An online alpha combination detector

Abstract

The online alpha particle detector of this invention integrates a ZnS(Ag) detector and a PIPS (ion-implanted passivated silicon) detector. Both ZnS(Ag) and PIPS are insensitive to ambient gamma rays, allowing the device to achieve low background and detection limits without additional shielding. ZnS(Ag) is also insensitive to beta rays; with proper threshold setting, the interference of beta rays on ZnS(Ag) is negligible. For PIPS, the energy spectrum of beta rays is concentrated in the low-energy region; interference from beta rays can be eliminated through energy spectrum analysis algorithms or by increasing the lower limit of the energy spectrum threshold. Thus, the influence of beta and gamma rays on the combined detector's measurement of alpha particles is greatly reduced, improving the detection accuracy of alpha particles. The ZnS(Ag) detector is coupled with multiple PMTs, further ensuring detection efficiency. The detection window structure, thanks to its unique design, is easy to replace, and the window materials—aluminum foil, titanium foil, and gold foil—are flexibly adaptable. The detector is resistant to strong acids and alkalis and corrosion, enabling a wider range of applications.

Description

Technical field

[0001] The invention relates to the technical field of α detectors, and in particular to an online α combination detector. Background technique

[0002] French physicist Becquerel first discovered the phenomenon of natural radioactivity in uranium salts. Since then, people have begun to study and utilize radionuclides. Among them, α-decay radionuclides account for a large proportion, and currently It has been widely used in medicine, aerospace, military, energy and other fields. However, during the research, production, storage, transportation and application of these nuclides, there is inevitably the risk of radioactive leakage;

[0003] Although research shows that alpha particles have weak penetrating ability and will quickly lose energy when running in the medium and will be absorbed within a few centimeters of air; however, alpha particles have strong ionization ability and will directly destroy internal organs once they enter the human body. cells, causing tissue damage;

[0004] Therefore, in view of the safety risks of alpha radionuclides during storage, transportation or use, locations where alpha radionuclides may be contaminated or leaked should be regularly tested to ensure the health of relevant personnel; or where alpha radioactive contamination already exists area, the degree of pollution can be determined through detection, and corresponding emergency measures can be taken; in these scenarios, the detection of alpha radionuclides is extremely important, and the alpha detector can also measure the alpha particles produced by radon and its daughters. Radioactive exploration to quantitatively search for certain radioactive mineral deposits, groundwater and solve other geological problems has 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 rays and gamma rays, have a higher background, and require additional shielding to have lower The lower detection limit of semiconductor detectors; among semiconductor detectors, traditional silicon surface barrier (SSΒ) detectors and diffuse junction (DJ) detectors have larger leakage currents and thicker dead layers, and their on-site detection efficiency is usually higher than that of scintillator detectors. Low; scintillator detectors have poor light transmittance, but have high luminous efficiency and high detection efficiency, but the energy resolution is not as good as semiconductor detectors; except for ZnS (Ag) detectors, most of them are sensitive to β rays and γ rays. It also has high sensitivity and will affect the measurement effect of alpha particles.

[0006] Moreover, the actual detection environment of the detector is often accompanied by strong acid, strong alkali and strong corrosiveness. However, the existing public α detector cannot take into account low detection limit, high detection efficiency, energy screening and resistance to harsh environments;

[0007] Therefore, those skilled in the art are committed to developing an online alpha combination detector, aiming to solve the deficiencies existing in the existing technology. Contents of the invention

[0008] In view of the above-mentioned defects of the prior art, the technical problems to be solved by the present invention are that in the prior art, the scintillator detector has poor energy spectral resolution, high sensitivity to beta and gamma rays, high background, and The detection environment of the detector is relatively harsh, and the existing α detector cannot take into account the low detection limit, high detection efficiency, energy screening performance and resistance to harsh environments.

[0009] In order to achieve the above purpose, the present invention proposes an online α combination detector, including a light-proof film and a bracket for the detector head threaded part, a PIPS fixed support, a ZnS (Ag) detector, a PMT collimation plate, a PIPS detector, and a PIPS detector. Detector fixing ring, PIPS front packaging tube, PMT, PMT fixings, M3 copper pillars and sleeves, springs, electronic circuit boards, mainboard connection copper pillars, hexagonal copper pillars, combined detector back cover, combined detector back cover Outlet board, combined detector casing, relative position fixing parts;

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

[0011] The head thread of the combined detector is located at the outermost layer of the front end of the combined detector;

[0012] The outer layer of the light-proof film holder has threads, and there is a threaded fit with the head thread of the combined detector, so that the two can fit closely together;

[0013] The light-proof film replacement part is located between the head threaded part and the bottom threaded part;

[0014] The PIPS fixing support allows the PIPS detector to be fixed in the combined detector casing;

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

[0016] The front end of the combined detector casing and the threaded part of the combined detector head can be fixed, and the rear end of the combined detector casing can cooperate with the back cover of the combined detector, thereby fixing the detector on the combined detector. inside the casing of the device;

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

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

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

[0020] The PIPS front packaging tube is located at the front center of the PIPS detector;

[0021] The PMT fixing piece is located behind the PMT to fix the PMT;

[0022] The tube base of each PMT is fixed on the structural member through screws. There are M3 copper pillars and sleeves on the structural member. There are springs on the copper pillars. The diameter of the spring is larger than the diameter of the round copper pillar, so that the round copper pillar can be squeezed. Press into the sleeve so that the spring always has an elastic support effect on the PMT, thereby ensuring that the PMT is always close to the ZnS (Ag) detector;

[0023] The relative position fixing piece 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 positions of the two;

[0024] The electronic circuit board of the combined detector includes: PMT analog board, power board, digital board, and PIPS processing board; the electronic circuit board is all provided with holes;

[0025] The PIPS detector and the PIPS processing board are connected through 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 anode of the PMT outputs a negative pulse signal to the PMT simulation board. After reverse amplification, threshold comparison and pulse shaping by the PMT simulation board, the TTL pulse signal is output 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 at intervals through M3 copper pillars;

[0029] One end of the M3 copper pillar is connected to the PMT tube base fixing piece, and the other end passes through the PMT simulation board and is connected to the motherboard connection copper pillar;

[0030] There is a communication port on the back cover of the combined detector, which can transmit information with the outside world;

[0031] There is a power interface on the back cover of the combination detector, and external power can be input to power the detector;

[0032] Further, the PIPS processing board contains signal conditioning and digital multi-channel;

[0033] Further, the bottom surface of the relative position fixing member is coated with a reflective coating;

[0034] Further, the digital board communicates with the outside world through the RS485 port;

[0035] Further, the light-shielding film holder can be rotated out separately and replaced without disassembling the combined detector;

[0036] Further, the metal material of the combined detector pipe sleeve is 316L stainless steel;

[0037] Further, the light-shielding film holder of the combined detector can be replaced, and the light-shielding film can be made of aluminum, titanium, or gold;

[0038] Using the above solution, the online α combination detector disclosed by the present invention has the following advantages:

[0039] (1) The online α combination detector of the present invention integrates a ZnS (Ag) solid flash detector and a PIPS detector; so that the present invention can not only perform energy spectrum measurement and nuclide identification, but also has a lower detection limit and is relatively High detection efficiency, taking into account high detection efficiency and energy spectrum measurement function, improves the accuracy of measuring α particles;

[0040] (2) The online alpha combination detector of the present invention is insensitive to environmental gamma rays, so that the device of the present invention does not require additional shielding devices and has a lower background and lower detection limit; among which the ZnS (Ag) detector is combined with multiple PMT coupling ensures detection efficiency; in addition, the ZnS (Ag) detector is not sensitive to β rays, and by setting the threshold appropriately, the interference of β rays to the ZnS (Ag) detector is negligible; while for the PIPS detector, β rays The energy spectrum is concentrated in the low-energy region. Through the energy spectrum analysis algorithm and raising the lower limit of the energy spectrum threshold, the interference of beta rays can also be eliminated; the impact of beta and gamma rays on the measurement results is greatly reduced, and the detection accuracy of alpha particles is improved. ;

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

[0042] To sum up, the online α combined detector disclosed in the present invention takes into account low detection lower limit, high detection efficiency and energy discrimination function, improves the accuracy of measurement, and reduces the risk of β and γ rays without the need for additional shielding devices. The impact on the combined detector's measurement of alpha particles improves the detection accuracy of alpha particles; and the detection window is easy to replace. When faced with harsh test environments such as strong acid and strong alkali corrosiveness, the window material can be flexibly replaced as needed, and it has more advantages. A wide range of usage scenarios can meet the measurement needs of complex environments.

[0043] The concepts, specific technical solutions and technical effects produced by the present invention will be further described below in conjunction with specific embodiments to fully understand the purpose, features and effects of the present invention. Description of the drawings

[0044] figure 1 It is a schematic cross-sectional structural diagram of the online α combination detector of the present invention;

[0045] figure 2 It is a schematic diagram of the explosion structure of the online alpha combination detector of the present invention;

[0046] image 3 It is a schematic diagram of the local explosion structure of the online α combination detector of the present invention;

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

[0048] Figure 5It is a schematic structural diagram of the light-proof film and bracket of the detector head threaded part of the online α combination detector of the present invention;

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

[0050] Figure 7 It is the PIPS background energy spectrum measurement chart in Example 1 of the present invention;

[0051] Figure 8 It is the alpha spectrum of americium-241 in a vacuum environment in Example 1 of the present invention;

[0052] Figure 9 It is the α spectrum obtained by testing americium-241 under coating conditions in Example 1 of the present invention;

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

[0054] Figure 11 It is a functional block diagram of the electronic circuit board of the online alpha combination detector of the present invention. Detailed ways

[0055] Several preferred embodiments of the present invention are introduced below to make the technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments. These embodiments are illustrative descriptions, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

[0056] Example 1. Test the detection performance of the α combination detector of the present invention;

[0057] The structural design of the combined detector in this embodiment 1 is as follows: figure 1 As shown, such as figure 1 Shown is a schematic cross-sectional structural diagram of the combined detector of the present invention; figure 2 It is a schematic diagram of the explosion structure of the combined detector of the present invention;

[0058] described figure 1 It includes the detector head threaded light-proof film and bracket, PIPS fixed support, ZnS (Ag) detector, PMT collimation plate, PIPS detector, PIPS detector fixing ring, PIPS front packaging tube, PMT, PMT fixings , M3 copper pillars and sleeves, springs, electronic circuit boards, mainboard connection copper pillars, hexagonal copper pillars, combination detector back cover, combination detector back cover outlet board, combination detector bushings, relative position fixing parts;

[0059] as the picture shows, Figure 5 It is a schematic structural diagram of the light-shielding film and bracket of the detector head threaded part of the combined detector of the present invention;

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

[0061] The head thread of the combined detector is located at the outermost layer of the front end of the combined detector;

[0062] as the picture shows, Figure 6 It is a schematic diagram of the front end of the combined detector of the present invention;

[0063] The outer layer of the light-proof film holder has threads, and there is a threaded fit with the head thread of the combined detector, so that the two can fit closely together;

[0064] The light-proof film replacement part is located between the head threaded part and the bottom threaded part;

[0065] The PIPS fixing support allows the PIPS detector to be fixed in the combined detector casing;

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

[0067] The front end of the combined detector casing and the threaded part of the combined detector head can be fixed, and the rear end of the combined detector casing can cooperate with the back cover of the combined detector, thereby fixing the detector on the combined detector. inside the casing of the device;

[0068] as the picture shows, image 3 It is a schematic diagram of the partial explosion structure of the combined detector of the present invention; Figure 4 It 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 the PIPS detector is hollowed out and embedded in the center of the ZnS (Ag) ring;

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

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

[0072] The PIPS front packaging tube is located at the front center of the PIPS detector;

[0073] The PMT fixing piece is located behind the PMT to fix the PMT;

[0074] The combined detector of this embodiment 1 selects 4 PMTs; the diameter of each PMT is The ZnS (Ag) detector has an outer diameter of 78mm and a middle through hole of 32.5mm;

[0075] This embodiment 1 combines the demand for PIPS resolution during actual measurement and selects the CMΑ20 model PIPS detector. The radius of the PIPS sensitive detection area is 19.5mm;

[0076] The tube base of each PMT is fixed on the structural member through screws. The structural member has 4 sets of customized M3 round copper columns and copper column sleeves (the structure is similar to a shock absorber). The round copper columns are covered with springs. The diameter is larger than the diameter of the round copper pillar, so that the round copper pillar can be squeezed into the sleeve, so that the spring always has an elastic support effect on the PMT, thereby ensuring that the PMT is always close to the ZnS (Ag) detector;

[0077] The relative position fixing piece 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 positions of the two;

[0078] The electronic circuit board of the combined detector includes: PMT analog board, power board, digital board, and PIPS processing board; the electronic circuit board is all provided with holes;

[0079] like Figure 11 Shown is a schematic block diagram of the implementation principle of the online α combination detector electronic circuit board in Embodiment 1 of the present invention;

[0080] The PIPS detector and the PIPS processing board are connected through 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 anode of the PMT outputs a negative pulse signal to the PMT simulation board. After reverse amplification, threshold comparison and pulse shaping by the PMT simulation board, the TTL pulse signal is output 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 detector adopts RS485 bus, which can ensure the reliability of long-distance communication;

[0084] During specific implementation, the negative pulse output by the PMT voltage divider first undergoes current amplification through a preamplifier (emitter follower), and then undergoes inverse amplification to obtain a positive pulse signal. Afterwards, the threshold value is compared, the noise signal is filtered out, and the signal is sent to the monostable trigger for pulse shaping; after the pulse shaping, the output pulse number TTL (5V pulse signal) is pulse counted by the digital board to achieve the detection purpose;

[0085] The head thread of the combined detector is located at the outermost layer of the front end of the combined detector;

[0086] The outer layer of the light-proof film holder has threads, and there is a threaded fit with the head thread of the combined detector, so that the two can fit closely together;

[0087] The light-proof film holder can be rotated out separately and replaced without disassembling the combined detector;

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

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

[0090] There is a communication port on the back cover of the combined detector, which can transmit information with the outside world;

[0091] There is a DC 12V power interface on the back cover of the combination detector, and 12V voltage is input from the outside to power the detector;

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

[0093] During the specific implementation, taking into account the additional effect of external lead shielding, the shell material of the combined detector is selected from 316L stainless steel, and the thickness of the shell is designed to be 8mm; the shape of the shell of the combined detector is modified by combining scintillator, PMT and electronic devices;

[0094] The light-proof film holder of the combined detector can be replaced, and the light-proof film can be made of aluminum, titanium, or gold;

[0095] During the specific implementation, the online α combination detector of the present invention is first subjected to a background test. The background test is conducted indoors at normal temperature, and no shielding measures are taken during the test. The test conditions are specifically: ORTEC high-voltage power supply provides high voltage, and PMT high-voltage setting is 900V; the measurement time is 10 minutes per group, single layer aluminum foil; the background count measurement results of the combined detector are shown in Table 1;

[0096] Table 1 Background test data

[0097]

[0098]

[0099] From Table 1, it can be concluded that the α combination detector of the present invention has a normal background count of the ZnS (Ag) detector in an indoor environment and has no light leakage;

[0100] During 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 an anti-corrosion detector;

[0101] The outer ring of the combined detector is a ZnS (Ag) ring detector, equipped with 4 evenly distributed PMTs. The detection diameter of each PMT is The middle of the combined detector is the PIPS detector. Therefore, a small-area planar source was used to first test the detector's counting function and energy spectrum measurement function; α-plane standard source nuclide: Americium-241, No.: Am20120705, 2π surface particle emissivity: 1.359E+04 / min, activity district The α plane source is placed in the center, and the PMTs in the combined detector are distributed around, so the detection efficiency is low; the α plane source measurement data are shown in Table 2, the distance between the detector and the source is 10mm, and the measurement time is 60 seconds per group; α source measurement data As shown in table 2;

[0102] Table 2 α source measurement data

[0103]

[0104] As can be seen from Table 2, the PMT counting function of the α combination detector is normal; the PIPS measured the background energy spectrum for about 30 minutes (actual 1853s), with a total count of 568, and the converted cps is 0.3065; the PIPS background energy spectrum measurement is as follows Figure 7 shown;

[0105] There is no high-energy spectrum peak in the background spectrum, and the energy is concentrated in the low-energy region (similar to the β spectrum). The background count of the PIPS part of the α combination detector is also at a normal level;

[0106] The energy spectrum measurement test is carried out below. The americium-241 planar source (No. Am20150412) is used for energy spectrum measurement with a spacing of 10mm; the spectrum is as follows Figure 8 , Figure 9 described;

[0107] described Figure 8 is the alpha spectrum of americium-241 in a vacuum environment; the Figure 9 It is the alpha spectrum obtained by testing americium-241 in a non-vacuum environment and under film coating conditions;

[0108] pass Figure 8 , Figure 9 From the comparison, it can be concluded that PIPS has better energy resolution under vacuum conditions; the α spectrum of americium-241 has a Gaussian-like shape, and most of the energy is concentrated in the α Gaussian spectrum peak, which is a normal α spectrum;

[0109] And during the specific implementation, a PIPS measurement beta plane source test was carried out, and the beta source and alpha source were measured successively to obtain the mixed spectrum; the combined detector measured the alpha plane source americium-241 and the beta plane source Sr-90 / Y-90 (No. Sr180728 ) energy spectrum, the distance between the detector and the source is 10mm; when measuring, first measure the β source for a period of time, and after the spectral line is stable, replace it with the α source;

[0110] The test results are as follows Figure 10 mentioned, by Figure 10 It can be seen from the mixed spectrum of α and β that β energy is concentrated in the low energy region and α energy is concentrated in the middle energy region; and the β spectrum has an exponential decay shape and the α spectrum has a Gaussian shape. There is a clear difference between the two, which can be distinguished between α sources and β source;

[0111] During specific implementation, the detection efficiency of the online α combination detector of the present invention is tested with or without purge gas;

[0112] In order to verify the influence of purge gas on the detection results, a purge gas test was carried out; the experimental plan: the air compressor and the air inlet of the device were connected through a hose, and the air was blown directly into the interior of the device; and then tested with or without purge. In the case of gas, analyze the detection efficiency of the detector; test conditions: α flake source: nuclide 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 detection efficiency results with purge gas are shown in Table 4;

[0116] Table 4 shows the purge gas detection efficiency

[0117]

[0118] It can be seen from the test data results in Table 3 and Table 4 above that the detection efficiency of the solid α source with or without purge gas is basically the same, and the purge gas has almost no impact on the detection efficiency of the α combination detector of the present invention;

[0119] During the specific implementation, a β source interference test was performed on the online α combination detector of the present invention; in order to test whether β rays interfered with measuring α rays by the α combination detector of the 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 distance between the detector and the β source is 10mm, and the PMT working voltage is 900V; the measurement time of each group is 1 minute, and the test results are shown in Table 5;

[0120] Table 5β source test results

[0121]

[0122] It can be seen from Table 5 that the counting results of the β source measured by the detector are at the same level as the background, and the deviation of the results is also within the fluctuation range; therefore, the β source will not cause the α combination detector to produce false counts, and the β source It has almost no impact on the alpha source count measured by the alpha combination detector;

[0123] Finally, the online α combination detector of the present invention was tested by replacing different window materials; during specific implementation, the detector replacement window material test was conducted indoors at normal temperature, and no shielding measures were taken during the test; test conditions: ORTEC high-voltage power supply provides high voltage , the detector was tested when the PMT high voltage was set to 900V. The measurement duration was 1 minute per group, the α source spacing was 10mm, the background measurement duration was 10 minutes per group, the number of measurements was 20, and the single-layer window material was used;

[0124] The test results of gold window materials are shown in Table 6 and Table 7;

[0125] Table 6 Combined detector background

[0126]

[0127] Table 7 Combination detector detection efficiency test data

[0128]

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

[0130] Table 8 Combined detector background test data

[0131]

[0132] Table 9 Combination detector test data

[0133]

[0134] The test results of aluminum window materials are shown in Table 10;

[0135] Table 10 Different high voltage detection efficiencies of aluminum window detector and source distance of 10mm

[0136]

[0137] It can be seen from the test results in Tables 6 to 10 that when aluminum windows are used, the detector efficiency (900V) is 59.78%. After replacing the aluminum windows with gold windows, the detection efficiency is reduced to 36.8%; after replacing the aluminum windows with titanium windows, the detection efficiency is reduced to 36.8%. The detection efficiency is 46%; in general, aluminum windows have the highest detection efficiency, so most usage scenario tests are conducted with aluminum windows; gold windows and titanium windows have better corrosion resistance and can be used when necessary, greatly enriching Understand the usage scenarios of α combination detector;

[0138] In summary, the online α combination detector of the present invention integrates a ZnS (Ag) solid flash detector and a PIPS detector; the device of the present invention can not only perform energy spectrum measurement and nuclide identification, but also has a lower detection limit and is relatively High detection efficiency, taking into account high detection efficiency and energy spectrum measurement function, improves the accuracy of measuring α particles;

[0139] The online alpha combination detector of the present invention is insensitive to environmental gamma rays, so that the device of the present invention does not require additional shielding devices and has a lower background and lower detection limit. Among them, the ZnS (Ag) detector is coupled with multiple PMTs to further ensure the detection efficiency; in addition, the ZnS (Ag) detector is not sensitive to β-rays. If the threshold is set appropriately, the interference of β-rays on the ZnS (Ag) detector can be reduced. Negligible; for PIPS detectors, the energy spectrum of β-rays is concentrated in the low-energy region. Through the energy spectrum analysis algorithm and increasing the lower limit of the energy spectrum threshold, the interference of β-rays can also be eliminated; in summary, the β- and γ-rays are greatly reduced. The impact on the combined detector’s measurement of alpha particles improves the detection accuracy of alpha particles;

[0140] The online α combination detector of the present invention provides a structure in which the material of the detection window of the light-proof bracket can be replaced, and the combination detector can be replaced without disassembling the combination detector. The window materials are aluminum foil, titanium foil and gold foil, making it possible to When faced with harsh testing environments such as strong acid, strong alkali and high corrosivity, it can be flexibly replaced as needed; the combined detector of the present invention can adapt to harsh and severe detection environments; it has a wider range of usage scenarios and can meet the measurement needs of complex environments.

[0141] The preferred specific embodiments of the present invention are described in detail above. It should be understood that those skilled in the art can make many modifications and changes based on the concept of the present invention without creative efforts. Therefore, any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited testing on the basis of the prior art based on the concept of the present invention should be within the scope of protection determined by the claims.

Claims

1. An online alpha combination detector, characterized in that: Includes detector head threaded light shielding film and bracket (1), 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 component (9), M3 copper pillar and sleeve (10), spring (11), electronic circuit board (12), 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 component (18); The detector head threaded component light shielding film and bracket (1) of the combined detector includes a head threaded component (101), a light shielding film replacement component (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 has threads, and there is a threaded engagement with the head threaded part (101) of the combined detector, so that the two can fit tightly together; The light-shielding film replacement part (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, and 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 to 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) to fix 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 fitted on the copper column. The diameter of the spring (11) is larger than the diameter of the copper column, so that the copper column can be squeezed into the sleeve. This ensures that the spring (11) always provides elastic support to 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 (12) 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 (12) 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 PMT(8) outputs a negative pulse signal from its anode to the PMT analog board (1201). After being amplified, compared, and shaped by the PMT analog board (1201), the PMT(8) outputs a TTL pulse signal to the digital board (1204) for pulse counting.

4. The combined detector as described in claim 1, characterized in that, The digital board (1204) has an interface for communicating with the outside world and exchanging data; The electronic circuit board (12) 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 the 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, and 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 1, 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 of the combined detector can be replaced, and the material of the light-shielding film can be aluminum, titanium, or gold.

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