CS196517B3 - Method of making the detection element of the dosimeter - Google Patents

Description

SUMMARY OF THE INVENTION The present invention provides a method for producing a dosimeter detector element for detecting ionizing radiation according to FIG. More specifically, the invention relates to an active dosimeter component consisting of an activated phosphor thermoluminescent glass.

Termoluminis valuation dosimeters (TLDs), containing a component suitable for measuring integrated accumulated exposure, have become increasingly important in clinical practice and in the monitoring of those exposed to nuclear radiation in recent years. Crystalline manganese-activated calcium fluoride (JHSchulmann: US Patent No. 3,115,578 (1960); activator-doped beryllium oxide selected from the group consisting of potassium, germanium, aluminum, cadmium, silicon, lithium, yttrium, and zinc are used as thermoluminescents for integrating aosimeters (N. Nada et al., U.S. Pat. No. 3,363,518 (1968); lithium fluoride with magnesium addition (D, E. Jones: U.S. Pat. 3,413,235) or lithium hydride (M.Oberhofer:

U.S. Patent No. 3,577,161 (1966); magnesium sulphate admixed with one or more elements selected from the group consisting of beryllium, cadmium, cobalt, lithium, nickel, lead, rhodium, sodium, thallium, tungsten, zinc and zirconium (T. Yamashita et al., British Patent Nos. 5,924,576); 1,139,377 (1969), zinc sulfide, activated with cobalt, nickel or calcium (VN Gorjushkin: USSR Patent No. 206,729 (1966); sodium sulfate with addition of dysprosium or holmium and the like);

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The preparation of crystals that would meet the requirements of dosimeters with their purity and physical parameters is relatively complex, difficult and expensive. Therefore, the interest of manufacturing companies has been focused on glasses that are cheaper in terms of mechanical strength and relatively chemically stable within the limits of reuse. A number of glasses of different composition, usually based on phosphorus pentoxide, have been proposed as an effective component of dosimeters. Thus J. Kocik and Z. Spurny described in MS. No. 123,817 glass, consisting (after recalculation) of 82 to 90% by weight of phosphorus pentoxide, 3 to 8% of magnesium oxide, 3 to 8% of alumina and 0.05 to 0.15% of manganese oxide. R.Bedier et al. In British Patent No. 974,157 (1962) reported silver-activated metaphosphate glass consisting, after recalculation, of 5.45% lithium oxide, 1.41% beryllium oxide, 6.38% sodium oxide, 58% alumina, 2.60% silver oxide and 77.58% phosphorus pentoxide. R. Yokata et al. In British Patent No. 1,119,815 (1966) described glass composed in a ratio of 1: 4 to 4 tears of beryllium and lithium metaphosphates, and from 1 to 10% silver phosphate, calculated on the weight of beryllium and lithium.

Also known from British Patent No. 1,169,312 (1969) is silver-activated glass containing 75 to 90 wt. % lithium and aluminum metaphosphates, 2 to 8 wt. % of silver metaphosphates, 7 to 20 wt. % of beryllium oxide and more than 2 wt. sodium nitrite. These types of glasses, especially silver doped, are used in photoluminescent dosimetry.

These glasses are generally made by casting molten glass obtained by either melting the batch from a mixture of glass raw materials, or melting a glass shard, or melting a frit, which has the advantage over the first two starting materials that it contains little dissolved gases.

Further research has found that thermoluminescent phosphor glass is not necessarily cast in the desired shapes for the manufacture of dosimeters. For example, so-called vykor (egg) is known from contemporary world technology, i.e. socio-boron-silicate glass, which, after shaping and heating at a temperature of 600 to 700 ° C, is precipitated by hot acid until most of the boron oxide is removed from the glass. and sodium, which are contained in the glass. There remains almost pure quartz glass, which has very fine pores in the diameter range of 20 to 40 S. and which, for example, is used for bacterial filters or, after sintering at about 1200 ° C, is used as a quartz replacement for the production of laboratory vessels. Its disadvantage is that due to the required working temperatures of about 1200 ° C and work with hot acid, the process is expensive and there is a significant change in the chemical composition of the glass, which in its final form could not be used as a component of dosimeters. '

Therefore, it has proved to be expedient and advantageous to solve the form of glass, since the treatment for the dosimeter component will be relatively technologically simple, inexpensive and will not result in chemical change of the material.

Said objects are met by the present invention of the method for producing a detection element of dosi198517 meter according to US. Certificate No. 170.016. SUMMARY OF THE INVENTION The present invention provides a process for compressing a glass powder consisting of from 90 to 99.9% by weight. particles with a diameter not exceeding 0,315 mm.

The invention utilizes the finding that a coherent block of phosphor thermoluminescent glass for dosages of satisfactory porosity can be obtained not only by pouring molten glass or the like, but also by sintering the glass powder at a temperature below the melting or softening point of the glass. Due to the surface energy that causes the mass to be transported to the interface of the two adjacent glass powder particles or the inwardly closed pore, the array of solid microscopic particles compacts while reducing the volume of the mass, increasing the bulk density and reducing the porosity.

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The sintering of the thermoluminescent phosphor powdered glass can also take place in the presence of a portion of the melt; The process produces a shaped phosphor luminescent glass of any shape and size suitable for use as a dosimeter component.

Advantageously, therefore, bodies can also be obtained from glasses which otherwise soften during processing. <

The glass according to the invention has the advantage over conventional poured thermoluminescence of phosphor glasses, that glass bodies of any shape and size can be produced in such a simple manner. Another advantage is that unnecessary material can be processed, for example, falling off in the processing of cast or blown glasses, such as grinding and similar technological processes.

Claims (1)

Method for producing a dosimeter detector element according to Basic Authorization Certificate No. 170.016, characterized in that a glass powder consisting of 90 to 99% by weight of particles having a diameter of not more than 0.315 mm is pressed.