An aerodynamic lens sample introduction device for single particle imaging
By introducing a stepped nozzle and a converging capillary into the aerodynamic lens sample introduction device, the problems of difficulty in focusing small particles and high gas scattering in the prior art are solved, and higher spatial resolution and particle focusing effect are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANGHAI TECH UNIV
- Filing Date
- 2023-06-25
- Publication Date
- 2026-07-03
AI Technical Summary
Existing aerodynamic lenses are difficult to focus effectively on particles as small as tens of nanometers, and the large air flow rate leads to high background scattering, which hinders the improvement of spatial resolution in single-particle imaging.
An aerodynamic lens injection device, comprising a stepped nozzle and a converging capillary, is employed to increase flow resistance, suppress Brownian motion, reduce gas flow rate, and improve particle focusing effect.
It suppresses the Brownian motion of small particles, reduces gas scattering, improves spatial resolution, and enables effective focusing of particles tens of nanometers.
Smart Images
Figure CN116793928B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of particle sample introduction technology, and in particular to an aerodynamic lens sample introduction device for single-particle imaging. Technical Background
[0002] Single-particle imaging is a key application of X-ray free-electron lasers, enabling three-dimensional imaging of weakly scattering samples such as biomolecules, viruses, cells, and nanoparticles. It also offers significant advantages in live-cell imaging and the study of dynamic processes. Single-particle imaging experiments typically use a large number of submicron particles with identical structures as samples. Two-dimensional diffraction patterns with random spatial orientations are collected under vacuum, and high-resolution three-dimensional structures of the particles are obtained through orientation localization and phase retrieval. Because the sample is destroyed by the ultrashort, ultra-intense X-ray pulse, a new sample must be provided for each X-ray pulse.
[0003] Based on the characteristics of this experimental process, single-particle imaging requires a sample introduction method with high sample concentration, rapid replacement of damaged samples, and low background scattering to deliver sample particles to the interaction region between X-rays and the sample.
[0004] Currently, the commonly used sample introduction method for single-particle imaging is aerodynamic lens introduction. In this method, an aerodynamic lens sequentially passes a particle-loaded aerosol through multiple coaxial circular pads with a central opening. The particles, under the influence of their own inertia and the drag force of the gas (the drag force being the resistance exerted by the fluid on a solid with relative velocity), converge near the axis of gravity and are finally ejected as a highly focused particle beam through an accelerating nozzle. However, due to the significant Brownian motion of small particles, the resulting diffusion broadening increases the width of the particle beam, making focusing difficult. Existing aerodynamic lenses struggle to effectively focus particles with diameters of tens of nanometers, and the large gas flow rate leads to high background scattering, hindering the improvement of spatial resolution in single-particle imaging. This invention aims to address these problems. Summary of the Invention
[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an aerodynamic lens sample introduction device for single-particle imaging, which can suppress the Brownian motion of small particles, improve the focusing of small particles and reduce the gas flow rate, thereby achieving the experimental purpose, while simultaneously reducing gas scattering and improving spatial resolution.
[0006] To achieve the above and other related objectives, this invention provides an aerodynamic lens sample introduction device for single-particle imaging. The device includes a degassing unit, a vacuum connection unit, and an aerodynamic lens; the degassing unit, vacuum connection unit, and aerodynamic lens are sequentially connected and interconnected; one end of the degassing unit is externally connected to an aerosol generator. The aerodynamic lens has an input end and an output end. The input end receives particles transmitted by the vacuum connection unit, and the output end delivers the focused particles to the experimental area. The output end of the aerodynamic lens has an accelerating nozzle, which includes a stepped nozzle and a converging capillary. The inner diameter of the stepped nozzle decreases sequentially along the particle transport direction. One end of the converging capillary is a tapered opening, and the other end passes through the stepped nozzle and communicates with the inner cavity of the aerodynamic lens.
[0007] In some specific embodiments, the stepped nozzle is a concentric reducing pipe; the stepped nozzle 341 includes a first reducing pipe, a second reducing pipe and a third reducing pipe with successively decreasing inner diameters; the inner diameter of the first reducing pipe is 15-30 mm and the length is 10-25 mm; the inner diameter of the second reducing pipe is 7-15 mm and the length is 10-25 mm; the inner diameter of the third reducing pipe is 0.2-0.8 mm and the corresponding length is 10-30 mm.
[0008] In some feasible embodiments, the inner diameter of the converging capillary 342 is 0.2 to 0.6 mm, the wall thickness is 0.1 to 0.3 mm, the length is 30 to 100 mm, the cone angle of the conical opening of the converging capillary 342 is 20 to 70°, and the inner diameter of the conical outlet is 0.1 to 0.5 mm.
[0009] In some feasible embodiments, the stepped nozzle 341 is a stainless steel tube.
[0010] In some feasible embodiments, the converging capillary 342 is a stainless steel tube or a glass tube.
[0011] In one specific embodiment, the degassing device includes an inlet cone, a degassing cone, and a differential extraction chamber; the inlet cone and the degassing cone pass through the inner wall of the differential extraction chamber and communicate with the inner cavity of the differential extraction chamber; the differential extraction chamber has an extraction port 131 on its side wall, and the extraction port 131 is connected to an external extraction device.
[0012] In one feasible embodiment, the central axes of the intake cone and the degassing cone are located on the same straight line. The input end of the intake cone is connected to an aerosol generator, and the output end of the intake cone is an inwardly converging conical opening. The input end of the degassing cone is also an inwardly converging conical opening. The output end of the intake cone is directly opposite the input end of the degassing cone.
[0013] In some feasible embodiments, the inner diameter of the intake cone 11 is 16-35 mm, the cone angle of the output end of the intake cone is 25-40°, and the inner diameter of the conical opening of the output end of the intake cone is 0.1-0.5 mm.
[0014] In some feasible embodiments, the inner diameter of the degassing cone 12 is 16-35 mm, the cone angle of the input end of the degassing cone is 35-60°, and the inner diameter of the conical opening of the input end of the degassing cone is 0.5-1.0 mm.
[0015] In some feasible implementations, the distance between the tip of the degassing cone at the input end and the tip of the degassing cone at the input end is 1 to 4 mm.
[0016] In one feasible embodiment, the intake cone, the degassing cone, and the differential extraction chamber are all made of stainless steel pipes.
[0017] In one feasible embodiment, at least one air extraction port 131 is provided on the side wall of the differential air extraction chamber.
[0018] In one specific embodiment, the vacuum connection device 2 is further provided with a vacuum chamber flange 21.
[0019] In one feasible embodiment, the vacuum chamber flange is located outside the vacuum connection device for detachable connection with the experimental chamber.
[0020] In one feasible embodiment, the vacuum connection device is further provided with a pressure detection port 22, which is connected to an external pressure detection device.
[0021] In one feasible embodiment, the vacuum connection device 2 is provided with at least one of the pressure detection ports 22.
[0022] In some feasible embodiments, the inner diameter of the vacuum connection device 2 is 40-65 mm.
[0023] In some feasible embodiments, the vacuum chamber flange 21 is of model CF100 or CF150.
[0024] In a specific real-time configuration, the aerodynamic lens includes an outer sleeve and multiple sets of duct lenses disposed within the outer sleeve; each set of duct lenses is arranged sequentially within the outer sleeve; each set of duct lenses includes a conical aperture lens and a spacer duct, and each conical aperture lens and each spacer duct are spaced apart; each conical aperture lens is provided with a conical through hole, and each conical through hole is provided with a narrow end 322 and a wide end 323; the wide end of the conical through hole faces the output end of the aerodynamic lens, and the central axes of each conical through hole are on a straight line.
[0025] In one feasible embodiment, the inner diameter of the narrow end 322 of the tapered through hole decreases sequentially along the particle conveying direction.
[0026] In some feasible embodiments, the outer sleeve has an inner diameter of 15-30 mm, a wall thickness of 3-5 mm, and a length of 100-300 mm.
[0027] In some feasible embodiments, the outer diameter of the tapered lens is smaller than the inner diameter of the outer sleeve, the thickness is 1.0–1.5 mm, the inner diameter of the narrow end of the tapered through-hole (322) is 0.4–2.0 mm, and the cone angle is 10–30°.
[0028] In one feasible embodiment, a sealing fastener is provided between the tapered lens and the spacer pipe.
[0029] In one feasible embodiment, both the outer sleeve and the spacer pipe are stainless steel pipes.
[0030] In one feasible embodiment, the tapered lens is a thin sheet of stainless steel.
[0031] The beneficial effects of the present invention are as follows:
[0032] 1. In this invention, the converging capillary has a large flow resistance, which increases the air pressure inside the aerodynamic lens, thereby suppressing the Brownian motion of small particles, obtaining a smaller particle beam width, and reducing the gas flow rate, thus reducing the scattering of the gas background.
[0033] 2. Compared with the traditional stepped acceleration nozzle, the acceleration nozzle in this invention has a smaller converging capillary geometry, which helps to avoid blocking high-angle scattered signals.
[0034] 3. Compared with traditional thin-film lenses, conical aperture lenses are thicker and have higher mechanical strength than commonly used circular thin-film lenses. Attached Figure Description
[0035] Figure 1 This is a schematic diagram of the overall structure of the present invention.
[0036] Figure 2 This is a schematic diagram of the degassing device in this invention.
[0037] Figure 3 This is a schematic diagram of the vacuum connection device of the present invention.
[0038] Figure 4 This is a schematic diagram of the aerodynamic lens structure of the present invention.
[0039] Figure 5 This is a schematic diagram of the structure of the aerodynamic lens and acceleration nozzle of the present invention.
[0040] Figure 6This is a schematic diagram of the acceleration nozzle structure of the present invention.
[0041] Figure 7 This is a schematic diagram of the tapered aperture lens and fixing screw structure of the present invention.
[0042] Figure 8 This is a schematic diagram of the structure of the conical aperture lens of the present invention.
[0043] Figure 9 This is an enlarged view of the structure of the conical aperture lens of the present invention.
[0044] Figure Labels
[0045] Degassing device 1, intake cone 11, degassing cone 12, differential extraction chamber 13, extraction port 131, vacuum connection device 2, vacuum chamber flange 21, pressure detection port 22, aerodynamic lens 3, outer sleeve 31, tapered aperture lens 32, tapered through hole 321, narrow end of tapered through hole 322, wide end of tapered through hole 323, spacer pipe 33, accelerating nozzle 34, stepped nozzle 341, converging capillary tube 342, sealing fastener 35, fixing screw 36. Detailed Implementation
[0046] The inventors of this invention have designed an aerodynamic lens sample introduction device for single-particle imaging through extensive experimentation. The aim of this device is to maintain a reasonable particle beam width, suppress Brownian motion of small particles, and preserve aerodynamic focusing. Increasing gas pressure can suppress diffusion broadening caused by Brownian motion, but it also increases gas flow, potentially disrupting the vacuum of the subsequent experimental chamber and increasing background scattering, thus affecting experimental results. This invention aims to address these issues. Research indicates that the particle beam width is controlled by two factors: the aerodynamic focusing effect of the lens and diffusion broadening caused by Brownian motion. Since Brownian motion is more pronounced with smaller particles, diffusion broadening caused by Brownian motion becomes the primary factor affecting the beam width of small particles. Diffusion broadening can be controlled by the root mean square displacement x. rms estimate:
[0047]
[0048] Where D is the particle diffusion coefficient, t is the particle residence time, α is the momentum regulation coefficient, and d p Where is the particle diameter, k is the Boltzmann constant, T is the gas temperature, P is the gas pressure, and mg is the gas molecular mass.
[0049] Increasing gas pressure reduces diffusion broadening caused by Brownian motion, resulting in a finer particle beam. However, for aerodynamic lenses, higher pressure leads to higher gas flow rates, which in turn disrupts the vacuum within the experimental chamber and increases background scattering. Therefore, the inventors incorporated a stepped structure into the nozzle of the aerodynamic lens and added specially shaped capillaries. By utilizing the greater flow resistance of the capillaries, they not only increased the pressure within the aerodynamic lens and suppressed Brownian motion but also achieved a narrower particle beam width, thus avoiding excessively high gas flow rates.
[0050] Compared with existing aerodynamic sample introduction devices, the main advantage of this device is that it suppresses the Brownian motion of small particles through aerodynamic lenses, thereby enabling the effective aggregation of particles with a diameter of tens of nanometers.
[0051] 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.
[0052] Example 1
[0053] like Figures 1-7 As shown, an aerodynamic lens sample introduction device for single-particle imaging includes a degassing device 1, a vacuum connection device 2, and an aerodynamic lens 3. The degassing device 1, vacuum connection device 2, and aerodynamic lens 3 are sequentially connected and interconnected. One end of the degassing device 1 is externally connected to an aerosol generator to remove excess gas from the aerosol and increase the particle concentration. The aerodynamic lens 3 has an input end and an output end. The input end receives particles transmitted by the vacuum connection device 2, and the output end delivers the focused particles to the experimental area. The output end of the aerodynamic lens 3 has an accelerating nozzle 34, which includes a stepped nozzle 341 and a converging capillary 342. The inner diameter of the stepped nozzle 341 decreases sequentially along the particle conveying direction. One end of the converging capillary 342 is a tapered opening, and the other end passes through the stepped nozzle 341 and communicates with the inner cavity of the aerodynamic lens 3. The aerodynamic lens 3 is used to focus particles in the aerosol, which can be particles with a diameter range of 30-3000 nm. The gas in the aerosol can be nitrogen or helium.
[0054] It's worth noting that aerosol generators are used to disperse solid particles contained in a solution into a gas (the solid particles themselves are in the solution). Aerosol generators use nitrogen or helium to atomize a solution containing particles into micron-sized droplets, each droplet containing several solid particles. These droplets evaporate rapidly, leaving only the particles.
[0055] It is worth noting that the stepped nozzle 341 is a concentric reducing tube with multiple reducing tubes. The stepped nozzle 341 is used to transmit the particle beam to the converging capillary 342. The inner diameter of the stepped nozzle 341 decreases sequentially, which can avoid the particle beam, which has been initially focused by multiple lenses, from being over-focused in the stepped nozzle 341, causing the particle beam to diverge rapidly and the beam width to widen.
[0056] In some feasible embodiments, the stepped nozzle 341 includes a first variable diameter tube, a second variable diameter tube, and a third variable diameter tube with successively decreasing inner diameters; the inner diameter of the first variable diameter tube is 15–30 mm, and its length is 10–25 mm; the inner diameter of the second variable diameter tube is 7–15 mm, and its length is 10–25 mm; the inner diameter of the third variable diameter tube is 0.2–0.8 mm, corresponding to a length of 10–30 mm. In some feasible embodiments, the converging capillary 342 has an inner diameter of 0.2–0.6 mm, a wall thickness of 0.1–0.3 mm, and a length of 30–100 mm; the cone angle of the converging capillary conical orifice is 20–70°, and the inner diameter of the converging capillary conical orifice is 0.1–0.5 mm. The converging capillary 342 is used to increase flow resistance, rapidly reduce pressure, and focus and accelerate particles.
[0057] It is worth noting that the number of stages, the inner diameter and length of each stage of the stepped nozzle 341, and the parameters of the converging capillary 342 in the above embodiments are interrelated. All parameters were obtained through simulation and experimental verification to determine the optimal dimensions. For example, a reasonable flow rate can be controlled by designing a reasonable inner diameter of the converging capillary conical orifice, and the focusing degree of the particle beam can be controlled by designing a reasonable cone angle. A cone angle that is too small or too large will cause the particle beam to widen: too small a cone angle results in insufficient focusing; too large a cone angle leads to over-focusing of the particle beam and rapid divergence. The cone angle of the converging capillary conical orifice is 20–70°, with options including 20–30°, 30–40°, 40–50°, 50–60°, and 60–70°.
[0058] In a preferred embodiment, the stepped nozzle 341 is a stainless steel tube.
[0059] In a preferred embodiment, the converging capillary 342 is a stainless steel tube or a glass tube.
[0060] like Figure 2 As shown, the degassing device 1 includes an inlet cone 11, a degassing cone 12, and a differential extraction chamber 13; the inlet cone 11 and the degassing cone 12 pass through the inner wall of the differential extraction chamber 13 and communicate with the inner cavity of the differential extraction chamber 13; an extraction port 131 is provided on the side wall of the differential extraction chamber 13, and an external extraction device is connected to the extraction port 131.
[0061] It is worth noting that the extraction equipment controls the overall gas volume within the degassing device 1. Extraction refers to removing excess gas and concentrating particles while simultaneously controlling the pressure at the inlet of the aerodynamic lens 3, thereby controlling the gas flow rate entering the aerodynamic lens 3.
[0062] In one feasible embodiment, the intake cone 11 and the degassing cone 12 are pipe structures, and the two ends of the intake cone 11 and the degassing cone 12 are respectively flat and converging cone; at the same time, the central axes of the intake cone 11 and the degassing cone 12 are located on the same straight line.
[0063] In one feasible embodiment, the input end of the intake cone 11 is a flat opening, and the output end of the intake cone 11 is a conical opening; the input end of the degassing cone 12 is a conical opening, and the output end of the degassing cone 12 is a flat opening; the input end of the intake cone 11 is connected to an aerosol generator, and the output end of the intake cone 11 is directly opposite the input end of the degassing cone 12. There is a gap between the intake cone and the degassing cone, and the gas comes out from the gap and is discharged through the exhaust port.
[0064] Specifically, the aerosol enters the inlet cone 11 through its input end. As the inner diameter of the inlet cone 11 decreases, the gas and particles continuously accelerate and enter the inner cavity of the degassing device 1 through its output end. Subsequently, a small amount of gas and most of the particles enter the degassing cone 12 through its input end and enter the vacuum connection device 2 through its output end. During this process, the pumping equipment evacuates the inner cavity of the degassing device 1, discharging most of the gas and increasing the concentration of particles entering the vacuum connection device 2.
[0065] In some specific embodiments, the inner diameter of the intake cone 11 is 16-35 mm, the cone angle of the intake cone output end is 25-40°, and the inner diameter of the intake cone output end is 0.1-0.5 mm.
[0066] In some specific embodiments, the inner diameter of the degassing cone 12 is 16-35 mm, the cone angle of the input end of the degassing cone is 35-60°, and the inner diameter of the input end of the degassing cone is 0.5-1.0 mm.
[0067] In some specific embodiments, the distance between the tips of the degassing cones is 1 to 4 mm.
[0068] It is worth noting that the parameters of the intake cone 11 and the degassing cone 12 were obtained through simulation and the optimized dimensions were verified by experiments.
[0069] In a preferred embodiment, the inlet cone 11, the degassing cone 12, and the differential extraction chamber 13 are all made of stainless steel pipes. The stainless steel structure improves the overall structural strength of the degassing device 1, preventing mechanical deformation caused by high pressure in the inner cavity, which could affect the experimental results.
[0070] In a preferred embodiment, at least one extraction port 131 is provided on the side wall of the differential extraction chamber 13. One extraction port 131 is externally connected to an extraction device, and the remaining extraction ports can be fitted with observation windows for observation. Figure 3 As shown, the vacuum connection device 2 is also provided with a vacuum chamber flange 21; the vacuum chamber flange 21 is located on the outside of the vacuum connection device 2 and is used for detachable connection with the experimental chamber.
[0071] In one specific embodiment, the vacuum chamber flange 21 is fixed to the experimental chamber by screws.
[0072] In one feasible embodiment, the vacuum connection device 2 is further provided with a pressure detection port 22, which is externally connected to a pressure detection device. A feedback mechanism is established between the pressure detection device and the pumping device, and the pumping volume of the pumping device is controlled by the pressure value fed back by the pressure detection device, thereby achieving the ideal gas volume for the experiment.
[0073] It is worth noting that although the gas flow rate required for the operation of the aerosol generator can be adjusted, the gas flow rate is too large for the aerodynamic lens 3, and some gas still needs to be removed. When the gas pressure is fixed, the gas flow rate is also fixed. Compared with controlling the gas flow rate, controlling the gas pressure is more convenient and simple, and the pressure index is easier to detect.
[0074] In a preferred embodiment, the vacuum connection device 2 is provided with at least one pressure detection port 22, and each pressure detection port 22 can be connected to an external pressure detection device.
[0075] Specifically, the pressure detection device and the pumping device form a feedback loop. The pressure inside the vacuum connection device 2 is controlled by the pumping rate of the pumping device. The pressure detection device detects the real-time pressure and feeds it back to the pumping device. The pumping device adaptively adjusts its pumping rate based on the pressure conditions required for sample injection and the real-time pressure data fed back by the pressure detection device, thereby slowing down or speeding up its pumping rate so that the pressure in the vacuum connection device 2 meets the requirements for sample injection.
[0076] In some specific embodiments, the inner diameter of the vacuum connection device 2 is 40–65 mm.
[0077] In some specific embodiments, the vacuum chamber flange 21 is model CF100 or CF150.
[0078] like Figures 4-8 As shown, the aerodynamic lens 3 includes an outer sleeve 31 and multiple sets of pipe lenses disposed within the outer sleeve 31, with each set of pipe lenses arranged sequentially within the outer sleeve 31.
[0079] Specifically, the outer sleeve 31 is detachably connected to multiple sets of pipe lenses.
[0080] More specifically, the outer sleeve 31 is detachably connected to multiple sets of pipe lenses by fixing screws 36.
[0081] Specifically, each group of pipe lenses includes a conical aperture lens 32 and a spacer pipe 33. Both the conical aperture lens 32 and the spacer pipe 33 are annular, and each conical aperture lens 32 and each spacer pipe 33 are spaced apart.
[0082] More specifically, such as Figure 9 As shown, each tapered aperture lens 32 is provided with a tapered through hole 321. The cross-sectional shape of the tapered through hole 321 resembles a beveled blade with its tips facing each other. The sides with the blade tips facing each other are designated as the narrow end 322 of the tapered through hole, and the other end is designated as the wide end 323 of the tapered through hole. The wide end 323 of the tapered through hole faces the output end of the aerodynamic lens 3, and the central axis of each tapered through hole 321 is on a straight line.
[0083] It is worth noting that the thickness of the conical aperture lens 32 is greater than that of the commonly used circular aperture lens. In order to ensure its focusing effect, the circular aperture lens has a thinner thickness, but its mechanical strength is not high and it is more easily damaged.
[0084] It is worth noting that each conical aperture lens 32 forms a contraction-expansion airflow field in front of and behind it. Under the influence of its own inertia and the drag force of the gas, the particles gather near the axis, thereby achieving the focusing function of the particles.
[0085] In one specific embodiment, the inner diameter of the narrow end 322 of the tapered through-hole decreases sequentially along the gas flow direction. The wide end 323 of the tapered through-hole is used to focus larger particles, while the narrow end 322 of the tapered through-hole is used to focus smaller particles, which are ultimately ejected through a converging capillary.
[0086] It is worth noting that the smaller the aperture, the faster the gas flow rate and the faster the particle flow rate; by adopting a step-by-step decreasing inner diameter method, the particles are continuously focused, thus optimizing the focusing effect.
[0087] In some specific embodiments, the inner diameter of the outer sleeve 31 is 15-30 mm, the wall thickness is 3-5 mm, and the length is 100-300 mm.
[0088] In some specific embodiments, the outer diameter of the tapered lens 32 is equal to the inner diameter of the outer sleeve 32, the thickness is 1.0 to 1.5 mm, the inner diameter of the narrow end of the tapered through hole 322 is 0.4 to 2.0 mm, and the cone angle is 10 to 30°.
[0089] It is worth noting that the thickness of the tapered lens 32, the inner diameter of the narrow end 322 of the tapered through hole, and the cone angle are all obtained through simulation and are optimized values verified by experiments. In a feasible embodiment, a sealing fastener 35 is provided between the tapered lens 32 and the spacer pipe 33.
[0090] In a preferred embodiment, both the outer sleeve 31 and the spacer pipe 33 are stainless steel pipes.
[0091] In a preferred embodiment, the tapered lens 32 is a thin sheet of stainless steel.
[0092] Here, the motion of the particles is described to better illustrate the coordination relationship between the above structures. The motion of the particles is shown below:
[0093] 1) The particles enter the aerosol generator in the form of aerosols through the input end of the inlet cone 11 and then flow out through the output end of the inlet cone 11. During this process, the particle flow is accelerated due to the reduction in the inner diameter of the inlet cone 11.
[0094] 2) After entering the degassing device 1, the extraction equipment extracts gas from the degassing device 1 to remove the excess gas input from the aerosol generator.
[0095] 3) After the gas volume is controlled by the degassing device 1, most of the particles and a small amount of gas flow into the degassing cone 12 through the input end and then flow out through the output end of the degassing cone 12. During this process, since the input port diameter of the degassing cone 12 is small, most of the gas is removed, and the remaining gas and most of the particles ejected from the intake cone 11 are received, while the particle concentration is increased.
[0096] 4) After the particles exit the degassing cone 12, they enter the vacuum connection device. During this process, the pressure detection device detects the gas pressure in the vacuum connection device 2 and feeds it back to the pumping equipment, forming a feedback mechanism. The pumping equipment automatically adjusts according to the set gas volume and the feedback data to meet the set pressure and gas flow rate in the vacuum connection device 2.
[0097] 5) After the particles flow out of the vacuum connection device 2, they enter the aerodynamic lens 3. In the aerodynamic lens 3, the particles enter through the narrow end 322 of the conical aperture lens and flow out through the wide end 323 of the conical aperture lens, thus passing through the conical aperture lens 32. During this process, a contraction-expansion airflow field is formed before and after each lens. Under the action of their own inertia and the drag force of the gas, the particles gather near the axis until they flow into the acceleration nozzle 34.
[0098] 6) In the accelerating nozzle 34, the particles, while maintaining initial focusing, enter the converging capillary 342 through the stepped nozzle 341. Since the stepped nozzle 341 is a multi-stage variable diameter tube, it can avoid over-focusing of the particles, thereby avoiding damage to the initial focusing effect of the upstream multi-stage conical aperture lens 32.
[0099] 7) After entering the converging capillary 342, the particles are further accelerated and focused at the exit of the converging capillary 342, delivering the sample particles to the interaction region between the X-ray and the sample. During this process, due to the small inner diameter and large length of the converging capillary 342, it has greater flow resistance, thus increasing the pressure inside the aerodynamic lens, thereby suppressing Brownian motion and obtaining a smaller particle beam width.
[0100] In the description of this invention, it should be noted that the terms "upper / lower end", "inner", "outer", "front", "back", "one side", "the other side", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.
[0101] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "set / sleeved," "sleeved," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0102] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. An aerodynamic lens sample introduction device for single-particle imaging, characterized in that: The sample introduction device includes a degassing device (1), a vacuum connection device (2), and an aerodynamic lens (3). The degassing device (1), the vacuum connection device (2), and the aerodynamic lens (3) are connected in sequence and in communication. The degassing device (1) is connected to an aerosol generator at one end to remove excess gas from the aerosol and increase the concentration of experimental particles. The aerodynamic lens (3) is provided with an input end and an output end; the input end is used to receive particles transmitted by the vacuum connection device (2); the output end is used to transport the focused particles to the experimental area; The aerodynamic lens (3) is provided with an acceleration nozzle (34) at its output end. The acceleration nozzle (34) includes a stepped nozzle (341) and a converging capillary (342). The inner diameter of the stepped nozzle (341) decreases sequentially along the particle conveying direction; One end of the converging capillary (342) is a tapered opening, and the other end passes through the stepped nozzle (341) and communicates with the inner cavity of the aerodynamic lens (3); The aerodynamic lens (3) includes an outer sleeve (31) and multiple sets of pipe lenses disposed within the outer sleeve (31); and each set of pipe lenses is arranged sequentially within the outer sleeve (31); each set of pipe lenses includes a conical aperture lens (32) and a spacer pipe (33), and each conical aperture lens (32) and each spacer pipe (33) are spaced apart; each conical aperture lens (32) is provided with a conical through hole (321), and each conical through hole (321) is provided with a narrow end (322) and a wide end (323); the wide end (323) of the conical through hole faces the output end of the aerodynamic lens (3), and the central axis of each conical through hole (321) is on a straight line.
2. The aerodynamic lens sample introduction device according to claim 1, characterized in that: Includes at least one of the following technical features: a1) The stepped nozzle (341) is a concentric reducing pipe; the stepped nozzle (341) includes a first reducing pipe, a second reducing pipe and a third reducing pipe with successively decreasing inner diameters; the inner diameter of the first reducing pipe is 15~30 mm and the length is 10~25 mm; the inner diameter of the second reducing pipe is 7~15 mm and the length is 10~25 mm; the inner diameter of the third reducing pipe is 0.2~0.8 mm and the length is 10~30 mm. a2) The inner diameter of the converging capillary (342) is 0.2~0.6 mm, the wall thickness is 0.1~0.3 mm, and the length is 30~100 mm. The cone angle of the converging capillary (342) is 20~70°, and the inner diameter of the converging capillary (342) is 0.1~0.5 mm. a3) The stepped nozzle (341) is a stainless steel tube; a4) The converging capillary (342) is a stainless steel tube or a glass tube.
3. The aerodynamic lens sample introduction device according to claim 1, characterized in that: The outer sleeve (31) is detachably connected to multiple sets of the pipe lenses.
4. The aerodynamic lens sample introduction device according to claim 3, characterized in that: The inner diameter of the narrow end (322) of the tapered through hole decreases sequentially along the particle conveying direction.
5. The aerodynamic lens sample introduction device according to claim 4, characterized in that: It also includes at least one of the following technical features: d1) The outer sleeve (31) has an inner diameter of 15~30 mm, a wall thickness of 3~5 mm, and a length of 100~300 mm; d2) The outer diameter of the tapered lens (32) is less than or equal to the inner diameter of the outer sleeve (31), the thickness is 1.0~1.5 mm, the inner diameter of the narrow end (322) of the tapered through hole is 0.4~2.0 mm, and the cone angle is 10~30°; d3) A sealing fastener (35) is provided between the tapered lens (32) and the spacer pipe (33); d4) Both the outer sleeve (31) and the spacer pipe (33) are stainless steel pipes; d5) The tapered aperture lens (32) is a thin sheet of stainless steel.
6. The aerodynamic lens sample introduction device according to claim 1, characterized in that: The degassing device (1) includes an inlet cone (11), a degassing cone (12), and a differential extraction chamber (13) that are interconnected. The intake cone (11) and the degassing cone (12) pass through the inner wall of the differential extraction chamber (13) and communicate with the inner cavity of the differential extraction chamber (13); The differential air extraction chamber (13) has an air extraction port (131) on its side wall, and the air extraction port (131) is connected to an external air extraction device.
7. The aerodynamic lens sample introduction device according to claim 6, characterized in that: The central axis of the intake cone (11) and the central axis of the degassing cone (12) are on the same straight line; the input end of the intake cone (11) is connected to an aerosol generator, and the output end of the intake cone (11) is an inwardly converging cone-shaped opening; The input end of the degassing cone (12) is an inwardly converging cone-shaped opening; The output end of the intake cone (11) is directly opposite the input end of the degassing cone (12).
8. The aerodynamic lens sample introduction device according to claim 7, further comprising at least one of the following technical features: b1) The intake cone (11), the degassing cone (12) and the differential extraction chamber (13) are all stainless steel pipes; b2) At least one air extraction port (131) is provided on the side wall of the differential air extraction chamber (13). b3) The inner diameter of the intake cone (11) is 16~35 mm, the cone angle of the output end of the intake cone (11) is 25~40°, and the inner diameter of the cone-shaped opening at the output end of the intake cone (11) is 0.1~0.5 mm. b4) The inner diameter of the degassing cone (12) is 16~35 mm, the cone angle of the input end of the degassing cone (12) is 35~60°, and the inner diameter of the conical opening of the input end of the degassing cone (12) is 0.5~1.0 mm; b5) The distance between the tip of the intake cone (11) at the output end and the tip of the degassing cone (12) at the input end is 1~4mm.
9. The aerodynamic lens sample introduction device according to claim 1, characterized in that: The vacuum connection device (2) is also provided with a vacuum chamber flange (21); The vacuum chamber flange (21) is located on the outside of the vacuum connection device (2) and is used for detachable connection with the experimental chamber. And / or, the vacuum connection device (2) is further provided with a pressure detection port (22), which is connected to an external pressure detection device.
10. The aerodynamic lens sample introduction device according to claim 9, further comprising at least one of the following technical features: c1) The vacuum connection device (2) is provided with at least one of the pressure detection ports (22); c2) The inner diameter of the vacuum connection device (2) is 40~65 mm; c3) The inner diameter of the pressure detection port (22) is 25 mm; c4) The model of the vacuum chamber flange (21) is CF100 or CF150.