thermionic tube

noun Electronics.

a vacuum tube in which the cathode is heated electrically to cause the emission of electrons by thermal agitation.

Origin of thermionic tube

First recorded in 1925–30
Also called hot-cathode tube. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Science definitions for thermionic tube

thermionic tube

[ thûr′mī-ŏnĭk ]

An electrical component, typically an electron tube, through which electric current flows via the emission of thermions from a heated cathode.
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