Alkali metal generating agent, alkali metal generator, photoelectric surface, secondary electron emission surface, electron tube, method for manufacturing photoelectric surface, method for manufacturing secondary electron emission surface, and method for manufacturing electron tube

A method of producing a photo-cathode for emitting a photoelectron corresponding to incident light or a secondary-electron emitting surface for emitting secondary electrons corresponding to an incident electron, the method comprising the steps of:

• preparing a container in which a layer comprised of constituent materials of the photo-cathode or secondary-electron emitting surface to react with an alkali metal is formed;
• preparing an alkali metal generating device which includes an alkali metal generating agent as a supply source of an alkali metal, the alkali metal generating agent comprising:
• an oxidizer comprising at least one vanadate with an alkali metal ion as a counter cation;
• and a reducer for initiating a redox reaction with the oxidizer at a predetermined temperature to reduce the alkali metal ion;
• setting the alkali metal generating device in a space continuing an inner space of the container;
• depressurizing the space where the alkali metal generating device is set and the inner space of the container by a predetermined vacuum;
• heating the alkali metal generating device set in the depressurized space to generate an alkali metal vapor in the depressurized space;
• guiding the alkali metal vapor generated from the heated alkali metal generating device, while controlling a temperature of the container, to an area where the layer is formed;
• and
• wherein, in the alkali metal generating agent, the vanadate is expressed by a chemical formula RVO3, where R is at least one metal element selected the group consisting of Na, K, Rh, and Cs.