travelling-wave tube

Noun

 * 1)  A type of vacuum tube which amplifies electromagnetic signals, where the electron gun fires down the tube with an unmodulated electron beam, that passes through an interaction array, where the EM-signal is fed, which interacts with the electron beam, bunching the electrons, and transferring power to the signal.

Usage notes
The TWT's electron gun is typically a thermionic cathodic emitters. The usual design for the interaction grid is a helix wrapped around the beam's transmission tube. Modern TWTs have a depressed collector to recuperate unused power in the electron beam after it has passed through the interaction grid. Modern tubes are metal- instead of glass-encased. Radiator fins may be attached for heat management.

Synonyms

 * abbreviation

Derived terms

 * (cold cathode TWT)
 * (cold cathode TWT)

Translations

 * Chinese:
 * Mandarin:
 * German: Wanderfeldröhre, Lauffeldröhre