Nuclear fusion has been "20 years away" for the last 50 years, but now, in the difficult struggle to achieve commercial high-yield fusion, the U.S. has a new ally: Thor.
Thor is the name of the new compact pulsed-power accelerator that's being constructed at the Sandia National Laboratories, and it will be able to study materials under extreme temperature and pressure conditions.
"Thor's magnetic field will reach about one million atmospheres, about the pressures at Earth's core," said David Reisman, lead theoretical physicist of the project, in a statement.
Sandia is also home to the Z Machine, the world's most powerful pulsed-power accelerator, which is able to generate a pressure of 5 million atmospheres. The completed Thor won’t be as powerful as it's significantly smaller, 2,000 compared to 10,000 square feet (185 and 930 square meters), but the design improvements make the new accelerator 40 times more efficient.
The Z Machine and Thor both use a technique called Z-pinch: plasma is confined and compressed (the pinch) by a magnetic field induced by an electrical current in the plasma itself. The pinch generates powerful X-rays that are used to study materials. The pinch is also sought because it is one of the possible ways to obtain nuclear fusion of hydrogen atoms.
Thor’s diminutive size has allowed physicists to design a simpler and more compact charging system that reduces energy losses while also allowing a higher degree of system control. Thor can also fire more frequently, which will allow scientists to test their ideas more often. If Thor lives up to expectations, it could significantly influence the design of future Z-pinch nuclear fusion reactors.
Sandia is building Thor in stages, with the first two stages to be completed and operational in 2016. "These are 'first-light' machines that will be used for initial experiments and validation," Reisman said.
Several academic institutions are looking with interest at Thor’s development. "Part of the motivation for Thor was to develop affordable and compact machines that could be operated at universities," Reisman added.
Thor is one of several newly designed machines that will try and tackle the fusion conundrum. It might not solve it, but it’s good to know that Thor might deem us worthy of wielding the power of nuclear fusion.
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