RU198180U1 - NON-ORIENTABLE QUANTUM RADIO OPTICAL MAGNETOMETER - Google Patents

Abstract

The utility model relates to geophysical instrumentation, in particular to quantum radio-optical magnetometers - devices for detecting superweak local magnetic anomalies (LMA), based on the principle of double radio-optical resonance (DDR). The utility model is a wide-range, automatic, non-orientable, highly sensitive, highly stable, noise-resistant and non-electromagnetic interference to other equipment remote-controlled quantum radio-optical magnetometer, which can be placed on board an aircraft or sea vessel. The technical result of the utility model is the creation of a non-orientable magnetometer, in which there are no dead zones of orientation, and a special orientation system of the optical axis of the sensor of the proposed magnetometer with respect to the direction of the field line of the measured field is not required. 1 ill.

Description

The proposed utility model relates to geophysical instrumentation, and in particular to quantum radio-optical magnetometers - devices for detecting superweak local magnetic anomalies (LMA), based on the principle of double radio-optical resonance (DDR).

The application of the proposed utility model will make it possible to construct a quantum radio-optical magnetometer with a wide-breadth, automatic, non-orientable, highly sensitive, highly stable, noise-resistant, and non-electromagnetic interference to other equipment.

The proposed utility model is a maintenance-free device with remote control, which can be placed on board an aircraft or sea vessel and can be controlled remotely using standardized workstations and an on-board information and telecommunication network of the facility in which it is used. Such a device can provide electromagnetic compatibility with other avionics that are susceptible to high frequency electromagnetic interference, and at the same time create such interference.

Using the proposed utility model of a non-orientable quantum radio-optical magnetometer, it is possible to measure weak magnetic fields with a strength significantly lower than the Earth’s magnetic field strength (MPS) from a ship or aircraft, in automatic mode, at any latitude (at any MPS intensity) and search for superweak LMA, which is very important when searching for mineral deposits, underground and underwater objects that have a weak magnetic moment.

As a prototype, a magnetometer with optical control, described in the book: N.M. Pomerantsev, V.M. Ryzhkov, G.V. Skrotsky. Physical Foundations of Quantum Magnetometry / Science, Main Edition of Physics and Mathematics Literature - M. 1972, 448 pp., Ill., Pp. 385-386, (see Fig. 80 in this book). This device is a quantum radio optical magnetometer with optical control and is designed to detect weak magnetic fields. It uses light intensity modulation. The magnitude of the signal for a magnetometer of this type varies depending on the orientation according to the law

S (ϑ) / S _max = sin ⁴ ϑ,

where: S (ϑ) is the signal level at the output of the photodetector;

S _max - the maximum signal level at the output of the photodetector;

ϑ is the orientation angle of the sensor.

The disadvantages of the device prototype include the following:

- the presence of dead zones of orientation, i.e. the presence of a range of orientation angles — angles between the direction of the optical axis of the sensor of the device and the direction of the line of force of the investigated magnetic field при, at which the signal at the output of amplifier 9 (see Fig. 80 of the above book) becomes weaker than the noise level;

- placement of a spectral lamp, and hence a sequential high-frequency and high-voltage resonant circuit of its pumping, in the immediate vicinity of the absorbing cell and photodetector, which creates powerful, high-frequency electromagnetic interference induced on the sensitive circuit of the photodetector and on other sensitive equipment susceptible to interference, placed close to the magnetometer sensor and limits the conditions of shielding and electromagnetic compatibility of the equipment complex;

- the lack of technical means to ensure noise immunity of the line connecting the amplifier and the phase detector, which limits the length of this line, and therefore the ability to remove the phase detector and other energy-intensive equipment from the sensor, which reduces the sensitivity of the device described in this book and limits the possibility of its remote control;

- the lack of automatic equipment for searching, capturing and holding the frequency of the Larmor precession necessary for automatic latitudinal operation of a quantum magnetometer, which implies a manual search for this frequency by manually tuning the radio frequency generator 12 (see Fig. 80 of this book), while visually observing the readings of instruments that monitor the amplitude of the signal at the output of the amplifier 9, the voltage of the error signal at the output of the phase detector 10, the frequency of the radio-frequency generator 12, and this creates significant limitations on the possibility of using the device described in this book as part of target electronic systems placed on board ships and aircraft;

- lack of computing equipment for processing the flow of values of the Larmor precession frequency, which is the main indicator of the measured magnetic field induction and its gradient, which does not allow the averaging of readings, reduction of the influence of noise, compensation of local magnetic fields and interference, gradient estimation using advanced flow processing algorithms values and detection of LMA, reduces sensitivity and limits the functionality of the device, and this significantly limits the capabilities of the device when searching for superweak LMA;

- the lack of technical means to ensure the temperature stability of the spectral lamp, which reduces the stability of the position of the spectral line of the radiation source, creates destabilizing factors during operation of the device for a long time in a wide range of operating temperatures.

The purpose of the proposed utility model is the creation of such a non-orientable quantum radio-optical magnetometer, in which, as in the prototype, the radio-frequency generator is used to modulate the light intensity pumping the working fluid, but which does not have dead zones and does not require a special orientation system of the optical axis of the sensor with respect to to the direction of the field line of the measured field, which has the technical means that significantly reduce the influence of electromagnetic interference and interference from the high-frequency generator and the high-voltage resonant circuit of the excitation of the spectral lamp to photodetector 8, amplifier 9, (see Fig. 80 of this book) and also to other sensitive electronic equipment of a magnetometer and other electronic systems, having technical means providing noise immunity of the line connecting the amplifier and the phase detector, through which very weak signals are transmitted in the capture mode and which is most exposed on susceptibility to interference, the creation of a magnetometer with automatic equipment for searching, capturing and holding the frequency of the Larmor precession and providing latitudinal work in automatic mode with remote control, which can be used as part of target electronic systems placed on board ships and aircraft, creating a magnetometer with computing equipment for processing the flow of values of the frequency of the Larmor precession and its gradient, which will allow us to average the readings, reduce the influence of noise, compensate for local magnetic fields and interference, estimate the gradient using advanced algorithms for processing the flow of values and increase the probability of detecting LMA, increase the sensitivity and significantly it will expand the functionality of the device, and also allow you to effectively use the created device when searching for superweak LMA, in addition, the creation of a device with technical means to ensure the stability of temperature of the spectral lamp, which will increase the stability of the position of the spectral line of the radiation source, create conditions for stable operation of the device for a long time in a wide range of operating temperatures, which is especially important when placing it on board aircraft and ships.

The proposed non-orientable quantum radio-optical magnetometer will find wide application in geological exploration when forecasting and searching for deposits of many minerals, in archeology, maritime and military affairs in the search for sunken ships, underwater treasures, explosive, hidden and other underground and underwater objects.

To achieve this goal, it is proposed to use a quantum radio-optical magnetometer with optical control, supplemented by a tuning speed adjuster, an analog switch, a selector, a solver circuit, a computer, compensator sensors, a matching device, a light guide, a light guide-collector, a beam-splitting polarizing device, a second polaroid, a second lens , the second absorption cell, the second modulation coil, thermostat.

The expected technical result of the utility model is the creation of a non-orientable magnetometer, that is, a device that does not have dead zones of orientation and a special orientation system of the optical axis of the sensor with respect to the direction of the magnetic field line.

The expected technical result is achieved in that an optical control magnetometer including a radio frequency generator, a modulator, a phase detector, a sound generator, a spectral lamp excitation generator, a spectral lamp module, a first modulation coil, a first lens, a first absorption cell, a light filter, a first polaroid, amplifier, photodetector, additionally introduced: tuning speed adjuster, analog switch, decision circuit, selector, calculator, temperature regulator, polarizing beam splitter, optical fiber, collector light guide, second absorption cell, second polaroid, second modulation coil, matching device, moreover, the adjuster tuning speed is connected to the first input of the analog switch, the output of which is connected to the input of the radio frequency generator, the second output of the radio frequency generator is connected to the first input of the computer, the second input of the analog switch is connected to the output of the phase detector, and the third is the control input of the analog the switch is connected to the output of the decision circuit, and the first output of the selector is connected to the first input of the phase detector, the second output of the selector is connected to the input of the decision circuit, the second input of the computer is connected to the output of the sensors of the compensator, the computer has a bi-directional interface in the direction of the computer network, the output of the amplifier is connected with the input of the matching device, and the output of the matching device is connected to the input of the selector, the electrical output of the spectral lamp module is connected to the input of the thermostat, the output of the temperature regulator is connected to the second input of the spectral lamp excitation generator, and the optical output of the spectral lamp module is connected to the first end of the fiber, the second end of which connected to one side of the filter, the second side of which is optically connected to a polarizing beam-splitting device, which also has an optical connection with the first and second polaroids, the second polaroid is connected to the second absorption cell, which has an optical connection with the second a second lens coupled to one of the inputs of the collector fiber, the second input of which is coupled to the first lens that collects light from the first absorption cell, and the collector fiber output is connected to the photodetector input, the second modulation coil is connected in series with the first modulation coil.

Achieving the goal and the technical result is achieved by ensuring the absence of dead zones of orientation and a special orientation system of the optical axis of the sensor with respect to the direction of the field line of the measured field by entering into the magnetometer:

a) polarizing beam-splitting devices;

b) the second polaroid;

c) a second absorption cell;

d) a second modulation coil;

e) a fiber optic collector.

In this case, the polarizing beam-splitting device has an optical connection with the light filter and with the first and second polaroids, the second polaroid is connected with the second absorption cell, which has an optical connection with the lens coupled to one of the inputs of the collector fiber, the second input of which is coupled to the second lens collecting light from the first absorption cell, and the output of the collector fiber is connected to the input of the photodetector, and the second modulation coil is connected in series with the first modulation coil.

In addition, the achievement of a technical result is achieved through the introduction of the following improvements:

- a significant reduction in the influence of electromagnetic interference, pickups from a high-frequency generator and a high-voltage resonant circuit of the excitation of a spectral lamp on a photodetector, amplifier, and also on other sensitive radio-electronic equipment of a magnetometer and other electronic systems, due to the fact that a fiber and a collector are introduced , the optical output of the spectral lamp module is connected to the first end of the fiber, the second end of which

connected to the sensor filter, one of the inputs of the collector fiber is coupled to a lens that collects light from the second absorption cell, its second input is paired with a second lens that collects light from the first absorption cell, and the output of the collector fiber is connected to the photodetector input, which allows you to remove the module the spectral lamp at a considerable distance from the sensitive circuits of the photodetector and amplifier and remove the magnetically sensitive sensor from the energy-intensive radio-electronic equipment of the magnetometer, thereby reducing the effect of high-power high-frequency devices on the sensitive circuits, and also remove the restrictions associated with the shielding of the spectral lamp, available, for example, in the prototype, and create conditions for high-quality electromagnetic shielding of the spectral lamp module remote from the sensor, and this provides a significant reduction in electromagnetic interference;

- ensuring noise immunity of the line connecting the amplifier and the phase detector, through which very weak signals are transmitted in the capture mode and which is most susceptible to interference, due to the fact that the matching device is connected to the magnetometer, the input of which is connected to the amplifier output, and the output is connected to a long line connected to the input of the selector;

- the introduction of automatic equipment for searching, capturing and holding the frequency of the Larmor precession and ensuring wide-ranging operation in automatic mode with remote control, which can be used as part of target electronic systems placed on board ships and aircraft, due to the fact that the magnetometer has been introduced tuning speed adjuster, analog switch, selector, decision circuit, tuning speed adjuster output is connected to the first input of the analog switch, the second input of the analog switch is connected to the output of the phase detector, the third input of the analog switch is connected to the output of the solving circuit, the output of the analog switch is connected to the radio frequency input generator, and the input of the decision circuit is connected to the second output of the selector;

- the introduction of computing equipment for processing the flow of values of the frequency of the Larmor precession and its gradient, which will allow us to average the readings, reduce the influence of noise, compensate for local magnetic fields and interference, evaluate the gradient using advanced algorithms for processing the flow of values and increase the probability of detecting LMA, increase the sensitivity and significantly expand the functionality of the device, as well as allow you to effectively use the created device when searching for superweak LMA, due to the fact that the calculator and compensator sensors are included in the magnetometer, the calculator has a bi-directional interface in the direction of the information and computer network, and the output of the compensator sensors

connected to the second input of the calculator, and the second output of the radio frequency generator is connected to the first input of the calculator;

- the introduction of technical means to ensure the temperature stability of the spectral lamp, which allows to increase the stability of the spectral line position of the radiation source, as well as create conditions for stable operation of the device for a long time in a wide range of operating temperatures, which is especially important when placing it on board aircraft and ships, due to the fact that a thermoregulator is included in the magnetometer, and the electrical output of the spectral lamp module is connected to the input of the thermostat, and the output of the temperature regulator is connected to the second input of the spectral lamp excitation generator.

Ensuring the high-quality operability of the non-orientable magnetometer, and hence the industrial applicability of this utility model, is achieved as a result of the combination of all the above improvements, which are causally related to obtaining the technical result - ensuring the absence of dead zones of orientation and a special orientation system of the optical axis of the sensor with respect to direction of the force line of the measured field (non-orientability of the magnetometer):

- reducing interference from a high-frequency generator leads to increased noise immunity and to prevent the creation of dead zones in the corner zones of a decrease in signal level due to a decrease in signal / noise ratio;

- ensuring noise immunity of the line creates an effect similar to the above and also contributes to the achievement of the claimed technical result;

- the presence of automatic equipment for searching, capturing and holding the frequency helps to restore the operability of a non-orientable magnetometer when the frequency is lost in the presence of angular zones of signal decrease, which is also aimed at achieving a technical result - non-orientability of the device;

- the availability of computing equipment and orientation sensors provides averaging of samples, which also increases noise immunity and ensures the operability of the device when working in the corner zones of signal decline, and therefore also aims to achieve a technical result - non-orientability;

- ensuring the temperature stability of the spectral lamp is aimed at ensuring the operation of a two-chamber sensor that requires increased power of the spectral line, and the normal functioning of such a sensor ensures the achievement of a technical result - non-orientability.

In FIG. 1 shows the implementation structure of a non-orientable quantum radio-optical magnetometer, where:

The purpose of these components is as follows:

- the tuning speed adjuster 1 is designed to set the tuning frequency of the radio frequency generator in the automatic search of the Larmar precession frequency, which is necessary to increase the probability of true frequency capture by the system and reduce the likelihood of not capture and false capture at the optimal search cycle duration;

- analog switch 2 is necessary to switch the frequency control signal of the radio frequency generator when switching from the search mode to the frequency capture mode under the control of the decision circuit 8;

- the radio frequency generator 3 is designed to generate a radio frequency signal used to modulate the light intensity of a spectral lamp;

- the modulator 4 is designed to modulate the excitation signal of the spectral lamp and the intensity of the spectral radiation of the lamp;

- a phase detector 5 is designed to compare the phase of the signal of the sound generator supplied to the modulation coils of the absorption cells and the phase of the first harmonic of the amplified signal from the photodetector, which is necessary for automatic tuning of the frequency of the radio frequency generator in the automatic tracking mode for this frequency over the entire tuning range of the radio frequency generator;

- selector 6 is intended for selection of the first and second harmonics of the amplified signal from the photodetector;

- the sound generator 7 is designed to form a reference low-frequency signal supplied to the modulation coils of both cells and to the first input of the phase detector;

- the decision circuit 8 is intended to make a decision on increasing the second harmonic level, which is a sign of approaching the frequency of the radio-optical resonance, as well as to generate a control signal, which is used to switch from the search (scanning) mode to the capture and tracking mode of the resonant frequency;

- the calculator 9 is designed to process the stream of values of the frequency of the Larmor precession and its gradient, averaging readings, reduce the influence of noise, compensate for local magnetic fields and interference, estimate the gradient using advanced algorithms for processing the stream of values and increase the probability of true detection of LMA, increase sensitivity and expand functionality instrument, remote control through the use of computer network;

- thermostat 10 is designed to ensure stability of the temperature of the spectral lamp, increase the stability of the spectral line of the radiation source, ensure stable operation of the device for a long time in a wide range of operating temperatures;

- the excitation generator of the spectral lamp 11 is designed to generate a powerful high-frequency electrical signal of a non-contact (using a high-voltage resonant circuit) excitation of a glow discharge in the gas of a spectral lamp and thereby generate spectral radiation - a light flux with an isotope spectral line used in absorption cells (for radiation light absorbed in these cells during the excitation of isotope atoms);

- the spectral lamp module is designed for non-contact excitation of the spectral lamp, input of the optical power of the spectral radiation into the optical fiber, shielding the high-voltage resonant circuit of the spectral lamp;

- the fiber 13 is designed to transmit optical power of spectral radiation from the spectral lamp module to the absorption cells, which allows you to remove the spectral lamp at a considerable distance from the magnetically sensitive element and organize a thorough electromagnetic shielding of the spectral lamp module;

- modulation coils 14, 27 are designed to create a low-frequency magnetic field inside the absorption cells, which ensures the excitation of Larmor precession (“twisting” of isotope atoms excited by spectral radiation) and the organization of the DDR;

- lenses 15.1 and 15.2 are designed to form a light beam inside the absorption cells, as well as to focus the light on the ends of the fiber-optic collector 16;

- the optical fiber-collector 16 is designed to combine optical signals from both absorption cells, which is necessary to ensure the absence of dead zones of the sensor;

- the first absorption cell 17 is designed to convert the induction of the magnetic field in conjunction with its location, the direction of the power line of the measured magnetic field into a modulated optical signal;

- the filter 18 is designed to highlight the wavelength band of spectral radiation and reduce the illumination current of the photodetector by side wave components;

- polaroids 19, 26 are intended to create a circular polarization of spectral radiation necessary for the excitation of DDR;

- polarizing beam splitting device 20 is designed for plane polarization of the light beam and its separation into two directions, which is necessary for excitation of the DDR in both absorption cells;

- the second absorption cell 21 is designed to convert the magnetic field induction into a modulated optical signal with the direction of the lines of force orthogonal to the direction of the field lines of the field being converted in the first absorption cell, which eliminates the formation of dead zones;

- matching device 22 is designed to coordinate the output of amplifier 23 with a symmetrical shielded line, which is necessary to ensure noise immunity when transmitting weak signals along this line due to the weakening of the influence of common-mode interference;

- the amplifier 23 is designed to amplify a weak electrical signal coming from the output of the photodetector;

- photodetector 24 is designed to convert a modulated optical signal from the outputs of the absorption cells into an electrical signal;

- compensator sensors 25 are designed to analyze the magnetic interference of the object on which the magnetometer is mounted for their subsequent compensation by subtraction, using specialized algorithms implemented in the calculator.

Elements of the structural diagram shown in FIG. 1 are interconnected as follows:

- adjuster speed adjustment 1 is connected to the first input of the analog switch 2,

- the output of the analog switch 2 is connected to the input of the radio frequency generator 3,

- the second output of the radio frequency generator 3 is connected to the first input of the calculator 9,

- the second input of the analog switch 2 is connected to the output of the phase detector 5,

- third - the control input of the analog switch 2 is connected to the output of the decision circuit 8,

- the first output of the selector 6 is connected to the first input of the phase detector 5,

- the second output of the selector 6 is connected to the input of the decision circuit 8,

- the second input of the calculator 9 is connected with the output of the sensors of the compensator 25,

- the calculator 9 has a bi-directional interface in the direction of the computer network,

- the output of the amplifier 23 is connected to the input of the matching device 22,

- the output of the matching device 22 is connected to the input of the selector 6,

- the electrical output of the spectral lamp module 12 is connected to the input of the thermostat 10,

- the output of the temperature controller 10 is connected to the second input of the excitation generator of the spectral lamp 11,

- the output of the excitation generator of the spectral lamp 11 is connected to the input of the module of the spectral lamp 12,

- the first output of the RF generator 3 is fed to the input of the modulator 4,

- the output of the modulator 4 is connected to the first input of the excitation generator of the spectral lamp 11,

- the optical output of the spectral lamp module 12 is connected to the first end of the light guide 13,

- the second end of the light guide 13 is connected to one side of the filter 18,

- the second side of the optical fiber 13 is optically coupled to a polarizing beam splitting device 20,

the polarizing beam splitting device 20 is in optical communication with the first and second polaroids 19, 26,

- the first polaroid 19 is connected with the first absorption cell 17,

- the second polaroid is paired 26 with the second absorption cell 21,

- the second absorption cell 21 is in optical communication with the second lens 15.2,

- the second lens 15.2 is paired with the first input of the collector fiber 16,

- the second input of the fiber optic collector 16 is paired with a first lens 15.1 that collects light from the first absorption cell 17,

- the output of the fiber optic collector 16 is connected to the input of the photodetector 24,

- the output of the photo detector 24 is connected to the input of the amplifier 23,

- the output of the sound generator 7 is fed to the second input of the phase detector 5,

- the output of the sound generator 7 is connected to the first and second modulation coils 14, 27 connected in series.

The proposed technical solution operates as follows.

The proposed quantum radio-optical magnetometer has two modes.

1 Frequency search mode of Larmor precession (search mode).

2 The frequency capture mode of the Larmor precession, followed by tracking its value (capture mode).

In search mode, the entire frequency range of the Larmor precession is scanned, i.e. sequential enumeration of all values of this frequency, which it can take for the working fluid used in the magnetometer at all latitudes from the South to the North magnetic poles of the Earth, over the entire range of changes in the magnetic field induction. For example, when using the ⁸⁷ RB isotope as a working fluid, this frequency varies in the range from 70 kHz to 500 kHz. Such scanning is carried out through the use of a special RF generator 3. The frequency of the RF generator 3 is tuned in the entire specified range. The frequency tuning is controlled by a special signal supplied from the output of the analog switch 2 to the control input of the RF generator 3. The RF generator 3 is constructed in such a way that when a constant control voltage is applied to the input, the frequency of the signal at the output of the RF generator 3 periodically scans the entire range (varies according to the sawtooth law from the beginning to the end of the range). In this case, the scanning direction (from bottom to top or top to bottom) depends on the sign of the control voltage (positive or negative), the scan speed is determined by the absolute value of this voltage, and at zero control voltage, the RF generator 3 remembers the current frequency value. This frequency control functionality allows you to automatically search and automatically adjust the frequency of the DDR using a radio frequency generator 3. At the output 2 of the radio frequency generator 3, a 26-bit digital code is issued corresponding to the current value of its frequency. This code corresponds to the frequency value of the RF generator 3 with an accuracy of approximately 0.01 Hz. The values of this code are periodically captured by the calculator 9 for further processing.

In the search mode under consideration, the signal from the output of the tuning speed adjuster 1 is supplied to the control input of the RF generator 3 through the analog switch 2 - a constant voltage specified by a special potentiometer that is part of the tuning speed adjuster 1, to which the reference voltage is applied. The position of the slider of this potentiometer sets the speed of frequency scanning in the search mode. Regulation of the scanning speed is necessary in order not to miss the frequency value corresponding to the DDR during scanning.

The signal with the frequency thus scanned is supplied from the output 1 of the RF generator 3 to the input of the modulator 4, and from the output of the modulator to the modulation input (first input) of the excitation lamp of the spectral lamp 11. The excitation generator of the spectral lamp 11 outputs a powerful, about 10 W, high-frequency a signal with amplitude modulation applied to the module of the spectral lamp 12, containing a high-frequency (about 100 MHz) serial (with voltage amplification) high-voltage (about 120 V) resonant circuit, creating a powerful electromagnetic field inside this module that supports a glow discharge in a non-contact gas-discharge spectral balloon lamps. In the volume of the lamp is a buffer gas and an isotope of the working fluid of the magnetometer. When a glow discharge is excited, the lamp creates spectral radiation in addition to visible light at the radiation (absorption) wavelength of the used isotope. Due to the fact that the excitation signal has amplitude modulation, the intensity of the spectral radiation is also modulated by the frequency of the signal supplied from the output of the radio-frequency generator 3. Moreover, the lamp bulb can be heated to high temperatures, and the wavelength of the spectral radiation can be unstable. To stabilize the temperature of the lamp cylinder, a miniature thermistor is glued onto the glass of the cylinder, which measures the temperature and is included in the temperature control system by controlling the high-frequency power of the excitation generator 11. Control is carried out by means of a thermostat 10, to the input of which the specified thermistor is connected, and from the output of the thermostat 10 the control voltage is supplied to the control input 2 of the excitation generator of the spectral lamp 11. The temperature controller 10 includes a lamp temperature setter (not highlighted in the diagram) - a potentiometer, through which the optimal temperature is set corresponding to the maximum spectral power and linear modulation characteristic of the lamp. The modulated optical signal is introduced into the light guide 13, from the output of which it enters the light filter 18. The light filter 18 cuts out the necessary spectrum and blocks visible light in order to avoid an excessive increase in the illumination current of the photodetector. The latter is undesirable, since it is accompanied by a decrease in sensitivity due to saturation of the photodetector and an increase in the noise level. From the output of the filter 18, a beam of spectral radiation hits the first face of the beam-splitting polarizing device 20, where it is divided into two beams directed to the first 17 and second 21 absorption cells. In a beam-splitting polarizing device, both rays are flatly polarized, and their circular polarization necessary to excite the atoms of the working fluid occurs in polaroids 19, 26. Thus, two rays of circularly polarized optical spectral radiation are directed to both absorption cells, where during excitation atoms of the working fluid, which is in the cells in a gaseous state, this radiation is absorbed (the cells become turbid and stop transmitting the optical rays entering them). By exposing the cells to a weak alternating magnetic field created by the modulation coils 14, 27 powered by the sound generator 7, they twist the excited atoms and excite DDR at the magnetically dependent frequency of the Larmor precession. When DDR occurs in the absorption cells 17, 21, a modulation of the frequency modulated by the frequency of the sound generator 7 is formed, which leads to the appearance of an optical signal modulated by the sound frequency at the output of these absorption cells, which is collected by the lenses 15.1 and 15.2 and introduced into the ends of the fiber-collector 16. On the opposite side the optical fiber 16 includes a photodetector 24, which sums the signals from the outputs of both absorption cells and converts the total optical signal into an electrical signal amplified by an amplifier 23. Moreover, if the carrier makes trajectory evolution, the optical signal disappears at the outputs of the absorption cells at certain angles ϑ due to the orientation dependence of the absorption cells. If we simultaneously sum the signal from two orthogonal absorption cells, then we can significantly reduce the decrease in signal level. This is achieved due to the fact that when critical angles occur in the first absorption cell 17, in the second absorption cell 21 orthogonally located with respect to it, the signal does not decrease, but rather increases. Thus, by summing the signals from the output of two orthogonal absorption cells, it is possible to significantly reduce the manifestation of dead zones, which is done in this utility model and which compares favorably with the prototype, where there is only one absorption cell.

From the output of the amplifier 23, the audio signal of the audio frequency is fed to the input of the matching device 22, which balances the interface in the direction of a long line connecting the matching device 22 to the symmetric input of the selector 6. It is known from electrical engineering that symmetrical lines are least susceptible to common mode interference, which often are aimed at the wiring sections of aircraft and ships due to the saturation of these objects with various energy-intensive AC equipment. Thus, by performing measures for balancing this line in the proposed utility model, along which very weak signals are transmitted in the DDR mode, which largely determine the noise level of the magnetometer, it was possible to significantly reduce the noise level and increase the sensitivity of the magnetometer. The selector 6 makes a separate selection of the first and second harmonics of the processed low-frequency signal. The first harmonic signal is used to track the frequency of the Larmor precession. The second harmonic signal is used to control the stop of scanning and the transfer of the device from the first mode to the second capture and tracking mode. The decision to increase the second harmonic level is made using decision scheme 8. It is known from the physics of DDR that when a DDR occurs, the signal at the output of the absorption cells in the so-called M _z magnetometers using search and tracking systems has a characteristic two-humped resonance dependence. In this case, the phase value of this signal during the transition through the resonance changes to the opposite. At the resonance frequency (between the two maxima of the amplitude of the first harmonic), the signal level drops sharply, and characteristic nonlinear distortions arise, leading to an increase in the signal level of the second harmonic. This property is used to control the search and to perform automatic tuning of the frequency of the RF generator 3 to the frequency of the Larmor precession of the working fluid of a quantum magnetometer, which depends on the induction of the measured magnetic field. The signal of the first harmonic from the first output of the selector 6 is fed to the first input of the phase detector 5, to the second input of which there is a signal from the output of the sound generator 7, simultaneously supplied to the modulation coils 14 and 27. When searching for the desired frequency of the Larmor precession during scanning, the second harmonic signal the output 2 of selector 6 increases sharply, the decision circuit 8 makes a decision to stop scanning and transfer the device to mode 2 of capturing the frequency of the Larmor precession, followed by tracking its value (capture mode). In this mode, under the influence of a control signal coming from the output of the decision circuit 8 to the control input 3 of the analog switch 2, the analog switch 2 is switched to the control input of the radio-frequency generator 3; now an error signal is output from the output of the phase detector 5, under the influence of which the frequency of the radio frequency is precisely tuned generator 3 under the frequency of the Larmor precession of the working body of the magnetometer, corresponding to the current value of the induction of the measured magnetic field. From the output 2 of the radio-frequency generator 3, this value is supplied in the form of a multi-bit digital code to the input 1 of the calculator 9, where these values are periodically selected and a stream of values of the induction of the measured field is generated, which is periodically processed by the calculator 9. In the process of software processing that implements the averaging algorithms , it is possible to compensate for the effect of noise and increase the accuracy of detecting anomalies. The combined processing of the induction values received from a quantum magnetometer at input 1 of calculator 9 and the values of local fields supplied to input 2 from compensator sensors 25, including high-side current meters, and also projectors of the magnetic field vector projection (flux-gate sensors), it is possible to register ultra-weak LMA Against the background of the MPZ, performing subtraction and other operations using a stream of values from a quantum magnetometer and a stream of values of compensation parameters. The detected signs of LMA are transmitted through the interface of the calculator 9 in the direction of the remote resources of the on-board information and computer network, where they are linked to the current coordinates of the object and time stamps, as well as the visualization on the monitors of the workplaces of the flight or marine personnel, from where the remote management of the proposed utility model.

The described principle for the detection of ultra-weak LMA allows one to build on the basis of the proposed utility model automatic, highly sensitive, highly stable, wide-latitude, airborne, noise-resistant, non-orientable, radio-optical magnetometers for predicting and searching for mineral deposits, as well as for solving a wide range of other problems associated with registering LMA.

The proposed quantum radio-optical magnetometer can be implemented on the basis of the following domestic components.

- tuning speed adjuster 1 - based on a multi-turn potentiometer SP5-1 WB 1 kOhm;

- analog switch 2 - on the chip of the multiplexer 564 KP1;

- RF generator 3 - on digital microcircuits of a series 1533, DAC 1108PA1, operational amplifiers of a series 140 and others;

- modulator 4 - on a 2T368B transistor;

- phase detector 5 - on the chip 564KP1, operational amplifier 544UD2A;

- selector 6 - on operational amplifiers 544UD2A, 140UD20A (7 pcs.);

- sound generator 7 - on digital circuits of the 1554 series;

- decision scheme 8 - on the chip 140UD20;

- calculator 9 - based on the domestic Elbrus processor;

- temperature regulator 10 - based on the operational amplifier 140UD20A;

- the excitation generator of the spectral lamp 11 - on transistors 2T913V, 2T922B and others, the driving generator GK261PS15BM85M5;

- spectral lamp module - based on a spectral lamp manufactured by OJSC TsNPO Leninets with ⁸⁷ RB isotope and krypton buffer gas, with a miniature thermistor TP-1.

- fiber 13 - domestic beam fiber with a diameter of 12 mm;

- modulation coils 14, 27 are wound with PEV-1 wire with a diameter of 0.12 mm;

- lenses 15.1 and 15.2 of optical glass, domestic production;

- fiber guide-collector 16 - domestic beam fiber guide-collector for two branches with a diameter of 12 mm;

- the first absorption cell 17 manufactured by OJSC TsNPO Leninets with the ⁸⁷ RB isotope and helium buffer gas;

- domestic filter 18, transmission 800 nm 80%;

- polaroids 19 quartz plates of domestic production 0.9 mm thick;

- polarizing beam splitting device 20 of domestic manufacture of optical glass with a facet height of 15 mm;

- the second absorption cell 21 manufactured by JSC TsNPO Leninets with the ⁸⁷ RB isotope and helium buffer gas;

- matching device 22 - a bridge amplifier balancing on operational amplifiers 140UD20 and on transistors 2T630A, 2T632A;

- amplifier 23 on an operational amplifier 544UD2A;

- photodetector 24 on the photodiode FD7K;

- compensator 25 sensors based on shunt resistors, flux-gate modules and a specialized electronic unit manufactured by OJSC TsNPO Leninets.

The described quantum radio-optical magnetometer was implemented and tested at JSC TsNPO Leninets as a full-scale model, about which there are corresponding protocols for laboratory research tests.

Claims (1)

A non-orientable quantum radio-optical magnetometer including a radio frequency generator, a modulator, a phase detector, a sound generator, a spectral lamp excitation generator, a spectral lamp module, a first modulation coil, a first lens, a first absorption cell, a light filter, a first polaroid, an amplifier, a photo detector, and the output of a radio frequency generator connected to the input of the modulator, the output of the modulator is connected to the input of the spectral lamp excitation generator, the output of which is connected to the spectral lamp module, the first polaroid is connected to the first absorption cell conjugated to the first lens, the output of the photodetector is connected to the input of the amplifier, the second input of the phase detector is fed a signal from the output of the sound generator, also associated with the first modulation coil, characterized in that it also includes a tuning speed adjuster, an analog switch, a decision circuit, a selector, a computer, a temperature regulator, a polarizing beam splitter, a fiber , a collector fiber, a second absorption cell, a second polaroid, a second modulation coil, a matching device, compensator sensors, and the tuning speed adjuster is connected to the first input of the analog switch, the output of which is connected to the input of the radio frequency generator, the second output of the radio frequency generator is connected to the first input of the calculator , the second input of the analog switch is connected to the output of the phase detector, and the third control input of the analog switch is connected to the output of the decision circuit, and the first output of the selector is connected to the first input of the phase detector, the second output of the selector is connected to the input of the decision circuit, the second input of the calculator is connected to the output of the sensors compensator, the calculator has a bi-directional interface in the direction of the computer network, the output of the amplifier is connected to the input of the matching device, and the output of the matching device is connected to the input of the selector, the electrical output of the spectral lamp module is connected to the input of the thermostat, the output is thermo the regulator is connected to the second input of the spectral lamp excitation generator, and the optical output of the spectral lamp module is connected to the first end of the fiber, the second end of which is connected to one side of the filter, the second side of which is optically connected to the beam-splitting polarizing device, which also has an optical connection with the first and second polaroids, the second polaroid is connected to the second absorption cell, which has an optical connection with the second lens coupled to one of the inputs of the collector fiber, the second input of which is coupled to the first lens that collects light from the first absorption cell, and the output of the collector fiber is connected to the input photodetector, the second modulation coil is connected in series with the first modulation coil.

Images