Method and apparatus for inhibiting reservoir effect in coated alkali metal atomic cell

Abstract

The application provides a method and device for inhibiting reservoir effect of a coated alkali metal atom gas cell, the method comprising: separately heating a bubble tail and a bubble body of a first coated gas cell placed with the bubble tail facing upwards to a first preset temperature and a second preset temperature, and maintaining the bubble tail and the bubble body at the respective preset temperatures for a first preset time, wherein the first preset temperature is greater than the second preset temperature; heating the bubble tail of the first coated gas cell naturally cooled to room temperature and placed with the bubble tail facing downwards to a third preset temperature, and maintaining the bubble tail at the third preset temperature for a second preset time; and separately heating the bubble body of the first coated gas cell naturally cooled to room temperature and placed with the bubble tail facing upwards to a fourth preset temperature, and maintaining the bubble body at the fourth preset temperature for a third preset time, so as to effectively inhibit the reservoir effect, improve the ground state polarization lifetime and anti-relaxation performance of the alkali metal atoms in the gas cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of secondary processing and performance optimization of atomic cell, and particularly relates to a method and device for inhibiting reservoir effect of plated alkali metal atomic cell. BACKGROUND

[0002] Atomic cells with long ground state polarization lifetime have wide application prospects and great application value in the fields of quantum electromagnetic sensing, optical storage and quantum frequency standard. In the implementation scheme of long ground state polarization lifetime, compared with buffer gas cell, plated atomic cell has the advantages of narrow magnetic resonance line width, low working temperature, longer polarization lifetime and smaller optical depth, and plays a core role in high-sensitivity atomic magnetometer and other quantum precision measurement applications using light and atom interaction.

[0003] For a long time, how to improve the ground state polarization lifetime of the plated atomic cell has been a key problem restricting the detection sensitivity of atomic magnetometers, atomic gyroscopes and other precision measurement instruments. For an optical atomic magnetometer based on a plated cell, the research goal is to approach the spin projection noise limit determined by spin-destruction collisions in high-temperature working at the melting temperature of the plated film, which requires extremely high anti-relaxation performance of the plated film to ensure that the longitudinal relaxation time of the cell is almost not affected by the relaxation rate of the plated film. For a general plated atomic cell, the gas exchange between the alkali metal atom reservoir in the cell body (bubble body) and the alkali metal atom reservoir in the tail (bubble tail) of the cell can cause the average effect of the anti-relaxation performance between the non-plated film region of the bubble tail and the plated film region of the bubble body, similar to a communicating vessel, which shortens the measured polarization lifetime, which is called “reservoir effect”. When the plated film has serious defects, this effect is not obvious, and is mainly limited by the intrinsic polarization lifetime in the bubble body, but it is very important in the plated cell with uniform film. By reducing the pore size of the capillary connecting the bubble body and the bubble tail, this effect can be inhibited. The existing international method for inhibiting the bubble tail reservoir effect is to add an adjustable pore size movable “glass lock” at the capillary. This method has several significant defects in practical application: first, the glass lock structure is complex, and fine parameter control needs to be added to the original design of the plated cell, which increases the complexity of application, and the reproducibility is poor. Currently, there is no precedent for successfully preparing multiple glass lock cells from the same batch of cells in international reports; secondly, the glass lock is not plated, and this part of the bare glass surface will be included in the measurement of the polarization lifetime of the bubble body after blocking the capillary, causing measurement error and shortening of the polarization lifetime. Currently, there have been reports that the measured polarization lifetime is shorter after the glass lock blocks the capillary than before, which loses the original purpose of designing the glass lock. SUMMARY

[0004] In view of the above technical problems, the application provides a method and device for inhibiting reservoir effect of a coated alkali metal atom gas cell.

[0005] In a first aspect, the application provides a method for inhibiting reservoir effect of a coated alkali metal atom gas cell, comprising:

[0006] The bubble tail and the bubble body of the first coated gas cell placed with the bubble tail upward are heated to a first preset temperature and a second preset temperature respectively, and the bubble tail and the bubble body are maintained at the respective preset temperatures for a first preset time, wherein the first preset temperature is greater than the second preset temperature;

[0007] The bubble tail of the first coated gas cell naturally cooled to room temperature and placed with the bubble tail downward is heated to a third preset temperature, and the bubble tail is maintained at the third preset temperature for a second preset time;

[0008] The bubble body of the first coated gas cell naturally cooled to room temperature and placed with the bubble tail upward is heated to a fourth preset temperature, and the bubble body is maintained at the fourth preset temperature for a third preset time;

[0009] After the bubble body is naturally cooled to room temperature, a second coated gas cell with inhibited reservoir effect is obtained.

[0010] The application provides a method for inhibiting reservoir effect of a coated alkali metal atom gas cell, which controls temperature heating of different parts of the gas cell during the maturation process of the coated gas cell, and constantly changes the placement of the gas cell. Excess molten coated material in the bubble tail and the bubble body is deposited in the capillary at the connection between the bubble tail and the bubble body under the action of gravity, and the bubble tail reservoir is sealed by the coated material, so that the reservoir effect is inhibited or even completely eliminated, and the ground state polarization lifetime and anti-relaxation performance of the alkali metal atom in the gas cell are improved.

[0011] In a possible implementation manner, the heating of the bubble body to the second preset temperature, the heating of the bubble tail to the third preset temperature, and the heating of the bubble body to the fourth preset temperature are all water bath heating;

[0012] During the water bath heating, the capillary at the connection between the bubble body and the bubble tail of the first coated gas cell is always immersed in distilled water for water bath heating.

[0013] In the embodiments of the present application, the heating scheme of water bath heating is used multiple times, which can make the coating part of the coating gas chamber uniformly heated, avoid damaging the original anti-relaxation performance of the coating gas chamber in the heating process, and be beneficial to the maintenance and improvement of the anti-relaxation performance of the coating gas chamber.

[0014] Further, the first coating gas chamber is a coating gas chamber with excess evaporation of coating material.

[0015] In the embodiments of the present application, the coating gas chamber with excess evaporation of coating material is defined as the processing object, which ensures that there is sufficient coating material in the gas chamber to block and cover the capillary tube at the connection between the bubble body and the bubble tail, and is also beneficial to coating the inner surface of the full-coating gas chamber body, thereby eliminating the negative impact of the bare glass surface on the anti-relaxation performance.

[0016] In one possible implementation, the method further includes stabilizing the atomic number density of the second coating gas chamber, including:

[0017] The second coating gas chamber is subjected to several heating and cooling operations to obtain a corresponding stable coating gas chamber, wherein the interval time between each heating and cooling operation is a fourth preset time, and each heating and cooling operation is specifically:

[0018] The bubble body of the second coating gas chamber placed with the bubble tail upwards is heated to a fifth preset temperature, and the bubble body is maintained at the fifth preset temperature for a fifth preset time.

[0019] The embodiments of the present application provide a method for stabilizing the atomic number density in the gas chamber. After obtaining the second coating gas chamber with inhibited reservoir effect, the relative stability of the atomic number density in the gas chamber in a wide temperature range can be further achieved through repeated heating. In addition, the second coating gas chamber is always in a blocked state at the capillary tube during the repeated heating process, so that the bubble tail and the bubble body do not interact to affect the relative stability of the atomic number density during the heating process. In addition, the temperature inside the bubble body is not affected by the temperature of the bubble tail during the temperature maintenance process, which further improves the stability of the atomic number density in the gas chamber and enriches the application scenarios of the present application.

[0020] Further, the fourth preset time and the fifth preset time are determined according to the atomic number density and the ground state polarization lifetime of the second coating gas chamber.

[0021] In one possible implementation, the method further includes reducing the second coating gas chamber to the first coating gas chamber, including:

[0022] The capillary tube at the connection between the bubble body and the bubble tail of the second coating gas chamber placed with the bubble tail upwards is heated to a sixth preset temperature.

[0023] continuously heating the capillary for a sixth preset time after the capillary reaches the sixth preset temperature;

[0024] After the bubble naturally cools to room temperature, a first plated film gas chamber is obtained by reducing the second plated film gas chamber.

[0025] The embodiment of the present application provides a reduction method of the plated film gas chamber for inhibiting the reservoir effect, the capillary blocked by the plated film material is dredged again by continuously heating the capillary, the reversibility and repeatability of the method for inhibiting the reservoir effect of the plated film alkali metal atom gas chamber are ensured, the application implementation is more flexible, and the inhibition of the reservoir effect of the plated film alkali metal atom gas chamber is safer.

[0026] In the second aspect, the present application provides a device for inhibiting the reservoir effect of the plated film alkali metal atom gas chamber, which is used for realizing any one of the methods for inhibiting the reservoir effect of the plated film alkali metal atom gas chamber, and the device comprises a heating furnace, a heating module and a temperature control module.

[0027] The heating furnace comprises a container and an insulation cover plate, wherein the container is used for loading the first plated film gas chamber for heating, and the insulation cover plate is used for isolating the bubble tail and the bubble body of the first plated film gas chamber during the heating process.

[0028] The heating furnace is connected with the heating module, the heating module comprises a high-temperature-resistant heating belt, two annular heating sheets, three programmable alternating current power supplies and two normally-off relays, wherein the high-temperature-resistant heating belt is wound on the surface of the container and connected with the first programmable alternating current power supply through the first normally-off relay, and is used for heating the container; the first annular heating sheet is located above the insulation cover plate and connected with the second programmable alternating current power supply through the second normally-off relay, and is used for heating the bubble tail passing through the insulation cover plate; and the second annular heating sheet is wound on the capillary at the connection position between the bubble body and the bubble tail of the first plated film gas chamber and connected with the third programmable alternating current power supply, and is used for continuously heating the capillary.

[0029] The temperature control module comprises two thermistor probes, a temperature data acquisition system and a multi-channel PID automatic control system, wherein the two thermistor probes are connected with the input end of the temperature data acquisition system, and are used for acquiring the temperature data of the preset position; and the multi-channel PID automatic control system is connected with the output end of the temperature data acquisition system and the two normally-off relays, respectively, and is used for controlling the on-off of the two normally-off relays through the temperature data, so as to control the heating temperature of the high-temperature-resistant heating belt and the first annular heating sheet.

[0030] The embodiment of the present application provides a device for inhibiting the reservoir effect of a coated alkali metal atom gas chamber, which is used for realizing any one of the methods for inhibiting the reservoir effect of the coated alkali metal atom gas chamber. The container and the heat preservation cover plate in the heating furnace can realize the isolation of different parts of the coated gas chamber, and the heating module can realize the heating of the fixed position through the programmable alternating current power supply and the corresponding connected heating belt or heating sheet, wherein the high-temperature-resistant heating belt is wound on the surface of the container, distilled water can be added into the container to realize water bath heating, and the annular heating sheet can directly heat the position contacted. Meanwhile, the device is also provided with a temperature control module, which can automatically control the heating module to heat to the preset temperature. In the heating process of the heating module, the temperature control module obtains the real-time temperature of the corresponding position through the thermistor probe, and transmits the real-time temperature to the multi-channel PID automatic control system, so that the multi-channel PID automatic control system compares the real-time temperature with the preset temperature, and controls the on-off of the normally open relay according to the comparison result, to realize the control of the heating temperature. The embodiment of the present application can automatically heat the specified position to the preset temperature while realizing the method for inhibiting the reservoir effect of the coated alkali metal atom gas chamber, and the implementation efficiency of the method is improved.

[0031] Further, the heat preservation cover plate is provided with a through hole with a preset diameter and embedded with a matched cross-shaped rubber plug, when the first coated gas chamber is placed with the bubble tail upwards, the bubble tail can pass out of the cross-shaped rubber plug and be fixed at any preset height.

[0032] In the embodiment of the present application, the through hole with a preset diameter is arranged on the heat preservation cover plate and embedded with the matched cross-shaped rubber plug, so that the coated gas chamber can pass the bubble tail out of the cross-shaped rubber plug to realize the isolated heating, and the cross-shaped rubber plug can also fix the coated gas chamber, so that the bubble body of the coated gas chamber is suspended in the heating furnace, the coated part of the coated gas chamber is uniformly heated, and the maintenance and improvement of the relaxation resistance of the coated gas chamber are facilitated.

[0033] In a possible implementation manner, the multi-channel PID automatic control system comprises an input difference module and a double-channel temperature feedback module, wherein the input difference module is used for differentiating the temperature data of two inputs to obtain the temperature difference between the two temperature data, and the double-channel temperature feedback module is used for comparing the temperature data of two inputs with the corresponding preset temperature respectively, and then controlling the on-off of the two normally open relays.

[0034] In the embodiment of the present application, the multi-channel PID automatic control system is constructed through the difference module and the double-channel temperature feedback module, so that the multi-channel PID automatic control system can adjust the on-off of the two normally open relays in real time according to the two temperature data obtained, and then accurately control the temperature difference of the bubble body and the bubble tail of the coated gas chamber in the heating and heat preservation process, to realize the differential temperature heating.

[0035] Further, the length of the second annular heating sheet is less than the length of the capillary tube, and the second annular heating sheet is provided with stone wool thermal insulation material between the second annular heating sheet and the bubble body.

[0036] In the embodiment of the present application, since the second annular heating sheet is mainly used for heating the capillary tube, thereby realizing reduction of the film-coating gas chamber, the length of the second annular heating sheet is set to be less than the length of the capillary tube, so as to avoid heating the bubble tail or the bubble body in the process of heating the capillary tube; similarly, the asbestos thermal insulation material is arranged below the second annular heating sheet, so as to avoid that the heating sheet directly contacts the film-coating bubble body under high temperature to damage the film-coating anti-relaxation performance, and the safety in the reduction process of the film-coating gas chamber is improved. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 FIG. 1 is a flowchart of a method for inhibiting the reservoir effect of a film-coated alkali metal atom gas chamber provided by the embodiment of the present application.

[0038] Figure 2 FIG. 2 is a structural schematic diagram of a device for inhibiting the reservoir effect of a film-coated alkali metal atom gas chamber provided by the embodiment of the present application in use.

[0039] Figure 3 FIG. 3 is a flowchart of a method for inhibiting the reservoir effect of a device for inhibiting the reservoir effect of a film-coated alkali metal atom gas chamber provided by the embodiment of the present application.

[0040] Figure 4 FIG. 4 is another structural schematic diagram of a device for inhibiting the reservoir effect of a film-coated alkali metal atom gas chamber provided by the embodiment of the present application in use. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0042] It should be noted that the step numbers in the text are only for the convenience of explanation of the specific embodiments, and do not serve as the function of limiting the execution sequence of the steps. In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features.

[0043] Throughout this specification, the coated gas chamber described herein is a coated alkali metal atom gas chamber, which is made by coating the inner wall of the alkali metal atom gas chamber with an anti-relaxation coating material and an anti-relaxation coating technology.

[0044] Example 1:

[0045] like Figure 1 As shown, Example 1 provides a method for suppressing the reservoir effect of alkali metal atoms in a coated film, comprising steps S1-S4:

[0046] Step S1: The bubble tail and bubble body of the first coating gas chamber, which are placed with the bubble tail facing upward, are respectively isolated and heated to a first preset temperature and a second preset temperature, and the bubble tail and bubble body are maintained at their respective preset temperatures for a first preset time, wherein the first preset temperature is greater than the second preset temperature.

[0047] Step S2: Heat the bubble tail of the first coating gas chamber, which has been naturally cooled to room temperature and is placed with the bubble tail facing down, to a third preset temperature, and maintain the bubble tail at the third preset temperature for a second preset time.

[0048] Step S3: The bubble body of the first coated air chamber, which has been naturally cooled to room temperature and is placed with the bubble tail facing upward, is isolated and heated to a fourth preset temperature, and the bubble body is maintained at the fourth preset temperature for a third preset time.

[0049] Step S4: After the bubble body cools naturally to room temperature, a second coated gas chamber with suppressed reservoir effect is obtained.

[0050] This application provides a method for suppressing the reservoir effect of coated alkali metal atoms in gas chambers. By controlling the temperature of different parts of the gas chamber during the curing process and continuously changing the placement of the gas chamber, the excess molten coating material in the bubble tail and bubble body is deposited in the capillary at the connection between the bubble tail and the bubble body by gravity. The coating material is used to seal the bubble tail reservoir, thereby suppressing or even completely eliminating the reservoir effect and improving the ground state polarization lifetime and anti-relaxation performance of alkali metal atoms in the gas chamber.

[0051] In a preferred embodiment, the first preset temperature is set to 70 degrees Celsius, the second preset temperature is set to 61 degrees Celsius, the third preset temperature is set to 63 degrees Celsius, the fourth preset temperature is set to 61 degrees Celsius, the room temperature is between 20 and 35 degrees Celsius, the first preset time is 2 hours, the second preset time is 9 hours, and the third preset time is 12 hours.

[0052] In a possible implementation, the heating of the bubble body to the second preset temperature, the heating of the bubble tail to the third preset temperature, and the heating of the bubble body to the fourth preset temperature are all water bath heating.

[0053] In the process of water bath heating, the capillary at the connection between the bubble body and the bubble tail of the first coated gas chamber is always immersed in the distilled water used for water bath heating.

[0054] In the embodiments of the present application, the heating scheme of water bath heating is used multiple times, which can make the coated part of the coated gas chamber uniformly heated, avoid damaging the original anti-relaxation performance of the coated gas chamber in the heating process, and be conducive to the maintenance and improvement of the anti-relaxation performance of the coated gas chamber.

[0055] Further, the first coated gas chamber is a coated gas chamber with excess evaporation of coating material.

[0056] In the embodiments of the present application, the coated gas chamber with excess evaporation of coating material is defined as the processing object, which ensures that there is sufficient coating material in the gas chamber to block and cover the capillary at the connection between the bubble body and the bubble tail, and is also conducive to coating the inner surface of the main body of the coated gas chamber, thereby eliminating the negative impact of the bare glass surface on the anti-relaxation performance.

[0057] In a possible implementation, after step S4 is completed, the method further includes stabilizing the atomic number density of the second coated gas chamber, including:

[0058] The second coated gas chamber is subjected to several heating and cooling operations to obtain a corresponding stable coated gas chamber, wherein the interval time between each heating and cooling operation is a fourth preset time, and each heating and cooling operation is specifically:

[0059] The bubble body of the second coated gas chamber placed with the bubble tail upward is heated to a fifth preset temperature, and the bubble body is maintained at the fifth preset temperature for a fifth preset time.

[0060] In a preferred embodiment, the fifth preset temperature is 47 degrees Celsius. Since the heating of the bubble body is isolated heating, the temperature of the bubble tail is always room temperature during this process. The fourth preset time is 30 days, and the fifth preset time is 30 minutes.

[0061] The embodiment of the present application provides a method for stabilizing the atom number density in a gas chamber. After obtaining a second coating gas chamber with inhibited reservoir effect, the relative stability of the atom number density in the gas chamber in a wide temperature range can be further achieved through repeated heating. Meanwhile, the reservoir effect is inhibited by the unique method of the present application. During the repeated heating process, the capillary of the second coating gas chamber is always in a blocked state. Therefore, the bubble tail and the bubble body do not exchange gas during the heating process, and the relative stability of the atom number density is not affected. During the temperature maintaining process, the temperature in the bubble body is not affected by the temperature of the bubble tail, and the stability of the atom number density in the gas chamber is further improved, and the application scenarios of the present application are enriched.

[0062] Further, the fourth preset time and the fifth preset time are determined according to the atom number density and the ground state polarization lifetime of the second coating gas chamber. In a preferred embodiment, the change of the atom number density and the ground state polarization lifetime in the coating gas chamber can be monitored every day in the interval time of each operation, and then the fourth preset time and the fifth preset time are dynamically adjusted. Further, the operation times of the heating and cooling operations can also be flexibly adjusted according to the change of the atom number density and the ground state polarization lifetime of the second coating gas chamber. Generally, for a paraffin coating gas chamber, the operation times of the heating and cooling operations need to be more than 3 times.

[0063] In a possible implementation manner, the method further includes reducing the second coating gas chamber to the first coating gas chamber, including:

[0064] The capillary at the connection between the bubble body and the bubble tail of the second coating gas chamber placed in the manner of the bubble tail upward is heated to a sixth preset temperature;

[0065] When the capillary reaches the sixth preset temperature, the capillary is continuously heated for a sixth preset time;

[0066] When the bubble body is naturally cooled to room temperature, the first coating gas chamber reduced from the second coating gas chamber is obtained.

[0067] In a preferred embodiment, the sixth preset temperature is set to 95 degrees Celsius, and the sixth preset time is set to 1 hour. In order to avoid the influence of the water bath heating scheme on other parts of the coating gas chamber, a heating sheet is generally used to contact heat the capillary.

[0068] The embodiment of the present application provides a reduction method of a coating gas chamber for inhibiting reservoir effect, the capillary blocked by the coating material is dredged again by continuously heating the capillary, the reversibility and repeatability of the method for inhibiting reservoir effect of the coating alkali metal atom gas chamber are ensured, the application is more flexible, and the inhibition of the reservoir effect of the coating alkali metal atom gas chamber is safer. For example, after a second coating gas chamber with poor performance is obtained due to improper operation, the second coating gas chamber can be reduced to a first coating gas chamber, and irreversible damage to the coating gas chamber is avoided.

[0069] Embodiment two:

[0070] Correspondingly, the embodiment two provides a device for inhibiting reservoir effect of a coating alkali metal atom gas chamber, the device is used for realizing any one of the methods for inhibiting reservoir effect of the coating alkali metal atom gas chamber, and the device comprises a heating furnace, a heating module and a temperature control module.

[0071] The heating furnace comprises a container and an insulation cover plate, the container is used for loading a first coating gas chamber for heating, and the insulation cover plate is used for isolating a bubble tail and a bubble body of the first coating gas chamber during the heating process.

[0072] The heating furnace is connected with the heating module, the heating module comprises a high-temperature-resistant heating belt, two annular heating sheets, three programmable alternating current power supplies and two normally-off relays, the high-temperature-resistant heating belt is wound on the surface of the container and connected with the first programmable alternating current power supply through the first normally-off relay, is used for heating the container, the first annular heating sheet is located above the insulation cover plate and connected with the second programmable alternating current power supply through the second normally-off relay, is used for heating the bubble tail passing through the insulation cover plate, and the second annular heating sheet is wound on the capillary at the connection position between the bubble body and the bubble tail of the first coating gas chamber and connected with the third programmable alternating current power supply, and is used for continuously heating the capillary.

[0073] The temperature control module comprises two thermistor probes, a temperature data acquisition system and a multi-channel PID automatic control system, the two thermistor probes are connected with the input end of the temperature data acquisition system and used for acquiring temperature data of preset positions, and the multi-channel PID automatic control system is connected with the output end of the temperature data acquisition system and the two normally-off relays respectively, is used for controlling the on-off of the two normally-off relays through the temperature data, and then controlling the heating temperature of the high-temperature-resistant heating belt and the first annular heating sheet.

[0074] The embodiment of the present application provides a device for inhibiting reservoir effect of a coated alkali metal atom gas chamber, which is used for realizing any one of the methods for inhibiting reservoir effect of the coated alkali metal atom gas chamber. The container and the heat preservation cover plate in the heating furnace can realize isolation of different parts of the coated gas chamber, and the heating module can realize heating of the fixed position through the programmable alternating current power supply and the corresponding connected heating belt or heating sheet, wherein the high-temperature-resistant heating belt is wound on the surface of the container, distilled water can be added into the container to realize water bath heating, and the annular heating sheet can directly heat the position contacted. Meanwhile, the device is also provided with a temperature control module, which can automatically control the heating module to heat to the preset temperature. In the heating process of the heating module, the temperature control module obtains the real-time temperature of the corresponding position through the thermistor probe, and transmits the real-time temperature to the multi-channel PID automatic control system, so that the multi-channel PID automatic control system compares the real-time temperature with the preset temperature, and controls the on-off of the normally open relay according to the comparison result, to realize control of the heating temperature. The embodiment of the present application can automatically heat the specified position to the preset temperature while realizing the method for inhibiting reservoir effect of the coated alkali metal atom gas chamber, and the implementation efficiency of the method is improved.

[0075] Further, the heat preservation cover plate is provided with a through hole with a preset diameter and embedded with a matched cross-shaped rubber plug, when the first coated gas chamber is placed with the bubble tail upwards, the bubble tail can pass through the cross-shaped rubber plug and be fixed at any preset height.

[0076] In the embodiment of the present application, the through hole with a preset diameter is arranged on the heat preservation cover plate and embedded with the matched cross-shaped rubber plug, so that the bubble tail of the coated gas chamber can pass through the cross-shaped rubber plug to realize isolated heating, and the cross-shaped rubber plug can also fix the coated gas chamber, so that the bubble body of the coated gas chamber is suspended in the heating furnace, the coated part of the coated gas chamber is uniformly heated, and the maintenance and improvement of the relaxation resistance of the coated gas chamber are facilitated.

[0077] In a possible implementation manner, the multi-channel PID automatic control system comprises an input difference module and a double-channel temperature feedback module, wherein the input difference module is used for differentiating the temperature data of two input channels to obtain the temperature difference between the two temperature data, and the double-channel temperature feedback module is used for comparing the temperature data of two input channels with the corresponding preset temperature respectively, and then controlling the on-off of the two normally open relays.

[0078] In the embodiment of the present application, the multi-channel PID automatic control system is constructed through the difference module and the double-channel temperature feedback module, so that the multi-channel PID automatic control system can adjust the on-off of the two normally open relays in real time according to the two temperature data obtained, and then accurately control the temperature difference of the bubble body and the bubble tail of the coated gas chamber in the heating and heat preservation process, to realize differential temperature heating.

[0079] Further, the length of the second annular heating sheet is less than the length of the capillary tube, and the second annular heating sheet is provided with stone wool thermal insulation material between the second annular heating sheet and the bubble body.

[0080] In the embodiment of the present application, since the second annular heating sheet is mainly used for heating the capillary tube, and then realizing the reduction of the coating gas chamber, the length of the second annular heating sheet is set to be less than the length of the capillary tube, so as to avoid the heating of the capillary tube to the bubble tail or the bubble body in the process of heating. Similarly, the asbestos thermal insulation material is arranged below the second annular heating sheet, so as to avoid the direct contact of the heating sheet at high temperature with the coating bubble body to damage the coating relaxation resistance, and improve the safety in the reduction process of the coating gas chamber.

[0081] In a preferred embodiment, a structure diagram of the device for inhibiting the reservoir effect of the coating alkali metal atom gas chamber is shown in Figure 2 The device includes a high-temperature-resistant heating belt 1, a boron nitride heating furnace 2, distilled water 3, a gas chamber bubble body 4, a connecting capillary tube 5, a first detachable annular heating sheet 6, a first waterproof thermistor probe 7, a temperature data acquisition system 8, a multi-channel PID automatic control system 9, a first normally open relay 10, a first programmable AC power supply 11, a first control output port 12, a second control output port 13, a second programmable AC power supply 14, a second normally open relay 15, a gas chamber bubble tail 16, a second detachable annular heating sheet 17, a third programmable AC power supply 18, a heat preservation cover plate 19, and a second waterproof thermistor probe 20.

[0082] The gas chamber bubble body 4 and the connecting capillary tube 5 are integrally immersed in the distilled water 3 in the boron nitride heating furnace 2, the heating furnace 2 is covered with the heat preservation cover plate 19, the heat preservation cover plate 19 is provided with a hole, and the first waterproof thermistor probe 7 and other heating devices can enter the inside of the heating furnace 2. The second detachable annular heating sheet 17 is wound and fixed outside the gas chamber bubble tail 16, and is controlled to heat by the second programmable AC power supply 14 and the normally open relay 15. The first detachable annular heating sheet 6 is wound outside the connecting capillary tube 5, and is controlled to heat by the third programmable AC power supply 18. The waterproof thermistor probes 7 and 20 are respectively fixed on the outer surfaces of the gas chamber bubble body 4 and the gas chamber bubble tail 16, and the other ends are connected with the input ports of the temperature data acquisition system 8. The high-temperature-resistant heating belt 1 is uniformly wound outside the boron nitride heating furnace 2, and is controlled to heat by the first programmable AC power supply 11 and the normally open relay 10.

[0083] The output port of the temperature data acquisition system 8 is connected to the input end of the multi-channel PID automatic control system 9, the control output ports 12 and 13 are respectively connected to the two normally-off relays 10 and 15 of the programmable AC power supply 11 and 14, and the on-off of the normally-off relays 10 and 15 is controlled through the temperature information provided by the temperature data acquisition system 8, so as to control the heating power of the corresponding boron nitride heating furnace and bubble tail, and realize the purpose of temperature separate regulation.

[0084] Further, as shown in Figure 3 The specific steps of the method for inhibiting the reservoir effect of the alkali metal atom gas chamber of the coated film by using the above device are as follows:

[0085] 1) Prepare a coated film gas chamber with excess evaporation of coated film material.

[0086] 2) Phase one: keep the programmable AC power supply 11, 14 and 18 off, inject sufficient distilled water 3 into the boron nitride heating furnace 2, place the gas chamber bubble tail 16 upwards into the heating furnace, and pass the bubble tail through the cross-shaped rubber plug on the heat preservation cover plate 19 to be fixed at a height so that the gas chamber bubble body 4 and the connecting capillary 5 are completely immersed in the distilled water 3; the two waterproof thermistor probes 7 and 20 are respectively fixed on the side walls of the gas chamber bubble body 4 and the gas chamber bubble tail 16.

[0087] 3) Set the first preset temperature and the second preset temperature of phase one of the multi-channel PID automatic control system 9: bubble tail 70℃, bubble body (water temperature) 61℃, turn on the programmable AC power supply 11 and 14, when the measured temperature of the waterproof thermistor probes 7 and 20 is lower than the set initial working temperature, the normally-off relays 10 and 15 are closed, and the high-temperature resistant heating band 1 and the detachable annular heating sheet 17 respectively perform AC heating on the bubble body 4 (inside the heating furnace 2) and the bubble tail 16.

[0088] 4) When the measured temperature of the two waterproof thermistor probes 7 and 20 reaches the first preset temperature and the second preset temperature for the first time, enter the temperature control maintaining stage of phase one, the multi-channel PID automatic control system 9 receives the data input by the temperature data acquisition system 8, controls the on-off of the normally-off relays 10 and 15 through the output ports 12 and 13 respectively, so as to maintain the temperature difference between the gas chamber bubble body 4 and the gas chamber bubble tail 16 for 2 hours, and then turn off the programmable AC power supply 11 and 14 to naturally cool the gas chamber bubble tail 16 and the gas chamber bubble body 4 to room temperature.

[0089] 5) Phase two: remove the second detachable annular heating sheet 17 and open the heat preservation cover plate 19, take out the coated film gas chamber which has been cooled to room temperature and place the gas chamber bubble tail 16 upside down into the boron nitride heating furnace 2 again, and fix the two waterproof thermistor probes 7 and 20 on the distilled water 3 and the bubble body 4 respectively. During the processing of phase two, the connecting capillary 5 is always immersed in the distilled water 3, and the schematic diagram of the device in phase two is as followsFigure 4 as shown.

[0090] 6) Set the third preset temperature of stage two for the multi-channel PID automatic control system 9: the temperature of the bubble body 4 (water temperature) is set to 63°C. During the process of stage two, the second waterproof thermistor probe 20 attached to the bubble body 4 always monitors the temperature of the air above the boron nitride heating furnace 2.

[0091] 7) When the measured temperature of the first waterproof thermistor probe 7 fixed in the distilled water 3 first reaches the third preset temperature, enter the stage two temperature control maintenance stage, maintain the current working temperature for 9 hours, and then turn off the first programmable AC power supply 11 to cool the interior of the boron nitride heating furnace 2 to room temperature.

[0092] 8) Stage three: repeat the placement and heating method of the coated gas chamber bubble in stage one, except that the bubble tail 16 is not heated, so that the bubble tail 16 always maintains room temperature. Set the fourth preset temperature of stage three for the multi-channel PID automatic control system 9: the temperature of the bubble body 4 (water temperature) is 61°C.

[0093] 9) When the measured temperature of the first waterproof thermistor probe 7 fixed in the bubble body 4 first reaches the fourth preset temperature, enter the stage three temperature control maintenance stage, maintain the current distilled water 3 temperature for 12 hours, then turn off the first programmable AC power supply 11 to naturally cool the interior of the boron nitride heating furnace 2 to room temperature, and obtain a second coated gas chamber with inhibited reservoir effect.

[0094] 10) According to different subsequent needs for the working performance of the coated gas chamber: if atomic number density in the gas chamber needs to be stabilized, steps 11 and 12 are performed; if gas exchange between the reservoir and the bubble body 4 needs to be restored, steps 13 and 14 are performed.

[0095] 11) Repeat the placement and heating method of the coated gas chamber bubble in stage one, except that the bubble tail 16 is not heated, so that the bubble tail 16 always maintains room temperature. Set the fifth preset temperature for the multi-channel PID automatic control system 9: the temperature of the bubble body 4 (water temperature) is 47°C. During the heating process, since the connecting capillary 5 has been blocked, fluctuations in the temperature of the bubble tail 16 will not affect the maintenance of the temperature of the bubble body 4.

[0096] 12) When the measured temperature of the first waterproof thermistor probe 7 attached to the bubble body 4 first reaches the fifth preset temperature in step 11, enter the temperature control maintenance stage, maintain the current distilled water 3 temperature for 30 minutes, then turn off the first programmable AC power supply 11 to naturally cool the interior of the boron nitride heating furnace 2 to room temperature. Steps 11 and 12 form a cycle, and the interval between single cycles is 30 days.

[0097] 13) Keep the programmable AC power supply 11, 14, 18 off, empty the distilled water 3 in the boron nitride heating furnace 2, put the film-coated gas chamber bubble tail 16 to be treated upside down into the heating furnace 2, the gas chamber bubble tail 16 passes through the cross-shaped rubber plug on the heat preservation cover plate 19 and is fixed, the second waterproof thermistor probe 20 is fixed on the connecting capillary 5 of the film-coated gas chamber, and the other end is connected to the temperature data acquisition system 8; and the sixth preset temperature is set for the multi-channel PID automatic control system 9: the connecting capillary 5 temperature is 95℃, and the programmable AC power supply 18 heats the connecting capillary 5 by the first detachable annular heating sheet. In this step, the negative effects of the water bath heating scheme on other parts of the gas chamber except the connecting capillary 5 are excluded.

[0098] 14) When the second waterproof thermistor probe 20 attached to the connecting capillary 5 measures the temperature to reach the sixth preset temperature in step 13 for the first time, keep the same current to continue heating, and count 1 hour, then turn off the programmable AC power supply 18, and let the boron nitride heating furnace 2 cool naturally to room temperature.

[0099] Wherein, the second detachable annular heating sheet 17 is a single-layer flexible PCB circuit board, which is tightly attached to the gas chamber bubble tail 16 in the heating process of phase one, the second waterproof thermistor probe 20 is fixed on the outside of the second detachable annular heating sheet 17 through the heat-conducting tape, and the first waterproof thermistor probe 7 enters the inside of the boron nitride heating furnace 2 through the cross-shaped rubber plug on the heat preservation cover plate 19 and is fixed on the inner side wall of the bubble body 4 through the heat-conducting tape. In phase two, when the gas chamber bubble tail 16 is inverted downward, the film-coated gas chamber does not need additional physical support, and relying on its own gravity can make the whole gas chamber bubble tail 16, connecting capillary 5 and part of the gas chamber bubble body 4 immersed in the distilled water 3.

[0100] In a preferred embodiment, the inhibition effect of the film-coated gas chamber reservoir effect by using the method and device provided in the present application is shown in Table 1. From the change of polarization life before and after the capillary plugging in Table 1, it can be concluded that the present application can effectively inhibit the reservoir effect, improve the ground state polarization life and anti-relaxation performance of alkali metal atoms in the gas chamber.

[0101] Table 1

[0102]

[0103] The above-described specific embodiments, purposes, technical solutions and beneficial effects of the present application are further described in detail, and it should be understood that the above-described is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of inhibiting reservoir effects in a coated alkali metal atom cell, comprising: The method comprises the following steps: heating the bubble tail and the bubble body of the first plated film gas cell placed with the bubble tail upward to first and second preset temperatures respectively, and maintaining the bubble tail and the bubble body at the respective corresponding preset temperatures for a first preset time, wherein the first preset temperature is greater than the second preset temperature, and the first plated film gas cell is a plated film gas cell with excess evaporation of plated film material; heating the bubble tail of the first plated film gas cell naturally cooled to room temperature and placed with the bubble tail downward to a third preset temperature, and maintaining the bubble tail at the third preset temperature for a second preset time; heating the bubble body of the first plated film gas cell naturally cooled to room temperature and placed with the bubble tail upward to a fourth preset temperature, and maintaining the bubble body at the fourth preset temperature for a third preset time; after the bubble body is naturally cooled to room temperature, obtaining a second plated film gas cell with reservoir effect inhibited; the heating of the bubble body to the second preset temperature, the heating of the bubble tail to the third preset temperature, and the heating of the bubble body to the fourth preset temperature are all water bath heating; during the water bath heating, the capillary at the connection between the bubble body and the bubble tail of the first plated film gas cell is always immersed in distilled water for water bath heating.

2. A method of suppressing reservoir effects in a coated alkali metal atomic cell as defined in claim 1, wherein, The method further comprises stabilizing the atomic number density of the second plated film gas cell, comprising: performing a plurality of heating and cooling operations on the second plated film gas cell to obtain a corresponding stable plated film gas cell, wherein the interval time between each heating and cooling operation is a fourth preset time, and each heating and cooling operation specifically comprises: heating the bubble body of the second plated film gas cell placed with the bubble tail upward to a fifth preset temperature without heating the bubble tail, and maintaining the bubble body at the fifth preset temperature for a fifth preset time, and then naturally cooling the bubble body to room temperature.

3. A method of suppressing reservoir effects in a coated alkali metal atomic cell as defined in claim 2, wherein, The fourth and fifth preset times are determined according to the atomic number density and ground state polarization lifetime of the second plated film gas cell.

4. A method of suppressing reservoir effects in a coated alkali metal atom cell as defined in claim 1, wherein The method further comprises reducing the second plated film gas cell to the first plated film gas cell, comprising: heating the capillary at the connection between the bubble body and the bubble tail of the second plated film gas cell placed with the bubble tail upward to a sixth preset temperature; continuing to heat the capillary for a sixth preset time after the capillary reaches the sixth preset temperature; after the bubble body is naturally cooled to room temperature, obtaining the first plated film gas cell reduced from the second plated film gas cell.

5. An apparatus for inhibiting reservoir effects in a coated alkali metal atom cell, comprising: The device is used to implement a method for inhibiting reservoir effect of a plated film alkali metal atom gas cell according to any one of claims 1-4, and the device comprises a heating furnace, a heating module, and a temperature control module; wherein the heating furnace comprises a container and an insulation cover plate, wherein the container is used to load the first plated film gas cell for heating, and the insulation cover plate is used to isolate the bubble tail and the bubble body of the first plated film gas cell during heating; The heating furnace is connected with the heating module outside, the heating module comprises a high-temperature-resistant heating belt, two annular heating sheets, three programmable alternating current power supplies and two always-off relays, wherein the high-temperature-resistant heating belt is wound on the surface of the container and connected with the first programmable alternating current power supply through the first always-off relay for heating the container, the first annular heating sheet is located above the heat preservation cover plate and connected with the second programmable alternating current power supply through the second always-off relay for heating the bubble tail passing through the heat preservation cover plate, and the second annular heating sheet is wound on the capillary at the connection between the bubble body and the bubble tail of the first film-coated air chamber and connected with the third programmable alternating current power supply for continuously heating the capillary. The temperature control module comprises two thermistor probes, a temperature data acquisition system and a multi-channel PID automatic control system, wherein the two thermistor probes are connected with the input end of the temperature data acquisition system for acquiring temperature data at preset positions, and the multi-channel PID automatic control system is connected with the output end of the temperature data acquisition system and the two always-off relays respectively for controlling the on-off of the two always-off relays through temperature data, thereby controlling the heating temperature of the high-temperature-resistant heating belt and the first annular heating sheet.

6. A device for inhibiting reservoir effects in a coated alkali metal atom cell as defined in claim 5, wherein, The heat preservation cover plate is provided with a through hole with a preset diameter and embedded with a matched cross-shaped rubber plug, when the first film-coated air chamber is placed with the bubble tail upward, the bubble tail can pass through the cross-shaped rubber plug and be fixed at any preset height.

7. A device for inhibiting reservoir effects in a coated alkali metal atom cell as defined in claim 5, wherein, The multi-channel PID automatic control system comprises an input difference module and a double-channel temperature feedback module, wherein the input difference module is used for differentiating the two-way input temperature data to obtain the temperature difference between the two-way temperature data, and the double-channel temperature feedback module is used for comparing the two-way input temperature data with the corresponding preset temperature respectively, thereby controlling the on-off of the two always-off relays.

8. A device for inhibiting reservoir effects in a coated alkali metal atom cell as defined in claim 5, wherein, The length of the second annular heating sheet is less than the length of the capillary, and the second annular heating sheet is padded with stone wool thermal insulation material between the bubble body.

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