Researchers who brought the nuclear process that brought stars to Earth to meet humanity’s growing electricity needs have broken a key record in the creation of superheated plasma.
The team at the Experimental Advanced Superconducting Tokamak (EAST) – China’s “artificial sun” fusion facility – have said that on December 30, 2021, they were able to generate 120 million degrees Fahrenheit plasma (about 70 million degrees Celsius) and keep it in the atmosphere. 1,056 seconds.
In its 15 years of operation, EAST, operated by the Chinese Academy of Sciences (ASIPP), has achieved both these temperatures and this control time, but never in combination making it an important fusion milestone.
Gong Jianzhu, a researcher at ASIPP, said: “We achieved a plasma temperature of 120 million °C (216 F) for 101 seconds in an experiment in the first half of 2021. This time, steady-state plasma operation was continuous at 70 million °C.” 1,056 seconds at temperatures close to Celsius, laying a solid scientific and experimental foundation towards running a fusion reactor.”
Tokamaks, like the donut-shaped EAST reactor, are often referred to as “artificial Suns” because they are instruments that replicate the fusion processes that occur within stars. These processes provide the energy radiated by these stellar bodies, and researchers here on Earth aim to distribute this energy in a controlled way to power our homes and cities.
Should scientists be successful in bringing this process to Earth, fusion power could provide the world with a safe, sustainable, environmentally responsible and abundant source of energy that is an alternative to fission nuclear power.
The fusion process is almost the opposite of the fission process that powers the current generation of nuclear power plants, in that instead of separating atoms of heavier elements, it forces atoms of lighter elements together to form heavier atoms.
In the super-hot plasma – a gas of ionized atoms – that makes up stars, the intense gravitational pressure forces the hydrogen atoms together at high speed to form helium.
One helium atom does not have as much mass as two hydrogen atoms and this difference in mass is released as energy that is carried away by stars.
To replicate this stellar process, Tokamax must heat heavy hydrogen atoms (deuterium and tritium) with lasers to hundreds of million degrees Fahrenheit, confining this plasma within powerful magnetic fields.
The plasma temperature in tokamaks must be hotter than in stars, where fusion processes occur at about 60 million F. This is because scientists associated with Earth cannot replicate the intense pressure exerted by gravity in the heart of a star.
That means compensating by heating the plasma to about 270 million F, the temperature at which the atomic nuclei in a tokamak will rapidly break together to kick-start nuclear fusion.
Additionally, in order to generate truly usable fusion energy, tokamaks must contain the plasma they generate and maintain it at these temperatures so that the atomic nuclei begin to break together and the process is self-sustaining.
Researchers working at EAST say they are working toward this goal, as are scientists from other tokamaks such as the Korea Institute of Fusion Energy’s Korea Superconducting Tokamak Advanced Research (KSTAR) reactor.
KSTAR set a world record in 2016 by maintaining a super-heated ionic gas of 90 million F for 70 seconds. EAST broke this record the following year by maintaining 90 million F plasma for 102 seconds.
In 2021, EAST topped this record by maintaining plasma at about 216 million F for about 101 seconds. This new development breaks the record for having super-heated plasma by keeping the plasma more than ten times longer, even when at a lower temperature.
Fusion is considered a cleaner process than fusion because it does not create any radioactive waste, the end product of the fusion process being helium. In addition, it consumes fuel that is a light and abundant material such as deuterium, rather than the expensive, rare and dangerous elements such as uranium or plutonium used in fusion plants.
Theoretically, these fuels can be obtained in large quantities from seawater, with some experts estimated that one liter of water is enough to provide enough crude fusion material to produce the energy equivalent to the combustion of 300 liters of oil.