An alkali metal atom precise charging method for alkali metal gas cell

Abstract

The application belongs to the technical field of alkali metal atom cell, and particularly relates to a single alkali metal atom precise charging method for an alkali metal cell, which specifically comprises a single alkali metal atom precise charging theoretical method, a temperature gradient construction method, a single alkali metal atom precise acquisition technical method and a single alkali metal atom quantitative charging technical method based on a temperature gradient. The application solves the problems in the prior art, such as low precision, inability to quantitatively control and low production efficiency in charging of single alkali metal atoms into an alkali metal cell through a traditional manual flame driving method in cooperation with an online density detection method. The method can realize quantitative single alkali metal atom automatic precise charging, the whole process operation is simple, the charging time is greatly reduced, and the charging precision is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alkali metal atom cell, and particularly relates to a single alkali metal atom precise charging method for an alkali metal cell. BACKGROUND

[0002] The spin exchange relaxation free (SERF) atomic gyroscope is based on quantum physics and can greatly improve the precision of inertial navigation and guidance. It is one of the representatives of the third generation of ultra-high precision atomic inertial measurement instruments, and can realize a magnitude improvement in theoretical precision compared with the second generation of optical-based inertial measurement instruments.

[0003] The alkali metal atom cell is a core sensitive device of the SERF atomic gyroscope, and mainly includes alkali metal atom vapor, buffer gas and quenching gas. The alkali metal atom vapor, as one of the important working media in the cell, contains all the information of the SERF atomic gyroscope during operation. Therefore, precise control of the alkali metal atom charging amount in the cell is of great significance for verification experiment research, improvement of the performance of the cell and substantial improvement of the performance index of the SERF atomic gyroscope.

[0004] In the current technology, the alkali metal atom charging method has the disadvantages of relying on the experience of workers and determining the charging amount by visually observing the size of the alkali metal atom condensation drop in the traditional manual method. The patent document CN201611037423 discloses a double alkali metal atom precise charging method, which also proposes a method of measuring the alkali metal atom density online based on spectral analysis to control the charging amount. However, this method has the problems of low measurement accuracy and poor consistency. Therefore, it is urgent to provide a single alkali metal atom precise charging method for an alkali metal cell, which mainly relates to the quantitative preparation and complete charging of single alkali metal atoms. SUMMARY

[0005] The present application provides a single alkali metal atom precise charging method for an alkali metal cell, which can realize precise quantitative control of the alkali metal atom charging and greatly shorten the time required for complete charging.

[0006] The technical solution of the present application is as follows:

[0007] A single alkali metal atom precise charging method for an alkali metal cell, characterized in that it comprises the following steps:

[0008] Step 1: Establish an alkali metal gas chamber filling platform model using the single alkali metal atom precise filling theory method. The alkali metal gas chamber filling platform model includes establishing a temperature gradient based on the molecular diffusion mass transfer theory to drive the movement of alkali metal vapor, so that alkali metal atoms are deposited unidirectionally into the alkali metal gas chamber.

[0009] Step 2 involves constructing a temperature gradient to ensure that a quantitative amount of alkali metal atoms are completely deposited unidirectionally into the alkali metal gas chamber. This includes using an oven heating system to place the glass main pipeline in a high-temperature region and using a water cooling system to place the alkali metal gas chamber in a low-temperature region. The alkali metal gas chamber is connected to the glass main pipeline through connecting pipes to form a temperature gradient.

[0010] Step 3 involves accurately obtaining the amount of a single alkali metal atom required for the alkali metal gas chamber, including calculating the amount of reactants using the chloride reduction method. The chemical reaction formula is as follows:

[0011]

[0012] Where X is a single alkali metal, X is potassium, rubidium or cesium, and after the reaction is completed, a solid powder containing X and BaCl2 is prepared, and the content of X in the solid powder is the amount of single alkali metal atoms required;

[0013] Step 4: The solid powder is vacuum heated in a tube furnace until the single alkali metal atoms in the solid powder are vaporized and enter the glass main pipeline. The temperature gradient in Step 2 is used to cause the single alkali metal atoms to be deposited unidirectionally into the alkali metal gas chamber, thus completing the filling of the alkali metal gas chamber.

[0014] Step 1 includes the following expression describing the particle deposition process using the diffusion equation in mass transfer:

[0015]

[0016] Where ρ represents the gas concentration and t represents time. Represents the velocity field. Let R represent the gradient operator, D represent the diffusion coefficient, and R represent the source term, which is a term describing the spatial and temporal effects on the concentration of a substance. The mean free path of gas molecules is given by denoted as , k is the Boltzmann constant, T represents the Kelvin temperature, d is the effective diameter of the molecule, and p represents the gas pressure. It is the Maxwell-Boltzmann distribution function, where m is the gas molecule mass and e is the natural constant.

[0017] Step 2 includes an oven heating system that heats the temperature in the heating chamber to 230°C to 300°C, the main glass pipe in the glass pipe is placed in the heating chamber, and the water cooling system that keeps the ambient temperature of the alkali metal gas chamber constant at 20°C.

[0018] The glass main pipeline is connected with a plurality of alkali metal gas chambers through the connecting pipeline in step 2.

[0019] The tubular furnace is heated to 300 DEG C in step 4, so that all the single alkali metal atoms in the solid powder are gasified, and the required amount of single alkali metal atoms is accurately obtained for the alkali metal gas chamber.

[0020] The tubular furnace is connected with a vacuum pumping system in step 4, and the working vacuum degree reaches 5*10 -6 Pa, and the vacuum leakage rate reaches 1*10 -8 PaL / S.

[0021] The technical effects of the present application are as follows: the single alkali metal atom accurate charging method for the alkali metal gas chamber solves the problems of low accuracy, unquantitative control and low production efficiency in the prior art, in which the single alkali metal atom is charged into the alkali metal gas chamber by the traditional manual flame driving method and the online density detection method.

[0022] Compared with the prior art, the present application has the following characteristics:

[0023] 1. The present application is a single alkali metal atom accurate charging method for the alkali metal gas chamber, and the whole method involves simple process operation, automatic charging, which can greatly shorten the charging time and improve the charging efficiency.

[0024] 2. The chloride reduction method is used to prepare quantitative alkali metal atom single substance in advance combined with the temperature gradient theory, and the charging accuracy is higher than that of the traditional manual visual method and the density detection method based on spectral absorption.

[0025] 3. The method can realize the accurate charging of single alkali metal atoms, improve the performance of the whole gas chamber, and further improve the overall performance of the SERF atomic inertial gyroscope. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a charging device structure schematic diagram of the single alkali metal atom accurate charging method for the alkali metal gas chamber.

[0027] Figure 2 It is a flowchart of the single alkali metal atom accurate charging method for the alkali metal gas chamber. Figure 2The process includes: Step 1, establishing an alkali metal gas chamber filling platform model using a single alkali metal atom precise filling theory method. This model includes establishing a temperature gradient based on molecular diffusion mass transfer theory to drive alkali metal vapor movement, enabling alkali metal atoms to unidirectionally deposit into the alkali metal gas chamber; Step 2, constructing a temperature gradient to ensure complete unidirectional deposition of a quantitative amount of alkali metal atoms into the alkali metal gas chamber. This includes heating the glass main pipeline to 300°C using an oven heating system and maintaining the ambient temperature of the alkali metal gas chamber at 20°C using a water cooling system. The alkali metal gas chamber is connected to the glass main pipeline via a connecting pipe, forming a temperature gradient; Step 3, accurately obtaining the required amount of single alkali metal atoms for the alkali metal gas chamber, including calculating the reactant amount using a chloride reduction method. Where X is a single alkali metal), prepare a reactant solid powder; in step 4, heat the solid powder in a tube furnace under vacuum until the single alkali metal atoms in the solid powder vaporize and enter the glass main circuit, and complete the filling by utilizing the temperature gradient in step 2.

[0028] The following are the annotations in the attached diagram: 1-glass tubing; 2-alkali metal gas chamber; 3-vacuum system; 4-tube furnace; 5-water cooling system; 6-oven heating system. Detailed Implementation

[0029] The following is in conjunction with the attached diagram ( Figures 1-2 The invention will be described in the following sections and examples.

[0030] Figure 1 This is a schematic diagram of the filling equipment involved in implementing the present invention, a method for precise filling of a single alkali metal atom into an alkali metal gas chamber. Figure 2 This is a schematic flowchart illustrating a method for precisely filling a single alkali metal atom into an alkali metal gas chamber according to the present invention. (Reference) Figures 1-2 As shown, a method for precise filling of a single alkali metal atom into an alkali metal gas chamber includes the following steps: Step 1, establishing an alkali metal gas chamber filling platform model using a theoretical method for precise filling of single alkali metal atoms. The alkali metal gas chamber filling platform model includes establishing a temperature gradient based on molecular diffusion mass transfer theory to drive the movement of alkali metal vapor, enabling alkali metal atoms to be deposited unidirectionally into the alkali metal gas chamber 2; Step 2, constructing a temperature gradient to ensure that a quantitative amount of alkali metal atoms are completely deposited unidirectionally into the alkali metal gas chamber 2. This includes using an oven heating system 6 to place the main glass pipe (one of the components in glass pipe 1) in a high-temperature region and using a water cooling system 5 to place the alkali metal gas chamber 2 in a low-temperature region. The alkali metal gas chamber 2 is connected to the main glass pipe (one of the components in glass pipe 1) through a connecting pipe to form a temperature gradient; Step 3, accurately obtaining the required amount of single alkali metal atoms for the alkali metal gas chamber 2, including calculating the amount of reactants using a chloride reduction method. The chemical reaction formula is as follows:

[0031]

[0032] wherein X is a single alkali metal, X is potassium or rubidium or cesium, after the reaction is completed, a solid powder containing X and BaCl2 is prepared, the content of X in the solid powder is the required amount of single alkali metal atoms;

[0033] Step 4, the solid powder is heated in a tube furnace 4 (the vacuum environment thereof is achieved by the vacuum system 3) to gasify the single alkali metal atoms in the solid powder into the glass main pipeline, and the single alkali metal atoms are unidirectionally deposited into the alkali metal gas chamber by using the temperature gradient in step 2, so as to complete the charging of the alkali metal gas chamber.

[0034] Step 1 includes the following expression for describing the particle deposition process by using the diffusion equation in mass transfer:

[0035]

[0036] wherein ρ represents the gas concentration, t represents time, represents the velocity field, represents the gradient operator, D represents the diffusion coefficient, R represents the source term, and the source term is a term for describing the influence on the concentration of the substance in space and time, represents the mean free path of the gas molecule movement, k is the Boltzmann constant, T represents the Kelvin temperature, d is the effective diameter of the molecule, and p represents the gas pressure, is the Maxwell-Boltzmann distribution function, m is the mass of the gas molecule, and e is the natural constant.

[0037] Step 2 includes that the oven heating system 6 heats the temperature in the heating cavity to 230-300°C, the glass main pipeline in the glass pipeline 1 is placed in the heating cavity, and the water cooling system 5 keeps the ambient temperature of the alkali metal gas chamber 2 constant at 20°C. Step 2 includes that the glass main pipeline is connected with a plurality of alkali metal gas chambers through the connecting pipeline.

[0038] Step 4 includes that the tube furnace 4 is heated to 300°C, so that all the single alkali metal atoms in the solid powder are gasified, and the required amount of single alkali metal atoms is accurately obtained for the alkali metal gas chamber. Step 4 includes that the tube furnace 4 is connected with the vacuum system 3, and the working vacuum degree reaches 5×10 -6 Pa, and the vacuum leakage rate reaches 1×10 -8 PaL / S.

[0039] This invention belongs to the technical field of alkali metal atom gas chambers, specifically relating to a method for the precise filling of single alkali metal atoms into alkali metal gas chambers. The method includes the following steps: a theoretical method for the precise filling of single alkali metal atoms; a temperature gradient construction method; a technical method for the precise acquisition of single alkali metal atoms; and a quantitative filling technique based on the temperature gradient. This invention solves the problems of low accuracy, lack of quantitative control, and low production efficiency in existing technologies that combine traditional artificial flame expulsion methods with online density detection methods for filling single alkali metal atoms into alkali metal gas chambers. This method enables automated and precise quantitative filling of single alkali metal atoms, simplifies the entire process, significantly reduces filling time, and achieves high filling accuracy.

[0040] A method for precisely filling a single alkali metal atom into an alkali metal gas chamber includes the following steps:

[0041] Step 1, Theoretical method for precise filling of single alkali metal atoms;

[0042] Step 2, Temperature gradient construction method;

[0043] Step 3, Precise Acquisition Techniques for Single Alkali Metal Atoms;

[0044] Step 4: A quantitative filling technique for single alkali metal atoms based on a temperature gradient.

[0045] like Figure 1 As shown, the single alkali metal atom precision filling device facing the alkali metal gas chamber includes a glass pipeline 1, an alkali metal gas chamber 2, a vacuum system 3, a tube furnace 4 for mixing powders to react, a liftable water cooling system 5, a liftable oven heating system 6.

[0046] like Figure 2 As shown, a method for precise filling of single alkali metal atoms into an alkali metal gas chamber includes a theoretical method for precise filling of single alkali metal atoms, a temperature gradient construction method, a technical method for precise acquisition of single alkali metal atoms, and a quantitative filling technical method for single alkali metal atoms based on the temperature gradient.

[0047] Step 1: Theoretical method for precise filling of single alkali metal atoms.

[0048] According to the molecular diffusion mass transfer theory, alkali metal vapors will move due to the presence of a temperature gradient, resulting in unidirectional deposition.

[0049] In mass transfer, the diffusion equation is used to describe the particle deposition process:

[0050]

[0051] Where ρ represents the gas concentration; t represents time; Represents the velocity field; denotes the gradient operator; D denotes the diffusion coefficient; R denotes the source term, which is a term describing the influence of the concentration of the substance in space and time.

[0052] The theoretical formula of the gas diffusion coefficient is:

[0053]

[0054] wherein The expression of the mean free path of gas molecule movement is:

[0055]

[0056] wherein k is the Boltzmann constant; T denotes the Kelvin temperature; d is the effective diameter of the molecule; and p denotes the gas pressure.

[0057] Velocity field It can be described using the Maxwell-Boltzmann distribution, wherein m is the mass of the gas molecule:

[0058]

[0059] It is derived that the diffusion coefficient follows the relationship between temperature and pressure:

[0060]

[0061] Therefore, the diffusion coefficient of the molecule can be affected by changing the temperature and pressure during the alkali metal atom charging process, so as to realize the control of the diffusion rate of the molecule, and the precise control of the alkali metal charging amount can be realized by controlling the time of the whole charging process.

[0062] According to the above theory, first, the automatic alkali metal gas chamber charging platform is physically modeled, second, comprehensive consideration is given to the thermodynamic, kinetic and fluid dynamic factors of the whole alkali metal atom evaporation and deposition process, a comprehensive and accurate theoretical framework is constructed, and finally the corresponding temperature field and vacuum conditions are set to simulate the whole alkali metal atom precise charging process in the simulation software, which can cover multiple stages such as atom evaporation, migration, deposition and possible surface reconstruction, so as to realize the comprehensive and detailed simulation of the whole charging process to ensure the rationality of the whole process and verify the simulation results with subsequent experimental results.

[0063] Step 2, temperature gradient construction method.

[0064] In the single alkali metal atom automatic charging platform, an oven heating system 6 and a water cooling system 5 are arranged, and the glass pipeline 1 includes a glass main pipeline, a connecting pipeline and an alkali metal gas chamber. The oven heating system is controllable in temperature and can be heated to about 300 DEG C; the water cooling system is controllable in temperature and can keep the temperature constant at 20 DEG C; the glass main pipeline is placed in the oven heating system, the alkali metal gas chamber is placed in the water cooling system, and the alkali metal gas chamber is connected with the glass main pipeline through the connecting pipeline; the oven heating system provides a high-temperature area, and the water cooling system provides a low-temperature area, and the two areas form a temperature gradient. Through this temperature gradient construction method, the quantitative alkali metal atom can be completely deposited into the alkali metal gas chamber in a single direction after a certain time.

[0065] Step 3: Single alkali metal atom precise acquisition technology method.

[0066] In this embodiment, the chloride reduction method is used to precisely acquire the quantitative single alkali metal atom. The alkali metal atom source is selected as rubidium (Rb), the required mass of alkali metal rubidium in each gas chamber is set to 200 μg, and the glass pipeline 1 is connected with 10 gas chambers 2, so the required mass of alkali metal rubidium is 2 mg.

[0067] According to the following reaction equation:

[0068]

[0069] Therefore, the required mass of each of the two reactants can be calculated:

[0070]

[0071]

[0072] After weighing, the corresponding solution is configured and poured into the reaction boat, and the mixed solution of the reactants is evaporated and dried into a mixed powder in a vacuum drying box, and the solid powder of the reactants is heated at high temperature in a tube furnace to realize the required amount of precise acquisition of single alkali metal atom.

[0073] The step 4 includes a vacuum pumping system 3, a tube furnace 4, an oven heating system 6, a water cooling system 5, and a glass pipeline 1 including a glass main pipeline, a connecting pipeline and an alkali metal gas chamber. The specific method is as follows:

[0074] Step 401: Start the vacuum pumping system, and the working vacuum degree can reach 5x10 -6 Pa, and the vacuum leakage rate can reach 1x10 -8 PaL / S;

[0075] Step 402: Start the oven heating system and perform high-temperature impurity removal.

[0076] Step 403: the tube furnace is heated to 300℃ to vaporize the single alkali metal atom, the oven heating system temperature is raised to 230℃ to provide a high temperature area, the water cooling system temperature is constant at 20℃ to provide a low temperature area, both of which build a temperature gradient, all systems are stably operated within a preset theoretical time period, the alkali metal atom is deposited into the alkali metal gas chamber in one direction, and the charging is completed;

[0077] Step 404: the alkali metal gas chamber is picked.

[0078] The contents not described in detail in the specification of the present application belong to the prior art known to those skilled in the art. It is pointed out that the above description is helpful for those skilled in the art to understand the present application, but does not limit the protection scope of the present application. Any implementation of equivalent replacement, modification, improvement and / or deletion of the above description without departing from the essential content of the present application falls within the protection scope of the present application.

Claims

1. A method of single alkali metal atom precise doping of an alkali metal gas cell, characterized by, The method comprises the following steps: Step 1, establishing an alkali metal gas chamber charging platform model by using a single alkali metal atom precise charging theory method, wherein the alkali metal gas chamber charging platform model comprises establishing a temperature gradient based on a molecular diffusion mass transfer theory to drive the movement of alkali metal vapor, so that the alkali metal atoms are deposited into the alkali metal gas chamber in a unidirectional manner; Step 2, constructing a temperature gradient to ensure that the quantitative alkali metal atoms are completely deposited into the alkali metal gas chamber in a unidirectional manner, comprising placing the glass main pipeline in a high-temperature region by using an oven heating system, and placing the alkali metal gas chamber in a low-temperature region by using a water cooling system, wherein the alkali metal gas chamber is connected with the glass main pipeline through a connecting pipeline, so as to form a temperature gradient; Step 3, accurately obtaining the required amount of single alkali metal atoms for the alkali metal gas chamber, comprising calculating the amount of reactants by using a chloride reduction method, and the chemical reaction formula is as follows: wherein X is a single alkali metal, X is potassium or rubidium or cesium, and after the reaction is completed, a solid powder containing X and BaCl2 is prepared, and the content of X in the solid powder is the required amount of single alkali metal atoms; Step 4, vacuum heating the solid powder in a tube furnace to gasify the single alkali metal atoms in the solid powder into the glass main pipeline, and using the temperature gradient in step 2 to make the single alkali metal atoms deposit into the alkali metal gas chamber in a unidirectional manner, thereby completing the charging of the alkali metal gas chamber.

2. The alkali metal gas cell oriented single alkali metal atom precision dosing method of claim 1, wherein, In step 1, the following expression is used to describe the particle deposition process in the mass transfer equation: where p denotes the gas concentration, t denotes time, denotes the velocity field, denotes the gradient operator, D denotes the diffusion coefficient, R denotes the source term, which is a term describing the influence on the concentration of the substance in space and time, denotes the mean free path of the gas molecules, k is the Boltzmann constant, T denotes the temperature in Kelvin, d is the effective diameter of the molecules, p denotes the gas pressure, is the Maxwell-Boltzmann distribution function, m is the mass of the gas molecules, e is the natural constant.

3. The alkali metal gas cell oriented single alkali metal atom precision dosing method of claim 1, wherein, In step 2, the oven heating system heats the temperature in the heating cavity to 230-300℃, and the glass main pipeline in the glass pipeline is placed in the heating cavity, and the water cooling system keeps the ambient temperature of the alkali metal gas chamber constant at 20℃.

4. The alkali metal gas cell oriented single alkali metal atom precision dosing method of claim 1, wherein, In step 2, the glass main pipeline is connected with a plurality of alkali metal gas chambers through connecting pipelines.

5. The alkali metal gas cell oriented single alkali metal atom precision dosing method of claim 1, wherein, In step 4, the tube furnace is heated to 300℃ to make the single alkali metal atoms in the solid powder completely gasify, so as to accurately obtain the required amount of single alkali metal atoms for the alkali metal gas chamber.

6. The alkali metal gas cell oriented single alkali metal atom precision dosing method of claim 1, wherein, The vacuum system connected to the tube furnace in step 4 works at a vacuum degree of 5x10 -6 Pa, and the vacuum leakage rate is 1x10 - 8 PaL / S.

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