- an electrode for the emission of secondary electrons in a vacuum tube.
- an electrode onto which a beam of electrons can fall, causing the emission of a greater number of electrons by secondary emission. They are used in photomultipliers to amplify the signal
- An electrode used in certain electron tubes, especially photomultipliers, to provide secondary emission. Dynodes are arranged by increasing voltage between the cathode and anode of the tube, each attracting the cascade of electrons from the one behind it, and releasing more electrons to the next.