photocathode exposed to a photon flux.

When light strikes a photocathode inside the tube, an electron is emitted, which accelerates toward the first anode in a multiplier unit.

Interactive Flash Tutorial Photomultiplier Tubes Discover how photomultipliers work by amplifying the electrons generated by a photocathode exposed to a photon flux.

photocathode material) via the photoelectric effect.

Any available light from the outside world enters the lens and strikes a special device called a photocathode.

The photocathode converts the few photons that strike it into a corresponding pattern of electrical energy called electrons.

The next evolution of the technology involved a more advanced photocathode that could further improve the amplification of light.

Instead, they allow light from a very dimly lit location to pass into the goggles, which converts that light into an electrical signal using a special surface called a photocathode.

Electrons from the photocathode are then amplified and projected onto a screen inside the goggles.