A photomultiplier is being used to detect 770 nm infrared photons from the excitation of potassium. These photons impinge on a 2 cm square cesium metal surface inside the photomultipler, there is enough energy to release electrons from this metal. What is the energy that an electron in the metal needs in order to be released from its surface.
If the photomultiplier is cooled to -30 degrees C, it is assumed that only the first atomic layer is active, and there is 1 electron per metal atom, how many electrons would leave the surface per second when the photomultiplier was in the dark? Cesium density = 1.93 grams per cubic centimeter. Ionization Energy: 3.894 eV