GB534612A - X-ray generating device - Google Patents

Abstract

534,612. R÷ntgen-ray tubes CALIFORNIA INSTITUTE OF TECHNOLOGY. June 8, 1939, No. 16789. Convention date, June 18, 1938. [Class 39 (i)] An X-ray tube construction comprises two vacuum-tight outer-connected parts, connected solidly with the extended anode target surface and the cathode respectively, the two parts forming an elongated envelope rotatably mounted about a line extending along the length of the envelope and the target face being disposed adjacent to one end of the envelope symmetrically with respect to the line at that end so that the X-rays are directed outwardly from the envelope at the same end. The two parts may be flexibly connected and surrounded by an enclosure for a cooling fluid. In the form shown in Fig. 1, the anode and cathode assemblies 5, 6 are secured together by a flexible member 7 and are rotatably mounted within members 27, 29 which are secured through a framework 8 to the detachable cover 2 of a casing 1. The framework 8 may be made of the material known under the Registered Trade Mark " Bakelite." The assemblies are driven by a motor 35 through gearing 33 so that the electron beam traces a circular path on the annular target L and the X-rays are directed through windows 11, 38 in the anode and the cover 2. Concentric members 13, 16, Fig. 4, supply current to the filament 14 and are connected to the plug coupling 22 through rotating contact rings 17, 18 and spring fingers. The members, 13, 16 are sealed by metal diaphragms 25 through a glass ring 26. For lubrication, cooling and electrical insulation, the casing 1 is filled with oil which may flow continuously through pipes 96, 97 and a cooler. In another form (Fig. 9, not shown), the axes of a conical anticathode, the exterior of which forms the target surface, and of the filament shaft are parallel but not axially arranged. In a further form, Fig. 6, the rotating tube 61 has an anode and cathode arranged co-axially and the electron beam is deflected onto the target 67 by a magnetic field from an electromagnet 68 or a permanent magnet within the casing 58. In another form, Fig. 8, the anode 73, and filament support 76 are arranged eccentrically and the anti-cathode is formed by the window 74. The cooling fluid within the casing may be fed to the conical anticathode (Fig. 9, not shown), by a pump which is arranged within the casing and is driven through gearing by the motor which rotates the tube. The window when forming the anticathode may be similarly cooled. The casing may be coated or lined with lead and a lead shield 80, Fig. 6, may be provided on the cathode stem. An electron beam of circular cross-section is used and the target may comprise lead or a gold layer on copper foil, or an alloy of gold and silver or of gold and copper.