Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • The physics behind the transition to H-mode

    H‐mode—or thesudden improvement of plasma confinement in the magnetic field of tokamaksby approximatelya factor of two—is thehigh confinement regime that all mo [...]

    Read more

  • In search of the green plasma

    Sébastien König's core competence is in planning and scheduling; his passion is in understanding the workings of the Universe. In his previous life, before join [...]

    Read more

  • An outing into the future

    Open Doors days occur with scientific regularity at ITER (spring and autumn) and yet—due to the rapid evolution of work on site—each event offers something new. [...]

    Read more

  • Fusion "grandfather" tells family story

    Grandfathers like to tell stories. And Robert Aymar, the 'grandfather' of the French fusion community, is no exception. 'Being so old,' he quipped at last week' [...]

    Read more

  • An AC/DC adapter ... ITER size

    Like flashlight and smartphones, the ITER magnets—all 10,000 tonnes of them—will run on direct current (DC). And like flashlight and smartphones they will need [...]

    Read more

Of Interest

See archived articles

Wendelstein achieves ultra-precise magnetic topology

A recent article in the online journal Nature Communications confirms that the complex topology of the magnetic field of Wendelstein 7-X—the world's largest stellarator—is highly accurate, with deviations from design configuration measured at fewer than 1-in-100,000.

To measure the magnetic field, the scientists launched an electron beam along the field lines. They next obtained a cross-section of the entire magnetic surface by using a fluorescent rod to intersect and sweep through the lines, thereby inducing fluorescent light in the shape of the surface. (Click to view larger version...)
To measure the magnetic field, the scientists launched an electron beam along the field lines. They next obtained a cross-section of the entire magnetic surface by using a fluorescent rod to intersect and sweep through the lines, thereby inducing fluorescent light in the shape of the surface.
In the complex shape of a stellarator, high engineering accuracy is needed because even the smallest magnetic field errors can have a large effect on the magnetic surfaces and the confinement of the plasma.

Wendelstein 7-X relies on a system of 50 non-planar and superconducting magnet coils to create a precisely shaped magnetic "cage" to confine the plasma for discharges of up to 30 minutes (projected). Following a first helium plasma in December 2015 and an initial hydrogen campaign with over 2,000 plasma pulses, the machine is now being prepared for high power operation at the Max-Planck-Institute für Plasmaphysik (IPP) in Germany.

Because a carefully tailored topology of nested magnetic surfaces is necessary for optimum confinement, the study's highly sensitive measurements provide welcome proof that such a topology is feasible and verifiable with the required accuracy.

Read the original article in Nature Communications.
Other reports at IPP and the Princeton Plasma Physics Laboratory, PPPL.


return to the latest published articles