(PhysOrg.com) -- The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California has set a new record for a laser shot. This past week, its combined 192 lasers fired a single 1.875-megajoule shot into an empty test chamber. After passing through the last of its focusing lens, the shot reached 2.03 megajoules, making it the first 2 megajoule ultraviolet laser.
Prior to this achievement, the most the facility had managed to coax out of the laser, the world’s largest, was 1.6 megajoules. Also, the new record shows that the NIF laser is capable of producing more than it was designed for, which was 1.8 megajoules. It also proved that it was capable of doing so without damaging its parts, allowing for another shot a day and a half later, which is important, because one of the goals for the laser is to get it to fire off shots at 15 per second eventually. That’s what researchers think will be needed to produce power economically from the laser system.
The ultimate goal of the NIF is to figure out a way to use a laser to produce nuclear fusion in a way that gets more energy out than is put in. Currently, that goal is still a ways off. Thus far, engineers at the project haven't even reached the break-even or ignition point, though they expect that to occur sometime this year. Tweaking the laser to produce more than it was designed for is a step in that direction. The NIF facility was designed to produce a fusion reaction by imploding hydrogen isotope pellets using the huge laser. To that end, the team has made steady progress. When the project first began eighteen months ago, it had just one percent of conditions in place that are believed necessary to achieve the ignition point. They have improved that mark to ten percent and it’s because the pace has picked up dramatically in recent months that they believe they will achieve the ignition point sometime over the next six months, which is when the original ignition campaign was slated to end.
Because the facility is funded by the US nuclear weapons complex, there has been debate about whether it would ever be used to prove or disprove the idea that lasers could be used to create nuclear fusion to produce electric power. Having the laser break records doesn’t really resolve that argument in the short term, but it might in the long run if it does eventually show that electricity could be created economically using such a process.
More information: The National Ignition Facility (NIF): https://lasers.llnl.gov/