Last spring, physics writer Andrew Grant reported on the lack of progress by the main U.S. nuclear fusion effort (“Ignition failed,” SN: 4/20/13, p. 26). As the researchers still contend, laser-initiated fusion should work. It works on paper. But in practice, even a set of extremely powerful lasers failed to trigger the fusion of hydrogen nuclei and the concomitant chain reaction and release of net energy expected.
In February, the National Ignition Facility scientists at Lawrence Livermore National Laboratory in California reported a small, if important, breakthrough, as Grant writes in "Step taken toward ignition." By using a different pattern of laser pulses, scientists were able to cajole some hydrogen atoms to fuse, resulting in more than 5,000 trillion fusion reactions before the effect