperatures greater than 150 million degrees Celsius such that it forms a plasma 'soup' made up of subatomic particles. A strong magnetic field ensures that this plasma does not come into contact with the walls of the reactor to avoid any loss of energy. For the fusion reaction to take place, plasma must be maintained under these conditions for long periods of time.
To understand what an achievement the Chinese scientists have accomplished, it is worth noting that the core temperature of the sun only reaches around 15 million degrees Celsius, ten times cooler than what EAST reached. The previous record was held by South Korea's KSTAR reactor which, in 2020, reached temperatures of 100 million degrees Celsius, sustaining them for 20 seconds.
Sustaining this temperature like the sun does though is the challenging bit. While the breakthrough at the EAST reactor is certainly significant, scientists believe that we are still decades away from being able to harness the power of the sun, and for nuclear fusion to turn into a viable energy source.
As such, although the technology is extremely alluring and does prompt one to imagine the possibilities of a future where energy is no longer an exhaustible resource, it is not something that we can immediately rely on to solve the growing climate crisis. Ultimately, a focus on proven clean power technologies is what is warranted to realistically materialise a post-carbon society.