Jump to content

Wendelstein II-A

Add links
From Wikipedia, the free encyclopedia
WII-A
Wendelstein II-A
The original Wendelstein II-A, preserved in the Deutsches Museum.
Device typeStellarator
LocationGarching, West Germany
AffiliationMax Planck Institute for Plasma Physics
Technical specifications
Major radius0.5 m (1 ft 8 in)[1]
Minor radius0.05 m (2.0 in)[1]
Magnetic field0.6 T (6,000 G)[1]
Plasma density< 3.5×1015 m−3[1]
History
Year(s) of operation1968[2][3]–1975[4][5]
Preceded byWendelstein I-B
Succeeded byWendelstein II-B

Wendelstein II-A was the first circular classical stellarator to be built in Germany, at the Max Planck Institute for Plasma Physics.[1]

It followed in the footsteps of the Princeton Model C stellarator in the USA, at that time one of the largest fusion experiments ever built, and the USA's flagship fusion experiment. Both the Model C and WII-A's own predecessors, WI-A and WI-B, had had 'racetrack' configurations, where straight sections were combined with curved sections. Only the curved sections produced the stellarator rotational transform needed to confine plasma, and it was believed at the time that the circularizers that transitioned from curved to straight sections were a cause of loss of confinement.[1]

WII-A had two pairs of helical electromagnetic coils to produce the stellarator magnetic field, and five field periods around the torus.[1]

WII-A used barium plasmas rather than hydrogen, meaning that probes were not needed and the plasma could be diagnosed with simple optical methods. The stellarator was found to have classical transport, a very low level and qualitatively much better than Model C, which suffered from Bohm diffusion. This, and the similar result on its predecessor, were the first demonstrations of classical confinement in any toroidal device.[1][6][7]

These results were presented at the 3rd Fusion Energy Conference of the IAEA in Novosibirsk in 1968, alongside the USSR's record-breaking results from its T-3 tokamak. Following initial skepticism of the German success at the previous conference in 1965, they showed definitively that the problems on Model C were a "Princeton Mystery" and not, as had hitherto been talked about, a "Munich Mystery". Stellarator research ceased in the USA, but continued in Germany, Japan, and the USSR itself.[8][9][10][11]

Due to the success of its experiments, a follow-on stellarator Wendelstein II-B was built with similar design and more powerful magnetic fields, and its own considerably larger successor Wendelstein 7-A was specified while WII-A was still operating.[1]

[edit]

References

[edit]
  1. 1 2 3 4 5 6 7 8 9 Grieger, G.; Renner, H.; Wobig, H. (1985). "Wendelstein Stellarators". Nuclear Fusion. 25 (5). doi:10.1088/0029-5515/25/9/040.
  2. ↑ Jahresbericht 1967 (Report). Max Planck Institute for Plasma Physics. 1968.
  3. ↑ Jahresbericht 1968 (Report). Max Planck Institute for Plasma Physics. 1969.
  4. ↑ Jahresbericht 1975 (Report). Max Planck Institute for Plasma Physics. 1976.
  5. ↑ Jahresbericht 1976 (Report). Max Planck Institute for Plasma Physics. 1977.
  6. ↑ Iiyoshi, A. (20 April 1991). Development of the Stellarator/Heliotron Research (PDF) (Report). National Institute for Fusion Science, Japan. Retrieved 9 October 2026.
  7. ↑ Wobig, H. (2001), Stellarator Research at the IPP in Garching, Current Trends in International Fusion Research: Proceedings of the Third Symposium, National Research Council Canada
  8. ↑ Reinders, L.J. (2021). The Fairy Tale of Nuclear Fusion. Cham: Springer Nature. p. 355-356. doi:10.1007/978-3-030-64344-7. ISBN 9783030643430.
  9. ↑ Cole, M.D.J. (2024). Fusion's Fading Star. London: Downend Press. p. 53-60. ISBN 9781068559303.
  10. ↑ Shafranov, V.D. (1980). "Stellarators". Nuclear Fusion. 20 (1075). doi:10.1088/0029-5515/20/9/005.
  11. ↑ Berkl, E.; et al. "Confinement of Contract-Ionized Barium Plasma in the Wendelstein Stellarator W II". Plasma Physics and Controlled Nuclear Fusion Research, Conference Proceedings, Novosibirsk, 1-7 August 1968.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Wendelstein_II-A&oldid=1379488318"