 The interior of the NIF target chamber . The service module carrying technicians can be seen on the left. The target positioner, which holds the target, is on the right. Credit: NIF |
One month ago today, the National Ignition Facility sent the first 192-beam laser shot to the center of its target chamber. The first test of the world’s biggest—and by up to 100 times the most energetic—laser system achieved 420 J of ultraviolet energy (or about 3ω) for each beam. Added up, the shot cycle produced 80 kJ of energy without incident.
The editors of
R&D Magazine had the honor of presenting an R&D 100 Award last year to the scientists and engineers behind the computation-intensive alignment system that allows the NIF to achieve such high power levels. Developed at Lawrence Livermore National Laboratory, the
Autonomous Alignment Process for Laser Fusion Systems (AAPLF) autonomously directs and aligns all 192 NIF laser beams. The system uses process leveling to distribute the system’s demanding computational load evenly among computer clusters. AAPLF completes the alignment process for the entire NIF laser system of 35,000 devices in just 15 minutes. Designed for scalability, the architecture can be adapted to future systems of other sizes.
 The target positioner and target alignment system precisely locate a target in the NIF target chamber. The target is positioned with an accuracy of less than the thickness of a human hair. Credit: NIF |
The final optics module at NIF was successfully installed on Feb. 4. The final piece of the puzzle before NIF begins its groundbreaking fusion R&D is final certification by the U.S. Dept. of Energy, which should arrive by March 31. After that, the NIF will enter uncharted waters: in as little as two years as officials expect to create controlled nuclear fusion reactions.
Kevin Bullis wrote about the NIF’s milestone and its mission in today’s
MIT Technology Review. An excerpt of the story and further links are below.
–Paul B. LivingstoneThe world's biggest laser powers up
By Kevin Bullis  This artist's rendering shows a NIF target pellet inside a hohlraum capsule with laser beams entering through openings on either end. The beams compress and heat the target to the necessary conditions for nuclear fusion to occur. Ignition experiments on NIF will be the culmination of more than 30 years of inertial confinement fusion research and development, opening the door to exploration of previously inaccessible physical regimes. Credit: NIF |
The most energetic laser system in the world, designed to produce nuclear fusion—the same reaction that powers the sun—is up and running. Within two to three years, scientists expect to be creating fusion reactions that release more energy than it takes to produce them. If they're successful, it will be the first time this has been done in a controlled way—in a lab rather than a nuclear bomb, that is—and could eventually lead to fusion power plants.
The
National Ignition Facility (NIF), at the U.S. Department of Energy's Lawrence Livermore National Laboratory (LLNL), comprises 192 lasers that fire simultaneously at precisely the same point in space: a sphere of fuel two millimeters in diameter. They are designed to deliver 1.8 mJ of energy in a few billionths of a second. That's enough to compress the fuel to a speck 50 μm across and heat it up to three million degrees Celsius. The lasers, which were fired together for the first time last month, have so far produced pulses of 1.1 mJ.
 The 10-m-dia target chamber, installed in June 1999, weighs 287,000 pounds. The spherical vacuum vessel was assembled from 18 four-inch-thick aluminum sections fabricated by Pitt-Des Moines, Inc., of Pittsburgh, Pennsylvania, and was installed with one of the largest cranes in the world. Credit: NIF |
"Depending on how you count it, it's between 60 and 100 times more energetic than any laser system that's ever been built," says
Edward Moses, the principle associate director for NIF and Photon Science at LLNL. Eventually, the fusion reactions produced by each pulse are expected to generate at least 10 times the energy delivered by the lasers, a significant net gain that could be useful for generating power.
The $3.5 billion facility, which has been in development for 15 years, was funded primarily as a way to better understand nuclear weapons, after a ban on testing in the 1990s. NIF will produce tiny thermonuclear explosions that give scientists insight into what happens when a nuclear bomb goes off. That data can, in turn, be used to verify computer simulations that help determine whether the United States' nuclear stockpile will continue to work as the weapons age. The data could also provide insight into the processes that power the sun and other stars, and answer other scientific questions. Finally, NIF could serve as a proof-of-concept design for a fusion power plant.
Read the rest of Kevin Bullis' storyNational Ignition FacilityFull details on the NIFWebcast of PBS report on NIFGood Forbes article about NIFAdditional NIF photos at FlickrSOURCE: MIT Technology Review; R&D Magazine
