Neutron Science In the News – 2014

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ORNL watches FY 2015 budget; stall could hurt neutron sources

Knoxville News Sentinel 11/29

Since Oct. 1, the beginning of fiscal year 2015, Oak Ridge National Laboratory -- like other federal installations -- has operated under a continuing budget resolution that freezes spending at 2014 levels.

So far, so good, according to ORNL Director Thom Mason, but he expressed concern about impacts later in the year if Congress doesn't pass an actual budget. The continuing resolution approved in September is due to expire Dec. 11 and could be extended if there's no budget agreement.

In a recent interview, Mason said the lab wasn't expecting big funding increases for FY2015, but the areas of most concern are the neutron sources -- the Spallation Neutron Source and the High Flux Isotope Reactor. They are two of the most widely used scientific resources at the Oak Ridge laboratory, and the SNS only recently restarted after being shut down for most of the fall because of repeated problems with the target vessel -- a key component in producing neutrons -- and other issues.

Neutrons galore at ORNL

Knoxville News Sentinel 11/21

The Spallation Neutron Source has returned to action and is providing neutrons for research experiments for the first time in a month, and officials hope there will be sustained operations for the first time since summer.

Oak Ridge National Laboratory Director Thom Mason said Wednesday that the SNS had been restarted at low power, and Associate Lab Director Ron Crone said the SNS resumed neutron production at 7 a.m. on Thursday "after addressing the recent target failures."

Crone said the High Flux Isotope Reactor, ORNL's other neutron source, also is operating again following an 18-day maintenance and refueling outage.

Accepting the SNS challenge: Lab works to overcome problems, restart experiments

Knoxville News Sentinel 11/15

These are tough times at the Spallation Neutron Source, which hasn't produced neutrons -- its reason for being -- on a regular basis since summer.

The shutdown has brought important experiments, exploring the very essence of materials and how they behave and interact with other materials, to a standstill.

But scientists and engineers are problem-solvers at heart, and the mood was surprisingly upbeat last week as they talked about what's gone wrong and how they hope to fix it.

ORNL Researchers Calculate Thermodynamic Forces Driving Transformation of Vanadium Oxide

AzoMaterials 11/12

Researchers from the Oak Ridge National Laboratory (ORNL) of the Department of Energy have made a breakthrough in comprehending vanadium oxide, a typical transition metal oxide, by calculating the thermodynamic forces that cause the transformation.

The results have been recorded in Nature, November 10, online issue. John Budai co-led the study with Jiawang Hong, a colleague in the Materials Science and Technology Division of ORNL.

Vanadium oxide enhances storage media and recording, improves strength of structural alloys and provides color to synthetic jewels. In the future it may be used as optical shutters turning opaque on satellites to hinder obtrusive signals, nanoscale actuators for switches and field-effect transistors for electronics manipulation in spintronics and semiconductors in devices maneuvering magnetic spin.


Big maintenance at High Flux Isotope Reactor

Knoxville News Sentinel 10/17

The High Flux Isotope Reactor returned to operation last week following a 38-day outage for refueling and maintenance, one of the longest of the year. According to Oak Ridge National Laboratory's reactor chief, Tim Powers, it was a productive outage and "very busy."

Workers installed a third digital instrument that monitors the neutron power level in the reactor core; replaced cables that supply power to the Cooling Tower Fans; and performed surveillance tests and inspections on a number of systems, including emergency power supply, ventilation filtration and reactor protection.

Neutron production resumes at SNS

Knoxville News Sentinel 10/17

After being shut down for more than a month because of multiple problems, the Spallation Neutron Source has resumed production of neutrons for research experiments.

Kevin Jones, director of the Oak Ridge National Laboratory's Research Acceleration Division, said the SNS systems were restarted over the weekend -- with neutron production resuming shortly before 6 a.m. Sunday.

The Spallation Neutron Source is one of the world's premier facilities for using neutrons to explore the properties and structure of materials, and it attracts scientists from around the United States and abroad. About 150 experiments reportedly had to be rescheduled because of the unplanned outage at the ORNL research complex atop Chestnut Ridge.

How magnetic dimers interact to create long-range order

PhysOrg 10/13

Researchers carrying out experiments at the U.S. Department of Energy's Advanced Photon Source (APS) and Spallation Neutron Source have shed new light on how magnetic long-range order forms and remains stable despite the presence of disruptive quantum fluctuations. Since the material under study, SrCu2(BO3)2 (SCBO), bears important similarities to layered Cu-O compounds that exhibit high-temperature superconductivity, the research, published in the Proceedings of the National Academy of Sciences of the United States of America, may provide insights into this form of quantum magnets as well, which has eluded thorough understanding for nearly 30 years.

The data showed that the antiferromagnetic state of SCBO becomes stabilized through subtle dimer contractions, elongations, and tilts, which impact the relative strengths of the intra-dimer and inter-dimer couplings.


Smallest-possible Diamonds Form Ultra-thin Nanothread

Carnegie Science 9/25

A team including Carnegie's Malcolm Guthrie and George Cody has, for the first time, discovered how to produce ultra-thin "diamond nanothreads" that promise extraordinary properties, including strength and stiffness greater than that of today's strongest nanotubes and polymer fibers. Such exceedingly strong, stiff, and light materials have an array of potential applications, everything from more fuel efficient vehicles or even the science fictional-sounding proposal for a "space elevator." Their work is published in Nature Materials.

"We used the large high-pressure Paris-Edinburgh device at Oak Ridge National Laboratory to compress a 6-millimeter-wide amount of benzene-a gigantic amount compared with previous experiments," said Guthrie. "We discovered that slowly releasing the pressure after sufficient compression at normal room temperature gave the carbon atoms the time they needed to react with each other and to link up in a highly ordered chain of single-file carbon tetrahedrons, forming these diamond-core nanothreads."

Research team aims to improve plant-based battery with neutrons, simulation

PhysOrg 9/18

When Orlando Rios first started analyzing samples of carbon fibers made from a woody plant polymer known as lignin, he noticed something unusual. The material's microstructure - a mixture of perfectly spherical nanoscale crystallites distributed within a fibrous matrix - looked almost too good to be true.

"I thought, this looks like a material that people would go through a lot of work modifying graphite to make it look this way," said Rios, a materials scientist at the Department of Energy's Oak Ridge National Laboratory. "It had a really distinct microstructure from any other graphite I'd seen."

Rios and his colleagues soon realized the lignin fiber's unique structure could make it useful as a battery anode, potentially improving upon graphitic materials found in most lithium-ion batteries. Lignin, a low-cost byproduct of the pulp, paper and biofuels industries, could be transformed into a cheaper version of highly engineered graphite through a simple and industrially scalable manufacturing process.

Spallation Neutron Source shut down prematurely; problem with newly installed target

Knoxville News Sentinel 9/15

The Spallation Neutron Source returned to operation Aug. 15 following its annual five-week summer maintenance period, but the SNS was shut down prematurely late last week after a problem was identified with a new target vessel that had been installed during the summer outage.

"We have begun the target replacement process, and should resume operation for users within two weeks," Ron Crone, assistant lab director, said via email. "Users who were scheduled during this unplanned down time have been notified; we are working to accommodate them by rescheduling their beam time."

The exact cause of the target failure has not been determined at this point, but it could be related to a new design for the vessel. "As part of our plans for continuous improvement, we installed a target with a modified design that included a new internal mercury flow pattern intended to minimize the internal cavitation damage at higher power operation," Crone said.

Imaging fuel injectors with neutrons

PhysOrg 9/15

Blowing bubbles may be fun for kids, but for engineers, bubbles can disrupt fluid flow and damage metal.

Researchers from the Fuels, Engines and Emissions Research Center at the Department of Energy's Oak Ridge National Laboratory and collaborators from ORNL's High Flux Isotope Reactor - a DOE Office of Science User Facility - are using neutrons to study the formation of these damage-causing bubbles in fuel injectors.

This team is attempting to make the first-ever neutron images of cavitation, the physical event that leads to bubble/gas formation, inside the body of a gasoline fuel injector. In August, they conducted their research at HFIR's CG-1D beam line, which is used for neutron radiography and computed tomography, to non-destructively study the internal structure of the fuel injector. With data in hand, they will be diving deep into the analysis of the images to identify both the location and the timing of the cavitation.

"We can measure the spray of a fuel injector using X-rays, but imaging the internal structure in operation is very challenging," said Hassina Bilheux, HFIR instrument scientist for CG-1D.

HFIR named Nuclear Historic Landmark; sixth ORNL facility to be designated

Knoxville News Sentinel 9/11

Oak Ridge National Laboratory's High Flux Isotope Reactor has been designated a Nuclear Historic Landmark by the American Nuclear Society.

The HFIR is the sixth facility at ORNL to gain that designation.

The 85-megawatt research reactor, which was built in the 1960s, remains an important part of the lab's research activities and production of radioisotopes for medicine, research and industry.

Here's what ORNL Director Thom Mason said in a statement: "This designation from the ANS recognizes HFIR's role in the history of the nuclear age, but it also speaks to the excellence of its design and operation. HFIR remains one of the world's most capable reactor-based neutron science, radioisotope production and materials irradiation facilities, and we expect that to continue for many years."


HFIR's fuel conversion seeming less likely

Knoxville News Sentinel 8/27

Despite its age, the High Flux Isotope Reactor is considered one of Oak Ridge National Laboratory's most valuable assets.

The High Flux Isotope Reactor was built in the 1960s. That's pretty old by reactor standards. But the HFIR has undergone a significant makeover in recent years - replacement parts, infrastructure upgrades and new research capabilities - and lab officials have stated their intention to operate the 85-megawatt reactor for decades to come.

It's apparently good to go.

One lingering question: When will Oak Ridge National Laboratory convert the reactor to use a lower-enriched uranium fuel?


ORNL, UTGSM Study Compares Structures of Huntington's Disease Protein

Newswise 7/16

Neutron scattering research at the Department of Energy's Oak Ridge National Laboratory has revealed clear structural differences in the normal and pathological forms of a protein involved in Huntington's disease.

Huntington's disease, an incurable neurodegenerative disorder, starts as a genetic mutation that leads to an overabundance of "huntingtin" protein fragments, which form clumps in the brain.

Valerie Berthelier of the University of Tennessee Graduate School of Medicine, who co-led the study published in Biophysical Journal with ORNL's Chris Stanley, said the goal was to establish a baseline understanding of huntingtin's structure in order to eventually determine the true structural basis of Huntington's disease.

Thom Mason on SNS expansion: 'Even in tough times, you need to be doing new things in science'

Knoxville News Sentinel 7/15

This is perceived to be a pretty tough time to get new projects funded in Congress, but Oak Ridge National Laboratory Director Thom Mason said there's still a plan to get started on an expansion of the Spallation Neutron Source sometime in the next two to four years.

The SNS expansion, which would include a second target facility and essentially double the research capabilities, has already received a preliminary blessing from the U.S. Department of Energy. DOE last year approved "Critical Decision-0," which means the agency agreed there is a "mission need" for the project.

Early estimates suggest that the expansion could cost a billion dollars or more, almost as much as the original SNS price tag of $1.4 billion.

SNS achieves a big milestone: full power

Knoxville News Sentinel 7/13

The Spallation Neutron Source is operating like it should, and that is not as simple as it sounds. Last month, eight years after construction was completed and seven years after operations began, the SNS finally achieved the beam power for which it was designed: 1.4 megawatts. Even at lower power levels, the accelerator-based center for materials research set all sorts of records, and scientists from around the globe flocked to Oak Ridge to do experiments with the richest source of neutrons available. It has been a productive journey, but even more is expected with the higher beam power.

Kevin Jones, who heads the Research Accelerators Division at Oak Ridge National Laboratory, noted that the SNS actually reached 1.4 megawatts last September, for about 30 minutes, but the system was too unstable to continue.

For the first time, the accelerator-based pulsed neutron source operated steadily for users at its baseline design power of 1.4 megawatts on June 26.

"Over the past year, we have implemented technical and operational improvements to provide stable operation at 1.4 MW with little operating margin," said Kevin Jones, director of ORNL's Research Accelerators Division. "This achievement is the result of a lot of hard work by the dedicated and talented staff of our division."

A record-breaking month for ORNL's Spallation Neutron Source

PhysOrg 7/3

The Spallation Neutron Source at the Department of Energy's Oak Ridge National Laboratory broke records for sustained beam power level as well as for integrated energy and target lifetime in the month of June.

For the first time, the accelerator-based pulsed neutron source operated steadily for users at its baseline design power of 1.4 megawatts on June 26.

"Over the past year, we have implemented technical and operational improvements to provide stable operation at 1.4 MW with little operating margin," said Kevin Jones, director of ORNL's Research Accelerators Division. "This achievement is the result of a lot of hard work by the dedicated and talented staff of our division."


Czech ambassador tours ORNL

Oak Ridge Today 6/14

Oak Ridge National Laboratory on Friday hosted a visit by Petr Gandalovic, ambassador of The Czech Republic.

The ambassador toured ORNLs High Flux Isotope Reactor and facilities for advanced reactor materials development and testing. He met with ORNL Director Thom Mason and held discussions with lab staff on topics including fluoride salt-cooled high-temperature reactors and the Consortium for Advanced Simulation of Light Water Reactors.


Superheavy element 117 confirmed

PhysOrg 5/2

The stage is set for a new, super-heavy element to be added to the periodic table following research published in the latest Physics Review Letters. Led by researchers at Germany's GSI laboratory, the team created atoms of element 117, matching the heaviest atoms ever observed, which are 40 per cent heavier than an atom of lead.

The periodic table of the elements is to get crowded towards its heaviest members. Evidence for the artificial creation of element 117 has recently been obtained at the GSI Helmholtz Centre for Heavy Ion Research, an accelerator laboratory located in Darm-stadt, Germany.

In a powerful example of international collaboration, this new measurement required close coordination between the accelerator and detection capabilities at GSI in Germany and the unique actinide isotope production and separation facilities at Oak Ridge National Laboratory (ORNL) in the U.S. The special berkelium target material, essential for the synthesis of element 117, was produced over an 18-month-long campaign. This required intense neutron irradiation at ORNL's High Flux Isotope Reactor, followed by chemical separation and purification at ORNL's Radiochemical Engineering Development Center.


First view of nature-inspired catalyst after ripping hydrogen apart provides insights for better, cheaper fuel cells

PhysOrg 4/23

Like a hungry diner ripping open a dinner roll, a fuel cell catalyst that converts hydrogen into electricity must tear open a hydrogen molecule. Now researchers have captured a view of such a catalyst holding onto the two halves of its hydrogen feast. The view confirms previous hypotheses and provides insight into how to make the catalyst work better for alternative energy uses.

"The combined amount of carbon in vegetation and the atmosphere is only half of the carbon stored in soils," said Melanie Mayes of ORNL's Environmental Sciences Division. "How quickly that carbon moves in and out of soils is one of the big uncertainties in modeling the carbon cycle."

This study is the first time scientists have shown precisely where the hydrogen halves end up in the structure of a molecular catalyst that breaks down hydrogen, the team reported online April 22 in Angewandte Chemie International Edition. The design of this catalyst was inspired by the innards of a natural protein called a hydrogenase enzyme.

"The catalyst shows us what likely happens in the natural hydrogenase system," said Morris Bullock of the Department of Energy's Pacific Northwest National Laboratory. "The catalyst is where the action is, but the natural enzyme has a huge protein surrounding the catalytic site. It would be hard to see what we have seen with our catalyst because of the complexity of the protein."


Researchers use neutrons, simulations to examine soil carbon

PhysOrg 3/31

Carbon dioxide in the atmosphere may get the lion's share of attention in climate change discussions, but the biggest repository of carbon is actually underfoot: soils store an estimated 2.5 trillion tons of carbon in the form of organic matter.

"The combined amount of carbon in vegetation and the atmosphere is only half of the carbon stored in soils," said Melanie Mayes of ORNL's Environmental Sciences Division. "How quickly that carbon moves in and out of soils is one of the big uncertainties in modeling the carbon cycle."

With an eye on the big picture, Mayes and her colleagues are taking a closer look at soil carbon by studying nanoscale interactions between organic matter and minerals in soil. The team's novel combination of neutron analysis and supercomputer simulations is providing experimental and theoretical data that challenge long-held assumptions in soil science.


Multiphysics Simulations Transmuting Designs for Safer Nuclear Power 1/7

Like the rest of the US's nuclear research reactors, Oak Ridge National Lab's (ORNL) high flux isotope reactor (HFIR) is moving from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU). As such, the safety of the system must be assessed to incorporate the changes in fuel properties and the subsequently modified fuel plate.

Due to the recent growth in multiphysics, fluid-structure dynamics calculations can be coupled using a fluid-structure interaction (FSI) solver. The FSI solver is the key to the analysis of the HFIR system. Due to a built-in fully coupled FSI solver, and implicit solution capabilities, ORNL chose COMSOL to obtain their stable and precise solution.

Comprehensive phonon "map" offers direction for engineering new thermoelectric devices

R&D Magazine 1/9

If you've ever been stuck in traffic on a hot, sunny afternoon, you might have noticed the rippling effect caused by the release of even hotter exhaust fumes. If so, you've watched opportunity drift away.

Automobiles, power plants, laptops and many other machines produce heat when they operate. Waste heat is an unavoidable energy loss, a tradeoff in order to produce the kind of energy for which the machine is intended. However, this heat could be partly recycled into electrical energy through thermoelectric technology, which converts a temperature difference into an electric voltage.

To understand how to design better thermoelectric materials, researchers are using neutron scattering at the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR) at the U.S. Dept. of Energy (DOE)'s Oak Ridge National Laboratory (ORNL) to study how silver antimony telluride is able to effectively prevent heat from propagating through it on the microscopic level. Heat in materials is carried by quantized sound waves, known to scientists as phonons. By mapping the phonons and their interactions with the atomic architecture of silver antimony telluride, researchers in ORNL's Quantum Condensed Matter and Materials Science groups discovered that a complex structure of nanoscale domains improved the thermoelectric properties of this compound.