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

  • Diagnostics | Measuring the behaviour of fast ions in the plasma

    A diagnostic probe, called the "lost alpha monitor," is being carefully designed to measure the behaviour of escaping ions. The lost alpha monitor wil [...]

    Read more

  • Fusion fashion | A collision of worlds

    As Gabriela Hearst, the Creative Director of the fashion brand Chloé, is quick to tell you, she is very excited about hydrogen fusion. She had read about ITER a [...]

    Read more

  • Manufacturing | Cold valve boxes for the ITER cryopumps

    Eight sophisticated 'cold valve boxes' will regulate the forced flow of supercritical helium to the eight cryopumps of the ITER vacuum system. European contract [...]

    Read more

  • Fusion world | A helium campaign kicks off at JET

    After achieving record-breaking results on the Joint European Torus during 2021 experiments with the high-performance fuel mix of deuterium and tritium, EUROfus [...]

    Read more

  • Coil winding table | Seven years of faithful service

    In November 2015, workers from the European contractor Sea Alp Engineering, an Italian company based in Turin, began installing a large circular structure at th [...]

    Read more

Of Interest

See archived entries

A predator-prey relationship in the plasma jungle

Data from the TJ-II stellarator showing oscillations in the turbulence, slightly ahead of oscillations in the flow. (Click to view larger version...)
Data from the TJ-II stellarator showing oscillations in the turbulence, slightly ahead of oscillations in the flow.
There is a predator on the loose in Madrid. It's been discovered in the fusion laboratories of CIEMAT, preying on its favourite victim ... Turbulence!

This predator is not a large feline, but a type of plasma behaviour known as zonal flows. Strangely enough the relationship between zonal flows and turbulence follows exactly the same pattern as that between the numbers of predators and their prey in the wild—a significant discovery for fusion scientists in the quest to control the turbulence that allows energy to escape from their experiments.

In the same way that a large number of prey—for example, deer—might support an increasing population of tigers, in certain conditions turbulence seems to trigger the growth of the zonal flow pattern.

However as they grow, the zonal flows inhibit the turbulence, which dies away, eventually undermining the zonal flows, in the same way as a large population of tigers would cause a decline in the deer population, leading to their own downfall. But as the tiger population drops, the deer begin to thrive again, and so the cycle begins anew. This oscillatory predator-prey relationship is exactly what has been measured in the TJ-II stellarator at CIEMAT, as shown in the figure.

The scientist who made the discovery is Dr Teresa Estrada, head of microwave and laser diagnostics at TJ-II. "It was a lucky discovery!" she said. "I was not looking for this, the timescale of the oscillations is milliseconds so I could easily have missed it. I saw [the oscillations] first in the turbulence, and so I looked at the flow and was excited to see them there too, with the characteristic ninety degree phase delay."

Read more on the EFDA website.


return to the latest published articles