| 摘要 |
PROBLEM TO BE SOLVED: To provide a cathode structure body in which the recovery time of the surface concentration of scandium after ion impact is shortened by forming a thin layer consisting of tungsten and/or tungsten compound powder, scandium and/or scandium compound powder, and rhenium and/or rhenium compound powder on an upper layer part of a cathode substrate body. SOLUTION: In an impregnated cathode structure body, a cup like fixing member 2 is so fixed in the inner side of one end of a cathode sleeve 1 as to be on the same plane as the aperture rim of the end of the cathode sleeve and a porous substrate 22 impregnated with electron emitting substance is fixed in the member 2. A cylindrical holder 4 is installed coaxially as to surround the cathode sleeve 1. The porous substrate body 22 comprises a porous tungsten substrate 22a, which is a tungsten sintered body, and a powder mixture non-sintered layer 22b formed on the substrate 22a. The substrate 22 is impregnated with an electron emitting substance 23. |
