Scientists measure how ions bombard fusion device walls

October 27, 2016, American Physical Society
Measured flow field of ions in a plasma overlaid on visual image of the system. Credit: West Virginia University

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. The measurements performed at WVU in a "helicon" plasma are the first ever 3D ion flow fields mapped in a volume.

The measurements show how plasmas in fusion tokamak devices and Hall thruster spacecraft engines accelerate parallel to the wall prior to impact. This causes the walls of these devices to erode more rapidly than previously thought, limiting their lifetimes. This flow is surprising because it is not predicted in theoretical models. The researchers are currently investigating the reasons for this behavior, looking at aspects of the plasma that were assumed to be unimportant in previous models.

These results, including the first fully 3D flow measurements (Figure 1), will be presented at the 2016 American Physical Society - Division of Plasma Physics meeting in San Jose, Oct. 31 to Nov. 4.

"These measurements have already yielded surprising insights into plasma behavior near walls," said Derek Thompson, who took the measurements with Miguel Hernandez and Umair Siddiqui in the research laboratory of Earl Scime at West Virginia University.

Explore further: Fixing deficits in boundary plasma models

More information: meetings.aps.org/Meeting/DPP16/Session/TP10.84

Related Stories

Fixing deficits in boundary plasma models

October 27, 2016

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.

Steering a fusion plasma toward stability

October 27, 2016

Plasmas in fusion-energy producing devices are gases heated to millions of degrees that can carry millions of amperes of current. These superhot plasmas must be kept away from material surfaces of the vacuum vessel that contains ...

A turbulent solution to a growing problem

October 27, 2016

A recent experiment lead by University of California, Los Angeles (UCLA), researchers on the DIII-D tokamak suggests that plasma turbulence can prevent filamentary structures called magnetic islands from growing so large ...

Extinguishing a fusion fire in a flash of light

October 27, 2016

Fusion energy researchers have discovered that they can rapidly extinguish and cool a magnetically confined fusion plasma hotter than the center of the sun by injecting a large quantity of neon gas to prevent damage to fusion-energy ...

Recommended for you

Information engine operates with nearly perfect efficiency

January 19, 2018

Physicists have experimentally demonstrated an information engine—a device that converts information into work—with an efficiency that exceeds the conventional second law of thermodynamics. Instead, the engine's efficiency ...

Team takes a deep look at memristors

January 19, 2018

In the race to build a computer that mimics the massive computational power of the human brain, researchers are increasingly turning to memristors, which can vary their electrical resistance based on the memory of past activity. ...

Artificial agent designs quantum experiments

January 19, 2018

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.