Transmitting type secondary electron surface and electron tube

A transmission secondary electron emitter which emits secondary electrons generated by the incidence of primary electrons, the transmission secondary electron emitter comprising:

• a secondary electron emitting layer which is made of diamond or a material containing diamond as a main component, and of which one surface is the surface of incidence for making the primary electrons incident thereon from a position outside of the secondary electron emitting layer, and the other surface is the surface of emission for emitting the secondary electrons corresponding to the incident energy of the primary electrons and generated in the secondary electron emitting layer;
• and
• a voltage applying means for applying a predetermined voltage between the surfaces of the incidence and the emission of the secondary electron emitting layer, wherein
• the voltage applying means includes a first electrode formed on the side of the surface of the incidence and a second electrode formed on the side of the surface of the emission for applying the predetermined voltage to form an electric field in the secondary electron emitting layer for accelerating the secondary electrons in the direction to the surface of the emission.