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  • richardmitnick 8:12 pm on September 5, 2019 Permalink | Reply
    Tags: "New national facility will explore low-temperature plasma a dynamic source of innovation for modern technologies", Also to be explored is the interface between plasma and solid-state physics., Low-temperature plasma contrasts with the superhot plasma that PPPL investigates that fuels the fusion energy that powers the sun and stars., PPPL, Scientists at PPPL and Princeton will provide guidance to collaborators who come to the facility from companies universities and laboratories throughout the country., The new facility will launch this October with U.S. Department of Energy (DOE) funding of $1.2 million a year for five years., The Princeton Plasma Physics Laboratory (PPPL) has teamed with Princeton University to become home to a collaborative facility open to researchers from across the country ., The total venture supported by the DOE’s Office of Science will be part of the Plasma Science and Technology Department at PPPL.   

    From PPPL: “New national facility will explore low-temperature plasma, a dynamic source of innovation for modern technologies” 

    From PPPL

    September 5, 2019
    John Greenwald

    1
    Princeton collaborative research team from left: Mikhail Shneider; Igor Kaganovich; Yevgeny Raitses; Sophia Gershman; Nirbhav Chopra, Princeton plasma physics graduate student who will use the new facility; Shurik Yatom; Arthur Dogariu. (Photo by Elle Starkman/Office of Communications)

    Low-temperature plasma, a rapidly expanding source of innovation in fields ranging from electronics to health care to space exploration, is a highly complex state of matter. So complex that the Princeton Plasma Physics Laboratory (PPPL) has teamed with Princeton University to become home to a collaborative facility open to researchers from across the country to advance the understanding and control of this dynamic physical state.

    Extensive resources

    The new facility, to launch this October with U.S. Department of Energy (DOE) funding of $1.2 million a year for five years, opens the extensive diagnostic and computational resources at PPPL and Princeton to the academic, scientific and industrial communities. More than 40 researchers are estimated to be interested in topics that the facility will explore, said PPPL physicist Yevgeny Raitses, principal investigator of the new unit, the Princeton Collaborative Research Facility on Low Temperature Plasma.

    Raitses heads the PPPL Laboratory for Plasma Nanosynthesis, which pioneers research on low-temperature plasma to improve the production of nanoparticles — substances millions of times thinner than a human hair found in everything from swimwear to pharmaceuticals. All state-of-the-art instruments housed in the plasma nanosynthesis laboratory will become available to collaborators in the new facility.

    Raitses and physicist Igor Kaganovich, deputy head of the PPPL Theory Department, have long extended the outreach of low-temperature plasma research. Over the past 10 years they have collaborated with companies on topics ranging from the fabrication of microchips to the production of medical treatments to the development of a power switch to modernize the electric grid.

    “World-class program”

    Such companies could now make use of the new facility. “I am delighted with this award,” PPPL Director Steve Cowley said of the new collaborative unit. “Through the leadership of Yevgeny and Igor and collaborations with Princeton University we have developed a world-class program in low temperature plasma science — this will take us to another level.”

    Low-temperature plasma contrasts with the superhot plasma that PPPL investigates that fuels the fusion energy that powers the sun and stars. Fusion plasmas consist chiefly of free-floating electrons and atomic nuclei, or ions, while low-temperature plasmas, which are up to 10,000 times cooler, include a large complement of neutral and partially ionized atoms mixed in with these particles.

    The mixture interacts with solids and liquids to produce applications in a wide range of fields. Among the key topics the facility will explore are interactions with liquids that can affect chemical processes and improve the production of environmental and health care systems, to cite two examples.

    New explorations

    Also to be explored is the interface between plasma and solid-state physics. The process could lead to low-cost and high-volume production of photovoltaic cells for turning sunlight into electricity, among other developments affecting solid-state matter.

    Hosting such research comes naturally to PPPL, the only national laboratory dedicated to the study of fusion energy and plasma science. “It’s important for the nation’s plasma physics lab to make a major contribution to understanding the physics of low-temperature plasmas,” said Jon Menard, deputy director for research at PPPL. “This facility will open all the tools in the laboratory’s low-temperature area for wider use.”

    Scientists at PPPL and Princeton will provide guidance to collaborators who come to the facility from companies, universities and laboratories throughout the country. Among physicists joining Raitses and Kaganovitch on the PPPL team will be Sophia Gershman, an expert in the interaction of plasma and liquids, and Shurik Yatom, who has developed methods for characterizing the synthesis of nanoparticles in plasma in situ, or while the process is taking place. Additional PPPL physicists will conduct research and give guidance to researchers using of the facility.

    Princeton laboratories and centers

    Heading the Princeton University team will be physicists Mikhail Shneider, an expert in plasma physics, fluid dynamics and non-linear optics, who will serve as co-principal investigator. Arthur Dogariu, who pioneered several advanced optical diagnostic techniques, will lead the collaborative center’s experimental efforts at Princeton. University laboratories and centers, including the Princeton Institute for the Science and Technology of Materials (PRISM), will provide access to collaborators, with faculty members and graduate students serving as users and partners in the new facility.

    The total venture, supported by the DOE’s Office of Science, will be part of the Plasma Science and Technology Department at PPPL that physicist Philip Efthimion heads. “We’ll be offering our diagnostic and computer modeling tools to the research community and the private sector,” Efthimion said. “This will provide new opportunities to collaborate between the community and the private sector and to expand our research on low-temperature plasmas.”

    See the full article here .


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

    Stem Education Coalition


    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 7:56 am on July 2, 2019 Permalink | Reply
    Tags: , , , PPPL   

    From PPPL: “Artificial intelligence accelerates efforts to develop clean, virtually limitless fusion energy” 

    From PPPL

    April 17, 2019 [Just found this in social media]
    John Greenwald

    1
    Depiction of fusion research on a doughnut-shaped tokamak enhanced by artificial intelligence. (Depiction by Eliot Feibush/PPPL and Julian Kates-Harbeck/Harvard University)

    Artificial intelligence (AI), a branch of computer science that is transforming scientific inquiry and industry, could now speed the development of safe, clean and virtually limitless fusion energy for generating electricity. A major step in this direction is under way at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Princeton University, where a team of scientists working with a Harvard graduate student is for the first time applying deep learning — a powerful new version of the machine learning form of AI — to forecast sudden disruptions that can halt fusion reactions and damage the doughnut-shaped tokamaks that house the reactions.

    Promising new chapter in fusion research

    “This research opens a promising new chapter in the effort to bring unlimited energy to Earth,” Steve Cowley, director of PPPL, said of the findings, which are reported in the current issue of Nature magazine. “Artificial intelligence is exploding across the sciences and now it’s beginning to contribute to the worldwide quest for fusion power.”

    Fusion, which 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 energy. Scientists are seeking to replicate fusion on Earth for an abundant supply of power for the production of electricity.

    Crucial to demonstrating the ability of deep learning to forecast disruptions — the sudden loss of confinement of plasma particles and energy — has been access to huge databases provided by two major fusion facilities: the DIII-D National Fusion Facility that General Atomics operates for the DOE in California, the largest facility in the United States, and the Joint European Torus (JET) in the United Kingdom, the largest facility in the world, which is managed by EUROfusion, the European Consortium for the Development of Fusion Energy. Support from scientists at JET and DIII-D has been essential for this work.

    DOE DIII-D Tokamak

    Joint European Torus, at the Culham Centre for Fusion Energy in the United Kingdom

    The vast databases have enabled reliable predictions of disruptions on tokamaks other than those on which the system was trained — in this case from the smaller DIII-D to the larger JET. The achievement bodes well for the prediction of disruptions on ITER, a far larger and more powerful tokamak that will have to apply capabilities learned on today’s fusion facilities.


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

    The deep learning code, called the Fusion Recurrent Neural Network (FRNN), also opens possible pathways for controlling as well as predicting disruptions.

    Most intriguing area of scientific growth

    “Artificial intelligence is the most intriguing area of scientific growth right now, and to marry it to fusion science is very exciting,” said Bill Tang, a principal research physicist at PPPL, coauthor of the paper and lecturer with the rank and title of professor in the Princeton University Department of Astrophysical Sciences who supervises the AI project. “We’ve accelerated the ability to predict with high accuracy the most dangerous challenge to clean fusion energy.”

    Unlike traditional software, which carries out prescribed instructions, deep learning learns from its mistakes. Accomplishing this seeming magic are neural networks, layers of interconnected nodes — mathematical algorithms — that are “parameterized,” or weighted by the program to shape the desired output. For any given input the nodes seek to produce a specified output, such as correct identification of a face or accurate forecasts of a disruption. Training kicks in when a node fails to achieve this task: the weights automatically adjust themselves for fresh data until the correct output is obtained.

    A key feature of deep learning is its ability to capture high-dimensional rather than one-dimensional data. For example, while non-deep learning software might consider the temperature of a plasma at a single point in time, the FRNN considers profiles of the temperature developing in time and space. “The ability of deep learning methods to learn from such complex data make them an ideal candidate for the task of disruption prediction,” said collaborator Julian Kates-Harbeck, a physics graduate student at Harvard University and a DOE-Office of Science Computational Science Graduate Fellow who was lead author of the Nature paper and chief architect of the code.

    Training and running neural networks relies on graphics processing units (GPUs), computer chips first designed to render 3D images. Such chips are ideally suited for running deep learning applications and are widely used by companies to produce AI capabilities such as understanding spoken language and observing road conditions by self-driving cars.

    Kates-Harbeck trained the FRNN code on more than two terabytes (1012) of data collected from JET and DIII-D. After running the software on Princeton University’s Tiger cluster of modern GPUs, the team placed it on Titan, a supercomputer at the Oak Ridge Leadership Computing Facility, a DOE Office of Science User Facility, and other high-performance machines.

    Tiger Dell Linux supercomputer at Princeton University

    ORNL Cray XK7 Titan Supercomputer, once the fastest in the world, now No.9 on the TOP500

    A demanding task

    Distributing the network across many computers was a demanding task. “Training deep neural networks is a computationally intensive problem that requires the engagement of high-performance computing clusters,” said Alexey Svyatkovskiy, a coauthor of the Nature paper who helped convert the algorithms into a production code and now is at Microsoft. “We put a copy of our entire neural network across many processors to achieve highly efficient parallel processing,” he said.

    The software further demonstrated its ability to predict true disruptions within the 30-millisecond time frame that ITER will require, while reducing the number of false alarms. The code now is closing in on the ITER requirement of 95 percent correct predictions with fewer than 3 percent false alarms. While the researchers say that only live experimental operation can demonstrate the merits of any predictive method, their paper notes that the large archival databases used in the predictions, “cover a wide range of operational scenarios and thus provide significant evidence as to the relative strengths of the methods considered in this paper.”

    From prediction to control

    The next step will be to move from prediction to the control of disruptions. “Rather than predicting disruptions at the last moment and then mitigating them, we would ideally use future deep learning models to gently steer the plasma away from regions of instability with the goal of avoiding most disruptions in the first place,” Kates-Harbeck said. Highlighting this next step is Michael Zarnstorff, who recently moved from deputy director for research at PPPL to chief science officer for the laboratory. “Control will be essential for post-ITER tokamaks – in which disruption avoidance will be an essential requirement,” Zarnstorff noted.

    Progressing from AI-enabled accurate predictions to realistic plasma control will require more than one discipline. “We will combine deep learning with basic, first-principle physics on high-performance computers to zero in on realistic control mechanisms in burning plasmas,” said Tang. “By control, one means knowing which ‘knobs to turn’ on a tokamak to change conditions to prevent disruptions. That’s in our sights and it’s where we are heading.”

    Support for this work comes from the Department of Energy Computational Science Graduate Fellowship Program of the DOE Office of Science and National Nuclear Security Administration; from Princeton University’s Institute for Computational Science and Engineering (PICsiE); and from Laboratory Directed Research and Development funds that PPPL provides. The authors wish to acknowledge assistance with high-performance supercomputing from Bill Wichser and Curt Hillegas at PICSciE; Jack Wells at the Oak Ridge Leadership Computing Facility; Satoshi Matsuoka and Rio Yokata at the Tokyo Institute of Technology; and Tom Gibbs at NVIDIA Corp.

    See the full article here .


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

    Stem Education Coalition


    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 4:28 pm on February 7, 2019 Permalink | Reply
    Tags: , , , , MRI [magnetorotational instability], PPPL   

    From PPPL: “Novel experiment validates a widely speculated and important mechanism during the formation of stars and planets” 


    From PPPL

    February 5, 2019
    John Greenwald

    1
    Water-filled version of MRI [magnetorotational instability] experiment showing transparent outer cylinder and blackened inner cylinder. Red lasers enter at bottom to measure the local speed of the water. (Photo courtesy of Eric Edlund and Elle Starkman)

    How have stars and planets developed from the clouds of dust and gas that once filled the cosmos? A novel experiment at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has demonstrated the validity of a widespread theory known as “magnetorotational instability,” or MRI, that seeks to explain the formation of heavenly bodies.

    The theory holds that MRI allows accretion disks, clouds of dust, gas, and plasma that swirl around growing stars and planets as well as black holes, to collapse into them. According to the theory, this collapse happens because turbulent swirling plasma, technically known as “Keplerian flows,” gradually grows unstable within a disk. The instability causes angular momentum — the process that keeps orbiting planets from being drawn into the sun — to decrease in inner sections of the disk, which then fall into celestial bodies.

    Unlike orbiting planets, the matter in dense and crowded accretion disks may experience forces such as friction that cause the disks to lose angular momentum and be drawn into the objects they swirl around. However, such forces cannot fully explain how quickly matter must fall into larger objects for planets and stars to form on a reasonable timescale.

    MRI experiment

    At PPPL, physicists have simulated the hypothesized broader process in the laboratory’s MRI experiment. The unique device consists of two concentric cylinders that rotate at different speeds. In this experiment, researchers filled the cylinders with water and attached a water-filled plastic ball tethered by a spring to a post in the center of the device; the stretching and bending spring mimicked the magnetic forces in the plasma in accretion disks. Researchers then rotated the cylinders and videoed the behavior of the ball as seen from the top down.

    The findings, reported in Communications Physics, compared the motions of the spring-tethered ball when rotating at different speeds. “With no stretching, nothing happens to the angular momentum,” said Hantao Ji, a professor of astrophysical sciences at Princeton University and principal researcher on the MRI and a coauthor of the paper. “Nothing also happens if the spring is too strong.”

    However, direct measurement of the results found that when the spring-tethering was weak — analogous to the condition of the magnetic fields in accretion disks —behavior of the angular momentum of the ball was consistent with MRI predictions of developments in a real accretion disk. The findings showed that the weakly tethered rotating ball gained angular momentum and shifted outward during the experiment. Since the angular momentum of a rotating body must be conserved, any gains in momentum must be matched by a loss of momentum in the inner section, allowing gravity to draw the disk into the object it has been orbiting.

    Contributing to research for this paper was lead author Derek Hung, a former Princeton graduate student, together with physicists Erik Gilson and Kyle Caspary of PPPL and astrophysicist Eric Blackman of the Department of Physics and Astronomy and the Laboratory for Laser Energetics at the University of Rochester, who brought up the idea. Support for this work comes from NASA, the National Science Foundation, the DOE Office of Science, the Simons Foundation, the Institute for Advanced Study, and the Kavli Institute for Theoretical Physics.

    See the full article here .


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

    Stem Education Coalition


    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 2:09 pm on December 7, 2018 Permalink | Reply
    Tags: , Magnetospheric Multiscale Satellite (MMS) mission launched in 2015, , PPPL, Princeton Magnetic Reconnection Experiment (MRX) at PPPL   

    From PPPL: “Experiments at PPPL show remarkable agreement with satellite sightings” 


    From PPPL

    December 7, 2018
    John Greenwald

    1
    Members of the MRX team with the device in the background. From left, Masaaki Yamada, Jongsoo Yoo, Jonathan Jara-Almonte, Will Fox, and Hantao Ji.
    (Photo by Elle Starkman/PPPL Office of Communications)

    1
    Illustration of the MMS spacecraft in orbit in Earth’s magnetic field. NASA

    As on Earth, so in space. A four-satellite mission that is studying magnetic reconnection — the breaking apart and explosive reconnection of the magnetic field lines in plasma that occurs throughout the universe — has found key aspects of the process in space to be strikingly similar to those found in experiments at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL). The similarities show how the studies complement each other: The laboratory captures important global features of reconnection and the spacecraft documents local key properties as they occur.

    NASA Magnetic reconnection, Credit: M. Aschwanden et al. (LMSAL), TRACE, NASA

    The observations made by the Magnetospheric Multiscale Satellite (MMS) mission, which NASA launched in 2015 to study reconnection in the magnetic field that surrounds the Earth, correspond quite well with past and present laboratory findings of the Magnetic Reconnection Experiment (MRX) at PPPL. Previous MRX research uncovered the process by which rapid reconnection occurs and identified the amount of magnetic energy that is converted to particle energy during the process, which gives rise to northern lights, solar flares and geomagnetic storms that can disrupt cell phone service, black out power grids and damage orbiting satellites.

    Guidelines for MMS measurements

    The previous MRX findings served as guidelines for measurements taken by the MMS mission, which seeks to understand the region in which the reconnection of field lines in plasma — the state of matter composed of free electrons and atomic nuclei, or ions — takes place. The latest PPPL experiments extend the findings to new areas of agreement. “Despite huge differences in the size of the reconnection layers in the MRX and in space, remarkably similar characteristics are observed in both,” said Masaaki Yamada, principal investigator on the MRX, and lead author of the recent paper reporting the results in the December 6 edition of Nature Communications .

    The past laboratory research examined “symmetric” reconnection, in which the density of the plasmas on each side of the reconnection regions are roughly the same. The new paper looks at reconnection in the magnetopause — the outer region of the magnetosphere — and in the MRX that is “asymmetric,” meaning that the plasma on one side of the region is at least 10 times denser than on the other. The MMS mission has focused its initial research on the asymmetric aspect of reconnection, since the plasma in the solar wind — the charged particles flowing from the sun — is vastly denser than the plasma in the magnetosphere.

    In the new paper, researchers examine what is called the “two-fluid” physics of reconnection that describes each behavior of ions and electrons differently during the process. Such physics dominates magnetic reconnection in both MRX and magnetospheric plasma systems, allowing for an unprecedented level of cross-examination between laboratory measurements and space observations.

    Key findings

    Following are key findings of the two-fluid, asymmetric research on MRX that is shown to be in striking agreement with measurements of electron and ion behavior by the space satellites and the conversion of magnetic energy to particle energy. Computer simulations aided these findings:

    • Electrons. The experiments demonstrated that electron current flows perpendicular, and not parallel as once thought, to the magnetic field. This flow is key to the conversion of magnetic energy in electrons that occurs in a narrow boundary layer called the “electron diffusion region” where rapid reconnection takes place. The finding is consistent with the recent MMS space measurements and new in the laboratory for asymmetric reconnection.

    • Ions. The ion current also flows perpendicular to the magnetic field as in the electron case, and likewise is key to the conversion of ion magnetic energy to particle energy. For ions, this conversion occurs in the wider “ion diffusion region” between converging plasmas and is a similarly recent finding about asymmetric reconnection in laboratory plasmas.

    The MRX experiments further studied different aspects of conversion in the symmetric and asymmetric cases. In symmetric reconnection, 50 percent of magnetic energy was previously found to be converted to ions and electrons, with one-third of the conversion affecting the electrons and two-thirds accelerating the ions. The total conversion rate remains roughly the same in the asymmetric case, as does the ratio of energy conversion for ions and electrons.

    PPPL researchers contributing to this study were Jongsoo Yoo, Will Fox, Jonathan Jara-Almote and Hantao Ji. Also contributing were physicists at the NASA Goddard Space Flight Center, Los Alamos National Laboratory, the Southwest Research Institute, and the universities of New Hampshire and Bergen in Bergen, Norway. Computer simulations were conducted at Los Alamos National Laboratory. Support for this work comes from DOE’s Office of Science, NASA, and the National Science Foundation.

    See the full article here .


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

    Stem Education Coalition


    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 9:14 pm on November 5, 2018 Permalink | Reply
    Tags: , , , , , PPPL, Space is permeated by magnetic fields with a wide range of strengths, Turbulence in space might solve outstanding astrophysical mystery   

    From PPPL: “Turbulence in space might solve outstanding astrophysical mystery” 


    From PPPL

    November 5, 2018
    Raphael Rosen

    1
    PPPL graduate student Denis St-Onge. (Photo by Elle Starkman)

    Contrary to what many people believe, outer space is not empty. In addition to an electrically charged soup of ions and electrons known as plasma, space is permeated by magnetic fields with a wide range of strengths. Astrophysicists have long wondered how those fields are produced, sustained, and magnified. Now, scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have shown that plasma turbulence might be responsible, providing a possible answer to what has been called one of the most important unsolved problems in plasma astrophysics.

    The researchers used powerful computers at the Princeton Institute for Computational Science and Engineering (PICSciE) and the National Energy Research Scientific Computing Center (NERSC) at the DOE’s Lawrence Berkeley National Laboratory to simulate how the turbulence could intensify magnetic fields through what is known as the dynamo effect, in which the magnetic fields become stronger as the magnetic field lines twist and turn.

    Tiger Dell Linux supercomputer at Princeton University

    NERSC

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


    LBL NERSC Cray XC30 Edison supercomputer


    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


    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.

    “This work constitutes an important step toward answering for the first time the question of whether turbulence can amplify magnetic fields to dynamical strengths in a hot, dilute plasma, such as that residing within clusters of galaxies,” said Matthew Kunz, an astrophysics professor at Princeton University and an author of the paper, which was published in The Astrophysical Journal Letters.

    Past research has focused on dynamos as they might occur in so-called collisional plasmas, in which particles collectively behave as a fluid. But intergalactic plasmas are collisionless, so past experiments are not necessarily relevant. This new research is meant to address that gap. “We wanted to see how the dynamo would behave in the collisionless regime,” said Denis St-Onge, graduate student in the Princeton Program in Plasma Physics at PPPL and lead author of the paper.

    St-Onge and Kunz focused on the ways in which the velocities and magnetic fields of individual particles within collisionless plasma are directly linked. This linkage — if one quantity increases or decreases, the other must, too — would seem to rule out the existence of a dynamo. “If this were the whole story, it would be disastrous for the dynamo,” said St-Onge. “To match what we observe in space, the dynamo would have to increase the strength of the seed magnetic field by at least a factor of one trillion, but the energy of the particles would also have to increase, and there’s just not enough available energy in the dynamo for that to happen.”

    To produce the strength of magnetic fields observed in space, the tie that binds particle energy to magnetism must be severed. This is just what St-Onge and Kunz observed in the computer simulations: that types of plasma turbulence known as mirror and firehose instabilities caused the plasma particles to scatter, and scattering broke the link between particle energy and magnetism and allowed the amplitudes of the magnetic fields to grow closer to what is observed in nature.

    Future research, St-Onge notes, will focus on why this turbulent scattering occurs. “In addition, we would like to investigate the specifics of particle scattering,” St-Onge said. “How exactly do the instabilities cause the particles to scatter, how often does the scattering occur, and can the scattering lead to sudden, dramatic growth of a magnetic field? The last idea is a notion proposed by PPPL Director Steven Cowley years ago. We would like to investigate whether this is true.”

    See the full article here .


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

    Stem Education Coalition


    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 9:27 am on September 26, 2018 Permalink | Reply
    Tags: , , , , Magnetic Reconnection Experiment, PPPL   

    From PPPL: “No longer whistling in the dark: Scientists uncover a little-understood source of waves generated throughout the universe” 


    From PPPL

    September 25, 2018
    John Greenwald

    1
    PPPL physicist Jongsoo Yoo stands next to the Magnetic Reconnection Experiment (MRX). (Photo by Elle Starkman)

    2
    PPPL Magnetic Reconnection Experiment (MRX). No image credit

    Magnetic reconnection, the snapping apart and violent reconnection of magnetic field lines in plasma — the state of matter composed of free electrons and atomic nuclei — occurs throughout the universe and can whip up space storms that disrupt cell phone service and knock out power grids. Now scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and other laboratories, using data from a NASA four-satellite mission that is studying reconnection, have developed a method for identifying the source of waves that help satellites determine their location in space.

    The team of researchers, led by PPPL physicist Jongsoo Yoo, have correlated magnetic field measurements taken by the Magnetospheric Multiscale (MMS) mission that is orbiting at the edge of the magnetic field that surrounds the Earth.

    NASA/MMS prior to launch


    NASA MMS satellites in space. Credit: NASA

    The findings identified the source of the propagation of “whistler waves” — waves with whistle-like sounds that drop from high to low and stem from reconnection — whose detection orients the satellites relative to reconnection activity that can affect the Earth.

    The research, reported in Geophysical Research Letters, marks development of “a new methodology for measuring how the wave propagates in reconnection,” said Yoo, lead author of the paper. The source, he said, is what are called “tail electrons” — particles with energy that is far greater than that of the bulk electrons in reconnecting field lines. Such electrons are “temperature anisotropic,” meaning that their temperature is not uniform but differs when measured in different directions.

    “What we prove is that you couldn’t have whistler waves without the active X-line” — the central reconnection region — “so whistler waves indicate that reconnection is near,” Yoo said.

    He began investigating the source of the waves after noticing the remarkable similarity between the activity of the waves that MMS detected and those produced in the Magnetic Reconnection Experiment (MRX) at PPPL. The similarity indicated that the physical processes were the same in both the laboratory and space and led to a search to uncover the cause. On the research team with PPPL were scientists from Columbia University, Los Alamos National Laboratory, and the NASA Goddard Space Flight Center.

    Going forward, the team plans to investigate the development of whistler waves near the electron diffusion region, the narrow region in the magnetosphere and laboratory experiments where electrons separate from field lines before reconnection takes place. Results could prove relevant to the MMS mission, whose goals include uncovering the role that electrons play in facilitating reconnection. Support for this work has come from the DOE Office of Science (FES) NASA, and the National Science Foundation.

    See the full article here .


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

    Stem Education Coalition


    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 5:57 pm on September 5, 2018 Permalink | Reply
    Tags: , , , , PPPL,   

    From PPPL and ALCF: “Artificial intelligence project to help bring the power of the sun to Earth is picked for first U.S. exascale system” 


    From PPPL

    and

    Argonne Lab

    Argonne National Laboratory ALCF

    August 27, 2018
    John Greenwald

    1
    Deep Learning Leader William Tang. (Photo by Elle Starkman/Office of Communications.)

    To capture and control the process of fusion that powers the sun and stars in facilities on Earth called tokamaks, scientists must confront disruptions that can halt the reactions and damage the doughnut-shaped devices.

    PPPL NSTX-U

    Now an artificial intelligence system under development at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Princeton University to predict and tame such disruptions has been selected as an Aurora Early Science project by the Argonne Leadership Computing Facility, a DOE Office of Science User Facility.

    Depiction of ANL ALCF Cray Shasta Aurora supercomputer

    The project, titled “Accelerated Deep Learning Discovery in Fusion Energy Science” is one of 10 Early Science Projects on data science and machine learning for the Aurora supercomputer, which is set to become the first U.S. exascale system upon its expected arrival at Argonne in 2021. The system will be capable of performing a quintillion (1018) calculations per second — 50-to-100 times faster than the most powerful supercomputers today.

    Fusion combines light elements

    Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — in reactions that generate massive amounts of energy. Scientists aim to replicate the process for a virtually inexhaustible supply of power to generate electricity.

    The goal of the PPPL/Princeton University project is to develop a method that can be experimentally validated for predicting and controlling disruptions in burning plasma fusion systems such as ITER — the international tokamak under construction in France to demonstrate the practicality of fusion energy. “Burning plasma” refers to self-sustaining fusion reactions that will be essential for producing continuous fusion energy.

    Heading the project will be William Tang, a principal research physicist at PPPL and a lecturer with the rank and title of professor in the Department of Astrophysical Sciences at Princeton University. “Our research will utilize capabilities to accelerate progress that can only come from the deep learning form of artificial intelligence,” Tang said.

    Networks analagous to a brain

    Deep learning, unlike other types of computational approaches, can be trained to solve with accuracy and speed highly complex problems that require realistic image resolution. Associated software consists of multiple layers of interconnected neural networks that are analogous to simple neurons in a brain. Each node in a network identifies a basic aspect of data that is fed into the system and passes the results along to other nodes that identify increasingly complex aspects of the data. The process continues until the desired output is achieved in a timely way.

    The PPPL/Princeton deep-learning software is called the “Fusion Recurrent Neural Network (FRNN),” composed of convolutional and recurrent neural nets that allow a user to train a computer to detect items or events of interest. The software seeks to speedily predict when disruptions will break out in large-scale tokamak plasmas, and to do so in time for effective control methods to be deployed.

    The project has greatly benefited from access to the huge disruption-relevant data base of the Joint European Torus (JET) in the United Kingdom, the largest and most powerful tokamak in the world today.

    Joint European Torus, at the Culham Centre for Fusion Energy in the United Kingdom

    The FRNN software has advanced from smaller computer clusters to supercomputing systems that can deal with such vast amounts of complex disruption-relevant data. Running the data aims to identify key pre-disruption conditions, guided by insights from first principles-based theoretical simulations, to enable the “supervised machine learning” capability of deep learning to produce accurate predictions with sufficient warning time.

    Access to Tiger computer cluster

    The project has gained from access to Tiger, a high-performance Princeton University cluster equipped with advanced image-resolution GPUs that have enabled the deep learning software to advance to the Titan supercomputer at Oak Ridge National Laboratory and to powerful international systems such as the Tsubame 3.0 supercomputer in Tokyo, Japan.

    Tiger supercomputer at Princeton University

    ORNL Cray XK7 Titan Supercomputer

    Tsubame 3.0 supercomputer in Tokyo, Japan

    The overall goal is to achieve the challenging requirements for ITER, which will need predictions to be 95 percent accurate with less than 5 percent false alarms at least 30 milliseconds or longer before disruptions occur.


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

    The team will continue to build on advances that are currently supported by the DOE while preparing the FRNN software for Aurora exascale computing. The researchers will also move forward with related developments on the SUMMIT supercomputer at Oak Ridge.

    ORNL IBM AC922 SUMMIT supercomputer. Credit: Carlos Jones, Oak Ridge National Laboratory/U.S. Dept. of Energy

    Members of the team include Julian Kates-Harbeck, a graduate student at Harvard University and a DOE Office of Science Computational Science Graduate Fellow (CSGF) who is the chief architect of the FRNN. Researchers include Alexey Svyatkovskiy, a big-data, machine learning expert who will continue to collaborate after moving from Princeton University to Microsoft; Eliot Feibush, a big data analyst and computational scientist at PPPL and Princeton, and Kyle Felker, a CSGF member who will soon graduate from Princeton University and rejoin the FRNN team as a post-doctoral research fellow at Argonne National Laboratory.

    See the full article here .

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

    Please help promote STEM in your local schools.

    Stem Education Coalition


    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 4:53 pm on August 22, 2018 Permalink | Reply
    Tags: , , , , PPPL, PPPL's QUEST journal,   

    From PPPL: Two Items 


    From PPPL

    Advances in plasma and fusion science are described in Quest, PPPL’s research magazine.

    1

    July 9, 2018
    Larry Bernard

    From analyzing solar flares to pursuing “a star in a jar” to produce virtually limitless electric power, scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have developed insights and discoveries over the past year that advance understanding of the universe and the prospect for safe, clean, and abundant energy for all humankind.

    “Our research sheds new light on the function of plasma, the state of matter that comprises 99 percent of the visible universe,” writes Steve Cowley, new director of PPPL, in the 2018 edition of Quest, PPPL’s annual research magazine. Quest, just published in July 2018, summarizes in short, easy-to-digest format, much of the research that occurred at PPPL over the last year.

    Among the stories are descriptions of how scientists are finding ways to calm instabilities that can lead to the disruption of fusion reactions. Such research is critical to the next steps in advancing fusion energy to enable fusion devices to produce and sustain reactions that require temperatures many times hotter than the core of the sun.

    Fusion, the power that drives the sun and stars, fuses light elements and releases enormous energy. If scientists can capture and control fusion on Earth, the process could provide clean energy to produce electricity for millions of years.

    Plasma, the state of matter composed of free electrons and atomic nuclei that fuels fusion reactions and makes up 99 percent of the visible universe, unites PPPL research from astrophysics to nanotechnology to the science of fusion energy. Could planets beyond our solar system be habitable, for example? PPPL and Princeton scientists say that stellar winds — the outpouring of charged plasma particles from the sun into space — could deplete a planet’s atmosphere and dry up life-giving water over hundreds of millions of years, rendering a blow to the theory that these planets could host life as we know it.

    Quest details efforts to understand the scientific basis of fusion and plasma behavior. For example, in the section on Advancing Fusion Theory, physicists describe how bubble-like “blobs” that arise at the edge of the plasma can carry off heat needed for fusion reactions. Improved understanding of such behavior could lead to better control of the troublesome blobs.

    Another story outlines how researchers are using a form of artificial intelligence called “machine learning” to predict when disruptions that can halt fusion reactions and damage fusion devices occur. The innovative technique has so far yielded outstanding results.

    Included in Quest are descriptions of collaborations PPPL scientists and engineers have working on fusion devices around the world. These collaborations include ITER, the large multinational fusion device under construction in France, as well as research on devices in China, South Korea, and at the National Ignition Facility in the United States.

    Read also about PPPL’s long-standing efforts to educate students, teachers, and the public around STEM (science, technology, engineering, and math), as well as some of the award-winning work by scientists and inventors at PPPL.

    Quest can be accessed here, or at this web address: https://www.pppl.gov/quest

    See the full article here .

    PPPL diagnostic is key to world record of German fusion experiment
    July 9, 2018
    John Greenwald

    2
    PPPL physicist Novimir Pablant, right, and Andreas Langenberg of the Max Planck Institute in front of the housing for the x-ray crystal spectrometer prior to its installation in the W7-X. (Photo by Scott Massida )

    When Germany’s Wendelstein 7-X (W7-X) fusion facility set a world record for stellarators recently, a finely tuned instrument built and delivered by the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) proved the achievement.

    Wendelstein 7-AS built in built in Greifswald, Germany

    The record strongly suggests that the design of the stellarator can be developed to capture on Earth the fusion that drives the sun and stars, creating “a star in a jar” to generate a virtually unlimited supply of electric energy.

    The record achieved by the W7-X, the world’s largest and most advanced stellarator, was the highest “triple product” that a stellarator has ever created. The product combines the temperature, density and confinement time of a fusion facility’s plasma — the state of matter composed of free electrons and atomic nuclei that fuels fusion reactions — to measure how close the device can come to producing self-sustaining fusion power. (The triple product was 6 x 1026 degrees x second per cubic meter — the new stellarator record.)

    Spectrometer maps the temperature

    The achievement produced temperatures of 40 million degrees for the ions and an energy confinement time, which measures how long it takes energy to leak out across the confining magnetic fields of 0.22 seconds. (The density was 0.8 x 1020 particles per cubic meter.) Measuring the temperature was an x-ray imaging crystal spectrometer (XICS) built by PPPL physicist Novimir Pablant, now stationed at W7-X, and engineer Michael Mardenfeld at PPPL. “The spectrometer provided the primary measurement,” said PPPL physicist Sam Lazerson, who also collaborates on W7-X experiments.

    Pablant implemented the device with scientists and engineers of the Max Planck Institute of Plasma Physics (IPP), which operates the stellarator in the Baltic Sea town of Greifswald, Germany. “It has been a great experience to work closely with my colleagues here on W7-X,” Pablant said. “Installing the XICS system was a major undertaking and it has been a pleasure to work with this world-class research team. The initial results from these high-performance plasmas are very exciting, and we look forward to using the measurements from our instrument to further understanding of the confinement properties of W7-X, which is a truly unique magnetic fusion experiment.”

    Researchers at IPP welcomed the findings. “Without XICS we could not have confirmed the record,” said Thomas Sunn Pedersen, director of stellarator edge and divertor physics at IPP. Concurred physicist Andreas Dinklage, lead author of a Nature Physics (link is external) paper confirming a key feature of the W7-X physical design: “The XICS data set was one of the very valuable inputs that confirmed the physics predictions.”

    PPPL physicist David Gates, technical coordinator of the U.S. collaboration on W7-X, oversaw construction of the instrument. “The XICS is an incredibly precise device capable of measuring very small shifts in wavelength,” said Gates. “It is a crucial part of our collaboration and we are very grateful to have the opportunity to participate in these important experiments on the groundbreaking W7-X device.”

    PPPL provides added components

    PPPL has designed and delivered additional components installed on the W7-X. These include a set of large trim coils that correct errors in the magnetic field that confines W7-X plasma, and a scraper unit that will lessen the heat reaching the divertor that exhausts waste heat from the fusion facility.

    The recent world record was a result of upgrades that IPP made to the stellarator following the initial phase of experiments, which began in December 2015. Improvements included new graphite tiles that enabled the higher temperatures and longer duration plasmas that produced the results. A new round of experiments is to begin this July using the new scraper unit that PPPL delivered.

    Stellarators, first constructed in the 1950s under PPPL founder Lyman Spitzer, can operate in a steady state, or continuous manner, with little risk of the plasma disruptions that doughnut-shaped tokamak fusion facilities face. But tokamaks are simpler to design and build, and historically have confined plasma better, which accounts for their much wider use in fusion laboratories around the world.

    An overall goal of the W7-X is to show that the twisty stellarator design can confine plasma just as well as tokamaks. When combined with the ability to operate virtually free of disruptions, such improvement could make stellarators excellent models for future fusion power plants.

    See the full article here .


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

    Stem Education Coalition


    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 11:37 am on July 31, 2018 Permalink | Reply
    Tags: Cori at NERSC, , , PPPL,   

    From PPPL: “Newest supercomputer to help develop fusion energy in international device” 


    From PPPL

    July 25, 2018
    John Greenwald

    Scientists led by Stephen Jardin, principal research physicist and head of the Computational Plasma Physics Group at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), have won 40 million core hours of supercomputer time to simulate plasma disruptions that can halt fusion reactions and damage fusion facilities, so that scientists can learn how to stop them. The PPPL team will apply its findings to ITER, the international tokamak under construction in France to demonstrate the practicality of fusion energy. The results could help ITER operators mitigate the large-scale disruptions the facility inevitably will face.

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

    Receipt of the highly competitive 2018 ASCR Leadership Computing Challenge (ALCC) award entitles the physicists to simulate the disruption on Cori, the newest and most powerful supercomputer at the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory.

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

    NERSC, a U.S. Department of Energy Office of Science user facility, is a world leader in accelerating scientific discovery through computation.

    Model the entire disruption

    “Our objective is to model development of the entire disruption from stability to instability to completion of the event,” said Jardin, who has led previous studies of plasma breakdowns. “Our software can now simulate the full sequence of an ITER disruption, which could not be done before.”

    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.

    The award of 40 million core hours on Cori, a supercomputer named for Nobel Prize-winning biochemist Gerty Cori that has hundreds of thousands of cores that act in parallel, will enable the physicists to complete in weeks what a single-core laptop computer would need thousands of years to accomplish. The high-performance computing machine will scale up simulations for ITER and perform other tasks that less powerful computers would be unable to complete.

    On Cori the team will run the M3D-C1 code primarily developed by Jardin and PPPL physicist Nate Ferraro. The code, developed and upgraded over a decade, will evolve the disruption simulation forward in a realistic manner to produce quantitative results. PPPL now uses the code to perform similar studies for current fusion facilities for validation.

    The simulations will also cover strategies for the mitigation of ITER disruptions, which could develop from start to finish within roughly a tenth of a second. Such strategies require a firm understanding of the physics behind mitigations, which the PPPL team aims to create. Together with Jardin and Ferraro on the team are physicist Isabel Krebs and computational scientist Jin Chen.

    See the full article here .


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

    Stem Education Coalition


    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 10:33 am on June 21, 2018 Permalink | Reply
    Tags: "Knighthood in hand, astrophysicist prepares to lead U.S. fusion lab" Steven Cowley, , PPPL, ,   

    From Science and PPPL: “Knighthood in hand, astrophysicist prepares to lead U.S. fusion lab” Steven Cowley 

    AAAS
    From Science Magazine

    and


    From PPPL

    1
    Steven Cowley, Princeton Plasma Physics Laboratory

    Jun. 19, 2018
    Daniel Clery

    It’s been quite a few weeks for Steven Cowley, the British astrophysicist who formerly headed the United Kingdom’s Culham Centre for Fusion Energy (CCFE). Last month, he was named as the new director of the Princeton Plasma Physics Laboratory (PPPL) in New Jersey, the United States’s premier fusion research lab. Then, last week he received a knighthood from the United Kingdom’s Queen Elizabeth II “for services to science and the development of nuclear fusion.”

    Cowley, or Sir Steven [in the U.K.], is now president of Corpus Christi College at the University of Oxford in the United Kingdom. He will take over his PPPL role on 1 July. He has a long track record in fusion research, having served as head of CCFE from 2008 to 2016 and as a staff scientist at PPPL from 1987 to 1993. PPPL is a Department of Energy (DOE)-funded national laboratory with a staff of more than 500 and an annual budget of $100 million. But in 2016, the lab took a knock when its main facility, the National Spherical Torus Experiment (NSTX), developed a series of disabling faults shortly after a $94 million upgrade.

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

    PPPL’s then-director, Stewart Prager, resigned soon after. DOE is now considering a recovery plan for the NSTX, which is expected to cost tens of millions of dollars.

    During Cowley’s tenure at CCFE, that lab also started an upgrade of its rival to the NSTX, the Mega Amp Spherical Tokamak (MAST).

    Mega Ampere Spherical Tokamak. Credit Culham Centre for Fusion Energy

    Spherical tokamaks are a variation on the traditional doughnut-shaped tokamak design whose ultimate expression, the giant ITER device in France, is now under construction.

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

    The plan is for ITER to demonstrate a burning plasma, one where the fusion reactions themselves generate all or most of the heat required to sustain the burn. But once that is done, researchers hope spherical tokamaks, or some other variation, will provide a route to commercial reactors that are smaller, simpler, and cheaper than ITER. By upgrading the NSTX and the MAST, the labs hope to show that this type of compact reactor can achieve the same sort of performance as CCFE’s Joint European Torus (JET), the world’s largest tokamak right now and the record holder on fusion performance.

    The Joint European Torus tokamak generator based at the CCFE.

    “We have to push down the cost and scale of fusion reactors,” Cowley told ScienceInsider shortly after the 16 May announcement of his PPPL appointment. “I fully support ITER because we have to do a burning plasma. But commercial reactors will need to be smaller and cheaper. A JET-sized machine would be so much more appealing. MAST and NSTX will be a dynamic team going forward.”

    Despite the good food and well-stocked cellar on the Corpus Christi campus, Cowley says he is eager to return to the cut and thrust of laboratory life. “It’s too much fun. I was really feeling I missed the everyday discussions about physics and what was going on. I’m a fusion nut. We’re going to crack it one of these days and I want to be part of it,” he says. And PPPL, he adds, will be central to that effort. “Princeton is the place where much of what we know now was figured out. It’s a legendary lab in plasma physics. It’ll be fun to go and work with these people.”

    His first job there will be to get the NSTX back on track. “I’m confident we can solve this problem. They’ve understood how the faults arose and they’ve understood how to fix them. If the money comes through, we will get NSTX back online,” he says.

    Cowley says the key goal for spherical tokamaks and other variants is to reduce turbulent transport, the process that allows swirling plasma to move heat from the core of the device to the edge where it can escape. If designers can figure out how to retain the heat more effectively, the reactor doesn’t need to be so large. Spherical tokamaks do this by seeking to hold the plasma in the center of the device, close to the central column.

    Another way to solve the heat problem is to increase a device’s magnetic field strength overall by using superconducting magnets, an approach being followed by researchers at the Massachusetts Institute of Technology in Cambridge.

    MIT SPARC fusion reactor tokamak

    “That can push the scale down,” Cowley says, “but high field is not enough on its own. If there is a disruption [a sudden loss of confinement], that can be very damaging” to the machine.

    Cowley thinks future machines may take elements from more then one type of reactor—including stellarators, a reactor type that has a doughnut shape that is similar to tokamaks, but with bizarrely twisted magnets that can confine current without needing the flow of current around the loop that tokamaks rely on. “There are beautiful ideas coming from the stellarators community,” he says. Wendelstein 7-X, a “phenomenal” new stellarator in Germany, has been a major driver, he says.

    KIT Wendelstein 7-X, built in Greifswald, Germany

    What has changed dramatically in the past couple of decades has been “the ability to calculate what’s going on,” Cowley says. Advances in both theory and computing power means “we have all these new ideas and can explore the spaces in silicon. The field is driven more by science and less by intuition,” he says. “It’s quite a revolution.”

    Meanwhile, ITER construction trundles on despite numerous delays and price hikes. Cowley acknowledges that things have improved since the current director, Bernard Bigot, took over. “Bigot is an extremely good leader. He’s steadied the ship; he makes decisions,” Cowley says. “And they’ve got their team. It took time to find the right set of people.” Building ITER is “an amazingly tough thing to do. Assembly [of the tokamak] will be quite challenging and hard to stay on schedule. But when it is finished it will be a technological wonder.”

    But perhaps the biggest obstacle to progress is a shortage of funding, which has been stagnant in the United States for many years. President Donald Trump has requested $340 million for DOE’s fusion research programs in the 2019 fiscal year that begins 1 October, a 36% cut from current levels, but Congress is unlikely to approve that cut. “There’s real hope [the 2019 budget] will move up, but it’s not energizing the field,” Cowley says. “If we can get NSTX to produce spectacular physics results—on a par with the performance of JET—we will energize the community with science [Lotsa luck, pal].”

    See the full article here .


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

    Stem Education Coalition


    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.

     
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