CS208043B1 - Method of manufacturing concave mirrors of x-ray objectives for sun observation - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a method for the manufacture of hollow mirrors used specifically for observing the Sun. The method facilitates the manufacture of internal mirror surfaces of deep hollow bodies.

The X-ray lens for imaging the Sun, as the main component, contains two hollow metal mirrors that are rigidly connected to each other. The first one has an inner surface in the form of a rotating paraboloid, the second in the shape of a rotating hyperboloid. Since the two rotary bodies are free of peaks, they form a tapered tube with a polished inner surface upon joining. Although the functional surfaces of mirrors are close to elongated cones, it follows from the theory that precise shaping according to prescribed equations is crucial for the resolution ability of the image. To date, each of the two mirrors is manufactured separately from a metal blank having an approximate shape of a tube made of, for example, nickel. The inner surfaces must be ground and then polished to form a hyperboloid and a paraboloid. However, the polished surface of a metal usually does not match the perfection of the polished glass surface. In addition, grinding internal surfaces is always more difficult than grinding external surfaces.

The advantages provided by the production method according to the invention consist in simplifying the production, since the technologically difficult grinding and polishing of the internal surfaces, which are now carried out on the external surface of the die, is eliminated. Furthermore, a mirror with a higher quality surface is obtained, since the glass surface of the matrix can be ground in a higher quality than the metal. The metal mirror guarantees shape stability. With proper metal deposition technology and a sharp rise in the temperature of the matrix, the matrix is not damaged when removed and can be reused.

The process according to the invention is characterized in that the outer surface of the glass matrix having the shape of the desired rotary body is polished, then silvered with the Brasher method and covered, for example, by galvanic, with a support metal. ° C and the matrix is pressed from the resulting metal mirror. The glass matrices, if they represent different rotating bodies, may be bonded to each other prior to metallization or may be made integrally.

For the method of making the mirrors of the present invention, a hollow mirror for displaying the Sun is shown in the accompanying drawing. It consists essentially of two hollow mirrors, one of which has the shape of a rotating paraboloid 1 and the other of the shape of a rotating hyperboloid 2. Both bodies represent segments of the rotating body without a vertex. The segments must be selected so that the contact faces 3 have the same diameter and at the same time the inner walls 4 have the necessary optical parameters. On these inner walls 4 there is a reflective thin layer of silver on which a multi-millimeter layer of carrier metal, for example nickel, has been electroplated.

The method of the invention employs precision glass matrices that represent the negative shape of a future hollow mirror. Thus, the matrix is approximately similar to a truncated cone whose surface follows the curve of a selected portion of the paraboloid or hyperboloid segment. The surface is precisely ground and polished to give the quality needed for optical purposes. These operations on the outer surface are much easier than on the inner surface of the hollow body. The shape of the matrix is interferometrically controlled by a spherical mirror, since numerical analysis has confirmed that the accuracy achieved by this control in the field of mirror parameters required leads to the full theoretical value of the resolution of the objectives. Prior to metallization, the matrices of future paraboloid and hyperboloid mirrors are joined so that

Claims (2)

SUBJECT A method of making hollow mirrors of X-ray lenses for observing the Sun, characterized in that the outer surface of a glass matrix having the shape of a desired rotating body is polished, then silvered by the Brasher method and covered, e.g. 1 surfaces 3 had the same diameter. It is also possible to produce a matrix of both mirror portions as a whole. First, a thin layer of silver is applied to the matrix, for example by the Brasher method, to which the carrier metal, usually nickel, is then applied in a layer of a few millimeters. The supporting metal is usually applied by electroplating. The carrier metal may contain various additives to increase the volume in a timely and sufficient manner in the event of a thermal shock. After both faces have been cleaned, the temperature of the metal-coated matrix has risen sharply by 300 ° C within 75 to 100 seconds and the matrix is pressed from the formulation. Due to the smooth surface of the glass matrix, a thin layer of silver remains attached to the carrier metal. This layer forms the inner reflecting reflective surface of the hollow body. The experiments confirmed that this would not cause disturbing defects in the mirror geometry. Mirrors have full resolution, are durable and have high reflection. BACKGROUND OF THE INVENTION from 75 to 100 seconds, the temperature is increased by 300 ° C and the matrix is pressed from the resulting metal mirror. 2. A method for producing hollow mirrors according to claim 1, characterized in that the glass matrix of the rotating paraboloid and the hyperboloid are joined together or produced as a whole prior to metallization.