Experiments at the National Ignition Facility probe carbon at record pressures

Decades of studies have shown that carbon’s crystal structure has a significant impact on material properties. In addition to graphite and diamond, the most common carbon structures found at ambient pressures, scientists have predicted several new structures of carbon that could be found above 1,000 gigapascals (GPa). These pressures, approximately 2.5 times the pressure in Earth’s core, are relevant for modeling exoplanet interiors but have historically been impossible to achieve in the laboratory. That is, until now. Under the Discovery Science program, which allows academic scientists access to Lawrence Livermore National Laboratory’s (LLNL) flagship National Ignition Facility (NIF), an international team of researchers led by LLNL and the University of Oxford has successfully measured carbon at pressures reaching 2,000 GPa (5 times the pressure in Earth’s core), nearly doubling the maximum pressure at which a crystal structure has ever been directly probed.

National Ignition Facility conducts first-ever shot with explosives

The first-ever shot to study a high explosive sample was recently conducted at the National Ignition Facility, the world’s most energetic laser. The results from the shot included novel data that will help researchers unlock the mysteries of high-explosive (HE) chemistry and position Lawrence Livermore National Laboratory to continue its legacy as a leader in HE science and diagnostic innovation.

Record EOS measurement pressures shed light on stellar evolution

Using the power of the National Ignition Facility (NIF), the world’s highest-energy laser system, researchers at Lawrence Livermore National Laboratory (LLNL) and an international team of collaborators have developed an experimental capability for measuring the basic properties of matter, such as the equation of state (EOS), at the highest pressures thus far achieved in a controlled laboratory experiment. The results are relevant to the conditions at the cores of giant planets, the interiors of brown dwarfs (failed stars), the carbon envelopes of white dwarf stars and many applied science programs at LLNL. According to the authors, the overlap with white dwarf envelopes is particularly significant – this new research enables experimental benchmarks of the basic properties of matter in this regime. The results should ultimately lead to improved models of white dwarfs, which represent the final stage of evolution for most stars in the universe.