There were 1,668 press releases posted in the last 24 hours and 442,767 in the last 365 days.

Graphite enters different states of matter

Anne M Stark, LLNL, (925) 422-9799, stark8@llnl.gov



Demonstration of ultrafast disintegration of matter by 2 keV LCLS pulses: The team combined techniques commonly used in solid state physics (Bragg reflection) with techniques from plasma physics (spectroscopy of diffusely-scattered light) to characterize ultrafast heating in graphite.

For the first time, scientists have seen an X-ray-irradiated mineral go to two different states of matter in about 40 femtoseconds (a femtosecond is one quadrillionth of a second).

Using the Linac Coherent Light Source (LCLS) X-ray Free-Electron Laser (XFEL) at SLAC National Accelerator Laboratory at Stanford, Stefan Hau-Riege of Lawrence Livermore National Laboratory and colleagues heated graphite to induce a transition from solid to liquid and to warm-dense plasma.

Ultrafast phase transitions from solid to liquid and plasma states are important in the development of new material-synthesis techniques, in ultrafast imaging, and high-energy density science.

By using different pulse lengths and calculating different spectra, the team was able to extract the time dependence of plasma parameters, such as electron and ion temperatures and ionization states.

"We found that the heating and disintegration of the ion lattice occurs much faster than anticipated," Hau-Riege said.

The research provides new insights into the behavior of matter irradiated by intense hard X-rays. Though the study ultimately serves as a breakthrough in plasma physics and ultrafast materials science, it also affects other fields such as single molecule biological imaging and X-ray optics.

For single-molecule bioimaging, the team found that in certain cases it may be substantially more difficult than anticipated because energy transfer is surprisingly fast. In X-ray optics, they found that the damage threshold is lower than anticipated.

This is the first XFEL high-energy density science experiment that used inelastic X-ray scattering as a plasma diagnostic.

The research appears in the May 15 edition Physical Review Letters.

Other Livermore researchers include Alexander Graf, Tilo DÃ'¶ppner, Rich London, Carsten Formann, Siegfried Glenzer, Matthias Frank and John Bradley.

In addition to SLAC National Accelerator Laboratory, participating institutions include Universitat Duisburg-Essen; Max Planck Advanced Study Group, Center for Free Electron Laser Science; Max Planck Institut fur medizinische Forschung; and Max Planck Institut fur Kernphysik, all of Germany.


More Information

SLAC Linac Coherent Light Source

"Scientists create new atomic X-ray laser," LLNL news release, Jan. 26, 2012

"Highest X-ray energy used to probe materials," LLNL news release, July 22, 2010

"Groundbreaking Science with the World's Brightest X-rays," Science & Technology Review, January/February 2011

"An Extraordinarily Bright Idea," Science & Technology Review, December 2003





Founded in 1952, Lawrence Livermore National Laboratory provides solutions to our nation's most important national security challenges through innovative science, engineering and technology. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Legal Disclaimer:

EIN Presswire provides this news content "as is" without warranty of any kind. We do not accept any responsibility or liability for the accuracy, content, images, videos, licenses, completeness, legality, or reliability of the information contained in this article. If you have any complaints or copyright issues related to this article, kindly contact the author above.