RADIATION SHIELDING GLASS HAVING ZINC-BARIUM-BOROSILICATE COMPOSITION

Abstract

Disclosed is a radiation shielding zinc-barium-borosilicate glass material produced from easily accessible, low-cost and abundantly available starting raw materials, particularly for X-rays and/or gamma rays and/or fast neutrons and/or the like, having unique glass compositions. In particular, disclosed is the use of sodium oxide (Na.sub.2O), silicon dioxide (SiO.sub.2), boron oxide (B.sub.2O.sub.3), calcium oxide (CaO), barium oxide (BaO), zinc oxide (ZnO), bismuth oxide (Bi.sub.2O.sub.3), gadolinium oxide (Gd.sub.2O.sub.3) and cerium oxide (CeO.sub.2), which when mixed provides a satisfactory and effective shielding effect against X-rays and/or gamma rays and/or fast neutrons and/or the like.

Claims

1. A radiation shielding zinc-barium-borosilicate glass which allows a transparent appearance to be provided in different areas where radiation-induced ionizing rays will occur, particularly in medical diagnostic centres and research institutes, and which can also be used to prevent harmful radiation from X-rays and/or gamma rays and/or fast neutrons and/or the like, wherein the glass comprises an addition of gadolinium oxide (Gd.sub.2O.sub.3) and/or bismuth oxide (Bi.sub.2O.sub.3) and/or cerium oxide (CeO.sub.2) to zinc-barium-borosilicate (ZnOBaOB.sub.2O.sub.3SiO.sub.2) glass powder.

2. The radiation shielding zinc-barium-borosilicate glass according to claim 1, comprising components in range values of 0.01-15 mol % Na.sub.2O, 0.01-5 mol % MgO, 0.01-5 mol % Al.sub.2O.sub.3, 15-75 mol % SiO.sub.2, 0.01-30 mol % B.sub.2O.sub.3, 0.01-13 mol % CaO, 0.01-35 mol % BaO, 0.01-2 mol % TiO.sub.2, 0.01-5 mol % SrO, 0.01-15 mol % ZnO, 0.01-4 mol % Li.sub.2O, 0.01-10.00 mol % Gd.sub.2O.sub.3, 0.01-10 mol % Bi.sub.2O.sub.3, 0.01-10 mol % CeO.sub.2, 0.01-5 mol % SB.sub.2O.sub.3 and 0.001-0.10 mol % Fe.sub.2O.sub.3.

3. The radiation shielding zinc-barium-borosilicate glass according to claim 1, used in applications such as bone densitometry, mammography, dental x-ray, X-ray imaging, magnetic resonance imaging (MRI), PET/CT, gamma knife and in the fields of space, defence, food and agriculture, and not limited to those mentioned.

4. The radiation shielding zinc-barium-borosilicate glass according to claim 1, wherein the Fe.sub.2O.sub.3 and Cr.sub.2O.sub.3 components have values of 1000 ppm or less.

5. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a melting temperature above 1000 C. and below 1400 C.

6. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having an annealing initial temperature above 400 C. and below 700 C.

7. The radiation shielding zinc-barium-borosilicate glass according to claim 1 wherein an annealing time is in the range of 80 to 120 minutes.

8. The radiation shielding zinc-barium-borosilicate glass according to claim 1, wherein the glass thickness is in the range of 3 to 100 mm.

9. The radiation shielding zinc-barium-borosilicate glass according to claim 1, comprising 15 pieces/30 grams of glass for a diameter of 0.001 to 0.01 mm, 10 pieces/30 grams of glass for a diameter of 0.01 to 0.1 mm, and 5 pieces/30 grams of glass for a diameter of 0.1 mm and above, in terms of the number of gas inclusions (blisters and/or bubbles).

10. The radiation shielding zinc-barium-borosilicate glass according to claim 1, wherein the glass density is 3.25 g/cm.sup.3 and above.

11. The radiation shielding zinc-barium-borosilicate glass according to claim 1, wherein the Young's modulus value is 75 GPa and above.

12. The radiation shielding zinc-barium-borosilicate glass according to claim 1, wherein the refractive index is 1.76 and above.

13. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a transmission of 50% or above at a wavelength of 400 nm and a thickness of at least 10 mm.

14. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a transmission of 75% or above at a wavelength of 550 nm and a thickness of at least 10 mm.

15. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a coefficient of thermal expansion of not more than 8.7510.sup.6/K.

16. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.217 cm.sup.1 and above at the 662 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO and Fe.sub.2O.sub.3.

17. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.155 cm.sup.1 and above at an energy level of 1173 keV for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO and Fe.sub.2O.sub.3.

18. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.150 cm.sup.1 and above at an energy level of 1332 keV for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO and Fe.sub.2O.sub.3.

19. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.254 cm.sup.1 and above at the 662 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3, Gd.sub.2O.sub.3, Bi.sub.2O.sub.3 and CeO.sub.2.

20. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.175 cm.sup.1 and above at the 1173 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3, Gd.sub.2O.sub.3, Bi.sub.2O.sub.3 and CeO.sub.2.

21. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.165 cm.sup.1 and above at the 1332 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3, Gd.sub.2O.sub.3, Bi.sub.2O.sub.3 and CeO.sub.2.

22. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.302 cm.sup.1 and above at the 662 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3 and Gd.sub.2O.sub.3.

23. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.206 cm.sup.1 and above at the 1173 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3 and Gd.sub.2O.sub.3.

24. The radiation shielding zinc-barium-borosilicate glass according to claim 1, having a linear attenuation coefficient value of 0.171 cm.sup.1 and above at the 1332 keV energy level for the components Na.sub.2O, SiO.sub.2, B.sub.2O.sub.3, CaO, BaO, ZnO, MgO, Al.sub.2O.sub.3, SrO, Fe.sub.2O.sub.3 and Gd.sub.2O.sub.3.

25. The radiation shielding zinc-barium-borosilicate glass according to claim 1, comprising silica sand, quartz, quartzite, barite, barium carbonate, colemanite, ulexite, soda ash, albite, limestone, dolomite, spodumene, sodium nitrate, sodium sulphate, zinc oxide, gadolinium oxide, gadolinium sulphate, bismuth oxide, bismuth nitrate, cerium oxide, antimony trioxide, strontium carbonate, anthracite, zinc selenite and cobalt oxide as starting raw materials.

Description

FIGURES TO HELP UNDERSTANDING THE INVENTION

[0022] FIG. 1 is a schematic view of the production process of the inventive radiation shielding zinc barium borosilicate glass material.

DESCRIPTION OF PART REFERENCES

[0023] 1. Raw material prescription [0024] 2. Weighing unit [0025] 3. Raw material mixer [0026] 4. Melting furnace [0027] 5. Forming mould [0028] 6. Annealing furnace [0029] 7. Glass Product

DETAILED DESCRIPTION OF THE INVENTION

[0030] In this detailed description, preferred embodiments of an inventive radiation shielding zinc-barium-borosilicate glass (ZnOBaOB.sub.2O.sub.3SiO.sub.2) are described only for the purpose of a better understanding of the subject matter.

[0031] The invention is a radiation shielding zinc-barium-borosilicate glass which allows a transparent appearance to be provided in different areas where radiation-induced ionizing rays may occur, particularly in medical diagnostic centres and research institutes, and which may also be used to prevent harmful emissions from X-rays and/or gamma rays and/or fast neutrons and/or the like, a zinc-barium-borosilicate (ZnOBaOB.sub.2O.sub.3SiO.sub.2) glass comprising the addition of gadolinium oxide (Gd.sub.2O.sub.3) and/or bismuth oxide (Bi.sub.2O.sub.3) and/or cerium oxide (CeO.sub.2). The glass in question is used in applications such as bone densitometry, mammography, dental x-ray, X-ray imaging, magnetic resonance (MR), PET/CT, gamma knife and in the fields of space, defence, food and agriculture and not limited to those mentioned.

[0032] The said radiation shielding glass; comprising 0.01-15 mol % Na.sub.2O, 0.01-5 mol % MgO, 0.01-5 mol % Al.sub.2O.sub.3, 15-75 mol % SiO.sub.2, 0.01-30 mol % B.sub.2O.sub.3, 0.01-13 mol % CaO, 0.01-35 mol % BaO, 0.01-2 mol % TiO.sub.2, 0.01-5 mol % SrO, 0.01-15 mol % ZnO, 0.01-4 mol % Li.sub.2O, 0.01-10.00 mol % Gd.sub.2O.sub.3, 0.01-10 mol % Bi.sub.2O.sub.3, 0.01-10 mol % CeO.sub.2, 0.01-5 mol % Sb.sub.2O.sub.3 and 0.001-0.10 mol % Fe.sub.2O.sub.3 components as range values.

[0033] The inventive radiation shielding glass has a melting temperature value above 1000 C. and below 1400 C. and an annealing initial temperature value above 400 C. and below 700 C. It also has an annealing time in the range of 80 to 120 minutes.

[0034] The thickness of the inventive radiation shielding glass is in the range of 3 to 100 mm. The glass density is 3.25 g/cm3 and above, and the Young's modulus is 75 GPa and above. The diffractive index of the said radiation shielding glass is 1.76 and above. The coefficient of thermal expansion is at most 8.75106/K.

[0035] The said radiation shielding glass shall have the following dimensions and numbers in terms of the number of gas inclusions (habbees, fissures, and/or freckles). [0036] 15 pieces/30 gram glass for 0.001 to 0.01 mm diameter, [0037] 10 pieces/30 gram glass for 0.01 to 0.1 mm diameter, [0038] 5 pieces/30 gram glass for diameters of 0.1 mm and above

[0039] The subject matter of the invention is a radiation shielding glass, has a 50% transmission rate and above at a wavelength of 400 nm and a thickness of at least 10 mm, and a 75% transmission rate and above at a wavelength of 550 nm and a thickness of at least 10 mm.

[0040] The radiation shielding glass of the invention has silica sand, quartz, quartzite, barite, barium carbonate, colemanite, urexite, soda ash, albite, limestone, dolomite, spodumene, sodium nitrate, sodium sulphate, zinc oxide, gadolinium oxide, gadolinium sulphate, bismuth oxide, bismuth nitrate, cerium oxide, antimony trioxide, strontium carbonate, anthracite, zinc selenite and cobalt oxide as the starting raw materials.

[0041] In order to prepare the glass blend, the chemical composition of the raw materials is very important. Accordingly, the invention utilises high purity raw materials having satisfactory chemical composition properties. High purity at this point means having at least 99.00% of the main component and a maximum of 1000 ppm Fe.sub.2O.sub.3. The raw materials are carefully weighed within limited tolerances. According to the predetermined quantity for each raw material, glass tolerances are set to a maximum of 0.01% of the weighed quantities.

[0042] Impurities such as Fe.sub.2O.sub.3 (iron oxide) and/or similar impurities (e.g. Cr.sub.2O.sub.3) contained in the raw materials used in the glass manufacturing process cause the problem such as colouring of melt or similar (e.g. gas bubbles) glass defects. The transparency of the glassware is important for effective radiation shielding, which controls the resulting colouring at iron oxide values. This means that iron oxide causes the natural colouration of the glass through a greenish tint, resulting in poor visibility. In order to produce glassware that can provide appropriate transparency, the amount of iron oxide should not exceed 1000 ppm.

[0043] In addition, a transparent glassware is at risk of visually revealing some defects, including scratches, bubbles or the like. In order to achieve a remarkable quality in glassware, it is important to remove imperfections.

[0044] Density is a critical parameter that is monitored in a specific way and is the result of the optimisation of the patent mixture in question. The higher the density of the glass system, the higher the performance of the shielding glass. The densities obtained for glass composition variations are generally considered to be greater than 2.75-3.00 g/cm.sup.3, preferably 3.00-3.25 g/cm.sup.3, more preferably 3.25-3.50 g/cm.sup.3 and best greater than 3.50 g/cm.sup.3. As a result of this study, it was determined that the densities of the glasses were greater than 3.25 g/cm.sup.3.

[0045] The radiation shielding glass material of the present invention contains a novel glass composition in molar percentages ranging from 0.01 to 15.00 mol % Na.sub.2O, 0.01 to 5.00 mol % MgO, 0.01 to 5.00 mol % Al.sub.2O.sub.3, 15.00 to 75.00 mol % SiO.sub.2, 0.01 to 30 mol % B.sub.2O.sub.3, 0.01 to 13 mol % CaO, 0.01 to 35 mol % BaO, 0.01 to 2.00 mol % TiO.sub.2, 0.01 to 5.00 mol % SrO, 0.01 to 15.00 mol % ZnO, 0.01 to 4.00 mol % Li.sub.2O, 0.01 to 10.00 mol % Gd.sub.2O.sub.3, 0.01 to 10.00 mol % Bi.sub.2O.sub.3, 0.01 to 10 mol % CeO.sub.2, 0.01 to 5 mol % Sb.sub.2O.sub.3 and 0.001 to 0.10 mol % Fe.sub.2O.sub.3. In addition, the refining agent cerium oxide in the range of 100 and 5,000 ppm can be used to remove glass defects such as cords, bubbles or similar. No other toxic refiners such as arsenic trioxide or the like are preferred in the present invention. In addition, the amount of iron oxide, which naturally causes the greenish colour in the glassware and is also the cause of low visibility, is strictly controlled during the melting process of the raw material mixture.

[0046] Sodium dioxide is a component that increases the mouldability of the glass composition as well as lowering its melting point. The sodium dioxide content is from 0 to 15 mol %, preferably from 5 to 10 mol %, more preferably from 10 to 15 mol %. If the sodium dioxide content exceeds 15 mol %, the high temperature viscosity becomes uncontrollable, resulting in insufficient radiation blocking capability.

[0047] Silicon dioxide is the structure of the glass composition and is also the main net formation agent of the present invention. The content herein is 15 to 75 mol %, preferably 55 to 60 mol %, more preferably 60 to 75 mol %. If the silicon dioxide content is greater than 75 mol %, the melting point of the glass composition increases, which leads to an uncontrollable viscosity characteristic. On the contrary, if the amount of silicon dioxide is lower than 15 mol %, the net forming becomes thermally unstable.

[0048] Boron oxide is a component that not only lowers the melting point of the glass composition, but also increases the thermal stability of the glass structure by changing its structure accordingly under suitable conditions. The boron oxide content is between 0 and 30 mol %, preferably between 0.1 and 5 mol %, more preferably between 5 and 10 mol %. If the boron oxide content is much higher than 30 mole %, the thermally stable state of the glass article in question deteriorates.

[0049] Calcium dioxide is a component which increases the chemical resistance of the glass composition, in particular to water. The calcium oxide content is between 0 and 13 mol %, preferably between 0.1 and 4 mol %, more preferably between 4 and 13 mol %. If the calcium oxide content is greater than 13 mol %, the formability becomes difficult, resulting in an insufficient radiation barrier against X-rays and/or gamma rays and/or fast neutrons and/or the like.

[0050] Barium oxide is a preferred component for increasing the radiation ability of glass materials due to the high atomic number of barium elements. The barium oxide content is from 0 to 35 mol %, preferably from 0.1 to 15 mol %, more preferably from 15 to 35 mol %. When the barium oxide content exceeds 30 mol %, the glass becomes thermally unstable.

[0051] Zinc oxide is a component that improves the ability to form glass and also provides higher UV transparency. The zinc oxide content is from 0 to 15 mol %, preferably from 0.1 to 4 mol %, more preferably from 4 to 8 mol %, even more preferably from 8 to 12 mol %. When the zinc oxide content exceeds 15 mol %, the radiation shielding performance of the glass in question is adversely affected.

[0052] Gadolinium oxide is used as a barrier against X-rays and/or gamma rays and/or fast neutrons and/or the like. Due to its high density value, it improves radiation shielding properties. The content of gadolinium oxide is from 0 to 10 mol %, preferably from 0.1 to 1 mol %, more preferably from 1 to 3 mol %, more preferably from 3 to 6 mol %. If the gadolinium oxide content is greater than 10 mole %, the glass loses transparency in terms of colour.

[0053] Bismuth oxide is a component that improves the radiation protection performance of glass systems due to the high atomic number of bismuth elements. The bismuth oxide content is from 0 to 10 mol %, preferably from 0.1 to 1 mol %, more preferably from 1 to 3 mol %, even more preferably from 3 to 6 mol %. If the bismuth oxide content is greater than 10 mole %, the glass becomes thermally unstable.

[0054] Cerium oxide is a component used as a clarifying agent in the glass system. The cerium oxide content is 1,000 to 5,0000 ppm, preferably 1,000 to 3,000 ppm. If the cerium oxide content is less than 1,000 ppm, insufficient refining of the glassware occurs, resulting in the inclusion of bubbles by the glassware.

[0055] Up to 10 mol % of any of the other components (e.g. Li.sub.2O, K.sub.2O) may be added as long as the properties of the glass are not impaired.

Glass Examples of the Invention

[0056] In a practical embodiment of an improved glass composition specifically designed for the attenuation of X-rays and/or gamma rays and/or fast neutrons and/or the like, the following blend mixtures are prepared in molar percentages. These blends may vary according to the chemical properties of the raw materials selected within the scope of the present invention. The utilisation of the raw materials in terms of the quantities obtained, both chemically and physically, is variable within predetermined tolerances.

[0057] FIG. 1 shows the production process diagram. Firstly, the selected raw materials are prepared in such a way that they have the glass composition listed in each different application and sub-prescription. Weighing is carried out depending on the mentioned tolerance percentage. After weighing each compound, the mixing process is carried out by means of a mill and/or a mechanical mixer in a dry environment with alumina balls in a porcelain container for 15 to 60 minutes at a rotation speed range of 250 to 500 rpm in order to form a homogeneous mixture. After obtaining the homogeneous mixture, the prepared glass stacks are melted in an electric resistance lift melting furnace and/or in a gold-platinum alloy crucible without any atmospheric control. Any temperature value between 100 and 1400 C. can be selected for the melting temperature. The holding time at the melting temperature is 60 to 180 minutes. As soon as the glass melt is obtained and the waiting time is over, preferably the glass melt is immediately poured into a graphite mould or placed in a gold-platinum alloy crucible for 5 to 10 minutes at room temperature. The glass product obtained by both methods is then taken either together with the mould containing the glass melt or from the gold-platinum alloy crucible and placed in an annealing furnace heated to any temperature between 40 and 700 C. for stress relief annealing for any time between 80 and 120 minutes, and after the completion of the waiting period, the glass product is removed from the annealing vessel and/or furnace to obtain the final glass product.

[0058] In table 1 below, Example 1: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like is provided. The code OR represents the basic recipe. The code BA indicates an increased amount of barium oxide (BaO). The BO code is associated with an increased amount of boron oxide (B.sub.2O.sub.3). Increasing both BaO and B.sub.2O.sub.3 improves the damping ability of the basic glass recipe, OR glass, against X-rays and/or gamma rays and/or fast neutrons and/or the like.

TABLE-US-00001 TABLE 1 Example 1: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like OR BA BO Na.sub.2O 6.31 6.60 6.24 SiO.sub.2 59.13 54.92 55.33 B.sub.2O.sub.3 10.15 10.61 12.24 CaO 8.55 8.95 10.26 BaO 9.31 11.96 9.15 ZnO 4.35 4.55 4.27 MgO 1.31 1.38 1.57 Al.sub.2O.sub.3 0.17 0.17 0.17 SrO 0.69 0.83 0.73 Fe.sub.2O.sub.3 0.03 0.03 0.04 Intensity (g/cm.sup.3) 3.1101 3.2017 3.1142

[0059] Firstly, the selected raw materials are prepared in such a way that they have the glass composition listed in each different application and sub-prescription. Weighing is performed depending on the tolerance percentage mentioned. After weighing each compound, the mixing process is carried out by means of a mill and/or a mechanical mixer in a dry medium with alumina balls in a porcelain container for 15 to 60 minutes at a rotation speed range of 250 to 500 rpm in order to form a homogeneous mixture. After obtaining the homogenous mixture, the prepared glass stacks are melted in a gold-platinum alloy crucible in an electric resistance box type and/or lift melting furnace without any atmospheric control. The melting temperature is any temperature between 100 and 1400 C. As a waiting time at the melting temperature, any temperature value between 60 and 180 minutes is selected. As soon as the glass melt is obtained and the waiting time of the melt is over, preferably the glass melt is immediately poured into a graphite mould or kept in a gold-platinum alloy crucible at room temperature for 5 to 10 minutes to obtain a glass product. The glass product obtained by both methods is then either taken from the mould with the glass melt or from the gold-platinum alloy crucible and placed in an annealing furnace heated to any temperature between 40 and 700 C. for stress relieving annealing for any period between 80 and 120 minutes, after completion of the waiting time, the glass product is removed from the annealing vessel and/or furnace and the final glass product is successfully obtained.

[0060] Radiation shielding glass, have a linear attenuation coefficient value of 0.217 cm1 and above at 662 keV energy level; Linear attenuation coefficient value of 0.155 cm1 and above at 1173 keV energy level; linear attenuation coefficient value of 0.150 cm1 and above at an energy level of 1332 keV for example 1 concrete components.

[0061] In table 2 below, Example 2: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like is given. The code BB represents the basic prescription. The code BBGd indicates the amount of gadolinium oxide (Gd.sub.2O.sub.3) added. The code BBBi indicates the amount of bismuth oxide (Bi.sub.2O.sub.3) added. The code BBCe indicates the amount of cerium oxide (CeO.sub.2) added. The addition of Gd.sub.2O.sub.3, Bi.sub.2O.sub.3 and CeO.sub.2 improves the damping ability of the basic glass prescription BB glass against X-rays and/or gamma rays and/or fast neutrons and/or the like.

TABLE-US-00002 TABLE 2 Example 2: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like BB BBGd BBBi BBCe Na.sub.2O 6.28 6.23 6.24 6.16 SiO.sub.2 52.82 52.31 52.43 51.76 B.sub.2O.sub.3 12.28 12.17 12.19 12.04 CaO 10.34 10.24 10.26 10.14 BaO 11.33 11.22 11.24 11.10 ZnO 4.31 4.26 4.27 4.22 MgO 1.59 1.57 1.57 1.55 Al.sub.2O.sub.3 0.17 0.17 0.17 0.17 SrO 0.84 0.83 0.83 0.82 Fe.sub.2O.sub.3 0.04 0.04 0.04 0.04 Gd.sub.2O.sub.3 0.00 0.96 0.00 0.00 Bi.sub.2O.sub.3 0.00 0.00 0.76 0.00 CeO.sub.2 0.00 0.00 0.00 2.00 Intensity (g/cm.sup.3) 3.1858 3.2248 3.2270 3.2650

[0062] Firstly, the selected raw materials are prepared in such a way that they have the glass composition listed in each different application and sub-prescription. Weighing is performed depending on the tolerance percentage mentioned. After weighing each compound, the mixing process is carried out by means of a mill and/or a mechanical mixer in a dry environment with alumina balls in a porcelain container for 15 to 60 minutes at a rotation speed range of 250 to 500 rpm in order to form a homogeneous mixture. After obtaining the homogeneous mixture, the prepared glass stacks are melted in an electric resistance lift melting furnace and/or in a gold-platinum alloy crucible without any atmospheric control. The melting temperature is selected any temperature between 100 and 1400 C. The waiting time at the melting temperature is selected between 160 and 180 minutes. As soon as the glass melt is obtained and the waiting time of the melt is over, preferably the glass melt is immediately poured into a graphite mould or kept in a gold-platinum alloy crucible at room temperature for 5 to 10 minutes to obtain a glass product. The glass product obtained by both methods is then either taken from the mould with the glass melt or from the gold-platinum alloy crucible and placed in an annealing furnace heated to any temperature between 40 and 700 C. for stress relieving annealing for any time between 80 and 120 minutes, after completion of the waiting time, the glass product is removed from the annealing vessel and/or furnace and the final glass product is successfully obtained.

[0063] The inventive radiation shielding glass has a linear attenuation coefficient value of 0.254 cm1 and above at 662 keV energy level; a linear attenuation coefficient value of 0.175 cm1 and above at 1173 keV energy level; a linear attenuation coefficient value of 0.165 cm1 and above at 1332 keV energy level for the embodiments of example 2.

[0064] In table 3 below, example 3: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like is given. The codes BBGd1, BBGd2 and BBGd3 represent increasing amounts of gadolinium oxide (Gd.sub.2O.sub.3). Increasing Gd.sub.2O.sub.3 improves the damping ability against X-rays and/or gamma rays and/or fast neutrons and/or the like.

TABLE-US-00003 TABLE 3 example 3: A glass composition for effectively blocking radiation such as X-rays and/or gamma rays and/or fast neutrons and/or the like BBGd1 BBGd2 BBGd3 Na.sub.2O 6.54 6.89 7.28 SiO.sub.2 48.91 45.14 40.92 B.sub.2O.sub.3 12.78 13.46 14.22 CaO 10.76 11.33 11.97 BaO 11.79 12.41 13.11 ZnO 4.48 4.71 4.98 MgO 1.65 1.74 1.84 Al.sub.2O.sub.3 0.17 0.18 0.19 SrO 0.87 0.92 0.97 Fe.sub.2O.sub.3 0.04 0.04 0.04 Gd.sub.2O.sub.3 2.01 3.17 4.48 Intensity (g/cm.sup.3) 3.3017 3.3867 3.4811

[0065] The linear attenuation coefficient (u) values obtained for Example 1, Example 2 and Example 3 are given in tables 4, 5 and 6 in cm1 units. Three different gamma ray energy levels 662, 1173 and 1332 keV were selected as sample energy levels. Within the measurement method, gamma-ray spectroscopic analysis was used. NaI was used as a detector. Co60 and Cs137 were selected as radiation sources.

TABLE-US-00004 TABLE 4 Linear attenuation loss () values (cm.sup.1) at 662, 1173 and 1332 keV for example 1. Sample Name 662 keV 1173 keV 1332 keV OR 0.217 0.155 0.150 BA 0.219 0.161 0.157 BO 0.222 0.166 0.164

TABLE-US-00005 TABLE 5 Linear attenuation loss () values (cm.sup.1) at 662, 1173 and 1332 keV for example 2 Sample Name 662 keV 1173 keV 1332 keV BB 0.254 0.175 0.165 BBGd 0.277 0.191 0.166 BBBi 0.290 0.197 0.166 BBCe 0.296 0.201 0.168

TABLE-US-00006 TABLE 6 Linear attenuation coefficient () values (cm.sup.1) at 662, 1173 and 1332 keV for example 3 Sample Name 662 keV 1173 keV 1332 keV BBGd1 0.302 0.206 0.171 BBGd2 0.315 0.213 0.173 BBGd3 0.327 0.219 0.180