Impregnated cathode structure

Abstract

Abstract PURPOSE:To prevent the penetration of a brazing material and besides obtain strong fixing, by impregnating a base matter of a porous sintered meterial of high-melting-point metal with an electron-emission material and then forming a thin and dense leyer on the bottom plane and then brazinq a cup. CONSTITUTION:A thin and dense layer 5 is formed by radiating laser beams on the bottom plane of a porous base matter 1 made of tungsten or the like. The layer 5 is then put into a cup made of Mo, Re, Ru, W, etc., with a brazing material 6 being interposed, and be fixed by brazing method. Thereafter pores of the base matter 1 are impregnated with an electron-emission material 3 such as barium calcium aluminate to compose an impregnated cathode structure. Hence, while the porous base matter 2 can be strongly fixed with the cup by brazing method, the brazing material 6 can be prevented from invading the porous base matter 2 due to the dense layer 5 in existence, together with removing deterioration of electron-emission characteristics and realizing improvement of raliability.

Inventors

• 👤 Hideo Tanabe
• 👤 英夫 田辺

Bibliographic Details