A calibration device for high-speed directional flow of rarefied gas

Abstract

The application relates to the technical field of space metrology, in particular to a rare gas high-speed directional flow calibration device, which comprises a beam generation unit, a gas supply system, a differential vacuum chamber, a gas extraction system, a vacuum calibration chamber, an instrument fixing platform and a standard beam measurement system, wherein: the beam generation unit is arranged between the gas supply system and the differential vacuum chamber; the gas extraction system is connected with the differential vacuum chamber and the vacuum calibration chamber respectively; the instrument fixing platform and the standard beam measurement system are arranged in the interior of the vacuum calibration chamber. The application can obtain a wide-range rare gas standard high-speed beam from a room temperature thermal motion speed to a first cosmic speed through the composite design of a thermal molecular beam generation module and an ion neutralization beam generation module in combination with a vacuum differential technology.

Description

Technical Field

[0001] This application relates to the field of space metrology technology, and more specifically, to a calibration device for high-speed directional flow of rarefied gas. Background Technology

[0002] Artificial spacecraft typically orbit at speeds exceeding the first cosmic velocity. Similarly, missions to explore comets and other celestial bodies require directional motion speeds far exceeding the thermal velocity of gases at room temperature, where rarefied gases exhibit directional beam characteristics relative to the spacecraft. Furthermore, particle accelerators and molecular beam epitaxy devices all require high-speed, directional rarefied gas beams as their working medium under vacuum. Accurate evaluation of the parameters of high-speed directional rarefied gas beams is crucial for aerospace exploration, high-energy physics experiments, and semiconductor process control. Establishing a high-speed directional rarefied gas beam calibration device can precisely calibrate the velocity and flux density parameters of various rarefied gas beams, providing metrological assurance for the reliable implementation of scientific experiments and engineering projects.

[0003] Traditional calibration of rarefied gas parameters in vacuum relies on vacuum calibration devices and methods. However, these devices can only obtain equilibrium gases conforming to Maxwell's distribution at constant temperatures. Directly calibrating the instrument in this equilibrium gas, regardless of whether it is in dynamic or static equilibrium, cannot equate to a non-equilibrium, high-speed directional beam. While rapid dynamic vacuum calibration techniques can utilize fast valve switching and rapid vacuum gauge measurements to achieve transient gas expansion and obtain instantaneous pressure, the beam shape of such devices remains divergent, failing to achieve beam collimation or obtain a high-speed, continuous molecular beam.

[0004] Christian B. Westermann et al. (Meas. Sci. Technol. 12 (2001) 1594-1603) proposed a device for obtaining a high-speed gas beam based on the expansion of a single hot nozzle. However, the maximum speed of this device can only reach 4 km / s, which cannot achieve a high-speed beam higher than the first cosmic velocity of Earth spacecraft. Furthermore, the gas molecule velocity and density measurement uses a fast-response ionization vacuum meter, with a measurement accuracy of only about ±10%, resulting in large uncertainties in density and flux measurement. Patent application number 201380057640.X proposes a neutral beam generator, but the energy and velocity dispersion reaches a distribution spanning orders of magnitude, making it impossible to obtain a stable and uniform standard beam, and unsuitable for the calibration and standardization of high-speed directional beams of rarefied gases. Summary of the Invention

[0005] This application provides a high-speed directional flow calibration device for rarefied gases, which aims to solve the technical problems in the prior art of being unable to generate a standard high-speed rarefied gas beam with stable beam velocity and uniform gas density distribution, and the difficulty in accurately calibrating rarefied gas beam measuring instruments.

[0006] To achieve the above objectives, this application provides a high-speed directional flow calibration device for rarefied gases, comprising a beam generation unit, a gas supply system, a differential vacuum chamber, a pumping system, a vacuum calibration chamber, an instrument mounting platform, and a standard beam measurement system. The beam generation unit is located between the gas supply system and the differential vacuum chamber and is used to generate a high-speed directional flow of rarefied gas. The pumping system is connected to both the differential vacuum chamber and the vacuum calibration chamber to provide a vacuum environment for beam transmission. Both the instrument mounting platform and the standard beam measurement system are located inside the vacuum calibration chamber. The instrument mounting platform is used to mount different types of rarefied gas detection instruments to be calibrated, and the standard beam measurement system is used for accurate measurement of the high-speed directional flow of rarefied gas, providing the calibrated detection instruments with standard rarefied gas directional flow values ​​of different velocities and fluxes.

[0007] Furthermore, the beam generation unit includes a thermal molecular beam generation module and an ion neutralization beam generation module, wherein: the input end of the thermal molecular beam generation module is connected to the gas supply system, and the output end is connected to the differential vacuum chamber; the input end of the ion neutralization beam generation module is connected to the gas supply system, and the output end is connected to the differential vacuum chamber; the thermal molecular beam generation module and the ion neutralization beam generation module are arranged in parallel and work alternately.

[0008] Furthermore, the thermal molecular beam generation module includes a heating device, a high-temperature hot nozzle, a heat insulation protection device, a nozzle adjustment device, and a gas sampler, wherein: the heating device surrounds the high-temperature hot nozzle and is used to heat the high-temperature hot nozzle to a preset temperature; the heat insulation protection device is located on the outside of the heating device; the high-temperature hot nozzle is fixed to the front end of the nozzle adjustment device; and the gas sampler is located at the front end of the high-temperature hot nozzle, with an adjustable gap between the two.

[0009] Furthermore, the heating method of the heating device includes any one of direct current heating, microwave heating or plasma heating; the high-temperature hot nozzle is any one of high-temperature resistant orifice plate structure, straight pipe structure or conical orifice structure; the gas sampler is a conical structure; the nozzle adjustment device is used to adjust the distance between the high-temperature hot nozzle and the gas sampler.

[0010] Furthermore, the ion neutralization beam generation module includes a plasma source and an ion neutralization device, wherein: the plasma source is used to generate high-density plasma under vacuum, and its type includes any one of DC discharge plasma source, radio frequency discharge plasma source or microwave discharge plasma source; the ion neutralization device is located downstream of the plasma source and is used to neutralize ions and electrons to form a neutral gas.

[0011] Furthermore, the evacuation system includes a first evacuation system and a second evacuation system, wherein: the first evacuation system is connected to the vacuum calibration chamber and is used to evacuate the vacuum calibration chamber; the second evacuation system is connected to the differential vacuum chamber and is used to evacuate the differential vacuum chamber.

[0012] Furthermore, it also includes a molecular beam collimation assembly, which is located between the differential vacuum chamber and the vacuum calibration chamber, for collimating and shaping the beam.

[0013] Furthermore, the vacuum level within the differential vacuum chamber increases progressively along the beam propagation direction.

[0014] Furthermore, the instrument fixing platform includes an installation platform and a multi-degree-of-freedom adjustment device, wherein: the installation platform is used to install and fix the calibrated detection instrument; the multi-degree-of-freedom adjustment device has multi-degree-of-freedom position and attitude adjustment function to ensure that the calibrated detection instrument can be calibrated at different angles.

[0015] Furthermore, the standard beam measurement system includes a beam standard velocity measurement module and a density measurement module. The beam standard velocity measurement module is used to measure the velocity of a high-speed directional flow of rarefied gas, and its measurement method includes time-of-flight method or spectroscopic method. The density measurement module is used to measure the density, composition and flux of rarefied gas, and its measurement method includes any one of mass spectrometry, spectroscopic method or electromagnetic method.

[0016] The rarefied gas high-speed directional flow calibration device provided in this application has the following beneficial effects: (1) This application uses a composite design of a thermal molecular beam generation module and an ion neutralization beam generation module, combined with vacuum differential technology, to obtain a wide range of rarefied gas standard high-speed beams from room temperature thermal motion velocity to the first cosmic velocity. (2) The thermal molecular beam generation module of this application generates a directional flow through high temperature and high pressure expansion, and the ion neutralization beam generation module generates a directional flow through ionization neutralization. The two work alternately to cover the calibration requirements of different speed ranges. (3) This application uses a molecular beam collimation assembly to collimate and shape the beam to form a standard rarefied gas directional flow with stable beam flow. (4) This application utilizes a standard beam measurement system to achieve accurate measurement of beam velocity and density, providing reliable calibration conditions for rarefied gas directional beam detection in fields such as artificial spacecraft detection, high-energy physics experiments and semiconductor processes. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a schematic diagram of the structure of a high-speed directional flow calibration device for rarefied gas provided in the embodiments of this application; In the figure: 1-Thermal molecular beam generation module, 11-Heating device, 12-High temperature hot nozzle, 13-Heat insulation protection device, 14-Nozzle adjustment device, 15-Gas sampler, 2-Ion neutralization beam generation module, 21-Plasma source, 22-Ion neutralization device, 3-Gas supply system, 4-Differential vacuum chamber, 5-First pumping system, 6-Second pumping system, 7-Vacuum calibration chamber, 8-Instrument fixing platform, 9-Standard beam measurement system, 10-Molecular beam collimation component. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] In addition, the term "multiple" should mean two or more.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, this application provides a high-speed directional flow calibration device for rarefied gases, including a beam generation unit, a gas supply system 3, a differential vacuum chamber 4, a pumping system, a vacuum calibration chamber 7, an instrument mounting platform 8, and a standard beam measurement system 9. The beam generation unit is located between the gas supply system 3 and the differential vacuum chamber 4 to generate a high-speed directional flow of rarefied gas. The pumping system is connected to both the differential vacuum chamber 4 and the vacuum calibration chamber 7 to provide a vacuum environment for beam transmission. Both the instrument mounting platform 8 and the standard beam measurement system 9 are located inside the vacuum calibration chamber 7. The instrument mounting platform 8 is used to mount different types of rarefied gas detection instruments to be calibrated, and the standard beam measurement system 9 is used for accurate measurement of the high-speed directional flow of rarefied gas, providing the calibrated detection instruments with standard rarefied gas directional flow values ​​of different velocities and fluxes.

[0025] Specifically, the rarefied gas high-speed directional flow calibration device provided in this application embodiment employs a beam generator combining thermal molecular expansion and ion neutralization phase recombination. Through beam collimation and shaping, a standard rarefied gas directional flow with stable beam flux is formed, enabling precise calibration of vacuum rarefied gas beam measurement instruments in a vacuum environment. The beam generation unit is located between the gas supply system 3 and the differential vacuum chamber 4 to generate a high-speed directional flow of rarefied gas. The gas supply system 3 includes a standard gas cylinder and a flow regulation system, installed before the beam generation unit via pipelines and valves to provide input of different types of test gases. The pumping system is connected to both the differential vacuum chamber 4 and the vacuum calibration chamber 7 to provide a vacuum environment for beam transmission. The instrument fixing platform 8 and the standard beam measurement system 9 are both located inside the vacuum calibration chamber 7. The instrument fixing platform 8 is used to mount different types of vacuum rarefied gas detection instruments to be calibrated, and the standard beam measurement system 9 is used for accurate measurement of the high-speed directional flow of rarefied gas, providing standard rarefied gas directional flow values ​​of different velocities and fluxes for the calibrated detection instruments.

[0026] Furthermore, the beam generation unit includes a thermal molecular beam generation module 1 and an ion neutralization beam generation module 2, wherein: the input end of the thermal molecular beam generation module 1 is connected to the gas supply system 3, and the output end is connected to the differential vacuum chamber 4; the input end of the ion neutralization beam generation module 2 is connected to the gas supply system 3, and the output end is connected to the differential vacuum chamber 4; the thermal molecular beam generation module 1 and the ion neutralization beam generation module 2 are arranged in parallel and work alternately.

[0027] Specifically, the thermal molecular beam generation module 1 and the ion neutralization beam generation module 2 are connected in parallel and operate alternately: when the thermal molecular beam generation module 1 is working, the ion neutralization beam generation module 2 is off; when the ion neutralization beam generation module 2 is working, the thermal molecular beam generation module 1 is off. The thermal molecular beam generation module 1 generates a directional flow of rarefied gas through high temperature and high pressure, while the ion neutralization beam generation module 2 generates a directional flow of rarefied gas through ionization and neutralization. The alternating operation of the two modules allows the device to cover a wide velocity range from room temperature thermal motion velocity to the first cosmic velocity.

[0028] Furthermore, the thermal molecular beam generating module 1 includes a heating device 11, a high-temperature hot nozzle 12, a heat insulation protection device 13, a nozzle adjustment device 14, and a gas sampler 15, wherein: the heating device 11 surrounds the high-temperature hot nozzle 12 and is used to heat the high-temperature hot nozzle 12 to a preset temperature; the heat insulation protection device 13 is disposed on the outside of the heating device 11; the high-temperature hot nozzle 12 is fixed to the front end of the nozzle adjustment device 14; the gas sampler 15 is disposed at the front end of the high-temperature hot nozzle 12, and an adjustable gap is maintained between the two.

[0029] Furthermore, the heating method of the heating device 11 includes any one of direct current heating, microwave heating or plasma heating; the high-temperature hot nozzle 12 is any one of high-temperature resistant orifice plate structure, straight pipe structure or conical orifice structure; the gas sampler 15 is a conical structure; the nozzle adjustment device 14 is used to adjust the distance between the high-temperature hot nozzle 12 and the gas sampler 15.

[0030] Specifically, the heating device 11 surrounds the high-temperature hot nozzle 12 to heat it to a preset temperature, preferably 2000K-3000K. The heating method can be flexibly selected from DC heating, microwave heating, or plasma heating depending on the required temperature range and heating efficiency. A heat insulation protection device 13 is located outside the heating device 11 to insulate and isolate the heat from the high-temperature nozzle, preventing heat conduction to surrounding structures. The high-temperature hot nozzle 12 is fixed to the front end of the nozzle adjustment device 14. The high-temperature hot nozzle 12 can be selected from a high-temperature resistant orifice plate structure, a straight pipe structure, or a conical orifice structure, depending on the actual situation. Different structures affect the velocity distribution and beam quality after gas expansion. A gas sampler 15 is located at the front end of the high-temperature hot nozzle 12, preferably a conical structure, which combines gas expansion acceleration and screening functions, enabling the extraction of a directional molecular beam with a narrow velocity distribution from the high-temperature nozzle jet. The nozzle adjustment device 14 is used to adjust the distance between the high-temperature hot nozzle 12 and the gas sampler 15 to optimize the beam distribution. During operation, the gas supply system 3 supplies 10 kJ / kg gas to the thermal molecular beam generation module 1. 4 -10 5 A single gas or a mixture of gases of Pa is introduced into a high-temperature hot nozzle 12. The gas is ejected from the nozzle under high temperature and high pressure. After being accelerated by adiabatic expansion, it obtains high-speed directional motion. After being sampled by a gas sampler 15, it enters the differential vacuum chamber 4.

[0031] Furthermore, the ion neutralization beam generation module 2 includes a plasma source 21 and an ion neutralization device 22, wherein: the plasma source 21 is used to generate high-density plasma under vacuum, and its type includes any one of DC discharge plasma source 21, radio frequency discharge plasma source 21 or microwave discharge plasma source 21; the ion neutralization device 22 is disposed downstream of the plasma source 21 and is used to neutralize ions and electrons to form a neutral gas.

[0032] Specifically, the plasma source 21 is used to generate high-density plasma under vacuum. Its type includes any one of a DC discharge plasma source, a radio frequency discharge plasma source, or a microwave discharge plasma source, which can be selected according to the required plasma density and stability. The ion neutralization device 22 is located downstream of the plasma source 21 and is used to neutralize ions and electrons to form a neutral gas. Its principle includes any one of grazing neutralization with a metal plate or collision neutralization in a neutral gas chamber, used to obtain a neutral high-speed directional beam and avoid interference from charged particles to the calibrated instrument. During operation, the gas supply system 3 supplies gas to the ion neutralization beam generation module 2. The gas enters the plasma source 21 and is ionized, reaching a specified velocity under the action of the electromagnetic field. It is then neutralized by the ion neutralization device 22 to become a rarefied directional gas flow.

[0033] Furthermore, the evacuation system includes a first evacuation system 5 and a second evacuation system 6, wherein: the first evacuation system 5 is connected to the vacuum calibration chamber 7 and is used to evacuate the vacuum calibration chamber 7; the second evacuation system 6 is connected to the differential vacuum chamber 4 and is used to evacuate the differential vacuum chamber 4.

[0034] Specifically, the first evacuation system 5 is connected to the vacuum calibration chamber 7 and is used to evacuate the vacuum calibration chamber 7, maintaining its vacuum level in the high vacuum or ultra-high vacuum range, providing the high vacuum environment required for calibration of the instrument being calibrated; the second evacuation system 6 is connected to the differential vacuum chamber 4 and is used to evacuate the differential vacuum chamber 4, maintaining the required vacuum level. The high vacuum environment ensures that the instrument being calibrated is not disturbed by background gas during the calibration process, and at the same time avoids secondary scattering of the beam before it reaches the instrument being calibrated.

[0035] Furthermore, a molecular beam collimation assembly 10 is included, which is disposed between the differential vacuum chamber 4 and the vacuum calibration chamber 7, for collimating and shaping the beam. The molecular beam collimation assembly 10 typically employs a multi-stage slit or pinhole aperture structure, using spatial filtering to extract the portion of the beam whose center velocity direction and spatial distribution are most uniform, thus ensuring excellent directional consistency and spatial uniformity of the beam entering the vacuum calibration chamber 7. The differential vacuum chamber 4 is connected to the vacuum calibration chamber 7 via the molecular beam collimation assembly 10, and the beam from the differential vacuum chamber 4 enters the vacuum calibration chamber 7 after collimation and shaping.

[0036] Furthermore, the vacuum level within the differential vacuum chamber 4 increases progressively along the beam propagation direction. The vacuum level within the differential vacuum chamber 4 increases progressively along the beam propagation direction, starting at approximately 10 at the initial end. -2 Pa increases with increasing vacuum level. This design is based on the relationship between the molecular mean free path and the characteristic dimensions of the chamber. As the vacuum level gradually increases, the mean free path of gas molecules gradually increases, and the probability of beam molecules colliding with background gas molecules during transmission decreases step by step. This can effectively ensure the quality of the rarefied directional flow and avoid beam divergence and velocity distribution broadening caused by scattering.

[0037] Furthermore, the instrument mounting platform 8 includes a mounting platform and a multi-degree-of-freedom adjustment device. The mounting platform is used to mount and fix the instrument to be calibrated; the multi-degree-of-freedom adjustment device has multi-degree-of-freedom position and attitude adjustment functions to ensure that the instrument to be calibrated can be calibrated at different angles. The mounting platform is used to mount and fix the instrument to be calibrated, such as various vacuum gauges, mass spectrometers, beam monitors, etc.; the multi-degree-of-freedom adjustment device has multi-degree-of-freedom position and attitude adjustment functions, including translation, rotation, and pitch, to ensure that the instrument to be calibrated can be calibrated at different angles, meeting the beam injection angle requirements of different types of instruments to be calibrated and expanding the calibration capability range of the device.

[0038] Furthermore, the standard beam measurement system 9 includes a beam standard velocity measurement module and a density measurement module. The beam standard velocity measurement module measures the velocity of a high-speed directional flow of rarefied gas using methods such as time-of-flight or spectrometry. The density measurement module measures the density, composition, and flux of the rarefied gas using methods such as mass spectrometry, spectrometry, or electromagnetic methods. Depending on the specific requirements, the beam standard velocity measurement module and the density measurement module can be installed separately or as a single unit on a multi-degree-of-freedom adjustment device. They can be independently moved into or out of the beam path, and after completing the standard value measurement, they can be moved out to make way for the calibration position of the instrument being calibrated.

[0039] Specifically, the rarefied gas high-speed directional flow calibration device provided in this application embodiment adopts a beam generator that combines thermal molecular expansion and ion neutralization phase, and combines vacuum differential technology and beam collimation and shaping to form a standard rarefied gas directional flow with stable beam flux. This enables accurate calibration of vacuum rarefied gas beam measurement instruments in a vacuum environment. The specific working process is as follows: First, select the beam generation module based on the required velocity range for calibration. If a lower velocity range of directional beam is needed, activate the thermal molecular beam generation module 1 and deactivate the ion neutralization beam generation module 2. The gas supply system 3 supplies 10... 4 -10 5 A single gas or a mixture of gases, at pressures of Pa, is introduced into a high-temperature hot nozzle 12. The heating device 11 heats the hot nozzle 12 to 2000K-3000K. The gas is ejected from the nozzle under high temperature and pressure, undergoes adiabatic expansion and acceleration to achieve high-speed directional motion, and is then sampled by a gas sampler 151. A directional molecular beam with a narrow velocity distribution is extracted from the central region of the jet and enters the differential vacuum chamber 4. If a higher velocity (approaching or reaching the first cosmic velocity) directional beam is required, the ion neutralization beam generation module 2 is activated, and the hot molecular beam generation module 1 is shut down. The gas supply system 3 supplies gas to the ion neutralization beam generation module 2. The gas enters the plasma source 21 and is ionized to generate high-density plasma. Under the action of an electromagnetic field, the ions are accelerated to a specified velocity and neutralized by the ion neutralization device 22 to become neutral gas, obtaining a neutral high-speed directional beam that enters the differential vacuum chamber 4.

[0040] After the beam enters the differential vacuum chamber 4, the vacuum level gradually increases along the beam transmission direction under the staged pumping action of the second pumping system 6, ensuring that the probability of collisions between gas molecules during the transmission of the rarefied directional flow is minimized. The beam is then collimated and shaped by the molecular beam collimation component 10 to obtain a collimated rarefied gas directional flow, which then enters the vacuum calibration chamber 7.

[0041] Inside the vacuum calibration chamber 7, the standard beam measurement system 9 first moves into the beam path, measuring the standard velocity and standard density / flux values ​​of the beam using the velocity measurement module and density measurement module, respectively. After standard value calibration, the standard beam measurement system 9 moves out of the beam path, and the instrument to be calibrated is mounted on the beam path via the multi-degree-of-freedom adjustment device of the instrument fixing platform 8 for calibration at different angles and positions. The first evacuation system 5 maintains the vacuum level in the vacuum calibration chamber 7 at a high vacuum or ultra-high vacuum range, better than 10. -5 Pa ensures that the instrument being calibrated is not affected by background gas during the calibration process.

[0042] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-speed directional flow calibration device for rarefied gases, characterized in that, It includes a beam generation unit, a gas supply system, a differential vacuum chamber, a pumping system, a vacuum calibration chamber, an instrument mounting platform, and a standard beam measurement system, among which: The beam generation unit is located between the gas supply system and the differential vacuum chamber, and is used to generate a high-speed directional flow of rarefied gas; The pumping system is connected to the differential vacuum chamber and the vacuum calibration chamber respectively, and is used to provide a vacuum environment for beam transmission; Both the instrument mounting platform and the standard beam measurement system are located inside the vacuum calibration chamber. The instrument mounting platform is used to install different types of vacuum rarefied gas detection instruments to be calibrated, and the standard beam measurement system is used for the accurate measurement of high-speed directional flow of rarefied gas, providing the calibrated detection instruments with standard rarefied gas directional flow values ​​of different velocities and fluxes.

2. The rarefied gas high-speed directional flow calibration device according to claim 1, characterized in that, The beam generation unit includes a thermal molecular beam generation module and an ion neutralization beam generation module, wherein: The input end of the thermal molecular beam generating module is connected to the gas supply system, and the output end is connected to the differential vacuum chamber. The input end of the ion neutralization beam generation module is connected to the gas supply system, and the output end is connected to the differential vacuum chamber. The thermal molecular beam generation module and the ion neutralization beam generation module are connected in parallel and work alternately.

3. The rarefied gas high-speed directional flow calibration device according to claim 2, characterized in that, The thermal molecular beam generating module includes a heating device, a high-temperature thermal nozzle, a heat insulation protection device, a nozzle adjustment device, and a gas sampler, wherein: The heating device encloses the high-temperature hot nozzle and is used to heat the high-temperature hot nozzle to a preset temperature; The heat insulation protection device is located on the outside of the heating device; The high-temperature hot nozzle is fixed to the front end of the nozzle adjustment device; The gas sampler is positioned at the front end of the high-temperature hot nozzle, with an adjustable gap between them.

4. The rarefied gas high-speed directional flow calibration device according to claim 3, characterized in that, The heating method of the heating device includes any one of direct current heating, microwave heating or plasma heating; the high-temperature hot nozzle is any one of high-temperature resistant orifice plate structure, straight pipe structure or conical orifice structure; the gas sampler is a conical structure; the nozzle adjustment device is used to adjust the distance between the high-temperature hot nozzle and the gas sampler.

5. The rarefied gas high-speed directional flow calibration device according to claim 2, characterized in that, The ion neutralization beam generating module includes a plasma source and an ion neutralization device, wherein: The plasma source is used to generate high-density plasma under vacuum, and its type includes any one of DC discharge plasma source, radio frequency discharge plasma source or microwave discharge plasma source. The ion neutralization device is located downstream of the plasma source and is used to neutralize ions and electrons to form a neutral gas.

6. The rarefied gas high-speed directional flow calibration device according to claim 1, characterized in that, The air extraction system includes a first air extraction system and a second air extraction system, wherein: The first pumping system is connected to the vacuum calibration chamber and is used to evacuate the vacuum calibration chamber. The second pumping system is connected to the differential vacuum chamber and is used to evacuate the differential vacuum chamber.

7. The rarefied gas high-speed directional flow calibration device according to claim 6, characterized in that, It also includes a molecular beam collimation assembly, which is disposed between the differential vacuum chamber and the vacuum calibration chamber, for collimating and shaping the beam.

8. The high-speed directional flow calibration device for rarefied gas according to claim 7, characterized in that, The vacuum level in the differential vacuum chamber increases gradually along the beam transmission direction.

9. The rarefied gas high-speed directional flow calibration device according to claim 1, characterized in that, The instrument mounting platform includes a mounting platform and a multi-degree-of-freedom adjustment device, wherein: The mounting platform is used to mount and fix the calibrated detection instrument. The multi-degree-of-freedom adjustment device has a multi-degree-of-freedom position and attitude adjustment function, which is used to ensure that the calibrated detection instrument can be calibrated at different angles.

10. The rarefied gas high-speed directional flow calibration device according to claim 1, characterized in that, The standard beam measurement system includes a beam standard velocity measurement module and a density measurement module, wherein: The beam standard velocity measurement module is used to measure the velocity of a high-speed directional flow of rarefied gas, and the measurement method includes time-of-flight method or spectroscopic method; The density measurement module is used to measure the density, composition, and flux of rarefied gases, and its measurement method includes any one of mass spectrometry, spectroscopy, or electromagnetic methods.

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