Featured Research

from universities, journals, and other organizations

A Step Toward Fusion Energy

Date:
March 12, 2007
Source:
University of Wisconsin-Madison
Summary:
A new project has come one step closer to making fusion energy possible. Plasma is very hot, ionized gas that can conduct electricity - essentially, it's what stars are made of. If heated to the point of ignition, hydrogen ions could fuse into helium, the same reaction that powers the sun. This fusion could be a clean, sustainable and limitless energy source.

Pictures of HSX during construction
Credit: Image courtesy of University of Wisconsin-Madison

A project by University of Wisconsin-Madison researchers has come one step closer to making fusion energy possible.

The research team, headed by electrical and computer engineering Professor David Anderson and research assistant John Canik, recently proved that the Helically Symmetric eXperiment (HSX), an odd-looking magnetic plasma chamber called a stellarator, can overcome a major barrier in plasma research, in which stellarators lose too much energy to reach the high temperatures needed for fusion.

Published in a recent issue of Physical Review Letters, the new results show that the unique design of the HSX in fact loses less energy, meaning that fusion in this type of stellarator could be possible.

Plasma is very hot, ionized gas that can conduct electricity - essentially, it's what stars are made of. If heated to the point of ignition, hydrogen ions could fuse into helium, the same reaction that powers the sun. This fusion could be a clean, sustainable and limitless energy source.

Current plasma research builds on two types of magnetic plasma confinement devices, tokamaks and stellarators. The HSX aims to merge the best properties of both by giving a more stable stellarator the confinement of a more energetically efficient tokamak. "The slower energy comes out, the less power you have to put in, and the more economical the reactor is," says Canik.

Tokamaks, the current leader in the fusion race, are powered by plasma currents, which provide part of the magnetic field that confines the plasma. However, they are prone to "disruptions."

"The problem is you need very large plasma currents and it's not clear whether we'll be able to drive that large of a current in a reactor-sized machine, or control it. It may blow itself apart," says Canik.

Stellarators do not have currents, and therefore no disruptions, but they tend to lose energy at a high rate, known as transport. The external magnetic coils used to generate the plasma-confining field are partially responsible for the high transport rates in conventional stellarators. The coils add some ripple to the magnetic field, and the plasma can get trapped in the ripple and lost.

The HSX is the first stellarator to use a quasi-symmetric magnetic field. The reactor itself looks futuristic: Twisted magnetic coils wrap around the warped doughnut-shaped chamber, with instruments and sensors protruding at odd angles. But the semi-helical coils that give the HSX its unique shape also direct the strength of the magnetic field, confining the plasma in a way that helps it retain energy.

The team designed and built the HSX with the prediction that quasisymmetry would reduce transport. As the team's latest research shows, that's exactly what it does. "This is the first demonstration that quasisymmetry works, and you can actually measure the reduction in transport that you get," says Canik.

These results excited and relieved the researchers who have spent years working on the project. "We all thought the machine would do what it's turning out to do, but there are a million reasons why it might not: the theory might be wrong, (or) we might have built it badly," says Anderson. "But everything is panning out and supporting the fact that the ideas on which it was based were correct, and really points the way of the future for the stellarator."

The next step for the project is to establish how much symmetry in the coils is necessary to achieve low transport rates. They hope to make the coils easier to engineer, with the mindset that the principles used in the HSX could someday be incorporated into fusion generators, the reason that Anderson and his team began designing the HSX 17 years ago.

"It's an exciting field. It's something where one can contribute positively to mankind with an energy source that's completely sustainable, doesn't involve nuclear proliferation or radioactive waste, with a limitless fuel supply," says Anderson. "Plus, the machines look cool."



Story Source:

The above story is based on materials provided by University of Wisconsin-Madison. Note: Materials may be edited for content and length.


Cite This Page:

University of Wisconsin-Madison. "A Step Toward Fusion Energy." ScienceDaily. ScienceDaily, 12 March 2007. <www.sciencedaily.com/releases/2007/03/070310145550.htm>.
University of Wisconsin-Madison. (2007, March 12). A Step Toward Fusion Energy. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2007/03/070310145550.htm
University of Wisconsin-Madison. "A Step Toward Fusion Energy." ScienceDaily. www.sciencedaily.com/releases/2007/03/070310145550.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins