A fully automatic low-background liquid scintillation analyzer

Abstract

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 measuring chamber, and an active shielding device. The measuring chamber comprises a three-way light chamber with a double coincidence ratio and a three-tube coincidence photomultiplier tube. The liquid scintillation bottle provided by the sample bottle storage device can be placed inside the three-way light chamber with a double coincidence ratio. The three-tube coincidence photomultiplier tube is horizontally arranged along the circumference of the three-way light chamber with a first measuring probe that extends into the three-way light chamber with a double coincidence ratio. The active shielding device comprises a plastic scintillation analyzer and two ordinary photomultiplier tubes. The plastic scintillation analyzer is arranged above the three-way light chamber with a double coincidence ratio and is used to convert the ambient radiation therein into an electrical signal. The ordinary photomultiplier tube is horizontally arranged along the circumference of the plastic scintillation analyzer and can extend into the plastic scintillation analyzer. The number of samples to be tested is determined based on the mixture of the sample to be tested and the scintillation liquid. The active shielding device can actively eliminate external radioactive interference and improve detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear radiation detection, in particular to a full-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, so 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] A low-background liquid scintillation analyzer, also known as a liquid scintillation analyzer, is an instrument commonly used for radionuclide measurement. It utilizes the properties of fluorescent substances precipitated in liquid to detect radionuclide radiation, enabling high-sensitivity and high-precision radionuclide counting.

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

[0005] The low-background liquid scintillation analyzer in the prior art has low measurement accuracy and 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-background liquid scintillation analyzers in the prior art in measuring radioactive samples with low measurement accuracy and low safety.

[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 radioactive 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 can hold the liquid scintillation bottle provided by the sample bottle storage device 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 penetrate into the three double coincidence ratio three-way light chamber, the coincidence photomultiplier tubes include a first measuring probe, and the first measuring probe penetrates into 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 electron 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 above the triple-double-coincidence three-way light chamber, and is used to determine the amount of ambient radiation in the triple-double-coincidence three-way light chamber. The active shielding device includes a plastic flash and two ordinary photomultiplier tubes. The plastic flash is arranged above the triple-double-coincidence three-way light chamber, and is used to convert the ambient 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 measurement probe, which 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 electron cascade, thereby causing more luminescence events. Through the sensitive first measurement probe of the coincident photomultiplier tube, these photons can be collected into the coincident photomultiplier tube. The first measurement probe of the coincident photomultiplier tube converts the light signal into an electrical signal. The electrical signal is then amplified by the amplifier circuit, and then analog-to-digital conversion is performed. It is then sent to the main board. The main board program then performs calculations to determine the amount of the sample to be tested (such as a nuclide). 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.

[0014] The first measurement probes of the triple-coincidence photomultiplier tubes are evenly spaced horizontally at 120 degrees around the triple-coincidence three-way light chamber. The distance between the first measurement probes of the triple-coincidence photomultiplier tubes and the scintillation vials can be fine-tuned to achieve parameter matching. The liquid scintillation vials are placed in the triple-coincidence three-way light chamber. Liquid scintillation vials are transparent bottles made of glass or plastic that transmit light and are tightly capped during testing. The liquid scintillation vials primarily emit light, which the first measurement probes of the triple-coincidence photomultiplier tubes can detect only when they are close together.

[0015] The plastic flash is an anti-coincidence plastic flash. Two conventional photomultiplier tubes are arranged horizontally at 120 degrees to form an active shielding measurement system. The plastic flash is a cylindrical material that converts radiation into optical signals, while the conventional photomultiplier tubes convert the optical signals into electrical signals. This active shielding device can actively measure environmental and cosmic radioactive rays and particles, eliminating external radioactive interference and improving 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0017] Figure 1 This 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 This 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 axonometric view of an embodiment of the present invention including a measurement chamber and an active shielding device;

[0020] Figure 4 is an axonometric 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 the movable jaw assembly structure according to an embodiment of the present invention;

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

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

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

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

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

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

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

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

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

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

[0034] Figure 18 is an isometric view of another side of the sample bottle clamping mechanism according to an embodiment of the present invention;

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

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

[0037] The reference numerals indicate:

[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 base plate; 21. Liquid scintillation vial; 22. Sample vial rack; 23. Calibration grating; 24. Sample vial drawer; 25. Drawer guide rails; 26. Safety door lock; 27. Matrix pressure film sensor; 31. Triple-double coincidence ratio three-way optical 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; 62. First photomultiplier tube sleeve; 63. Moving lead door assembly; 64. Second photomultiplier tube sleeve; 71. Anti-static ion nozzle; 72. Anti-static conductive adhesive; 73. Mounting bracket; 81. Semiconductor cooler; 91. Sample vial gripper 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 Steering 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 pressure block; 9137, anti-collision soft rubber column; 9138, proximity switch; 100, diffuse reflection optocoupler; 300, photoelectric detector. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0042] like Figures 1 to 20 , in conjunction 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 provided in the middle layer of the analyzer frame 1 and is used to store a plurality of liquid scintillation bottles 21 and to provide the liquid scintillation bottles 21 for the measuring chamber 3 . 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 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 held inside the three double coincidence comparison three-way light chamber 31, the three coincidence photomultiplier tubes 32 are arranged horizontally along the circumference of the three double coincidence comparison three-way light chamber 31, and can respectively pass through the three double coincidence comparison three-way light chamber 31, the three coincidence photomultiplier tubes 32 The apparatus comprises a first measuring probe, which extends into the triple-double coincidence three-way light chamber 31. When the liquid scintillation vial 21 is placed into the triple-double coincidence three-way light chamber 31, the radiation from the radioactive sample in the liquid scintillation vial 21 causes the fluorescent substance in the scintillation fluid to fluoresce and release charged particles. The ionized electrons move freely in the scintillation fluid, 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 vial 21, convert the luminescent light signal into an electrical signal, and amplify the luminescent light signal to obtain a first electrical signal.

[0045] The active shielding device 4 is disposed above the triple-double coincidence three-way light chamber 31 and is used to determine the amount of ambient radiation within the triple-double coincidence three-way light chamber 31. The active shielding device 4 includes a plastic light source 41 and two ordinary photomultiplier tubes 42. The plastic light source 41 is disposed above the triple-double coincidence three-way light chamber 31 and is used to convert the ambient radiation therein into an electrical signal. The ordinary photomultiplier tubes 42 are arranged horizontally along the circumference of the plastic light source 41 and are capable of respectively penetrating into the plastic light source 41. The ordinary photomultiplier tubes 42 include a second measuring probe that penetrates the plastic light source 41 and is used to convert the optical signal within the plastic light source 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 a liquid scintillation instrument is as follows: the sample to be tested is mixed with scintillation liquid. The radiation of the sample to be tested (e.g., a nuclide) causes the fluorescent substance in the scintillation liquid to fluoresce and release charged particles. These ionized electrons move freely in the scintillation liquid, generating a large number of secondary ionized electrons, forming an electron cascade, thereby causing more luminescence events. These photons can be collected by a sensitive first measurement probe that coincides with the photomultiplier tube 32. The first measurement probe that coincides with the photomultiplier tube 32 converts the light signal into an electrical signal. The electrical signal is then amplified by an amplifier circuit, converted to analog and digital, and sent to the mainboard. The mainboard program then performs calculations to determine the amount of the sample to be tested (e.g., a nuclide). 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. This is an absolute measurement method.

[0049] The first measuring probes of the three-tube coincident photomultiplier tubes 32 are evenly distributed horizontally at 120 degrees around the three-pair coincident three-way light chamber 31. This allows for fine-tuning of the distance between the first measuring probes of the three-pair coincident photomultiplier tubes 32 and the scintillation vials 21, thereby achieving parameter matching. The liquid scintillation vials 21 are placed within the three-pair coincident three-way light chamber 31. The liquid scintillation vials 21 are transparent bottles made of glass or plastic that are translucent and have a tight cap during testing. The liquid scintillation vials 21 primarily emit light, and the first measuring probes of the three-pair coincident photomultiplier tubes 32 can only detect the light when they are relatively close.

[0050] The plastic flash 41 is an anti-coincidence plastic flash, and two conventional photomultiplier tubes 42 are arranged horizontally at 120 degrees to form an active shielding measurement system. The plastic flash 41 is a cylindrical material that converts radiation into optical signals, while the conventional photomultiplier tubes 42 convert the optical signals into electrical signals. The active shielding device 4 can actively measure environmental, cosmic radioactive rays, and particles, eliminating external radioactive interference and improving detection accuracy.

[0051] Low background is the process of eliminating interference from 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) using anti-coincidence plastic flash and anti-coincidence ordinary photomultiplier tube 42, and then eliminate them using an algorithm. Anti-coincidence is active shielding, actively measuring the rays in the environment. The algorithm uses the data measured by the first measurement probe of the three-tube coincidence photomultiplier tube 32 to subtract the data measured by the second measurement probe of the anti-coincidence ordinary photomultiplier tube 42, 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 includes a passive shielding device 5, which surrounds the plastic scintillation analyzer 41 and the triple-double-coincidence three-way light chamber 31 and is used to shield external environmental radiation. The passive shielding device 5 includes a plastic layer PMMA 51, a copper layer Cu 52, a cadmium layer Cd 53, and a lead layer Pb 54 arranged from the inside to the 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 eliminate 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, reducing the interference of radioactive rays from the external environment of the measurement room 3, improving the lower limit of low background radioactive radiation measurement, and realizing low background measurement.

[0057] Preferably, the fully automatic low-background liquid scintillation analyzer further comprises a housing 6 , wherein the housing 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 triple-double-coincidence three-way light chamber 31;

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

[0060] The second photomultiplier tube sleeve 64 is connected to the measuring chamber tank body 61 , and each second photomultiplier tube sleeve 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 includes a heat preservation assembly 8, wherein the heat preservation assembly 8 includes a first liquid-cooled internal pipe provided at the bottom of the measuring chamber tank 61, a second liquid-cooled internal pipe provided at the bottom of each first photomultiplier tube sleeve 62, and a third liquid-cooled internal pipe provided at the bottom of each second photomultiplier tube sleeve 64;

[0062] The insulation component 8 also includes a semiconductor cooler 81 arranged outside the sleeve 6 and on the lower base plate 11 of the analyzer frame 1. The semiconductor cooler 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 cooler 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 maintain 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] Liquid cooling is performed by cooling the cold water in the water tank using a water pump, a water tank, and a semiconductor refrigerator 81, and heat preservation is achieved by the heat sink, fan, and insulation layer of the heat dissipation module. Liquid cooling can maintain the measurement chamber 3, the compliant photomultiplier tube 32, and the ordinary photomultiplier tube 42 at a low temperature and a constant temperature. 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 housing 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 housing 6 has a door opening, which is provided 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 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. The movable lead door 631 matches the door opening and is used 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. The upper plate of the movable lead door 631 slides on the two sets of rollers 632 to close the movable lead door 631. The reverse operation can open the movable lead door 631.

[0072] The position sensor is provided on the movable jaw 631, and the photoelectric sensor is provided on the measuring chamber tank 61 at a position corresponding to the movable jaw 631. When the movable jaw 631 is closed, the photoelectric sensor senses the position sensor, and the first motor 634 is reset to zero, and the first motor 634 stops. When the movable jaw 631 is opened, the photoelectric sensor senses the position sensor, and the distance moved by the movable jaw 631 is calculated.

[0073] The movable lead door 631 is used to place the liquid scintillation 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 perform fully enclosed passive shielding of the measuring chamber 3. The movable lead door 631 effectively blocks light and reduces 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 provided on the top plate of the measuring chamber tank 61;

[0076] The static electricity removal device 7 includes a static electricity removal ion 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 door 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 door 631, the static-eliminating ion wind nozzle 71 is used to remove static electricity from the liquid scintillator bottle 21 by blowing ion wind in a non-contact manner before the liquid scintillator bottle 21 enters the movable lead door 631, and the static-eliminating conductive glue 72 is used to contact the liquid scintillator bottle 21 to remove static electricity from the liquid scintillator bottle 21 before the liquid scintillator bottle 21 enters the movable lead door 631.

[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 simultaneously removed 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 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. The bottom plate of the sample bottle drawer box 24 is provided with a matching sample exchange hole 241, which can achieve repeated and accurate positioning of the sample bottle drawer each time it is opened and closed;

[0081] The sample 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 to the lower support plate 221, and the top of each matrix tube 223 passes through the upper support plate 222 and is fixed to the upper support plate 222. 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 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. A sensor is designed inside the safety door lock, and the sample bottle drawer box 24 cannot be opened under non-program control conditions, 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 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 includes a sample bottle clamping device 9, the sample bottle clamping device 9 including a sample bottle clamping assembly 91 and a three-axis motion mechanism 92, 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, the sample bottle clamping device 9 is provided 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 to the analyzer frame 1;

[0087] The three-axis motion mechanism 92 further includes an X-axis track 921 , and both 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 , which 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 automatic 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. The flexible anti-collision mechanism 913 is connected to the X-axis track 921 and can move along 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. The sample bottle clamping mechanism 911 is used to grasp and release the liquid scintillation vial 21. It can achieve free and precise three-dimensional movement of the sample bottle clamping mechanism 911, realize the sample replacement operation of the liquid scintillation vial 21, and thus realize the orderly automated 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 post 9133, a guide post 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 linear slide 9132 is vertically connected to the slider mounting frame 9131, and the clamping block base 9135 slides vertically on the ball linear slide 9132. The sliding of the clamping block base 9135 on the ball linear slide 9132 realizes the upward and downward movement guidance of the clamping block base 9135;

[0095] The ball linear slide 9132 includes a linear slide (installed on the slider mounting frame 9131) and a ball mounted within the linear slide (the ball is also attached to the clamping block base 9135), which slides within the linear slide. The guide post 9133 is vertically arranged, with its upper end extending through the slider mounting frame 9131 and capable of moving up and down to engage the upper portion of the slider mounting frame 9131. The lower end of the guide post 9133 extends 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 bracket 9131 and the clamping block base 9135;

[0097] When the sample bottle clamping mechanism 911 is vertically impacted (accidental situation), 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 provided below 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;

[0100] The proximity switch 9138 is provided on the slider mounting bracket 9131;

[0101] To prevent the liquid scintillation vial 21 from being impacted and broken by the sample bottle clamping mechanism 911 during movement due to uncontrollable factors or equipment-related issues, a flexible anti-collision mechanism 913 is designed. The flexible anti-collision mechanism 913 is mounted on a slider on the Z-axis track 923, thereby driving the entire sample bottle clamping mechanism 911 to move up and down on the Z-axis track 923. The flexible anti-collision mechanism 913 is connected to the sample bottle clamping mechanism 911 via a 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 effect 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 anti-collision function is implemented using soft anti-collision rubber columns 9137 and a proximity switch 9138. The proximity switch is a purchased sensor that uses electromagnetic induction. When the impact buffer moves a certain distance and senses it, the mainboard immediately controls the second motor 9116 to an emergency stop, preventing further impact and ensuring safe and effective 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 posts 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 profile of the T-shaped guide post 9113. The T-shaped guide post 9113 horizontally penetrates the hole groove on the horizontal mounting seat of the semi-clamping hub 9112 and is loosely matched with the hole groove; the two semi-circular rings can form an annular space, which is used to accommodate one of the liquid scintillation bottles 21;

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

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

[0112] There are two cams 9115, each of which is connected between the two horizontal mounting seats and close to the opposite end faces of the semi-circular shape. The profile of the cam 9115 contacts the end faces of the two semi-clamping hubs 9112. 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, both of which 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 gear shafts that penetrate 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 close; when the contour farthest from the base circle contacts the two horizontal mounting seats, the two half-clamping hubs 9112 open.

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

[0117] Because the tension spring 9114 is tightened and the cam 9115 is pushed open, even in the event of an abnormal power outage, the tension spring 9114 can prevent 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. The driven gears 9118 drive the cam 9115. This motion mechanism can effectively reduce installation space, has low 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 directly above 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 , which 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 vial 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 combined with the micro-stepping motor, it can accurately grasp and open and close the sample vial, which can effectively improve the accuracy and safety of changing the sample vial 21. To detect whether the sample bottle has been grasped by the liquid scintillation vial, the diffuse reflection sensor detects the bottle cap. When the bottle cap of the liquid scintillation vial 21 approaches the Hall sensor 9119, it can be detected. If it can be detected, it means that the bottle cap and the sample bottle clamping mechanism 911 are also in place. When the sample bottle clamping mechanism 911 is clamped, the liquid scintillation vial 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 three-axis motion mechanism 92 is used to accurately locate the upper coordinate position of the liquid scintillation bottle 21. For the sample bottle clamping mechanism 911, the cam 9115 is rotated forward to open the two half-clamping hubs 9112, 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 is reversed, 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 opens, and the Z-axis track 923 clamps the liquid scintillation vial 21 to the entrance of the movable lead door 631. The electrostatic ion nozzle 71 and the anti-static conductive glue 72 simultaneously remove static electricity from the liquid scintillation vial 21. After the static electricity is removed, the Z-axis track 923 descends to the bottom of the triple-double-coincidence three-way light chamber 31. The cam 9115 of the sample bottle clamping mechanism 911 rotates forward to open the two half-clamping hubs 9112, releasing the liquid scintillation vial 21. The Z-axis track 923 rises, the movable lead door 631 closes, and the first measuring probe of the triple-coincidence photomultiplier tube 32 begins operation. The operation of replacing the liquid scintillation vial 21 is the 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 photoelectric detector 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, control circuits, and power supply, and also requires display through a touch screen. Since these are all existing technologies, they are not described here and are not improved or protected.

[0127] The calibration grating 23 is used to calibrate the zero point 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 sequentially emits light at intervals. The photodetector 300 of the sample bottle clamping mechanism 911 receives the grating signal and determines the grating point based on the time of the received light emission, thereby performing position calibration. Specifically, the coordinates of each LED position are fixed, and the current position of the sample bottle clamping mechanism 911 is identified by sequential light emission. For example, when the third LED emits light, the photodetector 300 on the sample bottle clamping mechanism 911 receives the light signal. The program can then determine the relative position of the grating point and the center position of the sample bottle clamping mechanism 911. Furthermore, the XY coordinate value of the sample bottle clamping mechanism 911 at the third LED can be determined. Position calibration is thus performed, improving the accuracy and operational stability of the bottle clamping operation.

[0128] In summary, the triple double coincidence ratio three-way optical chamber 31 of the embodiment of the present invention, namely the triple double coincidence ratio (TDCR) three-tube coincidence optical 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 position 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, 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 foregoing 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 embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of a single disclosed embodiment. The appended claims are therefore hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0131] The above description of the disclosed embodiments is intended to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may 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 presented herein but is intended to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0132] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above embodiments, but one of ordinary skill in the art will recognize that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass all such changes, modifications and variations that fall within the scope of the appended claims. Furthermore, to the extent the term "comprising" is used in the specification or claims, the term is intended to be encompassed in a manner similar to the term "including," as explained in terms of "including," used as a transitional word in the claims. Furthermore, any use of the term "or" in the specification of the claims is intended to mean a "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) includes 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 can accommodate the liquid scintillation bottle (21) provided by the sample bottle storage device (2) inside the three double coincidence comparison three-way light chamber (31), the three coincidence photomultiplier tubes (32) are arranged horizontally along the circumference of the three double coincidence comparison three-way light chamber (31) and can respectively pass through the three double coincidence comparison three-way light chamber (31), the three coincidence photomultiplier tubes (32) are arranged horizontally along the circumference of the three double coincidence comparison three-way light chamber (31), and can respectively pass through the three double coincidence comparison three-way light chamber (31), The combined photomultiplier tube (32) includes a first measuring probe, which is connected to the three-way light chamber (31) with double coincidence ratio. When the liquid scintillator bottle (21) is placed in the three-way light chamber (31), the radiation of the radioactive sample in the liquid scintillator bottle (21) causes the fluorescent substance in the scintillator liquid to fluoresce and release charged particles. The ionized electrons move freely in the scintillator 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 scintillator bottle (21), convert the luminous light signal into an electrical signal, and amplify the luminous light signal to obtain a first electrical signal. The active shielding device (4) is arranged on the triple-double coincidence ratio three-way light chamber (31) and is used to determine the amount of environmental radiation in the triple-double coincidence ratio three-way light chamber (31); the active shielding device (4) includes a plastic flash (41) and two ordinary photomultiplier tubes (42); the plastic flash (41) is arranged on the triple-double coincidence ratio three-way light chamber (31) and is used to convert the environmental radiation in the plastic flash (41) into an electrical signal; the ordinary photomultiplier tubes (42) are arranged horizontally along the circumference of the plastic flash (41) and can respectively penetrate into the plastic flash (41); the ordinary photomultiplier tubes (42) include 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; 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 includes a passive shielding device (5), which 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) includes a plastic layer PMMA (51), a copper layer Cu (52), a cadmium layer Cd (53) and a lead layer Pb (54) arranged from the inside to the outside. The radiation in the external environment is shielded in sequence by the plastic layer PMMA (51), the copper layer Cu (52), the cadmium layer Cd (53) and the 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 generated 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 housing (6), wherein the housing (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 (61), and each of the first photomultiplier tube sleeves (62) is matched with one of the coincident photomultiplier tubes (32). The first photomultiplier tube sleeve (62) is used to wrap the matched coincident photomultiplier tube (32) together with the internal space of the measuring chamber tank (61); The second photomultiplier tube sleeve (64) is connected to the measuring chamber tank (61), and each second photomultiplier tube sleeve (64) is matched with 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 (61); The fully automatic low-background liquid scintillation analyzer further includes a heat preservation component (8), wherein the heat preservation component (8) includes a first liquid-cooled internal pipe provided at the bottom of the measuring chamber tank (61), a second liquid-cooled internal pipe provided at the bottom of each first photomultiplier tube sleeve (62), and a third liquid-cooled internal pipe provided at the bottom of each second photomultiplier tube sleeve (64); The heat preservation component (8) further comprises a semiconductor cooler (81) arranged outside the housing (6) and on the lower base plate (11) of the analyzer frame (1), wherein the semiconductor cooler (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 cooler (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 photomultiplier tube (32) and the ordinary photomultiplier tube (42) at a low temperature and a constant temperature through the refrigerant.

4. The fully automatic low-background liquid scintillation analyzer according to claim 3, characterized in that: The housing (6) further comprises a movable jaw assembly (63), and the movable jaw assembly (63) is used for shielding environmental external radiation; The housing (6) has a door opening, and the door opening is provided 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 sets 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) 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); 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 provided on the movable jaw (631), and the photoelectric sensor is provided on a position corresponding to the movable jaw (631) on the measuring chamber tank (61). After the movable jaw (631) is closed, the photoelectric sensor senses the position sensor, and the first motor (634) stops; after the movable jaw (631) is opened, the photoelectric sensor senses the position sensor, and the distance moved by the movable jaw (631) is calculated. The movable lead door (631) is used to place the liquid scintillation bottle (21) into the triple-double-coincidence 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), which is arranged on the top plate of the measuring chamber tank (61); The static electricity removal device (7) comprises a static electricity removal ion air 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) at a position adjacent to the movable lead gate (631); the static-eliminating ion air nozzle (71) is mounted on the top plate of the measuring chamber tank body (61); the static-eliminating conductive adhesive (72) is mounted on the mounting bracket (73) and aligned with the movable lead gate (631); the static-eliminating ion air nozzle (71) is used to remove static electricity from the liquid scintillation bottle (21) by blowing ion air in a non-contact manner before the liquid scintillation bottle (21) enters the movable lead gate (631); and the static-eliminating conductive adhesive (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), and 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 below 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 analyzer also includes a sample bottle clamping device (9), the sample bottle clamping device (9) including 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), and the sample bottle clamping device (9) is arranged in the analyzer frame (1) and located above the sample bottle storage device (2); The three-axis motion mechanism (92) includes two parallel Y-axis rails (922), 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); The three-axis motion mechanism (92) further includes an X-axis track (921), and both ends of the X-axis track (921) slide and move on the two Y-axis tracks (922); 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); 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) includes 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), and the lower end of the connecting rod (912) can be connected to the sample bottle clamping mechanism (911). The sample bottle clamping mechanism (911) 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) includes a slider mounting frame (9131), a ball linear slide (9132), a guide post (9133), a guide post compression spring (9134), a clamping block base (9135), a clamping pressure block (9136), an anti-collision soft rubber post (9137) and a proximity switch (9138); The ball linear slide (9132) is vertically connected to the slider mounting frame (9131), and the clamping block base (9135) slides vertically on the ball linear slide (9132). The sliding of the clamping block base (9135) on the ball linear slide (9132) realizes the upward and downward movement guidance of the clamping block base (9135); The guide column (9133) is vertically arranged, 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 below the slider mounting frame (9131) and is located between below 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) 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); 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 pillars (9113), and the two T-shaped guide pillars (9113) are symmetrically mounted on the clamping base (9111) by screws, and the horizontal mounting seat of the semi-clamping circular hub (9112) has a horizontal hole groove that matches the profile of the T-shaped guide pillar (9113), and the T-shaped guide pillar (9113) horizontally penetrates the hole groove of the horizontal mounting seat of the semi-clamping circular hub (9112) and is in clearance fit with the hole groove; the two semi-circular 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 arc when the semi-clamping 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), each of which is 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). The cam (9115) is 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 engaged 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). The Hall sensor (9119) and the magnet mounted 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 the first surface of the clamping base (9111); the diffuse reflection optical coupler (100) cooperates with the Hall sensor (9119) 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 includes a calibration grating (23), and the sample bottle clamping mechanism (911) further includes 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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