Researchers at the Lawrence Livermore National Laboratory in California are close to achieving a key goal in their research into nuclear fusion at the National Ignition Facility.
Nuclear fusion is the process that powers the sun and is capable of giving off vast amounts of energy. In a process called inertial confinement fusion, 192 beams from a laser are aimed at a small capsule containing deuterium and tritium, which are different forms of hydrogen. This process compresses the fuel to 100 times the density of lead and heats it up to 100 million degrees Celsius, which is actually hotter than the centre of the sun but required to start thermonuclear fusion.
In their latest experiment, researchers managed to use this method to produce 1.35 megajoules of energy in 100 trillionths of a second, essentially enough power to boil a kettle. This equates to roughly 70% of the energy that the pellet absorbed from the lasers. The ultimate goal is to reach the ignition point of the pellet where it will provide 100% or more energy than it absorbs. Previous tests in February saw 170 kilojoules produced, meaning the newest energy yield is much higher, giving hope that the ignition point may be achievable.
Reaching that ignition point will be a significant step, as harnessing fusion could provide a limitless and clean energy source as it won't produce long-lived radioactive nuclear waste and will largely emit helium as a by-product, not carbon dioxide. However, there are still significant leaps to be made once the ignition point is reached. For instance, scientists have to figure out how to stabilise the fuel for longer, allowing more of it to burn. It can also become self-sustaining, meaning the fusion reactions themselves provide the heat for more fusion.
Professor Chittenden said: "Turning this concept into a renewable source of electrical energy is likely to be a long process and will involve overcoming substantial technical challenges, such as being able to re-create this experiment several times a second to produce a steady source of power."
The hope is that one day this method of energy production can be commercialised and provide the world with a much-desired sustainable energy source.
