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  • richardmitnick 2:45 pm on February 23, 2017 Permalink | Reply
    Tags: , BNL NSLS II, Instrument finds new earthly purpose, NIST, , , Spectrometry, ,   

    From Symmetry: “Instrument finds new earthly purpose” 

    Symmetry Mag

    Symmetry

    02/23/17
    Amanda Solliday

    1
    Nordlund and his colleagues—Sangjun Lee, a SLAC postdoctoral research fellow, and Jamie Titus, a Stanford University doctoral student (pictured above at SSRL, from left: Lee, Titus and Nordlund)—have already used the transition-edge-sensor spectrometer at SSRL to probe for nitrogen impurities in nanodiamonds and graphene, as well as closely examine the metal centers of proteins and bioenzymes, such as hemoglobin and photosystem II. The project at SLAC was developed with 
support by the Department of Energy’s Laboratory Directed Research and Development.
    Andy Freeberg, SLAC National Accelerator Laboratory

    Detectors long used to look at the cosmos are now part of X-ray experiments here on Earth.

    Modern cosmology experiments—such as the BICEP instruments and the in Antarctica—rely on superconducting photon detectors to capture signals from the early universe.

    BICEP 3 at the South Pole
    BICEP 3 at the South Pole

    Keck Array
    Keck Array at the South Pole

    These detectors, called transition edge sensors, are kept at temperatures near absolute zero, at only tenths of a Kelvin. At this temperature, the “transition” between superconducting and normal states, the sensors function like an extremely sensitive thermometer. They are able to detect heat from cosmic microwave background radiation, the glow emitted after the Big Bang, which is only slightly warmer at around 3 Kelvin.

    Scientists also have been experimenting with these same detectors to catch a different form of light, says Dan Swetz, a scientist at the National Institute of Standards and Technology. These sensors also happen to work quite well as extremely sensitive X-ray detectors.

    NIST scientists, including Swetz, design and build the thin, superconducting sensors and turn them into pixelated arrays smaller than a penny. They construct an entire X-ray spectrometer system around those arrays, including a cryocooler, a refrigerator that can keep the detectors near absolute zero temperatures.

    2

    TES array and cover shown with penny coin for scale.
    Dan Schmidt, NIST

    Over the past several years, these X-ray spectrometers built at the NIST Boulder MicroFabrication Facility have been installed at three synchrotrons at US Department of Energy national laboratories: the National Synchrotron Light Source at Brookhaven National Laboratory, the Advanced Photon Source [APS] at Argonne National Laboratory and most recently at the Stanford Synchrotron Radiation Lightsource [SSRL] at SLAC National Accelerator Laboratory.

    BNL NSLS-II Interior
    BNL NSLS-II Interior

    ANL APS interior
    ANL APS interior

    SLAC/SSRL
    SLAC/SSRL

    Organizing the transition edge sensors into arrays made a more powerful detector. The prototype sensor—built in 1995—consisted of only one pixel.

    These early detectors had poor resolution, says physicist Kent Irwin of Stanford University and SLAC. He built the original single-pixel transition edge sensor as a postdoc. Like a camera, the detector can capture greater detail the more pixels it has.

    “It’s only now that we’re hitting hundreds of pixels that it’s really getting useful,” Irwin says. “As you keep increasing the pixel count, the science you can do just keeps multiplying. And you start to do things you didn’t even conceive of being possible before.”

    Each of the 240 pixels is designed to catch a single photon at a time. These detectors are efficient, says Irwin, collecting photons that may be missed with more conventional detectors.

    Spectroscopy experiments at synchrotrons examine subtle features of matter using X-rays. In these types of experiments, an X-ray beam is directed at a sample. Energy from the X-rays temporarily excites the electrons in the sample, and when the electrons return to their lower energy state, they release photons. The photons’ energy is distinctive for a given chemical element and contains detailed information about the electronic structure.

    As the transition edge sensor captures these photons, every individual pixel on the detector functions as a high-energy-resolution spectrometer, able to determine the energy of each photon collected.

    The researchers combine data from all the pixels and make note of the pattern of detected photons across the entire array and each of their energies. This energy spectrum reveals information about the molecule of interest.

    These spectrometers are 100 times more sensitive than standard spectrometers, says Dennis Nordlund, SLAC scientist and leader of the transition edge sensor project at SSRL. This allows a look at biological and chemical details at extremely low concentrations using soft (low-energy) X-rays.

    “These technology advances mean there are many things we can do now with spectroscopy that were previously out of reach,” Nordlund says. “With this type of sensitivity, this is when it gets really interesting for chemistry.”

    The early experiments at Brookhaven looked at bonding and the chemical structure of nitrogen-bearing explosives. With the spectrometer at Argonne, a research team recently took scattering measurements on high-temperature superconducting materials.

    “The instruments are very similar from a technical standpoint—same number of sensors, similar resolution and performance,” Swetz says. “But it’s interesting, the labs are all doing different science with the same basic equipment.”

    At NIST, Swetz says they’re working to pair these detectors with less intense light sources, which could enable researchers to do X-ray experiments in their personal labs.

    There are plans to build transition-edge-sensor spectrometers that will work in the higher energy hard X-ray region, which scientists at Argonne are working on for the next upgrade of Advanced Photon Source.

    To complement this, the SLAC and NIST collaboration is engineering spectrometers that will handle the high repetition rate of X-ray laser pulses such as LCLS-II, the next generation of the free-electron X-ray laser at SLAC. This will require faster readout systems. The goal is to create a transition-edge-sensor array with as many as 10,000 pixels that can capture more than 10,000 pulses per second.

    Irwin points out that the technology developed for synchrotrons, LCLS-II and future cosmic-microwave-background experiments provides shared benefit.

    “The information really keeps bouncing back and forth between X-ray science and cosmology,” Irwin says

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 2:36 pm on December 6, 2016 Permalink | Reply
    Tags: , , , , BNL NSLS II, Don DiMarzio,   

    From BNL: “Q&A with CFN User Don DiMarzio” 

    Brookhaven Lab

    December 6, 2016
    Ariana Tantillo
    atantillo@bnl.gov

    1
    Don DiMarzio. No image credit

    Don DiMarzio is an engineering fellow at Northrop Grumman and a senior scientist within the company’s advanced research, development, design, and demonstration group NG Next, where he studies nanomaterials and radio-frequency metamaterials. He is also an adjunct professor at Stony Brook University, where he teaches a nanotechnology class. Since March 2016, he has been using the advanced characterization labs at the Center for Functional Nanomaterials (CFN)—a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven Lab—primarily to investigate nanostructures whose self-assembly is directed through DNA scaffolds. CFN physicist Oleg Gang has been developing this DNA-based technique for several years.

    Northrop Grumman is typically known for building aircraft, such as the U.S. Air Force’s B-2 stealth bomber, as well as unmanned autonomous aircraft and satellites. How does basic research come into play?

    About two years ago, Tom Vice, corporate vice president and president of Northrop Grumman Aerospace Systems, began discussing with his leadership team how to reconstitute the basic research activity that had existed in various forms earlier in the company’s history. NG Next, which includes basic research, applied research and technology development, advanced design, and rapid prototyping, emerged from these discussions. The goal of NG Next is to position Northrop Grumman at the cutting edge of science and technology and to attract the best and brightest young talent.

    NG Next’s basic research group is led by Tom Pieronek, vice president of basic research. The group has eight thrusts or topic areas relevant to the aerospace industry. One of these topics is nanomaterials, which is the focus of the Nanomaterials Group, led by Jesse Tice. I belong to this group. Other thrusts within the basic research group include semiconductor materials, plasmonics, and cognitive autonomy. The charter of our basic research organization is to do real science that is nonproprietary and publishable, in collaboration with the nation’s top universities and government labs. Any fundamental new discoveries that we think are promising may be transferred over to our applied research and prototyping groups within NG Next.

    The Center for Functional Nanomaterials (CFN) is one of five U.S. Department of Energy Nanoscale Science Research Centers and is among the many nanoscale facilities located at universities across the United States. What influenced your decision to submit a user proposal to CFN?

    After I got my PhD in solid-state physics, I did a postdoc at Brookhaven’s National Synchrotron Light Source (NSLS) in the late 1980s and really enjoyed working at Brookhaven.

    BNL NSLS
    BNL NSLS Interior
    BNL/NSLS

    After my postdoc, I became a scientist at the Grumman Corporate Research Center in Bethpage, NY, but continued my collaborations with Brookhaven on and off throughout the years.

    When Northrop Grumman leadership began planning for the new basic research group last year, I got involved. Part of my planning and development work for the group included helping to organize workshops—one in nanomaterials and the other in radio-frequency metamaterials—at our regional headquarters in southern California. For these invite-only workshops, the goal was to learn what was at the cutting edge in research, where we should focus our efforts, and who we could collaborate with.

    Our Nanomaterials Workshop provided a broad perspective on cutting-edge research, from nanomaterials synthesis and structures fabrication through fundamental properties and applications. One area that showed great potential was in nanoparticle self-assembly, and one of the major players in that field is the CFN. Although I had been working with various nanotechnologies before the establishment of NG Next, the CFN was either not established yet or our research was both applied and highly proprietary. But with the establishment of the basic research group within NG Next, it became clear that there was a definite opportunity for collaboration, especially considering that the way CFN is set up aligns with NG Next’s charter to publish, make presentations, and collaborate.

    When I learned about CFN physicist Oleg Gang’s work on exploiting DNA to direct the self-assembly of nanoparticles, I became very intrigued. I was particularly impressed with the strength and flexibility of this DNA origami scaffolding to fabricate a wide range of structures relevant for device and materials applications, and the ability to transition these assemblies from “soft” to “hard” while preserving key functionalities. Northrop Grumman sees this work as a potentially ground-breaking area that may lead to revolutionary new fabrication capability for everything from sensor systems to structural composites.

    While most of NG Next’s basic research group is in California, I am here on Long Island (at our Bethpage facility), so CFN is conveniently located near where I work and live. The group in California is currently building out its own labs that will be separate from our traditional applied laboratories. As an existing facility with state-of-the-art equipment and expertise in nanomaterials synthesis, device fabrication, and advanced characterization, CFN was the perfect complement to our West Coast research operations.

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    Gold nanoparticles are coordinated by DNA origami octahedron into the prescribed cluster, as obtained from the 3D transmission electron microscopy reconstruction (based on Y. Tian et al. Nature Nanotechnology 10, 637–644, 2015).

    Are you working on any other projects at CFN besides the directed self-assembly?

    In nanomaterials research, I am supporting principal investigators who are using CFN’s advanced characterization tools, particularly those in microscopy, to look at cutting-edge 2D materials like tin selenide (SnSe) and black phosphorous, in collaboration with our university partners.

    For our nanomaterials work, I am also collaborating with an NG Next group involved in plasmonics research, leveraging our DNA assembly work to fabricate new and unique optical structures.

    What are some of the characterization techniques you use at CFN?

    To probe the composition of the DNA-based nanostructures, we focus on small-angle x-ray scattering (SAXS) and transmission electron microscopy (TEM). To probe the chemical states of 2D materials and devices, we use energy-dispersive x-ray spectroscopy and electron energy-loss spectroscopy. In addition to these traditional microscopy techniques, we employ aberration-corrected low-energy electron microscopy (LEEM) and angle-resolved photoemission spectroscopy (ARPES) for some of our 2D materials. This latter technique is important because the band structure, or electronic energy levels, of 2D materials often has directional dependence.

    Your work at CFN sounds like it could also benefit from the advanced characterization methods at the National Synchrotron Light Source II (NSLS-II). Are you collaborating with NSLS-II or do you have plans to?

    BNL NSLS II
    BNL NSLS Interior
    BNL/NSLS-II

    Plans are in the works for experiments at the NSLS-II, building on our current efforts at the CFN. We will be working with CFN scientists Dario Stacchiola and Jerzy Sadowski on the new LEEM/ARPES system during its commissioning in January, and we are evaluating the use of synchrotron SAXS for large-volume data acquisition from nanomaterials for additive manufacturing.

    Our leadership is very supportive of our interactions with Brookhaven’s DOE Office of Science User Facilities and would like to solidify relationships for the long term.

    How has it been coming back to Brookhaven more than 30 years later?

    Even though I work for Northrop Grumman, I feel like I am part of the family here at CFN. I am working at CFN pretty much every day. From the start, CFN leadership has been very accommodating. They helped us get rapid access while we started negotiations on our CRADA [cooperative research and development agreement] and submitted our long-range user proposals for the directed assembly and 2D materials projects.

    Since I arrived, CFN staff scientists have been very helpful with training on laboratory equipment such as the SAXS, TEM, and scanning TEM (STEM) systems. The CFN group leads have been particularly helpful in facilitating timely sample preparation, such as that with the focused-ion beam, and with scheduling the use of characterization tools.

    You mentioned you are at CFN basically every day. What keeps you coming back?

    I feel like a kid in a candy shop here. Everyone who works here is passionate about what they do, so coming in every day is something I look forward to. I have my own spare office, close to the group leaders who I am working with. Although I primarily work with Oleg, I get to interact with many other staff scientists and postdocs, not only through my research but also through my volunteer work at CFN. I am the elected vice chair of the CFN Users’ Executive Committee and co-chair of the 2017 NSLS-II & CFN Joint Users’ Meeting.

    How did you become interested in nanomaterials?

    Years ago, I was doing applied research in photocatalysis involving the use of titanium dioxide nanoparticles to create self-decontaminating surfaces—a DARPA [Defense Advanced Research Projects Agency] project. Subsequently, I got involved in developing lightweight carbon nanotube based electrical cables for Department of Defense applications. The carbon nanotube work is ongoing at Northrop Grumman, with applications for space systems and air platforms. Although these applications are important, my turn to basic research was rooted in the NG Next vision to investigate fundamental phenomena that will enable new game-changing technologies that will have applications to both Northrop Grumman’s traditional customers and future technology marketplaces.

    See the full article here .

    Please help promote STEM in your local schools.

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    BNL Campus

    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 10:42 am on October 14, 2016 Permalink | Reply
    Tags: , BNL NSLS II, Cuprates, , , X-ray photon correlation spectroscopy   

    From BNL: “Scientists Find Static “Stripes” of Electrical Charge in Copper-Oxide Superconductor” 

    Brookhaven Lab

    October 14, 2016
    Ariana Tantillo
    atantillo@bnl.gov
    (631) 344-2347
    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    Fixed arrangement of charges coexists with material’s ability to conduct electricity without resistance

    1
    Members of the Brookhaven Lab research team—(clockwise from left) Stuart Wilkins, Xiaoqian Chen, Mark Dean, Vivek Thampy, and Andi Barbour—at the National Synchrotron Light Source II’s Coherent Soft X-ray Scattering beamline, where they studied the electronic order of “charge stripes” in a copper-oxide superconductor. No image credit.

    Cuprates, or compounds made of copper and oxygen, can conduct electricity without resistance by being “doped” with other chemical elements and cooled to temperatures below minus 210 degrees Fahrenheit. Despite extensive research on this phenomenon—called high-temperature superconductivity—scientists still aren’t sure how it works. Previous experiments have established that ordered arrangements of electrical charges known as “charge stripes” coexist with superconductivity in many forms of cuprates. However, the exact nature of these stripes—specifically, whether they fluctuate over time—and their relationship to superconductivity—whether they work together with or against the electrons that pair up and flow without energy loss—have remained a mystery.

    Now, scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have demonstrated that static, as opposed to fluctuating, charge stripes coexist with superconductivity in a cuprate when lanthanum and barium are added in certain amounts. Their research, described in a paper published on October 11 in Physical Review Letters, suggests that this static ordering of electrical charges may cooperate rather than compete with superconductivity. If this is the case, then the electrons that periodically bunch together to form the static charge stripes may be separated in space from the free-moving electron pairs required for superconductivity.

    “Understanding the detailed physics of how these compounds work helps us validate or rule out existing theories and should point the way toward a recipe for how to raise the superconducting temperature,” said paper co-author Mark Dean, a physicist in the X-Ray Scattering Group of the Condensed Matter Physics and Materials Science Department at Brookhaven Lab. “Raising this temperature is crucial for the application of superconductivity to lossless power transmission.”

    Charge stripes put to the test of time

    To see whether the charge stripes were static or fluctuating in their compound, the scientists used a technique called x-ray photon correlation spectroscopy. In this technique, a beam of coherent x-rays is fired at a sample, causing the x-ray photons, or light particles, to scatter off the sample’s electrons. These photons fall onto a specialized, high-speed x-ray camera, where they generate electrical signals that are converted to a digital image of the scattering pattern. Based on how the light interacts with the electrons in the sample, the pattern contains grainy dark and bright spots called speckles. By studying this “speckle pattern” over time, scientists can tell if and how the charge stripes change.

    In this study, the source of the x-rays was the Coherent Soft X-ray Scattering (CSX-1) beamline at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility at Brookhaven.

    BNL NSLS-II Interior
    BNL NSLS-II

    “It would be very difficult to do this experiment anywhere else in the world,” said co-author Stuart Wilkins, manager of the soft x-ray scattering and spectroscopy program at NSLS-II and lead scientist for the CSX-1 beamline. “Only a small fraction of the total electrons in the cuprate participate in the charge stripe order, so the intensity of the scattered x-rays from this cuprate is extremely small. As a result, we need a very intense, highly coherent x-ray beam to see the speckles. NSLS-II’s unprecedented brightness and coherent photon flux allowed us to achieve this beam. Without it, we wouldn’t be able to discern the very subtle electronic order of the charge stripes.”

    The team’s speckle pattern was consistent throughout a nearly three-hour measurement period, suggesting that the compound has a highly static charge stripe order. Previous studies had only been able to confirm this static order up to a timescale of microseconds, so scientists were unsure if any fluctuations would emerge beyond that point.

    X-ray photon correlation spectroscopy is one of the few techniques that scientists can use to test for these fluctuations on very long timescales. The team of Brookhaven scientists—representing a close collaboration between one of Brookhaven’s core departments and one of its user facilities—is the first to apply the technique to study the charge ordering in this particular cuprate. “Combining our expertise in high-temperature superconductivity and x-ray scattering with the capabilities at NSLS-II is a great way to approach these kind of studies,” said Wilkins.

    To make accurate measurements over such a long time, the team had to ensure the experimental setup was incredibly stable. “Maintaining the same x-ray intensity and sample position with respect to the x-ray beam are crucial, but these parameters become more difficult to control as time goes on and eventually impossible,” said Dean. “When the temperature of the building changes or there are vibrations from cars or other experiments, things can move. NSLS-II has been carefully engineered to counteract these factors, but not indefinitely.”

    “The x-ray beam at CSX-1 is stable within a very small fraction of the 10-micron beam size over our almost three-hour practical limit,” added Xiaoqian Chen, co-first author and a postdoc in the X-Ray Scattering Group at Brookhaven. CSX-1’s performance exceeds that of any other soft x-ray beamline currently operational in the United States.

    In part of the experiment, the scientists heated up the compound to test whether thermal energy might cause the charge stripes to fluctuate. They observed no fluctuations, even up to the temperature at which the compound is known to stop behaving as a superconductor.

    “We were surprised that the charge stripes were so remarkably static over such long timescales and temperature ranges,” said co-first author and postdoc Vivek Thampy of the X-Ray Scattering Group. “We thought we may see some fluctuations near the transition temperature where the charge stripe order disappears, but we didn’t.”

    In a final check, the team theoretically calculated the speckle patterns, which were consistent with their experimental data.

    Going forward, the team plans to use this technique to probe the nature of charges in cuprates with different chemical compositions.

    X-ray scattering measurements were supported by the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by DOE’s Office of Science.

    See the full article here .

    Please help promote STEM in your local schools.

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    BNL Campus

    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 8:06 am on September 18, 2016 Permalink | Reply
    Tags: BNL NSLS II, , ,   

    From Science Alert: “Here’s how physicists accelerate particles to 99.99% the speed of light” 

    ScienceAlert

    Science Alert

    8

    Business Insider

    15 SEP 2016
    ALI SUNDERMIER

    1
    NSLS II. Brookhaven National Laboratory

    By now, you might be familiar with the concept of particle accelerators through the work of the Large Hadron Collider (LHC), the monstrous accelerator that enabled scientists to detect the Higgs boson.

    CERN/LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN

    But the LHC is not alone – the world is equipped with more than 30,000 particle accelerators that are used for a seemingly endless variety of tasks.

    Some of these machines, like the LHC, accelerate particles to nearly the speed of light to smash them together and probe the fundamental building blocks of our universe. Others are used to seal milk cartons and bags of potato chips.

    Brookhaven National Laboratory in New York is home to one of the world’s most advanced particle accelerators: the National Synchrotron Light Source II (NSLS II).

    The NSLS II will allow researchers to do a wide range of science varying from developing better drug treatments, to building more advanced computer chips, to analysing everything from the molecules in your body to the soil you walk on.

    When scientists accelerate particles to these crazy speeds in the NSLS II, they force them to release energy which they can manipulate to do a mind-boggling array of different experiments.

    As electrons moving at nearly the speed of light go around turns, they lose energy in the form of radiation, such as X-rays. The X-rays produced at the NSLS II are extremely bright – a billion times brighter than the X-ray machine at your dentist’s office.

    When scientists focus this extremely bright light onto a very small spot, it allows them to probe matter at an atomic scale. It’s kind of like a microscope on steroids.

    Here’s how the NSLS II pushes particles to 99.99 percent the speed of light – all in the name of science.

    First, the electron gun generates electron beams and feeds them into the linear accelerator, or linac.

    In the linac, electromagnets and microwave radio-frequency fields are used to accelerate the electrons, which must travel in a vacuum to ensure they don’t bump into other particles and slow down.

    Next, the electrons enter a booster ring, where magnets and radio-frequency fields accelerate them to approximately 99.9 percent percent the speed of light.

    Then they are injected into a circular ring called a storage ring.

    3
    Ali Sundermier

    In the storage ring, the electrons are steered by an assortment of magnets.

    The blue magnets bend the motion of the electrons, the yellow magnets focus and defocus the path of the electrons, and the red and orange magnets take outlying electrons and bring them into a closer path.

    The smaller magnets are corrector magnets, which keep the beam in line.

    4
    Ali Sundermier

    This is an insertion device in the storage ring. Insertion devices are magnetic structures that wiggle the electron beam as it passes through the device. This produces an extremely bright and focused beam.

    5
    Ali Sundermier

    As the electrons go around turns in the storage ring, they decelerate slightly, losing energy.

    The lost energy can be converted into different forms of electromagnetic radiation, such as X-rays, that are directed down beamlines running in straight lines tangential to the storage ring.

    At the end of the beamline, the X-rays crash into samples of whatever material is the subject of the experiment.

    6
    Ali Sundermier

    This is an X-ray spectroscopy beamline, where scientists analyse the chemical composition of materials by exciting the electrons in an atom.

    7
    Ali Sundermier

    The circumference of the NSLS-II is so big, nearly half a mile, that many people working there travel around on tricycles.

    The NSLS II is still in the early stages of its development, having just taken over for its successor (the NSLS), in 2014. When it’s complete, it will be able to accommodate about 70 different beamlines.

    8
    Ali Sundermier

    This article was originally published by Business Insider.

    See the full article here .

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  • richardmitnick 8:13 am on September 2, 2016 Permalink | Reply
    Tags: 2016 Microscopy Today Innovation Awards, , , BNL NSLS II, Nathalie Bouet, , X-ray scanning microscope   

    From Brookhaven: Women in STEM – “When Nanofabrication Leads to Nanoscience: Optics Developed at the CFN Bring NSLS-II’s Ultra-Bright x-rays into Focus for Scientific Imaging” Nathalie Bouet 

    Brookhaven Lab

    August 30, 2016
    Ariana Tantillo
    atantillo@bnl.gov

    Optics are critical components in a one-of-a-kind x-ray microscope that was recognized with a 2016 Microscopy Today Innovation Award and named a 2016 R&D 100 Award finalist.

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    Nathalie Bouet, who leads Brookhaven’s fabrication of multilayer Laue lenses, uses scanning electron microscopy at the Center for Functional Nanomaterials to image the multilayer after it has been grown. She measures the exact positioning of the layers, making sure these measurements match those expected from her team’s theoretical multilayer design. This quality check is needed before the multilayer can be transformed into usable optics for the microscope.

    At the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, nanofabrication—making structures or devices as small as a few atoms in size—is a daily occurrence at the Center for Functional Nanomaterials, a DOE Office of Science User Facility. Scientists at the National Synchrotron Light Source II (NSLS-II), another DOE Office of Science User Facility at Brookhaven, have been using CFN facilities to develop advanced x-ray focusing optics called multilayer Laue lenses (MLL). These optics have been incorporated into an x-ray scanning microscope installed at the Hard X-ray Nanoprobe (HXN) beamline, where they focus the extremely bright beams of “hard” (high energy) x-rays produced by NSLS-II to nanometer dimensions. Recently, this MLL-based microscope—the only one of its kind—was recognized with one of ten 2016 Microscopy Today Innovation Awards and was named a 2016 finalist for the R&D 100 Awards, which annually celebrate the world’s 100 most innovative technologies.

    “These honors recognize the full extent of the development and construction of the microscope, including all of the research and development work on MLL we’ve done at the CFN,” said NSLS-II physicist Nathalie Bouet, who is leading MLL fabrication at Brookhaven.

    2
    Inside the transmission electron microscopy sample preparation room at the Center for Functional Nanomaterials, Juan Zhou uses a polishing system to prepare a multilayer Laue lens.

    To achieve scientific imaging with extremely high spatial resolution, the optics are integrated onto a custom-built microscope with fine motors that allow extremely accurate positioning, active feedback controls that provide vibrational stability, and components that minimize thermal drifts. With this hardware, the microscope has a resolution equivalent to 50,000 times smaller than a grain of sand. Scientists at NSLS-II use the microscope to collect elemental, structural, and chemical information on everything from soil samples to biological proteins and battery materials.

    Named after physicist Max von Laue, who won the 1914 Nobel Prize in physics for his discovery of x-ray diffraction by crystals, the lenses are made up of several thousand alternating layers of two materials: silicon and tungsten silicide. To grow MLL, the scientists use a deposition system at NSLS-II that individually deposits each layer onto a silicon substrate. Layers are deposited according to a precisely controlled thickness gradient, with the thinnest layers (a few nanometers) laid first and the thickest ones (up to 25 nanometers) last.

    Because even the slightest error in the multilayer stack can have a significant impact on the properties of the optics and thus, the focusing of the x-ray beam, the scientists need to analyze carefully the quality of the stack after it has been grown. Using high-resolution scanning electron microscopy at the CFN, they image the multilayer to measure the exact positioning of the layers. They compare their measurements to those expected from the theoretical multilayer design, applying this information to correct any deviations.

    3
    The multilayer Laue lens module is part of the x-ray microscope (seen above in a vacuum chamber) installed at the National Synchrotron Light Source II’s Hard X-ray Nanoprobe beamline.

    Once the multilayer stack passes the quality test, the next step is to transform it into usable optics for the microscope. To convert the multilayer stack into optics that can be illuminated in transmission, scientists precisely extract very thin sections of the stack—a very challenging endeavor.

    “Sectioning is difficult because the width of the slices is significantly smaller than the thickness of the stacked layers sitting on top of the substrate,” said Brookhaven scientist Juan Zhou, a member of Bouet’s team. As a result, the multilayer sections are very susceptible to bending. If the sections contain any deformations, the lenses cannot effectively focus the x-ray beam. Therefore, very precise sectioning is crucial to ensuring that the lenses can bring x-rays into optimal focus.

    4
    Scientists used mechanical polishing and focused-ion beam milling to fabricate the multilayer Laue lens (MLL) seen in the above scanning electron microscope image. They glued a piece of silicon (Si) on top of the multilayer film to protect it from being damaged during the lens fabrication process.

    5
    This scanning electron microscope image shows the cross-section of a multilayer Laue lens (MLL) with a thickness of 43 micrometers. The cap layer (2 micrometers thick) gives the multilayer additional protection—beyond the protection offered by the glued silicon (Si) layer—against fabrication damages.

    At the CFN, scientists use one of two sectioning techniques, depending on the intrinsic characteristics of the multilayer, the energy of the x-rays that will be used, and the focal length of the lens (the distance between the lens and its focal point, where the x-rays converge). The first technique is based on mechanical polishing, in which both sides of the multilayer are “gritted” down with progressively finer abrasives until the desired thickness and smoothness of the sections are achieved. The second, developed at Brookhaven, is a patented technique based on reactive-ion etching—the removal or “etching” away of a material from its surface through bombardment with a plasma of chemically reactive ions. With both techniques, the scientists often use a focused-ion beam as a final polishing tool.

    Because the lenses are one-dimensional focusing optics, a pair of them is needed to make a focused beam in both directions. As a result, the spacing between the two lenses and the quality of their alignment impact the size of the x-ray beam.

    So far, Bouet’s team has succeeded in focusing x-rays down to 11 nanometers with MLL. But efforts are underway to push the focusing even further and to maximize the number of photons in the focused beam so that HXN users can take full advantage of NSLS-II’s brightness. The team is developing MLL with a “wedged” shape, in which the layers are tilted so that their thickness differs at both ends of the substrate. (The “flat” lenses of the microscope currently in use at the HXN beamline are of equal thickness on both sides of the substrate.) Introducing a gradient inside the multilayer means each layer forms a slightly different angle than the one before it. This geometry allows MLL to diffract x-rays more efficiently; early tests have demonstrated that the wedged lenses make use of 27 percent of the x-ray beam, twice the amount used by a flat MLL.

    The other members of the microscope development team are Brookhaven physicists Yong Chu (HXN beamline group leader), Xiaojing Huang, Evgeny Nazaretski, and Hanfei Yan, design engineer Brian Mullany, technical specialist Dennis Kuhne, software analyst Kenneth Lauer, as well as DOE Argonne National Lab engineer Deming Shu.

    See the full article here .

    Please help promote STEM in your local schools.

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    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 10:09 am on May 6, 2016 Permalink | Reply
    Tags: , BNL NSLS II, Supercooled Cavities for Particle Acceleration,   

    From BNL: “Supercooled Cavities for Particle Acceleration” 

    Brookhaven Lab

    May 3, 2016
    Ariana Tantillo

    Very low temperatures support research at Brookhaven National Laboratory’s National Synchrotron Light Source II

    BNL NSLS-II Building
    BNL NSLS-II Building

    BNL NSLS-II Interior
    BNL NSLS-II Interior

    1
    A superconducting radio-frequency cryomodule installed in the NSLS-II ring. No image credit.

    When you think about the coldest places on Earth, the National Synchrotron Light Source II (NSLS-II), a U.S. Department of Energy (DOE) Office of Science User Facility located at the DOE’s Brookhaven National Laboratory, probably doesn’t come to mind. But accelerating electrons around the half-mile-long ring of NSLS-II at nearly the speed of light requires some extremely cold temperatures, hundreds of degrees below the freezing point of water.

    Supercool temperatures mean super cool science research can go on.

    A continuous flow of electrons

    As electrons circle around NSLS-II’s ring, they emit extremely bright X-rays that scientists use to image materials, such as soil samples, batteries, and biological proteins. “The images are not necessarily photographs, but spectrum, absorption lines, or diffraction patterns,” explained James Rose, head of the Radio Frequency Systems Group for NSLS-II.

    By studying the fluorescence, diffraction, scattering, and absorption of X-rays, scientists can uncover a material’s atomic structure, which gives rise to its chemical, electronic, and structural properties. From examining soil samples to understand the uptake of chemical runoff, to watching in real time as batteries operate to discover where and how materials inside break down, to examining the structure of biological proteins to help design new drugs for treating disease, scientists at NSLS-II probe the inner workings of various kinds of materials.

    In producing these X-rays, the electrons lose energy and slow down. For the electrons to continue generating the high-power X-ray beams used by scientists from around the world to image materials, this energy must be replenished.

    At NSLS-II, electrons gain this energy by passing through two hollow metal (niobium) chambers called radio-frequency (RF) cavities that contain an electromagnetic field. The electric field transfers energy to the electrons, propagating them along the ring. “An RF cavity is a resonator like an organ pipe or guitar string,” said Rose. “Our cavities are tuned to a particular frequency such that an electron traveling around the ring passes through the cavity at the same phase each trip, and gains the same energy per pass as it loses energy to synchrotron radiation, or light. Giving energy to the electron at just the right time increases its energy, much like someone pushing a child on a swing.”

    When cooled to an extremely low, or cryogenic, temperature, the niobium in the RF cavity becomes superconducting—that is, it loses nearly all resistance to an electric current. As a result, electrons can flow freely through the cavities. If niobium were conducting electricity as it would at room temperature, there would be a large resistance to the flow of electrons. When electron flow is resisted, the electrical energy that moves the electrons is converted into heat energy—a waste product. Without this resistance, electricity can be delivered to the cavity much more efficiently.

    “If the cavities were not superconducting, almost seven times more energy would be required to keep the electrons flowing to produce high-intensity X-ray beams,” said Rose.

    The superconductivity not only reduces energy loss in the cavities but it also provides for electron beam stability.

    “Because we don’t need to worry about keeping resistive losses low, we can design the cavities with a large aperture that allows resonant frequencies above the cavity’s tuned frequency to leak out of the cavity into absorbers that damp, or reduce the amplitude of, the higher-frequency oscillations. If these higher frequencies were not damped, they would add and subtract energy from the beam out of sequence. That’s like pushing the child on the swing randomly, causing the swing to slow down or stopping the child short at the highest speed,” explained Rose.

    Supercooled cavities

    At NSLS-II, the RF cavities are continuously immersed in liquid helium, which, with the help of liquid nitrogen, cools niobium to its superconducting state. The cavities are installed within cryomodules, which are essentially vacuum-insulated containers like thermos bottles that maintain the ultra-cold temperatures of the liquid helium to allow for near-zero electrical resistance within the RF cavity.

    2
    Brookhaven Lab staff members (left to right) James Rose, John Gosman, and William Gash with one of the two electron bunch–lengthening radio-frequency cavities that will be installed at the National Synchrotron Light Source II (NSLS-II). By reducing the number and intensity of collisions between electrons circling the NSLS-II electron storage ring, these cavities will help prevent electron beam loss and thus extend the lifetime of the beams used to conduct experiments.

    “The only way to make liquid helium from gaseous helium is to cool it down,” explained Rose. “Because nitrogen is inexpensive as compared to helium, we use liquid nitrogen to precool the helium from room temperature down to liquid nitrogen’s boiling point of 321 degrees below zero. From there, we cool the helium down to approximately minus 450 degrees Fahrenheit.”

    Cooling helium gas into a liquid is a multistep process. First, the gas is squeezed in compressors. As the gas molecules are forced into a smaller volume, the pressure and temperature of the gas rise. The gas is then fed into an insulated enclosure called a cold box, where three fast-moving expansion turbines liquefy the gas by reducing its pressure, causing the gas molecules to spread apart. This rapid expansion causes the gas to cool and a portion of it to liquefy.

    “The cold box is the heart of the cryogenic plant,” said William Gash, a cryogenics engineer in Brookhaven’s Utilities Group. “Its turbines rotate at many thousands of revolutions per second, as compared to a car, which operates in revolutions per minute.”

    Once liquefied, the helium is stored in a large vacuum-insulated container and distributed through insulated piping and control valves directly into the cryomodules to surround the RF cavities.

    The remaining cooled gas is returned to the cold box, where it flows through heat exchangers to precool the incoming high-pressure gas before being sent to the compressor to start the cycle again.

    “The cryogenics plant is a closed-loop system,” explained Gash. “All of the helium is recovered. Even in the event of an emergency, we have a recovery system in place to ensure the supply is retrieved.”

    Longer-lived beams

    In the next five years or so, additional superconducting RF cavities and valves will be installed.

    “This installation will provide the RF power needed to support more beams and thus more experiments at NSLS-II,” said Rose.

    Two of the cavities will be electron bunch–lengthening cavities, which “lengthen” the bunches, or groups, of electrons traveling around the ring.

    In dense bunches, electrons circling the ring undergo collisions with other electrons in the bunch. “Imagine dancers that bump into one another on a crowded dance floor,” said Rose.

    These collisions scatter the electrons, causing some electrons to be ejected from the bunch. Eventually, these ejected electrons hit the beam pipe and lose their energy to radiation. “Some dancers leave the dance floor and go home,” said Rose. “By lengthening the electron bunches (increasing the size of the dance floor), we can reduce the density of electrons (spreading people out on the dance floor), thereby reducing the number and intensity of the collisions. Ultimately, these new cavities will extend the lifetime of the beams.”

    See the full article here .

    Please help promote STEM in your local schools.

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    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 11:57 am on March 22, 2016 Permalink | Reply
    Tags: , BNL NSLS II, NSLS-II user Pankaj Sarin   

    From BNL: “NSLS-II User Profiles: Pankaj Sarin” 

    Brookhaven Lab

    March 21, 2016
    Laura Mgrdichian
    mgrdichian@gmail.com

    1
    Pankaj Sarin and Dan Lowry are scientific users at the X-ray Powder Diffraction (XPD) beamline at NSLS-II.

    Pankaj Sarin, an assistant professor in the School of Materials Science and Engineering at Oklahoma State University, traveled to Brookhaven Lab recently to conduct research at the X-Ray Powder Diffraction (XPD) beamline. He and his group studied ceramic materials that can withstand extremely high temperatures and may be used to protect spacecraft during re-entry, descent, and landing.

    Tell us about your research interests.

    The goal of my research is to understand the interplay between the atomic structures and intrinsic properties of ceramic materials, as well as these materials’ processed microstructures and macroscopic properties. Currently, my research group at OSU is focused on the development of advanced ceramic materials for applications in aerospace, energy generation, energy storage, environmental remediation, and as orthopedic scaffolds.

    Ceramics have complex atomic structures and, therefore, offer numerous possibilities for the development of new, exciting functional materials by design. They are suitable for applications in several technologies due to certain key properties, such as stability even at high temperatures; high hardness; a wide range of ionic, electronic and thermal conductivities; and even biocompatibility. To apply these properties to solving some of the most challenging problems worldwide, we need a complete understanding of ceramic material structures, from their atomic structures to their macrostructures, and from static states to the dynamics that occur under the extreme conditions in real-life applications and during processing.

    As most ceramic materials are subjected to high temperatures either during processing or incorporated into applications, a substantial part of my research effort is devoted to the development of instrumentation to enable in-situ high temperature studies on ceramic materials using synchrotron radiation. This has allowed me and my group to conduct novel experimental studies to gain a fundamental understanding of the high-temperature phase transformations, thermal expansion, crystallization, melting, microstructure evolution, and oxidation of key ceramic material systems (the last being the subject of our current work at NSLS-II).

    What material were you studying at NSLS-II, and why?

    The goal of our research at NSLS-II is to develop oxidation-resistant hafnium diboride (HfB2) composites for aerospace applications beyond 2000°C in air. These composites belong to a class of materials usually referred to as ultra-high temperature ceramics, which have high melting points (greater than 3000°C), high hardness, good wear resistance, good mechanical strength, good chemical and thermal stability (under certain conditions), and high thermal conductivity.

    A considerable effort in the aerospace industry is focused on the design and development of materials and systems to protect spacecraft from extremely high temperatures during all phases of the mission, including entry, descent, and landing. Reusable thermal protection systems are also key technologies for future hyper-sonic cruise vehicles, which may be used in rapid global and space access missions. For example, it is projected that hypersonic Mach 10 vehicles with sharp aero-surfaces will require materials that can be heated to 2000ºC, can operate in air, and are re-usable. Ultra-high temperature ceramic composites are excellent candidates for these applications.

    At NSLS-II, we studied a type of ceramic material that may be resistant to oxidation at high temperatures, which can compromise the material. Specifically, we looked at a sample that could form a dense oxidation-resistant “skin” layer when exposed to oxygen at temperatures around 3000°F, which protects the material from further oxidation. We used the X-ray Powder Diffraction (XPD) beamline to perform x-ray diffraction and total scattering simultaneously, while heating the sample in a water-cooled quadrupole lamp furnace we developed for this purpose.

    In-situ x-ray diffraction using synchrotron radiation provides invaluable information toward our understanding of the oxidation of diboride ceramics. A complete understanding of the oxidation mechanism requires the identification of any defect structures as well as molten or amorphous phases and species. For the very first time, it is now possible to identify and quantify any intermediate crystalline and amorphous phases that are formed during the oxidation of HfB2, in real time. The kinetics and energetics of the oxidation reaction will be correlated with the microstructure of the oxidized sample.

    Why did you choose NSLS-II for this study?

    The oxidation kinetics and evolution of secondary phases in an HfB2 system have never been studied in-situ, and are not well understood. The XPD beamline is particularly suited for this work due to several critical features. These include the high photon flux, particularly for small beam sizes, parallel beam geometry, the available photon energy radiation, the capability to acquire high resolution diffraction and total scattering datasets in fraction of a second using the 2D Flat Panel Detectors, fast switching between diffraction and total scattering modes, and a diffractometer design that allows us to position the quadrupole lamp furnace in the beam path.

    Besides the hardware and software capabilities available at XPD, the profound experience of the beamline scientists in extreme-environment diffraction and total scattering experiments has been critical to guiding this research to hugely successful outcomes. In particular, I would like to thank associate physicist Dr. Sanjit Ghose and the XPD group leader, Dr. Eric Dooryhee.
    Who collaborated with you on this study?

    Daniel Lowry, a graduate student in the School of Materials Science and Engineering at OSU, worked with me on this research experiment. Daniel recently completed his MS degree at OSU and is now working with my group to earn his PhD in materials science engineering. I would also like to acknowledge Dr. Fnu Shikhar Jha, a postdoctoral researcher in the Department of Mechanical Engineering at the University of Colorado at Boulder.

    Our research receives sponsorship from the Oklahoma NASA Experimental Program to Stimulate Competitive Research (EPSCoR) program.

    See the full article here .

    Please help promote STEM in your local schools.

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    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 4:05 pm on March 15, 2016 Permalink | Reply
    Tags: , , , BNL NSLS II   

    From BNL: “Brookhaven Lab Facilities Team Up to Offer Beamline for Cutting-Edge Science” 

    Brookhaven Lab

    March 15, 2016
    Chelsea Whyte

    The Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline at the National Synchrotron Light Source II, which hosted its first users in February, was built in partnership with the Center for Functional Nanomaterials

    One of the most recent capabilities to begin hosting scientific users at the National Synchrotron Light Source II (NSLS-II) was built in partnership with the Center for Functional Nanomaterials (CFN), both of which are U.S. Department of Energy (DOE) Office of Science User Facilities located at Brookhaven National Laboratory.

    BNL NSLS II
    BNL NSLS-II Interior
    NSLS II

    BNL Center for Functional Nanomaterials interior
    CFN

    The Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline provides soft x-rays that are perfectly suited to the research needs of catalysis scientists visiting Brookhaven’s nanocenter.

    BNL NSLS II Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline
    Coherent Soft X-ray Scattering and Spectroscopy (CSX-2) beamline

    Combining these x-rays with a CFN endstation is a perfect marriage then.

    “The Center for Functional Nanomaterials is a cutting-edge facility in its own right, but now it’s also a path to bring users to NSLS-II,” said CFN Director Emilio Mendez. “I look forward to the innovative science made possible at the intersection of the capabilities at CFN and NSLS-II.”

    “The synergy between our two institutions strengthens us both,” said John Hill, Director of NSLS-II. “Partnerships like the one with CFN allow us to make the most of the expertise and facilities that make Brookhaven unique.”

    The CSX-2 beamline is well-suited to research in energy production and storage, with an emphasis on studying surface chemical processes relevant in heterogeneous catalysis in situ and in operando – as they would work in real time close to real world conditions. The beamline is also suited for studying processes in environmental and atmospheric chemistry.

    “Most of our users study model systems for catalysis,” said Ira Waluyo, a beamline scientist at CSX-2 “They can bring samples ranging from single crystals to nanoparticles to the beamline, and when they expose the samples to the reactant gases, they study how the catalyst and reactants evolve during a reaction. When they increase the temperature of the sample or change the composition or pressure of the gases, they can study how the catalyst is transformed and what new chemical species are formed on the surface. Our users can then pinpoint what exactly makes a catalyst active in a particular reaction.”

    The study of catalysts is an exploration of nanoscale interface science – research into the phenomena occurring as chemical reactions take place on the scale of a billionth of a meter. The ambient pressure photoelectron spectroscopy (APPES) endstation at CSX-2 allows scientists to do experiments that would normally require ultra-high vacuum conditions to be performed at pressures closer to realistic conditions.

    “Allowing scientists to study materials for energy solutions in operando is one of the benefits here. The understanding of these interactions will help us to engineer catalysts that work better and cost less,” said Anibal Boscoboinik, a CFN staff scientist and partner at CSX-2. “Industrial researchers can use the gained knowledge to engineer catalysts for energy transformations at lower cost and with fewer environmental impacts.”

    The APPES endstation was provided by CFN, while the infrastructure of the beamline was part of the NSLS-II Project. CSX-2 will dedicate about a quarter of its available research hours to scientific users from the nanocenter, while the rest of the time will be available for users from the light source.

    “With the capabilities already available at the CFN and this new beamline, we have complementary techniques available to scientists,” Boscoboinik said. Compared to the X1A1 beamline at NSLS, where the APPES endstation was previously located, CSX-2 has a larger energy range, much higher resolution, and at least 100 times more flux “This means we can now look at core levels we could not look at before and we get better quality data with better resolved features and less noise over a shorter period of time,” Waluyo said.

    “This is an exciting time and we are thrilled to be part of it,” Boscoboinik said.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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    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 5:59 pm on February 5, 2016 Permalink | Reply
    Tags: , , BNL NSLS II,   

    From BNL: “Scientists Guide Gold Nanoparticles to Form “Diamond” Superlattices” 

    Brookhaven Lab

    February 4, 2016
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    DNA scaffolds cage and coax nanoparticles into position to form crystalline arrangements that mimic the atomic structure of diamond.

    Using bundled strands of DNA to build Tinkertoy-like tetrahedral cages, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have devised a way to trap and arrange nanoparticles in a way that mimics the crystalline structure of diamond. The achievement of this complex yet elegant arrangement, as described in a paper published February 5, 2016, in Science, may open a path to new materials that take advantage of the optical and mechanical properties of this crystalline structure for applications such as optical transistors, color-changing materials, and lightweight yet tough materials.

    “We solved a 25-year challenge in building diamond lattices in a rational way via self-assembly,” said Oleg Gang, a physicist who led this research at the Center for Functional Nanomaterials (CFN) at Brookhaven Lab in collaboration with scientists from Stony Brook University, Wesleyan University, and Nagoya University in Japan.

    The scientists employed a technique developed by Gang that uses fabricated DNA as a building material to organize nanoparticles into 3D spatial arrangements. They used ropelike bundles of double-helix DNA to create rigid, three-dimensional frames, and added dangling bits of single-stranded DNA to bind particles coated with complementary DNA strands.

    “We’re using precisely shaped DNA constructs made as a scaffold and single-stranded DNA tethers as a programmable glue that matches up particles according to the pairing mechanism of the genetic code—A binds with T, G binds with C,” said Wenyan Liu of the CFN, the lead author on the paper. “These molecular constructs are building blocks for creating crystalline lattices made of nanoparticles.”
    The difficulty of diamond

    As Liu explained, “Building diamond superlattices from nano- and micro-scale particles by means of self-assembly has proven remarkably difficult. It challenges our ability to manipulate matter on small scales.”

    The reasons for this difficulty include structural features such as a low packing fraction—meaning that in a diamond lattice, in contrast to many other crystalline structures, particles occupy only a small part of the lattice volume—and strong sensitivity to the way bonds between particles are oriented. “Everything must fit together in just such a way without any shift or rotation of the particles’ positions,” Gang said. “Since the diamond structure is very open, many things can go wrong, leading to disorder.”

    “Even to build such structures one-by-one would be challenging,” Liu added, “and we needed to do so by self-assembly because there is no way to manipulate billions of nanoparticles one–by–one.”

    Gang’s previous success using DNA to construct a wide range of nanoparticle arrays suggested that a DNA-based approach might work in this instance.

    DNA guides assembly

    The team first used the ropelike DNA bundles to build tetrahedral “cages”—a 3D object with four triangular faces. They added single-stranded DNA tethers pointing toward the interior of the cages using T,G,C,A sequences that matched up with complementary tethers attached to gold nanoparticles. When mixed in solution, the complementary tethers paired up to “trap” one gold nanoparticle inside each tetrahedron cage.

    Double stranded DNA bundles (gray) form tetrahedral cages
    Schematic illustration of the experimental strategy: Double stranded DNA bundles (gray) form tetrahedral cages. Single stranded DNA strands on the edges (green) and vertices (red) match up with complementary strands on gold nanoparticles. This results in a single gold particle being trapped inside each tetrahedral cage, and the cages binding together by tethered gold nanoparticles at each vertex. The result is a crystalline nanoparticle lattice that mimics the long-range order of crystalline diamond. The images below the schematic are (left to right): a reconstructed cryo-EM density map of the tetrahedron, a caged particle shown in a negative-staining TEM image, and a diamond superlattice shown at high magnification with cryo-STEM.

    The arrangement of gold nanoparticles outside the cages was guided by a different set of DNA tethers attached at the vertices of the tetrahedrons. Each set of vertices bound with complementary DNA tethers attached to a second set of gold nanoparticles.

    When mixed and annealed, the tetrahedral arrays formed superlattices with long-range order where the positions of the gold nanoparticles mimics the arrangement of carbon atoms in a lattice of diamond, but at a scale about 100 times larger.

    “Although this assembly scenario might seem hopelessly unconstrained, we demonstrate experimentally that our approach leads to the desired diamond lattice, drastically streamlining the assembly of such a complex structure,” Gang said.

    The proof is in the images. The scientists used cryogenic transmission electron microscopy (cryo-TEM) to verify the formation of tetrahedral frames by reconstructing their 3D shape from multiple images. Then they used in-situ small-angle x-ray scattering (SAXS) at the National Synchrotron Light Source (NSLS), and cryo scanning transmission electron microscopy (cryo-STEM) at the CFN, to image the arrays of nanoparticles in the fully constructed lattice.

    “Our approach relies on the self-organization of the triangularly shaped blunt vertices of the tetrahedra (so called ‘footprints’) on isotropic spherical particles. Those triangular footprints bind to spherical particles coated with complementary DNA, which allows the particles to coordinate their arrangement in space relative to one another. However, the footprints can arrange themselves in a variety of patterns on a sphere. It turns that one particular placement is more favorable, and it corresponds to the unique 3D placement of particles that locks the diamond lattice,” Gang said.

    The team supported their interpretation of the experimental results using theoretical modeling that provided insight about the main factors driving the successful formation of diamond lattices.

    Sparkling implications

    “This work brings to the nanoscale the crystallographic complexity seen in atomic systems,” said Gang, who noted that the method can readily be expanded to organize particles of different material compositions. The group has demonstrated previously that DNA-assembly methods can be applied to optical, magnetic, and catalytic nanoparticles as well, and will likely yield the long-sought novel optical and mechanical materials scientists have envisioned.

    “We’ve demonstrated a new paradigm for creating complex 3D-ordered structures via self-assembly. If you can build this challenging lattice, the thinking is you can build potentially a variety of desired lattices,” he said.

    This work was funded by the DOE Office of Science (BES). CFN and NSLS are DOE Office of Science User Facilities.

    See the full article here .

    Please help promote STEM in your local schools.

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    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 12:35 pm on November 25, 2015 Permalink | Reply
    Tags: , BNL NSLS II,   

    From BNL: “NSLS-II User Profiles: Emmie Campbell & Karen DeRocher” 

    Brookhaven Lab

    November 23, 2015
    Laura Mgrdichian

    1
    Emmie Campbell and Karen DeRocher, from the Biomineral Engineering group at Northwestern University’s McCormick School of Engineering, studied microstructures that make up spicules or “bones” in larval sea urchins with the Hard X-Ray Nanoprobe at NSLS-II.

    Emmie Campbell and Karen DeRocher are Ph.D. students in the McCormick School of Engineering at Northwestern University. They are members of the Biomineral Engineering group led by Derk Joester, an associate professor of materials science and engineering. They recently completed beam time at the Hard X-Ray Nanoprobe at Brookhaven National Laboratory’s National Synchrotron Light Source II (NSLS-II), a U.S. Department of Energy Office of Science User Facility.

    BNL NSLS-II Interior
    BNL NSLS-II Building
    NSLS-II

    What are your research interests?

    We’re both interested in how organisms are able to manipulate crystal growth to deposit minerals with unique properties under biological conditions and with minimal energetic and material waste. But we took different paths to get to this field of materials science, and we plan to use what we learn in different ways.

    Emmie Campbell:

    I actually chose a field of materials science due to my interest in art history — my undergraduate degree is a double major in chemistry and art history. I worked at the Art Institute of Chicago through a Research Experiences for Undergraduates (REU) program with Northwestern, which inspired me to apply to the school’s Materials Science department. For the big picture aspect of biomineralization, we’re interested in understanding how organisms control mineral growth. This includes things with obvious value, like better understanding human teeth and bone growth to reduce disease and discomfort, or technological value, like materially and energetically efficient fabrication. Materials like magnetite — a hard, magnetic material — are usually formed under high pressure and heat under geological conditions. However, bacteria, bumble bees, and even humans are able to produce biogenic magnetite at ambient pressure and temperature. This happens in your brain! If we can harness this kind of fabrication, we’d reduce energy, material, and labor costs for biogenic minerals, which tend to have novel and interesting properties, and possibly even extend what we’ve learned to other materials.

    Karen DeRocher:

    Since I was an undergraduate I have been interested in using materials science to develop new, more efficient materials for structural or energy applications. After hearing about Professor Joester’s work studying biominerals, I was intrigued by this different approach to materials science. Instead of taking the more commonly used approach of mixing materials together to come up with something new, we look at how organisms naturally produce minerals, such as calcite or apatite. While these materials can also be made in the lab (sometimes requiring elevated temperature and pressure), organisms are able to achieve very complex, intricate structures at ambient temperature and pressure. The thought of mimicking their production methods to make highly ordered, functional materials without having to expend a lot of energy excited me. After joining the Joester group, my main research interest has become studying the chemical and structural changes that occur in human enamel as a cavity develops. Eventually, we hope that this work will lead to a deeper understanding of enamel formation, as well as the development of better detection and treatment options for cavities.

    What are you studying at NSLS-II?

    We are studying the skeletons of larval sea urchins, which consist of two single-crystal calcite “bones,” called spicules. The spicules have a highly specialized morphology: instead of the highly faceted structure of inorganically precipitated calcite, the spicules have a cylindrical cross-section and smooth curves. There is a biomolecular basis for this growth, but we’ve observed a microstructure in the spicule that we believe is evidence of a faceted growth-front within the spicule, indicating a second growth mechanism. This is one of the things we studied using the Hard X-Ray Nanoprobe.

    Why have you chosen NSLS-II for your research?

    The spicule microstructure is 400-600 nanometers (nm) in diameter, comprised of 20 nm occlusions. The Hard X-Ray Nanoprobe is uniquely capable of resolving these features, utilizing x-ray fluorescence and x-ray differential phase contrast imaging.

    This research is happening at the National Synchrotron Light Source II, which produces X-rays 10,000 times brighter than its predecessor (NSLS) and is the world’s brightest synchrotron light source.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    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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