Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Successful second round of experiments with Wendelstein 7-X

26.11.2018

The experiments conducted from July until November at the Wendelstein 7-X fusion device at the Max Planck Institute for Plasma Physics (IPP) in Greifswald have achieved higher values for the density and the energy content of the plasma and long discharge times of up to 100 seconds – record results for devices of the stellarator type. Meanwhile, the next round of the step-by-step upgrading of Wendelstein 7-X has begun. It is to equip the device for greater heating power and longer discharges. Wendelstein 7-X, the world’s largest fusion device of the stellarator type, is to investigate the suitability of this configuration for use in a power plant.

During the course of the step-by-step upgrading of Wendelstein 7-X, the plasma vessel was fitted with inner cladding since September of last year.


View inside the plasma vessel of Wendelstein 7-X fusion device

Photograph: IPP, Jan Michael Hosan


The record plasma with an energy content of over one megajoule

Photograph: IPP, Wigner RCP

Graphite tiles are now protecting the vessel walls. In addition, the so-called “divertor” is used to regulate the purity and density of the plasma. In ten broad strips on the wall of the plasma vessel, the divertor tiles follow the contour of the plasma edge.

Specifically, they cover the wall areas on which the particles from the edge of the plasma are diverted in a targeted way. After three months of experiments with the new equipment, the next round of upgrades began at the end of 2017; among other things, new measuring devices and heating systems were installed. The experiments were resumed from July 2018 onwards.

While the divertor had already demonstrated its good impact in the past (see PI 4/2018, https://www.ipp.mpg.de/de/aktuelles/presse/pi/2018/04_18), the plasma values with help of the extended plasma heating in combination with purified vessel walls could now be significantly increased.

The newly installed neutral particle heating injects fast hydrogen atoms into the plasma, which transfer their energy to the plasma particles via collisions. The result was high plasma densities of up to 2 x 10**20 particles per cubic meter – values that are sufficient for a future power station. At the same time, the ions and electrons of the hydrogen plasma reached an impressive temperature of 20 million degrees Celsius.

Record stellarator values achieved Wendelstein 7-X for the energy stored in the plasma. By strong microwave heating, the energy content of the plasma exceeded one megajoule for the first time, without the vessel wall becoming too hot. With good plasma values, long lasting plasmas over durations of 100 seconds have been obtained – also one of the best stellarator values to date.

These highly satisfying results attracted a great deal of attention at this year’s international conferences. Federal Research minister Anja Karliczek also commented on the results: “Congratulations to the Wendelstein 7-X team on the new world record.

The approach is the right one – in this way, important new findings have been made for the future use of fusion power stations. Alongside renewables, fusion energy could be THE energy source of the future. The researchers in Greifswald have taken an important step in this direction with their work. I wish the team every success with their future work.”

The final experiments were conducted in mid-October; in the meantime, the next round of upgrades on Wendelstein 7-X has begun. In order to be able to further increase the heating energy without overloading the vessel wall, the current graphite tiles of the divertor will be replaced over the next two years by water-cooleds elements made of carbon fibre-reinforced carbon.

With this equipment, work will be conducted on a step by step basis with the aim of achieving plasmas that last for 30 minutes. Then, it will remain to be seen whether Wendelstein 7-X can also fulfil its optimisation goals during continuous operation – the essential advantage of stellarators.

Background
The goal of fusion research is to develop a climate- and environment-friendly power station. Like the sun, it is to derive energy from the fusion of atomic nuclei. Since the fusion fire only ignites at temperatures of over 100 million degrees, the fuel – a low-density hydrogen plasma – must not come into contact with cold vessel walls. Held by magnetic fields, it floats in an almost contact-free manner in the interior of a vacuum chamber.

The magnetic cage of Wendelstein 7-X is generated by a ring of 50 superconductive magnetic coils which are about 3.5 meters high. Their specific forms are the result of elaborate optimisation calculations. Although Wendelstein 7-X is not designed to generate energy, the device is intended to prove that stellarators are suitable for use in power stations. With Wendelstein 7-X the intention is to achieve for the first time in a stellarator the quality of confinement afforded by competing devices of the tokamak type.

Weitere Informationen:

https://www.ipp.mpg.de/4550215/11_18

Isabella Milch | Max-Planck-Institut für Plasmaphysik

More articles from Power and Electrical Engineering:

nachricht The holy grail of nanowire production
20.02.2019 | Ecole Polytechnique Fédérale de Lausanne

nachricht Combining infrared radiation and air management to reduce energy use
19.02.2019 | Heraeus Noblelight GmbH

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

Im Focus: Famous “sandpile model” shown to move like a traveling sand dune

Researchers at IST Austria find new property of important physical model. Results published in PNAS

The so-called Abelian sandpile model has been studied by scientists for more than 30 years to better understand a physical phenomenon called self-organized...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

New therapeutic approach to combat African sleeping sickness

20.02.2019 | Life Sciences

Powering a pacemaker with a patient's heartbeat

20.02.2019 | Medical Engineering

The holy grail of nanowire production

20.02.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>