Compact radiation detection apparatus

Abstract

Disclosed is a technology related to a compact radiation detection apparatus used for aerial radiation measurement. The proposed compact radiation detection apparatus comprises: a cylindrical filter; and a detector assembly and a pump assembly fastened to both ends of the cylindrical filter. A negative pressure is formed in the inner space of the cylindrical filter by a vacuum pump, and accordingly, aerosol is continuously collected on the surface of the cylindrical filter. A detector located in the inner space of the cylindrical filter detects radiation emitted from the collected aerosol.

Description

Compact radiation detection device

[0001] A technology is disclosed relating to a miniature radiation detection device used for radiation measurement.

[0002] One method for measuring radiation involves capturing aerosols through filters driven by air pumps, then measuring the captured aerosols in a laboratory using precision measuring equipment to estimate nuclides or analyze the energy spectrum of the radiation. However, this method is limited by its inability to measure in real time.

[0003] Patent No. 2,327,710, filed and registered by the applicant, discloses a detection device that measures radiation while inhaling aerosol. Aerosol is captured through a filter, and radiation emitted from the captured aerosol is detected by a detector. While this device offers the advantage of simultaneously measuring aerosol concentration and radiation dose in real time, its structure, in which a filter captures aerosol from the air discharged from the outlet of the aerosol concentration sensor, presents a disadvantage in terms of sensing efficiency.

[0004] The proposed invention aims to improve the efficiency of a real-time airborne radiation detection device.

[0005] Furthermore, the proposed invention aims to make a real-time airborne radiation detection device smaller and lighter.

[0006] Furthermore, the proposed invention aims to present a novel structure of a real-time airborne radiation detection device having an aerosol capture function.

[0007] Furthermore, the proposed invention aims to present an improved structure of a real-time airborne radiation detection device having an aerosol capture function.

[0008] Furthermore, the proposed invention aims to provide a real-time airborne radiation detection device that is convenient to maintain.

[0009] Furthermore, the proposed invention aims to present a structure of a small radiation detection device that can be utilized as an Internet of Things sensor in various environments.

[0010] In order to achieve the above technical task, according to one aspect of the present invention, a negative pressure is formed in the internal space of a cylindrical filter by a pump, and a detector located in the internal space of the cylindrical filter detects radiation emitted from an aerosol captured on the surface of the cylindrical filter due to the flow of fluid formed thereby.

[0011] According to an additional aspect of the invention, the pump assembly and the detector assembly may be detachably fastened to each end of the filter section.

[0012] According to an aspect of the additional invention, a vacuum pump may be employed to create negative pressure in the internal space of the filter.

[0013] According to a further aspect of the proposed invention, the detector is supported and fixed such that the center of the detector surface is located near the center on the central axis of the filter having a cylindrical shape.

[0014] According to the present invention, the function of capturing aerosols for precision measurement and the function of detecting airborne radiation in real time can be integrated into a single device through a structure that captures aerosols through a cylindrical filter connected to a pump and detects radiation through a detector located within the internal space of the filter. Furthermore, the detection efficiency can be improved by combining the shape of the detection area of ​​the detector with the cylindrical filter.

[0015] Furthermore, according to the present invention, since the vacuum pump continues to operate even when a large amount of aerosol is captured in the filter, pump failure or loss of captured aerosol can be avoided. The pump assembly, filter unit, and detector assembly are each detachably connected to a structure that not only facilitates the precise measurement of captured aerosol by separating the filter unit, but also facilitates maintenance when a component fails or reaches the end of its lifespan.

[0016] Furthermore, the present invention provides a structure suitable for a small and lightweight aerial radiation detection device, so that the detection device according to the present invention can be suitable for mounting on a drone that is sensitive to the load weight.

[0017] FIG. 1 is a perspective view illustrating the exterior of a small radiation detection device according to one embodiment.

[0018] Fig. 2 is a perspective view showing the configuration of the filter unit in the embodiment illustrated in Fig. 1.

[0019] Figure 3 is a cross-sectional view illustrating the configuration of one embodiment of a pump assembly.

[0020] FIG. 4 is a perspective view illustrating an example of a detector assembly in the embodiment illustrated in FIG. 1.

[0021] FIG. 5 is a cross-sectional view of a small radiation detection device according to one embodiment, taken along a plane passing through the central axis of only the filter section.

[0022] The aforementioned and additional aspects are concretized through embodiments described with reference to the attached drawings. It is understood that various combinations of components of each embodiment are possible within the embodiment or with components of other embodiments, as long as there is no other mention or mutual contradiction. Based on the principle that an inventor can appropriately define the concept of terms to best describe his or her invention, the terms used in this specification and claims should be interpreted with meanings and concepts consistent with the disclosed content or proposed technical ideas. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0023] <Description of the invention in claim 1>

[0024] According to one aspect, a negative pressure is formed in the internal space of a cylindrical filter by a pump, and accordingly, a detector located in the internal space of the cylindrical filter detects radiation emitted from an aerosol captured on the surface of the cylindrical filter. Fig. 1 is a perspective view illustrating the exterior of a small radiation detection device according to one embodiment to which this aspect is applied. As illustrated, the small radiation detection device according to one embodiment includes a filter unit (100), a pump assembly (300), and a detector assembly (500).

[0025] The filter unit (100) has a cylindrical shape and includes a filter on at least a portion of the outer surface. The pump assembly (300) is connected to one end of the filter unit (100) and provides negative pressure to the filter unit (100). The detector assembly (500) is connected to the other end of the filter unit (100) and detects radiation from an aerosol captured by the filter of the filter unit (100) in the internal space of the filter unit (100) according to the negative pressure formed by the pump assembly (300).

[0026] <Description of the invention in claim 2>

[0027] FIG. 2 is a perspective view illustrating the configuration of a filter unit in the embodiment illustrated in FIG. 1. In one embodiment, the filter unit (100) includes a cylindrical filter housing (120) and a filter (140) mounted on a portion of the outer circumference thereof. In the illustrated embodiment, the filter (140) is widely mounted in the central portion of the filter housing (120) excluding the outer circumferences at both ends. The filter (140) may be one of a membrane filter, a pre-filter, a HEPA filter, and a medium filter. The filter housing (120) supports the filter (140) from the inside so as to withstand the negative pressure inside.

[0028] <Description of the invention in claim 3>

[0029] According to an additional aspect of the invention, the pump assembly and the detector assembly may be detachably fastened to both ends of the filter unit, respectively. As illustrated, the filter unit (100) has a pump fastening hole (121) formed at one end to which the pump assembly (300) is fastened, and a detector fastening hole (123) formed at the other end to which the detector assembly (500) is fastened. Screw grooves are formed in the pump fastening hole (121) and the detector fastening hole (123), respectively, to which the pump assembly (300) and the detector assembly (500) are threaded. In the illustrated embodiment, the pump fastening hole (121) side is open.

[0030] <Description of the invention in claim 4>

[0031] According to another aspect of the invention, a vacuum pump may be employed to provide negative pressure within the internal space of the filter. Fig. 3 is a cross-sectional view illustrating the configuration of one embodiment of a pump assembly employing this aspect. As illustrated, the pump assembly (300) according to one embodiment includes a vacuum pump (340), a circuit board (360), and a battery (380).

[0032] The vacuum pump (340) pumps air from the intake port (310) to the exhaust port (320) to provide negative pressure to the internal space of the cylindrical filter. Due to the negative pressure formed in the internal space of the filter, aerosol is captured on the filter surface and the captured aerosol is not released. When a general pump is applied, if the amount of captured aerosol increases, the pump may stop, causing the captured aerosol to be released or the amount of aerosol captured may be limited. The vacuum pump is advantageous in capturing aerosol for radiation measurement because the pump does not stop even when the amount of captured aerosol increases and the filter surface is almost blocked. A driving circuit for driving a motor (341) of the vacuum pump is formed on the circuit board (360). In addition, a power conversion circuit or the like may be formed on the circuit board (360). In the illustrated embodiment, the battery (380) is a lithium-ion battery and supplies power required for the operation of the pump assembly (300). The vacuum pump (340) can be driven to continue to operate before the power is turned off, for example, even if the detector assembly (500) is separated from the filter unit (100).

[0033] <Description of the invention in claim 5>

[0034] The vacuum pump (340), the circuit board (360), and the battery (380) are supported and fixed to the pump housing (390). In the illustrated embodiment, a first fastening portion (391) is formed on one side of the pump housing (390) of the pump assembly (300) to be fastened to one end of the filter portion (100). In the illustrated embodiment, the first fastening portion (391) is threadedly fastened to the pump fastening hole (121) of the filter portion (100). In addition, a first partition wall (393) is formed to close the filter portion (100) toward the first fastening portion (391) of the pump housing (390). The partition wall that closes the filter portion (100) toward the pump assembly (300) may be provided in the filter portion (100). For example, the partition wall may be provided on the inside of the filter (100) where the pump fastening hole (121) is formed. An intake port (310) is formed in the center of the first bulkhead (393). The inlet of the vacuum pump (340) is connected to this intake port (310) through a pipe. An exhaust port (320) is formed at the bottom of the pump housing (390) of the pump assembly (300). The outlet of the vacuum pump (340) is connected to this exhaust port (320) through a pipe.

[0035] <Description of the invention in claims 6 and 7>

[0036] FIG. 4 is a perspective view illustrating an example of a detector assembly in the embodiment illustrated in FIG. 1. As illustrated, a detector assembly (500) according to one embodiment includes a detector (520) and a multi-channel analyzer (540). In one embodiment, the detector (520) may be a CZT (CdZnTe) quasi-hemispherical detector. Among gamma-ray detectors, a CZT detector is suitable for room temperature gamma-ray detection, a Ge detector is suitable for high-resolution gamma-ray detection in a liquid nitrogen-cooled state, and a NaI detector is suitable for low-resolution gamma-ray detection. Since the proposed invention aims for a compact device, a CZT detector is adopted. This CZT detector is a compact, broadband semiconductor detector. Considering the difficulty of manufacturing a spherical shape of a hemispherical detector, it has a cubic shape, but has a structure in which a positive contact is located at the center of a flat surface and the remaining surface of the cube is grounded. The electric field is substantially radial and is much stronger near the positive contact, but gamma-ray collection occurs mostly on the remaining surface of the large cube. In one embodiment, the detector (520) is a DM500 CdZnTe detector from Ritec.

[0037] A multi-channel analyzer (MCA: Multi-Channel Analyzer) (540) generates radiation spectrum information from the output of a detector (520). The multi-channel analyzer (540) analyzes the detection signal output from the detector (520) and can output the detection frequency of radiation having an energy value within a set range in each channel. In the illustrated embodiment, the multi-channel analyzer (540) is a MCA527microE product from GBS Elektronic GmbH, Germany.

[0038] In the presented embodiment, the multi-channel analyzer (540) can operate in one of two modes: pulse height analysis (PHA) mode and multi-channel scaling (MCS) mode. In pulse height analysis (PHA) mode, the received pulses are characterized based on the amplitude (peak voltage) of the signal output from the detector. Each channel is assigned according to the range of amplitudes, and the output spectrum is a histogram of the pulse counts per channel. In multi-channel scaling (MCS) mode, the multi-channel analyzer (540) records the pulse count rate over time. Unlike pulse height analysis (PHA), multi-channel scaling (MCS) does not distinguish between pulses with different amplitudes. Instead, it records all counts measured on one channel for a set time interval and then switches to the next channel to record subsequent time intervals, etc.

[0039] The detector assembly (500) is fastened to the other end of the filter unit (100). In the illustrated embodiment, the detector assembly (500) is coupled to the filter unit by threading the second fastening portion (550) into the pump detector fastening hole (123) of the filter unit (100). Additionally, a second partition wall (570) is formed to close the filter unit (100) toward the second fastening portion (550) of the detector assembly (500). The partition wall that closes the filter unit (100) toward the pump assembly (300) may be provided in the filter unit (100). For example, the partition wall may be provided on the inside of the filter housing (120) in which the detector fastening hole (123) is formed.

[0040] <Description of the invention in claim 8>

[0041] According to an additional aspect of the proposed invention, the detector is supported and fixed so that the center of the detector surface is located near the center on the central axis of the filter having a cylindrical shape. FIG. 5 is a cross-sectional view of only the filter unit (100) in a small radiation detection device according to an embodiment along a plane passing through the central axis to explain this aspect. In order to increase the detection efficiency of the radiation detection device, it is preferable that the detector (500) and the filter unit (10) have a positional relationship such that the average distance between the detection area of ​​the detector (500) and the inner surface of the filter (140) is minimized. In the presented embodiment, since the detection area of ​​the detector (520) is approximately hemispherical, the filter housing (120) is preferably shaped to surround the detection area of ​​the detector (500) along the shape of the detection area, i.e., hemispherical. However, since it is difficult to install a hemispherical filter having a center on the rear surface of the detector, it may be installed in a cylindrical or truncated cone shape as in the illustrated embodiment. As illustrated, the surface center of the hexahedral detector (520) is supported and fixed so as to be located near the center on the central axis of the filter housing (120) having a cylindrical shape. Accordingly, the detection area of ​​the detector (520) and the center of the inner surface of the filter housing (120) are aligned with respect to the central axis, thereby improving detection efficiency.

[0042] <Description of the invention in claim 9>

[0043] Additionally, the detector assembly (500) may further include a connector (590) for externally outputting the output of the multi-channel analyzer (540). In the presented embodiment, the multi-channel analyzer (540) outputs data externally and receives operating power through the connector (590). In the illustrated embodiment, the connector (590) of the multi-channel analyzer (540) supports a USB interface. For example, the connector (590) may be connected to a connector of a data collector of a radiation measurement post. In another example, the connector (590) may be connected to a connector of a communication modem of a drone.

[0044] While the present invention has been described above through embodiments illustrated with reference to the attached drawings, it is not limited thereto and should be construed to encompass various modifications that would be readily apparent to those skilled in the art. The scope of the patent claims is intended to encompass such modifications.

Claims

1. A filter part having a cylindrical shape and including a filter on at least a portion of the outer surface; A pump assembly that is connected to one end of the filter section and provides negative pressure to the filter section; A detector assembly connected to the other end of the filter section and detecting radiation emitted from an aerosol captured in the filter of the filter section in the internal space of the filter section according to the negative pressure formed by the pump assembly; A small radiation detection device including:

2. In claim 1, the filter part: A small radiation detection device comprising a filter, which is one of a membrane filter, a pre-filter, a HEPA filter, and a medium filter, and a cylindrical filter housing that supports the filter against internal negative pressure.

3. In claim 1, a small radiation detection device in which the pump assembly and the detector assembly are detachably connected to one end and the other end of the filter section, respectively.

4. In claim 1, the pump assembly: A small radiation detection device comprising a vacuum pump, a circuit board having a driving circuit for driving the vacuum pump formed thereon, and a battery.

5. In claim 4, the pump assembly: A small radiation detection device including a first fastening part fastened to one end of the filter part, an intake port formed toward the first fastening part, an exhaust port formed downward, and a pump housing in which the vacuum pump, circuit board, and battery are supported and fixed in the internal space.

6. In claim 1, the detector assembly: A compact radiation detection device comprising a detector and a multi-channel analyzer for generating radiation spectrum information from the detector output.

7. A miniature radiation detection device according to claim 6, wherein the detector is a CZT quasi-hemispherical detector.

8. A small radiation detection device according to claim 7, wherein the center of the detector surface is supported and fixed so as to be located near the center on the central axis of a filter portion having a cylindrical shape.

9. In claim 1, the detector assembly: A connector for externally outputting the output of a multi-channel analyzer. A small radiation detection device further comprising:

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