Uniform heating device for NMRG atomic gas chamber

Abstract

The invention discloses a uniform heating device for an NMRG atomic gas chamber, and belongs to the technical field of quantum inertial sensing. The non-magnetic heat shielding layer wraps the outside of the full-transparent sealed heating cavity, the supporting structure is fixed in the full-transparent sealed heating cavity and used for fixing the atomic gas chamber to the center of the heating cavity, the full-transparent sealed heating cavity is filled with the heat conduction liquid, and the atomic gas chamber is completely soaked in the heat conduction liquid. The thermistor is arranged in the sealed heating cavity and soaked in the heat conduction liquid, and a thermistor wire is connected to external equipment of the non-magnetic heat shielding layer; the surface of the outer side of the full-transparent sealed heating cavity is plated with an ITO transparent conductive film, and the ITO transparent conductive film can heat the heat conduction liquid and the atomic gas chamber in the full-transparent sealed heating cavity after being electrified; and the heat-conducting liquid is matched with the refractive index of the atomic gas chamber shell material. The heating uniformity and stability of the atomic gas chamber are improved, meanwhile, the integration level of the atomic gas chamber is improved, and the influence of light beam deflection of the heating cavity on gyro signals is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum inertial sensing, and particularly relates to a uniform heating device for an NMRG atomic gas cell. Background Art

[0002] Nuclear magnetic resonance gyroscope (NMRG) is a new type of gyroscope with small volume, low power consumption and high precision. It is the preferred solution for the next generation of high-precision micro gyroscopes and has currently become a research hotspot in the field of inertial navigation.

[0003] As the core component of NMRG, the atomic gas cell provides the atomic medium for NMRG to work. To increase the atomic number density, the atomic gas cell needs to be heated uniformly and stably. Existing heating methods include hot air flow heating, intermittent heating, laser heating and high-frequency heating. The hot air flow heating has good uniformity but poor stability. Intermittent heating limits the bandwidth of the gyro. Laser heating has a small power and is unstable. Although high-frequency heating can achieve a stable and magnetic-free heating effect, it is limited by the existing optical through-hole design of the heating cavity and cannot achieve uniform heating. In order to improve the measurement accuracy of NMRG, it is urgent to find a heating method for the atomic gas cell with high stability, good uniformity and little magnetic field influence.

[0004] Publication No. CN115752407A proposes a heating and homogenizing device for a SERF atomic gas cell, which immerses the atomic gas cell in a sealed ceramic oven with a fluorine-bromine component liquid to achieve uniform heating. However, this device embeds glass in the optical through-hole of the oven to seal the homogenizing liquid, and at the same time sets spiral grooves on the outer surface of the oven for embedding twisted heating wires, with low integration and increased device complexity; using a fluorine-bromine component liquid as the homogenizing liquid, the refractive index is quite different from that of the commonly used atomic gas cell housing material BF33 glass, and the light beam is prone to deflection, which is not conducive to the adjustment and control of the optical path. Summary of the Invention

[0005] Aiming at the above deficiencies in the prior art, the present invention provides a uniform heating device for NMRG atoms. By utilizing the stable and uniform characteristics of water bath heating, using high-purity industrial glycerol with a refractive index close to that of BF33 glass as the heat-conducting liquid, immersing the atomic gas cell in a fully transparent sealed heating cavity, and plating an ITO transparent conductive film on the outer surface of the heating cavity, the uniformity and stability of the atomic gas cell heating are improved. At the same time, the integration of the atomic gas cell heating structure is improved, and the influence of the light beam deflection in the heating cavity on the gyro signal is reduced.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A uniform heating device for an NMRG atomic gas cell, comprising a non-magnetic thermal shielding layer, a fully transparent sealed heating chamber, a heat-conducting liquid, and a thermistor; the non-magnetic thermal shielding layer is coated outside the fully transparent sealed heating chamber, a support structure is fixed inside the fully transparent sealed heating chamber for fixing the atomic gas cell at the center of the heating chamber, the heat-conducting liquid fills the inside of the fully transparent sealed heating chamber, the atomic gas cell is completely immersed in the heat-conducting liquid, the thermistor is placed inside the sealed heating chamber and immersed in the heat-conducting liquid, and the thermistor wire is connected to an external device outside the non-magnetic thermal shielding layer; an ITO transparent conductive film is plated on the outer surface of the fully transparent sealed heating chamber, which can heat the heat-conducting liquid and the atomic gas cell inside the fully transparent sealed heating chamber after being electrified; the refractive index of the heat-conducting liquid matches that of the atomic gas cell housing material.

[0008] As a preference of the present invention, the non-magnetic thermal shielding layer is made of a material with non-magnetic, insulating, low thermal conductivity, and high support strength; preferably, the thermal conductivity is 0.001 - 0.1 W / (m·K).

[0009] As a preference of the present invention, the non-magnetic thermal shielding layer includes two parts, a thermal shielding chamber and a thermal shielding cover, which are bonded by a high-temperature-resistant adhesive with low thermal conductivity. A light-passing hole is opened at the center of each of the front, back, left, and right sides of the thermal shielding chamber, and the positions of the light-passing holes match those of the atomic gas cell.

[0010] As a preference of the present invention, the fully transparent sealed heating chamber is made of BF33 glass, the inner and outer surfaces of the heating chamber are polished, and an optical antireflection film is plated on the inner surface.

[0011] As a preference of the present invention, the heat-conducting liquid is industrial glycerol with a purity greater than 99.5%.

[0012] As a preference of the present invention, the thermistor uses a PTC platinum thermistor.

[0013] As a preference of the present invention, the fully transparent sealed heating chamber includes a heating chamber body and a heating chamber upper cover, and a support structure is fixedly installed on the bottom of the heating chamber body and the inner side of the heating chamber upper cover.

[0014] As a preference of the present invention, the support structure includes four upright plate-like components. One side of each plate-like component is fixed to the bottom of the heating chamber body or the inner side of the heating chamber upper cover, and the other side extends outward. The four plate-like components are distributed in a cross shape around the center and are opposite to each other in pairs. There is a gap between the plate-like components to form an open space; the support structure fixed to the bottom of the heating chamber body and the support structure fixed to the inner side of the heating chamber upper cover are arranged in an up-and-down corresponding manner, and the space enclosed therebetween is used to fix the atomic gas cell.

[0015] As a preference of the present invention, the material of the fully transparent sealed heating chamber is BF33 glass.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) The present invention uses high-purity industrial glycerol as the heat-conducting liquid, with a refractive index of 1.474, which is close to the refractive index of 1.4714 of the common BF33 glass used for the outer shell of the atomic gas chamber. At the same time, the BF33 glass is used to make a fully transparent sealed heating chamber to ensure that the refractive indices of the heating chamber, the heat-conducting liquid, and the outer shell of the atomic gas chamber are the same, avoiding the beam deflection caused by different refractive indices, which is beneficial to the adjustment of the optical path and the improvement of the gyro accuracy. In addition, industrial glycerol has stable properties and a high specific heat capacity, and the temperature fluctuation is smaller under the same environment, which is beneficial to improving the temperature stability of the atomic gas chamber.

[0018] (2) The present invention coats ITO transparent conductive films on the six outer surfaces of the fully transparent sealed heating chamber. After being energized, it heats the heat-conducting liquid and the atomic gas chamber, integrating the heating device with the sealed heating chamber, which not only ensures the light transmission but also realizes uniform heating, improving the integration degree of the atomic gas chamber and the heating uniformity.

[0019] (3) The present invention places the thermistor inside the fully transparent sealed heating chamber and immerses it in industrial glycerol together with the atomic gas chamber, which can more accurately measure the temperature of the atomic gas chamber and avoid the temperature measurement error caused by non-contact temperature measurement.

[0020] (4) The present invention immerses the atomic gas chamber in the heat-conducting liquid and heats it through the fully transparent sealed heating chamber, so that each surface of the atomic gas chamber is uniformly heated, avoiding the temperature gradient caused by the inability to heat the light-transmitting part of the traditional heating structure and improving the heating uniformity of the atomic gas chamber. Brief Description of the Drawings

[0021] Figure 1 is a sectional view of the device of the present invention;

[0022] Figure 2 is an assembly schematic diagram of the fully transparent sealed heating chamber, the heat-conducting liquid, and the atomic gas chamber;

[0023] Figure 3 is an exploded view of the fully transparent sealed heating chamber and the atomic gas chamber;

[0024] Figure 4 is a schematic diagram of the shape of the upper cover of the fully transparent sealed heating chamber and the supporting structure fixed inside the heating chamber;

[0025] Figure 5 is a sectional view of the heat shielding chamber;

[0026] Figure 6 is an exploded view of the device of the present invention;

[0027] In the figure: 101 thermal shielding cover, 102 thermal shielding cavity, 103 light passing hole, 104 upper cover of the heating cavity, 105 heating cavity body, 106 atomic gas cell, 107 heat-conducting liquid, 108 support structure, 109 thermistor. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] The present invention provides a uniform heating device for an NMRG atomic gas cell, as Figure 1 and Figure 6 shown, which includes a non-magnetic thermal shielding layer, a fully transparent sealed heating cavity, a heat-conducting liquid 107, and a thermistor 109.

[0030] The non-magnetic thermal shielding layer is placed on the outermost side of the device and consists of two parts: a thermal shielding cover 101 and a thermal shielding cavity 102. The cross-sectional view of the thermal shielding cavity 102 is as Figure 5 shown. The thermal shielding cover 101 and the thermal shielding cavity 102 are bonded by a high-temperature-resistant adhesive with low thermal conductivity to protect the fully transparent sealed heating cavity inside and minimize heat transfer with the external environment. The non-magnetic thermal shielding layer is made of materials with non-magnetic, insulating, low thermal conductivity, and high support strength, including but not limited to polyether ether ketone (PEEK), polytetrafluoroethylene, polyimide, etc. A groove is reserved on the thermal shielding cover 101 to connect the power supply wires of the ITO transparent conductive film on the outer shell of the fully transparent sealed heating cavity and the wires of the thermistor 109 to the outside. A light passing hole 103 is opened on each of the front, back, left, and right faces of the thermal shielding cavity 102, and the position of the light passing hole 103 matches that of the atomic gas cell 106.

[0031] The fully transparent sealed heating cavity includes two parts: an upper cover 104 of the fully transparent sealed heating cavity and a body 105 of the fully transparent sealed heating cavity. The two parts are fixed by a high-temperature-resistant heat-conducting adhesive. The support structure 108 is fixed inside the body 105 of the fully transparent sealed heating cavity by a high-temperature-resistant heat-conducting adhesive, that is, a pair of support structures 108 are respectively fixed at the bottom of the heating cavity body 105 and the inner side of the upper cover 104 of the heating cavity, as Figures 2-4As shown, the support structure 108 includes four upright plate-like components. One side of each plate-like component is fixed to the bottom of the heating chamber cavity 105 or the inner side of the upper cover 104 of the heating chamber, and the other side extends towards the periphery. The four plate-like components are distributed in a cross shape around the center, facing each other in pairs, and there are intervals between the plate-like components to form an open space; the support structure 108 fixed to the bottom of the heating chamber cavity 105 and the support structure 108 fixed to the inner side of the upper cover 104 of the heating chamber are arranged corresponding to each other up and down, and the space enclosed therebetween is used to fix the atomic gas chamber 106. Under this design, it is possible to support and limit the eight corners of the atomic gas chamber 106 in the horizontal and vertical directions, and fix the atomic gas chamber 106 at the center of the heating chamber. The heat-conducting liquid 107 fills the inside of the fully transparent sealed heating chamber, so that the atomic gas chamber 106 is immersed in the heat-conducting liquid 107, and the thermistor 109 is also placed inside the sealed heating chamber and immersed in the heat-conducting liquid 107. During encapsulation, first place the thermistor 109 in the empty fully transparent sealed heating chamber cavity 105. Both ends of the thermistor 109 are connected to two wires, and the wires pass through the small holes reserved on the upper cover 104 of the heating chamber to the outside of the heating chamber. Subsequently, bond the upper cover 104 of the fully transparent sealed heating chamber and the cavity 105 of the fully transparent sealed heating chamber with a high-temperature heat-conducting adhesive. Then, inject the heat-conducting liquid 107 into the fully transparent sealed heating chamber through the small holes reserved on the upper cover 104 of the heating chamber with a syringe until it is full. Finally, seal the small holes with a curing structural adhesive, and the curing structural adhesive used includes but is not limited to silicone rubber, epoxy resin, etc.

[0032] In a specific implementation of the present invention, the heat-conducting liquid 107 uses high-purity industrial glycerol (purity greater than 99.5%) with a high specific heat capacity, colorless and transparent, stable physical and chemical properties, and a refractive index close to that of the common atomic gas chamber outer shell material BF33 glass, and the thermistor 109 uses a PTC platinum thermistor with little influence of residual magnetism.

[0033] In a specific implementation of the present invention, the fully transparent sealed heating chamber is made of BF33 glass, which is the same as the common atomic gas chamber outer shell material. The six inner and outer surfaces of the heating chamber are polished, and an optical antireflection film is plated on the inner side; the six outer surfaces of the fully transparent sealed heating chamber are plated with an ITO transparent conductive film, which can heat the heat-conducting liquid 107 and the atomic gas chamber 106 inside the heating chamber after being powered on.

[0034] The above embodiments are used to explain and illustrate the present invention, rather than limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the protection of the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A uniform heating device for an NMRG atomic gas cell, characterized in that It includes a non-magnetic thermal shielding layer, a fully transparent sealed heating cavity, a heat-conducting liquid (107), and a thermistor (109); the non-magnetic thermal shielding layer is coated outside the fully transparent sealed heating cavity, a support structure (108) is fixed inside the fully transparent sealed heating cavity for fixing the atomic gas cell (106) at the center of the heating cavity, the heat-conducting liquid (107) fills the inside of the fully transparent sealed heating cavity, the atomic gas cell (106) is completely immersed in the heat-conducting liquid (107), the thermistor (109) is placed inside the sealed heating cavity and immersed in the heat-conducting liquid (107), and the wires of the thermistor (109) are connected to external devices outside the non-magnetic thermal shielding layer; an ITO transparent conductive film is plated on the outer surface of the fully transparent sealed heating cavity, which can heat the heat-conducting liquid (107) and the atomic gas cell (106) inside the fully transparent sealed heating cavity after being powered on; the refractive index of the heat-conducting liquid (107) matches that of the outer shell material of the atomic gas cell (106).

2. The uniform heating device for an NMRG atomic gas cell according to claim 1, characterized in that, The non-magnetic thermal shielding layer is made of a non-magnetic, insulating, and low heat-conductivity material.

3. The uniform heating device for an NMRG atomic gas cell according to claim 1 or 2, characterized in that, The non-magnetic thermal shielding layer includes two parts, a thermal shielding cavity (102) and a thermal shielding cover (101), which are bonded by a high-temperature-resistant adhesive with low heat conductivity. A light-passing hole (103) is opened at the center of each of the front, back, left, and right sides of the thermal shielding cavity (102), and the light-passing holes are matched with the positions of the atomic gas cells.

4. The uniform heating device for an NMRG atomic gas cell according to claim 1, wherein, The fully transparent sealed heating cavity is made of BF33 glass, and the inner and outer surfaces of the heating cavity are polished, and an optical antireflection film is plated on the inner surface.

5. The uniform heating device for the NMRG atomic gas cell according to claim 1, wherein, The heat-conducting liquid (107) is industrial glycerol with a purity greater than 99.5%.

6. The uniform heating device for an NMRG atomic gas cell according to claim 1, wherein The thermistor (109) uses a PTC platinum thermistor.

7. The uniform heating device for an NMRG atomic gas cell according to claim 1, characterized in that, The fully transparent sealed heating cavity includes a heating cavity body (105) and a heating cavity upper cover (104), and a support structure (108) is fixedly installed at the bottom of the heating cavity body (105) and the inner side of the heating cavity upper cover (104).

8. The uniform heating device for an NMRG atomic gas cell according to claim 7, wherein, The support structure includes four upright plate-shaped components. One side of each plate-shaped component is fixed to the bottom of the heating cavity body (105) or the inner side of the heating cavity upper cover (104), and the other side extends towards the periphery. The four plate-shaped components are distributed in a cross shape around the center and are opposite to each other in pairs. There is a gap between the plate-shaped components to form an open space; the support structure fixed to the bottom of the heating cavity body (105) and the support structure (108) fixed to the inner side of the heating cavity upper cover (104) are arranged corresponding to each other up and down, and the space enclosed therebetween is used to fix the atomic gas cell (106).

9. The uniform heating device for an NMRG atomic gas cell according to claim 1, characterized in that, The material of the fully transparent sealed heating cavity is BF33 glass.

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