Radio-attenuating metallic material

Abstract

The present invention relates to a radio-attenuating metallic material for the production of a protective screen or shield against ionizing radiation such as X-rays, gamma rays, or beta rays. This radio-attenuating material is characterized in that it consists of an alloy of at least bismuth and tin, with bismuth present in a proportion of at least 50% by weight in the final metallic material. Preferably, the radio-attenuating material comprises: - between 52 and 70% by weight of bismuth in the final material, and - between 30 and 48% by weight of tin in the final material.

Description

Title of the invention: Radio-attenuating metallic material Technical field of the invention

[0001] The present invention relates to the general field of protection against ionizing radiation.

[0002] It relates more particularly to a new radio-attenuating metallic material, for the production of protective screens, or protective shells, against ionizing radiation such as X-rays, gamma rays or beta rays. State of the art

[0003] The metallic materials generally used in the field of radiation protection are lead and tungsten.

[0004] Lead is widely used, in particular because of its low cost, its ease of implementation by molding, and its good radio-attenuation qualities.

[0005] But its use is increasingly regulated, due to its toxicity and the environmental or ecological problems it poses.

[0006] The handling of this metal presents health risks, and it is very often necessary to associate it with a coating such as paint or a plastic shell, which significantly complicates the manufacture and also the maintenance of the armor.

[0007] Tungsten is used in a limited way, as a replacement for lead.

[0008] However, it is an expensive, heavy material and its shaping must be done by machining because it cannot be easily molded.

[0009] The aim of the present invention is to propose a new radio-attenuating material that overcomes the aforementioned drawbacks of structures known to date. Presentation of the invention

[0010] For this purpose, the present invention proposes a radio-attenuating metallic material, for the production of a protective screen, or a protective shell, against ionizing radiation such as X-rays, gamma rays or beta rays, which material consists of an alloy of at least bismuth (Bi) and tin (Sn), the bismuth being present in a proportion of at least 50% by weight in the final metallic material.

[0011] Such a material ensures very good radio attenuation.

[0012] Its mechanical properties are advantageous; in particular, it is conformable by molding. Its production cost is low, and it is lighter than tungsten with equivalent protection.

[0013] Preferably, tin is present in a proportion of at least 30% (and even more preferably at least 40%) by weight in the final material.

[0014] The material according to the invention may include small proportions of other metals such as antimony and / or copper and / or silver, so as to adapt the mechanical properties of the final material, in particular according to the intended application.

[0015] The proportions of these other metals can be, for each one, on the order of a few percent maximum by weight in the final material.

[0016] For example, the proportion by weight in the final material of each other metal can be between 0.1 and 5%, preferably between 0.1 and 3%, and even more preferably between 0.1 and 2%.

[0017] Preferably, all of these other metals together constitute less than 5% by weight of the final metallic material.

[0018] The radio-attenuating material may comprise at least antimony and / or copper and / or gallium.

[0019] Antimony and / or copper and / or gallium together occupy less than 5% by weight of the final metallic material.

[0020] In an interesting embodiment, the radioprotective material according to the invention comprises:

[0021] - between 52 and 70% by weight of bismuth in the final material, and

[0022] - between 30 and 48% by weight of tin in the final material.

[0023] In a preferred embodiment, the material comprises:

[0024] - between 55 and 60% by weight of bismuth in the final material, and

[0025] - between 40 and 45% by weight of tin in the final material.

[0026] In general, this material is particularly suitable for use as a radio-attenuating material in the fields of imaging and therapy in nuclear medicine, and also in the field of radiology.

[0027] Such a material can for example be used for the production of a container for receiving a radioactive product or a container for receiving a container of radioactive product (for example to produce a syringe protector intended to contain a radioisotope, or to produce an armored transport case).

[0028] Such a container adapted for receiving a radioactive product or a container of radioactive product, is then at least partially made of radioprotective material according to the invention.

[0029] It can also be used for the production of screens adapted to form a barrier against ionizing radiation and in particular X-rays, gamma or beta rays.

[0030] Such a screen adapted to form a barrier against ionizing radiation and in particular X-rays, is then at least partially made of radioprotective material according to the invention.

[0031] Applications can also be envisaged in the field of shielding X-ray tubes, or gamma camera collimators. Example

[0032] The radio-attenuating metallic material may comprise: 58% by weight of bismuth, and 42% by weight of tin.

[0033] The Bi-Sn alloy is produced by heating a mixture of bismuth and tin beyond their melting point.

[0034] The molten and homogenized liquid alloy is poured into a mold, for example a steel mold, to obtain the molded material in the desired shape.

[0035] The desired product can be obtained by direct casting into the mold (for example a mold in the shape of a syringe protector).

[0036] A rough casting can also be made with a view to finishing by machining, cutting and / or stamping.

[0037] Where appropriate, extrusion techniques may also be used to shape the finished product.

[0038] The density of the material obtained is approximately 8.58. (compared to that of tungsten, which is 17.56) Results

[0039] A syringe protector made of the radio-attenuating material described above (58% bismuth and 42% tin) provides a radio-attenuation similar / comparable to that of a syringe protector made of tungsten, having the same structure and the same wall thickness, while being twice as light.

Claims

Demands

1. Radio-attenuating metallic material, for the production of a protective screen, or a protective shell, against ionizing radiation such as X-rays, gamma rays or beta rays, characterized in that it consists of an alloy of at least bismuth and tin, the bismuth being present in a proportion of at least 50% by weight in the final metallic material.

2. Radio-attenuating material according to claim 1, characterized in that it comprises tin in a proportion of at least 30% by weight in the final material.

3. Radio-attenuating material according to claim 2, characterized in that it comprises tin in a proportion of at least 40% by weight in the final material.

4. Radio-attenuating material according to any one of claims 1 to 3, characterized in that it comprises at least antimony and / or copper and / or gallium.

5. Radio-attenuating material according to claim 4, characterized in that antimony and / or copper and / or gallium together occupy less than 5% by weight of the final metallic material.

6. Radio-attenuating material according to any one of claims 1 to 5, characterized in that it comprises: - between 52 and 70% by weight of bismuth in the final material, and - between 30 and 48% by weight of tin in the final material.

7. Radio-attenuating material according to claim 6, characterized in that it comprises: - between 55 and 60% by weight of bismuth in the final material, and - between 40 and 45% by weight of tin in the final material.

8. A container made of radio-attenuating material suitable for receiving a radioactive product or a container for a radioactive product, which container is at least partially made of radio-protective material according to any one of claims 1 to 7.

9. A screen made of radio-attenuating material adapted to form a barrier against ionizing radiation and in particular X-rays, which screen is at least partially made of radioprotective material according to any one of claims 1 to 7.