The world’s only pure positive fusion experiment has steadily increased the amount of power it produces, TechCrunch learned.
In a recent attempt, the team at the U.S. Department of Energy’s National Ignition Facility (NIF) first became 5.2 megajoules, then 8.6 megajoules, and once again increased to 8.6 megajoules, according to sources with knowledge of the experiment.
The new result is a significant improvement over the 2022 historical experiment, which was the first controlled fusion reaction to generate more energy than it consumed.
The 2022 shot produced 3.15 megajoules. This is a small bump on top of 2.05 megajoules that the laser fed into the BB-sized fuel pellets.
None of the previous shots have been as effective as bringing electrons back into the grid, let alone offset the energy needed to power the entire facility. The facility is not designed to do that. For example, the first net positive shot required 300 megajoules to power the laser system only. However, they are ongoing evidence that controlled fusion is more than hypothetical.
NIF uses what is known as inertial confinement to generate fusion reactions. At the facility, the fused fuel is coated with diamonds and wrapped in a small gold cylinder called Hohlraum. The small pellet is dropped into a spherical vacuum chamber 10 meters in diameter, with 192 powerful laser beams converging on the target.
The cylinder evaporates under the onslaught and emits X-rays in the process of bombing the fuel pellets inside. The diamond coating on the pellet receives so much energy that it transforms into a magnifying plasma. This compresses the deuterium fuel within the nucleus into which the nucleus is fused, and in the process it releases energy.
Another main approach to fusion, magnetic confinement, uses a powerful superconducting magnet to compress and contain the plasma into a tight space sufficient to create the conditions required for fusion. Magnetic confinement experiments have not produced net positive results, but some have been constructed or designed with the hopes of hitting that milestone.
Several startups are pursuing inertial confinement, including Xcimer energy and concentrated energy.