Researchers at Sandia National Laboratories are using a powerful X-ray generator that cooks tiny squares of iron on Earth at sun-hot temperatures to learn what happens to the complex element under the influence of black holes and neutron stars.
The Z-machine (shown above) can generate X-rays similar to those that shoot from neutron stars and black holes, giving scientists at the New Mexico facility a chance to test theoretical models of how neutron stars affect their environment.
Iron is a good test element because it is widespread in the universe and has thousands of spectral lines in its "signature" when zapped by electromagnetic energy.
Physicists don't understand the intensities of those spectral lines when various combinations of iron's 23 (or so -- depending upon its atomic state) electrons are stripped away by the ionizing heat of a neutron star.
Modeling those patterns on Earth will help physicists understand the effects of X-ray pulses from stars on iron in space.
"We're looking with spectroscopic eyes at the atomic physics of ionized iron so that these can be compared with theoretical calculations," project collaborator and physicist Jim Bailey said in a prepared statement.
The experiments involve putting extremely thin squares of iron into the heart of the Z-machine where the metal receives a dose of magnetism that causes high-speed ionic collisions.
This heats the metal to temperatures of more than one million degrees Fahrenheit for a few billionths of a second and gives scientists a chance to take spectral readings that simulate those found in space.
The Sandia researchers succeeded last month at producing highly ionized iron and got an accurate measurement of the radiation produced by the machine, said Mark Foord, a Lawrence Livermore Laboratories physicist collaborating with the Sandia physicists. Sandia and Livermore are Department of Energy facilities.
More experiments will follow in a few months and next summer, he said.
Data from recent tests with the Z machine could help astronomers interpret images from NASA's Chandra X-ray Observatory, currently orbiting Earth and snapping shots in the X-ray segment of the spectrum of powerful energy sources in the universe such as black holes and galactic collisions.
Sandia usually focuses on the end-process of bomb building for the government. With the Z-machine experiments, the methods developed may also bear on weapons physics, Bailey said.
advertisement
