| 摘要 |
PURPOSE:To make this cathode small-size and enhance a current density by obtaining an alloy substrate, where the sheet metal processing is easy, by adding a prescribed quantity of W to Ni and pressing them and forming an emitter layer consisting of a powder mixed material of W, Ba3WO6 and Zr on this alloy substrate. CONSTITUTION:A Ni-W alloy plate obtained by adding 10 to 30 weight % of W to Ni is used as cylindrical substance metal 11 which constitutes a thermion emission cathode, and is subjected to the press processing or the sheet metal processing into a cylindrical body. At this time, if the addition quantity of W is below 10 weight %, this body lacks in strength when being used as a cathode; and if the addition quantity of W is over 30 weight %, a prescribed processing efficiency cannot be obtained. Next, mixed powder layer 14 consisting of alloy powder of 10 to 30 weight % of W and the rest of Ni, Ba3WO6 powder, and Zr powder is provided in the external of the bottom of substance metal 11. Further, a mixed material of alloy powder, which has the same components as substance metal 11, Ba3WO6 powder, and Zr powder is used to for emitter layer 12 through layer 14. Thus, this cathode can be proof against a high current density and can be made small-size. |
