Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Open Doors Day | An intense and unforgettable experience

    Saturday was Jacques's birthday. At age 90, the long-retired engineer from Aix-en-Provence had only one item on his wish list: to visit ITER for a third time an [...]

    Read more

  • Power conversion | A potent illustration of the "One ITER" spirit

    Europe made the buildings; the piping came from India; China and Korea provided the transformers; Russia manufactured the massive 'busbar' network. The ITER Org [...]

    Read more

  • Fusion world | Upgrade completed on DIII-D tokamak

    The DIII-D National Fusion Program (US) has completed a series of important enhancements to its fusion facility, providing researchers with several first-of-a-k [...]

    Read more

  • Vacuum lab | Ensuring leak test sensitivity

    A helium leak test is one of several factory acceptance tests planned for the sectors of the ITER vacuum vessel before they are shipped to ITER. In a vacuum lab [...]

    Read more

  • Bookmark | The Future of Fusion Energy

    To write about fusion is to walk a fine line between the temptation of lyricism and the arid demands of scientific accuracy. Whereas the general media tends to [...]

    Read more

Of Interest

See archived entries

Fusion on the micro scale

Florian Aigner, Vienna University of Technology

Artur Golczewski from the Vienna University of Technology mounting the high precision scale. Photo courtesy of the Vienna University of Technology. (Click to view larger version...)
Artur Golczewski from the Vienna University of Technology mounting the high precision scale. Photo courtesy of the Vienna University of Technology.
One of the world's most accurate scales is currently being used for fusion research at the Institute of Applied Physics at the Vienna University of Technology (VUT). A research group led by Professor Aumayr reproduces the physical conditions on the fusion reactor's walls in its experiments. In the laboratory, the interaction between high-energy ions and solid surfaces can be studied much more precisely than it ever could inside an actual fusion reactor.

A key tool for this research is the quartz crystal microbalance, which was developed by Professor Michael Schmid from VUT. A small piece of the surface material, which is supposed to be used in the fusion reactor, is irradiated with high-energy particle beams, and tiny changes of its weight are measured with great accuracy. This way, one can determine whether the particle bombardment knocks atoms out of the surface, reducing the mass of the specimen, or whether the incident particles are instead implanted into the material, thereby increasing its mass.

The vacuum chamber in which the high-precision measurements with the quartz crystal scale are being performed. Photo courtesy of the Vienna University of Technology. (Click to view larger version...)
The vacuum chamber in which the high-precision measurements with the quartz crystal scale are being performed. Photo courtesy of the Vienna University of Technology.
The microscale developed at VUT is one of the world's most accurate scales. "Mass changes of as little as one billionth of a gram can be measured," says Katharina Dobes, research assistant at the Institute of Applied Physics. Even if the particle bombardment only removes one single atomic layer from the surface, the resulting change in mass can still be evaluated.

The fundamental idea behind this incredible precision is rather simple: a quartz crystal is vibrated and its resonance frequency is measured. This frequency depends very sensitively on the crystal's mass. If the crystal surface is coated with the material under investigation and then hit by particles, the changing resonance frequency of the crystal can be translated in a mass change of the material on top of it. That way it is possible to determine the effect the particle bombardment has on the surface.

The application of this measuring device is not restricted to fusion research. "In particle-surface interactions, there are many quantum mechanical phenomena which play a crucial role. In this field, many interesting fundamental questions are yet to be answered," Professor Aumayr believes.


return to the latest published articles