An online alpha combination detector

Abstract

The online alpha combination detector of the application integrates ZnS(Ag) detector and PIPS (ion implantation type passivated silicon) detector; ZnS(Ag) and PIPS are not sensitive to environmental gamma rays, so that the device of the application has a lower background and a lower detection limit without additional shielding device; ZnS(Ag) is also not sensitive to beta rays, and the interference of beta rays on ZnS(Ag) can be ignored by reasonably setting the threshold value; for PIPS, the energy spectrum of beta rays is concentrated in the low energy region, and the interference of beta rays can also be excluded by energy spectrum analysis algorithm or improving the lower limit of the energy spectrum threshold; in this way, the influence of beta and gamma rays on the combination detector for measuring alpha particles is greatly reduced, and the detection accuracy of alpha particles is improved; the ZnS(Ag) detector is coupled with multiple PMTs, which further ensures the detection efficiency; the detection window structure benefits from the unique design and is easy to replace; the window materials such as aluminum foil, titanium foil and gold foil are flexibly adapted; the detector is resistant to strong acid and strong alkali and corrosion, and has a wider use scenario.

Description

Technical Field

[0001] This invention relates to the field of alpha detector technology, and more particularly to an online alpha combination detector. Background Technology

[0002] French physicist Henri Becquerel first discovered natural radioactivity in uranium salts, after which people began to study and utilize radionuclides. Alpha decay radionuclides account for a large proportion of these, and they are now widely used in medicine, aerospace, military, and energy fields. However, the risk of radioactive leakage is unavoidable during the research, production, storage, transportation, and application of these radionuclides.

[0003] Although research shows that alpha particles have weak penetrating power and lose energy rapidly when running in a medium, and are absorbed within a few centimeters of air; however, alpha particles have strong ionizing power, and once they enter the human body, they can directly damage internal organ tissue cells, causing tissue damage.

[0004] Therefore, to address the safety risks associated with the storage, transportation, or use of alpha radionuclides, locations where alpha radionuclide contamination or leakage may occur should be regularly inspected to ensure the health of relevant personnel. Alternatively, for areas already contaminated with alpha radionuclides, the degree of contamination should be assessed through detection, allowing for appropriate emergency measures to be taken. In these scenarios, the detection of alpha radionuclides becomes extremely important. Furthermore, alpha detectors can also be used to locate certain radioactive mineral deposits, groundwater, and address other geological issues through radioactive exploration by measuring the number of alpha particles produced by radon and its decay products, demonstrating broad application prospects.

[0005] Currently, commonly used alpha particle radiation detectors mainly include gas detectors, semiconductor detectors, and scintillator detectors. Gas detectors are more sensitive to beta and gamma rays, but have a high background, requiring additional shielding to achieve a lower detection limit. Among semiconductor detectors, traditional silicon surface barrier (SSB) detectors and diffused junction (DJ) detectors have large leakage currents and thick dead layers, resulting in lower on-site detection efficiency compared to scintillator detectors. Scintillator detectors have poor light transmittance but high luminous efficiency, leading to high detection efficiency, but their energy resolution is lower than that of semiconductor detectors. Except for ZnS (Ag) detectors, most are also highly sensitive to beta and gamma rays, which can affect the measurement results of alpha particles.

[0006] Furthermore, the actual detection environment of the detector is often accompanied by strong acids, strong alkalis and strong corrosion, while the existing publicly available alpha detectors cannot simultaneously achieve low detection limit, high detection efficiency, energy discrimination and resistance to harsh environments.

[0007] Therefore, those skilled in the art are dedicated to developing an online alpha combination detector to address the shortcomings of existing technologies. Summary of the Invention

[0008] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the existing scintillator detectors have poor energy spectral resolution, high sensitivity to β and γ rays, high background, and the detector detection environment is relatively harsh. The existing α detectors cannot simultaneously achieve low detection limit, high detection efficiency, energy discrimination performance and resistance to harsh environments.

[0009] To achieve the above objectives, this invention proposes an online α-combination detector, comprising a detector head threaded light-shielding film and bracket, a PIPS fixing support, a ZnS (Ag) detector, a PMT collimating plate, a PIPS detector, a PIPS detector fixing ring, a PIPS front encapsulation tube, a PMT, a PMT fixing component, an M3 copper pillar and sleeve, a spring, an electronic circuit board, a motherboard connecting copper pillar, a hexagonal copper pillar, a combination detector rear cover, a combination detector rear cover cable outlet plate, a combination detector sleeve, and a relative position fixing component;

[0010] The detector head threaded component, light-shielding film, and bracket of the combined detector include a head threaded component, a light-shielding film bracket, and a bottom threaded component.

[0011] The head threaded part of the combined detector is located at the outermost front end of the combined detector.

[0012] The outer layer of the light-shielding film support has threads, and there is a threaded engagement between it and the threaded part of the head of the combined detector, so that the two can fit tightly together.

[0013] The light-shielding membrane support is located between the head threaded component and the bottom threaded component;

[0014] The PIPS fixing support allows the PIPS detector to be fixed in the combined detector sleeve.

[0015] The combined detector sleeve is made of metal, the combined detector is in the shape of a concentric sleeve, and all the components of the combined detector are assembled inside the combined detector sleeve.

[0016] The front end of the combined detector sleeve can be fixed to the threaded part of the combined detector head, and the rear end of the combined detector sleeve can be fitted with the rear cover of the combined detector, thereby fixing the detector inside the sleeve of the combined detector.

[0017] The ZnS(Ag) detector is in the shape of a ring, and a PIPS detector is hollowed out and embedded in the center of the ZnS(Ag) ring.

[0018] The PIPS detector is fixed to the ZnS(Ag) detector by a PIPS detector fixing ring;

[0019] The front end of the combined detector is a ZnS(Ag) detector coupled with a PMT, and 2-6 PMTs are equally spaced around the PIPS detector.

[0020] The PIPS front-end package tube is located at the center of the front end of the PIPS detector;

[0021] The PMT fixing component is located at the rear of the PMT and secures the PMT.

[0022] Each PMT's socket is fixed to the structural component by screws. The structural component has an M3 copper pillar and a sleeve. A spring is fitted on the copper pillar. The diameter of the spring is larger than the diameter of the copper pillar, so that the copper pillar can be squeezed into the sleeve. This ensures that the spring always provides elastic support to the PMT, thereby ensuring that the PMT is always in close contact with the ZnS (Ag) detector.

[0023] The relative position fixing component is located at the front of the combined detector, with one side in contact with the ZnS(Ag) detector and the other side in contact with the PIPS detector, thereby fixing the relative position of the two.

[0024] The combined detector electronic circuit board includes: a PMT analog board, a power supply board, a digital board, and a PIPS processing board; all of the electronic circuit boards have holes.

[0025] The PIPS detector and the PIPS processing board are connected by wires. The PIPS detector outputs a positive pulse signal to the PIPS processing board for energy spectrum analysis, and the obtained energy spectrum data is then transmitted to the digital board.

[0026] The PMT outputs a negative pulse signal from its anode to the PMT analog board. After being amplified, compared, and shaped by the PMT analog board, the signal is then output as a TTL pulse signal to the digital board for pulse counting.

[0027] The digital board has an interface for communicating with the outside world and exchanging data;

[0028] The electronic circuit board and the back cover of the combined detector are fixed and connected by M3 copper pillars at a certain distance.

[0029] One end of the M3 copper pillar is connected to the PMT tube socket fixing component, and the other end passes through the PMT simulation board and connects to the main board connecting copper pillar.

[0030] The combined detector has a communication port on its rear cover, which allows it to transmit information to the outside world.

[0031] The combined detector has a power interface on its rear cover, allowing external power to be supplied to the detector.

[0032] Furthermore, the PIPS processing board includes signal conditioning and digital multichannel processing.

[0033] Furthermore, a reflective coating is added to the bottom surface of the relative position fixing component;

[0034] Furthermore, the digital board communicates with the outside world via an RS485 port;

[0035] Furthermore, the light-shielding film support can be unscrewed and replaced separately without disassembling the combined detector;

[0036] Furthermore, the metal material selected for the combined detector tube sleeve is 316L stainless steel;

[0037] Furthermore, the light-shielding film support of the combined detector can be replaced, and the material of the light-shielding film can be aluminum, titanium or gold;

[0038] By adopting the above scheme, the online α-combination detector disclosed in this invention has the following advantages:

[0039] (1) The online α-particle combination detector of the present invention integrates a ZnS(Ag) solid scintillator and a PIPS detector; thus, the present invention can perform energy spectrum measurement and nuclide identification, and has a low detection limit and high detection efficiency, thus taking into account both high detection efficiency and energy spectrum measurement function, and improving the accuracy of α-particle measurement.

[0040] (2) The online α-particle combination detector of the present invention is insensitive to ambient γ-rays, so the device of the present invention does not require an additional shielding device and has a low background and detection limit. The ZnS(Ag) detector is coupled with multiple PMTs to ensure detection efficiency. In addition, the ZnS(Ag) detector is insensitive to β-rays, and by reasonably setting the threshold, the interference of β-rays on the ZnS(Ag) detector can be ignored. As for the PIPS detector, the energy spectrum of β-rays is concentrated in the low-energy region. By using the energy spectrum analysis algorithm and increasing the lower limit of the energy spectrum threshold, the interference of β-rays can also be eliminated. This greatly reduces the influence of β and γ-rays on the measurement results and improves the detection accuracy of α particles.

[0041] (3) The online α combined detector of the present invention provides a structure with a replaceable light-shielding bracket detection window material, and the combined detector can be replaced without disassembling it. The window material can be aluminum foil, titanium foil and gold foil, so that it can be flexibly replaced as needed when facing harsh test environments such as strong acid, strong alkali and strong corrosion. The combined detector of the present invention can adapt to harsh and severe detection environments and has a wider range of application scenarios.

[0042] In summary, the online alpha combination detector disclosed in this invention combines a low detection limit, high detection efficiency, and energy discrimination function, thereby improving measurement accuracy. Without requiring additional shielding devices, it reduces the influence of beta and gamma rays on the combined detector's measurement of alpha particles, improving the detection accuracy of alpha particles. Furthermore, the detection window is easily replaceable, allowing for flexible replacement of window materials as needed in harsh testing environments such as those with strong acids and alkalis, thus enabling a wider range of applications and meeting the measurement needs of complex environments.

[0043] The following will further explain the concept, specific technical solution and technical effects of the present invention in conjunction with specific embodiments, so as to fully understand the purpose, features and effects of the present invention. Attached Figure Description

[0044] Figure 1 This is a schematic cross-sectional view of the online α-combination detector of the present invention;

[0045] Figure 2 This is a schematic diagram of the exploded structure of the online α-combination detector of the present invention;

[0046] Figure 3 This is a schematic diagram of the partial explosion structure of the online α-combination detector of the present invention;

[0047] Figure 4 This is a partial structural schematic diagram of the online α-combination detector of the present invention;

[0048] Figure 5 This is a schematic diagram of the light-shielding film and support structure of the threaded part of the detector head of the online α-combination detector of the present invention;

[0049] Figure 6 This is a schematic diagram of the front end of the online α-combination detector of the present invention;

[0050] Figure 7 This is the PIPS background energy spectrum measurement diagram in Embodiment 1 of the present invention;

[0051] Figure 8 This is the α spectrum of Americium-241 in a vacuum environment in Embodiment 1 of the present invention;

[0052] Figure 9 This is the α spectrum obtained by testing Americium-241 under coated conditions in Embodiment 1 of the present invention;

[0053] Figure 10 This is the α and β mixed spectrum in Embodiment 1 of the present invention;

[0054] Figure 11 This is a schematic block diagram of the electronic circuit board for the online α-combination detector of this invention. Detailed Implementation

[0055] The following describes several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, which are described exemplarily, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0056] Example 1: The detection performance of the α-combination detector of the present invention was tested;

[0057] The structural design of the combined detector in Embodiment 1 is as follows: Figure 1 As shown, Figure 1 The diagram shown is a cross-sectional view of the combined detector of the present invention. Figure 2 This is a schematic diagram of the exploded structure of the combined detector of the present invention;

[0058] The Figure 1 The components include: detector head threaded parts, light shielding film and bracket, PIPS fixing support, ZnS (Ag) detector, PMT collimating plate, PIPS detector, PIPS detector fixing ring, PIPS front encapsulation tube, PMT, PMT fixing parts, M3 copper pillars and sleeves, springs, electronic circuit board, motherboard connecting copper pillars, hexagonal copper pillars, combined detector rear cover, combined detector rear cover cable outlet plate, combined detector sleeve, and relative position fixing parts;

[0059] As shown in the figure Figure 5 This is a schematic diagram of the light-shielding film and support structure of the detector head threaded component of the combined detector of the present invention;

[0060] The detector head threaded component, light-shielding film, and bracket of the combined detector include a head threaded component, a light-shielding film bracket, and a bottom threaded component.

[0061] The head threaded part of the combined detector is located at the outermost front end of the combined detector.

[0062] As shown in the figure Figure 6 This is a schematic diagram of the front end of the combined detector of the present invention;

[0063] The outer layer of the light-shielding film support has threads, and there is a threaded engagement between it and the threaded part of the head of the combined detector, so that the two can fit tightly together.

[0064] The light-shielding membrane support is located between the head threaded component and the bottom threaded component;

[0065] The PIPS fixing support allows the PIPS detector to be fixed in the combined detector sleeve.

[0066] The combined detector sleeve is made of metal, the combined detector is in the shape of a concentric sleeve, and all the components of the combined detector are assembled inside the combined detector sleeve.

[0067] The front end of the combined detector sleeve can be fixed to the threaded part of the combined detector head, and the rear end of the combined detector sleeve can be fitted with the rear cover of the combined detector, thereby fixing the detector inside the sleeve of the combined detector.

[0068] As shown in the figure Figure 3 This is a schematic diagram of a partial explosion structure of the combined detector of the present invention; Figure 4 This is a partial structural schematic diagram of the combined detector of the present invention;

[0069] The ZnS(Ag) detector is in the shape of a ring, and a PIPS detector is hollowed out and embedded in the center of the ZnS(Ag) ring.

[0070] The PIPS detector is fixed to the ZnS(Ag) detector by a PIPS detector fixing ring;

[0071] The front end of the combined detector is a ZnS(Ag) detector coupled with a PMT, and four PMTs are equally spaced around the PIPS detector.

[0072] The PIPS front-end package tube is located at the center of the front end of the PIPS detector;

[0073] The PMT fixing component is located at the rear of the PMT and secures the PMT.

[0074] In this embodiment 1, the combined detector uses 4 PMTs; each PMT has a diameter of φ18mm, the ZnS(Ag) detector has an outer diameter of 78mm, and the central through hole is 32.5mm.

[0075] In this example, considering the actual measurement requirements for PIPS resolution, the CMA20 model PIPS detector was selected, with a PIPS sensitive detection area radius of 19.5 mm.

[0076] Each PMT's socket is fixed to the structural component by screws. The structural component has 4 sets of customized M3 round copper pillars and copper pillar sleeves (similar in structure to shock absorbers). Springs are fitted on the round copper pillars. The diameter of the springs is larger than the diameter of the round copper pillars, so that the round copper pillars can be squeezed into the sleeves. This ensures that the springs always provide elastic support to the PMT, thereby ensuring that the PMT is always in close contact with the ZnS (Ag) detector.

[0077] The relative position fixing component is located at the front of the combined detector, with one side in contact with the ZnS(Ag) detector and the other side in contact with the PIPS detector, thereby fixing the relative position of the two.

[0078] The combined detector electronic circuit board includes: a PMT analog board, a power supply board, a digital board, and a PIPS processing board; all of the electronic circuit boards have holes.

[0079] like Figure 11 The diagram shown is a schematic block diagram illustrating the implementation principle of the electronic circuit board of the online α-combination detector in Embodiment 1 of the present invention.

[0080] The PIPS detector and the PIPS processing board are connected by wires. The PIPS detector outputs a positive pulse signal to the PIPS processing board, and the processed energy spectrum data is then transmitted to the digital board.

[0081] The PMT outputs a negative pulse signal from its anode to the PMT analog board. After being amplified, compared, and shaped by the PMT analog board, the signal is then output as a TTL pulse signal to the digital board for pulse counting.

[0082] The digital board has an interface for communicating with the outside world and exchanging data;

[0083] The communication of the combined detectors all uses RS485 bus, which can ensure the reliability of long-distance communication.

[0084] In practice, the negative pulse output by the PMT voltage divider is first amplified by a preamplifier (emitter follower) and then inverted to obtain a positive pulse signal. Afterward, a threshold comparison is performed to filter out noise signals, and the signal is sent to a monostable multivibrator for pulse shaping. Once the pulse is shaped, the output pulse count (TTL, 5V pulse signal) is counted by a digital board, thus achieving the detection purpose.

[0085] The head threaded part of the combined detector is located at the outermost front end of the combined detector.

[0086] The outer layer of the light-shielding film support has threads, and there is a threaded engagement between it and the threaded part of the head of the combined detector, so that the two can fit tightly together.

[0087] The light-shielding film bracket can be unscrewed and replaced separately without disassembling the combined detector;

[0088] The combined detector sleeve is made of metal, the combined detector is in the shape of a concentric sleeve, and all the components of the combined detector are assembled inside the combined detector sleeve.

[0089] The front end of the combined detector sleeve can be fixed to the threaded part of the combined detector head. The fixing ring presses down on the detector back cover and is then fixed to the rear end of the detector sleeve through threads, thereby fixing the detector inside the combined detector sleeve. The internal spring is compressed to provide elastic support and ensure that the internal components of the detector will not loosen.

[0090] The combined detector has a communication port on its rear cover, which allows it to transmit information to the outside world.

[0091] The combined detector has a DC 12V power interface on its rear cover, allowing external 12V voltage to power the detector.

[0092] The metal material selected for the combined detector tube sleeve is 316L stainless steel;

[0093] In practice, considering the enhanced effect of external lead shielding, the housing material of the combined detector is 316L stainless steel, and the housing thickness is designed to be 8mm. The shape of the combined detector housing is modified in combination with the scintillator, PMT and electronic components.

[0094] The light-shielding film bracket of the combined detector can be replaced, and the material of the light-shielding film can be aluminum, titanium, or gold.

[0095] In specific implementation, the background test of the online α combination detector of the present invention was first carried out. The background test was carried out in an indoor room temperature environment, and no shielding measures were taken during the test. The specific test conditions were: the ORTEC high voltage power supply provided high voltage, the PMT high voltage was set to 900V; the measurement time was 10 minutes per group, and a single layer of aluminum foil was used. The background count measurement results of the combination detector are shown in Table 1.

[0096] Table 1. Baseline Test Data

[0097]

[0098] Based on Table 1, it can be concluded that the α-combination detector of the present invention has normal background count and no light leakage in an indoor environment for the ZnS(Ag) detector.

[0099] In specific implementation, the counting function and energy spectrum measurement function of the online α combination detector of the present invention are tested; and in order to meet the stringent conditions for the use of the detector, this test is conducted using a corrosion-resistant detector.

[0100] The outer ring of the combined detector is a ZnS(Ag) ring detector, equipped with four uniformly distributed PMTs, each with a detection diameter of φ18mm; the center of the combined detector is a PIPS detector. Therefore, a small-area planar source was used to test the counting and energy spectrum measurement functions of the detector. The α-plane standard source nuclide is Americium-241, number: Am20120705, 2π surface particle emissivity: 1.359E+04 / min, active area φ25mm. The α-plane source was placed in the center, while the PMTs in the combined detector were distributed around it, resulting in lower detection efficiency. The α-plane source measurement data is shown in Table 2. The distance between the detector and the source was 10mm, and the measurement time was 60s per group. The α-source measurement data is shown in Table 2.

[0101] Table 2 α source measurement data

[0102]

[0103] Table 2 shows that the PMT counting function of the α-combination detector is normal; the PIPS background spectrum measurement took approximately 30 minutes (actually 1853 seconds), with a total count of 568, which translates to a cps of 0.3065; the PIPS background spectrum measurement is as follows... Figure 7 As shown;

[0104] No high-energy peaks appeared in the background spectrum, and the energy was concentrated in the low-energy region (similar to the β spectrum). The PIPS background count of the α combined detector was also at a normal level.

[0105] The following is an energy spectrum measurement test, using an Americium-241 planar source (reference number Am20150412) with a spacing of 10 mm; the spectrum is shown below. Figure 8 , Figure 9 The above;

[0106] The Figure 8 This is the alpha spectrum of Americium-241 under vacuum conditions; the... Figure 9 This is the α spectrum obtained by testing Americium-241 under non-vacuum conditions and with a coated film.

[0107] pass Figure 8 , Figure 9 By comparison, it can be concluded that PIPS has better energy resolution under vacuum conditions;

[0108] The alpha spectrum of Americium-241 is Gaussian-like, with most of the energy concentrated in the alpha Gaussian peak, which is a normal alpha spectrum.

[0109] In practice, PIPS measurements were conducted on the β-plane source, and the β and α sources were measured sequentially to obtain the mixed spectrum. The combined detector was used to measure the energy spectra of the α-plane source Americium-241 and the β-plane source Sr-90 / Y-90 (numbered Sr180728), with the detector 10 mm away from the source. During the measurement, the β source was measured for a period of time first, and after the spectrum stabilized, the α source was switched on.

[0110] Test results are as follows Figure 10 As stated, by Figure 10 The mixed α and β spectra show that the β energy is concentrated in the low energy region and the α energy is concentrated in the medium energy region; moreover, the β spectrum exhibits an exponential decay shape, while the α spectrum exhibits a Gaussian shape, and there is a clear difference between the two, which can be used to distinguish between α and β sources.

[0111] In specific implementation, the detection efficiency of the online α-combination detector of the present invention is tested under conditions of purge gas presence and absence.

[0112] To verify the impact of purge gas on detection results, a purge gas test was conducted. Experimental procedure: An air compressor was connected to the device's air inlet via a flexible hose, allowing air to be directly blown into the device. The detector's detection efficiency was then analyzed with and without purge gas. Test conditions: α-sheet source: plutonium-239, number: 2, 2π surface emissivity: 6.803E+04 (min) -1 The detection efficiency results without purge gas are shown in Table 3.

[0113] Table 3. Detection efficiency without purge gas

[0114]

[0115] The results of the purge gas detection efficiency are shown in Table 4.

[0116] Table 4. Detection efficiency with purge gas

[0117]

[0118] As can be seen from the test data results in Tables 3 and 4 above, the detection efficiency of the solid α source with and without purge gas is basically the same, and the purge gas has almost no effect on the detection efficiency of the α combination detector of the present invention.

[0119] In specific implementation, a β-source interference test was conducted on the online α-combination detector of the present invention. To test whether β-rays interfered with the α-ray measurement of the α-combination detector of the present invention, a β-source interference test was carried out. Experimental conditions: β-plane source: Sr-90 / Y-90, plane source number: Sr180728, 2π surface particle emissivity: 1.632E+04 (min) -1 The detector was 10mm away from the β source, and the PMT was operating at a high voltage of 900V. Each measurement lasted for 1 minute, and the test results are shown in Table 5.

[0120] Table 5 β source test results

[0121]

[0122] As can be seen from Table 5, the counting results of the detector measuring the β source are at the same level as the background, and the deviation of the results is within the fluctuation range; therefore, the β source will not cause the α combination detector to produce false counts, and the β source has almost no effect on the α combination detector's measurement of the α source count.

[0123] Finally, the online α-combination detector of the present invention was tested by changing different window materials. In specific implementation, the detector window material replacement test was carried out in an indoor normal temperature environment, and no shielding measures were taken during the test. Test conditions: the ORTEC high voltage power supply provided high voltage, the PMT high voltage was set to 900 V to test the detector, the measurement time was 1 min per group, the α source spacing was 10 mm, the background measurement time was 10 min per group, the number of measurements was 20, and the single-layer window material was used.

[0124] The test results of the gold window material are shown in Tables 6 and 7.

[0125] Table 6 Background of the Combined Detector

[0126]

[0127] Table 7 Test data of combined detector detection efficiency

[0128]

[0129] The test results of titanium window materials are shown in Tables 8 and 9;

[0130] Table 8 Background test data of the combined detector

[0131]

[0132] Table 9 Test data for the combined detector

[0133]

[0134] The test results for aluminum window materials are shown in Table 10.

[0135] Table 10. High-voltage detection efficiency of aluminum window detectors and detectors with a source spacing of 10mm.

[0136]

[0137] As shown in Tables 6-10, the detector efficiency (900V) is 59.78% when using an aluminum window. After replacing the aluminum window with a gold window, the detection efficiency decreases to 36.8%. After replacing the aluminum window with a titanium window, the detection efficiency is 46%. Overall, the detection efficiency is the highest when using an aluminum window, so aluminum windows are used in most application scenarios. Gold and titanium windows have better corrosion resistance and can be used when necessary, greatly enriching the application scenarios of the α combined detector.

[0138] In summary, the online alpha combination detector of the present invention integrates a ZnS(Ag) solid scintillator and a PIPS detector; the device of the present invention can perform energy spectrum measurement and nuclide identification, and has a low detection limit and high detection efficiency, thus balancing high detection efficiency and energy spectrum measurement function and improving the accuracy of alpha particle measurement.

[0139] The online alpha particle detector of this invention is insensitive to ambient gamma rays, eliminating the need for additional shielding and thus achieving a low background and detection limit. The ZnS(Ag) detector is coupled with multiple PMTs, further ensuring detection efficiency. Furthermore, the ZnS(Ag) detector is also insensitive to beta rays; with a properly set threshold, the interference from beta rays is negligible. For the PIPS detector, the beta ray energy spectrum is concentrated in the low-energy region; interference from beta rays can be eliminated through energy spectrum analysis algorithms and by increasing the lower limit of the energy spectrum threshold. In summary, this significantly reduces the impact of beta and gamma rays on the combined detector's measurement of alpha particles, improving the detection accuracy of alpha particles.

[0140] The online α-combination detector of the present invention provides a structure with a replaceable light-shielding bracket and detection window material, which can be replaced without disassembling the combination detector. The window material can be selected from aluminum foil, titanium foil, and gold foil, which allows for flexible replacement as needed when facing harsh testing environments with strong acid and alkali corrosion. The combination detector of the present invention can adapt to harsh and severe detection environments and has a wider range of application scenarios, which can meet the measurement needs of complex environments.

[0141] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An online alpha combination detector, characterized in that: Includes detector head threaded parts light shielding film and bracket, PIPS fixing support (2), ZnS (Ag) detector (3), PMT collimating plate (4), PIPS detector (5), PIPS detector fixing ring (6), PIPS front encapsulation tube (7), PMT (8), PMT fixing part (9), M3 copper pillar and sleeve (10), spring (11), electronic circuit board, main board connecting copper pillar (13), hexagonal copper pillar (14), combined detector back cover (15), combined detector back cover cable outlet plate (16), combined detector sleeve (17), relative position fixing part (18); The detector head threaded component, light shielding film, and bracket of the combined detector include a head threaded component (101), a light shielding film bracket (102), and a bottom threaded component (103). The head threaded part (101) of the combined detector is located at the outermost front end of the combined detector. The outer layer of the light-shielding film bracket (102) has threads, and there is a threaded engagement between it and the head threaded part (101) of the combined detector, so that the two can fit tightly together; The light-shielding film support (102) is located between the head threaded part (101) and the bottom threaded part (103); The PIPS fixing support (2) allows the PIPS detector (5) to be fixed in the combined detector sleeve (17); The combined detector sleeve (17) is made of metal. The combined detector is in the shape of a concentric sleeve. All components of the combined detector are assembled inside the combined detector sleeve (17). The front end of the combined detector sleeve (17) can be fixed to the threaded part (101) of the combined detector head, and the rear end of the combined detector sleeve (17) can be fitted with the rear cover of the combined detector, thereby fixing the detector inside the sleeve of the combined detector. The ZnS(Ag) detector (3) is in the shape of a ring, and a PIPS detector (5) is hollowed out and embedded in the center of the ZnS(Ag) ring. The PIPS detector (5) is fixed together with the ZnS(Ag) detector (3) by the PIPS detector fixing ring (6); The front end of the combined detector is a ZnS(Ag) detector (3) coupled with a PMT (8), and 2-6 PMTs (8) are evenly distributed around the PIPS detector (5). The PIPS front-end encapsulation tube (7) is located at the center of the front end of the PIPS detector (5); The PMT collimator (4) is located in front of the PMT (8); The PMT fastener (9) is located behind the PMT (8) and secures the PMT (8).

2. The combined detector as described in claim 1, characterized in that, The socket of each PMT (8) is fixed to the structural component by screws. The structural component has an M3 copper column and a sleeve (10). A spring (11) is sleeved on the copper column. The diameter of the spring (11) is larger than the diameter of the round copper column, so that the round copper column can be squeezed into the sleeve, so that the spring (11) always has an elastic support effect on the PMT (8), thereby ensuring that the PMT (8) is always in close contact with the ZnS (Ag) detector (3). The relative position fixing member (18) is located at the front of the combined detector, with one side in contact with the ZnS (Ag) detector (3) and the other side in contact with the PIPS detector (5), thereby fixing the relative position of the two.

3. The combined detector as described in claim 1, characterized in that, The combined detector electronic circuit board includes: a PMT analog board (1201), a power board (1202), a digital board (1204), and a PIPS processing board (1203); all of the electronic circuit boards have holes. The PIPS detector (5) and the PIPS processing board (1203) are connected by wires. The PIPS detector (5) outputs a positive pulse signal to the PIPS processing board (1203) for energy spectrum analysis. The obtained energy spectrum data is then transmitted to the digital board (1204) for further processing. The negative pulse signal output from the anode of the PMT (8) is sent to the PMT analog board (1201). After being amplified in reverse, compared with the threshold and shaped by the PMT analog board (1201), the TTL pulse signal is output to the digital board (1204) for pulse counting.

4. The combined detector as described in claim 3, characterized in that, The digital board (1204) has an interface for communicating with the outside world and exchanging data; The electronic circuit board and the back cover (15) of the combined detector are fixed and connected by M3 copper pillars; One end of the M3 copper pillar is connected to the tube seat fixing component of PMT (8), and the other end passes through the PMT simulation board (1201) and is connected to the main board connecting copper pillar (13).

5. The combined detector as described in claim 1, characterized in that, The combined detector sleeve (17) is made of metal. The combined detector is in the shape of a concentric sleeve. All components of the combined detector are assembled inside the combined detector sleeve (17). The front end of the combined detector sleeve (17) can be fixed to the threaded part (101) of the combined detector head, and the rear end of the combined detector sleeve (17) can be fitted with the combined detector rear cover (15) to fix the detector inside the sleeve of the combined detector. The rear cover (15) of the combined detector has a communication port, which can transmit information with the outside world; The combined detector has a power interface on its rear cover (15), which allows external power to be input to power the detector.

6. The combined detector as described in claim 3, characterized in that, The bottom surface of the relative position fixing member (18) is coated with a reflective coating; The digital board (1204) communicates with the outside world through an RS485 port; The light-shielding film bracket can be unscrewed and replaced separately without disassembling the combined detector; The metal material selected for the combined detector tube sleeve is 316L stainless steel.

7. The combined detector as described in claim 1, characterized in that, The light-shielding film bracket (102) of the combined detector can be replaced, and the light-shielding film is made of aluminum, titanium or gold.

Images