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  • richardmitnick 2:41 pm on June 25, 2020 Permalink | Reply
    Tags: "Scientists develop new tool to design better fusion devices", Fusion technology, ,   

    From PPPL: “Scientists develop new tool to design better fusion devices” 


    From PPPL

    June 24, 2020
    Raphael Rosen

    One way that scientists seek to bring to Earth the fusion process that powers the sun and stars is trapping hot, charged plasma gas within a twisting magnetic coil device shaped like a breakfast cruller. But the device, called a stellarator, must be precisely engineered to prevent heat from escaping the plasma core where it stokes the fusion reactions.

    Wendelstgein 7-X stellarator, built in Greifswald, Germany

    Now, researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have demonstrated that an advanced computer code could help design stellarators that confine the essential heat more effectively.

    The code, called XGC-S, opens new doors in stellarator research. “The main result of our research is that we can use the code to simulate both the early, or linear, and turbulent plasma behavior in stellarators,” said PPPL physicist Michael Cole, lead author of the paper reporting the results in Physics of Plasmas. “This means that we can start to determine which stellarator shape contains heat best and most efficiently maintains conditions for fusion.”

    Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — and generates massive amounts of energy in the sun and stars. Scientists aim to replicate fusion in devices on Earth for a virtually inexhaustible supply of safe and clean power to generate electricity.

    The PPPL scientists simulated the behavior of plasma inside fusion machines that look like a donut but with pinches and deformations that make the device more efficient, a kind of shape known as quasi-axisymmetric . The researchers used an updated version of XGC, a state-of-the-art code developed at PPPL for modeling turbulence in doughnut-shaped fusion facilities called tokamaks, which have a simpler geometry. The modifications by Cole and his colleagues allowed the new XGC-S code to also model plasmas in the geometrically more complicated stellarators.

    The simulations showed that a type of disturbance limited to a small area can become complex and expand to fill a larger space within the plasma. The results showed that XGC-S could simulate this type of stellarator plasma more accurately than what was previously possible.

    “I think this is the beginning of a really important development in the study of turbulence in stellarators,” said David Gates, head of the Department of Advanced Projects at PPPL. “It opens up a big window for getting new results.”

    The findings demonstrate the successful modification of the XGC code to simulate turbulence in stellarators. The code can calculate the turbulence in stellarators all the way from the plasma core to the edge, providing a more complete picture of the plasma’s behavior.

    “Turbulence is one of the primary mechanisms causing heat to leak out of fusion plasmas,” Cole said. “Because stellarators can be built in a greater variety of shapes than tokamaks, we might be able to find shapes that control turbulence better than tokamaks do. Searching for them by building lots of big experiments is too expensive, so we need big simulations to search for them virtually.”

    The researchers plan to modify XGC-S further to produce an even clearer view of how turbulence causes heat leakage. The more complete a picture, the closer scientists will be to simulating stellarator experiments in the virtual realm. “Once you have an accurate code and a powerful computer, changing the stellarator design you are simulating is easy,” Cole said.

    Researchers performed the simulations using resources at the National Energy Research Scientific Computing Center (NERSC), a DOE User Facility. Support for this research came from the DOE Office of Science (Fusion Energy Sciences).

    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.http://www.energy.gov.

    Princeton University campus

     
  • richardmitnick 10:33 am on May 27, 2020 Permalink | Reply
    Tags: "Return of the Blob: Scientists find surprising link to troublesome turbulence at the edge of fusion plasmas", Blobs can wreak havoc in plasma required for fusion reactions., Fusion technology, ,   

    From PPPL: “Return of the Blob: Scientists find surprising link to troublesome turbulence at the edge of fusion plasmas” 


    From PPPL

    May 26, 2020
    John Greenwald

    1
    Image showing spiraling magnetic field fluctuations at the edge of the NSTX tokamak. (Photo courtesy of Physics of Plasmas. Composition by Elle Starkman/Office of Communications.)

    PPPL NSTX -U at Princeton Plasma Physics Lab, Princeton, NJ,USA

    Blobs can wreak havoc in plasma required for fusion reactions. This bubble-like turbulence swells up at the edge of fusion plasmas and drains heat from the edge, limiting the efficiency of fusion reactions in doughnut-shaped fusion facilities called “tokamaks.” Researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have now discovered a surprising correlation of the blobs with fluctuations of the magnetic field that confines the plasma fueling fusion reactions in the device core.

    New aspect of understanding

    Further investigation of this correlation and its role in the loss of heat from magnetic fusion reactors will help to produce on Earth the fusion energy that powers the sun and stars. “These results add a new aspect to our understanding of the plasma edge heat loss in a tokamak,” said physicist Stewart Zweben, lead author of a paper (link is external) in Physics of Plasmas that editors have selected as a featured article. “This work also contributes to our understanding of the physics of blobs, which can help to predict the performance of tokamak fusion reactors.”

    Fusion reactions combine light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei that makes up 99 percent of the visible universe — to produce massive amounts of energy. Scientists are seeking to create and control fusion on Earth as a source of safe, clean and virtually limitless power to generate electricity.

    PPPL researchers discovered the surprising link last year when re-analyzing experiments made in 2010 on PPPL’s National Spherical Torus Experiment (NSTX) — the forerunner of today’s National Spherical Torus Experiment-Upgrade (NSTX-U). The blobs and fluctuations in the magnetic field, called “magnetohydrodynamic (MHD)” activity, develop in all tokamaks and have traditionally been seen as independent of each other.

    Surprise clue

    The first clue to the correlation was the striking regularity of the trajectory of large blobs, which travel at roughly the speed of a rifle bullet, in experiments analyzed in 2015 and 2016. Such blobs normally move randomly in what is called the “scrape-off layer” at the edge of tokamak plasma, but in some cases all large blobstraveled at nearly the same angle and speed. Moreover, the time between the appearance of each large blob at the edge of the plasma was nearly always the same, virtually coinciding with the frequency of dominant MHD activity in the plasma edge.

    Researchers then tracked the diagnostic signals of the blobs and the MHD activity in relation to each other to measure what is called the “cross-correlation coefficient,” which they used to evaluate a set of the 2010 NSTX experiments. Roughly 10 percent of those experiments were found to show a significant correlation between the two variables.

    The scientists then analyzed several possible causes of the correlation, but could find no single compelling explanation. To understand and control this phenomenon, Zweben said, further data analysis and modeling will have to be done — perhaps by readers of the Physics of Plasmas paper.

    Support for this work comes from the DOE Office of Science, with portions of the research performed under the auspices of Lawrence Livermore National Laboratory.

    See the full article here .


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    Please help promote STEM in your local schools.

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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.http://www.energy.gov.

    Princeton University campus

     
  • richardmitnick 12:46 pm on May 21, 2020 Permalink | Reply
    Tags: "DIII-D scientists unravel challenge in improving fusion performance", , Fusion technology,   

    From The College of William & Mary: “DIII-D scientists unravel challenge in improving fusion performance” 

    From The College of William & Mary

    May 20, 2020
    Zabrina Johal

    1
    Team leader: Saskia Mordijck, an assistant professor in William & Mary’s physics department, led the multi-institutional research team at the DIII-D National Fusion Facility that untangled three elements of the fusion reaction. Their work advances progress toward practical, safe fusion-powered energy. File photo by Stephen Salpukas

    A team at the DIII-D National Fusion Facility led by a William & Mary physicist has made a significant advancement in physics understanding that represents a key step toward practical fusion energy.

    DOE DIII-D Tokamak, in San Diego, California

    The work, published in an article in the journal Nuclear Fusion, helps better explain the relationship among three variables – plasma turbulence, the transport of electrons through the plasma and electron density in the core. Because these factors are key elements of the fusion reaction, this understanding could significantly improve the ability to predict performance and efficiency of fusion plasmas, a necessary step toward achieving commercial fusion power plants.

    “We’ve known for some time that there is a relationship between core electron density, electron-ion collisions and particle movement in the plasma,” said William & Mary’s Saskia Mordijck, who led the multi-institutional research team at DIII-D. “Unfortunately, until now research has not been able to untangle that relationship from the other components that affect electron density patterns.”

    Mordijck, an assistant professor in William & Mary’s Department of Physics, notes that in addition to the international effort at DIII-D, W&M has been a contributor to similar experiments in the European Union.

    ITER experimental tokamak nuclear fusion reactor that is being built next to the Cadarache facility in Saint Paul les-Durance south of France

    DIII-D, which General Atomics operates as a national user facility for the Department of Energy’s Office of Science, is the largest magnetic fusion research facility in the country. It hosts researchers from more than 100 institutions across the globe, including 40 universities. The heart of the facility is a tokamak that uses powerful electromagnets to produce a doughnut-shaped magnetic vessel containment for confining a fusion plasma. In DIII-D, plasma temperatures more than 10 times hotter than the Sun are routinely achieved. At such extremely high temperatures, hydrogen isotopes can fuse together and release energy.

    In a tokamak, fusion power is determined by temperature, plasma density and confinement time. Fusion gain, expressed as the symbol Q, is the ratio of fusion power to the input power required to maintain the reaction and is thus a key indicator of the device’s efficiency. At Q = 1, the breakeven point has been reached, but because of heat losses, self-sustaining plasmas are not reached until about Q = 5. Current systems have achieved extrapolated values of Q = 1.2. The ITER experiment under construction in France is expected to achieve Q = 10, but commercial fusion power plants will likely need to achieve even higher Q values to be economical.

    Because electron density in the plasma core is a critical element of fusion gain, scientists are developing methods to achieve greater peak densities. One previously identified approach that shows promise is reducing electron-ion collisions, a parameter that plasma physicists refer to as collisionality. However, previous research was not able to establish the exact relationship between density peaking and collisionality, nor isolate the effect from other characteristics of the plasma.

    The DIII-D team conducted a series of experiments in which only plasma collisionality was varied while other parameters were held constant. The results demonstrated that low collisionality improves electron density peaking through the formation of an internal barrier to particle movement through the plasma, which in turn altered the plasma turbulence. Previous work had suggested the effect might be due to plasma heating by neutral beam injection, but the experiments show that it was linked to particle transport and turbulence.

    “This work substantially improves the understanding of electron behavior in the plasma core, which is an area of great importance for increasing fusion gain,” said David Hill, director of DIII-D. “This is another important step toward practical fusion energy in future commercial reactors.”

    In addition to William & Mary, participants included the University of California, Los Angeles, the VTT Technical Research Centre of Finland, General Atomics, the University of Wisconsin – Madison and Chalmers University of Technology in Sweden.

    See the full article here .

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    The College of William & Mary (also known as William & Mary, W&M, and officially The College of William and Mary in Virginia) is a public research university in Williamsburg, Virginia. Founded in 1693 by letters patent issued by King William III and Queen Mary II, it is the second-oldest institution of higher education in the United States, after Harvard University.

    William & Mary educated American Presidents Thomas Jefferson (third), James Monroe (fifth), and John Tyler (tenth) as well as other key figures important to the development of the nation, including the fourth U.S. Supreme Court Chief Justice John Marshall of Virginia, Speaker of the House of Representatives Henry Clay of Kentucky, sixteen members of the Continental Congress, and four signers of the Declaration of Independence, earning it the nickname “the Alma Mater of the Nation.” A young George Washington (1732–1799) also received his surveyor’s license through the college. W&M students founded the Phi Beta Kappa academic honor society in 1776, and W&M was the first school of higher education in the United States to install an honor code of conduct for students. The establishment of graduate programs in law and medicine in 1779 makes it one of the earliest higher level universities in the United States.

    In addition to its undergraduate program, W&M is home to several graduate programs (including computer science, public policy, physics, and colonial history) and four professional schools (law, business, education, and marine science). In his 1985 book Public Ivies: A Guide to America’s Best Public Undergraduate Colleges and Universities, Richard Moll categorized William & Mary as one of eight “Public Ivies”.

     
  • richardmitnick 7:38 am on May 11, 2020 Permalink | Reply
    Tags: "Scientists explore the power of radio waves to help control fusion reactions", “RF [radio frequency] current condensation”, Fusion technology, ITER- the international tokamak under construction in France.,   

    From PPPL: “Scientists explore the power of radio waves to help control fusion reactions” 


    From PPPL

    April 28, 2020
    John Greenwald

    A key challenge to capturing and controlling fusion energy on Earth is maintaining the stability of plasma — the electrically charged gas that fuels fusion reactions — and keeping it millions of degrees hot to launch and maintain fusion reactions. This challenge requires controlling magnetic islands, bubble-like structures that form in the plasma in doughnut-shaped tokamak fusion facilities. These islands can grow, cool the plasma and trigger disruptions — the sudden release of energy stored in the plasma — that can halt fusion reactions and seriously damage the fusion facilities that house them.

    Improved island control

    Research by scientists at Princeton University and at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) points toward improved control of the troublesome magnetic islands in ITER, the international tokamak under construction in France, and other future fusion facilities that cannot allow large disruptions.

    ITER experimental tokamak nuclear fusion reactor that is being built next to the Cadarache facility in Saint Paul les-Durance south of France

    “This research could open the door to improved control schemes previously deemed unobtainable,” said Eduardo Rodriguez, a graduate student in the Princeton Program in Plasma Physics and first author of a paper in Physics of Plasmas that reports the findings.

    The research follows up on previous work by Allan Reiman and Nat Fisch, which identified a new effect called “RF [radio frequency] current condensation” that can greatly facilitate the stabilization of magnetic islands. The new Physics of Plasmas paper shows how to make optimal use of the effect. Reiman is a Distinguished Research Fellow at PPPL and Fisch is a Princeton University professor and Director of the Princeton Program in Plasma Physics and Associate Director of Academic Affairs at PPPL.

    Fusion reactions combine light elements in the form of plasma — the state of matter composed of free electrons and atomic nuclei — to generate massive amounts of energy in the sun and stars. Scientists throughout the world are seeking to reproduce the process on Earth for a virtually inexhaustible supply of safe and clean power to generate electricity for all humanity.

    The new paper, based on a simplified analytical model, focuses on use of RF waves to heat the islands and drive electric current that causes them to shrink and disappear. When the temperature gets sufficiently high, complicated interactions can occur that lead to the RF current condensation effect, which concentrates the current in the center of the island and can greatly enhance the stabilization. But as the temperature increases, and the gradient of the temperature between the colder edge and the hot interior of the island grows larger, the gradient can drive instabilities that make it more difficult to increase the temperature further.

    Point-counterpoint

    This point-counterpoint is an important indicator of whether the RF waves will accomplish their stabilizing goal. “We analyze the interaction between the current condensation and the increased turbulence from the gradient the heating creates to determine whether the system is stabilized or not,” Rodriguez says. “We want the islands not to grow.” The new paper shows how to control the power and aiming of the waves to make optimal use of the RF current condensation effect, taking account of the instabilities. Focusing on this can lead to improved stabilization of fusion reactors,” Rodriguez said.

    The researchers now plan to introduce new aspects into the model to develop a more detailed investigation. Such steps include work being done towards including the condensation effect in computer codes to model the behavior of launched RF waves and their true effect. The technique would ultimately be used in designing optimal island stabilization schemes.

    The Program in Plasma Physics is a graduate program at Princeton University, academically located within the Department of Astrophysical Sciences. Support for this work comes from the DOE Office of Science through PPPL and the Department of Astrophysical Sciences.

    See the full article here .


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    Please help promote STEM in your local schools.

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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.http://www.energy.gov.

    Princeton University campus

     
  • richardmitnick 9:13 am on February 21, 2020 Permalink | Reply
    Tags: , , , Fusion technology, HB11 Energy, , Laser-driven technique for creating fusion energy.,   

    From University of New South Wales: “Pioneering technology promises unlimited, clean and safe energy” 

    U NSW bloc

    From University of New South Wales

    21 Feb 2020
    Yolande Hutchinson
    UNSW Sydney External Relations
    0420 845 023
    y.hutchinson@unsw.edu.au

    Dr Warren McKenzie
    HB11 Energy
    0400 059 509

    Professor Heinrich Hora
    UNSW Physics
    0414 471 424

    A UNSW spin-out company has secured patents for its ground-breaking approach to energy generation.

    1
    HB11 Energy, has been granted patents for its laser-driven technique for creating fusion energy. Picture: Shutterstock

    UNSW Sydney spin-out company, HB11 Energy, has been granted patents for its laser-driven technique for creating fusion energy. Unlike earlier methods, the technique is completely safe as it does not rely on radioactive fuel and leaves no toxic radioactive waste.

    HB11 Energy secured its intellectual property rights in Japan last week, following recent grants in China and the USA.

    Conceived by UNSW Emeritus Professor of theoretical physics Heinrich Hora, HB11 Energy’s concept differs radically from other experimental fusion projects.

    “After investigating a laser-boron fusion approach for over four decades at UNSW, I am thrilled that this pioneering approach has now received patents in three countries,” Professor Hora said.

    “These granted patents represent the eve of HB11 Energy’s seed-stage fundraising campaign that will establish Australia’s first commercial fusion company, and the world’s only approach focused on the safe hydrogen – boron reaction using lasers.”

    The preferred fusion approach employed by most fusion groups is to heat Deuterium-Tritium fuel well beyond the temperature of the sun (or almost 15 million degrees Celsius). Rather than heating the fuel, HB11’s hydrogen-boron fusion is achieved using two powerful lasers whose pulses apply precise non-linear forces to compress the nuclei together.

    “Tritium is very rare, expensive, radioactive and difficult to store. Fusion reactions employing Deuterium-Tritium also shed harmful neutrons and create radioactive waste which needs to be disposed of safely. I have long favored the combination of cheap and abundant hydrogen H and boron B-11. The fusion of these elements does not primarily produce neutrons and is the ideal fuel combination,” Professor Hora said.

    Most other sources of power production, such as coal, gas and nuclear, rely on heating liquids like water to drive turbines. In contrast, the energy generated by hydrogen-boron fusion converts directly into electricity allowing for much smaller and simpler generators.

    The two-laser approach needed for HB11 Energy’s hydrogen-boron fusion only became possible recently thanks to advances in laser technology that won the 2018 Nobel Prize in Physics.

    2
    Schematic of a hydrogen-boron fusion reactor.

    Hora’s reactor design is deceptively simple: a largely empty metal sphere, where a modestly sized HB11 fuel pellet is held in the center, with apertures on different sides for the two lasers. One laser establishes the magnetic containment field for the plasma and the second laser triggers the ‘avalanche’ fusion chain reaction.

    The alpha particles generated by the reaction would create an electrical flow that can be channeled almost directly into an existing power grid with no need for a heat exchanger or steam turbine generator.

    “The clean and absolutely safe reactor can be placed within densely populated areas, with no possibility of a catastrophic meltdown such as that which has been seen with nuclear fission reactors,” Professor Hora added.

    With experiments and simulations measuring a laser-initiated chain reaction creating one billion-fold higher reaction rates than predicted (under thermal equilibrium conditions), HB11 Energy stands a high chance of reaching the goal of ‘net-energy gain’ well ahead of other groups.

    “HB11 Energy’s approach could be the only way to achieve very low carbon emissions by 2050. As we aren’t trying to heat fuels to impossibly high temperatures, we are sidestepping all of the scientific challenges that have held fusion energy back for more than half a century,” Dr Warren McKenzie, Managing Director of HB11 Energy, said.

    “This means our development roadmap will be much faster and cheaper than any other fusion approach,” Dr McKenzie added.

    See the full article here .


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    Please help promote STEM in your local schools.

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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.

     
      • richardmitnick 2:40 pm on February 23, 2020 Permalink | Reply

        Many people could not find this article. I had over 2000 views on the article in the blog. But not one signed up to receive the blog. I notified UNSW of the problem.

        Like

    • Mark Peak 10:11 am on February 24, 2020 Permalink | Reply

      Richard,
      I’m happy to receive your blog. There did not appear to be link to request it. I am very interested in seeing the advances in more environmentally friendly forms of energy and being kept abreast of what is discovered and can be made available globally.

      Like

      • richardmitnick 10:43 am on February 24, 2020 Permalink | Reply

        Mark- Thank you so very much for taking the blog. The events around this article are very strange. Apparently somehow the original article disappeared even though I found a copy. I am in the U.S. but for my blog I follow a lot of universities and institutions in Australia, which as a country is a hotbed of Basic and Applied Scientific Research, just up my alley. UNSW is a very important center for research. I generally do about ten blog posts per day and get around 250 views per day. For this post from UNSW I have received over 3,000 views. I did write to UNSW to let them know about this set of events. I am sure I am not the only person who notified the university. Again, thanks for your interest and your comment.

        Like

  • richardmitnick 10:30 am on January 9, 2020 Permalink | Reply
    Tags: "Electrons and positrons in an optimised stellarator", , At KIT Wendelstein a hydrogen plasma is used to investigate how energy can be generated by nuclear fusion reactions., Confine a matter-antimatter plasma in a magnetic cage of a small optimised stellarator., Eve Stenson, Fusion technology, KIT Wendelstein 7-AS built in built in Greifswald Germany, , New idea: APEX-D electron-positron plasma trap., , The APEX collaboration, The research group “Electrons and Positrons in an Optimised Stellarator”,   

    From Max Planck Institute for Plasma Physics: Women in STEM-“Electrons and positrons in an optimised stellarator” Eve Stenson 

    MPIPP bloc

    From Max Planck Institute for Plasma Physics

    January 09, 2020

    1
    Dr. Eve Stenson.Photo: IPP, Axel Griesch

    Helmholtz Young Investigators Group headed by Eve Stenson takes up work.

    Dr. Eve Stenson is one of ten young researchers selected by the Helmholtz Association in 2018 to establish their own research group. This was preceded by a multi-stage competition procedure with external peer review.

    From December 2019, Eve Stenson, born in Cleveland, Ohio/USA in 1981, is working with her IPP junior research group “Electrons and Positrons in an Optimised Stellarator” to create a plasma of electrons and their antiparticles, the positrons. The aim of this new branch of the APEX collaboration is to confine a matter-antimatter plasma in a magnetic cage of a small optimised stellarator. It is much simpler but still related to the large stellarator devices of fusion researchers such as Wendelstein 7-X in Greifswald.

    KIT Wendelstein 7-AS built in built in Greifswald, Germany

    There, a hydrogen plasma is used to investigate how energy can be generated by nuclear fusion reactions.

    Magnetically confined matter-antimatter plasmas have been investigated theoretically and computationally for several decades. However, such a plasma has never been produced in the laboratory before. According to theory, it should show special properties, such as being very stably trapped in certain magnetic field configurations, including optimised stellarators. The aim of the new junior research group will be to produce such plasmas and to investigate them experimentally – thus bringing together two frontiers of plasma physics research, i.e. stellarator optimisation and pair plasma experimentation.

    3
    Design of the APEX-D electron-positron plasma trap. A circular superconducting magnet coil (red) is producing the dipole field inside a vacuum vessel. This coil is levitated by a ring-shaped conductor (pink) which is installed above the vessel. It attracts the coil feedback-controlled. Graphic: IPP

    The exotic matter-antimatter plasmas differ from the “normal” plasmas of fusion researchers in one important respect: while the positively and negatively charged particles in an electron-positron plasma have exactly the same mass, the positively charged hydrogen ions in fusion plasmas are much heavier than the negatively charged electrons. This leads to a very different behaviour. The investigation of exotic matter-antimatter plasmas is therefore expected to provide fundamental insights into the physics of plasmas in general and opportunities to test computational simulations of plasma behaviour. It should even be possible to gain new insights about optimisation that can be used for the planning of new stellarators for fusion research. Since it is assumed that matter-antimatter plasmas occur in the vicinity of neutron stars and black holes, it is also astrophysically interesting to investigate these strange plasmas.

    Including last year’s – fifteenth – selection round, the Helmholtz Association has so far made 230 junior research groups possible. The costs – 300,000 euros per year for each group over a period of six years – are shared between the institute where the IPP is based and the Helmholtz Association, to which the IPP is affiliated as an associated institute.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    MPIPP campus

    The Max Planck Institute of Plasma Physics (Max-Planck-Institut für Plasmaphysik, IPP)is a physics institute for the investigation of plasma physics, with the aim of working towards fusion power. The institute also works on surface physics, also with focus on problems of fusion power.

    The IPP is an institute of the Max Planck Society, part of the European Atomic Energy Community, and an associated member of the Helmholtz Association.

    The IPP has two sites: Garching near Munich (founded 1960) and Greifswald (founded 1994), both in Germany.

    It owns several large devices, namely

    the experimental tokamak ASDEX Upgrade (in operation since 1991)
    the experimental stellarator Wendelstein 7-AS (in operation until 2002)
    the experimental stellarator Wendelstein 7-X (awaiting licensing)
    a tandem accelerator

    It also cooperates with the ITER and JET projects.

     
  • richardmitnick 5:51 am on December 19, 2019 Permalink | Reply
    Tags: , , China National Nuclear Corporation HL-2M tokamak, Fusion technology   

    From Science Alert: “China Could Be Turning on Its ‘Artificial Sun’ Fusion Reactor Really Soon” 

    ScienceAlert

    From Science Alert

    19 DEC 2019
    KRISTIN HAUSER

    1
    (sakkmesterke/iStock)

    In March, Chinese researchers, China National Nuclear Corporation, predicted that the nation’s HL-2M tokamak – a device designed to replicate nuclear fusion, the same reaction that powers the Sun – would be built before the end of 2019.

    2
    China National Nuclear Corporation HL-2M Tokamak

    No word yet on whether that’s still the case, but in November, Duan Xuru, one of the scientists working on the “artificial sun,” did provide an update, saying that construction was going smoothly and that the device should be operational in 2020 – a milestone that experts now tell Newsweek could finally make nuclear fusion a viable energy option on Earth.

    If scientists can figure out how to harness the power produced by nuclear fusion, it could provide a near-limitless source of clean energy.

    For decades, that’s made fusion power a holy grail for energy researchers.

    But the problem is that they’ve yet to figure out a cost-effective way to keep extremely hot plasma confined and stable long enough for fusion to take place.

    China’s HL-2M tokamak might be the device that’s finally up to that challenge – or at least yields the clues needed to overcome it.

    “HL-2M will provide researchers with valuable data on the compatibility of high-performance fusion plasmas with approaches to more effectively handle the heat and particles exhausted from the core of the device,” fusion physicist James Harrison, who isn’t involved with the project, told Newsweek.

    “This is one of the biggest issues facing the development of a commercial fusion reactor,” he continued, “and the results from HL-2M, as part of the international fusion research community, will influence the design of these reactors.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

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  • richardmitnick 3:13 pm on November 20, 2019 Permalink | Reply
    Tags: , Fusion technology, ,   

    From ASCR Discovery: “Tracking tungsten” 

    From ASCR Discovery
    ASCR – Advancing Science Through Computing


    From From ASCR Discovery

    November 2019

    Supercomputer simulations provide a snapshot of how plasma reacts with – and can damage – components in large fusion reactors.

    1
    A cross-section view of plasma (hotter yellow to cooler blues and purples) as it interacts with the tungsten surface of a tokamak fusion reactor divertor (gray walls in lower half of image), which funnels away gases and impurities. Tungsten atoms can sputter, migrate and redeposit (red squiggles), and smaller ions of helium, deuterium and tritium (red circles) can implant. Some of these interactions are beneficial, but other effects can degrade the tungsten surface and deplete and even quench the fusion reaction over time. Image courtesy of Tim Younkin, University of Tennessee.

    Nuclear fusion offers the tantalizing possibility of clean, sustainable power – if tremendous scientific and engineering challenges are overcome. One key issue: Nuclear engineers must understand how extreme temperatures, particle speeds and magnetic field variations will affect the plasma – the superheated gas where fusion happens – and the reactor materials designed to contain it. Predicting these plasma-material interactions is critical for understanding the function and safety of these machines.

    Brian Wirth of the University of Tennessee and the Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) is working with colleagues on one piece of this complex challenge: simulating tungsten, the metal that armors a key reactor component in ITER, the France-based world’s largest tokamak fusion reactor.

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

    ITER is expected to begin first plasma experiments in 2025 with the hope of producing 10 times more power than is required to heat it. Wirth’s team is part of DOE’s Scientific Discovery through Advanced Computing (SciDAC) program, and has collaborated with the Advanced Tokamak Modeling (AToM), another SciDAC project to develop computer codes that model the full range of plasma physics and material reactions inside a tokamak.

    “There’s no place today in a laboratory that can provide a similar environment to what we’re expecting on ITER,” Wirth says. “SciDAC and the high-performance computing (HPC) environment really give us an opportunity to simulate in advance how we expect the materials to perform, how we expect the plasma to perform, how we expect them to interact and talk to each other.” Modeling these features will help scientists learn about the effects of particular conditions and how long components might last. Such insights could support better design choices for fusion reactors.

    A tokamak’s doughnut-shaped reaction chamber confines rapidly moving, extremely hot, gaseous hydrogen ions – deuterium and tritium – and electrons within a strong magnetic field as a plasma, the fourth state of matter. The ions collide and fuse, spitting out alpha particles (two neutrons and two protons bound together) and neutrons. The particles release their kinetic energy as heat, which can boil water to produce steam that spins electricity-generating turbines. Today’s tokamaks don’t employ temperatures and magnetic fields high enough to produce self-sustaining fusion, but ITER could approach those benchmarks, over the next decades, toward producing 500 MW from 50 MW of input heat.

    Fusion plasmas must reach core temperatures up to hundreds of millions of degrees, and tokamak components could routinely experience temperatures approaching a thousand degrees – extreme conditions across a large range. Wirth’s group focuses on a component called the divertor, comprising 54 cassette assemblies that ring the doughnut’s base to funnel away waste gas and impurities. Each assembly includes a tungsten-armored plate supported by stainless steel. The divertor faces intensive plasma interactions. As the deuterium and tritium ions fuse, fast-moving neutrons, alpha particles and debris fall to the bottom of the reaction vessel and strike the divertor surface. Though only one part of the larger system, interactions between the metal and the reactive plasma have important implications for sustaining a fusion reaction and the durability of the divertor materials.

    Until recently, carbon fiber composites, protected divertors and other plasma-facing tokamak components, but such surfaces can react with tritium and retain it, a process that also limits recycling, the return of tritium to the plasma to continue the fusion reaction. Tungsten, with a melting point of more than 3,400 degrees, is expected to be more resilient. However, as plasma interacts with it, the ions can implant in the metal, forming bubbles or even diffusing hundreds of nanometers below the surface. Wirth and his colleagues are looking at how that process degrades the tungsten and quantifying the extent to which these interactions deplete tritium from the plasma. Both of these issues affect the rate of fusion reactions over time and can even entirely shut down, or quench, the fusion plasma.

    Exploring these questions requires integrating approaches at different time and length scales. The researchers use other SciDAC project codes to model the fundamental characteristics of the background plasma at steady state and how that energetic soup will interact with the divertor surface. Those results feed in to hPIC and F-TRIDYN, codes developed by Davide Curreli at the University of Illinois at Urbana-Champaign that describe the angles and energies of ions and alpha particles as they strike the tungsten surface. Building on those results, Wirth’s team can apply its own codes to characterize plasma particles as they interact with the tungsten and affect its surface.

    Developing these codes required combining top-down and bottom-up design approaches. To understand tungsten and its interaction with the helium ions (alpha particles) the fusion reaction produces, Wirth’s team has used molecular dynamics (MD) techniques. The simulations examined 20 million atoms, a relatively modest number compared with the largest calculations that approach 100 times that size, he notes. But they follow the materials for longer times, approximately 1.5 microseconds, approximately 1,500 times longer than most MD simulations. Those longer spans provide physics benchmarks for the top-down approach they developed to simulate the interactions of tungsten and plasma particles within cluster dynamics in a code called Xolotl, after the Aztec god of lightning and death. As part of this work, University of Tennessee graduate student Tim Younkin also has developed GITR (pronounced “guitar” for Global Impurity Transport). “With GITR we simulate all the species that are eroded off the surface, where do they ionize, what are their orbits following the plasma physics and dynamics of the electromagnetism, where do they redeposit,” Wirth says.

    The combination of codes has simulated several divertor operational scenarios on ITER, including a 100-second-long discharge of deuterium and tritium plasma designed to generate 100 MW of fusion power, about 20 percent of that which researchers plan to achieve on ITER. Overall the team found that the plasma causes tungsten to erode and re-deposit. Helium particles tend to erode tungsten, which could be a potential problem, Wirth says, though sometimes they also seem to block tritium from embedding deep within the tungsten, which could be beneficial overall because it would improve recycling.

    Although these simulations are contributing important insights, they are just the first steps toward understanding realistic conditions within ITER. These initial models simulate plasma with steady heat and ion-particle fluxes, but conditions in an operating tokamak constantly change, Wirth notes, and could affect overall material performance. His group plans to incorporate those changes in future simulations.

    The researchers also want to model beryllium, an element used to armor the main fusion chamber walls. Beryllium will also be eroded, transported and deposited into divertors, possibly altering the tungsten surface’s behavior.

    The researchers must validate all of these results with experiments, some of which must await ITER’s operation. Wirth and his team also collaborate with the smaller WEST tokamak in France on experiments to validate their coupled SciDAC plasma-surface interaction codes.

    Ultimately Wirth hopes these integrated codes will provide HPC tools that can truly predict physical response in these extreme systems. With that validation, he says, “we can think about using them to design better-functioning material components for even more aggressive operating conditions that could enable fusion to put energy on the grid.”

    See the full article here.


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    ASCRDiscovery is a publication of The U.S. Department of Energy

     
  • richardmitnick 11:51 am on October 4, 2019 Permalink | Reply
    Tags: , Fusion technology, , Quantum Astrometry   

    From Brookhaven National Lab: “Department of Energy Announces $21.4 Million for Quantum Information Science Research” 

    From Brookhaven National Lab

    October 1, 2019
    Ariana Manglaviti,
    amanglaviti@bnl.gov
    (631) 344-2347, or

    Peter Genzer,
    genzer@bnl.gov
    (631) 344-3174

    Projects linked to both particle physics and fusion energy

    Today, the U.S. Department of Energy (DOE) announced $21.4 million in funding for research in Quantum Information Science (QIS) related to both particle physics and fusion energy sciences.

    “QIS holds great promise for tackling challenging questions in a wide range of disciplines,” said Under Secretary for Science Paul Dabbar. “This research will open up important new avenues of investigation in areas like artificial intelligence while helping keep American science on the cutting edge of the growing field of QIS.”

    Funding of $12 million will be provided for 21 projects of two to three years’ duration in particle physics. Efforts will range from the development of highly sensitive quantum sensors for the detection of rare particles, to the use of quantum computing to analyze particle physics data, to quantum simulation experiments connecting the cosmos to quantum systems.

    Funding of $9.4 million will be provided for six projects of up to three years in duration in fusion energy sciences. Research will examine the application of quantum computing to fusion and plasma science, the use of plasma science techniques for quantum sensing, and the quantum behavior of matter under high-energy-density conditions, among other topics.

    Fiscal Year 2019 funding for the two initiatives totals $18.4 million, with out-year funding for the three-year particle physics projects contingent on congressional appropriations.

    Projects were selected by competitive peer review under two separate Funding Opportunity Announcements (and corresponding announcements for DOE laboratories) sponsored respectively by the Office of High Energy Physics and the Office of Fusion Energy Sciences with the Department’s Office of Science.

    A list of particle physics projects can be found here and fusion energy sciences projects here, both under the heading “What’s New.”

    Quantum Convolutional Neural Networks for High-Energy Physics Data Analysis

    1
    (From left to right) Brookhaven computational scientist Shinjae Yoo (principal investigator), Brookhaven physicist Chao Zhang, and Stony Brook University quantum information theorist Tzu-Chieh Wei are developing deep learning techniques to efficiently handle sparse data using quantum computer architectures. Data sparsity is common in high-energy physics experiments.

    Over the past few decades, the scale of high-energy physics (HEP) experiments and size of data they produce have grown significantly. For example, in 2017, the data archive of the Large Hadron Collider (LHC) at CERN in Europe—the particle collider where the Higgs boson was discovered—surpassed 200 petabytes.

    CERN LHC

    CERN CMS Higgs Event May 27, 2012


    CERN ATLAS Higgs Event

    For perspective, consider Netflix streaming: a 4K movie stream uses about seven gigabytes per hour, so 200 petabytes would be equivalent to 3,000 years of 4K streaming. Data generated by future detectors and experiments such as the High-Luminosity LHC, the Deep Underground Neutrino Experiment (DUNE), Belle II, and the Large Synoptic Survey Telescope (LSST) will move into the exabyte range (an exabyte is 1,000 times larger than a petabyte).

    FNAL LBNF/DUNE from FNAL to SURF, Lead, South Dakota, USA

    Belle II KEK High Energy Accelerator Research Organization Tsukuba, Japan

    LSST telescope, The Vera Rubin Survey Telescope currently under construction on the El Peñón peak at Cerro Pachón Chile, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile, alongside the existing Gemini South and Southern Astrophysical Research Telescopes.

    These large data volumes present significant computing challenges for simulating particle collisions, transforming raw data into physical quantities such as particle position, momentum, and energy (a process called event reconstruction), and performing data analysis. As detectors become more sensitive, simulation capabilities improve, and data volumes increase by orders of magnitude, the need for scalable data analytics solutions will only increase.

    A viable solution could be QIS. Quantum computers and algorithms have the capability to solve problems exponentially faster than classically possible. The Quantum Convolutional Neural Networks (CNNs) for HEP Data Analysis project will exploit this “quantum advantage” to develop machine learning techniques for handling data-intensive HEP applications. Neural networks refer to a class of deep learning algorithms that are loosely modelled on the architecture of neuron connections in the human brain. One type of neural network is the CNN, which is most commonly used for computer vision tasks, such as facial recognition. CNNs are typically composed of three types of layers: convolution layers (convolution is a linear mathematical operation) that extract meaningful features from an image, pooling layers that reduce the number of parameters and computations, and fully connected layers that classify the extracted features into a label.

    In this case, the scientists on the project will develop a quantum-accelerated CNN algorithm and quantum memory optimized to handle extremely sparse data. Data sparsity is common in HEP experiments, for which there is a low probability of producing exotic and interesting signals; thus, rare events must be extracted from a much larger amount of data. For example, even though the size of the data from one DUNE event could be on the order of gigabytes, the signals represent one percent or less of those data. They will demonstrate the algorithm on DUNE data challenges, such as classifying images of neutrino interactions and fitting particle trajectories. Because the DUNE particle detectors are currently under construction and will not become operational until the mid-2020s, simulated data will be used initially.

    4
    Neutrino interaction events are characterized by extremely sparse data, as can be seen in the above 3-D image reconstruction from 2-D measurements.

    “Customizing a CNN to work efficiently on sparse data with a quantum computer architecture will not only benefit DUNE but also other HEP experiments,” said principal investigator Shinjae Yoo, a computational scientist in the Computer Science and Mathematics Department of Brookhaven Lab’s Computational Science Initiative (CSI).

    The co-investigator is Brookhaven physicist Chao Zhang. Yoo and Zhang will collaborate with quantum information theorist Tzu-Chieh Wei, an associate professor at Stony Brook University’s C.N. Yang Institute for Theoretical Physics.

    Quantum Astrometry

    3
    (Left photo, left to right) Brookhaven Lab physicists Paul Stankus, Andrei Nomerotski (principal investigator), Sven Herrmann, and (right photo) Eden Figueroa (a Stony Brook University joint appointee) are developing a new quantum technique that will enable more precise measurements for studies in astrophysics and cosmology. They will use a fiber-coupled telescope with adaptive optics (seen in left photo) for the proof-of-principle measurements.

    The resolution of any optical telescope is fundamentally limited by the size of the aperture, or the opening through which particles of light (photons) are collected, even after the effects of atmospheric turbulence and other fluctuations have been corrected for. Optical interferometry—a technique in which light from multiple telescopes is combined to synthesize a large aperture between them—can improve resolution. Though interferometers can provide the clearest images of very small astronomical objects such as distant galaxies, stars, and planetary systems, the instruments’ intertelescope connections are necessarily complex. This complexity limits the maximum separation distance (“baseline”)—and hence the ultimate resolution.

    An alternative approach to overcoming the aperture resolution limit is to quantum mechanically interfere star photons with distributed entangled photons at separated observing locations. This approach exploits the phenomenon of quantum entanglement, which occurs when two particles such as photons are “linked.” Though these pairs are not physically connected, measurements involving them remain correlated regardless of the distance between them.

    5
    Schematic of two-photon interferometry. If the two photons are close enough together in time and frequency, the pattern of coincidences between measurements at detectors c and d in L and detectors g and h in R will be sensitive to the phase differences. The phase differences from each source can be related to their angular position in the sky.

    The Quantum Astrometry project seeks to exploit this phenomenon to develop a new quantum technique for high-resolution astrometry—the science of measuring the positions, motions, and magnitudes of celestial objects—based on two-photon interferometry. In traditional optical interferometry, the optical path for the photons from the telescopes must be kept highly stable, so the baseline for today’s interferometers is about 100 meters. At this baseline, the resolution is sufficient to directly see exoplanets or track stars orbiting the supermassive black hole in the center of the Milky Way. One goal of quantum astrometry is to reduce the demands for intertelescope links, thereby enabling longer baselines and higher resolutions.

    Pushing the resolution even further would allow more precise astrometric measurements for studies in astrophysics and cosmology. For example, black hole accretion discs—flat astronomical structures made up of a rapidly rotating gas that slowly spirals inward—could be directly imaged to test theories of gravity. An orders-of-magnitude higher resolution would also enable scientists to refine measurements of the expansion rate of the universe, map gravitational microlensing events (temporary brightening of distant objects when light is bent by another object passing through our line of sight) to probe the nature of dark matter (a type of “invisible” matter thought to make up most of the universe’s mass), and measure the 3-D “peculiar” velocities of stars (their individual motion with respect to that of other stars) across the galaxy to determine the forces acting on all stars.

    In classical interferometry, photons from an astronomical source strike two telescopes with some relative delay (phase difference), which can be determined through interference of their intensities. Using two photons in the form of entangled pairs that can transmit simultaneously to both stations and interfere with the star photons would allow arbitrarily long baselines and much finer resolution on this relative phase difference and hence on astrometry.

    “This is a very exploratory project where for the first time we will test ideas of two-photon optical interferometry using quantum entanglement for astronomical observations,” said principal investigator Andrei Nomerotski, a physicist in the Lab’s Cosmology and Astrophysics Group. “We will start with simple proof-of-principle experiments in the lab, and in two years, we hope to have a demonstrator with real sky observations.

    “It’s an example of how quantum techniques can open new ranges for scientific sensors and detectors,” added Paul Stankus, a physicist in Brookhaven’s Instrumentation Division who is working on QIS.

    The other team members are Brookhaven physicist Sven Herrmann, a collaborator on several astrophysics projects, including LSST, and Brookhaven–Stony Brook University joint appointee Eden Figueroa, a leading figure in quantum communication technology.

    See the full article here .


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    BNL Campus


    BNL Center for Functional Nanomaterials

    BNL NSLS-II


    BNL NSLS II

    BNL RHIC Campus

    BNL/RHIC Star Detector

    BNL RHIC PHENIX

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
    i1

     
  • richardmitnick 1:06 pm on September 20, 2019 Permalink | Reply
    Tags: "How to predict crucial plasma pressure in future fusion facilities", Accurate predictions of the pressure of the plasma, , Fusion technology, ,   

    From PPPL- “Today’s forecast: How to predict crucial plasma pressure in future fusion facilities” 

    From PPPL

    September 20, 2019
    John Greenwald

    1
    Physicist Michael Churchill. (Photo by Elle Starkman/Office of Communications)

    A key requirement for future facilities that aim to capture and control on Earth the fusion energy that drives the sun and stars is accurate predictions of the pressure of the plasma — the hot, charged gas that fuels fusion reactions inside doughnut-shaped tokamaks that house the reactions. Central to these predictions is forecasting the pressure that the scrape-off layer, the thin strip of gas at the edge of the plasma, exerts on the divertor — the device that exhausts waste heat from fusion reactions.

    Researchers at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have developed new insights into the physics governing the balance of pressure in the scrape-off layer. This balance must ensure that the pressure of the plasma throughout the tokamak is high enough to produce a largely self-heating fusion reaction. The balance must also limit the potentially damaging impact of heat and plasma particles that strike the divertor and other plasma-facing components of the tokamak.

    “Previous simple assumptions about the balance of pressure in the scrape-off layer are incomplete,” said PPPL physicist Michael Churchill, lead author of a Nuclear Fusion paper that describes the new findings. “The codes that simulate the scrape-off layer have often thrown away important aspects of the physics, and the field is starting to recognize this.”

    Fusion, the power that drives the sun and stars, is the fusing of light 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.

    Key factors

    Churchill and PPPL colleagues determined the key factors behind the pressure balance by running the state-of-the-art XGCa computer code on the Cori and Edison supercomputers at the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility.

    NERSC at LBNL

    NERSC Cray Cori II supercomputer, named after Gerty Cori, the first American woman to win a Nobel Prize in science

    NERSC Hopper Cray XE6 supercomputer, named after Grace Hopper, One of the first programmers of the Harvard Mark I computer

    NERSC Cray XC30 Edison supercomputer

    NERSC GPFS for Life Sciences


    The Genepool system is a cluster dedicated to the DOE Joint Genome Institute’s computing needs. Denovo is a smaller test system for Genepool that is primarily used by NERSC staff to test new system configurations and software.

    NERSC PDSF computer cluster in 2003.

    PDSF is a networked distributed computing cluster designed primarily to meet the detector simulation and data analysis requirements of physics, astrophysics and nuclear science collaborations.

    Future:

    Cray Shasta Perlmutter SC18 AMD Epyc Nvidia pre-exascale supeercomputer

    NERSC is a DOE Office of Science User Facility.

    The code treats plasma at a detailed kinetic — or particle motion— level rather than as a fluid.

    Among key features found was the impact of the bulk drift of ions, an impact that previous codes have largely ignored. Such drifts “can play an integral role” the authors wrote, and “are very important to take into account.”

    Also seen to be important in the momentum or pressure balance were the kinetic particle effects due to ions having different temperatures depending on their direction. Since the temperature of ions is hard to measure in the scrape-off layer, the paper says, “increased diagnostic efforts should be made to accurately measure the ion temperature and flows and thus enable a better understanding of the role of ions in the SOL.”

    The new findings could improve understanding of the scrape-off layer pressure at the divertor, Churchill said, and could lead to accurate forecasts for the international ITER experiment under construction in France and other next-generation tokamaks.

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

    Support for this work comes from the DOE Office of Science under the SciDAC Center for High Fidelity Boundary Plasma Simulation (HBPS). The research used resources of the National Energy Research Scientific Computing Center (NERSC). Coauthors of the paper were PPPL physicists C.S Chang, Seung-Ho Ku, Robert Hager, Rajesh Maingi, Daren Stotler and Hong Qin.

    See the full article here .


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    Please help promote STEM in your local schools.

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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.http://www.energy.gov.

    Princeton University campus

     
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