Temperature control circuit of atomic magnetometer and atomic magnetometer

Abstract

The embodiment of the invention discloses a temperature control circuit of an atomic magnetometer. The temperature control circuit of the atomic magnetometer comprises a main control circuit, a temperature acquisition circuit and a heating module, wherein the temperature measuring circuit is connected with the temperature sensor and is used for measuring the temperature of an atomic gas chamber of the atomic magnetometer, acquiring temperature data of the atomic gas chamber and sending the temperature data to the main control circuit; the master control circuit comprises a PID control module, a DAC module and a DMA module. The PID control module is used for determining a sine wave array peak-to-peak value according to the temperature data; the DMA module is used for transmitting the sine wave array peak-to-peak value to the DAC module; the DAC module is used for outputting sine wave signals according to the sine wave array peak-to-peak value so as to drive the heating module; and the heating module is connected with the atomic gas chamber and is used for heating the atomic gas chamber according to the sine wave signal.

Description

Technical Field

[0001] The present invention relates to the technical field of atomic magnetometers, and in particular to a temperature control circuit of an atomic magnetometer and the atomic magnetometer. Background Art

[0002] Atomic magnetometers have important applications in geological exploration, geomagnetic navigation, submarine cable detection, and other fields. An atomic magnetometer is an instrument that detects magnetic fields by utilizing the specific phenomena produced by the interaction between alkali metal atoms and pump light. The atomic gas chamber is an important component of the optically pumped magnetometer probe, providing the magnetometer with a high density of working atoms. The atomic density in the gas chamber is proportional to the temperature of the atomic gas chamber, so a temperature control system is required to heat the atomic gas chamber and control it at a specific temperature to obtain the required atomic density. Therefore, whether the temperature control system can heat to the optimal operating temperature and its stability are crucial. The heating signal output by the temperature control circuit in the related art has a low frequency, which affects the heating stability. Summary of the Invention

[0003] In view of this, an embodiment of the present invention provides a temperature control circuit of an atomic magnetometer and an atomic magnetometer.

[0004] The technical solution of the embodiment of the present invention is achieved as follows:

[0005] An embodiment of the present invention provides a temperature control circuit for an atomic magnetometer, the temperature control circuit comprising: a main control circuit, a temperature acquisition circuit and a heating module; wherein,

[0006] The temperature measurement circuit is connected to the temperature sensor, and is used to measure the temperature of the atomic gas chamber of the atomic magnetometer, obtain the temperature data of the atomic gas chamber, and send the temperature data to the main control circuit;

[0007] The main control circuit includes: a proportional, integral and differential PID control module, a digital-to-analog converter DAC module and a direct memory access DMA module; the PID control module is used to determine the peak-to-peak value of the sine wave array according to the temperature data; the DMA module is used to transmit the peak-to-peak value of the sine wave array to the DAC module; the DAC module is used to output a sine wave signal according to the peak-to-peak value of the sine wave array to drive the heating module;

[0008] The heating module is connected to the atomic gas chamber and is used to heat the atomic gas chamber according to the sinusoidal wave signal.

[0009] In the above solution, the temperature sensor is a three-wire platinum thermal resistor.

[0010] In the above solution, the temperature measurement circuit includes: a dual current source, and the dual current source is used to drive the temperature sensor.

[0011] In the above solution, the temperature measurement circuit further includes: a differential amplifier and an analog-to-digital converter, wherein:

[0012] The differential amplifier is used to differentially amplify the voltage signal of the temperature sensor;

[0013] The analog-to-digital converter is used to perform analog-to-digital conversion on the voltage signal after differential amplification.

[0014] In the above solution, the PID control module uses a fuzzy adaptive control algorithm to adjust the PID parameters.

[0015] In the above solution, the temperature control circuit further includes: a power amplifier circuit, connected to the main control circuit and the heating module respectively, for amplifying the power of the sinusoidal wave signal output by the main control circuit.

[0016] In the above solution, the heating module is a heating wire, and the heating wire is evenly wrapped around the atomic gas chamber by a folded and twisted method.

[0017] In the above solution, the heating wire is made of nickel-chromium alloy.

[0018] On the other hand, an embodiment of the present application provides an atomic magnetometer, comprising the above-mentioned temperature control circuit and an atomic gas chamber connected to a heating module in the temperature control circuit.

[0019] In the above solution, the atomic magnetometer includes a spin-exchange relaxation-free magnetometer and an optically pumped magnetometer.

[0020] The temperature control circuit of the atomic magnetometer of the embodiment of the present invention includes: a main control circuit, a temperature acquisition circuit and a heating module; wherein the temperature measurement circuit is connected to the temperature sensor, and is used to measure the temperature of the atomic gas chamber of the atomic magnetometer, obtain the temperature data of the atomic gas chamber, and send the temperature data to the main control circuit; the main control circuit includes: a PID control module, a DAC module and a DMA module; the PID control module is used to determine the peak-to-peak value of the sine wave array according to the temperature data; the DMA module is used to transmit the peak-to-peak value of the sine wave array to the DAC module; the DAC module is used to output a sine wave signal according to the peak-to-peak value of the sine wave array to drive the heating module; the heating module is connected to the atomic gas chamber, and is used to heat the atomic gas chamber according to the sine wave signal. The embodiment of the present application transmits the peak-to-peak value of the sine wave array to the DAC module for digital-to-analog conversion through DMA, and can generate the required sine wave without occupying the CPU resources of the main control circuit, thereby solving the problem that directly using the built-in DAC to output the sine wave will occupy CPU resources and cause the output sine wave frequency to be low, can ensure temperature control stability, and is conducive to circuit miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0022] Figure 1 A schematic structural diagram of a temperature control circuit of an atomic magnetometer provided by the present invention;

[0023] Figure 2 A schematic structural diagram of a temperature control circuit of another atomic magnetometer provided by the present invention;

[0024] Figure 3 A schematic structural diagram of a temperature control circuit of another atomic magnetometer provided by the present invention;

[0025] Figure 4 It is a structural schematic diagram of a non-magnetic temperature control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention are further elaborated in detail below with reference to the accompanying drawings and embodiments. The described embodiments should not be regarded as limiting the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In the following description, references to "some embodiments" describe a subset of all possible embodiments. However, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments, and may be combined with each other without conflict. The terms "first" and "second" are used solely to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that the specific order or sequence of "first" and "second" may be interchanged where permitted, so that the embodiments of the present invention described herein can be implemented in an order other than that illustrated or described herein.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein are for the purpose of describing the present invention only and are not intended to limit the present invention.

[0029] Atomic magnetometers have important applications in geological exploration, geomagnetic navigation, and submarine cable detection. They detect magnetic fields by exploiting the specific phenomena produced by the interaction between alkali metal atoms and pump light. Optically pumped magnetometers use lasers to excite atoms or molecules in a sample, changing their spin states and then generating a magnetic resonance effect under an external magnetic field. When the atomic chamber is heated to its optimal operating temperature, the atoms within the chamber become fully active, fully exposed to the pump light, and output a high-quality optical signal. By detecting this changing optical signal, optically pumped magnetometers can measure magnetic field strength with high sensitivity and accuracy.

[0030] The atomic gas cell is a crucial component of the optically pumped magnetometer probe, providing the magnetometer with a high density of working atoms. The atomic density within the cell is proportional to the cell temperature, so a temperature control system is required to heat and control the cell to a specific temperature to achieve the desired atomic density. Therefore, ensuring that the temperature control system is heated to the optimal operating temperature and maintaining its stability is crucial.

[0031] Figure 1 A schematic structural diagram of a temperature control circuit 10 of an atomic magnetometer provided by the present invention is shown in FIG. Figure 1 As shown, the temperature control circuit includes: a main control circuit 11, a temperature acquisition circuit 12 and a heating module 13; wherein,

[0032] The temperature measurement circuit 12 is connected to the temperature sensor 14 and is used to measure the temperature of the atomic gas chamber of the atomic magnetometer, obtain the temperature data of the atomic gas chamber, and send the temperature data to the main control circuit 11;

[0033] The main control circuit 11 includes: a proportional, integral, and differential (PID) control module 111, a digital-to-analog converter (DAC) module 112, and a direct memory access (DMA) module 113; the PID control module 111 is used to determine the peak-to-peak value of the sine wave array according to the temperature data; the DMA module 113 is used to transmit the peak-to-peak value of the sine wave array to the DAC module 112; the DAC module 112 is used to output a sine wave signal according to the peak-to-peak value of the sine wave array to drive the heating module 13;

[0034] The heating module 13 is connected to the atomic gas chamber and is used to heat the atomic gas chamber according to the sinusoidal wave signal.

[0035] The temperature measurement circuit 12 is connected to the temperature sensor and is used to measure the temperature of the atomic gas chamber, obtain temperature data of the atomic gas chamber surface in real time, and send the data to the main control circuit. Multiple temperature sensors can be included, and the temperature measurement circuit 12 performs weighted calculation based on the data from the multiple temperature sensors.

[0036] The temperature sensor 14 may be placed on the surface of the atomic gas chamber. The resistance value of the temperature sensor 14 may change according to the change of the temperature of the atomic gas chamber.

[0037] The temperature acquisition circuit 12 can acquire the resistance value of the temperature sensor 14 . The temperature acquisition circuit 12 can convert the variation of the resistance value into a voltage variation. The temperature data of the atomic gas chamber can include the voltage variation.

[0038] The temperature acquisition circuit 12 sends the temperature data of the atomic gas chamber to the main control circuit 11. The PID control module 111 in the main control circuit 11 determines the peak-to-peak value of the sine wave array of the sine wave signal output by the DAC module 112 based on the temperature data. The DMA module 113 transmits the peak-to-peak value of the sine wave array to the DAC module 112. The DAC module 112 outputs a sine wave signal to the heating module 13 based on the peak-to-peak value of the sine wave array.

[0039] The PID control module may be a software function module of a central processing unit (CPU) in the main control circuit 11 , and is configured to output the peak-to-peak value of a sine wave signal according to temperature data.

[0040] In some embodiments, the main control circuit 11 can use STM32 as a control chip. There are two ways to generate waveforms based on STM32: an external signal generator and a built-in DAC output. The former adds redundant circuits, while the latter can make full use of the built-in resources of STM32. However, the program will occupy CPU resources, resulting in a low frequency of the output sine wave. The built-in DAC of STM32 can trigger DMA, which is a direct memory access technology. Simply put, its function is to move data from one address to another. DMA is used to provide high-speed data transmission between peripherals and memory or between memory and memory. Without CPU intervention, data can be moved quickly through DMA, which saves CPU resources for other operations. The process of using DAC to cooperate with DMA for digital-to-analog conversion can generate the required sine wave without occupying CPU resources, solving the problem of directly using the built-in DAC to output the sine wave, which is conducive to circuit miniaturization.

[0041] A DAC works by generating an analog output voltage or current based on the value of a digital input signal. It typically receives a binary digital input representing a specific range of values. The DAC converts this digital value into an analog voltage or current level, which is then output.

[0042] Using DAC with DMA to output sine waves has the following advantages:

[0043] 1. Reduce CPU load and do not occupy CPU resources

[0044] In traditional methods, the CPU must continuously send data to the DAC to output a sine wave, which consumes a significant amount of CPU time, especially when high-frequency sine waves are required. With DMA, the CPU only needs to set the DMA transfer parameters at the beginning. The DMA controller then automatically reads the sine wave data from memory and transfers it to the DAC without constant CPU intervention, significantly reducing the CPU load.

[0045] 2. Improve data transmission efficiency

[0046] DMA enables high-speed data transfer, typically limited only by the system bus bandwidth and peripheral device performance. In contrast, data transfer via the CPU requires numerous instruction executions and register operations, resulting in a relatively slow transfer speed. For applications requiring continuous, high-speed data transfer, such as sine wave output, DMA ensures timely and accurate data transfer to the DAC, thereby improving the output quality and stability of the sine wave.

[0047] 3. Reduce the number of interruptions

[0048] Without DMA, the CPU typically needs to use interrupts to send data to the DAC. Each interrupt requires the CPU to perform a context switch, which increases system overhead and can cause system instability. However, with DMA, the CPU can remain uninterrupted for longer periods of time, reducing the number of interrupts. This reduces the probability of system failure and improves system reliability.

[0049] 4. Improve the accuracy of data transmission

[0050] DMA controllers typically include data checking and error handling capabilities to ensure data transmission accuracy. In contrast, when data is transmitted through the CPU, data accuracy may be affected by factors such as CPU load and interrupt latency. For applications that require high data accuracy, such as sine wave output, using DMA can ensure the accuracy of the sine wave data, thereby improving the output quality.

[0051] 5. Easy to implement dynamic adjustment:

[0052] Using DMA makes it easy to dynamically adjust sine wave parameters. For example, you can modify the sine wave data table in memory to change the sine wave's frequency, amplitude, phase, and other parameters without modifying the CPU program code. This enables the system to quickly adjust the sine wave output according to different application requirements, improving the system's flexibility and adaptability.

[0053] The heating module 13 performs heating according to the sinusoidal current signal. The sinusoidal wave controlled heating module controls the heating power by adjusting the amplitude of the AC sinusoidal wave. Unlike the traditional pulse width modulation (PWM) circuit (Pulse Width Modulation) pulse heating, the sinusoidal wave control can make the current waveform continuous and smooth, reducing high-frequency harmonic interference.

[0054] In some embodiments, the heating module 13 can be a heating wire wound around the outer layer of the atomic gas chamber. After the heating current passes through the heating wire, the surrounding magnetic field will definitely change. In order to reduce this magnetic field noise, the heating wire can be evenly wrapped around the atomic gas chamber by folding the heating wire in half and twisting it in two. The currents passing through two adjacent heating wires are opposite in direction and of the same magnitude. According to the Biot-Savart law, the magnetic field generated by two loop wires with currents of the same magnitude and opposite directions in the middle of the two wires is of the same magnitude and opposite in direction, while the magnetic field generated at a random point outside the two wires is related to the distance between the two loop wires. In addition, due to the use of zero-crossing sine wave heating, the current direction on the twisted pair changes alternately. Since the magnetic field direction is related to the current direction, the magnetic field direction and magnitude at any point also change periodically, and the frequency is consistent with the heating sine wave frequency. It can be filtered out by back-end signal processing, which is conducive to reducing the residual magnetic field caused by electric heating.

[0055] The temperature control circuit of the atomic magnetometer of the embodiment of the present invention includes: a main control circuit, a temperature acquisition circuit and a heating module; wherein the temperature measurement circuit is connected to the temperature sensor, and is used to measure the temperature of the atomic gas chamber of the atomic magnetometer, obtain the temperature data of the atomic gas chamber, and send the temperature data to the main control circuit; the main control circuit includes: a PID control module, a DAC module and a DMA module; the PID control module is used to determine the peak-to-peak value of the sine wave array according to the temperature data; the DMA module is used to transmit the peak-to-peak value of the sine wave array to the DAC module; the DAC module is used to output a sine wave signal according to the peak-to-peak value of the sine wave array to drive the heating module; the heating module is connected to the atomic gas chamber, and is used to heat the atomic gas chamber according to the sine wave signal. The embodiment of the present application transmits the peak-to-peak value of the sine wave array to the DAC module for digital-to-analog conversion through DMA, and can generate the required sine wave without occupying the CPU resources of the main control circuit, thereby solving the problem that directly using the built-in DAC to output the sine wave will occupy CPU resources and cause the output sine wave frequency to be low, can ensure temperature control stability, and is conducive to circuit miniaturization.

[0056] In one embodiment, the temperature sensor is a three-wire platinum thermal resistor.

[0057] In this embodiment, a three-wire Pt100 may be used as the temperature sensor.

[0058] The resistance of a PT100, or platinum resistance thermometer, is directly proportional to temperature. Specifically, at 0°C, the resistance is 100 ohms; at 100°C, the resistance rises to approximately 138.5 ohms. This behavior follows a specific industrial principle: at 0°C, the resistance of a PT100 is 100 ohms, and as the temperature rises, the resistance gradually increases at a uniform rate.

[0059] Thermal resistors are typically connected using a three-wire system to eliminate measurement errors caused by wire resistance. Since the circuit used to measure thermal resistors is typically an unbalanced bridge, the thermal resistor acts as one arm of the bridge, and its connecting wires also form part of this arm resistance. This resistance is unknown and varies with ambient temperature, leading to measurement errors. Using a three-wire system, connecting one wire to the power supply terminal of the bridge and the remaining two wires to the arm containing the thermal resistor and its adjacent arm, effectively eliminates measurement errors caused by wire resistance.

[0060] like Figure 2 As shown, in one embodiment, the temperature measurement circuit 12 includes: a dual current source 121, and the dual current source 121 is used to drive the temperature sensor.

[0061] To address the line resistance problem of the three-wire Pt100, a dual current source driving method can be used to weaken the influence of the three-wire Pt100 line resistance.

[0062] The temperature measurement method can be a three-wire dual constant current source ratio method, which eliminates the wire resistance error through the constant current source and resistance ratio method.

[0063] like Figure 2 As shown, in one embodiment, the temperature measurement circuit 12 further includes: a differential amplifier 122 and an analog-to-digital converter 123, wherein:

[0064] The differential amplifier 122 is used to differentially amplify the voltage signal of the temperature sensor;

[0065] The analog-to-digital converter 123 is used to perform analog-to-digital conversion on the voltage signal after differential amplification.

[0066] After device selection and optimization, a dual current source driver can be used to address the line resistance issue of a three-wire Pt100. Since the voltage signal is weak, differential amplification is required. Furthermore, since a controller is required for control, the voltage signal needs to be converted to analog-to-digital. In other words, the temperature measurement circuit requires Pt100 drive, differential amplification, and analog-to-digital conversion. This embodiment can use the ADS1248 to meet these requirements. The ADS1248 features dual current sources, a built-in differential amplifier with up to 128x amplification, and a 24-bit analog-to-digital converter. A single chip can complete multiple steps, facilitating circuit miniaturization.

[0067] In one embodiment, the PID control module 111 uses a fuzzy adaptive control algorithm to adjust PID parameters.

[0068] Fuzzy adaptive PID control is based on the PID algorithm, takes the error e and the error change rate ec as input, uses fuzzy rules for fuzzy reasoning, queries the fuzzy matrix table for parameter adjustment, and adjusts the three parameters K of the PID controller online through fuzzy reasoning. p , K i and K d .

[0069] PID control is a very powerful concept used in almost all temperature control systems, and it is not easy to use.

[0070] In one embodiment, if Figure 3 As shown, the temperature control circuit further includes: a power amplifier circuit 15, which is connected to the main control circuit 11 and the heating module 13 respectively, and is used to power amplify the sinusoidal wave signal output by the main control circuit.

[0071] The heating module 13 is connected to the power amplifier circuit 15 for heating the atomic gas chamber. The power amplifier circuit 15 is used to amplify the power of the current wave signal output by the DAC module 112 in the main control circuit 11.

[0072] In one embodiment, the heating module is a heating wire, and the heating wire is evenly wrapped around the atomic gas chamber by a folded and twisted method.

[0073] The residual magnetism caused by electric heating can be reduced by folding the twisted heating wire in half.

[0074] In one embodiment, the heating current passing through the heating wires inevitably causes changes in the surrounding magnetic field. To reduce this magnetic field noise, the heating wires are folded in half and twisted evenly around the atomic gas chamber. The currents passing through two adjacent heating wires are of opposite direction but equal magnitude. According to the Biot-Savart law, two looped wires carrying equal and opposite currents generate magnetic fields of equal magnitude and opposite direction between the two wires, while the magnitude of the magnetic field generated at random points outside the looped wires is related to the distance between the two looped wires. Furthermore, because zero-crossing sinusoidal heating is used, the direction of the current in the twisted wires alternates. Because the magnetic field direction is related to the current direction, the direction and magnitude of the magnetic field at any point also vary periodically, with a frequency consistent with the heating sinusoidal wave frequency. This can be filtered out through back-end signal processing, thus reducing the residual magnetic field caused by electrical heating.

[0075] In one embodiment, the heating wire is made of nickel-chromium alloy.

[0076] In some embodiments, the heating module is a heating coil, which is driven by a high-frequency AC signal to reduce the magnetic field brought by the heating coil, ensure that the atomic gas chamber is not disturbed by the magnetic field generated by the heating module, and output accurate AC signals to achieve precise temperature control of the atomic gas chamber.

[0077] like Figure 4 As shown, Figure 4 This is a structural diagram of a non-magnetic temperature control system provided by an embodiment of the present invention, wherein the temperature acquisition circuit is connected to the temperature sensor Pt100 to collect temperature data of the atomic gas chamber. The temperature acquisition circuit can use the ADS1248 chip, which performs Pt100 drive, differential amplification and analog-to-digital conversion.

[0078] The STM32, acting as the control chip, receives digital signals from the temperature acquisition circuit via the Serial Peripheral Interface (SPI). The STM32's PID control program then controls the amplitude of the output signal from the STM32's digital-to-analog converter based on the digital input signal. The PID control operates on the peak-to-peak value of a sine wave array generated by the STM32's internal program. This array is transferred from the CPU to the STM32's built-in DAC via DMA, which then outputs a sine wave signal.

[0079] The STM32 outputs a high-power AC signal, which is used to evenly wrap the heating wire around the atomic gas chamber by folding it in half and twisting it in two. The sinusoidal wave signal output by the STM32 is amplified by the power amplifier circuit and then drives the heating wire to heat up.

[0080] This embodiment achieves a miniaturized design through chip selection and circuit design, and can be heated to 75°C and 150°C at room temperature and stabilized within ±0.2°C.

[0081] An embodiment of the present application provides an atomic magnetometer, comprising the above-mentioned temperature control circuit and an atomic gas chamber connected to a heating module in the temperature control circuit.

[0082] The atomic gas cell is a crucial component of the magnetometer probe, providing the magnetometer with a high density of working atoms. The atomic density within the cell is proportional to its temperature, so a temperature control system is required to heat and control the cell to a specific temperature to achieve the desired atomic density. Therefore, ensuring that the temperature control system can reach the optimal operating temperature and maintain its stability is crucial.

[0083] This embodiment controls the temperature of the atomic gas chamber through the temperature control circuit, achieving high-precision temperature control and non-magnetic effect, and can significantly improve the temperature stability of the atomic gas chamber.

[0084] In the above solution, the atomic magnetometer includes a spin-exchange relaxation-free (SERF) magnetometer and an optical pumping magnetometer.

[0085] This embodiment can meet the temperature control requirements of both the tracking optical pumping magnetometer and the temperature control requirements and temperature stability of the self-selected exchange relaxation (SERF) magnetometer, and reduce the magnetic field noise caused by electric heating through the designed heating wire and heating current.

[0086] The various embodiments / implementations provided herein may be combined with one another as long as no conflicts arise. The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0087] The features, structures or characteristics described above can be combined in one or more embodiments in any suitable manner, and if possible, the features discussed in each embodiment are interchangeable. In the above description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, it will be appreciated by those skilled in the art that the technical solutions of the present invention can be put into practice without one or more of the specific details, or other methods, components, materials, etc. can be adopted. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring the various aspects of the present invention.

[0088] In this specification, the terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising", "including" and "having" are used to express open-ended inclusion and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used only as labels and are not intended to limit the quantity of their objects.

[0089] It will be understood that the present invention is not limited in its application to the detailed construction and arrangement of components set forth in this specification. The present invention is capable of other embodiments and can be implemented and carried out in a variety of ways. The aforementioned variations and modifications fall within the scope of the present invention. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more individual features mentioned or evident in the text and / or the drawings. All of these different combinations constitute multiple alternative aspects of the present invention. The embodiments described in this specification illustrate the best mode known for implementing the invention and will enable those skilled in the art to utilize the invention.

Claims

1. A temperature control circuit for an atomic magnetometer, characterized in that: The temperature control circuit includes: a main control circuit, a temperature acquisition circuit and a heating module; wherein, The temperature measurement circuit is connected to the temperature sensor, and is used to measure the temperature of the atomic gas chamber of the atomic magnetometer, obtain the temperature data of the atomic gas chamber, and send the temperature data to the main control circuit; The main control circuit includes: a proportional, integral and differential PID control module, a digital-to-analog converter DAC module and a direct memory access DMA module; the PID control module is used to determine the peak-to-peak value of the sine wave array according to the temperature data; the DMA module is used to transmit the peak-to-peak value of the sine wave array to the DAC module; the DAC module is used to output a sine wave signal according to the peak-to-peak value of the sine wave array to drive the heating module; The heating module is connected to the atomic gas chamber and is used to heat the atomic gas chamber according to the sinusoidal wave signal.

2. The temperature control circuit according to claim 1, characterized in that: The temperature sensor is a three-wire platinum thermal resistor.

3. The temperature control circuit according to claim 2, characterized in that: The temperature measurement circuit includes a dual current source, and the dual current source is used to drive the temperature sensor.

4. The temperature control circuit according to claim 3, characterized in that: The temperature measurement circuit further includes: a differential amplifier and an analog-to-digital converter, wherein: The differential amplifier is used to differentially amplify the voltage signal of the temperature sensor; The analog-to-digital converter is used to perform analog-to-digital conversion on the voltage signal after differential amplification.

5. The temperature control circuit according to claim 1, characterized in that: The PID control module uses a fuzzy adaptive control algorithm to adjust the PID parameters.

6. The temperature control circuit according to claim 1, characterized in that: The temperature control circuit further includes: a power amplifier circuit, which is connected to the main control circuit and the heating module respectively, and is used to amplify the power of the sinusoidal wave signal output by the main control circuit.

7. The temperature control circuit according to claim 1, characterized in that: The heating module is a heating wire, and the heating wire is evenly wound around the atomic gas chamber by a folded and twisted method.

8. The temperature control circuit according to claim 7, characterized in that: The heating wire is made of nickel-chromium alloy.

9. An atomic magnetometer, characterized in that The invention comprises the temperature control circuit according to any one of claims 1 to 8 and an atomic gas chamber connected to a heating module in the temperature control circuit.

10. The atomic magnetometer according to claim 9, characterized in that The atomic magnetometer includes a spin-exchange relaxation-free magnetometer and an optical pumping magnetometer.

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