History of the Magnetron

Written by patricia arnett
  • Share
  • Tweet
  • Share
  • Pin
  • Email
History of the Magnetron
Magnetrons are most commonly used in microwave ovens. (micro wave oven image by mattmatt73 from Fotolia.com)

A magnetron is a vacuum tube designed to create microwave radiation. Magnetrons proved very useful during World War II, as they provided the technology to build radar sets to help locate enemy planes, ships and submarines.

Other People Are Reading

First Magnetron

Albert W. Hull was a professor of physics at the Worcester Polytechnic Institute and also worked at General Electric's Research Laboratory in New York. During his research in 1920, Hull invented the first magnetron. This magnetron tube was made of glass and had a wire that emitted electrons. The elections would collect on a cylindrical plate in curved paths by way of a magnetic field. This process generated energy. Hull's invention, however, produced little power and did not have many uses.

Cavity Magnetron

In 1939, physicists Harry Boot and John Randall, working to construct a defence system for Britain, wanted to improve on the Hull's magnetron. For their magnetron, they used black copper for the tube instead of glass. They drilled holes (cavities) into the cylindrical block to achieve a certain wavelength of the microwaves being discharged. They placed their device into a powerful magnetic field. It was tested in 1940 and proved a success by producing 400 watts of power. Not long after, they improved the prototype, and the United States soon began to manufacture the cavity magnetron.


Cavity magnetrons are still used in radar systems today. They are most commonly used in microwave ovens to heat and cook food. Certain lighting systems, such as sulphur lamps, also use magnetrons.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.