Titan Simulation Reveals New Details of Fissioning Plutonium

By John Russell

July 26, 2016

In a first study of its kind, a team led by the University of Washington’s Aurel Bulgac captured the real-time dynamics of a fissioning plutonium-240 nucleus by simulating the process on the Titan supercomputer at the Oak Ridge Leadership Computing Facility (OLCF), a US Department of Energy (DOE) Office of Science User Facility.

To create feasible nuclear fission models for current supercomputers, nuclear physicists had to devise shortcuts that often rely on approximations and constraints. The most successful of these approaches, density functional theory (DFT), describes nuclear dynamics by tracking changes in the density of the nucleus. To apply this method to fissile elements like uranium and plutonium, which contain more than 200 protons and neutrons, scientists need to extend the method to superfluid nuclei and then implement and validate DFT on leadership-class supercomputers.

A team led by Aurel Bulgac is spearheading this effort by developing a novel theoretical approach that extends DFT to superfluid nuclei, which exhibit characteristics similar to other strongly interacting systems of many fermions, or particles with half-integer spin such as superconducting materials. The method, called time-dependent superfluid local density approximation (TDSLDA), has shown promise for capturing real-time dynamics of nuclear evolution without imposing the constraints that other models require.

The simulation results achieved notable fidelity, and the predicted kinetic energy agreed with that produced by experiments. Additionally, the simulation suggested that the final stages of fission last about 10 times longer than previously calculated, a finding with wide ramifications for nuclear science and astrophysics. A full account is on the OCLF web site.

Bulgac’s team applied its TDSLDA model under an allocation on Titan, a Cray XK7 capable of 27 petaflops (or 27 quadrillion calculations per second), awarded through the OLCF’s Director’s Discretionary program. The team conducted previous work on the model on an allocation awarded by DOE’s Office of Advanced Scientific Computing Research Leadership Computing Challenge (ALCC) program.

Calculating the plutonium-240 problem required more than 1,700 of Titan’s GPUs to solve around 56,000 partial differential equations. The simulation consisted of a plutonium-240 nucleus in a femtometer-size simulation box equivalent to a few quadrillionths of a meter in dimension. To shorten the time to scission, the simulation began with the nucleus on the cusp of splitting.

Prior to this particular study, Bulgac’s team undertook an extensive overhaul of its nuclear physics code to take advantage of Titan’s GPU accelerators. The effort resulted in a 10- to 25-fold performance improvement, depending on the size of the problem.

“The bigger the problem, the faster our code runs [compared to the CPU-only version],” Bulgac said. “Even though Titan has about 300,000 CPU cores and less than 19,000 GPUs, 90 percent of its speed lies in GPUs. The reason we succeeded in this effort is that we learned how to use Titan’s heterogeneous architecture.”

This year, Bulgac’s team is continuing to refine its model under a new ALCC allocation. The goal is to study nuclear fission properties under differing conditions. For example, the team plans to investigate the sensitivity of density functional parameters within known reasonable limits and to modify the incoming energy of the fission-inducing neutron.

Link to article on ORNL website: https://www.olcf.ornl.gov/2016/07/26/fundamental-fission-modeling-finds-a-foothold/

Link to related paper: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.122504

Subscribe to HPCwire's Weekly Update!

Be the most informed person in the room! Stay ahead of the tech trends with industy updates delivered to you every week!

AI Thought Leaders on Capitol Hill

July 14, 2018

On Thursday, July 12, the House Committee on Science, Space, and Technology heard from four academic and industry leaders – representatives from Berkeley Lab, Argonne Lab, GE Global Research and Carnegie Mellon University – on the opportunities springing from the intersection of machine learning and advanced-scale computing. Read more…

By Tiffany Trader

HPC Serves as a ‘Rosetta Stone’ for the Information Age

July 12, 2018

In an age defined and transformed by its data, several large-scale scientific instruments around the globe might be viewed as a ‘mother lode’ of precious data. With names seemingly created for a ‘techno-speak’ glossary, these interferometers, cyclotrons, sequencers, solenoids, satellite altimeters, and cryo-electron microscopes are churning out data in previously unthinkable and seemingly incomprehensible quantities -- billions, trillions and quadrillions of bits and bytes of electro-magnetic code. Read more…

By Warren Froelich

Can Markov Logic Take Machine Learning to the Next Level?

July 11, 2018

Advances in machine learning, including deep learning, have propelled artificial intelligence (AI) into the public conscience and forced executives to create new business plans based on data. However, the scarcity of hig Read more…

By Alex Woodie

HPE Extreme Performance Solutions

Introducing the First Integrated System Management Software for HPC Clusters from HPE

How do you manage your complex, growing cluster environments? Answer that big challenge with the new HPC cluster management solution: HPE Performance Cluster Manager. Read more…

IBM Accelerated Insights

ORNL Summit Supercomputer Is Officially Here

Oak Ridge National Laboratory (ORNL) together with IBM and Nvidia celebrated the official unveiling of the Department of Energy (DOE) Summit supercomputer today at an event presided over by DOE Secretary Rick Perry. Read more…

CSIR, Nvidia Partner to Launch GPU-Powered AI Center in India

July 10, 2018

As reported by a number of Indian news outlets, India’s Council of Scientific and Industrial Research (CSIR) is partnering with Nvidia to establish a new, AI-focused Centre of Excellence in New Delhi, India's capital. Read more…

By Oliver Peckham

AI Thought Leaders on Capitol Hill

July 14, 2018

On Thursday, July 12, the House Committee on Science, Space, and Technology heard from four academic and industry leaders – representatives from Berkeley Lab, Argonne Lab, GE Global Research and Carnegie Mellon University – on the opportunities springing from the intersection of machine learning and advanced-scale computing. Read more…

By Tiffany Trader

HPC Serves as a ‘Rosetta Stone’ for the Information Age

July 12, 2018

In an age defined and transformed by its data, several large-scale scientific instruments around the globe might be viewed as a ‘mother lode’ of precious data. With names seemingly created for a ‘techno-speak’ glossary, these interferometers, cyclotrons, sequencers, solenoids, satellite altimeters, and cryo-electron microscopes are churning out data in previously unthinkable and seemingly incomprehensible quantities -- billions, trillions and quadrillions of bits and bytes of electro-magnetic code. Read more…

By Warren Froelich

Tsinghua Powers Through ISC18 Field

July 10, 2018

Tsinghua University topped all other competitors at the ISC18 Student Cluster Competition with an overall score of 88.43 out of 100. This gives Tsinghua their s Read more…

By Dan Olds

HPE, EPFL Launch Blue Brain 5 Supercomputer

July 10, 2018

HPE and the Ecole Polytechnique Federale de Lausannne (EPFL) Blue Brain Project yesterday introduced Blue Brain 5, a new supercomputer built by HPE, which displ Read more…

By John Russell

Pumping New Life into HPC Clusters, the Case for Liquid Cooling

July 10, 2018

High Performance Computing (HPC) faces some daunting challenges in the coming years as traditional, industry-standard systems push the boundaries of data center Read more…

By Scott Tease

Meet the ISC18 Cluster Teams: Up Close & Personal

July 6, 2018

It’s time to meet your ISC18 Student Cluster Competition teams. While I was able to film them live at the ISC show, the trick was finding time to edit the vid Read more…

By Dan Olds

PRACEdays18 Keynote Allan Williams (Australia/NCI): We’re Open for Business Down Under!

July 5, 2018

The University of Ljubljana in Slovenia hosted the third annual EHPCSW18 and fifth annual PRACEdays18 events which opened with a plenary session on May 29, 2018 Read more…

By Elizabeth Leake (STEM-Trek for HPCwire)

HPC Under the Covers: Linpack, Exascale & the Top500

June 28, 2018

HPCers can get painted as a monolithic bunch by outsiders, but internecine disagreements abound over the HPCest of HPC jargon, as was evident at ISC this week. Read more…

By Tiffany Trader

Leading Solution Providers

SC17 Booth Video Tours Playlist

Altair @ SC17

Altair

AMD @ SC17

AMD

ASRock Rack @ SC17

ASRock Rack

CEJN @ SC17

CEJN

DDN Storage @ SC17

DDN Storage

Huawei @ SC17

Huawei

IBM @ SC17

IBM

IBM Power Systems @ SC17

IBM Power Systems

Intel @ SC17

Intel

Lenovo @ SC17

Lenovo

Mellanox Technologies @ SC17

Mellanox Technologies

Microsoft @ SC17

Microsoft

Penguin Computing @ SC17

Penguin Computing

Pure Storage @ SC17

Pure Storage

Supericro @ SC17

Supericro

Tyan @ SC17

Tyan

Univa @ SC17

Univa

  • arrow
  • Click Here for More Headlines
  • arrow
Do NOT follow this link or you will be banned from the site!
Share This