Neutron field generating device

Abstract

The invention relates to the technical field of ionizing radiation measurement, in particular to a neutron field generating device which comprises a support. The neutron generation structure is arranged on the bracket and is used for emitting a neutron field; the moderation part is arranged in the support in the neutron field emission direction of the neutron generation structure, and the moderation part comprises a liquid moderation dielectric layer; the loading part is used for loading a neutron dose monitor; the loading part is connected to the first adjusting part, and the first adjusting part is used for adjusting the thickness of the liquid moderation dielectric layer between the loading part and the neutron generation structure according to the neutron field intensity requirement, so that the neutron field intensity of the plane where the loading part is located is adjusted, and the requirement for the neutron field intensity during calibration of various neutron dose monitors is met; and in addition, in the transportation process, the liquid moderation medium of the moderation part can be emptied, and the overall weight is reduced. The liquid moderation dielectric layer can absorb neutrons and ensure that the radiation level is in a safe level range.

Description

Technical Field

[0001] The present disclosure relates to the technical field of ionizing radiation measurement, and in particular to a neutron field generating device. Background Art

[0002] Neutron monitoring is one of the routine monitoring items in nuclear power plants, nuclear material production bases and other nuclear-related sites. Neutron dose monitors are usually used to obtain the numerical value of the neutron injection rate, as well as the change of neutrons over time and their spatial distribution data, so as to monitor the operating power of the reactor, the environmental radiation dose rate, etc. Therefore, improving the calibration technology of neutron radiation monitors is particularly important in ensuring the quality of monitoring, so as to ensure the safe and stable operation of nuclear facilities, avoid environmental pollution and protect the safety of personnel. In related technologies, it is usually necessary to place the neutron dose monitor in the neutron field for calibration, but the equipment that generates the neutron field is inconvenient to use, and the intensity of the generated neutron field cannot meet the measurement range of various neutron dose monitors, and the usage scenario is relatively single.

[0003] Therefore, it is necessary to propose a neutron field generating device to at least partially solve the problems existing in the prior art. Summary of the Invention

[0004] The present disclosure aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] To this end, the present disclosure provides a neutron field generating device.

[0006] In view of this, according to an embodiment of the present disclosure, a neutron field generating device is proposed, comprising: Bracket; A neutron generating structure, arranged on the bracket, for emitting a neutron field; A moderator is disposed in the bracket along the direction in which the neutron generating structure emits the neutron field, wherein the moderator comprises a liquid moderator medium layer; a loading portion, used for loading a neutron dose monitor; The first adjusting part is connected to the loading part, and the first adjusting part is used to adjust the thickness of the liquid moderation medium layer between the loading part and the neutron generating structure according to the neutron field intensity requirement.

[0007] In a feasible embodiment, the first adjustment unit includes: A first driving structure is provided on the bracket; a first connecting member, the loading portion being connected to the first driving structure via the first connecting member; The first controller is used to control the first driving structure to drive the first connecting member to drive the loading part to move toward or away from the neutron generating structure according to the neutron field intensity requirement.

[0008] In a feasible implementation manner, the first driving structure includes: a first drive motor; A first lead screw is connected to the power output shaft of the first drive motor, and the first connecting member is connected to the first lead screw; The first guide rail is arranged on the bracket along the transmission direction of the first screw, and the first connecting member is slidably connected to the first guide rail.

[0009] In a feasible embodiment, the neutron field generating device further includes: an absorbing portion, arranged in the bracket along the direction in which the neutron generating structure emits the neutron field; The second adjusting portion is connected to the absorbing portion, and the second adjusting portion is used to adjust the distance between the absorbing portion and the neutron generating structure according to the uniformity requirement of the neutron field.

[0010] In a feasible embodiment, the above-mentioned absorption part includes: a support member connected to the second adjusting portion; a first absorber, disposed on the support member; The second absorber is arranged around the first absorber.

[0011] In a feasible embodiment, the second adjustment unit includes: A second driving structure is provided on the bracket; a second connecting member, the supporting member being connected to the second driving structure via the second connecting member; The second controller is used to control the second driving structure to drive the second connecting member to drive the supporting member to move toward or away from the neutron generating structure according to the neutron uniformity requirement.

[0012] In a feasible implementation manner, the second driving structure includes: a second drive motor; A second lead screw is connected to the power output shaft of the second drive motor, and the support member is connected to the second lead screw; The second guide rail is arranged on the bracket along the transmission direction of the second screw, and the second connecting member is slidably connected to the second guide rail.

[0013] In a feasible embodiment, the neutron field generating device further includes: A waterproof housing connected to the first connecting member, wherein the loading portion is disposed in the waterproof housing; The reflective structure is arranged in the waterproof shell, and the loading portion is located between the reflective structure and the neutron generating structure.

[0014] In a feasible embodiment, the neutron generating structure includes: A slide rail connected to the bracket; A mounting frame is slidably connected to the slide rail via a slide; a neutron source, arranged in the mounting frame; The shielding layer is arranged on the bracket and faces away from the emission end of the neutron source.

[0015] In a feasible embodiment, the neutron field generating device further includes: The moving part is arranged at the bottom of the bracket; The brake component is arranged at the bottom of the bracket and is used for stopping the moving part.

[0016] Compared to the prior art, the present disclosure provides at least the following advantages: The neutron field generating device provided in the embodiments of the present disclosure comprises a support, a neutron generating structure, a moderator, a loading section, and a first adjustment section. The neutron generating structure is disposed within the support and emits a neutron field into the interior of the support through the neutron generating structure. The moderator is disposed within the support along the direction of neutron emission from the neutron generating structure and contains a liquid moderator. Fast neutrons emitted by the neutron generating structure lose energy during continuous collisions with atomic nuclei in the liquid moderator, gradually decreasing in energy and velocity to become thermal neutrons, thereby forming a thermal neutron field within the support. The liquid moderator can be emptied of the liquid moderator during transportation to reduce overall weight and facilitate transport. During use, the liquid moderator can be refilled to form a liquid moderator layer. This liquid moderator layer absorbs neutrons, ensuring that the radiation level in the environment surrounding the neutron field generating device remains within a safe range, protecting both the environment and personnel. A neutron dose monitor can be loaded via the loading unit, and the neutron field intensity can be adjusted via the first adjustment unit. Specifically, the loading unit is connected to the first adjustment unit, which can adjust the thickness of the liquid moderator layer between the loading unit and the neutron generating structure based on the neutron field intensity required for neutron dose monitor calibration. When the first adjustment unit drives the loading unit toward the neutron generating structure, the thickness of the liquid moderator layer between the loading unit and the neutron generating structure decreases, and the neutron field intensity in the plane where the loading unit is located increases. When the first adjustment unit drives the loading unit away from the neutron generating structure, the thickness of the liquid moderator layer between the loading unit and the neutron generating structure increases, and the neutron field intensity in the plane where the loading unit is located decreases. This allows for free adjustment of the neutron field intensity to meet the neutron field intensity requirements of various neutron dose monitors during calibration operations, thereby improving applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the exemplary embodiments below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present disclosure. The same reference symbols are used throughout the drawings to represent the same components. In the drawings: Figure 1 A schematic structural diagram of a neutron field generating device according to an embodiment of the present disclosure; Figure 2 A schematic structural diagram of a neutron field generating device in a working state according to an embodiment of the present disclosure; Figure 3 A schematic diagram showing the relationship between the thermal neutron field intensity and the thickness of the liquid moderator layer of a neutron field generating device according to an embodiment of the present disclosure; Figure 4This is a comparison diagram of the thermal neutron uniformity of a neutron field generating device of an embodiment provided in the present disclosure before and after the action of the reflective structure and the absorption part.

[0018] in, Figure 1 and Figure 2 The corresponding relationship between the reference numerals and component names is as follows: 100 neutron field generating device, 110 bracket, 111 first displacement sensor, 112 first positioning plate, 113 second displacement sensor, 114 second positioning plate, 120 neutron generating structure, 121 slide rail, 122 mounting frame, 123 neutron source, 124 shielding layer, 130 moderator, 140 loading unit, 150 first adjustment unit, 151 first drive structure, 1511 first drive motor, 1512 first lead screw, 1513 first guide rail, 152 first connecting member, 153 horizontal adjustment structure, 160 absorption unit, 161 support member, 162 first absorber, 163 second absorber, 170 second adjustment unit, 171 second drive structure, 1711 second drive motor, 1712 second lead screw, 1713 second guide rail, 172 second connecting member, 180 waterproof housing, 181 reflection structure, 190 moving unit. DETAILED DESCRIPTION

[0019] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0020] like Figure 1 and Figure 2 As shown, according to an embodiment of the present disclosure, a neutron field generating device 100 is proposed, comprising: a bracket 110; a neutron generating structure 120, which is arranged on the bracket 110 and is used to emit a neutron field; a moderator 130, which is arranged in the bracket 110 along the direction in which the neutron generating structure 120 emits the neutron field, wherein the moderator 130 includes a liquid moderator layer; a loading portion 140, which is used to load a neutron dose monitor; a first adjusting portion 150, wherein the loading portion 140 is connected to the first adjusting portion 150, and the first adjusting portion 150 is used to adjust the thickness of the liquid moderator layer between the loading portion 140 and the neutron generating structure 120 according to the neutron field intensity requirement.

[0021] It is understood that the neutron field generating device 100 provided in the embodiment of the present disclosure is provided with a support 110, a neutron generating structure 120, a moderator 130, a loading portion 140, and a first adjustment portion 150. The neutron generating structure 120 is disposed on the support 110, and the neutron field is emitted into the interior of the support 110 through the neutron generating structure 120. The moderator 130 is disposed in the support 110 along the direction in which the neutron generating structure 120 emits neutrons, and the moderator 130 is provided with a liquid moderator. The fast neutrons emitted by the neutron generating structure 120 lose energy during continuous collisions with the atomic nuclei of the liquid moderator, gradually reducing their energy and speed to become thermal neutrons, thereby forming a thermal neutron field within the support 110. During transportation, the neutron field generating device 100 can be emptied of the liquid moderator 130 to reduce the overall weight and facilitate transportation. During use, the liquid moderator can be refilled to form a liquid moderator layer. This layer can absorb neutrons, ensuring that the radiation level in the environment surrounding the neutron field generating device 100 is within a safe range to protect the environment and personnel. A neutron dose monitor can be loaded via the loading section 140, and the neutron field intensity can be adjusted via the first adjustment section 150. Specifically, the loading section 140 is connected to the first adjustment section 150, which can adjust the thickness of the liquid moderator layer between the loading section 140 and the neutron generating structure 120 based on the neutron field intensity required for neutron dose monitor calibration. Among them, when the first adjustment part 150 drives the loading part 140 to move toward the neutron generating structure 120, the thickness of the liquid moderation medium layer between the loading part 140 and the neutron generating structure 120 decreases, and the neutron field intensity in the plane where the loading part 140 is located increases; when the first adjustment part 150 drives the loading part 140 to move toward the direction away from the neutron generating structure 120, the thickness of the liquid moderation medium layer between the loading part 140 and the neutron generating structure 120 increases, and the neutron field intensity in the plane where the loading part 140 is located decreases, thereby realizing free adjustment of the neutron field intensity to meet the neutron field intensity requirements of various neutron dose monitors in calibration operations and improving applicability.

[0022] It is understandable that if Figure 1 and Figure 2 In the illustrated orientation, moderator 130 may be provided with a liquid tank, which is disposed within bracket 110 with its opening facing upward. Neutron generating structure 120 is disposed at the bottom of bracket 110 to emit neutrons upward. The size of the liquid tank and the amount of liquid moderator can be easily adjusted to ensure that the irradiation field of the thermal neutron field generated by moderator 130 meets the size requirements of the neutron dose monitor to be calibrated, thereby improving applicability.

[0023] It is understood that the moderator 130 may also be provided with a solid moderator. Specifically, the solid moderator may be provided at the loading portion 140 or between the liquid moderator layer and the loading portion 140, depending on the uniformity requirements of the neutron field, to improve the uniformity of the neutron field. For example, the solid moderator may be a boron-containing material.

[0024] For example, the liquid storage tank can be made of aluminum, stainless steel, or polyethylene. Its shape can be rectangular, cylindrical, or spherical, depending on actual usage. Bracket 110 can be made of stainless steel or aluminum. Water can be used as the liquid moderator, as it is low-cost and readily available.

[0025] In some examples, such as Figure 1 and Figure 2 As shown, the first adjustment part 150 includes: a first driving structure 151, which is arranged on the bracket 110; a first connecting member 152, and the loading part 140 is connected to the first driving structure 151 through the first connecting member 152; a first controller, which is used to control the first driving structure 151 to drive the first connecting member 152 to drive the loading part 140 to move toward or away from the neutron generating structure 120 according to the neutron field intensity requirement.

[0026] It is understood that the first adjustment unit 150 may be provided with a first drive structure 151, a first connector 152, and a first controller. The first drive structure 151 is disposed at the top of the bracket 110, and the loading unit 140 may be connected to the first drive structure 151 via the first connector 152, so that the first drive structure 151 can drive the first connector 152 to move the loading unit 140 toward or away from the neutron generating structure 120. The first adjustment unit 150 may also be provided with a first positioning plate 112 and a first displacement sensor 111. The first positioning plate 112 is disposed at the bottom of the loading unit 140, and the first displacement sensor 111 may be disposed at the bottom of the liquid storage tank. The first displacement sensor 111 can detect the movement distance of the first positioning plate 112. The first controller can determine the distance between the loading part 140 and the neutron generating structure 120 according to the neutron field strength required by the neutron dose monitor to be calibrated, thereby adjusting the neutron dose monitor to the corresponding neutron field strength by adjusting the thickness of the liquid moderation medium layer between the loading part 140 and the neutron generating structure 120, thereby realizing automatic adjustment of the neutron field strength.

[0027] For example, a horizontal adjustment structure 153 may be provided between the first connecting member 152 and the loading portion 140 to adjust the horizontality of the loading portion 140 and improve the uniformity of the neutron field emitted to the loading portion 140 .

[0028] In some examples, such as Figure 1 and Figure 2 As shown, the above-mentioned first driving structure 151 includes: a first driving motor 1511; a first screw 1512, connected to the power output shaft of the above-mentioned first driving motor 1511, and the above-mentioned first connecting member 152 is connected to the above-mentioned first screw 1512; a first guide rail 1513, arranged on the above-mentioned bracket 110 along the transmission direction of the above-mentioned first screw 1512, and the above-mentioned first connecting member 152 and the above-mentioned first guide rail 1513 are slidably connected.

[0029] It is understood that the first drive structure 151 is provided with a first drive motor 1511, a first lead screw 1512 and a first guide rail 1513. The first lead screw 1512 is provided on the bracket 110, and the first lead screw 1512 is connected to the power output shaft of the first drive motor 1511. The rotational power of the first drive motor 1511 is converted into the linear motion of the first lead screw 1512. Figure 1 In the direction shown, the first lead screw 1512 can be arranged in the vertical direction. The first guide rail 1513 is arranged on the bracket 110, and the first guide rail 1513 and the first lead screw 1512 are parallel to each other. The first connecting member 152 is connected to the first lead screw 1512, so that it slides along the first guide rail 1513 under the drive of the first lead screw 1512. The first controller can control the start and stop of the first drive motor 1511, and through the transmission action of the first lead screw 1512, accurately move the loading unit 140 to the corresponding height position of the liquid moderator layer.

[0030] In some examples, such as Figure 1 and Figure 2 As shown, the neutron field generating device 100 further includes: an absorbing portion 160, which is arranged in the bracket 110 along the direction in which the neutron field is emitted by the neutron generating structure 120; a second adjusting portion 170, and the absorbing portion 160 is connected to the second adjusting portion 170, and the second adjusting portion 170 is used to adjust the distance between the absorbing portion 160 and the neutron generating structure 120 according to the neutron field uniformity requirement.

[0031] It is understandable that the neutron field generating device 100 may also be provided with an absorption portion 160 and a second adjustment portion 170. The absorption portion 160 may be provided in the bracket 110 along the direction in which the neutron field is emitted by the neutron generating structure 120. The absorption portion 160 absorbs the neutron flux to improve the uniformity of the thermal neutron field, avoid the uncertainty of the neutron dose monitor calibration due to the uneven thermal neutron field, and improve the calibration reliability. The second adjustment portion 170 is provided in the bracket 110. The second adjustment portion 170 may adjust the distance between the absorption portion 160 and the neutron generating structure 120 according to the neutron field uniformity requirements required for the neutron dose monitor calibration, thereby adjusting the absorption effect of the absorption portion 160 on neutrons to adjust the neutron field uniformity. This can meet the neutron field uniformity requirements of various neutron dose monitors during calibration operations and improve applicability.

[0032] Exemplarily, the absorption portion 160 may be made of a boron-containing material to absorb a wider range of neutron energies, thereby ensuring the absorption and regulation effects on thermal neutrons, thereby improving the uniformity of the thermal neutron field and providing a uniform thermal neutron field in the horizontal direction.

[0033] It is understandable that the shape of the absorption portion 160 can be adjusted according to the neutron field intensity distribution generated by different neutron generating structures 120 to absorb neutrons in areas with higher local neutron field intensity, thereby improving the uniformity of the neutron field distribution.

[0034] It can be understood that the calculation formula for neutron field uniformity is as follows:

[0035] Where k is the thermal neutron field uniformity; is the maximum neutron injection rate in the horizontal direction; is the minimum neutron injection rate in the horizontal direction; is the average neutron fluence rate in the horizontal direction.

[0036] In some examples, such as Figure 1 and Figure 2 As shown, the absorption portion 160 includes: a support member 161 connected to the second adjustment portion 170 ; a first absorber 162 disposed on the support member 161 ; and a second absorber 163 disposed around the first absorber 163 .

[0037] It is understood that the absorbing portion 160 may be provided with a support member 161, a first absorber 162 and a second absorber 163. The support member 161 may be connected to the second adjusting portion 170, and as shown in FIG. Figure 2In the direction shown, the support member 161 is arranged horizontally and is adjusted by the second adjustment portion 170 to move the support member 161 vertically to move closer to or further away from the neutron generating structure 120. The first absorber 162 is arranged on the support member 161 and absorbs the thermal neutron flux in the central region of the neutron field. The second absorber 163 can be arranged in an annular structure and is arranged around the first absorber 162. The second absorber 163 absorbs the thermal neutron flux at the edge of the non-central region.

[0038] It should be noted that the sizes of the first absorber 162 and the second absorber 163 can be modified according to the irradiation field range required by the neutron dose monitor to meet the screen uniformity requirements of different neutron dose monitors.

[0039] For example, a protrusion may be provided in the middle of the first absorber 162 to improve the effect of absorbing neutrons in the middle of the first absorber 162 .

[0040] In some examples, such as Figure 1 and Figure 2 As shown, the second adjustment part 170 includes: a second driving structure 171, which is arranged on the bracket 110; a second connecting member 172, and the support member 161 is connected to the second driving structure 171 through the second connecting member 172; a second controller, which is used to control the second driving structure 171 to drive the second connecting member 172 to drive the support member 161 to move toward or away from the neutron generating structure 120 according to the neutron uniformity requirement.

[0041] It is understood that the second drive structure 171 is provided with a second drive motor 1711, a second lead screw 1712 and a second guide rail 1713. The second lead screw 1712 is provided on the bracket 110, and the second lead screw 1712 is connected to the power output shaft of the second drive motor 1711. The rotational power of the second drive motor 1711 is converted into the linear motion of the second lead screw 1712. Figure 1In the direction shown, the second lead screw 1712 can be arranged in the vertical direction. The second guide rail 1713 is arranged on the bracket 110, and the second guide rail 1713 and the second lead screw 1712 are parallel to each other. The second connecting member 172 is connected to the second lead screw 1712, so that it slides along the second guide rail 1713 under the drive of the second lead screw 1712. The second controller can control the start and stop of the second drive motor 1711, and adjust the height position of the support member 161 through the transmission action of the second lead screw 1712. The second adjustment part 170 can also be provided with a second positioning plate 114 and a second displacement sensor 113, wherein the second positioning plate 114 is arranged at the bottom of the support member 161, and the second displacement sensor 113 can be arranged at the bottom of the liquid storage tank, and the second displacement sensor 113 can detect the moving distance of the second positioning plate 114. The second controller can determine the distance between the absorption part 160 and the neutron generating structure 120 according to the requirements of different neutron dose monitors for neutron field uniformity during calibration operations to adjust the neutron field uniformity and achieve automatic adjustment of the neutron field uniformity.

[0042] It should be noted that the calibration steps of the neutron field strength of the neutron field generating device 100 for different moderating medium layer heights are as follows: Step 1: Determine the type and intensity of the neutron source 123 and the thermal neutron fluence rate distribution at the corresponding heights of each liquid moderator layer in the neutron field generating device 100.

[0043] Step 2: Regularly monitor the neutron fluence rate distribution using a calibrated He-3 sphere. The He-3 sphere has been calibrated in the dose monitoring mechanism for metered value transmission. By moving the calibrated He-3 sphere within the neutron field generating device 100 for scanning, the thermal neutron intensity at each liquid moderator layer is measured to determine the neutron fluence rate distribution at the corresponding location, thereby determining the neutron field uniformity at the corresponding location.

[0044] Step 3: Use a calibrated neutron monitoring detector to move in the neutron field generating device 100 to obtain the standard value of the neutron fluence rate at each height position of the liquid moderator layer.

[0045] After completing the calibration through the above steps, the standard value of the neutron field intensity corresponding to the height of each liquid moderator layer in the neutron field generating device 100 can be confirmed, thereby ensuring data accuracy and improving reliability.

[0046] In some examples, such as Figure 1 and Figure 2As shown, the neutron field generating device 100 further includes: a waterproof shell 180, connected to the first connecting member 152, and the loading portion 140 is arranged in the waterproof shell 180; a reflective structure 181, arranged in the waterproof shell 180, and the loading portion 140 is located between the reflective structure 181 and the neutron generating structure 120.

[0047] It is understood that the neutron field generating device 100 may also be provided with a waterproof housing 180 and a reflective structure 181. The waterproof housing 180 is connected to the first connecting member 152, and the loading portion 140 may be provided inside the waterproof housing 180 to prevent the liquid moderator from entering the loading portion 140 and causing the neutron dose monitor to be calibrated to fail, thereby improving protection. The reflective structure 181 may be provided inside the waterproof housing 180, and as shown in FIG. Figure 1 In the direction shown, some thermal neutrons in the thermal neutron field will be emitted from above the loading section 140, resulting in a certain amount of waste and increasing the external environmental radiation dose. Installing a reflective structure 181 above the loading section 140 reflects neutrons above the loading section 140, thereby reducing the waste of thermal neutrons. Furthermore, it can reflect thermal neutrons at the center of the loading section 140 to the edge of the loading section 140, increasing the number of thermal neutrons at the edge and improving uniformity.

[0048] Exemplarily, the material of the reflective structure 181 can be polyethylene.

[0049] In some examples, such as Figure 1 and Figure 2 As shown, the neutron generating structure 120 includes: a slide rail 121, connected to the bracket 110; a mounting frame 122, slidably connected to the slide rail 121 through a slide; a neutron source 123, arranged in the mounting frame 122; and a shielding layer 124, arranged on the bracket 110, away from the emission end of the neutron source 123.

[0050] It is understood that the neutron generating structure 120 may be provided with a slide rail 121, a mounting frame 122, a neutron source 123, and a shielding layer 124. The slide rail 121 is provided at the bottom of the bracket 110, the mounting frame 122 may be slidably connected to the slide rail 121 via a slide, and the neutron source 123 is provided in the mounting frame 122 so as to be protected by the mounting frame 122. With such a configuration, during the transportation of the neutron field generating device 100, the mounting frame 122 may be removed to ensure transportation safety, and after the transportation is completed, the mounting frame 122 may be slid along the slide rail 121 to a designated position via a slide for easy installation and removal. A shielding layer 124 is provided on the side away from the emission end of the neutron source 123 to absorb and shield the neutrons generated by the neutron source 123, thereby reducing radiation to the outside world and improving safety.

[0051] Exemplarily, the neutron source 123 may be a radioactive source, an isotope neutron source 123 , a neutron tube, an accelerator neutron source 123 , or the like.

[0052] In some examples, such as Figure 1 and Figure 2 As shown, the neutron field generating device 100 further includes: a moving portion 190 disposed at the bottom of the bracket 110 ; and a brake member disposed at the bottom of the bracket 110 for stopping the moving portion 190 .

[0053] It is understood that the neutron field generating device 100 may also be provided with a movable portion 190 and a brake portion. The movable portion 190 is disposed at the bottom of the bracket 110 to facilitate transport of the neutron field generating device 100. When the neutron field generating device 100 needs to be fixed in position, the movable portion 190 can be stopped by a brake to ensure stability. For example, the movable portion 190 may utilize universal wheels.

[0054] It should be noted that the method of using the neutron field generating device 100 is as follows: Step 1: Calibrate the neutron field strength at different liquid moderator layer heights in the neutron field production device. Specifically, move the calibrated neutron dose monitor to the height of the liquid moderator layer to be calibrated, start the neutron generating structure 120, and emit neutrons in the direction of the neutron dose monitor through the neutron source 123. Determine whether the measured neutron fluence rate meets the standard fluence rate requirement corresponding to the above-mentioned neutron source 123. If so, continue to move the calibrated neutron dose monitor to calibrate the liquid moderator layer at other heights; if not, it is necessary to re-perform the above-mentioned calibration steps of the neutron field generating device 100 for the neutron field strength at different liquid moderator layer heights to re-calibrate, and after calibration, close the neutron generating structure 120.

[0055] Step 2: Place the neutron dose monitor to be calibrated in the loading portion 140 , and assemble the loading portion 140 to the bracket 110 , and confirm whether the loading portion 140 is properly installed by measuring the distance between the first displacement sensor 111 and the first positioning plate 112 .

[0056] Step 3: Confirm the neutron field intensity and uniformity requirements for the neutron dose monitor to be calibrated. Specifically, the required neutron field intensity and uniformity for the neutron dose monitor to be calibrated can be input into the control software. The control software will provide the most suitable liquid moderator layer height and the height and thickness of the absorber 160. The user can modify or confirm these information based on this information.

[0057] Step 4: After user confirmation, the control software controls the first driving structure 151 through the first controller to drive the first connecting member 152 to drive the loading unit 140 to the corresponding height position of the liquid moderation medium layer. The control software controls the second driving structure 171 through the second controller to drive the supporting member 161 to drive the absorbing unit 160 to the corresponding height position, so as to realize the automation of neutron field intensity and uniformity adjustment and ensure the movement accuracy of the loading unit 140 and the supporting member 161.

[0058] Step 5: Start the neutron generating structure 120 to emit fast neutrons toward the moderator 130 , and form a uniform thermal neutron field under the action of the moderator 130 and the absorption part 160 .

[0059] Step 6: Control the neutron dose monitor to be calibrated to perform calibration measurement, and close the neutron generating structure 120 after completing the calibration measurement.

[0060] Step 7: Repeat steps 2 to 6 until the calibration measurement operations for all neutron dose monitors to be calibrated are completed.

[0061] For example, the relationship between the thermal neutron field intensity in the horizontal direction of the loading portion 140 and the liquid moderator layer can be calculated using Monte Carlo physics modeling. Figure 3 As shown in FIG. 1 , when the neutron source 123 is 2.5 MeV and the thickness of the liquid moderator layer is 5 cm, 10 cm, 15 cm, 20 cm, 25 cm and 30 cm respectively, the thermal neutron field intensity relationship of the loading portion 140 region with a radius of 10 cm is obtained. Figure 4 As shown in FIG. 1 , when the thickness of the liquid moderator layer is 5 cm, under the action of the reflective structure 181 and the absorbing part 160, the thermal neutron field intensity improvement effect in the range of -10 cm to 10 cm in the horizontal direction of the loading part 140 is obtained with the center of the loading part 140 as the coordinate origin. Figure 4 The upper middle curve is the original thermal neutron field distribution when the reflective structure 181 and the absorbing part 160 are not used, and the lower curve is the improved thermal neutron field distribution when the reflective structure 181 and the absorbing part 160 are used, and the uniformity effect is about 2.5%.

[0062] It should be understood that the terms first, second, etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments of the present invention.

[0063] It should be understood that the term "and / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, B exists alone, and A and B exist at the same time. The term " / and" in this article describes another type of association object relationship, indicating that two relationships may exist. For example, A / and B can represent two situations: A exists alone, and A and B exist alone. In addition, the character " / " in this article generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0064] It should be understood that in the description of the present invention, the terms "upper", "vertical", "inside", "outside" and the like indicate orientations or positional relationships in which the disclosed product is conventionally placed when in use, or are orientations or positional relationships conventionally understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0065] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0066] The terms used herein are used only to describe specific embodiments and are not intended to limit the exemplary embodiments of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms "comprise," "include," "include," and / or "comprising" when used herein specify the presence of claimed features, integers, steps, operations, units, and / or components, and do not preclude the presence or addition of one or more other features, quantities, steps, operations, units, components, and / or combinations thereof.

[0067] In the following description, certain details are provided to facilitate a thorough understanding of the exemplary embodiments. However, one of ordinary skill in the art will appreciate that the exemplary embodiments may be practiced without these specific details. In other embodiments, well-known processes, structures, and techniques may not be shown in unnecessary detail in order to avoid obscuring the exemplary embodiments.

[0068] The above are merely specific embodiments of the present application to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather is intended to conform to the widest scope consistent with the principles and novel features of the present application.

[0069] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

Claims

1. A neutron field generating device, characterized in that: include: Bracket; a neutron generating structure, disposed on the support, for emitting a neutron field; a moderator, disposed in the bracket along a direction in which the neutron generating structure emits a neutron field, wherein the moderator comprises a liquid moderator medium layer; a loading portion, used for loading a neutron dose monitor; The first regulating part is connected to the loading part, and the first regulating part is used to adjust the thickness of the liquid moderation medium layer between the loading part and the neutron generating structure according to the neutron field intensity requirement.

2. The neutron field generating device according to claim 1, characterized in that: The first adjustment unit includes: A first driving structure is provided on the bracket; a first connecting member, the loading portion being connected to the first driving structure via the first connecting member; The first controller is configured to control the first driving structure to drive the first connecting member to move the loading portion toward or away from the neutron generating structure according to the neutron field intensity requirement.

3. The neutron field generating device according to claim 2, characterized in that: The first driving structure includes: a first drive motor; a first lead screw connected to a power output shaft of the first drive motor, and the first connecting member connected to the first lead screw; A first guide rail is arranged on the bracket along the transmission direction of the first screw, and the first connecting member is slidably connected to the first guide rail.

4. The neutron field generating device according to any one of claims 1 to 3, characterized in that: Also includes: an absorbing portion, arranged in the bracket along the direction in which the neutron field is emitted by the neutron generating structure; The second adjusting portion is connected to the absorbing portion, and the second adjusting portion is used to adjust the distance between the absorbing portion and the neutron generating structure according to the uniformity requirement of the neutron field.

5. The neutron field generating device according to claim 4, characterized in that: The absorption part includes: a support member connected to the second adjusting portion; a first absorber, disposed on the support member; The second absorber is disposed around the first absorber.

6. The neutron field generating device according to claim 5, characterized in that: The second adjusting unit includes: A second driving structure is provided on the bracket; a second connecting member, the supporting member being connected to the second driving structure via the second connecting member; The second controller is used to control the second driving structure to drive the second connecting member to drive the supporting member to move toward or away from the neutron generating structure according to the neutron uniformity requirement.

7. The neutron field generating device according to claim 6, characterized in that: The second driving structure includes: a second drive motor; a second lead screw connected to a power output shaft of the second drive motor, and the support member is connected to the second lead screw; The second guide rail is arranged on the bracket along the transmission direction of the second screw, and the second connecting member is slidably connected to the second guide rail.

8. The neutron field generating device according to claim 2, characterized in that: Also includes: a waterproof housing connected to the first connecting member, wherein the loading portion is disposed in the waterproof housing; The reflective structure is arranged in the waterproof shell, and the loading portion is located between the reflective structure and the neutron generating structure.

9. The neutron field generating device according to any one of claims 1 to 3, characterized in that: The neutron generating structure comprises: a slide rail connected to the bracket; A mounting frame, slidably connected to the slide rail via a slide; a neutron source, disposed in the mounting frame; The shielding layer is arranged on the bracket and faces away from the emission end of the neutron source.

10. The neutron field generating device according to any one of claims 1 to 3, characterized in that: Also includes: A moving part, arranged at the bottom of the bracket; A brake component is provided at the bottom of the bracket and is used for stopping the moving part.

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