Nuclear fusion reactor now becomes efficient

Nuclear fusion reactor produces more energy than it uses for the first time

Science! By Ryan Whitwam Oct. 9

It’s easy to forget that the sun, so warm and pleasant in the sky, is actually a boiling cauldron of hydrogen and other elements undergoing nuclear fusion. That energy makes life on Earth possible, but we power society by much less efficient means. Scientists have been chasing the dream of nuclear fusion here on Earth for years, and a team at the US National Ignition Facility may be getting close to a breakthrough. For the first time ever, a fusion reactor has produced more energy than it consumed.

Every previous fusion reaction initiated on Earth required more power than was produced, which makes it a poor choice for a power source. The reactor at the National Ignition Facility uses an array of 192 powerful lasers directed at the walls of the sample container, which is called a hohlraum. Inside the hohlraum is a pellet of supercooled hydrogen isotopes in a solid state.

The beams striking the wall of the hohlraum produce x-rays that bombard the sample. This process strips off hydrogen atoms from the pellet and heats them to millions of degrees, causing them to fuse. In the process, a small amount of mass is converted to a lot of energy. It’s the same thing going on in the sun, but the gravitational pressure of the star’s mass is sufficient to keep it burning.

Inefficiencies in all previous fusion systems have prevented all the energy from lasers or other ignition sources from being delivered to the fuel. A fusion reaction capable of actually producing energy could become self-sustaining as long as it is provided with a source of fuel. Simply creating energy with fusion on Earth is a huge step in the right direction. The National Ignition Facility at Lawrence Livermore National Laboratory is also the site of nuclear weapons development, but this advancement is expected to provide a boost to fusion energy research at the facility.

Leave a Reply