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Fungal Enzymes Team Up to More Efficiently Break Down Cellulose

Cost-effectively breaking down bioenergy crops into sugars that can then be converted into fuel is a barrier to commercially producing sustainable biofuels. Enabled by DOE User Facilities, a team reports that early lineages of fungi can form enzyme complexes capable of degrading plant biomass.

Argonne Scientists Make Vanadium Into a Useful Catalyst for Hydrogenation

In a new study, Argonne chemist Max Delferro boosted and analyzed the unprecedented catalytic activity of an element called vanadium for hydrogenation - a reaction that is used for making everything from vegetable oils to petrochemical products to vitamins.

Printed, Flexible and Rechargeable Battery Can Power Wearable Sensors

Nanoengineers at the University of California San Diego have developed the first printed battery that is flexible, stretchable and rechargeable. The zinc batteries could be used to power everything from wearable sensors to solar cells and other kinds of electronics. The work appears in the April 19, 2017 issue of Advanced Energy Materials.

Neutrons Provide the First Nanoscale Look at a Living Cell Membrane

A research team from the Department of Energy's Oak Ridge National Laboratory has performed the first-ever direct nanoscale examination of a living cell membrane. In doing so, it also resolved a long-standing debate by identifying tiny groupings of lipid molecules that are likely key to the cell's functioning.

How X-Rays Helped to Solve Mystery of Floating Rocks

Experiments at Berkeley Lab's Advanced Light Source have helped scientists to solve a mystery of why some rocks can float for years in the ocean, traveling thousands of miles before sinking.

Special X-Ray Technique Allows Scientists to See 3-D Deformations

In a new study published last Friday in Science, researchers at Argonne used an X-ray scattering technique called Bragg coherent diffraction imaging to reconstruct in 3-D the size and shape of grain defects. These defects create imperfections in the lattice of atoms inside a grain that can give rise to interesting material properties and effects.

Neptune: Neutralizer-Free Plasma Propulsion

The most established plasma propulsion concepts are gridded-ion thrusters that accelerate and emit a larger number of positively charged particles than those that are negatively charged. To enable the spacecraft to remain charge-neutral, a "neutralizer" is used to inject electrons to exactly balance the positive ion charge in the exhaust beam. However, the neutralizer requires additional power from the spacecraft and increases the size and weight of the propulsion system. Researchers are investigating how the radio-frequency self-bias effect can be used to remove the neutralizer altogether, and they report their work in this week's Physics of Plasmas.

Report Sheds New Insights on the Spin Dynamics of a Material Candidate for Low-Power Devices

In a report published in Nano LettersArgonne researchers reveal new insights into the properties of a magnetic insulator that is a candidate for low-power device applications; their insights form early stepping-stones towards developing high-speed, low-power electronics that use electron spin rather than charge to carry information.

Researchers Find Computer Code That Volkswagen Used to Cheat Emissions Tests

An international team of researchers has uncovered the mechanism that allowed Volkswagen to circumvent U.S. and European emission tests over at least six years before the Environmental Protection Agency put the company on notice in 2015 for violating the Clean Air Act. During a year-long investigation, researchers found code that allowed a car's onboard computer to determine that the vehicle was undergoing an emissions test.

Physicists Discover That Lithium Oxide on Tokamak Walls Can Improve Plasma Performance

A team of physicists has found that a coating of lithium oxide on the inside of fusion machines known as tokamaks can absorb as much deuterium as pure lithium can.


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University of Wisconsin-Milwaukee Joins Energy-Focused National Science Foundation Research Center

The University of Wisconsin-Milwaukee is joining a National Science Foundation-backed research center that will develop new technologies for storing, controlling and distributing energy that could ward off cybersecurity threats and lower energy bills.

Rensselaer Polytechnic Institute Graduates Urged to Embrace Change at 211th Commencement

Describing the dizzying pace of technological innovation, former United States Secretary of Energy Ernest J. Moniz urged graduates to "anticipate career change, welcome it, and manage it to your and your society's benefit" at the 211th Commencement at Rensselaer Polytechnic Institute (RPI) Saturday.

ORNL Welcomes Innovation Crossroads Entrepreneurial Research Fellows

Oak Ridge National Laboratory today welcomed the first cohort of innovators to join Innovation Crossroads, the Southeast region's first entrepreneurial research and development program based at a U.S. Department of Energy national laboratory.

Department of Energy Secretary Recognizes Argonne Scientists' Work to Fight Ebola, Cancer

Two groups of researchers at Argonne earned special awards from the office of the U.S. Secretary of Energy for addressing the global health challenges of Ebola and cancer.

Jefferson Science Associates, LLC Recognized for Leadership in Small Business Utilization

Jefferson Lab/Jefferson Science Associates has a long-standing commitment to doing business with and mentoring small businesses. That commitment and support received national recognition at the 16th Annual Dept. of Energy Small Business Forum and Expo held May 16-18, 2017 in Kansas City, Mo.

Rensselaer Polytechnic Institute President's Commencement Colloquy to Address "Criticality, Incisiveness, Creativity"

To kick off the Rensselaer Polytechnic Institute Commencement weekend, the annual President's Commencement Colloquy will take place on Friday, May 19, beginning at 3:30 p.m. The discussion, titled "Criticality, Incisiveness, Creativity," will include the Honorable Ernest J. Moniz, former Secretary of Energy, and the Honorable Roger W. Ferguson Jr., President and CEO of TIAA, and will be moderated by Rensselaer President Shirley Ann Jackson.

ORNL, University of Tennessee Launch New Doctoral Program in Data Science

The Tennessee Higher Education Commission has approved a new doctoral program in data science and engineering as part of the Bredesen Center for Interdisciplinary Research and Graduate Education.

SurfTec Receives $1.2 Million Energy Award to Develop Novel Coating

The Department of Energy has awarded $1.2 million to SurfTec LLC, a company affiliated with the U of A Technology Development Foundation, to continue developing a nanoparticle-based coating to replace lead-based journal bearings in the next generation of electric machines.

Ames Laboratory Scientist Inducted Into National Inventors Hall of Fame

Iver Anderson, senior metallurgist at Ames Laboratory, has been inducted into the National Inventors Hall of Fame.

DOE HPC4Mfg Program Funds 13 New Projects to Improve U.S. Energy Technologies Through High Performance Computing

A U.S. Department of Energy (DOE) program designed to spur the use of high performance supercomputers to advance U.S. manufacturing is funding 13 new industry projects for a total of $3.9 million.


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Casting a Wide Net

Designed molecules will provide positive impacts in energy production by selectively removing unwanted ions from complex solutions.

New Software Tools Streamline DNA Sequence Design-and-Build Process

Enhanced software tools will accelerate gene discovery and characterization, vital for new forms of fuel production.

The Ultrafast Interplay Between Molecules and Materials

Computer calculations by the Center for Solar Fuels, an Energy Frontier Research Center, shed light on nebulous interactions in semiconductors relevant to dye-sensitized solar cells.

Supercapacitors: WOODn't That Be Nice

Researchers at Nanostructures for Electrical Energy Storage, an Energy Frontier Research Center, take advantage of nature-made materials and structure for energy storage research.

Groundwater Flow Is Key for Modeling the Global Water Cycle

Water table depth and groundwater flow are vital to understanding the amount of water that plants transmit to the atmosphere.

Finding the Correct Path

A new computational technique greatly simplifies the complex reaction networks common to catalysis and combustion fields.

Opening Efficient Routes to Everyday Plastics

A new material from the Inorganometallic Catalyst Design Center, an Energy Frontier Research Center, facilitates the production of key industrial supplies.

Fight to the Top: Silver and Gold Compete for the Surface of a Bimetallic Solid

It's the classic plot of a buddy movie. Two struggling bodies team up to drive the plot and do good together. That same idea, when it comes to metals, could help scientists solve a big problem: the amount of energy consumed by making chemicals.

Saving Energy Through Light Control

New materials, designed by researchers at the Center for Excitonics, an Energy Frontier Research Center, can reduce energy consumption with the flip of a switch.

Teaching Perovskites to Swim

Scientists at the ANSER Energy Frontier Research Center designed a two-component layer protects a sunlight-harvesting device from water and heat.


Saturday May 20, 2017, 12:05 PM

Rensselaer Polytechnic Institute Graduates Urged to Embrace Change at 211th Commencement

Rensselaer Polytechnic Institute (RPI)

Monday May 15, 2017, 01:05 PM

ORNL, University of Tennessee Launch New Doctoral Program in Data Science

Oak Ridge National Laboratory

Friday April 07, 2017, 11:05 AM

Champions in Science: Profile of Jonathan Kirzner

Department of Energy, Office of Science

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High-Schooler Solves College-Level Security Puzzle From Argonne, Sparks Interest in Career

Argonne National Laboratory

Tuesday March 28, 2017, 12:05 PM

Champions in Science: Profile of Jenica Jacobi

Department of Energy, Office of Science

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Great Neck South High School Wins Regional Science Bowl at Brookhaven Lab

Brookhaven National Laboratory

Wednesday February 15, 2017, 04:05 PM

Middle Schoolers Test Their Knowledge at Science Bowl Competition

Argonne National Laboratory

Friday January 27, 2017, 04:00 PM

Haslam Visits ORNL to Highlight State's Role in Discovering Tennessine

Oak Ridge National Laboratory

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Internship Program Helps Foster Development of Future Nuclear Scientists

Oak Ridge National Laboratory

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More Than 12,000 Explore Jefferson Lab During April 30 Open House

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Giving Back to National Science Bowl

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NMSU Undergrad Tackles 3D Particle Scattering Animations After Receiving JSA Research Assistantship

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Shannon Greco: A Self-Described "STEM Education Zealot"

Princeton Plasma Physics Laboratory

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Meet Robert Palomino: 'Give Everything a Shot!'

Brookhaven National Laboratory

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University of Utah Makes Solar Accessible

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Student Innovator at Rensselaer Polytechnic Institute Seeks Brighter, Smarter, and More Efficient LEDs

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Friday November 16, 2012, 10:00 AM

Texas Tech Energy Commerce Students, Community Light up Tent City

Texas Tech University

Wednesday November 23, 2011, 10:45 AM

Don't Get 'Frosted' Over Heating Your Home This Winter

Temple University

Wednesday July 06, 2011, 06:00 PM

New Research Center To Tackle Critical Challenges Related to Aircraft Design, Wind Energy, Smart Buildings

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Friday April 22, 2011, 09:00 AM

First Polymer Solar-Thermal Device Heats Home, Saves Money

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Like Superman, American University Will Get Its Energy from the Sun

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Thursday February 10, 2011, 05:00 PM

ARRA Grant to Help Fund Seminary Building Green Roof

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UC San Diego Installing 2.8 Megawatt Fuel Cell to Anchor Energy Innovation Park

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Monday November 01, 2010, 12:50 PM

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New Model of Plasma Stability Could Help Researchers Predict and Avoid Disruptions in Fusion Machines

Article ID: 674483

Released: 2017-05-10 15:05:27

Source Newsroom: Princeton Plasma Physics Laboratory

  • Credit: Elle Starkman

    Physicists Steve Sabbagh and Jack Berkery in front of the National Spherical Torus Experiment (NSTX-U)

  • Credit: Elle Starkman

    Physicist Steve Sabbagh

  • Credit: Elle Starkman

    Physicist Jack Berkery

Physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have helped develop a new computer model of plasma stability in doughnut-shaped fusion machines known as tokamaks. The new model incorporates recent findings gathered from related research efforts and simplifies the physics involved so computers can process the program more quickly. The model could help scientists predict when a plasma might become unstable and then avoid the underlying conditions.

This research was reported in a paper published in Physics of Plasmas in February 2017, and received funding from the DOE’s Office of Science (Fusion Energy Sciences).

The plasma stability code was written in part by Jack Berkery, a research scientist in the Applied Physics and Applied Mathematics Department at Columbia University who has been associated with PPPL for almost 10 years. He is working on this project with Steve Sabbagh, a senior research scientist and adjunct professor of applied physics at Columbia who has collaborated with PPPL for almost three decades. Both Berkery and Sabbagh are part of the Columbia group at PPPL.

The new research is the latest in the physicists’ combined effort to develop a larger and more capable plasma-stabilizing computer program known as the Disruption Event Characterization and Forecasting (DECAF) code that will predict and help avoid disruptions.

Within tokamak plasmas, many forces balance to create a stable equilibrium. One force is an expanding pressure created by the intrinsic properties of the plasma — a soup of electrically charged particles. Another force is produced by magnets that confine the plasma, preventing it from touching the tokamak’s inner walls and cooling down.

Plasma physicists and engineers want the plasma to be under as much magnetic pressure as possible, because high pressure means that the plasma particles are interacting more frequently, increasing both the chances that fusion reactions will occur and the amount of heat produced by the tokamak. Past research by Berkery and Sabbagh on machines including the National Spherical Torus Experiment-Upgrade (NSTX-U) at PPPL has shown that high plasma pressure can be contained in a stable way if other properties of the plasma, like the way in which it rotates, have particular characteristics.

“Ideally, you want to operate tokamaks at high pressure because to get good fusion performance, you want to have the highest pressure you can,” Berkery continued. “Unfortunately, when you do that, instabilities can arise. So if you can find a way to stabilize the plasma, then you can operate your tokamak at a higher pressure.”

The updated program was written to predict the conditions that would best contain the high-pressure plasma. The program, though, is only one component of the DECAF code, which includes many modules that each monitor different aspects of a plasma in an effort to determine when the plasma is becoming unstable. “For years, we’ve been investigating which conditions lead to instability and how we can try to avoid those conditions,” Berkery said.

The code gathers information that includes the plasma’s density, temperature, and the shape of the plasma’s rotation. It then calculates which combinations of these conditions produce a stable plasma, simultaneously uncovering which combinations of conditions produce an unstable plasma. The new code specifically looks for signs of an oncoming unstable state known as a resistive wall mode. A plasma enters this state when forces causing the plasma to expand are stronger than the forces confining the plasma. The plasma’s intrinsic magnetic fields then expand outward and strike the interior of the tokamak’s walls. 

Sabbagh, Berkery, and other researchers are now in the process of adding more modules to DECAF, increasing its ability to predict instabilities. They are also planning to use DECAF to help guide a rotation-control system on a tokamak like NSTX-U. The system would prevent the plasma from becoming unstable by producing stability-conducive plasma rotation profiles.

PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single 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