GB617373A - Improvements in or relating to x-ray tubes - Google Patents

Abstract

617,373. X-ray tubes. PHILIPS LAMPS, Ltd. Sept 27, 1946, No. 28918. Convention date, March 15, 1943. [Class 39 (i)] An X-ray tube is provided with a thin metal plate anode, the side of the anode remote from the side struck by electrons being in intimate thermal relation through a layer of liquid having a high thermal conductivity with a cooling body whose surface moves continuously over the surface of the anode. The X-ray tube 1 has a metal portion 3 provided with an aperture 4 closed by a thin tungsten plate anode 5. The heat produced in the anode 5 is transmitted to a rotating cooling body 8 by means of a liquid, for example a liquid metal or metal alloy such as mercury, which completely fills the casing 6 and is present between the anode 5 and cooling body 8. The heat is conveyed by the liquid to the wall of the casing 6 which is provided with cooling ribs 7 and may be provided with an envelope, a liquid or gaseous cooling agent being led through the space between the casing and the envelope. In an alternative arrangement the rotating body 8 may be cooled by exposure to the air. The rotating body 8 may be a cylinder or a disc and as shown is a copper disc in the form of a frustum of a cone fixed to a motor-driven shaft 9 which passes through a gland 10. The rotating body 8 may be hollow with separate cooling liquid entering and leaving it along its axis of rotation. When the area of the anode 5 struck by the electrons has an elongated shape it is advantageous if the direction of motion of the rotating body 8 over the anode 5 is at right-angles to the longest dimension of the area of impact of the electrons. The metal portion 3 is connected to a glass portion 11 having a re-entrant part 12 carrying a mounting 13 containing a cathode 14. The casing 6 is fastened to a thickened end wall of the metal portion 3 by a flanged connection 18. The X-rays generated are transmitted through a thin glass window covering an aperture 22.