GB749071A - An improved x-ray tube - Google Patents

Abstract

749,071. X-ray tubes. ELY, R. E. V. July 1, 1954 [May 5, 1953], No. 12407/53. Class 39 (1). [Also in Group XX] The anode 9 of an X-ray tube is of truncated cone shape, and the cathode 7 is surrounded by a conductive sleeve 8 with a forward extension 15 whose bore is intermediate between the larger and smaller diameters of the coned part of the anode. The cathode and the sleeve are independently adjustable axially from outside the tube casing 4 by micrometer screws 12, 12a. The anode is also adjustable axially, and provision may additionally be made for lateral adjustment of the electrodes. An inspection window 17 enables the adjustment to be estimated visually. The apparatus is supported from a mounting plate 22, with a movable disc 27 between plate 22 and a further plate 28; plate 28 bears against the flanged base 29 of the tube casing. Rubber rings 30 in recesses in plates 27, 28 provide sealing for the evacuated space in the tube. The plate 27 has a window 35 of aluminium or beryllium through which X-rays emerge from the apparatus; the window is retained in position by a threaded ring 34. Two such windows are provided in the plate 27, which can be rotated by an arm 38, 39, so that either window, or different parts of the same window, can be brought into use. This is to eliminate streakiness due to possible irregularities in the structure of the window material. The window may be slightly oriented with respect to the beam, which may also pass through more than one window in succession.