Laser fusion is a process of using lasers to heat and compress a small pellet of fuel, typically hydrogen, until the atoms fuse together. The resulting energy release can be harnessed to generate electricity or propel spacecraft. Laser fusion has been touted as a “clean” energy source because it does not produce greenhouse gases or long-lived radioactive waste.
The first successful laser fusion experiment was conducted in 1974 at the Lawrence Livermore National Laboratory (LLNL) in California. A team of scientists led by Edward Teller, the “father” of the hydrogen bomb, used the world’s most powerful laser at the time to heat and compress a tiny target less than one millimeter in diameter. The target was vaporized by the intense laser light, and the resulting shock wave compressed the fuel so that atoms could fuse together. This process released a large amount of energy—equivalent to that produced by detonating several tons of TNT—and created a miniscule amount of high-energy radiation.
In subsequent years, LLNL researchers refined their technique and were able to increase the efficiency of energy production from laser fusion reactions. In 1991, they set a record by generating more than twice as much energy as had been input into their system—a significant milestone known as “ignition.” In 1993, LLNL announced plans to build an experimental facility called National Ignition Facility (NIF), which would use 192 beams from giant lasers to achieve practical ignition for power generation on Earth. Construction on NIF began in 1997 and was completed in 2009 at a cost of approximately $3 billion.
Today, NIF is operational and continues to push the boundaries of what is possible with laser fusion technology. In recent years, researchers have made significant progress towards achieving self-sustaining nuclear fusion reactions—known as “burning plasmas”—in which more energy is generated than is required to maintain the reaction. This goal remains elusive, but scientists are hopeful that it may be achievable within the next few decades with continued research and development efforts.