A measurement system and method for inverting a vacuum level based on first principles

Abstract

The application relates to the technical field of vacuum metering, in particular to a measurement system and method for inverting vacuum degree based on a first principle, which comprises a high-purity gas cylinder, a pressure stabilizing chamber, a vacuum degree test chamber, an ionization vacuum gauge, a non-evaporable getter pump, a magnetic suspension turbo molecular pump and a dry pump, wherein the high-purity gas cylinder is connected with the pressure stabilizing chamber through a first metal stop valve; the pressure stabilizing chamber is connected with the vacuum degree test chamber through a metal regulating valve; the ionization vacuum gauge is connected with the vacuum degree test chamber; the magnetic suspension turbo molecular pump is connected with the vacuum degree test chamber through a first plug-in valve; the non-evaporable getter pump is connected with the vacuum degree test chamber through a second plug-in valve; and the dry pump is connected with the magnetic suspension turbo molecular pump through a second metal stop valve. The method for inverting vacuum degree in a magnetic potential barrier based on the first principle is not limited by the types of gases, different gases can be used for testing, and the calibration of the relative sensitivity of the ionization vacuum gauge to different gases can be realized.

Description

Technical Field

[0001] This application relates to the field of vacuum measurement technology, and more specifically, to a measurement system and method for vacuum degree inversion based on first principles. Background Technology

[0002] The 26th General Conference on Weights and Measures decided to redefine the International System of Units (SI), ushering in the era of quantum metrology. In the field of ultra-high / ultra-high vacuum, ionization vacuum gauges based on the principle of neutral gas ionization are currently used to measure vacuum levels. However, to meet application requirements, calibration is necessary on equipment such as dynamic flow method standard devices during practical use. Furthermore, when measuring ultra-high / ultra-high vacuum, ionization vacuum gauges themselves alter the measured environment due to physicochemical processes such as high-temperature filament radiation, gas absorption and desorption, and catalytic chemical reactions. Specifically, when directly measuring ultra-high / ultra-high vacuum, the measurement uncertainty of ionization vacuum gauges is typically U ≥ 20% (k = 2), and the effective lower limit of measurement is only 10⁻⁶. 10 Pa, cannot satisfy 10- 10 For ultra-high vacuum measurements below Pa, ionization vacuum gauges, being relative vacuum gauges, require calibration on a dynamic flow method ultra-high and ultra-high vacuum standard device before use to meet accuracy requirements. However, the calibration lower limit is only 3 × 10⁻⁶. 9 Pa, and is mainly applicable to calibration using N2, therefore, the actual measurement result is the result of equivalent N2.

[0003] Compared to ionization vacuum gauges, the method of measuring ultra-high / extremely high vacuum levels by using trapped atoms in a magnetic barrier based on first-principles calculations inverts the vacuum level from the intrinsic physical properties of matter, such as the collision scattering cross section. It has the least measurement uncertainty, does not require calibration, and is a quantum-level ultra-high and extremely high vacuum measurement method. Summary of the Invention

[0004] This application provides a measurement system and method for vacuum degree based on first-principles inversion, which is not limited by the type of gas, is not subject to measurement limitations, does not require calibration, and can achieve accurate measurement of ultra-high and extremely high vacuum.

[0005] To achieve the above objectives, this application provides a first-principles inversion vacuum measurement system, comprising a high-purity gas cylinder, a pressure stabilizing chamber, a vacuum testing chamber, an ionization vacuum gauge, a non-evaporable getter pump, a magnetically levitated turbomolecular pump, and a dry pump, wherein: the high-purity gas cylinder is used to store the test gas and is connected to the pressure stabilizing chamber via a first metal shut-off valve; the pressure stabilizing chamber is used to maintain the pressure of the test gas and is connected to the vacuum testing chamber via a metal regulating valve; the ionization vacuum gauge is connected to the vacuum testing chamber and is used to measure the vacuum level inside the vacuum testing chamber; the magnetically levitated turbomolecular pump is connected to the vacuum testing chamber via a first gate valve; the non-evaporable getter pump is connected to the vacuum testing chamber via a second gate valve; and the dry pump is connected to the magnetically levitated turbomolecular pump via a second metal shut-off valve.

[0006] Furthermore, a capacitive thin-film vacuum gauge is connected to the voltage stabilizing chamber.

[0007] Furthermore, the metal regulating valve is a molecular flow controllable metal regulating valve.

[0008] Furthermore, the vacuum testing chamber is set between the upper and lower anti-Helmholtz coils, and atoms are trapped using three-dimensional magneto-optical trap technology.

[0009] Furthermore, it also includes photomultiplier tubes, which are used to measure the loss rate of trapped atoms in a vacuum chamber.

[0010] Furthermore, this application also provides a method for applying a measurement system based on first-principles inversion of vacuum degree, comprising the following steps: Step 1: Close the first metal shut-off valve, adjust the molecular flow conductance of the metal regulating valve to the maximum, open the dry pump, the second metal shut-off valve, the magnetic levitation turbomolecular pump, and the first gate valve to evacuate the vacuum degree test chamber; when the vacuum degree inside the vacuum degree test chamber measured by the ionization vacuum gauge reaches 10... -3 At a pressure of 150°C for 7 days, the vacuum test chamber is heated to 150°C. After heating, the vacuum test chamber is cooled to room temperature. Then, the second gate valve is opened, and the non-evaporative getter pump is turned on to evacuate the vacuum test chamber. Step 2: When the vacuum test chamber reaches the ultimate vacuum, the second gate valve is closed, the first metal shut-off valve is opened, and the test gas from the high-purity gas cylinder is introduced into the pressure stabilizing chamber. The vacuum level in the pressure stabilizing chamber is measured using a capacitive thin-film vacuum gauge, and the vacuum level in the pressure stabilizing chamber is maintained at 10 Pa. 4 Pa level; by adjusting the flow conductance of the metal regulating valve, the test gas in the pressure stabilizing chamber is introduced into the vacuum test chamber. After dynamic equilibrium is reached, the vacuum level in the vacuum test chamber is maintained at 10. -7Step 3: Using standard three-dimensional magneto-optical trap technology, the trapped atoms are cooled and confined in a vacuum chamber. The confinement magnetic field is generated by passing equal but opposite currents through the upper and lower anti-Helmholtz coils, with a magnetic field gradient of 10 G / cm. Step 4: The laser in the three-dimensional magneto-optical trap system is turned off, and only the upper and lower anti-Helmholtz coils are used to confine the trapped atoms in the vacuum chamber. Then, a radio frequency magnetic field is applied to the anti-Helmholtz coils, and the frequency f of the radio frequency magnetic field is adjusted to change the energy E of the trapped atoms in the vacuum chamber. Step 5: The physical quantities are measured and calculated using a photomultiplier tube and an ionization vacuum meter. And the test result curve Numerical fitting was performed; the average total cross section of the trapped atom-neutral gas velocity-averaged collision was obtained according to the fitting formula <σ. tot The value of v> and the reading of the ionization vacuum gauge p' i calibration factor i g Step 6: Calculate the quantum scattering energy U according to the formula. d The value of the trapped atom-neutral gas velocity-average collision loss cross section <σ loss The value of (E),v> ​​is then used to generate 10 in the vacuum test chamber by adjusting the molecular flow conductance of the metal regulating valve. -6 -10 -10 Test gases were used in the ultra-high / extremely high vacuum range, and the collision loss rate Γ at each vacuum level was measured using a photomultiplier tube. loss (E), and finally, the vacuum degree p, derived from the first-principles inversion of the trapped-state atom collision loss, can be calculated according to the formula. i The value of .

[0011] Furthermore, in step 4, the relationship between the energy E of the trapped atom and the frequency f of the modulating radio frequency magnetic field is: E = hf, where h is Planck's constant.

[0012] Furthermore, in step 6, the quantum scattering energy U d The value is calculated using the following formula:

[0013]

[0014] Where: m t The mass of the trapped atom. Let k be the most probable velocity of a gas molecule of mass m at temperature T. B is the Boltzmann constant.

[0015] Furthermore, in step 6, the velocity-average collision loss cross section between trapped atoms and neutral gas is <σ loss The value of (E),v> ​​is calculated using the following formula:

[0016]

[0017] In the formula: E is the energy of the trapped atom. f min I0 is the minimum frequency of the radio frequency magnetic field, I0 is the minimum current required to overcome the effect of gravity on atomic trapping, I is the current applied to the radio frequency magnetic field coil, and T is the gas temperature.

[0018] Furthermore, in step 6, the vacuum degree p i The value is calculated using the following formula:

[0019]

[0020] The present invention provides a measurement system and method for vacuum degree based on first-principles inversion, which has the following beneficial effects:

[0021] This application utilizes a first-principles inversion method for vacuum degree in a magnetic barrier, which is not limited by the type of gas and can be used for testing with different gases. This allows for the calibration of the ionization vacuum meter for the relative sensitivity of different gases, extending the measurement lower limit to 10. -10 Below Pa, and since the first-principles method is essentially based on the intrinsic physical properties of neutral gas-trapped atoms, the uncertainty of the measurement in this application is minimal. Attached Figure Description

[0022] 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:

[0023] Figure 1 This is a schematic diagram of a vacuum degree measurement system based on first-principles inversion provided according to an embodiment of this application;

[0024] In the diagram: 1-High-purity gas cylinder, 2-First metal shut-off valve, 3-Capacitive thin-film vacuum gauge, 4-Pressure stabilizing chamber, 5-Metal regulating valve, 6-Upper anti-Helmholtz coil, 7-Trap-state atoms, 8-Vacuum degree testing chamber, 9-First gate valve, 10-Ionization vacuum gauge, 11-Second gate valve, 12-Non-evaporative getter pump, 13-Lower anti-Helmholtz coil; 14-Magnetic levitation turbomolecular pump, 15-Second metal shut-off valve, 16-Dry pump. Detailed Implementation

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] In addition, the term "multiple" should mean two or more.

[0030] 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.

[0031] like Figure 1As shown, this application provides a vacuum degree measurement system based on first-principles inversion, including a high-purity gas cylinder 1, a pressure stabilizing chamber 4, a vacuum degree testing chamber 8, an ionization vacuum gauge 10, a non-evaporable getter pump 12, a magnetic levitation turbomolecular pump 14, and a dry pump 16. Specifically: the high-purity gas cylinder 1 is used to store the test gas and is connected to the pressure stabilizing chamber 4 via a first metal shut-off valve 2; the pressure stabilizing chamber 4 is used to maintain the pressure of the test gas and is connected to the vacuum degree testing chamber 8 via a metal regulating valve 5; the ionization vacuum gauge 10 is connected to the vacuum degree testing chamber 8 and is used to measure the vacuum degree within the vacuum degree testing chamber 8; the magnetic levitation turbomolecular pump 14 is connected to the vacuum degree testing chamber 8 via a first gate valve 9; the non-evaporable getter pump 12 is connected to the vacuum degree testing chamber 8 via a second gate valve 11; and the dry pump 16 is connected to the magnetic levitation turbomolecular pump 14 via a second metal shut-off valve 15.

[0032] Specifically, the first-principles inversion vacuum measurement system provided in this application constructs the loss rate coefficient <σ of the trapped atom-neutral gas collision system. loss (E),v> ​​and velocity-averaged collision cross section<σ tot A theoretical model satisfying the relationship between ,v> was used to precisely control the atomic energy in the magnetic barrier and combined with numerical fitting experiments to measure the velocity-average collision cross section <σ between trapped atoms and neutral gas. tot ,v>, thereby accurately obtaining the collision loss rate coefficient <σ of trapped atom-neutral gas. loss(E),v>, finally realizing ultra-high / ultra-high vacuum precision measurement based on the first principle of quantum mechanics, laying the theoretical foundation for establishing a new generation of ultra-high / ultra-high vacuum quantum metrology standard device based on the collision loss characteristics of trapped atoms 7. Among them, the high-purity gas cylinder 1 is mainly used to store the test gas; the first metal shut-off valve 2 is mainly used to control the opening and closing of the gas path between the high-purity gas cylinder 1 and the pressure stabilizing chamber 4; the pressure stabilizing chamber 4 is mainly used to maintain the pressure of the test gas and ensure the stability of the gas vacuum; the metal regulating valve 5 is mainly used to control the opening and closing of the gas path between the pressure stabilizing chamber 4 and the vacuum degree testing chamber 8, and the metal regulating valve 5 can also control the flow conduction of the test gas molecules; the vacuum degree testing chamber 8 is mainly used to cool and trap the trapped atoms 7 using standard three-dimensional magneto-optical trap technology, and subsequently, the trapped atoms 7 collide with the incoming test gas, and the vacuum degree can be inverted according to the first principle of collision loss; the first gate valve 9 is mainly used to control the vacuum degree measurement. The second metal shut-off valve 15 is mainly used to control the gas flow between the test chamber 8 and the magnetic levitation turbomolecular pump 14; the second gate valve 11 is mainly used to control the gas flow between the vacuum test chamber 8 and the non-evaporable getter pump 12; the magnetic levitation turbomolecular pump 14, the dry pump 16, and the non-evaporable getter pump 12 are all used to evacuate the vacuum test chamber 8. The two magnetic levitation turbomolecular pumps 14 are connected in series to increase the compression ratio of H2, thereby obtaining a better vacuum. The non-evaporable getter pump 12 is a high-vacuum pump with a strong pumping capacity for reactive gases such as H2. The combination of the three can achieve a vacuum of 10... -10 Extremely high vacuum in the Pa range; the ionization vacuum gauge 10 is mainly used to measure the vacuum level in the vacuum test chamber 8.

[0033] Furthermore, a capacitive thin-film vacuum gauge 3 is connected to the pressure stabilizing chamber 4. The capacitive thin-film vacuum gauge 3 is mainly used to measure the vacuum level within the pressure stabilizing chamber 4. The capacitive thin-film vacuum gauge itself has no gas intake or exhaust characteristics, resulting in very high measurement accuracy, reaching 0.025% of the reading. During operation, the test gas enters the pressure stabilizing chamber 4, and the vacuum level within the chamber is maintained at 10... 4 Pa.

[0034] Furthermore, the metal regulating valve 5 is a molecular flow controllable metal regulating valve, mainly used to regulate and control the gas pressure entering the vacuum test chamber 8.

[0035] Furthermore, the vacuum testing chamber 8 is positioned between the upper anti-Helmholtz coil 6 and the lower anti-Helmholtz coil 13, using three-dimensional magneto-optical trap technology to confine atoms. Inside the vacuum testing chamber 8, atoms are first confined by a three-dimensional magneto-optical trap system (three pairs of lasers and one pair of magnetic field coils). After the lasers are turned off, atoms can be confined solely by the magnetic fields generated by the upper anti-Helmholtz coil 6 and the lower anti-Helmholtz coil 13.

[0036] Furthermore, it also includes a photomultiplier tube, which is used to measure the loss rate of trapped atoms 7 in the vacuum test chamber 8.

[0037] Furthermore, embodiments of this application also provide a method for applying a measurement system for vacuum degree inversion based on first principles, comprising the following steps:

[0038] Step 1: Close the first metal shut-off valve 2, adjust the molecular flow conductance of the metal regulating valve 5 to the maximum, and open the dry pump 16, the second metal shut-off valve 15, the magnetic levitation turbomolecular pump 14, and the first gate valve 9 to evacuate the vacuum test chamber 8; when the vacuum degree inside the vacuum test chamber 8 measured by the ionization vacuum gauge 10 reaches 10... -3 At Pa, the vacuum test chamber 8 is heated at 150℃ for 7 days to remove the water vapor inside the vacuum test chamber 8; after heating is completed, the vacuum test chamber 8 is cooled to room temperature, and then the second gate valve 11 is opened and the non-evaporative getter pump 12 is turned on to evacuate the vacuum test chamber 8.

[0039] Step 2: After the vacuum test chamber 8 reaches the ultimate vacuum, close the second gate valve 11, open the first metal shut-off valve 2, and introduce the test gas from the high-purity gas cylinder 1 into the pressure stabilizing chamber 4. Measure the vacuum level in the pressure stabilizing chamber 4 using the capacitive thin-film vacuum gauge 3, and maintain the vacuum level in the pressure stabilizing chamber 4 at 10. 4 Pa level; by adjusting the flow conductance of the metal regulating valve 5, the test gas in the pressure stabilizing chamber 4 is introduced into the vacuum test chamber 8, and after dynamic equilibrium is reached, the vacuum level in the vacuum test chamber 8 is maintained at 10. -7 Pa level;

[0040] Step 3: The trapped atoms 7 are cooled and trapped in the vacuum test chamber 8 using standard three-dimensional magneto-optical trap technology. The trapped atoms are generally alkali metal atoms. The trapping magnetic field is generated by passing equal and opposite currents through the upper anti-Helmholtz coil 6 and the lower anti-Helmholtz coil 13. The magnetic field gradient is 10G / cm.

[0041] Step 4: Turn off the laser in the three-dimensional magneto-optical trap system, and use only the upper anti-Helmholtz coil 6 and the lower anti-Helmholtz coil 13 to trap the trapped atoms 7 in the vacuum degree test chamber 8. Then apply a radio frequency magnetic field to the anti-Helmholtz coil, adjust the frequency f of the radio frequency magnetic field, and change the energy E of the trapped atoms 7 in the vacuum degree test chamber 8, where E = hf, and h is Planck's constant.

[0042] Step 5: Measure and calculate physical quantities using a photomultiplier tube and an ionization vacuum gauge 10. And the test result curve Numerical fitting was performed; the average total cross section of the trapped atom-neutral gas velocity-averaged collision was obtained according to the fitting formula <σ.tot The value of v> and the reading of the ionization vacuum gauge p' i calibration factor i g ;

[0043] Among them, the collision loss rate Γ of trapped atom-neutral gas corresponding to different atomic energies E loss (E) Collision loss rate of trapped atom-neutral gas system corresponding to different energies E <σ loss The relationship between (E) and v> is Γ loss (E)=n i <σ loss (E),v>,n i This represents the density of neutral gas molecules. Therefore, if the gas molecule density n in the vacuum test chamber is maintained... i (i.e., gas vacuum degree p) i If Γ remains unchanged, then the collision loss rate Γ loss (E) and collision loss rate coefficient <σ loss The ratios of (E) and v> satisfy the following relationship:

[0044]

[0045] According to the equation and equation Γ loss (E)=n i <σ loss (E),v> ​​yields:

[0046]

[0047] Step 6: Calculate the quantum scattering energy U according to the following formula. d Value:

[0048]

[0049] Where: m t The mass of the trapped atom in its trapped state is 7. Let k be the most probable velocity of a gas molecule of mass m at temperature T. B Boltzmann's constant;

[0050] The velocity-average collision loss cross section between trapped atoms and neutral gas is calculated using the following formula: <σ loss The value of (E),v>:

[0051]

[0052] In the formula: E is the energy of the trapped atom 7. f minI0 is the minimum frequency of the radio frequency magnetic field, I0 is the minimum current required to overcome the effect of gravity on atomic trapping, I is the current applied in the radio frequency magnetic field coil, and T is the gas temperature.

[0053] Because <σ loss (E), v> and U d A physical constant independent of vacuum level; therefore, for a certain test gas, when <σ loss When (E), v>, the molecular flow conductance of the metal regulating valve 5 can be adjusted to generate 10 in the vacuum test chamber 8. -6 -10 -10 Test gases were used in the ultra-high / extremely high vacuum range, and the collision loss rate Γ at each vacuum level was measured using a photomultiplier tube. loss (E), and finally, the vacuum degree p derived from the first-principles inversion of the collision loss of trapped atoms 7 can be calculated according to the following formula. i Value:

[0054]

[0055] The vacuum level p measured using atoms 7 trapped in a magnetic potential barrier i The reading p' of the ionization vacuum gauge connected to the vacuum test chamber can be calibrated and corrected. i , i.e. p' i =i g p i =i g n i k B T, where i g This is the calibration factor for the ionization vacuum gauge 10.

[0056] More specifically, the first principles described in the embodiments of this application mainly refer to the analysis of the core parameter <σ> for the collision system of cold atoms and gas molecules, starting from the intrinsic quantum properties of microscopic particles, without relying on any empirical parameters, solely based on quantum mechanics theory. loss (E),v>, is not limited by the type of gas and can be tested using different gases, thereby enabling the calibration of the ionization vacuum meter for the relative sensitivity of different gases, and extending the measurement lower limit to 10. -10 Below Pa.

[0057] 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 method for using a measurement system based on first-principles inversion to determine vacuum level, said measurement system comprising a high-purity gas cylinder, a pressure stabilizing chamber, a vacuum level testing chamber, an ionization vacuum gauge, a non-evaporative getter pump, a magnetically levitated turbomolecular pump, and a dry pump, wherein: The high-purity gas cylinder is used to store the test gas and is connected to the pressure stabilizing chamber via a first metal shut-off valve; the pressure stabilizing chamber is used to maintain the pressure of the test gas and is connected to the vacuum test chamber via a metal regulating valve; the ionization vacuum gauge is connected to the vacuum test chamber and is used to measure the vacuum degree inside the vacuum test chamber; the magnetic levitation turbomolecular pump is connected to the vacuum test chamber via a first gate valve; the non-evaporative getter pump is connected to the vacuum test chamber via a second gate valve; the dry pump is connected to the magnetic levitation turbomolecular pump via a second metal shut-off valve; the vacuum test chamber is located between the upper anti-Helmholtz coil and the lower anti-Helmholtz coil, and atoms are trapped using three-dimensional magneto-optical trap technology; it also includes a photomultiplier tube, which is used to measure the loss rate of trapped atoms in the vacuum test chamber; a capacitive thin-film vacuum gauge is connected to the pressure stabilizing chamber; the metal regulating valve is a molecular flow controllable metal regulating valve, characterized by the following steps: Step 1: Close the first metal shut-off valve, adjust the molecular flow conductance of the metal regulating valve to maximum, and open the dry pump, the second metal shut-off valve, the magnetic levitation turbomolecular pump, and the first gate valve to evacuate the vacuum test chamber; when the vacuum degree inside the vacuum test chamber measured by the ionization vacuum gauge reaches 10... -3 At Pa, the vacuum test chamber is heated to 150℃ for 7 days; after heating, the vacuum test chamber is cooled to room temperature, and then the second gate valve is opened and the non-evaporative getter pump is turned on to evacuate the vacuum test chamber. Step 2: Once the vacuum testing chamber reaches its ultimate vacuum, close the second gate valve and open the first metal shut-off valve to introduce the test gas from the high-purity gas cylinder into the pressure stabilizing chamber. Measure the vacuum level inside the pressure stabilizing chamber using a capacitive thin-film vacuum gauge, maintaining the vacuum level inside the pressure stabilizing chamber at 10. 4 Pa level; by adjusting the flow conductance of the metal regulating valve, the test gas in the pressure stabilizing chamber is introduced into the vacuum test chamber. After dynamic equilibrium is reached, the vacuum level in the vacuum test chamber is maintained at 10. -7 Pa level; Step 3: The trapped atoms are cooled and trapped in a vacuum chamber using standard three-dimensional magneto-optical trap technology. The trapping magnetic field is generated by passing equal but opposite currents through the upper and lower anti-Helmholtz coils, with a magnetic field gradient of 10 G / cm. Step 4: Turn off the laser in the three-dimensional magneto-optical trap system, and use only the upper and lower anti-Helmholtz coils to trap the trapped atoms in the vacuum test chamber. Then, apply a radio frequency magnetic field to the anti-Helmholtz coils and adjust the frequency f of the radio frequency magnetic field to change the energy E of the trapped atoms in the vacuum test chamber. Step 5: Measure and calculate physical quantities using a photomultiplier tube and an ionization vacuum meter. and the test result curve Numerical fitting was performed; the velocity-averaged total cross section of the trapped atom-neutral gas collision was obtained according to the fitting formula. Values ​​and ionization vacuum gauge readings calibration factor i g ; Where, k B Where is Boltzmann's constant, and T is the gas temperature. This represents the loss rate of trapped atoms due to collisions with the background gas. This is the reading from the ionization vacuum gauge; Step 6: Calculate the quantum scattering energy U according to the formula. d The value and the velocity-average collision loss cross section of trapped atoms-neutral gas The value is then adjusted, and the molecular flow conductance of the metal regulating valve is adjusted to generate 10 in the vacuum test chamber. -6 -10 -10 Test gases were used in the ultra-high / extremely high vacuum range, and the collision loss rate at each vacuum level was measured using a photomultiplier tube. Finally, the vacuum degree p, derived from first-principles inversion based on the collision loss of trapped atoms, can be calculated using the formula. i The value of .

2. The method for applying a measurement system based on first-principles inversion of vacuum degree according to claim 1, characterized in that, In step 4, the relationship between the energy E of the trapped atom and the frequency f of the radio frequency magnetic field is: E = hf, where h is Planck's constant.

3. The method for applying a measurement system based on first-principles inversion of vacuum degree according to claim 2, characterized in that, In step 6, the quantum scattering energy U d The value is calculated using the following formula: ， In the formula: h is Planck's constant, m t The mass of the trapped atom. Let k be the most probable velocity of a gas molecule of mass m at temperature T. B Boltzmann's constant, The total cross section of the collision is the velocity-averaged value.

4. The method for applying a measurement system based on first-principles inversion of vacuum degree according to claim 3, characterized in that, In step 6, the velocity-averaged collision loss cross section between trapped atoms and neutral gas. The value is calculated using the following formula: ， In the formula: E is the energy of the trapped atom. f min I0 is the minimum frequency of the radio frequency magnetic field, I0 is the minimum current required to overcome the effect of gravity on atomic trapping, I is the current applied to the radio frequency magnetic field coil, and T is the gas temperature.

5. The method for applying a measurement system based on first-principles inversion of vacuum degree according to claim 4, characterized in that, In step 6, the vacuum degree p i The value is calculated using the following formula: 。

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