Science and Technology Making Headlines
Sept. 29, 2023
In July, scientists at the National Ignition Facility at Lawrence Livermore National Laboratory generated a burst of energy by bombarding a pellet of hydrogen with 192 lasers, reproducing for a brief moment the process of fusion that powers the sun. It was a repeat of an experiment last December, but this time the scientists generated even more energy with nearly a factor of two in gain compared with the energy of the incoming lasers.
“We again repeated ignition,” Richard Town, the associate program director of the laser fusion program at Livermore, said. He gave a talk about the July experiment on Monday at a conference in Denver.
The Livermore results raise hopes that fusion can one day be used to generate bountiful amounts of electricity without producing greenhouse gases or long-lived radioactive waste.
The experiment in December generated a whirlwind of accolades when it produced about three megajoules of energy — equivalent to about 1.5 pounds of TNT, or about 1.5 times the energy of the incoming lasers. It was the first time that a fusion reaction in a laboratory setting produced more energy than it took to start the reaction.
The July experiment was essentially identical to the December one. “We expected a similar yield,” Town said. “On the order of three megajoules.” The actual output was 3.88 megajoules.
The better-than-predicted result indicates that with a few tweaks, laser fusion can become markedly more efficient.
The picturesque California Delta, often referred to as the Sacramento-San Joaquin Delta, is emerging as a geological sweet spot in California’s ambitious journey toward reaching net zero carbon emissions. Its unique geology presents a compelling case for carbon sequestration, an essential strategy in the battle against climate change.
Recent developments, including a collaborative effort between SCS and Lawrence Livermore National Laboratory on a Class VI permit application for Pelican Renewables – a company formed by delta landowners and residents to pursue geologic storage – are indicative of the region’s growing importance in California’s carbon mitigation strategy.
The California Delta is a vast inland delta formed by the confluence of the Sacramento and San Joaquin rivers and their tributaries as they meet the waters of the San Francisco Bay. Its unique geology makes it an ideal candidate for carbon sequestration.
California has set an ambitious goal to achieve net zero carbon emissions by 2045, a milestone in the fight against climate change. Achieving this objective necessitates reducing emissions and actively removing and storing carbon from the atmosphere. Carbon sequestration in the California Delta can play a pivotal role in this endeavor. The delta’s geological potential aligns seamlessly with the state’s commitment to sustainable practices and environmental responsibility.
Engineers and chemists at Lawrence Livermore National Laboratory (LLNL) and Meta have developed a new kind of 3D-printed material capable of replicating characteristics of biological tissue, an advancement that could impact the future of “augmented humanity.”
LLNL and Meta researchers describe a framework for creating a “one-pot” 3D-printable resin in which light is used to pattern smooth gradients in stiffness to approximate gradients found in biology, such as where bone meets muscle. The framework addresses a key challenge in developing more lifelike wearables: “mechanical mismatch.” Whereas natural tissues are soft, electronic devices are usually made of rigid materials and it can be difficult and time-consuming to assemble such devices using traditional means.
“For engineers, it’s very hard to get a softer material combined with a stiffer material such as is common in nature,” explained LLNL engineer Sijia Huang. “Engineers make a part that is stiff and another part that is soft, and then manually assemble them together, so we have a very sharp interface that compromises the mechanical property. This work has been looking into whether we can design continuous mechanical gradients from soft to stiff in a single resin system. Here, we're printing everything we're seeing, just using the light dosage to control the modulus.”
Huang said the technique works by manipulating the intensity of light applied to a photopolymer resin though the Digital Light Processing 3D printing process — a layer-by-layer technique that can rapidly produce parts by projecting light into a liquid resin — to modulate the deposited plastic material. A lower light intensity results in a softer material, while a higher light intensity results in a stiffer material.
With the delivery of the U.S. Department of Energy’s (DOE’s) first exascale system, Frontier, in 2022, and the upcoming deployment of Aurora and Lawrence Livermore’s El Capitan systems by next year, researchers will have the most sophisticated computational tools at their disposal. Exascale machines, which can perform more than a quintillion operations per second, are 1,000 times faster and more powerful than their petascale predecessors, enabling simulations of complex physical phenomena in unprecedented detail to push the boundaries of scientific understanding well beyond its current limits.
This feat of research, development and deployment has been made possible through a national effort to maximize the benefits of high-performance computing (HPC) for strengthening U.S. economic competitiveness and national security. The Exascale Computing Project (ECP) has been an integral part of that endeavor.
In the project’s final year, ECP collaborations have involved more than 1,000 team members working on 25 different mission-critical applications for research in areas ranging from energy and environment to materials and data science; 70 unique software products; and integrated continuous testing and delivery of ECP products on targeted DOE systems.
“ECP enabled these different groups — applications, software, and hardware — to establish healthy, collaborative working relationships where specialists in each area came together to create something greater than the sum of its parts,” said Erik Draeger, the Scientific Computing group leader in the Center for Applied Scientific Computing at Lawrence Livermore National Laboratory and the deputy director for ECP Applications Development.
A collaborative team has developed a new type of filter for kidney dialysis machines that can clean the blood more efficiently and improve patient care. Partners include Vanderbilt University Medical Center, University of California, San Francisco and Lawrence Livermore.
Chronic kidney disease, a condition where kidney damage results in poor blood filtration, affects approximately 697.5 million people—or 9% of the global population. Treatment includes hemofiltration, hemodialysis or kidney transplantation. Hemofiltration and hemodialysis support the kidneys by filtering toxins and waste products from blood.
The new filter uses carbon nanotubes — tiny tubes formed by a sheet of carbon atoms bonded in a hexagonal honeycomb mesh structure — hat have very small, smooth channels. These channels make it easier to remove toxins and waste from the blood without letting important proteins escape, which can be a problem with traditional filters.
The work also yielded fundamental insights on how biomolecules transport in nanoscale constrictions. Like an octopus that can contort itself to fit in the smallest spaces and then expand, the team discovered that biomolecules squeeze into the entrance of the nanotube in the membrane, travel through it and expand again on the other side. This knowledge can help researchers and engineers design membranes for biological separations beyond dialysis.