Subscribe free to our newsletters via your
. 24/7 Space News .




ENERGY TECH
Deuterium Uptake in Magnetic Fusion Devices with Lithium Conditioned Carbon Walls
by Staff Writers
Knoxville TN (SPX) Feb 01, 2013


Dynamic in lithiated graphite: a) Experiments show that deuterium bombardment dramatically increases the surface oxygen; b) Simulation shell for the D-impact chemistry in lithiated and oxidized carbon.

The research of a multi-institutional team from the U.S., Japan, and France, led by Predrag S. Krstic of the Joint Institute for Computational Sciences and Jean Paul Allain of Purdue University has answered the question of how the behavior of plasma-the extremely hot gases of nuclear fusion-can be controlled with ultra-thin lithium films on graphite walls lining thermonuclear magnetic fusion devices.

"It is remarkable that seemingly insignificant lithium depositions can profoundly influence the behavior of something as powerful as fusion plasmas," Krstic said.

Krstic and his team explain their research in a paper titled "Deuterium Uptake in Magnetic Fusion Devices with Lithium Conditioned Carbon Walls," recently accepted for publication in Physical Review Letters.

"How lithium coatings on graphite surfaces control plasma behavior has largely remained a mystery until our team was able to combine predictions from quantum-mechanical supercomputer simulations on the Kraken and Jaguar systems at Oak Ridge National Laboratory and in situ experimental results from the Purdue group to explain the causes of the delicate tunability of plasma behavior by a complex lithiated graphitic system," Krstic said.

"Surprisingly, we find that the presence of oxygen in the surface plays the key role in the bonding of deuterium, while lithium's main role is to bring the oxygen to the surface. Deuterium atoms preferentially bind with oxygen and carbon-oxygen when there is a comparable amount of oxygen to lithium at the surface. That finding well matches a number of controversial experimental results obtained within the last decade."

The performance demands on plasma-facing components and the other materials that would surround future fusion power reactors is one of the reasons the U.S. National Academy of Engineering has ranked the quest for fusion as one of the top grand challenges for engineering in the 21st Century.

Harnessing energy from thermonuclear magnetic fusion has been challenged in part by the extreme environment of hot and dense plasma interacting with the boundary fusion reactor walls.

The strong coupling between the plasma edge and the wall surface, which causes erosion of the wall material, retention of radioactive tritium, and pollution of the plasma, has been hampered by a lack of fundamental understanding of what takes place at the interface where the plasma and solid material meet.

Recent research in which lithium coatings have been deposited on a variety of metallic and graphitic surfaces has provided evidence that plasma strongly responds on the deposited films.

In fact, the use of ultra-thin coatings of lithium on graphite has resulted in an unprecedented influence on plasma behavior, including control of hydrogen recycling-one of the most important issues in the construction of future magnetic fusion-energy devices-and extraordinary improvements in energy confinement.

The study of the lithium coatings also impacts many areas beyond magnetic fusion, including nanoelectronics, lithium batteries, computational materials science, bioengineering and biophysics, plasma physics, and theoretical physics and chemistry.

"This work can lead to improvement of the hydrogen-recycling properties of the fusion materials facing plasma, as well as advancements in other areas," Krstic said.

"We hope that our finding will inspire future theoretical and experimental work in diverse applications not only with lithium coatings on various materials but also with combinations of other types of materials that are potentially good 'oxygen-getters'-for example elements of the first two groups of the periodic system."

Authors of the paper are P.S. Krstic, J.P. Allain, C.N. Taylor, J. Dadras, S. Maeda, K. Morokuma, J. Jakowski, A. Allouche, and C.H. Skinner. Support for the project was provided by the U.S. Department of Energy (DOE); the National Science Foundation (NSF), including its Extreme Science and Engineering Discovery Environment; and the Japan Science and Technology Agency.

.


Related Links
Joint Institute for Computational Sciences
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








ENERGY TECH
Fusion helped by collision science
Heidelberg, Germany (SPX) Jan 16, 2013
An international team of physicists has calculated the efficiency of a reaction involving an incoming electron kicking out an electron from the metal beryllium (Be) or its hydrogen compound molecules, in an article about to be published in EPJ D. The efficiency, which partly depends on the electron's incoming speed, is encapsulated in a quantity referred to as electron-impact ionisation cr ... read more


ENERGY TECH
US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

Mission would drag asteroid to the moon

ENERGY TECH
AAS Division For Planetary Sciences Issues Statement On Mars 2020 Program

Curiosity Maneuver Prepares for Drilling

Ridges on Mars suggest ancient flowing water

Changes on Mars Caused by Seasonal Thawing of CO2

ENERGY TECH
Sierra Nevada Corporation and Lockheed Martin Space Systems Company Partner On Dream Chaser Programs

NASA Launches Next-Gen Communications Satellite

NASA Takes Strides Forward to Launch Americans from U.S. Soil

Iran Takes First Step to Send Man to Space

ENERGY TECH
Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

ENERGY TECH
NASA to Send Inflatable Pod to International Space Station

ISS to get inflatable module

ESA workhorse to power NASA's Orion spacecraft

Competition Hopes To Fine Tune ISS Solar Array Shadowing

ENERGY TECH
Site of space rocket launch to become home of S. Korea's space program

Payload preps continue for first Ariane 5 flights of 2013

NASA Wallops Rocket Mission January 29 Prepping for Future Projects

Russia's Troubled Rocket Cleared for Launch

ENERGY TECH
TW Hydrae: There's more to astronomers' favorite planetary nursery than previously thought

The Origin And Maintenance Of A Retrograde Exoplanet

New Evidence Indicates Auroras Occur Outside Our Solar System

Glitch has space telescope shut down

ENERGY TECH
NTU research embraces laser and sparks cool affair

Bioinspired fibers change color when stretched

Stanford Researchers Break Million-core Supercomputer Barrier

Scientists trick iron-eating bacteria into breathing electrons instead




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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. 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