Posted on: 19th December 2015

#19 Preventing unwanted oscillations in electron beam tubes

Image source: FUTTA webpage. http://www.esa-tec.eu/fusion-technologies/from-fusion/prevention-of-parasitic-oscillations-in-electron-beam-tubes/

Image source: FUTTA webpage. http://www.esa-tec.eu/fusion-technologies/from-fusion/prevention-of-parasitic-oscillations-in-electron-beam-tubes/

Electron beam tubes, such as gyrotrons, are used in fusion devices to transfer high energy through high frequency electromagnetic oscillations. However, unwanted oscillations, termed parasitic oscillations, occur during the transfer process and greatly reduce the efficiency of energy transfer. To prevent this, researchers used alternately arranged metal rings, with corrugations on the inner surface, and ceramic rings. These rings prevent the rise of parasitic oscillations that could damage the tube. The technology has successfully been applied in the nuclear fusion domain. Further application areas include application to space technology for high frequency communication in satellites.

The complexity and the multidisciplinary nature of fusion research produced number of spin-offs that have found applications in industry, other scientific disciplines, and technological advances. The areas that have benefited from fusion research span a variety of fields ranging from medicine and material science to computing and astrophysics.

EUROfusion has identified some of these spin-offs, looked at fusion research aspects that have the potential for short-term benefits, and prepared a non-exhaustive list of fusion spin-offs which demonstrate the short-term benefits of fusion research on the way to fusion electricity.