Nav: Home

Scientists move step closer to solving fusion plasma dilemma

December 12, 2016

A team of researchers, affiliated with UNIST claims to have made yet another step towards finding a solution to one of the critical but unsolved fusion plasma physics problems, which is to mitigate or suppress the potentially harmful plasma edge instabilities, so-called the Edge Localised Modes (ELMs).

The energy bursts caused by the ELMs would be a detrimental event, as it can potentially damage the internal components of the fusion plasma devices like ITER. Therefore, the fundamental understanding of the ELMs and comprehensive physics of the role of magnetic perturbation (MP) as a promising suppression technique have been debated for a long time in fusion community.

The research results achieved by the Fusion Plasma Research Center at UNIST and led by Prof. Hyeon Park in collaboration with Prof. Gunsu Yun at POSTECH was published in the August issue of the prestigious journal, Physical Review Letters.

Through the study, the research team has discovered underlying physics of the suppression mechanism, in which the swirling turbulent flow driven by MP may prevent the ELM crashes in fusion plasmas.

Dr. Jaehyun Lee (UNIST Fusion Plasma Research Center), the first author of the paper has demonstrated that the ELM is weakened by losing energy through interaction with the turbulence induced by MP for the first time. The analysis confirmed coexistence of the ELM and turbulence induced by MP in the ELM-crash suppression phase. The dispersion relation of the turbulence together with spatial structure were directly measured and the nonlinear interaction between the ELM and turbulence was explicitly demonstrated.

This research result was possible by the 3D electron cyclotron emission imaging (ECEI) system, pioneered by Prof. Park a decade ago. The most advanced ECEI system has been developed for KSTAR while he was at POSTECH and currently maintained by the UNIST Fusion Plasma Research Center together with the POSTECH team.

Prof. Park says, "This research result will be a corner-stone for the predictable modeling of the suppression of mechanism of the ELM-crash which will be beneficial for the international project like ITER." He adds, "Also, such an innovative new research result will position the KSTAR as a leading physics research device in the worldwide fusion community."
-end-
This research was supported by National R&D Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning.

Journal Reference

Jaehyun Lee, Gunsu S. Yun, Minjun J. Choi, Jae-Min Kwon, Young-Mu Jeon, Woochang Lee, Neville C. Luhmann, Jr., and Hyeon K. Park, "Nonlinear interaction of edge-localized modes and turbulent eddies in toroidal plasma under n=1 magnetic perturbation," Phys. Rev. Lett., 117, 075001 (2016).

Ulsan National Institute of Science and Technology(UNIST)

Related Turbulence Articles:

Table top plasma gets wind of solar turbulence
Scientists from India and Portugal recreate solar turbulence on a table top using a high intensity ultrashort laser pulse to excite a hot, dense plasma and followed the evolution of the giant magnetic field generated by the plasma dynamics.
Swirling swarms of bacteria offer insights on turbulence
When bacteria swim at just the right speed, swirling vortices emerge.
Clarifying the mechanism for suppressing turbulence through ion mass
The National Institutes of Natural Sciences National Institute for Fusion Science, in collaborative research with Nagoya University, has clarified through theory and simulation research that turbulence in a plasma confined in the magnetic field is suppressed and the heat and particle losses are reduced in cases with larger ion mass.
Buckle up! Climate change to increase severe aircraft turbulence
Turbulence strong enough to catapult unbuckled passengers and crew around the aircraft cabin could become twice or even three times as common because of climate change, according to a new study from the University of Reading published in Advances in Atmospheric Sciences.
Reading between the lines of highly turbulent plasmas
Plasma, the ionised state of matter found in stars, is still not fully understood.
How plankton cope with turbulence
Microscopic marine plankton are not helplessly adrift in the ocean.
From the butterfly's wing to the tornado: Predicting turbulence
Remember the butterfly-triggers-tornado adage? Chaos theory says calculating turbulence to find out if that's true must be impossible.
How donut-shaped fusion plasmas managed to decrease adverse turbulence
In a paper published in EPJ H, Fritz Wagner from the Max Planck Institute for Plasma Physics in Germany, gives a historical perspective outlining how our gradual understanding of improved confinement regimes for what are referred to as toroidal fusion plasmas -- confined in a donut shape using strong magnetic fields-- has developed since the 1980s.
HSE experts investigate how order emerges from chaos
Igor Kolokolov and Vladimir Lebedev, scientific experts from HSE's Faculty of Physics and the Landau Institute for Theoretical Physics of Russian Academy of Sciences, have developed an analytical theory, which binds the structure of coherent vortices formed due to inverse cascades in 2-D turbulence with the statistical properties of hydrodynamic fluctuations.
A turbulent solution to a growing problem
Plasma turbulence can help prevent small magnetic islands from growing and becoming harmful.

Related Turbulence Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...