BLOGS

Cross-section of a fulgurite sample showing fused sand and melted conductor metal from a downed powerline. Credit: Luca Bindi et al.

Topics: Condensed Matter Physics, Energy, Materials Science

A team of researchers from Università di Firenze, the University of South Florida, California Institute of Technology, and Princeton University has found an incidence of a quasicrystal formed during an accidental electrical discharge.

In their paper published in Proceedings of the National Academy of Sciences, the group describes their study of a quasicrystal found in a sand dune in Nebraska.

Quasicrystals, as their name suggests, are crystal-like substances. They possess characteristics not found in ordinary crystals, such as a non-repeating arrangement of atoms. To date, quasicrystals have been found embedded in meteorites and in the debris from nuclear blasts. In this new effort, the researchers found one embedded in a sand dune in Sand Hills, Nebraska.

A study of the quasicrystal showed it had 12-fold, or dodecagonal, symmetry—something rarely seen in quasicrystals. Curious about how it might have formed and ended up in the sand dune, the researchers did some investigating. They discovered that a power line had fallen on the dune, likely due to a lightning strike. They suggest the electrical surge from either the power line or the lightning could have produced the quasicrystal.

The researchers note that the quasicrystal was found inside a tubular piece of fulgurite. They suggest it was also formed during the electrical surge due to the fusing of melted sand and metal from the power line.

Quasicrystal formed during accidental electrical discharge, Bob Yirka, Phys.org

National Ignition Facility operators inspect a final optics assembly during a routine maintenance period in August. Photo credit: Lawrence Livermore National Laboratory

Topics: Alternate Energy, Applied Physics, Climate Change, Energy, Global Warming, Lasers, Nuclear Fusion

After the heady, breathtaking coverage of pop science journalism, I dove into the grim world inhabited by the Bulletin of the Atomic Scientists on their take on the first-ever fusion reaction. I can say that I wasn’t surprised. With all this publicity, it will probably get the Nobel Prize nomination (my guess). Cool Trekkie trivia: the National Ignition Facility was the backdrop for the Enterprise's warp core for Into Darkness.

*****

This week’s headlines have been full of reports about a “major breakthrough” in nuclear fusion technology that, many of those reports misleadingly suggested, augurs a future of abundant clean energy produced by fusion nuclear power plants. To be sure, many of those reports lightly hedged their enthusiasm by noting that (as The Guardian put it) “major hurdles” to a fusion-powered world remain.

Indeed, they do.

The fusion achievement that the US Energy Department announced this week is scientifically significant, but the significance does not relate primarily to electricity generation. Researchers at Lawrence Livermore National Laboratory’s National Ignition Facility, or NIF, focused the facility’s 192 lasers on a target containing a small capsule of deuterium–tritium fuel, compressing it and inducing what is known as ignition. In a written press release, the Energy Department described the achievement this way: “On December 5, a team at LLNL’s National Ignition Facility (NIF) conducted the first controlled fusion experiment in history to reach this [fusion ignition] milestone, also known as scientific energy breakeven, meaning it produced more energy from fusion than the laser energy used to drive it. This historic, first-of-its-kind achievement will provide the unprecedented capability to support [the National Nuclear Security Administration’s] Stockpile Stewardship Program and will provide invaluable insights into the prospects of clean fusion energy, which would be a game-changer for efforts to achieve President Biden’s goal of a net-zero carbon economy.”

Because of how the Energy Department presented the breakthrough in a news conference headlined by Energy Secretary Jennifer Granholm, news coverage has largely glossed over its implications for monitoring the country’s nuclear weapons stockpile. Instead, even many serious news outlets focused on the possibility of carbon-free, fusion-powered electricity generation—even though the NIF achievement has, at best, a distant and tangential connection to power production.

To get a balanced view of what the NIF breakthrough does and does not mean, I (John Mecklin) spoke this week with Bob Rosner, a physicist at the University of Chicago and a former director of the Argonne National Laboratory who has been a longtime member of the Bulletin’s Science and Security Board. The interview has been lightly edited and condensed for readability.

See their chat at the link below.

The Energy Department’s fusion breakthrough: It’s not really about generating electricity, John Mecklin, The Bulletin of the Atomic Scientists, Editor-in-Chief

A floating artificial leaf – which generates clean fuel from sunlight and water – on the River Cam near King's College Chapel in Cambridge, UK. (Courtesy: Virgil Andrei)

Topics: Climate Change, Energy, Environment, Materials Science, Solar Power

Leaf-like devices that are light enough to float on water could be used to generate fuel from solar farms located on open water sources. This avenue hasn’t been explored before, according to researchers from the University of Cambridge in the UK who developed them. The new devices are made from thin, flexible substrates and perovskite-based light-absorbing layers. Tests showed that they can produce either hydrogen or syngas (a mixture of hydrogen and carbon monoxide) while floating on the River Cam.

Artificial leaves like these are a type of photoelectrochemical cell (PEC) that transforms sunlight into electrical energy or fuel by mimicking some aspects of photosynthesis, such as splitting water into its constituent oxygen and hydrogen. This differs from conventional photovoltaic cells, which convert light directly into electricity.

Because PEC artificial leaves contain both light harvesting and catalysis components in one compact device, they could, in principle, be used to produce fuel from sunlight cheaply and simply. The problem is that current techniques for making them can’t be scaled up. What is more, they are often composed of fragile and heavy bulk materials, which limits their use.

In 2019 a team of researchers led by Erwin Reisner developed an artificial leaf that produced syngas from sunlight, carbon dioxide, and water. This device contained two light absorbers and catalysts, but it also incorporated a thick glass substrate and coatings to protect against moisture, which made it cumbersome.

Floating artificial leaves could produce solar-generated fuel, Isabelle Dumé, Physics World

Artist's rendition of a future colony on Mars., e71lena via Shutterstock

Topics: Applied Physics, Energy, Mars, Space Exploration

(Inside Science) -- Mars is known for its dust storms, which can cause problems for lander equipment and block out the sun that fuels solar panels. These punishing storms, which can last for weeks, have already caused damage to equipment and even killed NASA’s Opportunity rover. But they could also be dangerous to astronauts on the ground, who would rely on solar power for oxygen, heat, and water cleansing during future missions.

Vera Schorbach, a professor of wind energy at the Hamburg University of Applied Sciences in Germany, was curious to see whether wind turbines could harness the power of these storms, filling in for solar panels on the Red Planet during times of need.

"I asked myself, 'Why don't they have a wind turbine if they have dust storms,'" said Schorbach, the lead author of a study about the potential for wind power on Mars published recently in the journal Acta Astronautica.

Could martian dust storms help astronauts keep the lights on? Joshua Rapp Leam, Astronomy/Inside Science

Topics: Battery, Energy, Green Tech, Research, Solid-State Physics

Janus, in Roman religion, the animistic spirit of doorways (januae) and archways (Jani). Janus and the nymph Camasene were the parents of Tiberinus, whose death in or by the river Albula caused it to be renamed Tiber. Source: Encylopedia Britannica

Over the past decade, lithium-ion batteries have seen stunning improvements in their size, weight, cost, and overall performance. (See Physics Today, December 2019, page 20.) But they haven’t yet reached their full potential. One of the biggest remaining hurdles has to do with the electrolyte, the material that conducts Li⁺ ions from anode to cathode inside the battery to drive the equal and opposite flow of charge in the external circuit.

Most commercial lithium-ion batteries use organic liquid electrolytes. The liquids are excellent conductors of Li⁺ ions, but they’re volatile and flammable, and they offer no defense against the whisker-like Li-metal dendrites that can build up between the electrodes and eventually short-circuit the battery. Because safety comes first, battery designers must sacrifice some performance in favor of not having their batteries catch fire.

A solid-state electrolyte could solve those problems. But what kind of solid conducts ions? An ordered crystal won’t do—when every site is filled in a crystalline lattice, Li⁺ ions have nowhere to move to. A solid electrolyte, therefore, needs to have a disordered, defect-riddled structure. It must also provide a polar environment to welcome the Li⁺ ions, but with no negative charges so strong that the Li⁺ ions stick to them and don’t let go.

For several years, Jenny Pringle, Maria Forsyth, and colleagues at Deakin University in Australia have been exploring a class of materials, called organic ionic plastic crystals (OIPCs), that could fit the bill. As a mix of positive and negative ions, an OIPC offers the necessary polar environment for conducting Li⁺. And because the constituent ions are organic, the researchers have lots of chemical leeways to design their shapes so they can’t easily fit together into a regular lattice but are forced to adopt a disordered, Li⁺-permeable structure.

Two-faced ions form a promising battery material, Johanna L. Miller, Physics Today

An aerial view of peat fields in Elva, Estonia. September 30, 2021. REUTERS/Janis Laizans

Topics: Battery, Biofuels, Chemistry, Energy, Green Tech

TARTU, Estonia, Oct 11 (Reuters) - Peat, plentiful in bogs in northern Europe, could be used to make sodium-ion batteries cheaply for use in electric vehicles, scientists at an Estonian university say.

Sodium-ion batteries, which do not contain relatively costly lithium, cobalt, or nickel, are one of the new technologies that battery makers are looking at as they seek alternatives to the dominant lithium-ion model.

Scientists at Estonia's Tartu University say they have found a way to use peat in sodium-ion batteries, which reduces the overall cost, although the technology is still in its infancy.

"Peat is a very cheap raw material - it doesn't cost anything, really," says Enn Lust, head of the Institute of Chemistry at the university.

Energy from bogs: Estonian scientists use peat to make batteries, Janis Laizans and Andrius Sytas, Reuters Science

LAWRENCE LIVERMORE NATIONAL LABORATORY

Topics: Energy, Environment, Modern Physics, Nuclear Fusion, Nuclear Power

More than a decade ago, the world’s most energetic laser started to unleash its blasts on tiny capsules of hydrogen isotopes, with managers promising it would soon demonstrate a route to limitless fusion energy. Now, the National Ignition Facility (NIF) has taken a major leap toward that goal. Last week, a single laser shot sparked a fusion explosion from a peppercorn-size fuel capsule that produced eight times more energy than the facility had ever achieved: 1.35 megajoules (MJ)—roughly the kinetic energy of a car traveling at 160 kilometers per hour. That was also 70% of the energy of the laser pulse that triggered it, making it tantalizingly close to “ignition”: a fusion shot producing an excess of energy.

 “After many years at 3% of ignition, this is super exciting,” says Mark Herrmann, head of the fusion program at Lawrence Livermore National Laboratory, which operates NIF.

NIF’s latest shot “proves that a small amount of energy, imploding a small amount of mass, can get fusion. It’s a wonderful result for the field,” says physicist Michael Campbell, director of the Laboratory for Laser Energetics (LLE) at the University of Rochester.

“It’s a remarkable achievement,” adds plasma physicist Steven Rose, co-director of the Centre for Inertial Fusion Studies at Imperial College London. “It’s made me feel very cheerful. … It feels like a breakthrough.”

And it is none too soon, as years of slow progress have raised questions about whether laser-powered fusion has a practical future. Now, according to LLE Chief Scientist Riccardo Betti, researchers need to ask: “What is the maximum fusion yield you can get out of NIF? That’s the real question.”

Fusion, which powers stars, forces small atomic nuclei to meld together into larger ones, releasing large amounts of energy. Extremely hard to achieve on Earth because of the heat and pressure required to join nuclei, fusion continues to attract scientific and commercial interest because it promises copious energy, with little environmental impact.

With explosive new result, laser-powered fusion effort nears ‘ignition’, Daniel Clery, Science Magazine

(Image by Shutterstock/muratart.)

Topics: Climate Change, Energy, Environment, Existentialism, Global Warming, Green Tech

Thankfully, we're not. Hat tip to Marvel, and Rotten Tomatoes.

Scientists aren’t superheroes. Or are they? Superheroes defend the defenseless and save humanity from any number of disasters, both natural and unnatural, often using powers of logic and some really hip techno-gadgets.

The Earth is in crisis and while it has its own mechanisms to fight back, it could use a helping hand. Earth could use a superhero.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are stepping up and applying decades of expertise and research to combat some of Earth’s toughest foes, from waste and pollution to climate change. And they’ve assembled a cache of some of the world’s coolest technology for this crusade.

So, this Earth Day, we take a look at just a few of the ways Argonne’s scientist-superheroes are swooping in to keep Earth healthy and its citizens safe.

Predicting Earth’s future

What better way to save the planet than knowing what the future holds? Argonne and DOE are leaders in modeling Earth’s complex natural systems to help us keep tabs on the planet’s health. The best of these models can simulate how changes in these systems and our own actions might influence climate and ecosystems many years into the future. They give us a better understanding of the roles played by tropical rain forests, ice sheets, permafrost, and oceans in maintaining carbon levels and help us devise strategies for protecting them — ultimately, identifying how much carbon dioxide (CO₂) we need to reduce from human activities and remove from the atmosphere to stabilize the planet’s temperature.

8 Things Argonne is Doing to Save the Earth, Argonne National Laboratory

FIG. 1. (a) Schematic of La Mer and Dinegar's model for the synthesis of monodispersed CQDs. (b) Representation of the apparatus employed for CQD synthesis. Reproduced with permission from Murray et al., Annu. Rev. Mater Res. 30(1), 545–610 (2000). Copyright 2000 Annual Reviews.

Topics: Energy, Materials Science, Nanotechnology, Quantum Mechanics, Solar Power

ABSTRACT
Solution-processed colloidal quantum dot (CQD) solar cells are lightweight, flexible, inexpensive, and can be spray-coated on various substrates. However, their power conversion efficiency is still insufficient for commercial applications. To further boost CQD solar cell efficiency, researchers need to better understand and control how charge carriers and excitons transport in CQD thin films, i.e., the CQD solar cell electrical parameters including carrier lifetime, diffusion length, diffusivity, mobility, drift length, trap state density, and doping density. These parameters play key roles in determining CQD thin film thickness and surface passivation ligands in CQD solar cell fabrication processes. To characterize these CQD solar cell parameters, researchers have mostly used transient techniques, such as short-circuit current/open-circuit voltage decay, photoconductance decay, and time-resolved photoluminescence. These transient techniques based on the time-dependent excess carrier density decay generally exhibit an exponential profile, but they differ in the signal collection physics and can only be used in some particular scenarios. Furthermore, photovoltaic characterization techniques are moving from contact to non-contact, from steady-state to dynamic, and from small-spot testing to large-area imaging; what are the challenges, limitations, and prospects? To answer these questions, this Tutorial, in the context of CQD thin film and solar cell characterization, looks at trends in characterization technique development by comparing various conventional techniques in meeting research and/or industrial demands. For a good physical understanding of material properties, the basic physics of CQD materials and devices are reviewed first, followed by a detailed discussion of various characterization techniques and their suitability for CQD photovoltaic devices.

Advanced characterization methods of carrier transport in quantum dot photovoltaic solar cells, Lilei Hu, Andreas Mandelis, Journal of Applied Physics

Students and instructors wave bye to each other after the close of a virtual session of All About Energy. (Image by Argonne National Laboratory.)

Topics: Education, Energy, Research, STEM

Argonne Educational Programs and Outreach transitioned to virtual summer programming, ensuring that Argonne continues to build the next generation of STEM leaders.

At the U.S. Department of Energy’s (DOE) Argonne National Laboratory, scientists and educators have found new ways to balance their work with safety needs as the laboratory’s Educational Programs and Outreach Department successfully transitioned all of its summer programming to a virtual learning environment.

By connecting scientific and research divisions across the laboratory, Argonne was able to create multiple virtual programs, helping young people stay connected and engage with the laboratory’s science, technology, engineering and math (STEM) education opportunities.

“Providing STEM opportunities and a constant presence with our next generation of STEM professions during a time that is unsettling and turbulent for everyone, but especially our school age and university student populations, was our top priority.” — Meridith Bruozas, Educational Programs, and Outreach manager

“Argonne continues to adapt and lead impactful science during the ongoing pandemic, a strategy that includes strengthening the STEM pipeline with unique educational programs for future scientists and engineers,” said Argonne Director Paul Kearns. ​“For years, hundreds of students have pursued summer learning opportunities at Argonne that are not available anywhere else. I’m pleased that in 2020 our lab community came together to maintain these high-quality STEM experiences through a successful virtual program for next-generation researchers.”

Argonne provides STEM opportunities for more than 800 students during pandemic, Nathan Schmidt, Argonne National Laboratory