Subscribe options

Select your newsletters:

Please enter your email address:

@

Your email address will only be used for the purpose of sending you the ITER Organization publication(s) that you have requested. ITER Organization will not transfer your email address or other personal data to any other party or use it for commercial purposes.

If you change your mind, you can easily unsubscribe by clicking the unsubscribe option at the bottom of an email you've received from ITER Organization.

For more information, see our Privacy policy.

News & Media

Latest ITER Newsline

  • Top management | ITER Council appoints new Director-General

    Convening in an extraordinary session in Paris, the ITER Council has appointed Pietro Barabaschi as the next Director-General of the ITER Organization. Mr Barab [...]

    Read more

  • On site | Open Doors for ITER families

    In a first at ITER, the gates of the monumental worksite opened on Saturday 17 September for a family-only Open Doors Day event, reserved for the families of st [...]

    Read more

  • Manufacturing | Russia ships four gyrotron sets

    Twenty-four electromagnetic wave generators called gyrotrons are at the heart of electron cyclotron resonance heating—the system on ITER that will ini [...]

    Read more

  • Fusion world | Science to resume at Wendelstein 7-X

    Improved equipment on Wendelstein 7-X will permit the stellarator device to achieve new scientific heights in a campaign planned to begin this autumn. Science a [...]

    Read more

  • ITER International School | On operation scenarios and control

    The 11th ITER International School concluded successfully in San Diego, USA, on 29 July after five days of lectures and discussions on the development of tokama [...]

    Read more

Of Interest

See archived entries

New "strike force" to deal with runaway electrons

Physicist Dylan Brennan is co-lead principal investigator for the new task force on runaway electrons. Photo: Elle Starkman, PPPL (Click to view larger version...)
Physicist Dylan Brennan is co-lead principal investigator for the new task force on runaway electrons. Photo: Elle Starkman, PPPL
Runaway electrons, a searing, laser-like beam of electric current released by plasma disruptions, could damage the interior walls of future tokamaks the size of ITER. To help overcome this challenge, leading experts in the field have launched a multi-institutional centre to find ways to prevent or mitigate such events.

"This is like a strike force to solve the problem and we need to get it right," said physicist Dylan Brennan of the US Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) and Princeton University. "It's very clear that runaways will be a problem," said Brennan, who with Xianzhu Tang of Los Alamos National Laboratory is co-lead principal investigator. "The goal is to take different scenarios for runaway electrons and come up with a recipe for solving them."

The project, called "Simulation Center for Runaway Electron Avoidance and Mitigation," will combine simulations and data from worldwide experiments to explore the causes and solutions for runaway electrons. Members are from nine US universities and national laboratories. Participants include the Oak Ridge, Lawrence Berkeley and Los Alamos national laboratories, the universities of Texas, California-San Diego, Columbia University and General Atomics in San Diego. Support totals $3.9 million over two years from the DOE's Office of Science.

Runaway electrons are relativistic—they travel at nearly the speed of light. To control these particles, researchers must utilize equations derived from Einstein's special theory of relativity, which describes the effect of relativistic speeds on moving bodies.

These equations apply to the huge ITER Tokamak. "ITER will be operating in a regime of plasma parameters well beyond the reach of any existing tokamak experiment," said Amitava Bhattacharjee, head of the Theory Department at PPPL.

"Therefore, one must rely on the predictive power of theory and simulation, which must be validated by comparison with present-day experiments and extrapolated to ITER conditions."

Research of the centre will contribute to a disruption mitigation system to be incorporated in ITER. The US ITER Project Office, based at Oak Ridge National Laboratory (ORNL), will be responsible for the system. Projected tasks include establishing the physics basis for the generation and evolution of runaway electrons, exploring how to avoid them, and investigating the best candidate techniques for mitigating the problem.

Read the full article on the PPPL website.


return to the latest published articles