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  • richardmitnick 12:59 pm on December 10, 2018 Permalink | Reply
    Tags: Electronic switching in an exotic ultrathin material that can carry a charge with nearly zero loss at room temperature, LBNL ALS, , Topological Matters: Toward a New Kind of Transistor   

    From Lawrence Berkeley National Lab: “Topological Matters: Toward a New Kind of Transistor” 

    Berkeley Logo

    From Lawrence Berkeley National Lab

    December 10, 2018
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    X-ray experiments at Berkeley Lab provide first demonstration of room temperature switching in ultrathin material that could serve as a ‘topological transistor’.

    1
    James Collins, a researcher at Monash University in Australia, works on an experiment at Beamline 10.0.1, part of Berkeley Lab’s Advanced Light Source. (Credit: Marilyn Chung/Berkeley Lab)

    LBNL/ALS

    Billions of tiny transistors supply the processing power in modern smartphones, controlling the flow of electrons with rapid on-and-off switching.

    But continual progress in packing more transistors into smaller devices is pushing toward the physical limits of conventional materials. Common inefficiencies in transistor materials cause energy loss that results in heat buildup and shorter battery life, so researchers are in hot pursuit of alternative materials that allow devices to operate more efficiently at lower power.

    Now, an experiment conducted at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has demonstrated, for the first time, electronic switching in an exotic, ultrathin material that can carry a charge with nearly zero loss at room temperature. Researchers demonstrated this switching when subjecting the material to a low-current electric field.

    2
    From left to right: Shujie Tang, a postdoctoral researcher at Berkeley Lab’s Advanced Light Source (ALS); Sung-Kwan Mo, an ALS staff scientist; and James Collins and Mark Edmonds, researchers at Monash University, gather during an experiment at ALS Beamline 10.0.1 in November. (Credit: Marilyn Chung/Berkeley Lab)

    The team, which was led by researchers at Monash University in Australia and included Berkeley Lab scientists, grew the material from scratch and studied it with X-rays at the Advanced Light Source (ALS) [see above], a facility at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab).

    The material, known as sodium bismuthide (Na3Bi), is one of two materials that is known to be a “topological Dirac semimetal,” meaning it has unique electronic properties that can be tuned to behave in different ways – in some cases more like a conventional material and in other cases more like a topological material. Its topological properties were first confirmed in earlier experiments at the ALS.

    Topological materials are considered promising candidates for next-generation transistors, and for other electronics and computing applications, because of their potential to reduce energy loss and power consumption in devices. These properties can exist at room temperature – an important distinction from superconductors that require extreme chilling – and can persist even when the materials have structural defects and are subject to stress.

    3
    Researchers at Berkeley Lab’s Advanced Light Source used an X-ray technique known as ARPES to produce these images showing the electronic ranges of energy in an ultrathin material. (Credit: Berkeley Lab, Monash University)

    Materials with topological properties are the focus of intense research by the global scientific community (see a related article), and in 2016 the Nobel Prize in physics was awarded for theories related to topological properties in materials.

    The ease in switching the material studied at the ALS from an electrically conducting state to an insulating, or non-conducting state, bode well for its future transistor applications, said Sung-Kwan Mo, a staff scientist at the ALS who participated in the latest study. The study is detailed in the Dec. 10 edition of the journal Nature.

    See the full article here .

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    In the world of science, Lawrence Berkeley National Laboratory (Berkeley Lab) is synonymous with “excellence.” Thirteen Nobel prizes are associated with Berkeley Lab. Seventy Lab scientists are members of the National Academy of Sciences (NAS), one of the highest honors for a scientist in the United States. Thirteen of our scientists have won the National Medal of Science, our nation’s highest award for lifetime achievement in fields of scientific research. Eighteen of our engineers have been elected to the National Academy of Engineering, and three of our scientists have been elected into the Institute of Medicine. In addition, Berkeley Lab has trained thousands of university science and engineering students who are advancing technological innovations across the nation and around the world.

    Berkeley Lab is a member of the national laboratory system supported by the U.S. Department of Energy through its Office of Science. It is managed by the University of California (UC) and is charged with conducting unclassified research across a wide range of scientific disciplines. Located on a 202-acre site in the hills above the UC Berkeley campus that offers spectacular views of the San Francisco Bay, Berkeley Lab employs approximately 3,232 scientists, engineers and support staff. The Lab’s total costs for FY 2014 were $785 million. A recent study estimates the Laboratory’s overall economic impact through direct, indirect and induced spending on the nine counties that make up the San Francisco Bay Area to be nearly $700 million annually. The Lab was also responsible for creating 5,600 jobs locally and 12,000 nationally. The overall economic impact on the national economy is estimated at $1.6 billion a year. Technologies developed at Berkeley Lab have generated billions of dollars in revenues, and thousands of jobs. Savings as a result of Berkeley Lab developments in lighting and windows, and other energy-efficient technologies, have also been in the billions of dollars.

    Berkeley Lab was founded in 1931 by Ernest Orlando Lawrence, a UC Berkeley physicist who won the 1939 Nobel Prize in physics for his invention of the cyclotron, a circular particle accelerator that opened the door to high-energy physics. It was Lawrence’s belief that scientific research is best done through teams of individuals with different fields of expertise, working together. His teamwork concept is a Berkeley Lab legacy that continues today.

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  • richardmitnick 11:46 am on September 25, 2018 Permalink | Reply
    Tags: , , , Coherence, Critical Decision 1 or CD-1, Lab founder Ernest Lawrence’s construction of the first cyclotron particle accelerator in 1930, LBNL ALS, , , Smaller-scale explorations of magnetic properties in multilayer data-storage materials, The dozens of beamlines maintained and operated by Berkeley Lab staff and scientists at the ALS conduct experiments simultaneously at all hours, The upgrade project is dubbed ALS-U, Toward a New Light: Advanced Light Source Upgrade Project Moves Forward,   

    From Lawrence Berkeley National Lab: “Toward a New Light: Advanced Light Source Upgrade Project Moves Forward” 

    Berkeley Logo

    From Lawrence Berkeley National Lab

    September 25, 2018
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582


    VIDEO: Berkeley Lab’s Advanced Light Source takes a next step toward a major upgrade. (Credit: Berkeley Lab)

    The Advanced Light Source (ALS), a scientific user facility at the Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab), has received federal approval to proceed with preliminary design, planning and R&D work for a major upgrade project that will boost the brightness of its X-ray beams at least a hundredfold.

    LBNL/ALS

    The upgrade will give the ALS, which this year celebrates its 25th anniversary, brighter beams with a more ordered structure – like evenly spaced ripples in a pond – that will better reveal nanoscale details in complex chemical reactions and in new materials, expanding the envelope for scientific exploration.

    “This upgrade will make it possible for Berkeley Lab to be the leader in soft X-ray research for another 25 years, and for the ALS to remain at the center of this Laboratory for that time,” said Berkeley Lab Director Mike Witherell.

    Steve Kevan, ALS Director, added, “The upgrade will transform the ALS. It will expand our scientific frontiers, enabling studies of materials and phenomena that are at the edge of our understanding today. And it will renew the ALS’s innovative spirit, attracting the best researchers from around the world to our facility to conduct their experiments in collaboration with our scientists.”

    2
    This computer rendering provides a top view of the ALS and shows equipment that will be installed during the ALS-U project. (Credit: Berkeley Lab)

    The latest approval by the DOE, known as Critical Decision 1 or CD-1, authorizes the start of engineering and design work to increase the brightness and to more precisely focus the beams of light produced at the ALS that drive a broad range of science experiments. The upgrade project is dubbed ALS-U.

    The dozens of beamlines maintained and operated by Berkeley Lab staff and scientists at the ALS conduct experiments simultaneously at all hours, attracting more than 2,000 researchers each year from across the country and around the globe through its role in a network of DOE Office of Science User Facilities.

    This upgrade is intended to make the ALS the brightest storage ring-based source of soft X-rays in the world. Soft X-rays have an energy range that is especially useful for observing chemistry in action and for studying a material’s electronic and magnetic properties in microscopic detail.

    3
    4
    Click the play button on the full article at bottom left to view a slideshow. This slideshow chronicles the history of the Advanced Light Source and the building that houses it, which was formerly home to a 184-inch cyclotron – another type of particle accelerator. It also shows the science conducted at the ALS and includes computer renderings of new equipment that will be installed as a part of the ALS-U project. (Credit: Berkeley Lab)

    The planned upgrade will significantly increase the brightness of the ALS by focusing more light on a smaller spot. X-ray beams that today are about 100 microns (thousandths of an inch) across – smaller than the diameter of a human hair – will be squeezed down to just a few microns after the upgrade.

    “That’s very exciting for us,” said Elke Arenholz, a senior staff scientist at the ALS. The upgrade will imbue the X-rays with a property known as “coherence” that will allow scientists to explore more complex and disordered samples with high precision. The high coherence of the soft X-ray light generated by the ALS-U will approach a theoretical limit.

    “We can take materials that are more in their natural state, resolve any fluctuations, and look much more closely at the structure of materials, down to the nanoscale,” Arenholz said.

    Among the many applications of these more precise beams are smaller-scale explorations of magnetic properties in multilayer data-storage materials, she said, and new observations of battery chemistry and other reactions as they occur. The upgrade should also enable faster data collection, which can allow researchers to speed up their experiments, she noted.

    “We will have a lot of very interesting, new data that we couldn’t acquire before,” she said. Analyzing that data and feeding it back into new experiments will also draw upon other Berkeley Lab capabilities, including sample fabrication, complementary study techniques, and theory work at the Lab’s Molecular Foundry; as well as data processing, simulation and analysis work at the Lab’s National Energy Research Scientific Computing Center (NERSC).

    William Chueh, an assistant professor of materials science at Stanford University who also heads up the users’ association for researchers who use the ALS or are interested in using the ALS, said that the upgrade will aid his studies by improving the resolution in tracking how charged particles move through batteries and fuel cells, for example.

    “I am very excited by the science that the ALS-U project will enable. Such a tool will provide insights and design rules that help us to develop tomorrow’s materials,” Chueh said.

    The upgrade project is a massive undertaking that will draw upon most areas at the Lab, said ALS-U Project Director David Robin, requiring the expertise of accelerator physicists, mechanical and electrical engineers, computer scientists, beamline optics and controls specialists, and safety and project management personnel, among a long list.

    Berkeley Lab’s pioneering history of innovation and achievements in accelerator science, beginning with Lab founder Ernest Lawrence’s construction of the first cyclotron particle accelerator in 1930, have well-prepared the Lab for this latest project, Robin said.

    He noted the historic contribution by the late Klaus Halbach, a Berkeley Lab scientist whose design of compact, powerful magnetic instruments known as permanent magnet insertion devices paved the way for the design of the current ALS and other so-called third-generation light sources of its kind.

    4
    An interior view of the Advanced Light Source. (Credit: Berkeley Lab)

    The ALS-U project will remove more than 400 tons of equipment associated with the existing ALS storage ring, which is used to circulate electrons at nearly the speed of light to generate the synchrotron radiation that is ultimately emitted as X-rays and other forms of light.

    A new magnetic array known as a “multi-bend achromat lattice” will take its place, and a secondary, “accumulator” ring will be added that will enhance beam brightness. Also, several new ALS beamlines are already optimized for the high brightness and coherence of the ALS-U beams, and there are plans for additional beamline upgrades.

    5
    This 1940s photograph shows the original building that housed a 184-inch cyclotron and that now contains the ALS. (Credit: Berkeley Lab)

    The iconic domed building that houses the ALS – which was designed in the 1930s by Arthur Brown Jr., the architect for San Francisco landmark Coit Tower – will be preserved in the upgrade project. The ALS dome originally housed an accelerator known as the 184-inch cyclotron.

    Robin credited the ALS-U project team, with support from all areas of the Lab, in the continuing progress toward the upgrade. “They have done a tremendous job in getting us to the point that we are at today,” he said.

    Witherell said, “The fact that we will have this upgraded Advanced Light Source is an enormous vote of confidence in us by the federal government and the taxpayers.”

    Berkeley Lab’s ALS, Molecular Foundry, and NERSC are all DOE Office of Science user facilities.

    More information:

    ALS-U Overview
    Transformational X-ray Project Takes a Step Forward, Oct. 3, 2016
    A Brief History of the ALS

    See the full article here .


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  • richardmitnick 12:14 pm on August 23, 2018 Permalink | Reply
    Tags: , , Infrared Beams Show Cell Types in a Different Light, Infrared sudies, , LBNL ALS,   

    From Lawrence Berkeley National Lab: “Infrared Beams Show Cell Types in a Different Light” 

    Berkeley Logo

    From Lawrence Berkeley National Lab

    August 23, 2018

    Glenn Robert Jr.
    geroberts@lbl.gov
    (510) 486-5582

    Berkeley Lab scientists developing new system to identify cell differences.

    1
    From left to right: Aris Polyzos, Edward Barnard, and Lila Lovergne, pictured here at Berkeley Lab’s Advanced Light Source, are part of a research team that is developing a cell-identification technique based on infrared imaging and machine learning. (Credit: Marilyn Chung/Berkeley Lab)

    By shining highly focused infrared light on living cells, scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) hope to unmask individual cell identities, and to diagnose whether the cells are diseased or healthy.

    They will use their technique to produce detailed, color-based maps of individual cells and collections of cells – in microscopic and eventually nanoscale detail – that will be analyzed using machine-learning techniques to automatically sort out cell characteristics.

    Using microscopic color maps to unlock cell identity

    Their focus is on developing a rapid way to easily identify cell types, and features within cells, to aid in biological and medical research by providing a way to probe living cells in their native environment without harming the cells or requiring obtrusive cell-labeling techniques.

    “This is totally noninvasive,” said Cynthia McMurray, a biochemist and senior scientist in Berkeley Lab’s Molecular Biophysics and Integrated Bioimaging Division who is leading this new imaging effort with Michael Martin, a physicist and senior staff scientist at Berkeley Lab’s Advanced Light Source (ALS).

    LBNL/ALS

    The ALS has dozens of beamlines that produce beams of intensely focused light, from infrared to X-rays, for a broad range of experiments.

    “We’re looking at the signatures that define what a cell is. We’re interested in cell identity and what determines it,” McMurray said. “I’ve been involved in looking at tissue and the differences in diseased and normal states for a long time, and what I realized is that we could use these infrared beamlines at the ALS to come up with signatures for these cells.”

    Researchers also plan to use the technique to identify and decipher the molecular properties of microbes and plants.

    A goal of the infrared-imaging research, which builds on Berkeley Lab’s strengths in neuroscience, infrared imaging, computation, visualization, engineering, and machine learning, is to find out whether a cell’s specialization is imposed by its environment or whether it is part of the cell’s inherent identity, she said.

    The research could help light a path toward controlling the specialization of cells, for example.

    To verify that the technique works, the team is comparing their infrared-based images side-by-side with images captured using a more conventional imaging technique known as immunofluorescence.

    Already, through unpublished research the team has found differences in the same types of brain cells taken from different locations in the brain. “On the surface they don’t look any different, but if you probe it with infrared light, something about them is different,” she said. The imaging technique can be used to show the location and variety of cell types and cell signatures present in tissue samples. “We are very interested in the interactivity of cells.”

    Initiative targets disease

    Long-term goals for the research are to understand disease progression at a cellular level, and to explore how stem cells transform into other cell types. “We want to watch cells differentiate. What allows cells to make the choice to be something else?” she said.

    Berkeley Lab scientists received a round of seed money through the philanthropic Chan Zuckerberg Initiative DAF (CZI), an advised fund of Silicon Valley Community Foundation, to support their effort, dubbed “spectral phenotyping.”

    An Aug. 8 news article in the journal Science highlighted their work and that of a larger research project called the Human Cell Atlas that aims to provide “a unique ID card for each cell type,” as well as a 3D map of how cells form tissues, and new insights into disease.

    The Chan Zuckerberg Initiative, launched by Facebook founder Mark Zuckerberg and Priscilla Chan, a pediatrician and philanthropist who is married to Zuckerberg, has three focus areas: science, education, and justice and opportunity. The stated goal of the science focus is to support interdisciplinary teams in developing “science and technology that will help make it possible to cure, prevent, or manage all diseases by the end of the century.”

    A key to the infrared-imaging technique, McMurray said, is that it allows cells to exist in their native environment, and doesn’t require any labels or special prepping that could damage or otherwise alter the cells.

    A global focus

    Martin, who is part of the infrared-based cell-imaging research, noted that the properties of infrared light produced at the ALS are rare among the world’s research institutions, and its possible applications in cell identification are largely unexplored.

    The detectors at one of the ALS infrared beamlines are capable of scanning across 1,000 wavelengths for each pixel of the detector – the pixel is the smallest unit of the image – so the cell imaging can generate a large volume of data.

    In designing computer algorithms to sort out cells’ differences, Martin said, “It’s not just about picking one feature. We think it’s more powerful to ask broader questions: What’s the whole suite of differences?”

    By looking across a wide range of infrared wavelengths in each cell image, “Hopefully we’ll find something much deeper,” he said.

    3
    To improve infrared cell-identification to tens-of-nanometers resolution, researchers plan to adapt a synchrotron infrared nanospectroscopy (SINS) system, shown above. The system incorporates highly focused infrared light produced by the Advanced Light Source (integral to “rapid-scan FTIR” or Fourier-transform infrared spectroscopy) and a technique known as atomic force microscopy (AFM). (Credit: Berkeley Lab)

    here are plans to use a new, higher-resolution infrared beamline at the ALS that could resolve cell features down to tens of nanometers (billionths of a meter), he also noted, and to develop a way to flow living cells through the infrared beam for high-throughput imaging.

    While the properties of infrared light produced at the ALS are relatively unique, Martin and McMurray said it’s their hope that the cell-imaging data they generate will prove useful for researchers working with lower-power infrared-imaging tools, too.

    The team’s proposal to the Chan Zuckerberg Initiative outlines a plan to develop a complete, push-button system that ultimately could be used by the broader research community.

    “We want to bring all of this together to develop something that is open to the rest of the world,” Martin said.

    See the full article here .


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  • richardmitnick 7:45 pm on April 26, 2018 Permalink | Reply
    Tags: , DESY FLASH free-electron laser at Germany’s Deutsches Elektronen-Synchrotron, Flowing sheets of liquid just 100 water molecules thick that persist for days in a vacuum, Images of samples suspended in water with two types of light – infrared and ‘soft’, LBNL ALS, , Researchers used X-ray pulses to heat the liquid sheets to thousands of degrees to simulate the extremely warm dense form of water present in giant planets like Jupiter, , The nozzle is a tiny glass chip with three microscopic channels, There are many mysteries in those big planets and they’re important for understanding the evolution of our planetary system as well as others, Thin free-flowing sheets 100 times thinner than any produced before, X-Ray Scientists Create Tiny Super-Thin Sheets of Flowing Water that Shimmer Like Soap Bubbles   

    From SLAC: “X-Ray Scientists Create Tiny, Super-Thin Sheets of Flowing Water that Shimmer Like Soap Bubbles” 


    SLAC Lab

    April 26, 2018
    Glennda Chui

    The liquid sheets – less than 100 water molecules thick – will let researchers probe chemical, physical and biological processes, and even the nature of water itself, in a way they could never do before.

    1
    This tiny glass chip creates super-thin sheets of flowing liquid for X-ray experiments at SLAC’s X-ray laser, LCLS. A stream of liquid flowing through the middle channel is shaped by flows of gas coming in from the channels on either side. (Dawn Harmer/SLAC National Accelerator Laboratory.)

    Water is an essential ingredient for life as we know it, making up more than half of the adult human body and up to 90 percent of some other living things. But scientists trying to examine tiny biological samples with certain wavelengths of light haven’t been able to observe them in their natural, watery environments because the water absorbs too much of the light.

    Now there’s a way around that problem: A team led by scientists at the Department of Energy’s SLAC National Accelerator Laboratory turned tiny liquid jets that carry samples into the path of an X-ray beam into thin, free-flowing sheets, 100 times thinner than any produced before. They’re so thin that X-rays pass through them unhindered, so images of the samples they carry come out clear.

    The new method opens new windows on critical processes in chemistry, physics and biology, including the nature of water itself, the researchers said in an April 10 report in Nature Communications.

    The method was developed at SLAC’s X-ray free-electron laser, the Linac Coherent Light Source (LCLS), but they said it can also work in experiments with synchrotron light sources, tabletop lasers and electron beams.

    SLAC/LCLS

    3
    A series of movies shows how increasing flows of gas that shape a stream of liquid affects the formation of liquid sheets and their soap-bubble-like sheen.

    “This opens up possibilities in a lot of fields,” said SLAC staff scientist Jake Koralek, who led the research with Daniel DePonte, leader of the LCLS Sample Environment Department.

    “Until now, we haven’t been able to make images of samples suspended in water with two types of light – infrared and ‘soft’, lower-energy X-rays – that are important for studying basic processes in physics, chemistry and biology, including the physics of water,” Koralek said.

    “The new nozzle we developed, which can create flowing sheets of liquid just 100 water molecules thick that persist for days in a vacuum, solves that problem. The sheets can even be used to image samples with electron beams that resolve even smaller details.”

    Shaping Liquid with Gas

    The nozzle is a tiny glass chip with three microscopic channels. A stream of liquid flows through the middle channel, shaped by flows of gas coming in from the channels on either side. This particular nozzle was made with photolithography, a technique used to manufacture computer chips, but it could also be crafted with 3-D printing, the researchers noted.

    As the scientists turn up the speed of the gas flow, the liquid stream spreads into a series of sheets whose width and thickness can be precisely controlled. The sheet closest to the nozzle is the widest and thinnest; the farther they get from the nozzle, the narrower and thicker the sheets become until they finally merge into a cylindrical stream.

    53
    These images show the formation of tiny sheets of liquid shaped by jets of gas from a nozzle developed at SLAC. Top: As the gas flow increases, the liquid sheets become bigger. Bottom: The nozzle produces a series of liquid sheets; the one closest to the nozzle is the widest and thinnest. Each sheet is perpendicular to the previous one, so we are seeing the second and fourth sheets from the side.

    The sheets shimmer like soap bubbles in a variety of colors, the result of light reflecting off both the front and back surfaces of the sheet. And just as the contour lines on a topographic map mark differences in elevation, the hue and spacing of a sheet’s ever-changing bands of color indicate how thick it is and how much the thickness changes from one point to another.

    “It’s a very flexible and reliable design for creating both ultrathin and slightly thicker liquid sheets, which can be desirable for some applications” said Linda Young, a distinguished fellow at DOE’s Argonne National Laboratory and professor at the University of Chicago who was not involved in the study.

    She said she will be using the nozzle to make slightly thicker sheets of water for an LCLS study of how water molecules behave after one of their electrons has been ripped away. These ionized water molecules persist for only a few hundred femtoseconds, or millions of a billionth of a second, and “the X-rays provide a completely new and clean wayto monitor their electronic response in their natural environment, so that’s why we’re excited about it,” Young said.

    A New Way to Study Extreme Forms of Water

    The liquid sheets have already been used in experiments that explore the properties of water in extreme environments like those on giant planets, said co-author Siegfried Glenzer, a SLAC professor and head of the lab’s High Energy Density Science Division.

    Those experiments were performed with the FLASH free-electron laser at Germany’s Deutsches Elektronen-Synchrotron (DESY).

    7
    DESY FLASH free-electron laser at Germany’s Deutsches Elektronen-Synchrotron.

    Researchers used X-ray pulses to heat the liquid sheets to thousands of degrees to simulate the extremely warm, dense form of water present in giant planets like Jupiter. Then they measured the reflectivity and conductivity of the super-hot water with optical laser pulses in the instant before the water vaporized. These measurements could only be made on a flat sheet of water.

    “There are many mysteries in those big planets and they’re important for understanding the evolution of our planetary system as well as others,” Glenzer said. “This is a beautiful tool for studying water itself, and in the future we will also study other materials that we can mix into it.”

    8
    A SLAC research team at the LCLS experimental station where they carried out experiments with the sheet-forming nozzle this week. From left: Paper co-authors Zhijiang Chen, Stefan Moeller, Siegfried Glenzer, Jake Koralek and Chandra Curry and area manager Bob Sublett of the LCLS Sample Environment Department. (Dawn Harmer/SLAC National Accelerator Laboratory)

    The team measured the thickness of the sheets with a beam of infrared light at the Advanced Light Source at the DOE’s Lawrence Berkeley National Laboratory, and also demonstrated that the sheets could be used for infrared spectroscopy, where light absorbed by a material reveals its chemical makeup.

    LBNL/ALS

    LCLS and the Advanced Light Source are DOE Office of Science user facilities. In addition to researchers from SLAC, Berkeley Lab and DESY, scientists from the ELI Beamlines Institute of Physics of the Czech Academy of Sciences, Dartmouth College, the University of Alberta in Canada and the European X-ray Free-Electron Laser Facility (European XFEL) in Germany contributed to this work. Major funding came from the DOE Office of Science and the National Institutes of Health, National Institute of General Medical Sciences.

    See the full article here .

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    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.

     
  • richardmitnick 11:27 am on April 4, 2018 Permalink | Reply
    Tags: , , , LBNL ALS, , Scientists confirm water trapped inside diamonds deep below Earth’s surface,   

    From University of Chicago: “Scientists confirm water trapped inside diamonds deep below Earth’s surface” 

    U Chicago bloc

    University of Chicago

    March 30, 2018
    Karen Mellen

    1
    Researchers working at Argonne National Laboratory have identified a form of water trapped within diamonds that crystallized deep in the Earth’s mantle. (Pictured: Rough diamond in kimberlite.) Copyright Getty Images.

    Water occurs naturally as far as at least 250 miles below the Earth’s surface, according to a study published in Science last week by researchers from the University of Chicago and others. The discovery, which relies on extremely bright X-ray beams from the Advanced Photon Source at Argonne National Laboratory, could change our understanding of how water circulates deep in the Earth’s mantle and how heat escapes from the lower regions of our planet.


    ANL/APS

    The researchers identified a form of water known as Ice-VII, which was trapped within diamonds that crystallized deep in the Earth’s mantle. This is the first time Ice-VII has been discovered in a natural sample, making the compound a new mineral accepted by the International Mineralogical Association.

    The study is the latest in a long line of research projects at the Advanced Photon Source, a massive X-ray facility used by thousands of researchers every year, which have shed light on the composition and makeup of the deep Earth. Humans cannot explore these regions directly, so the Advanced Photon Source lets them use high-powered X-ray beams to analyze inclusions in diamonds formed in the deep Earth.

    2
    UChicago researchers involved in the work at Argonne’s Advanced Photon Source included (from left): Vitali Prakapenka, Tony Lanzirotti, Matt Newville, Eran Greenberg and Dongzhou Zhang. (Photo by Rick Fenner / Argonne National Laboratory).

    “We are interested in those inclusions because they tell us about the chemical composition and conditions in the deep Earth when the diamond was formed,” said Antonio Lanzirotti, a UChicago research associate professor and co-author on the study.

    In this case, researchers analyzed rough, uncut diamonds mined from regions in China and Africa. Using an optical microscope, mineralogists first identified inclusions, or impurities, which must have formed when the diamond crystallized. But to positively identify the composition of these inclusions, mineralogists needed a stronger instrument: the University of Chicago’s GeoSoilEnviroCARS’s beam lines at the Advanced Photon Source.

    Thanks to the very high brightness of the X-rays, which are a billion times more intense than typical X-ray machines, scientists can determine the molecular or atomic makeup of specimens that are only micrometers across. When the beam of X-rays hits the molecules of the specimen, they scatter into unique patterns that reveal their molecular makeup.

    What the team identified was surprising: water, in the form of ice.

    The composition of the water is the same as the water that we drink and use every day, but in a cubic crystalline form—the result of the extremely high pressure of the diamond.

    This form of water, Ice-VII, was created in the lab decades ago, but this study was the first to confirm that it also forms naturally. Because of the pressure required for diamonds to form, the scientists know that these specimens formed between 410 and 660 kilometers (250 to 410 miles) below the Earth’s surface.

    The researchers said the significance of the study is profound because it shows that flowing water is present much deeper below the Earth’s surface than originally thought. Going forward, the results raise a number of important questions about how water is recycled in the Earth and how heat is circulated. Oliver Tschauner, the lead author on the study and a mineralogist at University of Nevada in Las Vegas, said the discovery can help scientists create new, more accurate models of what’s going on inside the Earth, specifically how and where heat is generated under the Earth’s crust. This may help scientists better understand one of the driving mechanisms for plate tectonics.

    ___________________________________________________________
    “[T]hanks to the amazing technical capabilities of the Advanced Photon Source, this team of researchers was able to pinpoint and study the exact area on the diamonds that trapped the water”
    Stephen Streiffer, associate laboratory director for photon sciences
    ___________________________________________________________

    “This wasn’t easy to find,” said Vitali Prakapenka, a UChicago research professor and a co-author of the study. “People have been searching for this kind of inclusion for a long time.”

    For now, the team is wondering whether the mineral Ice-VII will be renamed, now that it is officially a mineral. This is not the first mineral to be identified thanks to research done at the Advanced Photon Source GSECARS beamlines: Bridgmanite, the Earth’s most abundant mineral and a high-density form of magnesium iron silicate, was researched extensively there before it was named. Tschauner was a lead author on that study, too.

    “In this study, thanks to the amazing technical capabilities of the Advanced Photon Source, this team of researchers was able to pinpoint and study the exact area on the diamonds that trapped the water,” said Stephen Streiffer, Argonne associate laboratory director for photon sciences and director of the Advanced Photon Source. “That area was just a few microns wide. To put that in context, a human hair is about 75 microns wide.

    “This research, enabled by partners from the University of Chicago and the University of Nevada, Las Vegas, among other institutions, is just the latest example of how the APS is a vital tool for researchers across scientific disciplines,” he said.

    Other GSECARS co-authors are Eran Greenberg, Dongzhou Zhang and Matt Newville.

    In addition to the University of Chicago and UNLV, other institutions cited in the study include the California Institute of Technology, China University of Geosciences, the University of Hawaii at Manoa and the Royal Ontario Museum, Toronto. Data also was collected at Carnegie Institute of Washington’s High Pressure Collaborative Access Team at the Advanced Photon Source and the Advanced Light Source at Lawrence Berkeley National Lab.

    LBNL/ALS

    LBNL Advanced Light Source storage ring

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  • richardmitnick 3:12 pm on March 21, 2018 Permalink | Reply
    Tags: , , , LBNL ALS,   

    From LBNL: “News Center COSMIC Impact: Next-Gen X-ray Microscopy Platform Now Operational” 

    Berkeley Logo

    Berkeley Lab

    March 21, 2018

    A next-generation X-ray beamline now operating at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) brings together a unique set of capabilities to measure the properties of materials at the nanoscale.

    Called COSMIC, for Coherent Scattering and Microscopy, this X-ray beamline at Berkeley Lab’s Berkeley Lab’s Advanced Light Source (ALS) allows scientists to probe working batteries and other active chemical reactions, and to reveal new details about magnetism and correlated electronic materials.

    1
    From left to right: Advanced Light Source scientists Tony Warwick, Sujoy Roy, and David Shapiro at the COSMIC beamline. (Credit: Lori Tamura/Berkeley Lab)

    LBNL/ALS

    COSMIC has two branches that focus on different types of X-ray experiments: one for X-ray imaging experiments and one for scattering experiments. In both cases, X-rays interact with a sample and are measured in a way that provides, structural, chemical, electronic, or magnetic information about samples.

    The beamline is also intended as an important technological bridge toward the planned ALS upgrade, dubbed ALS-U, that would maximize its capabilities.

    Now, after a first-year ramp-up during which staff tested and tuned its components, the scientific results from its earliest experiments are expected to get published in journals later this year.

    A study published earlier this month in the journal Nature Communications, based primarily on work at a related ALS beamline, successfully demonstrated a technique known as ptychographic computed tomography that mapped the location of reactions inside lithium-ion batteries in 3-D. That experiment tested the instrumentation that is now permanently installed at the COSMIC imaging facility.

    A next-generation X-ray beamline now operating at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) brings together a unique set of capabilities to measure the properties of materials at the nanoscale.

    Called COSMIC, for Coherent Scattering and Microscopy, this X-ray beamline at Berkeley Lab’s Berkeley Lab’s Advanced Light Source (ALS) allows scientists to probe working batteries and other active chemical reactions, and to reveal new details about magnetism and correlated electronic materials.

    COSMIC has two branches that focus on different types of X-ray experiments: one for X-ray imaging experiments and one for scattering experiments. In both cases, X-rays interact with a sample and are measured in a way that provides, structural, chemical, electronic, or magnetic information about samples.

    The beamline is also intended as an important technological bridge toward the planned ALS upgrade, dubbed ALS-U, that would maximize its capabilities.

    Now, after a first-year ramp-up during which staff tested and tuned its components, the scientific results from its earliest experiments are expected to get published in journals later this year.

    A study published earlier this month in the journal Nature Communications, based primarily on work at a related ALS beamline, successfully demonstrated a technique known as ptychographic computed tomography that mapped the location of reactions inside lithium-ion batteries in 3-D. That experiment tested the instrumentation that is now permanently installed at the COSMIC imaging facility.

    “This scientific result came out of the R&D effort leading up to COSMIC,” said David Shapiro, a staff scientist in the Experimental Systems Group (ESG) at Berkeley Lab’s ALS and the lead scientist for COSMIC’s microscopy experiments.

    That result was made possible by ALS investments in R&D, and collaborations with the University of Illinois at Chicago and with Berkeley Lab’s Center for Advanced Mathematics for Energy Research Applications (CAMERA), he noted.

    3
    X-rays strike a scintillator material at the COSMIC beamline, causing it to glow. (Credit: Simon Morton/Berkeley Lab)

    “We aim to provide an entirely new class of tools for the materials sciences, as well as for environmental and life sciences,” Shapiro said. Ptychography achieves spatial resolution finer than the X-ray spot size by phase retrieval from coherent diffraction data, and “The ALS has done this with world-record spatial resolution in two and now three dimensions,” he added.

    The ptychographic tomography technique that researchers used in this latest study allowed them to view the chemical states within individual nanoparticles. Young-Sang Yu, lead author of the study and an ESG scientist, said, “We looked at a piece of a battery cathode in 3-D with a resolution that was unprecedented for X-rays. This provides new insight into battery performance both at the single-particle level and across statistically significant portions of a battery cathode.”

    COSMIC is focused on a range of “soft” or low-energy X-rays that are particularly well-suited for analysis of chemical composition within materials

    Ptychographic tomography can be particularly useful for looking at cellular components as well as batteries or other chemically diverse materials in extreme detail. Shapiro said that the X-ray beam at COSMIC is focused to a spot about 50 nanometers (billionths of a meter) in diameter; however, ptychography can enhance the spatial resolution routinely by a factor of 10 or more. The current work was performed with a 120-nanometer beam that achieved a 3-D resolution of about 11 nanometers.

    COSMIC’s X-ray beam is also brighter than the ALS beamline that was used to test its instrumentation, and it will become even brighter once ALS-U is complete. This brightness can translate to an even higher nanoscale resolution, and can also enable far more precision in time-dependent experiments.

    Making efficient use of this brightness requires fast detectors, which are developed by the ALS detector group. The current detector can operate at a data rate of up to 400 megabytes per second and can now generate a few terabytes of data per day – enough to store about 500 to 1,000 feature-length movies. Next-generation detectors, to be tested shortly, will produce data 100 times faster.

    “We are expecting to be the most data-intensive beamline at the ALS, and an important component of COSMIC is the development of advanced mathematics and computation able to quickly reconstruct information from the data as it is collected,” Shapiro said.

    To develop these tools COSMIC coupled with CAMERA, which was created to bring state-of-the-art mathematics and computing to DOE scientific facilities.

    CAMERA Director James Sethian said, “Building real-time advanced algorithms and the high-performance ptychographic reconstruction code for COSMIC has been a highly successful multiyear effort between mathematicians, computer scientists, software engineers, software experts, and beamline scientists.”

    The code the team developed to improve ptychographic imaging at COSMIC, dubbed SHARP, is now available to all light sources across the DOE complex. For COSMIC, the SHARP code runs on a dedicated graphics processing unit (GPU) cluster managed by Berkeley Lab’s High Performance Computing Services.

    Besides ptychography, COSMIC is also equipped for experiments that use X-ray photon correlation spectroscopy, or XPCS, a technique that is useful for studying fluctuations in materials associated with exotic magnetic and electronic properties.

    COSMIC enables scientists to see such fluctuations occurring in milliseconds, or thousandths of a second, compared to time increments of multiple seconds or longer at predecessor beamlines. A new COSMIC endstation with applied magnetic field and cryogenic capabilities is now being built, with early testing set to begin this summer.

    Scientists have already used COSMIC’s imaging capabilities to explore a range of nanomaterials, battery anode and cathode materials, cements, glasses, and magnetic thin films, Shapiro said.

    “We’re still in the mode of learning and tuning, but the performance is fantastic so far,” he said. He credited the ALS crew, led by ESG scientist Tony Warwick, for working quickly to bring COSMIC up to speed. “It’s pretty remarkable to get to such high performance in such a short amount of time.”

    The ALS is a DOE Office of Science User Facility. Development and deployment of the COSMIC beamline was supported by the DOE Office of Science.

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  • richardmitnick 12:53 pm on March 5, 2018 Permalink | Reply
    Tags: , , , , , LBNL ALS, , Pyrene   

    From LBNL: “Chemical Sleuthing Unravels Possible Path to the Formation of Life’s Building Blocks in Space” 

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    Berkeley Lab

    March 5, 2018
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    Experiments at Berkeley Lab’s Advanced Light Source reveal how a hydrocarbon called pyrene could form near stars.

    LBNL/ALS

    1
    The atomic structure of pyrene molecules (upper left and upper right) are represented in an artist’s rendering of an asteroid belt, with carbon atoms shown in black and hydrogen atoms in white. A new study shows chemical steps for how pyrene, a type of hydrocarbon found in some meteorite samples, could form in space. (Credit: NASA-JPL-Caltech, Wikimedia Commons).

    Scientists have used lab experiments to retrace the chemical steps leading to the creation of complex hydrocarbons in space, showing pathways to forming 2-D carbon-based nanostructures in a mix of heated gases.

    The latest study, which featured experiments at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), could help explain the presence of pyrene, which is a chemical compound known as a polycyclic aromatic hydrocarbon, and similar compounds in some meteorites.

    A team of scientists, including researchers from Berkeley Lab and UC Berkeley, participated in the study, published March 5 in the Nature Astronomy journal. The study was led by scientists at the University of Hawaii at Manoa and also involved theoretical chemists at Florida International University.

    “This is how we believe some of the first carbon-based structures evolved in the universe,” said Musahid Ahmed, a scientist in Berkeley Lab’s Chemical Sciences Division who joined other team members to perform experiments at Berkeley Lab’s Advanced Light Source (ALS).

    “Starting off from simple gases, you can generate one-dimensional and two-dimensional structures, and pyrene could lead you to 2-D graphene,” Ahmed said. “From there you can get to graphite, and the evolution of more complex chemistry begins.”

    Pyrene has a molecular structure composed of 16 carbon atoms and 10 hydrogen atoms. Researchers found that the same heated chemical processes that give rise to the formation of pyrene are also relevant to combustion processes in vehicle engines, for example, and the formation of soot particles.

    The latest study builds on earlier work that analyzed hydrocarbons with smaller molecular rings that have also been observed in space, including in Saturn’s moon Titan – namely benzene and naphthalene.

    Ralf I. Kaiser, one of the study’s lead authors and a chemistry professor at the University of Hawaii at Manoa, said, “When these hydrocarbons were first seen in space, people got very excited. There was the question of how they formed.” Were they purely formed through reactions in a mix of gases, or did they form on a watery surface, for example?

    Ahmed said there is an interplay between astronomers and chemists in this detective work that seeks to retell the story of how life’s chemical precursors formed in the universe.

    “We talk to astronomers a lot because we want their help in figuring out what’s out there,” Ahmed said, “and it informs us to think about how it got there.”

    Kaiser noted that physical chemists, on the other hand, can help shine a light on reaction mechanisms that can lead to the synthesis of specific molecules in space.

    2
    A researcher handles a fragment and a test tube sample of the Murchison meteorite, which has been shown to contain a a variety of hydrocarbons and amino acids, in this photo from a previous, unrelated study at Argonne National Laboratory. Experiments at Berkeley Lab are helping to retrace the chemical steps by which complex hydrocarbons like pyrene could form in the Murchison meteorite and other meteorites. (Credit: Argonne National Laboratory)

    Pyrene belongs to a family known as polycyclic aromatic hydrocarbons, or PAHs, that are estimated to account for about 20 percent of all carbon in our galaxy. PAHs are organic molecules that are composed of a sequence of fused molecular rings. To explore how these rings develop in space, scientists work to synthesize these molecules and other surrounding molecules known to exist in space.

    Alexander M. Mebel, a chemistry professor at Florida International University who participated in the study, said, “You build them up one ring at a time, and we’ve been making these rings bigger and bigger. This is a very reductionist way of looking at the origins of life: one building block at a time.”

    For this study, researchers explored the chemical reactions stemming from a combination of a complex hydrocarbon known as the 4-phenanthrenyl radical, which has a molecular structure that includes a sequence of three rings and contains a total of 14 carbon atoms and nine hydrogen atoms, with acetylene (two carbon atoms and two hydrogen atoms).

    Chemical compounds needed for the study were not commercially available, said Felix Fischer, an assistant professor of chemistry at UC Berkeley who also contributed to the study, so his lab prepared the samples. “These chemicals are very tedious to synthesize in the laboratory,” he said.

    At the ALS, researchers injected the gas mixture into a microreactor that heated the sample to a high temperature to simulate the proximity of a star. The ALS generates beams of light, from infrared to X-ray wavelengths, to support a range of science experiments by visiting and in-house researchers.

    The mixture of gases was jetted out of the microreactor through a tiny nozzle at supersonic speeds, arresting the active chemistry within the heated cell. The research team then focused a beam of vacuum ultraviolet light from the synchrotron on the heated gas mixture that knocked away electrons (an effect known as ionization).

    They then analyzed the chemistry taking place using a charged-particle detector that measured the varied arrival times of particles that formed after ionization. These arrival times carried the telltale signatures of the parent molecules. These experimental measurements, coupled with Mebel’s theoretical calculations, helped researchers to see the intermediate steps of the chemistry at play and to confirm the production of pyrene in the reactions.

    Mebel’s work showed how pyrene (a four-ringed molecular structure) could develop from a compound known as phenanthrene (a three-ringed structure). These theoretical calculations can be useful for studying a variety of phenomena, “from combustion flames on Earth to outflows of carbon stars and the interstellar medium,” Mebel said.

    Kaiser added, “Future studies could study how to create even larger chains of ringed molecules using the same technique, and to explore how to form graphene from pyrene chemistry.”

    3
    A reaction pathway that can form a hydrocarbon called pyrene through a chemical method known as hydrogen-abstraction/acetylene-addition, or HACA, is shown at the top. At bottom, some possible steps by which pyrene can form more complex hydrocarbons via HACA (red) or another mechanism (blue) called hydrogen abstraction – vinylacetylene addition (HAVA). (Credit: Long Zhao, Ralf I. Kaiser, et al./Nature Astronomy, DOI: 10.1038/s41550-018-0399-y)

    Other experiments conducted by team members at the University of Hawaii will explore what happens when researchers mix hydrocarbon gases in icy conditions and simulate cosmic radiation to see whether that may spark the creation of life-bearing molecules.

    “Is this enough of a trigger?” Ahmed said. “There has to be some self-organization and self-assembly involved” to create life forms. “The big question is whether this is something that, inherently, the laws of physics do allow.”

    The study was supported by the U.S. Department of Energy’s Office Sciences, and UC Berkeley, the University of Hawaii, Florida International University, and the National Science Foundation.

    The ALS is a DOE Office of Science User Facility.

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  • richardmitnick 1:10 pm on January 16, 2018 Permalink | Reply
    Tags: , LBNL ALS, , X-Rays Reveal ‘Handedness’ in Swirling Electric Vortices   

    From LBNL: “X-Rays Reveal ‘Handedness’ in Swirling Electric Vortices” 

    Berkeley Logo

    Berkeley Lab

    January 15, 2018
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    1
    Just as people can be left-handed or right-handed, scientists have observed chirality or “handedness” in swirling electric vortices in a layered material. (Credit: Pixabay)

    Scientists used spiraling X-rays at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) to observe, for the first time, a property that gives handedness to swirling electric patterns – dubbed polar vortices – in a synthetically layered material.

    This property, also known as chirality, potentially opens up a new way to store data by controlling the left- or right-handedness in the material’s array in much the same way magnetic materials are manipulated to store data as ones or zeros in a computer’s memory.

    Researchers said the behavior also could be explored for coupling to magnetic or optical (light-based) devices, which could allow better control via electrical switching.

    Chirality is present in many forms and at many scales, from the spiral-staircase design of our own DNA to the spin and drift of spiral galaxies; it can even determine whether a molecule acts as a medicine or a poison in our bodies.

    A molecular compound known as d-glucose, for example, which is an essential ingredient for human life as a form of sugar, exhibits right-handedness. Its left-handed counterpart, l-glucose, though, is not useful in human biology.

    “Chirality hadn’t been seen before in this electric structure,” said Elke Arenholz, a senior staff scientist at Berkeley Lab’s Advanced Light Source (ALS), which is home to the X-rays that were key to the study, published Jan. 15 in the journal Proceedings of the National Academy of Sciences.

    LBNL/ALS

    The experiments can distinguish between left-handed chirality and right-handed chirality in the samples’ vortices. “This offers new opportunities for fundamentally new science, with the potential to open up applications,” she said.

    “Imagine that one could convert a right-handed form of a molecule to its left-handed form by applying an electric field, or artificially engineer a material with a particular chirality,” said Ramamoorthy Ramesh, a faculty senior scientist in Berkeley Lab’s Materials Sciences Division and associate laboratory director of the Lab’s Energy Technologies Area, who co-led the latest study.

    Ramesh, who is also a professor of materials science and physics at UC Berkeley, custom-made the novel materials at UC Berkeley.

    Padraic Shafer, a research scientist at the ALS and the lead author of the study, worked with Arenholz to carry out the X-ray experiments that revealed the chirality of the material.

    The samples included a layer of lead titanate (PbTiO3) and a layer of strontium titanate (SrTiO3) sandwiched together in an alternating pattern to form a material known as a superlattice. The materials have also been studied for their tunable electrical properties that make them candidates for components in precise sensors and for other uses.

    2
    This diagram shows the setup for the X-ray experiment that explored chirality, or handedness, in a layered material. The blue and red spirals at upper left show the X-ray light that was used to probe the material. The X-rays scattered off of the layers of the material (arrows at upper right and associated X-ray images at top), allowing researchers to measure chirality in swirling electrical vortices within the material. (Credit: Berkeley Lab)

    Neither of the two compounds show any handedness by themselves, but when they were combined into the precisely layered superlattice, they developed the swirling vortex structures that exhibited chirality.

    “Chirality may have additional functionality,” Shafer said, when compared to devices that use magnetic fields to rearrange the magnetic structure of the material.

    The electronic patterns in the material that were studied at the ALS were first revealed using a powerful electron microscope at Berkeley Lab’s National Center for Electron Microscopy, a part of the Lab’s Molecular Foundry, though it took a specialized X-ray technique to identify their chirality.

    “The X-ray measurements had to be performed in extreme geometries that can’t be done by most experimental equipment,” Shafer said, using a technique known as resonant soft X-ray diffraction that probes periodic nanometer-scale details in their electronic structure and properties.

    Spiraling forms of X-rays, known as circularly polarized X-rays, allowed researchers to measure both left-handed and right-handed chirality in the samples.

    Arenholz, who is also a faculty member of the UC Berkeley Department of Materials Science & Engineering, added, “It took a lot of time to understand the results, and a lot of modeling and discussions.” Theorists at the University of Cantabria in Spain and their network of computational experts performed calculations of the vortex structures that aided in the interpretation of the X-ray data.

    The same science team is pursuing studies of other types and combinations of materials to test the effects on chirality and other properties.

    “There is a wide class of materials that could be substituted,” Shafer said, “and there is the hope that the layers could be replaced with even higher functionality materials.”

    Researchers also plan to test whether there are new ways to control the chirality in these layered materials, such as by combining materials that have electrically switchable properties with those that exhibit magnetically switchable properties.

    “Since we know so much about magnetic structures,” Arenholz said, “we could think of using this well-known connection with magnetism to implement this newly discovered property into devices.”

    The Advanced Light Source and the Molecular Foundry are both DOE Office of Science User Facilities.

    Also participating in the research were scientists from the UC Berkeley Department of Electrical Engineering and Computer Sciences, the Institute of Materials Science of Barcelona, the University of the Basque Country, and the Luxembourg Institute of Science and Technology. The work was supported by the U.S. Department of Energy Office of Science, the National Science Foundation, the Luxembourg National Research Fund, the Spanish Ministry of Economy and Competitiveness, and the Gordon and Betty Moore Foundation.

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  • richardmitnick 2:06 pm on December 12, 2017 Permalink | Reply
    Tags: Electric car makers are intensely interested in lithium-rich battery cathodes that could significantly increase driving range, LBNL ALS, Scientists Discover Path to Improving Game-Changing Battery Electrode, ,   

    From SLAC: “Scientists Discover Path to Improving Game-Changing Battery Electrode” 


    SLAC Lab

    Electric car makers are intensely interested in lithium-rich battery cathodes that could significantly increase driving range. A new study opens a path to making them live up to their promise.

    1
    Electric car makers are intensely interested in lithium-rich battery cathodes that could significantly increase driving range. A new study opens a path to making them live up to their promise. (Stanford University/3Dgraphic)

    2
    SLAC and Stanford researchers at an SSRL beamline used for battery research. From left: SLAC staff scientists Apurva Mehta and Kevin Stone; Stanford graduate students Will Gent and Kipil Lim; and SLAC distinguished staff scientist Mike Toney. (Dawn Harmer/SLAC National Accelerator Laboratory)

    December 12, 2017
    If you add more lithium to the positive electrode of a lithium-ion battery – overstuff it, in a sense ­– it can store much more charge in the same amount of space, theoretically powering an electric car 30 to 50 percent farther between charges. But these lithium-rich cathodes quickly lose voltage, and years of research have not been able to pin down why – until now.

    After looking at the problem from many angles, researchers from Stanford University, two Department of Energy national labs and the battery manufacturer Samsung created a comprehensive picture of how the same chemical processes that give these cathodes their high capacity are also linked to changes in atomic structure that sap performance.

    “This is good news,” said William E. Gent, a Stanford University graduate student and Siebel Scholar who led the study. “It gives us a promising new pathway for optimizing the voltage performance of lithium-rich cathodes by controlling the way their atomic structure evolves as a battery charges and discharges.”

    Michael Toney, a distinguished staff scientist at SLAC National Accelerator Laboratory and a co-author of the paper, added, “It is a huge deal if you can get these lithium-rich electrodes to work because they would be one of the enablers for electric cars with a much longer range. There is enormous interest in the automotive community in developing ways to implement these, and understanding what the technological barriers are may help us solve the problems that are holding them back.”

    The team’s report appears today in Nature Communications.

    The researchers studied the cathodes with a variety of X-ray techniques at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) and Lawrence Berkeley National Laboratory’s Advanced Light Source (ALS).

    SLAC/SSRL

    LBNL/ALS

    Theorists from Berkeley Lab’s Molecular Foundry, led by David Prendergast, were also involved, helping the experimenters understand what to look for and explain their results.

    The cathodes themselves were made by Samsung Advanced Institute of Technology using commercially relevant processes, and assembled into batteries similar to those in electric vehicles.

    “This ensured that our results represented an understanding of a cutting-edge material that would be directly relevant for our industry partners,” Gent said. As an ALS doctoral fellow in residence, he was involved in both the experiments and the theoretical modelling for the study.

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  • richardmitnick 9:28 am on November 13, 2017 Permalink | Reply
    Tags: , , Fuel Cell X-Ray Study Details Effects of Temperature and Moisture on Performance, , , LBNL ALS,   

    From LBNL: “Fuel Cell X-Ray Study Details Effects of Temperature and Moisture on Performance” 

    Berkeley Logo

    Berkeley Lab

    November 13, 2017
    Glenn Roberts Jr.
    geroberts@lbl.gov
    (510) 486-5582

    1
    This animated 3-D rendering (view larger size), generated by an X-ray-based imaging technique at Berkeley Lab’s Advanced Light Source, shows tiny pockets of water (blue) in a fibrous sample. The X-ray experiments showed how moisture and temperature can affect hydrogen fuel-cell performance. (Credit: Berkeley Lab)

    Like a well-tended greenhouse garden, a specialized type of hydrogen fuel cell – which shows promise as a clean, renewable next-generation power source for vehicles and other uses – requires precise temperature and moisture controls to be at its best. If the internal conditions are too dry or too wet, the fuel cell won’t function well.

    But seeing inside a working fuel cell at the tiny scales relevant to a fuel cell’s chemistry and physics is challenging, so scientists used X-ray-based imaging techniques at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Argonne National Laboratory to study the inner workings of fuel-cell components subjected to a range of temperature and moisture conditions.

    The research team, led by Iryna Zenyuk, a former Berkeley Lab postdoctoral researcher now at Tufts University, included scientists from Berkeley Lab’s Energy Storage and Distributed Resources Division and the Advanced Light Source (ALS), an X-ray source known as a synchrotron.

    LBNL/ALS

    The ALS lets researchers image in 3-D at high resolution very quickly, allowing them to look inside working fuel cells in real-world conditions. The team created a test bed to mimic the temperature conditions of a working polymer-electrolyte fuel cell that is fed hydrogen and oxygen gases and produces water as a byproduct.

    “The water management and temperature are critical,” said Adam Weber, a staff scientist in the Energy Technologies Area at Berkeley Lab and deputy director for a multi-lab fuel cell research effort, the Fuel Cell Consortium for Performance and Durability (FC-PAD).

    The study has been published online in the journal Electrochimica Acta.

    2
    Temperature-controlled X-ray experiments on fuel-cell components were conducted at Berkeley Lab’s Advanced Light Source (bottom left) and Argonne National Laboratory’s Advanced Photon Source (bottom right).

    ANL/APS

    The computer renderings (top) show the specialized sample holder, which included a heating element near the top and cooling coils at the base. (Credit: Berkeley Lab)

    The research aims to find the right balance of humidity and temperature within the cell, and how water moves out of the cell.

    Controlling how and where water vapor condenses in a cell, for example, is critical so that it doesn’t block incoming gases that facilitate chemical reactions.

    “Water, if you don’t remove it, can cover the catalyst and prevent oxygen from reaching the reaction sites,” Weber said. But there has to be some humidity to ensure that the central membrane in the cell can efficiently conduct ions.

    The research team used an X-ray technique known as micro X-ray computed tomography to record 3-D images of a sample fuel cell measuring about 3 to 4 millimeters in diameter.

    “The ALS lets us image in 3-D at high resolution very quickly, allowing us to look inside working fuel cells in real-world conditions,” said Dula Parkinson, a research scientist at the ALS who participated in the study.

    The sample cell included thin carbon-fiber layers, known as gas-diffusion layers, which in a working cell sandwich a central polymer-based membrane coated with catalyst layers on both sides. These gas-diffusion layers help to distribute the reactant chemicals and then remove the products from the reactions.

    Weber said that the study used materials that are relevant to commercial fuel cells. Some previous studies have explored how water wicks through and is shed from fuel-cell materials, and the new study added precise temperature controls and measurements to provide new insight on how water and temperature interact in these materials.

    Complimentary experiments at the ALS and at Argonne’s Advanced Photon Source, a synchrotron that specializes in a different range of X-ray energies, provided detailed views of the water evaporation, condensation, and distribution in the cell during temperature changes.

    “It took the ALS to explore the physics of this,” Weber said, “so we can compare this to theoretical models and eventually optimize the water management process and thus the cell performance,” Weber said.

    The experiments focused on average temperatures ranging from about 95 to 122 degrees Fahrenheit, with temperature variations of 60 to 80 degrees (hotter to colder) within the cell. Measurements were taken over the course of about four hours. The results provided key information to validate water and heat models that detail fuel-cell function.

    3
    Water clusters in sample fuel-cell components shrink over time in this sequence of images, produced by a 3-D imaging technique known as micro X-ray computed tomography. The water clusters were contained in a fibrous membrane that was exposed to different temperatures. The mean temperature began at about 104 degrees Fahrenheit and was gradually increased to about 131 degrees Fahrenheit. The top side of the images was the hotter side of the sample, and the bottom of the images was the colder side. (Credit: Berkeley Lab)

    This test cell included a hot side designed to show how water evaporates at the site of the chemical reactions, and a cooler side to show how water vapor condenses and drives the bulk of the water movement in the cell.

    While the thermal conductivity of the carbon-fiber layers – their ability to transfer heat energy – decreased slightly as the moisture content declined, the study found that even the slightest degree of saturation produced nearly double the thermal conductivity of a completely dry carbon-fiber layer. Water evaporation within the cell appears to dramatically increase at about 120 degrees Fahrenheit, researchers found.

    The experiments showed water distribution with millionths-of-a-meter precision, and suggested that water transport is largely driven by two processes: the operation of the fuel cell and the purging of water from the cell.

    The study found that larger water clusters evaporate more rapidly than smaller clusters. The study also found that the shape of water clusters in the fuel cell tend to resemble flattened spheres, while voids imaged in the carbon-fiber layers tend to be somewhat football-shaped.

    There are also some ongoing studies, Weber said, to use the X-ray-based imaging technique to look inside a full subscale fuel cell one section at a time.

    “There are ways to stitch together the imaging so that you get a much larger field of view,” he said. This process is being evaluated as a way to find the origin of failure sites in cells through imaging before and after testing. A typical working subscale fuel cell measures around 50 square centimeters, he added.

    Other researchers participating in this study were from Tufts University, Argonne National Laboratory, and the Norwegian University of Science and Technology. The work was supported by the U.S. Department of Energy’s Fuel Cell Technologies Office and Office of Energy Efficiency and Renewable Energy, and the National Science Foundation.

    The Advanced Light Source and the Advanced Photon Source are DOE Office of Science User Facilities that are open to visiting scientists from around the U.S. and world.

    See the full article here .

    Please help promote STEM in your local schools.

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