JP2023133936A - Radiation source installation jig and measurement system - Google Patents

Abstract

To provide a radiation source installation jig capable of appropriately mounting a jig to a detector in a shielding body, and a measurement system.SOLUTION: A radiation source installation jig 10 comprises a first end part 31, a second end part 32, and a support part 33. The first end part 31 is attached to a tip part 22a of an end cap housing 22 of a radiation detector 11. The second end part 32 holds a radiation source 10a. The support part 33 supports the first end part 31 and the second end part 32 at a predetermined distance in a first axial direction Q parallel to a central axis P. The second end part 32 comprises a contact part 32a and a peripheral part 32b that are integrally formed. The contact part 32a is in contact with the radiation source 10a. The peripheral part 32b is provided at a peripheral edge of the contact part 32a, and has a tip surface 32B that does not protrude outward with respect to a tip surface 32A of the contact part 32a in the first axial direction Q.SELECTED DRAWING: Figure 2

Description

The present invention relates to a radiation source installation jig and a measurement system.

Conventionally, a radiation source holder has been known that positions and fixes a radiation source such as a standard radiation source at a predetermined position relative to a radiation detector when measuring the relative efficiency of the radiation detector (for example, in Non-Patent Document 1). reference).

“Radioactivity Measurement Series 7 Gamma Ray Spectrometry Using Germanium Semiconductor Detector”, Nuclear Regulation Authority, 2020, p.178

By the way, when attaching the radiation source holder according to the above-mentioned prior art to a radiation detector inside a shielding body, it is necessary to adjust the position of the head (tip of the end cap, etc.) in response to changes in the position of the head (tip of the end cap, etc.) due to, for example, replacement of the radiation detector. Therefore, it becomes necessary to secure a space within the shielding body for mounting the radiation source holder on the head of a suitable radiation detector. However, when increasing the space inside the shield while ensuring the desired shielding performance, the increase in the mass of the shield limits the places where the shield can be installed, and the cost required to construct the shield increases. The problem of bulkiness arises.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radiation source installation jig and a measurement system that allow the jig to be properly mounted on a detector within a shielding body.

In order to solve the above problems and achieve the objects, the present invention employs the following aspects.
(1) A radiation source installation jig according to one aspect of the present invention is a radiation source installation jig for positioning and fixing a radiation source with respect to an end cap of a radiation detector inside a shield, and a first end that is attached to the distal end of the radiation source, a second end that holds the radiation source, and a predetermined distance between the first end and the second end in an axial direction parallel to the central axis. the second end is provided at the periphery of the contact portion and the contact portion that contacts the radiation source, and is located outwardly from the distal end surface of the contact portion in the axial direction. and a peripheral edge having a non-protruding tip surface.

(2) In the radiation source installation jig according to (1) above, the tip surface of the peripheral portion has a first axial direction that is the axial direction relative to a second axial direction that is parallel to the central axis of the end cap. When the radiation source and the contact portion are tilted at a predetermined angle or less, the radiation source and the contact portion do not need to protrude outward beyond the tips of the radiation source and the contact portion in the second axis direction.

(3) In the radiation source installation jig according to (2) above, the first end portion has a size necessary for changing its attitude to the first state, second state, and third state with respect to the end cap. The first state is such that only a part of the tip of the end cap is in the first state by inclining the first axial direction with respect to the second axial direction by an angle equal to or less than the predetermined angle. The second state is a state in which the inside of the first end is inserted by gradually reducing the inclination of the first axial direction with respect to the second axial direction from the first state. or by gradually increasing the inclination of the first axial direction with respect to the second axial direction from the third state. The third state is a state where the portion of the distal end of the end cap to be inserted is reduced, and the third state is a state in which the first axial direction and the second axial direction are parallel, and the entire distal end of the end cap is reduced. It may be in a state where it is inserted inside the first end.

(4) A measurement system according to an aspect of the present invention includes the radiation source installation jig according to any one of (1) to (3) above, the shield, and the and the radiation detector to which a radiation source installation jig is attached.

(5) A measurement system according to one aspect of the present invention includes a shield, an electromagnetic wave or sound wave detector, and a source of the electromagnetic wave or sound wave that is positioned and fixed inside the shield with respect to the head of the detector. The jig includes a first end that is attached to the tip of the head, a second end that holds the generation source, and the first end and the second end. a support part that supports the at a predetermined distance in an axial direction parallel to the central axis, and the second end part is provided with a contact part in contact with the generation source and a peripheral edge of the contact part, and the second end part is provided on the periphery of the contact part, and and a peripheral edge portion having a distal end surface that does not protrude outward beyond the distal end surface of the contact portion in the direction.

According to the radiation source installation jig according to the aspect described in (1) above, the axial direction of the radiation source installation jig can be set at the end, for example, when the radiation source protrudes outward beyond the distal end surface of the contact part. It is possible to suppress the tip end surface of the peripheral edge portion from protruding outward beyond the tips of the radiation source and the contact portion when the cap is tilted with respect to the axial direction. By tilting the axial direction of the radiation source installation jig with respect to the axial direction of the end cap at the initial stage of attachment of the radiation source installation jig to the end cap or at the end of removal, a part of the end cap can be placed inside the first end. inserted into. For example, when the axial direction of the radiation source installation jig and the axial direction of the end cap are parallel, the end cap is The distance between the radiation source and the tip of the contact portion and the tip surface of the end cap in the axial direction can be reduced. As a result, the radiation source installation jig can be properly attached to and removed from the end cap of the radiation detector inside the shield while suppressing the need to increase the space inside the shield.

In the case of (2) above, the tip surface of the peripheral portion is prevented from protruding outward beyond the tips of the radiation source and the contact portion when the first axis direction is inclined at a predetermined angle or less with respect to the second axis direction. be able to. By tilting the first axial direction at a predetermined angle or less with respect to the second axial direction at the beginning of the installation of the radiation source installation jig to the end cap or at the end of the removal, the radiation source and the contact part in the second axial direction are The distance between the tip and the tip surface of the end cap can be reduced. Thereby, when attaching and removing the radiation source installation jig to and from the end cap of the radiation detector inside the shield, it is possible to suppress the need to increase the space inside the shield.

In the case of (3) above, even if the first axis direction is inclined at a predetermined angle or less with respect to the second axis direction, the radiation source installation jig cannot be properly attached to or removed from the end cap of the radiation detector. It can be carried out.

According to the measurement system according to the aspect described in (4) above, when the radiation source installation jig is attached to and removed from the end cap of the radiation detector inside the shield, the space inside the shield is It is possible to suppress the need to increase the amount. Thereby, it is possible to suppress an increase in the mass of the shield and a limitation on the place where the shield is installed, and it is possible to suppress an increase in the cost required for constructing the shield.

According to the measurement system according to the aspect described in (5) above, when attaching and removing the jig to and from the head of the detector inside the shield, it is necessary to increase the space inside the shield. This can be suppressed. Thereby, it is possible to suppress an increase in the mass of the shield and a limitation on the place where the shield is installed, and it is possible to suppress an increase in the cost required for constructing the shield.

1 is a configuration diagram showing an example of a measurement system including a radiation source installation jig according to an embodiment of the present invention, and is a diagram showing a radiation shield in a broken state. FIG. 1 is a sectional view of a radiation source installation jig according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of a state in which a radiation source installation jig according to an embodiment of the present invention is mounted on a radiation detector inside a radiation shield. FIG. 3 is a cross-sectional view showing a first state of the radiation source installation jig according to the embodiment of the present invention and a state of a first comparative example. FIG. 3 is a cross-sectional view showing a first state of a radiation source installation jig according to an embodiment of the present invention and a radiation source installation jig of a second comparative example. FIG. 7 is a sectional view showing a first state of a radiation source installation jig according to a first modification of the embodiment of the present invention and a radiation source installation jig of a second comparative example. The figure which looked at the radiation source installation jig concerning the 1st modification of an embodiment of the present invention from the 1st axis direction. FIG. 7 is a sectional view showing a first state and a third state of a radiation source installation jig according to a second modification of the embodiment of the present invention. FIG. 7 is a sectional view showing a first state and a third state of a radiation source installation jig according to a third modification of the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A radiation source installation jig and measurement system according to an embodiment of the present invention will be described below with reference to the accompanying drawings.
<Measurement system>
FIG. 1 is a configuration diagram showing an example of a measurement system 1 including a radiation source installation jig 10 according to an embodiment, and is a diagram showing a radiation shield 12 in a broken state.
As shown in FIG. 1, the measurement system 1 of this embodiment includes a radiation source installation jig 10, a radiation detector 11, and a radiation shield 12. Furthermore, the measurement system 1 includes, for example, a pedestal 14, a base 15, a detector stand 16, a position adjustment mechanism 17, and a slide mechanism 18.
The radiation source installation jig 10 of this embodiment is used to position and fix the radiation source 10a with respect to the radiation detector 11 inside the radiation shield 12. The radiation detector 11 detects radiation emitted from the radiation source 10a positioned and fixed inside the radiation shield 12.
In the following, the directions of the X, Y, and Z axes, which are orthogonal to each other in a three-dimensional space, are parallel to each axis. For example, the Z-axis direction is parallel to the vertical direction of the measurement system 1, the Y-axis direction is parallel to the left-right direction of the measurement system 1, and the X-axis direction is parallel to the front-rear direction of the measurement system 1.

The radiation detector 11 is, for example, a semiconductor detector such as a germanium semiconductor detector or a silicon semiconductor detector.
In a vertical cryostat 21, the radiation detector 11 includes a semiconductor crystal such as germanium crystal or silicon crystal that is sensitive to radiation in a vacuum region inside an end cap housing 22 having a radiation entrance window (not shown). (not shown).

The inside of the cryostat 21 is cooled by thermal contact with a cooling rod (not shown) made of copper and immersed in liquid nitrogen stored inside the dewar 23.
A crystal electrode (not shown) formed in the semiconductor crystal is connected to a charge type preamplifier (not shown) housed inside the end cap housing 22 .
The charge type preamplifier outputs an output signal pulse having a peak value corresponding to the energy of radiation incident on the semiconductor crystal from an output terminal (not shown) exposed to the outside.

The radiation shield 12 accommodates therein the radiation source installation jig 10 that holds the radiation detector 11 and the radiation source 10a to be measured, and shields the radiation detector 11 from background radiation.
The outer shape of the radiation shield 12 is, for example, formed into a box shape formed by a combination of a plurality of members. The plurality of members are, for example, the first member 12a, the second member 12b, the third member 12c, the fourth member 12d, and the fifth member 12e. The first member 12a forms the upper part of the radiation shield 12 in the vertical direction (for example, in the vertical direction). The second member 12b forms a side portion and a rear portion that are integrated in the front-rear direction and the left-right direction (for example, horizontal direction, etc.) perpendicular to the up-down direction of the radiation shielding body 12. The third member 12c and the fourth member 12d form the lower part of the radiation shield 12 in the vertical direction. A space (deficient portion) into which the end cap housing 22 of the radiation detector 11 is inserted is formed in the third member 12c from the front end in the front-rear direction toward the rear. The fourth member 12d is disposed in front of the missing portion of the third member 12c, and is attached to and detached from the third member 12c by being displaced in the front-rear direction. The fifth member 12e forms the front portion of the radiation shield 12 in the front-rear direction. The fifth member 12e forms an opening/closing door that opens and closes the opening formed by the first member 12a, the second member 12b, the third member 12c, and the fourth member 12d.

The radiation shield 12 includes a lead shielding part 13a containing lead, a steel shielding part 13b having a steel material provided so as to cover the surface of the lead shielding part 13a, and a corrosion prevention material covering the surface of the steel shielding part 13b. A non-conductive coating film (not shown) is provided. The radiation shield 12 includes, for example, a first lining (not shown) made of oxygen-free copper and a second lining (not shown) made of resin such as acrylic on its inner surface.

The measurement system 1 includes, for example, a mount 14, a base 15, a detector stand 16, a position adjustment mechanism 17, and a slide mechanism 18.
The pedestal 14 supports the radiation shield 12. The external shape of the pedestal 14 is, for example, box-shaped. The pedestal 14 is made of a material such as a steel material 14b having a surface coated with a non-conductive coating film 14a for corrosion prevention or the like. The pedestal 14 includes an opening/closing door 14c at the front end in the front-rear direction that opens and closes the inside. The pedestal 14 houses the dewar 23 therein.
The base 15 supports the pedestal 14. The outer shape of the base 15 is, for example, plate-shaped. The base 15 is made of a material such as steel and has a surface coated with a non-conductive coating film for corrosion prevention or the like.

The detector stand 16 supports the dewar 23 of the radiation detector 11 inside the pedestal 14 . The outer shape of the detector stand 16 is, for example, plate-shaped. The detector stand 16 is made of a metal material such as aluminum.
The position adjustment mechanism 17 adjusts the position of the detector stand 16 in the vertical direction.
The slide mechanism 18 carries the dewar 23 of the radiation detector 11 into and out of the pedestal 14 by sliding the detector pedestal 16 back and forth.

<Radiation source installation jig>
The radiation source installation jig 10 of the embodiment is a so-called radiation source holder, and positions and fixes the radiation source 10a to the end cap housing 22 of the radiation detector 11 inside the radiation shield 12.
FIG. 2 is a sectional view of the radiation source installation jig 10 according to the embodiment.
As shown in FIG. 2, the radiation source installation jig 10 includes, for example, a first end 31, a second end 32, and a support portion 33.
The first end 31 is attached to the tip 22a of the end cap housing 22 of the radiation detector 11. The outer shape of the first end portion 31 is, for example, a cylindrical (hollow columnar) cap shape having an end portion in which a through hole is formed in the axial direction, corresponding to the hollow columnar end cap housing 22 . The inner diameter of the main body (cylindrical portion) of the first end portion 31 is formed to be larger than at least the outer diameter of the end cap housing 22 .

The second end 32 holds the radiation source 10a. The outer shape of the second end portion 32 is, for example, a hollow truncated cone shape in which a recess and a through hole are formed coaxially in the axial direction, corresponding to the disc-shaped radiation source 10a. The second end portion 32 includes, for example, a contact portion 32a and a peripheral portion 32b that are integrally formed.
The contact portion 32a contacts the periphery of the radiation source 10a. The outer shape of the contact portion 32a is, for example, an annular plate shape in which a recess and a through hole are formed coaxially in the axial direction. For example, the contact portion 32a causes the radiation source 10a to protrude outward from the distal end surface 32A of the contact portion 32a in an axial direction (first axial direction) Q parallel to the central axis P of the radiation source installation jig 10. Fix it in the fixed position. The outward direction in the first axial direction Q is a direction opposite to the first end 31 side with respect to the second end 32 in the first axial direction Q. The tip surface 32A of the contact portion 32a is, for example, orthogonal to the first axial direction Q, and its position in the first axial direction Q is constant.

The peripheral portion 32b is provided at the peripheral edge of the contact portion 32a. The outer shape of the peripheral edge portion 32b is, for example, a hollow conical shape with a through hole formed in the axial direction, and has a tapered shape whose outer diameter gradually decreases toward the outside in the first axial direction Q. The peripheral portion 32b has a distal end surface 32B that does not protrude outward beyond the distal end surface 32A of the contact portion 32a in the first axial direction Q. As the tip surface 32B of the peripheral portion 32b moves away from the central axis P in the orthogonal direction, for example like the side surface of a truncated cone, the distance between it and the first end 31 in the first axial direction Q gradually decreases. It is inclined at a predetermined angle with respect to the direction perpendicular to the first axial direction Q so as to change in a decreasing tendency. As will be described later, the distal end surface 32B of the peripheral portion 32b is arranged so that the first axial direction Q is at a predetermined angle θ or less with respect to the second axial direction (for example, the Z-axis direction) S parallel to the central axis O of the end cap housing 22. When the contact portion 32a is tilted in the second axial direction S, the contact portion 32a is formed so as not to protrude outward beyond the tips of the radiation source 10a and the contact portion 32a.

The support portion 33 supports the first end 31 and the second end 32 at a predetermined distance in the first axial direction Q. The outer shape of the support portion 33 is, for example, cylindrical. For example, the outer diameter of the support portion 33 is smaller than the outer diameter of the first end 31 and the same as the outer diameter of the second end 32.

FIG. 3 is a cross-sectional view showing an example of a state in which the radiation source installation jig 10 according to the embodiment is mounted on the radiation detector 11 inside the radiation shield 12. FIG. 4 is a cross-sectional view showing the first state of the radiation source installation jig 10 according to the embodiment and the state of the first comparative example.
As shown in FIG. 3, when the radiation source installation jig 10 is attached to the tip 22a of the end cap housing 22 of the radiation detector 11 inside the radiation shield 12, the radiation source installation jig 10 is attached to the first axis of the central axis P. The end cap housing 22 is inserted into the radiation shield 12 with the direction Q inclined at a predetermined angle θ or less with respect to the second axial direction S parallel to the central axis O of the end cap housing 22 . For example, when the radiation source installation jig 10 does not tilt the first axial direction Q with respect to the second axial direction S by tilting the first axial direction Q with respect to the second axial direction S by a predetermined angle θ or less The distance between the radiation shielding body 12 and the inner surface (top surface) 12A of the first member 12a in the second axial direction S is reduced compared to the above. The direction of inclination of the first axial direction Q with respect to the second axial direction S is, for example, the opposite direction to the direction of movement of the end cap housing 22 in the direction orthogonal to the central axis O of the end cap housing 22.

As shown in FIG. 4, at the beginning of attaching the radiation source installation jig 10 to the end cap housing 22 or at the end of removing the radiation source installation jig 10, the radiation source installation jig 10 is installed in the first position. The end cap housing 22 is moved in a direction perpendicular to the central axis O of the end cap housing 22 while the axial direction Q is inclined at a predetermined angle θ or less with respect to the second axial direction S.
The posture of the radiation source installation jig 10 is changed, for example, into a first state, a second state, and a third state when it is attached to and removed from the end cap housing 22.

In the first state, only a part of the tip portion 22a of the end cap housing 22 is It is in a state where it is inserted inside the first end portion 31 .
The second state is a portion of the tip portion 22a of the end cap housing 22 that is inserted into the first end portion 31 by gradually reducing the inclination of the first axial direction Q with respect to the second axial direction S from the first state. or gradually increase the inclination of the first axial direction Q with respect to the second axial direction S from the third state, thereby adjusting the portion of the tip 22a of the end cap housing 22 that is inserted into the first end 31. This is a state in which it is reduced.
The third state is a state in which the first axial direction Q and the second axial direction S are parallel, and the entire tip 22a of the end cap housing 22 is inserted into the first end 31.
Note that the first end portion 31 of the radiation source installation jig 10 is formed to have a size necessary to change its attitude to the first state, second state, and third state with respect to the end cap housing 22. .

Regarding the distance between the radiation source 10a and the tip of the contact portion 32a of the radiation source installation jig 10 and the surface (tip surface) of the tip 22a of the end cap housing 22 in the second axial direction S, the distance in the first state is h is smaller than the distance h1 in the state of the first comparative example. In the state of the first comparative example, the radiation source installation jig 10 is attached to the end cap housing 22 with the first axial direction Q and the second axial direction S parallel to each other at the initial stage of installation or at the end of the removal of the radiation source installation jig 10. This is a state of movement in a direction orthogonal to the central axis O.
A part of the tip 22a of the end cap housing 22 is inserted into the first end 31 according to the inclination of the first axial direction Q with respect to the second axial direction S, so that the tip 22a becomes the first end. 31, the distance h in the first state is smaller than the distance h1 in the state of the first comparative example.

FIG. 5 is a sectional view showing a first state of the radiation source installation jig 10 according to the embodiment and a radiation source installation jig 40 of a second comparative example.
A radiation source installation jig 40 of the second comparative example shown in FIG. 5 includes, for example, a third end 41 in place of the second end 32 in the radiation source installation jig 10 of the embodiment. The third end 41 holds the radiation source 10a. The external shape of the third end portion 41 is, for example, an annular plate shape in which a concave portion and a through hole are formed coaxially in the axial direction, corresponding to the disk-shaped radiation source 10a. For example, the third end portion 41 moves the radiation source 10a outward from the distal end surface 41A in an axial direction (third axial direction) Q1 parallel to the central axis P1 of the radiation source installation jig 40 of the second comparative example. Fix it so that it sticks out. The outward direction in the third axial direction Q1 is the direction opposite to the first end 31 side with respect to the third end 41 in the third axial direction Q1. The tip surface 41A of the third end portion 41 is parallel to a direction orthogonal to the third axial direction Q1, and has a constant position in the third axial direction Q1.

The third end 41 of the radiation source installation jig 40 of the second comparative example includes the contact part 32a of the radiation source installation jig 10 of the embodiment, and the tip surface 41A of the third end 41 is the contact part 32a of the radiation source installation jig 40 of the second comparative example. It includes a tip surface 32A. For example, when the first axial direction Q and the third axial direction Q1 are parallel, in each axial direction Q, Q1, the tip surface 41A of the third end 41 in the second comparative example is the contact portion in the embodiment. It is located at the same position as the distal end surface 32A of the contact portion 32a, and protrudes outward from the distal end surface 32B of the contact portion 32a. Distance in the second axial direction S between the tip of the radiation source 10a and the third end 41 of the radiation source installation jig 40 of the second comparative example and the surface (tip surface) of the tip 22a of the end cap housing 22 h2 is larger than the distance h in the first state in the embodiment.

As described above, according to the radiation source installation jig 10 according to the present embodiment, by tilting the first axial direction Q with respect to the second axial direction S at the initial stage of attachment to the end cap housing 22 or at the end of disassembly, , an increase in the distance between the distal ends of the radiation source 10a and the contact portion 32a and the surface (distal end surface) of the end cap housing 22 in the second axial direction S can be suppressed. When attaching and removing the radiation source installation jig 10 to and from the end cap housing 22 of the radiation detector 11 inside the radiation shield 12, it is necessary to increase the space inside the radiation shield 12. Can be suppressed.
The first end 31 of the radiation source installation jig 10 is formed to have a size necessary to change its attitude to the first state, second state, and third state with respect to the end cap housing 22. The radiation source installation jig 10 can be properly attached to and removed from the end cap housing 22.

According to the measurement system 1 according to the present embodiment, it is possible to suppress the need to increase the space inside the radiation shield 12, increase the mass of the radiation shield 12, and the location where the radiation shield 12 is installed. It is possible to prevent the radiation shielding body 12 from being limited and to prevent the cost required for configuring the radiation shielding body 12 from increasing.

Modifications of the above-described embodiment will be described below.
In the embodiment described above, the peripheral edge portion 32b of the second end portion 32 has a tapered shape in the first axial direction Q, but the shape is not limited to this. For example, at least a portion of the distal end surface 32B of the peripheral portion 32b may be formed so as not to protrude outward beyond the distal end surface 32A of the contact portion 32a in the first axial direction Q.
FIG. 6 is a sectional view showing the first state of the radiation source installation jig 10A according to the first modification of the embodiment and the radiation source installation jig 40 of the second comparative example. FIG. 7 is a diagram of a radiation source installation jig 10A according to a first modification of the embodiment viewed from the first axial direction Q.
As shown in FIGS. 6 and 7, a radiation source installation jig 10A according to the first modification includes a second end 51 of the first modification instead of the second end 32 in the embodiment. The second end portion 51 of the first modified example includes, for example, the contact portion 32a in an embodiment formed integrally and the peripheral edge portion 51a of the first modified example.

The peripheral edge portion 51a of the first modification is provided at the peripheral edge of the contact portion 32a. The outer shape of the peripheral portion 51a is, for example, a hollow columnar shape with a through hole formed in the axial direction. The peripheral portion 51a includes a first tip surface 51A and a second tip surface 51B. The first tip surface 51A is orthogonal to the first axial direction Q, and is at the same position as the tip surface 32A of the contact portion 32a in the first axial direction Q. The second tip surface 51B does not protrude outward beyond the tip surface 32A of the contact portion 32a in the first axial direction Q, similarly to the tip surface 32B of the embodiment. For example, as the second tip surface 51B moves away from the central axis P in the orthogonal direction, the distance between the second end surface 51B and the first end 31 in the first axial direction Q gradually decreases. It is inclined at a predetermined angle with respect to the direction orthogonal to the first axial direction Q. When the first axial direction Q is inclined at a predetermined angle θ or less with respect to the second axial direction S, the second distal end surface 51B is a radiation source in the second axial direction S, similar to the distal end surface 32B of the embodiment. 10a and the contact portion 32a so as not to protrude outward beyond the tips thereof.

In the embodiment described above, the peripheral edge portion 32b of the second end portion 32 has a tapered shape in the first axial direction Q, but the shape is not limited to this. For example, the distal end surface 32B of the peripheral portion 32b may be formed to be perpendicular to the first axial direction Q and located closer to the first end portion 31 than the distal end surface 32A of the contact portion 32a.
FIG. 8 is a sectional view showing a first state and a third state of a radiation source installation jig 10B according to a second modification of the embodiment.
As shown in FIG. 8, a radiation source installation jig 10B according to the second modification includes a second end 52 of the second modification instead of the second end 32 in the embodiment. The second end portion 52 of the second modification includes, for example, the contact portion 32a in an embodiment formed integrally and the peripheral edge portion 52a of the second modification.

The peripheral edge part 52a of the second modification is provided at the peripheral edge of the contact part 32a. The outer shape of the peripheral portion 52a is, for example, an annular plate shape with a through hole formed in the axial direction. A distal end surface 52A of the peripheral edge portion 52a is perpendicular to the first axial direction Q. The distal end surface 52A is located closer to the first end 31 than the distal end surface 32A of the contact portion 32a in the first axial direction Q. When the first axial direction Q is inclined at a predetermined angle θ or less with respect to the second axial direction S, the distal end surface 52A is similar to the distal end surface 32B of the embodiment, in which the radiation source 10a and It is formed so as not to protrude outward beyond the tip of the contact portion 32a.

In the embodiment described above, the outer shape of the support portion 33 is cylindrical, but the outer shape is not limited to this. For example, the outer shape of the support portion 33 may be formed into another shape such as a rod shape.
FIG. 9 is a sectional view showing a first state and a third state of a radiation source installation jig 10C according to a third modification of the embodiment.
As shown in FIG. 9, a radiation source installation jig 10C according to the third modification includes at least one support section 53 of the third modification instead of the support section 33 of the second modification of the embodiment. . The radiation source installation jig 10C of the third modification includes, for example, two support parts 53. The outer shape of the support portion 53 of the third modification is, for example, rod-shaped. Both ends of the support portion 53 of the third modification in the first axial direction Q are fixed to a recess 31a formed in the first end 31 and a recess 52b formed in the second end 52. The recess 31a of the first end 31 is formed, for example, on the surface of the first end 31 on the second end 52 side in the first axial direction Q. The recess 52b of the second end 52 is formed, for example, on the surface of the second end 52 on the first end 31 side in the first axial direction Q.

In the embodiment described above, the measurement system 1 includes the radiation source installation jig 10, the radiation detector 11, and the radiation shield 12, but is not limited thereto. For example, the measurement system according to the fourth modification of the embodiment may measure electromagnetic waves or sound waves other than radiation.
The measurement system according to the fourth modification includes, for example, a shield for electromagnetic waves or sound waves, a detector, and a jig for positioning and fixing the source of the electromagnetic waves or sound waves with respect to the head of the detector inside the shield. Be prepared.
The jig has a first end that is attached to the tip of the detector head, a second end that holds the source, and a jig that extends in an axial direction parallel to the central axis. and a support portion that supports the device at a predetermined distance.
The second end portion includes a contact portion that contacts the generation source, and a peripheral edge portion that is provided at the periphery of the contact portion and has a tip surface that does not protrude outward beyond the tip surface of the contact portion in the axial direction.

The embodiments of the invention are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

DESCRIPTION OF SYMBOLS 1...Measurement system, 10, 10A, 10B, 10C...Radiation source installation jig, 10a...Radiation source, 11...Radiation detector, 12...Radiation shield, 22...End cap housing, 22a...Tip part, 31...No. 1 end, 32...second end, 32a...contact part, 32A...tip surface, 32b...periphery, 32B...tip surface, 33...support part, 51...second end, 51a...periphery, 51A... First tip surface, 51B...Second tip surface, 52...Second end, 52a...Periphery, 52A...Tip surface, 53...Support part, O...Central axis line, P...Central axis line, Q...First axial direction , S...second axis direction, θ...predetermined angle.

Claims (5)

A radiation source installation jig for positioning and fixing a radiation source with respect to an end cap of a radiation detector inside a shield,
a first end attached to the tip of the end cap;
a second end holding the radiation source;
a support part that supports the first end part and the second end part at a predetermined distance in an axial direction parallel to the central axis,
The second end portion is
a contact portion in contact with the radiation source;
A radiation source installation jig, characterized in that the radiation source installation jig is provided with a peripheral edge part that is provided at the peripheral edge of the contact part and has a tip surface that does not protrude outward beyond the tip surface of the contact part in the axial direction. The tip surface of the peripheral edge portion is
When the first axial direction, which is the axial direction, is inclined at a predetermined angle or less with respect to the second axial direction parallel to the central axis of the end cap, the radiation source and the contact portion are tilted in the second axial direction. The radiation source installation jig according to claim 1, characterized in that the jig does not protrude outward beyond the tip. The first end portion is formed in a size necessary to change the attitude of the end cap to a first state, a second state, and a third state,
In the first state, only a part of the tip of the end cap is inside the first end by tilting the first axis at an angle equal to or less than the predetermined angle with respect to the second axis. It is inserted,
The second state is such that the tip portion of the end cap inserted into the first end portion is gradually reduced from the first state to the inclination of the first axial direction with respect to the second axial direction. A portion of the tip portion of the end cap that is inserted into the first end portion by increasing the portion or gradually increasing the inclination of the first axial direction with respect to the second axial direction from the third state. It is a state that reduces
The third state is a state in which the first axial direction and the second axial direction are parallel, and the entire tip of the end cap is inserted into the first end. The radiation source installation jig according to item 2. The radiation source installation jig according to any one of claims 1 to 3;
the shield;
A measurement system comprising: the radiation detector to which the radiation source installation jig is mounted inside the shield. a shield,
an electromagnetic wave or sound wave detector;
a jig for positioning and fixing a source of electromagnetic waves or sound waves with respect to the head of the detector inside the shield,
The jig is
a first end attached to the tip of the head;
a second end holding the source;
a support part that supports the first end part and the second end part at a predetermined distance in an axial direction parallel to the central axis,
The second end portion is
a contact part in contact with the generation source;
A measurement system comprising: a peripheral edge part that is provided on a peripheral edge of the contact part and has a tip surface that does not protrude outward beyond a tip surface of the contact part in the axial direction.

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