| 摘要 |
1,255,358. X-ray diffraction apparatus. INCENTIVE RESEARCH & DEVELOPMENT A.B. 15 Jan., 1969 [25 Jan., 1968], No. 2482/69. Heading H5R. An X-ray diffraction camera having an airtight and evacuable casing with an X-ray transparent window houses a crystal holder for a monochromotor crystal mounted on a support plate rotatable about an axis perpendicular to an X-ray beam incident through the window, and a guide rail upon which first and second carriages may be moved radially with respect to the axis of rotation, and with respect to which they may be locked in selected positions, a specimen holder being mounted on one carriage, and a film holder being mechanically coupled to, and having its position determined by, the second carriage. As shown, the X-ray beam 4 enters the evacuable, air-tight camera casing through a window 2, and is incident upon a monochromotor crystal mounted in a crystal holder 33 which is rotatable about an axis M, and which is maintained in a desired position by the urging of a spring 38 upon an arm 37 of the holder which abuts against a micrometer screw 39. The crystal, with a reflecting surface ground to a radius of 2R, is urged against a pair of curved surfaces by spring-biased pins (Figs. 6 and 7, not shown) such that its reflecting surface has a radius of curvature R. A guide rail 45 is adjustably mounted-either pivotally or, as shown, by the provision in the casing of suitable different sets of support screw holessuch that it extends radially from the axis M, two carriages 49 and 50 being movable therealong and lockable in any desired position. The filmholder 5 is freely supported on the rail 45 by the engagement therewith of feet 6, 7, and 8 (see also Fig. 9, not shown) to facilitate its ready removal from the camera, but its position along the rail is determined by the abutment, under gravity, of a projection 51 on its underside with the end of the carriage 49. The filmholder includes a shutter (Figs. 10 and 11, not shown) for permitting a reduced time of exposure of the film to the unrefracted beam. A specimen aperture 52, and specimen holder 53 rotatable by a motor 57, are mounted on the carriage 50, the distance of which from carriage 49, and hence the spacing between the specimen and the film, being adjustable by a screw 58. The entrance aperture arrangement 16 of the camera is formed by four slides movable in perpendicular directions, whereby both the size and the position of the aperture may be adjusted (see also Fig. 3, not shown). The camera as a whole is adjustably mounted on the X-ray tube casing 9 by the cantilever 11 and screw 14, correct alignment of the camera with respect to the beam being determined with a fluorescent screen placed in front of the lead glass window 3. |
