Tag: High Energy Physics

Some mosquitoes like it hot

Newswise — Certain populations of mosquitoes are more heat tolerant and better equipped to survive heat waves than others, according to new research from Washington University in St. Louis.

This is bad news in a world where vector-borne diseases are an increasingly global health concern. Most models that scientists use to estimate vector-borne disease risk currently assume that mosquito heat tolerances do not vary. As a result, these models may underestimate mosquitoes’ ability to spread diseases in a warming world.

Researchers led by Katie M. Westby, a senior scientist at Tyson Research Center, Washington University’s environmental field station, conducted a new study that measured the critical thermal maximum (CTmax), an organism’s upper thermal tolerance limit, of eight populations of the globally invasive tiger mosquito, Aedes albopictus. The tiger mosquito is a known vector for many viruses including West Nile, chikungunya and dengue.

“We found significant differences across populations for both adults and larvae, and these differences were more pronounced for adults,” Westby said. The new study is published Jan. 8 in Frontiers in Ecology and Evolution.

Westby’s team sampled mosquitoes from eight different populations spanning four climate zones across the eastern United States, including mosquitoes from locations in New Orleans; St. Augustine, Fla.; Huntsville, Ala.; Stillwater, Okla.; St. Louis; Urbana, Ill.; College Park, Md.; and Allegheny County, Pa.

The scientists collected eggs in the wild and raised larvae from the different geographic locations to adult stages in the lab, tending the mosquito populations separately as they continued to breed and grow. The scientists then used adults and larvae from subsequent generations of these captive-raised mosquitoes in trials to determine CTmax values, ramping up air and water temperatures at a rate of 1 degree Celsius per minute using established research protocols.

The team then tested the relationship between climatic variables measured near each population source and the CTmax of adults and larvae. The scientists found significant differences among the mosquito populations.

The differences did not appear to follow a simple latitudinal or temperature-dependent pattern, but there were some important trends. Mosquito populations from locations with higher precipitation had higher CTmax values. Overall, the results reveal that mean and maximum seasonal temperatures, relative humidity and annual precipitation may all be important climatic factors in determining CTmax.

“Larvae had significantly higher thermal limits than adults, and this likely results from different selection pressures for terrestrial adults and aquatic larvae,” said Benjamin Orlinick, first author of the paper and a former undergraduate research fellow at Tyson Research Center. “It appears that adult Ae. albopictus are experiencing temperatures closer to their CTmax than larvae, possibly explaining why there are more differences among adult populations.”

“The overall trend is for increased heat tolerance with increasing precipitation,” Westby said. “It could be that wetter climates allow mosquitoes to endure hotter temperatures due to decreases in desiccation, as humidity and temperature are known to interact and influence mosquito survival.”

Little is known about how different vector populations, like those of this kind of mosquito, are adapted to their local climate, nor the potential for vectors to adapt to a rapidly changing climate. This study is one of the few to consider the upper limits of survivability in high temperatures — akin to heat waves — as opposed to the limits imposed by cold winters.

“Standing genetic variation in heat tolerance is necessary for organisms to adapt to higher temperatures,” Westby said. “That’s why it was important for us to experimentally determine if this mosquito exhibits variation before we can begin to test how, or if, it will adapt to a warmer world.”

Future research in the lab aims to determine the upper limits that mosquitoes will seek out hosts for blood meals in the field, where they spend the hottest parts of the day when temperatures get above those thresholds, and if they are already adapting to higher temperatures. “Determining this is key to understanding how climate change will impact disease transmission in the real world,” Westby said. “Mosquitoes in the wild experience fluctuating daily temperatures and humidity that we cannot fully replicate in the lab.”

Washington University in St. Louis

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January 7, 2024
Seeking Supermassive Black Holes Early On

Newswise — Supermassive black holes (SMBHs) – black holes with masses exceeding a million times that of the Sun – are known to prevail in the universe today. However, it is not clear yet when, where, and how they formed during the 13.8 billion years of cosmic history. Observations in the past few decades have revealed that every galaxy harbors a SMBH in the center, and that the black hole mass is almost always one-thousandth of the host galaxy mass. This close relationship implies that galaxies and SMBHs have co-evolved together. Revealing the origin of SMBHs is thus crucial not only to understand SMBHs themselves, but also to elucidate the formation processes of galaxies, the major constituents of the visible universe.
A key to addressing this issue lies in the early universe, where the time elapse since the Big Bang (i.e., the beginning of the universe) was less than a billion years. Thanks to the finite speed of light, we can look back at the past by observing the distant universe. Did SMBHs already exist when the universe was only a billion years old or less? Is it possible for a black hole to acquire such a large mass (exceeding a million solar masses and sometimes reaching billions of solar masses) in such a short time? If so, what are the underlying physical mechanisms and conditions? In order to close in on the origin of SMBHs, we need to observe them and compare their properties with predictions from theoretical models. And in order to do so, we first need to find where they are in the sky.
We used the Subaru Telescope at the top of Maunakea, Hawaii, for the present study. One of the biggest advantages of Subaru is its widefield observing capability, which is particularly suited for our purpose. Since SMBHs do not emit light, we looked for a special class called “quasars” – SMBHs with shining outskirts where the infalling material releases gravitational energy. We observed a wide sky area equivalent to 5000 times the full moon, and successfully discovered 162 quasars residing in the early universe. In particular, 22 of them lived in the era when the universe was less than 800 million years old – the most ancient period in which quasars have been recognized to date. The large number of quasars we discovered has allowed us to determine the most fundamental measure called the “luminosity function”, which describes the space density of quasars as a function of radiation energy. We found that quasars were forming very rapidly in the early universe, while the overall shape of the luminosity function (except for the amplitude) remained unchanged over time. This characteristic behavior of the luminosity function provides strong constraints on theoretical models, which could ultimately reproduce all the observables and describe the origin of SMBHs.
On the other hand, the universe was known to have experienced a major phase transition called “cosmic reionization” in its early stage. Past observations suggest that the whole intergalactic space was ionized in this event. The source of the ionization energy is still under debate, with radiation from quasars being considered as a promising candidate. By integrating the above luminosity function, we found that quasars emit 10²⁸ photons per second in a unit volume of 1 light-year on a side in the early universe. This is less than 1% of the photons needed to maintain the ionized state of the intergalactic space at that time, and thus indicates that quasars made only a minor contribution to cosmic reionization. Other energy sources are critically needed, which, according to other recent observations, may be the integrated radiation from massive hot stars in forming galaxies.

Ehime University

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September 1, 2023
Calculations Predict Surprising Quark Diffusion in Hot Nuclear Matter

The Science

Scientists can use powerful colliders to smash atomic nuclei together to create a quark-gluon plasma (QGP). This “soup” of quarks and gluons, some of the fundamental building blocks of matter, filled the early universe. Tracking how high energy jets of quarks travel through the QGP can reveal information about the QGP’s properties. Scientists’ simplest assumption is that local interactions with the quarks and gluons will deflect these energetic particles. But recent theoretical calculations that also include non-local quantum interactions—those interactions beyond a particle’s immediate surroundings—predict a super-diffusive process. This means that the complex interactions in QGP deflect quarks faster and at wider angles than can be explained by local interactions alone.

The Impact

Testing these predictions at particle colliders will provide new insight into the interactions between quarks and gluons. These interactions are governed by the strong nuclear force, one of the four fundamental forces that govern the universe. The new theoretical explanation points to the importance of the non-local nature of these quantum interactions. The findings suggest that the description of the QGP as a collection of point-like particles may break down even at short distances. The discovery of the importance of longer-range quantum interactions might also offer a new perspective for understanding why the QGP flows like a nearly perfect fluid–a fluid with very low viscosity.

Summary

Scientists use particle colliders to recreate a form of early universe matter known as a QGP. Tracking how energetic jets of particles move through the QGP can reveal information about its properties. Early calculations based on the theory of strong interactions suggested that jets would undergo a diffusive process caused by random deflections as the energetic particles interacted with the quarks and gluons that make up the plasma—similar to the way pollen particles on the surface of a pond get “kicked” around by water molecules.

Counter to these early calculations, nuclear theorists at Brookhaven National Laboratory recently discovered that including non-local quantum effects—which arise from long-lived gluon fluctuations—predicts significant deviations from the expected diffusion pattern in QGP. Including these non-local effects predicts that energetic jets will undergo a super-diffusive process, broadening the angle of the jet faster than local interactions alone can explain. The predictions can be tested by tracking energetic jets in the QGP created in high-energy heavy ion collisions at the Relativistic Heavy Ion Collider (a Department of Energy user facility at Brookhaven National Laboratory) and the Large Hadron Collider in Europe.

Funding

This research was funded by the Department of Energy Office of Science, Office of Nuclear Physics and by the National Science Foundation.

Journal Link: Journal of High Energy Physics, Sep-2022
Journal Link: Physical Review D, Sep-2022

Department of Energy, Office of Science

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August 25, 2023
Department of Energy grant supports inclusive high energy physics research

Newswise — The new project creates opportunities for researchers from historically underrepresented groups to develop technology that will help us understand the forces behind an expanding universe.

The U.S. Department of Energy’s (DOE) Argonne National Laboratory and the Missouri University of Science and Technology (Missouri S&T) have been awarded funding for a program that aims to generate insights about the universe while expanding diversity in the high energy physics field.

Through the $589,000, three-year grant from DOE’s Funding for Accelerated, Inclusive Research (FAIR) initiative, the research team will create a computer modeling framework to map a set of distant galaxies known as emission line galaxies. The grant also supports the participation of students from historically underrepresented groups.

Shun Saito, assistant professor of physics at Missouri S&T, is leading the research project with Andrew Hearin, an Argonne physicist, as the DOE national laboratory partner. The goal is to unravel some of the mystery surrounding dark energy, the force thought to drive the universe’s accelerated expansion.

“You really need supercomputing resources to be able to make predictions for galaxies in the large volumes we are simulating. Our modeling approach has been designed from the ground up to do exactly that.” — Andrew Hearin, Argonne physicist

The project relates to the DOE-funded Dark Energy Spectroscopic Instrument (DESI), which is measuring the trajectory of this expansion by mapping emission line galaxies. Emission lines are light signals emanating from galaxies across billions of years. These lines can be used in mapping the galaxies and determining their histories. Saito and team will build a simulation-based framework to predict a clustering pattern of faraway emission line galaxies that can then be used to understand the nature of dark energy.

“In the last decade, we have seen a lot of progress in measuring the nearby universe,” Saito said. “Now we want to locate more distant galaxies to fully map out the evolution of cosmological expansion.”

The research will take advantage of high performance computing at Argonne’s Laboratory Computing Resource Center.

“You really need supercomputing resources to be able to make predictions for galaxies in the large volumes we are simulating,” Hearin said. “Our modeling approach has been designed from the ground up to do exactly that.”

The project continues efforts by Saito and Hearin, who are longtime collaborators, to create a more inclusive community of high energy physics researchers. In 2019, they founded the Midwest Cosmology Network to provide a collaborative forum for researchers who belong to relatively small, isolated cosmology groups at colleges and universities.

In addition to research positions for one undergraduate, doctorate and postdoctorate student each, the program will also enable the collaborative work at Argonne.

The resulting framework and data will be available to other researchers who seek to analyze data from DESI and similar surveys. “People working on understanding galaxies can use the catalogs generated by this project,” Saito said.

In total, the DOE Office of Science awarded $37 million in funding to 52 projects representing 44 institutions. Hearin’s and Saito’s project is one of 10 projects affiliated with Argonne to receive this funding. The FAIR initiative aims to build research capacity, infrastructure and expertise at institutions historically underrepresented in the Office of Science portfolio, including minority serving institutions and emerging research institutions.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

Argonne National Laboratory

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August 15, 2023
Physicist Vinícius Duarte wins a $2.5 million Early Career Research Award

Newswise — Vinícius Duarte, a research physicist at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), has won a prestigious $2.5 million Early Career Research Program Award sponsored by the DOE’s Office of Science. Duarte will use the five-year funding to advance the understanding of processes that lead to the loss of high-energy particles in tokamak fusion facilities. The award is one of 93 totaling $135 million that the DOE has provided this year to recipients at universities and national laboratories.

“I feel honored and excited to receive this award,” said Duarte, who received his doctorate from the University of São Paulo in 2017 and was a postdoctoral fellow at PPPL before becoming a member of the research staff in 2020. “This will provide the resources for our team to address an important research gap for ITER and next-generation fusion devices.”

Devices such as ITER, the international tokamak under construction in the south of France, combine light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — to generate massive amounts of energy. Scientists around the world are seeking to reproduce and control fusion for a virtually inexhaustible supply of safe and clean power to generate electricity.

Energetic particles

This Early Career Award, which will include support for two postdoctoral researchers, will enable the team to study the behavior of energetic particles in the presence of different types of external heating and different waves that can destabilize fusion plasmas. Efficiently confining such particles will be essential to the design of future fusion power plants, Duarte said.

His Early Career Award is the ninth won by a PPPL physicist since 2010 and the latest recognition for Duarte, who received the Brazilian Physical Society prize for his doctoral thesis. He began a three-year term on the editorial advisory board of Physics of Plasmas, a monthly peer-reviewed journal, in January of this year.

Duarte grew interested in plasma physics as an undergraduate at the University of Campinas in Brazil. Two factors drew him into the field. First, plasmas combine several physics disciplines such as electrodynamics and statistical physics within it. Second, studying plasmas allowed Duarte to develop and use more physical intuition than the study of other topics such as quantum mechanics or particle physics. “I was very fortunate to be introduced to plasma physics as an undergraduate by a great teacher and mentor,” he recalled. Read more about the 2023 award program here.

PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science

Princeton Plasma Physics Laboratory

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August 4, 2023
Four Brookhaven Scientists Receive Early Career Research Awards

Newswise — UPTON, NY—Four scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have been selected by DOE’s Office of Science to receive significant funding through its Early Career Research Program. The program, which began in 2010, bolsters the nation’s scientific workforce by supporting exceptional researchers at the outset of their careers, when many scientists do their most formative work.

The awards are a part of the DOE’s long-standing efforts to develop the next generation of STEM leaders to solidify America’s role as the driver of science and innovation around the world.

“Supporting America’s scientists and researchers early in their careers will ensure the United States remains at the forefront of scientific discovery,” said U.S. Secretary of Energy Jennifer M. Granholm. “The funding announced today gives the recipients the resources to find the answers to some of the most complex questions as they establish themselves as experts in their fields.”

DOE is recognizing a total of 93 awardees representing 47 universities and 12 DOE National Laboratories in 27 states. Awardees were selected based on peer review by outside scientific experts.

The projects announced today are selections for negotiation of a financial award, and cover projects lasting up to five years in duration. The final details for each are subject to final grant and contract negotiations between DOE and the awardees. The Early Career Research Program is funded by DOE’s Office of Science.

Information about the 93 awardees and their research projects is available on the Early Career Research Program webpage.

This year’s Brookhaven Lab awardees are:

Elizabeth (Liza) Brost, “Shining Light on the Higgs Self-Interaction”

Elizabeth Brost, an associate scientist in Brookhaven Lab’s Physics Department, will receive funding through the DOE’s Office of High Energy Physics to study properties of the Higgs boson, including its self-interaction.

Discovered in 2012 at the Large Hadron Collider (LHC) at CERN in Switzerland, the Higgs boson is the fundamental particle associated with the Higgs field, which imparts mass to other fundamental particles. The Standard Model of particle physics, scientists’ best understanding of the particles and forces that make up our world, predicts that the Higgs field can interact with itself. This self-interaction should contribute to the production of pairs of Higgs bosons at the LHC. Brost’s studies of Higgs pair production will provide a path towards measuring the Higgs self-interaction—and ultimately a deeper understanding of the Higgs boson’s role in the Standard Model.

One major challenge is that pair production of Higgs bosons is extraordinarily rare in proton-proton collisions at the LHC—more than 1000 times rarer than collisions producing single Higgs bosons! In this project, Brost will lead the development of novel techniques to select fruitful collision data in real time using machine learning algorithms. Using data from the LHC’s ATLAS detector, she and her collaborators will search for the direct and indirect effects of “new physics” beyond the Standard Model on Higgs pair production. These measurements may confirm that the Higgs behaves as expected in the Standard Model. Or they may point to the influences of new physics, which must then be incorporated into explanations of the Higgs mechanism and other areas of physics.

“I am honored to receive this Early Career Award, which will enable me to pursue some of the most interesting open questions in high energy physics,” Brost said. “The analysis and data-collection techniques developed through this project will advance our understanding of the Higgs boson at unprecedented scales, not only at the LHC but also at proposed future colliders.”

Brost earned her undergraduate degree in physics and French from Grinnell College in 2010 and her Ph.D. in physics from the University of Oregon in 2016. After serving as a postdoctoral research associate at Northern Illinois University from 2016 to 2019, she joined Brookhaven National Laboratory as an assistant physicist. She was promoted to associate physicist in 2021. Stationed at Europe’s CERN laboratory, home to the LHC, Brost has led groups of hundreds of ATLAS physicists on a range of analyses and detector upgrades, many associated with “di-Higgs” searches. She also has extensive experience mentoring students and postdocs, who will play important roles in executing the goals of this Early Career Award project.

Esther Tsai, “Virtual Scientific Companion for Synchrotron Beamlines”

Esther Tsai, a scientist in the Electronic Nanomaterials Group of the Center for Functional Nanomaterials (CFN), aims to strengthen the interactions between human scientists and the artificial intelligence/machine learning (AI/ML) tools that can accelerate their research. With funding from the DOE Office of Basic Energy Sciences, she is developing a revolutionary system that will allow scientists to launch experiments and analyze data using a conversational interface.

She’s particularly interested in alleviating bottlenecks at the National Synchrotron Light Source II (NSLS-II)—a source of extremely intense x-rays used by more than 1,700 researchers from universities, industry, and other national laboratories each year to study the properties of a wide range of materials. Currently, CFN and NSLS-II staff collaborate with these facility “users,” assisting in the setup, scientific planning/discussion, and analysis of data from experiments at several beamlines run in partnership by these two DOE Office of Science user facilities. Their research on complex materials has the potential to improve the performance of electronics, solar cells, batteries, and other applications. But the beamlines are often understaffed and oversubscribed.

“Beamline scientists have the daunting mission of supporting various aspects of beamline operation and user science through tireless and sleepless efforts,” Tsai said.

Her goal is to develop a virtual scientific companion, known as VISION, that will synergistically connect researchers with computational tools to speed up the experimentation so everyone can make more discoveries—and possibly get more sleep.

The virtual assistant will leverage modern developments in natural language (NL) processing and language models—the technology underpinning the revolutionary capabilities of chatbots and AI assistants. Tsai will tailor these methods to scientific experiments, allowing researchers to input queries in ordinary language without the need for complex coding. VISION will transcribe NL voice to text, acquire and analyze data, visualize results, and provide advanced learning algorithms and physics modeling to suggest optimal experiment design or hypotheses for further exploration. This powerful, general approach can be extended to a host of scientific instruments to accelerate the pace of discovery across the DOE complex.

“We’re not taking humans out of the picture; we’re actually making it easier for humans to use their natural form of expression, whether speaking or texting, to leverage the strengths of powerful AI/ML programming. We envision a new era where human NL-based communication will be the only needed interface for scientific experimentation and design,” said Tsai.

“It is a great honor and responsibility to receive this Early Career Award. I am so very grateful for the support I’ve received from colleagues at Brookhaven and especially my group leader, Kevin Yager,” Tsai said. “I will continue to need their support to introduce this new paradigm of NL-controlled scientific expedition.”

Tsai earned a bachelor’s degree in electrical engineering in 2009 and a Ph.D. in electrical and computer engineering in 2014, both from Purdue University. Before joining Brookhaven Lab’s CFN as an assistant scientist in 2018, she conducted postdoctoral research and provided user support at the Swiss Light Source at the Paul Scherrer Institute from 2015 to 2018. She was promoted to associate scientist at Brookhaven in 2021, and to scientist in 2023.

Derong Xu, “Luminosity Maximization with Flat Hadron Beams”

Derong Xu, an assistant physicist working on the future Electron-Ion Collider (EIC) at Brookhaven Lab, is striving to maximize the collider’s most important figure of merit by maintaining the flatness of a beam of ions travelling at nearly the speed of light.

The EIC will collide two beams—one containing electrons and the other containing protons or other atomic nuclei. The collisions between individual electrons and other ions will produce data that scientists will use to study the internal structure of protons and nuclei, including the arrangement of those particles’ quarks and gluons. If more particle collisions occur, scientists can produce and analyze more data that contribute to our understanding of how visible matter evolved from the quark-gluon plasma studied over the past two decades at the Relativistic Heavy Ion Collider (RHIC), an Office of Science user facility at Brookhaven.

Physicists can increase the likelihood of these collisions occurring by reducing beam size—packing the same number of particles into a smaller space. This methodology, known as maximizing “luminosity,” is exactly what Xu will work on for the EIC with funding from DOE’s Office of Nuclear Physics. According to calculations by Xu and his colleagues, flattening the ion beam of the EIC will help attain the maximum luminosity. This approach has never been used in a hadron collider—a machine that collides composite particles made of quarks and gluons.

Though scientists can generate flat ion beams, maintaining this flatness as trillions of charged particles whirl around a collider is a challenge. There are numerous potential interactions, such as those between beams and the superconducting accelerator magnets, that could compromise the quality of the beam and make it harder to focus it to a small, flat spot size at the collision point. Xu’s work will dissect the interactions that could alter beam flatness and investigate methods to reduce or eliminate these effects to maintain high luminosity.

“Our efforts to improve the luminosity for the EIC will also benefit other future colliders,” said Xu. “I am excited to contribute to this important research endeavor.”

“I am deeply honored to receive this award and express my heartfelt gratitude for this exceptional opportunity,” Xu added. “The challenge of using a flat beam in future colliders captivates me, and I am eager to explore this topic further.”

Xu studied accelerator physics at the University of Science and Technology of China (USTC), receiving a bachelor’s degree in 2011 and a Ph.D. in 2016. Xu was a postdoctoral fellow from 2017 to 2018 and then a research fellow from 2018 to 2019 at the National Synchrotron Radiation Laboratory at USTC. Xu’s work on the EIC began at Michigan State University in 2019 and continued at Brookhaven when he joined the Lab in 2021 as an assistant physicist.

Joanna M Zajac, “Interactions of QDs’ Fast Light in Rb Vapors for Hybrid Quantum Information Science and Technology”

Joanna M Zajac, a quantum scientist in the Instrumentation Division, is tackling one of the biggest challenges in quantum networking—developing a fundamental understanding of fast light-matter interconnects that could one day facilitate long distance quantum networks.

With funding from the DOE Office of Basic Energy Sciences, she will design and build systems that use quantum dots (QD) to generate identical single photons (the simplest fundamental portions of light) in the wavelengths used for optical telecommunication. Quantum dots are light-emitting semiconductor nanostructures whose emission can be tuned to different wavelengths. They could potentially generate photons suitable to work at telecommunication and atomic wavelengths. That would help to reduce the high losses currently experienced when quantum information travels through the telecommunication optical fibers network.

The goal is then to couple QD single photons with alkali vapors, such as rubidium (Rb), which can reliably store quantum information. These light-matter interconnects may one day operate as a basis for quantum repeaters that receive and then re-emit quantum information making up nodes of quantum network connected by optical links over long distances. This research could be applied to a range of areas in quantum information science and technology such as quantum computing, quantum communications, and quantum sensing.

“Fast light-matter interconnects made of alkali atomic ensembles and photons from quantum dots (QDs) create a heterogenous system that combines the advantages of its homogenous components’, Zajac said. “Within this project we are going to develop fundamental understanding of interactions therein allowing us to develop components of long-distance quantum networks in the future. This DOE award gives me a fantastic opportunity to explore this important topic among the vibrant scientific community in Brookhaven Lab’s Instrumentation Division and beyond.”

Zajac pursued her education in the United Kingdom, earning her master’s degree in physics from Southampton University in 2008 and her Ph.D. in physics from Cardiff University in 2013. She was a postdoctoral research associate at Heriot-Watt University from 2013 to 2016 and a research fellow at St. Andrews University in 2016. Before joining Brookhaven Lab’s Instrumentation Division as a quantum scientist in 2021, she was a senior researcher at Oxford University (2020-21), United Kingdom.

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.

Follow @BrookhavenLab on social media. Find us on Instagram, LinkedIn, Twitter, and Facebook.

Denise Yazak and Danielle Roedel contributed to the writing of this news release.

Brookhaven National Laboratory

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August 4, 2023
Five ORNL scientists to receive DOE Early Career Research awards

Newswise — The Department of Energy’s Office of Science has selected five Oak Ridge National Laboratory scientists for Early Career Research Program awards.

Since its inception in 2010, the program bolsters national scientific discovery by supporting early career researchers in fields related to the Office of Science’s eight major program offices: Advanced Scientific Computing Research, Biological and Environmental Research, Basic Energy Sciences, Fusion Energy Sciences, High Energy Physics, Nuclear Physics, Accelerator R&D and Production and Isotope R&D and Production.

The awards are typically restricted to scientists in the first 10 years of their careers, but eligibility this year was extended to 12 years in recognition of complications from the COVID-19 pandemic. Many researchers complete their most formative work in these early career years.

“Supporting America’s scientists and researchers early in their careers will ensure the United States remains at the forefront of scientific discovery,” said U.S. Secretary of Energy Jennifer M. Granholm. “The funding announced today gives the recipients the resources to find the answers to some of the most complex questions as they establish themselves as experts in their fields.”

A total of 93 scientists nationwide, employed across 12 DOE national laboratories and 47 universities, will receive funding through this year’s program.

“Support for these talented researchers is vital to ORNL’s goal of furthering the nation’s scientific priorities,” ORNL Interim Director Jeff Smith said. “Their scientific contributions will help in addressing challenges in quantum materials and computing, environmental systems and fusion energy.”

The ORNL researchers receiving awards include:

Matthew Brahlek, an R&D staff scientist in the Materials Science and Technology Division, was selected by the Basic Energy Sciences program for his proposal, “Epitaxially Imposed Control of Chiral Transport Phenomena.”

Due to their exotic states, materials with chiral symmetry, or a lack of mirror symmetry, offer key advantages in quantum-based technologies. To fully exploit their properties, however, scientists must simultaneously control a material’s underlying symmetry and dimensionality. In this project, Brahlek will create new chiral systems by combining dissimilar materials at the atomic level as atomically thin crystalline films. These new materials will allow for targeted control of symmetry and dimensionality to enable the discovery of new exotic superconductors and unusual low dimensional states. The resulting fundamental design principles established will drive the development of a new generation of quantum materials.

Jack Cahill, an R&D associate scientist in the Biosciences Division, was selected by the Biological and Environmental Research Program for his proposal, “Elucidation and Validation of Genes Associated with Biological Nitrification Inhibition in Populus.”

Nitrogen use efficiency, the amount of nitrogen used by a crop compared to the amount of nitrogen added, greatly impacts natural carbon sequestration. Bioenergy crops typically have low nitrogen use efficiency – as much as 70% of added nitrogen is lost as waste – which leads to poor carbon sequestration. Biological nitrification inhibitor molecules released from plants prevent such nitrogen loss by slowing nitrification processes. With this proposal, Cahill will conduct experiments to identify genes associated with such molecules in common bioenergy crop poplar, analyze nitrification in the soil surrounding poplar roots and ultimately improve crops’ efficiency and carbon sequestration.

Eugene Dumitrescu, a staff research scientist in the Computational Science and Engineering Division, was selected by the Advanced Scientific Computing Research program for his proposal, “MLRep4QC3: Multi-Linear Representations for Quantum Characterization, Control, and Computation.”

Quantum processes have greatly expanded the boundaries of modern science, but scientists lack high-level operational methods for controlling quantum states. Dumitrescu aims to accelerate computational science by identifying where quantum control is possible with classical computing resources. To overcome scalability problems with prior models, Dumitrescu will develop multi-linear representation, or MLRep, algorithms, powerful tools to represent quantum states and minimize computational requirements for quantum characterization. Dumitrescu will then assess the quality of quantum processes and demonstrate the feasibility of MLRep algorithms for controlling quantum states. Finally, the algorithms will be compiled into a linear algebra package evaluating classical computing’s potential in quantum control.

Takaaki Koyanagi, an R&D staff scientist in the Materials Science and Technology Division, was selected by the Fusion Energy Sciences Program for his proposal, “Mechanistic framework for additive manufacturing of highly radiation-resistant SiC components.”

Despite its potential as a carbon-free energy source, fusion power still faces several challenges, including a need for irradiation-resistant components. Koyanagi aims to develop these critical parts by combining the benefits of silicon carbide, a promising material for fusion energy system components, with the flexibilities of additive manufacturing. Specifically, Koyanagai will use binder jet 3D printing and chemical vapor infiltration of silicon carbide, a novel process developed at ORNL, to additively manufacture components. He will determine the products’ ideal microstructure for fusion through neutron irradiation experiments at ORNL’s High Flux Isotope Reactor, high-throughput processing and machine learning data analysis.

Dan Lu, a senior staff scientist in the Computational Sciences and Engineering Division, was selected by the Biological and Environmental Research program for her proposal, “Integrating Machine Learning Models into E3SM for Understanding Coastal Compound Flooding.”

Coastal urban regions have a unique importance to economic and environmental health. Because of population increases and coastal development, these areas are acutely threatened by the risk of severe flooding. Further research is needed to understand backwater effects, which occur when downstream water levels are higher than river water levels and are often responsible for coastal flooding. To address this need, Lu will use DOE’s Energy Exascale Earth System Model, or E3SM, alongside machine learning methods to create a data- and physics-driven river model for evaluating backwater effects and modeling floods, with the goal of establishing reliable predictions to mitigate floods.

Awardees will receive a combined $135 million across five years to cover salary and research expenses. The final details for each project award are subject to final grant and contract negotiations between DOE and the awardees.

UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.

Oak Ridge National Laboratory

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August 4, 2023
Camera array detects optical emission of gamma-ray burst

Newswise — Researchers led by Dr. XIN Liping from the Space-based Multi-band Astronomical Variable Objects Monitor (SVOM) research team, National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), have detected the prompt optical emission and its transition to the early afterglow of a gamma-ray burst (GRB 201223A), using the Ground Wide Angle Camera Array (GWAC) located at Xinglong Observatory of NAOC.

The study was published in Nature Astronomy on April 10.

Gamma-ray bursts (GRBs) are produced by the collapse of massive stars or the merger of binary neutron stars. They are accompanied by extreme relativistic jets emitting enormous amounts of energy within a few seconds of the bursts. This phenomenon includes the prompt emission caused by the shock in the jet and the afterglow produced by interaction between the jet and external medium.

Typical high-energy emission lasts only a few milliseconds to tens of seconds, and it is difficult to follow up in real time when ground-based optical telescopes receive alerts triggered by space-based high-energy instruments. Up till now, only a few cases of optical emission have been detected before the end of prompt high-energy emission. These GRBs have longer duration of high-energy emission (>30 seconds). Furthermore, all these measurements were contaminated with reverse shock, making it difficult to clearly review the transition from prompt emission to afterglow.

GWAC, proposed and led by Prof. WEI Jianyan, principal investigator of the SVOM mission, is one of the key ground-based telescopes for the SVOM project. It can cover an ultra-large sky area with a temporal resolution of 15 seconds and a detection capability of magnitude 16. Its scientific purpose is to conduct systematic research on the prompt optical emission of GRBs discovered by the SVOM mission.

In this study, GWAC recorded the entire process—before, during and after the trigger time of the burst. The duration of the high-energy emission was 29 seconds. The emergence of optical and gamma-ray emissions was detected simultaneously.

“The prompt optical emission is far brighter than expected by about four orders of magnitude, if only gamma-ray emission is analyzed, which requires a special physical interpretation for these measurements,” said by Dr. XIN.

According to joint analysis using the follow-up observations by F60A, an optical telescope jointly operated by NAOC and Guangxi University, the complete transition from prompt optical emission to afterglow was clearly achieved without any contamination from reverse shock.

The extremely early unique data provided by GWAC place a fine constraint on the characteristics of the progenitor. Scientists expect strong stellar winds around a massive star, which is thought to be the ideal progenitor of a gamma-ray burst. However, the stellar wind is quite small for this event, even at a very close distance from the burst, thus suggesting the progenitor has a small stellar mass.

After the launch of SVOM, simultaneous observations by GWAC and SVOM space-based instruments will have the potential to provide essential data for GRB studies, and finally a large sample with prompt optical observations will be built during SVOM mission.

Chinese Academy of Sciences

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April 28, 2023
Garnet solid electrolytes can be recycled via thermal healing

Newswise — Metallic lithium is considered as the ultimate anode material of next-generation high-performance energy storage system, owing to its ultrahigh theoretical specific capacity (3860 mA h g^-1), ultralow electrochemical potential (-3.04 V vs. the standard hydrogen electrode), and low density (0.534 g cm^-3). Employing Li metal as high-capacity anode, solid-state lithium-metal batteries (SSLMBs) are becoming one of the most promising candidates for next-generation energy storage devices, due to their high safety and potential high energy density. SSLMBs are expected to be the future for conventional lithium-ion batteries. However, the development of SSLMBs is still limited, due to the severe safety issues caused by the uncontrolled Li dendrite formation and growth. Besides, the strategies focusing on healing or recycling solid electrolytes with Li dendrite penetration are rarely reported.

Recently, a study is led by the group of Prof. Wei Liu (School of Physical Science and Technology, ShanghaiTech University). In this study, they demonstrate a facile method for healing and recycling garnet electrolytes (Ta doped Li₇La₃Zr₂O₁₂: LLZTO) with Li dendrites through heat treatment. Excitingly, the recycled garnet ceramic pellets have increased ionic conductivity with higher relative density, which is due to the dendrite-derived species (LiOH and Li₂CO₃) in the grain boundaries are able to promote further densification of garnet electrolyte pellets during thermal healing process as sintering aids (Figure). Compared with pristine garnet electrolyte pellets, the relative density of the recycled garnet pellets is improved from 90.9% to 95.3%, and ionic conductivity is improved from 0.39 to 0.62 mS cm^-1. Benefited from the enhanced relative density and ionic conductivity, a higher critical current density (CCD) is achieved, suggesting a better suppression effect on Li dendrite penetration.

See the article:

Recycling of garnet solid electrolytes with lithium-dendrite penetration by thermal healing

https://link.springer.com/article/10.1007/s40843-022-2371-9

Science China Press

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April 21, 2023
Citizen Science: From the cosmos to the classroom

Newswise — Citizen science projects offer the general public, or segments of that public such as school students, an opportunity to take part in scientific research. The Extreme Energy Events (EEE) Project in Italy is a cooperation between particle physicists studying cosmic rays and school students, and their teachers, throughout the country.

This has the twin aims of bringing cosmic ray research into schools and setting up a country-wide ‘open laboratory’ of particle detectors. One of the lead researchers from the EEE Project consortium, Silvia Pisano of the Italian Centro Fermi and Laboratori Nazionali di Frascati of INFN, Rome, Italy, has summarised the results from about 20 years of this project in a new paper in EPJ Plus.

Cosmic rays are high-energy particles that travel through space at nearly the speed of light; when they come into contact with the earth’s atmosphere they produce a variety of secondary particles that can be detected when they reach ground level. One primary cosmic ray can produce a shower of such particles that completely covers a city the size of, for instance, Bologna. “There are still many open questions about these secondary particles, such as the full details of their energy spectra,” explains Pisano.

The EEE network consists of about 60 detectors or “EEE telescopes” located across Italy, mostly in high schools. Students and their teachers are involved in all aspects of the project: installation and maintenance of the equipment, data collection and analysis, and disseminating the results. “The peculiarity of an experiment designed in this way is that it can look for correlations between events that are hundreds of kilometres apart,” adds Pisano. She and her collaborators are now planning to extend the network to include more schools, including some outside Italy.

Another ongoing development is the design of a mixture of gases for the detectors to replace the powerful greenhouse gas tetrafluoroethane; school students are involved in this and other improvements. “This experiment provides a unique environment for educating future generations in the practice of science,” Pisano concludes.

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Reference:

S. Pisano on behalf of the EEE Collaboration. The extreme energy events project. Eur. Phys. J. Plus 137, 1190 (2022). https://doi.org/10.1140/epjp/s13360-022-03331-0

Further information:

This is the first paper of the EPJ Plus Focus Point Issue “Citizen science for physics: From Education and Outreach to Crowdsourcing Fundamental Research” which is open for submissions until 30th June 2023. Suitable papers will be published if and as soon as accepted. For further information see the Call for Papers.

Springer

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January 20, 2023
Playing all the angles: A high-contrast grating structure for direction-tunable lasing

Newswise — Lasers find applications across several fields ranging from telecommunications and remote sensing to medicine. There are many ways in which one can generate laser emission, or lasing, from a device or material. Consequently, there are many types of lasers with different principles of operation.

One emerging and promising method to achieve lasing with high energy efficiency is by leveraging what are known as “bound states in the continuum” (BICs). In simple terms, these states describe waves that remain highly localized in space but co-exist with a continuous spectrum of waves that are not localized (traveling waves). When dealing with light, an electromagnetic wave, BICs can be realized by carefully designing the geometry of a confining periodic structure.

Although scientists have already reported a few types of BIC-based lasers, most of them can only emit a beam in a perfectly or almost perfectly vertical direction away from the surface of the device. This limitation hinders the use of such BIC lasers in applications where angling the emitted beam is necessary.

To tackle this problem, a research team from National Yang Ming Chiao Tung University (NYCU) in Taiwan recently engineered a new BIC laser device whose lasing direction can be easily tuned. Their study, published in Advanced Photonics, was headed by Tien-Chang Lu, Distinguished Professor in the Department of Photonics at NYCU. According to Lu, one of the main reasons that motivated the team to create this new directional laser was its potential use in lidar systems. “In current lidar techniques, laser light scanning is primarily done using mechanical or microelectromechanical mirrors, which are bulky, expensive, and potentially unreliable in rugged road conditions,” he explains. “Many people are trying hard to build a true solid-state lidar system that can eliminate these mechanical mirrors yet meet the demand for beam-steering capabilities.”

The proposed BIC laser design addresses precisely this demand for beam steerability. In their work, the team carefully designed a device geometry that produces Friedrich–Wintgen BIC (FW-BIC). This type of BIC originates from the coupling of two resonance states (energy states behaving as bound states near the resonance energy but as continuum states at energies far from the resonance energy) residing in the same cavity and radiating over the same emission channel. The main condition to create FW-BIC is that the radiation coming from these resonances should interfere destructively with each other in the far field (that is, away from the device) region, ensuring that their energy is necessarily trapped within the cavity. Simply put, the light contained in an FW-BIC laser device is strongly confined and undergoes very little attenuation over time (implying a high Q factor), providing a perfect environment for reaching lasing conditions.

But how does FW-BIC help develop a directional laser? To find out, the researchers constructed a laser cavity using a one-dimensional suspended high-contrast grating structure that gave rise to FW-BIC. They found that changing the geometry of this grating affected the coupling modes of the FW-BIC and, in turn, altered the direction of the emitted beam. This fascinating property provided a straightforward way to change the emission angle with great precision. “In our experiments, we could adjust the emission angle over a wide range, specifically from -40° to +40°, which is the largest angle demonstrated experimentally for BIC lasers,” highlights Lu. “This feature also provides greater flexibility and could allow us to design a laser array for multi-angle lasing with a field of view of up to 80°. This would be a desirable feature for solid-state lidar applications.”

The team has high expectations for their proposed beam-steering solution, which does not require any external passive components to modulate the emission angle and, thus, achieves a higher power efficiency. Hopefully, the proposed design would bring about the development of large-scale, high-resolution laser scanning systems with applications in lidar and 3D sensing.

Read the Gold Open Access article by Z.-T. Huang et al., “Tunable lasing direction in one-dimensional suspended high-contrast grating using bound states in the continuum,” Adv. Photon. 4(6), 066004 (2022), 10.1117/1.AP.4.6.066004.

SPIE

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January 3, 2023
Opening the eye of the storm

Newswise — For the first time, high-energy muon particles created in the atmosphere have allowed researchers to explore the structures of storms in a way that traditional visualization techniques, such as satellite imaging, cannot. The detail offered by this new technique could aid researchers modeling storms and related weather effects. This could also lead to more accurate early warning systems.

It’s hard not to notice the number of stories in the news about heavy storms in different parts of the world, often attributed to climate change. Weather prediction and early warning systems have always been important, but with increased storm activity it seems especially so these days. A team of researchers, led by Professor Hiroyuki Tanaka from Muographix at the University of Tokyo, offer the world of meteorology a novel way of detecting and exploring tropical cyclones using a quirk of particle physics that takes place above our heads all the time.

“You’ve probably seen photographs of cyclones taken from above, showing swirling vortices of clouds. But I doubt you’ve ever seen a cyclone from the side, perhaps as a computer graphic, but never as actual captured sensor data,” said Tanaka. “What we offer the world is the ability to do just this, visualize large-scale weather phenomena like cyclones from a 3D perspective, and in real time too. We do this using a technique called muography, which you can think of like an X-ray, but for seeing inside truly enormous things.”

Muography creates X-ray-like images of large objects, including volcanoes, the pyramids, bodies of water, and now, for the first time, atmospheric weather systems. Special sensors called scintillators are joined together to make a grid, a little like the pixels on your smartphone’s camera sensor. However, these scintillators don’t see optical light, but instead see particles called muons which are created in the atmosphere when cosmic rays from deep space collide with the atoms in the air. Muons are special because they pass through matter easily without scattering as much as other types of particles. But the small amount they do deviate by as they pass through solid, liquid, or even gaseous matter, can reveal details of their journey between the atmosphere and the sensors. By capturing a large number of muons passing through something, an image of it can be reconstructed.

“We successfully imaged the vertical profile of a cyclone, and this revealed density variations essential to understanding how cyclones work,” said Tanaka. “The images show cross sections of the cyclone which passed through Kagoshima Prefecture in western Japan. I was surprised to see clearly it had a low-density warm core that contrasted dramatically with the high-pressure cold exterior. There is absolutely no way to capture such data with traditional pressure sensors and photography.”

The detector the researchers used has a viewing angle of 90 degrees, but Tanaka envisages combining similar sensors to create hemispherical and therefore omnidirectional observation stations which could be placed along the length of a coastline. These could potentially see cyclones as far away as 300 kilometers. Although satellites already track these storms, the extra detail offered by muography could improve predictions about approaching storms.

“One of the next steps for us now will be to refine this technique in order to detect and visualize storms at different scales,” said Tanaka. “This could mean better modeling and prediction not only for larger storm systems, but more local weather conditions as well.”

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Journal article: Hiroyuki K.M. Tanaka, Jon Gluyas, Marko Holma, Jari Joutsenvaara, Pasi Kuusiniemi, Giovanni Leone, Domenico Lo Presti, Jun Matsushima, László Oláh, Sara Steigerwald, Lee F. Thompson, Ilya Usoskin, Stepan Poluianov, Dezső Varga, Yusuke Yokota. “Atmospheric Muography for Imaging and Monitoring Tropic Cyclones”. Scientific Reports.

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University of Tokyo

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October 7, 2022