A photomultiplier tube emits two electrons when a single photon interacts with an electron, initiating the photoelectric effect. The first emitted electron is accelerated towards the electrodes, where it collides with the surface and triggers secondary emission, resulting in the release of additional electrons. This process amplifies the initial signal, allowing for the detection of very low light levels. The interaction of one photon with one electron leads to a cascade effect, enhancing the overall electron output. Understanding this mechanism is crucial for applications in photodetection technology.
