Subscribe to our free daily newsletters
  Energy News  




Subscribe to our free daily newsletters



ENERGY TECH
Fixing deficits in boundary plasma models
by Staff Writers
Kyoto, Japan (SPX) Oct 28, 2016


Simulations reproduce the plasma temperature (top) and density (bottom) in the divertor region. Image courtesy ORNL. For a larger version of this image please go here.

Researchers working on the DIII-D tokamak in San Diego are working to show how plasma transport and atomic physics come together to provide power exhaust solutions. One of the grand challenges facing fusion scientists is dealing with the massive power fluxes exhausted by fusion plasmas, which are created in devices called tokamaks like the DIII-D National Fusion Facility.

Left to its own devices, the intense power carried in a tokamak plasma would be focused into such a small area that it would rapidly destroy any material in its way.

The standard strategy for handling the power exhaust in reactors is to convert the heat into electromagnetic radiation, which spreads the power more evenly and gives the metal walls surrounding the plasma a fighting chance. This process occurs in the tokamak's divertor, a device that serves as a buffer region between the fusing plasma and the surrounding chamber walls.

Until now, simulations have predicted far less radiation than is measured in experiments. This has been attributed to the highly complicated combination of atomic and molecular physics at play in the divertor region, which is challenging to fully include in simulations.

Researchers at DIII-D have taken another approach to study the problem: eliminate the molecular physics from the experiment by running plasmas using Helium, a noble gas that does not form molecules (Figure 1).

These experiments have shown that the radiation can be fully reproduced in simulations, provided that the divertor plasma parameters are accurately accounted for (Figure 2). Doing this accounting relied on matching the density directly measured in the divertor- a measurement uniquely available at DIII-D.

Using measurements in the more distant edge of the main plasma as input to the simulation, as is usually done, isn't good enough, bringing out that a link is missing in the plasma transport connecting the main plasma to the divertor. Once this is accounted for, the plasma within the divertor can also be reproduced using the models.

"These results give significantly more confidence in our ability to use simulations to design radiating exhaust solutions for the future, which is critical to the success of the fusion endeavor," said Dr. John Canik of Oak Ridge National Laboratory, which led the team that included scientists from Lawrence Livermore National Laboratory and General Atomics, which operates the DIII-D facility in cooperation with the U.S. Department of Energy.

This success also points to the importance of capturing the more complicated atomic and molecular physics of standard plasmas, explained Dr. Canik. The team's results will be reported at the 58th annual conference of the American Physical Society Division of Plasma Physics in San Jose

"This work has brought out a 'missing link' in the plasma transport connecting the divertor back up to the main plasma," he said, noting that their work will be the subject of future experiments.

Abstract JI3.00002: The role of atomic and molecular physics for dissipative divertor operation in helium and deuterium plasmas.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
American Physical Society
Powering The World in the 21st Century at Energy-Daily.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
ENERGY TECH
Scientists measure how ions bombard fusion device walls
Washington DC (SPX) Oct 28, 2016
For the first time, researchers at West Virginia University (WVU) have directly measured the complicated 3D patterns of flowing plasma as it strikes the walls of fusion and space propulsion devices. Understanding how this process occurs, and how scientists and engineers can prevent it, is critical to the development of the next generation of energy and space exploration technologies. ... read more


ENERGY TECH
Australian consortium buys power grid after Chinese bid blocked

UNESCO urges Bangladesh to scrap Sundarbans plant

NREL releases new cost and performance data for electricity generation

Strong at the coast, weak in the cities - the German energy-transition patchwork

ENERGY TECH
Fixing deficits in boundary plasma models

First results of NSTX-U research operations

Breakthrough in Z-pinch implosion stability opens new path to fusion

A turbulent solution to a growing problem

ENERGY TECH
Cuomo announces major progress in offshore wind development

OX2 signs 148 MW wind power deal with Aquila Capital and Google

Prysmian Secures Contract for Offshore Wind Farm Inter-Array Submarine Cables Supply in Belgium

Wind turbines killing more than just local birds

ENERGY TECH
CPP, SolarCity Deal Keeps Colton, Calif., Community Affordable and Sustainable

Schools in oil-rich Alberta to get solar panels

Renewable energy on the rise, IEA finds

Researchers discover ways to expand temperature stability range of solar cells

ENERGY TECH
Rosatom Considers No Restrictions on Commercial Supplies of Uranium to US

A new method to help solve the problem of nuclear waste

Greenland uranium mining opponents join government

Bulgaria to pay Russia 600 mn euros for dropped nuclear plant

ENERGY TECH
Turning biofuel waste into wealth in a single step

State partnerships can promote increased bio-energy production, reduce emissions

Biomass heating could get a 'green' boost with the help of fungi

Algae discovery offers potential for sustainable biofuels

ENERGY TECH
US, China hold second meeting on advancing space cooperation

China to enhance space capabilities with launch of Shenzhou-11

Ambitious space satellite projects set for liftoff

China's permanent station plans ride on mission

ENERGY TECH
Commonwealth brainstorms on climate change reversal

Atmospheric CO2 concentration at Syowa Station in Antarctica exceeds 400 ppm

What the ancient CO2 record may mean for future climate change

Atom-by-atom growth chart for shells helps decode past climate




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement