Shielding device and installation method

Abstract

The invention relates to a device for shielding against neutron and / or gamma radiation and to a method for installing such a device. A device (10) for shielding against neutron and / or gamma radiation comprises multiple shielding elements (12) with a shielding material (14, 15). An area (16) for receiving a target (17) is provided in the interior of the device (10), and the shielding elements (12) are arranged in a plurality of modules (19) which can be connected together and can be released from one another.

Description

[0001] Shielding device and assembly method

[0002] Description

[0003] The invention relates to a device for shielding against neutron and / or gamma radiation and a method for assembling such a device.

[0004] In experiments involving neutron radiation, shielding is necessary to prevent the uncontrolled release of neutron and / or gamma radiation. For this purpose, plates made of a shielding material such as lead or boron-based polyethylene are used. In conventional experimental setups, the shielding is constructed in one piece from so-called heavy concrete. This reliably prevents the release of radiation. However, such devices have the disadvantage of being very heavy and therefore not transportable.

[0005] The object of the invention is to provide an improved device for shielding against neutron and / or gamma radiation and a method for assembling such a device. In particular, the disadvantages of the prior art are to be at least partially remedied.

[0006] The shielding device according to claim 1 and the method according to the independent claim serve to achieve this object. Advantageous embodiments are specified in the subclaims.

[0007] To solve this problem, a device for shielding against neutron and / or gamma radiation is used. The device comprises several shielding elements with a shielding material. A space for accommodating a target is provided inside the device. The shielding elements are arranged in several interconnectable and detachable modules.

[0008] Thanks to its modular design, the device can be easily and quickly disassembled, transported, and reassembled at another location. This allows for flexible use. Furthermore, the weight of the individual modules is reduced to such an extent that they can be handled, for example, with a crane. The device is preferably used to shield a radiation source that emits neutron and / or gamma radiation from its surroundings. The radiation source is, in particular, a target that is bombarded with radiation, in particular a proton beam. When bombarded, the target itself can become a radiation source. For example, the shielding can be used for an accelerator-based neutron source, such as an HBS (High Brilliance Neutron Source). A TMR (Target-Moderator-Reflector) unit can be used.

[0009] Each shielding element comprises a shielding material. The shielding material is typically suitable for shielding neutron and / or gamma radiation. The shielding elements can contain or be made from the shielding material.

[0010] In one embodiment, the shielding elements are designed as shielding plates. A shielding plate is a plate-shaped shielding element. Plate-shaped means that the extension in one direction of extension is significantly smaller than in the other two directions of extension, for example, by a factor of at least 5 or at least 10. Typically, the sides of a plate that delimit the plate in the small direction of extension are parallel to each other.

[0011] In particular, the plurality of shielding elements are arranged such that, starting from the target, at least one shielding element is present in each spatial direction, so that radiation is shielded in each spatial direction. In one embodiment, the shielding elements are arranged such that, starting from the target, at least two shielding elements are present one behind the other in each spatial direction.

[0012] A module within the meaning of the invention is a part of a shielding device with a shielding element that has a shielding material against neutron and / or gamma radiation. The shielding device is composed of several such modules. Preferably, more than two modules are present. This allows the weight of the individual modules to be reduced. Typically, several modules are identical. This allows the design and manufacturing costs to be reduced. The device can comprise several groups of identical modules. Interconnectable and detachable modules within the meaning of the invention mean the following: The modules can be connected to one another when detached from one another. The modules can be detached from one another when connected. This applies to all interconnectable and detachable objects of the invention. A connection within the meaning of the invention is a mechanical connection.The connection is in particular a force-locking and / or a one-sided or two-sided form-locking connection in at least one spatial direction.

[0013] In particular, the device has a height of more than 2 m, for example approximately 3 m, and / or a horizontal extension of more than 2 m, for example approximately 3 m.

[0014] In one embodiment, a module comprises an outer wall. The outer wall can have a thickness of approximately 10 mm on the sides and top. The bottom can have a thickness of approximately 20 mm. The outer wall is made, in particular, of steel, preferably low-cobalt steel. Low-cobalt steel can have a cobalt content of less than 500 ppm, preferably less than 100 ppm. Furthermore, the outer wall is typically provided with a decontaminating coating. This facilitates handling, decontamination, and subsequent decommissioning of the device.

[0015] In one embodiment, the modules have a stepped outer contour. This ensures that the modules interlock. A continuous gap through which radiation from the target could escape is thus prevented. So-called baffles are formed to prevent direct radiation. For example, each module has at least two steps and preferably at least three steps.

[0016] In one embodiment, the modules have a stepped outer contour in plan view. In one embodiment, the modules have a stepped outer contour in the front and / or side view.

[0017] In particular, adjacent modules have corresponding outer contours, so that when arranged adjacently, they together form a substantially closed contour. Adjacent elements are elements that are arranged adjacent to one another, at least in some areas, for the intended use of the device. In particular, their outer surfaces run parallel to one another, at least in some areas. A slight gap may remain, preferably less than 10 mm. The presence of a slight gap cannot be technically prevented.

[0018] In one embodiment, a step height of a step corresponds to at least ten times a gap between adjacent modules.

[0019] In particular, this applies to each pair of adjacent modules. In this way, it can be ensured that, even if a gap exists between the modules, the formation of a continuous gap through which radiation from the target could escape to the outside is particularly reliably prevented. In particular, this applies to each gap between adjacent modules. In particular, this also applies to all gaps between a module and a base module and between a module and a cover module. In one embodiment, a step height is at least 5 cm, preferably at least 10 cm and particularly preferably at least 15 cm and / or at most 100 cm, preferably at most 80 cm and particularly preferably at most 50 cm.

[0020] In one embodiment, modules are distributed circumferentially around the space for accommodating the target in plan view. Preferably, the modules are distributed substantially evenly. Thus, shielding is achieved in all directions in plan view.

[0021] In one embodiment, eight modules are provided, distributed particularly circumferentially around the space for accommodating the target. An ideal shield would be spherical, since the same array of shielding elements is required in every spatial direction. However, this is very complex to construct. For example, eight modules can essentially form an octagonal shape in plan view. This saves space and material, and thus weight and cost, compared to a conventional square design.

[0022] In one embodiment, modules are arranged in levels one above the other. In particular, at least two levels are present. In particular, the space for accommodating the target is located in the second level from the bottom. This ensures sufficient clearance from the floor. Thus, a proton source and / or at least one instrument can be positioned at a suitable height within the device.

[0023] In one embodiment, three levels are present. The space for receiving the target can be located on a middle level.

[0024] In one embodiment, the device further comprises a base module having at least one shielding element. In particular, the base module is configured to provide downward shielding. In particular, the base module is connectable to and detachable from at least one module.

[0025] The floor module can be a single-piece or multi-piece design. In the case of a multi-piece design, the parts of the floor module can, in particular, be connectable to and detachable from one another. The floor module can be connectable to and detachable from modules of the device. The floor module can have several shielding elements, e.g., shielding plates. These can be made with or from different shielding materials.

[0026] In one embodiment, the device further comprises a cover module having at least one shielding element. In particular, the cover module is configured for shielding upwards. In particular, the cover module is connectable to and detachable from at least one module.

[0027] The cover module is, in particular, a one-piece structure. It can be mounted on the assembled modules of the device. The cover module can be connectable to and detachable from the modules. The cover module can have multiple shielding elements, e.g., shielding plates. These can be made with or from different shielding materials.

[0028] In one embodiment, each module has at least two shielding elements. Several shielding elements are generally arranged one behind the other in the beam direction. In one embodiment, at least one shielding element or all of the shielding elements are designed as a shielding plate.

[0029] In one embodiment, each module has at least one first shielding element with a first shielding material and at least one further shielding element with a second shielding material different from the first shielding material.

[0030] The first shielding material is, for example, lead or borated polyethylene (boron-PE). The second shielding material is, for example, borated polyethylene or lead.

[0031] In one embodiment, each module has at least two, at least three, or at least four shielding plates with a first shielding material. Thus, several layers of the same shielding material are arranged one behind the other. Layers of a different shielding material can be arranged between them.

[0032] In one embodiment, the device comprises more than 20 modules and / or fewer than 40 modules. The number of modules is typically greater than 10, preferably greater than 20, and particularly preferably greater than 25. In this way, the weight of a single module is not excessive, so that handling is still relatively easy. Alternatively or additionally, the number of modules is typically less than 50, preferably less than 40, and particularly preferably less than 35. In this way, the total number of modules is not excessively large, in order to limit the technical complexity for design and manufacturing.

[0033] In one embodiment, the weight of a module is greater than 2 t, in particular greater than or equal to 31, and / or less than 5 t, in particular less than or equal to 41. The weight of a base module or part of a base module can be between 4 t and 51. The weight of a cover module can be between 61 and 81. The total weight of the elements of the device can be between 601 and 100 t, in particular approximately 801.

[0034] In one embodiment, relative movement between a first part of the device and a second part of the device is possible. In particular, this enables access to the interior of the device; access means, in particular, manual access or entry by an operator of the device. In particular, the first part is movable, for example by means of rollers and / or rails. The displacement allows the device to be opened to gain access. The interior is, in particular, a space enclosed by the shielding elements and / or modules. In particular, access to the space for receiving the target can be enabled. In particular, a drive is provided with which the first part can be displaced in a motorized manner. This embodiment enables simple and flexible access to the interior of the device, for example for maintenance work or for access to internal components.

[0035] In one embodiment, the device has a tube which describes an angle α. In one embodiment, the tube is arranged in the first part of the device or in the second part of the device. In other words, the tube is arranged entirely in one of the two parts, which are movable relative to one another. In this way, the tube is not impaired or separated when access to the interior of the device is granted. As a result, the tube can in particular be designed without a window. This prevents any impairment of the intensity, for example of the proton beam. In addition, the construction of the tube is simpler and technically less complex. The entire tube can be vacuum-sealed as a single unit.

[0036] The tube is also referred to as an L-shaped tube. In particular, the tube is vacuum-sealed. In particular, the tube runs from the outside into the room and back out again. In particular, the tube is aligned along a horizontal plane. In other words, the angle is measured in particular in a plan view. The angle is greater than 0°. Typically, the angle is between 45° and 135°, preferably approximately 90°. In particular, the tube serves to guide a proton beam toward the target and / or to guide radiation away from the target.

[0037] A further aspect of the invention is a method for assembling a device for shielding against neutron and / or gamma radiation, in particular a device according to the invention. The device comprises a plurality of shielding elements with a shielding material, which are arranged in a plurality of modules that can be connected to one another and detached from one another. The method comprises positioning a plurality of modules and fastening the modules. All of the above-mentioned advantages, features, and properties of the initially mentioned aspect of the invention also apply to the method and vice versa. The positioning is, in particular, positioning a module in relation to or on another module. The positioning can comprise moving the module in relation to the other module. The fastening of the modules can comprise fastening two adjacent modules to one another, for example, directly or indirectly screwing them together.With indirect screwing, a fastener can be screwed to both the first and second modules. The fastening can also involve attaching each module to another object. An assembly of interconnected objects can also be used to attach individual modules. The modules are then indirectly attached to each other.

[0038] The fastening is, in particular, a force-fitting fastening and / or a form-fitting fastening on both sides in at least one spatial direction. In one embodiment, the fastening is a fastening in all spatial directions.

[0039] In one embodiment, the method further comprises displacing a first portion of the device relative to a second portion of the device to enable access to an interior of the device.

[0040] A further aspect of the invention is a device for shielding against neutron and / or gamma radiation, comprising a plurality of shielding elements with a shielding material, wherein a space for receiving a target is present in the interior of the device, characterized in that a first part of the device is displaceable relative to a second part of the device in order to allow access to an interior of the device.

[0041] Below, exemplary embodiments of the invention are explained in more detail with reference to the figures. Features of the exemplary embodiments can be combined individually or in multiples with the claimed subject matter, unless otherwise stated. The claimed scope of protection is not limited to the exemplary embodiments.

[0042] They show:

[0043] Figure 1 : a perspective view of a device for

[0044] Shielding,

[0045] Figure 2: a sectional view of the device from Figure 1, Figure 3: a schematic representation of a stage,

[0046] Figure 4: a horizontal section through a device for

[0047] Shielding,

[0048] Figure 5: a perspective view of another device for

[0049] Shielding,

[0050] Figures 6A to 6C: a module of a shielding device, and

[0051] Figures 7A to 7D: Parts of a shielding device.

[0052] Figure 1 shows a device 10 for shielding against neutron and gamma radiation. The device is composed of 24 modules 19, with eight modules 19 arranged in a lower level 24, a middle level 25, and an upper level 26. The modules 19 are mechanically connected to one another in a non-destructive manner and can be separated again as needed. In particular, the modules 19 are screwed together.

[0053] Inside the device is a chamber (not shown separately) for accommodating a target. Instrument channels 37 provide access to this chamber. This allows released radiation to be guided outward to suitable instruments for analysis.

[0054] Figure 2 shows a cross-sectional view of the same device 10. The chamber 16 is visible. It can also be seen that, in addition to the eight modules 19, the lower level 24 contains three floor modules 28 (or a three-part floor module 28) that shield the chamber 16 from below.

[0055] The modules 19 are provided with steps in all spatial directions and thus interlock with each other horizontally and vertically. The horizontal interlocking is visible on the open top. In particular, the surfaces of all steps run vertically and / or horizontally in plan view. The vertical interlocking is visible in the cut surfaces. In addition, the floor modules 28 are provided with steps and thus interlock with the neighboring modules 19. A direct beam from the room 16 is thus prevented in any spatial direction.

[0056] In addition to the instrument channels 37, which are particularly provided with a rectangular cross-section, a channel 38 is shown, which is particularly provided with a round cross-section. The tube 34 is inserted into this channel, which is described in detail below with reference to Figure 4.

[0057] Between the modules 19 and between the base modules 28 and the adjoining modules 19, there is a gap 21 that cannot be completely avoided for technical reasons. Figure 3 schematically shows the gap 21 with its gap width in relation to the step height 22 of the respective step 20. The step height is at least 10 times larger than the gap width, preferably by at least 20 times. This typically applies to all modules 19, the base modules 28, and the cover module 29 of the device 10. In this way, unwanted radiation emission can be particularly reliably prevented.

[0058] Figure 4 shows a horizontal section through a central plane 25 of a device 10 according to the invention. In the space 16 for receiving the target 17 there is a tube 34 which forms a right angle α. This is also referred to as an L-tube. The target 17 can be arranged in the tube 34. One or more moderators can be used outside the target. These can also be arranged in the space 16. In this way, neutrons can be slowed down before they reach the instruments. A proton beam 35 can be fired from below through the lower part of the tube 34 onto the target 17. The tube 34 can preferably be vacuum-sealed. The instrument channels 37 extend outwards from the space 16 for receiving the target in many spatial directions. Pairs of instrument channels 37 extending upwards and to the right in the figure preferably form an angle ß of approximately 22° or greater than 22° between each other.Typically, the tube 34 and the instrument channels 37 run in the same horizontal plane.

[0059] In addition, the shielding elements 12 can be seen in the sectioned modules 19. Each module contains three layers, each with two shielding elements 12, which are designed as shielding plates. A total of six shielding elements 12 are thus present in each spatial direction. Each layer contains one shielding element 12 with or made of a first shielding material 14 and one shielding element 12 with or made of a second shielding material 15.

[0060] The device 10 is divided into two parts, with relative movement between the two parts being possible. A first part 31 comprises those modules 19 shown in Figure 4 on the left, bottom left, and bottom. This also applies to the lower level 24 and the upper level 26 (not shown here). Furthermore, the first part 31 comprises the tube 34. Additional components can also be located above the tube 34 to encompass the entire circumference of the tube 34. These are also arranged in the first part 31. The second part 32 comprises the remaining modules 19.

[0061] Figure 5 shows how the two parts 31, 32 of the device 10 can be moved apart. The first part 31 is arranged to be displaceable relative to the second part 32 to allow access to the interior of the device 10. It is also possible for the first part 31 to remain stationary with the tube 34 and for the second part 32 to be displaced relative to it, or for both parts 31, 32 to be displaced to allow relative movement. The tube 34 is only connected to the modules 19 of one of the parts 31, 32. Thus, the tube 34 can remain unchanged and self-contained even during movement to create access.

[0062] Figure 5 also shows the cover module 29, which also comprises three layers, each with two shielding elements 12. This structure also applies to the three-part base module 28.

[0063] Plates, in particular made of metal such as steel, are provided as fastening elements 40 and are screwed to adjacent modules 19.

[0064] Figures 6A to 6C show a perspective and partially sectioned view of a module 19. The stepped outer contour with the steps 20 is visible, as are the instrument channels 37 arranged in the module 19. In addition, three attachment points 44 are provided to enable the module 19 to be moved with a crane. Figure 6B shows the module 19 before the insertion of the instrument channels 37, which are already inserted in Figure 6A. Figure 6C shows the insertion of the shielding elements 12 in the form of shielding plates made of the different shielding materials 14 and 15. The first shielding material 14 is lead, with the lead plate used being in particular 50 mm thick and / or containing approximately 99.5% lead. The second shielding material 15 is boron-PE, with the plate used being in particular 120 mm thick and / or having a boron content of approximately 5% by mass. In particular, the instrument channels 37 are only inserted after the shielding elements have been inserted.Figures 7A to 7D show perspective views of various modules 19, as well as the cover module 29 and the base module 28 (collectively referred to as elements). The outer contours provided with steps 20 are visible. Furthermore, some or all of the elements shown may have stop points 44 and / or guide pins 42. Guide pins 42 serve for the relative positioning of adjacent elements, in particular elements arranged one above the other, and / or point vertically upward. In this way, the relative positioning of the elements during assembly can be achieved particularly easily. Furthermore, this ensures that the elements are secured to one another, at least horizontally.

[0065] List of reference symbols

[0066] Device 10

[0067] Shielding element 12

[0068] First shielding material 14

[0069] Second shielding material 15

[0070] Room 16

[0071] Target 17

[0072] Module 19

[0073] Level 20

[0074] Gap 21

[0075] Step height 22

[0076] Lower Level 24

[0077] Middle Level 25

[0078] Upper Level 26

[0079] Floor module 28

[0080] Cover module 29

[0081] Part One 31

[0082] Part Two 32

[0083] Pipe 34

[0084] Proton beam 35

[0085] Target channel 36

[0086] Instrument channel 37

[0087] Channel 38

[0088] Fastening element 40

[0089] Guide pin 42

[0090] Anchor point 44

[0091] Angle a

[0092] Angle ß

Claims

Claims 1. Device (10) for shielding against neutron and / or gamma radiation, comprising a plurality of shielding elements (12) with a shielding material (14, 15), wherein a space (16) for receiving a target (17) is provided inside the device (10), characterized in that the shielding elements (12) are arranged in a plurality of modules (19) which can be connected to one another and detached from one another.

2. Device (10) according to claim 1, characterized in that the modules (19) have a step-like outer contour.

3. Device (10) according to claim 2, characterized in that a step height (22) of a step (20) corresponds to at least ten times a gap (21) between adjacent modules (19).

4. Device (10) according to one of the preceding claims, characterized in that modules (19) are distributed in plan view in the circumferential direction around the space (16) for receiving the target (17).

5. Device (10) according to the preceding claim, characterized in that there are eight modules (19) distributed around the space (16) for receiving the target (17).

6. Device (10) according to one of the preceding claims, characterized in that modules (19) are arranged one above the other in planes (24, 25, 26).

7. Device (10) according to one of the preceding claims, characterized in that the device (10) further comprises a floor module (28) which has at least one shielding element (12), wherein the floor module (28) is designed for shielding downwards and is connectable to and detachable from at least one module (19).

8. Device (10) according to one of the preceding claims, characterized in that the device (10) further comprises a cover module (29) which has at least one shielding element (12), wherein the cover module (29) is designed for shielding upwards and can be connected to and detached from at least one module (19).

9. Device (10) according to one of the preceding claims, characterized in that each module (19) has at least two shielding plates as shielding elements (12).

10. Device (10) according to one of the preceding claims, characterized in that each module (19) contains as a shielding element (12) at least one first shielding plate with a first shielding material (14) and as a further shielding element (12) at least one second shielding plate with a second shielding material (15) different from the first shielding material (14).

11. Device (10) according to one of the two preceding claims, characterized in that each module (19) has at least two shielding plates with a first shielding material (14).

12. Device (10) according to one of the preceding claims, characterized in that the device (10) comprises more than 20 modules (19) and / or less than 40 modules (19).

13. Device (10) according to one of the preceding claims, characterized in that a relative movement between a first part (31) of the device (10) and a second part (32) of the device (10) is possible in order to enable access to an interior of the device (10).

14. Device (10) according to the preceding claim, characterized in that the device (10) has a tube (34) which describes an angle a, wherein the tube (34) is arranged in the first part (31) of the device (10) or in the second part (32) of the device (10).

15. Method for assembling a device (10) for shielding against neutron and / or gamma radiation, in particular according to one of the preceding claims, wherein the device (10) comprises several Shielding elements (12) with a shielding material (14, 15) which are arranged in a plurality of modules (19) which can be connected to one another and detached from one another, the method comprising positioning a plurality of modules (19) and fastening the modules (19).

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