Princeton and PPPL projects selected to run on super-powerful computer to be delivered to Oak Ridge Leadership Computing Facility
Three Princeton University-related computer programs have been chosen to run on a new supercomputer that will deliver enhanced scientific findings when it begins crunching numbers in 2018. The projects, consisting of a Princeton Department of Geosciences program and two studies involving the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL), encompass high-performance computer codes to map the interior of the Earth and advance the scientific basis for developing fusion energy to generate electricity.
The codes will run on Summit, a supercomputer that will have more than five times the computing power of Titan, the current U.S. leader, which can perform up to 27 quadrillion — or million billion — calculations a second. The DOE’s Oak Ridge Leadership Computing Facility, which houses Titan, plans to take delivery of Summit in 2017 and place it in operation the following year. “Summit is the next leap in leadership-class computing systems for open science,” Jack Wells, director of science for the National Center for Computational Sciences at Oak Ridge National Laboratory (ORNL), said of the supercomputer, which IBM and Nvidia Corp. processors will power.
The three Princeton-related projects were among 13 selected to run in the Center for Accelerated Application Readiness (CAAR) program at Oak Ridge. The three projects include:
Mapping the Earth’s interior using Big Data. Princeton University researchers led by Jeroen Tromp plan to use Summit to map the planet’s interior down to the center of its white-hot inner core. The team previously used Titan to image the Earth’s entire mantle, the rocky shelf that extends some 1,800 miles between the Earth’s crust and outer core. While that work employed seismic wave data from a few hundred earthquakes, the new study will crunch data from thousands of earthquakes, said Tromp, Blair Professor of Geology and a professor of geosciences and applied and computational mathematics and associate director of the Princeton Institute for Computational Science & Engineering (PICSciE). The new study will also model the propagation of waves with frequencies of just one-to-two seconds to reveal greater detail than current capabilities that are limited to simulating less frequent waves are able to produce.
Simulating fusion plasmas from hot core to cold wall. Physicists led by C.S. Chang of PPPL will use Summit to model the dazzlingly complex conditions at the edge of the plasma that fuels fusion reactions in magnetic fusion facilities called tokamaks. Of particular interest are conditions that lead to the creation of turbulence that causes plasma to leak from magnetic confinement from the hot core of the plasma to the cold material wall. The team has been using Titan to study a special type of turbulence called “blobs” that have been observed in tokamak experiments and could critically affect the pattern of heat lost to the wall in ITER, the international tokamak under construction in France. Using Summit will enable the team to simulate conditions 10 times faster and in greater detail than current supercomputers allow. Complex runs to study ITER plasma will thus be performed on a daily basis rather than over the lengthier periods now required, said Chang. Results could lead to improved planning for experiments on ITER.
Modeling plasma turbulence for sustainable fusion reactions in ITER. This research will model the behavior of billions to trillions of individual plasma particles in multiple dimensions while accounting for the electromagnetic waves these particles excite as they move within a tokamak. Achieving this dual capability represents “clearly a computational grand challenge” said physicist William Tang of PICSciE and PPPL. Tang serves as co-principal investigator for the project with Principal Investigator Zhihong Lin, professor of physics and astronomy at the University of California, Irvine. The simulations are expected to deepen insight into the conditions required for sustained fusion reactions by enhancing understanding of plasma confinement and the impact of turbulence. The balance between energy losses and the self-heating rate of fusion reactions will ultimately determine the size and cost of a fusion reactor.
Preparing these codes to run on Summit will take months of planning developed through the CAAR program. The new supercomputer, said Wells of ORNL, will enable these and other projects “to address, with greater complexity and higher fidelity, questions concerning DOE's science and energy-technology mission, increased industrial competitiveness, and fundamental understanding of our place in the world and our world's place in the cosmos.”
Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.
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