IMPREGNATED TYPE CATHODE-RAY STRUCTURE, MANUFACTURE OF IMPREGNATED TYPE CATHODE-RAY STRUCTURE, ELECTRON GUN STRUCTURE AND ELECTRON TUBE

摘要

PROBLEM TO BE SOLVED: To exhibit sufficient ion impact resistance and satisfactory electron emitting property and low-temperature operability even under a high voltage and high frequency condition by providing a composite layer consisting of a layer containing a high melting point metal and a layer containing scandium on the electron emitting surface-side surface of a porous cathode base impregnated with an electron emitting material. SOLUTION: A porous tungsten base 21 consisting of tungsten particle is manufactured by sintering, and an electron emitting material 22 consisting of a mixture of BaO, CaO and Al2 O3 is fused and impregnated in the pore part of the base 21 by heating it under hydro gen atmosphere. An undefined ratio tungsten oxide layer 23 formed by sputtering with oxygen-containing guseous argon by using tungsten as target material and an undefined ratio hydrogen scandium layer 24 formed by sputtering with oxygen-containing gaseous argon by use of metal scandium as target material are alternately formed on the surface of the base 21 so that the thickness per layer is 50 nm or less to constitute a composite layer.