Abstract: A limiting device (9) for electromagnetic radiation (3; 5; 7) includes an essentially flat beam cross-section limiter (10) which partly or completely encloses at least one passage aperture (12; 13) for beams (5; 7) and is constructed so that it also includes at least one second beam cross-section limiter (14) which, in the active position, constitutes at least one longitudinal component extending at an angle to the first beam cross-section limiter (10).

Abstract: An X-ray optical diaphragm (3; 4) which is provided with at least one passage opening (3a; 4a) for rays is constructed in such a manner that the edge zone (9; 10) of the X-ray optical diaphragm (3; 4) which faces the passage opening (3a; 4a) is angulated at least partly relative to the direction of propagation (7) of the rays.

Abstract: A limiting device (9) for electromagnetic radiation (3; 5; 7) includes an essentially flat beam cross-section limiter (10) which partly or completely encloses at least one passage aperture (12; 13) for beams (5; 7) and is constructed so that it also includes at least one second beam cross-section limiter (14) which, in the active position, constitutes at least one longitudinal component extending at an angle to the first beam cross-section limiter (10).

Abstract: The partial evaporation of the sample liquid during X-ray analysis of liquids gives rise to problems, since the quantity of the sample liquid does not remain constant and evaporated gas is liable to invade the measuring paths in which it may lead to measurement falsifications. In order to solve this problem, there is provided a sample container for receiving a sample liquid, which container leaves open an opening at its top, and a cover is placed on the free surface of the sample liquid. The cover is not rigidly connected to the wall of the sample container and, therefore, allows pressure equalization. Evaporation phenomena are almost completely precluded as a result of the covering of the liquid surface.

Abstract: X-ray diffraction measurements are often carried out in a given atmosphere which may vary in respect of a variety of parameters, such as pressure, temperature, etc. Notably soft X-rays are very sensitive to atmospheric absorption. Therefore, the measured intensity is dependent not only on the material variables to be measured for the sample to be examined (10), but also on the varying absorption which thus constitutes a disturbing influencing of the X-rays in the X-ray optical path (16, 46, 50, 10, 52) from the X-ray source (7) to the detector (30). According to the invention a second X-ray optical path (54, 56, 58, 60) is established; this second path deviates from the first X-ray optical path and serves to carry out reference measurements, during or between the actual measurements, in order to determine the absorption of the atmosphere and to determine a correction factor for the X-ray intensity measured during the actual measurements.

Abstract: Method of polishing a surface (5a) of copper or an alloy comprising mainly copper, in which a polishing means is moved across the surface while exerting a polishing pressure of approximately 500 g/cm.sup.2 for obtaining a plane and smooth polished surface without any defects. A composition of a polishing component comprising a colloidal suspension of SiO.sub.2 particles having an average particle size of between 20 and 50 nm in an alkali solution, demineralized water and a chemical activator is used as a polishing means.

Abstract: In a cathode-ray tube for displaying colored pictures comprising in an evacuated envelope means to generate a number of electron beams, a display screen comprising a number of regions luminescing in different colors, and color selection means comprising a large number of apertures which assign each electron beam to luminescent regions of one color, in which color selection means a magnetic quadrupole field is generated to form a magnetic quadrupole electron lens in each aperture, which luminescent regions have the shape of substantially parallel strips the longitudinal direction of which is substantially parallel to the defocusing direction of the quadrupole lens, characterized in that the apertures are elongate, substantially hexagonal and symmetrical relative to their longitudinal axes and are situated with their longitudinal axes in a number of parallel rows which extend substantially parallel to the strips and the apertures of two juxtaposed rows are shifted relative to each other, it is possible, in spit