Page "Electron" Paragraph 19

Electrons are at the heart of cathode ray tubes, which have been used extensively as display devices in laboratory instruments, computer monitors and television sets.

In a photomultiplier tube, every photon striking the photocathode initiates an avalanche of electrons that produces a detectable current pulse.

Vacuum tubes use the flow of electrons to manipulate electrical signals, and they played a critical role in the development of electronics technology.

However, they have been largely supplanted by solid-state devices such as the transistor.