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  • richardmitnick 7:27 am on May 10, 2016 Permalink | Reply
    Tags: , , RIKEN SACLA, ,   

    From BNL: “Ultra-fast X-ray Lasers Illuminate Elusive Atomic Spins” 

    Brookhaven Lab

    May 9, 2016
    Justin Eure
    (631) 344-2347
    jeure@bnl.gov

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

    New x-ray technique reveals never-before-seen, trillionth-of-a-second magnetic fluctuations that transform the electronic and magnetic properties of materials.

    1
    Brookhaven Lab physicists Pavol Juhas, John Hill, Mark Dean, Yue Cao, and Vivek Thampy, all of the Condensed Matter Physics and Materials Science Department, except Hill, who is director of NSLS-II.

    A quick flash of light can make ordinary materials extraordinary, potentially inducing qualities such as the perfect efficiency of superconductivity even at room temperature. But these subatomic transformations are infamously fleeting—they vanish in just trillionths of a second.

    Now, an international team of scientists has used synchronized infrared and x-ray laser pulses to simultaneously manipulate and reveal the ultra-fast magnetic properties of this promising quantum landscape. The rapid, light-driven switching between magnetic states, explored here with unprecedented precision, could one day revolutionize the reading and writing of data in computers and other digital devices.

    The study, published* May 9, 2016, in the journal Nature Materials, was led by scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and included researchers from the U.S., China, Germany, Japan, Spain, and the UK.

    “We developed a way to reveal light-induced femtosecond magnetic dynamics in as yet unseen detail,” said Mark Dean, a physicist at Brookhaven Lab and lead author on the study. “This brings us closer to perfecting a recipe for manipulating these materials on ultra-fast time scales.”

    This novel x-ray technique, called time-resolved resonant inelastic scattering, revealed the subtle spin correlations, which travel as waves through the material and define its magnetic properties. Crucially, they behaved differently between two- and three-dimensional spaces when sparked by an infrared laser pulse.

    “Within a two-dimensional atomic plane, the novel state lasted just a few picoseconds,” said Brookhaven physicist and study coauthor Yue Cao. “But three-dimensional correlations also cross between planes, and these took hundreds of picoseconds to vanish—on this scale, that difference is tremendous. It is enormously exciting to help pioneer a new technique and see it succeed.”

    The bulk of the experimental work relied on the powerful and precise x-ray lasers available at SLAC National Accelerator Laboratory’s Linac Coherent Light Source, a DOE Office of Science User Facility, and the SACLA facility in Japan.

    SLAC/LCLS
    SLAC/LCLS

    SACLA Free-Electron Laser Riken Japan
    SACLA Free-Electron Laser Riken Japan

    Doping with light

    To introduce novel magnetic and electronic qualities, scientists often use a technique called chemical doping to augment the atomic configuration of a material. Electrons can be meticulously added or removed, but the process is permanent.

    “We wanted to access similar states transiently, so we used photo-doping,” Dean said. “A laser pulse supplies the needed photons, which changes the electron and spin configuration in the sample—the same spins thought to be responsible for phenomena like superconductivity. Moments later, the material returns to its native state.”

    In this work, the scientists used a strontium-iridium-oxygen compound (Sr2IrO4), selected for its strong magnetic interactions. Manipulating spin in the material was relatively easy—the real challenge was catching it in motion.

    Bright, fast flashes

    The collaboration turned to two powerful photon sources: the LCLS and SACLA, both uniquely capable of illuminating a quantum spin wave mid-stride. Both facilities can produce x-ray pulses with extremely short duration and high brightness.

    “Knowing that these facilities could produce fast and accurate enough laser pulses inspired this entire collaboration,” said study coauthor John Hill, the director of Brookhaven Lab’s National Synchrotron Light Source II, another DOE Office of Science User Facility.

    BNL NSLS-II Interior
    BNL NSLS-II

    For the experiment, an initial infrared laser pulse struck the layered Sr2IrO4 compound, destroying the native magnetic state. For a brief moment, the electrons inside the material formed spin waves that rippled through the material and radically changed its electronic and magnetic properties. Trillionths of a second later, an x-ray pulse followed and bounced off those emergent waves. By measuring the change in both momentum and the angles of diffraction, the scientists could deduce the transient electronic and magnetic qualities.

    This specific process of bouncing and tracking x-rays, called resonant inelastic x-ray scattering (RIXS), was also pioneered by members of this collaboration to explore similar phenomena in condensed matter systems. The new research builds on that to include time-resolved data points.

    “Beyond the remarkable capabilities of LCLS and SACLA to supply ultra-short femtosecond x-ray pulses, the challenge we were facing was how to detect the response of the spins,” said study coauthor Xuerong Liu from the Institute of Physics in Beijing. “That is, we needed a specialized x-ray detection system or ‘camera.'”

    The scientists developed a highly specialized RIXS spectrometer, which used millimeter-sized silicon crystals to measure the exact energy of the rebounding x-rays.

    The data revealed a clear difference in the propagation and timescale of the magnetic phenomena, with the inter-layer correlations taking hundreds of times longer to recover than those within each layer.

    “The findings match theoretical expectations, which is encouraging, but more importantly they demonstrate the strength and precision of this technique,” said collaborator Michael Först of the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany. “We can now dive deeper into the mechanism and think of strategies to fine-tune the control of magnetic properties with light.”

    Next, the scientists plan to explore optical pulses at even longer wavelengths, which will shift atoms within the material without directly exciting the electrons and spins. That work may help reveal the native magnetic coupling within the material, which in turn will clarify how to best break that coupling and toggle between different electronic and magnetic states.

    The research was funded in part by the DOE’s Office Science (BES), which supported experimentation at LCLS.

    *Science paper:
    Ultrafast energy- and momentum-resolved dynamics of magnetic correlations in the photo-doped Mott insulator Sr2IrO4

    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 12:43 pm on April 13, 2016 Permalink | Reply
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    From BNL: “Elusive State of Superconducting Matter Discovered after 50 Years” 

    Brookhaven Lab

    Karen McNulty Walsh
    (631) 344-8350
    kmcnulty@bnl.gov

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

    1
    A schematic image representing a periodic variation in the density of Cooper pairs (pairs of blue arrows pointing in opposite directions) within a cuprate superconductor. Densely packed rows of Cooper pairs alternate with regions having lower pair density and no pairs at all. Such a “Cooper pair density wave” was predicted 50 years ago but was just discovered using a unique “scanning Josephson tunneling microscope. No image credit

    The prediction was that “Cooper pairs” of electrons in a superconductor could exist in two possible states. They could form a “superfluid” where all the particles are in the same quantum state and all move as a single entity, carrying current with zero resistance — what we usually call a superconductor. Or the Cooper pairs could periodically vary in density across space, a so-called “Cooper pair density wave.” For decades, this novel state has been elusive, possibly because no instrument capable of observing it existed.

    Now a research team led by J.C. Séamus Davis, a physicist at Brookhaven Lab and the James Gilbert White Distinguished Professor in the Physical Sciences at Cornell, and Andrew P. Mackenzie, Director of the Max-Planck Institute CPMS in Dresden, Germany, has developed a new way to use a scanning tunneling microscope (STM) to image Cooper pairs directly.

    The studies were carried out by research associate Mohammed Hamidian (now at Harvard) and graduate student Stephen Edkins (St. Andrews University in Scotland), working as members of Davis’ research group at Cornell and with Kazuhiro Fujita, a physicist in Brookhaven Lab’s Condensed Matter Physics and Materials Science Department.

    Superconductivity was first discovered in metals cooled almost to absolute zero (-273.15 degrees Celsius or -459.67 Fahrenheit). Recently developed materials called cuprates – copper oxides laced with other atoms – superconduct at temperatures as “high” as 148 degrees above absolute zero (-125 Celsius). In superconductors, electrons join in pairs that are magnetically neutral so they do not interact with atoms and can move without resistance.

    Hamidian and Edkins studied a cuprate incorporating bismuth, strontium, and calcium (Bi2Sr2CaCu2O8) using an incredibly sensitive STM that scans a surface with sub-nanometer resolution, on a sample that is refrigerated to within a few thousandths of a degree above absolute zero.

    At these temperatures, Cooper pairs can hop across short distances from one superconductor to another, a phenomenon known as Josephson tunneling. To observe Cooper pairs, the researchers briefly lowered the tip of the probe to touch the surface and pick up a flake of the cuprate material. Cooper pairs could then tunnel between the superconductor surface and the superconducting tip. The instrument became, Davis said, “the world’s first scanning Josephson tunneling microscope.”

    Flow of current made of Cooper pairs between the sample and the tip reveals the density of Cooper pairs at any point, and it showed periodic variations across the sample, with a wavelength of four crystal unit cells. The team had found a Cooper pair density wave state in a high-temperature superconductor, confirming the 50-year-old prediction.

    A collateral finding was that Cooper pairs were not seen in the vicinity of a few zinc atoms that had been introduced as impurities, making the overall map of Cooper pairs into “Swiss cheese.”

    The researchers noted that their technique could be used to search for Cooper-pair density waves in other cuprates as well as more recently discovered iron-based superconductors.

    This work was supported by a grant to Davis from the EPiQS Program of the Gordon and Betty Moore Foundation and by the U.S. Department of Energy’s Office of Science. The collaboration also included scientists in Scotland, Germany, Japan and Korea.

    Science paper: Detection of a Cooper-pair density wave in Bi2Sr2CaCu2O8+x

    These authors contributed equally to this work.
    M. H. Hamidian, S. D. Edkins & Sang Hyun Joo

    Authors and Affiliations

    Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
    M. H. Hamidian
    Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
    S. D. Edkins, A. Kostin, M. J. Lawler, E.-A. Kim & J. C. Séamus Davis
    School of Physics and Astronomy, University of St Andrews, Fife KY16 9SS, UK
    S. D. Edkins, A. P. Mackenzie & J. C. Séamus Davis
    Institute of Applied Physics, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea
    Sang Hyun Joo & Jinho Lee
    Center for Correlated Electron Systems, Institute of Basic Science, Seoul 151-742, South Korea
    Sang Hyun Joo & Jinho Lee
    Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan
    H. Eisaki & S. Uchida
    Department of Physics, University of Tokyo, Bunkyo, Tokyo 113-0011, Japan
    S. Uchida
    Department of Physics, Binghamton University, Binghamton, New York 13902-6000, USA
    M. J. Lawler
    Max Planck Institute for Chemical Physics of Solids, D-01187 Dresden, Germany
    A. P. Mackenzie
    Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
    K. Fujita & J. C. Séamus Davis
    Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, USA
    J. C. Séamus Davis

    Contributions

    M.H.H., S.D.E., A.K., and J.L. developed the SJTM techniques and carried out the experiments. K.F., H.E. and S.U. synthesized and characterized the samples. M.H.H., S.D.E., A.K., S.H.J. and K.F. developed and carried out analyses. E.-A.K. and M.J.L. provided theoretical guidance. A.P.M., J.L. and J.C.S.D. supervised the project and wrote the paper with key contributions from M.H.H., S.D.E. and K.F. The manuscript reflects the contributions and ideas of all authors.

    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 9:50 am on April 8, 2016 Permalink | Reply
    Tags: , , Radio isotopes   

    From BNL: “Boosting Production of Radioisotopes for Diagnostics and Therapeutics” 

    Brookhaven Lab

    April 4, 2016
    Ariana Tantillo

    Upgrades to Brookhaven Lab’s isotope production and research facility increase the yield of key medical isotopes

    1
    In the Brookhaven Linac Isotope Producer (BLIP) control room, (clockwise from back) Leonard Mausner, Deepak Raparia, and Robert Michnoff, who worked on the upgrade efforts, and Jason Nalepa, a BLIP operator, inspect recent changes to the raster beam profile. A live plot of the rastered beam, as measured with the new beam position monitoring system, is shown on the laptop screen. The small and large radii are visible. The electronics for the raster system are installed in the equipment racks seen in the background. No image credit.

    From imaging blood flow to the heart and other vital organs, to tracking the progression of bone disease, to destroying cancer cells, radioisotopes—radioactive forms of chemical elements—are used in the diagnosis and treatment of a variety of illnesses and diseases.

    Yet certain medically useful isotopes can only be produced by nuclear reactions that rely on high-energy particle accelerators, which are expensive to build and operate. As such, these isotopes are not typically available from commercial vendors. Instead, they are produced at facilities with unique capabilities, like the national labs built and funded by the U.S. Department of Energy (DOE).

    The DOE Office of Science’s Nuclear Physics Isotope Development and Production for Research and Applications program (DOE Isotope Program) seeks to make critical isotopes more readily available for energy, medical, and national security applications and for basic research. Under this program, scientists, engineers, and technicians at DOE’s Brookhaven National Laboratory recently completed the installation of a beam raster (or scanning) system designed to increase the yield of critical isotopes produced at the Brookhaven Linac Isotope Producer (BLIP), the Lab’s radioisotope production and research facility, in operation since 1972.

    The new raster system became operational in Jan. 2016 and is contributing to increased production of strontium-82 (Sr-82), an isotope used for cardiac imaging, and to research and development of actinium-225 (Ac-225), an isotope that may be a promising treatment for targeting many forms of cancer, including leukemia and melanoma.

    Making isotopes at BLIP

    BLIP produces isotopes by directing a high-energy (up to 200 million electron volts), high-intensity narrow beam of protons at a water-cooled array of several target materials. When the protons collide with the target materials, a reaction occurs, producing radioactive products in the target.

    More than one isotope is being produced at any given time, so multiple targets are hit with the beam. As the beam passes through the first to last targets, its energy decays. The targets are lined up in an order that maximizes production of the desired isotopes: the targets needed to produce isotopes requiring higher energy are put in the front of the array.

    A small fraction of each of the products is the desired isotopes, which can be extracted and purified through chemical processing conducted inside lead-enclosed “hot” cells at Brookhaven Lab’s Isotope Research Processing Laboratory. Inside these hot cells, which are designed for safely handling radioactive materials, the irradiated targets are cut open and their contents are dissolved to separate out the desired isotopes. Personnel use manipulators to remotely handle the radioactive material. The isotopes are then shipped in specialized containers to suppliers, who distribute them to hospitals for medical use or to universities for ongoing research.

    What makes BLIP unique is its high-energy capacity. “A minimum of 70 million electron volts is required to make Sr-82,” explained Leonard Mausner, the head of research and development and facility upgrades within Brookhaven Lab’s Medical Isotope Research and Production Program.

    Mausner proposed both the new beam raster system and a complementary effort to increase the beam intensity of the Brookhaven Linear Accelerator, or Linac, which provides the beam used at BLIP. “To date, there are no commercial accelerators in the United States with the power required to produce this critical isotope used to image 300,000 patients per year,” said Mausner.
    Focusing the beam

    However, the targets’ ability to handle BLIP’s high intensities has, until now, been largely hindered by the way the beam was positioned on the target. The beam, which significantly heats up the target, had always been narrowly focused on a single area of the target. As a result, the targets—such as the rubidium chloride (RbCl) used to produce Sr-82—became very hot only in the region of highest beam intensity.

    “The beam pulse, which is 450 microseconds long and happens every 150 milliseconds, would hit the targets in the same exact spot 24/7 over a period of weeks, potentially damaging the targets when high beam current was applied,” explained Robert Michnoff, project manager for the BLIP beam raster system and an engineer in Brookhaven Lab’s Collider-Accelerator Department.

    “Because the RbCl target was being heated unevenly, a small molten zone would form, then expand and push out into the cooler outer edges of the target area, where the material would solidify,” said Mausner. “We want the target fully solid or fully molten, as a uniform density may improve isotope yield.”

    Uneven heating causes the density of a target to vary across its diameter. As a result, the energy of the beam exiting the target will also vary across this diameter, impacting the energy that enters the next target in the array.

    “The distribution in beam energy increases as it travels through one target to the next, making it difficult to assess how much energy is transferred. We want to optimize production of isotopes in the downstream targets,” said Cathy Cutler, director of Brookhaven Lab’s Medical Isotope Research and Production Program.

    “Painting” the beam

    The new beam raster system provides a more uniform distribution of the beam on the target by rapidly “painting” the beam on the target in a circular raster fashion using two custom-designed magnets.

    2
    The difference in beam distribution on the target with the raster system off (left) and with the raster system on (right). The different color bands delineate the y-scale divisions, which are different on each plot. Note that although the total integrated beam density is equivalent in both plots, the peak beam density is five times higher when the raster system is off. The raster system clearly provides a more even beam distribution on the entire target. No image credit.

    But, rapidly sweeping the beam in one circular motion is not enough to uniformly distribute the beam across the target. “The beam intensity pattern would resemble a donut or a volcanic crater—a circle with a hollow center,” said Mausner.

    Instead, the beam is moved in a circular pattern at two different radii, essentially creating a larger and smaller circle. The radius values and the number of beam pulses for each radius can be programmed to optimize beam distribution.

    “The rastering pattern allows us to achieve near-uniform beam current density on the target,” said Michnoff, who mentioned plans to test a “middle” radius, which may help to provide even better beam distribution.

    Paving the way for higher beam intensities

    The new raster system provides an opportunity for researchers to safely apply increasingly higher beam currents on targets—an approach that Brookhaven scientists have been actively exploring to further increase isotope production yield.

    In a complementary effort to the BLIP raster upgrade, the scientists worked to increase the beam intensity of the Brookhaven Linac by optimizing operating parameters of the hydrogen ion source, neutralizing the electric charge generated by the beam, and increasing the length of the beam pulse by placing the beam earlier in the radio-frequency pulse used to accelerate the ions.

    “At higher currents, the beam’s electric charge causes the beam to spread out, resulting in defocusing of the beam and ultimately a loss of current. We use Xenon gas to neutralize that charge,” explained Deepak Raparia, head of the linac pre-injector system, project manager of the linac upgrade, and a scientist in Brookhaven Lab’s Collider-Accelerator Department. “By increasing the length of the beam pulse, we can deliver more beam current to the BLIP target station and thus increase the quantity of isotopes produced.”

    4
    The linac’s yearly average beam current delivered to BLIP. No image credit.

    In 2015, the Brookhaven Linac’s beam intensity was increased from 115 to 147 microamps, surpassing the initial project goal of 140 microamps. After the raster system was commissioned in 2016, the beam was further optimized, achieving 165 microamps.

    According to Mausner, yield could rise significantly at this higher intensity: “If the beam current can be maintained at 165 microamps, production levels could potentially increase by 40 percent.”

    In a second proposed phase of the Linac upgrade, the Brookhaven team hopes to double beam current by doubling the beam pulse length from 450 to 900 microseconds. Accelerating and extracting significantly more beam current out of the linac and transporting that current to BLIP will require the linac’s radio-frequency system and beam-focusing elements to be upgraded. “These upgrades will increase the duration of accelerating and focusing fields to cover the entire beam pulse,” said Raparia.
    Enabling research and development

    The capability to handle higher and higher beam intensities without targets failing not only increases the yield of routinely produced medical isotopes, such as Sr-82, but also enables scientists to investigate other promising isotopes for medical and other applications.

    Among these isotopes is Ac-225, a short-lived alpha emitter—it quickly releases a high amount of energy in the form of alpha particles that can only travel short distances. As such, Ac-225 has the ability to destroy targeted cancer cells without destroying healthy surrounding tissue. Traditionally, Ac-225 has been produced through the natural decay of thorium-229 from uranium-233, which is not readily available and has an extremely long half-life, or rate of decay.

    In collaboration with Los Alamos National Laboratory and Oak Ridge National Laboratory, Brookhaven Lab has been developing an accelerator-based capability to scale up the production of Ac-225, the demand for which is 50 to 100 times greater than the current supply.

    Scientists from all three laboratories are working to develop a new Ac-225 production approach in which readily available thorium metal targets are bombarded with high-energy protons. Initial experiments demonstrated that an irradiation lasting less than a week’s time could produce the annual quantity of Ac-225 currently in supply. “The raster system will ultimately aid us in the research and development of Ac-225, which could eventually be manufactured into an active pharmaceutical ingredient used in cancer therapy,” said Mausner.

    However, before Ac-225 can become a routine medical isotope, several challenges must be overcome.

    “Hundreds of isotopes are produced when thorium is hit with protons, so it is difficult to separate out Ac-225 during chemical processing of the target,” explained Mausner.

    A small number of clinical cancer treatment trials are ongoing using the currently limited supply of Ac-225. Initial results indicate that Ac-225 has the potential to put terminal cancer patients with acute myeloid leukemia, a cancer of the blood and bone marrow, into remission.

    “The increased beam intensity, coupled with this new raster system, will enable higher production levels of desirable radioisotopes for the nuclear medicine community and industry, and will increase the number of patients who could benefit across our nation,” said Mausner.

    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 3:23 pm on April 7, 2016 Permalink | Reply
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    From Symmetry: “Physicists build ultra-powerful accelerator magnet” 

    Symmetry Mag

    Symmetry

    04/07/16
    Sarah Charley

    Magnet built for LHC

    The next generation of cutting-edge accelerator magnets is no longer just an idea. Recent tests revealed that the United States and CERN have successfully co-created a prototype superconducting accelerator magnet that is much more powerful than those currently inside the Large Hadron Collider.

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

    Engineers will incorporate more than 20 magnets similar to this model into the next iteration of the LHC, which will take the stage in 2026 and increase the LHC’s luminosity by a factor of ten. That translates into a ten-fold increase in the data rate.

    “Building this magnet prototype was truly an international effort,” says Lucio Rossi, the head of the High-Luminosity (HighLumi) LHC project at CERN. “Half the magnetic coils inside the prototype were produced at CERN, and half at laboratories in the United States.”

    During the original construction of the Large Hadron Collider, US Department of Energy national laboratories foresaw the future need for stronger LHC magnets and created the LHC Accelerator Research Program (LARP): an R&D program committed to developing new accelerator technology for future LHC upgrades.

    MQXF1 quadrupole 1.5-meter prototype magnet sits at Fermilab before testing.
    MQXF1 quadrupole 1.5-meter prototype magnet sits at Fermilab before testing. G. Ambrosio (US-LARP and Fermilab), P. Ferracin and E. Todesco (CERN TE-MSC)

    This 1.5-meter-long model, which is a fully functioning accelerator magnet, was developed by scientists and engineers at Fermilab [FNAL], Brookhaven National Laboratory [BNL], Lawrence Berkeley National Laboratory [LBL], and CERN.

    FNAL II photo
    FNAL

    BNL Logo (2)
    BNL

    LBL Big
    LBL

    CERN
    CERN

    The magnet recently underwent an intense testing program at Fermilab, which it passed in March with flying colors. It will now undergo a rigorous series of endurance and stress tests to simulate the arduous conditions inside a particle accelerator.

    This new type of magnet will replace about 5 percent of the LHC’s focusing and steering magnets when the accelerator is converted into the High-Luminosity LHC, a planned upgrade which will increase the number and density of protons packed inside the accelerator. The HL-LHC upgrade will enable scientists to collect data at a much faster rate.

    The LHC’s magnets are made by repeatedly winding a superconducting cable into long coils. These coils are then installed on all sides of the beam pipe and encased inside a superfluid helium cryogenic system. When cooled to 1.9 Kelvin, the coils can carry a huge amount of electrical current with zero electrical resistance. By modulating the amount of current running through the coils, engineers can manipulate the strength and quality of the resulting magnetic field and control the particles inside the accelerator.

    The magnets currently inside the LHC are made from niobium titanium, a superconductor that can operate inside a magnetic field of up to 10 teslas before losing its superconducting properties. This new magnet is made from niobium-three tin (Nb3Sn), a superconductor capable of carrying current through a magnetic field of up to 20 teslas.

    “We’re dealing with a new technology that can achieve far beyond what was possible when the LHC was first constructed,” says Giorgio Apollinari, Fermilab scientist and Director of US LARP. “This new magnet technology will make the HL-LHC project possible and empower physicists to think about future applications of this technology in the field of accelerators.”

    High-Luminosity LHC coil
    High-Luminosity LHC coil similar to those incorporated into the successful magnet prototype shows the collaboration between CERN and the LHC Accelerator Research Program, LARP.
    Photo by Reidar Hahn, Fermilab

    This technology is powerful and versatile—like upgrading from a moped to a motorcycle. But this new super material doesn’t come without its drawbacks.

    “Niobium-three tin is much more complicated to work with than niobium titanium,” says Peter Wanderer, head of the Superconducting Magnet Division at Brookhaven National Lab. “It doesn’t become a superconductor until it is baked at 650 degrees Celsius. This heat-treatment changes the material’s atomic structure and it becomes almost as brittle as ceramic.”

    Building a moose-sized magnet from a material more fragile than a teacup is not an easy endeavor. Scientists and engineers at the US national laboratories spent 10 years designing and perfecting a new and internationally reproducible process to wind, form, bake and stabilize the coils.

    “The LARP-CERN collaboration works closely on all aspects of the design, fabrication and testing of the magnets,” says Soren Prestemon of the Berkeley Center for Magnet Technology at Berkeley Lab. “The success is a testament to the seamless nature of the collaboration, the level of expertise of the teams involved, and the ownership shown by the participating laboratories.”

    This model is a huge success for the engineers and scientists involved. But it is only the first step toward building the next big supercollider.

    “This test showed that it is possible,” Apollinari says. “The next step is it to apply everything we’ve learned moving from this prototype into bigger and bigger magnets.”

    See the full article here .

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    Symmetry is a joint Fermilab/SLAC publication.


     
  • richardmitnick 1:11 pm on February 19, 2016 Permalink | Reply
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    From Brookhaven: “Most Precise Measurement of Reactor Antineutrino Spectrum Reveals Intriguing Surprise” 

    Brookhaven Lab

    February 12, 2016
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    Daya Bay
    Antineutrino detectors installed in the far hall of the Daya Bay experiment. Credit: LBL Qiang

    Members of the International Daya Bay Collaboration, who track the production and flavor-shifting behavior of electron antineutrinos generated at a nuclear power complex in China, have obtained the most precise measurement of these subatomic particles’ energy spectrum ever recorded. The data generated from the world’s largest sample of reactor antineutrinos indicate two intriguing discrepancies with theoretical predictions and provide an important measurement that will shape future reactor neutrino experiments. The results have been published in the journal Physical Review Letters.

    Studying the behavior of elusive neutrinos holds the potential to unlock many secrets of physics, including details about the history, makeup, and fate of our universe. Neutrinos were among the most abundant particles at the time of the Big Bang, and are still generated abundantly today in the nuclear reactions that power stars and in collisions of cosmic rays with Earth’s atmosphere.

    They are also emitted as a by-product of power generation in man-made nuclear reactors, giving scientists a powerful way to study them on Earth in a controlled manner. In fact, the study of particles emitted by reactors led to the first detection of neutrinos in the 1950s, a finding once considered impossible due to the extreme inert nature of these particles, which were then only predicted. Since that time reactor experiments, including Daya Bay, have played a crucial role in uncovering the secrets of neutrino oscillation—their tendency to switch among three known flavors: electron, muon, and tau—and other important neutrino properties.

    A crucial factor for many of these experiments is knowing how many antineutrinos are emitted in total in these nuclear reactions (the flux), and how many are being produced at particular energies (the energy distribution, or spectrum). In early studies, scientists relied on calculations or other indirect means, such as electron spectrum measurements made on reactor fuels, to estimate these numbers, based on their understanding of the complex fission processes in the reactor core. These methods have rather strong dependence on theoretical models.

    The Daya Bay Collaboration now provides the most precise model-independent measurement of the energy spectrum of these elusive particles, and a new measurement of total antineutrino flux. The data were gathered by analyzing more than 300,000 reactor antineutrinos collected over the course of 217 days. The most challenging part of this work was to accurately calibrate the energy response of the detectors. Through dedicated calibration and analysis effort, Daya Bay was able to measure the neutrino energy to an unprecedented precision, better than 1 percent, over a broad energy range of the reactor antineutrinos.

    The measured reactor antineutrino spectrum shows a surprising feature: an excess of antineutrinos at an energy of around 5 million electron volts (MeV) compared with theoretical expectations. This represents a deviation of about 10 percent between the experimental measurement and calculations based on the theoretical models—well beyond the uncertainties—leading to a discrepancy of up to four standard deviations [σ]. “This unexpected disagreement between our observation and predictions strongly suggested that the current calculations would need some refinement,” commented Kam-Biu Luk of the University of California at Berkeley and DOE’s Lawrence Berkeley National Laboratory, a co-spokesperson of the Daya Bay Collaboration. Two other experiments have shown a similar excess at this energy, though with less precision than the new Daya Bay result.

    Such deviation shows the importance of the direct measurement of the reactor antineutrino spectrum, particularly for experiments that use the spectrum to measure neutrino oscillations, and may indicate the need to revisit the models underlying the calculations. “We expect that the spectrum measured by Daya Bay will improve with more data and better understanding of the detector response. These improved measurements will be essential for next-generation reactor neutrino experiments such as JUNO,” said Jun Cao of the Institute of High Energy Physics (IHEP) in China, a co-spokesperson of Daya Bay and the deputy spokesperson of JUNO, an experiment being built 200 kilometers away from Daya Bay.

    Daya Bay’s measurement of antineutrino flux—the total number of antineutrinos emitted across the entire energy range—indicates that the reactors are producing 6 percent fewer antineutrinos overall when compared to some of the model-based predictions. This result is consistent with past measurements. This observed deficit has been named the “Reactor Antineutrino Anomaly.” This disagreement could arise from the imperfection of the models. Or, more intriguingly, it could be the result of an oscillation involving a new kind of neutrino, the so-called sterile neutrino—postulated by some theories but yet to be detected. Whether the anomaly exists is still an open question.

    Background on Daya Bay

    The Daya Bay nuclear power complex is located on the southern coast of China, 55 kilometers northeast of Hong Kong. It consists of three nuclear power plants, each with two reactor cores. All six cores are pressurized water reactors with similar design, and each can generate up to 2.9 gigawatt thermal power. Every second, the six reactors emit 3,500 billion billon electron antineutrinos. For this measurement, the Daya Bay experiment used six detectors located at 360 meters to 1.9 kilometers from the reactors. Each detector contains 20 tons of gadolinium-doped liquid scintillator to catch the reactor antineutrinos.
    Contact Information

    Jun Cao, co-spokesperson, IHEP, +86-10-88235808, caoj@ihep.ac.cn
    Kam-Biu Luk, co-spokesperson, UC Berkeley and Lawrence Berkeley National Laboratory, 510-642-8162, 510-486-7054, k_luk@berkeley.edu

    For more information, visit http://dayabay.ihep.ac.cn/

    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 12:03 pm on February 8, 2016 Permalink | Reply
    Tags: , , , Scientists Propose "Pumpjack" Mechanism for Splitting and Copying DNA   

    From BNL: “Scientists Propose “Pumpjack” Mechanism for Splitting and Copying DNA” 

    Brookhaven Lab

    High-resolution structural details of cells’ DNA-replicating proteins offer new insight into how these molecular machines function

    February 8, 2016
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    BNL Mcm2-7 hexamer
    Two images showing the structure of the helicase protein complex from above. (a) A surface-rendered three-dimensional electron density map as obtained by cryo-EM. (b) A computer-generated “ribbon diagram” of the atomic model built based on the density map. The helicase has three major components: the Mcm2-7 hexamer ring in green, which encircles the DNA strand; the Cdc45 protein in magenta; and the GINS 4-protein complex in marine blue. Cdc45 and GINS recruit and tether other replisome components to the helicase, including the DNA polymerases that copy each strand of the DNA.

    New close-up images of the proteins that copy DNA inside the nucleus of a cell have led a team of scientists from the U.S. Department of Energy’s Brookhaven National Laboratory, Stony Brook University, Rockefeller University, and the University of Texas to propose a brand new mechanism for how this molecular machinery works. The scientists studied proteins from yeast cells, which share many features with the cells of complex organisms such as humans, and could offer new insight into ways that DNA replication can go awry.

    “DNA replication is a major source of errors that can lead to cancer,” explained Huilin Li, a biologist with a joint appointment at Brookhaven Lab and Stony Brook University and the lead author on a paper describing the new results in Nature Structural & Molecular Biology. “The entire genome—all 46 chromosomes—gets replicated every few hours in dividing human cells,” Li said, “so studying the details of how this process works may help us understand how errors occur.”

    The research builds on previous work by Li and others, including last year’s collaboration with the same team that produced the first-ever images of the complete DNA-copying protein complex, called the replisome.

    Replisome
    A representation of the structures of the replisome during DNA replication

    That study revealed a surprise about the location of the DNA-copying enzymes—DNA polymerases. This new study zooms in on the atomic-level details of the “helicase” portion of the protein complex—the part that encircles and splits the DNA double helix so the polymerases can synthesize two daughter strands by copying from the two separated parental strands of the “twisted ladder.”

    The scientists produced high-resolution images of the helicase using a technique known as cryo-electron microscopy (cryo-EM). One advantage of this method is that the proteins can be studied in solution, which is how they exist in the cells.

    “You don’t have to produce crystals that would lock the proteins in one position,” Li said. That’s important because the helicase is a molecular “machine” made of 11 connected proteins that must be flexible to work. “You have to be able to see how the molecule moves to understand its function,” Li said.


    download mp4 video here .

    download mp4 video here .

    The top movie shows the helicase protein complex from all angles, and reveals how its shape changes back and forth between two forms. The bottom movie shows how the rocking action of this conformational change might split the DNA double helix and move the helicase along one strand so it can be copied by DNA polymerase.

    Using computer software to sort out the images revealed that the helicase has two distinct conformations—one with components stacked in a compact way, and one where part of the structure is tilted relative to a more “fixed” base.

    The atomic-level view allowed the scientists to map out the locations of the individual amino acids that make up the helicase complex in each conformation. Then, combining those maps with existing biochemical knowledge, they came up with a mechanism for how the helicase works.

    “One part binds and releases energy from a molecule called ATP. It converts the chemical energy into a mechanical force that changes the shape of the helicase,” Li said. After kicking out the spent ATP, the helicase complex goes back to its original shape so a new ATP molecule can come in and start the process again.

    “It looks and operates similar to an old style pumpjack oil rig, with one part of the protein complex forming a stable platform, and another part rocking back and forth,” Li said. Each rocking motion could nudge the DNA strands apart and move the helicase along the double helix in a linear fashion, he suggested.

    This linear translocation mechanism appears to be quite different from the way helicases are thought to operate in more primitive organisms such as bacteria, where the entire complex is believed to rotate around the DNA, Li said. But there is some biochemical evidence to support the idea of linear motion, including the fact that the helicase can still function even when the ATP hydrolysis activity of some, but not all, of the components is knocked out by mutation.

    “We acknowledge that this proposal may be controversial and it is not really proven at this point, but the structure gives an indication of how this protein complex works and we are trying to make sense of it,” he said.

    The study was funded by the U.S. National Institutes of Health and the Howard Hughes Medical Institute (HHMI), with additional support from the Brookhaven Lab Biology Department. High-resolution cryo-EM data were collected at HHMI and the University of Texas Health Science Center.

    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 8:31 pm on January 14, 2016 Permalink | Reply
    Tags: , , , ,   

    From BNL: “New Theory of Secondary Inflation Expands Options for Avoiding an Excess of Dark Matter” 

    Brookhaven Lab

    January 14, 2016
    Chelsea Whyte, (631) 344-8671
    Peter Genzer, (631) 344-3174

    Physicists suggest a smaller secondary inflationary period in the moments after the Big Bang could account for the abundance of the mysterious matter.

    Temp 1
    No image credit found

    Standard cosmology—that is, the Big Bang theory with its early period of exponential growth known as inflation—is the prevailing scientific model for our universe, in which the entirety of space and time ballooned out from a very hot, very dense point into a homogeneous and ever-expanding vastness. This theory accounts for many of the physical phenomena we observe. But what if that’s not all there was to it?

    A new theory from physicists at the U.S. Department of Energy’s Brookhaven National Laboratory, Fermi National Accelerator Laboratory, and Stony Brook University, which will publish online on January 18 in Physical Review Letters, suggests a shorter secondary inflationary period that could account for the amount of dark matter estimated to exist throughout the cosmos.

    Temp 2
    Brookhaven Lab physicist Hooman Davoudiasl published a theory that suggests a shorter secondary inflationary period that could account for the amount of dark matter estimated to exist throughout the cosmos.

    “In general, a fundamental theory of nature can explain certain phenomena, but it may not always end up giving you the right amount of dark matter,” said Hooman Davoudiasl, group leader in the High-Energy Theory Group at Brookhaven National Laboratory and an author on the paper. “If you come up with too little dark matter, you can suggest another source, but having too much is a problem.”

    Measuring the amount of dark matter in the universe is no easy task. It is dark after all, so it doesn’t interact in any significant way with ordinary matter. Nonetheless, gravitational effects of dark matter give scientists a good idea of how much of it is out there. The best estimates indicate that it makes up about a quarter of the mass-energy budget of the universe, while ordinary matter—which makes up the stars, our planet, and us—comprises just 5 percent. Dark matter is the dominant form of substance in the universe, which leads physicists to devise theories and experiments to explore its properties and understand how it originated.

    Some theories that elegantly explain perplexing oddities in physics—for example, the inordinate weakness of gravity compared to other fundamental interactions such as the electromagnetic, strong nuclear, and weak nuclear forces—cannot be fully accepted because they predict more dark matter than empirical observations can support.

    This new theory solves that problem. Davoudiasl and his colleagues add a step to the commonly accepted events at the inception of space and time.

    In standard cosmology, the exponential expansion of the universe called cosmic inflation began perhaps as early as 10-35 seconds after the beginning of time—that’s a decimal point followed by 34 zeros before a 1. This explosive expansion of the entirety of space lasted mere fractions of a fraction of a second, eventually leading to a hot universe, followed by a cooling period that has continued until the present day. Then, when the universe was just seconds to minutes old – that is, cool enough – the formation of the lighter elements began. Between those milestones, there may have been other inflationary interludes, said Davoudiasl.

    “They wouldn’t have been as grand or as violent as the initial one, but they could account for a dilution of dark matter,” he said.

    In the beginning, when temperatures soared past billions of degrees in a relatively small volume of space, dark matter particles could run into each other and annihilate upon contact, transferring their energy into standard constituents of matter—particles like electrons and quarks. But as the universe continued to expand and cool, dark matter particles encountered one another far less often, and the annihilation rate couldn’t keep up with the expansion rate.

    “At this point, the abundance of dark matter is now baked in the cake,” said Davoudiasl. “Remember, dark matter interacts very weakly. So, a significant annihilation rate cannot persist at lower temperatures. Self-annihilation of dark matter becomes inefficient quite early, and the amount of dark matter particles is frozen.”

    However, the weaker the dark matter interactions, that is, the less efficient the annihilation, the higher the final abundance of dark matter particles would be. As experiments place ever more stringent constraints on the strength of dark matter interactions, there are some current theories that end up overestimating the quantity of dark matter in the universe. To bring theory into alignment with observations, Davoudiasl and his colleagues suggest that another inflationary period took place, powered by interactions in a “hidden sector” of physics. This second, milder, period of inflation, characterized by a rapid increase in volume, would dilute primordial particle abundances, potentially leaving the universe with the density of dark matter we observe today.

    “It’s definitely not the standard cosmology, but you have to accept that the universe may not be governed by things in the standard way that we thought,” he said. “But we didn’t need to construct something complicated. We show how a simple model can achieve this short amount of inflation in the early universe and account for the amount of dark matter we believe is out there.”

    Proving the theory is another thing entirely. Davoudiasl said there may be a way to look for at least the very feeblest of interactions between the hidden sector and ordinary matter.

    “If this secondary inflationary period happened, it could be characterized by energies within the reach of experiments at accelerators such as the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider [LHC],” he said.

    BNL RHIC Campus
    BNL RHIC
    RHIC with map

    CERN LHC Map
    CERN LHC Grand Tunnel
    CERN LHC particles
    LHC at CERN with map.

    Only time will tell if signs of a hidden sector show up in collisions within these colliders, or in other experimental facilities.

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

    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 1:07 pm on December 28, 2015 Permalink | Reply
    Tags: , BNL Beam Energy Scan Theory Collaboration, , BNL TMD Collaboration   

    From BNL: “Brookhaven Scientists to Lead Two New Nuclear Theory Collaborative Projects” 

    Brookhaven Lab

    December 28, 2015
    Karen McNulty Walsh, (631) 344-8350
    Peter Genzer, (631) 344-3174

    1
    An aerial view of the Relativistic Heavy Ion Collider

    Theoretical physicists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory will serve as principal investigators for two of three recently announced collaborative projects exploring the theoretical underpinnings of nuclear physics. These five-year “Topical Collaborations in Nuclear Theory” were selected through a competitive peer review process for funding by the Office of Nuclear Physics within the DOE Office of Science and are just getting underway.

    “Brookhaven Lab is a leader in the field of nuclear physics, running the Relativistic Heavy Ion Collider (RHIC), one of the field’s essential experimental facilities, and supporting a world-renowned nuclear theory group with diverse intellectual interests and capabilities. It is therefore particularly gratifying that the peer review process, which considered a number of strong proposals, has afforded Brookhaven the opportunity to provide intellectual leadership on two of the three selected projects,” said Berndt Mueller, Brookhaven Lab’s Associate Laboratory Director for Nuclear and Particle Physics.

    Advances in nuclear theory—along with experiments those theories help to drive and interpret—expand our understanding of the building blocks of matter, the astrophysical origin of elements, the properties of fundamental particles, and their implications for broader theories that describe the world around us. Some of the central goals of the Topical Collaborations in Nuclear Theory are to bring together groups of leading nuclear theorists, leverage the resources of small research groups, and provide expanded opportunities for the next generation of nuclear theorists. The collaborations are intended to function as hubs of a network of scientists that support sustained interaction and communication within the network and provide a mechanism for placing new researchers in permanent positions in nuclear theory.

    The two Brookhaven-led projects are directly related to the research at RHIC, a DOE Office of Science User Facility where nearly one thousand nuclear physicists from around the world collaborate to explore the fundamental building blocks of nuclear matter—the quarks and gluons that make up protons and neutrons—and the force through which they interact. They do so by colliding the nuclei of large atoms such as gold to recreate tiny specks of matter as it existed in the very early universe, before quarks became confined within larger particles such as the protons and neutrons that make up most of the visible matter of the universe today.

    Beam Energy Scan Theory Collaboration

    2
    Physicists in the Beam Energy Scan Theory Collaboration are helping to map points on the nuclear phase diagram.

    One project, led by Swagato Mukherjee, will construct and provide a theoretical framework for interpreting the results from the ongoing Beam Energy Scan program at RHIC.

    “The Beam Energy Scan is a systematic exploration of how the transition of ordinary nuclear matter (protons and neutrons) to quark-gluon plasma (QGP) changes over various collision energies,” Mukherjee said. “This project has two main goals. One is to discover (or put constraints on the existence of) a ‘critical point’ in the nuclear phase diagram—the point where the transition from ordinary nuclear matter to QGP changes from a smooth crossover between the two phases to a sudden shift, like water boiling in a pot. The second goal is to locate the onset of ‘chiral symmetry restoration’—the definitive point where quarks and gluons are set ‘free’ from the bounds of individual protons and neutrons—by observing correlations related to anomalous hydrodynamic effects in the quark-gluon plasma.”

    The theorists will develop a set of tools, models, and codes that will be used to analyze RHIC Beam Energy Scan data and will be made available to the research community.

    The collaboration plans to provide partial support for hiring at least two tenure-track nuclear theorists at universities in the U.S., and will organize workshops and summer schools related to the physics goals of the collaboration.

    Partnering institutions include: Indiana University, Lawrence Berkeley National Laboratory, McGill University, Michigan State University, MIT, North Carolina State University, Ohio State University, Stony Brook University, University of Chicago, University of Connecticut, University of Houston, and the University of Illinois at Chicago.

    The TMD Collaboration

    4
    The TMD Collaboration will explore the internal structure of the proton and how it relates to overall nucleon properties such as proton spin.

    The second project, led by Jianwei Qiu, will develop theoretical tools for studying the three-dimensional (3D) motion of quarks and gluons while they are confined inside protons and neutrons (collectively known as nucleons), which are the fundamental building blocks of all atomic nuclei.

    “The nucleon is not static but has a complex internal structure, the dynamics of which are only beginning to be revealed in modern experiments,” Qiu said. “But understanding this internal structure and how it relates to the overall nucleon properties, such as proton spin, is a great intellectual challenge, because the most powerful detector cannot see the quarks and gluons individually within the nucleons. Instead, we must develop reliable theoretical tools for connecting experimental measurements of protons to the quarks and gluons inside them so we can extract tomographic images of the protons’ internal quark-gluon structure.”

    This collaboration establishes a unique three-pronged scientific effort pulling together expertise in both theory and phenomenology of quantum chromodynamics (QCD)—the theory that describes the interactions of quarks and gluons—as well as in “lattice QCD,” the supercomputer-based calculation method used to solve the complex mathematical equations of QCD. This group of theorists, known as the TMD Collaboration, will further develop and perfect the “transverse momentum dependent (TMD) QCD factorization.” This is theoretical framework that enables physicists to relate experimental measurements to the 3D momentum landscape inside the nucleon using data from research facilities such as RHIC, Jefferson Laboratory, CERN, and a future proposed Electron-Ion Collider.

    “We are making a concerted effort to bring in new people and to train young scientists,” Qiu said, noting that the project will support two new tenure-track junior faculty positions and leverage existing support to have six new postdoctoral fellows and five graduate or undergraduate students working with the collaboration.

    Partner institutions for this project include Duke University, Jefferson Laboratory, Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, MIT, New Mexico State University, Penn State University at Berks, Old Dominion University, Temple University, University of Arizona, University of Kentucky, University of Maryland, and the University of Virginia.

    “Our scientists are excited and honored to be selected to lead these projects, which will support research in priority areas of the new Long Range Plan for Nuclear Science and are of strategic importance to the national nuclear physics community,” Mueller said.

    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 8:43 pm on December 3, 2015 Permalink | Reply
    Tags: , ,   

    From BNL: “Brookhaven Lab Climate Scientists Embark on New Efforts to Study Ocean Clouds, Mountain Storms” 

    Brookhaven Lab

    December 3, 2015
    Kara Manke

    1
    ARM’s Eastern North Atlantic observation facility on Graciosa Island in the Azores will collect data on the interaction of clouds, aerosols, and precipitation as part of the ACE-ENA field campaign to investigate the impact of aerosols on low-lying marine clouds. Image courtesy of U.S. Department of Energy ARM Climate Research Facility.

    Climate scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory will play key roles in two upcoming field campaigns funded by DOE’s Atmospheric Radiation Measurement (ARM) Climate Research Facility, a DOE Office of Science User Facility.

    These campaigns will deploy ARM’s advanced aircraft- and surface- based instrumentation to explore the interactions between clouds and the environment in two remote regions of the globe: the Eastern North Atlantic and the Argentinian Andes. The data collected in these experiments will shed light on regional climate dynamics and improve global climate simulations. They were among five missions recently selected by ARM, to deploy key components of its facility between 2016 and 2019.

    Exploring Sun-blocking Clouds

    2
    Brookhaven Lab’s Jian Wang will lead the ACE-ENA field campaign.

    Jian Wang, a researcher in Brookhaven Lab’s Environmental and Climate Science Department, will lead the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign to investigate marine boundary layer clouds over the Atlantic Ocean.

    Wang says that this persistent layer of clouds plays a major role in global climate by acting as a solar “mirror.”

    “By reflecting a large portion of the incoming sunlight before it reaches the ocean surface, these clouds have a significant impact on Earth’s energy balance,” Wang said. “But despite this importance, the atmospheric processes that control the properties of these clouds are poorly understood.”

    Aerosols, tiny airborne particles, have a strong impact on the formation of marine boundary layer clouds, but the magnitude of this impact is unclear —a major source of the uncertainty in global climate models. A big challenge is measuring both aerosols and clouds, and how they vary with space and time, over the ocean.

    In summer 2017 and winter 2018, the campaign will use instruments aboard the ARM Aerial Facility (AAF) Gulfstream-1, a twin turboprop aircraft, to collect data on clouds and aerosols above the Azores, an island archipelago 850 miles west of continental Portugal. Radars and other instruments stationed at ARM’s permanent research site on the Azores’ Graciosa Island will simultaneously monitor precipitation and cloud cover from the ground.

    “A key advantage of this campaign is the coupling of the measurements from the aircraft with those taken from the surface,” Wang said.

    Other contributors to the project include Scott Giangrande, Michael Jensen, Chongai Kuang, Ernie Lewis, Edward Luke, Yangang Liu, and Arthur Sedlacek, researchers in Brookhaven Lab’s Environmental and Climate Science Department; and Pavlos Kollias, a collaborator from Stonybrook University.

    Peering into Mountain Storms

    3
    Brookhaven Lab’s Michael Jensen is a member of the CACTI campaign team.

    4
    The CACTI field campaign will deploy surface- and aircraft- based instrumentation to the Córdoba mountain range of north-central Argentina to collect data on the initiation and lifecycle of violent storms in the region. Image courtesy of Carlos Marro and licensed under CC BY 2.0 via Creative Commons.

    The campaign is set to collect unprecedented amounts of data on the interaction between storms and the environment in subtropical South America, and promises to improve long-term climate simulations in this critical agriculture region.

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

    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 12:51 pm on November 25, 2015 Permalink | Reply
    Tags: , ,   

    From BNL: “Postdoc Alesha Harris: Tackling Chemistry from Nanoparticles to Neutrinos” 

    Brookhaven Lab

    November 24, 2015
    Kay Cordtz

    1
    Alesha Harris

    Alesha Harris has three degrees in chemistry and has taught the subject in her home state of Texas. Although her graduate work was in nanoparticles—materials just a billionth of a meter in size—she joined the U.S. Department of Energy’s Brookhaven National Laboratory as an Alliance for Graduate Education and the Professoriate–Transformation (AGEP-T) postdoc working with Minfang Yeh, who leads the neutrino and nuclear chemistry group. Before becoming acquainted with Brookhaven Lab and Yeh’s work, Harris had never heard of the mysterious neutrinos, invisible subatomic particles.

    “In all of my years of study, education, and books, I had never heard of them,” Harris said. “It’s not something that they taught in any of my classes. So it was very ambitious of me to take this on, just like it was ambitious of Dr. Yeh to take me on. Nonetheless, he emphasized that he wanted someone who was less familiar with the area who could bring fresh ideas.”

    Harris comes from a family of high achievers. Her father is a CPA, a college vice president for Business and Finance, as well as a preacher. Her mother is a dentist and recently retired from the US Public Health Service, where she oversaw the quality of health care in 11 states. Harris’ grandfather was a physicist, an architect, a pilot, and a mathematician.

    “I have an uncle who is a lawyer, an aunt working on her PhD in human resources and a cousin who is an archaeologist and speaks Hebrew fluently,” said Harris. “In our family, we go for the opportunity and we work at it.”

    Her career in science is a result of Harris pursuing an earlier goal.

    “When I was younger, I wanted to be a fashion designer,” she said. “So I took sewing classes and I drew all the time. Somewhere along the way I thought that in order to be a fashion designer, you’re probably going to have to have some money, so you should use your other skills to help you get financing. “

    Harris credits a high school teacher with fostering her love of chemistry.

    “She really made me enjoy it,” she said. “ I had to work hard like everybody else but there was something about the way she taught that made me feel success at the end of solving a problem.”

    As an undergraduate at Dillard University in New Orleans, Harris majored in chemistry with a minor in math. She did her graduate work – earning a MS and a PhD in inorganic chemistry — at the University of North Texas.

    “My research was on nanoparticles for targeted drug delivery,” she said. “We used polymers to create nanoparticles as carriers, and our drugs of choice were transition metals. I worked with pancreatic cancer cells as well as cervical cancer cells and I did a variety of experiments from the synthesis and analysis of the nanoparticles and loading of the metals to the toxicity studies. So I learned a lot by doing all those different things, and I think that made my resume interesting to Dr. Yeh.”

    “The study of neutrinos is in a precision era that could use a lot of help from chemistry for the development of the next-generation detector, “ said Yeh. “I enjoy working with young scientists because of their fresh minds and creativity. Alesha has great passion for science and loves to learn. I am happy to have her joining the group.”

    Yeh’s group at Brookhaven works with liquid scintillators for the detection of the elusive neutrinos, and is experimenting with surfactants to generate stability in a new and improved metal-doped scintillation water.

    The AGEP-T program aims to prepare its participants for a possible teaching career, something Harris has already experienced. After receiving her PhD, she taught general chemistry at a small historically black college in Texas.

    “Most of the students I had were only familiar with chemistry at a very basic high school level,” she said. “I think I was able to teach them ways to learn chemistry. I think that’s one thing that should be taught more: how to study.”

    Harris also taught the math portion of the Graduate Record Examination and helped interest students in science and technology careers. She became aware of Brookhaven’s AGEP-T program through networking at conferences.

    “I really appreciate that the program emphasizes mentorship,” she said. “I know that Dr. Yeh is one of the best in his field, and I like the fact that I can attend conferences, go to seminars and have a group of people who are trying to develop me professionally not just scientifically. Since I’ve been here, I’ve been able to learn to use more instruments than I did in graduate school and I’m looking forward to punching out papers.

    “I love health, it’s still my passion,” she said. “The skills that I learn here can be used in many areas of science, including health research. Although, maybe I will just fall in love with studying neutrinos! I’m still young and have time to change my mind, but at least I’m here and learning from the best.”

    In addition to her work in the lab, Harris is involved with numerous outside activities. She plays volleyball — on and off campus—and is part of the sorority Alpha Kappa Alpha. The group focuses on community service, and before the school year began, they assembled backpacks for elementary, middle and high school students. She also recently joined Toastmasters.

    “I think I can do a good job taking difficult information and making it a little bit easier to digest for decision makers. Given that as my goal, I’m ready to start working on the craft of speaking. I’d like to be a science liaison, the person who explains science to decision makers and community members.”

    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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