Radioactivity detector, radioactivity detection method and detector assembly

Abstract

The invention discloses a radioactivity detector, a radioactivity detection method and a detector assembly, and belongs to the field of radioactivity detectors, the radioactivity detector comprises a shell, a packaging part, a gas detector, a motor focusing ring and a signal reading device, the shell is internally provided with a test cavity, the shell is provided with a window communicated with the test cavity, the packaging part covers the window, and the gas detector is arranged in the test cavity. The packaging part is configured to allow rays to penetrate through, the gas detector is installed on the inner wall, away from the window, in the testing cavity, the electrode focusing ring is installed on the inner wall, away from the window, in the testing cavity, the electrode focusing ring is arranged around the gas detector, and the signal reading device is installed on the shell. And the signal reading device is used for reading a detection result of the gas detector. According to the invention, the electrode focusing ring is arranged to generate a repulsive electric field, electrons are restrained in the detection range of the gas detector, electron collection of the gas detector can be enhanced, and the space sensitivity in the test cavity can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radioactive detection devices, and in particular to a radioactive detection instrument, a radioactive detection method and a detection instrument component. Background Art

[0002] In order to reduce unnecessary contamination of personnel, environment and equipment by radioactive substances and ensure the safe use of nuclear energy, nuclear power plants need to monitor areas that may be contaminated by radioactivity, including work surfaces, equipment surfaces, walls, floors and human bodies. The objects of radioactive surface contamination monitoring in nuclear power plants mainly include α and β radioactive surface contamination. Radiation safety staff need to use appropriate instruments for monitoring to ensure the accuracy and effectiveness of monitoring.

[0003] A ray detection device is disclosed in the related art, including a shell and a field cage, a photoelectric detector and a gas detector located in the shell. A window is provided at the upper end of the shell, an incident film and a supporting net are connected at the window, a cathode electrode is provided below the incident film, a field cage is provided below the cathode electrode, and a gas detector is provided below the field cage. The field cage is used to form a uniform drift electric field. The photoelectric detector is located between the outer wall of the field cage and the inner wall of the shell. The fluorescence generated by the sample in the test cavity can pass through the hollow part of the field cage and be detected by the photoelectric detector. The photoelectric detector is used to measure the time zero point of the particle incident in the sample, and the gas detector is used to measure the time, position and amplitude of the particle ionization signal in the sample reaching the gas detector plane. In this ray detection device, the effective detection area of ​​the ray detection device is the projection area of ​​the field cage on the incident film, and the photoelectric detector is provided between the outer wall of the field cage and the inner wall of the shell, so that the ratio of the area of ​​the effective detection area of ​​the ray detection device to the cross-sectional area of ​​the shell is smaller, and the part of the radioactive material to be detected is easily located outside the effective detection area. When the radioactive material to be detected is subjected to nuclear radiation detection, it is easy to miss the detection, and the reliability is poor. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a radioactivity detector without a field cage structure, adopting an electrode focusing ring design, having a compact structure, low cost and high reliability.

[0005] A radioactivity detector according to an embodiment of the present invention includes:

[0006] A shell, wherein a test cavity is disposed in the shell, and a window communicating with the test cavity is disposed on the shell;

[0007] A packaging member, covering the window, the packaging member is used to seal the window, and the packaging member is configured to allow radiation to pass through;

[0008] A gas detector is installed on an inner wall of the test chamber away from the window;

[0009] An electrode focusing ring is mounted on an inner wall of the test chamber away from the window, the electrode focusing ring is arranged around the gas detector and is configured to form an electric field for confining electrons;

[0010] A signal reading device is installed on the housing, and is used to read the detection result of the gas detector.

[0011] A radioactivity detector according to an embodiment of the present invention has at least the following beneficial effects:

[0012] The radioactive material on the surface of the object to be detected releases radioactive particles into the test cavity, and the gas in the test cavity is ionized to produce positive ions and electrons; under the action of the electric field in the test cavity, the positive ions move toward the inner wall of the shell, and the electrons move toward the gas detector. A repulsive electric field is generated around the electrode focusing ring, which confines the electrons within the detection range of the gas detector. After the gas detector collects the electrons, it forms a signal and transmits it to the signal reading device; the electron collection of the gas detector can be enhanced, the spatial sensitivity in the test cavity can be improved, and the detection dead zone in the test cavity can be reduced. The ratio of the effective detection area of ​​the radioactive detector to the cross-sectional area of ​​the shell is large, and it is not easy to miss the detection when the radioactive material to be detected is tested for nuclear radiation. The overall structure is relatively compact, the cost is low, and the reliability is high.

[0013] According to some embodiments of the present invention, the package includes an incident diaphragm and a first supporting net, the incident diaphragm and the first supporting net are installed at the window, the first supporting net supports the incident diaphragm, and the incident diaphragm is configured to allow β rays to pass through or to allow α rays and β rays to pass through.

[0014] According to some embodiments of the present invention, the housing is provided with a first channel and a second channel communicating with the test cavity, the first channel is used for air intake, the second channel is used for air outlet, a first valve for controlling the opening and closing of the first channel is provided at the first channel, and a second valve for controlling the opening and closing of the second channel is provided at the second channel;

[0015] Wherein, the gas detector is a gas flow type gas detector, the first channel and the second channel are in an open state, and the first channel is connected to an external gas source through a pipeline;

[0016] Alternatively, the gas detector is a gas-tight type gas detector, and the first channel and the second channel are in a closed state.

[0017] According to some embodiments of the present invention, the radiation detector also includes a protective cover, a switch door and a second supporting net, the protective cover includes a accommodating cavity with an open lower end, the protective cover and the second supporting net cover the window of the outer shell, the open end of the accommodating cavity faces the window, the second supporting net is used to support the object to be tested, the protective cover is provided with an entrance and exit connected to the accommodating cavity, and the switch door can openably cover the entrance and exit.

[0018] According to some embodiments of the present invention, the radioactivity detector is configured as follows: the housing is used for grounding, the gas detector is used for connecting a positive voltage, and the electrode focusing ring is used for connecting a negative voltage.

[0019] A radioactivity detection method according to an embodiment of the present invention, applied to the radioactivity detector, comprises the following steps:

[0020] Allowing radioactive particles released by the object to be tested to enter the test cavity;

[0021] Ionizing the gas in the test chamber to generate positive ions and electrons;

[0022] The electrons are confined within the detection range of the gas detector by a repulsive electric field formed by the electrode focusing ring;

[0023] The signal formed after the gas detector collects the electrons is read by a signal reading device.

[0024] A radioactivity detection method according to an embodiment of the present invention has at least the following beneficial effects:

[0025] The radioactive material on the surface of the object to be detected releases radioactive particles into the test cavity, and the gas in the test cavity is ionized to produce positive ions and electrons; under the action of the electric field in the test cavity, the positive ions move toward the inner wall of the shell, and the electrons move toward the gas detector. A repulsive electric field is generated around the electrode focusing ring, which confines the electrons within the detection range of the gas detector. After the gas detector collects the electrons, it forms a signal and transmits it to the signal reading device; the ratio of the effective detection area of ​​the radioactivity detector to the cross-sectional area of ​​the shell is large, and it is not easy to miss the detection when the radioactive material to be detected is tested for nuclear radiation. The overall structure is relatively compact, the cost is low, and the reliability is high.

[0026] A detector assembly according to an embodiment of the present invention includes a plurality of the above-mentioned radioactive detectors, wherein the plurality of the above-mentioned radioactive detectors are detachably connected, and the windows of the plurality of the above-mentioned radioactive detectors are all exposed and face the same side.

[0027] A detector assembly according to an embodiment of the present invention has at least the following beneficial effects:

[0028] The radioactive material on the surface of the object to be detected releases radioactive particles into the test cavity, and the gas in the test cavity is ionized to produce positive ions and electrons; under the action of the electric field in the test cavity, the positive ions move toward the inner wall of the shell, and the electrons move toward the gas detector. A repulsive electric field is generated around the electrode focusing ring, which confines the electrons within the detection range of the gas detector. After the gas detector collects the electrons, it forms a signal and transmits it to the signal reading device; the electron collection of the gas detector can be enhanced, the spatial sensitivity in the test cavity can be improved, and the detection dead zone in the test cavity can be reduced. The ratio of the effective detection area of ​​the radioactive detector to the cross-sectional area of ​​the shell is large, and it is not easy to miss the detection when the radioactive material to be detected is tested for nuclear radiation. The overall structure is relatively compact, and the frame of the shell can be set narrower, thereby reducing the splicing dead zone, which is conducive to the detachable connection of multiple radioactive detectors to expand the application, with low cost and high reliability.

[0029] Combining and using multiple radioactive detectors together can increase the detection area and meet the various radioactive surface contamination detection needs of nuclear power plants.

[0030] According to some embodiments of the present invention, the radiation detector is provided with a first connecting plate and a second connecting plate, the first connecting plate is provided with a first connecting hole for the locking member to pass through, and the second connecting plate is provided with a second connecting hole for the locking member to pass through;

[0031] The two adjacent radioactivity detectors are respectively a first detector and a second detector, and the first connecting plate of the first detector and the second connecting plate of the second detector are detachably connected via a locking piece.

[0032] According to some embodiments of the present invention, the first connecting plate includes a first connecting portion and a first positioning portion that are bent and connected, the first connecting portion is connected to the first detector, and the first connecting hole is provided on the first connecting portion; the second connecting plate includes a second connecting portion and a second positioning portion that are bent and connected, the second connecting portion is connected to the second detector, and the second connecting hole is provided on the second connecting portion, the first positioning portion abuts against the second detector and the second connecting portion, and the second positioning portion abuts against the first detector and the first connecting portion.

[0033] According to some embodiments of the present invention, the first detector and the second detector are connected via a connecting handle, the connecting handle comprising a handle portion and two third connecting portions, the two third connecting portions are bent and connected to the two ends of the handle portion, the handle portion is spaced apart from the first detector and the second detector, both of the two third connecting portions are provided with limiting grooves, both of the three third connecting portions are provided with third connecting holes that penetrate through the side walls of the limiting grooves and are used for the locking piece to pass through, and the first connecting plate and the second connecting plate are limitedly connected in the limiting grooves.

[0034] Additional aspects and advantages of the invention will be set forth in part in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0036] Figure 1 It is a structural schematic diagram of a first radioactivity detector according to an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of the installation of a gas detector and an electrode focusing ring in a radioactivity detector according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic structural diagram of a first support network of a radioactivity detector according to an embodiment of the present invention;

[0039] Figure 4 is a structural schematic diagram of a second radioactivity detector according to an embodiment of the present invention;

[0040] Figure 5 A schematic structural diagram of a third radioactivity detector according to an embodiment of the present invention;

[0041] Figure 6 It is a structural schematic diagram of a first detector assembly according to an embodiment of the present invention;

[0042] Figure 7 for Figure 6 A magnified view of middle;

[0043] Figure 8 A schematic diagram of the structure of a radioactivity detector according to an embodiment of the present invention;

[0044] Fig. 9 is a structural schematic diagram of a second detector assembly according to an embodiment of the present invention;

[0045] Fig.10 It is a structural schematic diagram of a connecting handle of a second detector assembly according to an embodiment of the present invention;

[0046] Fig.11Schematic diagram of the particle incident direction and electron movement direction during the detection process of the radioactivity detector of an embodiment of the present invention.

[0047] Figure Number:

[0048] 100, housing; 110, test chamber; 120, window; 130, first channel; 140, second channel; 150, handle; 160, first control display; 170, bracket;

[0049] 200, packaging component; 210, incident diaphragm; 220, first supporting net;

[0050] 300, gas detector; 310, electrode focusing ring; 320, signal reading device;

[0051] 400, protective cover; 410, accommodating chamber; 420, entrance and exit; 430, second supporting net; 440, switch door; 450, second control display;

[0052] 500, first detector; 510, first connecting plate; 511, first connecting portion; 512, first positioning portion; 513, first connecting hole;

[0053] 600, second detector; 610, second connecting plate; 611, second connecting portion; 612, second positioning portion; 613, second connecting hole;

[0054] 700, connecting handle; 710, handle portion; 720, third connecting portion; 721, limiting groove; 722, third connecting hole. DETAILED DESCRIPTION

[0055] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0056] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] See also Figure 1 , Figure 2 and Figure 3 A radioactive detector according to an embodiment of the present invention comprises a housing 100, a package 200, a gas detector 300, an electrode focusing ring 310 and a signal reading device 320. A test cavity 110 is arranged in the housing 100, and a window 120 is arranged on the housing 100, and the window 120 is connected to the test cavity 110. The package 200 covers the window 120, and the package 200 is used to seal the window 120, and the package 200 can allow rays to pass through. The gas detector 300 is installed on the inner wall of the test cavity 110 away from the window 120, and the electrode focusing ring 310 is installed on the inner wall of the test cavity 110 away from the window 120. The electrode focusing ring 310 is arranged around the gas detector 300, and the electrode focusing ring 310 is used to form an electric field that confines electrons. The signal reading device 320 is installed on the housing 100, and the signal reading device 320 can read the detection result of the gas detector 300, the signal reading device 320. When in use, the housing 100 is grounded and used as a cathode, the gas detector 300 is connected to a positive high voltage and used as an anode, and the electrode focusing ring 310 is connected to a negative voltage.

[0059] The electrode focusing ring 310 is connected to a negative voltage to generate a negative electric field, which has a repulsive effect on the electrons in the test chamber 110, and repels the electrons around the electrode focusing ring 310 away from the electrode focusing ring 310, so that the electrons originally located outside the sensitive area of ​​the gas detector 300 can be repelled by the electrode focusing ring 310 into the sensitive area of ​​the gas detector 300, thereby increasing the signal collection of the radioactivity detector.

[0060] The radioactive material on the surface of the object to be tested releases radioactive particles into the test chamber 110, and the gas in the test chamber 110 is ionized to generate positive ions and electrons; see Fig.11 Under the action of the electric field in the test cavity 110, positive ions move toward the inner wall of the shell 100, and electrons move toward the gas detector 300. A repulsive electric field is generated around the electrode focusing ring 310, which confines the electrons within the detection range of the gas detector 300. The gas detector 300 collects the electrons and forms a signal to transmit to the signal reading device 320; the electron collection of the gas detector 300 can be enhanced, the spatial sensitivity in the test cavity 110 can be improved, and the detection dead zone in the test cavity 110 can be reduced. The ratio of the effective detection area of ​​the radioactive detector to the cross-sectional area of ​​the shell 100 is large, and it is not easy to miss the detection when the radioactive material to be detected is tested for nuclear radiation. The overall structure is relatively compact, the cost is low, and the reliability is high.

[0061] In some embodiments, see Figure 1 and Figure 3 The package 200 includes an incident diaphragm 210 and a first supporting net 220. The incident diaphragm 210 and the first supporting net 220 are installed at the window 120. The first supporting net 220 supports the incident diaphragm 210. The incident diaphragm 210 is configured to allow β rays to pass through or to allow α rays and β rays to pass through. According to different detection requirements (only β, α and β), the incident diaphragm 210 can be made of different materials with a thickness of 1μm to 20μm. There is a layer of first supporting net 220 under the incident diaphragm 210. The transmittance (ratio of hole area to net area) of the first supporting net 220 is greater than 90%. The first supporting net 220 is used to fix the incident diaphragm 210 and increase the airtightness of the test chamber 110.

[0062] The incident diaphragm 210 may be made of polyimide, silicon nitride, polyester, mica, etc. The first support mesh 220 may be made of stainless steel, carbon fiber, titanium alloy, aluminum alloy, etc.

[0063] In some embodiments, see Figure 1The housing 100 is provided with a first channel 130 and a second channel 140, the first channel 130 and the second channel 140 are connected to the test chamber 110, the first channel 130 is used for air intake, and the second channel 140 is used for air discharge. A first valve is provided at the first channel 130, and the first valve can control the opening and closing of the first channel 130. A second valve is provided at the second channel 140, and the second valve can control the opening and closing of the second channel 140.

[0064] The gas detector 300 can be a gas flow type gas detector 300, the first channel 130 and the second channel 140 are in an open state, and the first channel 130 is connected to an external gas source through a pipeline; the gas source can be selected according to different detection modes. Inert gases such as argon and neon can be mixed with single-component gases and polyatomic molecular gases in different proportions, such as carbon dioxide, isobutane, methane, etc.

[0065] The gas detector 300 may also be a closed-gas type gas detector 300, in which the first channel 130 and the second channel 140 are in a closed state.

[0066] The gas detector 300 is a gas flow type gas detector 300 or a gas closed type gas detector 300, and the corresponding radioactive detector is a gas flow mode or a gas closed mode. Different types of gas detectors 300 and radioactive detectors with different working modes can be selected according to different detection requirements.

[0067] The first channel 130 and the second channel 140 are provided on the shell 100, and the opening and closing of the first channel 130 and the second channel 140 can be controlled, so that the shell 100 can be applied to the radioactive detector in the air flow mode and the radioactive detector in the air-locking mode. The shell 100 has strong applicability and is easy to process.

[0068] In some embodiments, see Figure 1 The housing 100 is the main supporting structure of the instrument. The cavity is designed with a detector gas flange interface (first channel 130 and second channel 140), a high-voltage interface (for external positive high voltage of the gas detector 300), a detector mounting and fixing interface (for installing the gas detector 300), and a readout electronics mounting interface (for installing the signal reading device 320). A window 120 for radiation incidence is cut on the radiation-sensitive surface of the instrument, and an incident diaphragm 210 and a first supporting net 220 are installed. The housing 100 is sealed as a whole, grounded, and used as a cathode. The outer surface of the housing 100 is smoothed to reduce radioactive contamination of the instrument itself and facilitate contamination removal.

[0069] In some embodiments, see Figure 1 and Figure 2The gas detector 300 is a two-dimensional position-sensitive microstructure gas detector 300, connected to positive high voltage, sensitive to the detection target α, β contamination, and insensitive to the γ background interference. The two-dimensional position-sensitive microstructure gas detector 300 can be selected from a microgrid gas detector 300, a multi-layer grid gas detector 300, a gas electron multiplier, a resistive micro-well detector, etc. The corresponding readout electrode is used to realize the two-dimensional position sensitivity of the detector to meet the detection of the contamination size and position, such as strip readout, pixel readout, etc.

[0070] In some embodiments, see Figure 1 and Figure 2 The signal reading device 320 may be a readout electronics, which is connected to the readout pole of the gas detector 300 and is installed outside the housing 100, and mainly includes a front-end electronics module, a waveform digitization module, and a back-end data processing system. The readout electronics may be connected to the host computer for communication, and the readout electronics reads the detection result of the gas detector 300 and sends it to the host computer.

[0071] In some embodiments, see Figure 1 , the incident diaphragm 210 is set to have a size of 350mm*150mm, the material is aluminum-plated Mylar film, and the thickness is 5μm. The size of the first support net 220 is 355mm*155mm, the material is aluminum alloy, the thickness is 1mm, and the transmittance is 95%. The size of the shell 100 is set to 360mm*160mm*50mm, and the material is aluminum alloy. The gas detector 300 adopts a gas flow micro-grid gas detector 300, whose sensitive surface size is 320mm*120mm, and the readout method is XY two-dimensional strip readout (a total of 22 readouts), and the working gas is a mixed gas of 95% argon and 5% carbon dioxide by volume. The electrode focusing ring 310 is a 340mm*140mm copper wire frame. The signal reading device 320 is a readout electronics, with a total of 22 readout signals, using a front-end electronics module, a waveform digitization module and a back-end data processing module manufactured based on ASIC, and can communicate and control with a host computer. The overall structure is compact, the cost is low and the reliability is high.

[0072] In some embodiments, see Figure 4 The radiation detector includes a handle 150, which is connected to the housing 100 and can improve the portability of the radiation detector.

[0073] The radioactivity detector further comprises a first control display 160 , which is electrically connected to the gas detector 300 and the readout electronics, and is used for controlling the measurement process and displaying the detection results.

[0074] In some embodiments, see Figure 4The size of the incident diaphragm 210 is set to 170mm*100mm, the material is aluminum-plated Mylar film, and the thickness is 5μm. The size of the first support net 220 is 175mm*105mm, the material is aluminum alloy, the thickness is 1mm, and the transmittance is 90%. The size of the shell 100 is 180mm*500mm*110mm, and the material is aluminum alloy. The gas detector 300 adopts a closed-air micro-grid gas detector 300, whose sensitive surface size is 150mm*80mm, and the readout method is XY two-dimensional strip readout (a total of 15 readouts), and the working gas is a mixed gas of 97% argon and 3% isobutane by volume. The electrode focusing ring 310 is a 170mm*100mm copper wire frame. The signal reading device 320 is a readout electronics, with a total of 15 readout signals, using a front-end electronics module, a waveform digitization module, and a back-end data processing module based on ASIC manufacturing. The first control display 160 is an information touch screen, which uses an LCD panel for display and can perform touch operations.

[0075] In some embodiments, see Figure 5 The radioactive detector further includes a protective cover 400, a switch door 440 and a second support net 430. The protective cover 400 includes a receiving chamber 410, and the lower end of the receiving chamber 410 is open. The protective cover 400 and the second support net 430 cover the window 120 of the housing 100, and the open end of the receiving chamber 410 faces the window 120. The second support net 430 is used to support the object to be tested. The protective cover 400 is provided with an entrance and exit 420, and the entrance and exit 420 is connected to the receiving chamber 410. The switch door 440 can be opened to cover the entrance and exit 420. When testing is required, the switch door 440 is opened, the object to be tested is placed on the second support net 430, and the switch door 440 is closed. The protective cover 400 can play a protective effect and reduce the release of nuclear radiation from the object to be tested.

[0076] A second control display 450 is also provided on the protective cover 400. The second control display 450 is electrically connected to the gas detector 300 and the readout electronics. The second control display 450 is used for controlling the measurement process and displaying the detection results.

[0077] A bracket 170 is disposed below the housing 100 , and the bracket 170 supports the entire radiation detector.

[0078] In some embodiments, see Figure 5The incident diaphragm 210 is set to have a size of 450mm*450mm, and the material is aluminum-plated Mylar film with a thickness of 5μm. The size of the first support net 220 is 455mm*455mm, the material is aluminum alloy, the thickness is 1mm, and the transmittance is 95%. The size of the protective cover 400 is 500mm*500mm*400mm, the material is aluminum alloy, and the side door can be used to put in the tool to be tested. The size of the housing 100 is 500mm*500mm*50mm, and the material is aluminum alloy. The gas detector 300 adopts a gas flow type gas electron multiplier, and its sensitive surface size is 450mm*450mm. The readout method is pixel readout (a total of 275 readouts), and the working gas is a mixed gas of 90% argon and 10% carbon dioxide by volume. The electrode focusing ring 310 is a 470mm*470mm copper wire frame. The signal reading device 320 is a readout electronics, with a total of 275 readout signals, using a front-end electronics module, a waveform digitization module, and a back-end data processing module based on ASIC manufacturing, and can communicate and control with the host computer. The second control display 450 is an industrial tablet computer, which is placed above the measurement cavity to control the measurement process.

[0079] See also Figure 1 and Fig.11 A radioactivity detection method according to an embodiment of the present invention is applied to a radioactivity detector, comprising the following steps:

[0080] The radioactive particles released by the object to be detected enter the test cavity 110. The object to be detected is close to the window of the housing 100, and the object to be detected releases radioactive particles into the test cavity 110.

[0081] The radioactive particles ionize the gas in the test chamber 110 to generate positive ions and electrons. Under the action of the electric field in the test chamber 110, the positive ions move toward the housing 100 and the electrons move toward the gas detector 300.

[0082] The repulsive electric field formed by the electrode focusing ring 310 confines the electrons within the detection range of the gas detector 300 .

[0083] The signal generated after the gas detector 300 collects the electrons is read by the signal reading device 320 .

[0084] The radioactive material on the surface of the object to be detected releases radioactive particles into the test cavity 110, and the gas in the test cavity 110 is ionized to generate positive ions and electrons; under the action of the electric field in the test cavity 110, the positive ions move toward the inner wall of the shell 100, and the electrons move toward the gas detector 300. A repulsive electric field is generated around the electrode focusing ring 310, which confines the electrons within the detection range of the gas detector 300. After the gas detector 300 collects the electrons, it forms a signal and transmits it to the signal reading device 320; the ratio of the effective detection area of ​​the radioactive detector to the cross-sectional area of ​​the shell 100 is large, and it is not easy to miss the detection when the radioactive material to be detected is tested for nuclear radiation. The overall structure is relatively compact, the cost is low, and the reliability is high.

[0085] See also Figure 1 and Figure 6 A detector assembly according to an embodiment of the present invention includes a plurality of radioactive detectors, the plurality of radioactive detectors are detachably connected, and the windows 120 of the plurality of radioactive detectors are all exposed and face the same side.

[0086] The radioactive material on the surface of the object to be detected releases radioactive particles into the test cavity 110, and the gas in the test cavity 110 is ionized to generate positive ions and electrons; under the action of the electric field in the test cavity 110, the positive ions move toward the inner wall of the shell 100, and the electrons move toward the gas detector 300, and a repulsive electric field is generated around the electrode focusing ring 310, which confines the electrons within the detection range of the gas detector 300. After the gas detector 300 collects the electrons, it forms a signal and transmits it to the signal reading device 320; the electron collection of the gas detector 300 can be enhanced, the spatial sensitivity in the test cavity 110 can be improved, and the detection dead zone in the test cavity 110 can be reduced. The ratio of the effective detection area of ​​the radioactive detector to the cross-sectional area of ​​the shell 100 is large, and it is not easy to miss the detection when the radioactive material to be detected is subjected to nuclear radiation detection. The overall structure is relatively compact, and the frame of the shell 100 can be set narrower, thereby reducing the splicing dead zone, which is conducive to the detachable connection of multiple radioactive detectors to expand the application, with low cost and high reliability.

[0087] Combining and using multiple radioactive detectors together can increase the detection area and meet the various radioactive surface contamination detection needs of nuclear power plants.

[0088] In some embodiments, see Figure 6 , Figure 7 and Figure 8, a first connecting plate 510 and a second connecting plate 610 are provided on the radioactivity detector. A first connecting hole 513 is provided on the first connecting plate 510, and a second connecting hole 613 is provided on the second connecting plate 610. The two adjacent radioactivity detectors are respectively the first detector 500 and the second detector 600. The first connecting plate 510 of the first detector 500 and the second connecting plate 610 of the second detector 600 are detachably connected by a locking member, and the locking member may be a connecting bolt or a connecting pin. The first detector 500 and the second detector 600 are detachably connected by the locking member, which is convenient for disassembly and assembly. When multiple radioactivity detectors are combined and used together, the detection area can be increased to meet the various radioactive surface contamination detection requirements of nuclear power plants.

[0089] In some embodiments, see Figure 6 , Figure 7 and Figure 8 When the first detector 500 and the second detector 600 are connected along the width direction of the first detector 500, the first connecting plate 510 is provided at both ends of the first detector 500 along the length direction, and the second connecting plate 610 is provided at both ends of the second detector 600 along the width direction of the second detector 600. The second detector 600 is connected in the width direction of the first detector 500, the overall width of the detector assembly is increased, the detection area is increased, and various radioactive surface contamination detection requirements of nuclear power plants are met.

[0090] In some embodiments, see Figure 6 , Figure 7 and Figure 8 The first connecting plate 510 includes a first connecting portion 511 and a first positioning portion 512 that are bent and connected, the first connecting portion 511 is connected to the first detector 500, and the first connecting hole 513 is provided on the first connecting portion 511. The second connecting plate 610 includes a second connecting portion 611 and a second positioning portion 612 that are bent and connected, the second connecting portion 611 is connected to the second detector 600, and the second connecting hole 613 is provided on the second connecting portion 611. The first positioning portion 512 abuts against the second detector 600 and the second connecting portion 611, and the second positioning portion 612 abuts against the first detector 500 and the first connecting portion 511. The first positioning portion 512 and the second positioning portion 612 are provided to facilitate the positioning of the first connecting plate 510 and the second connecting plate 610, facilitate the alignment of the first connecting hole 513 with the second connecting hole 613, and facilitate the disassembly and assembly of the first detector 500 and the second detector 600.

[0091] The first connection portion 511 and the first positioning portion 512 are arranged in an L shape, the first connection portion 511 is located at the edge of the first detector 500, and the first positioning portion 512 is protruded and connected to the first connection portion 511. The second connection portion 611 and the second positioning portion 612 are arranged in an L shape, the second connection portion 611 is located at the edge of the second detector 600, and the second positioning portion 612 is protruded and connected to the second connection portion 611.

[0092] The first positioning portion 512 and the second positioning portion 612 can limit the movement of the first detector 500 relative to the second detector 600 along the thickness direction of the first detector 500, and can also limit the movement of the first detector 500 relative to the second detector 600 along the length direction of the first detector 500, thereby ensuring the structural stability of the detector assembly during the detection process.

[0093] In some embodiments, see Figure 7 , Fig. 9 and Fig.10 The first detector 500 and the second detector 600 are connected by a connecting handle 700. The connecting handle 700 includes a handle portion 710 and two third connecting portions 720. The two third connecting portions 720 are bent and connected at both ends of the handle portion 710. The handle portion 710 is arranged at intervals from the first detector 500 and the second detector 600, which is convenient for human hand holding. The two third connecting portions 720 are both provided with a limiting groove 721, and the two third connecting portions 720 are both provided with a third connecting hole 722. The third connecting hole 722 penetrates the side wall of the limiting groove 721. The first connecting plate 510 and the second connecting plate 610 are limitedly connected in the limiting groove 721. The locking member is penetrated through the first connecting hole 513, the second connecting hole 613 and the third connecting hole 722. The first connecting plate 510, the second connecting plate 610 and the third connecting portion 720 are connected by the locking member.

[0094] The limiting groove 721 on the third connection part 720 can clamp the first connection plate 510 and the second connection plate 610, thereby limiting the separation of the first connection plate 510 and the second connection plate 610 along the width direction of the first detector 500, so that the detector assembly is firmly connected. The connecting handle 700 can ensure the stable connection of the detector assembly and increase the portability of the detector assembly.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A radioactivity detector, characterized in that: include: A shell, wherein a test cavity is disposed in the shell, and a window communicating with the test cavity is disposed on the shell; A packaging member, covering the window, the packaging member is used to seal the window, and the packaging member is configured to allow radiation to pass through; A gas detector is installed on an inner wall of the test chamber away from the window; An electrode focusing ring is mounted on an inner wall of the test chamber away from the window, the electrode focusing ring is arranged around the gas detector and is configured to form an electric field for confining electrons; A signal reading device is installed on the housing, and is used to read the detection result of the gas detector.

2. The radioactivity detector according to claim 1, characterized in that: The package includes an incident diaphragm and a first supporting net, wherein the incident diaphragm and the first supporting net are installed at the window, the first supporting net supports the incident diaphragm, and the incident diaphragm is configured to allow β rays to pass through or to allow α rays and β rays to pass through.

3. The radioactivity detector according to claim 1, characterized in that: The housing is provided with a first channel and a second channel connected to the test cavity, the first channel is used for air intake, the second channel is used for air outlet, a first valve for controlling the opening and closing of the first channel is provided at the first channel, and a second valve for controlling the opening and closing of the second channel is provided at the second channel; Wherein, the gas detector is a gas flow type gas detector, the first channel and the second channel are in an open state, and the first channel is connected to an external gas source through a pipeline; Alternatively, the gas detector is a gas-tight type gas detector, and the first channel and the second channel are in a closed state.

4. The radioactivity detector according to claim 1, characterized in that: It also includes a protective cover, a switch door and a second supporting net, the protective cover includes a accommodating cavity with an open lower end, the protective cover and the second supporting net cover the window of the shell, the open end of the accommodating cavity faces the window, the second supporting net is used to support the object to be tested, the protective cover is provided with an entrance and exit connected to the accommodating cavity, and the switch door can be opened to cover the entrance and exit.

5. The radioactivity detector according to claim 1, characterized in that: The radioactivity detector is configured as follows: the housing is used for grounding, the gas detector is used for connecting a positive voltage, and the electrode focusing ring is used for connecting a negative voltage.

6. A radioactivity detection method, applied to the radioactivity detector as claimed in any one of claims 1 to 4, characterized in that: The steps include: Allowing radioactive particles released by the object to be tested to enter the test cavity; Ionizing the gas in the test chamber to generate positive ions and electrons; The electrons are confined within the detection range of the gas detector by a repulsive electric field formed by the electrode focusing ring; The signal formed after the gas detector collects the electrons is read by a signal reading device.

7. A detector assembly, characterized in that: It comprises a plurality of radioactive detectors as described in any one of claims 1 to 3, wherein the plurality of radioactive detectors are detachably connected, and the windows of the plurality of radioactive detectors are all exposed and face the same side.

8. The detector assembly according to claim 7, characterized in that: The radiation detector is provided with a first connecting plate and a second connecting plate, the first connecting plate is provided with a first connecting hole for the locking member to pass through, and the second connecting plate is provided with a second connecting hole for the locking member to pass through; The two adjacent radioactivity detectors are respectively a first detector and a second detector, and the first connecting plate of the first detector and the second connecting plate of the second detector are detachably connected via a locking piece.

9. The detector assembly according to claim 8, characterized in that: The first connecting plate includes a first connecting portion and a first positioning portion that are bent and connected, the first connecting portion is connected to the first detector, and the first connecting hole is provided on the first connecting portion; the second connecting plate includes a second connecting portion and a second positioning portion that are bent and connected, the second connecting portion is connected to the second detector, and the second connecting hole is provided on the second connecting portion, the first positioning portion abuts against the second detector and the second connecting portion, and the second positioning portion abuts against the first detector and the first connecting portion.

10. The detector assembly according to claim 8, characterized in that: The first detector and the second detector are connected through a connecting handle, which includes a handle portion and two third connecting portions, wherein the two third connecting portions are bent and connected to the two ends of the handle portion, and the handle portion is spaced apart from the first detector and the second detector, and limiting grooves are provided on the two third connecting portions, and third connecting holes are provided on the two third connecting portions, which penetrate through the side walls of the limiting grooves and are used for the locking members to pass through, and the first connecting plate and the second connecting plate are limitedly connected in the limiting grooves.

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