A radiation detection device

Abstract

This invention discloses a radiation detection device, comprising a detector and a housing. The housing has an internal space within which the detector is housed. The thickness of the housing is not less than five times the thickness of the half-value layer of the corresponding radiation. The half-value layer thickness is the thickness of the material that attenuates the radiation energy to half its initial value. The housing has a through-hole extending from its exterior into the internal space. This invention allows for measurement simply by immersing the detector and housing in waste liquid, eliminating the need to modify the radioactive waste liquid pool or perform multiple sampling measurements. This simplifies operation, improves measurement efficiency, and reduces costs. Simultaneously, the housing isolates the detector from external radiation, maximizing the accuracy of the measurement data.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radiation detection, and more particularly to a radiation detection device for monitoring radioactive waste liquid. BACKGROUND

[0002] With the popularization of nuclear technology in the medical field, more and more large tertiary hospitals have opened a nuclear treatment ward and use high-energy radioactive nuclides for the treatment of various diseases. For example, iodine-131 nuclides are used to treat patients after surgery for differentiated thyroid cancer. Since differentiated thyroid cancer tissue can specifically uptake iodine like normal thyroid tissue, after the thyroid cancer patients orally take a large dose of iodine-131, the iodine-131 is taken up by the thyroid tissue, residual cancer tissue and metastatic lesions through the blood, and the beta rays emitted by iodine-131 during the decay process kill cancer cells, causing the residual cancer tissue to necrose, thereby reducing the recurrence and metastasis rate of the tumor after surgery. However, since the half-life of the radioactive nuclide iodine-131 used during treatment can be as long as 8.3 days, and will flow out with the patient's excreta, the hospital will usually collect the excreta into a radioactive decay tank. The excreta waste liquid is naturally decayed in the radioactive decay tank, and can only be discharged when its specific activity is lower than the national safety limit value (such as 10000 Bq / L for iodine-131).

[0003] Therefore, during the natural decay period of the excreta waste liquid, the specific activity value in the radioactive decay tank needs to be monitored in real time. The existing method for monitoring radioactive excreta waste liquid includes sampling method and bypass detector method. In the sampling method, the excreta waste liquid sample is collected from the radioactive decay tank by manual operation during measurement, and then the volume (mL) and activity (Bq) are measured respectively to calculate the specific activity. In the bypass detector method, a bypass pipe 2 is connected to the discharge pipe 1 of the decay tank to lead the excreta waste liquid out to the outside, and a radiation detector 3 is installed close to the bypass pipe 2. The specific activity of the excreta waste liquid in the discharge pipe 1 is inferred by the measurement of the radiation detector 3, as shown in FIG. 1. Figure 1

[0004] ​However, the prior art has at least the following problems in monitoring the specific activity in the radioactive decay tank: first, the sampling is manually operated and the operator needs to frequently contact the dangerous radioactive liquid, which is risky; second, the sampling area is limited and can only be sampled at the liquid surface of the radioactive decay tank, which cannot truly reflect the specific activity of the waste liquid in the entire decay tank; third, the measurement result is not real-time, the data acquisition is performed after sampling, which leads to data lag and cannot provide real-time specific activity value; fourth, the bypass detector method needs to modify the existing pipeline, which is complex to install and high in cost; and finally, the measurement deviation is large, the radiation in the environment will affect the detector result, and the different pipeline (thickness, diameter, etc.) environments during installation will cause deviation of the measurement value of the detector. SUMMARY

[0005] The purpose of the present application is to provide a radiation detection device to solve at least one of the above problems.

[0006] The radiation detection device provided by the present application comprises a detector and a shell, the shell has a containing space inside, the detector is contained in the containing space, the thickness of the shell is not less than five times the half-value layer thickness of the corresponding ray, the half-value layer thickness is the thickness of the material that attenuates the ray energy to half of the initial value, and the shell is provided with a through hole extending from the outside of the shell to the containing space.

[0007] According to one embodiment of the present application, the thickness of the shell is uniform.

[0008] According to one embodiment of the present application, the shell has a first shell, a second shell arranged in parallel with the first shell, and a third shell connecting the first shell and the second shell, and the first shell, the second shell and the third shell enclose the containing space.

[0009] According to one embodiment of the present application, the first shell, the second shell and the third shell are integrally formed.

[0010] According to one embodiment of the present application, the shell is made of lead, tungsten, iron, bricks or concrete.

[0011] According to one embodiment of the present application, the extension direction of the through hole forms a plane that does not coincide with the position of the detector.

[0012] According to one embodiment of the present application, the shell is provided with a clamping device, a cable passes through the clamping device and is in communication connection with the detector inside the shell, and the detector sends count rate data through the cable.

[0013] According to one embodiment of the present application, the radiation detection device further comprises a cable, the cable passing through the through hole and being in communication connection with the detector, the detector sending count rate data through the cable.

[0014] According to one embodiment of the present application, the detector has a wireless sending module, the detector sending count rate data through the wireless sending module.

[0015] According to one embodiment of the present application, the through holes are two in number, and the two through holes have a spacing therebetween.

[0016] According to one embodiment of the present application, the extension directions of the two through holes are parallel to each other, and the detector does not overlap with the plane formed by the extension directions of the two through holes.

[0017] According to one embodiment of the present application, the through holes are two rows in number, wherein each row of the through holes is located on the same plane, and the detector is arranged between the planes on which the two rows of the through holes are located.

[0018] According to one embodiment of the present application, each row of the through holes has the same size and uniform spacing therebetween.

[0019] According to one embodiment of the present application, the shell is cylindrical, the two rows of the through holes are located on the side wall of the shell and are symmetrically arranged about the shell, and the through holes are cylindrical through holes.

[0020] According to one embodiment of the present application, the spacing H between the two rows of the through holes satisfies H>2h(R-t) / t, wherein h represents the diameter of the through hole, R represents the radius of the shell, and t represents the thickness of the shell.

[0021] The radiation detection device provided by the present application has the following advantages: first, full-process monitoring only needs to be sampled once, without the need for manual sampling at each monitoring time as in the traditional sampling method, and the measurement data can be automatically recorded throughout the monitoring process, thereby avoiding the risk of exposing the staff to the radiation environment and improving the measurement efficiency; second, the sampling point can be arbitrarily set by fixing the depth of the cable, and the position of the detector can be flexibly installed according to the actual situation, so as to achieve the purpose of sampling and measuring at different depths and positions; third, the present application only needs to put the detector and the shell into the waste liquid to perform measurement, thereby avoiding any modification of the existing pipeline and realizing low-cost measurement; and finally, the present application isolates the influence of external environmental radiation on the detector through the shell, thereby maximizing the accuracy of the measurement data. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 is a structural schematic diagram of measuring specific activity of radioactive waste liquid according to bypass detector method of prior art;

[0024] Figure 2 is a perspective schematic diagram of radiation detection device according to one embodiment of the present application;

[0025] Figure 3 is a sectional schematic diagram of radiation detection device according to Figure 2 ;

[0026] Figure 4 is a perspective schematic diagram of radiation detection device improved according to Figure 3 ;

[0027] Figure 5 is a sectional schematic diagram of radiation detection device according to Figure 4 ;

[0028] Figure 6 is a perspective schematic diagram of radiation detection device according to another embodiment of the present application;

[0029] Figure 7 is a sectional schematic diagram of radiation detection device according to Figure 6 ;

[0030] Figure 8 is a perspective schematic diagram of radiation detection device according to yet another embodiment of the present application;

[0031] Figure 9 is a sectional schematic diagram of radiation detection device according to Figure 8 ;

[0032] Figure 10 is a sectional schematic diagram of safety zone calculation of radiation detection device according to Figure 8 ;

[0033] Figure 11 is another sectional schematic diagram of safety zone calculation of radiation detection device according to Figure 8 ;

[0034] Figure 12 is a sectional schematic diagram of radiation detection device according to yet another embodiment of the present application. DETAILED DESCRIPTION

[0035] The present application will be further described with reference to the following specific examples. It is to be understood that the following examples are provided by way of illustration of the present application and not by way of limitation thereof.

[0036] It is to be noted that when a component / element is referred to as being "on" another component / element, it can be directly on the other component / element or intervening components / elements can also be present. When a component / element is referred to as being "connected / linked" to another component / element, it can be directly connected / linked to the other component / element or intervening components / elements can also be present. The term "connected / linked" as used herein can include electrical and / or mechanical physical connection / links. The term "comprising / including" as used herein indicates the presence of the features, steps or components / elements but does not preclude the presence or addition of one or more other features, steps or components / elements. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0038] In addition, in the description of the present application, the terms "first", "second", and the like are used only for the purpose of description and distinguishing similar objects, and there is no precedence or significance unless otherwise noted. In addition, in the description of the present application, the meaning of "a plurality of" is two or more unless otherwise specified.

[0039] Figure 2 is a perspective view of a radiation detection device according to an embodiment of the present application, and Figure 2 It can be known that the radiation detection device provided by the present application has a shell 10, the shell 10 has a first shell 11 and a second shell 12 arranged oppositely, and a third shell 13 between the first shell 11 and the second shell 12, the first shell 11, the second shell 12 and the third shell 13 together form a box-shaped or pot-shaped shell 10 with an accommodating space inside; the first shell 11 is provided with a clamping device 15, the clamping device 15 is fixed on the top of the first shell 11, a cable 20 extends to the inside of the shell 10 after passing through the clamping device 15 and the first shell 11, and the cable 20 is fixed on the first shell 11 through the clamping device 15; the shell 10 is also provided with a through hole 14, for example, the through hole 14 can be provided on the first shell 11 or the third shell 13, and the shape of the through hole 14 can be circular, rectangular or other shapes.

[0040] The skilled in the art should understand that when the shell 10 is put into the radioactive decay pool, the through hole 14 can make the excrement waste liquid flow into the inside of the shell 10, and when the shell 10 is taken out from the radioactive decay pool, the excrement waste liquid can flow out from the inside of the shell 10 through the through hole 14.

[0041] Further, Figure 3 is according to Figure 2 the cross-sectional view of the radiation detection device, by Figure 3 Combining Figure 2 it can be known that one part of the clamping device 15 passes through the first shell 11 and is fixed on the first shell 11, one part of the cable 20 extends to the inside of the shell 10 after passing through the clamping device 15 and the first shell 11, the cable 20 is fixed on the first shell 11 through the clamping device 15 at the same time, and the end of the cable 20 is in communication connection with the detector 30; by Figure 3 It can be more clearly seen that the through hole 14 is arranged close to the first shell 11, and there is a spacing between the through hole 14 and the detector 30, that is, the position of the detector 30 does not coincide with the plane where the through hole 14 is located, so as to prevent the radiation emitted by the excrement waste liquid outside the shell from irradiating into the inside of the shell 10 when testing, thereby affecting the accuracy of the measured data of the detector 30.

[0042] The first shell 11, the second shell 12 and the third shell 13 should all be made of high-density materials, such as lead, tungsten, iron, bricks or concrete, so as to create a fixed volume of space for the detector 30 contained in the inside of the shell 10, which is not disturbed by the radiation outside the shell, which is conducive to accurately determining the radioactive data in the excrement waste liquid. At the same time, the skilled in the art should note that in order to ensure the radiation shielding performance of the shell, the thickness of the first shell 11, the second shell 12 and the third shell 13 should all at least reach 5 times the half-value layer thickness of the corresponding highest energy ray in the waste liquid, and the half-value layer thickness represents the thickness of the material that can attenuate the energy of the ray to half of the initial value, for example, the energy of the γ ray emitted by the iodine 131 isotope is 364keV, if the material of the shell 10 is lead (the half-value layer of lead corresponding to 364keV ray is about 3.5mm, which can be obtained through relevant technical manuals), then the thickness of the shell 10 should at least reach 17.5mm (i.e. 5x3.5mm).

[0043] The detector 30 can be a device commonly used in the art for measuring the count rate of high-energy rays in a liquid, such as a scintillation crystal detector, etc. Preferably, the detector 30 should have a sealing function so that it can still work normally when it is immersed in the excrement waste liquid, which is easily achieved by those skilled in the art and will not be described here. The count rate measured by the detector 30 is the number of events received per unit time. When a high-energy photon in a high-energy ray enters the scintillation crystal in the detector 30, the scintillation crystal converts the high-energy photon into visible light, and the visible light is further converted into an electrical signal by a photoelectric conversion device coupled to the scintillation crystal. Each conversion of a high-energy photon into visible light is called an event.

[0044] Those skilled in the art will note that, for the convenience of installation and measurement, as shown in Figure 4 and Figure 5 , the cable 20 can be directly extended into the inside of the shell 10 through the through hole 14 and connected in communication with the detector 30. First, the cable 20 should not block the through hole 14, i.e. the cable 20 should not affect the flow of the excrement waste liquid into and out of the inside of the shell 10; second, the detector 30 should be placed in a place where the external radiation cannot directly reach, such as Figure 4 , where the detector 30 is placed in the corner near the first shell 11. When the shell 10 and the detector are placed in the radioactive decay tank, the detector 30 only measures the radiation data inside the shell 10.

[0045] Figure 6 a perspective view of a radiation detection device according to another embodiment of the present application, Figure 7 a sectional view of a radiation detection device according to Figure 6 . In the embodiments of Figure 6 and Figure 7 , the same or similar components as in the previous embodiment are marked by adding reference numerals 100, and only the differences will be described in combination with Figure 6 and Figure 7It can be seen that two through holes 114 can also be provided on the outer shell 110. Both through holes 114 are provided on the third shell 113. One through hole 114 is located near the first shell 111, and the other through hole 114 is located near the second shell 112. There is a gap between the two through holes 114, so that the liquid flow effect is better when the outer shell 110 is put into or taken out of the excrement waste liquid. The detector 130 is located inside the outer shell 110 and is connected to an external computer via cable 115. The position of the detector 130 does not coincide with the plane of either through hole 14, so as to prevent the radiation emitted by the excrement waste liquid outside the shell from shining into the interior of the outer shell 110 during the test, which would affect the accuracy of the data measured by the detector 130. Those skilled in the art should note that the position of the through hole 114 can also be configured such that one through hole 114 is provided on the first housing 111, and the other through hole 114 is provided on the second housing 112 or the third housing 113. It is only necessary to ensure that the two through holes 114 are not on the same plane. This is something that those skilled in the art can easily implement according to the content of the present invention, and will not be elaborated here.

[0046] Figure 8 This is a perspective view of a radiation detection device according to yet another embodiment of the present invention. Figure 9 It is based on Figure 8 A cross-sectional schematic diagram of a radiation detection device, in Figure 8 and Figure 9 In the embodiment, by adding 200 reference numerals to the corresponding figures... Figure 2 Components that are the same or similar in the embodiments are indicated here; only the differences are described in conjunction with the embodiments. Figure 8 and Figure 9 It can be seen that the through holes 214 can be arranged in two rows, with each row of through holes 214 arranged at equal intervals along the circumference of the third housing 213. One row of through holes 214 is close to the first housing 211, and the other row of through holes 214 is close to the second housing 212. The through holes 214 can also be arranged in more than two rows, and the spacing between adjacent through holes 214 can also be set differently. The through holes 214 can also be respectively arranged on the first housing 211 and the second housing 212. This is something that those skilled in the art can easily think of in conjunction with the technical teachings of this application, and will not be elaborated here. Each row of through holes 214 is positioned consistently in the height direction of the third housing 213. There is a gap between the row of through holes 214 near the first housing 211 and the other row of through holes 214 near the second housing 212. The detector 230 is positioned within this gap, meaning that the position of the detector 230 does not coincide with the plane of any row of through holes 214. This prevents radiation emitted by waste liquid outside the housing from entering the interior of the housing 210 during testing, thus affecting the accuracy of the data measured by the detector 230.

[0047] Furthermore, such asFigure 10 As shown, since the shell 210 needs to be immersed in the radioactive decay pool during measurement, the rays in the excrement waste liquid are randomly divergent, although the shell 210 can block most of the rays from outside the shell to the inside of the shell 210, but a part of the rays will pass through the through hole 214 and enter the inside of the shell 210, if this part of the rays enters the detector 230, it will cause the detection result of the detector 230 to be erroneous, in order to eliminate this error, the shell 10 needs to be further designed. Since the direction of the rays from outside the shell incident at each through hole 214 is random, for the through hole 214 close to the first shell body 211, when the incident rays are incident in a horizontal direction or a direction deviated from the first shell body 211, the rays cannot directly irradiate on the detector 230, and have basically no effect on the detector 230, when the incident rays are incident in a direction deviated from the second shell body 212, the rays can directly irradiate on the detector 230, and will have an effect on the detection result of the detector 230; similarly, for the through hole 214 close to the second shell body 212, when the incident rays are incident in a horizontal direction or a direction deviated from the second shell body 212, the rays cannot directly irradiate on the detector 230, and have basically no effect on the detector 230, when the incident rays are incident in a direction deviated from the first shell body 211, the rays can directly irradiate on the detector 230, and will have an effect on the detection result of the detector 230. Therefore, as shown, when the spacing H between the two rows of through holes 214 is long enough, a safe area not affected by directly incident rays will be generated, that is, the area surrounded by the polygon ABCDEF, in this area, the detector 230 will only receive irradiation of rays from the excrement waste liquid in the inside of the shell 210, at this time, the data detected by the detector 230 can accurately reflect the radiation level in the inside of the shell 210. Figure 5

[0048] Therefore, in combination with Figure 10 and Figure 11 It can be known that the spacing H can be determined in the following manner: when the shell 210 adopts a circular pot shape, and the two rows of through holes 214 are designed symmetrically, the radius of the first shell body 211 and the second shell body 212 is denoted as R, the diameter of the cylindrical through hole 214 is denoted as h, the diameter of the through hole 214 is the direction perpendicular to the plane where the first shell body 211 or the second shell body 212 is located, the depth of the through hole 214 is denoted as t, which is also the thickness of the shell 210, and the outside rays have a critical intersection point O when they are incident to the inside, at this time, according to the proportional relationship, it can be known that:

[0049] h / t=(H / 2) / (R-t)

[0050] Therefore, it can be deduced that H=2h(R-t) / t. In order to make the outside rays not directly irradiate on the detector 30, it is required that H>2h(R-t) / t. When the shell 10 adopts other shapes, those skilled in the art can determine the spacing H through the relationship between the depth of the through hole and the thickness of the shell.​Figure 8 and Figure 9 The technical inspiration of the minimum value of the interval H does not need to be created, and details are not described here.

[0051] Further, since the radioactive decay tank may contain rays of multiple energies, in order to cope with different situations in different radioactive decay tanks, the energy distribution of the rays in the radioactive decay tank can be collected in advance in the present application, so as to calculate the thickness t of the corresponding shell, and according to the diameter h of the designed through hole, the size of the interval H corresponding to different thickness t and diameter h is calculated, so as to pre-manufacture a plurality of shells of different sizes, so as to facilitate selection of shells of different sizes for measurement according to needs during actual measurement, and improve the measurement efficiency.

[0052] Those skilled in the art need to understand that in Figures 8-11 embodiments, the through holes 214 are arranged in two rows, and in fact, the number of rows of the through holes 214 can be arranged as needed, and is not limited to two rows. At the same time, the specific shape of the through holes 214 and the shape between the adjacent two through holes 214 can also be selected as needed. When the number of rows, shape and interval of the through holes 214 are selected, those skilled in the art can determine the size of the corresponding parameters according to the inspiration of the above embodiments, and details are not described here.

[0053] Figure 12 is a cross-sectional view of a radiation detection device according to another embodiment of the present application, in Figure 12 embodiments, the same or similar components are denoted by the reference numerals increased by 300, and only the differences compared with Figure 2 embodiments are described here. The detector 330 comprises a wireless transmitter 331, which is fixed to the inside of the shell through the fixing rod 316, such as being fixed to the first shell body 311; the wireless transmitter 331 can send the count rate data collected by the detector 330 to the matched computer for processing. At this time, the clamping device 315 no longer passes through the first shell body 311, but is arranged on the top of the first shell body 311 to facilitate the connection of the cable 320, so as to facilitate the shell into the radioactive decay tank, and at this time the cable 320 no longer has the data transmission function but is only used as a winding and unwinding rope.

[0054] The radiation detection device provided by the present application should be paid attention to when in use, when the radiation in the radioactive decay tank needs to be monitored, first, the type of radionuclide contained in the radioactive decay tank needs to be confirmed with relevant personnel, for example, for the radiology department of a hospital, the type of radionuclide is recorded by the doctor when the radionuclide treatment is carried out, and the type of radionuclide in the radioactive decay tank corresponding to the radiology department can be easily obtained by medical staff. When the type of radionuclide is determined, since the energy corresponding to each type of radionuclide is known, the radionuclide with the highest energy can be selected as a reference to calculate the thickness of the shell, and then different specifications of the shell are selected according to the needs. When monitoring, first, a sample of excrement waste liquid with a volume of V1 is collected, then the activity value H1 of the sample is measured by using an activity meter and the count rate C1 of the sample is measured by using the detector, so that the specific activity of the excrement waste liquid sample is calculated as: H1 / V1, and the specific activity conversion parameter Q = H1 / (C1V1). After the specific activity conversion parameter is determined, it can be input into the detector or computer, and at the same time, the shell and the detector are put into the radioactive decay tank through the cable, at this time, the real-time count rate value in the radioactive decay tank is measured by the detector in real time, and the change of the real-time specific activity value in the radioactive decay tank can be monitored by the following formula:

[0055] Real-time specific activity = Real-time count rate value * Q.

[0056] The radiation monitoring device provided by the present application has the following advantages: first, full monitoring only needs to be sampled once, unlike the traditional sampling method which needs to be manually sampled at each monitoring time, the measurement data can be automatically recorded throughout the monitoring process, which avoids the risk of exposing workers to a radiation environment and improves the measurement efficiency; second, the sampling point can be arbitrarily set by fixing the depth of the cable, and the position of the detector can be flexibly installed according to the actual situation to achieve the purpose of sampling and measuring at different depths and positions; third, the present application only needs to put the detector and the shell into the waste liquid to perform measurement, which avoids any modification of the existing pipeline and can realize low-cost measurement; finally, the present application isolates the influence of external environmental radiation on the detector through the shell, which maximizes the accuracy of the measurement data.

[0057] The above is only a preferred embodiment of the present application, not to limit the scope of the present application, and various changes can be made to the above embodiment of the present application. That is, any simple, equivalent changes and modifications made according to the content of the claims and description of the present application fall within the scope of the claims of the present application. The present application is not described in detail.

Claims

1. A radiation detection device, characterized by, The radiation detection device comprises: a detector; and A shell has a receiving space inside, the detector is received in the receiving space, the thickness of the shell is not less than five times of the half-value layer thickness of the corresponding ray, the half-value layer thickness is the thickness of the material which attenuates the ray energy to half of the initial value, the shell is provided with through holes extending from the outside of the shell to the receiving space, the through holes are two rows, the distance H between the two rows of through holes is greater than 2 h ( R - t / t , wherein, h D represents the diameter of the through hole, R R represents the radius of the shell, t T represents the thickness of the shell; The extension direction of the through hole forms a plane which does not coincide with the position of the detector; The shell is provided with a clamping device, a cable passes through the clamping device and is in communication connection with the detector inside the shell, the detector sends count rate data through the cable, and the cable is fixed on the shell through the clamping device.

2. The radiation detection apparatus according to claim 1, characterized by The thickness of the shell is uniform.

3. The radiation detection apparatus according to claim 1, characterized by The shell has a first shell, a second shell and a third shell connected with the first shell and the second shell arranged in parallel, and the first shell, the second shell and the third shell enclose the accommodation space.

4. The radiation detection apparatus according to claim 3, characterized by The first shell, the second shell and the third shell are integrally formed.

5. The radiation detection apparatus according to claim 1, characterized by The shell is made of lead, tungsten, iron, brick or concrete.

6. The radiation detection apparatus of claim 1, wherein The through holes are two in number and have a spacing therebetween.

7. The radiation detection apparatus as claimed in claim 6, characterized in that The extension directions of the two through holes are parallel to each other, and the detector does not overlap with the plane formed by the extension directions of the two through holes.

8. The radiation detection apparatus as claimed in claim 1, characterized in that, Each row of the through holes is located on the same plane, and the detector is arranged between the planes on which the two rows of the through holes are located.

9. The radiation detection apparatus as claimed in claim 8, characterized in that The size of each row of the through holes is the same and the spacing therebetween is uniform.

10. The radiation detection apparatus as claimed in claim 9, characterized in that The shell is cylindrical, the two rows of the through holes are located on the side wall of the shell and are symmetrically arranged about the shell, and the through holes are cylindrical through holes.

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