Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Cryolines | Not just any pipes

    In order to produce and sustain plasmas ten times hotter than the core of the Sun, some essential elements of the ITER machine need to be cooled to temperatures [...]

    Read more

  • Symposium in Japan | Fusion attracts strong political support

    A recent symposium in Japan on fusion energy attracted 500 participants. The Fusion Energy Forum of Japan was established in 2002 for the purpose of promoting [...]

    Read more

  • Fiction | "Steampunk" fusion machine travels in time

    Ever since a 'Mr Fusion' device appeared on Doc's time-travelling DeLorean in the first opus of the Back to the Future trilogy (1985), fusion energy has exerted [...]

    Read more

  • Construction | Honouring the crown mockup

    Medieval stone masons used to engrave their personal mark on the walls and pillars of the cathedrals they contributed to building. Their present-day counterpart [...]

    Read more

  • Neutral beam diagnostics | Right in the line of the beam

    A high-precision diagnostic is about to enter into service at the ITER Neutral Beam Test Facility, where scientists are testing key aspects of ITER's external h [...]

    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