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  • richardmitnick 3:22 pm on June 14, 2018 Permalink | Reply
    Tags: , Fusion technology, , NIF achieves record double fusion yield,   

    From NIF at LLNL: “NIF achieves record double fusion yield” 

    From National Ignition Facility at Lawrence Livermore National Laboratory

    LLNL/NIF

    June 13, 2018
    Breanna Bishop
    bishop33@llnl.gov
    925-423-9802

    1
    This rendering of the inside of NIF’s target chamber shows the target positioner moving into place. Pulses from NIF’s high-powered lasers race through the facility at the speed of light and arrive at the center of the target chamber within a few trillionths of a second of each other, aligned to the accuracy of the diameter of a human hair. No image credit.

    An experimental campaign conducted at Lawrence Livermore National Laboratory’s (LLNL) National Ignition Facility (NIF) has achieved a total fusion neutron yield of 1.9e16 (1.9×1016) and 54 KJ of fusion energy output — double the previous record. Researchers in LLNL’s Inertial Confinement Fusion Program (ICF) detail the results in a paper that will be published this week in Physical Review Letters.

    NIF is the world’s largest and most energetic laser, designed to perform experimental studies of fusion ignition and thermonuclear burn, the phenomenon that powers the sun, stars and modern nuclear weapons. As a key component of the National Nuclear Security Administration’s Stockpile Stewardship Program, experiments fielded on NIF enable researchers to gain fundamental understanding of extreme temperatures, pressures and densities — knowledge that helps ensure the current and future nuclear stockpile is safe and reliable.

    The record-breaking experiments utilized a diamond capsule — a layer of ultra-thin high-density carbon containing the deuterium-tritium (DT) fusion fuel — seated inside a depleted uranium hohlraum. This approach allowed the researchers to greatly improve their control over the symmetry of the X-rays that drive the capsule, producing “rounder” and more symmetric implosions.

    “These results represent significant progress,” said Sebastien Le Pape, lead author of the paper and lead experimenter for the campaign. “By controlling the uniformity of the implosion, we’ve improved the compression of the hot spot leading to unprecedented hot spot pressure and areal density.”

    In addition to increased yield, the experiments produced other critical results. For the first time, the hot spot pressure topped out at approximately 360 Gbar (360 billion atmospheres) — exceeding the pressure at the center of the sun. Further, these record yields mean there was a record addition of energy to the hot spot due to fusion alpha particles. By depositing their energy rather than escaping, the alpha particles further heat the fuel, increasing the rate of fusion reactions and thus producing more alpha particles. This leads to yield amplification, which in these experiments was almost a factor of 3. As the implosions are further improved, this yield amplification could eventually lead to fusion ignition.

    “Because of the extreme levels of compression that these implosions have achieved, we are now at the threshold of achieving a ‘burning plasma’ state, where alpha-particle deposition in the fusing plasma is the dominant source of heating in that plasma,” said Omar Hurricane, chief scientist for the ICF Program.

    “Each experiment we do unlocks important data that informs how we design and field future experiments,” added NIF Director Mark Herrmann. “These results represent a significant advancement in our knowledge and will enable our next steps in tackling the difficult scientific challenge of ignition.”

    In addition, the experiments achieved conditions that now enable access to a range of nuclear and astrophysical regimes. The density, temperature and pressure of the hot spot are the closest to conditions in the sun, and the neutron density is now applicable for nucleosynthesis studies, which have traditionally needed an intense, laboratory-based neutron source. The conditions also are relevant for studying fundamental nuclear weapons physics.

    Additional experiments have shown similar levels of performance, confirming the importance of this approach. Looking ahead, LLNL plans to advance its experiments by exploring increased capsule size, energy delivery on NIF and improvements to features such as the capsule fill tube.

    “Every time we make progress, we can better understand what challenges lie ahead,” said Laura Berzak Hopkins, lead designer for the experiments. “Now, we’re in an exciting place where we understand our system a lot better than before, and we’ve been able to take that understanding and translate it into increased performance. I’m very excited about the progress we’ve been able to make, and where we can go next.”

    In addition to Le Pape, Hurricane and Berzak Hopkins, co-authors include Laurent Divol, Arthur Pak, Eduard Dewald, Suhas Bhandarkar, Laura Benedetti, Thomas Bunn, Juergen Biener, Daniel Casey, David Fittinghoff, Clement Goyon, Steven Haan, Robert Hatarik, Darwin Ho, Nobuhiko Izumi, Shahab Khan, Tammy Ma, Andrew Mackinnon, Andrew MacPhee, Brian MacGowan, Nathan Meezan, Jose Milovich, Marius Millot, Pierre Michel, Sabrina Nagel, Abbas Nikroo, Prav Patel, Joseph Ralph, Janes Ross, David Strozzi, Michael Stadermann, Charles Yeamans, Christopher Weber and Deborah Callahan of LLNL; Jay Crippen Martin Havre, Javier Jaquez and Neal Rice of General Atomics; Dana Edgell of the University of Rochester’s Laboratory for Laser Energetics; Maria Gatu-Johnson of the Massachusetts Institute of Technology’s Plasma Science and Fusion Center; George Kyrala and Petr Volegov of Los Alamos National Laboratory; and Christoph Wild of Diamond Materials Gmbh.

    See the full article here .


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    The National Ignition Facility, or NIF, is a large laser-based inertial confinement fusion (ICF) research device, located at the Lawrence Livermore National Laboratory in Livermore, California. NIF uses lasers to heat and compress a small amount of hydrogen fuel with the goal of inducing nuclear fusion reactions. NIF’s mission is to achieve fusion ignition with high energy gain, and to support nuclear weapon maintenance and design by studying the behavior of matter under the conditions found within nuclear weapons. NIF is the largest and most energetic ICF device built to date, and the largest laser in the world.

    Construction on the NIF began in 1997 but management problems and technical delays slowed progress into the early 2000s. Progress after 2000 was smoother, but compared to initial estimates, NIF was completed five years behind schedule and was almost four times more expensive than originally budgeted. Construction was certified complete on 31 March 2009 by the U.S. Department of Energy, and a dedication ceremony took place on 29 May 2009. The first large-scale laser target experiments were performed in June 2009 and the first “integrated ignition experiments” (which tested the laser’s power) were declared completed in October 2010.

    Bringing the system to its full potential was a lengthy process that was carried out from 2009 to 2012. During this period a number of experiments were worked into the process under the National Ignition Campaign, with the goal of reaching ignition just after the laser reached full power, some time in the second half of 2012. The Campaign officially ended in September 2012, at about 1⁄10 the conditions needed for ignition. Experiments since then have pushed this closer to 1⁄3, but considerable theoretical and practical work is required if the system is ever to reach ignition. Since 2012, NIF has been used primarily for materials science and weapons research.

    National Igniton Facility- NIF at LLNL

    The preamplifiers of the National Ignition Facility are the first step in increasing the energy of laser beams as they make their way toward the target chamber

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

    LLNL is self-described as “a premier research and development institution for science and technology applied to national security.”[1] Its principal responsibility is ensuring the safety, security and reliability of the nation’s nuclear weapons through the application of advanced science, engineering and technology. The Laboratory also applies its special expertise and multidisciplinary capabilities to preventing the proliferation and use of weapons of mass destruction, bolstering homeland security and solving other nationally important problems, including energy and environmental security, basic science and economic competitiveness.

    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security Administration

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  • richardmitnick 11:06 am on June 12, 2018 Permalink | Reply
    Tags: , Fusion technology, Korean Superconducting Tokamak Advanced Research (KSTAR), Magnetic islands- bubble-like structures form in fusion plasmas, ,   

    From PPPL: “New model sheds light on key physics of magnetic islands that halt fusion reactions” 


    From PPPL

    June 6, 2018
    John Greenwald

    1
    The Korean Superconducting Tokamak Advanced Research facility. (Photo courtesy of the Korean National Fusion Research Institute.

    Magnetic islands, bubble-like structures that form in fusion plasmas, can grow and disrupt the plasmas and damage the doughnut-shaped tokamak facilities that house fusion reactions. Recent research at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has used large-scale computer simulations to produce a new model that could be key to understanding how the islands interact with the surrounding plasma as they grow and lead to disruptions.

    The findings, which overturn long-held assumptions of the structure and impact of magnetic islands, are from simulations led by visiting physicist Jae-Min Kwon. Kwon, on a year-long sabbatical from the Korean Superconducting Tokamak Advanced Research (KSTAR) facility, worked with physicists at PPPL to model the detailed and surprising experimental observations recently made on KSTAR.

    Researchers intrigued

    “The experiments intrigued many KSTAR researchers including me,” said Kwon, first author of the new theoretical paper selected as an Editor’s Pick in the journal Physics of Plasmas. “I wanted to understand the physics behind the sustained plasma confinement that we observed,” he said. “Previous theoretical models assumed that the magnetic islands simply degraded the confinement instead of sustaining it. However, at KSTAR, we didn’t have the proper numerical codes needed to perform such studies, or enough computer resources to run them.”

    The situation turned Kwon’s thoughts to PPPL, where he has interacted over the years with physicists who work on the powerful XGC numerical code that the Laboratory developed. “Since I knew that the code had the capabilities that I needed to study the problem, I decided to spend my sabbatical at PPPL,” he said.

    Kwon arrived in 2017 and worked closely with C.S. Chang, a principal research physicist at PPPL and leader of the XGC team, and PPPL physicists Seung-Ho Ku, and Robert Hager. The researchers modeled magnetic islands using plasma conditions from the KSTAR experiments. The structure of the islands proved markedly different from standard assumptions, as did their impact on plasma flow, turbulence, and plasma confinement during fusion experiments.

    Fusion, the power that drives the sun and stars, is the fusing of light atomic elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

    Long-absent understanding

    “Understanding how islands interact with plasma flow and turbulence has been absent until now,” Chang said. “Because of the lack of detailed calculations on the interaction of islands with complicated particle motions and plasma turbulence, the estimate of the confinement of plasma around the islands and their growth has been based on simple models and not well understood.”

    The simulations found the plasma profile inside the islands not to be constant, as previously thought, and to have a radial structure. The findings showed that turbulence can penetrate into islands and that the plasma flow across them can be strongly sheared so that it moves in opposite directions. As a result, plasma confinement can be maintained while the islands grow.

    These surprising findings contradicted past models and agreed with the experimental observations made on KSTAR. “The study exhibits the power of supercomputing on problems that could not be studied otherwise,” Chang said. “These findings could lay new groundwork for understanding the physics of plasma disruption, which is one of the most dangerous events a tokamak reactor could encounter.”

    Millions of processor hours

    Computing the new model required 6.2 million processor-core hours on the Cori supercomputer at the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science user facility at Lawrence Berkeley National Laboratory. The processing time equaled thousands of years on a desktop computer. “What I wanted was quantitatively accurate results that could be directly compared with the KSTAR data,” Kwon said. “Fortunately, I could access enough resources on NERSC to achieve that goal through the allocation given to the XGC program. I am grateful for this opportunity.”

    Going forward, a larger scale computer could allow the XGC code to start from the spontaneous formation of the magnetic islands and show how they grow, in self-consistent interaction, with the sheared plasma flow and plasma turbulence. The results could lead to a way to prevent disastrous disruptions in fusion reactors.

    Coauthors of the Physics of Plasmas paper together with the PPPL researchers were Minjun Choi, Hyungho Lee, and Hyunseok Kim of the Korean National Fusion Research Institute (NFRI), and Eisung Yoon of Rensselaer Polytechnic Institute. Support for this work comes from the DOE Office of Science and NFRI.

    See the full article here .


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    PPPL campus

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. 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. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. 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.

     
  • richardmitnick 1:12 pm on March 11, 2018 Permalink | Reply
    Tags: , , , Eni, Fusion technology,   

    From MIT: “A new era in fusion research at MIT” 

    MIT News

    MIT Widget

    MIT News

    March 9, 2018
    Francesca McCaffrey | MIT Energy Initiative

    MIT Energy Initiative founding member Eni announces support for key research through MIT Laboratory for Innovation in Fusion Technologies.

    1

    A new chapter is beginning for fusion energy research at MIT.

    This week the Italian energy company Eni, a founding member of the MIT Energy Initiative (MITEI), announced it has reached an agreement with MIT to fund fusion research projects run out of the MIT Plasma Science and Fusion Center (PSFC)’s newly created Laboratory for Innovation in Fusion Technologies (LIFT). The expected investment in these research projects will amount to about $2 million over the following years.

    This is part of a broader engagement with fusion research and the Institute as a whole: Eni also announced a commitment of $50 million to a new private company with roots at MIT, Commonwealth Fusion Systems (CFS), which aims to make affordable, scalable fusion power a reality.

    “This support of LIFT is a continuation of Eni’s commitment to meeting growing global energy demand while tackling the challenge of climate change through its research portfolio at MIT,” says Robert C. Armstrong, MITEI’s director and the Chevron Professor of Chemical Engineering at MIT. “Fusion is unique in that it is a zero-carbon, dispatchable, baseload technology, with a limitless supply of fuel, no risk of runaway reaction, and no generation of long-term waste. It also produces thermal energy, so it can be used for heat as well as power.”

    Still, there is much more to do along the way to perfecting the design and economics of compact fusion power plants. Eni will fund research projects at LIFT that are a continuation of this research and focus on fusion-specific solutions. “We are thrilled at PSFC to have these projects funded by Eni, who has made a clear commitment to developing fusion energy,” says Dennis Whyte, the director of PSFC and the Hitachi America Professor of Engineering at MIT. “LIFT will focus on cutting-edge technology advancements for fusion, and will significantly engage our MIT students who are so adept at innovation.”

    Tackling fusion’s challenges

    The inside of a fusion device is an extreme environment. The creation of fusion energy requires the smashing together of light elements, such as hydrogen, to form heavier elements such as helium, a process that releases immense amounts of energy. The temperature at which this process takes place is too hot for solid materials, necessitating the use of magnets to hold the hot plasma in place.

    One of the projects PSFC and Eni intend to carry out will study the effects of high magnetic fields on molten salt fluid dynamics. One of the key elements of the fusion pilot plant currently being studied at LIFT is the liquid immersion blanket, essentially a flowing pool of molten salt that completely surrounds the fusion energy core. The purpose of this blanket is threefold: to convert the kinetic energy of fusion neutrons to heat for eventual electricity production; to produce tritium — a main component of the fusion fuel; and to prevent the neutrons from reaching other parts of the machine and causing material damage.

    It’s critical for researchers to be able to predict how the molten salt in such an immersion blanket would move when subjected to high magnetic fields such as those found within a fusion plant. As such, the researchers and their respective teams plan to study the effects of these magnetohydrodynamic forces on the salt’s fluid dynamics.

    A history of innovation

    During the 23 years MIT’s Alcator C-Mod tokamak fusion experiment was in operation, it repeatedly advanced records for plasma pressure in a magnetic confinement device. Its compact, high-magnetic-field fusion design confined superheated plasma in a small donut-shaped chamber.

    “The key to this success was the innovations pursued more than 20 years ago at PSFC in developing copper magnets that could access fields well in excess of other fusion experiments. The coupling between innovative technology development and advancing fusion science is in the DNA of the Plasma Science and Fusion Center,” says PSFC Deputy Director Martin Greenwald.

    In its final run in 2016, Alcator C-Mod set a new world record for plasma pressure, the key ingredient to producing net energy from fusion. Since then, PSFC researchers have used data from these decades of C-Mod experiments to continue to advance fusion research. Just last year, they used C-Mod data to create a new method of heating fusion plasmas in tokamaks which could result in the heating of ions to energies an order of magnitude greater than previously reached.

    A commitment to low-carbon energy

    MITEI’s mission is to advance low-carbon and no-carbon emissions solutions to efficiently meet growing global energy needs. Critical to this mission are collaborations between academia, industry, and government — connections MITEI helps to develop in its role as MIT’s hub for multidisciplinary energy research, education, and outreach.

    Eni is an inaugural, founding member of the MIT Energy Initiative, and it was through their engagement with MITEI that they became aware of the fusion technology commercialization being pursued by CFS and its immense potential for revolutionizing the energy system. It was through these discussions, as well, that Eni investors learned of the high-potential fusion research projects taking place through LIFT at MIT, spurring them to support the future of fusion at the Institute itself.

    Eni CEO Claudio Descalzi said, “Today is a very important day for us. Thanks to this agreement, Eni takes a significant step forward toward the development of alternative energy sources with an ever lower environmental impact. Fusion is the true energy source of the future, as it is completely sustainable, does not release emissions or waste, and is potentially inexhaustible. It is a goal that we are determined to reach quickly.” He added, “We are pleased and excited to pursue such a challenging goal with a collaborator like MIT, with unparalleled experience in the field and a long-standing and fruitful alliance with Eni.”

    These fusion projects are the latest in a line of MIT-Eni collaborations on low- and no-carbon energy projects. One of the earliest of these was the Eni-MIT Solar Frontiers Center, established in 2010 at MIT. Through its mission to develop competitive solar technologies, the center’s research has yielded the thinnest, lightest solar cells ever produced, effectively able to turn any surface, from fabric to paper, into a functioning solar cell. The researchers at the center have also developed new, luminescent materials that could allow windows to efficiently collect solar power.

    Other fruits of MIT-Eni collaborations include research into carbon capture systems to be installed in cars, wearable technologies to improve workplace safety, energy storage, and the conversion of carbon dioxide into fuel.

    See the full article here .

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  • richardmitnick 4:32 pm on March 9, 2018 Permalink | Reply
    Tags: Fusion technology, ,   

    From MIT: “MIT and newly formed company launch novel approach to fusion power” 

    MIT News

    MIT Widget

    MIT News

    March 9, 2018
    David Chandler

    1
    Visualization of the proposed SPARC tokamak experiment. Using high-field magnets built with newly available high-temperature superconductors, this experiment would be the first controlled fusion plasma to produce net energy output. Visualization by Ken Filar, PSFC research affiliate.

    Goal is for research to produce a working pilot plant within 15 years.

    Progress toward the long-sought dream of fusion power — potentially an inexhaustible and zero-carbon source of energy — could be about to take a dramatic leap forward.

    Development of this carbon-free, combustion-free source of energy is now on a faster track toward realization, thanks to a collaboration between MIT and a new private company, Commonwealth Fusion Systems. CFS will join with MIT to carry out rapid, staged research leading to a new generation of fusion experiments and power plants based on advances in high-temperature superconductors — work made possible by decades of federal government funding for basic research.

    CFS is announcing today that it has attracted an investment of $50 million in support of this effort from the Italian energy company Eni. In addition, CFS continues to seek the support of additional investors. CFS will fund fusion research at MIT as part of this collaboration, with an ultimate goal of rapidly commercializing fusion energy and establishing a new industry.

    “This is an important historical moment: Advances in superconducting magnets have put fusion energy potentially within reach, offering the prospect of a safe, carbon-free energy future,” says MIT President L. Rafael Reif. “As humanity confronts the rising risks of climate disruption, I am thrilled that MIT is joining with industrial allies, both longstanding and new, to run full-speed toward this transformative vision for our shared future on Earth.”

    “Everyone agrees on the eventual impact and the commercial potential of fusion power, but then the question is: How do you get there?” adds Commonwealth Fusion Systems CEO Robert Mumgaard SM ’15, PhD ’15. “We get there by leveraging the science that’s already developed, collaborating with the right partners, and tackling the problems step by step.”

    MIT Vice President for Research Maria Zuber, who has written an op-ed on the importance of this news that appears in today’s Boston Globe, notes that MIT’s collaboration with CFS required concerted effort among people and offices at MIT that support innovation: “We are grateful for the MIT team that worked tirelessly to form this collaboration. Associate Provost Karen Gleason’s leadership was instrumental — as was the creativity, diligence, and care of the Office of the General Counsel, the Office of Sponsored Programs, the Technology Licensing Office, and the MIT Energy Initiative. A great job by all.”

    Superconducting magnets are key

    Fusion, the process that powers the sun and stars, involves light elements, such as hydrogen, smashing together to form heavier elements, such as helium — releasing prodigious amounts of energy in the process. This process produces net energy only at extreme temperatures of hundreds of millions of degrees Celsius, too hot for any solid material to withstand. To get around that, fusion researchers use magnetic fields to hold in place the hot plasma — a kind of gaseous soup of subatomic particles — keeping it from coming into contact with any part of the donut-shaped chamber.

    The new effort aims to build a compact device capable of generating 100 million watts, or 100 megawatts (MW), of fusion power. This device will, if all goes according to plan, demonstrate key technical milestones needed to ultimately achieve a full-scale prototype of a fusion power plant that could set the world on a path to low-carbon energy. If widely disseminated, such fusion power plants could meet a substantial fraction of the world’s growing energy needs while drastically curbing the greenhouse gas emissions that are causing global climate change.

    “Today is a very important day for us,” says Eni CEO Claudio Descalzi. “Thanks to this agreement, Eni takes a significant step forward toward the development of alternative energy sources with an ever-lower environmental impact. Fusion is the true energy source of the future, as it is completely sustainable, does not release emissions or long-term waste, and is potentially inexhaustible. It is a goal that we are increasingly determined to reach quickly.”

    CFS will support more than $30 million of MIT research over the next three years through investments by Eni and others. This work will aim to develop the world’s most powerful large-bore superconducting electromagnets — the key component that will enable construction of a much more compact version of a fusion device called a tokamak. The magnets, based on a superconducting material that has only recently become available commercially, will produce a magnetic field four times as strong as that employed in any existing fusion experiment, enabling a more than tenfold increase in the power produced by a tokamak of a given size.

    Conceived at PSFC

    The project was conceived by researchers from MIT’s Plasma Science and Fusion Center, led by PSFC Director Dennis Whyte, Deputy Director Martin Greenwald, and a team that grew to include representatives from across MIT, involving disciplines from engineering to physics to architecture to economics. The core PSFC team included Mumgaard, Dan Brunner PhD ’13, and Brandon Sorbom PhD ’17 — all now leading CFS — as well as Zach Hartwig PhD ’14, now an assistant professor of nuclear science and engineering at MIT.

    Once the superconducting electromagnets are developed by researchers at MIT and CFS — expected to occur within three years — MIT and CFS will design and build a compact and powerful fusion experiment, called SPARC, using those magnets. The experiment will be used for what is expected to be a final round of research enabling design of the world’s first commercial power-producing fusion plants.

    SPARC is designed to produce about 100 MW of heat. While it will not turn that heat into electricity, it will produce, in pulses of about 10 seconds, as much power as is used by a small city. That output would be more than twice the power used to heat the plasma, achieving the ultimate technical milestone: positive net energy from fusion.

    This demonstration would establish that a new power plant of about twice SPARC’s diameter, capable of producing commercially viable net power output, could go ahead toward final design and construction. Such a plant would become the world’s first true fusion power plant, with a capacity of 200 MW of electricity, comparable to that of most modern commercial electric power plants. At that point, its implementation could proceed rapidly and with little risk, and such power plants could be demonstrated within 15 years, say Whyte, Greenwald, and Hartwig.

    Complementary to ITER

    The project is expected to complement the research planned for a large international collaboration called ITER, currently under construction as the world’s largest fusion experiment at a site in southern France.

    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    If successful, ITER is expected to begin producing fusion energy around 2035.

    “Fusion is way too important for only one track,” says Greenwald, who is a senior research scientist at PSFC.

    By using magnets made from the newly available superconducting material — a steel tape coated with a compound called yttrium-barium-copper oxide (YBCO) — SPARC is designed to produce a fusion power output about a fifth that of ITER, but in a device that is only about 1/65 the volume, Hartwig says. The ultimate benefit of the YBCO tape, he adds, is that it drastically reduces the cost, timeline, and organizational complexity required to build net fusion energy devices, enabling new players and new approaches to fusion energy at university and private company scale.

    The way these high-field magnets slash the size of plants needed to achieve a given level of power has repercussions that reverberate through every aspect of the design. Components that would otherwise be so large that they would have to be manufactured on-site could instead be factory-built and trucked in; ancillary systems for cooling and other functions would all be scaled back proportionately; and the total cost and time for design and construction would be drastically reduced.

    “What you’re looking for is power production technologies that are going to play nicely within the mix that’s going to be integrated on the grid in 10 to 20 years,” Hartwig says. “The grid right now is moving away from these two- or three-gigawatt monolithic coal or fission power plants. The range of a large fraction of power production facilities in the U.S. is now is in the 100 to 500 megawatt range. Your technology has to be amenable with what sells to compete robustly in a brutal marketplace.”

    Because the magnets are the key technology for the new fusion reactor, and because their development carries the greatest uncertainties, Whyte explains, work on the magnets will be the initial three-year phase of the project — building upon the strong foundation of federally funded research conducted at MIT and elsewhere. Once the magnet technology is proven, the next step of designing the SPARC tokamak is based on a relatively straightforward evolution from existing tokamak experiments, he says.

    “By putting the magnet development up front,” says Whyte, the Hitachi America Professor of Engineering and head of MIT’s Department of Nuclear Science and Engineering, “we think that this gives you a really solid answer in three years, and gives you a great amount of confidence moving forward that you’re giving yourself the best possible chance of answering the key question, which is: Can you make net energy from a magnetically confined plasma?”

    The research project aims to leverage the scientific knowledge and expertise built up over decades of government-funded research — including MIT’s work, from 1971 to 2016, with its Alcator C-Mod experiment, as well as its predecessors — in combination with the intensity of a well-funded startup company. Whyte, Greenwald, and Hartwig say that this approach could greatly shorten the time to bring fusion technology to the marketplace — while there’s still time for fusion to make a real difference in climate change.

    MITEI participation

    Commonwealth Fusion Systems is a private company and will join the MIT Energy Initiative (MITEI) as part of a new university-industry partnership built to carry out this plan. The collaboration between MITEI and CFS is expected to bolster MIT research and teaching on the science of fusion, while at the same time building a strong industrial partner that ultimately could be positioned to bring fusion power to real-world use.

    “MITEI has created a new membership specifically for energy startups, and CFS is the first company to become a member through this new program,” says MITEI Director Robert Armstrong, the Chevron Professor of Chemical Engineering at MIT. “In addition to providing access to the significant resources and capabilities of the Institute, the membership is designed to expose startups to incumbent energy companies and their vast knowledge of the energy system. It was through their engagement with MITEI that Eni, one of MITEI’s founding members, became aware of SPARC’s tremendous potential for revolutionizing the energy system.”

    Energy startups often require significant research funding to further their technology to the point where new clean energy solutions can be brought to market. Traditional forms of early-stage funding are often incompatible with the long lead times and capital intensity that are well-known to energy investors.

    “Because of the nature of the conditions required to produce fusion reactions, you have to start at scale,” Greenwald says. “That’s why this kind of academic-industry collaboration was essential to enable the technology to move forward quickly. This is not like three engineers building a new app in a garage.”

    Most of the initial round of funding from CFS will support collaborative research and development at MIT to demonstrate the new superconducting magnets. The team is confident that the magnets can be successfully developed to meet the needs of the task. Still, Greenwald adds, “that doesn’t mean it’s a trivial task,” and it will require substantial work by a large team of researchers. But, he points out, others have built magnets using this material, for other purposes, which had twice the magnetic field strength that will be required for this reactor. Though these high-field magnets were small, they do validate the basic feasibility of the concept.

    In addition to its support of CFS, Eni has also announced an agreement with MITEI to fund fusion research projects run out of PSFC’s Laboratory for Innovation in Fusion Technologies. The expected investment in these research projects amounts to about $2 million in the coming years.

    “Conservative physics”

    SPARC is an evolution of a tokamak design that has been studied and refined for decades. This included work at MIT that began in the 1970s, led by professors Bruno Coppi and Ron Parker, who developed the kind of high-magnetic-field fusion experiments that have been operated at MIT ever since, setting numerous fusion records.

    “Our strategy is to use conservative physics, based on decades of work at MIT and elsewhere,” Greenwald says. “If SPARC does achieve its expected performance, my sense is that’s sort of a Kitty Hawk moment for fusion, by robustly demonstrating net power, in a device that scales to a real power plant.”

    See the full article here .

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  • richardmitnick 4:12 pm on March 8, 2018 Permalink | Reply
    Tags: , Fusion technology, ,   

    From Science: “Scientists rally to save U Rochester OMEGA EP Laser System that Trump has targeted for closure” 

    AAAS
    Science Magazine

    Mar. 7, 2018
    Daniel Clery

    U Rochester Omega Laser facility

    U Rochester OMEGA EP Laser System

    U Rochester Laboratory for Laser Energetics

    U Rochester


    Physicists and politicians are rallying to the defense of the Omega laser at the University of Rochester (U of R) in New York, an iconic facility in the search for fusion energy that President Donald Trump has proposed defunding.

    The move to wind down the lab over 3 years, included in the Department of Energy’s (DOE’s) fiscal 2019 budget request released last month, came as a bolt from out of the blue. In addition to being a mainstay of efforts to figure out how to use lasers to create fusion energy, the 23-year-old facility also does pioneering work in studying matter at high-energy density. And it has been deeply involved in DOE’s stockpile stewardship program, which aims to ensure the reliability of U.S. nuclear weapons. “We were not consulted, there was no discussion whatsoever,” about the funding change, says E. Michael Campbell, director of U of R’s Laboratory for Laser Energetics (LLE), which runs the laser. “It makes no sense for the long-term vision of how stockpile stewardship works.”

    The budget request calls for a 20% reduction in DOE’s inertial confinement fusion (ICF) program, which supports Omega, to $419 million. The request would initiate the 3-year phaseout of the LLE by cutting its budget from $68 million in 2017 to $45 million in 2019. (Congress has yet to set the 2018 budget.)

    Fusion is the process of generating energy by melding together light atoms; it requires heating the fusion fuel (hydrogen isotopes) to tens or hundreds of millions of degrees. Inertial confinement fusion achieves this by crushing tiny capsules of fuel with intense laser or magnetic field pulses to achieve the required conditions. The hot, dense plasma produced is also the state of matter created in a nuclear explosion, hence the importance of this field to understanding nuclear bombs in the absence of explosive testing.

    Omega led the field from 1999 until 2005, when it was overtaken by the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in Livermore, California, but it continues to do important work refining the fusion process.

    National Ignition Facility at LLNL

    “Omega does 80% of the shots in this field,” Campbell says.

    The president’s request also calls for cuts to fusion work at NIF and an immediate axing of funding to the Nike laser at the U.S. Naval Research Laboratory (NRL) in Washington, D.C.

    3
    Navy Research Lab Nike Laser Facility | Plasma Physics Division

    “The loss of NRL and eventual loss of LLE would greatly reduce the physics capability and innovation in the ICF program,” says NRL’s Stephen Obenschain. A program to manufacture fusion targets and support for academic scientists who want to use the facilities would also be cut.

    Lobbying push

    Leaders of the U of R lab are making frequent trips to Washington, D.C., to win over members of Congress who will make the final decision on spending. Researchers from other labs have also been sending letters of support. “They all asked what they could do to help,” says Riccardo Betti, an assistant director at LLE.

    Omega’s closure would have “irreversible and disastrous ramifications for maintaining the safety and reliability of our nuclear stockpile,” Richard Petrasso of the Massachusetts Institute of Technology’s (MIT’s) Plasma Science and Fusion Center in Cambridge wrote in one letter to Representative Joe Kennedy III (D–MA). “Such an action would be calamitous for the field and would largely eliminate, not only for MIT, but for all other universities, the training and education of Ph.D. scientists working in [high energy density physics].”

    Fifty-one fusion researchers from across Europe signed a letter to Energy Secretary Rick Perry stating: “The Omega lasers … are the world’s most productive facilities in fielding experiments in high energy density physics. They are not only key to the mission of the US national laboratories but also accessible to the larger academic community to carry out experiments that often led to breakthroughs in physics … we petition the US government to reverse this misguided decision.”

    Lawmakers are alert to the issue. At a hearing yesterday on fusion research held by the House of Representatives Committee on Science, Space, and Technology, Representative Paul Tonko (D–NY) noted that LLE had been “targeted for severe cuts” in the budget request. “Omega deserves our support,” he added. NIF Director Mark Herrmann, who was giving testimony, said, “It would be a great loss if LLE shut down.” Committee member Representative Bill Foster (D–IL) agreed that it would be “tremendously damaging, especially to NIF.”

    Senator Charles Schumer (D–NY), the Senate’s top Democrat, is also supporting the lab. He visited LLE on 5 March and said: “Let me be clear, I will work hard to vaporize any efforts to cut or eliminate Rochester’s laser lab.” He also said that he “will be urging Congress to include $75 million worth of federal funding for the LLE” in this year’s appropriations bill, which Congress expects to complete later this month.

    See the full article here .

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  • richardmitnick 2:17 pm on February 16, 2018 Permalink | Reply
    Tags: , Fusion technology, , , PRIMA   

    From MIT: “Integrated simulations answer 20-year-old question in fusion research” 

    MIT News

    MIT Widget

    MIT News

    February 16, 2018
    Leda Zimmerman

    To make fusion energy a reality, scientists must harness fusion plasma, a fiery gaseous maelstrom in which radioactive particles react to generate heat for electricity. But the turbulence of fusion plasma can confront researchers with unruly behaviors that confound attempts to make predictions and develop models. In experiments over the past two decades, an especially vexing problem has emerged: In response to deliberate cooling at its edges, fusion plasma inexplicably undergoes abrupt increases in central temperature.

    These counterintuitive temperature spikes, which fly against the physics of heat transport models, have not found an explanation — until now.

    A team led by Anne White, the Cecil and Ida Green Associate Professor in the Department of Nuclear Science and Engineering, and Pablo Rodriguez Fernandez, a graduate student in the department, has conducted studies that offer a new take on the complex physics of plasma heat transport and point toward more robust models of fusion plasma behavior. The results of their work appear this week in the journal Physical Review Letters. Rodriguez Fernandez is first author on the paper.

    In experiments using MIT’s Alcator C-Mod tokamak (a toroidal-shaped device that deploys a magnetic field to contain the star-furnace heat of plasma), the White team focused on the problem of turbulence and its impact on heating and cooling.

    Alcator C-Mod tokamak at MIT, no longer in operation

    In tokamaks, heat transport is typically dominated by turbulent movement of plasma, driven by gradients in plasma pressure.

    Hot and cold

    Scientists have a good grasp of turbulent transport of heat when the plasma is held at steady-state conditions. But when the plasma is intentionally perturbed, standard models of heat transport simply cannot capture plasma’s dynamic response.

    In one such case, the cold-pulse experiment, researchers perturb the plasma near its edge by injecting an impurity, which results in a rapid cooling of the edge.

    “Now, if I told you we cooled the edge of hot plasma, and I asked you what will happen at the center of the plasma, you would probably say that the center should cool down too,” says White. “But when scientists first did this experiment 20 years ago, they saw that edge cooling led to core heating in low-density plasmas, with the temperature in the core rising, and much faster than any standard transport model would predict.” Further mystifying researchers was the fact that at higher densities, the plasma core would cool down.

    Replicated many times, these cold-pulse experiments with their unlikely results defy what is called the standard local model for the turbulent transport of heat and particles in fusion devices. They also represent a major barrier to predictive modeling in high-performance fusion experiments such as ITER, the international nuclear fusion project, and MIT’s own proposed smaller-scale fusion reactor, ARC.

    MIT ARC Fusion Reactor

    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    To achieve a new perspective on heat transport during cold-pulse experiments, White’s team developed a unique twist.

    “We knew that the plasma rotation, that is, how fast the plasma was spinning in the toroidal direction, would change during these cold-pulse experiments, which complicates the analysis quite a bit,” White notes. This is because the coupling between momentum transport and heat transport in fusion plasmas is still not fully understood,” she explains. “We needed to unambiguously isolate one effect from the other.”

    As a first step, the team developed a new experiment that conclusively demonstrated how the cold-pulse phenomena associated with heat transport would occur irrespective of the plasma rotation state. With Rodriguez Fernandez as first author, White’s group reported this key result in the journal Nuclear Fusion in 2017.

    A new integrated simulation

    From there, a tour de force of modeling was needed to recreate the cold-pulse dynamics seen in the experiments. To tackle the problem, Rodriguez Fernandez built a new framework, called PRIMA, which allowed him to introduce cold-pulses in time-dependent simulations. Using special software that factored in the turbulence, radiation and heat transport physics inside a tokamak, PRIMA could model cold-pulse phenomena consistent with experimental measurements.

    “I spent a long time simulating the propagation of cold pulses by only using an increase in radiated power, which is the most intuitive effect of a cold-pulse injection,” Rodriguez Fernandez says.

    Because experimental data showed that the electron density increased with every cold pulse injection, Rodriguez Fernandez implemented an analogous effect in his simulations. He observed a very good match in amplitude and time-scales of the core temperature behavior. “That was an ‘aha!’ moment,” he recalls.

    Using PRIMA, Rodriguez Fernandez discovered that a competition between types of turbulent modes in the plasma could explain the cold-pulse experiments. These different modes, explains White, compete to become the dominant cause of the heat transport. “Whichever one wins will determine the temperature profile response, and determine whether the center heats up or cools down after the edge cooling,” she says.

    By determining the factors behind the center-heating phenomenon (the so-called nonlocal response) in cold-pulse experiments, White’s team has removed a central concern about limitations in the standard, predictive (local) model of plasma behavior. This means, says White, that “we are more confident that the local model can be used to predict plasma behavior in future high performance fusion plasma experiments — and eventually, in reactors.”

    “This work is of great significance for validating fundamental assumptions underpinning the standard model of core tokamak turbulence,” says Jonathan Citrin, Integrated Modelling and Transport Group leader at the Dutch Institute for Fundamental Energy Research (DIFFER), who was not involved in the research. “The work also validated the use of reduced models, which can be run without the need for supercomputers, allowing to predict plasma evolution over longer timescales compared to full-physics simulations,” says Citrin. “This was key to deciphering the challenging experimental observations discussed in the paper.”

    The work isn’t over for the team. As part of a separate collaboration between MIT and General Atomics, Plasma Science and Fusion Center scientists are installing a new laser ablation system to facilitate cold-pulse experiments at the DIII-D tokamak in San Diego, California, with first data expected soon. Rodriguez Fernandez has used the integrated simulation tool PRIMA to predict the cold-pulse behavior at DIII-D, and he will perform an experimental test of the predictions later this year to complete his PhD research.

    The research team included Brian Grierson and Xingqiu Yuan, research scientists at Princeton Plasma Physics Laboratory; Gary Staebler, research scientist at General Atomics; Martin Greenwald, Nathan Howard, Amanda Hubbard, Jerry Hughes, Jim Irby and John Rice, research scientists from the MIT Plasma Science and Fusion Center; and MIT grad students Norman Cao, Alex Creely, and Francesco Sciortino. The work was supported by the US DOE Fusion Energy Sciences.

    See the full article here .

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    MIT Seal

    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

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  • richardmitnick 8:33 am on February 12, 2018 Permalink | Reply
    Tags: , , Fusion technology, ,   

    From GeekWire: “TAE Technologies pushes plasma machine to a new high on the nuclear fusion frontier” 

    1

    GeekWire

    February 10, 2018
    Alan Boyle

    1
    TAE Technologies’ Norman plasma generator is pushing the envelope in fusion research. (TAE Technologies Photo)

    TAE Technologies, the California-based fusion company backed by Microsoft co-founder Paul Allen, said its latest and greatest plasma generator has exceeded the headline-grabbing performance of its previous machine.

    “This announcement is an important milestone on our quest to deliver world-changing, clean fusion energy to help combat climate change and improve the quality of life for people globally,” Michl Binderbauer, the company’s president and chief technology officer, said in a news release. “This achievement further validates the robustness of TAE’s underlying science and unique pathway.”

    The $100 million machine, which went into operation less than a year ago, has been christened “Norman” in honor of physicist Norman Rostoker, the late founder of TAE (formerly known as Tri Alpha Energy). It takes the place of TAE’s C-2U plasma generator, which maintained high-temperature plasma rings in confinement for a record-setting 5 milliseconds back in 2015. Over the course of more than 100,000 experiments, the maximum confinement time eventually went even longer, to 11.5 milliseconds.

    TAE said that the C-2U experiment checked off half of what’s called the “Hot Enough, Long Enough” requirement — that is, demonstrating that a high-temperature plasma could be held in confinement long enough to sustain a nuclear fusion reaction. Such a reaction could take advantage of the same process that powers the sun to produce abundant, relatively cheap, relatively clean energy.

    Just as the C-2U machine met the “Long Enough” standard, the Norman machine is making progress on the “Hot Enough” standard. After 4,000 experiments, TAE said the temperature of Norman’s plasma has reached a high of nearly 20 million degrees Celsius (35.5 million degrees Fahrenheit).

    That’s almost twice as hot as C-2U’s top temperature, and hotter than the temperature of the sun’s core (which is estimated at 15 million degrees C, 27 million degrees F).

    TAE attributed its rapid progress to its collaboration with Google on machine-learning simulations of plasma physics. The company is also taking advantage of a U.S. Department of Energy supercomputer program to boost its data-processing resources.

    There’s still has a long way to go. TAE’s research team is aiming for a hydrogen-boron fusion reaction, which is cleaner than the typical deuterium-tritium reaction but more difficult to achieve. That means the target plasma temperature will eventually have to reach on the order of 3 billion degrees C, which will require building a successor to Norman and conducting years of follow-on experiments.

    Despite the challenges ahead, TAE Technologies CEO Steven Specker said he was heartened by the latest achievement.

    “It is profound to see TAE’s scientific innovations bear out in Norman’s performance,” Specker said in the news release. “Our remarkable
    progress signals the reality of a future powered by fusion energy, and hydrogen-boron is as safe and clean a fuel source as you can find. It’s a win-win for us all.”

    TAE’s approach to fusion involves shooting “smoke rings” of high-energy plasma at each other within a magnetic confinement chamber, with neutral beams directed into the chamber to improve plasma stability. In a recent interview, TAE’s Binderbauer told GeekWire that the technologies under development could be used for applications other than power generation.

    “There’s a medical application that’s particularly interesting that we’ve started,” he said, “and we’ve enabled that because we’ve gotten these beams to reactor-level performance already.”

    TAE says it has attracted $500 million in investment for private-sector fusion research over the past 20 years. In addition to Allen’s Vulcan Capital, institutional investors include the Rockefeller family’s Venrock venture capital firm and Rusnano, a Russian investment firm.

    Other privately funded fusion ventures include Helion Energy in Redmond, Wash., which has won backing from tech billionaire Peter Thiel’s Mithril investment firm; and General Fusion, which is headquartered in Burnaby, B.C., and counts Amazon’s billionaire founder, Jeff Bezos, among its investors.

    Those all come in addition to research efforts backed by government and academic funding, such as the multinational $20 billion ITER experimental reactor under construction in France, and the $1.1 billion Wendelstein 7-X stellarator in Germany.

    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    KIT Wendelstein 7-X, built in Greifswald, Germany

    For what it’s worth, the Joint European Torus, or JET, has achieved plasma temperatures of around 100 million degrees C (180 million degrees F). And for just an instant at a time, Europe’s Large Hadron Collider can create quark-gluon plasma at temperatures in excess of 5 trillion degrees C (9 trillion degrees F).

    See the full article here .

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  • richardmitnick 1:30 pm on December 30, 2017 Permalink | Reply
    Tags: A.I.P., , Fusion technology, , Lifetime of primary runaway electrons estimated for high-plasma-current fusion devices, ,   

    From AIP: “Lifetime of primary runaway electrons estimated for high-plasma-current fusion devices” 

    AIP Publishing Bloc

    American Institute of Physics

    November 2017
    Meeri Kim

    Analysis of field and collision influence on runaway electrons produced during plasma disruptions provides insight into lifetime trends.

    1
    No image caption or credit.

    For ITER and other high-plasma-current fusion devices, runaway electrons are a matter of concern.

    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    [ITER, way behind schedule and way over budget, is about as good as it gets in the search for Fusion Technology, which has been 30 years away for the last thirty years.]

    These highly accelerated electrons, produced in great numbers during plasma disruptions, can form a runaway beam that hits and damages the wall of the machine.

    A recent U.S. initiative called SCREAM (Simulation Center for Runaway Electron Avoidance and Mitigation) combines theoretical models with advanced simulation and analysis to address the runaway problem. As part of SCREAM, two physicists used kinetic analysis to predict the lifetime of primary runaway electrons, reporting the results in Physics of Plasmas.

    The authors wanted to understand the distribution of primary runaway electrons by taking into account the interplay of three factors: acceleration by electric field, collisions with plasma electrons and ions, and synchrotron losses. Their analysis dealt with the kinetic equation for relativistic electrons in a straight and homogeneous magnetic field, which they were able to simplify and rescale to highlight its similarity features.
    They found that the lifetime of seed runaways increases exponentially with the electric field, with the rate depending on a combination of parameters collectively called “alpha,” that includes the effects of ion charge and synchrotron time scale. For alpha much less than one, the lifetimes can be long when the electric field is only slightly about the renowned Connor-Hastie critical value, when the friction, or drag, on the relativistic electrons from ion collisions becomes energy independent and the electrons can be accelerated continuously. For alpha much larger than one, significantly stronger electric fields are necessary for runaway seed electron survival.

    Long-lived runaway electrons have greater opportunity to multiply via an avalanche effect. Knowing the parameter range that creates long lifetimes will inform ITER researchers about what regimes to avoid in planned experiments.

    See the full article here .

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    AIP Building

    AIP serves a federation of physical science societies in a common mission to promote physics and allied fields.

     
  • richardmitnick 12:24 pm on December 24, 2017 Permalink | Reply
    Tags: As a result the fractal fibers can reduce secondary electron emission by up to 80 percent, , Charles Swanson and Igor Kaganovich, Feathers and whiskers help keep plasma superhot in fusion reactions, Fusion technology, , , , This work builds on previous experiments showing that surfaces with fibered textures can reduce the amount of secondary electron emission   

    From PPPL: “Feathers and whiskers help keep plasma superhot in fusion reactions” 


    PPPL

    December 21, 2017
    Raphael Rosen

    1
    Physicist Charles Swanson. (Photo by Elle Starkman/Office of Communications)

    Physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have found a way to prevent plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — from causing short circuits in machines such as spacecraft thrusters, radar amplifiers, and particle accelerators. In findings published online in the Journal of Applied Physics, Charles Swanson and Igor Kaganovich report that applying microscopic structures that resemble feathers and whiskers to the surfaces inside these machines keeps them operating at peak performance.

    The physicists calculated that tiny fibers called “fractals,” because they look the same when viewed at different scales, can trap electrons dislodged from the interior surfaces by other electrons zooming in from the plasma. Researchers refer to the dislodged surface electrons as “secondary electron emissions” (SEE); trapping them prevents such particles from causing electric current that interferes with the functions of machines.

    Building on previous experiments

    This work builds on previous experiments showing that surfaces with fibered textures can reduce the amount of secondary electron emission. Past research has indicated that surfaces with plain fibers called “velvet” that lack feather-like branches can prevent about 50 percent of the secondary electrons from escaping into the plasma. The velvet only traps half of such electrons, since if the electrons from the plasma strike the fibers at a shallow angle the secondary electrons can bounce away without obstruction.

    “When we looked at velvet, we observed that it didn’t suppress SEE from shallowly incident electrons well,” Swanson said. “So we added another set of fibers to suppress the remaining secondary electrons and the fractal approach does appear to work nicely.”

    The new research shows that feathered fibers can capture secondary electrons produced by the electrons that approach from a shallow angle. As a result, the fractal fibers can reduce secondary electron emission by up to 80 percent.

    Swanson and Kaganovich verified the findings by performing computer calculations that compared velvet and fractal feathered textures. “We numerically simulated the emission of secondary electrons, initializing many particles and allowing them to follow ballistic, straight-line trajectories until they interacted with the surface,” Swanson said. “It was apparent that adding whiskers to the sides of the primary whiskers reduced the secondary electron yield dramatically.”

    Provisional patent

    The two scientists now have a provisional patent on the feathered-texture technique. This research was funded by the Air Force Office of Scientific Research, and follows similar experimental work done at PPPL by other physicists. Specifically, Yevgeny Raitses, working at PPPL; Marlene Patino, a graduate student at the University of California, Los Angeles; and Angela Capece, a professor at the College of New Jersey, have in the past year published experimental findings on how secondary electron emission is affected by different wall materials and structures, based on research they did at PPPL.

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    PPPL campus

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. 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. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. 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.

     
  • richardmitnick 9:18 pm on December 15, 2017 Permalink | Reply
    Tags: Fusion technology, Laser-boron fusion now ‘leading contender’ for energy,   

    From UNSW: ” Laser-boron fusion now ‘leading contender’ for energy” 

    U NSW bloc

    University of New South Wales

    14 Dec 2017
    Wilson da Silva

    Media Contacts
    Prof Heinrich Hora
    UNSW Physics
    +61 2 9544 4332
    h.hora@unsw.edu.au

    Dr Warren McKenzie
    HB11 Energy
    +61 400 059 509
    warren.mckenzie@hb11.energy

    Wilson da Silva
    Faculty of Engineering
    +61 407 907 017
    w.dasilva@unsw.edu.au

    A laser-driven technique for creating fusion that dispenses with the need for radioactive fuel elements and leaves no toxic radioactive waste is now within reach, says a UNSW physicist.

    1
    Artist’s impression of the core of a laser-ignited hydrogen-boron fusion reactor.

    A laser-driven technique for creating fusion that dispenses with the need for radioactive fuel elements and leaves no toxic radioactive waste is now within reach, say researchers.

    Dramatic advances in powerful, high-intensity lasers are making it viable for scientists to pursue what was once thought impossible: creating fusion energy based on hydrogen-boron reactions. And an Australian physicist is in the lead, armed with a patented design and working with international collaborators on the remaining scientific challenges.

    In a paper in the scientific journal Laser and Particle Beams, lead author Heinrich Hora from UNSW Sydney and international colleagues argue that the path to hydrogen-boron fusion is now viable, and may be closer to realisation than other approaches, such as the deuterium-tritium fusion approach being pursued by US National Ignition Facility (NIF) and the International Thermonuclear Experimental Reactor under construction in France.


    LLNL/NIF


    ITER Tokamak in Saint-Paul-lès-Durance, which is in southern France

    3
    The central core of the large laser-based inertial confinement fusion research device of the National Ignition Facility in the USA.

    “I think this puts our approach ahead of all other fusion energy technologies,” said Hora, who predicted in the 1970s that fusing hydrogen and boron might be possible without the need for thermal equilibrium.

    Rather than heat fuel to the temperature of the Sun using massive, high-strength magnets to control superhot plasmas inside a doughnut-shaped toroidal chamber (as in NIF and ITER), hydrogen-boron fusion is achieved using two powerful lasers in rapid bursts, which apply precise non-linear forces to compress the nuclei together.

    Hydrogen-boron fusion produces no neutrons and, therefore, no radioactivity in its primary reaction. And unlike most other sources of power production – like coal, gas and nuclear, which rely on heating liquids like water to drive turbines – the energy generated by hydrogen-boron fusion converts directly into electricity.

    But the downside has always been that this needs much higher temperatures and densities – almost 3 billion degrees Celsius, or 200 times hotter than the core of the Sun.

    4
    Schematic of a hydrogen-boron fusion reactor.

    However, dramatic advances in laser technology are close to making the two-laser approach feasible, and a spate of recent experiments around the world indicate that an ‘avalanche’ fusion reaction could be triggered in the trillionth-of-a-second blast from a petawatt-scale laser pulse, whose fleeting bursts pack a quadrillion watts of power. If scientists could exploit this avalanche, Hora said, a breakthrough in proton-boron fusion was imminent.

    “It is a most exciting thing to see these reactions confirmed in recent experiments and simulations,” said Hora, an Emeritus Professor of Theoretical Physics at UNSW. “Not just because it proves some of my earlier theoretical work, but they have also measured the laser-initiated chain reaction to create one billion-fold higher energy output than predicted under thermal equilibrium conditions.”

    Together with 10 colleagues in six nations – including from Israel’s Soreq Nuclear Research Centre and the University of California, Berkeley – Hora describes a roadmap for the development of hydrogen-boron fusion based on his design, bringing together recent breakthroughs and detailing what further research is needed to make the reactor a reality.

    An Australian spin-off company, HB11 Energy, holds the patents for Hora’s process. “If the next few years of research don’t uncover any major engineering hurdles, we could have a prototype reactor within a decade,” said Warren McKenzie, managing director of HB11.

    “From an engineering perspective, our approach will be a much simpler project because the fuels and waste are safe, the reactor won’t need a heat exchanger and steam turbine generator, and the lasers we need can be bought off the shelf,” he added.

    Other researchers involved in the study were Shalom Eliezer of Israel’s Soreq Nuclear Research Centre; Jose M. Martinez-Val from Spain’s Polytechnique University in Madrid; Noaz Nissim from University of California, Berkeley; Jiaxiang Wang of East China Normal University; Paraskevas Lalousis of Greece’s Institute of Electronic Structure and Laser; and George Miley at the University of Illinois, Urbana.

    See the full article here .

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    U NSW Campus

    Welcome to UNSW Australia (The University of New South Wales), one of Australia’s leading research and teaching universities. At UNSW, we take pride in the broad range and high quality of our teaching programs. Our teaching gains strength and currency from our research activities, strong industry links and our international nature; UNSW has a strong regional and global engagement.

    In developing new ideas and promoting lasting knowledge we are creating an academic environment where outstanding students and scholars from around the world can be inspired to excel in their programs of study and research. Partnerships with both local and global communities allow UNSW to share knowledge, debate and research outcomes. UNSW’s public events include concert performances, open days and public forums on issues such as the environment, healthcare and global politics. We encourage you to explore the UNSW website so you can find out more about what we do.

     
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