Sandia experiment improves nuclear security

  • Published
  • By Ryan Stark
  • Nucleus writer
KIRTLAND AIR FORCE BASE, N.M. --  A team based at Sandia National Laboratories at Kirtland reported encouraging results from recent fusion experiments.

The experiments allow scientists to gather data about nuclear detonations without having to stage actual test detonations.

In a recently published academic paper -- titled "Experimental Demonstration of Fusion-Relevant Conditions in Magnetized Linear Internal Fusion" by Matt Gomez, Steve Slutz and Adam Sefkow -- experiments with Sandia's "Z machine" have yielded a new approach for generating neutrons. The project is called Magnetized Linear Internal Fusion, or MagLIF.

The Z machine is a device that uses powerful magnetic fields to produce high temperatures, high pressures and powerful X-rays for research.

Under those highly energetic conditions, researchers introduce a fuel source -- in this case deuterium, which is hydrogen with an extra neutron. The material is heated with a laser and, using a magnetic field, squeezed and contained using magnetic fields.

As complicated as that process sounds, the resultant data is important to Sandia, the Air Force and others interested in safeguarding American nuclear weapons. Supercomputers are used to crunch information about subatomic particles released during the experiments, and those test results replace the need to do actual detonations.

Daniel Sinars, senior manager of Sandia's Radiation and Fusion Physics Division, said as technology changes and weapons are updated, they must be reassessed to safeguard against accidental detonation or other issues. That's where the MagLIF data comes in, he said.

"We just want to make (the weapons) better," he said. "Yet when we make changes, we are unable to test the weapon in order to ensure we didn't cause a problem. Over the years, one might worry that an accumulation of small changes may result in something that no longer works when you need it to."

Sandia, the University of Rochester in New York and the Lawrence Livermore National Laboratories in California are the three sites where this type of nuclear arsenal assurance work is taking place.

There could be more applications for the MagLIF process down the road, such as power generation. But Sandia officials caution that the power generation "technique is a toddler," and that many design specifics are still being worked on.

For power generation to work, officials say, a different kind of fuel will have to be used. It would need to yield 1,000 times more neutrons than deuterium to reach what is called the "break-even" point for power output, according to officials.