Abstract: The present invention employs a mechanical mixture of titanium dioxide and calcium oxide which is sintered and ground to produce a ceramic powder for application to a target of an X-ray tube. The powder is fused by baking the target at a predetermined baking temperature to produce a coating having an enhanced coefficient of emissivity. The required baking temperature is controllable by varying the proportion of titanium dioxide to calcium oxide. Baking time may be extended without degrading the coating by mechanically mixing zirconium dioxide to the sintered and ground ceramic powder prior to application to the X-ray target in order to enhance outgassing from the target substrate. The resulting coating on the target improves the emissivity thereof and exhibits and improved bond strength over coatings of the prior art.

Abstract: A dimensionally stable, temperature responsive microwave energy moderator. The moderator may comprise a sheet-like laminate having at least one lamina of microwave energy reflective material with at one aperture formed therein of such dimensions as to enable passage therethrough of a substantial portion of impinging microwave energy of a predetermined nominal frequency. At least one aperture-bridging microwave energy reflective member is provided together with means responsive to a predetermined temperature range to shift the aperture-bridging member from an inactive position to a position bridging the aperture, whereby to reduce the transmission of the microwave energy through the aperture. The moderator also has outer laminae of electrically insulative, microwave energy transmitting material with the microwave energy reflective lamina, the aperture-bridging means and the temperature responsive means located therebetween.

Abstract: A vessel, reflective to microwave electromagnetic energy, having at least one aperture to permit passage of said microwave energy to its contents and a shielding device, responsive to a preselected internal temperature of the vessel contents, to close said at least one aperture to prevent further passage of said microwave energy to the vessel contents.