Full-automatic low-background liquid scintillation analyzer

Abstract

The embodiment of the invention provides a full-automatic low-background liquid scintillation analyzer. The full-automatic low-background liquid scintillation analyzer comprises an analyzer frame body, a sample bottle storage device, a measuring chamber and an active shielding device, the measuring chamber comprises a three-pair coincidence three-way light chamber and a three-tube coincidence photomultiplier tube, and a liquid flash bottle provided by the sample bottle storage device can be contained in the three-pair coincidence three-way light chamber; the three-tube coincidence photomultiplier is horizontally arranged along the circumferential direction of the three-double coincidence three-way light chamber, and a first measuring probe of the three-tube coincidence photomultiplier penetrates into the three-double coincidence three-way light chamber; the active shielding device comprises plastic flashes and two common photomultipliers along the plastic flashes, the plastic flashes are arranged on the three double-coincidence three-way light chambers and used for converting environmental radiation in the three double-coincidence three-way light chambers into electric signals, and the common photomultipliers are horizontally arranged in the circumferential direction of the plastic flashes and can penetrate into the plastic flashes respectively. The number of the to-be-detected samples is determined according to the mixed solution of the to-be-detected samples and the scintillation solution, external radioactive interference can be actively eliminated through the active shielding device, and the detection accuracy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear radiation detection, and in particular to a fully automatic low-background liquid scintillation analyzer. Background Art

[0002] Liquid scintillation technology is an effective method for measuring low-energy beta rays developed in the early 1950s. It can also be used to detect alpha rays, neutrons, gamma rays and other radiation. Liquid scintillation instruments are widely used in many fields such as industry, agriculture, biology, chemistry, medicine, pharmacy, geology, hydrology, archaeology, and environment. In particular, they have important application value in nuclear pharmacy, environmental monitoring, and nuclear reactor safety monitoring. Since the scintillator is a liquid, the radioactive sample is dissolved, dispersed or suspended in the scintillation liquid and is in close contact with the scintillation liquid. The geometric conditions are close to 4π, and there is no influence of sample self-absorption, scattering, and geometric conditions. Therefore, the measurement accuracy and efficiency are greatly improved. It has become a measurement method. 3 H. 14 C and other soft beta rays are the most sensitive and commonly used methods.

[0003] Low-background liquid scintillation analyzer, also known as liquid scintillation analyzer, is an instrument commonly used for radionuclide measurement. It uses the characteristics of fluorescent substances precipitated in liquid to detect the radiation of radionuclides, and can achieve high-sensitivity and high-precision radionuclide counting.

[0004] In the process of implementing the present invention, the applicant discovered that there are at least the following problems in the prior art:

[0005] The low-background liquid scintillation analyzer in the prior art has low measurement accuracy and low safety when measuring radioactive samples. Summary of the invention

[0006] The embodiment of the present invention provides a fully automatic low-background liquid scintillation analyzer, which can solve the technical problems of low measurement accuracy and low safety of low-background liquid scintillation analyzers in the prior art in measuring radioactive samples.

[0007] To achieve the above-mentioned object, an embodiment of the present invention provides a fully automatic low-background liquid scintillation analyzer, comprising an analyzer frame, a sample bottle storage device, a measurement chamber, an active shielding device, a first data transmission line and a second data transmission line;

[0008] The sample bottle storage device is arranged in the middle layer of the analyzer frame, and is used to store a plurality of liquid scintillation bottles and can provide the liquid scintillation bottles for the measuring chamber, wherein the liquid scintillation bottles contain scintillation liquid and radiation samples;

[0009] The measuring chamber is arranged on the lower bottom plate of the analyzer frame and below the sample bottle storage device; the measuring chamber includes three double coincidence ratio three-way light chambers and three coincidence photomultiplier tubes, the three double coincidence ratio three-way light chambers are arranged horizontally and the liquid scintillation bottle provided by the sample bottle storage device can be held inside the three double coincidence ratio three-way light chamber, the three coincidence photomultiplier tubes are arranged horizontally along the circumference of the three double coincidence ratio three-way light chamber, and can respectively pass through the three double coincidence ratio three-way light chamber, the coincidence photomultiplier tube includes a first measuring probe, and the first measuring probe passes through the three double coincidence ratio three-way light chamber; when the liquid scintillation bottle is placed in the three double coincidence ratio three-way light chamber, the radiation of the radioactive sample in the liquid scintillation bottle will cause the fluorescent substance in the scintillation liquid to fluoresce and release charged particles, and the ionized electrons move freely in the scintillation liquid to generate a large number of secondary ionized electrons, forming an electronic cascade, thereby causing more luminescence; the first measuring probe is used to collect the luminescence in the liquid scintillation bottle, convert the luminous light signal into an electrical signal and amplify it to obtain a first electrical signal;

[0010] The active shielding device is arranged on the three-double coincidence ratio three-way light chamber, and is used to determine the amount of environmental radiation in the three-double coincidence ratio three-way light chamber; the active shielding device includes a plastic flash and two ordinary photomultiplier tubes along the plastic flash, the plastic flash is arranged on the three-double coincidence ratio three-way light chamber, and is used to convert the environmental radiation therein into an electrical signal, the ordinary photomultiplier tubes are arranged horizontally along the circumference of the plastic flash, and can respectively penetrate into the plastic flash, the ordinary photomultiplier tubes include a second measuring probe, the second measuring probe penetrates into the plastic flash, and is used to convert the optical signal in the plastic flash into an electrical signal to obtain a second electrical signal;

[0011] The first data transmission line is used to transmit the first electrical signal to the mainboard;

[0012] The second data transmission line is used to transmit the second electrical signal to the mainboard.

[0013] The above technical solution has the following beneficial effects: liquid scintillation is a liquid luminescence test method. The working principle of the liquid scintillation instrument is: the sample to be tested is mixed with the scintillation liquid. The radiation of the sample to be tested (such as a nuclide) will cause the fluorescent substance in the scintillation liquid to fluoresce and release charged particles. These ionized electrons will move freely in the scintillation liquid, generating a large number of secondary ionized electrons, forming an electronic cascade, thereby causing more luminescence events. Through the sensitive first measurement probe of the photomultiplier tube, these photons can be collected into the photomultiplier tube, and the light signal is converted into an electrical signal through the first measurement probe of the photomultiplier tube. The electrical signal is then amplified by the amplifier circuit, and then analog-to-digital conversion is performed, and then sent to the main board. The main board program then performs calculations to determine the number of samples to be tested (such as nuclides). The activity value of the sample can be directly obtained according to the counting rate of the sample to be tested, without relying on standard substances. It is an absolute measurement method.

[0014] The first measuring probe of the three-tube coincident photomultiplier tube is evenly distributed at 120 degrees around the three-pair coincident three-way light chamber, and the distance between the first measuring probe of the coincident photomultiplier tube and the scintillation bottle can be fine-tuned to achieve the purpose of parameter matching; the liquid scintillation bottle is placed in the three-pair coincident three-way light chamber. The liquid scintillation bottle is a transparent bottle made of glass or plastic, which can transmit light. The bottle cap is tightly closed during detection. The liquid scintillation bottle mainly emits light, and the first measuring probe of the coincident photomultiplier tube can only be detected at a relatively close distance.

[0015] The plastic flash is an anti-coincidence plastic flash. Two ordinary photomultiplier tubes are arranged horizontally at 120 degrees to form an active shielding measurement. The plastic flash is a barrel, which is a material that can convert rays into light signals. Ordinary photomultiplier tubes convert light signals into electrical signals. The active shielding device can actively measure the environment, cosmic radioactive rays and particles, eliminate external radioactive interference, and improve detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a first isometric view of a fully automatic low-background liquid scintillation analyzer according to an embodiment of the present invention;

[0018] Figure 2 It is a second isometric view of a fully automatic low-background liquid scintillation analyzer according to an embodiment of the present invention;

[0019] Figure 3is an isometric view of an embodiment of the present invention including a measurement chamber and an active shielding device;

[0020] Figure 4 is an isometric view of a measurement chamber according to an embodiment of the present invention;

[0021] Figure 5 is a cross-sectional view of an embodiment of the present invention including a measurement chamber and an active shielding device;

[0022] Figure 6 is an isometric view of the movable jaw assembly structure of an embodiment of the present invention;

[0023] Figure 7 is an isometric view of a portion of a movable jaw assembly structure of an embodiment of the present invention;

[0024] Figure 8 is an isometric view of a structure including a sleeve body and a part of a movable jaw assembly according to an embodiment of the present invention;

[0025] Fig. 9 is a cross-sectional view of a sample bottle storage device, a measuring chamber, an active shielding device and a sleeve body according to an embodiment of the present invention;

[0026] Fig.10 is a cross-sectional view of an embodiment of the present invention including a sample bottle storage device, a measuring chamber and an active shielding device;

[0027] Fig.11 is an isometric view of a sample bottle storage device (part) according to an embodiment of the present invention;

[0028] Fig.12 is a top view of a sample bottle storage device according to an embodiment of the present invention;

[0029] Fig.13 is an isometric view of a sample-carrying bottle rack according to an embodiment of the present invention;

[0030] Fig.14 : is an isometric view of a three-axis motion mechanism according to an embodiment of the present invention

[0031] Fig.15 is an isometric view of a sample bottle gripping assembly according to an embodiment of the present invention;

[0032] Fig.16 is an isometric view of a flexible anti-collision mechanism according to an embodiment of the present invention;

[0033] Fig.17 is a side isometric view of a sample bottle clamping mechanism according to an embodiment of the present invention;

[0034] Fig.18 is another side isometric view of the sample bottle clamping mechanism of the embodiment of the present invention;

[0035] Fig.19is an axonometric view of a semi-clamping hub according to an embodiment of the present invention;

[0036] Fig. 20 1 is an isometric view of a T-shaped guide column according to an embodiment of the present invention.

[0037] The reference numerals are as follows:

[0038] 1. Analyzer frame; 2. Sample bottle storage device; 3. Measuring chamber; 4. Active shielding device; 5. Passive shielding device; 6. Housing; 7. Anti-static device; 8. Insulation component; 9. Sample bottle clamping device;

[0039] 11. Lower bottom plate; 21. Liquid scintillation bottle; 22. Sample bottle rack; 23. Calibration grating; 24. Sample bottle drawer box; 25. Drawer rail; 26. Safety door lock; 27. Matrix pressure film sensor; 31. Triple double coincidence ratio three-way light chamber; 32. Coincidence photomultiplier tube; 41. Plastic scintillation; 42. Ordinary photomultiplier tube; 51. Plastic layer PMMA; 52. Copper layer Cu; 53. Cadmium layer Cd; 54. Lead layer Pb; 61. Measuring chamber tank; 62. First photomultiplier tube sleeve; 63. Moving lead door assembly; 64. Second photomultiplier tube sleeve; 71. Anti-static ion nozzle; 72. Anti-static conductive glue; 73. Mounting bracket; 81. Semiconductor refrigerator; 91. Sample bottle clamping assembly; 92. Three-axis motion mechanism;

[0040] 221, lower support plate; 222, upper support plate; 223, matrix tube; 241, sample exchange hole; 631, movable jaw; 632, row of rollers; 633, matching gear rack assembly; 634, first motor; 911, sample bottle clamping mechanism; 912, connecting rod; 913, flexible anti-collision mechanism; 921, X-axis track; 922, Y-axis track; 923, Z-axis track; 9111, clamping base; 9112, semi-clamping hub; 9113, T-shaped guide Column; 9114, tension spring; 9115, cam; 9116, second motor; 9117, driving gear; 9118, driven gear; 9119, Hall sensor; 9131, slider mounting bracket; 9132, ball linear slide; 9133, guide column; 9134, guide column compression spring; 9135, clamping block base; 9136, clamping block; 9137, anti-collision soft rubber column; 9138, proximity switch; 100, diffuse reflection optical coupler; 300, photoelectric detector. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] like Figures 1 to 20 , in combination with an embodiment of the present invention, a fully automatic low-background liquid scintillation analyzer is provided, comprising an analyzer frame 1, a sample bottle storage device 2, a measurement chamber 3, an active shielding device 4, a first data transmission line and a second data transmission line;

[0043] The sample bottle storage device 2 is arranged in the middle layer of the analyzer frame 1, and is used to store a plurality of liquid scintillation bottles 21 and can provide the liquid scintillation bottles 21 for the measuring chamber 3, wherein the liquid scintillation bottles 21 contain scintillation liquid and radioactive samples;

[0044] The measuring chamber 3 is arranged on the lower bottom plate 11 of the analyzer frame 1 and below the sample bottle storage device 2; the measuring chamber 3 includes a three-way light chamber 31 with double coincidence ratio and a three-tube coincidence photomultiplier tube 32, the three-way light chamber 31 with double coincidence ratio is arranged horizontally and the liquid scintillation bottle 21 provided by the sample bottle storage device 2 can be contained inside the three-way light chamber 31 with double coincidence ratio, the three-tube coincidence photomultiplier tube 32 is arranged horizontally along the circumference of the three-way light chamber 31 with double coincidence ratio and can penetrate into the three-way light chamber 31 with double coincidence ratio respectively, the three-tube coincidence photomultiplier tube 32 The invention comprises a first measuring probe, which penetrates into the three-way light chamber 31 of the three-way coincidence ratio; when the liquid scintillator bottle 21 is placed in the three-way coincidence ratio light chamber 31, the radiation of the radioactive sample in the liquid scintillator bottle 21 will cause the fluorescent substance in the scintillator liquid to fluoresce and release charged particles, and the ionized electrons move freely in the scintillator liquid to generate a large number of secondary ionized electrons, forming an electron cascade, thereby causing more luminescence; the first measuring probe is used to collect the luminescence in the liquid scintillator bottle 21, convert the luminescent light signal into an electrical signal and amplify it to obtain a first electrical signal;

[0045] The active shielding device 4 is arranged on the three-double coincidence ratio three-way light chamber 31, and is used to determine the amount of environmental radiation in the three-double coincidence ratio three-way light chamber 31; the active shielding device 4 includes a plastic flash 41 and two ordinary photomultiplier tubes 42 along the plastic flash 41, the plastic flash 41 is arranged on the three-double coincidence ratio three-way light chamber 31, and is used to convert the environmental radiation in it into an electrical signal, the ordinary photomultiplier tube 42 is horizontally arranged along the circumference of the plastic flash 41, and can penetrate into the plastic flash 41 respectively, the ordinary photomultiplier tube 42 includes a second measuring probe, the second measuring probe penetrates into the plastic flash 41, and is used to convert the optical signal in the plastic flash 41 into an electrical signal to obtain a second electrical signal;

[0046] The first data transmission line is used to transmit the first electrical signal to the mainboard;

[0047] The second data transmission line is used to transmit the second electrical signal to the mainboard.

[0048] Liquid scintillation is a liquid luminescence test method. The working principle of the liquid scintillation instrument is: the sample to be tested is mixed with the scintillation liquid. The radiation of the sample to be tested (such as a nuclide) will cause the fluorescent substance in the scintillation liquid to fluoresce and release charged particles. These ionized electrons will move freely in the scintillation liquid, generating a large number of secondary ionized electrons, forming an electronic cascade, thereby causing more luminescence events. Through the sensitive first measurement probe that conforms to the photomultiplier tube 32, these photons can be collected into the photomultiplier tube 32, and the light signal is converted into an electrical signal through the first measurement probe that conforms to the photomultiplier tube 32. The electrical signal is then amplified by the amplifier circuit, and then analog-to-digital conversion is performed, and then sent to the main board. The main board program then performs calculations to determine the number of samples to be tested (such as nuclides). The activity value of the sample can be directly obtained based on the counting rate of the sample to be tested, without relying on standard substances. It is an absolute measurement method.

[0049] The first measuring probe of the three-tube coincident photomultiplier tube 32 is evenly distributed at 120 degrees around the three-pair coincident three-way light chamber 31, and the distance between the first measuring probe of the three-pair coincident photomultiplier tube 32 and the scintillation bottle 21 can be fine-tuned, so as to achieve the purpose of parameter matching; the liquid scintillation bottle 21 is placed in the three-pair coincident three-way light chamber 31, and the liquid scintillation bottle 21 is a transparent bottle made of glass or plastic, which can transmit light, and the bottle cap is tightly closed during detection. The liquid scintillation bottle 21 mainly emits light, and the first measuring probe of the photomultiplier tube 32 can only be detected when the distance is relatively close.

[0050] The plastic flash 41 is an anti-coincidence plastic flash, and two ordinary photomultiplier tubes 42 are arranged horizontally at 120 degrees to form an active shielding measurement. The plastic flash 41 is a barrel, which is a material that can convert rays into optical signals, and the ordinary photomultiplier tube 42 converts the optical signals into electrical signals. The active shielding device 4 can actively measure the environment, cosmic radioactive rays and particles, eliminate external radioactive interference, and improve detection accuracy.

[0051] Low background is to eliminate the interference of external radiation rays for measurement and analysis. External radiation rays include weak radiation rays from the earth and the universe. There is an active shielding method to eliminate external radiation rays. Active shielding is to actively measure external radiation rays (such as gamma rays) with anti-coincidence plastic flash and anti-coincidence ordinary photomultiplier tube 42, and then eliminate them with an algorithm. Anti-coincidence is active shielding, actively measuring the rays in the environment. The data measured by the first measurement probe of the three-tube coincident photomultiplier tube 32 is subtracted from the data measured by the second measurement probe of the anti-coincidence ordinary photomultiplier tube 42 through an algorithm, so that the active environment low background measurement data can be eliminated, thereby improving the accuracy of the low background measurement data.

[0052] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a passive shielding device 5, which surrounds the plastic scintillation 41 and the triple-double-coincidence three-way light chamber 31 and is used to shield external environmental radiation, and the passive shielding device 5 comprises a plastic layer PMMA51, a copper layer Cu52, a cadmium layer Cd53 and a lead layer Pb54 arranged from inside to outside;

[0053] The radiation in the external environment is shielded in sequence by the plastic layer PMMA51, the copper layer Cu52, the cadmium layer Cd53 and the lead layer Pb54;

[0054] The secondary radiation generated by the radiation in the external environment in the passive shielding device 5 is shielded in sequence by the plastic layer PMMA51, the copper layer Cu52, the cadmium layer Cd53 and the lead layer Pb54;

[0055] From the outside to the inside, the radiation generated by the copper in the copper layer Cu52, the cadmium in the cadmium layer Cd53 and the lead in the lead layer Pb54 are shielded: the radiation emitted by the lead in the lead layer Pb54 is shielded by the cadmium layer Cd53, the radiation emitted by the cadmium in the cadmium layer Cd53 is shielded by the copper layer Cu52, and the radiation emitted by the copper in the copper layer Cu52 is shielded by the plastic layer PMMA51.

[0056] To exclude external radiation, there is also passive shielding. Passive shielding uses shielding materials to shield external rays and external radiation, so that all or most of the environmental and cosmic radioactive radiation cannot enter the measurement room, reduce the interference of radioactive rays from the external environment of the measurement room 3, increase the lower limit of low-background radioactive radiation measurement, and achieve low-background measurement.

[0057] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a casing 6, wherein the casing 6 comprises a measuring chamber tank 61, three first photomultiplier tube sleeves 62 and two second photomultiplier tube sleeves 64;

[0058] The measuring chamber tank 61 encloses the plastic flash 41 and the three-way light chamber 31 of the three-double-coincidence ratio;

[0059] The first photomultiplier tube sleeve 62 is connected to the measuring chamber tank body 61, and each of the first photomultiplier tube sleeves 62 is matched with one of the matching photomultiplier tubes 32, and the first photomultiplier tube sleeve 62 is used to wrap the matching one of the matching photomultiplier tubes 32 together with the internal space of the measuring chamber tank body 61;

[0060] The second photomultiplier tube sleeve 64 is connected to the measuring chamber tank body 61 , and each of the second photomultiplier tube sleeves 64 matches a common photomultiplier tube 42 . The second photomultiplier tube sleeve 64 is used to wrap the matched common photomultiplier tube 42 together with the internal space of the measuring chamber tank body 61 .

[0061] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a heat preservation component 8, wherein the heat preservation component 8 comprises a first liquid-cooled internal pipe arranged at the inner bottom of the measuring chamber tank 61, a second liquid-cooled internal pipe arranged at the inner bottom of each of the first photomultiplier tube sleeves 62, and a third liquid-cooled internal pipe arranged at the inner bottom of each of the second photomultiplier tube sleeves 64;

[0062] The thermal insulation component 8 also includes a semiconductor refrigerator 81 arranged outside the sleeve 6 and on the lower bottom plate 11 of the analyzer frame 1. The semiconductor refrigerator 81 is respectively connected to the first liquid-cooled internal pipeline, the second liquid-cooled internal pipeline and the third liquid-cooled internal pipeline, and is used to control the semiconductor refrigerator 81 to cool the first liquid-cooled internal pipeline, the second liquid-cooled internal pipeline and the third liquid-cooled internal pipeline through the mainboard, so as to keep the measuring chamber 3, the compliant photomultiplier tube 32 and the ordinary photomultiplier tube 42 at a low temperature and constant temperature through the refrigerant.

[0063] The cold water in the water tank is cooled by a water pump, a water tank and a semiconductor refrigerator 81, and the heat preservation is achieved by the heat sink, the fan and the insulation layer of the heat dissipation module. The measurement chamber 3, the compliant photomultiplier tube 32 and the ordinary photomultiplier tube 42 can be kept at a low temperature and constant temperature by liquid cooling. The stable low temperature can effectively reduce the thermal noise of the compliant photomultiplier tube 32, the ordinary photomultiplier tube 42 and the electronic components, and maintain the chemical stability of the liquid scintillator in the liquid scintillator bottle 21.

[0064] Preferably, the casing 6 further comprises a movable jaw assembly 63, and the movable jaw assembly 63 is used to shield the external radiation of the environment;

[0065] The casing 6 has a door opening, which is arranged on the peripheral side of the measuring chamber tank 61 and on the top plate connected to the peripheral side;

[0066] The movable jaw assembly 63 includes a movable jaw 631, two sets of row rollers 632, a gear rack assembly 633, a first motor 634, a position sensor and a photoelectric sensor;

[0067] The movable lead door 631 includes an upper plate and a vertical plate connected to the upper plate, and the movable lead door 631 matches the door opening to close the door opening;

[0068] The row of rollers 632 is arranged on the inner side of the top plate of the measuring chamber tank 61 where the door opening is located, and two groups of the row of rollers 632 are symmetrically installed;

[0069] The first motor 634 and the rack and pinion assembly 633 are arranged outside the door opening;

[0070] The gear rack assembly 633 includes a gear and a rack, the rack is connected to the outside of the vertical plate of the movable jaw 631, and the gear is connected to the first motor 634;

[0071] The first motor 634 drives the gear to rotate, and the gear moves on the rack to push the movable lead door 631 toward the door opening, and the upper plate of the movable lead door 631 slides on the two groups of rollers 632 in a row to close the movable lead door 631. The movable lead door 631 can be opened by operating in the opposite direction;

[0072] The position sensor is arranged on the movable jaw 631, and the photoelectric sensor is arranged on the measuring chamber tank 61 at a position corresponding to the movable jaw 631. After the movable jaw 631 is closed, the photoelectric sensor senses the position sensor, the first motor 634 returns to zero, and the first motor 634 stops; after the movable jaw 631 is opened, the photoelectric sensor senses the position sensor and calculates the moving distance of the movable jaw 631.

[0073] The movable lead door 631 is used to place the liquid scintillator bottle 21 into the triple-double-coincidence three-way light chamber 31 after opening, and to shield the external environment radiation.

[0074] The movable lead door 631 adopts a group of rollers 632 to effectively reduce the moving friction resistance of the movable lead door 631. The gear rack assembly 633 can realize the rapid and stable opening and closing of the movable lead door 631, and the measuring chamber 3 is fully enclosed and passively shielded. The movable lead door 631 is effectively shielded from light, thereby reducing external interference with the liquid scintillation bottle 21.

[0075] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a static electricity removal device 7, wherein the static electricity removal device 7 is arranged on the top plate of the measuring chamber tank body 61;

[0076] The static electricity removal device 7 includes a static electricity removal ion air nozzle 71, a static electricity removal conductive glue 72 and a mounting bracket 73;

[0077] The mounting bracket 73 is mounted on the top plate of the measuring chamber tank body 61 near the movable lead gate 631, the anti-static ion wind nozzle 71 is mounted on the top plate of the measuring chamber tank body 61, the anti-static conductive glue 72 is mounted on the mounting bracket 73 and aligned with the movable lead gate 631, the anti-static ion wind nozzle 71 is used to remove static electricity from the liquid scintillation bottle 21 by blowing ion wind in a non-contact manner before the liquid scintillation bottle 21 enters the movable lead gate 631, and the anti-static conductive glue 72 is used to contact the liquid scintillation bottle 21 before the liquid scintillation bottle 21 enters the movable lead gate 631 to remove static electricity from the liquid scintillation bottle 21.

[0078] The electrostatic ion nozzle 71 and the anti-static conductive glue 72 are installed just above the movable lead door 631. Before the liquid scintillation bottle 21 enters the measuring chamber 3, static electricity is removed simultaneously by the electrostatic ion nozzle 71 and the anti-static conductive glue 72. The two methods of removing static electricity are safer and better, and can effectively eliminate the interference caused by the luminescence of the liquid scintillation solution caused by static electricity.

[0079] Preferably, the sample bottle storage device 2 further includes a sample bottle rack 22, a sample bottle drawer box 24, a drawer guide rail 25, two safety door locks 26 with sensors, and a matrix pressure film sensor 27;

[0080] The sample bottle rack 22 is mounted on the sample bottle drawer box 24, and the sample bottle drawer box 24 is slidably connected to the analyzer frame 1 through the drawer guide rail 25. A matching sample exchange hole 241 is provided on the bottom plate of the sample bottle drawer box 24, which can achieve repeated and accurate positioning of the sample bottle drawer each time it is opened and closed;

[0081] The sample-carrying bottle rack 22 includes a lower support plate 221, an upper support plate 222, and a plurality of vertically arranged matrix tubes 223, the bottom of each matrix tube 223 is fixed on the lower support plate 221, the top of each matrix tube 223 passes through the upper support plate 222 and is fixed on the upper support plate 222, and each matrix tube 223 is used to hold one liquid scintillation bottle 21;

[0082] The safety door lock 26 is installed on the analyzer frame 1 and is located at the innermost end when the sample bottle drawer box 24 is closed. The safety door lock 26 is used to monitor the position of the sample bottle drawer box 24. A sensor is designed inside the safety door lock, and the sample bottle drawer box 24 cannot be opened without program control, thereby achieving safety and reliability.

[0083] The matrix pressure film sensor 27 is disposed under the matrix tube 223 and is used to monitor and detect in real time whether the liquid scintillation bottle 21 is in place, thereby realizing intelligent management and control.

[0084] A liquid cooling pipeline is provided under the sample carrying bottle rack 22 , and a liquid cooling box is provided to provide the liquid cooling pipeline with a refrigerant to achieve low-temperature constant temperature refrigeration, thereby effectively maintaining the chemical stability of the liquid scintillator liquid in the liquid scintillator bottle 21 .

[0085] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a sample bottle clamping device 9, wherein the sample bottle clamping device 9 comprises a sample bottle clamping assembly 91 and a three-axis motion mechanism 92, wherein the three-axis motion mechanism 92 is used to support the sample bottle clamping assembly 91 to move to clamp and release the liquid scintillation bottle 21 in the sample bottle storage device 2, and the sample bottle clamping device 9 is disposed in the analyzer frame 1 and is located above the sample bottle storage device 2;

[0086] The three-axis motion mechanism 92 includes two parallel Y-axis rails 922, and the Y-axis rails 922 are arranged along the opening and closing movement direction of the sample bottle drawer box 24, and the Y-axis rails 922 are fixed on the analyzer frame 1;

[0087] The three-axis motion mechanism 92 further includes an X-axis track 921, and two ends of the X-axis track 921 slide and move on the two Y-axis tracks 922;

[0088] The three-axis motion mechanism 92 further includes a Z-axis track 923, wherein the Z-axis track 923 is perpendicular to a plane formed by the two Y-axis tracks 922 and the X-axis track 921, and the Z-axis track 923 slides on the X-axis track 921;

[0089] The sample bottle clamping assembly 91 can be connected to the X-axis track 921. The sample bottle clamping assembly 91 can drive the sample bottle clamping assembly 91 to move along the Z-axis track 923, along the Y-axis track 922, and along the X-axis track 921 through the X-axis track 921.

[0090] It can realize free and precise three-dimensional movement and sample replacement operation of the liquid scintillation bottle 21, thereby realizing orderly and automated measurement of a large number of samples.

[0091] Preferably, the sample bottle clamping assembly 91 includes a sample bottle clamping mechanism 911, a connecting rod 912 and a flexible anti-collision mechanism 913, wherein the flexible anti-collision mechanism 913 is connected to the X-axis track 921 and can move along the direction of the X-axis track 921, the upper end of the connecting rod 912 can be connected to the sample bottle clamping mechanism 911, and the lower end of the connecting rod 912 can be connected to the sample bottle clamping mechanism 911, and the sample bottle clamping mechanism 911 is used to grab and release the liquid scintillation bottle 21. It can realize the free and precise three-dimensional movement of the sample bottle clamping mechanism 911, realize the sample replacement operation of the liquid scintillation bottle 21, and thus realize the orderly automatic measurement of a large number of samples.

[0092] Preferably, the flexible anti-collision mechanism 913 is installed on the Z-axis track 923, and the flexible anti-collision mechanism 913 is connected to the sample bottle clamping mechanism 911 by clamping the connecting rod 912;

[0093] The flexible anti-collision mechanism 913 includes a slider mounting frame 9131, a ball linear slide 9132, a guide column 9133, a guide column compression spring 9134, a clamping block base 9135, a clamping block 9136, an anti-collision soft rubber column 9137 and a proximity switch 9138;

[0094] The ball bearing linear slide 9132 is vertically connected to the slider mounting frame 9131, and the clamping block base 9135 vertically slides on the ball bearing linear slide 9132, and the clamping block base 9135 is guided to move up and down by sliding the clamping block base 9135 on the ball bearing linear slide 9132;

[0095] The ball linear slide 9132 includes a linear slide (set on the slider mounting frame 9131) and a ball (the ball is also connected to the clamping block base 9135) set in the linear slide, and the ball slides in the linear slide. The guide column 9133 is arranged vertically, and the upper end of the guide column 9133 passes through the slider mounting frame 9131 and the upper end of the guide column 9133 can move up and down and fall on the upper part of the slider mounting frame 9131, and the lower end of the guide column 9133 passes through the clamping block base 9135;

[0096] The guide post compression spring 9134 is sleeved outside the guide post 9133 and is located in the space between the slider mounting frame 9131 and the clamping block base 9135;

[0097] When the sample bottle clamping mechanism 911 is hit vertically (accidentally), the entire connecting rod 912 will slide upward, and the guide column compression spring 9134 can play a buffering role.

[0098] The clamping block base 9135 and the clamping pressure block 9136 are cooperatively connected to clamp the upper end of the connecting rod 912;

[0099] The anti-collision soft rubber column 9137 is arranged under the slider mounting frame 9131 and between the slider mounting frame 9131 and the top of the clamping block base 9135;

[0100] The proximity switch 9138 is disposed on the slider mounting frame 9131;

[0101] When there are uncontrollable factors or equipment problems, in order to prevent the liquid scintillation bottle 21 from being hit and broken during the movement of the sample bottle clamping mechanism 911, a flexible anti-collision mechanism 913 is designed. The flexible anti-collision mechanism 913 is installed on the slider of the Z-axis track 923, so that the entire sample bottle clamping mechanism 911 can be driven to move up and down on the Z-axis track 923, and is connected to the sample bottle clamping mechanism 911 through the clamping connecting rod 912.

[0102] The clamping block base 9135 is guided to move up and down by sliding the clamping block base 9135 on the ball linear slide 9132; the purpose of the up and down movement of the clamping block base 9135 is to provide a buffering and guiding function during collision.

[0103] The slider mounting frame 9131 and the upper part of the clamping block base 9135 are flexibly connected through three guide posts 9133 and guide post compression springs 9134 to achieve flexible up and down movement.

[0104] The soft anti-collision rubber column 9137 and the proximity switch 9138 are installed to realize the anti-collision function. The proximity switch is an external sensor that adopts the principle of electromagnetic induction. After the impact buffer moves a certain distance and senses it, the main board immediately controls the second motor 9116 to stop urgently to prevent further impact and realize the safety and effectiveness of movement.

[0105] The sample bottle clamping mechanism 911 includes a clamping base 9111, a semi-clamping hub 9112, a T-shaped guide column 9113, a tension spring 9114, a cam 9115, a second motor 9116, a driving gear 9117, a driven gear 9118 and a Hall sensor 9119;

[0106] The semi-clamping hub 9112, the T-shaped guide column 9113, the tension spring 9114, and the cam 9115 are all located on the first surface of the clamping base 9111;

[0107] The second motor 9116, the driving gear 9117, the driven gear 9118 and the Hall sensor 9119 are all located on the second surface of the clamping base 9111;

[0108] There are two symmetrical semi-clamping hubs 9112, each of which has a horizontal mounting seat and a vertical semi-circular ring connected to the horizontal mounting seat.

[0109] There are two T-shaped guide columns 9113, which are symmetrically mounted on the clamping base 9111 by screws, and the horizontal mounting seat of the semi-clamping hub 9112 has a horizontal hole groove that matches the contour of the T-shaped guide column 9113, and the T-shaped guide column 9113 horizontally penetrates the hole groove on the horizontal mounting seat of the semi-clamping hub 9112 and is in clearance with the hole groove; the two semicircular rings can form an annular space, and the annular space is used to accommodate one of the liquid scintillation bottles 21;

[0110] The horizontal mounting seat of the semi-clamping hub 9112 can be installed in cooperation with the T-shaped guide column 9113 on the same side, and the semi-clamping hub 9112 can move left and right along the T-shaped guide column 9113. The T-shaped guide column 9113 is used to guide the semi-circular ring to move along the arc when the semi-clamping hub 9112 is opened or closed;

[0111] There are two tension springs 9114, and the tension springs 9114 are connected between the two opposite end faces of the semi-circular shape. When the two semi-clamping hubs 9112 are closed to clamp the liquid scintillation bottle 21, the symmetrically distributed tension springs 9114 tighten the left and right semi-clamping hubs 9112.

[0112] There are two cams 9115, which are connected between the two horizontal mounting seats and close to the opposite end faces of the semi-circular shape, and the profile of the cam 9115 contacts the end faces of the two semi-clamping hubs 9112, and the cam 9115 is located between the tension spring 9114 and the clamping base 9111 on the same side;

[0113] The second motor 9116 is used to drive the driving gear 9117;

[0114] There are two driven gears 9118, and both driven gears 9118 are meshed with the driving gear 9117 through the driving gear 9117. The transmission ratio between the driving gear 9117 and the driven gear 9118 is 1:1. The two driven gears 9118 are connected to the cam 9115 on the same side through the gear shaft passing through the clamping base 9111.

[0115] When the driven gear 9118 drives the cam 9115 to rotate, when the contour closest to the base circle contacts the two horizontal mounting seats, the two half-clamping hubs 9112 are closed; when the contour farthest from the base circle contacts the two horizontal mounting seats, the two half-clamping hubs 9112 are opened.

[0116] The free opening and closing and clamping functions of the sample bottle clamping mechanism 911 are realized by the two half clamping hubs 9112 , the tension spring 9114 and the cam 9115 , so as to realize the clamping and releasing of the liquid scintillation bottle 21 .

[0117] Since the tension spring 9114 is tightened and the cam 9115 is pushed open, even in the case of abnormal power failure, the tension spring 9114 can keep the liquid scintillation bottle 21 from falling, thereby ensuring the safety of the liquid scintillation bottle 21. The sample bottle clamping mechanism 911 adopts a large driving gear 9117 and two driven gears 9118, and the driven gear 9118 drives the cam 9115. This motion mechanism can effectively reduce the installation space, has a small torque and is stable.

[0118] The Hall sensor 9119 is located directly below the driving gear 9117 between the driving gear 9117 and the clamping base 9111. The Hall sensor 9119 and the magnet installed on the driving gear 9117 jointly locate the rotation position of the driven gear 9118. When the driven gear 9118 rotates to the top of the Hall sensor 9119, a signal is output, and the driven gear 9118 can be reset to zero.

[0119] The sample bottle clamping mechanism 911 further includes a diffuse reflection optical coupler 100, and the diffuse reflection optical coupler 100 is mounted on the first surface of the clamping base 9111;

[0120] The diffuse reflection optical coupler 100 cooperates with the Hall sensor 200 to detect whether the liquid scintillation bottle 21 is grasped in place by the sample bottle clamping mechanism 911; the diffuse reflection optical coupler 100 cooperates with the Hall sensor 9119 to rotate and accurately position, and can accurately realize the clamping and opening and closing in combination with the micro-stepping motor, which can effectively improve the accuracy and safety of the sample replacement liquid scintillation bottle 21. To detect whether the sample bottle has been clamped to the liquid scintillation bottle, the diffuse reflection sensor detects the bottle cap, and the bottle cap of the liquid scintillation bottle 21 can be detected when it is close to the Hall sensor 9119. If it can be detected, it means that the bottle cap and the sample bottle clamping mechanism 911 are also combined in place. When the sample bottle clamping mechanism 911 is clamped, the liquid scintillation bottle 21 will not fall.

[0121] The lower end of the connecting rod 912 is connected to the second surface of the clamping base 9111 .

[0122] The coordinate upper position of the liquid scintillation bottle 21 is precisely located by the three-axis motion mechanism 92. For the sample bottle clamping mechanism 911, the two half clamping hubs 9112 are pushed open by the cam 9115, and the Z-axis track 923 descends. When the diffuse reflection optical coupler 100 of the clamping mechanism detects the liquid scintillation bottle 21, the Z-axis track 923 stops descending, the cam 9115 reverses, and the tension spring 9114 tightens the two half clamping hubs 9112 to clamp the bottle cap of the liquid scintillation bottle 21. Then, the Z-axis track 923 rises, and the three-axis motion mechanism 92 moves to the top of the measuring chamber 3. The movable lead door 631 is moved through the gear teeth. The bar assembly 633 is opened, the Z-axis track 923 clamps the liquid scintillation bottle 21 to the door position of the movable lead door 631, and the electrostatic ion nozzle 71 and the static-eliminating conductive glue 72 perform static-eliminating operation on the liquid scintillation bottle 21. After the static-eliminating operation is completed, the Z-axis track 923 descends to the bottom of the three-double-coincidence three-way light chamber 31, and the cam 9115 of the sample bottle clamping mechanism 911 rotates forward to open the two half clamping hubs 9112, the liquid scintillation bottle 21 is released, the Z-axis track 923 rises, the movable lead door 631 is closed, and the first measuring probe of the three-tube coincidence photomultiplier tube 32 starts to work. The operation of replacing the liquid scintillation bottle 21 is a reverse process.

[0123] Preferably, the sample bottle storage device 2 further includes a calibration grating 23, and the sample bottle clamping mechanism 911 further includes a photoelectric detector 300, and the calibration grating 23 cooperates with the photoelectric detector 300 to calibrate the position of the sample bottle clamping assembly 91;

[0124] The calibration grating 23 is installed in the sample bottle drawer box 24 and does not overlap with the sample bottle rack 22. The calibration grating 23 is a matrix grating formed by multiple rows and columns of gratings.

[0125] The photodetector 300 is mounted on the first surface of the clamping base 9111 .

[0126] The completion of the embodiments of the present invention also requires the support of various circuits such as measurement circuits and control circuits, as well as power supply, and display through a touch screen. Because these are all existing technologies, they are not described here and are not improved or protected.

[0127] The calibration grating 23 is used for zero point calibration of the sample bottle clamping mechanism 911. The calibration grating 23 is a matrix grating formed by multiple rows and columns of gratings. The matrix grating 23 emits light in sequence at intervals. The photoelectric detector 300 of the sample bottle clamping mechanism 911 receives the grating signal and determines the grating point according to the time point of receiving the light emission, thereby performing position calibration. That is, the coordinates of the position of each light-emitting diode are fixed, and the current position of the sample bottle clamping mechanism 911 is identified by sequential light emission. For example, when the third light-emitting diode emits light, the photoelectric detector 300 on the sample bottle clamping mechanism 911 receives the light signal, and the program can determine the relative position of the grating point and the center position of the sample bottle clamping mechanism 911, and further determine the XY coordinate value position of the sample bottle clamping mechanism 911 at the third light-emitting diode, thereby performing position calibration to improve the accuracy and operation stability of the clamping bottle operation.

[0128] In summary, the triple double coincidence ratio three-way light chamber 31 of the embodiment of the present invention, namely the triple double coincidence ratio (TDCR) three-tube coincidence light chamber, anti-coincidence plastic flash, and graded shielding layer, can improve detection accuracy; low-temperature constant temperature refrigeration improves detection stability; the matrix pressure film sensor 27 for judging the presence of the sample bottle and the intelligent clamping of the sample bottle clamping mechanism 911 improve detection safety and intelligence.

[0129] Compared with the two-tube coincidence photomultiplier tube 32, the three-tube coincidence photomultiplier tube 32 can effectively suppress photoluminescence and chemiluminescence, effectively suppress dark noise, have good linearity, stable counting rate, and strong radionuclide identification ability.

[0130] It should be understood that in the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than those clearly stated in each claim. On the contrary, as reflected in the attached claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the attached claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0131] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0132] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

[0133] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fully automatic low-background liquid scintillation analyzer, characterized in that: It comprises an analyzer frame (1), a sample bottle storage device (2), a measuring chamber (3), an active shielding device (4), a first data transmission line and a second data transmission line; The sample bottle storage device (2) is arranged in the middle layer of the analyzer frame (1), and is used to store a plurality of liquid scintillation bottles (21) and can provide the liquid scintillation bottles (21) for the measuring chamber (3), wherein the liquid scintillation bottles (21) contain scintillation liquid and radioactive samples; The measuring chamber (3) is arranged on the lower bottom plate (11) of the analyzer frame (1) and below the sample bottle storage device (2); the measuring chamber (3) comprises three double coincidence comparison three-way light chambers (31) and three coincidence photomultiplier tubes (32); the three double coincidence comparison three-way light chambers (31) are arranged horizontally and the liquid scintillation bottle (21) provided by the sample bottle storage device (2) can be contained inside the three double coincidence comparison three-way light chambers (31); the three coincidence photomultiplier tubes (32) are arranged horizontally along the circumference of the three double coincidence comparison three-way light chambers (31) and can respectively pass through the three double coincidence comparison three-way light chambers (31); the three coincidence photomultiplier tubes (32) are arranged horizontally along the circumference of the three double coincidence comparison three-way light chambers (31) and can respectively pass through the three double coincidence comparison three-way light chambers (31); The combined photomultiplier tube (32) comprises a first measuring probe, which is connected to the three-way light chamber (31) of the three-way coincidence comparison. When the liquid scintillation bottle (21) is placed in the three-way coincidence comparison light chamber (31), the radiation of the radioactive sample in the liquid scintillation bottle (21) causes the fluorescent substance in the scintillation liquid to fluoresce and release charged particles. The ionized electrons move freely in the scintillation liquid, generating a large number of secondary ionized electrons, forming an electron cascade, thereby causing more luminescence. The first measuring probe is used to collect the luminescence in the liquid scintillation bottle (21), convert the luminescent light signal into an electrical signal and amplify it to obtain a first electrical signal. The active shielding device (4) is arranged on the three-way light chamber (31) of the three-way coincidence ratio and is used to determine the amount of environmental radiation in the three-way coincidence ratio and three-way light chamber (31); the active shielding device (4) comprises a plastic light (41) and two ordinary photomultiplier tubes (42); the plastic light (41) is arranged on the three-way coincidence ratio and three-way light chamber (31) and is used to convert the environmental radiation in the plastic light chamber into an electrical signal; the ordinary photomultiplier tubes (42) are arranged horizontally along the circumference of the plastic light chamber (41) and can respectively penetrate into the plastic light chamber (41); the ordinary photomultiplier tubes (42) comprise a second measuring probe, the second measuring probe penetrates into the plastic light chamber (41) and is used to convert the optical signal in the plastic light chamber (41) into an electrical signal to obtain a second electrical signal; The first data transmission line is used to transmit the first electrical signal to the mainboard; The second data transmission line is used to transmit the second electrical signal to the mainboard.

2. The fully automatic low-background liquid scintillation analyzer according to claim 1, characterized in that: The invention also comprises a passive shielding device (5), the passive shielding device (5) surrounds the outer periphery of the plastic flash (41) and the triple double-coincidence three-way light chamber (31) and is used to shield external environmental radiation, the passive shielding device (5) comprises a plastic layer PMMA (51), a copper layer Cu (52), a cadmium layer Cd (53) and a lead layer Pb (54) arranged from inside to outside; The radiation in the external environment is shielded in sequence by a plastic layer PMMA (51), a copper layer Cu (52), a cadmium layer Cd (53) and a lead layer Pb (54); The secondary radiation generated by the radiation in the external environment in the passive shielding device (5) is shielded in sequence by a plastic layer PMMA (51), a copper layer Cu (52), a cadmium layer Cd (53) and a lead layer Pb (54); The radiation emitted by the copper in the copper layer Cu (52), the cadmium in the cadmium layer Cd (53) and the lead in the lead layer Pb (54) is shielded from the outside to the inside: the radiation emitted by the lead in the lead layer Pb (54) is shielded by the cadmium layer Cd (53), the radiation emitted by the cadmium in the cadmium layer Cd (53) is shielded by the copper layer Cu (52), and the radiation emitted by the copper in the copper layer Cu (52) is shielded by the plastic layer PMMA (51).

3. The fully automatic low-background liquid scintillation analyzer according to claim 1, characterized in that: It also includes a casing (6), wherein the casing (6) includes a measuring chamber tank (61), three first photomultiplier tube sleeves (62) and two second photomultiplier tube sleeves (64); The measuring chamber tank (61) encloses the plastic flash (41) and the triple-double-coincidence three-way light chamber (31); The first photomultiplier tube sleeve (62) is connected to the measuring chamber tank body (61), and each of the first photomultiplier tube sleeves (62) is matched with one of the matching photomultiplier tubes (32), and the first photomultiplier tube sleeve (62) is used to wrap the matching one of the matching photomultiplier tubes (32) together with the internal space of the measuring chamber tank body (61); The second photomultiplier tube sleeve (64) is connected to the measuring chamber tank body (61), each of the second photomultiplier tube sleeves (64) is matched with a common photomultiplier tube (42), and the second photomultiplier tube sleeve (64) is used to wrap the matched common photomultiplier tube (42) together with the internal space of the measuring chamber tank body (61); The fully automatic low-background liquid scintillation analyzer further comprises a heat preservation component (8), wherein the heat preservation component (8) comprises a first liquid-cooled internal pipe arranged at the inner bottom of the measuring chamber tank (61), a second liquid-cooled internal pipe arranged at the inner bottom of each of the first photomultiplier tube sleeves (62), and a third liquid-cooled internal pipe arranged at the inner bottom of each of the second photomultiplier tube sleeves (64); The heat preservation component (8) also includes a semiconductor refrigerator (81) arranged outside the sleeve (6) and on the lower bottom plate (11) of the analyzer frame (1), and the semiconductor refrigerator (81) is respectively connected to the first liquid-cooled internal pipe, the second liquid-cooled internal pipe and the third liquid-cooled internal pipe, and is used to control the semiconductor refrigerator (81) to cool the first liquid-cooled internal pipe, the second liquid-cooled internal pipe and the third liquid-cooled internal pipe through the main board, so as to keep the measuring chamber (3), the compliant photomultiplier tube (32) and the ordinary photomultiplier tube (42) at a low temperature and constant temperature through the refrigerant.

4. The fully automatic low-background liquid scintillation analyzer according to claim 3, characterized in that: The casing (6) further comprises a movable jaw assembly (63), wherein the movable jaw assembly (63) is used for shielding environmental external radiation; The casing (6) has a door opening, and the door opening is arranged on the peripheral side of the measuring chamber tank (61) and on a top plate connected to the peripheral side; The movable jaw assembly (63) comprises a movable jaw (631), two groups of rollers (632), a gear rack assembly (633), a first motor (634), a position sensor and a photoelectric sensor; The movable lead door (631) comprises an upper plate and a vertical plate connected to the upper plate, and the movable lead door (631) matches the door opening and is used to close the door opening; The row of rollers (632) is arranged on the inner side of the top plate of the measuring chamber tank (61) where the door opening is located, and two groups of the row of rollers (632) are symmetrically installed; The first motor (634) and the rack and pinion assembly (633) are arranged outside the door opening; The gear rack assembly (633) comprises a gear and a rack, the rack is connected to the outside of the vertical plate of the movable jaw (631), and the gear is connected to the first motor (634); The first motor (634) drives the gear to rotate, and the gear drives the rack to move to push the movable lead door (631) toward the door opening, and the upper plate of the movable lead door (631) slides on the two groups of rollers (632) in a row to close the movable lead door (631); The position sensor is arranged on the movable jaw door (631), and the photoelectric sensor is arranged at a position on the measuring chamber tank body (61) corresponding to the movable jaw door (631). After the movable jaw door (631) is closed, the photoelectric sensor senses the position sensor and the first motor (634) stops; after the movable jaw door (631) is opened, the photoelectric sensor senses the position sensor and calculates the moving distance of the movable jaw door (631); The movable lead door (631) is used to place the liquid scintillation bottle (21) into the triple double coincidence comparison three-way light chamber (31) after opening, and to shield the external environment radiation.

5. The fully automatic low-background liquid scintillation analyzer according to claim 4, characterized in that: It also includes a static electricity removal device (7), wherein the static electricity removal device (7) is arranged on the top plate of the measuring chamber tank body (61); The static electricity removal device (7) comprises a static electricity removal ion wind nozzle (71), a static electricity removal conductive glue (72) and a mounting bracket (73); The mounting bracket (73) is mounted on the top plate of the measuring chamber tank body (61) near the movable lead gate (631); the static-eliminating ion wind nozzle (71) is mounted on the top plate of the measuring chamber tank body (61); the static-eliminating conductive glue (72) is mounted on the mounting bracket (73) and aligned with the movable lead gate (631); the static-eliminating ion wind nozzle (71) is used to remove static electricity from the liquid scintillation bottle (21) by blowing ion wind in a non-contact manner before the liquid scintillation bottle (21) enters the movable lead gate (631); and the static-eliminating conductive glue (72) is used to contact the liquid scintillation bottle (21) before the liquid scintillation bottle (21) enters the movable lead gate (631) to remove static electricity from the liquid scintillation bottle (21).

6. The fully automatic low-background liquid scintillation analyzer according to claim 1, characterized in that: The sample bottle storage device (2) further comprises a sample bottle rack (22), a sample bottle drawer box (24), a drawer guide rail (25), a safety door lock with a sensor (26), and a matrix pressure film sensor (27); The sample bottle rack (22) is mounted on the sample bottle drawer box (24), the sample bottle drawer box (24) is slidably connected to the analyzer frame (1) via the drawer guide rail (25), and a matching sample exchange hole (241) is provided on the bottom plate of the sample bottle drawer box (24); The sample-carrying bottle rack (22) comprises a lower support plate (221), an upper support plate (222) and a plurality of vertically arranged matrix tubes (223), the bottom of each matrix tube (223) is fixed on the lower support plate (221), the top of each matrix tube (223) passes through the upper support plate (222) and is fixed on the upper support plate (222), and each matrix tube (223) is used to hold one liquid scintillation bottle (21); The safety door lock (26) is installed on the analyzer frame (1) and is located at the innermost end of the sample bottle drawer box (24) when it is closed. The safety door lock (26) is used to monitor the position of the sample bottle drawer box (24); The matrix pressure film sensor (27) is arranged under the matrix tube (223) and is used to monitor whether the liquid scintillation bottle (21) is in place.

7. The fully automatic low-background liquid scintillation analyzer according to claim 6, characterized in that: The apparatus also comprises a sample bottle clamping device (9), the sample bottle clamping device (9) comprising a sample bottle clamping assembly (91) and a three-axis motion mechanism (92), the three-axis motion mechanism (92) being used to support the sample bottle clamping assembly (91) to move to clamp and release the liquid scintillation bottle (21) in the sample bottle storage device (2), the sample bottle clamping device (9) being arranged in the analyzer frame (1) and located above the sample bottle storage device (2); The three-axis motion mechanism (92) comprises two parallel Y-axis rails (922), the Y-axis rails (922) are arranged along the opening and closing motion direction of the sample bottle drawer box (24), and the Y-axis rails (922) are fixed on the analyzer frame (1); The three-axis motion mechanism (92) further comprises an X-axis track (921), and two ends of the X-axis track (921) slide and move on the two Y-axis tracks (922); The three-axis motion mechanism (92) further comprises a Z-axis track (923), wherein the Z-axis track (923) is perpendicular to a plane formed by the two Y-axis tracks (922) and the X-axis track (921), and the Z-axis track (923) slides on the X-axis track (921); The sample bottle clamping assembly (91) can be connected to the X-axis track (921), and the sample bottle clamping assembly (91) can drive the sample bottle clamping assembly (91) to move along the Z-axis track (923) through the X-axis track (921), can move along the Y-axis track (922), and can move along the X-axis track (921).

8. The fully automatic low-background liquid scintillation analyzer according to claim 7, characterized in that: The sample bottle clamping assembly (91) comprises a sample bottle clamping mechanism (911), a connecting rod (912) and a flexible anti-collision mechanism (913); the flexible anti-collision mechanism (913) is connected to the X-axis track (921) and can move along the direction of the X-axis track (921); the upper end of the connecting rod (912) can be connected to the sample bottle clamping mechanism (911); the lower end of the connecting rod (912) can be connected to the sample bottle clamping mechanism (911); the sample bottle clamping mechanism (9110) is used to grasp and release the liquid scintillation bottle (21).

9. The fully automatic low-background liquid scintillation analyzer according to claim 8, characterized in that: The flexible anti-collision mechanism (913) is installed on the Z-axis track (923), and the flexible anti-collision mechanism (913) is connected to the sample bottle clamping mechanism (911) by clamping the connecting rod (912); The flexible anti-collision mechanism (913) comprises a slider mounting frame (9131), a ball linear slide (9132), a guide column (9133), a guide column compression spring (9134), a clamping block base (9135), a clamping pressure block (9136), an anti-collision soft rubber column (9137) and a proximity switch (9138); The ball bearing linear slide (9132) is vertically connected to the slider mounting frame (9131), and the clamping block base (9135) vertically slides on the ball bearing linear slide (9132), and the clamping block base (9135) is guided to move up and down by sliding the clamping block base (9135) on the ball bearing linear slide (9132); The guide column (9133) is arranged vertically, the upper end of the guide column (9133) passes through the slider mounting frame (9131) and the upper end of the guide column (9133) can move up and down to be stuck on the upper part of the slider mounting frame (9131), and the lower end of the guide column (9133) passes through the clamping block base (9135); The guide post compression spring (9134) is sleeved outside the guide post (9133) and is located in the space between the slider mounting frame (9131) and the clamping block base (9135); The clamping block base (9135) and the clamping pressure block (9136) are cooperatively connected to clamp the upper end of the connecting rod (912); The anti-collision soft rubber column (9137) is arranged under the slider mounting frame (9131) and is located between the bottom of the slider mounting frame (9131) and the top of the clamping block base (9135); The proximity switch (9138) is arranged on the slider mounting frame (9131); The sample bottle clamping mechanism (911) comprises a clamping base (9111), a semi-clamping hub (9112), a T-shaped guide column (9113), a tension spring (9114), a cam (9115), a second motor (9116), a driving gear (9117), a driven gear (9118) and a Hall sensor (9119); The semi-clamping hub (9112), the T-shaped guide column (9113), the tension spring (9114), and the cam (9115) are all located on the first surface of the clamping base (9111); The second motor (9116), the driving gear (9117), the driven gear (9118) and the Hall sensor (9119) are all located on the second surface of the clamping base (9111); There are two symmetrical semi-clamping hubs (9112), each of which has a horizontal mounting seat and a vertical semi-circular ring connected to the horizontal mounting seat; There are two T-shaped guide columns (9113), and the two T-shaped guide columns (9113) are symmetrically mounted on the clamping base (9111) by screws, and the horizontal mounting seat of the semi-clamping hub (9112) has a horizontal hole groove that matches the contour of the T-shaped guide column (9113), and the T-shaped guide column (9113) horizontally penetrates the hole groove of the horizontal mounting seat of the semi-clamping hub (9112) and is in clearance fit with the hole groove; the two semicircular rings can form an annular space, and the annular space is used to accommodate one of the liquid scintillation bottles (21); The T-shaped guide column (9113) is used to guide the semicircular ring to move along the circular arc when the semi-clamping circular hub (9112) is opened or closed; There are two tension springs (9114), and the tension springs (9114) are connected between the opposite end surfaces of the two semi-annular shapes; There are two cams (9115), and the cams (9115) are connected between the two horizontal mounting seats and close to the opposite end faces of the semi-circular shape, and the profile of the cams (9115) contacts the end faces of the two semi-clamping hubs (9112), and the cams (9115) are located between the tension spring (9114) and the clamping base (9111) on the same side; The second motor (9116) is used to drive the driving gear (9117); There are two driven gears (9118), and both driven gears (9118) are meshed with the driving gear (9117) through the driving gear (9117). The two driven gears (9118) are connected to the cam (9115) on the same side through the gear shaft passing through the clamping base (9111); The Hall sensor (9119) is located on the driving gear shaft directly below the driving gear (9117) between the driving gear (9117) and the clamping base (9111), and the Hall sensor (9119) and the magnet installed on the driving gear (9117) jointly locate the rotation position of the driven gear (9118); The sample bottle clamping mechanism (911) further comprises a diffuse reflection optical coupler (100), wherein the diffuse reflection optical coupler (100) is mounted on a first surface of the clamping base (9111); the diffuse reflection optical coupler (100) cooperates with the Hall sensor (200) to detect whether the liquid scintillation bottle (21) is grasped in place by the sample bottle clamping mechanism (911); The lower end of the connecting rod (912) is connected to the second surface of the clamping base (9111).

10. The fully automatic low-background liquid scintillation analyzer according to claim 9, characterized in that: The sample bottle storage device (2) further comprises a calibration grating (23), and the sample bottle clamping mechanism (911) further comprises a photoelectric detector (300), wherein the calibration grating (23) cooperates with the photoelectric detector (300) to calibrate the position of the sample bottle clamping assembly (91); The calibration grating (23) is installed in the sample bottle drawer box (24) and does not overlap with the sample bottle rack (22). The calibration grating (23) is a matrix grating formed by multiple rows and columns of gratings. The photoelectric detector (300) is mounted on the first surface of the clamping base (9111).

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