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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.

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