Measuring of emitted photo-electrons from cathode

A microchannel plate was used to measure the number of emitted photoelectrons from cathodes of Cu, Fe, and Al. The number of photoelectrons is shown to differ according to wavelength. Also, there is a difference in the number of photoelectrons between samples. Even in sample cathodes of the same material, there is a difference in the number of the photoelectrons. The differences in the number of photoelectrons are ranked as follows: Cu>Fe>Al. The number of photoelectrons changes according to the breakdown treatment. It is noted that it is difficult to change the number of the emitted photoelectrons according to the current of the light source