Method for precisely filling alkali metal atoms in an atomic cell

Abstract

The application belongs to the technical field of alkali metal atom cell, and particularly relates to a method for precisely charging mixed alkali metal atoms in an atom cell, which is combined with a theoretical method for precisely charging and quantitatively detecting mixed alkali metal atoms, a technical method for precisely obtaining mixed alkali metal atoms, an accurate charging technology based on a temperature gradient method, and an in-situ quantitative detection technology based on a differential scanning calorimetry method, so that high-precision regulation and real-time verification of the content of mixed alkali metal atoms in the atom cell can be realized. The method is simple in process and high in charging efficiency, ensures accurate control of the amount of alkali metal atoms in the atom cell, effectively improves the performance of the atom cell, and further optimizes the overall performance and measurement accuracy of the SERF atom gyroscope.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alkali metal atom gas cell, and particularly relates to a method for precisely charging mixed alkali metal atoms in an atom gas cell. BACKGROUND

[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 a result of these technologies, gyro technology has undergone changes and innovations from mechanical-electrical gyroscopes, fiber-optic gyroscopes to atomic gyroscopes. Among them, the spin exchange relaxation free (SERF) atomic gyroscope is widely considered as the key development direction of the next generation of ultra-high precision gyroscopes, and its theoretical precision can reach 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 the core component is an alkali metal gas cell. The performance of the alkali metal gas cell directly determines the overall precision and stability of the SERF atomic gyroscope. Under the working state of the SERF atomic gyroscope, the gas cell usually contains multiple 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. Precise control of the content of multiple alkali metal atoms in the gas cell can significantly improve the performance of the gas cell, thereby improving the measurement precision and sensitivity of the SERF atomic gyroscope.

[0004] In the current technology, the charging of mixed alkali metal atoms still faces problems such as low charging precision, poor consistency of atomic content, and large detection error of the charging amount. Existing patent documents, such as CN201711420607 (an atomic gas cell preparation device and method for alkali metal quantitative filling), mainly achieve directional deposition of alkali metal by precisely controlling the temperature distribution of the device, but do not involve the detailed process flow of mixed alkali metal atom charging. Another patent document CN201611037423 (a double-alkali metal atom precise charging method) proposes a method of controlling the charging amount by online measuring the alkali metal atom density, but experimental verification shows that this method has problems such as insufficient measurement precision, poor consistency of results, and lack of reference standards.

[0005] Therefore, there is an urgent need for a high-precision and reliable mixed alkali metal atom charging process flow in the existing technology. The present application proposes a method for precisely charging mixed alkali metal atoms in an atom gas cell, which can achieve precise charging and quantitative verification of mixed alkali metal atoms in the gas cell. The process is simple to operate, has high charging precision, can significantly improve the charging efficiency of alkali metal atoms, ensure the consistency and accuracy of the charging amount, and provide a strong guarantee for the performance improvement of the SERF atomic gyroscope. SUMMARY

[0006] The present application aims at the deficiencies in the existing mixed alkali metal atom charging technology, especially the poor consistency of the mixed alkali metal atom density ratio in the same batch gas chamber caused by manual experience control based on flame driving method, and the low precision of online density ratio detection, and proposes a precise charging method for mixed alkali metal atoms in an atomic gas chamber. The method can realize accurate 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 charging method. The charging process provided by the present application is simple and has high precision, significantly improves the charging efficiency of mixed alkali metal atoms, 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 application is as follows:

[0008] A precise charging method for mixed alkali metal atoms in an atomic gas chamber, characterized in that it comprises the following steps:

[0009] Step 1: Establish a mixed alkali metal atom charging platform model using the mixed alkali metal atom precise charging and quantitative detection theoretical method;

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

[0011]

[0012] Where X represents the first alkali metal in the mixed alkali metal, and Y represents the second alkali metal in the mixed alkali metal;

[0013] Step 3: Perform mixed alkali metal atom precise charging based on the temperature gradient method, including placing the alkali metal gas chamber in a low temperature area provided by a constant temperature system, connecting the charging inlet of the alkali metal gas chamber to the first reaction furnace and the second reaction furnace through pipelines, forming an ultra-high temperature area in the first reaction furnace to cause vaporization reaction of the first alkali metal solid powder, and making the first alkali metal atom vapor enter 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, forming an ultra-high temperature area in the second reaction furnace to cause vaporization reaction of the second alkali metal solid powder, and making the second alkali metal atom vapor enter 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 removing the alkali metal gas chamber after completing the temperature gradient driven charging;

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

[0015] The mixed alkali metal atom charging platform in step 1 comprises an oven, wherein a four-way structure glass pipeline is arranged, a transverse glass pipeline in the four-way structure is closed at one end and connected to a impurity removal system through a valve at the other end, a longitudinal glass pipeline in the four-way structure is connected to a first reaction furnace through a valve at one end and connected to a second reaction furnace through a valve at the other end, and an alkali metal gas chamber is connected to both sides of the transverse glass pipeline, and the alkali metal gas chamber is located in a constant temperature system.

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

[0017]

[0018] logp=A+B / T,

[0019]

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

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

[0022]

[0023] wherein m KCl is a required amount of a reactant KCl, M KCl is a molecular weight of KCl, M K is an atomic weight of K, m K is a required amount of K for each alkali metal gas chamber, is a required amount of a reactant BaN6 corresponding to m K , is a molecular weight of BaN6, m RbCl is a required amount of a reactant RbCl, M Rb is an atomic weight of Rb, m Rb is a required amount of Rb for each alkali metal gas chamber, is a required amount of a reactant RbCl corresponding to mRb Amount of required reactant BaN6, M RbCl is the molecular weight of RbCl.

[0024] The ultra-high temperature in step 3 is 400℃, the high temperature is 300℃, and the low temperature is 20℃. The temperature gradient formed by the ultra-high temperature region, the high temperature region and the low temperature region enables the mixed alkali metal atom vapor to be deposited from the two pipelines into the alkali metal gas chamber in a one-way manner, respectively.

[0025] Step 3 includes the following steps:

[0026] Step 301: Turn on the impurity removal system to reach the required vacuum degree, and use nitrogen to purge the pipeline to remove air, water vapor and other impurities.

[0027] Step 302: Turn on the oven for high-temperature secondary impurity removal.

[0028] Step 303: The pipeline uses a glass double pipeline, and the two ends of the glass double pipeline are heated to the respective solid powders to react and vaporize the alkali metal atoms. The temperature gradient drives the two kinds of alkali metal atoms to deposit into the alkali metal gas chamber.

[0029] Step 304: Extract the alkali metal gas chamber.

[0030] 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 with a sealed cover. The closed furnace body is provided with a first temperature and heat flow sensor and a second temperature and heat flow sensor. 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. The sample gas chamber is filled with mixed alkali metal atoms.

[0031] In step 4, the temperature in the closed furnace body 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 sequence. The heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, generates corresponding heat absorption peak values, and reflects the respective heat absorption characteristics of the mixed alkali metal atoms in the phase transition process. The content of each mixed alkali metal atom in the sample gas chamber is determined by using the respective heat absorption characteristics.

[0032] The technical effects of the present application are as follows: the present application is a method for precisely charging mixed alkali metal atoms in an atomic cell, which combines the theoretical method of precise charging and quantitative detection of mixed alkali metal atoms, the precise charging technology based on the temperature gradient method, and the in-situ quantitative detection technology based on the differential scanning calorimetry method, so as to realize high-precision regulation and real-time verification of the content of mixed alkali metal atoms in the cell. The method is simple in process and high in charging efficiency, which ensures the precise control of the amount of alkali metal atoms in the cell and effectively improves the performance of the cell, thereby further optimizing the overall performance and measurement accuracy of the SERF atomic gyroscope.

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

[0034] 1. The present application designs a mixed alkali metal atom precise charging process based on differential scanning calorimetry, which quantitatively configures the precursor of mixed alkali metal atoms through chemical reaction to realize high-precision control of the content of alkali metal atoms and significantly improve the regulation accuracy of the density of mixed alkali metal atoms in the cell.

[0035] 2. The mixed alkali metal charging method uses theoretical simulation and experimental results to verify each other, which not only simplifies the operation process, but also significantly improves the accuracy and efficiency of the charging process, thereby improving the overall charging efficiency and ensuring the consistency of the content of mixed alkali metal atoms in the cell.

[0036] 3. The content of mixed alkali metal atoms in the cell is detected in real time by differential scanning calorimetry, and the results are verified with the results of quantitative preparation by chemical reduction method, so as to realize precise control of the content of mixed alkali metal atoms in the cell, facilitate secondary charging when necessary, and significantly improve the controllability of the cell.

[0037] 4. The method realizes precise charging of mixed alkali metal atoms, significantly optimizes the performance of the cell, and further improves the overall accuracy and stability of the SERF atomic inertial gyroscope, providing a solid technical guarantee for realizing higher precision inertial measurement. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a charging device structure schematic diagram related to the present application.

[0039] Figure 2 is a mixed alkali metal in-situ quantitative detection device schematic diagram based on differential scanning calorimetry related to the present application.

[0040] Figure 3 is a flowchart of the present application. Figure 3The method includes the following steps: 1. establishing a mixed alkali metal atom charging platform model using a theoretical method for precise charging and quantitative detection of mixed alkali metal atoms; the mixed alkali metal atom charging platform model has the characteristics of precise charging function, temperature gradient mass transfer mechanism and two-way channel structure; the alkali metal gas chamber charging platform model can be associated with a mixed alkali metal atom phase transition model in an alkali metal gas chamber with quantitative detection and differential scanning calorimetry; and 2. a technical method for precisely obtaining mixed alkali metal atoms, including determining the required amount of mixed alkali metal atom reactants from the required mixed alkali metal atom content using the following chemical reaction formula: X is the first alkali metal in the mixed alkali metals, and Y is the second alkali metal in the mixed alkali metals; Step 3, a technical method for precise filling of mixed alkali metal atoms based on a temperature gradient method, including starting an impurity removal system to ensure that the vacuum degree and impurity content meet the requirements; starting an oven for secondary high-temperature impurity removal; heating the reactor at both ends of the glass double-pipeline until the respective solid powders react, and temperature gradient-driven filling; removing 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 content of each mixed alkali metal atom is calculated based on the absorption peak; if the deviation is large, a secondary filling is performed.

[0041] The accompanying drawings are explained 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 ( Figures 1-3 ) and Examples illustrate the present invention.

[0043] Figure 1 The present invention is a schematic structural diagram of a filling device involved in a method for accurately filling mixed alkali metal atoms in an atomic gas chamber. Figure 2 The present invention is a schematic diagram of an in-situ quantitative detection device for mixed alkali metals based on differential scanning calorimetry, which is involved in a method for accurately filling mixed alkali metal atoms in an atomic chamber according to the present invention. Figure 3 This is a schematic 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 precise charging of mixed alkali metal atoms in an atomic cell includes the following steps: Step 1, establishing a mixed alkali metal atom charging platform model using a mixed alkali metal atom precise charging and quantitative detection theoretical method; 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 a first alkali metal in the mixed alkali metal, and Y represents a second alkali metal in the mixed alkali metal;

[0046] Step 3, performing mixed alkali metal atom precise charging based on a temperature gradient method, including placing an alkali metal cell in a low-temperature region provided by a constant temperature system, a charging inlet of the alkali metal cell being connected to a first reaction furnace and a second reaction furnace through pipelines, the first reaction furnace forming an ultrahigh-temperature region to cause a vaporization reaction of a first alkali metal solid powder, first alkali metal atom vapor entering the alkali metal cell in the low-temperature region from the ultrahigh-temperature region through the pipeline in a high-temperature region in an oven, the second reaction furnace forming an ultrahigh-temperature region to cause a vaporization reaction of a second alkali metal solid powder, second alkali metal atom vapor entering the alkali metal cell in the low-temperature region from the ultrahigh-temperature region through the pipeline in the high-temperature region in the oven, and removing the alkali metal cell after completing the temperature gradient driven charging; and Step 4, performing in-situ quantitative detection of mixed alkali metal atoms based on a differential scanning calorimetry method to determine respective contents of the mixed alkali metal atoms in the alkali metal cell.

[0047] The mixed alkali metal atom charging platform in Step 1 includes an oven 5, the oven 5 being provided with a four-way structure glass pipeline (for example, a glass double pipeline 7), a transverse glass pipeline in the four-way structure being closed at one end and connected to a impurity removal system 1 through a valve at the other end, a longitudinal glass pipeline in the four-way structure being connected to a first reaction furnace 2 through a valve 4 at one end and connected to a second reaction furnace 3 through a valve at the other end, both sides of the transverse glass pipeline being connected to an alkali metal cell, and the alkali metal cell being located in a constant temperature system 6.

[0048] The mixed alkali metal atom charging 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 pre-factor, 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 temperature change rate, 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 a 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 corresponding to 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 corresponding to m Rb The amount of BaN6 required as reactant, M RbCl is the molecular weight of RbCl.

[0057] The ultra-high temperature in step 3 is 400 DEG C, the high temperature is 300 DEG C, and the low temperature is 20 DEG C. The temperature gradient formed by the ultra-high temperature region, the high temperature region and the low temperature region enables the mixed alkali metal atom vapor to be deposited into the alkali metal gas chamber from the two pipelines in a one-way manner. Step 3 includes the following steps: step 301, starting the impurity removal system to reach the working requirement of vacuum degree, and blowing nitrogen to remove air, water vapor and other impurities in the pipeline; step 302, starting the oven for high-temperature secondary impurity removal; step 303, the pipeline adopts a glass double pipeline, the two ends of the glass double pipeline are heated to the respective solid powders to react and make the alkali metal atoms vaporize, and the temperature gradient drives the two kinds of alkali metal atoms to deposit into the alkali metal gas chamber; step 304, taking out the alkali metal gas chamber. Step 4 includes a mixed alkali metal in-situ quantitative detection device based on differential scanning calorimetry, which includes a closed furnace body 22 with a sealing cover 21, the closed furnace body 22 is provided with first and second temperature and heat flow sensors (i.e. temperature and heat flow sensors 23), the first temperature and heat flow sensor is connected with a reference gas chamber 24, the second temperature and heat flow sensor is connected with 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 the respective phase transition temperatures in sequence, the heat flow sensor monitors the temperature difference signal between the sample gas chamber and the reference gas chamber in real time, generates the corresponding heat absorption peak, and reflects the respective heat absorption characteristics of the mixed alkali metal atoms in the phase transition process, so as to determine the content of each mixed alkali metal atom in the sample gas chamber by using the respective heat absorption characteristics.

[0058] The application belongs to the technical field of alkali metal atom gas chambers, and particularly relates to a method for precisely charging mixed alkali metal atoms in an atom gas chamber. The method comprises a theoretical method for precisely charging and quantitatively detecting mixed alkali metal atoms, a technical method for precisely obtaining mixed alkali metal atoms, a precise charging technology based on a temperature gradient method, and an in-situ quantitative detection technology based on differential scanning calorimetry. The existing charging method based on a flame driving method relies on manual experience control, which leads to poor consistency of the density ratio of mixed alkali metal atoms in the same batch of gas chambers, low online density ratio detection accuracy, and difficulty in precisely controlling the amount of alkali metal atoms, thereby significantly reducing the theoretical performance of the gas chamber and limiting the accuracy improvement of the SERF atom gyroscope. To solve the above problems, the application provides a method for precisely charging mixed alkali metal atoms in an atom gas chamber, which can realize high-precision regulation and real-time verification of the content of mixed alkali metal atoms in the gas chamber. The method is simple in process and high in charging efficiency, ensures the precise 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 atom gyroscope.

[0059] A method for precisely charging mixed alkali metal atoms in an atomic cell, comprising the following steps:

[0060] Step 1, a theoretical method for precisely charging mixed alkali metal atoms and quantitative detection;

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

[0062] Step 3, a technical method for precisely charging mixed alkali metal atoms based on temperature gradient method;

[0063] Step 4, a technical method for in-situ quantitative detection of mixed alkali metal atoms based on differential scanning calorimetry.

[0064] The theoretical method for precisely charging mixed alkali metal atoms of step 1 mainly includes:

[0065] The different alkali metal atom solid reactants in the two channels are reacted by simultaneous heating, and the 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 pre-exponential factor, 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 reaction conversion rate-time relationship can be expressed as:

[0069]

[0070] where t represents the reaction time, a represents the reaction conversion rate, and k(T) represents the reaction rate constant calculated according to the temperature.

[0071] In the two channels, two kinds of alkali metal atom solid reactants are respectively placed, and after the required reaction temperatures of the two are determined, the time required for complete reaction of the two alkali metal atom reactants can be obtained according to the above formula, and based on this, the temperature and time program of the reaction furnace of each channel can be set.

[0072] After the reaction is completed, the required two kinds of alkali metal atom elements in solid form are respectively generated in the two channels. According to the saturated vapor pressure theory, at a certain temperature, the gas pressure reaches a dynamic equilibrium between the liquid (or solid) substance and its gas state at this time, and 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 the saturated vapor pressure, A and B represent constants, and T represents temperature.

[0075] Since the entire glass pipeline is in a vacuum condition, at a set temperature, the ambient pressure cannot reach the saturated vapor pressure of the two alkali metal atoms, and the two alkali metal atoms in the two channels continuously become single-atom gas and flow in the pipeline.

[0076] The alkali metal atoms have the characteristics of transferring from high temperature to low temperature, and according to the temperature gradient mass transfer theory, the expression of the one-way deposition diffusion coefficient of particles is:

[0077]

[0078] where D represents the diffusion coefficient, T represents the temperature, and p represents the pressure.

[0079] The glass main pipeline, the glass connecting pipeline, and the air chamber form a temperature gradient region from high to low temperature, and according to the above formula, the two flowing single-atom gas alkali metal atoms continuously deposit and mix at the bottom of the low-temperature air chamber. Through this method, as long as the amount of the mixture required by the respective alkali metal atom reactants in the two channels is set, the quantitative charging of the mixed alkali metal atoms in the air chamber can be finally realized.

[0080] The quantitative detection theory method 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, and thus the heat effect information such as heat absorption, heat release, and specific heat change of the sample during temperature change can be obtained. 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, and β represents the temperature change rate, represents the first derivative of the 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 absorption amount of the enthalpy effect of the mixed alkali metal atoms in the air chamber, the respective content of the mixed alkali metal atoms can be accurately calculated, and the expression is:

[0084]

[0085] m represents the content of the alkali metal atoms, Q represents the total heat absorption, and λ represents the conversion coefficient.

[0086] Thus, a theoretical basis is provided for accurately detecting the content of the 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] According to the reaction equation, the mass of each reactant required for quantitative mixing of alkali metal atoms can be calculated. After preparing the reactant mixed solution of two alkali metal atoms, it is placed in a vacuum drying oven to dry into a solid powder.

[0090] The step 3 includes five parts of a decontamination system, a reaction furnace, an oven, a constant temperature system, and a glass double pipeline (including a glass connecting pipeline and an alkali metal gas chamber). The decontamination system can be subjected to 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 of the solid powder and forms an ultrahigh temperature area, the oven provides a high temperature area, and the constant temperature cooling system provides a low temperature area, which builds a temperature gradient, so that the mixed alkali metal atom vapor is deposited into the alkali metal gas chamber from the two pipelines in one direction. Specifically includes the following steps:

[0091] Step 301, turn on the decontamination system, so that the vacuum degree reaches the working requirement, and the nitrogen purging removes air, water vapor and other impurities in the pipeline;

[0092] Step 302, turn on the oven for high-temperature secondary decontamination;

[0093] Step 303, heat the reaction furnace at both ends of the glass double pipeline to a temperature at which the respective solid powder reacts and the alkali metal atoms vaporize, and the temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber;

[0094] Step 304, take out 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 the corresponding heat absorption peak value, and thus reflects the respective heat absorption characteristics of the mixed alkali metal atoms in the phase transition process. Through accurate 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 the measurement result deviates greatly, the required amount of mixed alkali metal atoms will be recalculated according to the deviation, and a second charging 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] As shown in Figure 1 The system includes a dedusting 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 gas chamber).

[0097] As shown in Figure 2 The mixed alkali metal in-situ quantitative detection device based on differential scanning calorimetry 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] As shown in Figure 3 The implementation of the present application is a precise charging method for mixed alkali metal atoms in an atomic gas chamber, which includes a mixed alkali metal atom precise charging and quantitative detection theoretical method, a mixed alkali metal atom precise acquisition technical method, a mixed alkali metal atom precise charging technical method based on temperature gradient method, and a mixed alkali metal atom in-situ quantitative detection technical method based on differential scanning calorimetry.

[0099] Step 1, mixed alkali metal atom precise charging and quantitative detection theoretical method.

[0100] The two paths are heated simultaneously to make the different alkali metal atom solid reactants in each path react. This reaction is a heat-induced solid-phase reaction. According to the chemical kinetics principle, the reaction rate constant conforms to the Arrhenius equation:

[0101]

[0102] where k(T) represents the reaction rate constant, A represents the pre-exponential factor, 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 reaction conversion rate-time relationship can be expressed as:

[0104]

[0105] where t represents the reaction time, a represents the reaction conversion rate, and k(T) represents the reaction rate constant calculated according to the temperature.

[0106] Two kinds of alkali metal atom solid reactants are placed in two paths, and the required reaction temperature of both is set to 200 degrees Celsius. According to the above formula, the time required for complete reaction of the two alkali metal atom reactants can be calculated, and the heating time in both paths is set to 1 hour to ensure the reaction sufficiency.

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

[0108] log p=A+B / T

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

[0110] Because the entire glass pipeline is in a vacuum condition, at a set temperature, the ambient pressure cannot reach the saturated vapor pressure of the two kinds of alkali metal atoms, and the two kinds of alkali metal atoms in the two channels continuously become single-atom gas and flow in the pipeline.

[0111] Alkali metal atoms have the characteristic of transferring from high temperature to low temperature. According to the temperature gradient mass transfer theory, the one-way deposition diffusion coefficient of particles is expressed as:

[0112]

[0113] where D represents the diffusion coefficient, T represents the temperature, and p represents 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 kinds of flowing single-atom gas alkali metal atoms continuously deposit and mix at the bottom of the low-temperature gas chamber. Through this method, as long as the amount of the mixture of the reactants of the alkali metal atoms in the two channels is set, the quantitative charging of the mixed alkali metal atoms in the gas chamber can be finally realized.

[0115] The mixed alkali metal atom quantitative detection theory method 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, from which the heat effect information of the sample in the temperature change process, such as heat absorption, heat release, and specific heat change, can be obtained. 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, and β represents the temperature change rate, represents the first derivative of the enthalpy, R represents the measurement sensitivity, θ represents the temperature difference signal, and τ represents the time constant, θ b represents the blank baseline signal.

[0118] By measuring the heat absorption of the mixed alkali metal atoms in the gas chamber, the content of the mixed alkali metal atoms can be accurately calculated, and the expression is:

[0119]

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

[0121] Thus, a theoretical basis is provided for accurately detecting the mixed alkali metal atom content.

[0122] Step 2, accurate acquisition technology method of mixed alkali metal atoms

[0123] In this embodiment, the selected mixed alkali metal atom sources are potassium (K) and rubidium (Rb), and the required mass of alkali metal potassium in each gas chamber is set to 100 μg, and the mass of rubidium is set to 200 μg, Figure 1 The glass double pipeline 7 is connected with 8 alkali metal gas chambers, and therefore the required mass of alkali metal potassium is 800 μg, and the mass of rubidium is 1600 μg.

[0124] According to the following reaction equation:

[0125]

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

[0127] The required mass of KCl

[0128] The required mass of BaN6

[0129] The required mass of RbCl

[0130] The required mass of BaN6

[0131] The mass of the reactants of the two kinds of alkali metals is weighed respectively, and the corresponding mixed reactant solution is configured, and the solution is poured into two clean reaction boats, and the solution in the two reaction boats is evaporated and dried to solid powder in a vacuum drying box at 90 degrees Celsius.

[0132] Step 3, accurate charging technology method of mixed alkali metal atoms based on the temperature gradient method

[0133] As Figure 1As shown, the step 3 includes five parts: impurity removal system, reactor, oven, constant temperature system, and glass double pipe (including glass connecting pipe 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 reactor 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 reactor provides the reaction temperature required 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 deposited unidirectionally from the two pipes 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] In step 303, the temperature of the reaction furnaces at both ends of the double-tube glass tube 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 and the constant temperature system is controlled at 20°C. The temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber.

[0137] Step 304: remove the alkali metal gas cell.

[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 rises, the mixed alkali metal atoms in the sample chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample chamber 26 and the reference chamber 24 in real time, generating a corresponding heat absorption peak, thereby reflecting the respective heat absorption characteristics of the mixed alkali metal atoms during the phase transition process. Through the precise analysis of these heat flow signals, the content of each mixed alkali metal atom in the sample chamber can be calculated with high precision. During the result analysis, if it is found that the measurement result has 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 meets 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] The sample cell 26 containing mixed alkali metal atoms is placed on one side of the temperature and heat flow sensor 23, and a reference cell (i.e. reference cell 24) of the same size is placed on the other side of the temperature and heat flow sensor 23, and the sealing cover 21 is screwed tightly; the closed furnace body 22 is gradually heated, and during the process, because the melting points of the two alkali metal atoms are different, the detection curve generates two distinct absorption peaks, the absorption peak areas are calculated, and the content of the two alkali metal atoms is obtained according to the formula The content of the two alkali metal atoms is obtained respectively, and is verified with the expected content of the mixed alkali metal atoms. In this embodiment, taking the rubidium atom absorption peak as an example, the absorption peak area is 5.234 J, the heat of fusion is 25.65 J / mg, and the mass of the alkali metal rubidium can be obtained as 204 μg, which has a relative error of 2% with the theoretical calculation result, and is within an acceptable error range, and therefore accurate charging is obtained.

[0142] 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 indicated herein 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 for accurately filling an atomic gas chamber with mixed alkali metal atoms, characterized in that: The following steps are involved: Step 1: Establish a mixed alkali metal atom filling platform model using a theoretical method for precise filling and quantitative detection of mixed alkali metal atoms; Step 2: Determine the required amount of mixed alkali metal atom reactants based on 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 a temperature gradient method, including placing an alkali metal gas chamber in a low-temperature region provided by a constant temperature system, wherein the filling inlet of the alkali metal gas chamber is connected to a first reactor and a second reactor respectively through pipelines, wherein the first reactor forms an ultra-high temperature region to cause a vaporization reaction of the first alkali metal solid powder, and the first alkali metal atomic vapor enters the alkali metal gas chamber in the low-temperature region from the ultra-high temperature region through the pipeline in the high-temperature region of the oven, and the second reactor forms an ultra-high temperature region to cause a vaporization reaction of the second alkali metal solid powder, and the second alkali metal atomic vapor enters the alkali metal gas chamber in the low-temperature region from the ultra-high temperature region through the pipeline in the high-temperature region of the oven, and after completing the temperature gradient driven filling, the alkali metal gas chamber is removed; Step 4, performing 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; 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 pre-factor, 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 temperature change rate, 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.

2. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, wherein: Step 1 includes a mixed alkali metal atom filling platform, which includes an oven. A four-way glass pipe is provided in the oven. 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. Both sides of the horizontal glass pipe are connected to the alkali metal gas chamber, and the alkali metal gas chamber is located in the constant temperature system.

3. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, wherein: 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 a 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 corresponding to 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 corresponding to m Rb The amount of BaN6 required as reactant, M RbCl is the molecular weight of RbCl.

4. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, wherein: 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.

5. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, wherein: 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 pipeline with nitrogen to remove air, water vapor and other impurities; Step 302: Start the oven and perform secondary impurity removal at high temperature; Step 303: The pipeline uses a glass double pipeline. The reactors at both ends of the glass double pipeline are heated to a temperature where the solid powders react and the alkali metal atoms are vaporized. The temperature gradient drives the two alkali metal atoms to deposit into the alkali metal gas chamber. Step 304: remove the alkali metal gas cell.

6. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 1, wherein: 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.

7. The method for accurately filling an atomic gas chamber with mixed alkali metal atoms according to claim 6, 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 chamber will reach their respective phase transition temperatures in turn. The heat flow sensor monitors the temperature difference signal between the sample chamber and the reference chamber in real time, generating a corresponding heat absorption peak, thereby reflecting the respective heat absorption characteristics of the mixed alkali metal atoms during the phase transition process. The respective heat absorption characteristics are used to determine the content of each mixed alkali metal atom in the sample chamber.

Images