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  • richardmitnick 7:46 pm on May 29, 2018 Permalink | Reply
    Tags: Adaptive Input/Output System (ADIOS) and the BigData Express (BDE), , ITER Tokamak in Saint-Paul-lès-Durance which is in southern France, , PPPL Princeton Plasma Physics Laboratory   

    From Fermilab and OLCF: “ADIOS and BigData Express offer new data streaming capabilities” 

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    From Fermilab is an enduring source of strength for the US contribution to scientific research world wide.

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    Projects large enough to run on high-performance computing (HPC) resources pack data—and a lot of it. Transferring this data between computational and experimental facilities is a challenging but necessary part of projects that rely on experiments to validate computational models.

    Staff at two U.S. Department of Energy (DOE) Office of Science User Facilities — the Oak Ridge Leadership Computing Facility (OLCF) and Fermi National Accelerator Laboratory — facilitated this process by executing the integration of the Adaptive Input/Output System (ADIOS) and the BigData Express (BDE) high-speed data transfer service.

    Now ADIOS and BDE developers are changing the way researchers can transport and analyze data by incorporating a new methodology into the tool that allows for compressing and streaming of data coming out of simulations in real time. The methodology is being tested by OLCF user C. S. Chang, a plasma physics researcher at Princeton Plasma Physics Laboratory (PPPL) who studies the properties of the plasmas that exist in giant fusion devices called tokamaks.

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

    Chang seeks an understanding of the power needed to run ITER and the heat load to the material wall that will surround its plasma, both of which are key to fusion’s viability.

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

    ITER is an international collaboration working to design, construct, and assemble a burning plasma experiment that can demonstrate the scientific and technological feasibility of fusion power for the commercial power grid. ITER, which counts DOE’s Oak Ridge National Laboratory (ORNL) among its partners, is currently under construction in southern France.

    “If users can separate out the most important pieces of data and move those to another processor that can recognize the intended prioritization and reduce the data, it can provide them with feedback that they may need to stop a simulation if necessary,” said Scott Klasky, leader of the ADIOS framework and group leader for ORNL’s Scientific Data Group.

    Wenji Wu, principal investigator of the BDE project and principal network research investigator of Fermilab’s Core Computing Division, added, “The new approach leverages the software-defining network [SDN] capabilities for resource scheduling and the high-performance data streaming capabilities of BDE.”

    SDN allows users to dynamically control network resources rather than manually request to connect.

    “This combination enables real-time data streaming with guaranteed quality of service, whether it be over short or long distances,” Wu said. “In addition, this approach yields small memory footprints.”

    Although the project is still in the development phase, preliminary tests allowed Chang and his team to successfully transfer fusion data between the OLCF — located at ORNL — and PPPL.

    “With this new methodology, users can stream data on the network without ever touching the file system and request network resources on the fly,” said ADIOS and BDE researcher Qing Liu, who has a joint appointment with the New Jersey Institute of Technology and ORNL.

    Without streaming capabilities, scientists can perform only after-the-fact analyses for many experiments, such as KSTAR, the Korean Superconducting Tokamak Advanced Research.

    KSTAR Korean Superconducting Tokamak Advanced Research

    But with simulations and experiments increasing in size, near–real-time monitoring and control are becoming necessary. The new ADIOS–BDE integration could also play a major role in large experimental projects, such as the fusion project Chang is leading and the Square Kilometer Array, an effort involving dozens of institutions to build the world’s largest radio telescope.

    SKA Square Kilometer Array

    The new streaming capabilities could more easily enable the capture of short-lived events such as pulsars — neutron stars that emit electromagnetic radiation — that the telescope aims to record.

    “KSTAR wants to transfer their data as the experiment is happening, to process their data during the experiment,” Klasky said. “These additions to ADIOS will enable both sides to quickly perform data analysis and visualization in real time.”

    Seo-Young Noh, director of the Global Science Experimental Data Hub Center at the Korea Institute of Science and Technology Information, leads a group that has contributed significantly to the BDE project.

    “Our work has made cross-Pacific, real-time data streaming possible,” Noh said.

    Klasky, Liu, and their collaborators will give a best paper plenary talk related to these new capabilities—titled “Understanding and Modeling Lossy Compression Schemes on HPC Scientific Data” — at the 32nd IEEE International Parallel and Distributed Processing Symposium. The team noted that the new ADIOS methodology will allow scientists to efficiently select the type of compression that will best fit their scientific and research needs, affording them the ability to analyze their data faster than ever before.

    Liang Zhang, the developer of BDE data streaming capabilities, is working with Liu to enhance and test the tool. They expect the tool’s new capabilities to be fully tested and deployed by late 2019. This work also involves ADIOS researcher Jason Wang and BDE researchers Nageswara Rao, Phil DeMar, Qiming Lu, Sajith Sasidharan, S. A. R. Shah, Jin Kim, and Huizhang Luo.

    ORNL is managed by UT-Battelle for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

    See the full article here .


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    Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics. Fermilab is America’s premier laboratory for particle physics and accelerator research, funded by the U.S. Department of Energy. Thousands of scientists from universities and laboratories around the world
    collaborate at Fermilab on experiments at the frontiers of discovery.


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

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


    PPPL

    December 21, 2017
    Raphael Rosen

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

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

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

    Building on previous experiments

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

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

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

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

    Provisional patent

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

    See the full article here .

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    PPPL campus

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

     
  • richardmitnick 6:56 pm on September 26, 2017 Permalink | Reply
    Tags: , , , PPPL Princeton Plasma Physics Laboratory   

    From PPPL: “Research led by PPPL provides reassurance that heat flux will be manageable in ITER” 


    PPPL

    September 26, 2017
    John Greenwald

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    A major issue facing ITER, the international tokamak under construction in France that will be the first magnetic fusion device to produce net energy, is whether the crucial divertor plates that will exhaust waste heat from the device can withstand the high heat flux, or load, that will strike them. Alarming projections extrapolated from existing tokamaks suggest that the heat flux could be so narrow and concentrated as to damage the tungsten divertor plates in the seven-story, 23,000 ton tokamak and require frequent and costly repairs. This flux could be comparable to the heat load experienced by spacecraft re-entering Earth’s atmosphere.

    New findings of an international team led by physicist C.S. Chang of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) paint a more positive picture. Results of the collaboration, which has spent two years simulating the heat flux, indicate that the width could be well within the capacity of the divertor plates to tolerate.

    Good news for ITER

    “This could be very good news for ITER,” Chang said of the findings, published in August in the journal Nuclear Fusion. “This indicates that ITER can produce 10 times more power than it consumes, as planned, without damaging the divertor plates prematurely.”

    At ITER, spokesperson Laban Coblentz, said the simulations were of great interest and highly relevant to the ITER project. He said ITER would be keen to see experimental benchmarking, performed for example by the Joint European Torus (JET) at the Culham Centre for Fusion Energy in the United Kingdom, to strengthen confidence in the simulation results.

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

    Chang’s team used the highly sophisticated XGC1 plasma turbulence computer simulation code developed at PPPL to create the new estimate. The simulation projected a width of 6 millimeters for the heat flux in ITER when measured in a standardized way among tokamaks, far greater than the less-than 1 millimeter width projected through use of experimental data.

    Deriving projections of narrow width from experimental data were researchers at major worldwide facilities. In the United States, these tokamaks were the National Spherical Torus Experiment before its upgrade at PPPL; the Alcator C-Mod facility at MIT, which ceased operations at the end of 2016; and the DIII-D National Fusion Facility that General Atomics operates for the DOE in San Diego.

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    National Spherical Torus Experiment at PPPL

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    Alcator C-Mod tokamak at MIT

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    DIII-D National Fusion Facility, San Diego

    Widely different conditions

    The discrepancy between the experimental projections and simulation predictions, said Chang, stems from the fact that conditions inside ITER will be too different from those in existing tokamaks for the empirical predictions to be valid. Key differences include the behavior of plasma particles within today’s machines compared with the expected behavior of particles in ITER. For example, while ions contribute significantly to the heat width in the three U.S. machines, turbulent electrons will play a greater role in ITER, rendering extrapolations unreliable.

    Chang’s team used basic physics principles, rather than empirical projections based on the data from existing machines, to derive the simulated wider prediction. The team first tested whether the code could predict the heat flux width produced in experiments on the U.S. tokamaks, and found the predictions to be valid.

    Researchers then used the code to project the width of the heat flux in an estimated model of ITER edge plasma. The simulation predicted the greater heat-flux width that will be sustainable within the current ITER design.

    Supercomputers enabled simulation

    Supercomputers made this simulation possible. Validating the code on the existing tokamaks and producing the findings took some 300 million core hours on Titan and Cori, two of the most powerful U.S. supercomputers, housed at the DOE’s Oak Ridge Leadership Computing Facility and the National Energy Research Scientific Computing Center, respectively.

    ORNL Cray XK7 Titan Supercomputer

    NERSC Cray Cori II supercomputer

    A core hour is one processor, or core, running for one hour.

    Researchers from eight U.S. and European institutions collaborated on this research. In addition to PPPL, the institutions included ITER, the Culham Centre for Fusion Energy, the Institute of Atomic and Subatomic Physics at the Technical University of Vienna, General Atomics, MIT, Oak Ridge National Laboratory and Lawrence Livermore National Laboratory.

    Support for this work comes from the DOE Office of Science Offices of Fusion Energy Sciences and Office of Advanced Scientific Computing Research.

    See the full article here .

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    PPPL campus

    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

     
  • richardmitnick 1:05 pm on September 11, 2017 Permalink | Reply
    Tags: , , NSTX-U Tokamak at PPPL, PPPL Princeton Plasma Physics Laboratory   

    From PPPL: “PPPL has a new interim director and is moving ahead with construction of prototype magnets” 


    PPPL

    September 8, 2017
    Jeanne Jackson DeVoe

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    Rich Hawryluk (Photo by Elle Starkman )

    Rich Hawryluk has been appointed interim director of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) while an international search for a permanent director moves forward, Princeton University Vice President for PPPL David McComas announced recently. Hawryluk, who has been heading the NSTX-U Recovery Project, is an internationally-known physicist and a former deputy director of PPPL.

    PPPL NSTX-U

    “Rich has earned my highest respect and the respect of his colleagues and staff at PPPL and of researchers throughout the world for his work as a scientist, project manager, and leader. I am delighted he has agreed to head the Laboratory as we move into the next phase of the NSTX-U recovery,” McComas said.

    Hawryluk said that he was grateful for the opportunity to lead the Laboratory where he has worked for more than four decades. “I feel deeply about this place,” he said. “It has given me enormous opportunities to do research, as well as scientific and technical management. I feel it’s incumbent on me to do all I possibly can to give the scientists and the engineers and the staff here exciting and productive scientific opportunities both in the near future as well for the long term.”

    Terry Brog, who served as interim director since September 2016, will return to his previous position as deputy director for operations and chief operating officer that he assumed in June of 2016. Stacia Zelick, who served as interim deputy director for operations under Brog, will continue to serve in a leadership role. Michael Zarnstorff, the deputy director for research, will remain in his position. Physicists Jon Menard, head of NSTX-U research and Stefan Gerhardt, deputy engineering director for the project, will now lead the NSTX-U Recovery Project. Charles Neumeyer will remain as the NSTX-U Recovery Project engineering director and deputy head of engineering for NSTX-U.

    The leadership change comes as PPPL moves ahead with constructing prototype magnets in preparation for replacing the one that failed last year and five others that were built under similar conditions.

    Construction of the first prototype magnet follows a comprehensive review of each system of NSTX-U by a team of engineers and scientists from PPPL as well as nearly 50 external experts from the United States and around the world.

    “For the Laboratory to succeed, we must utilize the talents, creativity and skills of all of the staff,” Hawryluk said. “My job is to enable other people to address the issues facing the Laboratory and to set a firm foundation for the future director.”

    Hawryluk and McComas both thanked Brog and Zelick for their leadership during the past several months. “I’m extremely grateful for all the work that Terry and Stacia have done in their respective roles over the last year,” McComas said. Hawryluk also noted that it was his pleasure to work with the NSTX-U team and, in particular, Charlie Neumeyer, Stefan Gerhardt and Jon Menard who “are very dedicated to bringing NSTX-U back on line.”

    The new interim director has been at PPPL for most of his career. He came to PPPL in 1974 after receiving a Ph.D. in physics from MIT. He headed the Tokamak Fusion Test Reactor, then the largest magnetic confinement fusion facility in the United States, from 1991 to 1997. Hawryluk oversaw all research and technical operations as deputy director of the Laboratory for 11 years from 1997 to 2008. He was then head of PPPL’s ITER and Tokamaks Department from 2009 to 2011. From 2011 to 2013, Hawryluk worked at ITER in France, serving as the deputy director-general for the Administration Department of ITER.

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

    In 2013, Hawryluk returned to the Laboratory as head of the ITER and Tokamaks department. He remained in that position until he became head of the Recovery Project last year. Hawryluk has received numerous awards during his career including a Department of Energy Distinguished Associate Award, a Kaul Foundation Prize for Excellence in Plasma Physics Research and Technology, a Fusion Power Award, and an American Physical Society Prize for Excellence in Plasma Physicswith physicists Rob Goldston and James Strachan. A fellow of the American Association for the Advancement of Science since 2008 and of the American Physical Society since 1986, he also chairs the board of editors of Nuclear Fusion, a monthly journal devoted to controlled fusion energy.

    Hawryluk and his wife Mary Katherine Hawryluk, a school psychologist working with special needs children at the New Road School in Parlin, New Jersey, met as undergraduates and have been married for 41 years. They have two grown sons: Kevin, who lives in Chicago, and David, who lives in Los Angeles. In his spare time, Hawryluk is an avid reader.

    “I’m taking on this task because I really believe in PPPL and its critical role in furthering the field of plasma physics with the goal of developing fusion energy,” Hawryluk said. “I am committed to addressing issues that are central to the long-term success of the Laboratory.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    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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