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  • richardmitnick 2:04 pm on October 13, 2017 Permalink | Reply
    Tags: , , BNL, , , ,   

    From BNL: “Scientists Use Machine Learning to Translate ‘Hidden’ Information that Reveals Chemistry in Action” 

    Brookhaven Lab

    October 10, 2017
    Karen McNulty Walsh
    kmcnulty@bnl.gov
    (631) 344-8350

    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    New method allows on-the-fly analysis of how catalysts change during reactions, providing crucial information for improving performance.

    1
    A sketch of the new method that enables fast, “on-the-fly” determination of three-dimensional structure of nanocatalysts. The neural network converts the x-ray absorption spectra into geometric information (such as nanoparticle sizes and shapes) and the structural models are obtained for each spectrum. No image credit.

    Chemistry is a complex dance of atoms. Subtle shifts in position and shuffles of electrons break and remake chemical bonds as participants change partners. Catalysts are like molecular matchmakers that make it easier for sometimes-reluctant partners to interact.

    Now scientists have a way to capture the details of chemistry choreography as it happens. The method—which relies on computers that have learned to recognize hidden signs of the steps—should help them improve the performance of catalysts to drive reactions toward desired products faster.

    The method—developed by an interdisciplinary team of chemists, computational scientists, and physicists at the U.S. Department of Energy’s Brookhaven National Laboratory and Stony Brook University—is described in a new paper published in the Journal of Physical Chemistry Letters. The paper demonstrates how the team used neural networks and machine learning to teach computers to decode previously inaccessible information from x-ray data, and then used that data to decipher 3D nanoscale structures.

    Decoding nanoscale structures

    “The main challenge in developing catalysts is knowing how they work—so we can design better ones rationally, not by trial-and-error,” said Anatoly Frenkel, leader of the research team who has a joint appointment with Brookhaven Lab’s Chemistry Division and Stony Brook University’s Materials Science Department. “The explanation for how catalysts work is at the level of atoms and very precise measurements of distances between them, which can change as they react. Therefore it is not so important to know the catalysts’ architecture when they are made but more important to follow that as they react.”

    2
    Anatoly Frenkel (standing) with co-authors (l to r) Deyu Lu, Yuewei Lin, and Janis Timoshenko. No image credit.

    Trouble is, important reactions—those that create important industrial chemicals such as fertilizers—often take place at high temperatures and under pressure, which complicates measurement techniques. For example, x-rays can reveal some atomic-level structures by causing atoms that absorb their energy to emit electronic waves. As those waves interact with nearby atoms, they reveal their positions in a way that’s similar to how distortions in ripples on the surface of a pond can reveal the presence of rocks. But the ripple pattern gets more complicated and smeared when high heat and pressure introduce disorder into the structure, thus blurring the information the waves can reveal.

    So instead of relying on the “ripple pattern” of the x-ray absorption spectrum, Frenkel’s group figured out a way to look into a different part of the spectrum associated with low-energy waves that are less affected by heat and disorder.

    “We realized that this part of the x-ray absorption signal contains all the needed information about the environment around the absorbing atoms,” said Janis Timoshenko, a postdoctoral fellow working with Frenkel at Stony Brook and lead author on the paper. “But this information is hidden ‘below the surface’ in the sense that we don’t have an equation to describe it, so it is much harder to interpret. We needed to decode that spectrum but we didn’t have a key.”

    Fortunately Yuewei Lin and Shinjae Yoo of Brookhaven’s Computational Science Initiative and Deyu Lu of the Center for Functional Nanomaterials (CFN) had significant experience with so-called machine learning methods. They helped the team develop a key by teaching computers to find the connections between hidden features of the absorption spectrum and structural details of the catalysts.

    “Janis took these ideas and really ran with them,” Frenkel said.

    The team used theoretical modeling to produce simulated spectra of several hundred thousand model structures, and used those to train the computer to recognize the features of the spectrum and how they correlated with the structure.

    “Then we built a neural network that was able to convert the spectrum into structures,” Frenkel said.

    When they tested to see if the method would work to decipher the shapes and sizes of well-defined platinum nanoparticles (using x-ray absorption spectra previously published by Frenkel and his collaborators) it did.

    “This method can now be used on the fly,” Frenkel said. “Once the network is constructed it takes almost no time for the structure to be obtained in any real experiment.”

    That means scientists studying catalysts at Brookhaven’s National Synchrotron Light Source II (NSLS-II), for example, could obtain real-time structural information to decipher why a particular reaction slows down, or starts producing an unwanted product—and then tweak the reaction conditions or catalyst chemistry to achieve desired results. This would be a big improvement over waiting to analyze results after completing the experiments and then figuring out what went wrong.

    In addition, this technique can process and analyze spectral signals from very low-concentration samples, and will be particularly useful at new high flux and high-energy-resolution beamlines incorporating special optics and high-throughput analysis techniques at NSLS-II.

    “This will offer completely new methods of using synchrotrons for operando research,” Frenkel said.

    This work was funded by the DOE Office of Science (BES) and by Brookhaven’s Laboratory Directed Research and Development program. Previously published spectra for the model nanoparticles used to validate the neural network were collected at the Advanced Photon Source (APS) at DOE’s Argonne National Laboratory and the original National Synchrotron Light Source (NSLS) at Brookhaven Lab, now replaced by NSLS-II. CFN, NSLS-II, and APS are DOE Office of Science User Facilities. In addition to Frenkel and Timoshenko, Lu and Lin are co-authors on the paper.

    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 4:42 pm on October 6, 2017 Permalink | Reply
    Tags: (DAMA) group - Brookhaven’s Data Acquisition Management and Analysis, Bluesky software, BNL,   

    From BNL: “Software Developed at Brookhaven Lab Could Advance Synchrotron Science Worldwide” 

    Brookhaven Lab

    October 2, 2017
    Stephanie Kossman
    skossman@bnl.gov

    1
    Thomas Caswell (left) and Dan Allan (right), two of Bluesky’s creators.

    Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have developed new software to streamline data acquisition (DAQ) at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility. Called “Bluesky,” the software significantly eases the process of collecting and comparing data at NSLS-II, and could be used to facilitate scientific collaboration between light sources worldwide.

    NSLS-II is one of the most advanced synchrotrons in the nation, and as the facility continues to expand, researchers need dynamic DAQ software to effectively capture and process the large volume and variety of data their experiments produce. Typically at synchrotrons, each beamline (experimental station) uses DAQ software that was developed specifically for that beamline. These beamline-specific types of software are often incompatible with each other, making it difficult for scientists to compare data from different beamlines, as well as other light sources. That’s why Brookhaven’s Data Acquisition, Management and Analysis (DAMA) group developed Bluesky.

    “We wanted to make software that is designed the way scientists think when they are doing an experiment,” said Dan Allan, a member of DAMA. “Bluesky is a language for expressing the steps in a science experiment.”

    2
    From left to right: (Back row) Thomas Caswell, Richard Farnsworth, Arman Arkilic; (Front Row) Yong-Nian Tang, Dan Allan, Stuart Campbell, Li Li

    Allan, alongside DAMA member Thomas Caswell, conceptualized Bluesky as the top “layer” of an existing DAQ system. At the bottom layer is the beamline’s equipment, which works with vendor-supplied software to write electrons onto a disc. The next layer is the Experimental Physics and Industrial Control Software (EPICS).

    “Up to a point, EPICS makes all devices look the same. You can speak a common language to EPICS in the same way you can speak a common language to different websites. It’s the equivalent of the ‘http’ in a web address, but for hardware control,” Allan said. “We’re trying to build a layer up from that.”

    Bluesky stands on the shoulders of EPICS, and provides additional capabilities such as live visualization and data processing tools, and can export data into nearly any file format in real time. Bluesky was developed using “Python,” a common programming language that will make Bluesky simple for future scientists to modify, and to implement at new beamlines and light sources.

    Scientists at NSLS-II are already using Bluesky at the majority of the facility’s beamlines. In particular, Bluesky has benefitted researchers by minimizing the amount of steps involved with DAQ and operating in-line with their experimental protocol.

    “Bluesky is the cruise control for a scientific experiment,” said Richard Farnsworth, the controls program manager at NSLS-II. “Its modular design incorporates a hardware abstraction library called Ophyd and a package for databases called Data Broker, both of which can also be used independently.”

    A version of Bluesky has been operating at NSLS-II since 2015, and ever since, the software has continued to develop smoothly and successfully as DAMA adds new features and upgrades.

    “I think one of the key things that made us successful is that our team wasn’t assigned to one beamline,” Caswell said. “If you’re working on one beamline, it’s very easy to build something tuned to that beamline, and if you ever try to apply it to another, you suddenly discover all sorts of design decisions that were driven by the original beamline. Being facility-wide from the start of our project has been a great advantage.”

    Another important aspect of Bluesky’s success is the fact that it was built for scientists, by scientists.

    “A lot of the beamline scientists don’t see this as the typical customer-client relationship,” said Stuart Campbell, the group leader for DAMA. “They see Bluesky as a collaborative project.”

    As DAMA continues to improve upon Bluesky, the team gives scientists at NSLS-II the opportunity to influence how the software is developed. DAMA tests Bluesky directly on NSLS-II beamlines, and discusses the software with scientists on the experimental floor as they work.

    “I also think it’s very important that Dan and I both have physics PhDs, because that gives us a common language to communicate with the beamline staff,” Caswell said.

    Caswell and Allan first met while they were pursuing their graduate degrees in physics. Through an open source project on the internet, they discovered they each had the missing half to the other’s thesis. Combined, their work formed a project that is still used by research groups around the world, and illustrated the value of building software collaboratively and in the open, as DAMA has done with Bluesky.

    “We were solving the same problem from opposite ends, and I happened to find his project on the internet when we had just about met in the middle,” Allan said. “We both felt satisfaction in creating a tool that we imagined scientists might someday use.”

    Bluesky will be an ongoing project for Campbell, Caswell, Allan, and the rest of the DAMA group, but the software is already being tested at other light sources, including two other DOE Office of Science User Facilities: the Advanced Photon Source at DOE’s Argonne National Laboratory and the Linac Coherent Light Source at DOE’s SLAC National Accelerator Laboratory. DAMA’s goal is to share Bluesky as an open source project with light sources around the world and, gradually, build new layers on top of Bluesky for even more enhanced data visualization and analysis.

    Related Links

    Synchrotron Radiation News: Towards Integrated Facility-Wide Data Acquisition and Analysis at NSLS-IITaylor and Francis online

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

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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 4:20 pm on October 6, 2017 Permalink | Reply
    Tags: , , BNL, , The end goal is to break out those molecular building blocks—the protons and electrons—to make fuels such as hydrogen   

    From BNL: “New Efficient Catalyst for Key Step in Artificial Photosynthesis” 

    Brookhaven Lab

    October 3, 2017
    Karen McNulty Walsh
    kmcnulty@bnl.gov
    (631) 344-8350

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    Process sets free protons and electrons that can be used to make fuels.

    1
    Research team leader Javier Concepcion (standing, left) with Yan Xie, David Shaffer, and David Szalda

    Chemists at the U.S. Department of Energy’s Brookhaven National Laboratory have designed a new catalyst that speeds up the rate of a key step in “artificial photosynthesis”—an effort to mimic how plants, algae, and some bacteria harness sunlight to convert water and carbon dioxide into energy-rich fuels. This step—called water oxidation—releases protons and electrons from water molecules, producing oxygen as a byproduct.

    This “single-site” catalyst—meaning the entire reaction sequence takes place on a single catalytic site of one molecule—is the first to match the efficiency of the catalytic sites that drive this reaction in nature. The single-site design and high efficiency greatly improve the potential for making efficient solar-to-fuel conversion devices.

    “The end goal is to break out those molecular building blocks—the protons and electrons—to make fuels such as hydrogen,” said David Shaffer, a Brookhaven research associate and lead author on a paper describing the work in the Journal of the American Chemical Society. “The more efficient the water oxidation cycle is, the more energy we can store.”

    But breaking apart water molecules isn’t easy.

    “Water is very stable,” said Brookhaven chemist Javier Concepcion, who led the research team. “Water can undergo many boiling/condensing cycles and it stays as H2O. To get the protons and electrons out, we need to make the water molecules react with each other.”

    The catalyst acts as a chemical handler, shuffling around the water molecules’ assets—electrons, hydrogen ions (protons), and oxygen atoms—to get the reaction to happen.


    Bubbles indicate the rapid production of oxygen (O2) when the catalyst is added to the solution. For each O2 molecule produced, four protons (H+) and four electrons are released—enough to make two hydrogen (H2) molecules. No video credit.

    The new catalyst design builds on one the group developed last year, led by graduate student Yan Xie, which was also a single-site catalyst, with all the components needed for the reaction on a single molecule. This approach is attractive because the scientists can optimize how the various parts are arranged so that reacting molecules come together in just the right way. Such catalysts don’t depend on the free diffusion of molecules in a solution to achieve reactions, so they tend to continue functioning even when fixed to a surface, as they would be in real-world devices.

    “We used computer modeling to study the reactions at the theoretical level to help us design our molecules,” Concepcion said. “From the calculations we have an idea of what will work or not, which saves time before we get into the lab.”

    In both Xie’s design and the new improvement, there’s a metal at the core of the molecule, surrounded by other components the scientists can choose to give the catalyst particular properties. The reaction starts by oxidizing the metal, which pulls electrons away from the oxygen on a water molecule. That leaves behind a “positively charged,” or “activated,” oxygen and two positively charged hydrogens (protons).

    “Taking electrons away makes the protons easier to release. But you need those protons to go somewhere. And it’s more efficient if you remove the electrons and protons at the same time to prevent the build-up of excess charges,” Concepcion said. “So Xie added phosphonate groups as ligands on the metal to act as a base that would accept those protons,” he explained. Those phosphonate groups also made it easier to oxidize the metal to remove the electrons in the first place.

    But there was still a problem. In order to activate the H2O molecule, you first need it to bind to the metal atom at the center of the catalyst.

    In the first design, the phosphonate groups were so strongly bound to the metal that they were preventing the water molecule from binding to the catalyst early enough to keep the process running smoothly. That slowed the catalytic cycle down.

    So the team made a substitution. They kept one phosphonate group to act as the base, but swapped out the other for a less-tightly-bound carboxylate.

    “The carboxylate group can more easily adjust its coordination to the metal center to allow the water molecule to come in and react at an earlier stage,” Shaffer said.

    “When we are trying to design better catalysts, we first try to figure out what is the slowest step. Then we redesign the catalyst to make that step faster,” he said. “Yan’s work made one step faster, and that made one of the other steps end up being the slowest step. So in the current work we accelerated that second step while keeping the first one fast.”

    The improvement transformed a catalyst that created two or three oxygen molecules per second to one that produces more than 100 per second—with a corresponding increase in the production of protons and electrons that can be used to create hydrogen fuel.

    2
    The new catalyst has a ruthenium (Ru) atom at its core, a “pendant” phosphonate group to act as a base that accepts protons (H+) from water, and a more flexible, or “labile,” carboxylate group that facilitates the interaction of the catalyst with water. No image credit.

    “That’s a rate that is comparable to the rate of this reaction in natural photosynthesis, per catalytic site,” Concepcion said. “The natural photosynthesis catalyst has four metal centers and ours only has one,” he explained. “But the natural system is very complex with thousands and thousands of atoms. It would be extremely hard to replicate something like that in the lab. This is a single molecule and it does the same function as that very complex system.”

    The next step is to test the new catalyst in devices incorporating electrodes and other components for converting the protons and electrons to hydrogen fuel—and then later, with light-absorbing compounds to provide energy to drive the whole reaction.

    “We have now systems that are working quite well, so we are very hopeful,” Concepcion said.

    This work was supported by the DOE Office of Science.

    Scientific paper: Lability and Basicity of Bipyridine-Carboxylate-Phosphonate Ligand Accelerate Single-Site Water Oxidation by Ruthenium-Based Molecular Catalysts JACS

    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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  • richardmitnick 6:15 pm on September 18, 2017 Permalink | Reply
    Tags: , , BNL, , , , , , ,   

    From BNL: “Three Brookhaven Lab Scientists Selected to Receive Early Career Research Program Funding” 

    Brookhaven Lab

    August 15, 2017 [Just caught up with this via social media.]
    Karen McNulty Walsh,
    kmcnulty@bnl.gov
    (631) 344-8350
    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    Three scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have been selected by DOE’s Office of Science to receive significant research funding through its Early Career Research Program.

    The program, now in its eighth year, is designed to bolster the nation’s scientific workforce by providing support to exceptional researchers during the crucial early career years, when many scientists do their most formative work. The three Brookhaven Lab recipients are among a total of 59 recipients selected this year after a competitive review of about 700 proposals.

    The scientists are each expected to receive grants of up to $2.5 million over five years to cover their salary plus research expenses. A list of the 59 awardees, their institutions, and titles of research projects is available on the Early Career Research Program webpage.

    This year’s Brookhaven Lab awardees include:

    1
    Sanjaya Senanayake

    Brookhaven Lab chemist Sanjaya D. Senanayake was selected by DOE’s Office of Basic Energy Sciences to receive funding for “Unraveling Catalytic Pathways for

    Low Temperature Oxidative Methanol Synthesis from Methane.” His overarching goal is to study and improve catalysts that enable the conversion of methane (CH4), the primary component of natural gas, directly into methanol (CH3OH), a valuable chemical intermediate and potential renewable fuel.

    This research builds on the recent discovery of a single step catalytic process for this reaction that proceeds at low temperatures and pressures using inexpensive earth abundant catalysts. The reaction promises to be more efficient than current multi-step processes, which are energy-intensive, and a significant improvement over other attempts at one-step reactions where higher temperatures convert most of the useful hydrocarbon building blocks into carbon monoxide and carbon dioxide rather than methanol. With Early Career funding, Senanayake’s team will explore the nature of the reaction, and build on ways to further improve catalytic performance and specificity.

    The project will exploit unique capabilities of facilities at Brookhaven Lab, particularly at the National Synchrotron Light Source II (NSLS-II), that make it possible to study catalysts in real-world reaction environments (in situ) using x-ray spectroscopy, electron imaging, and other in situ methods.

    BNL NSLS-II


    BNL NSLS II

    Experiments using well defined model surfaces and powders will reveal atomic level catalytic structures and reaction dynamics. When combined with theoretical modeling, these studies will help the scientists identify the essential interactions that take place on the surface of the catalyst. Of particular interest are the key features that activate stable methane molecules through “soft” oxidative activation of C-H bonds so methane can be converted to methanol using oxygen (O2) and water (H2O) as co-reactants.

    This work will establish and experimentally validate principles that can be used to design improved catalysts for synthesizing fuel and other industrially relevant chemicals from abundant natural gas.

    “I am grateful for this funding and the opportunity to pursue this promising research,” Senanayake said. “These fundamental studies are an essential step toward overcoming key challenges for the complex conversion of methane into valued chemicals, and for transforming the current model catalysts into practical versions that are inexpensive, durable, selective, and efficient for commercial applications.”

    Sanjaya Senanayake earned his undergraduate degree in material science and Ph.D. in chemistry from the University of Auckland in New Zealand in 2001 and 2006, respectively. He worked as a research associate at Oak Ridge National Laboratory from 2005-2008, and served as a local scientific contact at beamline U12a at the National Synchrotron Light Source (NSLS) at Brookhaven Lab from 2005 to 2009. He joined the Brookhaven staff as a research associate in 2008, was promoted to assistant chemist and associate chemist in 2014, while serving as the spokesperson for NSLS Beamline X7B. He has co-authored over 100 peer reviewed publications in the fields of surface science and catalysis, and has expertise in the synthesis, characterization, reactivity of catalysts and reactions essential for energy conversion. He is an active member of the American Chemical Society, North American Catalysis Society, the American Association for the Advancement of Science, and the New York Academy of Science.

    3
    Alessandro Tricoli

    Brookhaven Lab physicist Alessandro Tricoli will receive Early Career Award funding from DOE’s Office of High Energy Physics for a project titled “Unveiling the Electroweak Symmetry Breaking Mechanism at ATLAS and at Future Experiments with Novel Silicon Detectors.”

    CERN/ATLAS detector

    His work aims to improve, through precision measurements, the search for exciting new physics beyond what is currently described by the Standard Model [SM], the reigning theory of particle physics.

    The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    The discovery of the Higgs boson at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) in Switzerland confirmed how the quantum field associated with this particle generates the masses of other fundamental particles, providing key insights into electroweak symmetry breaking—the mass-generating “Higgs mechanism.”

    CERN ATLAS Higgs Event

    But at the same time, despite direct searches for “new physics” signals that cannot be explained by the SM, scientists have yet to observe any evidence for such phenomena at the LHC—even though they know the SM is incomplete (for example it does not include an explanation for gravity).

    Tricoli’s research aims to make precision measurements to test fundamental predictions of the SM to identify anomalies that may lead to such discoveries. He focuses on the analysis of data from the LHC’s ATLAS experiment to comprehensively study electroweak interactions between the Higgs and particles called W and Z bosons. Any discovery of anomalies in such interactions could signal new physics at very high energies, not directly accessible by the LHC.

    This method of probing physics beyond the SM will become even more stringent once the high-luminosity upgrade of ATLAS, currently underway, is completed for longer-term LHC operations planned to begin in 2026.

    Tricoli’s work will play an important role in the upgrade of ATLAS’s silicon detectors, using novel state-of-the art technology capable of precision particle tracking and timing so that the detector will be better able to identify primary particle interactions and tease out signals from the background events. Designing these next-generation detector components could also have a profound impact on the development of future instruments that can operate in high radiation environments, such as in future colliders or in space.

    “This award will help me build a strong team around a research program I feel passionate about at ATLAS and the LHC, and for future experiments,” Tricoli said.

    “I am delighted and humbled by the challenge given to me with this award to take a step forward in science.”

    Alessandro Tricoli received his undergraduate degree in physics from the University of Bologna, Italy, in 2001, and his Ph.D. in particle physics from Oxford University in 2007. He worked as a research associate at Rutherford Appleton Laboratory in the UK from 2006 to 2009, and as a research fellow and then staff member at CERN from 2009 to 2015, receiving commendations on his excellent performance from both institutions. He joined Brookhaven Lab as an assistant physicist in 2016. A co-author on multiple publications, he has expertise in silicon tracker and detector design and development, as well as the analysis of physics and detector performance data at high-energy physics experiments. He has extensive experience tutoring and mentoring students, as well as coordinating large groups of physicists involved in research at ATLAS.

    4
    Chao Zhang

    Brookhaven Lab physicist Chao Zhang was selected by DOE’s Office of High Energy Physics to receive funding for a project titled, “Optimization of Liquid Argon TPCs for Nucleon Decay and Neutrino Physics.” Liquid Argon TPCs (for Time Projection Chambers) form the heart of many large-scale particle detectors designed to explore fundamental mysteries in particle physics.

    Among the most compelling is the question of why there’s a predominance of matter over antimatter in our universe. Though scientists believe matter and antimatter were created in equal amounts during the Big Bang, equal amounts would have annihilated one another, leaving only light. The fact that we now have a universe made almost entirely of matter means something must have tipped the balance.

    A US-hosted international experiment scheduled to start collecting data in the mid-2020s, called the Deep Underground Neutrino Experiment (DUNE), aims to explore this mystery through the search for two rare but necessary conditions for the imbalance: 1) evidence that some processes produce an excess of matter over antimatter, and 2) a sizeable difference in the way matter and antimatter behave.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    The DUNE experiment will look for signs of these conditions by studying how protons (one of the two “nucleons” that make up atomic nuclei) decay as well as how elusive particles called neutrinos oscillate, or switch identities, among three known types.

    The DUNE experiment will make use of four massive 10-kiloton detector modules, each with a Liquid Argon Time Projection Chamber (LArTPC) at its core. Chao’s aim is to optimize the performance of the LArTPCs to fully realize their potential to track and identify particles in three dimensions, with a particular focus on making them sensitive to the rare proton decays. His team at Brookhaven Lab will establish a hardware calibration system to ensure their ability to extract subtle signals using specially designed cold electronics that will sit within the detector. They will also develop software to reconstruct the three-dimensional details of complex events, and analyze data collected at a prototype experiment (ProtoDUNE, located at Europe’s CERN laboratory) to verify that these methods are working before incorporating any needed adjustments into the design of the detectors for DUNE.

    “I am honored and thrilled to receive this distinguished award,” said Chao. “With this support, my colleagues and I will be able to develop many new techniques to enhance the performance of LArTPCs, and we are excited to be involved in the search for answers to one of the most intriguing mysteries in science, the matter-antimatter asymmetry in the universe.”

    Chao Zhang received his B.S. in physics from the University of Science and Technology of China in 2002 and his Ph.D. in physics from the California Institute of Technology in 2010, continuing as a postdoctoral scholar there until joining Brookhaven Lab as a research associate in 2011. He was promoted to physics associate III in 2015. He has actively worked on many high-energy neutrino physics experiments, including DUNE, MicroBooNE, Daya Bay, PROSPECT, JUNO, and KamLAND, co-authoring more than 40 peer reviewed publications with a total of over 5000 citations. He has expertise in the field of neutrino oscillations, reactor neutrinos, nucleon decays, liquid scintillator and water-based liquid scintillator detectors, and liquid argon time projection chambers. He is an active member of the American Physical Society.

    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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  • richardmitnick 10:28 am on September 18, 2017 Permalink | Reply
    Tags: Alex Himmel of Fermilab, , BNL, Chao Zhang of BNL, Congratulations to two award-winning DUNE collaborators, , , ,   

    From NUS TO SURF: “Congratulations to two award-winning DUNE collaborators” 

    NUS TO SURF

    1

    “It is great news that the US DOE has recognized the talents of two early career DUNE scientists — both Alex and Chao have made invaluable contributions to DUNE and are both deserving recipients of these prestigious funding awards.”
    — DUNE spokespersons Mark Thomson and Ed Blucher

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    2
    Chao Zhang of BNL. Credit: BNL

    Exerpted and adapted from Three Brookhaven Lab Scientists Selected to Receive Early Career Research Program Funding, BNL Newsroom, 15 Aug 2017.

    Brookhaven Lab physicist and DUNE collaborator Chao Zhang was selected by DOE’s Office of High Energy Physics to receive funding for a project titled Optimization of Liquid Argon TPCs for Nucleon Decay and Neutrino Physics. Liquid Argon TPCs form the heart of many large-scale particle detectors designed to explore fundamental mysteries in particle physics.

    Chao’s aim is to optimize the performance of the DUNE far detector LArTPCs to fully realize their potential to track and identify particles in three dimensions, with a particular focus on making them sensitive to rare proton decays.

    His team at Brookhaven Lab will establish a hardware calibration system to ensure the experiment’s ability to extract subtle signals using specially designed cold electronics that will sit within the detector. They will also develop software to reconstruct the three-dimensional details of complex events, and analyze data collected at a prototype experiment (ProtoDUNE, located at Europe’s CERN laboratory) to verify that these methods are working, before incorporating any needed adjustments into the design of the detectors for DUNE.

    “I am honored and thrilled to receive this distinguished award,” said Chao. “With this support, my colleagues and I will be able to develop many new techniques to enhance the performance of LArTPCs, and we are excited to be involved in the search for answers to one of the most intriguing mysteries in science, the matter-antimatter asymmetry in the universe.”

    Read full article.


    Alex Himmel of Fermilab. Credit: Fermilab

    This article is excerpted and adapted from a Fermilab news article, 14 September 2017.

    Fermilab’s Alex Himmel expects to spend a large chunk of his career working on the Deep Underground Neutrino Experiment (DUNE), the flagship experiment of the U.S. particle physics community. That is incentive, he says, to lay the groundwork now to ensure its success.

    The Department of Energy has selected Himmel, a Wilson fellow, for a 2017 DOE Early Career Research Award to do just that. He will receive $2.5 million over five years to build a team and optimize software that will measure the flashes of ultraviolet light generated in neutrino collisions in a way that will determine the energy of the neutrino more precisely than is currently possible.

    Photons released from neutrino collisions will arrive at their detectors deteriorated and distorted due to scattering and reflections; the light measured is not the same as what was given off.

    “What we want to know is, given an amount of energy deposited in the argon, how much light do we see, taking out all the other things we know about how the light moves inside the detector,” he explained.

    Researchers are already looking forward to the long-term, positive impact of Himmel’s research.

    “Alex has been a true leader in understanding the physics potential of scintillation light in liquid-argon detectors,” said Ed Blucher. “His plan to develop techniques to make the most effective use of photon detection will help to enable the best and broadest possible physics program for DUNE.”

    Himmel has deep ties with Fermilab and neutrinos, starting with his first job as a summer student at Fermilab when he was 16. In 2012, he won the Universities Research Association Thesis Award for his research on muon antineutrino oscillations at Fermilab’s MINOS experiment.

    Read full article.

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  • richardmitnick 12:14 pm on August 25, 2017 Permalink | Reply
    Tags: , Basic science research seeks to improve our understanding of the world around us, BNL, , Center for Frontiers of Nuclear Science, , , Nucleons, ,   

    From BNL: “Research Center Established to Explore the Least Understood and Strongest Force Behind Visible Matter” 

    Brookhaven Lab

    August 22, 2017
    Peter Genzer
    genzer@bnl.gov
    (631) 344-3174

    1
    In an Electron-Ion Collider, a beam of electrons (e-) would scatter off a beam of protons or atomic nuclei, generating virtual photons (λ)—particles of light that penetrate the proton or nucleus to tease out the structure of the quarks and gluons within.

    Science can explain only a small portion of the matter that makes up the universe, from the earth we walk on to the stars we see at night. Stony Brook University and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory (BNL) have established the Center for Frontiers of Nuclear Science to help scientists better understand the building blocks of visible matter. The new Center will push the frontiers of knowledge about quarks, gluons and their interactions that form protons, neutrons, and ultimately 99.9 percent of the mass of atoms – the bulk of the visible universe.

    “The Center for Frontiers in Nuclear Science will bring us closer to understanding our universe in ways in which it has never before been possible,” said Samuel L. Stanley Jr., MD, President of Stony Brook University. “Thanks to the vision of the Simons Foundation, scientists from Stony Brook, Brookhaven Laboratory and many other institutions are now empowered to pursue the big ideas that will lead to new knowledge about the structure of the building blocks of everything in the universe today.”

    Bolstered by a new $5 million grant from the Simons Foundation and augmented by $3 million in research grants received by Stony Brook University, the Center will be a research and education hub to ultimately help scientists unravel more secrets of the universe’s strongest and least-understood force to advance both fundamental science and applications that transform our lives.

    Jim Simons, PhD, Chairman of the Simons Foundation said, “Nuclear physics is a deep and important discipline, casting light on many poorly understood facets of matter in our universe. It is a pleasure to support research in this area conducted by members of the outstanding team to be assembled by Brookhaven Lab and Stony Brook University. We much look forward to the results of this effort.”

    “Basic science research seeks to improve our understanding of the world around us, and it can take human understanding to wonderful and unexpected places,” said Marilyn Simons, President of the Simons Foundation. “Exploring the qualities and behaviors of fundamental particles seems likely to do just that.”

    The Center brings together current Stony Brook faculty and BNL staff, and scientists around the world with students and new scientific talent to investigate the structure of nucleons and nuclei at a fundamental level. Despite the importance of nucleons in all visible matter, scientists know less about their internal structure and dynamics than about any other component of visible matter. Over the next several decades, the Center is slated to become a leading international intellectual hub for quantum chromodynamics (QCD), a branch of physics that describes the properties of nucleons, starting from the interactions of the quarks and gluons inside them.

    2
    An Electron-Ion Collider would probe the inner microcosm of protons to help scientists understand how interactions among quarks (colored spheres) and glue-like gluons (yellow) generate the proton’s essential properties and the large-scale structure of the visible matter in the universe today.

    As part of the Center’s mission as a destination of research, collaboration and education for international scientists and students, workshops and seminars are planned for scientists to discuss and investigate theoretical concepts and promote experimental measurements to advance QCD-based nuclear science. The Center will support graduate education in nuclear science and conduct visitor programs to support and promote the Center’s role as an international research hub for physics related to a proposed Electron Ion Collider (EIC).

    One of the central aspects of the Center’s focus during its first few years will be activities on the science of a proposed EIC, a powerful new particle accelerator that would create rapid-fire, high-resolution “snapshots” of quarks and gluons contained in nucleons and complex nuclei. An EIC would enable scientists to see deep inside these objects and explore the still mysterious structures and interactions of quarks and gluons, opening up a new frontier in nuclear physics.

    “The role of quarks and gluons in determining the properties of protons and neutrons remains one of the greatest unsolved mysteries in physics,” said Doon Gibbs, Ph.D., Brookhaven Lab Director. “An Electron Ion Collider would reveal the internal structure of these atomic building blocks, a key part of the quest to understand the matter we’re made of.”

    Building an EIC and its research program in the United States would strengthen and expand U.S. leadership in nuclear physics and stimulate economic benefits well into the 2040s. In 2015, the DOE and the National Science Foundation’s Nuclear Science Advisory Committee recommended an EIC as the highest priority for new facility construction. Similar to explorations of fundamental particles and forces that have driven our nation’s scientific, technological, and economic progress for the past century — from the discovery of electrons that power our sophisticated computing and communications devices to our understanding of the cosmos — groundbreaking nuclear science research at an EIC will spark new innovations and technological advances.

    Stony Brook and BNL have internationally renowned programs in nuclear physics that focus on understanding QCD. Stony Brook’s nuclear physics group has recently expanded its expertise by adding faculty in areas such as electron scattering and neutrino science. BNL operates the Relativistic Heavy Ion Collider, a DOE Office of Science User Facility and the world’s most versatile particle collide. RHIC has pioneered the study of quark-gluon matter at high temperatures and densities—known as quark-gluon plasma— and is exploring the limits of normal nuclear matter. Together, these cover a major part of the course charted by the U.S. nuclear science community in its 2015 Long Range Plan.

    Abhay Deshpande, PhD, Professor of experimental nuclear physics in the Department of Physics and Astronomy in the College of Arts and Sciences at Stony Brook University, has been named Director of the Center. Professor Deshpande has promoted an EIC for more than two decades and helped create a ~700-member global scientific community (the EIC Users Group, EICUG) interested in pursuing the science of an EIC. In the fall of 2016, he was elected as the first Chair of its Steering Committee, effectively serving as its spokesperson, a position from which he has stepped down to direct the new Center. Concurrently with his position as Center Director, Dr. Deshpande also serves as Director of EIC Science at Brookhaven Lab.

    Scientists at the Center, working with EICUG, will have a specific focus on QCD inside the nucleon and how it shapes fundamental nucleon properties, such as spin and mass; the role of high-density many-body QCD and gluons in nuclei; the quark-gluon plasma at the high temperature frontier; and the connections of QCD to weak interactions and nuclear astrophysics. Longer term, the Center’s programmatic focus is expected to reflect the evolution of nuclear science priorities in the United States.

    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 4:03 pm on August 24, 2017 Permalink | Reply
    Tags: , , BNL, , , , , , , , SURF LBNF/ DUNE,   

    From Symmetry: “Mega-collaborations for scientific discovery” 

    Symmetry Mag

    Symmetry

    08/24/17
    Leah Poffenberger

    1
    DUNE joins the elite club of physics collaborations with more than 1000 members. Photo by Reidar Hahn, Fermilab.

    Sometimes it takes lot of people working together to make discovery possible. More than 7000 scientists, engineers and technicians worked on designing and constructing the Large Hadron Collider at CERN, and thousands of scientists now run each of the LHC’s four major experiments.

    LHC

    CERN/LHC Map

    CERN LHC Tunnel

    CERN LHC particles

    Not many experiments garner such numbers. On August 15, the Deep Underground Neutrino Experiment (DUNE) became the latest member of the exclusive clique of particle physics experiments with more than a thousand collaborators.

    Meet them all:

    3

    4,000+: Compact Muon Solenoid Detector (CMS) Experiment

    CMS is one of the two largest experiments at the LHC. It is best known for its role in the discovery of the Higgs boson.

    The “C” in CMS stands for compact, but there’s nothing compact about the CMS collaboration. It is one of the largest scientific collaborations in history. More than 4000 people from 200 institutions around the world work on the CMS detector and use its data for research.

    About 30 percent of the CMS collaboration hail from US institutions*. A remote operations center at the Department of Energy’s Fermi National Accelerator Laboratory in Batavia, Illinois, serves as a base for CMS research in the United States.

    4

    3,000+: A Toroidal LHC ApparatuS (ATLAS) Experiment

    The ATLAS experiment, the other large experiment responsible for discovering the Higgs boson at the LHC, ranks number two in number of collaborators. The ATLAS collaboration has more than 3000 members from 182 institutions in 38 countries. ATLAS and CMS ask similar questions about the building blocks of the universe, but they look for the answers with different detector designs.

    About 30 percent of the ATLAS collaboration are from institutions in the United States*. Brookhaven National Laboratory in Upton, New York, serves as the US host.

    2,000+: Linear Collider Collaboration

    Proposed LC Linear Collider schematic. Location not yet decided.

    The Linear Collider Collaboration (LCC) is different from CMS and ATLAS in that the collaboration’s experiment is still a proposed project and has not yet been built. LCC has around 2000 members who are working to develop and build a particle collider that can produce different kinds of collisions than those seen at the LHC.

    LCC members are working on two potential linear collider projects: the compact linear collider study (CLIC) at CERN and the International Linear Collider (ILC) in Japan. CLIC and the ILC originally began as separate projects, but the scientists working on both joined forces in 2013.

    Either CLIC or the ILC would complement the LHC by colliding electrons and positrons to explore the Higgs particle interactions and the nature of subatomic forces in greater detail.

    1,500+; A Large Ion Collider Experiment (ALICE)

    5

    ALICE is part of LHC’s family of particle detectors, and, like ATLAS and CMS, it too has a large, international collaboration, counting 1500 members from 154 physics institutes in 37 countries. Research using ALICE is focused on quarks, the sub-atomic particles that make up protons and neutrons, and the strong force responsible for holding quarks together.

    1,000+: Deep Underground Neutrino Experiment (DUNE)

    The Deep Underground Neutrino Experiment is the newest member of the club. This month, the DUNE collaboration surpassed 1000 collaborators from 30 countries.

    From its place a mile beneath the earth at the Sanford Underground Research Facility in South Dakota, DUNE will investigate the behavior of neutrinos, which are invisible, nearly massless particles that rarely interact with other matter. The neutrinos will come from Fermilab, 800 miles away.

    Neutrino research could help scientists answer the question of why there is an imbalance between matter and antimatter in the universe. Groundbreaking for DUNE occurred on July 21, and the experiment will start taking data in around 2025.

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA


    FNAL DUNE Argon tank at SURF


    Surf-Dune/LBNF Caverns at Sanford



    SURF building in Lead SD USA

    Honorable mentions

    A few notable collaborations have made it close to 1000 but didn’t quite make the list. LHCb, the fourth major detector at LHC, boasts a collaboration 800 strong.

    CERN/LHCb

    Over 700 collaborators work on the Belle II experiment at KEK in Japan, which will begin taking data in 2018, studying the properties of B mesons, particles that contain a bottom quark.

    Belle II super-B factory experiment takes shape at KEK
    5

    The 600-member SLAC/Babar collaboration at SLAC National Accelerator Laboratory also studies B mesons.

    SLAC/Babar

    STAR, a detector at Brookhaven National Laboratory that probes the conditions of the early universe, has more than 600 collaborators from 55 institutions.

    BNL/RHIC Star Detector

    The CDF and DZero collaborations at Fermilab, best known for their co-discovery of the top quark in 1995, had about 700 collaborators at their peak.

    FNAL/Tevatron DZero detector

    FNAL/Tevatron CDF detector

    *Among the reasons why I started this blog was that this level of U.S. involvement was invisible in our highly vaunted press. CERN had taken over HEP from FNAL. Our idiot Congress in 1993 had killed off the Superconducting Super Collider. So it looked like we had given up. But BNL had 600 people on ATLAS. FNAL had 1000 people on CMS. So we were far from dead in HEP, just invisible. So, I had a story to tell. Today I have 1000 readers. Not too shabby for Basic and Applied Science.

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 11:32 am on August 18, 2017 Permalink | Reply
    Tags: , , BNL, Successful Test of Small-Scale Accelerator with Big Potential Impacts for Science and Medicine   

    From BNL: “Successful Test of Small-Scale Accelerator with Big Potential Impacts for Science and Medicine” 

    Brookhaven Lab

    August 16, 2017
    Karen McNulty Walsh
    kmcnulty@bnl.gov

    “Fixed-field” accelerator transports multiple particle beams at a wide range of energies through a single beam pipe.

    1
    Members of the team testing a fixed-field, alternating-gradient beam transport line made with permanent magnets at Brookhaven Lab’s Accelerator Test Facility (ATF), left to right: Mark Palmer (Director of ATF), Dejan Trbojevic, Stephen Brooks, George Mahler, Steven Trabocchi, Thomas Roser, and Mikhail Fedurin (ATF operator and experimental liaison).

    An advanced particle accelerator designed at the U.S. Department of Energy’s Brookhaven National Laboratory could reduce the cost and increase the versatility of facilities for physics research and cancer treatment. It uses lightweight, 3D-printed frames to hold blocks of permanent magnets and an innovative method for fine-tuning the magnetic field to steer multiple beams at different energies through a single beam pipe.

    With this design, physicists could accelerate particles through multiple stages to higher and higher energies within a single ring of magnets, instead of requiring more than one ring to achieve these energies. In a medical setting, where the energy of particle beams determines how far they penetrate into the body, doctors could more easily deliver a range of energies to zap a tumor throughout its depth.

    Scientists testing a prototype of the compact, cost-effective design at Brookhaven’s Accelerator Test Facility (ATF)—a DOE Office of Science User Facility—say it came through with flying colors. Color-coded images show how a series of electron beams accelerated to five different energies successfully passed through the five-foot-long curve of magnets, with each beam tracing a different pathway within the same two-inch-diameter beam pipe.

    2
    Brooks’ proof-of-principle experiment showed that electron beams of five different energies could make their way through the arc of permanent magnets, each taking a somewhat different, color-coded path: dark green (18 million electron volts, or MeV), light green (24MeV), yellow (36MeV), red (54MeV), and purple (70MeV).

    “For each of five energy levels, we injected the beam at the ‘ideal’ trajectory for that energy and scanned to see what happens when it is slightly off the ideal orbit,” said Brookhaven Lab physicist Stephen Brooks, lead architect of the design. Christina Swinson, a physicist at the ATF, steered the beam through the ATF line and Brooks’ magnet assembly and played an essential role in running the experiments.

    “We designed these experiments to test our predictions and see how far away you can go from the ideal incoming trajectory and still get the beam through. For the most part, all the beam that went in came out at the other end,” Brooks said.

    The beams reached energies more than 3.5 times what had previously been achieved in a similar accelerator made from significantly larger electromagnets, with a doubling of the ratio between the highest and lowest energy beams.

    “These tests give us confidence that this accelerator technology can be used to carry beams at a wide range of energies,” Brooks said.

    No wires required

    Most particle accelerators use electromagnets to generate the powerful magnetic fields required to steer a beam of charged particles. To transport particles of different energies, scientists change the strength of the magnetic field by ramping up or down the electrical current passing through the magnets.

    Brooks’ design instead uses permanent magnets, the kind that stay magnetic without an electrical current—like the ones that stick to your refrigerator, only stronger. By arranging differently shaped magnet blocks to form a circle, Brooks creates a fixed magnetic field that varies in strength across different positions within the central aperture of each donut-shaped magnet array.

    When the magnets are lined up end-to-end like beads on a necklace to form a curved arc—as they were in the ATF experiment with assistance from Brookhaven’s surveying team to achieve precision alignment—higher energy particles move to the stronger part of the field. Alternating the field directions of sequential magnets keeps particles oscillating along their preferred trajectory as they move through the arc, with no power needed to accommodate particles of different energies.

    No electricity means less supporting infrastructure and easier operation—which all contribute to the significant cost savings potential of this non-scaling, fixed-field, alternating-gradient accelerator technology.

    Simplified design

    4
    Brooks’ successful test lays the foundation for the CBETA accelerator, in which bunches of electrons will be accelerated to four different energies and travel simultaneously within the same beampipe, as shown in this simulation.

    Brooks worked with George Mahler and Steven Trabocchi, engineers in Brookhaven’s Collider-Accelerator Department, to assemble the deceptively simple yet powerful magnets.

    First they used a 3D printer to create plastic frames to hold the shaped magnetic blocks, like pieces in a puzzle, around the central aperture. “Different sizes, or block thicknesses, and directions of magnetism allow a customized field within the aperture,” Brooks said.

    After the blocks were tapped into the frames with a mallet to create a coarse assembly, John Cintorino, a technician in Lab’s magnet division, measured the strength of the field. The team then fine-tuned each assembly by inserting different lengths of iron rods into as many as 64 positions around a second 3D-printed cartridge that fits within the ring of magnets. A computational program Brooks wrote uses the coarse assembly field-strength measurements to determine exactly how much iron goes into each slot. He’s also currently working on a robot to custom cut and insert the rods.

    The end-stage fine-tuning “compensates for any errors in machining and positioning of the magnet blocks,” Brooks said, improving the quality of the field 10-fold over the coarse assembly. The final magnets’ properties match or even surpass those of sophisticated electromagnets, which require much more precise engineering and machining to create each individual piece of metal.

    “The only high-tech equipment in our setup is the rotating coil we use to do the precision measurements,” he said.

    Applications and next steps

    The lightweight, compact components and simplified operation of Brooks’ permanent magnet beam transport line would be “a dramatic improvement from what is currently on the market for delivering particle beams in cancer treatment centers,” said Dejan Trbojevic, Brooks’ supervisor, who holds several patents on designs for particle therapy gantries.

    A gantry is the arced beamline that delivers cancer-killing particles from an accelerator to a patient. In some particle therapy facilities the gantry and supporting infrastructure can weigh 50 tons or more, often occupying a specially constructed wing of a hospital. Trbojevic estimates that a gantry using Brooks’ compact design would weigh just one ton. That would bring down the cost of constructing such facilities.

    “Plus with no need for electricity [to the magnets] to change field strengths, it would be much easier to operate,” Trbojevic said.

    The ability to accelerate particles rapidly to higher and higher energy levels within a single accelerator ring could also bring down the cost of proposed future physics experiments, including a muon collider, a neutrino factory, and an electron-ion collider (EIC). In these cases, additional accelerator components would boost the beams to higher energy.

    For example, Brookhaven physicists have been collaborating with physicists at Cornell University on a similar fixed-field design called CBETA. That project, developed with funding from the New York State Energy Research and Development Authority (NYSERDA), is a slightly larger version of Brooks’ machine and includes all the accelerator components for bringing electron beams up to the energies required for an EIC. CBETA also decelerates electrons once they’ve been used for experiments to recover and reuse most of the energy. It will also test beams of multiple energies at the same time, something Brooks’ proof-of-principle experiment at the ATF did not do. But Brooks’ successful test strengthens confidence that the CBETA design is sound.

    “Everyone in Brookhaven’s Collider-Accelerator Department has been very supportive of this project,” said Trbojevic, Brookhaven’s Principal Investigator on CBETA.

    As Collider-Accelerator Department Chair Thomas Roser noted, “All these efforts are working toward advanced accelerator concepts that will ultimately benefit science and society as a whole. We’re looking forward to the next chapter in the evolution of this technology.”

    The magnets for Brooks’ experiment were built with Brookhaven’s Laboratory Directed Research and Development funds for the CBETA project as part of the R&D effort for an early version of Brookhaven’s proposed design for an EIC, known as eRHIC. Operation of the ATF is supported by the DOE Office of Science.

    See the full article here .

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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 10:11 am on August 11, 2017 Permalink | Reply
    Tags: , BNL, Modulating semiconductors, ,   

    From BNL: “Scientists Find New Method to Control Electronic Properties of Nanocrystals” 

    Brookhaven Lab

    August 10, 2017
    Stephanie Kossman

    1
    From Left to Right: XPD beamline scientist Sanjit Ghose, postdoctoral researcher Anna Plonka, and Brookhaven Chemist Anatoly Frenkel.

    Researchers from The Hebrew University of Jerusalem, Stony Brook University, and the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have discovered new effects of an important method for modulating semiconductors. The method, which works by creating open spaces or “vacancies” in a material’s structure, enables scientists to tune the electronic properties of semiconductor nanocrystals (SCNCs)—semiconductor particles that are smaller than 100 nanometers. This finding will advance the development of new technologies like smart windows, which can change opaqueness on demand.

    Scientists use a technique called “chemical doping” to control the electronic properties of semiconductors. In this process, chemical impurities—atoms from different materials—are added to a semiconductor in order to alter its electrical conductivity. Though it is possible to dope SCNCs, it is very difficult due to their tiny size. The amount of impurities added during chemical doping is so small that in order to dope a nanocrystal properly, no more than a few atoms can be added to the crystal. Nanocrystals also tend to expel impurities, further complicating the doping process.

    Seeking to control the electronic properties of SCNCs more easily, researchers studied a technique called vacancy formation. In this method, impurities are not added to the semiconductor; instead, vacancies in its structure are formed by oxidation-reduction (redox) reactions, a type of chemical reaction where electrons are transferred between two materials. During this transfer, a type of doping occurs as missing electrons, called holes, become free to move throughout the structure of the crystal, significantly altering the electrical conductivity of the SCNC.

    “We have also identified size effects in the efficiency of the vacancy formation doping reaction,” said Uri Banin, a nanotechnologist from the Hebrew University of Jerusalem. “Vacancy formation is actually more efficient in larger SCNCs.”

    In this study, the researchers investigated a redox reaction between copper sulfide nanocrystals (the semiconductor) and iodine, a chemical introduced in order to influence the redox reaction to occur.

    2
    (Top) The removal of copper from copper sulfide nanocrystals and the growth of copper iodine on nanocrystal facets is depicted by results from XAFS; (Bottom left) Larger nanocrystals are doped more efficiently by vacancy formation; (Right) Vacancy formation is observed by XRD.

    “If you reduce copper sulfide, you will pull out copper from the nanocrystal, generating vacancies and therefore holes,” said Anatoly Frenkel, a chemist at Brookhaven National Laboratory holding a joint appointment with Stony Brook University, and the lead Brookhaven researcher on this study.

    The researchers used the x-ray powder diffraction (XPD) beamline at the National Synchrotron Light Source II (NSLS-II)—a DOE Office of Science User Facility—to study the structure of copper sulfide during the redox reaction.

    BNL NSLS-II


    BNL NSLS II

    By shining ultra-bright x-rays onto their samples, the researchers are able to determine the amount of copper that is pulled out during the redox reaction.

    Based on their observations at NSLS-II, the team confirmed that adding more iodine to the system caused more copper to be released and more vacancies to form. This established that vacancy formation is a useful technique for tuning the electronic properties of SCNCs.

    Still, the researchers needed to find out what exactly was happening to copper when it left the nanocrystal. Understanding how copper behaves after the redox reaction is crucial for implementing this technique into smart window technology.

    “If copper uncontrollably disappears, we can’t pull it back into the system,” Frenkel said. “But suppose the copper that is taken out of the crystal is hovering around, ready to go back in. By using the reverse process, we can put it back into the system, and we can make a device that would be easy to switch from one state to the other. For example, you would be able to change the transparency of a window on demand, depending on the time of day or your mood.”

    To understand what was happening to copper, the researchers used x-ray absorption fine structure (XAFS) spectroscopy at the Advanced Photon Source (APS)—also a DOE Office of Science User Facility—at Argonne National Laboratory. This technique allows the researchers to study the extremely small copper complexes that x-ray diffraction cannot detect. XAFS revealed that copper was combining with iodine to form copper iodine, a positive result that indicated copper could be put back into the nanocrystal and that the researchers have full control of the electronic properties.

    The researchers say the next step is to study materials in real-time during redox reactions using NSLS-II.

    This study was supported by the National Science Foundation, the US-Israel Binational Science Foundation, and Northwestern University. DOE’s Office of Science also supports operations at NSLS-II and APS.

    See the full article here .

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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 11:35 am on August 4, 2017 Permalink | Reply
    Tags: 'Perfect Liquid' Quark-Gluon Plasma is the Most Vortical Fluid, , BNL, , New record for "vorticity", , , STAR detector's Time Project Chamber   

    From BNL: “‘Perfect Liquid’ Quark-Gluon Plasma is the Most Vortical Fluid” 

    Brookhaven Lab

    August 2, 2017
    Karen McNulty Walsh
    kmcnulty@bnl.gov
    (631) 344-8350

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    Swirling soup of matter’s fundamental building blocks spins ten billion trillion times faster than the most powerful tornado, setting new record for “vorticity”.

    1
    Ohio State University graduate student Isaac Upsal helped lead the analysis of results from the STAR detector that revealed a “vorticity” record for the quark-gluon plasma created in collisions at the Relativistic Heavy Ion Collider (RHIC).

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    Particle collisions recreating the quark-gluon plasma (QGP) that filled the early universe reveal that droplets of this primordial soup swirl far faster than any other fluid. The new analysis of data from the Relativistic Heavy Ion Collider (RHIC) — a U.S. Department of Energy Office of Science User Facility for nuclear physics research at Brookhaven National Laboratory — shows that the “vorticity” of the QGP surpasses the whirling fluid dynamics of super-cell tornado cores and Jupiter’s Great Red Spot by many orders of magnitude, and even beats out the fastest spin record held by nanodroplets of superfluid helium.

    The results, just published in Nature, add a new record to the list of remarkable properties ascribed to the quark-gluon plasma. This soup made of matter’s fundamental building blocks — quarks and gluons — has a temperature hundreds of thousands of times hotter than the center of the sun and an ultralow viscosity, or resistance to flow, leading physicists to describe it as “nearly perfect.” By studying these properties and the factors that control them, scientists hope to unlock the secrets of the strongest and most poorly understood force in nature — the one responsible for binding quarks and gluons into the protons and neutrons that form most of the visible matter in the universe today.

    Specifically, the results on vorticity, or swirling fluid motion, will help scientists sort among different theoretical descriptions of the plasma. And with more data, it may give them a way to measure the strength of the plasma’s magnetic field — an essential variable for exploring other interesting physics phenomena.

    “Up until now, the big story in characterizing the QGP is that it’s a hot fluid that expands explosively and flows easily,” said Michael Lisa, a physicist from Ohio State University (OSU) and a member of RHIC’s STAR collaboration. “But we want to understand this fluid at a much finer level. Does it thermalize, or reach equilibrium, quickly enough to form vortices in the fluid itself? And if so, how does the fluid respond to the extreme vorticity?” The new analysis, which was led by Lisa and OSU graduate student Isaac Upsal, gives STAR a way to get at those finer details.

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    Telltale signs of a lambda hyperon (Λ) decaying into a proton (p) and a pion (π-) as tracked by the Time Projection Chamber of the STAR detector. Because the proton comes out nearly aligned with the hyperon’s spin direction, tracking where these “daughter” protons strike the detector can be a stand-in for tracking how the hyperons’ spins are aligned.

    Aligning spins

    “The theory is that if I have a fluid with vorticity — a whirling substructure — it tends to align the spins of the particles it emits in the same direction as the whirls,” Lisa said. And, while there can be many small whirlpools within the QGP all pointing in random directions, on average their spins should align with what’s known as the angular momentum of the system — a rotation of the system generated by the colliding particles as they speed past one another at nearly the speed of light.

    To track the spinning particles and the angular momentum, STAR physicists correlated simultaneous measurements at two different detector components. The first, known as the Beam-Beam Counters, sit at the front and rear ends of the house-size STAR detector, catching subtle deflections in the paths of colliding particles as they pass by one another. The size and direction of the deflection tells the physicists how much angular momentum there is and which way it is pointing for each collision event.

    Meanwhile, STAR’s Time Project Chamber, a gas-filled chamber that surrounds the collision zone, tracks the paths of hundreds or even thousands of particles that come out perpendicular to the center of the collisions.

    “We’re specifically looking for signs of Lambda hyperons, spinning particles that decay into a proton and a pion that we measure in the Time Projection Chamber,” said Ernst Sichtermann, a deputy STAR spokesperson and senior scientist at DOE’s Lawrence Berkeley National Laboratory. Because the proton comes out nearly aligned with the hyperon’s spin direction, tracking where these “daughter” protons strike the detector can be a stand-in for tracking how the hyperons’ spins are aligned.

    “We are looking for some systematic preference for the direction of these daughter protons aligned with the angular momentum we measure in the Beam-Beam Counters,” Upsal said. “The magnitude of that preference tells us the degree of vorticity — the average rate of swirling — of the QGP.”

    4
    Tracking particle spins reveals that the quark-gluon plasma created at the Relativistic Heavy Ion Collider is more swirly than the cores of super-cell tornados, Jupiter’s Great Red Spot, or any other fluid!

    Super spin

    The results reveal that RHIC collisions create the most vortical fluid ever, a QGP spinning faster than a speeding tornado, more powerful than the fastest spinning fluid on record. “So the most ideal fluid with the smallest viscosity also has the most vorticity,” Lisa said.

    This kind of makes sense, because low viscosity in the QGP allows the vorticity to persist, Lisa said. “Viscosity destroys whirls. With QGP, if you set it spinning, it tends to keep on spinning.”

    The data are also in the ballpark of what different theories predicted for QGP vorticity. “Different theories predict different amounts, depending on what parameters they include, so our results will help us sort through those theories and determine which factors are most relevant,” said Sergei Voloshin, a STAR collaborator from Wayne State University. “But most of the theoretical predications were too low,” he added. “Our measurements show that the QGP is even more vortical than predicted.”

    This discovery was made during the Beam Energy Scan program, which exploits RHIC’s unique ability to systematically vary the energy of collisions over a range in which other particularly interesting phenomena have been observed. In fact, theories suggest that this may be the optimal range for the discovery and subsequent study of the vorticity-induced spin alignment, since the effect is expected to diminish at higher energy.

    Increasing the numbers of Lambda hyperons tracked in future collisions at RHIC will improve the STAR scientists’ ability to use these measurements to calculate the strength of the magnetic field generated in RHIC collisions. The strength of magnetism influences the movement of charged particles as they are created and emerge from RHIC collisions, so measuring its strength is important to fully characterize the QGP, including how it separates differently charged particles.

    “Theory predicts that the magnetic field created in heavy ion experiments is much higher than any other magnetic field in the universe,” Lisa said. At the very least, being able to measure it accurately may nab another record for QGP.

    Research at RHIC and with the STAR detector is funded primarily by the DOE Office of Science.

    See the full article here .

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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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