Thermionic emission

1873 Thermionic emission

The book of science

Tom Sharp

Frederick Guthrie, Thomas Edison electromagnetism

Thermionic emission


On a Relation between Heat and Static Electricity

Edison effect

Schottky effect

Thermion dance

The work function of a surface is the energy that an electron needs to escape into space. For a metal, this energy varies for different arrangements of atoms on crystal faces. Once an electron is free, it can be accelerated by an electric field toward the anode of a vacuum tube.

John Ambrose Fleming created the first thermionic vacuum tube, the Fleming valve. Guthrie was a mentor to Fleming but Fleming was more inspired by the Edison effect embodied in vacuum tubes.

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