Extremely high vacuum quantum measurement device and measurement method

Abstract

The invention provides an extremely high vacuum quantum measurement device and a measurement method. The device comprises a magneto-optical trap mechanism and a shell, the magneto-optical trap mechanism is arranged in the shell; the magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the shell is provided with a plurality of interfaces; the plurality of interfaces comprise an alkali metal distributor interface, an ionization vacuum gauge interface, a background gas interface, a first vacuumizing interface and a second vacuumizing interface; the two-dimensional grating magneto-optical trap system is respectively connected with an alkali metal distributor interface and a first vacuumizing interface; the three-dimensional grating magneto-optical trap system is connected with the ionization vacuum gauge interface, the second vacuumizing interface and the background gas interface, the background gas interface is provided with a variable leakage valve, the extremely high vacuum quantum measurement device and the measurement method are high in measurement accuracy, and the size of the quantum vacuum measurement device is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of vacuum measurement, and in particular to an extremely high vacuum quantum measurement device and a measurement method. Background Art

[0002] Currently in ultra-high / ultra-high vacuum (P<10 –6 In the field of vacuum measurement, ionization meters based on the principle of neutral gas ionization are commonly used to measure vacuum degree. However, the traditional ionization meters have electron excitation desorption effect, soft X-ray and hot cathode outgassing effects that affect the measurement accuracy during use. As the measurement lower limit continues to decrease, especially to 10 –10 At the Pa level, higher requirements are placed on the measurement accuracy. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide an extremely high vacuum quantum measurement device and a measurement method, which have high measurement accuracy and effectively reduce the volume of the quantum vacuum measurement device.

[0004] An extremely high vacuum quantum measurement device provided in an embodiment of the present application comprises: a magneto-optical trap mechanism and a shell; the magneto-optical trap mechanism is arranged inside the shell;

[0005] The magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the two-dimensional grating magneto-optical trap system and the three-dimensional grating magneto-optical trap system are connected via the differential tube;

[0006] The housing is provided with a plurality of interfaces, including: an alkali metal distributor interface, an ionization vacuum gauge interface, a background gas interface, a first vacuum pumping interface, and a second vacuum pumping interface;

[0007] The two-dimensional grating magneto-optical trap system is respectively connected to the alkali metal distributor interface and the first vacuum pumping interface;

[0008] The three-dimensional grating magneto-optical trap system is respectively connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface, and a variable leakage valve is arranged on the background gas interface.

[0009] In some embodiments, in the ultra-high vacuum quantum measurement device, the first vacuum pump interface is a first ion pump interface, and the first ion pump interface is used to connect a first ion pump to vacuum the two-dimensional grating magneto-optical trap system;

[0010] The second vacuum pumping interface includes a second ion pump interface and a non-evaporable air pump interface; the second ion pump interface is used to connect a second ion pump to initially vacuum the three-dimensional grating magneto-optical trap system; the non-evaporable air pump interface is used to connect a non-evaporable air pump to finely vacuum the three-dimensional grating magneto-optical trap system.

[0011] In some embodiments, in the ultra-high vacuum quantum measurement device, the two-dimensional grating magnetic optical trap system includes a first vacuum cavity, a two-dimensional diffraction grating chip, and two pairs of anti-Helmholtz coils;

[0012] The two-dimensional diffraction grating chip is located inside the first vacuum cavity; the anti-Helmholtz coils are placed outside the first vacuum cavity, one pair of anti-Helmholtz coils are perpendicular to the two-dimensional diffraction grating chip, and the other pair of anti-Helmholtz coils are parallel to the two-dimensional diffraction grating chip.

[0013] In some embodiments, in the ultra-high vacuum quantum measurement device, the three-dimensional grating magnetic optical trap system includes a second vacuum cavity, a three-dimensional diffraction grating chip, and an anti-magnetic trap chip;

[0014] The three-dimensional diffraction grating chip is located inside the second vacuum cavity; the anti-magnetic trap chip is located outside the second vacuum cavity and directly below the three-dimensional diffraction grating chip.

[0015] In some embodiments, in the ultra-high vacuum quantum measurement device, the alkali metal dispenser interface is used to connect an alkali metal dispenser, the alkali metal dispenser is used as an atomic source, and the working cold atoms are alkali metal atoms.

[0016] In some embodiments, in the ultra-high vacuum quantum measurement device, the ionization vacuum gauge interface is used to connect an ionization vacuum gauge; the ionization vacuum gauge monitors the vacuum pressure of the three-dimensional grating magneto-optical trap system, and the monitoring result of the ionization vacuum gauge is used as a vacuum standard to calibrate the measurement result of the ultra-high vacuum measurement device.

[0017] In some embodiments, in the ultra-high vacuum quantum measurement device, the background gas interface is used to connect a background gas source, so that the background gas from the background gas source flows into the three-dimensional grating magnetic optical trap system through the background gas interface;

[0018] The variable leakage valve on the background gas interface is used to control the inflow rate of the background gas into the three-dimensional grating magneto-optical trap system.

[0019] In some embodiments, an extremely high vacuum quantum measurement method is further provided, wherein the measurement is performed using the extremely high vacuum quantum measurement device as claimed in claim 1, and the measurement method comprises:

[0020] Corresponding components are installed at the interface of the ultra-high vacuum quantum measurement device, and based on the installed components, vacuum preparation of a two-dimensional grating magneto-optical trap system and a three-dimensional grating magneto-optical trap system is realized, and after background gas is introduced into the three-dimensional grating magneto-optical trap system, alkali metal atoms are allowed to enter the two-dimensional grating magneto-optical trap system, and the alkali metal atom group captured by the two-dimensional grating magneto-optical trap system is pushed to the three-dimensional grating magneto-optical trap system through a differential tube by a push laser beam;

[0021] Measure the number of atoms in alkali metal atom groups in a three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of a three-dimensional grating magneto-optical trap system;

[0022] According to atomic collision theory, based on the collision loss rate between the alkali metal atoms and the background gas and the potential well depth of the three-dimensional grating magneto-optical trap system, the vacuum degree in the three-dimensional grating magneto-optical trap system is inverted;

[0023] Comparing the measured vacuum degree with the monitoring result of the ionization vacuum gauge to determine the evaluation result of the measured vacuum degree;

[0024] When the evaluation result of the measured vacuum degree is valid, the vacuum degree of the measured environment is measured using the ultra-high vacuum quantum measurement device.

[0025] In some embodiments, in the ultra-high vacuum quantum measurement method, the measurement of the number of atoms of alkali metal atom groups in a three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system comprises:

[0026] The detection light is transmitted through the second vacuum chamber of the three-dimensional grating magneto-optical trap system and hits the alkali metal atom group. The other end is received by a charge coupled device for imaging. The number of atoms in the alkali metal atom group is measured based on the absorption imaging principle.

[0027] By using a photomultiplier tube, the fluorescence intensity of the alkali metal atom group is measured to be reduced to a fluorescence signal curve of 0V, the number of atoms of the alkali metal atom group at an initial moment and another moment is obtained by using an absorption imaging method, and based on the number of atoms of the alkali metal atom group at the initial moment and another moment, the collision loss rate of the alkali metal atom with the background gas is determined;

[0028] The escape probability of alkali metal atoms under catalytic laser induction is taken as a function of frequency detuning, and the potential well depth is measured based on the function of frequency detuning.

[0029] In some embodiments, in the ultra-high vacuum quantum measurement method, according to the atomic collision theory, based on the collision loss rate of the alkali metal atoms and the background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system, the vacuum degree in the three-dimensional grating magneto-optical trap system is inverted; comprising:

[0030] Determining the average thermal loss rate coefficient of cold atoms of the alkali metal atom group based on the relationship between the potential well depth and the average thermal loss rate coefficient of cold atoms;

[0031] The vacuum degree in the three-dimensional grating magneto-optical trap system is determined based on the average heat loss rate coefficient of the cold atoms and the collision loss rate of the alkali metal atoms and the background gas.

[0032] In an embodiment of the present application, an extremely high vacuum quantum measurement device and a measurement method are proposed, wherein the device comprises: a magneto-optical trap mechanism and a shell; the magneto-optical trap mechanism is arranged inside the shell; the magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the two-dimensional grating magneto-optical trap system and the three-dimensional grating magneto-optical trap system are connected via the differential tube; a plurality of interfaces are arranged on the shell; the plurality of interfaces comprise: an alkali metal dispenser interface, an ionization vacuum gauge interface, a background gas interface, a first vacuum pumping interface, and a second vacuum pumping interface; the two-dimensional grating magneto-optical trap system is connected to the alkali metal dispenser, the ionization vacuum gauge interface, the background gas interface, the first vacuum pumping interface, and the ... interface, a first vacuum pumping interface; the three-dimensional grating magneto-optical trap system is respectively connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface, and a variable leakage valve is arranged on the background gas interface; the ultra-high vacuum quantum measurement device is used to measure the ultra-high vacuum, based on the law of cold atom loss caused by the collision between neutral particles in the magneto-optical trap system and trapped cold atoms in the potential well, the cold atom loss rate coefficient and the collision loss rate are accurately measured and calculated, so as to accurately invert the vacuum value, with high measurement accuracy, strong temporal and spatial reproducibility, and effectively reducing the volume of the quantum vacuum measurement device, and having high system reliability and strong anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the structure of the ultra-high vacuum quantum measurement device described in an embodiment of the present application is shown;

[0035] Figure 2 A schematic diagram of a two-dimensional diffraction grating chip located inside a two-dimensional grating magneto-optical trap system according to an embodiment of the present application is shown;

[0036] Figure 3 A schematic diagram of a three-dimensional diffraction grating chip located inside a three-dimensional grating magneto-optical trap system according to an embodiment of the present application is shown;

[0037] Figure 4 A flow chart of the ultra-high vacuum quantum measurement method described in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0038] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0039] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0040] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0041] With the redefinition of the International System of Units, the value of vacuum has accelerated its quantization process. Among them, the research direction of quantum vacuum measurement based on optical methods has further developed, including the refractive index method, absorption spectroscopy and cold atom method, which is of great significance for the reproduction of vacuum values ​​and the future redefinition of the International System of Units.

[0042] Currently in ultra-high / ultra-high vacuum (P<10 –6 In the field of vacuum measurement, ionization meters based on the principle of neutral gas ionization are commonly used to measure vacuum degree. However, the traditional ionization meters have electron excitation desorption effect, soft X-ray and hot cathode outgassing effects that affect the measurement accuracy during use. As the measurement lower limit continues to decrease, especially to 10 –10 At the Pa level, higher requirements are placed on the measurement accuracy.

[0043] Based on this, in an embodiment of the present application, an extremely high vacuum quantum measurement device and a measurement method are proposed, wherein the device comprises: a magneto-optical trap mechanism and a shell; the magneto-optical trap mechanism is arranged inside the shell; the magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the two-dimensional grating magneto-optical trap system and the three-dimensional grating magneto-optical trap system are connected through the differential tube; a plurality of interfaces are arranged on the shell; the plurality of interfaces comprise: an alkali metal dispenser interface, an ionization vacuum gauge interface, a background gas interface, a first vacuum pumping interface, and a second vacuum pumping interface; the two-dimensional grating magneto-optical trap system is respectively connected to the ... The three-dimensional grating magneto-optical trap system is connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface respectively, and a variable leakage valve is arranged on the background gas interface; the ultra-high vacuum quantum measurement device is used to measure the ultra-high vacuum, and based on the law of cold atom loss caused by the collision between neutral particles in the magneto-optical trap system and trapped cold atoms in the potential well, the cold atom loss rate coefficient and the collision loss rate are accurately measured and calculated, so as to accurately invert the vacuum value, with high measurement accuracy, strong temporal and spatial reproducibility, and effectively reducing the volume of the quantum vacuum measurement device, and having high system reliability and strong anti-interference ability.

[0044] Please refer to Figure 1 , Figure 1 The structure diagram of the ultra-high vacuum quantum measurement device according to the embodiment of the present application is shown; the ultra-high vacuum quantum measurement device comprises: a magneto-optical trap mechanism and a housing 9; the magneto-optical trap mechanism is arranged inside the housing 9;

[0045] The magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system 2, a three-dimensional grating magneto-optical trap system 6 and a differential tube 3, wherein the two-dimensional grating magneto-optical trap system 2 and the three-dimensional grating magneto-optical trap system 6 are connected via the differential tube 3;

[0046] The housing 9 is provided with a plurality of interfaces, including: an alkali metal distributor interface 1, an ionization vacuum gauge interface, a background gas interface 12, a first vacuum pumping interface, and a second vacuum pumping interface;

[0047] The two-dimensional grating magneto-optical trap system 2 is respectively connected to the alkali metal dispenser interface 1 and the first vacuum pumping interface;

[0048] The three-dimensional grating magneto-optical trap system 6 is respectively connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface 12 , and a variable leakage valve 13 is provided on the background gas interface.

[0049] The housing 9 is used to fix the two-dimensional grating magneto-optical trap system 2 and the three-dimensional grating magneto-optical trap system 6 as well as a plurality of external interfaces.

[0050] The interface is used to connect external components.

[0051] Specifically, the alkali metal distributor interface 1 is used to connect the alkali metal distributor; the ionization vacuum gauge interface is used to connect the ionization vacuum gauge 8; and the background gas interface 12 is used to connect the background gas source.

[0052] In the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the first vacuum pumping interface is a first ion pump interface, and the first ion pump interface is used to connect the first ion pump 14 to vacuum the two-dimensional grating magneto-optical trap system 2;

[0053] The second vacuum pumping interface includes a second ion pump interface and a non-evaporative air pump 10 interface; the second ion pump interface is used to connect the second ion pump 11 to initially vacuum the three-dimensional grating magneto-optical trap system 6; the non-evaporative air pump 10 interface is used to connect the non-evaporative air pump 10 to finely vacuum the three-dimensional grating magneto-optical trap system 6.

[0054] The first ion pump 14 is responsible for maintaining the vacuum state of the two-dimensional grating magneto-optical trap system 2; the second ion pump 11 and the non-evaporative getter pump 10 are connected to the three-dimensional grating magneto-optical trap system 6 through the interface on the shell 9, and are responsible for maintaining the vacuum state of the three-dimensional grating magneto-optical trap system 6.

[0055] The elastic collision between the cold atomic clusters trapped in the three-dimensional grating magneto-optical trap system 6 and the background gas results in the collision loss rate, and the potential well depth of the cold atomic clusters is measured, and the thermal average loss rate coefficient of the cold atomic clusters is measured. The vacuum degree can be inverted based on the thermal average loss rate coefficient and the collision loss rate; therefore, the three-dimensional grating magneto-optical trap system 6 has higher requirements for the vacuum degree, and it is necessary to use a second ion pump 11 to initially evacuate the three-dimensional grating magneto-optical trap system 6, and use a non-evaporative suction pump 10 to finely evacuate the three-dimensional grating magneto-optical trap system 6, so as to better maintain the extremely high vacuum state of the three-dimensional grating magneto-optical trap system 6.

[0056] In the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the alkali metal distributor interface 1 is used to connect an alkali metal distributor, and the alkali metal distributor serves as an atom source, and alkali metal atoms are selected as working cold atoms.

[0057] Specifically, the alkali metal distributor is connected below the two-dimensional grating magneto-optical trap system 2 .

[0058] In the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the ionization vacuum gauge interface is used to connect the ionization vacuum gauge 8; the ionization vacuum gauge 8 monitors the vacuum pressure of the three-dimensional grating magneto-optical trap system 6, and the monitoring result of the ionization vacuum gauge 8 is used as a vacuum standard to calibrate the measurement result of the ultra-high vacuum measurement device.

[0059] The ionization vacuum gauge 8 is connected to the three-dimensional grating magneto-optical trap system 6 through the shell 9 to monitor the vacuum degree of the three-dimensional grating magneto-optical trap system 6 and calibrate the measured vacuum degree to determine whether the vacuum degree measured by the ultra-high vacuum quantum measurement device is valid.

[0060] In the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the background gas interface 12 is used to connect a background gas source so that the background gas from the background gas source flows into the three-dimensional grating magneto-optical trap system 6 through the background gas interface 12;

[0061] The variable leakage valve 13 on the background gas interface 12 is used to control the inflow rate of the background gas into the three-dimensional grating MOT system 6 .

[0062] The background gas interface 12 is connected to the three-dimensional grating MOT through the shell 9 . The background gas must first pass through the variable leakage valve 13 in the shell 9 , and the variable leakage valve 13 controls the rate at which the background gas flows into the three-dimensional grating MOT system 6 .

[0063] Specifically, the variable leakage valve 13 is opened to allow the background gas to enter the three-dimensional grating magneto-optical trap system 6 , and the variable leakage valve 13 is closed after the background gas is loaded.

[0064] Please refer to Figure 2 , Figure 2 FIG. 2 shows a schematic diagram of a two-dimensional diffraction grating chip located inside a two-dimensional grating magneto-optical trap system 2 according to an embodiment of the present application; wherein the arrow indicates the direction of the magnetic field; Figure 2 As shown, in the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the two-dimensional grating magneto-optical trap system 2 includes a first vacuum cavity, a two-dimensional diffraction grating chip 201, and two pairs of anti-Helmholtz coils 4;

[0065] The two-dimensional diffraction grating chip 201 is located inside the first vacuum chamber; the anti-Helmholtz coils 4 are placed outside the first vacuum chamber, one pair of anti-Helmholtz coils 4 are perpendicular to the two-dimensional diffraction grating chip 201, and the other pair of anti-Helmholtz coils 4 are parallel to the two-dimensional diffraction grating chip 201.

[0066] Please refer to Figure 3 , Figure 3 Schematic diagram of a three-dimensional diffraction grating chip located inside the three-dimensional grating magneto-optical trap system 6 described in an embodiment of the present application is shown; wherein the arrow represents the direction of the magnetic field; Figure 3 As shown, in the ultra-high vacuum quantum measurement device described in the embodiment of the present application, the three-dimensional grating magneto-optical trap system 6 includes a second vacuum cavity, a three-dimensional diffraction grating chip 601, and an anti-magnetic trap chip 7;

[0067] The three-dimensional diffraction grating chip 601 is located inside the second vacuum cavity; the inverted magnetic trap chip 7 is located outside the second vacuum cavity and directly below the three-dimensional diffraction grating chip.

[0068] The three-dimensional grating magneto-optical trap system 6 uses a photomultiplier tube equipped with a bandpass filter. The photomultiplier tube is used to monitor the fluorescence radiated by cold atoms.

[0069] In the embodiment of the present application, the three-dimensional diffraction grating chip may also be referred to as a three-dimensional grating chip.

[0070] The three-dimensional grating magneto-optical trap system 6 described in the embodiment of the present application adopts a three-dimensional diffraction grating chip to replace the traditional three-beam laser beam, and adopts an anti-Helmholtz magneto-optical trap chip 7 to replace the anti-Helmholtz coil 4 and the geomagnetic compensation coil, which effectively reduces the volume of the cold atom trap system. Compared with the traditional magneto-optical trap, the two-dimensional grating magneto-optical trap system 2 and the three-dimensional grating magneto-optical trap system 6 do not require a large number of mounting brackets and optical devices, effectively reducing the overall volume of the vacuum measurement device, and the system has high stability and strong anti-interference ability.

[0071] Based on this, in the embodiment of the present application, a two-dimensional grating magneto-optical trap system 2 and a three-dimensional grating magneto-optical trap system 6 are provided to replace the two-dimensional magneto-optical trap and the three-dimensional magneto-optical trap in the traditional vacuum degree measurement system, so as to effectively reduce the measurement volume of the device; the gradient magnetic field required to trap the cold atomic clusters is provided by the anti-H-type magnetic trap chip 7; the alkali metal distributor is connected below the two-dimensional grating magneto-optical trap system, and the alkali metal atoms enter the two-dimensional grating magneto-optical trap system 2 and are captured to form cold atomic clusters; the two-dimensional grating magneto-optical trap system 2 and the three-dimensional grating magneto-optical trap system 6 are connected by a differential tube 3, and the cold atomic clusters captured by the two-dimensional grating magneto-optical trap system 2 are pushed to the three-dimensional grating magneto-optical trap system 6 by a push laser 5 via the differential tube 3.

[0072] The working principle of the two-dimensional grating magneto-optical trap system 2 is as follows: the two-dimensional grating magneto-optical trap system 2 includes a first vacuum cavity, a two-dimensional diffraction grating chip, and two pairs of anti-Helmholtz coils 4; the cooling light and the re-pumping light are collimated and vertically incident on the two-dimensional diffraction grating chip, the alkali metal distributor is turned on, so that the alkali metal atoms enter the two-dimensional grating magneto-optical trap system 2, and the cooling light and the re-pumping light are combined and irradiated on the two-dimensional diffraction grating chip; the power supply of the anti-Helmholtz coil 4 is turned on, and the anti-Helmholtz coil 4 provides a gradient magnetic field; the two act simultaneously to form a magneto-optical trap; the alkali metal atoms are captured by the two-dimensional grating magneto-optical trap system 2 to form cold atomic clusters.

[0073] In the embodiment of the present application, the cold atomic group may also be referred to as an alkali metal atomic group.

[0074] The working principle of the three-dimensional grating magneto-optical trap system 6 is as follows: turn on the three-dimensional grating magneto-optical trap system 6 to form a three-dimensional magneto-optical trap; push the laser 5 to push the cold atomic cluster into the three-dimensional grating magneto-optical trap system 6 through the differential tube 3; the detection light is hit on the cold atomic cluster through the vacuum cavity, and the other end is received by the charge coupled device for imaging, and the number of atoms in the cold atomic cluster can be measured by the absorption imaging principle.

[0075] There are elastic collisions between background gas molecules and alkali metal atoms and inelastic collisions between alkali metal atoms in the three-dimensional grating magnetic optical trap system 6, which gradually reduce the fluorescence intensity of the cold atomic group. The fluorescence signal received by the photomultiplier tube is displayed on the oscilloscope as a fluorescence signal curve that gradually approaches 0V.

[0076] The collision loss rate Γ1 between the alkali metal atoms and the background gas is measured by the fluorescence signal curve of the photomultiplier tube; a beam of catalytic laser is used to hit the cold atom cluster, and the alkali metal atoms in the cold atom cluster obtain the maximum escape velocity by adjusting the duty cycle and detuning of the catalytic laser, and then the potential well depth of the three-dimensional grating magneto-optical trap is calculated, and the thermal average loss rate coefficient k of the cold atom cluster can be calculated from the potential well depth. loss .

[0077] According to atomic collision theory, based on the collision loss rate between the alkali metal atoms and the background gas and the potential well depth of the three-dimensional grating magneto-optical trap system 6, the vacuum degree in the three-dimensional grating magneto-optical trap system 6 is inverted.

[0078] The collision loss rate between the alkali metal atoms and the background gas may also be referred to as the collision loss rate, the alkali metal atom collision loss rate, the cold atom collision loss rate, etc. in the embodiments of the present application.

[0079] The core principle of the miniaturized ultra-high vacuum quantum measurement device described in the embodiment of the present application for measuring vacuum is the law of cold atom loss caused by the collision between neutral particles and trapped cold atoms in the potential well. The key to improving the accuracy of inverted vacuum is the loss rate coefficient k loss Accurate calculation of collision loss rate Γ1 and precise measurement of collision loss rate Γ1.

[0080] The specific steps of using the miniaturized ultra-high vacuum quantum measurement device are described below.

[0081] Corresponding components are installed at the interface of the ultra-high vacuum quantum measurement device, and based on the installed components, vacuum preparation of the two-dimensional grating magnetic light trap system 2 and the three-dimensional grating magnetic light trap system 6 is realized, and after the background gas is introduced into the three-dimensional grating magnetic light trap system 6, the alkali metal atoms are allowed to enter the two-dimensional grating magnetic light trap system 2, and the alkali metal atom group captured by the two-dimensional grating magnetic light trap system 2 is pushed to the three-dimensional grating magnetic light trap system 6 through the differential tube 3 by a push laser 5;

[0082] Measuring the number of atoms of alkali metal atom groups in the three-dimensional grating magneto-optical trap system 6, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system 6;

[0083] According to the atomic collision theory, based on the collision loss rate between the alkali metal atoms and the background gas and the potential well depth of the three-dimensional grating magneto-optical trap system 6, the vacuum degree in the three-dimensional grating magneto-optical trap system 6 is inverted;

[0084] Comparing the measured vacuum degree with the monitoring result of the ionization vacuum gauge 8 to determine the evaluation result of the measured vacuum degree;

[0085] When the evaluation result of the measured vacuum degree is qualified, the vacuum degree of the measured environment is measured using the ultra-high vacuum quantum measurement device.

[0086] Corresponding components are installed at the interface of the ultra-high vacuum quantum measurement device, and based on the installed components, vacuum preparation of the two-dimensional grating magneto-optical trap system 2 and the three-dimensional grating magneto-optical trap system 6 is realized, and after the background gas is introduced into the three-dimensional grating magneto-optical trap system 6, alkali metal atoms are allowed to enter the two-dimensional grating magneto-optical trap system 2, and the alkali metal atom group captured by the two-dimensional grating magneto-optical trap system 2 is pushed to the three-dimensional grating magneto-optical trap system 6 through a differential tube 3 by a push laser 5; specifically, the following steps are included:

[0087] Install components corresponding to various interfaces of the ultra-high vacuum quantum measurement device to obtain an installed ultra-high vacuum quantum measurement device;

[0088] Evacuate the interior of a first vacuum chamber of the two-dimensional grating magnetic light trap system 2 and the interior of a second vacuum chamber of the three-dimensional grating magnetic light trap system 6 of the ultra-high vacuum quantum measurement device;

[0089] Open the variable leakage valve 13 on the background gas interface 12 to allow the background gas to flow into the second vacuum chamber of the three-dimensional grating magneto-optical trap system 6;

[0090] Opening the alkali metal distributor connected to the alkali metal distributor to allow the alkali metal atoms to enter the two-dimensional grating magneto-optical trap system 2;

[0091] The alkali metal atom group captured by the two-dimensional grating magneto-optical trap system 2 is pushed to the three-dimensional grating magneto-optical trap system 6 through the differential tube 3 by a push laser beam 5 .

[0092] Install the components corresponding to each interface of the ultra-high vacuum quantum measurement device. Specifically, first install and connect them, connect the anti-Helmholtz magnetic trap chip 7 and the anti-Helmholtz coil 4 of the ultra-high vacuum quantum measurement device to the power supply, and connect each interface on the shell 9 to the corresponding device (component).

[0093] Specifically, the alkali metal dispenser interface 1 is connected to the alkali metal dispenser; the ionization vacuum gauge interface is connected to the ionization vacuum gauge 8; the background gas interface 12 is connected to the background gas source; the first ion pump interface is connected to the first ion pump 14; the second vacuum pump interface is connected to the second ion pump 11; the non-evaporable air pump 10 interface is connected to the non-evaporable air pump 10.

[0094] The vacuum preparation process is as follows: the first vacuum chamber of the two-dimensional grating magneto-optical trap system 2 is evacuated by the first ion pump 14; the second vacuum chamber of the three-dimensional grating magneto-optical trap system 6 is initially evacuated by the second ion pump 11, and the second vacuum chamber of the three-dimensional grating magneto-optical trap system 6 is finely evacuated by the non-evaporative suction pump 10.

[0095] The alkali metal atoms are allowed to enter the two-dimensional grating magneto-optical trap system 2. Specifically, the alkali metal dispenser is first opened to allow the alkali metal atoms to enter the two-dimensional grating magneto-optical trap system 2. Then, the cooling light and the re-pumped photosynthetic beam are irradiated onto the two-dimensional diffraction grating chip to form a two-dimensional magneto-optical trap. The alkali metal atoms are captured in the two-dimensional grating magneto-optical trap system 2 to form cold atomic clusters.

[0096] The cold atomic clusters are pushed by the push laser 5 through the differential tube 3 into the three-dimensional grating magneto-optical trap system 6, and the cold atomic clusters are loaded into the three-dimensional grating magneto-optical trap system 6.

[0097] In the embodiment of the present application, the method of measuring the number of atoms of alkali metal atom groups in the three-dimensional grating magneto-optical trap system 6, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system 6 includes:

[0098] The detection light is transmitted through the second vacuum chamber of the three-dimensional grating magneto-optical trap system 6 and hits the alkali metal atom group. The other end is received by a charge coupled device for imaging. The number of atoms in the alkali metal atom group is measured based on the absorption imaging principle.

[0099] By using a photomultiplier tube, the fluorescence intensity of the alkali metal atom group is measured to be reduced to a fluorescence signal curve of 0V, the number of atoms of the alkali metal atom group at an initial moment and another moment is obtained by using an absorption imaging method, and based on the number of atoms of the alkali metal atom group at the initial moment and another moment, the collision loss rate of the alkali metal atom with the background gas is determined;

[0100] The escape probability of alkali metal atoms under catalytic laser induction is taken as a function of frequency detuning, and the potential well depth is measured based on the function of frequency detuning.

[0101] The principle of measuring the collision loss rate of alkali metal atoms with background gas is as follows.

[0102] There are elastic collisions between background gas molecules and alkali metal atoms and inelastic collisions between alkali metal atoms in the three-dimensional grating magnetic optical trap system, which gradually reduce the fluorescence intensity of the cold atomic group. The fluorescence signal received by the photomultiplier tube is displayed on the oscilloscope as a curve that gradually decreases to 0V; the mathematical model of this process is the following formula (1)

[0103]

[0104] In the formula, is the rate of change of the number of trapped cold atoms over time; N is the number of cold atoms trapped in the magneto-optical trap, R is the loading rate of alkali metal atoms, Γ1 is the collision loss rate of alkali metal atoms and background gas, and N(t) is the number of trapped cold atoms at time t; the last term represents the two-body inelastic collision loss between cold atoms, β is the two-body collision loss rate, is the average density of trapped atoms.

[0105] The average density of trapped atoms is determined based on the following formula (2):

[0106]

[0107] Where n(r,t) is the density distribution of trapped atoms at time t and spatial position r, and N is the number of cold atoms trapped in the magneto-optical trap.

[0108] The density of cold atoms in the experiment was controlled at 10 10 cm –3 When , the cold atom cluster presents a Gaussian density distribution, that is, the following formula (3)

[0109]

[0110] Where n0(t) is the peak density and ω is the Gaussian radius, so the following formula (4) can be obtained:

[0111]

[0112] Based on the above formula 4, the total number of atoms N(t) corresponding to time t can be obtained by integrating the atomic density, that is, the following formula (5):

[0113]

[0114] Therefore, the above formula (1) can be simplified to the following formula (6)

[0115]

[0116] Where α is determined by the following formula (7):

[0117]

[0118] When the loss of cold atoms in the MOT reaches equilibrium with the loading, the 2D MOT laser and the push laser are turned off to stop loading. At this time, the loss process of cold atoms can be expressed by the following differential equation (8):

[0119]

[0120] Assuming that the number of atoms at the initial time t = 0 is N0, the solution of equation (1) is as follows:

[0121]

[0122] The fluorescence signal curve received by the photomultiplier tube is extracted, and the absorption imaging method is used to obtain the fluorescence signal at t = 0 and another time t a Substituting the required number of atoms into formula (9) can obtain the collision loss rate Γ1.

[0123] Based on the number of atoms of the alkali metal atom group at the initial time and another time, the collision loss rate of the alkali metal atom and the background gas is determined; specifically,

[0124] Based on the following formula (9) and formula (7), the collision loss rate of alkali metal atoms with the background gas is determined:

[0125]

[0126] In the formula, N0 is the number of atoms of the alkali metal atomic group at the initial time, and N(t) is the number of atoms of the alkali metal atomic group at another time t.

[0127] The escape probability of alkali metal atoms under catalytic laser induction is taken as a function of frequency detuning, and the potential well depth is measured based on the frequency detuning function. The specific principle is as follows.

[0128] The potential well depth is measured, and the escape probability P(Δ) of the cold atom under the induction of the catalytic laser is used as a function of the frequency detuning amount Δ. The well depth W is measured based on the function of the frequency detuning amount Δ. Under the action of the catalytic laser, when two alkali metal atoms in the magneto-optical trap approach each other and collide, they will resonantly absorb a photon from the catalytic laser field, and at the same time obtain hΔ energy to be excited to the molecular state (h is Planck's constant). This molecule dissociates in a time far less than the lifetime of the excited state and separates with equal and opposite momentum in the center of mass coordinate system. Finally, each atom obtains E cat = hΔ / 2 kinetic energy (E cat is the atomic kinetic energy), if this kinetic energy is less than the potential well depth W, the cold atoms will remain in the well, and the catalytic laser-induced loss rate can be observed to gradually increase with the frequency detuning amount Δ until this kinetic energy approaches or exceeds the potential well depth W.

[0129] In the embodiment of the present application, the ultra-high vacuum quantum measurement method, according to the atomic collision theory, based on the collision loss rate of the alkali metal atoms and the background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system, inverts the vacuum degree in the three-dimensional grating magneto-optical trap system; comprising:

[0130] Determining the average thermal loss rate coefficient of cold atoms of the alkali metal atom group based on the relationship between the potential well depth and the average thermal loss rate coefficient of cold atoms;

[0131] The vacuum degree in the three-dimensional grating magneto-optical trap system is determined based on the average heat loss rate coefficient of the cold atoms and the collision loss rate of the alkali metal atoms and the background gas.

[0132] Specifically, when measuring the vacuum degree, the potential well depth W and the average heat loss rate coefficient k of the cold atoms are loss The relationship is as follows:

[0133] k loss =〈σ loss v bg > (10)

[0134] σ loss is the collision loss cross section, V bg is the velocity of the background gas molecules.

[0135] The σ loss The following formula (11)

[0136]

[0137] Where C6 is the van der Waals coefficient, m t is the mass of the cold atom, W is the potential well depth; due to the background gas molecule velocity V bg The loss rate coefficient k loss It can be obtained by integrating the Maxwell-Boltzman distribution, as described in the following formula (12):

[0138]

[0139] In the formula, m bg is the background gas mass; K B is the Boltzmann constant; T is the temperature of the atomic group; m t is the mass of the cold atom, W is the potential well depth; Substituting the value of the potential well depth into k loss .

[0140] The vacuum degree P is calculated according to the theoretical formula (13) for inverting the vacuum degree P.

[0141]

[0142] Compare the calculated vacuum degree P with the reading of the ionization vacuum gauge to evaluate the accuracy and effectiveness of the vacuum degree P.

[0143] The miniaturized ultra-high vacuum quantum measurement device provided in the embodiment of the present application is based on the collision theory between working atoms and background gas atoms / molecules. There is no need to repeatedly calibrate the measurement device, and it solves the problems of large measurement uncertainty due to many effects in the measurement process of traditional vacuum degree measurement, as well as large scale, complex structure, and difficult operation and maintenance of current laboratory-scale ultra-high vacuum quantum measurement equipment. The overall device is based on the basic physical properties of cold atoms, and the scale of the system is reduced while retaining the unique advantages of current ultra-high vacuum quantum measurement equipment such as no need for calibration, high accuracy, and good time and space reproducibility.

[0144] Based on the same inventive concept, an extremely high vacuum quantum measurement method corresponding to the extremely high vacuum quantum measurement device is also provided in the embodiments of the present application. Since the principle of solving the problem by the method in the embodiments of the present application is similar to that of the above-mentioned device in the embodiments of the present application, the implementation of the method can refer to the implementation of the device, and the repeated parts will not be repeated.

[0145] Please refer to Figure 4 , Figure 4 The flowchart of the extremely high vacuum quantum measurement method described in the embodiment of the present application is shown; the extremely high vacuum quantum measurement method is measured using the extremely high vacuum quantum measurement device described in the present application, and the measurement method includes the following steps S401-S405:

[0146] S401, installing corresponding components at the interface of the ultra-high vacuum quantum measurement device, and realizing vacuum preparation of a two-dimensional grating magneto-optical trap system and a three-dimensional grating magneto-optical trap system based on the installed components, and introducing background gas into the three-dimensional grating magneto-optical trap system, so that alkali metal atoms enter the two-dimensional grating magneto-optical trap system, and push the alkali metal atom group captured by the two-dimensional grating magneto-optical trap system to the three-dimensional grating magneto-optical trap system through a differential tube by a push laser;

[0147] S402, measuring the number of atoms of alkali metal atom groups in the three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system;

[0148] S403, according to atomic collision theory, based on the collision loss rate of the alkali metal atoms and the background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system, inverting to obtain the vacuum degree in the three-dimensional grating magneto-optical trap system;

[0149] S404, comparing the measured vacuum degree with the monitoring result of the ionization vacuum gauge to determine the evaluation result of the measured vacuum degree;

[0150] S405, when the evaluation result of the measured vacuum degree is valid, using the ultra-high vacuum quantum measurement device to measure the vacuum degree of the measured environment;

[0151] The ultra-high vacuum quantum measurement device comprises: a magneto-optical trap mechanism and a shell; the magneto-optical trap mechanism is arranged inside the shell;

[0152] The magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the two-dimensional grating magneto-optical trap system and the three-dimensional grating magneto-optical trap system are connected via the differential tube;

[0153] The housing is provided with a plurality of interfaces, including: an alkali metal distributor interface, an ionization vacuum gauge interface, a background gas interface, a first vacuum pumping interface, and a second vacuum pumping interface;

[0154] The two-dimensional grating magneto-optical trap system is respectively connected to the alkali metal distributor interface and the first vacuum pumping interface;

[0155] The three-dimensional grating magneto-optical trap system is respectively connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface, and a variable leakage valve is arranged on the background gas interface.

[0156] In some embodiments, in the ultra-high vacuum quantum measurement method, the measurement of the number of atoms of alkali metal atom groups in a three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system comprises:

[0157] The detection light is transmitted through the second vacuum chamber of the three-dimensional grating magneto-optical trap system and hits the alkali metal atom group. The other end is received by a charge coupled device for imaging. The number of atoms in the alkali metal atom group is measured based on the absorption imaging principle.

[0158] By using a photomultiplier tube, the fluorescence intensity of the alkali metal atom group is measured to be reduced to a fluorescence signal curve of 0V, the number of atoms of the alkali metal atom group at an initial moment and another moment is obtained by using an absorption imaging method, and based on the number of atoms of the alkali metal atom group at the initial moment and another moment, the collision loss rate of the alkali metal atom with the background gas is determined;

[0159] The escape probability of alkali metal atoms under catalytic laser induction is taken as a function of frequency detuning, and the potential well depth is measured based on the function of frequency detuning.

[0160] In some embodiments, in the ultra-high vacuum quantum measurement method, according to the atomic collision theory, based on the collision loss rate of the alkali metal atoms and the background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system, the vacuum degree in the three-dimensional grating magneto-optical trap system is inverted; comprising:

[0161] Determining the average thermal loss rate coefficient of cold atoms of the alkali metal atom group based on the relationship between the potential well depth and the average thermal loss rate coefficient of cold atoms;

[0162] The vacuum degree in the three-dimensional grating magneto-optical trap system is determined based on the average heat loss rate coefficient of the cold atoms and the collision loss rate of the alkali metal atoms and the background gas.

[0163] In some embodiments, in the ultra-high vacuum quantum measurement method, in the ultra-high vacuum quantum measurement device, the first vacuum pump interface is a first ion pump interface, and the first ion pump interface is used to connect a first ion pump to vacuum the two-dimensional grating magneto-optical trap system;

[0164] The second vacuum pumping interface includes a second ion pump interface and a non-evaporable air pump interface; the second ion pump interface is used to connect a second ion pump to initially vacuum the three-dimensional grating magneto-optical trap system; the non-evaporable air pump interface is used to connect a non-evaporable air pump to finely vacuum the three-dimensional grating magneto-optical trap system.

[0165] In some embodiments, in the ultra-high vacuum quantum measurement method, in the ultra-high vacuum quantum measurement device, the two-dimensional grating magnetic optical trap system includes a first vacuum cavity, a two-dimensional diffraction grating chip, and two pairs of anti-Helmholtz coils;

[0166] The two-dimensional diffraction grating chip is located inside the first vacuum cavity; the anti-Helmholtz coils are placed outside the first vacuum cavity, one pair of anti-Helmholtz coils are perpendicular to the two-dimensional diffraction grating chip, and the other pair of anti-Helmholtz coils are parallel to the two-dimensional diffraction grating chip.

[0167] In some embodiments, in the ultra-high vacuum quantum measurement method, in the ultra-high vacuum quantum measurement device, the three-dimensional grating magnetic optical trap system includes a second vacuum cavity, a three-dimensional diffraction grating chip, and an anti-magnetic trap chip;

[0168] The three-dimensional diffraction grating chip is located inside the second vacuum cavity; the anti-magnetic trap chip is located outside the second vacuum cavity and directly below the three-dimensional diffraction grating chip.

[0169] In some embodiments, in the ultra-high vacuum quantum measurement method and the ultra-high vacuum quantum measurement device, the alkali metal dispenser interface is used to connect an alkali metal dispenser, the alkali metal dispenser is used as an atomic source, and alkali metal atoms are selected as working cold atoms.

[0170] In some embodiments, in the ultra-high vacuum quantum measurement method and the ultra-high vacuum quantum measurement device, the ionization vacuum gauge interface is used to connect an ionization vacuum gauge; the ionization vacuum gauge monitors the vacuum pressure of the three-dimensional grating magneto-optical trap system, and the monitoring result of the ionization vacuum gauge is used as a vacuum standard to calibrate the measurement result of the ultra-high vacuum measurement device.

[0171] In some embodiments, in the ultra-high vacuum quantum measurement method and the ultra-high vacuum quantum measurement device, the background gas interface is used to connect a background gas source so that the background gas from the background gas source flows into the three-dimensional grating magneto-optical trap system through the background gas interface;

[0172] The variable leakage valve on the background gas interface is used to control the inflow rate of the background gas into the three-dimensional grating magneto-optical trap system.

[0173] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An extremely high vacuum quantum measurement device, characterized in that: The device comprises: a magneto-optical trap mechanism and a shell; the magneto-optical trap mechanism is arranged inside the shell; The magneto-optical trap mechanism comprises a two-dimensional grating magneto-optical trap system, a three-dimensional grating magneto-optical trap system and a differential tube, and the two-dimensional grating magneto-optical trap system and the three-dimensional grating magneto-optical trap system are connected via the differential tube; The housing is provided with a plurality of interfaces, including: an alkali metal distributor interface, an ionization vacuum gauge interface, a background gas interface, a first vacuum pumping interface, and a second vacuum pumping interface; The two-dimensional grating magneto-optical trap system is respectively connected to the alkali metal distributor interface and the first vacuum pumping interface; The three-dimensional grating magneto-optical trap system is respectively connected to the ionization vacuum gauge interface, the second vacuum pumping interface, and the background gas interface, and a variable leakage valve is arranged on the background gas interface.

2. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The first vacuum pump interface is a first ion pump interface, and the first ion pump interface is used to connect a first ion pump to vacuum the two-dimensional grating magneto-optical trap system; The second vacuum pumping interface includes a second ion pump interface and a non-evaporable air pump interface; the second ion pump interface is used to connect a second ion pump to initially vacuum the three-dimensional grating magneto-optical trap system; the non-evaporable air pump interface is used to connect a non-evaporable air pump to finely vacuum the three-dimensional grating magneto-optical trap system.

3. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The two-dimensional grating magnetic optical trap system comprises a first vacuum cavity, a two-dimensional diffraction grating chip, and two pairs of anti-Helmholtz coils; The two-dimensional diffraction grating chip is located inside the first vacuum cavity; the anti-Helmholtz coils are placed outside the first vacuum cavity, one pair of anti-Helmholtz coils are perpendicular to the two-dimensional diffraction grating chip, and the other pair of anti-Helmholtz coils are parallel to the two-dimensional diffraction grating chip.

4. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The three-dimensional grating magneto-optical trap system comprises a second vacuum cavity, a three-dimensional diffraction grating chip, and an anti-magnetic trap chip; The three-dimensional diffraction grating chip is located inside the second vacuum cavity; the anti-magnetic trap chip is located outside the second vacuum cavity and directly below the three-dimensional diffraction grating chip.

5. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The alkali metal distributor interface is used to connect an alkali metal distributor. The alkali metal distributor serves as an atom source, and alkali metal atoms are selected as working cold atoms.

6. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The ionization vacuum gauge interface is used to connect an ionization vacuum gauge; the ionization vacuum gauge monitors the vacuum pressure of the three-dimensional grating magneto-optical trap system, and uses the monitoring result of the ionization vacuum gauge as a vacuum standard to calibrate the measurement result of the ultra-high vacuum measuring device.

7. The ultra-high vacuum quantum measurement device according to claim 1, characterized in that: The background gas interface is used to connect a background gas source, so that the background gas from the background gas source flows into the three-dimensional grating magneto-optical trap system through the background gas interface; The variable leakage valve on the background gas interface is used to control the inflow rate of the background gas into the three-dimensional grating magneto-optical trap system.

8. An extremely high vacuum quantum measurement method, characterized in that: The measurement is performed using the ultra-high vacuum quantum measurement device according to any one of claims 1 to 7, wherein the measurement method comprises: Corresponding components are installed at the interface of the ultra-high vacuum quantum measurement device, and based on the installed components, vacuum preparation of a two-dimensional grating magneto-optical trap system and a three-dimensional grating magneto-optical trap system is realized, and after background gas is introduced into the three-dimensional grating magneto-optical trap system, alkali metal atoms are allowed to enter the two-dimensional grating magneto-optical trap system, and the alkali metal atom group captured by the two-dimensional grating magneto-optical trap system is pushed to the three-dimensional grating magneto-optical trap system through a differential tube by a push laser beam; Measure the number of atoms in alkali metal atom groups in a three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of a three-dimensional grating magneto-optical trap system; According to atomic collision theory, based on the collision loss rate between the alkali metal atoms and the background gas and the potential well depth of the three-dimensional grating magneto-optical trap system, the vacuum degree in the three-dimensional grating magneto-optical trap system is inverted; Comparing the measured vacuum degree with the monitoring result of the ionization vacuum gauge to determine the evaluation result of the measured vacuum degree; When the evaluation result of the measured vacuum degree is valid, the vacuum degree of the measured environment is measured using the ultra-high vacuum quantum measurement device.

9. The ultra-high vacuum quantum measurement method according to claim 8, characterized in that: The method measures the number of atoms of alkali metal atom groups in the three-dimensional grating magneto-optical trap system, the collision loss rate of alkali metal atoms and background gas, and the potential well depth of the three-dimensional grating magneto-optical trap system; include: The detection light is transmitted through the second vacuum chamber of the three-dimensional grating magneto-optical trap system and hits the alkali metal atom group. The other end is received by a charge coupled device for imaging. The number of atoms in the alkali metal atom group is measured based on the absorption imaging principle. By using a photomultiplier tube, the fluorescence intensity of the alkali metal atom group is measured to be reduced to a fluorescence signal curve of 0V, the number of atoms of the alkali metal atom group at an initial moment and another moment is obtained by using an absorption imaging method, and based on the number of atoms of the alkali metal atom group at the initial moment and another moment, the collision loss rate of the alkali metal atom with the background gas is determined; The escape probability of alkali metal atoms under catalytic laser induction is taken as a function of frequency detuning, and the potential well depth is measured based on the function of frequency detuning.

10. The ultra-high vacuum quantum measurement method according to claim 8, characterized in that: According to the atomic collision theory, based on the collision loss rate between the alkali metal atoms and the background gas and the potential well depth of the three-dimensional grating magneto-optical trap system, the vacuum degree in the three-dimensional grating magneto-optical trap system is inverted; including: Determining the average thermal loss rate coefficient of cold atoms of the alkali metal atom group based on the relationship between the potential well depth and the average thermal loss rate coefficient of cold atoms; The vacuum degree in the three-dimensional grating magneto-optical trap system is determined based on the average heat loss rate coefficient of the cold atoms and the collision loss rate of the alkali metal atoms and the background gas.

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