Abstract:
Method and apparatus for producing electrodes capable of receiving considerable cathode bombardment and which are formed so as to remove gas from an electron tube, are disclosed. The electrodes are formed by powdered metallurgy by mixing getter material powders such as zirconium, titanium or other getter material powders with carbon powder such as graphite and then forming the electrodes by pressing the mixture into a mold with a small amount of pressure and sintering in the range, for example, of 800* to 1,400* centigrade to produce the electrodes which have good gas absorption capability and which can be worked with little difficulty.
Abstract:
In a sublimation pump the cooled gas-adsorbing metal surface of the pump cylinder and a heated metal filament are made the anode and cathode, respectively, of a space-charged limited current diode which is included in a bridge circuit for detection of changes in its current-voltage characteristics. Potential differences across the bridge circuit resulting from changes in extent of adsorption of gas and deposition of vaporizable metal on the anode are amplified and utilized to control the source which effects heating of the vaporizable metal in the cylinder.