energy (4)

Nearing Ignition...

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An artist’s rendering shows how the National Ignition Facility’s 192 beams enter an eraser-size cylinder of gold and heat it from the inside to produce x-rays, which then implode the fuel capsule at its center to create fusion.

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

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Argonne, Assemble...

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(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

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Colloidal Quantum Dots...

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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

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Argonne, and STEM...

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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

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