Supercomputer and visualization resources lend insight into plasma dynamic

November 21, 2014 by Aaron Dubrow, National Science Foundation
This image visualizes the effect of gravity waves on an initially relatively stable rotating column of electron density, twisting into a turbulent vortex on the verge of complete chaotic collapse. These computer generated graphics are visualizations of data from a simulation of plasma turbulence in Earth's ionosphere. The same physics are also applied to the research team's investigations of turbulence in the tokamak, a device used in nuclear fusion experiments. Credit: Visualization: Greg Foss, TACC Visualization software support: Anne Bowen, Greg Abram, TACC Science: Wendell Horton, Lee Leonard, U. of Texas at Austin

Studying the intricacies and mysteries of the sun is physicist Wendell Horton life's work. A widely known authority on plasma physics, his study of the high temperature gases on the sun, or plasma, consistently leads him around the world to work on a diverse range of projects that have great impact.

Fusion energy is one such key scientific issue that Horton is investigating and one that has intrigued researchers for decades.

"Fusion energy involves the same thermonuclear reactions that take place on the sun," Horton said. "Fusing two isotopes of hydrogen to create helium releases a tremendous amount of energy—10 times greater than that of nuclear fission."

It's no secret that the demand for energy around the world is outpacing the supply. Fusion energy has tremendous potential. However, harnessing the power of the sun for this burgeoning energy source requires extensive work.

Through the Institute for Fusion Studies at The University of Texas at Austin, Horton collaborates with researchers at ITER, a fusion lab in France and the National Institute for Fusion Science in Japan to address these challenges. At ITER, Horton is working with researchers to build the world's largest tokamak—the device that is leading the way to produce fusion energy in the laboratory.

"Inside the tokamak, we inject 10 to 100 megawatts of power to recreate the conditions of burning hydrogen as it occurs in the sun," Horton said. "Our challenge is confining the , since temperatures are up to 10 times hotter than the center of the sun inside the machine."

Perfecting the design of the tokamak is essential to producing , and since it is not fully developed, Horton performs supercomputer simulations on the Stampede supercomputer at the Texas Advanced Computing Center (TACC) to model plasma flow and turbulence inside the device.

"Simulations give us information about plasma in three dimensions and in time, so that we are able to see details beyond what we would get with analytic theory and probes and high-tech diagnostic measurements," Horton said.

The simulations also give researchers a more holistic picture of what is needed to improve the tokamak design. Comparing simulations with fusion experiments in nuclear labs around the world helps Horton and other researchers move even closer to this breakthrough energy source.

Plasma in the ionosphere

Because the mathematical theories used to understand fusion reactions have numerous applications, Horton is also investigating space , which has important implications in GPS communications.

GPS signaling, a complex form of communication, relies on signal transmission from satellites in space, through the ionosphere, to GPS devices located on Earth.

"The ionosphere is a layer of the atmosphere that is subject to solar radiation," Horton explained. "Due to the sun's high-energy solar radiation plasma wind, nitrogen and oxygen atoms are ionized, or stripped of their electrons, creating plasma gas."

These plasma structures can scatter signals sent between global navigation satellites and ground-based receivers resulting in a "loss-of-lock" and large errors in the data used for navigational systems.

Most people who use GPS navigation have experienced "loss-of-lock," or instance of system inaccuracy. Although this usually results in a minor inconvenience for the casual GPS user, it can be devastating for emergency response teams in disaster situations or where issues of national security are concerned.

To better understand how plasma in the ionosphere scatters signals and affects GPS communications, Horton is modeling plasma turbulence as it occurs in the ionosphere on Stampede. He is also sharing this knowledge with research institutions in the United States and abroad including the UT Space and Geophysics Laboratory.

Seeing is believing

Although Horton is a long-time TACC partner and Stampede user, he only recently began using TACC's visualization resources to gain deeper insight into plasma dynamics.

"After partnering with TACC for nearly 10 years, Horton inquired about creating visualizations of his research," said Greg Foss, TACC Research Scientist Associate. "I teamed up with TACC research scientist, Anne Bowen, to develop visualizations from the myriad of data Horton accumulated on plasmas."

Since plasma behaves similarly inside of a fusion-generating tokamak and in the ionosphere, Foss and Bowen developed visualizations representing generalized plasma turbulence. The team used Maverick, TACC's interactive visualization and data analysis system to create the visualizations, allowing Horton to see the full 3-D structure and dynamics of plasma for the first time in his 40-year career.

"It was very exciting and revealing to see how complex these plasma structures really are," said Horton. "I also began to appreciate how the measurements we get from laboratory diagnostics are not adequate enough to give us an understanding of the full three-dimensional plasma structure."

Word of the plasma visualizations soon spread and Horton received requests from physics researchers in Brazil and researchers at AMU in France to share the visualizations and work to create more. The visualizations were also presented at the XSEDE'14 Visualization Showcase and will be featured at the upcoming SC'14 conference.

Horton plans to continue working with Bowen and Foss to learn even more about these complex plasma structures, allowing him to further disseminate knowledge nationally and internationally, also proving that no matter your experience level, it's never too late to learn something new.

Explore further: Physicists use supercomputer to gain insight into plasma dynamics

Related Stories

Using radio waves to control the density in a fusion plasma

October 28, 2014

Recent fusion experiments on the DIII-D tokamak at General Atomics (San Diego) and the Alcator C-Mod tokamak at MIT (Cambridge, Massachusetts), show that beaming microwaves into the center of the plasma can be used to control ...

Postcards from the plasma edge

October 28, 2014

For magnetic fusion energy to fuel future power plants, scientists must find ways to control the interactions that take place between the volatile edge of the plasma and the walls that surround it in fusion facilities. Such ...

Recommended for you

On the rebound

January 22, 2018

Our bodies have a remarkable ability to heal from broken ankles or dislocated wrists. Now, a new study has shown that some nanoparticles can also "self-heal" after experiencing intense strain, once that strain is removed.

Nanoparticle gel controls twisted light with magnetism

January 22, 2018

"Help me, Obi Wan Kenobi. You're my only hope." For many of those around at the release of Star Wars in 1977, that scene was a first introduction to holograms—a real technology that had been around for roughly 15 years.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

HannesAlfven
2 / 5 (4) Nov 22, 2014
The structures are indeed incredibly complex ... spinny cartwheel structures, skeletal tubular structures -- somewhat like lightning, but more like spaghetti or those foam poolside noodles. I don't know if they're using it, but MHD would not serve these guys so well. Skeletal structures in tokamaks suggest E-fields are common.
cantdrive85
1 / 5 (3) Dec 04, 2014
allowing Horton to see the full 3-D structure and dynamics of plasma for the first time in his 40-year career.


Really, a well known "authority" in plasma physics? That's rich.

"It was very exciting and revealing to see how complex these plasma structures really are," said Horton. "I also began to appreciate how the measurements we get from laboratory diagnostics are not adequate enough to give us an understanding of the full three-dimensional plasma structure."


And it only took this guy 40 some years, well at least that's consistent with the astrophysicists. Maybe he'll be the one to convince astrophysicists their models of space plasmas are rudimentary and incomplete, but I doubt it.

BTW, gravity waves are a fictional creation, as such the above "simulation" is GIGO.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.