Radiation protection container and set

Abstract

A radiation protection container (10, 20) having a receptacle (13, 23) for a radioactive source, and having a diaphragm (15, 25) for defining the spatial radiation profile of the radioactive source, wherein the radiation protection container (10, 20) consists of at least two separate parts, wherein the receptacle (13, 23) for the radioactive source is arranged in a first part (11, 21) of the radiation protection container (10, 20), and wherein a second part (12, 22) of the radiation protection container (10, 20) either forms the diaphragm (15, 25) for the radioactive source or contains the diaphragm (15, 25) for the radioactive source, wherein the radioactive source is arranged such that it is rotatable relative to the diaphragm (15, 25) about an axis (A, A') which is eccentric to the diaphragm (15, 25), and the second part (12, 22) of the radiation protection container (10, 20) is rotatable is arranged on the first part (11,21) of the radiation protection container (10,20), characterized in that the first part (11,21) of the radiation protection container (10,20) and the second part (12,22) of the radiation protection container (10,20) are hermetically separated from each other, so that a transfer of material from the first part (11,21) of the radiation protection container (10,20) to the second part (12,22) of the radiation protection container (10,20) or vice versa is prevented.

Description

[0001] Radiation protection containers are typically used to safely store radioactive sources both during periods when they are being used for a given application and in between. Safe means, in particular, that the release of radioactive radiation is reduced to an acceptable level in every direction when the source is not in use, and that, when the source is in use, it occurs in a strictly defined emission geometry and is reduced to an acceptable level in all other directions not corresponding to this emission geometry. Accordingly, such radiation protection containers regularly have a receptacle for the – usually encapsulated – radioactive source and a cover that defines the emission geometry, which can be closed if necessary during periods when the radioactive source is not in use.

[0002] In a number of applications, it is necessary to use radiation protection containers with different apertures. An example of such an application is radiometric level measuring devices with at least one radioactive source arranged in a radiation protection container that emits radiation into a spatial volume - in particular a container - whose fill level, limit level, density and / or mass flow of matter is to be monitored, and with at least one detector assigned to the spatial volume whose fill level, limit level, density and / or mass flow of matter is to be monitored, for the direct or indirect detection of radiation from the radioactive source or of interaction products of the radiation from the radioactive source with matter present in the spatial volume, as known, for example, from DE 10 2014 101 373 A1, and for which the aperture must be adapted to the geometry of the spatial volume or container and / or the detector.This means that, according to the current state of the art, several different model lines of radiation protection containers, each with different apertures to achieve different radiation geometries, must be produced and assembled.

[0003] Further prior art is known from DE 10 2014 101 373 A1, DE 10 2011 077 637 A1, DE 10 2011 077 304 A1, DD 69 853 A1, US 3 231 740 A and JP S51-105 600 A.

[0004] The object of the invention is therefore to provide a radiation protection container that is easy to produce and easily adaptable to different application requirements, particularly for radiometric level measurement systems. This object is achieved by a radiation protection container having the features of patent claim 1 and a set having the features of patent claim 8. Advantageous developments of the invention are the subject of the dependent claims.

[0005] The radiation protection container according to the invention has a receptacle for a radioactive source and a diaphragm for defining the spatial radiation profile of the radioactive source. Essential to the invention is that the radiation protection container consists of at least two separate parts, with the receptacle for the radioactive source being arranged in a first part of the radiation protection container, and with a second part of the radiation protection container either forming the diaphragm for the radioactive source or containing the diaphragm for the radioactive source.

[0006] Because the aperture is designed as a separate part or arranged on a separate part according to the invention, only these separate aperture parts need to be manufactured and kept in different variants, while all other parts of the radiation protection container can be based on a common design. This also offers the purchaser the advantage that, for adaptation to the intended use, e.g., the geometry of the container to be monitored in the case of a radiometric level measuring device, only a new aperture part needs to be purchased, rather than, as was previously the case, a completely new radiation protection container.

[0007] Of course, the holder for the radioactive source can be designed for loading with the radioactive source from below, ie from the desired radiation direction, or for loading with the radioactive source from above, ie from the direction opposite to the desired radiation direction.

[0008] In a particularly preferred development of the invention, the aperture for the radioactive source is formed by a wedge-shaped, cylindrical, conical, truncated wedge, or truncated cone-shaped recess in the second part of the radiation protection container, wherein the tip of the wedge-shaped or conical recess or the narrow side of the truncated wedge-shaped or truncated cone-shaped recess faces the radioactive source when the aperture is open; preferably in such a way that they lie opposite one another. This is a particularly simple way of realizing apertures with different exit angles for the radiation. Embodiments in which the radioactive source, in particular one of its surfaces or its center, is located at the tip of the wedge-shaped recess or the narrow side of the truncated wedge-shaped or truncated cone-shaped recess are particularly preferred.positioned at the imaginary tip, which is created by the imaginary extension of the truncated wedge or truncated cone in its tapering direction.

[0009] According to the invention, the radioactive source is arranged such that it is rotatable relative to the diaphragm about an axis which runs eccentrically to the diaphragm, i.e. in particular offset but parallel relative to the axis of symmetry of a conical or mirror plane of a wedge-shaped diaphragm, so that opening or closing of the diaphragm can be achieved particularly easily by arranging them in the open position on a common axis parallel to the axis of rotation and by rotating the source about the axis of rotation out of the opening area of the diaphragm. In a preferred development of this embodiment, this can be done in particular by drive means for carrying out the rotary movement, for example via a mechanical, electrical or pneumatic drive.

[0010] An inventive configuration of the radiation protection container, with which such rotation enables the aperture to be opened and closed, provides that the second part of the radiation protection container is rotatably mounted on the first part of the radiation protection container. The aperture opening and the receptacle for the radioactive source are then each arranged eccentrically, for example, at the same distance from the rotation axis, so that there is a position achievable by rotation in which the receptacle and the aperture are arranged along a straight line parallel to the rotation axis, which represents the open aperture position. The aperture is then closed by rotating away from this position.

[0011] A second configuration of the radiation protection container, with which the aperture can be opened and closed by such a rotation, provides that the second part of the radiation protection container is arranged on a third part of the radiation protection container and that the first part of the radiation protection container is rotatably arranged in the third part of the radiation protection container. In this embodiment, the part containing the receptacle for the radioactive source is rotatably arranged within the third part of the radiation protection container such that there is a position that can be reached by rotation, in which the receptacle and the aperture or their axis of symmetry are arranged along a straight line parallel to the axis of rotation, which represents the open aperture position. The aperture, which remains stationary on the third part of the radiation protection container, is then closed by rotating the first part within the third part away from this position.

[0012] It is particularly preferred if at least one part of the radiation protection container has at least one projection, wherein either the projection engages in a corresponding, i.e. complementary, recess of another part of the radiation protection container or the projection of the radiation protection container overlaps another part of the radiation protection container at least in sections, so that in both cases the dividing line between the corresponding parts of the radiation protection container is not linear, but stepped, angled, or curved. In this way, the escape of "leakage radiation," which propagates freely through a gap remaining between the first part and the second part of the radiation protection container, is reliably prevented.

[0013] The same purpose is served by the advantageous measure of setting the receptacle for the radioactive source back relative to the dividing line between the first part of the radiation protection container and the second part of the radiation protection container. In particular, it can then also be arranged beneath a layer of lead.

[0014] To connect the first part of the radiation protection container with the second part of the radiation protection container, it has proven effective for the first part of the radiation protection container and the second part of the radiation protection container to be screwed onto one another or locked together.

[0015] According to the invention, and in particular when the radiation protection container has lead as an essential component for shielding, which is advantageous, the first part of the radiation protection container and the second part of the radiation protection container are hermetically separated from one another - for example by coating them with a layer of a material with the highest possible melting point - so that a transfer of material from the first part of the radiation protection container to the second part of the radiation protection container or vice versa is prevented.

[0016] The set according to the invention comprises a first part of a radiation protection container, in which a receptacle for a radioactive source is arranged, and several interchangeable second parts of the radiation protection container, each of which either forms the aperture for the radioactive source or contains the aperture for the radioactive source. By providing such a set, the user receives a highly flexible radiation protection container and no longer needs to purchase a separate radiation protection container for each aperture configuration. For example, the aperture angles of the second parts of the radiation protection container can vary.

[0017] The invention is explained in more detail below with reference to figures showing exemplary embodiments of the invention. It shows: Fig. 1: a cross-section through a first radiation protection container, and Fig. 2: a cross-section through a second radiation protection container.

[0018] Fig. Figure 1 shows a cross-section through a first radiation protection container 10, whose outer contour is cylindrically symmetrical, with the cross-section running through a plane in which the imaginary cylinder axis lies. The radiation protection container 10 has a first part 11, which has a receptacle 13 for a radioactive source on its front side. The receptacle 13 can thus be loaded with the radioactive source from below, opposite its desired radiation direction. Furthermore, the radiation protection container 10 has a second part 12, which includes a conical recess as a diaphragm 15 for defining the spatial radiation profile of the radioactive source.

[0019] The second part 12 of the radiation protection container 10 is arranged on a third part 16 of the radiation protection container 10, which has projections 14 that overlap a portion of the second part 12 of the radiation protection container 10. The dividing line between the second part 12 of the radiation protection container 10 and the third part of the radiation protection container 10 is thus non-linear, but rather stepped or angled.

[0020] The first part 11 is rotatably mounted about the axis A in the third part 16 of the radiation protection container 10. The axis A does not coincide with the axis of symmetry of the conical aperture 15 (not shown), but runs parallel to it and is thus arranged eccentrically to the aperture 15.

[0021] In the Fig. In the situation illustrated in Figure 1, the receptacle 13 for the radioactive source and the aperture 15 are arranged along an imaginary straight line parallel to the rotation axis A, which coincides with the axis of symmetry of the aperture 15, representing the open aperture position. The aperture 15, which remains stationary on the third part 16 of the radiation protection container 10, is then closed by rotating the first part 11 within the third part away from this position.

[0022] Fig. 2 shows a cross-section through a second radiation protection container 20, the outer contour of which is also cylindrically symmetrical, with the cross-section running through a plane in which the imaginary cylinder axis lies. The radiation protection container 20 has a first part 21, which has a receptacle 23 for a radioactive source, slightly set back from its front side. The receptacle 23 can be loaded with the radioactive source from above, i.e. in its desired radiation direction, which is then also shielded in this direction by inserting a third part 26 into the receptacle 23. Furthermore, the radiation protection container 20 has a second part 22, which includes a frustoconical recess as a diaphragm 25 for defining the spatial radiation profile of the radioactive source.

[0023] The second part 22 of the radiation protection container 20 is arranged on the front side of the first part 21 of the radiation protection container 20 and has a central projection 24 that engages in a corresponding, complementary recess in the first part 21 of the radiation protection container 20. The dividing line between the second part 22 of the radiation protection container 20 and the first part 21 of the radiation protection container 20 is thus non-linear, but rather stepped or angled.

[0024] The second part 22 is mounted on the first part 21 of the radiation protection container 20 for rotation about the axis A'. The axis A' does not coincide with the axis of symmetry of the truncated cone-shaped aperture 25 (not shown), but runs parallel to it and is thus arranged eccentrically to the aperture 25 or its axis of symmetry.

[0025] The receptacle 23 is located at the same distance from the rotation axis A' as the axis of symmetry of the frustoconical aperture 25 and is further arranged in the first part 21 such that there is a rotational position of the first part 21 relative to the second part 22 when rotating about the rotation axis A', in which the receptacle 23 for the radioactive source and the aperture 25 are arranged along an imaginary straight line parallel to the rotation axis A', which coincides with the axis of symmetry of the aperture 15, which represents the open aperture position.

[0026] In addition, the receptacle 23 is arranged in the first part 21 in such a way that the imaginary extensions of the converging side walls of the frustoconical recess in the second part 22, which forms the aperture, intersect at the center of the radioactive source when the latter is arranged in the recess 23.

[0027] The aperture 25, which is rotatably arranged on the first part 21 of the radiation protection container 20, is then moved away from the first part 11 by rotating the second part 21 relative to the first part 11. Fig. 2 shown open aperture position closed. List of reference symbols 10.20 radiation protection containers 11.21 first part 12.22 second part 13.23 Recording 14.24 lead 15.25 aperture 16.26 third part A,A' axis of rotation

Claims

[1] Radiation protection container (10, 20) with a receptacle (13, 23) for a radioactive source, and with a diaphragm (15, 25) for defining the spatial radiation profile of the radioactive source, wherein the radiation protection container (10, 20) consists of at least two separate parts, wherein the receptacle (13, 23) for the radioactive source is arranged in a first part (11, 21) of the radiation protection container (10, 20) and wherein a second part (12, 22) of the radiation protection container (10, 20) either forms the diaphragm (15, 25) for the radioactive source or contains the diaphragm (15, 25) for the radioactive source, wherein the radioactive source is arranged such that it is rotatable relative to the diaphragm (15, 25) about an axis (A, A') which is eccentric to the diaphragm (15, 25) and the second part (12, 22) of the radiation protection container (10,20) is rotatably arranged on the first part (11,21) of the radiation protection container (10,20), characterized bythat the first part (11,21) of the radiation protection container (10,20) and the second part (12,22) of the radiation protection container (10,20) are hermetically separated from one another, so that a transfer of material from the first part (11,21) of the radiation protection container (10,20) to the second part (12,22) of the radiation protection container (10,20) or vice versa is prevented. [2] Radiation protection container (10, 20) according to claim 1, characterized by that the aperture (15,25) for the radioactive source is formed by a wedge-shaped, conical, cylindrical, truncated wedge or truncated cone-shaped recess in the second part (12,22) of the radiation protection container (10,20), wherein the tip (S,S') of the wedge-shaped or conical recess or the narrow side of the truncated wedge or truncated cone-shaped recess faces the radioactive source when the aperture (15,25) is open. [3] Radiation protection container (10, 20) according to one of the preceding claims, characterized bythat drive means are available to carry out the rotary movement. [4] Radiation protection container (10) according to one of the preceding claims, characterized by that the second part (12) of the radiation protection container (10) is arranged on a third part (16) of the radiation protection container (10) and that the first part (11) of the radiation protection container (10) is rotatably arranged in the third part (16) of the radiation protection container (10). [5] Radiation protection container (10, 20) according to one of the preceding claims, characterized bythat at least one part of the radiation protection container (10, 20) has at least one projection (14, 24), wherein either the projection (24) engages in a corresponding recess of another part of the radiation protection container (20) or the projection (14) of the radiation protection container (10) overlaps another part of the radiation protection container (10) at least in sections, so that in both cases the dividing line between the corresponding parts of the radiation protection container (10, 20) of the radiation protection container (10, 20) is non-linear. [6] Radiation protection container (10, 20) according to one of the preceding claims, characterized by that the receptacle (13,23) for the radioactive source is set back relative to the dividing line between the first part (11,21) of the radiation protection container (10,20) and the second part (12,22) of the radiation protection container (10,20). [7] Radiation protection container (10, 20) according to one of the preceding claims, characterized bythat the first part (11,21) of the radiation protection container (10,20) and the second part (12,22) of the radiation protection container (10,20) are screwed onto one another or locked together. [8] Set for forming the radiation protection container (10, 20) according to one of the preceding claims, comprising the first part (11, 21) of the radiation protection container (10, 20), in which the receptacle (13, 23) for the radioactive source is arranged and several of the second parts (12, 22) of the radiation protection container (10, 20), which are interchangeable with one another.

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