ACCUMULATING TYPE CATHODE AND MANUFACTURE THEREOF

PURPOSE: To enhance porosity and reduce shrinkage by stacking a plurality of layers each having the specified thickness and composition and firmly bonding them. CONSTITUTION: A first layer 1 is formed with a sintered body of tungsten, and a second layer 2 is a sintered body of osmium. Porous layers 1, 2 are a storage body formed by compressing powder and sintering the compressed body, having a thickness of 0.01-10mm, and different compositions. The storage body comprising the layers 1, 2 is impregnated with an electron emitting material, and the electron emitting material is made of at least an oxide of an alkali earth metal. The storage body is bonded to the wall surface of a plate- shaped member of a cathode sleeve 5, with heat sufficiently shut off, and the free surface 4 of the layer 2 forms an electron emitting surface. Powder mixture for forming the layer 2 is arranged on the surface 4, and the layers 1, 2 are bonded by weak compression. By firmly bonding the layers 1, 2, the storage body contains a large amount of osmium, porosity is enhanced, and shrinkage is reduced.