The Machlett Laboratories, Incorporated

Varian Associates, Inc.

James R Caraher

Ming-Wei P Xu

Donald F DeCou

Albert F Fengler

William C Deits

William M Rappoport

An x-ray rotor structure wherein a target support stem has an externally threaded end portion brazed to an internally threaded surface of an encircling bushing which is provided with a barrier layer of oxidation restricting material. The stem is made of predominantly molybdenum material and the bushing is made of iron cobalt nickel alloy material having therein a small percentage by weight of titanium. The barrier layer comprises a layer of substantially pure nickel material which coats the entire inner surface of the bushing including the internally threaded portion thereof. Thus, the titanium is restricted from leaching to the surface during brazing and forming oxides which prevent the surface from being completely wetted by the brazing material. As a result, during brazing, the liquified brazing material alloys with the nickel material of the barrier layer to wet the inner surface of the bushing completely. Consequently, upon cooling, the alloyed brazing material and the nickel material of the barrier layer constitute an interlocking layer forming a durable brazed joint for fixedly attaching the bushing to the stem.

Rotor structure brazed joint

An image intensifier tube comprising a sealed envelope having therein means for controllably liberating oxygen within the envelope, and an input screen including an oxygen conditioned layer of fluorescent material and an overlying layer of photoemissive material which may be oxidized to improve the photon-to-electron conversion efficiency of the input screen. A method of improving the conversion efficiency of an image intensifier tube input screen including the steps of exposing a layer of fluorescent material to oxygen prior to the deposition of an overlying layer of photoemissive material, and subsequently exposing the layer of photoemissive material to oxygen, if desired, after the tube envelope has been sealed.

Oxygenated photosensitive screen

An image intensifier tube comprising an evacuated envelope wherein two spaced electrodes are insulatingly secured to one another by a dielectric member having an end portion extended within closely spaced walls of a hollow conductive shielding means attached to one of the electrodes for protecting the end portion from conductive vaporous material released within the envelope during processing and from resulting voltage breakdown during operation of the tube.

Image intensifier tube with insulator shield

An image intensifier tube comprising a sealed envelope having therein means for controllably liberating oxygen within the envelope, and an iput screen including an oxygen conditioned layer of fluorescent material and an overlying layer of photoemissive material which may be oxidized to improve the photo-to-electron conversion efficiency of the input screen. A method of improving the conversion efficiency of an image intensifier tube input screen including the steps of exposing a layer of fluorescent material to oxygen prior to the deposition of an overlying layer of photoemissive material, and subsequently exposing the layer of photoemissive material to oxygen, if desired, after the tube envelope has been sealed.

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Stamford, CT, United States of America

James R Caraher