JP7445546B2 - radiation shield - Google Patents

Description

TECHNICAL FIELD This disclosure relates to radiation shielding.

A neutron irradiation device generates neutrons by irradiating a target with charged particles to cause a nuclear fragmentation reaction (see, for example, Patent Document 1). In such a neutron irradiation device, a target is placed inside a radiation shield that has a cylindrical main body made of a material with excellent radiation absorption properties, such as tungsten, in order to shield the radiation generated due to nuclear spallation reactions. It has the following configuration.

Japanese Patent Application Publication No. 2015-145882

The radiation shield described above is attached within the outer cylinder so that one end of the main body in the axial direction of the central axis is supported, and is positioned with respect to the outer cylinder. Further, in the case of maintenance or the like, the radiation shield is removed from the outer cylinder after its positioning with respect to the outer cylinder is released.

The radiation shield is provided with a chucking portion that protrudes from the outer peripheral surface of the main body and contacts the outer cylinder when positioning the main body on the outer cylinder. This chucking part is stored inside the main body part during the operation of attaching the radiation shield. In conventional radiation shields, when protruding the chucking portion, it was necessary to manually operate from the other end side of the main body, and this operation took time. For this reason, it took time to install the radiation shield.

The present disclosure has been made in view of the above, and an object of the present disclosure is to provide a radiation shield that allows a chucking portion to be protruded in a short time.

A radiation shield according to the present disclosure includes a main body that is formed into a cylindrical shape using tungsten and that houses a target that generates neutrons when irradiated with charged particles, and a main body that is arranged in the axial direction of the central axis of the main body. a movable protrusion that is provided to protrude from one end in the axial direction and moves inward of the main body when pressed in a direction opposite to the protruding direction along the axial direction; A chucking part correspondingly provided on the main body and protruding in the radial direction of the main body from the outer circumferential surface of the main body in conjunction with the movement of the movable protrusion inward of the main body. .

According to the present disclosure, it is possible to provide a radiation shield and a neutron irradiation device that allow the protruding work of the chucking portion to be performed in a short time.

FIG. 1 is a schematic diagram showing an example of a neutron irradiation device according to the first embodiment. FIG. 2 is a diagram showing an example of the arrangement of radiation shields according to this embodiment. FIG. 3 is a diagram showing an example of the radiation shield according to the present embodiment viewed from one side in the axial direction of the central axis. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. FIG. 5 is a diagram showing an example of a radiation shield installation work. FIG. 6 is a diagram illustrating an example of the operation when the end face of a radiation shield comes into contact with the end face of an adjacent shield. FIG. 7 is a diagram showing an example of the radiation shield according to the second embodiment viewed from one side in the axial direction of the central axis. FIG. 8 is a sectional view taken along line BB in FIG.

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings, but the present disclosure is not limited thereto. The components of each embodiment described below can be combined as appropriate. Furthermore, some components may not be used. Further, the components in the embodiments described below include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

[First embodiment]
FIG. 1 is a schematic diagram showing an example of a neutron irradiation device 1 according to the first embodiment. The neutron irradiation device 1 irradiates the irradiated object S with neutrons N. The neutron irradiation device 1 is used, for example, for inspection purposes, medical purposes, radioisotope production purposes, and the like.

As shown in FIG. 1, the neutron irradiation device 1 includes an accelerator 2 that accelerates charged particles and ejects charged particles P, and an adjustment device 3 that adjusts the irradiation state of the charged particles P ejected from the accelerator 2. , a target 5 that generates neutrons N by irradiation with charged particles P, a deceleration device 6 that decelerates the neutrons N generated by the target 5, and a collimator 7 that collimates the neutrons N emitted from the deceleration device 6. ing. The irradiated object S is irradiated with neutrons N emitted from the collimator 7. The neutron irradiation device 1 according to this embodiment includes a radiation shield 100 that accommodates the target 5.

Accelerator 2 includes a circular accelerator or a linear accelerator. The accelerator 2 accelerates charged particles (protons, electrons, or heavy particles) to generate charged particles (proton beams, electron beams, or heavy particle beams) P, and injects them in a predetermined irradiation direction.

The adjustment device 3 includes a plurality of electromagnets, and adjusts the irradiation state of the charged particles P ejected from the accelerator 2. The irradiation state of the charged particles P includes adjustment of the traveling direction of the charged particles P and shaping of the charged particles P. The adjustment device 3 suppresses the divergence of the charged particles P and focuses the charged particles P. The adjustment device 3 guides the charged particles P ejected from the accelerator 2 to the scanning device 4 .

The scanning device 4 scans the charged particles P and adjusts the irradiation position of the charged particles P with respect to the target 5. The scanning device 4 also shapes the charged particles P that are irradiated onto the target 5. Note that the scanning device 4 may not be provided.

The charged particles P ejected from the accelerator 2 and passed through the adjustment device 3 and the scanning device 4 are irradiated onto the target 5 . The target 5 generates neutrons N by being irradiated with the charged particles P. In the target 5, high-energy fast neutrons are generated as the neutrons N, for example. The target 5 is a neutron generating member that generates neutrons. The target 5 includes a liquid or solid plate-shaped member made of, for example, beryllium (Be), lithium (Li), or a compound containing them. The target 5 may be a circular or rectangular plate-shaped solid member, or may be heated liquid lithium. For example, liquid lithium that is continuously poured so as to have a constant thickness may be used as the target 5. The target 5 is housed in a radiation shield 100, which will be described later.

The deceleration device 6 decelerates the neutrons N generated at the target 5. The decelerator 6 is arranged between the target 5 and the irradiated body S in the path of the neutrons N. The deceleration device 6 reduces the energy of fast neutrons generated by the target 5 to generate slow and low energy neutrons (thermal neutrons, epithermal neutrons, or cold neutrons).

The collimator 7 collimates the neutron beam N emitted from the decelerator 6. The neutron beam N is collimated by the collimator 7 and emitted from the collimator 7, and the irradiated object S is irradiated with the neutron beam N.

Next, the radiation shield 100 will be explained. FIG. 2 is a diagram showing an example of the arrangement of the radiation shield 100 according to this embodiment. As shown in FIG. 2, the radiation shield 100 has a cylindrical shape and is housed inside an outer cylinder 101, with one end supported by an adjacent shield 102 and the other end supported by a support device 103. fixed in the state. The radiation shield 100 is positioned on the outer tube 101 by a chucking section 30, which will be described later.

FIG. 3 is a diagram showing an example of the radiation shield 100 according to the present embodiment viewed from one side in the axial direction of the central axis AX. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3. As shown in FIGS. 3 and 4, the radiation shield 100 includes a main body portion 10, a movable projection portion 20, a chucking portion 30, and an elastic portion 40.

The main body portion 10 is formed into a cylindrical shape using tungsten. The main body portion 10 accommodates the target 5 described above therein. The main body portion 10 has an inner circumferential surface 12, an outer circumferential surface 13, a stepped portion 14, and end surfaces 16 and 17. The inner circumferential surface 12 and the outer circumferential surface 13 are cylindrical. The end surface 16 is formed at one end of the main body 10 in the axial direction of the central axis AX. The end surface 17 is formed at the other end of the main body 10 in the axial direction of the central axis AX. The end surfaces 16 and 17 are each planar. The step portion 14 is formed between the end surface 16 and the outer circumferential surface 13 of the main body portion 10 . The step portion 14 forms an end outer circumferential surface 13 a on one end side of the outer circumferential surface 13 . Note that the stepped portion 14 may not be provided. In other words, the outer circumferential surface 13 may extend to one end of the main body 10 .

The main body part 10 has a storage part 11 on one end side. The storage section 11 stores a movable projection section 20 and a chucking section 30, which will be described later. The storage part 11 is provided so that the movable protrusion part 20 and the chucking part 30 are sufficiently movable.

The movable protrusion 20 is provided to protrude from the end surface 16 of the main body 10 in the axial direction. The movable protrusion 20 moves inside the storage section 11 of the main body section 10 by being pressed along the axial direction in a direction opposite to the protrusion direction. Three or more movable protrusions 20 are arranged in a direction around the central axis AX. In this embodiment, a configuration in which four movable protrusions 20 are arranged around the central axis AX is exemplified, but the present invention is not limited to this, and a configuration in which three or five or more movable protrusions 20 are arranged is also possible. It's okay. Although the movable protrusions 20 are arranged at equal intervals in the direction around the center axis AX, the arrangement is not limited thereto, and the intervals in the direction around the center axis AX may be different.

The chucking portion 30 protrudes radially outward from the end outer circumferential surface 13a of the main body portion 10 in conjunction with the movement of the movable projection portion 20 inside the main body portion 10. The chucking portion 30 contacts the inner circumferential surface of the outer tube 101 in the protruding state. Three or more chucking parts 30 are arranged in a direction around the central axis AX, corresponding to the movable projection part 20. In this embodiment, a configuration in which four chucking parts 30 are arranged in the direction around the center axis AX is taken as an example, but the configuration is not limited to this, and three chucking parts 30 are arranged in accordance with the number of movable protrusions 20. Alternatively, it may be a configuration in which five or more are arranged. In addition, the chucking parts 30 are arranged at equal intervals in the direction around the central axis AX in accordance with the arrangement of the movable protrusions 20, but the present invention is not limited thereto. The intervals may be different.

In this embodiment, the movable protrusion 20 and the chucking part 30 are provided in such a manner that they are included in one member, and are integrated. Hereinafter, a description will be given assuming that the movable protrusion 20 and the chucking part 30 constitute one rotating member 50.

The rotating member 50 is provided so as to be rotatable about the rotating shaft 15 . The rotation shaft 15 is provided in a direction perpendicular to the center axis AX and the radial direction of the main body portion 10, respectively. The rotating member 50 is moved toward the storage portion of the main body 10 by the movable protrusion 20 being pressed toward the main body 10 along the axial direction of the central axis AX with a force greater than the elastic force of the elastic portion 40 (described later). Rotate towards the inside of 11. The chucking portion 30 rotates integrally with the rotation of the movable protrusion 20, and protrudes radially outward from the end outer circumferential surface 13a of the main body portion 10. The chucking portion 30 comes into contact with the inner circumferential surface 101a of the outer cylinder 101 by protruding from the end outer circumferential surface 13a. More specifically, the force of pressing the movable protrusion 20 causes the chucking part 30 to press the inner circumferential surface 101a of the outer cylinder 101.

Each chucking part 30 is provided so that the amount of protrusion from the end outer circumferential surface 13a is the same. By each chucking part 30 contacting and pressing the inner circumferential surface 101a of the outer cylinder 101, the main body part 10 can be positioned with respect to the outer cylinder 101. In other words, the main body part 10 The central axis AX of the outer cylinder 101 can be made to coincide with the central axis of the outer cylinder 101.

The elastic part 40 is attached to the rotating member 50. The elastic portion 40 applies an elastic force to the rotating member 50 so as to return the chucking portion 30 to the inside of the main body portion 10 . That is, when the pressing force on the movable protrusion 20 is released, the elastic force of the elastic part 40 causes the rotation member 50 to rotate so that the chucking part 30 is stored in the storage part 11. This rotation causes the movable protrusion 20 to return to the state in which it protrudes from the end surface 16.

Next, a case will be described in which the radiation shield 100 configured as described above is attached to the outer tube 101. FIG. 5 is a diagram showing an example of the installation work of the radiation shield 100. As shown in FIG. 5, the radiation shield 100 is inserted into the outer tube 101 from the end surface 16 side with the other end side (end surface 17 side) supported by the support device 103. The radiation shield 100 is adjusted in advance to a height position corresponding to the outer cylinder 101 by the support device 103. In this case, for example, the height position of the central axis AX on the end surface 17 and the height position of the central axis of the outer cylinder 101 are adjusted so as to match. The radiation shield 100 is inserted into the outer tube 101 until the end surface 16 contacts the end surface 102a of the adjacent shield 102. In this way, the radiation shield 100 is inserted into the outer cylinder 101 in a cantilevered state with the end portion on the end face 17 side supported by the support device 103.

FIG. 6 is a diagram showing an example of the operation when the end surface 16 of the radiation shield 100 comes into contact with the end surface 102a of the adjacent shield 102. As shown in the upper diagram of FIG. 6, the radiation shield 100 moves toward the end surface 102a of the adjacent shield 102 with the movable protrusion 20 protruding from the end surface 16. The radiation shield 100 moves while ensuring a clearance with, for example, the outer cylinder 101.

From this state, when the end surface 16 of the radiation shield 100 comes into contact with the end surface 102a of the adjacent shield 102, as shown in the lower diagram of FIG. , that is, it rotates toward the inside of the storage section 11 . Further, the chucking portion 30 rotates integrally with the rotation of the movable protrusion 20, and protrudes radially outward from the end outer circumferential surface 13a of the main body portion 10. The chucking portion 30 protrudes from the end outer circumferential surface 13a of the main body portion 10, thereby coming into contact with the inner circumferential surface 101a of the outer cylinder 101 and pressing the inner circumferential surface 101a outward. The radiation shield 100 and the outer cylinder 101 are positioned by the chucking part 30 contacting and pressing the inner circumferential surface 101a. In this case, the radiation shield 100 is supported by the inner peripheral surface 101a via the chucking part 30. That is, the radiation shield 100 is in a state in which the end surface 17 side is supported by the support device 103 and the end surface 16 side is supported by the inner peripheral surface of the outer cylinder 101 via the chucking part 30. Therefore, the radiation shield 100 is supported in a stable state. Furthermore, in this embodiment, since the protrusion amount of each chucking part 30 from the end outer circumferential surface 13a is equal, the central axis AX of the main body part 10 and the central axis of the outer cylinder 101 can be made to coincide.

Further, after performing the neutron N irradiation operation with the radiation shield 100 attached to the outer cylinder 101, the radiation shield 100 may be removed from the outer cylinder 101, for example, for maintenance or the like. In this case, the radiation shield 100 is pulled out while being supported by the support device 103 in the opposite direction from when it was attached. As a result, the end surface 16 of the radiation shield 100 separates from the end surface 102a of the adjacent shield 102 from the state shown in the lower diagram of FIG. 6, for example. When the end surface 16 of the radiation shield 100 separates from the end surface 102a of the adjacent shield 102, the force of the end surface 102a that presses the movable protrusion 20 toward the inside of the main body 10 is released. Therefore, due to the elastic force of the elastic part 40, the rotating member 50 rotates so that the chucking part 30 is stored in the storage part 11. This rotation releases the positioning of the radiation shield 100 and returns the movable protrusion 20 to the state in which it protrudes from the end surface 16.

By moving the radiation shield 100 in this manner, the radiation shield 100 can be positioned and unpositioned without the operator directly operating the rotating member 50.

As described above, the radiation shield 100 according to the present embodiment includes a main body 10 that is formed into a cylindrical shape using tungsten and houses therein the target 5 that generates neutrons N when irradiated with charged particles P. , is provided to protrude in the axial direction at one end of the central axis AX of the main body 10 in the axial direction, and moves inside the main body 10 by being pressed in the opposite direction to the protruding direction along the axial direction. A movable protrusion 20 and a chucking part 30 that is provided on the main body 10 and protrudes radially from the end outer circumferential surface 13a of the main body 10 in conjunction with the movement of the movable protrusion 20 inward of the main body 10. Equipped with.

Therefore, by moving the main body 10 and bringing one end of the main body 10 into contact with an external support, the movable protrusion 20 can be pressed in the opposite direction to the protrusion direction, and the movable protrusion In conjunction with the operation of the portion 20, the chucking portion 30 can be made to protrude from the end outer circumferential surface 13a. Thereby, the chucking part 30 can be made to protrude from the end outer circumferential surface 13a of the main body part 10 without being directly operated, so that the protrusion work of the chucking part 30 can be performed in a short time.

In the radiation shield 100 according to the present embodiment, the main body 10 is housed in the outer cylinder 101 so that one end thereof is supported, and the chucking part 30 protrudes from the end outer circumferential surface 13a and is attached to the outer cylinder 101. It is possible to contact the inner circumferential surface 101a of. Therefore, the work of protruding the chucking part 30 and positioning it with the inner circumferential surface 101a of the outer cylinder 101 can be performed in a short time.

In the radiation shield 100 according to the present embodiment, the main body 10 has a cylindrical shape, and three or more movable projections 20 and three or more chucking parts 30 are arranged at corresponding positions in the periaxial direction of the central axis AX. The king portions 30 have the same amount of protrusion from the end outer circumferential surface 13a. Therefore, by protruding the plurality of chucking parts 30 with the main body 10 disposed inside the cylinder, it is possible to perform positioning work in a short time to align the central axis AX of the main body 10 with the central axis of the cylinder. can. For example, when housing it in the cylindrical outer tube 101 as in this embodiment, the positioning work of aligning the center axis AX of the main body 10 and the center axis of the outer tube 101 can be performed in a short time.

The radiation shield 100 according to the present embodiment further includes an elastic section 40 that applies an elastic force to the chucking section 30 so that it returns to the inside of the main body section 10 . Therefore, by releasing the pressing force on the movable protrusion 20, the chucking part 30 can be returned to the inside of the main body part 10 by the elastic force of the elastic part 40. Thereby, the protruding state of the chucking part 30 can be released without directly operating the chucking part 30.

In the radiation shield 100 according to the present embodiment, the movable protrusion 20 and the chucking part 30 are integrally provided, and when the movable protrusion 20 is pressed, the movable protrusion 20 rotates and moves inside the main body 10 and is movable. The chucking portion 30 is rotatably provided around a predetermined rotation axis 15 so that the chucking portion 30 rotates together with the rotation of the projection portion 20 and projects from the end outer circumferential surface 13a of the main body portion 10. Therefore, the protrusion work of the chucking portion 30 can be performed in a short time with a simple configuration.

The radiation shield 100 according to the present embodiment includes an accelerator that accelerates and ejects charged particles P, a target 5 that is irradiated with the charged particles P ejected from the accelerator and generates neutrons N, and a target 5 that is placed inside. A chuck comprising: the radiation shield 100 according to any one of claims 1 to 8; The king portion 30 is connected to a portion of the inner circumferential surface 101a of the outer cylinder 101 in a protruding state. Therefore, when attaching the radiation shield 100 to the outer tube 101, it is possible to perform the connection work with the outer tube 101 in a short time. Thereby, it becomes possible to perform the installation work of the radiation shield 100 in a short time. Moreover, when the elastic part 40 is provided, it becomes possible to perform the work of releasing the connection with the outer cylinder 101 in a short time. This makes it possible to take out the radiation shield 100 in a short time.

[Second embodiment]
Next, a second embodiment will be described. FIG. 7 is a diagram showing an example of the radiation shield 200 according to the second embodiment viewed from one side in the axial direction of the central axis AX. FIG. 8 is a sectional view taken along line BB in FIG. As shown in FIGS. 7 and 8, the radiation shield 200 includes a main body portion 110, a movable projection portion 120, a chucking portion 130, and an elastic portion 140. The radiation shield 200 according to this embodiment is different from the first embodiment in the configuration of the movable protrusion 120 and the chucking section 130. Therefore, the following description will focus on the differences from the first embodiment.

The main body portion 110 has an inner circumferential surface 112, an outer circumferential surface 113, a stepped portion 114, and an end surface 116. Further, the main body section 110 has an end surface (not shown) corresponding to the end surface 17 of the main body section 10 described in the first embodiment. The step portion 114 forms an end outer circumferential surface 113 a on one end side of the outer circumferential surface 113 .

The main body part 110 has a storage part 111 on one end side. The storage section 111 stores a movable projection section 120 and a chucking section 130, which will be described later. The storage part 111 is provided so that the movable protrusion part 120 and the chucking part 130 are sufficiently movable. The storage section 111 has a guide surface 111a that guides the movable protrusion 120 and a guide surface 111b that guides the chucking section 130. The guide surface 111a is formed along the axial direction of the central axis AX from the end surface 16 to the inside of the storage section 111. The guide surface 111b is formed in a direction intersecting the central axis AX from the end outer circumferential surface 13a to the inside of the storage section 111. In this embodiment, the guide surface 111b is formed, for example, in a direction perpendicular to the central axis AX, but is not limited thereto, and may be formed in a direction inclined with respect to the direction perpendicular to the central axis AX. Furthermore, the storage section 111 is provided with a stopper 115 that determines the moving position of the movable protrusion 120, which will be described later.

The movable protrusion 120 is provided to protrude from the end surface 116 of the main body 110 in the axial direction. The movable protrusion 120 moves inside the storage section 111 of the main body section 110 by being pressed in a direction opposite to the protrusion direction along the axial direction of the central axis AX. The movable protrusion 120 is movable along the guide surface 111a of the storage section 111 in the axial direction. As in the first embodiment, three or more movable protrusions 120 are arranged in the direction around the center axis AX, and in this embodiment, for example, four movable protrusions 120 are arranged. Although the movable protrusions 120 are arranged at equal intervals in the direction around the center axis AX, the arrangement is not limited thereto, and the intervals in the direction around the center axis AX may be different.

The movable protrusion 120 has an inclined surface 121. The inclined surface 121 is provided at a corner of a portion of the movable protrusion 120 disposed inside the storage section 111 on the outer circumferential surface 113 side (end outer circumferential surface 113a side). The inclined surface 121 contacts an inclined surface 131 of a chucking part 130, which will be described later. The movable protrusion 120 has a recess 122 . The recessed part 122 is provided so as not to interfere with the elastic part 140 arranged inside the storage part 111.

The chucking part 130 is provided separately from the movable projection part 120. The chucking portion 130 protrudes from the end outer peripheral surface 113a of the main body portion 110 in conjunction with the movement of the movable protrusion portion 120 inside the main body portion 110. The chucking section 130 is movable along the guide surface 111b of the storage section 111 in a direction perpendicular to the axial direction. The chucking portion 130 contacts the inner circumferential surface 101a of the outer tube 101 in the protruding state. Three or more chucking parts 130 are arranged in a direction around the center axis AX in correspondence with the movable projection part 120, and in this embodiment, for example, four chucking parts 130 are arranged. The chucking parts 130 are arranged at equal intervals in a direction around the central axis AX, corresponding to the arrangement of the movable protrusions 120.

The chucking part 130 has an inclined surface 131. The inclined surface 131 is provided at a corner of the portion of the chucking section 130 located inside the storage section 111 on the end surface 16 side. The inclined surface 131 contacts the inclined surface 121 of the movable protrusion 120 described above.

The movable projection 120 moves into the storage section 111 along the guide surface 111a by being pressed toward the main body 10 along the axial direction of the center axis AX. At this time, the movable protrusion 120 moves to the position of the stopper 115 while pushing the inclined surface 131 of the chucking section 130 upward by the inclined surface 121. Due to this force, the chucking part 130 moves radially outward of the main body part 110 along the guide surface 111b and protrudes from the end outer circumferential surface 113a.

The elastic part 140 applies an elastic force to the chucking part 130 so that it returns to the inside of the main body part 110 . When the pressing force on the movable protrusion 120 is released, the elastic force of the elastic part 140 moves the chucking part 130 to be stored in the storage part 111. This movement causes the movable protrusion 120 to return to the state in which it protrudes from the end surface 16.

As described above, in the radiation shield 200 according to the second embodiment, the movable protrusion 120 is provided so as to be movable along the axial direction of the central axis AX, and the chucking section 130 is provided so as to be movable along the axial direction of the central axis AX. The movable protrusion 120 and the chucking part 130 are movably provided, and the movable protrusion 120 and the chucking part 130 are pushed by the movable protrusion 120 moving inward of the main body 110 so that the chucking part 130 moves radially outward of the main body 110. It has inclined surfaces 121 and 131 that are in contact with each other. Therefore, even when the movable protrusion 120 and the chucking part 130 are formed separately, the chucking part 130 can be made to protrude from the end outer circumferential surface 113a of the main body part 110 without directly operating the chucking part 130. It becomes possible to perform the protrusion work of the king part 130 in a short time.

The technical scope of the present invention is not limited to the above embodiments, and changes can be made as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, the case where the main body part 10 is cylindrical is described as an example, but the present invention is not limited to this. The main body portion 10 may have a polygonal cylindrical shape.

1 Neutron irradiation device 2 Accelerator 3 Adjustment device 4 Scanning device 5 Target 6 Deceleration device 7 Collimator 10, 110 Main body portion 11, 111 Storage portion 12, 101a, 112 Inner peripheral surface 13, 113 Outer peripheral surface 13a, 113a End outer peripheral surface 14, 114 Step portion 15 Rotating shaft 16, 17, 102a, 116 End face 20, 120 Movable protrusion 30, 130 Chucking portion 40, 140 Elastic portion 50 Rotating member 100, 200 Radiation shield 101 Outer cylinder 102 Adjacent shield 103 Support device 111a, 111b Guide surface 115 Stopper 121, 131 Inclined surface 122 Recessed portion AX Central axis N Neutron P Charged particle S Irradiated object

Claims (6)

A main body portion formed in a cylindrical shape using tungsten and housing therein a target that generates neutrons when irradiated with charged particles;
It is provided to protrude in the axial direction from one end in the axial direction of the central axis of the main body, and moves inside the main body when pressed in the opposite direction to the protruding direction along the axial direction. a movable protrusion;
A chuck is provided on the main body corresponding to the movable protrusion and protrudes in the radial direction of the main body from the outer peripheral surface of the main body in conjunction with the movement of the movable protrusion inward of the main body. A radiation shield with a king part and . The main body portion is housed in an outer cylinder so that the one end portion is supported,
The radiation shield according to claim 1, wherein the chucking portion is capable of protruding from the outer circumferential surface and contacting the inner circumferential surface of the outer cylinder. The main body has a cylindrical shape,
Three or more of the movable projections and the chucking parts are arranged at corresponding positions in a direction around the central axis,
The radiation shield according to claim 1 or 2, wherein the chucking portions have the same amount of protrusion from the outer circumferential surface. The radiation shield according to any one of claims 1 to 3, further comprising an elastic part that applies an elastic force to the chucking part so as to return to the inside of the main body part. The movable protrusion and the chucking part are integrally provided, and when the movable protrusion is pressed, the movable protrusion rotates and moves inside the main body, and together with the rotation of the movable protrusion, the chucking part rotates. The radiation source according to any one of claims 1 to 4, wherein the chucking part is rotatably provided about a predetermined rotation axis so as to rotate and protrude from the outer circumferential surface of the main body part. shield. The movable protrusion is provided movably along the axial direction,
The chucking part is provided movably in a direction intersecting the axial direction,
The movable protrusion and the chucking part have inclined surfaces that contact each other so that the movable protrusion moves inward of the main body and the chucking part moves outward in the radial direction. The radiation shield according to any one of claims 1 to 4.

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