The world’s only positive fusion experiment has improved its results. Scientists at the National Ignition Facility (NIF) have set a new record in a laser fusion experiment. The energy output reached 8.6 megajoules, more than double last year’s result and nearly four times more than the first launch in 2022.
Image Credit: Damien Jemison/LLNL/TechCrunch
According to TechCrunch, in the latest tests, the reaction power was first increased to 5.2 MJ, and then to 8.6 MJ. In 2022, the result was 3.15 MJ with 2.05 MJ spent on heating the fuel. However, experts have not yet said anything about practical application. The energy obtained is not enough even to partially return electricity to the grid, since about 300 MJ is required to power the laser system alone.
The NIF facility used a method called inertial compression of fuel (inertial confinement), in which the reaction occurs so quickly that the reaction products do not have time to dissipate. A special tiny capsule with fuel, the size of a pea, was coated with a diamond shell and placed inside a gold cylinder, a golraum. It was then lowered into a vacuum chamber 10 meters in diameter, where 192 lasers were focused on the target. Under the action of the lasers, the walls of the golraum began to evaporate and emit X-rays, which uniformly compressed the fuel capsule, causing compression and the launch of a thermonuclear reaction. In this case, deuterium and tritium nuclei entered into a fusion reaction, forming a helium nucleus and releasing neutrons along with a huge amount of energy.
Interestingly, another approach, magnetic plasma confinement, has not yet achieved a positive energy yield, but work in this direction continues. For example, in France, the largest toroidal magnetic plasma confinement facility (tokamak) is being built for the ITER project. At the same time, startups such as Xcimer Energy and Focused Energy are focusing on inertial confinement. All this research is bringing the world closer to an energy source with minimal environmental impact and virtually inexhaustible fuel.