Lab Report

In its latest ambitious roadmap to tackle climate change, California relies on capturing carbon out of the air and storing it deep underground on a scale that’s not yet been seen in the United States.

The plan — advanced by Democratic Gov. Gavin Newsom’s administration — comes just as the Biden administration has boosted incentives for carbon capture projects in an effort to spur more development nationwide.

There are currently no active carbon capture projects in California. To demonstrate the technology is viable and people can get permits for it, it’s essential to build the first projects, said George Peridas, director of carbon management partnerships at Lawrence Livermore National Laboratory.

Peridas said one area with potential to store carbon dioxide is the Sacramento-San Joaquin River Delta, a vast estuary on the western edge of the Central Valley that’s a vital source of drinking water and an ecologically sensitive home to hundreds of species.

A levee-ringed island of farmland in the region that’s nearly half the size of Manhattan would be an ideal place for storing carbon dioxide safely, Peridas said.

At 1:03 a.m. on Monday, Dec. 5, scientists at the National Ignition Facility aimed their 192-beam laser at a cylinder containing a tiny diamond fuel capsule.

That powerful burst of laser light created immense temperatures and pressures and sparked a fusion reaction — the reaction which powers the sun.

One of the key components at NIF is a peppercorn-sized synthetic diamond capsule, which holds the fuel. The properties of that spherical capsule are crucial to creating a successful fusion experiment. The sphere has to be perfectly smooth and contaminant-free - any anomalies could ruin the reaction.

High-power lasers now create record-high numbers of electron-positron pairs, opening exciting opportunities to study extreme astrophysical processes, such as black holes and gamma-ray bursts.

Positrons, or "anti-electrons," are anti-particles with the same mass as an electron but with opposite charge. The generation of energetic electron-positron pairs is common in extreme astrophysical environments associated with the rapid collapse of stars and formation of black holes. These pairs eventually radiate their energy, producing extremely bright bursts of gamma rays.

Gamma-ray bursts (GRBs) are the brightest electromagnetic events known to occur in the universe and can last from ten milliseconds to several minutes. The mechanism of how these GRBs are produced is still a mystery.

That's where high-power lasers come in. In the laboratory, jets of electron-positron pairs can be generated by shining intense laser light into a gold foil. The interaction produces high-energy radiation that traverses the material and creates electron-positron pairs as it interacts with the nuclei of the gold atoms along its path.

A new review of the current breakthroughs in the creation of electron-positron pair plasma, its main challenges and the future of the field, authored by Lawrence Livermore National Laboratory (LLNL) physicist Hui Chen and SLAC National Accelerator Laboratory scientist Frederico Fiuza, appears in Physics of Plasmas.

Fusion is here creating handmade suns, sources of unlimited clean energy. These glorious pet stars, requiring only everyday hydrogen to whip up in a lab, won’t belch out carbon or radioactive waste. Instead, they’ll exhale helium. That nonrenewable resource that’s already running low. Fusion means infinite carbonless energy.

In December 2022 — a solid century since physicists first identified fusion as the source of star power —American scientists at the National Ignition Facility in Livermore, where ignition is a way of life, had a breakthrough. They’d aimed 192 lasers at the inside of a pearl-sized gold can called a hohlraum, creating a radiation bath that heated up the outside of a peppercorn-sized spherical nubbin of hydrogen coated in diamond in the center of the little can.

Atoms flew off the nubbin, forcing it to implode at a speed of nearly 400 kilometers per second — about four times a bolt of lightning. This created 100 million-degree plasma under hundreds of billions of atmospheres of pressure — a gas so hot that electrons were freed from atomic nuclei. At 1:03 am on Dec. 5, humanity hit the threshold for fusion ignition in a lab. The first flash of a handmade sun.

Though it blinked out rather quickly, after less than 100 trillionths of a second, the reaction created 3.15 megajoules of energy when a mere 2.05 went in — a 150 percent return on investment.

New research led by Lawrence Livermore National Laboratory (LLNL) provides a better understanding of ejecta production, which has been the subject of broad interest for more than 60 years throughout the scientific community.

Ejecta are particles of material forced out or ejected from an area. The phenomena are observed across many multi-disciplinary applications, including volcanic eruptions, asteroid impacts on planets, surface shielding on spacecrafts and satellites, engineering applications for powder spraying and laser-induced material ablation.

LLNL’s Garry Maskaly said the research team identified a previously unknown ejecta production mechanism called Shallow Bubble Collapse (SBC) that is not based on Richtmyer-Meshkov instabilities (RMI), when shock waves interact with and separate two fluids of different density. RMI ejecta previously have been believed to be the main source of shock-driven metal ejecta and have been the subject of decades of research.

The key highlights from this research summarized how the SBC mechanism can produce substantially more ejecta (10 times) with a much higher temperature (two times) than RMI ejecta produced under similar shock strengths.