Patent GB-1153878-A (GB)
Title: X-ray Spectrometers comprising each an X-ray Tube and an X-ray Detector
IPC: G01N23/20
Filed: 1966-09-15
Abstract: 1,153,878. X-ray spectrometer and specimen carrier. SIEMENS A.G. 15 Sept., 1966 [16 Sept., 1965], No. 41355/66. Heading H5R. An X-ray spectrometer (Figs. 1 and 2) comprises an X-ray tube 11 and an X-ray detector 12, 13 mounted in a housing which has a flat wall, e.g. 4 which extends, when in position, around a specimen support plate 1 having a flat surface 2 which is able to support a small specimen and which is coplanar with the surface 8 (when casing 4 is closed) to provide a substantially unbroken flat extended surface adjacent which large specimens may be positioned for examination, the support plate 1 being formed with at least one orifice for passing X-rays to and from the specimen under examination, the tube 11 being positioned to supply such rays and the detector 12, 13 being arranged to receive them, the support plate 1 also being movable relative to the wall 8. Preferably as shown, the wall is a cover 4 movable with respect to the rest of the housing to give, as shown in Fig. 2, access to the interior of the apparatus, the arrangement being such that when closed the surface 8 of cover 4 is coplanar with the surface 2 of the support plate 1. There may be releasably attached to the specimen support plate, a drum 5 which rotates about an axis perpendicular to the support plate to position specimen holders which it contains sequentially over the examination location in the plate 1. The X-ray tube 11 crystal changer 12 and detector 13 may be mounted on a common support 22 which is pivotally mounted on bearings 23, 24 (Fig. 1) in the housing, the pivot axis extending adjacent the plate 1 in the region on the same side of this plate as the X-ray tube. The holder for the smaller specimens of solid, powder or liquid used with the present spectrometer may be attached to the external surface of the specimen support plate in a manner such that a surface of the small specimen when in position lies parallel to and at a finite distance from the flat external surface of the support plane 1. Preferably as shown in Fig. 4, the specimen holder comprises a cup-like part 31 which holds the specimen 30 in the desired orientation. The cup-like portion has a cylindrical wall with a base portion extending perpendicular thereto at one end thereof, the thickness of the base portion being substantially equal to said finite distance. The base portion preferably consists of a material which upon excitation by X-rays emits secondary rays, the wavelength of which is sufficiently great to lie outside the range of the spectrometer, e.g. the material may be high purity graphite. The cup-like part may be suspended e.g. by pins 32, 33 from auxiliary holder 34, the combination of cup and holder being removably inserted in a cylinder substantially coaxial with the cup-member, the base of the cup being adjacent one end of the cylinder. A spring 37 may be fitted to urge the cup away from the auxiliary holder 34. The cylinder 35 may be fitted, e.g. with bearings 45, so that it may be rotated about its own axis. The auxiliary holder may be such that it comprises a closure member to close the cup-like parts. The inside lip of the cylinder 35 may be formed with a conical surface 36 to facilitate insertion of the holder-cup combination into it. A stirrup member 38 may be attached to the auxiliary holder the ends 39, 40, of which stirrup co-operate with the cylinder such that when the stirrup is in a first position relative to the auxiliary holder it serves to lock the holder in position and when in a second position relative to the holder it serves to push the auxiliary holder up out of the cylinder. A single specimen holder of the above type may be attached to the specimen support plate and a result of such attachment is that the spring 37 forces cup 31 into contact with the support plate 1. Several such specimen holders may be mounted in drum 5 wherein during change of the specimen being examined the base of the cup-like portion slides over the flat surface of the support plate 1. An X-ray absorbent cover 9 may be used to cover the plate 1, and it may be attached to the cover 4.