LAB REPORT

Scientists have come tantalizingly close to reproducing the power of the sun — albeit only in a speck of hydrogen for a fraction of a second.

Researchers at Lawrence Livermore National Laboratory reported on Tuesday that by using 192 gigantic lasers to annihilate a pellet of hydrogen, they were able to ignite a burst of more than 10 quadrillion watts of fusion power — energy released when hydrogen atoms are fused into helium, the same process that occurs within stars.

Indeed, Mark Herrmann, Livermore’s deputy program director for fundamental weapons physics, compared the fusion reaction to the 170 quadrillion watts of sunshine that bathe Earth’s surface.

“This is about 10 percent of that,” Herrmann said. And all of the fusion energy emanated from a hot spot about as wide as a human hair, he said.

But the burst — essentially a miniature hydrogen bomb — lasted only 100 trillionths of a second.

Still, that spurred a burst of optimism for fusion scientists who have long hoped that fusion could someday provide a boundless, clean energy source for humanity.

Hundreds of top scientists, including three from Lawrence Livermore, released a devastating report this month on the danger that human-caused climate change poses to the world. 

Calling it "code red for humanity," the landmark report was released in Geneva by the United Nations' Intergovernmental Panel on Climate Change (IPCC). 

Many of the changes seen in the world's climate are unprecedented in thousands, if not hundreds of thousands, of years, and some of the changes already set in motion — such as a rise in sea levels — are irreversible over hundreds to thousands of years, according to the report.

Wild weather events, such as storms and heat waves, are expected to worsen and become more frequent. The report, which calls climate change clearly human-caused and “unequivocal,” makes more precise and warmer forecasts for the 21^st century than it did last time it was issued, in 2013.

Scientists and engineers at Lawrence Livermore are 3D printing flow-through electrodes (FTEs), which are critical components in electrochemical reactors. Electrochemical reactors can convert carbon dioxide into a renewable source of energy while significantly reducing carbon emissions. With the design freedom afforded by 3D printing, scientists are able to create shapes and pathways they never could before, thus maximizing reactor performance.

Electrochemistry has seen a boom within the last decade from both industry scientists and academics. Electrons can act as traceless agents during redox chemistry, effectively relieving the need to use toxic or hazardous reductants. Similar to how the world has begun harvesting electricity from solar and wind energy, thus reducing greenhouse gas emissions from fossil fuels, so too does the electrification of the chemical industry provide the opportunity to locally create commodity materials without having to store, transport, or waste hazardous chemicals.

Traditional materials used in FTEs, such as carbon fiber foams and felts, have a disordered structure and cannot be easily modified. In turn, these materials suffer from uneven flow. The mass transport distribution, and adoption of this technology on a commercial scale, is dependent upon efficiency of mass transfer. However, 3D printing with advanced materials, such as carbon aerogels, has provided scientists from LLNL the ability to create a macrostructure with novel geometries, including porous designs.

A Lawrence Livermore National Laboratory scientist and collaborators have demonstrated the first-ever "defect microscope" that can track how populations of defects deep inside bulk materials move collectively.

The research shows a classical example of a dislocation (line defect) boundary, then demonstrates how these same defects move exotically just at the edge of melting temperatures.

"This work presents a large step forward for materials science, physics and related fields, as it offers a unique new way to view the 'intermediate scales' that connect microscopic defects to the bulk properties they cause," said Leora Dresselhaus-Marais, a former Lawrence fellow and now assistant professor of Materials Science and Engineering at Stanford University.

Connecting a bulk material's microscopic defects to its macroscopic properties is an age-old problem in materials science. Long-range interactions between dislocations are known to play a key role in how materials deform or melt, but scientists have until now lacked the tools to connect these dynamics to the macroscopic properties.

Sandia National Laboratories' Z machine — generator of the world's most powerful electrical pulses — and Lawrence Livermore National Laboratory's National Ignition Facility — the planet's most energetic laser source — in a series of 10 experiments have detailed the responses of gold and platinum at pressures so extreme that their atomic structures momentarily distorted like images in a fun-house mirror.

Similar high-pressure changes induced in other settings have produced oddities like hydrogen appearing as a metallic fluid, helium in the form of rain and sodium a transparent metal. But until now there has been no way to accurately calibrate these pressures and responses, the first step to controlling them.

Following experiments on the two big machines, researchers developed tables of gold and platinum responses to extreme pressure. The experiments will provide a standard to help future researchers calibrate the responses of other metals under similar stress.

A Lawrence Livermore team has taken a closer look at how nuclear weapon blasts close to the Earth’s surface create complications in their effects and apparent yields. Attempts to correlate data from events with low heights of burst revealed a need to improve the theoretical treatment of strong blast waves rebounding from hard surfaces.

This led to an extension of the fundamental theory of strong shocks in the atmosphere, which was first developed by G.I. Taylor in the 1940s. The work represents an improvement to the Lab team’s basic understanding of nuclear weapon effects for near-surface detonations.

The results indicate that the shock wave produced by a nuclear detonation continues to follow a fundamental scaling law when reflected from a surface, which enables the team to more accurately predict the damage a detonation will produce in a variety of situations, including urban environments.