Submicron CT freezing three-dimensional imaging device with low vibration and high stability

Abstract

The invention relates to the technical field of X-ray three-dimensional imaging, in particular to a low-vibration and high-stability submicron CT freezing three-dimensional imaging device which comprises an in-situ device base, a Dewar flask, a support disc, a hollow red copper tube, a red copper beam, a sample clamp hollow column, an adjustable sample clamp, a high-transmittance imaging area module, a heat preservation movable cover and a temperature monitoring system. The Dewar flask is arranged on the in-situ device base and used for storing liquid nitrogen. The support disc is fixed in the Dewar flask through threads, a support through hole is formed in the support disc, and a hollow red copper pipe is fixed through an elastic screw knob. According to the three-dimensional imaging device, the imaging stability can be remarkably improved, the built-in Dewar flask is combined with a double-path cooling design to eradicate external vibration, a stable environment is provided for long-time and high-resolution scanning, and the imaging quality is improved. The built-in cold source simplifies the device, and the safety and the experiment efficiency of a laboratory are integrally improved.

Description

Technical Field

[0001] This invention relates to the field of X-ray three-dimensional imaging technology, specifically a submicron CT cryo-three-dimensional imaging device with low vibration and high stability. Background Technology

[0002] Multi-scale, multi-dimensional characterization and analysis of micro-area morphology and structure is of great significance for various materials and life science research. X-ray tomography can perform non-destructive three-dimensional imaging of samples from micrometer to centimeter scales, effectively compensating for the limitations of cryo-electron microscopy in three-dimensional imaging of large samples.

[0003] However, X-ray three-dimensional imaging of water-containing samples faces significant challenges. Direct scanning of water-containing samples is prone to imaging failure due to dehydration and deformation; if the sample is dried before imaging, the drying process will destroy the original morphology and structure of the sample. Therefore, achieving cryo-X-ray three-dimensional imaging of water-containing samples is crucial.

[0004] Currently, existing commercial in-situ devices for submicron CT scans have significant limitations: The lowest temperature is only -20℃, which will cause the water in the sample to crystallize into ice. The ice crystals expand and damage the sample structure.

[0005] The single cooling method using base-based heat conduction results in poor temperature uniformity and stability.

[0006] The excessively wide diameter of the X-ray penetration zone (up to 6 cm) results in limited resolution, longer imaging time, and low testing efficiency.

[0007] In addition, another technical solution, which involves continuously introducing liquid nitrogen gas into the imaging chamber to achieve freezing, has problems such as high liquid nitrogen consumption, high potential safety risks, poor sample stability caused by the pumped airflow, continuous leakage of liquid nitrogen through the holes and formation of ice crystals, damage to core CT components, and high system complexity and cost.

[0008] Therefore, there is an urgent need in this field for a cryogenic 3D imaging device that can provide ultra-low temperature, high stability, low vibration and good compatibility. Summary of the Invention

[0009] The purpose of this invention is to provide a submicron CT cryo-3D imaging device with low vibration and high stability to solve the problems mentioned in the background art.

[0010] The objective of this invention can be achieved through the following technical solutions: The device mainly includes an in-situ device base, a Dewar flask, a support plate, a hollow copper tube, a copper bundle, a hollow column for sample clamps, an adjustable sample clamp, a high-transparency imaging zone module, an insulated movable cover, and a temperature monitoring system.

[0011] The Dewar flask is placed on the base of the in-situ device and is used to store liquid nitrogen. A support plate is threaded into the Dewar flask and has a support through-hole, with a hollow copper tube secured by a tightening screw. The hollow copper tube contains one or more copper bundles to enhance thermal conductivity. The top of the hollow copper tube connects to a hollow column of a sample holder, which in turn connects to an adjustable sample holder for holding the sample. The adjustable sample holder is a modular, hollow design that can be replaced according to the sample type (e.g., biological tissue, soft materials, gel) and size, ensuring that liquid nitrogen diffuses upwards, keeping the sample continuously in a low-temperature environment.

[0012] The high-transmittance imaging module surrounds the adjustable sample holder, is covered by a vacuum insulation layer, and is positioned by a fitting sleeve, which is also covered by an insulation layer. The high-transmittance imaging module has a cylindrical structure made of a low atomic number material with high X-ray transmittance. Its diameter can be flexibly changed according to the required imaging resolution, allowing the X-ray source and detector to be closer to the sample, improving resolution and signal-to-noise ratio, and shortening scanning time.

[0013] The heat-insulating cover is placed on top of the high-transparency imaging module, and it has a vent. The cold air generated after the liquid nitrogen vaporizes flows through the support through-hole, the hollow copper tube, and the hollow column of the sample holder, and finally exits from the vent. This process not only continuously cools the sample and imaging area, but also maintains the safe air pressure inside the device.

[0014] The temperature monitoring system includes a temperature sensor probe, temperature sensor circuitry, and an external temperature sensor digital display screen located next to the sample holder. It is used to monitor in real time and ensure that the sample area is always in a stable ultra-low temperature environment (approximately -150°C to -100°C).

[0015] The beneficial effects of this invention are: 1. The three-dimensional imaging device proposed in this invention can significantly improve imaging stability: the built-in Dewar flask combined with the dual-path cooling design eliminates external vibrations and provides a stable environment for long-term, high-resolution scanning.

[0016] 2. Efficiency and convenience: The built-in cold source simplifies the equipment and improves the overall safety and efficiency of the laboratory.

[0017] 3. Maximize sample structure fidelity: Standardized and personalized freezing preparation and low-temperature treatment throughout the process effectively suppress ice crystal damage and preserve the original and true microstructure of water-containing samples to the greatest extent.

[0018] 4. Enhanced system compatibility and flexibility: The modular multi-specification sample fixture and imaging window design enables the system to widely adapt to the high-quality imaging needs of water-containing samples of different disciplines, types, and sizes. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 yes Figure 1 A cross-sectional view of the middle Dewar flask; Figure 3 This is a schematic diagram of the hollow clamp for thin-film samples proposed in this invention; Figure 4 This is a schematic diagram of the structure of the hollow clamp for thick sheet samples proposed in this invention; Figure 5 This is a schematic diagram of the structure of the hollow clamp for block samples proposed in this invention.

[0020] The attached figures are labeled as follows: 1. Vent; 2. Insulated movable cover; 3. High-transparency imaging zone module; 4. Adjustable sample clamp; 5. Temperature sensor probe; 6. Hollow column of sample clamp; 7. Vacuum insulation layer; 8. Temperature sensor circuit; 9. Insulation layer; 10. Fitting sleeve; 11. Dewar flask insulated cover; 12. Support through hole; 13. Support plate; 14. Tightening screw; 15. Temperature sensor digital display screen; 16. Hollow copper tube; 17. Dewar flask; 18. Copper bundle; 19. Support holder; 20. In-situ device base. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The specific embodiments of the present invention are described in detail below with reference to the technical solutions and accompanying drawings.

[0023] Figure 2 A submicron CT cryo-in-situ imaging device for low vibration and high stability was demonstrated. The device consists of three parts: an in-situ device base located at the bottom of the overall device, a main body and thermal insulation and ventilation area located in the overall device, and a temperature and humidity sensor located on the outside of the device, as detailed below: The base 20 is located at the bottom of the device, on which the complete Dewar bottle 17 is placed, and the Dewar bottle insulation cover 11 is located above the Dewar bottle 17.

[0024] The hollow copper tube 16 is fixed in the support plate 13 with the loosening screw 14. The entire support plate 13 is fixed in the Dewar flask 17 by the thread and is upright at the bottom of the Dewar flask 17 with the hollow support 19.

[0025] The central area of ​​the support plate 13 has multiple support through holes 12. The hollow copper tube 16 contains one or more copper bundles 18.

[0026] The outer side of the fitted sleeve 10 is covered with a thermal insulation layer 9, located inside the Dewar flask insulation cap 11. The outer side of the high-transparency imaging area module 3 is covered with a vacuum insulation layer 7, located inside the fitted sleeve 10.

[0027] The top of the hollow copper tube 16 is connected to the hollow column 6 of the sample clamp, and the upper part is detachably connected to the adjustable sample clamp 4. The temperature sensor probe 5 is connected to the clamp of the adjustable sample clamp 4. The temperature sensor circuit 8 is connected to the temperature sensor digital display screen 15 through the lower pipe.

[0028] like Figure 3 , Figure 4 and Figure 5 The adjustable sample clamp 4 is a hollow modular clamp that can be replaced according to the shape and size of the sample. It includes different types of clamps suitable for thin sheet samples, thick sheet samples and block samples. The detachable connection method can be selected from existing technologies such as threaded connection, bolt fixing or snap connection, which will not be described in detail here.

[0029] The heat-insulating movable cover 2 is placed on top of the high-transparency imaging area module 3. The upper middle area of ​​the heat-insulating movable cover 2 has a vent 1. After the liquid nitrogen is vaporized, it passes through the support through hole 12, the hollow copper tube 16 and the hollow column 6 of the sample holder, and is discharged from the device through the vent 1, so as to continuously maintain the safe gas pressure inside the imaging module and the cooling effect of liquid nitrogen evaporation on the imaging area and the sample.

[0030] The working principle of the low-vibration, high-stability submicron CT cryo-3D imaging device provided by this invention is as follows: After injecting an appropriate amount of liquid nitrogen into the Dewar flask 17, the insulated lid 11 of the Dewar flask is quickly closed. The low-temperature nitrogen gas generated by the natural vaporization of the liquid nitrogen flows sequentially through the support through-hole 12 of the support plate 13, the interior of the hollow copper tube 16, and the hollow column 6 of the sample holder, and finally exits from the vent 1 at the top. This airflow path simultaneously achieves "atmosphere cooling" of the sample and "conductive cooling" through the copper components. The temperature sensor probe 5 monitors the temperature of the sample area in real time. Once the temperature stabilizes within the required ultra-low temperature range, submicron CT can be initiated for three-dimensional scanning imaging.

[0031] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A low-vibration, high-stability submicron CT cryo-3D imaging device, comprising an in-situ device base (20), characterized in that, Also includes: A Dewar flask (17) is placed on the base (20) of the in-situ device for storing liquid nitrogen; The support plate (13) is fixed inside the Dewar flask (17) by threads, and the support plate (13) is provided with a support through hole (12). Hollow copper tube (16) is fixed to the support plate (13) by tightening screw (14), and one or more copper bundles (18) are provided inside the hollow copper tube (16). The hollow column (6) in the sample holder is connected to the top of the hollow copper tube (16); An adjustable sample clamp (4) is connected to the upper part of the hollow column (6) in the sample clamp and is used to hold the sample. The high-transparency imaging area module (3) is surrounded by an adjustable sample clamp (4).

2. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 1, characterized in that, It also includes a Dewar bottle insulated cap (11), which is placed on top of the Dewar bottle (17).

3. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 2, characterized in that, The high-transparency imaging module (3) is positioned by the fitting sleeve (10), the fitting sleeve (10) is covered with a heat insulation layer (9) on the outside, and the high-transparency imaging module (3) is covered with a vacuum heat insulation layer (7) on the outside.

4. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 1, characterized in that, A hollow support (19) is provided below the support plate (13), and the hollow support (19) is placed upright at the bottom of the Dewar bottle (17).

5. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 1, characterized in that, The high-transparency imaging module (3) is a cylindrical structure made of low atomic number material, and its diameter can be changed according to the imaging resolution requirements.

6. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 1, characterized in that, The entire device is made of low-temperature compatible materials, and its dimensions are matched with the sample stage space and movement stroke of the target submicron CT equipment.

7. A low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 1, characterized in that, The three-dimensional imaging device also includes a temperature monitoring system, which includes a temperature sensor probe (5) located next to the adjustable sample holder (4), a temperature sensor line (8) connected to the probe, and an external temperature sensor digital display screen (15).

8. The low-vibration, high-stability submicron CT cryo-3D imaging device according to claim 3, characterized in that, The high-transparency imaging area module (3) is provided with a heat-insulating movable cover (2) on its top, and a vent hole (1) is opened on the heat-insulating movable cover (2).

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