Definition of magnetron in US English:



  • An electron tube for amplifying or generating microwaves, with the flow of electrons controlled by an external magnetic field.

    • ‘Today, magnetrons are used as the source of heat in microwave ovens.’
    • ‘You remember there had been developed in my laboratory by Randall and Boot, a cavity magnetron which made microwave radar possible and I went to America in connection with the early days of this.’
    • ‘Randall had set up the unit on the basis of his wartime reputation, having developed (with Henry Boot) the cavity magnetron, the heart of airborne radar and a crucial element in the Allies' narrow victory in the battle of the Atlantic.’
    • ‘In 1940, aided by John Randall and Henry Boot from Birmingham University, Watson-Watt invented the cavity magnetron.’
    • ‘Should absorption not take place - if, for example, the oven is activated when empty, some energy will re-enter the waveguide and cause over-heating of the magnetron.’


1920s: from magnetic + -tron from electron.