Ditmire described the experiment on March 23 to a crowded session at the Centennial Meeting of the American Physical Society in Atlanta. The new fusion scheme is no energy panacea, researchers insist. The laser dumps about 10 million times more energy into the plasma than the neutrons carry back out. The lost energy goes into heating ions and electrons and producing photons that make the plasma glow. For a fusion reactor to produce an energy gain, it must confine its fuel long enough, usually no less than a few nanoseconds, to ignite a self-sustaining thermonuclear burn.
Fusion energy powers the sun, the stars, and thermonuclear bombs.
Scientists have labored since the 1950s to tame fusion reactions for commercial power, but practical reactors remain decades away, at best. Expected to be the world's largest laser, it will hurl a mighty bolt of nearly 2 million joules of energy at a fuel capsule. By contrast, the tabletop fusion laser puts out just a tenth of a joule. Ditmire says, however, that his team's technique will permit new types of laser fusion experiments and may lead to compact neutron sources for studying materials. Ditmire, T., et al .