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  • richardmitnick 3:49 pm on April 22, 2014 Permalink | Reply
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    From Brookhaven Lab: “Disorder on the Nanoscale May Be Responsible for Solar-cell Efficiency” 

    Brookhaven Lab

    April 22, 2014
    Chelsea Whyte

    In the past few years, perovskite solar cells have made large leaps forward in efficiency, recently achieving energy conversion with up to 16 percent efficiency. These simple and promising devices are easy enough to make and are made up of earth abundant materials, but little work has been done to explore their atomic makeup.

    ml
    Methylammonium lead iodide perovskite

    Researchers at Brookhaven National Laboratory and Columbia University used high-energy x-rays at the National Synchrotron Light Source (NSLS) to characterize the structure of methylammonium lead iodide (MAPbI3) in titanium oxide – the active material in high-performance perovskite solar cells. Their results are reported in a paper published online in Nano Letters on November 22, 2013.

    Brookhaven NSLS
    Brookhaven NSLS

    Photoluminescent properties of these materials are thought to depend sensitively on the degree of structural order and defects. To characterize the structure, the researchers used beamline X17A at NSLS to study samples of the MAPbI3. Atomic pair distribution function analysis of x-ray diffraction data revealed that 30 percent of the material forms a tetragonal perovskite phase, while 70 percent exists in a disordered state. The presence of disordered material correlates with strong changes in the photoluminescence and absorbance spectra.

    This disordered structure has been undetected by conventional x-ray diffraction techniques used in previous studies. “This nanostructure is expected to have a significant impact on the optoelectronic properties and device performance of the perovskites,” said Simon Billinge, coauthor on the paper and a physicist with a joint appointment at Brookhaven National Laboratory and Columbia University.

    For example, the absorption of this composite material, made of both ordered and disordered states, is blue shifted by about 50 meV compared to the bulk perovskite crystalline structure. They also found that disordered MAPbI3 is photoluminescent, while the crystalline material is not.

    This new understanding of the structure of these materials will lead to better deposition and processing methods that may increase the performance and efficiency of future solar cells.

    The high-energy x-ray atomic pair distribution function analysis performed in this paper will be applied to a wide range of even more challenging problems at the higher brightness XPD-2 beamline (PDF) at NSLS-II.

    Brookhaven NSLS II Photo
    NSLS-II at Brookhaven Lab

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 8:16 pm on April 21, 2014 Permalink | Reply
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    From Brookhaven Lab: “A New Approach to Engineering the Materials of the Future” 

    Brookhaven Lab

    April 21, 2014
    Laura Mgrdichian

    Some of the most interesting and fascinating electronic devices that will someday be available to consumers, from paper-thin computers to electronic fabric, will be the result of advanced materials designed by scientists. Indeed, some remarkable discoveries have already been made. To innovate further, scientists must learn how to precisely engineer the chemical structures of materials at the nanoscale in such a way as to yield specific macroscopic properties and functions.

    A research group, jointly working at the National Synchrotron Light Source, has found a new way to do just that. They have synthesized a new class of macromolecules that organize themselves, or “self-assemble,” into various ordered structures with feature sizes smaller than 10 nanometers. Called “giant surfactants,” these large molecules mimic the structural features of small surfactants (substances that significantly lower the surface tension between two liquids, such as detergents), but have been transformed into functional molecular nanoparticles by being “clicked” with polymer chains. The resulting materials are unique because they bridge the gap between small molecule surfactants and traditional block copolymers and thus possess an interesting “duality” in their self-assembly behaviors.

    Brookhaven NSLS
    Brookhaven NSLS

    new
    Transmission electron microscope (TEM) images and GISAXS paEerns (insets) of two giant surfactant thin‐film samples. The TEM images show ordered nanoscale paEerns.

    “This class of materials provides a versatile platform for engineering nanostructures that have features smaller than 10 nanometers, which is a scale that is very relevant to the blueprints of nanotechnology and microelectronics,” said the study’s corresponding scientist Stephen Cheng, a researcher in the University of Akron’s College of Polymer Science and Polymer Engineering. “More broadly, we are also interested in how our results could help advance our understanding of the chemical and physical principles that underlie self-assembly.”

    Surfactants play a huge role in our everyday life, although most people are unaware of them. They are present in household cleaners and soaps, adhesives, paint, ink, plastics, and many, many other products. Naturally, they are a key part of materials research.

    Giant surfactants have the potential to be even more versatile than their smaller counterparts because they have the advantages of both a polymer and a surfactant. They are of particular interest to the electronics industry because they can spontaneously self-assemble into nanodomains just a few nanometers in size. This length scale must be achieved in order to allow the continual downsizing of computer chips but proven very difficult to achieve for conventional technologies. The production of nanopatterned thin films – which are the foundation of modern computer chips – could be directly affected by giant surfactants. If films can be produced with smaller nanoscale features, they could lead to denser, faster computer chips.

    The group used several techniques to study different giant surfactant samples in thin-film form, as well as in bulk form and in solution. These techniques included grazing-incidence small-angle x-ray scattering (GISAXS) at NSLS beamline X9. GISAXS is suited to studying thin film samples that have ordered nanoscale features, typically between 5 and 20 nanometers, and can tell researchers about the shape, size, and orientation of these features, among other information. It is widely used to study self-assembled thin films with nanoscale features.

    This research is published in the June 18, 2013 issue of the Proceedings of the National Academy of Sciences. The team, which includes scientists from the University of Akron, National Tsing Hua University (Taiwan), McMaster University (Canada), and Peking University (China), has also described this research in a pending patent application.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 12:04 pm on November 19, 2013 Permalink | Reply
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    From Brookhaven Lab: “Infrared Light Fills a ‘Gap’ in Iron-based Superconductor Research” 

    Brookhaven Lab

    November 18, 2013
    Laura Mgrdichian

    Superconductors are a fascinating group of materials in which electrons can flow with almost zero resistance. They have the potential to revolutionize electronics and power distribution, but no existing superconductors have an ideal combination of properties necessary to realize these applications. To design the ideal superconductor, scientists need a complete understanding of the complex, atomic-level electrical and magnetic behaviors that produce the phenomenon.

    Many groups have focused their efforts on “high-temperature” (high-Tc) superconductors that operate at temperatures well above the conventional superconducting materials. Conventional superconductors must be chilled to almost absolute zero (the coldest temperature possible), making them impractical for many applications. The most widely studied high-Tc materials, known as cuprates because they contain layers of copper and oxygen atoms, avoid the ultra-low temperature requirement, but exhibit other properties that limit their practical use.

    Recently, a new family of iron-based superconductors was discovered that do not seem to superconduct in the same way as conventional superconductors or quite like the cuprates. This iron-based family has been found to be quite large and diverse, so physicists are hoping that studying all of its members will yield a clear picture of how they operate, and point the way to a high-Tc material that has other necessary properties.

    graph
    (a) Data taken from 3 to 30K showing the temperature dependence of infrared transmission through the LaFeAsO1-‐xFx thin film, normalized to the transmission at 33K (b) Time-‐resolved infrared transmission data through the sample from about 2K to 15K. The slow (ns) relaxation time indicates the presence of a full superconducting gap.

    In this work, researchers from Brookhaven National Laboratory and the Leibniz Institute for Solid State Physics in Dresden, Germany, investigated an iron pnictide compound composed of lanthanum (La), iron (Fe), arsenic (As), oxygen (O), and an added fluorine (F) “dopant” that replaces about 10 percent of the O atoms. Abbreviated LaFeAsO1-xFx (the ‘x’ denotes the number of F and, therefore, O atoms per molecule), it was the first iron-based superconductor found to operate at temperatures higher than most conventional superconductors. Still, little is known about how it works.

    This work may be a key step in changing that. Using beams of infrared light produced at Brookhaven’s National Synchrotron Light Source, the group discovered evidence that LaFeAsO1-xFx has a full “superconducting gap” – the energy required for electrons in the lowest energy state, the ground state, to “jump” into higher energy levels. This gap is one hallmark of a superconductor and an indicator of its performance under certain conditions. For example, the gap in the cuprates actually disappears for electrons traveling in certain directions.

    “Understanding the details of the gap is essential for unraveling the superconducting mechanism, yet questions about gap structure in this material have persisted even after years of research,” said Brookhaven researcher Xiaoxiang Xi, who was the lead experimenter in the study. “Establishing these details experimentally, as we have done, puts constraints on the possible theories that could explain the origin of the superconductivity in these materials.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 11:03 am on November 15, 2013 Permalink | Reply
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    From Brookhaven Lab: “Small Particles, Big Findings” 

    Brookhaven Lab

    November 15, 2013
    Karen McNulty Walsh

    Sometimes big change comes from small beginnings. That’s especially true in the research of Anatoly Frenkel, a professor of physics at Yeshiva University, who is working to reinvent the way we use and produce energy by unlocking the potential of some of the world’s tiniest structures: nanoparticles.

    “The nanoparticle is the smallest unit in most novel materials, and all of its properties are linked in one way or another to its structure,” said Frenkel. “If we can understand that connection, we can derive much more information about how it can be used for catalysis, energy, and other purposes.”

    three
    Eric Stach and Dmitri Zakharov of the CFN with Anatoly Frenkel of Yeshiva University and his postdoc, Yuanyuan Li, sitting at the Titan 80/300 Environmental Transmission Electron Microscope at the CFN.

    “This work could lead to big gains in energy efficiency and cost savings for industrial processes.” — Eric Stach, CFN

    Frenkel is collaborating with materials scientist Eric Stach and others at the U.S. Department of Energy’s Brookhaven National Laboratory to develop new ways to study how nanoparticles behave in catalysts—the “kick-starters” of chemical reactions that convert fuels to useable forms of energy and transform raw materials to industrial products.

    “We are developing a new ‘micro-reactor’ that enables us to explore many aspects of catalytic function using multiple approaches at Brookhaven’s National Synchrotron Light Source (NSLS), the soon-to-be-completed NSLS-II, and the Center for Functional Nanomaterials (CFN),” said Stach, who works at the CFN. “This approach lets us understand multiple aspects of how catalysts work so that we can tweak their design to improve their function. This work could lead to big gains in energy efficiency and cost savings for industrial processes.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 9:41 am on November 7, 2013 Permalink | Reply
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    From Brookhaven Lab: “New Camera Reveals How Light Breaks Molecules Apart” 

    Brookhaven Lab

    November 4, 2013
    Andrei Nomerotski and Michael White

    Way beyond pure illumination—from bright sunshine to intense x-rays at the National Synchrotron Light Source (NSLS)—light can pack a powerful punch down at the atomic scale. When light strikes organic compounds bound to certain surfaces, it can split them into atomic and molecular fragments called photoproducts. These fractured pieces offer crucial clues to how and why light breaks some chemical bonds, which is at the core of understanding how solar energy can be used to remove pollutants from the environment.

    Just one organic molecule can break into many photoproducts and capturing each one presents a considerable, time-consuming challenge. We used a highly specialized system—the Pixel Imaging Mass Spectrometry (PImMS) camera—to bring this light-induced process into focus. Results of our experiments using the new PImMS camera to capture these telltale photoproducts were just published in the Journal of Chemical Physics and highlighted in Physics Today. With PImMS performing beautifully, the technology could also be used in research at NSLS-II and the proposed electron-ion collider, eRHIC.

    camera
    From left: Physicist Andrei Nomerotski, Stony Brook University graduate student Matt Kershis, and chemist Michael White use this instrument to prepare organic molecule samples for tests with the new PImMS camera.

    Tracking Photoproducts, Pre-PImMS

    Several years ago, Michael and his colleagues in the Chemistry Department began exploring how ultraviolet (UV) light can cause organic molecules on titanium dioxide surfaces to decompose into photoproducts. This important reaction, called photo-oxidation, removes organic pollutants from air and water and is the basis for windows and building exteriors’ self-cleaning coatings.

    Before PImMS, we used a technique called ion imaging and a conventional imaging camera—with a charge-coupled device (CCD) sensor similar to those in consumer cameras—to track photoproducts that struck a two-dimensional detector. But in this method, each of these many photoproducts must be captured as individual images, requiring multiple sample preparations and time-consuming repetition. We needed a better camera to catch all the action.

    Enter the PImMS Camera

    Fortunately, an Oxford University group—including Andrei, who only recently joined Brookhaven’s Physics Department to work on the Large Synoptic Survey Telescope—developed a new camera capable of conventional imaging while simultaneously measuring the arrival time for each photoproduct that strikes the detector. This information acts much like a photographic time stamp and could essentially reveal all the photoproducts with a single image exposure.

    Now, instead of repeatedly capturing and reading out whole frames, one after another, PImMS records up to four ion arrival times inside each pixel, a bit like multiple exposures on a film camera. We then read out the sensor just once at the very end of the experimental cycle to gather all that information, accelerating the entire process. In fact, the PImMS camera has an effective imaging speed of just 10 nanoseconds—that’s 100,000 times faster than a conventional CCD camera—and experimental cycles can now take 25 percent of the time they used to. The new sensor combines time-of-flight mass spectrometry to identify multiple molecules, and sensitive ion imaging, which revolutionized the field of chemical reaction dynamics.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 9:07 pm on September 18, 2013 Permalink | Reply
    Tags: , Brookhaven CFN, , Brookhaven NSLS, , ,   

    From Brookhaven Lab: “Nanocrystal Catalyst Transforms Impure Hydrogen into Electricity” 

    Brookhaven Lab

    Brookhaven Lab scientists use simple, ‘green’ process to create novel core-shell catalyst that tolerates carbon monoxide in fuel cells and opens new, inexpensive pathways for zero-emission vehicles

    September 18, 2013
    Contacts: Justin Eure, (631) 344-2347 or Peter Genzer, (631) 344-3174

    The quest to harness hydrogen as the clean-burning fuel of the future demands the perfect catalysts—nanoscale machines that enhance chemical reactions. Scientists must tweak atomic structures to achieve an optimum balance of reactivity, durability, and industrial-scale synthesis. In an emerging catalysis frontier, scientists also seek nanoparticles tolerant to carbon monoxide, a poisoning impurity in hydrogen derived from natural gas. This impure fuel—40 percent less expensive than the pure hydrogen produced from water—remains largely untapped.

    “Our highly scalable, ‘green’ synthesis method, as revealed by atomic-scale imaging techniques, opens new and exciting possibilities for catalysis and sustainability.”
    — Brookhaven Lab Chemist Jia Wang

    team
    Brookhaven Lab scientists Radoslav Adzic, Vyacheslov Volcov, Lijun Wu (back), Wei An, Jia Wang, and Dong Su (front) gathered in the control room for a scanning transmission electron microscope (STEM) in the Center for Functional Nanomaterials.

    Now, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory—in research published online September 18, 2013 in the journal Nature Communications—have created a high-performing nanocatalyst that meets all these demands. The novel core-shell structure—ruthenium coated with platinum—resists damage from carbon monoxide as it drives the energetic reactions central to electric vehicle fuel cells and similar technologies.

    “These nanoparticles exhibit perfect atomic ordering in both the ruthenium and platinum, overcoming structural defects that previously crippled carbon monoxide-tolerant catalysts,” said study coauthor and Brookhaven Lab chemist Jia Wang. “Our highly scalable, ‘green’ synthesis method, as revealed by atomic-scale imaging techniques, opens new and exciting possibilities for catalysis and sustainability.”

    Scientists at Brookhaven Lab’s National Synchrotron Light Source (NSLS) revealed the atomic density, distribution, and uniformity of the metals in the nanocatalysts using a technique called x-ray diffraction, where high-frequency light scatters and bends after interacting with individual atoms. The collaboration also used a scanning transmission electron microscope (STEM) at Brookhaven’s Center for Functional Nanomaterials (CFN) to pinpoint the different sub-nanometer atomic patterns. With this instrument, a focused beam of electrons bombarded the particles, creating a map of both the core and shell structures.

    “We found that the elements did not mix at the core-shell boundary, which is a critical stride,” said CFN physicist Dong Su, coauthor and STEM specialist. “The atomic ordering in each element, coupled with the right theoretical models, tells us about how and why the new nanocatalyst works its magic.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 7:06 am on September 6, 2013 Permalink | Reply
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    From Brookhaven Lab: “Molecular Structure Reveals How the Antibiotic Streptomycin Works” 

    Brookhaven Lab

    September 5, 2013
    Laura Mgrdichian

    Streptomycin was the first antibiotic developed to treat tuberculosis yet until recently, scientists did not completely understand how it works at the molecular level. They knew that streptomycin blocks a critical process, the synthesis of proteins by ribosomes leading to bacterial cell death, but certain details of the interaction remained undiscovered. At Brookhaven National Laboratory’s National Synchrotron Light Source, researchers have used x-ray crystallography to complete the picture.

    strep
    A) A ribbon diagram of the ribosome’s streptomycin binding site. B) A close-up of the rectangular area outlined in A. Streptomycin Is represented as yellow sHcks and spheres, helices are colored red, dark green, cyan, orange, and blue.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 2:21 pm on August 23, 2013 Permalink | Reply
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    From Brookhaven Lab: "Mastering Microbunching for Linac-based Light Sources" 

    Brookhaven Lab

    August 19, 2013
    Boris Podobedov, Sergei Seletskiy, and Xi Yang

    “Designing accelerators requires years of research and development. Throughout the Lab’s history, scientists and engineers at Brookhaven have helped lead the way in designing accelerator technologies for cutting-edge facilities here on site and at institutions around the world.

    Our team in the Photon Sciences Directorate and Yuzhen Shen, who is now with the U.S. Patent and Trademark Office, recently tackled a significant problem in accelerator design, a phenomenon called microbunching instability that has been identified as one of the most serious challenges to the performance of advanced linear accelerator (linac)-based light sources.

    three
    Brookhaven Lab accelerator physicists (from left) Xi Yang, Sergei Seletskiy, and Boris Podobedov

    Light sources, including the National Synchrotron Light Source (NSLS) and the future NSLS-II at Brookhaven, are important tools for producing ultra-bright light that scientists can use to analyze the atomic and molecular structures for advances in different areas of science, ranging from biology and physics to chemistry and geophysics, as well as medicine and materials science. Some light sources are linac-based and others, such as NSLS and NSLS-II, are based on storage rings. In both kinds, the bright light—large quantities of photons—is produced from electron beams that travel in bunches through certain accelerator components, for instance bending magnets or undulators.

    Electrons are never distributed completely evenly inside a bunch and any small ‘noise’ in an unstable bunch can cause the electrons to form microstructures as they clump closer or spread further apart. This effect, the microbunching instability, results in chaotic changes of beam density distribution. In extreme cases, especially for more intense bunches that provide higher brightness at light sources, bunches simply split apart. This effect degrades the quality of electron beams and the photon beams they produce.

    The microbunching instability is rather common and especially important in the fourth generation light sources, such as the Linear Coherent Light Source at SLAC National Accelerator Laboratory in California. They rely on short-wavelength free electron lasers (FELs) that use short, dense bunches of electrons traveling at nearly the speed of light to make short photon bunches.

    Recently, a lot of research has been completed to address the microbunching instability, but thorough understanding had not been achieved, mainly because experimental data was scarce and inconclusive. This isn’t surprising. Noise is impossible to control, so any phenomenon that initiates from it is hard to study experimentally. Measurable effects such as the final shape of an electron bunch could vary wildly from one bunch to the next.

    Microbunching for Our Benefit

    An electron bunch, as seen on the spectrometer screen. By controlling the microbunching instability, this bunch is completely split into about 10 sub–bunches spaced 25 micrometers apart. The ability to control the number of sub-bunches, the distance between them, and their intensity could be beneficial for a number of light sources.

    In our recent work, performed at the NSLS Source Development Laboratory photoinjected linac, we used a novel technique to overcome this challenge. By pre-shaping the electron clumps inside a bunch in a controlled fashion, we were able to ‘seed’ the instability and then study how it developed. With this technique, we were able to—for the first time—systematically characterize the microbunching instability and validate important theoretical predictions. Furthermore, our results suggested approaches for designing an accelerator that suppresses this instability, even for very intense bunches in which the effect is more likely to degrade the quality of both electron beams and the light they emit.

    Perhaps even more interesting, we showed that modern linac-based light sources could actually benefit from microbunching instability. This is something the accelerator physics community has contemplated, but it wasn’t demonstrated until now.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 1:38 pm on July 2, 2013 Permalink | Reply
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    From Brookhaven Lab: “Scientists Identify Promising Antiviral Compounds” 

    Brookhaven Lab

    Structural details and computational modeling may lead to rational design of drugs to combat adenovirus

    July 2, 2013
    Contacts: Karen McNulty Walsh, (631) 344-8350 or Peter Genzer, (631) 344-3174printer iconPrint

    “Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have identified two promising candidates for the development of drugs against human adenovirus, a cause of ailments ranging from colds to gastrointestinal disorders to pink eye. A paper published in FEBS Letters, a journal of the Federation of European Biochemical Societies, describes how the researchers sifted through thousands of compounds to determine which might block the effects of a key viral enzyme they had previously studied in atomic-level detail.

    mn
    Brookhaven biophysicist Walter Mangel. No image credit.

    ‘This research is a great example of the potential for rational drug design,’ said lead author Walter Mangel, a biologist at Brookhaven Lab. ‘Based on studies of the atomic-level structure of an enzyme that’s essential for the maturation of adenovirus and how that enzyme becomes active—conducted at Brookhaven’s National Synchrotron Light Source (NSLS)—we used computational modeling to search for compounds that might interfere with this enzyme and tested the best candidates in the lab.’

    virus
    Structures of the adenovirus proteinase in inactive form (turquoise) and activated (yellow) by binding of a co-factor (beige), in association with a promising inhibitor compound identified in this research (circular “ball and stick” molecule). In the inactive form, left, the inhibitor blocks the “pocket” into which the co-factor binds, thus preventing the enzyme from becoming active. In the fully activated enzyme, right, the inhibitor binds in the now-exposed protein-cleaving “active site,” thus blocking the enzyme’s protein-cleaving ability. The fact that this inhibitor works to disable the proteinase in two different ways at two different sites increases the chance that drugs based on this compound will be successful at fighting adenovirus infection. It also makes it less likely that adenovirus will develop resistance to such drugs.

    Out of 140,000 compounds in a national database, the scientists identified two they expect to be able to turn into antiviral agents to combat adenovirus.”

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 4:14 pm on June 21, 2013 Permalink | Reply
    Tags: , , Brookhaven NSLS,   

    From Brookhaven Lab: “Extreme Insulating-to-conducting Nanowires Promise Novel Applications” 

    Brookhaven Lab

    June 21, 2013
    Laura Mgrdichian

    “Scientists are just beginning to discover and investigate materials that can change from insulators to conductors at room temperature under an applied voltage. There are only a few known examples, but their potential for use in new technologies – as futuristic as the ‘invisibility cloak’ donned by Harry Potter in the book series by the same name – is very exciting.

    nano
    Scanning transmission image of synthesized crystalline nanowires. No image credit.

    At NSLS, researchers have studied a new addition to this elite group – nanowires made of vanadium oxide bronze – and measured drastic, never-before-seen transitions from insulator to conductor. Their work also hints at what happens at the atomic-level. This is a crucial step toward developing possible applications, which include a type of computer memory known as a memristor, now in development at some companies; new varieties of electrochromic coatings, thin films that reversibly change color in response to an applied voltage; and transistors.

    See the full article here.

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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