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  • richardmitnick 6:01 pm on November 26, 2014 Permalink | Reply
    Tags: , , , Energy,   

    From Caltech: “New Technique Could Harvest More of the Sun’s Energy” 

    Caltech Logo
    Caltech

    11/26/2014
    Jessica Stoller-Conrad

    As solar panels become less expensive and capable of generating more power, solar energy is becoming a more commercially viable alternative source of electricity. However, the photovoltaic cells now used to turn sunlight into electricity can only absorb and use a small fraction of that light, and that means a significant amount of solar energy goes untapped.

    A new technology created by researchers from Caltech, and described in a paper published online in the October 30 issue of Science Express, represents a first step toward harnessing that lost energy.

    m
    An ultra-sensitive needle measures the voltage that is generated while the nanospheres are illuminated.
    Credit: AMOLF/Tremani – Figure: Artist impression of the plasmo-electric effect.

    Sunlight is composed of many wavelengths of light. In a traditional solar panel, silicon atoms are struck by sunlight and the atoms’ outermost electrons absorb energy from some of these wavelengths of sunlight, causing the electrons to get excited. Once the excited electrons absorb enough energy to jump free from the silicon atoms, they can flow independently through the material to produce electricity. This is called the photovoltaic effect—a phenomenon that takes place in a solar panel’s photovoltaic cells.

    Although silicon-based photovoltaic cells can absorb light wavelengths that fall in the visible spectrum—light that is visible to the human eye—longer wavelengths such as infrared light pass through the silicon. These wavelengths of light pass right through the silicon and never get converted to electricity—and in the case of infrared, they are normally lost as unwanted heat.

    “The silicon absorbs only a certain fraction of the spectrum, and it’s transparent to the rest. If I put a photovoltaic module on my roof, the silicon absorbs that portion of the spectrum, and some of that light gets converted into power. But the rest of it ends up just heating up my roof,” says Harry A. Atwater, the Howard Hughes Professor of Applied Physics and Materials Science; director, Resnick Sustainability Institute, who led the study.

    Now, Atwater and his colleagues have found a way to absorb and make use of these infrared waves with a structure composed not of silicon, but entirely of metal.

    The new technique they’ve developed is based on a phenomenon observed in metallic structures known as plasmon resonance. Plasmons are coordinated waves, or ripples, of electrons that exist on the surfaces of metals at the point where the metal meets the air.

    While the plasmon resonances of metals are predetermined in nature, Atwater and his colleagues found that those resonances are capable of being tuned to other wavelengths when the metals are made into tiny nanostructures in the lab.

    “Normally in a metal like silver or copper or gold, the density of electrons in that metal is fixed; it’s just a property of the material,” Atwater says. “But in the lab, I can add electrons to the atoms of metal nanostructures and charge them up. And when I do that, the resonance frequency will change.”

    “We’ve demonstrated that these resonantly excited metal surfaces can produce a potential”—an effect very similar to rubbing a glass rod with a piece of fur: you deposit electrons on the glass rod. “You charge it up, or build up an electrostatic charge that can be discharged as a mild shock,” he says. “So similarly, exciting these metal nanostructures near their resonance charges up those metal structures, producing an electrostatic potential that you can measure.”

    This electrostatic potential is a first step in the creation of electricity, Atwater says. “If we can develop a way to produce a steady-state current, this could potentially be a power source. He envisions a solar cell using the plasmoelectric effect someday being used in tandem with photovoltaic cells to harness both visible and infrared light for the creation of electricity.

    Although such solar cells are still on the horizon, the new technique could even now be incorporated into new types of sensors that detect light based on the electrostatic potential.

    “Like all such inventions or discoveries, the path of this technology is unpredictable,” Atwater says. “But any time you can demonstrate a new effect to create a sensor for light, that finding has almost always yielded some kind of new product.”

    This work was published in a paper titled, Plasmoelectric Potentials in Metal Nanostructures. Other coauthors include first author Matthew T. Sheldon, a former postdoctoral scholar at Caltech; Ana M. Brown, an applied physics graduate student at Caltech; and Jorik van de Groep and Albert Polman from the FOM Institute AMOLF in Amsterdam. The study was funded by the Department of Energy, the Netherlands Organization for Scientific Research, and an NSF Graduate Research Fellowship.

    See the full article here.

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 8:04 am on November 18, 2014 Permalink | Reply
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    From phys.org: “Electrochemical cell converts waste heat into electricity” 

    physdotorg
    phys.org

    November 18, 2014
    Tessa Evans

    Picture a device that can produce electricity using nothing but the ambient heat around it. Thanks to research published in the Proceedings of the National Academy of Science today, this scenario is a step closer – a team from MIT has created an electrochemical cell which uses different temperatures to convert heat to electricity.

    The cell only needs low-grade waste heat – less than 100C – to charge batteries, and is a significant step forward compared to similar devices which either require an external circuit for charging or high temperature heat sources (300C).

    sc
    Diagram depicting how energy is generated as temperature varied. Credit: Gang Chen, CC BY

    “It’s a great idea to be able to recover useful electrical energy from waste heat,” Anthony Vassallo, Delta Electricity Chair in Sustainable Energy Development at The University of Sydney, said.

    At higher temperatures (60C), the cell (which is made of Prussian blue nanoparticles and ferrocyanide) was charged, and following cooling to 15C, the cell discharged energy. At lower temperatures the cell discharged more energy than was used to charge it, so converted heat to electricity.

    The amount of heat energy generated is dependent on the temperature and the Carnot limit. The Carnot limit is the maximum absolute amount of heat energy that can be converted to useful electricity.

    In cars, engine heat efficiency has reached around 20%, while the Carnot limit – the absolute efficiency which could be reached at that operating temperature – is 37%

    gl
    Credit: Tao Zero/Flickr, CC BY-NC-SA

    This means that most heat energy conversion is based on high temperature, and low-grade heat conversion devices will never be able to achieve high conversion efficiencies.

    This first prototype can only convert 2% heat energy to electricity, and, Professor Vassallo predicted, will have a Carnot limit of “less than 10%”.

    “While this will no doubt be improved, there are thermodynamic limits which basically say the maximum efficiency will always be low at the sort of temperatures these electrochemical cells could work at,” he said.

    When dealing with such low conversion efficiencies (generating watts rather than kilowatts), Damon Honnery – a research engineer at Monash University – said that “overcoming system losses can be a significant technical barrier”.

    But it’s not all bad, according to Associate Professor Honnery: “There is a demand for low power sources. Lots of electrical systems require low power, and there could be niche uses for smaller devices where the energy density doesn’t need to be so high.”

    On the road to application

    The researchers want to try use the technology to harvest heat from the environment in remote areas. But as solar arrays already dominate the market, and operate more efficiently, it is unlikely heat conversion technology will supercede them any time soon.

    And as the heat conversion battery needs two temperatures to operate, the battery would require fairly extreme fluctuations in temperature in order to function outside the laboratory.

    While this would be easy over long 24-hour cycles, rapid discharging is unlikely, so the amount of electricity generated over a day would be small.

    Adam Best, a senior research scientist at CSIRO, said: “like all things in batteries, it’s a materials science challenge. Can you get better materials which are able to convert this heat in a more efficient fashion?”

    Dr Best suggested the technology may be better used in industrial facilities or in tandem with other energy systems to further enhance energy production.

    See the full article here.

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

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  • richardmitnick 2:25 pm on November 12, 2014 Permalink | Reply
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    From SLAC: “Study at SLAC Explains Atomic Action in High-Temperature Superconductors “ 


    SLAC Lab

    November 12, 2014

    A study at the Department of Energy’s SLAC National Accelerator Laboratory suggests for the first time how scientists might deliberately engineer superconductors that work at higher temperatures.

    In their report, a team led by SLAC and Stanford University researchers explains why a thin layer of iron selenide superconducts — carries electricity with 100 percent efficiency — at much higher temperatures when placed atop another material, which is called STO for its main ingredients strontium, titanium and oxygen.

    bs
    In this illustration, a single layer of superconducting iron selenide (balls and sticks) has been placed stop another material known as STO for its main ingredients strontium, titanium and oxygen. The STO is shown as blue pyramids, which represent the arrangement of its atoms. A study at SLAC found that when natural vibrations (green glow) from the STO move up into the iron selenide film, electrons in the film (white spheres) can pair up and conduct electricity with 100 percent efficiency at much higher temperatures than before. The results suggest a way to deliberately engineer superconductors that work at even higher temperatures. (SLAC National Accelerator Laboratory)

    side
    This view from the side makes an important point: Putting iron selenide on top of STO enhances its superconductivity only if it’s applied in a single layer (left). When more than one layer is applied, the natural vibrations coming up from the STO layer don’t give electrons the boost of energy they need to pair up and superconduct (right). (SLAC National Accelerator Laboratory)

    These findings, described today in the journal Nature, open a new chapter in the 30-year quest to develop superconductors that operate at room temperature, which could revolutionize society by making virtually everything that runs on electricity much more efficient. Although today’s high-temperature superconductors operate at much warmer temperatures than conventional superconductors do, they still work only when chilled to minus 135 degrees Celsius or below.

    In the new study, the scientists concluded that natural trillion-times-per-second vibrations in the STO travel up into the iron selenide film in distinct packets, like volleys of water droplets shaken off by a wet dog. These vibrations give electrons the energy they need to pair up and superconduct at higher temperatures than they would on their own.

    “Our simulations indicate that this approach – using natural vibrations in one material to boost superconductivity in another – could be used to raise the operating temperature of iron-based superconductors by at least 50 percent,” said Zhi-Xun Shen, a professor at SLAC and Stanford University and senior author of the study.

    While that’s still nowhere close to room temperature, he added, “We now have the first example of a mechanism that could be used to engineer high-temperature superconductors with atom-by-atom control and make them better.”

    Spying on Electrons

    The study probed a happy combination of materials developed two years ago by scientists in China. They discovered that when a single layer of iron selenide film is placed atop STO, its maximum superconducting temperature shoots up from 8 degrees to nearly 77 degrees above absolute zero (minus 196 degrees Celsius).

    While this was a huge and welcome leap, it would be hard to build on this advance without understanding what, exactly, was going on.

    In the new study, SLAC Staff Scientist Rob Moore and Stanford graduate student J.J. Lee and postdoctoral researcher Felix Schmitt built a system for growing iron selenide films just one layer thick on a base of STO.

    The team examined the combined material at SLAC’s Stanford Synchrotron Radiation Lightsource, a DOE Office of Science User Facility. They used an exquisitely sensitive technique called ARPES to measure the energies and momenta of electrons ejected from samples hit with X-ray light. This tells scientists how the electrons inside the sample are behaving; in superconductors they pair up to conduct electricity without resistance. The researchers also got help from theorists who did simulations to help explain what they were seeing.

    SLAC SSRL
    SSRL at SLAC

    A Promising New Direction

    “This is a very impressive experiment, one that would have been very difficult to impossible to do anywhere else,” said Andrew Millis, a theoretical condensed matter physicist at Columbia University, who was not involved in the study. “And it’s clearly telling us something important about why putting one thin layer of iron selenide on this substrate, which everyone thought was inert and boring, changes things so dramatically. It opens lots of interesting questions, and it will definitely stimulate a lot of research.”

    Scientists still don’t know what holds electron pairs together so they can effortlessly carry current in high-temperature superconductors. With no way to deliberately invent new high-temperature superconductors or improve old ones, progress has been slow.

    The new results “point to a new direction that people have not considered before,” Moore said. “They have the potential to really break records in high-temperature superconductivity and give us a new understanding of things we’ve been struggling with for years.”

    He added that SLAC is developing a new X-ray beamline at SSRL with a more advanced ARPES system to create and study these and other exotic materials. “This paper predicts a new pathway to engineering superconductivity in these materials,” Moore said, “and we’re building the tools to do just that.”

    In addition to researchers from SLAC’s Materials Science Division and from Stanford, scientists from the University of British Columbia, the University of Tennessee, Lawrence Berkeley National Laboratory and the University of California, Berkeley contributed to this study. The work was funded by the DOE Office of Science.

    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.
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  • richardmitnick 2:29 pm on November 11, 2014 Permalink | Reply
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    From PPPL: “PPPL researchers present cutting edge results at APS Plasma Physics Conference” 


    PPPL

    November 10, 2014
    Kitta MacPherson
    Email: kittamac@pppl.gov
    Phone: 609-243-2755

    Some 135 researchers, graduate students, and staff members from PPPL joined 1,500 research scientists from around the world at the 56th annual meeting of the American Physical Society Division of Plasma Physics Conference from Oct. 27 to Oct. 31 in New Orleans. Topics in the sessions ranged from waves in plasma to the physics of ITER, the international physics experiment in Cadarache, France; to women in plasma physics. Dozens of PPPL scientists presented the results of their cutting-edge research into magnetic fusion and plasma science. There were about 100 invited speakers at the conference, more than a dozen of whom were from PPPL.

    sw
    Conceptual image of the solar wind from the sun encountering the Earth’s magnetosphere. No image credit

    The press releases in this issue are condensed versions of press releases that were prepared by the APS with the assistance of the scientists quoted and with background material written by John Greenwald and Jeanne Jackson DeVoe. The full text is available at the APS Virtual Pressroom 2014: http://www.aps.org/units/dpp/meetings/vpr/2014/index.cfm.

    How magnetic reconnection goes “Boom!”

    MRX research reveals how magnetic energy turns into explosive particle energy

    Paper by: M. Yamada, J. Yoo

    Magnetic reconnection, in which the magnetic field lines in plasma snap apart and violently reconnect, creates massive eruptions of plasma from the sun. But how reconnection transforms magnetic energy into explosive particle energy has been a major mystery.

    Now research conducted on the Magnetic Reconnection Experiment (MRX) at PPPL has taken a key step toward identifying how the transformation takes place, and measuring experimentally the amount of magnetic energy that turns into particle energy. The investigation showed that reconnection in a prototypical reconnection layer converts about 50 percent of the magnetic energy, with one-third of the conversion heating the electrons and two-thirds accelerating the ion in the plasma.

    “This is a major milestone for our research,” said Masaaki Yamada, the principal investigator for the MRX. “We can now see the entire picture of how much of the energy goes to the electrons and how much to the ions in a prototypical reconnection layer.”

    What a Difference a Magnetic Field Makes

    Experiments on MRX confirm the lack of symmetry in converging space plasmas

    Paper by: J. Yoo

    Spacecraft observing magnetic reconnection have noted a fundamental gap between most theoretical studies of the phenomenon and what happens in space. While the studies assume that the converging plasmas share symmetrical characteristics such as temperature, density and magnetic strength, observations have shown that this is hardly the case.

    PPPL researchers have now found the disparity in plasma density in experiments conducted on the MRX. The work, done in collaboration with the Space Science Center at the University of New Hampshire, marks the first laboratory confirmation of the disparity and deepens understanding of the mechanisms involved.

    Data from the MRX findings could help to inform a four-satellite mission—the Magnetospheric Multiscale Mission, or MMS—that NASA plans to launch next year to study reconnection in the magnetosphere. The probes could produce a better understanding of geomagnetic storms and lead to advanced warning of the disturbances and an improved ability to cope with them.

    Using radio waves to control density in fusion plasma

    Experiments show how heating electrons in the center of hot fusion plasma can increase turbulence, reducing the density in the inner core

    Paper by: D. Ernst, K. Burrell, W. Guttenfelder, T. Rhodes, A. Dimits

    Recent fusion experiments on the DIII-D tokamak at General Atomics in San Diego and the Alcator C-Mod tokamak at MIT show that beaming microwaves into the center of the plasma can be used to control the density in the center of the plasma. The experiments and analysis were conducted by a team of researchers as part of a National Fusion Science Campaign.

    The new experiments reveal that turbulent density fluctuations in the inner core intensify when most of the heat goes to electrons instead of plasma ions, as would happen in the center of a self-sustaining fusion reaction. Supercomputer simulations closely reproduce the experiments, showing that the electrons become more turbulent as they are more strongly heated, and this transports both particles and heat out of the plasma.

    “As we approached conditions where mainly the electrons are heated, pure trapped electrons begin to dominate,” said Walter Guttenfelder, who did the supercomputer simulations for the DIII-D experiments along with Andris Dimits of Lawrence Livermore National Laboratory. Guttenfelder was a co-leader of the experiments and simulations with Keith Burrell of General Atomics and Terry Rhoades of UCLA. Darin Ernst of MIT led the overall research.

    Calming the Plasma Edge: The Tail that Wags the Dog

    Lithium injections show promise for optimizing the performance of fusion plasmas

    Paper by: G.L. Jackson, R. Maingi, T. Osborne, Z. Yan, D. Mansfield, S.L. Allen

    Experiments on the DIII-D tokamak fusion reactor that General Atomics operates for the U.S. Department of Energy have demonstrated the ability of lithium injections to transiently double the temperature and pressure at the edge of the plasma and delay the onset of instabilities and other transients. Researchers conducted the experiments using a lithium-injection device developed at PPPL.

    Lithium can play an important role in controlling the edge region and hence the evolution of the entire plasma. In the present work, lithium diminished the frequency of instabilities known as “edge localized modes” (ELMs), which have associated heat pulses that can damage the section of the vessel wall used to exhaust heat in fusion devices.

    The tailored injections produced ELM-free periods of up to 0.35 seconds, while reference discharges without lithium showed no ELM-free periods above 0.03 sec. The lithium rapidly increased the width of the pedestal region—the edge of the plasma where temperature drops off sharply—by up to 100 percent and raised the electron pressure and total pressure in the edge by up to 100 percent and 60 percent respectively. These dramatic effects produced a 60 percent increase in total energy-confinement time.

    Scratching the surface of a material mystery

    Scientists shed new light on how lithium conditions the volatile edge of fusion plasmas

    Paper by: Angela Capece

    For fusion energy to fuel future power plants, scientists must find ways to control the interactions that take place between the volatile edge of fusion plasma and the physical walls that surround it in fusion facilities. Such interactions can profoundly affect conditions at the superhot core of the plasma in ways that include kicking up impurities that cool down the core and halt fusion reactions. Among the puzzles is how temperature affects the ability of lithium to absorb and retain the deuterium particles that stray from the fuel that creates fusion reactions.

    Answers are now emerging from a new surface-science laboratory at PPPL that can probe lithium coatings that are just three atoms thick. The experiments showed that the ability of ultrathin lithium films to retain deuterium drops as the temperature of the molybdenum substrate rises—a result that provides insight into how lithium affects the performance of tokamaks

    Experiments further showed that exposing the lithium to oxygen improved deuterium retention at temperatures below about 400 degrees Kelvin. But without exposure to oxygen, lithium films could retain deuterium at higher temperatures as a result of lithium-deuterium bonding during a PPPL experiment.

    Putting Plasma to Work Upgrading the U.S. Power Grid

    PPPL lends GE a hand in developing an advanced power-conversion switch

    Paper by: Johan Carlsson, Alex Khrabrov, Igor Kaganovich, Timothy Summerer

    When researchers at General Electric sought help in designing a plasma-based power switch, they turned to PPPL. The proposed switch, which GE is developing under contract with the DOE’s Advanced Research Projects Agency-Energy, could contribute to a more advanced and reliable electric grid and help lower utility bills.

    The switch would consist of a plasma-filled tube that turns current on and off in systems that convert the direct current coming from long-distance power lines to the alternating current that lights homes and businesses; such systems are used to reverse the process as well.

    To assist GE, PPPL used a pair of computer codes to model the properties of plasma under different magnetic configurations and gas pressures. GE also studied PPPL’s use of liquid lithium, which the laboratory employs to prevent damage to the divertor that exhausts heat in a fusion facility. The information could help GE develop a method for protecting the liquid-metal cathode—the negative terminal inside the tube—from damage from the ions carrying the current flowing through the plasma.

    Laser experiments mimic cosmic explosions

    Scientists bring plasma tsunamis into the lab

    Researchers are finding ways to understand some of the mysteries of space without leaving earth. Using high-intensity lasers at the University of Rochester’s OMEGA EP Facility focused on targets smaller than a pencil’s eraser, they conducted experiments to create colliding jets of plasma knotted by plasma filaments and self-generated magnetic fields.

    In two related experiments, researchers used powerful lasers to recreate a tiny laboratory version of what happens at the beginning of solar flares and stellar explosions, creating something like a gigantic plasma tsunami in space. Much of what happens in those situations is related to magnetic reconnection, which can accelerate particles to high energy and is the force driving solar flares towards earth.

    Laboratory experiment aims to identify how tsunamis of plasma called “shock waves” form in space

    By W. Fox, G. Fisksel (LLE), A. Bhattacharjee

    William Fox, a researcher at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory, and his colleague Gennady Fiksel, of the University of Rochester, got an unexpected result when they used lasers in the Laboratory to recreate a tiny version of a gigantic plasma tsunami called a “shock wave.” The shock wave is a thin area found at the boundary between a supernova and the colder material around it that has a turbulent magnetic field that sweeps up plasma into a steep tsunami-like wave of plasma.

    Fox and Fiksel used two very powerful lasers to zap two tiny pieces of plastic in a vacuum chamber to 10 million degrees and create two colliding plumes of extremely hot plasma. The researchers found something they had not anticipated that had not previously been seen in the laboratory: When the two plasmas merged they broke into clumps of long thin filaments due to a process called the “Weibel instability.” This instability could be causing the turbulent magnetic fields that form the shock waves in space. Their research could shed light on the origin of primordial magnetic fields that formed when galaxies were created and could help researchers understand how cosmic rays are accelerated to high energies.

    Magnetic reconnection in the laboratory

    By: G. Fiksel (LLE), W. Fox, A. Bhattacharjee

    Many plasmas in space already contain a strong magnetic field, so colliding plasmas there behave somewhat differently. Gennady Fiksel, of the University of Rochester, and William Fox continued their previous research by adding a magnetic field by pulsing current through very small wires. They then created the two colliding plumes of plasma as they did in an earlier experiment. When the two plasmas collided it compressed and stretched the magnetic field and a tremendous amount of energy accumulated in the field like a stretched rubber band. As the magnetic field lines pushed close together, the long lines broke apart and reformed like a single stretched rubber band, forming a slingshot that propels the plasma and releases the energy into the plasma, accelerating the plasma and heating it.

    The experiment showed that the reconnection process happens faster than theorists had previously predicted. This could help shed light on solar flares and coronal mass ejections, which also happen extremely quickly. Coronal mass ejections can trigger geomagnetic storms that can interfere with satellites and wreak havoc with cellphone service.

    The laser technique the scientists are using is new in the area of high energy density plasma and allows scientists to control the magnetic field to manipulate it in various ways.

    See the full article here.

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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  • richardmitnick 7:10 am on November 11, 2014 Permalink | Reply
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    From PPPL: “Hole in one: Technicians smoothly install the center stack in the NSTX-U vacuum vessel” 


    PPPL

    November 10, 2014
    John Greenwald

    With near-surgical precision, PPPL technicians hoisted the 29,000-pound center stack for the National Spherical Torus Experiment-Upgrade (NSTX-U) over a 20-foot wall and lowered it into the vacuum vessel of the fusion facility. The smooth operation on Oct. 24 capped more than two years of construction of the center stack, which houses the bundle of magnetic coils that form the heart of the $94 million upgrade.

    lift
    Closeup of the center stack being lowered into position by an overhead crane. (Photo by Elle Starkman/PPPL Office of Communications)

    “This was really a watershed moment,” said Mike Williams, the head of engineering and infrastructure at PPPL and associate director of the Laboratory. “The critical path [or key sequence of steps for the upgrade] was fabrication of the magnets, and that has now been done.”

    The lift team conducted the final steps largely in silence, attaching the bundled coils in their casing to an overhead crane and guiding the 21 foot-long center stack into place. The clearances were tiny: The bottom of the casing passed just inches over the shielding wall and the top of the vacuum vessel. Inserting the center stack into the vessel was like threading a needle, since the clearance at the opening was only about an inch. Guidance came chiefly from hand signals, with some radio communication at the end.

    more

    Key features

    The installation merged three key features of the upgrade that had been developed separately. These included the casing, the bundled coils and the work to ready the vacuum vessel for the center stack. Slipping the casing over the bundle was a highly precise task, with the space between them less than an inch. “The key word is ‘fit-up,’” said Ron Strykowsky, who heads the upgrade project. “We had a robust-enough design to handle all the very fine tolerances.”

    Installation of the center stack completed a key portion of the upgrade and opened another chapter. “For me, the burden is off our shoulders,” said Jim Chrzanowski, who led the coil project and retired on Oct. 31 after 39 years at PPPL. “We’ve delivered the center stack and are happy,” added Steve Raftopoulos, who worked alongside Chrzanowski and succeeds him as head of coil building. “This is my baby now,” said Raftopoulos, noting that he will be called on to resolve any problems that occur once the center stack is in operation.

    Praise for technicians

    The two leaders praised the many technicians who made the center stack possible. They ranged from a core of roughly a dozen workers who had been with the project from the beginning to technicians throughout the Laboratory who were called on to pitch in. “We drafted everyone,” Chrzanowski said.

    Their tasks included sanding, welding and applying insulation tape to each of the 36 copper conductors that went into the center stack, and sealing them all together through multiple applications of vacuum pressure impregnation — a potentially volatile process. Next came fabrication and winding of the ohmic heating coil that wraps around the conductors to put current into the hot, charged plasma that fuels fusion reactions.

    “Everyone who worked on this feels a lot of pride and ownership,” Raftopoulos said. “Steve and I were the conductors, but the technicians were the orchestra,” Chrzanowski said. “We’ve got to give credit to the guys who actually build the machines. They take our problems and make them go away.”

    Completion of the upgrade now rests with technicians working under engineer Erik Perry. Their jobs include connecting the center stack to the facility’s outer coils to complete a donut-shape magnetic field that will be used to confine the plasma. The work calls for installation of layers of custom-made electrical equipment plus hoses for water to cool the coils, all of which must fit around diagnostic and other equipment. Also ahead lies the task of connecting a second neutral beam injector for heating the plasma to the vacuum vessel. “It’s like a big puzzle,” said Perry. “Everything must fit together, and that’s what we excel at.”

    See the full article here.

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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  • richardmitnick 3:20 pm on October 29, 2014 Permalink | Reply
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    From LBL: “New Lab Startup Afingen Uses Precision Method to Enhance Plants” 

    Berkeley Logo

    Berkeley Lab

    October 29, 2014
    Julie Chao (510) 486-6491

    Imagine being able to precisely control specific tissues of a plant to enhance desired traits without affecting the plant’s overall function. Thus a rubber tree could be manipulated to produce more natural latex. Trees grown for wood could be made with higher lignin content, making for stronger yet lighter-weight lumber. Crops could be altered so that only the leaves and certain other tissues had more wax, thus enhancing the plant’s drought tolerance, while its roots and other functions were unaffected.

    By manipulating a plant’s metabolic pathways, two scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), Henrik Scheller and Dominique Loqué, have figured out a way to genetically rewire plants to allow for an exceptionally high level of control over the spatial pattern of gene expression, while at the same time boosting expression to very high levels. Now they have launched a startup company called Afingen to apply this technology for developing low-cost biofuels that could be cost-competitive with gasoline and corn ethanol.

    two
    Henrik Scheller (left) and Dominique Loque hold a tray of Arabidopsis Thaliana plants, which they used in their research. (Berkeley Lab photo)

    “With this tool we seem to have found a way to control very specifically what tissue or cell type expresses whatever we want to express,” said Scheller. “It’s a new way that people haven’t thought about to increase metabolic pathways. It could be for making more cell wall, for increasing the stress tolerance response in a specific tissue. We think there are many different applications.”

    Cost-competitive biofuels

    Afingen was awarded a Small Business Innovation Research (SBIR) grant earlier this year for $1.72 million to engineer switchgrass plants that will contain 20 percent more fermentable sugar and 40 percent less lignin in selected structures. The grant was provided under a new SBIR program at DOE that combines an SBIR grant with an option to license a specific technology produced at a national laboratory or university through DOE-supported research.

    “Techno-economic modeling done at (the Joint BioEnergy Institute, or JBEI) has shown that you would get a 23 percent reduction in the price of the biofuel with just a 20 percent reduction in lignin,” said Loqué. “If we could also increase the sugar content and make it easier to extract, that would reduce the price even further. But of course it also depends on the downstream efficiency.”

    Scheller and Loqué are plant biologists with the Department of Energy’s Joint BioEnergy Institute (JBEI), a Berkeley Lab-led research center established in 2007 to pursue breakthroughs in the production of cellulosic biofuels. Scheller heads the Feedstocks Division and Loqué leads the cell wall engineering group.

    The problem with too much lignin in biofuel feedstocks is that it is difficult and expensive to break down; reducing lignin content would allow the carbohydrates to be released and converted into fuels much more cost-effectively. Although low-lignin plants have been engineered, they grow poorly because important tissues lack the strength and structural integrity provided by the lignin. With Afingen’s technique, the plant can be manipulated to retain high lignin levels only in its water-carrying vascular cells, where cell-wall strength is needed for survival, but low levels throughout the rest of the plant.

    The centerpiece of Afingen’s technology is an “artificial positive feedback loop,” or APFL. The concept targets master transcription factors, which are molecules that regulate the expression of genes involved in certain biosynthetic processes, that is, whether certain genes are turned “on” or “off.” The APFL technology is a breakthrough in plant biotechnology, and Loqué and Scheller recently received an R&D 100 Award for the invention.

    An APFL is a segment of artificially produced DNA coded with instructions to make additional copies of a master transcription factor; when it is inserted at the start of a chosen biosynthetic pathway—such as the pathway that produces cellulose in fiber tissues—the plant cell will synthesize the cellulose and also make a copy of the master transcription factor that launched the cycle in the first place. Thus the cycle starts all over again, boosting cellulose production.

    The process differs from classical genetic engineering. “Some people distinguish between ‘transgenic’ and ‘cisgenic.’ We’re using only pieces of DNA that are already in that plant and just rearranging them in a new way,” said Scheller. “We’re not bringing in foreign DNA.”

    Other licensees and applications

    This breakthrough technique can also be used in fungi and for a wide variety of uses in plants, for example, to increase food crop yields or to boost production of highly specialized molecules used by the pharmaceutical and chemical industries. “It could also increase the quality of forage crops, such as hay fed to cows, by increasing the sugar content or improving the digestibility,” Loqué said.

    Another intriguing application is for biomanufacturing. By engineering plants to grow entirely new pharmaceuticals, specialty chemicals, or polymer materials, the plant essentially becomes a “factory.” “We’re interested in using the plant itself as a host for production,” Scheller said. “Just like you can upregulate pathways in plants that make cell walls or oil, you can also upregulate pathways that make other compounds or properties of interest.”

    Separately, two other companies are using the APFL technology. Tire manufacturer Bridgestone has a cooperative research and development agreement (CRADA) with JBEI to develop more productive rubber-producing plants. FuturaGene, a Brazilian paper and biomass company, has licensed the technology for exclusive use with eucalyptus trees and several other crops; APFL can enhance or develop traits to optimize wood quality for pulping and bioenergy applications.

    “The inventors/founders of Afingen made the decision to not compete for a license in fields of use that were of interest to other companies that had approached JBEI. This allowed JBEI to move the technology forward more quickly on several fronts,” said Robin Johnston, Berkeley Lab’s Acting Deputy Chief Technology Transfer Officer. “APFL is a very insightful platform technology, and I think only a fraction of the applications have even been considered yet.”

    Afingen currently has one employee—Ai Oikawa, a former postdoctoral researcher and now the director of plant engineering—and will be hiring three more in November. It is the third startup company to spin out of JBEI. The first two were Lygos, which uses synthetic biology tools to produce chemical compounds, and TeselaGen, which makes tools for DNA synthesis and cloning.

    See the full article here.

    A U.S. Department of Energy National Laboratory Operated by the University of California

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  • richardmitnick 3:35 pm on October 27, 2014 Permalink | Reply
    Tags: , , Energy, , ,   

    From AAAS: “After Election 2014: FUSION RESEARCH” 

    AAAS

    AAAS

    ScienceInsider

    24 October 2014
    Adrian Cho

    Should we stay or should we go? Once the voters have spoken, that’s the question Congress will have to answer regarding the United States’ participation in ITER, the hugely overbudget fusion experiment under construction in Cadarache, France. Some lawmakers say it may be time for the United States to bow out, especially as the growing ITER commitment threatens to starve U.S.-based fusion research programs. The next Congress may have to decide the issue—if the current one doesn’t pull the plug first when it returns to Washington, D.C., for a 6-week lame-duck session.

    ITER Tokamak
    ITER Tokamak

    For those tired of the partisan squabbling on Capitol Hill, the ITER debate may provide curious relief. ITER appears to enjoy bipartisan support in the House of Representatives—and bipartisan opposition among key senators.

    ITER aims to prove that nuclear fusion is a viable source of energy, and the United States has agreed to build 9% of the reactor’s hardware, regardless of the cost. Recent estimates suggest the U.S. price tag could be $3.9 billion or more—nearly quadrupling original estimates and raising alarm among some lawmakers. In response, this past June a Senate appropriations subcommittee proposed a budget bill that would end U.S. participation in the project next year. In contrast, the next month the House passed a bill that would increase U.S. spending on ITER.

    Some observers think the current Congress will kick the issue to the next one by passing a stop-gap budget for fiscal year 2015, which began 1 October, that will keep U.S. ITER going. “I don’t think in the end they can come out and kill ITER based on what the Senate subcommittee did,” says Stephen Dean, president of Fusion Power Associates, a research and educational foundation in Gaithersburg, Maryland. Others say a showdown could come by year’s end.

    Trouble over ITER has been brewing for years. ITER was originally proposed in 1985 as a joint U.S.-Soviet Union venture. The United States backed out of the project in 1998 because of cost and schedule concerns—only to rejoin in 2003. At the time, ITER construction costs were estimated at $5 billion. That number had jumped to $12 billion by 2006, when the European Union, China, India, Japan, Russia, South Korea, and the United States signed a formal agreement to build the device. At the time, ITER was supposed to start running in 2016. By 2011, U.S. costs for ITER had risen to more than $2 billion, and the date for first runs had slid to 2020. But even that date was uncertain; U.S. ITER researchers did not have a detailed cost projection and schedule—or performance baseline—to go by.

    Then in 2013, the Department of Energy (DOE) argued in its budget request for the following year that U.S. ITER was not a “capital asset” and therefore did not have to go through the usual DOE review process for large construction projects—which requires a performance baseline. Even though DOE promised to limit spending on ITER to $225 million a year so as not to starve domestic fusion research efforts, that statement irked Senators Dianne Feinstein (D–CA) and Lamar Alexander (R–TN), the chair and ranking member of the Senate Appropriations Subcommittee on Energy and Water Development, respectively. They and other senators asked the Government Accountability Office (GAO) to investigate the U.S. ITER project.

    This year, things appeared to come to a head. This past April, researchers working on U.S. ITER released their new $3.9 billion cost estimate and moved back the date for first runs to 2024 or later. Two months later, GAO reported that even that new estimate was not reliable and that the cost to the United States could reach $6.5 billion. Based on that report, the Senate energy and water subcommittee moved to kill U.S. ITER in its markup of the proposed 2015 budget, giving it only $75 million for the year, half of what the White House had requested and just enough to wind things down. Alexander supported the move, even though the U.S. ITER office is based in his home state of Tennessee, at Oak Ridge National Laboratory.

    ITER still has friends in the House, however. In their version of the DOE budget for 2015, House appropriators gave ITER $225 million, $75 million more than the White House request. Moreover, the project seems to have bipartisan support in the House, as shown by a hearing of the energy subcommittee of the House Committee on Science, Space, and Technology. Usually deeply divided along party lines, the subcommittee came together to lavish praise on ITER, with representative Lamar Smith (R–TX), chair of the full committee, and Representative Eric Swalwell (D–CA), the ranking member on the subcommittee, agreeing that ITER was, in Swalwell’s words, “absolutely essential to proving that magnetically confined fusion can be a viable clean energy source.” Swalwell called for spending more than $225 million per year on ITER.

    When and how this struggle over ITER plays out depends on the answers to several questions. First, how will Congress deal with the already late budget for next year? The Senate, controlled by the Democrats, has yet to pass any of its 13 budget bills, including the one that would fund energy research. And if the House and Senate decide to simply continue the 2014 budget past the end of the year, then the decision on ITER will pass to the next Congress. If, on the other hand, Congress passes a last-minute omnibus budget for fiscal year 2015, then the fight over ITER could play out by year’s end.

    Second, how sincere is the Senate move to kill ITER? The Senate subcommittee’s move may have been meant mainly to send a signal to the international ITER organization that it needs to shape up, says one Democratic staffer in the House. The international ITER organization received scathing criticism in an independent review in October 2013. That review called for 11 different measures to overhaul the project’s management, and the Senate’s markup may have been meant primarily to drive home the message that those measures had to be taken to ensure continued U.S. involvement, the staffer says.

    Third, how broad is the House’s support for ITER? Over the past decade or so, the House has been more supportive of fusion in general, the Democratic staffer says. But some observers credit that support mainly to one person, Representative Rodney Frelinghuysen (R-NJ), a longtime member of the House Appropriations Committee. “Over the years he’s become a champion of fusion,” Dean says. “He protects it in the House.” Dean and others say that’s likely because the DOE’s sole dedicated fusion laboratory, the Princeton Plasma Physics Laboratory (PPPL), is in his home state of New Jersey (but not Frelinghuysen’s district).

    Indeed, observers say that Frelinghuysen has been instrumental in preventing cuts to the domestic fusion program proposed by DOE itself. For example, for fiscal 2014, DOE requested $458 million for its fusion energy sciences program, including $225 million for ITER. That meant cutting the domestic fusion program by about 20% to $233 million and closing one of three tokamak reactors in the United States. The Senate went along with those numbers, but House appropriators bumped the budget up to $506 million, the number that held sway in the final 2014 spending plan. But some observers speculate that Frelinghuysen might be willing to let ITER go if he could secure a brighter future for PPPL.

    PPPL Tokamak
    PPPL Tokamak

    PPPL NSTX
    PPPL National Spherical Torus Experiment

    Finally, the biggest question surrounding U.S. participation in ITER is: How will the international ITER organization respond to the calls for changes in its management structure? That should become clear within months. So far, officials with U.S. ITER have not been able to produce a baseline cost estimate and schedule in large measure, because the ITER project as a whole does not have a reliable schedule. The international ITER organization has said it will produce one by next July, the House staffer says. And if the international organization doesn’t produce a credible schedule, the staffer says, “the project will be very difficult to defend, even by its most ardent supporters.”

    See the full article here.

    The American Association for the Advancement of Science is an international non-profit organization dedicated to advancing science for the benefit of all people.

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  • richardmitnick 7:15 pm on October 14, 2014 Permalink | Reply
    Tags: , Energy,   

    From ORNL: “New ORNL electric vehicle technology packs more punch in smaller package” 

    i1

    Oak Ridge National Laboratory

    Oct. 14, 2014
    Media Contact: Ron Walli
    Communications
    865.576.0226

    Using 3-D printing and novel semiconductors, researchers at the Department of Energy’s Oak Ridge National Laboratory have created a power inverter that could make electric vehicles lighter, more powerful and more efficient.

    At the core of this development is wide bandgap material made of silicon carbide with qualities superior to standard semiconductor materials. Power inverters convert direct current into the alternating current that powers the vehicle. The Oak Ridge inverter achieves much higher power density with a significant reduction in weight and volume.

    “Wide bandgap technology enables devices to perform more efficiently at a greater range of temperatures than conventional semiconductor materials,” said ORNL’s Madhu Chinthavali, who led the Power Electronics and Electric Machinery Group on this project. “This is especially useful in a power inverter, which is the heart of an electric vehicle.”

    Specific advantages of wide bandgap devices include: higher inherent reliability; higher overall efficiency; higher frequency operation; higher temperature capability and tolerance; lighter weight, enabling more compact systems; and higher power density.

    Additive manufacturing helped researchers explore complex geometries, increase power densities, and reduce weight and waste while building ORNL’s 30-kilowatt prototype inverter.

    thing
    ORNL’s 30-kilowatt power inverter offers greater reliability and power in a compact package.

    “With additive manufacturing, complexity is basically free, so any shape or grouping of shapes can be imagined and modeled for performance,” Chinthavali said. “We’re very excited about where we see this research headed.”

    Using additive manufacturing, researchers optimized the inverter’s heat sink, allowing for better heat transfer throughout the unit. This construction technique allowed them to place lower-temperature components close to the high-temperature devices, further reducing the electrical losses and reducing the volume and mass of the package.

    Another key to the success is a design that incorporates several small capacitors connected in parallel to ensure better cooling and lower cost compared to fewer, larger and more expensive “brick type” capacitors.

    The research group’s first prototype, a liquid-cooled all-silicon carbide traction drive inverter, features 50 percent printed parts. Initial evaluations confirmed an efficiency of nearly 99 percent, surpassing DOE’s power electronics target and setting the stage for building an inverter using entirely additive manufacturing techniques.

    Building on the success of this prototype, researchers are working on an inverter with an even greater percentage of 3-D printed parts that’s half the size of inverters in commercially available vehicles. Chinthavali, encouraged by the team’s results, envisions an inverter with four times the power density of their prototype.

    Others involved in this work, which was to be presented today at the Second Institute of Electrical and Electronics Engineers Workshop on Wide Bandgap Power Devices and Applications in Knoxville, were Curt Ayers, Steven Campbell, Randy Wiles and Burak Ozpineci.

    Research for this project was conducted at ORNL’s National Transportation Research Center and Manufacturing Demonstration Facility, DOE user facilities, with funding from DOE’s Office of Energy Efficiency and Renewable Energy.

    See the full article here.

    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.

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  • richardmitnick 8:57 pm on October 3, 2014 Permalink | Reply
    Tags: , Energy, , ,   

    From MIT: “Crumpled graphene could provide an unconventional energy storage” 


    MIT News

    October 3, 2014
    David L. Chandler | MIT News Office

    Two-dimensional carbon “paper” can form stretchable supercapacitors to power flexible electronic devices.

    When someone crumples a sheet of paper, that usually means it’s about to be thrown away. But researchers have now found that crumpling a piece of graphene “paper” — a material formed by bonding together layers of the two-dimensional form of carbon — can actually yield new properties that could be useful for creating extremely stretchable supercapacitors to store energy for flexible electronic devices.

    temp
    To form the crumpled graphene, a sheet of polymer material is stretched in both dimensions, then graphene paper is bonded to it. When the polymer is released in one direction, the graphene forms pleats, as shown in the bottom left image, taken with a scanning electron microscope (SEM). Then, when released in the other direction, it forms a chaotic crumpled pattern (top left). At top right, an SEM image shows the material in a partially crumpled state. At bottom right, SEM image of a piece that has been crumpled and then flattened out. Image courtesy of the researchers

    The finding is reported in the journal Scientific Reports by MIT’s Xuanhe Zhao, an assistant professor of mechanical engineering and civil and environmental engineering, and four other authors. The new, flexible supercapacitors should be easy and inexpensive to fabricate, the team says.

    “Many people are exploring graphene paper: It’s a good candidate for making supercapacitors, because of its large surface area per mass,” Zhao says. Now, he says, the development of flexible electronic devices, such as wearable or implantable biomedical sensors or monitoring devices, will require flexible power-storage systems.

    Like batteries, supercapacitors can store electrical energy, but they primarily do so electrostatically, rather than chemically — meaning they can deliver their energy faster than batteries can. Now Zhao and his team have demonstrated that by crumpling a sheet of graphene paper into a chaotic mass of folds, they can make a supercapacitor that can easily be bent, folded, or stretched to as much as 800 percent of its original size. The team has made a simple supercapacitor using this method as a proof of principle.

    The material can be crumpled and flattened up to 1,000 times, the team has demonstrated, without a significant loss of performance. “The graphene paper is pretty robust,” Zhao says, “and we can achieve very large deformations over multiple cycles.” Graphene, a structure of pure carbon just one atom thick with its carbon atoms arranged in a hexagonal array, is one of the strongest materials known.

    To make the crumpled graphene paper, a sheet of the material was placed in a mechanical device that first compressed it in one direction, creating a series of parallel folds or pleats, and then in the other direction, leading to a chaotic, rumpled surface. When stretched, the material’s folds simply smooth themselves out.

    Forming a capacitor requires two conductive layers — in this case, two sheets of crumpled graphene paper — with an insulating layer in between, which in this demonstration was made from a hydrogel material. Like the crumpled graphene, the hydrogel is highly deformable and stretchable, so the three layers remain in contact even while being flexed and pulled.

    Though this initial demonstration was specifically to make a supercapacitor, the same crumpling technique could be applied to other uses, Zhao says. For example, the crumpled graphene material might be used as one electrode in a flexible battery, or could be used to make a stretchable sensor for specific chemical or biological molecules.

    “This work is really exciting and amazing to me,” says Dan Li, a professor of materials engineering at Monash University in Australia who was not involved in this research. He says the team “provides an extremely simple but highly effective concept to make stretchable electrodes for supercapacitors by controlled crumpling of multilayered graphene films.” While other groups have made flexible supercapacitors, he says, “Making supercapacitors stretchable has been a great challenge. This paper provides a very smart way to tackle this challenge, which I believe will bring wearable energy storage devices closer.”

    The research team also included Jianfeng Zang at Huazhong University of Science and Technology and Changyang Cao, Yaying Feng, and Jie Liu at Duke University. The work was supported by the Office of Naval Research, the National Science Foundation, and the National 1000 Talents Program of China.

    See the full article here.

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  • richardmitnick 4:29 pm on September 29, 2014 Permalink | Reply
    Tags: , , Energy, ,   

    From PPPL: “PPPL successfully tests system for mitigating instabilities called ‘ELMs’ “ 


    PPPL

    September 29, 2014
    John Greenwald

    PPPL has successfully tested a Laboratory-designed device to be used to diminish the size of instabilities known as “edge localized modes (ELMs)” on the DIII–D tokamak that General Atomics operates for the U.S. Department of Energy in San Diego. Such instabilities can damage the interior of fusion facilities.

    DIII-D
    DIII–D

    The PPPL device injects granular lithium particles into tokamak plasmas to increase the frequency of the ELMs. The method aims to make the ELMs smaller and reduce the amount of heat that strikes the divertor that exhausts heat in fusion facilities.

    The system could serve as a possible model for mitigating ELMs on ITER, the fusion facility under construction in France to demonstrate the feasibility of fusion energy.

    iter tok
    ITER Tokamak

    “ELMs are a big issue for ITER,” said Mickey Wade, director of the DIII-D national fusion program at General Atomics. Large-scale ELMs, he noted, could melt plasma-facing components inside the ITER tokamak.

    General Atomics plans to install the PPPL-designed device, developed by physicist Dennis Mansfield and engineer Lane Roquemore, on DIII-D this fall. Previous experiments using deuterium-injection rather than lithium-injection have demonstrated the ability to increase the ELMs frequency on DIII-D, the ASDEX-Upgrade in Germany and the Joint European Torus in the United Kingdom.

    jet
    Joint European Torus

    Researchers at DIII-D now want to see how the results for lithium-injection compare with those obtained in the deuterium experiments on the San Diego facility. “We want to put them side-by-side,” Wade said.

    PPPL-designed systems have proven successful in mitigating ELMs on the EAST tokamak in Hefei, China, and have been used on a facility operated by the Italian National Agency for New Technologies in Frascati, Italy. A system also is planned for PPPL’s National Spherical Torus Experiment (NSTX), the Laboratory’s major fusion experiment, which is undergoing a $94 million upgrade.

    PPPL NSTX
    PPPL NSTX

    PPPL used salt grain-sized plastic pellets as proxies for lithium granules in testing the system for DIII-D. The pellets fell through a pinhole-sized opening inside a dropper to a rotating high-speed propeller that projected them onto a target precisely as planned.

    Joining Mansfield and Roquemore for the tests were physicists Erik Gilson and Alessandro Bortolon, a former University of Tennessee researcher now at PPPL who will begin an assignment to the DIII-D tokamak at General Atomics this fall. Also participating were Rajesh Maingi, the head of research on edge physics and plasma-facing components at PPPL, and engineer Alexander Nagy, who is on assignment to DIII-D.

    See the full article here.

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.

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