Featured Research

from universities, journals, and other organizations

Plasma experiment demonstrates admirable self-control

Date:
November 13, 2013
Source:
American Physical Society
Summary:
A self-generated, or "bootstrap," current has significant implications for the cost-effectiveness of fusion power.

Scientists from the EAST tokamak experiment work with their US colleagues in control room of the DIII-D tokamak where they carried out experiments to test concepts that will enable groundbreaking experiments in EAST in 2014.
Credit: Andrea Garofalo

A team of Chinese and American scientists has learned how to maintain high fusion performance under steady conditions by exploiting a characteristic of the plasma itself: the plasma self-generates much of the electrical current needed for plasma containment in a tokamak fusion reactor. This self-generated, or "bootstrap," current has significant implications for the cost-effectiveness of fusion power.

Magnetic fusion energy research uses magnetic fields to confine the fusion fuel in the form of a plasma (ionized gas) while it is heated to the very high temperatures (more than 100 million degrees) necessary for the ions to fuse and release excess energy that can then be turned into electricity. The most developed approach uses the tokamak magnetic confinement geometry (a torus shaped vessel), and it is the basis for ITER, a 500-MW heat generating fusion plant currently being built in France by a consortium of seven parties -- China, the European Union, India, Japan, Russia, South Korea and the United States.

In the tokamak configuration, the confining magnetic field is generated by external coils and by an electric current flowing within the plasma. The cost of driving these currents has a strong impact on the economic attractiveness of a fusion reactor based on the tokamak approach. One step to minimizing this cost is to make the external coils of superconducting wire. The second step is to take full advantage of a surprising feature of the tokamak configuration: under certain conditions the electric current in the plasma can be generated by the plasma itself ("bootstrap" current).

The recent joint experiment, carried out on the DIII-D National Fusion Facility at General Atomics in San Diego, involved scientists from the DIII-D tokamak and from the Experimental Advanced Superconducting Tokamak (EAST), a fusion energy research facility at the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) in Hefei, China. Building on earlier DIII-D work, the experiment found that it is feasible for a tokamak to operate reliably at high fusion performance with most (more than 85 percent) of its plasma current consisting of bootstrap current. These conditions were maintained for several seconds, beyond the characteristic time scale of the plasma current evolution, and limited only by DIII-D pulse length constraints.

"It is often said that a plasma with a high fraction of self-generated (bootstrap) current would be difficult to control. However, these experiments show that a high bootstrap fraction plasma is very stable against transients: the plasma seems to 'like' a state where a large fraction of the current is self-generated," said Dr. Andrea Garofalo, General Atomics scientist and co-leader of the joint experiment.

These results build the foundation for follow-up experiments to be conducted on EAST, where the superconducting coils enable extension to very long pulse, and verification of the compatibility of this regime with reactor relevant boundary conditions.

ASIPP Director Prof. Jiangang Li remarked, "After the successful joint experiments in DIII-D, I am fully convinced that the DIII-D results can be reproduced on EAST in the near future, which will help us achieve the demonstration of high fusion performance in long pulse tokamak discharges."


Story Source:

The above story is based on materials provided by American Physical Society. Note: Materials may be edited for content and length.


Cite This Page:

American Physical Society. "Plasma experiment demonstrates admirable self-control." ScienceDaily. ScienceDaily, 13 November 2013. <www.sciencedaily.com/releases/2013/11/131113132311.htm>.
American Physical Society. (2013, November 13). Plasma experiment demonstrates admirable self-control. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2013/11/131113132311.htm
American Physical Society. "Plasma experiment demonstrates admirable self-control." ScienceDaily. www.sciencedaily.com/releases/2013/11/131113132311.htm (accessed September 22, 2014).

Share This



More Matter & Energy News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thousands March in NYC Over Climate Change

Thousands March in NYC Over Climate Change

AP (Sep. 21, 2014) — Accompanied by drumbeats, wearing costumes and carrying signs, thousands of demonstrators filled the streets of Manhattan and other cities around the world on Sunday to urge policy makers to take action on climate change. (Sept. 21) Video provided by AP
Powered by NewsLook.com
What This MIT Sensor Could Mean For The Future Of Robotics

What This MIT Sensor Could Mean For The Future Of Robotics

Newsy (Sep. 20, 2014) — MIT researchers developed a light-based sensor that gives robots 100 times the sensitivity of a human finger, allowing for "unprecedented dexterity." Video provided by Newsy
Powered by NewsLook.com
MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) — The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) — Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 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