Skip to main content

For Once, Beryllium Outshines Diamond

Researchers from Sandia National Laboratories used the speed of sound to determine the shock melting pressure of diamond – and found it to be remarkably high. Not exactly the result researchers hoping to use diamond in inertial confinement fusion (ICF) fuel capsules were hoping to hear.

ICF is a technique that uses high-powered lasers to detonate the outer layer (called the ablator) of a small fuel capsule. This creates an inward-traveling shock wave that raises the temperature and pressure at the center of the capsule to fusion-igniting levels.

The ablator must be made of a material that can absorb the x-ray energy emitted in ICF but that also has a low atomic mass. Diamond and beryllium have been identified as prime candidates for use. Although diamond is attractive from a manufacturing and fabrication point of view, this research shows that it’s probably not the right choice for ICF applications.

The experiment showed that shock waves stronger than 10 million times atmospheric pressure are needed to completely melt diamond. Beryllium, however, needs less than 3 million times. In addition, diamond is a solid-liquid mix over a much larger range of pressures than beryllium is, placing further constraints on the design of ICF capsules made with diamond.

The researchers determined the pressure needed to melt diamond by hitting samples with aluminum/copper plates traveling at up to 54,000 mph. This created shock waves that caused a pressure wave to travel through the diamond at the speed of sound. The speed of sound is highly dependent on the phase of the diamond, so researchers were able to measure the pressures where melting started and was completed.

Recent advances in laser power and efficiency make ICF an attractive candidate for alternative energy sources. In addition, it has promising applications in defense and fundamental physics research.

You can read more about this research in the press release for the group's upcoming talk at the American Physical Society's Meeting of the Division of Plasma Physics.


  1. Though I don't understand this technology, its interesting to get back to chemistry and physics which I last did at school.
    Now my question here is:
    When you say ICF can be used as an alternatve energy source, how exactly do you mean it can be used.

  2. The basic idea is to build ICF power plants where the energy (heat and radiation) from the fusion is used to drive a conventional steam turbine. There is a pretty good explanation of this at
    (see the "How to build an IFE power plant).

  3. mooooooo oooooo ooooo


Post a Comment

Popular Posts

How 4,000 Physicists Gave a Vegas Casino its Worst Week Ever

What happens when several thousand distinguished physicists, researchers, and students descend on the nation’s gambling capital for a conference? The answer is "a bad week for the casino"—but you'd never guess why.

Ask a Physicist: Phone Flash Sharpie Shock!

Lexie and Xavier, from Orlando, FL want to know: "What's going on in this video ? Our science teacher claims that the pain comes from a small electrical shock, but we believe that this is due to the absorption of light. Please help us resolve this dispute!"

The Science of Ice Cream: Part One

Even though it's been a warm couple of months already, it's officially summer. A delicious, science-filled way to beat the heat? Making homemade ice cream. (We've since updated this article to include the science behind vegan ice cream. To learn more about ice cream science, check out The Science of Ice Cream, Redux ) Image Credit: St0rmz via Flickr Over at Physics@Home there's an easy recipe for homemade ice cream. But what kind of milk should you use to make ice cream? And do you really need to chill the ice cream base before making it? Why do ice cream recipes always call for salt on ice?