Tagged: Neutron Science Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 11:13 am on June 8, 2020 Permalink | Reply
    Tags: "Crystalline ‘nanobrush’ clears way to advanced energy and information tech", Advanced Materials, , Atom probe tomography-APT at the Center for Nanophase Materials Sciences a DOE Office of Science User Facility at ORNL., Neutron Science, ,   

    From Oak Ridge National Laboratory: “Crystalline ‘nanobrush’ clears way to advanced energy and information tech” 


    From Oak Ridge National Laboratory

    June 8, 2020
    Dawn M Levy

    A nanobrush made by pulsed laser deposition of CeO2 and Y2O3 with dim and bright bands, respectively, is seen in cross-section with scanning transmission electron microscopy. Credit: Oak Ridge National Laboratory, U.S. Dept. of Energy.

    A team led by the Department of Energy’s Oak Ridge National Laboratory synthesized a tiny structure with high surface area and discovered how its unique architecture drives ions across interfaces to transport energy or information. Their “nanobrush” contains bristles made of alternating crystal sheets with vertically aligned interfaces and plentiful pores.

    “These are major technical accomplishments and may prove useful in advancing energy and information technologies,” said ORNL’s Ho Nyung Lee, who led the study published in Nature Communications. “This is an excellent example of work that is only feasible with the unique expertise and capabilities available at national labs.”

    The team’s researchers hail from DOE national labs Oak Ridge and Argonne and Massachusetts Institute of Technology, or MIT, University of South Carolina, Columbia, and University of Tennessee, Knoxville.

    The bristles of their multilayer crystal, or “supercrystal,” are grown freestanding on a substrate. Former ORNL postdoctoral fellow Dongkyu Lee synthesized the supercrystals using pulsed laser epitaxy to deposit and build up alternating layers of fluorite-structure cerium oxide (CeO2) and bixbyite-structure yttrium oxide (Y2O3). Realization of the nanoscale bristles was made possible by the development of a novel precision synthesis approach that controls atom diffusion and aggregation during the growth of thin-film materials. Using scanning transmission electron microscopy, or STEM, former ORNL postdoctoral fellow Xiang Gao was surprised to discover atomically precise crystalline interfaces within the bristles.

    Scanning transmission electron microscope (200 kV Jeol prototype) equipped with a 3rd-order spherical aberration corrector. Materialscientist.

    To see the distribution of CeO2 and Y2O3 within the nanobrush, ORNL’s Jonathan Poplawsky measured samples from the bristles using atom probe tomography, or APT, at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility at ORNL. “APT is the only technique available that is capable of probing the three-dimensional positions of atoms in a material with sub-nanometer resolution and 10 parts per million chemical sensitivity,” Poplawsky said. “APT clarifies the local distributions of atoms within a nanosized object and was an excellent platform for providing information about the 3D structure of the interface between the cerium oxide and yttrium oxide layers.”

    For a 2017 paper [Advanced Science], the ORNL-led researchers used epitaxy by pulsed laser deposition to precisely synthesize nanobrushes with bristles containing only one compound. For the 2020 paper, they used the same method to layer two compounds, CeO2 and Y2O3, fabricating the first hybrid bristles with interfaces between the two materials. Traditionally, interfaces are aligned laterally by layering different crystals in thin films, whereas in the novel nanobrushes when grown on a particular surface, interfaces are aligned vertically through surface energy minimization in bristles that are only 10 nanometers wide — about 10,000 times thinner than a human hair.

    “This is a truly innovative way to build crystalline nanoarchitectures, providing unprecedented vertical interfaces that were never thought viable,” Ho Nyung Lee said. “You cannot achieve these perfect crystalline architectures from any other synthesis method.”

    He added, “There are many ways to utilize interfaces, which is why 2000 Nobel Prize winner Herbert Kroemer said, ‘the interface is the device.’” Conventionally, depositing layers of thin film materials on substrates creates interfaces that are horizontally aligned, allowing ions or electrons to move along the substrate’s 2D plane. The ORNL-led achievement is proof of concept that it is possible to create vertically aligned interfaces through which electrons or ions can be transported out of the substrate’s plane. Moreover, architectures like the nanobrush could be combined with other nanoscale architectures to create devices for quantum technologies and sensing as well as energy storage.

    The low-energy configuration of the fluorite structure caused the formation of unique chevron patterns, or inverted “V” shapes. A slight mismatch between different structures of fluorite and bixbyite crystal subunits causes mismatch of the electronic charges at their interfaces, causing oxygen atoms to vacate the fluorite side, which leads to the formation of functional defects. The spaces that are left behind can form interfacial oxygen ions and create an atomic-scale channel through which the ions can flow. “We are using the interfaces not only to artificially create oxygen ions, but also to guide ion movement in a more deliberate way,” Lee said.

    With the help of ORNL’s Matthew Chisholm, Gao used STEM to uncover the atomic structure of the crystal and electron energy-loss spectroscopy to reveal chemical and electronic insights about the interface. “We observed that a quarter of oxygen atoms are lost at the interfaces,” said Chisholm. “We were also surprised by the chevron growth pattern. It was critical at the beginning to really understand how the interfaces form within the bristles.”

    The nanobrush has a high porosity, and its architecture is advantageous for applications needing large surface area to maximize electronic and chemical interactions, such as sensors, membranes and electrodes. But how could the scientists determine the porosity of their material? Neutrons — neutral particles that pass through materials without destroying them — provided an excellent tool for characterizing porosity of the bulk material. The scientists used resources of the Spallation Neutron Source, a DOE Office of Science User Facility at ORNL, for extended Q-range small-angle neutron scattering that determined the upper limit of porosity to be 49%. “Quickly grown bristles can provide about 200 times as much surface area as a 2D thin film,” said ORNL co-author Michael Fitzsimmons.

    He added, “What we learn may advance applications of neutron science in the process. Whereas thin films do not provide sufficient surface area for neutron spectroscopy studies, ORNL’s novel nanobrush architecture does, and could be a platform for learning more about interfacial materials when an even brighter neutron beam becomes available at SNS’s Second Target Station, which is a funded construction project.”

    Theoretical calculations of the material system from the electronic and atomic level supported findings about oxygen-vacancy creation at the interfaces. MIT contributor Lixin Sun performed density functional theory calculations and molecular dynamics simulations under the direction of Bilge Yildiz.

    “Our theoretical calculations revealed how this interface can accommodate a largely different chemistry at this type of unique interface compared to bulk materials,” said Yildiz. The MIT calculations predicted the energy needed to remove a neutral oxygen atom to form a vacancy close to the interface or in the middle of a cerium oxide layer. “In particular, we found that a large fraction of oxygen ions is removed at the interface without deteriorating the lattice structure.”

    Lee said, “Indeed, these critical interfaces could form inside of nanobrush architectures, making them more promising than conventional thin films in many technological applications. Their much greater surface area and larger number of interfaces — potentially, thousands inside each bristle — may prove a game changer in future technologies in which the interface is the device.”

    The DOE Office of Science supported the research. The work used resources of the Center for Nanophase Materials Sciences and the Spallation Neutron Source, which are DOE Office of Science User Facilities at ORNL, as well as resources of the National Energy Research Scientific Computing Center and the Advanced Photon Source, DOE Office of Science User Facilities at Lawrence Berkeley National Laboratory and Argonne National Laboratory, respectively.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s 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.


  • richardmitnick 1:45 pm on May 23, 2019 Permalink | Reply
    Tags: "Unexpected observation of ice at low temperature high pressure questions ice and water theory", Neutron Science, ,   

    From Oak Ridge National Laboratory: “Unexpected observation of ice at low temperature, high pressure questions ice, water theory” 


    From Oak Ridge National Laboratory

    May 22, 2019

    Sara S Shoemaker

    An ORNL-led team’s observation of certain crystalline ice phases challenges accepted theories about super-cooled water and non-crystalline ice. Their findings, reported in the journal Nature, will also lead to better understanding of ice and its various phases found on other planets, moons and elsewhere in space. Credit: Jill Hemman/Oak Ridge National Laboratory, U.S. Dept. of Energy.

    Through an experiment designed to create a super-cold state of water, scientists at the Department of Energy’s Oak Ridge National Laboratory used neutron scattering to discover a pathway to the unexpected formation of dense, crystalline phases of ice thought to exist beyond Earth’s limits.

    Observation of these particular crystalline ice phases, known as ice IX, ice XV and ice VIII, challenges accepted theories about super-cooled water and amorphous, or non-crystalline, ice. The researchers’ findings, reported in the journal Nature, will also lead to better basic understanding of ice and its various phases found on other planets and moons and elsewhere in space.

    “Hydrogen and oxygen are among the most abundant elements in the universe, and the simplest molecular compound of the two, H2O, is common,” said Chris Tulk, ORNL neutron scattering scientist and lead author. “In fact, a popular theory suggests that most of Earth’s water was brought here through collisions with icy comets.”

    On Earth, when water molecules reach zero degrees Celsius, they enter a lower energy state and settle onto a hexagonal crystalline lattice. This frozen form is denoted as ice Ih, the most common phase of water that can be found in household freezers or at skating rinks.

    Ice IX, ice XV and ice VIII are three of at least 17 ice phases realized when molecules reorganize into a stable crystalline structure at varying super-low temperatures and very high pressures, conditions that don’t occur naturally on Earth.

    “As ice changes phases, it’s similar to water going from a gas to a liquid to a solid except at low temperatures and high pressure—the ice transforms between various different solid forms,” Tulk said.

    Each known ice phase is characterized by its unique crystal structure within its pressure-temperature range of stability, where the molecules reach equilibrium and the water molecules exhibit a regular three-dimensional pattern, and the structure becomes stable.

    Initially, Tulk and colleagues at the National Research Council of Canada and from the University of California at Los Angeles were exploring the structural nature of amorphous ice—a state of ice that forms with no ordered crystalline structure—as it recrystallizes at even higher pressures.

    ORNL scientists Chris Tulk, left, and Jamie Molaison were part of a team that discovered a pathway to the unexpected formation of dense, crystalline phases of ice thought to exist beyond Earth’s limits. They used the unique neutron scattering capability of the Spallation Neutrons and Pressure Diffractometer at ORNL’s Spallation Neutron Source for the experiment. Credit: Genevieve Martin/Oak Ridge National Laboratory, U.S. Dept. of Energy.

    ORNL Spallation Neutron Source

    ORNL Spallation Neutron Source

    To make amorphous ice, scientists freeze water into a high-pressure device that is cooled to minus 173 degrees Celsius and pressurized to approximately 10,000 atmospheres, or 147,000 pounds per square inch (car tires are inflated to about 32 pounds per square inch).

    “This type of amorphous ice is thought to be related to liquid water, and understanding that link was the original purpose of this study,” said Tulk.

    At ORNL’s Spallation Neutron Source, the team froze a three-millimeter sphere, or about half a drop, of deuterated water, which has an additional neutron in the hydrogen nucleus needed for neutron scattering analysis. Then, they programmed the Spallation Neutrons and Pressure, or SNAP, diffractometer to minus 173 degrees C. The instrument increased the pressure incrementally every couple of hours up to 411,000 pounds per square inch, or about 28,000 atmospheres while collecting neutron scattering data between each hike in pressure.

    “Once we achieved amorphous ice, we planned to raise the temperature and pressure and observe the local molecular ordering as the amorphous ice ‘melts’ into a supercooled liquid and then recrystallizes,” Tulk said. However, after analyzing the data, they were surprised to learn they had not created amorphous ice, but rather a sequence of crystalline transformations through four phases of ice with ever-increasing density: from ice Ih to ice IX to ice XV to ice XIII. There was no evidence of amorphous ice at all.

    “I’ve made many of these samples always by compressing ice at low temperature,” said co-author Dennis Klug from the National Research Council of Canada, the lab that originally discovered the pressure-induced amorphization of ice in 1984. “I’ve never previously seen this pressure-temperature path result in a series of crystalline forms like this.”

    “If the data from our experiment was true, it would mean that amorphous ice is not related to liquid water but is rather an interrupted transformation between two crystalline phases, a major departure from widely accepted theory,” Klug added.

    At first, the team thought their observation was the result of a contaminated sample.

    Three more experiments with a fresh, carefully handled samples on SNAP produced identical results, reconfirming the structural transformation sequence with no formation of amorphous ice.

    The key was the slow rate of pressure increase and collection of data at a lower pressure that allowed the ice structure to relax and become the stable ice IX form. Previous experiments quickly passed over the ice IX structure without relaxation, this resulted in the amorphous phase.

    For 35 years, scientists have been researching the properties of super-cold water and looking for what’s known as the second critical point, which is buried within the solid ice phases. But these results question its very existence. “The relationship between pressure-induced amorphous ice and water is now in doubt, and the second critical point may not even exist,” Tulk said.

    “The results of this paper will form the basis of the analysis of future studies of amorphous ice phases during upcoming experiments done at the SNS,” he added.

    Co-authors of the study titled, “Absence of amorphous forms when ice is compressed at low temperature,” included Chris A. Tulk and Jamie J. Molaison of ORNL; Adam Makhluf and Craig E. Manning of UCLA; and Dennis D. Klug of the NRC of Canada.

    Experimental measurements were performed at ORNL’s Spallation Neutron Source, a DOE Office of Science User Facility, using the Spallation Neutrons and Pressure diffractometer. The research was supported by DOE’s Office of Science and the Sloan Foundation’s Deep Carbon Observatory, a global community of more than 1,000 scientists working to better understand the quantities, movements, forms and origins of carbon inside the Earth.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science. DOE’s 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.


  • richardmitnick 12:17 pm on September 21, 2018 Permalink | Reply
    Tags: , , LLNL/LBNL team named as Gordon Bell Award finalists for work on modeling neutron lifespans, Neutron Science, , ,   

    From Lawrence Livermore National Laboratory: “LLNL/LBNL team named as Gordon Bell Award finalists for work on modeling neutron lifespans” 

    From Lawrence Livermore National Laboratory

    Sept. 20, 2018
    Jeremy Thomas

    Beta decay, the decay of a neutron (n) to a proton (p) with the emission of an electron (e) and an electron-anti-neutrino (ν). In the figure gA is depicted as the white node on the red line. The square grid indicates the lattice. Image by Evan Berkowitz/Forschungszentrum Jülich/Institut für Kernphysik /Institute for Advanced Simulation

    A team of scientists and physicists headed by the Lawrence Livermore and Lawrence Berkeley national laboratories has been named as one of six finalists for the prestigious 2018 Gordon Bell Award, one of the world’s top honors in supercomputing.

    Using the Department of Energy’s newest supercomputers, LLNL’s Sierra and Oak Ridge’s Summit, a team led by computational theoretical physicists Pavlos Vranas of LLNL and André Walker-Loud of LBNL developed an improved algorithm and code that can more precisely determine the lifetime of a neutron, an achievement that could lead to discovering new, previously unknown physics, researchers said.

    LLNL SIERRA IBM supercomputer

    ORNL IBM AC922 SUMMIT supercomputer. Credit: Carlos Jones, Oak Ridge National Laboratory/U.S. Dept. of Energy

    The team’s approach involves simulating the fundamental theory of quantum chromodynamics (QCD) on a fine grid of space-time points called the lattice. QCD theory describes how particles like quarks and gluons make up protons and neutrons.

    The lifetime of a neutron, which begins to decay after about 15 minutes, is important because it has a profound effect on the mass composition of the universe, Vranas explained. Using previous generation supercomputers at ORNL and LLNL, the team was the first to calculate the nucleon axial coupling, a figure (denoted by gA) directly related to the neutron lifetime, at 1 percent precision. Two different real-world experiments have measured neutron lifetime with results that differ at an experimental accuracy of about 0.1 percent, which researchers believe may be related to new physics affecting each experiment.

    To resolve this discrepancy, Vranas and his team have advanced their calculation onto the new generation supercomputers Sierra and Summit, aiming to improve their precision to less than 1 percent and get closer to the experimental results. The team has fully optimized their codes on the new CPU (Central Processing Unit)/GPU (Graphics Processing Unit) architectures of the two supercomputers, which involved developing an algorithm that exponentially speeds up calculations, a method for optimally distributing GPU resources and a job manager that allows CPU and GPU jobs to be interleaved.

    “New machines like Sierra and Summit are disruptively fast and require the ability to manage and process more tasks, amounting to about a factor of 10 increase. As we move toward exascale, job management is becoming a huge factor for success. With Sierra and Summit, we will be able to run hundreds of thousands of jobs and generate several petabytes of data in a few days — a volume that is too much for the current standard management methods,” said LBNL’s Walker-Loud. “The fact that we have an extremely fast GPU code (QUDA) and were able to wrap our entire lattice QCD scientific application with new job managers we wrote (METAQ and MPI_JM) got us to the Gordon Bell finalist stage, I believe.”

    The resulting axial coupling calculation, Vranas said, will provide the neutron lifetime that the fundamental theory of QCD predicts. Any deviations from the theory may be signs of new physics beyond current understanding of nature and the reach of the Large Hadron Collider.

    “We’ve demonstrated that we can use this next generation of computers efficiently, at about 15-20 percent of peak speed,” Vranas said. “This research takes us further, and now with these computers we can move forward with precision better than one percent, in an attempt to find new physics. This is an exciting time.”

    On Sierra and Summit, the team was able to reach sustained performance of about 20 petaFLOPS (FLOPS stands for floating-point operations per second), or roughly 15 percent of the peak performance for Sierra. The team discovered that the number of calculations they could do on the new machines will keep rising in a constant linear fashion, a solid indication that using more of the GPUs in the machines will result in even faster calculations. In turn this will result in producing more data and therefore to improved precision of the calculation of the neutron lifetime, researchers said.

    “Every time a new supercomputer comes along it just amazes you,” Vranas said. “These systems are significantly different than their predecessors, and it was quite an effort on the code side to make this happen. This is important science and Sierra and Summit will accelerate it in a meaningful and impactful way.”

    LLNL postdoctoral researcher Arjun Gambhir contributed to the research. Co-authors include Evan Berkowitz (Institute for Advanced Simulation, Jülich Supercomputing Centre), M.A. Clark (NVIDIA), Ken McElvain (LBNL and University of California, Berkeley), Amy Nicholson (University of North Carolina), Enrico Rinaldi (RIKEN-Brookhaven National Laboratory), Chia Cheng Chang (LBNL), Ba ́lint Joo ́ (Thomas Jefferson National Accelerator Facility), Thorsten Kurth (NERSC/LBNL) and Kostas Orginos (College of William and Mary).

    The Gordon Bell Prize is awarded each year to recognize outstanding achievements in high performance computing, with an emphasis on rewarding innovations in science applications, engineering and large-scale data analytics.

    Other finalists include an LBNL-led collaboration using exascale deep learning on Summit to identify extreme weather patterns; a team from ORNL that developed a genomics application on Summit capable of determining the genetic architectures for chronic pain and opioid addiction at up to five orders of magnitude beyond the current state-of-the-art; an ORNL team that used an artificial intelligence system to automatically develop a deep learning network on Summit capable of identifying information from raw electron microscopy data; a team from the University of Tokyo that applied artificial intelligence and trans-precision arithmetic to accelerate simulations of earthquakes in cities; and a team led by China’s Tsinghua University that developed a framework for efficiently utilizing an entire petascale system to process multi-trillion edge graphs in seconds.

    The Gordon Bell winner will be announced at the 2018 International Conference for High Performance Computing, Networking, Storage and Analysis (SC18) in Dallas this November.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    LLNL Campus

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration
    Lawrence Livermore National Laboratory (LLNL) is an American federal research facility in Livermore, California, United States, founded by the University of California, Berkeley in 1952. A Federally Funded Research and Development Center (FFRDC), it is primarily funded by the U.S. Department of Energy (DOE) and managed and operated by Lawrence Livermore National Security, LLC (LLNS), a partnership of the University of California, Bechtel, BWX Technologies, AECOM, and Battelle Memorial Institute in affiliation with the Texas A&M University System. In 2012, the laboratory had the synthetic chemical element livermorium named after it.

    LLNL is self-described as “a premier research and development institution for science and technology applied to national security.” Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

    The Laboratory is located on a one-square-mile (2.6 km2) site at the eastern edge of Livermore. It also operates a 7,000 acres (28 km2) remote experimental test site, called Site 300, situated about 15 miles (24 km) southeast of the main lab site. LLNL has an annual budget of about $1.5 billion and a staff of roughly 5,800 employees.

    LLNL was established in 1952 as the University of California Radiation Laboratory at Livermore, an offshoot of the existing UC Radiation Laboratory at Berkeley. It was intended to spur innovation and provide competition to the nuclear weapon design laboratory at Los Alamos in New Mexico, home of the Manhattan Project that developed the first atomic weapons. Edward Teller and Ernest Lawrence,[2] director of the Radiation Laboratory at Berkeley, are regarded as the co-founders of the Livermore facility.

    The new laboratory was sited at a former naval air station of World War II. It was already home to several UC Radiation Laboratory projects that were too large for its location in the Berkeley Hills above the UC campus, including one of the first experiments in the magnetic approach to confined thermonuclear reactions (i.e. fusion). About half an hour southeast of Berkeley, the Livermore site provided much greater security for classified projects than an urban university campus.

    Lawrence tapped 32-year-old Herbert York, a former graduate student of his, to run Livermore. Under York, the Lab had four main programs: Project Sherwood (the magnetic-fusion program), Project Whitney (the weapons-design program), diagnostic weapon experiments (both for the Los Alamos and Livermore laboratories), and a basic physics program. York and the new lab embraced the Lawrence “big science” approach, tackling challenging projects with physicists, chemists, engineers, and computational scientists working together in multidisciplinary teams. Lawrence died in August 1958 and shortly after, the university’s board of regents named both laboratories for him, as the Lawrence Radiation Laboratory.

    Historically, the Berkeley and Livermore laboratories have had very close relationships on research projects, business operations, and staff. The Livermore Lab was established initially as a branch of the Berkeley laboratory. The Livermore lab was not officially severed administratively from the Berkeley lab until 1971. To this day, in official planning documents and records, Lawrence Berkeley National Laboratory is designated as Site 100, Lawrence Livermore National Lab as Site 200, and LLNL’s remote test location as Site 300.[3]

    The laboratory was renamed Lawrence Livermore Laboratory (LLL) in 1971. On October 1, 2007 LLNS assumed management of LLNL from the University of California, which had exclusively managed and operated the Laboratory since its inception 55 years before. The laboratory was honored in 2012 by having the synthetic chemical element livermorium named after it. The LLNS takeover of the laboratory has been controversial. In May 2013, an Alameda County jury awarded over $2.7 million to five former laboratory employees who were among 430 employees LLNS laid off during 2008.[4] The jury found that LLNS breached a contractual obligation to terminate the employees only for “reasonable cause.”[5] The five plaintiffs also have pending age discrimination claims against LLNS, which will be heard by a different jury in a separate trial.[6] There are 125 co-plaintiffs awaiting trial on similar claims against LLNS.[7] The May 2008 layoff was the first layoff at the laboratory in nearly 40 years.[6]

    On March 14, 2011, the City of Livermore officially expanded the city’s boundaries to annex LLNL and move it within the city limits. The unanimous vote by the Livermore city council expanded Livermore’s southeastern boundaries to cover 15 land parcels covering 1,057 acres (4.28 km2) that comprise the LLNL site. The site was formerly an unincorporated area of Alameda County. The LLNL campus continues to be owned by the federal government.


    DOE Seal

  • richardmitnick 8:56 am on September 26, 2015 Permalink | Reply
    Tags: , Neutron Science,   

    From TRIUMF: “Setting the trap for Ultra-Cold Neutrons” 


    August 19, 2015

    For most of the lab, the end of the annual cyclotron shutdown period marks the beginning of a new experimental season, as beam time makes its way around the facilities.

    But for the team behind TRIUMF’s Ultra-Cold Neutron (UCN) project., it is a time to reflect on the progress that was made and assess the final steps towards realizing a first production of ultra-cold neutrons by early 2017.

    TRIUMF UCN Project

    The UCN source will produce, through a tungsten spallation target, ultra-cold neutrons, which will enable researchers to study the neutron electric dipole moment. Essentially, the team will be probing the distance of the electric charges in the neutron. This requires complex infrastructure.

    The problem: it can only be installed during the shutdown period.

    Ruediger Picker (RP), a researcher in the particle physics department and UCN project leader, spoke with Communications Assistant Kelsey Litwin (KL) to provide an update on the installation process.

    KL: During our last check-in, at the end of the 2014 annual shutdown, the UCN team had just tackled the “immovable block,” hidden underneath the support system of the M15 beam line. It had been in the direct path of the new UCN beam line, which will deliver protons to the tungsten spallation target. Can you give us a summary of what was done since then?

    RP: A lot of planning. While the front-end of the M13 beam line and the PIENU experimental areas were cleaned up, the downstream section of the UCN beam line and the kicker cable routing was planned.

    The kicker magnet for the UCN beam line is a fast ramping magnet. It ramps up and down in less than 50 microseconds. As a result, the cable to power the supply needs to be very large and heavy. The power supply sits on top of the cyclotron vault roof, while the kicker is below in the vault tunnel area. The cable therefore has to penetrate the cyclotron roof beams, needing an S curve routing to avoid radiation shine upward.

    KL: The plan for the beginning of the 2015 shutdown was to decommission the M13 beam line and prepare the experimental area. How did that go?

    RP: The decommissioning was planned between the 2014 and the 2015 shutdowns. There was a special focus was on the two dipole magnets, B1 and B2. It was decided that the active iron yoke of the B1 dipole would be used as shielding.

    During the shutdown, the B2 yoke of the dipole magnet was retrofitted to make it a shielding block, the B1 magnet was moved temporarily for later use, and the M13 beam tube has been sealed to allow pumping down to vacuum. This renders the M13 beam line fully decommissioned.

    The experimental area was cleaned up in preparation for the continued installation. As well, the kicker cable was successfully routed as we had planned and the downstream section of the UCN beam line, BL1U, was installed. Finally, the base layer of shielding below the tungsten spallation target was laid down.

    All in all, I would say that all important shutdown projects were completed successfully.

    KL: With hopes to stay on track for first beam time in late-2016/early-2017, your team certainly does not have any downtime. What is the team up to while physical work is not underway?

    RP: We are currently planning the UCN source integration. The source cryostat needs to be incorporated into the TRIUMF infrastructure, in a way that is safe and able to be controlled remotely.

    We are also designing the last three meters of the beam line, including the target crypt, which connects to the BL1U beam pipe and the target remote handling system, and the target itself. A target remote handling review was conducted in July and we will receive the review report soon.

    The schedule for finishing the target remote handling system is tight, but doable. So far, the plan is to have first beam in BL1U by mid 2016, beam on target towards the end of 2016.

    KL: You provided us with a time-lapse video of the installation taking place in the Meson Hall over a four-month period. What would you like for someone watching it to take away?

    There are four things that I would like to show people. Building a scientific apparatus is 1) a lot of real work, 2) heavy lifting, 3) still a little bit like playing with LEGO, and 4) a shame that we have to cover all the nice equipment back up after each shutdown.

    • Kelsey Litwin, Communications Assistant

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    Triumf Campus
    Triumf Campus
    World Class Science at Triumf Lab, British Columbia, Canada
    Canada’s national laboratory for particle and nuclear physics
    Member Universities:
    University of Alberta, University of British Columbia, Carleton University, University of Guelph, University of Manitoba, Université de Montréal, Simon Fraser University,
    Queen’s University, University of Toronto, University of Victoria, York University. Not too shabby, eh?

    Associate Members:
    University of Calgary, McMaster University, University of Northern British Columbia, University of Regina, Saint Mary’s University, University of Winnipeg, How bad is that !!

  • richardmitnick 3:51 pm on June 4, 2014 Permalink | Reply
    Tags: , , Neutron Science, ,   

    From SLAC: “Scientists Search for Exotic Decay with Straightforward Implications” 

    SLAC Lab

    June 4, 2014
    Lori Ann White

    Search for ‘Neutrinoless Double-beta Decay” Could Reveal Valuable Information About Neutrinos

    Two years ago researchers began using a tank of liquid xenon installed more than 2,000 feet deep in a salt formation in the southeastern corner of New Mexico to study neutrinos.

    SLAC engineers Robert Conley (left) and Knut Skarpaas VIII during the delicate task of welding the xenon vessel shut. It did not yet contain liquid xenon, but, said Skarpaas, directly behind the weld were delicate cables and light detectors which had to be protected from the heat. (Courtesy EXO-200 Collaboration)

    One half of the time projection chamber before being inserted in the xenon vessel. The time projection chamber detects both light and electrons that have been knocked loose from xenon atoms. (Courtesy EXO-200 Collaboration

    The completed xenon vessel, mounted and ready to be inserted into the cryostat that will keep the xenon in a liquid state (Courtesy EXO-200 Collaboration)

    They’re looking for clues to one of the biggest puzzles about the tiny particles: What is their mass? Finding the mass of the neutrino can help answer big questions such as how the universe grew into its present form.

    This tank of liquid xenon, located near Carlsbad, New Mexico in the Waste Isolation Pilot Plant (WIPP), is the Enriched Xenon Observatory – 200 (EXO-200), the most sensitive instrument of its kind in the world. In a progress report published in the journal Nature, the scientists of the EXO-200 experiment shared what two years of data tell them about the phenomenon they’re searching for: neutrinoless double-beta decay, one of the rarest processes in the universe. There’s currently no proof this type of particle decay takes place, but if it does, it can give scientists valuable information about neutrino mass.

    As the experiment is in the data-gathering phase, “It’s far too soon to tell the ultimate outcome of our search,” said Giorgio Gratta, Stanford physics professor and principal investigator for EXO-200. However, the experiment has achieved an almost threefold increase in sensitivity over their initial neutrinoless beta-decay search, the result of which was published in Physical Review Letters in 2012. Some of this increase can be attributed to having more data, but the team can also point to upgrades to the EXO-200 detector and software.

    Particle and Antiparticle: One and the Same ?

    The clues to neutrino mass the EXO-200 researchers are looking for are hidden in the way xenon transforms into the element barium. The isotope of xenon used by EXO-200, xenon-136, follows a rare variant of a well-known natural process called beta decay in which two neutrons decay simultaneously, emitting two electrons and two anti-neutrinos to create two protons, and one atom of xenon moves forward two spots in the Periodic Table, landing on barium.

    In one version of this process, called two-neutrino double-beta decay, all four particles from the two beta decays (two electrons and two anti-neutrinos) are emitted. EXO-200 was the first to see this in xenon-136; they published the result in Physical Review Letters in 2011.

    That leaves the possibility of neutrinoless double-beta decay, the variant EXO-200 was designed to detect. In this version the two anti-neutrinos never appear. They annihilate each other before they can escape. This would confirm to researchers that neutrinos, unlike other particles, are their own antiparticles. (The typical partners in an antimatter pair, such as electrons and positrons, have electric charge and are distinguishable; neutrinos have no charge.)

    Measuring Mass

    Zeroing in on the half-life of xenon-136 – how long it would take half the xenon-136 atoms to undergo neutrinoless double-beta decay – is also necessary because the half-life is related to the neutrino’s “effective” mass: the longer the half-life, the smaller the effective mass.

    The effective mass of a neutrino is a parameter that accounts for the process of neutrino mixing (“oscillations”) taking place among the three types, or flavors, of neutrinos, called electron neutrinos, muon neutrinos and tau neutrinos. The effective mass is a particular mix of the same mass parameters that govern neutrino oscillations – a mix specific to the process of neutrinoless double-beta decay. The EXO-200 results, as reported in Nature, are consistent with an effective mass for the neutrino ranging between 190 to 450 thousandths of an electronvolt – if it is its own antiparticle. For comparison consider the electron, which weighs in at half a million electronvolts.

    If it does exist, neutrinoless double-beta decay is one of the rarest processes in the universe. “Given two xenon-136 atoms, you could wait many, many times longer than the universe has existed before one of them decays,” said Gratta.

    To get around the “many times the current age of the universe” issue, EXO-200’s tank holds 200 kilograms of xenon – enough atoms, said Gratta, to considerably improve the team’s chances of seeing a decay. Its underground location in the salt formation helps protect it from background sources, such as cosmic rays or the radioactive signatures of other naturally decaying elements, which could also trigger the detectors.

    Getting Better at Gathering Data

    Gratta said the researchers originally planned to take data for three years, but have additional upgrades in the works that could increase the instrument’s sensitivity yet again.

    However, new upgrades will need to wait until some issues at WIPP are resolved.

    “Problems at the WIPP facility have sidelined our experiment since Feb. 5 and, while we intend to continue the program, it is unclear when we’ll be able to resume,” said SLAC physicist and EXO-200 member Peter Rowson.

    When they do, he said, the second round of upgrades is expected to significantly improve performance.

    “We’ve already tested and plan to install an upgrade to the electronics,” Gratta said; this should increase the detector’s ability to find the signals of the decay – if they exist. With other planned improvements, including a plan to reduce the natural background radiation even further, he said, the EXO-200 team looks forward to substantial further improvement in the search sensitivity from an additional three years of operation.

    See the full article here.

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

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 11:47 am on November 22, 2013 Permalink | Reply
    Tags: , , , Neutron Science, ,   

    From Fermilab: “Managing and moving massive data for NOvA” 

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Nov. 22, 2013
    Nathan Mayer, Tufts University,
    Gavin Davies, Iowa State University

    Members of the NOvA experiment, along with personnel from the Scientific Computing Division and systems administrators from participating Open Science Grid institutions, recently deployed the experiment’s large-scale C++ analysis code to run on demand on participating OSG sites. The resulting production campaign was the culmination of several months of work.

    NOvA is attempting to observe the appearance of electron neutrinos as a result of neutrino oscillations within the NuMI beam. The NOvA far detector is usually run with two main independent output-event streams, a cosmic trigger and a beam trigger, which contains the oscillated neutrino signal. The data is transferred back to Fermilab as soon as it becomes available and is cataloged and archived for permanent storage. To extract the oscillated neutrino signal from this data, it is critical to understand the cosmic-ray background in great detail. This is done through computing simulations, the focus of the computational activity on OSG.

    far detector
    NOvA Far Detector in Minnesota

    Far Detector Building

    The deployment team faced two major obstacles that they needed to overcome: deploying a consistent version of rapidly changing software to many different OSG sites and efficiently transferring large amounts of data to these sites. To overcome the first challenge, they used the CERN Virtual Machine File System. CVMFS stores an experiment’s entire software suite, including all of the external dependencies, on a set of distribution servers. As individual worker nodes require access to software libraries, they download the needed libraries and store them in a local cache. The system downloads only the software that is needed for an individual job rather than the entire suite.

    The second challenge, efficiently transferring data to sites, was tackled by using Fermilab’s file cataloging front end, using software called dCache, to its ENSTORE mass storage system. From dCache, the sequential access via metadata (SAM) data management system retrieves the input file and then transfers the files in series to the worker nodes, which process the input file. Once the processing is completed, output files are automatically transferred back to Fermilab for cataloging and archiving. The NOvA collaboration targeted the generation of 1,000,000 events — about three times as many events as have ever been produced in the past. This was achieved by running 10,000 jobs, requiring almost 90,000 CPU hours and producing 2 terabytes of data during two weeks of operations.

    NOvA’s Andrew Norman and Fermilab’s Gabriele Garzoglio spearheaded this effort, along with collaborators from Southern Methodist University, University of Nebraska-Lincoln, University of Chicago, University of California, San Diego, University of Wisconsin – Madison and FermiCloud. The lessons learned and success of these accomplishments serve as good precursors for use of the OSG by other similar experiments, such as LBNE.

    See the full article here.

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 10:57 am on August 13, 2013 Permalink | Reply
    Tags: , , , Neutron Science,   

    From ORNL Lab: “Neutrons’ view of hydrogen yields insight into HIV drug design” 

    ORNL-led study demonstrates relevance of neutrons in biomedical research

    August 13, 2013
    Morgan McCorkle

    “A new study from an international team led by the Department of Energy’s Oak Ridge National Laboratory is guiding drug designers toward improved pharmaceuticals to treat HIV. The scientists used neutrons and x-rays to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug commonly used to block virus replication.

    An ORNL-led team used neutrons to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug called amprenavir commonly used to block virus replication. The magenta mesh is the neutron scattering density map showing the exact locations of hydrogen atoms bound to oxygen atoms. The blue dashed lines represent the strongest hydrogen bonds between the drug and the enzyme. This knowledge will help researchers improve the drug’s chemistry and increase its effectiveness.No image credit.

    Using neutrons from the Institut Laue-Langevin in Grenoble, France, the researchers gained a never-before-seen view of hydrogen bonds that connect the HIV protease and the drug. Unlike x-rays, neutrons can easily detect the position of hydrogen atoms.

    ‘Knowing where hydrogen atoms are located gives researchers a much better idea about the nature and strength of the interactions,’ said lead author Andrey Kovalevsky of ORNL. ‘By applying neutron crystallography we have effectively increased the clarity of this picture, because hydrogen atoms become visible in the neutron structures. Using neutrons, we are now able to see every atom in a protein-drug complex, all the way to the smallest atom in nature.’

    The research, published in the Journal of Medicinal Chemistry, presents drug designers with a set of new potential sites for the improvement of the drug’s surface chemistry to significantly strengthen the binding, thereby increasing the effectiveness of the drugs and reducing the necessary dosages.”

    See the full article here.


    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 2:34 pm on February 28, 2013 Permalink | Reply
    Tags: , Neutron Science,   

    From ORNL: “ORNL begins implementation of new californium-252 production contract” 

    Oak Ridge National Laboratory

    Feb. 28, 2013
    Bill Cabage

    The Department of Energy’s Oak Ridge National Laboratory – home of one of only two reactor facilities in the world capable of producing californium-252 (Cf-252) – has begun implementing a new six-year contract between the DOE Isotope Program and industry to make this unique and versatile radioisotope.

    The new contract follows the successful completion of a four-year Cf-252 program under an agreement with a consortium of industries that use the neutron emitting radioisotope for a number of applications that focus mostly on analysis, detection and nuclear energy.

    ‘Californium-252 serves as a unique, portable neutron source,’ said Julie Ezold, who manages ORNL’s Cf-252 production program. ‘A cross-cut of industries including coal, oil and mineral companies rely on it for critical applications, and it is used in defense and national security applications.'”

    See the full article here.


    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science.


    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 1:54 pm on February 20, 2013 Permalink | Reply
    Tags: , , , , , Neutron Science   

    From Fermilab: “NOvA data concentrator modules near completion” 

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Wednesday, Feb. 20, 2013
    Leah Hesla

    News on Fermilab’s NOvA experiment has largely focused on the assembly of the enormous blocks that make up the football-field-sized particle detector in Minnesota. But elsewhere in the NOvA collaboration, engineers have been diligently plugging away at a more hidden-away part of the detector, a component without which the giant device would never be able to intelligibly reveal what it sees.

    The NOvA data concentrator module collects and organizes all the particle interaction information generated inside the detector. Engineers are completing the design and testing of the system. Photo: Reidar Hahn

    This crucial component is the circuitry and computer code that make up NOvA’s data concentrator modules, or DCMs. Now, after several years of design work and many months of testing and prototyping, engineers are completing the system. Nearly all that remains is for the modules to be installed onto the NOvA detector blocks as they, too, are installed.

    ‘Many people worked hard to develop a DCM system we expect to run very smoothly,’ said Fermilab’s Ron Rechenmacher, who led one of the DCM hardware-software integration efforts.

    The NOvA DCM is a key component of the detector’s data acquisition system, which is responsible for collecting and organizing all the particle interaction information generated inside NOvA’s two detectors. When a particle interacts inside the detector, its energy is transmitted through the detector’s fiber optic system as light signals, which get converted to digital signals by electronics boards, travel through the DCMs and eventually make their way to the larger data acquisition system. The electronics boards and DCM together convert the signals into language that experimenters can later analyze.

    NOvA’s DCM system comprises about 180 modules. Each of these custom modules, about the size of a briefcase, attaches to the detector. One hundred sixty-eight of them are assigned to NOvA’s far detector in Minnesota, and a dozen or so belong to the smaller near detector at Fermilab.”

    See the full article here.

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.

    ScienceSprings is powered by MAINGEAR computers

  • richardmitnick 10:55 am on February 15, 2013 Permalink | Reply
    Tags: , , , Neutron Science,   

    From Fermilab- “Frontier Science Result: MiniBooNE Nudging the community towards measuring where all the antimatter went” 

    Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

    Friday, Feb. 15, 2013
    Joe Grange

    Joe Grange, University of Florida, performed the analysis for this MiniBooNE result.

    Like many of the processes we study at Fermilab, neutrino interactions probe fundamental properties of the universe. The focus of the MiniBooNE experiment has been to identify whether muon-type neutrinos spontaneously change into electron-type neutrinos in one of the neutrino beams created at the lab, possibly implying an extra neutrino state. However, recent work on the interactions of the muon-type neutrinos themselves has proven compelling as well, and this new result provides a first look at a specific muon antineutrino interaction.

    This fundamental cross section shows the probability for a muon antineutrino to interact with a nucleon and produce a positively charged muon and any number of nucleons. For the first time, the MiniBooNE experiment has been able to split this measurement into a function of muon energy and scattering angle. By directly measuring the muon kinematics, these new data offer unprecedented insight into the behavior of the muon in antineutrino CCQE [(traditionally called a charged current quasi-elastic, or CCQE, interaction)]interactions. No image credit

    In 2010, MiniBooNE released the first measurement of the cross section for muon-type neutrinos to elastically interact with a neutron to produce a muon and nucleons (traditionally called a charged current quasi-elastic, or CCQE, interaction) as a function of both muon energy and production angle relative to the incoming neutrino.

    The new data presented here provides the world’s first look at how muon antineutrinos behave in similar reactions. Like the neutrino-based measurement of 2010, this antineutrino result also contributes to our knowledge of nuclear physics processes. Together, these measurements significantly advance the preparedness of the community to search for new physics with neutrinos.”

    See the full article here. Follow the links for added information.

    Fermilab Campus

    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics.

    ScienceSprings is powered by MAINGEAR computers

Compose new post
Next post/Next comment
Previous post/Previous comment
Show/Hide comments
Go to top
Go to login
Show/Hide help
shift + esc
%d bloggers like this: