Accurate filling method for mixed alkali metal atoms in atomic gas chamber

Abstract

The invention belongs to the technical field of alkali metal atom gas chambers, and particularly relates to a method for precisely filling mixed alkali metal atoms in an atom gas chamber, which comprises a theoretical method for precisely filling and quantitatively detecting the mixed alkali metal atoms, a technical method for precisely acquiring the mixed alkali metal atoms and a precise filling technology based on a temperature gradient method. The method is combined with an in-situ quantitative detection technology based on a differential scanning calorimetry, so that high-precision regulation and control and real-time verification of the content of the mixed alkali metal atoms in the gas chamber can be realized. The method is simple and convenient in process and high in filling efficiency, ensures accurate control of the atomic weight of the alkali metal in the air chamber, effectively improves the performance of the air chamber, and further optimizes the overall performance and the measurement precision of the SERF atom gyroscope.

Description

Technical Field

[0001] The invention belongs to the technical field of alkali metal atom gas chambers, and in particular relates to a method for accurately filling mixed alkali metal atoms in an atomic gas chamber. Background Art

[0002] With the rapid development of modern physics, significant progress has been made in the fields of quantum mechanics, atomic manipulation and modern optics. As the culmination of these technologies, gyroscope technology has undergone changes and innovations from electromechanical gyroscopes, fiber optic gyroscopes to atomic gyroscopes. Among them, spin exchange relaxation free (SERF) atomic gyroscopes are widely considered to be the key development direction of the next generation of ultra-high precision gyroscopes, with a theoretical accuracy of up to 10 -8 ° / h, becoming an important part of national strategic equipment.

[0003] The SERF atomic gyroscope uses atomic spin as a sensitive detection medium, and its core component is the alkali metal gas chamber. The performance of the alkali metal gas chamber directly determines the overall accuracy and stability of the SERF atomic gyroscope. When the SERF atomic gyroscope is in operation, the gas chamber usually contains a variety of alkali metal atoms, inert gases, and functional gases (such as quenching gas, buffer gas, etc.). The types and contents of these gases and alkali metal atoms directly affect the performance of the gyroscope. Accurately controlling the contents of various alkali metal atoms in the gas chamber can significantly improve the performance of the gas chamber, thereby improving the measurement accuracy and sensitivity of the SERF atomic gyroscope.

[0004] In the current technology, the filling of mixed alkali metal atoms still faces problems such as low filling accuracy, poor atomic content consistency, and large filling amount detection errors. Existing patent documents, such as CN201711420607 (a device and method for preparing an atomic gas chamber for quantitative filling of alkali metals) mainly realize the directional deposition of alkali metals by accurately controlling the temperature distribution of the device, but do not involve the detailed process flow of mixed alkali metal atom filling; another patent document CN201611037423 (a method for precise filling of double alkali metal atoms) proposes a method for controlling the filling amount by online measurement of alkali metal atom density, but after experimental verification, this method has problems such as insufficient measurement accuracy, poor result consistency, and lack of reference standards.

[0005] Therefore, the prior art urgently needs a set of high-precision and reliable mixed alkali metal atom filling process flow. The patent of this invention proposes a method for accurately filling mixed alkali metal atoms in an atomic gas chamber, which can realize the accurate filling and quantitative verification of mixed alkali metal atoms in the gas chamber. The process is easy to operate and has high filling accuracy. It can significantly improve the filling efficiency of alkali metal atoms, ensure the consistency and accuracy of the filling amount, and provide a strong guarantee for the performance improvement of SERF atomic gyroscope. Summary of the invention

[0006] The present invention aims at the deficiencies in the existing mixed alkali metal atom filling technology, especially the problems of poor consistency of the density ratio of mixed alkali metal atoms in the same batch of gas chambers and low accuracy of online density ratio detection caused by artificial experience control based on the flame driving method, and proposes a method for accurately filling mixed alkali metal atoms in atomic gas chambers. The method can realize the precise regulation and verification of the content of mixed alkali metal atoms in the gas chamber, overcoming the technical bottleneck that the amount of mixed alkali metal atoms cannot be accurately controlled in the traditional filling method. The filling process provided by the present invention is simple to operate and has high precision, which significantly improves the efficiency of mixed alkali metal atom filling, ensures that the amount of alkali metal atoms in the gas chamber can be accurately controlled, and thus effectively improves the performance of the alkali metal gas chamber.

[0007] The technical solution of the present invention is as follows:

[0008] A method for accurately filling mixed alkali metal atoms in an atomic gas chamber, characterized by comprising the following steps:

[0009] Step 1, using the theoretical method of accurate filling and quantitative detection of mixed alkali metal atoms to establish a mixed alkali metal atom filling platform model;

[0010] Step 2, determining the required amount of mixed alkali metal atom reactants from the required mixed alkali metal atom content using the following chemical reaction formula:

[0011]

[0012] wherein X represents the first alkali metal in the alkali metal mixture, and Y represents the second alkali metal in the alkali metal mixture;

[0013] Step 3, performing precise filling of mixed alkali metal atoms based on the temperature gradient method, including placing the alkali metal gas chamber in a low temperature area provided by a constant temperature system, the filling inlet of the alkali metal gas chamber being connected to the first reaction furnace and the second reaction furnace respectively through pipelines, the first reaction furnace forming an ultra-high temperature area to cause a vaporization reaction of the first alkali metal solid powder, the first alkali metal atomic vapor enters the alkali metal gas chamber in the low temperature area from the ultra-high temperature area through the pipeline in the high temperature area in the oven, the second reaction furnace forming an ultra-high temperature area to cause a vaporization reaction of the second alkali metal solid powder, the second alkali metal atomic vapor enters the alkali metal gas chamber in the low temperature area from the ultra-high temperature area through the pipeline in the high temperature area in the oven, and the alkali metal gas chamber is removed after completing the temperature gradient driven filling;

[0014] Step 4: Perform in-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry to determine the content of each mixed alkali metal atom in the alkali metal gas chamber.

[0015] Step 1 includes a mixed alkali metal atom filling platform, which includes an oven, in which a glass pipe with a four-way structure is arranged, one end of the horizontal glass pipe in the four-way structure is closed, and the other end is connected to the impurity removal system through a valve, one end of the vertical glass pipe in the four-way structure is connected to the first reaction furnace through a valve, and the other end is connected to the second reaction furnace through a valve, and both sides of the horizontal glass pipe are connected to alkali metal gas chambers, and the alkali metal gas chambers are located in a constant temperature system.

[0016] The mixed alkali metal atom filling platform model in step 1 includes the following expressions:

[0017]

[0018] logp=A+B / T,

[0019]

[0020] Where k(T) represents the reaction rate constant, A represents the prefactor, and E a represents the reaction activation energy, R represents the gas constant, T represents the reaction temperature, e is the natural constant, t represents the reaction time, α represents the reaction conversion rate, p represents the saturated vapor pressure, A and B represent constants, D represents the diffusion coefficient, q represents the heat flow signal, C p represents the specific heat capacity of the sample, m represents the actual mass of the sample, β represents the rate of temperature change, represents the first-order differential of thermal enthalpy H, R1 represents the measurement sensitivity, θ represents the temperature difference signal, τ represents the time constant, θ b represents the blank baseline signal, m1 represents the alkali metal atom content, Q represents the total absorbed heat, and λ represents the conversion coefficient.

[0021] In step 2, the first alkali metal is K, and the second alkali metal is Rb. The corresponding chemical reaction formula is as follows:

[0022]

[0023] Where m KCl is the amount of KCl required as reactant, M KCl is the molecular weight of KCl, M K is the atomic weight of K, m K is the amount of K required for each alkali metal gas chamber, is the corresponding m K The amount of BaN6 required as reactant, is the molecular weight of BaN6, m RbCl is the amount of reactant RbCl required, M Rb is the atomic weight of Rb, m Rb is the amount of Rb required for each alkali metal gas cell, is the corresponding mRb Required amount of reactant BaN6, M RbCl is the molecular weight of RbCl.

[0024] The ultra-high temperature in step 3 is 400°C, the high temperature is 300°C, and the low temperature is 20°C. The temperature gradient constructed by the ultra-high temperature area, the high temperature area and the low temperature area allows the mixed alkali metal atomic vapor to be deposited unidirectionally from two pipelines into the alkali metal gas chamber.

[0025] Step 3 includes the following steps:

[0026] Step 301, start the impurity removal system to make the vacuum degree reach the working requirement, and purge the air, water vapor and other impurities in the pipeline with nitrogen;

[0027] Step 302, start the oven and perform secondary impurity removal at high temperature;

[0028] Step 303, the pipeline adopts a glass double pipeline, and the reaction furnaces at both ends of the glass double pipeline are heated to the temperature of each solid powder to react and vaporize the alkali metal atoms, and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber;

[0029] Step 304, removing the alkali metal gas chamber.

[0030] Step 4 includes an in-situ quantitative detection device for mixed alkali metals based on differential scanning calorimetry, wherein the in-situ quantitative detection device for mixed alkali metals includes a closed furnace body with a sealing cover, wherein a first temperature and heat flow sensor and a second temperature and heat flow sensor are arranged in the closed furnace body, wherein the first temperature and heat flow sensor is connected to a reference gas chamber, and the second temperature and heat flow sensor is connected to a sample gas chamber, wherein the sample gas chamber is filled with mixed alkali metal atoms.

[0031] In step 4, the temperature in the closed furnace is increased. As the temperature gradually increases, the mixed alkali metal atoms in the sample gas chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, and generates a corresponding heat absorption peak value, thereby reflecting the respective heat absorption characteristics of the mixed alkali metal atoms during the phase change process. The content of each mixed alkali metal atom in the sample gas chamber is determined using the respective heat absorption characteristics.

[0032] The technical effects of the present invention are as follows: The present invention provides a method for accurately filling mixed alkali metal atoms in an atomic gas chamber, which can achieve high-precision control and real-time verification of the content of mixed alkali metal atoms in the gas chamber by combining a theoretical method for accurate filling and quantitative detection of mixed alkali metal atoms, a technical method for accurate acquisition of mixed alkali metal atoms, an accurate filling technology based on a temperature gradient method, and an in-situ quantitative detection technology based on a differential scanning calorimetry method. The method is simple in process and has high filling efficiency, which ensures accurate control of the amount of alkali metal atoms in the gas chamber, effectively improves the performance of the gas chamber, and further optimizes the overall performance and measurement accuracy of the SERF atomic gyroscope.

[0033] Compared with the prior art, the present invention has the following characteristics:

[0034] 1. The present invention designs a precise filling process of mixed alkali metal atoms based on differential scanning calorimetry, which quantitatively configures the precursor materials of mixed alkali metal atoms through chemical reactions, realizes high-precision control of the alkali metal atom content, and greatly improves the regulation accuracy of the alkali metal atom density in the gas chamber.

[0035] 2. The mixed alkali metal filling method that is mutually verified by theoretical simulation and experimental results not only simplifies the operation process, but also significantly improves the accuracy and efficiency of the filling process, thereby improving the overall filling efficiency and ensuring the consistency of the mixed alkali metal atomic content in the gas chamber.

[0036] 3. The content of mixed alkali metal atoms in the gas chamber is detected in real time in situ by differential scanning calorimetry, and the result is cross-checked with the quantitative preparation result of chemical reduction method, so as to realize precise control of the content of mixed alkali metal atoms in the gas chamber, facilitate secondary filling when necessary, and significantly improve the controllability of the gas chamber.

[0037] 4. This method achieves precise filling of mixed alkali metal atoms, significantly optimizes the performance of the gas chamber, and thus improves the overall accuracy and stability of the SERF atomic inertial gyroscope, providing a solid technical guarantee for achieving higher-precision inertial measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention is a schematic diagram of the structure of a filling device involved in a method for accurately filling mixed alkali metal atoms in an atomic gas chamber.

[0039] Figure 2 It is a schematic diagram of an in-situ quantitative detection device for mixed alkali metals based on differential scanning calorimetry involved in a method for accurately filling mixed alkali metal atoms in an atomic gas chamber of the present invention.

[0040] Figure 3 The present invention is a schematic flow chart of a method for accurately filling mixed alkali metal atoms in an atomic gas chamber. Figure 3The method comprises the steps of: 1, establishing a mixed alkali metal atom charging platform model by using a theoretical method for accurate charging and quantitative detection of mixed alkali metal atoms, wherein the mixed alkali metal atom charging platform model has the characteristics of accurate charging function, temperature gradient mass transfer mechanism and two-way channel structure, and the alkali metal gas chamber charging platform model can be associated with a mixed alkali metal atom phase change model in an alkali metal gas chamber with quantitative detection and differential scanning calorimetry; and 2, a technical method for accurate acquisition of mixed alkali metal atoms, comprising determining the required amount of mixed alkali metal atom reactants from the required mixed alkali metal atom content by using the following chemical reaction formula: X is the first alkali metal in the mixed alkali metal, and Y is the second alkali metal in the mixed alkali metal; step 3, a technical method for precise filling of mixed alkali metal atoms based on the temperature gradient method, including starting the impurity removal system to make the vacuum degree and impurity content meet the requirements; starting the oven, high-temperature secondary impurity removal; heating the reactors at both ends of the glass double pipeline until the respective solid powders react, and the temperature gradient drives the filling; picking the alkali metal gas chamber; step 4, a technical method for in-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry, including using heat flow signals to reflect the respective heat absorption characteristics of the mixed alkali metal atoms during the phase change process, m represents the alkali metal atom content, Q represents the total absorbed heat, and λ represents the conversion coefficient; the respective contents of the mixed alkali metal atoms are calculated based on the absorption peaks; and secondary charging is performed when the deviation is large.

[0041] The description of the accompanying drawings is as follows: 1-impurity removal system; 2-first reaction furnace; 3-second reaction furnace; 4-valve; 5-oven; 6-constant temperature system; 7-glass double pipeline (including glass connecting pipeline and alkali metal gas chamber); 21-sealing cover; 22-closed furnace body; 23-temperature and heat flow sensor; 24-reference gas chamber; 25-mixed alkali metal atoms; 26-sample gas chamber. DETAILED DESCRIPTION

[0042] Below is the attached figure ( Figure 1-Figure 3 ) and Examples illustrate the present invention.

[0043] Figure 1 The present invention is a schematic diagram of the structure of a filling device involved in a method for accurately filling mixed alkali metal atoms in an atomic gas chamber. Figure 2 It is a schematic diagram of an in-situ quantitative detection device for mixed alkali metals based on differential scanning calorimetry involved in a method for accurately filling mixed alkali metal atoms in an atomic gas chamber of the present invention. Figure 3 This is a schematic diagram of a flow chart of a method for accurately filling mixed alkali metal atoms in an atomic gas chamber according to the present invention. Figures 1 to 3As shown, a method for accurately filling mixed alkali metal atoms in an atomic gas chamber comprises the following steps: Step 1, establishing a mixed alkali metal atom filling platform model using a theoretical method for accurate filling and quantitative detection of mixed alkali metal atoms; Step 2, determining the required amount of mixed alkali metal atom reactants from the required mixed alkali metal atom content using the following chemical reaction formula:

[0044]

[0045] wherein X represents the first alkali metal in the alkali metal mixture, and Y represents the second alkali metal in the alkali metal mixture;

[0046] Step 3, performing precise filling of mixed alkali metal atoms based on the temperature gradient method, including placing the alkali metal gas chamber in a low-temperature area provided by a constant temperature system, the filling inlet of the alkali metal gas chamber being connected to a first reactor and a second reactor through pipelines, the first reactor forming an ultra-high temperature area to cause a vaporization reaction of the first alkali metal solid powder, the first alkali metal atomic vapor enters the alkali metal gas chamber in the low-temperature area from the ultra-high temperature area through the pipeline in the high-temperature area of ​​the oven, the second reactor forming an ultra-high temperature area to cause a vaporization reaction of the second alkali metal solid powder, the second alkali metal atomic vapor enters the alkali metal gas chamber in the low-temperature area from the ultra-high temperature area through the pipeline in the high-temperature area of ​​the oven, and the alkali metal gas chamber is removed after the temperature gradient driven filling is completed; Step 4, performing in-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry to determine the respective contents of mixed alkali metal atoms in the alkali metal gas chamber.

[0047] Step 1 includes a mixed alkali metal atom filling platform, and the mixed alkali metal atom filling platform includes an oven 5, and a glass pipeline with a four-way structure (for example, a double glass pipeline 7) is arranged in the oven 5. One end of the horizontal glass pipeline in the four-way structure is closed, and the other end is connected to the impurity removal system 1 through a valve. One end of the longitudinal glass pipeline in the four-way structure is connected to the first reaction furnace 2 through a valve 4, and the other end is connected to the second reaction furnace 3 through a valve. Both sides of the horizontal glass pipeline are connected to alkali metal gas chambers, and the alkali metal gas chambers are located in the constant temperature system 6.

[0048] The mixed alkali metal atom filling platform model in step 1 includes the following expressions:

[0049]

[0050] log p=A+B / T,

[0051]

[0052]

[0053] Where k(T) represents the reaction rate constant, A represents the prefactor, and E a represents the reaction activation energy, R represents the gas constant, T represents the reaction temperature, e is the natural constant, t represents the reaction time, α represents the reaction conversion rate, p represents the saturated vapor pressure, A and B represent constants, D represents the diffusion coefficient, q represents the heat flow signal, C p represents the specific heat capacity of the sample, m represents the actual mass of the sample, β represents the rate of temperature change, represents the first-order differential of thermal enthalpy H, R1 represents the measurement sensitivity, θ represents the temperature difference signal, τ represents the time constant, θ b represents the blank baseline signal, m1 represents the alkali metal atom content, Q represents the total absorbed heat, and λ represents the conversion coefficient.

[0054] In step 2, the first alkali metal is K, and the second alkali metal is Rb. The corresponding chemical reaction formula is as follows:

[0055]

[0056] Where m KCl is the amount of KCl required as reactant, M KCl is the molecular weight of KCl, M K is the atomic weight of K, m K is the amount of K required for each alkali metal gas chamber, is the corresponding m K The amount of BaN6 required as reactant, is the molecular weight of BaN6, m RbCl is the amount of reactant RbCl required, M Rb is the atomic weight of Rb, m Rb is the amount of Rb required for each alkali metal gas cell, is the corresponding m Rb Required amount of reactant BaN6, M RbCl is the molecular weight of RbCl.

[0057] The ultra-high temperature in step 3 is 400°C, the high temperature is 300°C, and the low temperature is 20°C. The temperature gradient constructed by the ultra-high temperature area, the high temperature area, and the low temperature area allows the mixed alkali metal atomic vapor to be deposited unidirectionally from two pipelines into the alkali metal gas chamber. Step 3 includes the following steps: Step 301, turn on the impurity removal system to make the vacuum degree meet the working requirements, and purge the air, water vapor and other impurities in the pipeline with nitrogen; Step 302, turn on the oven, and perform secondary impurity removal at high temperature; Step 303, the pipeline adopts a glass double pipeline, and the reactors at both ends of the glass double pipeline are heated to the temperature of each solid powder to react and vaporize the alkali metal atoms, and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber; Step 304, remove the alkali metal gas chamber. Step 4 includes a mixed alkali metal in-situ quantitative detection device based on differential scanning calorimetry, the mixed alkali metal in-situ quantitative detection device includes a closed furnace body 22 with a sealing cover 21, a first temperature and heat flow sensor and a second temperature and heat flow sensor (i.e., a temperature and heat flow sensor 23) are arranged in the closed furnace body 22, the first temperature and heat flow sensor is connected to a reference gas chamber 24, and the second temperature and heat flow sensor is connected to a sample gas chamber 26, and the sample gas chamber 26 is filled with mixed alkali metal atoms 25. In step 4, the temperature in the closed furnace body is increased, and as the temperature gradually increases, the mixed alkali metal atoms in the sample gas chamber will reach their respective phase transition temperatures in turn, and the heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, generates a corresponding heat absorption peak, thereby reflecting the respective heat absorption characteristics of the mixed alkali metal atoms in the phase transition process, and the respective heat absorption characteristics are used to determine the content of each mixed alkali metal atom in the sample gas chamber.

[0058] The present invention belongs to the technical field of alkali metal atomic gas chambers, and specifically relates to a method for accurately filling mixed alkali metal atoms in an atomic gas chamber. The method includes: a theoretical method for accurate filling and quantitative detection of mixed alkali metal atoms, a technical method for accurately acquiring mixed alkali metal atoms, an accurate filling technology based on a temperature gradient method, and an in-situ quantitative detection technology based on differential scanning calorimetry. The existing filling method based on the flame driving method relies on artificial experience control, resulting in poor consistency of the density ratio of mixed alkali metal atoms in the same batch of gas chambers, and low online density ratio detection accuracy, making it difficult to accurately control the amount of alkali metal atoms, thereby significantly reducing the theoretical performance of the gas chamber and limiting the accuracy improvement of the SERF atomic gyroscope. In view of the above problems, the present invention proposes a method for accurately filling mixed alkali metal atoms in an atomic gas chamber, which can achieve high-precision control and real-time verification of the content of mixed alkali metal atoms in the gas chamber. The method has a simple process and high filling efficiency, ensures the accurate control of the amount of alkali metal atoms in the gas chamber, effectively improves the performance of the gas chamber, and further optimizes the overall performance and measurement accuracy of the SERF atomic gyroscope.

[0059] A method for accurately filling mixed alkali metal atoms in an atomic gas chamber comprises the following steps:

[0060] Step 1, theoretical method for accurate filling and quantitative detection of mixed alkali metal atoms;

[0061] Step 2, a technical method for accurately obtaining mixed alkali metal atoms;

[0062] Step 3, a mixed alkali metal atom precise filling technology method based on the temperature gradient method;

[0063] Step 4: In-situ quantitative detection technology of mixed alkali metal atoms based on differential scanning calorimetry.

[0064] The theoretical method for accurate filling of mixed alkali metal atoms in step 1 mainly comprises:

[0065] The different alkali metal atom solid reactants in the two channels are made to react separately by simultaneous heating. This reaction is a heat-induced solid-phase reaction. According to the principle of chemical kinetics, the reaction rate constant conforms to the Arrhenius equation:

[0066]

[0067] Where k(T) represents the reaction rate constant, A represents the prefactor, and E a represents the reaction activation energy, R represents the gas constant, and T represents the reaction temperature.

[0068] For the case where the reaction order is 1, the relationship between the reaction conversion rate and time can be expressed as:

[0069]

[0070] Where t represents the reaction time, α represents the reaction conversion rate, and k(T) represents the reaction rate constant calculated based on the temperature.

[0071] Two solid reactants of two alkali metal atoms are placed in the two channels respectively. After determining the required reaction temperatures of each, the time required for the two alkali metal atomic reactants to react completely can be calculated according to the above formula. Based on this, the temperature and time program of each reactor in the two channels can be set.

[0072] After the reaction is completed, the two alkali metal atoms produced in the two channels are in solid form. According to the saturated vapor pressure theory, at a certain temperature, the pressure of the gaseous state when the liquid (or solid) substance reaches a dynamic equilibrium with its gaseous state, at this time, the evaporation rate is equal to the condensation rate. The empirical formula for the saturated vapor pressure of alkali metal atoms is:

[0073] log p=A+B / T

[0074] p represents saturated vapor pressure, A and B represent constants, and T represents temperature.

[0075] Since the entire glass pipeline is in vacuum conditions, at the set temperature, the ambient pressure can never reach the saturated vapor pressure of the two alkali metal atoms, and the two alkali metal atoms in the two channels continuously turn into single atomic gas and flow in the pipeline.

[0076] Alkali metal atoms have the property of transferring from high temperature to low temperature. According to the temperature gradient mass transfer theory, the particle unidirectional deposition diffusion coefficient expression is:

[0077]

[0078] Where D is the diffusion coefficient, T is the temperature, and p is the pressure.

[0079] The glass main pipeline, the glass connecting pipeline and the gas chamber form a temperature gradient area from high to low temperature. According to the above formula, the two flowing monoatomic gaseous alkali metal atoms are continuously deposited and mixed to the bottom of the low-temperature gas chamber. Through this method, as long as the amount of the mixture required by the alkali metal atomic reactants in each of the two channels is set, the quantitative filling of the mixed alkali metal atoms in the gas chamber can be finally achieved.

[0080] The theoretical method for quantitative detection of mixed alkali metal atoms is mainly based on differential scanning calorimetry. Its basic principle is that under temperature control, the heat flow difference between the sample end and the reference end will change with temperature or time, thereby obtaining thermal effect information such as heat absorption, heat release, and specific heat change of the sample during temperature change. The principle expression is:

[0081]

[0082] q represents the heat flow signal, C p represents the specific heat capacity of the sample, m represents the actual mass of the sample, β represents the rate of temperature change, represents the first-order differential of thermal enthalpy, R represents the measurement sensitivity, θ represents the temperature difference signal, τ represents the time constant, and θ b Represents the blank baseline signal.

[0083] By measuring the heat absorbed by the mixed alkali metal atoms in the gas chamber due to the thermal enthalpy effect, the content of each mixed alkali metal atom can be accurately calculated as follows:

[0084]

[0085] m represents the alkali metal atomic content, Q represents the total absorbed heat, and λ represents the conversion coefficient.

[0086] This provides a theoretical basis for accurately detecting the content of mixed alkali metal atoms.

[0087] The step 2 specifically includes the following reaction equation and steps, wherein X and Y represent two different alkali metal atoms:

[0088]

[0089] The masses of the respective reactants required for quantitatively mixing the alkali metals can be calculated according to the reaction equation. After the mixed solution of the reactants of the two alkali metal atoms is prepared, it is placed in a vacuum drying oven and dried to form a solid powder.

[0090] The step 3 includes five parts: impurity removal system, reaction furnace, oven, constant temperature system, and glass double pipeline (including glass connecting pipeline and alkali metal gas chamber). The impurity removal system can perform vacuum treatment and nitrogen purging treatment, and the vacuum degree and pressure are controllable; the reaction furnace can be heated to 400°C, the oven can be heated to 300°C, and the constant temperature system can maintain a constant temperature of 20°C, and the temperature is controllable; the reaction furnace provides the required reaction temperature for the solid powder and forms an ultra-high temperature area, the oven provides a high temperature area, and the constant temperature cooling system provides a low temperature area. The three construct a temperature gradient, so that the mixed alkali metal atomic vapor is unidirectionally deposited from the two pipelines into the alkali metal gas chamber. Specifically including the following steps:

[0091] Step 301, start the impurity removal system to make the vacuum degree reach the working requirement, and purge the air, water vapor and other impurities in the pipeline with nitrogen;

[0092] Step 302, start the oven and perform secondary impurity removal at high temperature;

[0093] Step 303, the temperature of the reaction furnaces at both ends of the glass double pipe is raised until the respective solid powders react and the alkali metal atoms are vaporized, and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber;

[0094] Step 304, removing the alkali metal gas chamber.

[0095] The step 4 includes a temperature and heat flow sensor, a sample gas chamber and a reference gas chamber. During the experiment, as the temperature gradually increases, the mixed alkali metal atoms in the sample gas chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, generates a corresponding heat absorption peak, and thus reflects the respective heat absorption characteristics of the mixed alkali metal atoms during the phase change process. Through the precise analysis of these heat flow signals, the content of each mixed alkali metal atom in the sample gas chamber can be calculated with high precision. When analyzing the results, if it is found that the measurement results have a large deviation, the required amount of mixed alkali metal atoms will be recalculated according to the deviation, and a secondary filling will be performed according to the recalculated value to ensure that the content of the mixed alkali metal atoms reaches the predetermined standard. Through this method, accurate quantitative determination of the content of mixed alkali metal atoms can be achieved, and dynamic adjustment and optimization can be achieved during the experiment.

[0096] like Figure 1 As shown, it includes an impurity removal system 1, two reaction furnaces 2, 3, a valve 4, an oven 5, a constant temperature system 6, and a glass double pipeline 7 (including a glass connecting pipeline and an alkali metal gas chamber).

[0097] like Figure 2 The mixed alkali metal in-situ quantitative detection device based on differential scanning calorimetry shown includes a sealing cover 21, a closed furnace body 22, a temperature and heat flow sensor 23, a reference gas chamber 24, mixed alkali metal atoms 25, and a sample gas chamber 26.

[0098] like Figure 3 The illustrated process of a method for accurately filling an atomic gas chamber with mixed alkali metal atoms in accordance with the present invention includes a theoretical method for accurately filling and quantitatively detecting mixed alkali metal atoms; a technical method for accurately acquiring mixed alkali metal atoms; a technical method for accurately filling mixed alkali metal atoms based on a temperature gradient method; and a technical method for in-situ quantitative detection of mixed alkali metal atoms based on a differential scanning calorimetry method.

[0099] Step 1: Theoretical method for precise filling and quantitative detection of mixed alkali metal atoms.

[0100] The different alkali metal atom solid reactants in the two channels are made to react separately by simultaneous heating. This reaction is a heat-induced solid-phase reaction. According to the principle of chemical kinetics, the reaction rate constant conforms to the Arrhenius equation:

[0101]

[0102] Where k(T) represents the reaction rate constant, A represents the prefactor, and E a represents the reaction activation energy, R represents the gas constant, and T represents the reaction temperature.

[0103] For the case where the reaction order is 1, the relationship between the reaction conversion rate and time can be expressed as:

[0104]

[0105] Where t represents the reaction time, α represents the reaction conversion rate, and k(T) represents the reaction rate constant calculated based on the temperature.

[0106] Two solid reactants of two alkali metal atoms are placed in the two channels respectively. The required reaction temperature of both is set to 200 degrees Celsius. According to the above formula, the time required for the complete reaction of the two alkali metal atomic reactants can be calculated respectively. To ensure the adequacy of the reaction, the heating time in the two channels is set to 1 hour.

[0107] After the reaction is completed, the two alkali metal atoms produced in the two channels are in solid form. According to the saturated vapor pressure theory, at a certain temperature, the pressure of the gaseous state when the liquid (or solid) substance reaches a dynamic equilibrium with its gaseous state, at this time, the evaporation rate is equal to the condensation rate. The empirical formula for the saturated vapor pressure of alkali metal atoms is:

[0108] log p=A+B / T

[0109] p represents saturated vapor pressure, A and B represent constants, and T represents temperature.

[0110] Since the entire glass pipeline is in vacuum conditions, at the set temperature, the ambient pressure can never reach the saturated vapor pressure of the two alkali metal atoms, and the two alkali metal atoms in the two channels continuously turn into single atomic gas and flow in the pipeline.

[0111] Alkali metal atoms have the property of transferring from high temperature to low temperature. According to the temperature gradient mass transfer theory, the particle unidirectional deposition diffusion coefficient expression is:

[0112]

[0113] Where D is the diffusion coefficient, T is the temperature, and p is the pressure.

[0114] The glass main pipeline, the glass connecting pipeline and the gas chamber form a temperature gradient area from high to low temperature. According to the above formula, the two flowing monoatomic gaseous alkali metal atoms are continuously deposited and mixed to the bottom of the low-temperature gas chamber. Through this method, as long as the amount of the mixture required by the alkali metal atomic reactants in each of the two channels is set, the quantitative filling of the mixed alkali metal atoms in the gas chamber can be finally achieved.

[0115] The theoretical method for quantitative detection of mixed alkali metal atoms is mainly based on differential scanning calorimetry. Its basic principle is that under temperature control, the heat flow difference between the sample end and the reference end will change with temperature or time, thereby obtaining thermal effect information such as heat absorption, heat release, and specific heat change of the sample during temperature change. The principle expression is:

[0116]

[0117] q represents the heat flow signal, C p represents the specific heat capacity of the sample, m represents the actual mass of the sample, β represents the rate of temperature change, represents the first-order differential of thermal enthalpy, R represents the measurement sensitivity, θ represents the temperature difference signal, τ represents the time constant, and θ b Represents the blank baseline signal.

[0118] By measuring the heat absorbed by the mixed alkali metal atoms in the gas chamber due to the thermal enthalpy effect, the content of each mixed alkali metal atom can be accurately calculated as follows:

[0119]

[0120] m represents the alkali metal atomic content, Q represents the total absorbed heat, and λ represents the conversion coefficient.

[0121] This provides a theoretical basis for accurately detecting the content of mixed alkali metal atoms.

[0122] Step 2: Technical method for accurately obtaining mixed alkali metal atoms.

[0123] The types of mixed alkali metal atomic sources selected in this embodiment are potassium (K) and rubidium (Rb), and the mass of alkali metal potassium required in each gas chamber is set to 100 μg, and the mass of rubidium is set to 200 μg. Figure 1 A total of eight alkali metal gas chambers are connected in the glass double tube 7, so 800 μg of alkali metal potassium and 1600 μg of rubidium are required.

[0124] According to the following reaction equation:

[0125]

[0126] The mass of reactants required for each of the mixed alkali metal atoms can be calculated:

[0127] Required mass of K chloride

[0128] The required BaN6 mass

[0129] Required Rb chloride mass

[0130] The required BaN6 mass

[0131] Weigh the masses of the two alkali metal reactants respectively, prepare the corresponding mixed reactant solutions, pour the solutions into two clean reaction boats, put them into a vacuum drying oven at 90 degrees Celsius to evaporate the solutions in the two reaction boats to dry into solid powders.

[0132] Step 3: Precision filling technology of mixed alkali metal atoms based on temperature gradient method

[0133] like Figure 1As shown, step 3 includes five parts: impurity removal system, reaction furnace, oven, constant temperature system, and glass double pipeline (including glass connecting pipeline and alkali metal gas chamber). The impurity removal system can perform vacuum treatment and nitrogen purging treatment, and the vacuum degree and pressure are both controllable; the reaction furnace can be heated to 400°C, the oven can be heated to 300°C, and the constant temperature system can maintain a constant temperature of 20°C, and the temperature is controllable; the reaction furnace provides the required reaction temperature for the solid powder and forms an ultra-high temperature area, the oven provides a high temperature area, and the constant temperature cooling system provides a low temperature area. The three construct a temperature gradient, so that the mixed alkali metal atomic vapor is unidirectionally deposited from the two pipelines into the alkali metal gas chamber. Specifically including the following steps:

[0134] Step 301, start the impurity removal system and make the vacuum degree reach 5×10 -6 Pa, nitrogen purge to remove air, water vapor and other impurities in the pipeline;

[0135] Step 302, start the oven and perform secondary impurity removal at a high temperature of 300°C;

[0136] Step 303, the temperature of the reaction furnaces at both ends of the glass double pipe is simultaneously raised to 380° C. to react the respective solid powders and vaporize the alkali metal atoms. The oven temperature is controlled at 230° C., the constant temperature system is controlled at 20° C., and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber;

[0137] Step 304, removing the alkali metal gas chamber.

[0138] Step 4: In-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry

[0139] like Figure 2 As shown, step 4 includes a temperature and heat flow sensor 23 , a sample gas chamber 26 and a reference gas chamber 24 .

[0140] During the experiment, as the temperature gradually increases, the mixed alkali metal atoms in the sample gas chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample gas chamber 26 and the reference gas chamber 24 in real time, generates a corresponding heat absorption peak, and thus reflects the heat absorption characteristics of the mixed alkali metal atoms during the phase change process. Through the precise analysis of these heat flow signals, the content of each mixed alkali metal atom in the sample gas chamber can be calculated with high precision. When analyzing the results, if it is found that the measurement results have a large deviation, the required amount of mixed alkali metal atoms will be recalculated based on the deviation, and a secondary filling will be performed based on the recalculated value to ensure that the content of the mixed alkali metal atoms reaches the predetermined standard. Through this method, accurate quantitative determination of the content of mixed alkali metal atoms can be achieved, and dynamic adjustment and optimization can be achieved during the experiment.

[0141] Place the sample gas chamber 26 filled with mixed alkali metal atoms on one side of the temperature and heat flow sensor 23, and place a reference gas chamber (i.e., reference gas chamber 24) of the same size on the other side of the temperature and heat flow sensor 23, and tighten the sealing cover 21; gradually heat up the closed furnace body 22. During this process, due to the different melting points of the two alkali metal atoms, the detection curve generates two obvious absorption peaks. The absorption peak area is calculated according to the formula The two alkali metal atomic contents were obtained respectively, which were mutually confirmed with the expected mixed alkali metal atomic contents. In this embodiment, taking the rubidium atomic absorption peak as an example, the absorption peak area is 5.234J, the melting heat is 25.65J / mg, and the mass of the alkali metal rubidium can be obtained to be 204μg, which is 2% relative to the theoretical calculation result, within the acceptable error range, so accurate filling is obtained.

[0142] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. It is pointed out here that the above description helps those skilled in the art to understand the invention, but does not limit the protection scope of the invention. Any equivalent replacement, modification and / or simplification of the above description without departing from the essence of the invention falls within the protection scope of the invention.

Claims

1. A method for accurately filling mixed alkali metal atoms in an atomic gas chamber, characterized in that: The following steps are involved: Step 1, using the theoretical method of accurate filling and quantitative detection of mixed alkali metal atoms to establish a mixed alkali metal atom filling platform model; Step 2, determining the required amount of mixed alkali metal atom reactants from the required mixed alkali metal atom content using the following chemical reaction formula: wherein X represents the first alkali metal in the alkali metal mixture, and Y represents the second alkali metal in the alkali metal mixture; Step 3, performing precise filling of mixed alkali metal atoms based on the temperature gradient method, including placing the alkali metal gas chamber in a low temperature area provided by a constant temperature system, the filling inlet of the alkali metal gas chamber being connected to the first reaction furnace and the second reaction furnace respectively through pipelines, the first reaction furnace forming an ultra-high temperature area to cause a vaporization reaction of the first alkali metal solid powder, the first alkali metal atomic vapor enters the alkali metal gas chamber in the low temperature area from the ultra-high temperature area through the pipeline in the high temperature area in the oven, the second reaction furnace forming an ultra-high temperature area to cause a vaporization reaction of the second alkali metal solid powder, the second alkali metal atomic vapor enters the alkali metal gas chamber in the low temperature area from the ultra-high temperature area through the pipeline in the high temperature area in the oven, and the alkali metal gas chamber is removed after completing the temperature gradient driven filling; Step 4: Perform in-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry to determine the content of each mixed alkali metal atom in the alkali metal gas chamber.

2. The method for accurately filling mixed alkali metal atoms in an atomic gas chamber according to claim 1, characterized in that: Step 1 includes a mixed alkali metal atom filling platform, which includes an oven, in which a glass pipe with a four-way structure is arranged, one end of the horizontal glass pipe in the four-way structure is closed, and the other end is connected to the impurity removal system through a valve, one end of the vertical glass pipe in the four-way structure is connected to the first reaction furnace through a valve, and the other end is connected to the second reaction furnace through a valve, and both sides of the horizontal glass pipe are connected to alkali metal gas chambers, and the alkali metal gas chambers are located in a constant temperature system.

3. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, characterized in that: The mixed alkali metal atom filling platform model in step 1 includes the following expressions: log p=A+B / T, Where k(T) represents the reaction rate constant, A represents the prefactor, and E a represents the reaction activation energy, R represents the gas constant, T represents the reaction temperature, e is the natural constant, t represents the reaction time, α represents the reaction conversion rate, p represents the saturated vapor pressure, A and B represent constants, D represents the diffusion coefficient, q represents the heat flow signal, C p represents the specific heat capacity of the sample, m represents the actual mass of the sample, β represents the rate of temperature change, represents the first-order differential of thermal enthalpy H, R1 represents the measurement sensitivity, θ represents the temperature difference signal, τ represents the time constant, θ b represents the blank baseline signal, m1 represents the alkali metal atom content, Q represents the total absorbed heat, and λ represents the conversion coefficient.

4. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, characterized in that: In step 2, the first alkali metal is K, and the second alkali metal is Rb. The corresponding chemical reaction formula is as follows: Where m KCl is the amount of KCl required as reactant, M KCl is the molecular weight of KCl, M K is the atomic weight of K, m K is the amount of K required for each alkali metal gas chamber, is the corresponding m K The amount of BaN6 required as reactant, is the molecular weight of BaN6, m RbCl is the amount of reactant RbCl required, M Rb is the atomic weight of Rb, m Rb is the amount of Rb required for each alkali metal gas cell, is the corresponding m Rb Required amount of reactant BaN6, M RbCl is the molecular weight of RbCl.

5. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, characterized in that: The ultra-high temperature in step 3 is 400°C, the high temperature is 300°C, and the low temperature is 20°C. The temperature gradient constructed by the ultra-high temperature area, the high temperature area and the low temperature area allows the mixed alkali metal atomic vapor to be deposited unidirectionally from two pipelines into the alkali metal gas chamber.

6. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, characterized in that: Step 3 includes the following steps: Step 301, start the impurity removal system to make the vacuum degree reach the working requirement, and purge the air, water vapor and other impurities in the pipeline with nitrogen; Step 302, start the oven and perform secondary impurity removal at high temperature; Step 303, the pipeline adopts a glass double pipeline, and the reaction furnaces at both ends of the glass double pipeline are heated to the temperature of each solid powder to react and vaporize the alkali metal atoms, and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber; Step 304, removing the alkali metal gas chamber.

7. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, characterized in that: Step 4 includes an in-situ quantitative detection device for mixed alkali metals based on differential scanning calorimetry, wherein the in-situ quantitative detection device for mixed alkali metals includes a closed furnace body with a sealing cover, wherein a first temperature and heat flow sensor and a second temperature and heat flow sensor are arranged in the closed furnace body, wherein the first temperature and heat flow sensor is connected to a reference gas chamber, and the second temperature and heat flow sensor is connected to a sample gas chamber, wherein the sample gas chamber is filled with mixed alkali metal atoms.

8. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 7, characterized in that: In step 4, the temperature in the closed furnace is increased. As the temperature gradually increases, the mixed alkali metal atoms in the sample gas chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, and generates a corresponding heat absorption peak value, thereby reflecting the respective heat absorption characteristics of the mixed alkali metal atoms during the phase change process. The content of each mixed alkali metal atom in the sample gas chamber is determined using the respective heat absorption characteristics.

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