Lasers

Giant lasers compress iron oxide, revealing the secret interior structure of rocky exoplanets

Advances in astronomical observations have resulted in the discovery of an extraordinary number of extrasolar planets, some of which are believed to have a rocky composition similar to Earth. Learning more about their interior structure could provide important clues about their potential habitability. Led by Lawrence Livermore National Laboratory (LLNL), a team of researchers aims to unlock some of these secrets by understanding the properties of iron oxide – one of the constituents of Earth’s mantle – at the extreme pressures and temperatures that are likely found in the interiors of these large rocky extrasolar planets.

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.

UCI physicists exploring use of Blu-ray disc lasers to kill COVID-19, other viruses

Irvine, Calif., May 19, 2020 – A new weapon in the arsenal against the coronavirus may be sitting in your home entertainment console. A team led by physicist Chris Barty of the University of California, Irvine is researching the use of diodes from Blu-ray digital video disc devices as deep-ultraviolet laser photon sources to rapidly disinfect surfaces and the indoor air that swirls around us.

Under pressure: Researchers compress copper, creating the densest object on Earth

If copper was found in the core of Saturn it would have the same crystalline structure as the copper pipes found in many homes, according to new research from Lawrence Livermore National Laboratory (LLNL) and Johns Hopkins University.

In a paper published today by Physical Review Letters, the research team reveals that copper maintains its crystalline structure at pressures ranging from one atmosphere (room pressure) to more than 30 million atmospheres.