An apparatus, method and computer device for online distributed optical fiber radiation dose measurement

Abstract

The application provides an online distributed optical fiber radiation dose measurement device, method and computing device, which is used for spatial distribution measurement of radiation dose, and comprises a reference laser generation unit, a test unit, a comparison unit and a data acquisition and analysis unit, wherein the reference laser generation unit is used for generating reference laser; the test unit is used for testing the test optical fiber arranged in a radiation field and outputting a first beat frequency time domain signal to the data acquisition and analysis unit; the comparison unit is used for receiving the reference laser and outputting a first clock trigger signal to the data acquisition and analysis unit; and the data acquisition and analysis unit is used for data acquisition and data analysis and calculating the radiation dose in the radiation field. According to the technical scheme of the application, the fast and high spatial resolution measurement of the radiation dose can be realized, the test cost is low, and the application can be widely applied to various research and development and application scene spatial radiation dose tests.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation measurement, in particular to an online distributed optical fiber radiation dose measurement device, method and computer equipment. BACKGROUND

[0002] Nuclear technology has been applied in many fields and has made outstanding contributions to the economic development and social benefits of mankind. However, due to the characteristics of the rays, if not controlled, it will cause great harm to personnel and the environment. Therefore, in the research and application of nuclear technology, monitoring the distribution of nuclear radiation dose is crucial for the protection of personnel and the environment.

[0003] At present, there are many different measurement techniques for radiation dose measurement at home and abroad, mainly including ionization chamber dosimeter, thermoluminescence dosimeter, gel dosimeter and film dosimeter. Among them, the ionization chamber dosimeter has problems such as angle dependence and ion recombination, and can only measure the dose at a single point; the thermoluminescence dosimeter requires tedious calibration for radiation measurement, and cannot perform real-time high-resolution dose measurement; the polymer gel dosimeter is complex to operate, time-consuming and expensive, making it unsuitable for widespread use; the film dosimeter also has problems such as high cost and inability to measure in real time. These methods and devices cannot achieve online, rapid and high spatial resolution measurement of radiation dose.

[0004] Therefore, a technical solution is needed that can achieve rapid and high spatial resolution measurement of radiation dose while being widely applicable to various research and application scenarios for radiation dose distribution measurement due to its low cost advantage. SUMMARY

[0005] The present application aims to provide an online distributed optical fiber radiation dose measurement device, method and computer program product, which can achieve rapid and high spatial resolution measurement of radiation dose while being widely applicable to various research and application scenarios for spatial radiation dose monitoring due to its low cost advantage.

[0006] According to an aspect of the present application, an online distributed optical fiber radiation dose measurement device is provided, which is used for spatial distribution measurement of radiation dose and includes a reference laser generating unit, a test unit, a comparison unit and a data acquisition and analysis unit, wherein,

[0007] The reference laser generating unit is used to generate reference laser and transmit it to the test unit and the comparison unit;

[0008] The test unit comprises a test optical fiber for receiving the reference laser from the reference laser generation unit and applying the reference laser to test the test optical fiber arranged in a radiation field and output a first beat frequency time domain signal to the data acquisition and analysis unit;

[0009] The comparison unit is configured to receive the reference laser from the reference laser generation unit and output a first clock trigger signal to the data acquisition and analysis unit;

[0010] The data acquisition and analysis unit is configured to perform data acquisition and data analysis calculation on the first beat frequency time domain signal of the test unit according to the first clock trigger signal from the comparison unit to obtain the radiation dose in the radiation field where the test optical fiber is located.

[0011] The test optical fiber is a radiation-sensitive optical fiber, which is fixed in the radiation field according to the path to be measured. The test optical fiber interacts with the radiation, generates corresponding defects in the test optical fiber, and causes the reference laser transmitted by the test optical fiber to be attenuated.

[0012] According to some embodiments, the radiation-sensitive optical fiber comprises a radiation-sensitive doped single-mode optical fiber, which comprises a core, a cladding and a coating layer. The coating layer is a radiation-sensitive material, including but not limited to lead, gold and lithium. The core is made of quartz material, and 0-10wt% of a doping element is added to the quartz material. The doping element includes but is not limited to phosphorus and aluminum.

[0013] According to some embodiments, the device further comprises an optical fiber sensor configured to acquire temperature information of the test optical fiber.

[0014] According to some embodiments, the reference laser generation unit comprises a tunable laser and a first optical splitter,

[0015] The tunable laser is configured to generate the reference laser and input the first optical splitter;

[0016] The first optical splitter divides the reference laser into two paths and inputs the two paths to the test unit and the comparison unit, respectively.

[0017] The test unit further comprises a second optical splitter, a third optical splitter, a circulator and a first photodetector,

[0018] The second optical splitter is configured to receive the reference laser from the reference laser generation unit and divide the reference laser into two paths and input the two paths to the third optical splitter and the circulator, respectively.

[0019] The circulator receives the reference laser from the second optical splitter and inputs the scattered laser signal returned from the test optical fiber after the reference laser into the third optical splitter;

[0020] The third optical splitter receives the reference laser from the second optical splitter and the scattered laser signal from the circulator and inputs the reference laser and the scattered laser signal into the first photodetector;

[0021] The first photodetector is used to convert the optical signal into an electrical signal, and the reference laser and the scattered laser signal interfere on the surface of the first photodetector to generate a first mixed frequency signal, and the first photodetector converts the first mixed frequency signal into the first beat frequency time domain signal and inputs it into the data acquisition and analysis unit;

[0022] The comparison unit comprises a fourth optical splitter, a fifth optical splitter, a fiber delay unit and a second photodetector,

[0023] The fourth optical splitter is used to receive the reference laser from the reference laser generating unit and divide the reference laser into two paths and input them into the fifth optical splitter and the fiber delay unit respectively;

[0024] The fiber delay unit receives the reference laser from the fourth optical splitter, controls the delay output of the reference laser, and inputs the delayed reference laser into the fifth optical splitter;

[0025] The fifth optical splitter receives the reference laser from the fourth optical splitter and the delayed reference laser from the fiber delay unit, and inputs the reference laser and the delayed reference laser into the second photodetector;

[0026] The second photodetector is used to convert the optical signal into an electrical signal, and the reference laser and the delayed reference laser interfere on the surface of the second photodetector to generate a second mixed frequency signal, and the second photodetector converts the second mixed frequency signal into the first clock trigger signal and inputs it into the data acquisition and analysis unit;

[0027] The data acquisition and analysis unit comprises a data acquisition card and a computing device,

[0028] The data acquisition card is used to collect the first beat frequency time domain signal from the test unit according to the first clock trigger signal from the comparison unit, and transmit the collected time domain signal to the computing device;

[0029] The computing device receives the time domain signal from the data acquisition card and performs data analysis to obtain the radiation dose in the radiation field where the test optical fiber is located,

[0030] The data acquisition and analysis unit is configured to:

[0031] The acquired time domain signal is subjected to Fourier transformation to the frequency domain, from which the frequency information of the time domain signal is extracted;

[0032] The scattering points of the test optical fiber are located according to the frequency information;

[0033] The radiation-induced attenuation information of the scattering points of the test optical fiber at different positions is obtained;

[0034] The radiation dose of the test optical fiber in the radiation field is calculated according to the radiation-induced attenuation information at different positions.

[0035] According to another aspect of the present application, an online distributed optical fiber radiation dose measurement method is provided, which is used for measuring the radiation dose in a radiation field by using an optical fiber, and the method comprises:

[0036] The reference laser is divided into two paths, one of which is a test branch, and the other is a comparison branch;

[0037] In the test branch, the reference laser is again divided into two branches, one of which is a test branch, and the other is a first reference branch, the reference laser of the test branch is input into the test optical fiber to generate Rayleigh backscattering signals, and then returned, and the reference laser of the first reference branch is subjected to interference to generate a first beat frequency time domain signal;

[0038] In the comparison branch, the reference laser is again divided into two branches, one of which is a delay branch, and the other is a second reference branch, the reference laser of the delay branch is subjected to delay processing, and then subjected to interference with the reference laser of the second reference branch to generate a first clock trigger signal;

[0039] The first beat frequency time domain signal is subjected to data acquisition according to the first clock trigger signal to obtain a time domain signal, and data analysis and calculation are performed according to the time domain signal to obtain the radiation dose of the test optical fiber in the radiation field:

[0040] The acquired time domain signal is subjected to Fourier transformation to the frequency domain, from which the frequency information of the time domain signal is extracted;

[0041] The scattering points of the test optical fiber are located according to the frequency information;

[0042] The radiation-induced attenuation information of the scattering points of the test optical fiber at different positions is obtained;

[0043] The radiation dose of the test optical fiber in the radiation field is calculated according to the radiation-induced attenuation information at different positions.

[0044] According to some embodiments, the formula for locating the scattering point of the test optical fiber according to the frequency information is as follows:

[0045]

[0046] wherein f0is the obtained beat frequency time domain signal, x is the position corresponding to the scattering point on the test optical fiber, γ is the sweep speed, v f is the propagation speed of light in the test optical fiber.

[0047] According to some embodiments, the formula for calculating the radiation dose of the test optical fiber in the radiation field according to the radiation-induced attenuation information at different positions is as follows:

[0048]

[0049] wherein D T is the radiation dose to be measured at T temperature, c λ is the radiation sensitivity coefficient of the test optical fiber at λ wavelength, RIA (T，λ) is the measured radiation-induced attenuation amount of the test optical fiber at T temperature at λ wavelength.

[0050] According to some embodiments, the optional laser wavelength band of the reference laser includes: 1550 nm wavelength as the center, 1050 nm wavelength as the center, or different wavelength bands in the ultraviolet-visible light region.

[0051] According to some embodiments, the test optical fiber improves the radiation sensitivity and reusability through laser annealing.

[0052] According to another aspect of the present application, a computing device is provided, comprising:

[0053] a processor; and a memory storing a computer program which, when executed by the processor, causes the processor to perform the method of any one of the above.

[0054] According to another aspect of the present application, a non-transitory computer readable storage medium is provided, having stored thereon computer readable instructions which, when executed by a processor, cause the processor to perform the method of any one of the above.

[0055] According to the embodiment of the present application, the design scheme of the present application fully plays the advantages of light weight, flexible structure, flexible arrangement in the measuring environment according to the measuring needs, etc., so that the device can be arranged in the irradiation test environment structure and tested in a large range in a more flexible and efficient manner. The test optical fiber selects a radiation-sensitive doped single-mode optical fiber, which improves the test precision, and through annealing or other methods to improve the radiation sensitivity or the reusability of the optical fiber, further saves the cost, so that the radiation test device can be widely applied. The light signal transmitted in the optical fiber can effectively measure the radiation dose information in a high-temperature high-pressure or complex electromagnetic environment, ensuring the stability of the test and the reliability of the data information; by applying the optical frequency domain reflection technology, the positioning accuracy of the light signal of the test optical fiber can be improved to the micron level, the test distance can reach kilometers, and the measurement precision, sensitivity and real-time radiation monitoring range are greatly improved.

[0056] It should be understood that the foregoing general description and the following detailed description are only examples and do not limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows.

[0058] Figure 1 A schematic diagram of an online distributed optical fiber radiation dose measurement device according to an example embodiment is shown.

[0059] Figure 2 A schematic diagram of a test optical fiber in an online distributed optical fiber radiation dose measurement device according to an example embodiment is shown.

[0060] Figure 3 A structural diagram of an online distributed optical fiber radiation dose measurement device according to an example embodiment is shown.

[0061] Figure 4 A test result schematic diagram of an online distributed optical fiber radiation dose measurement device according to an example embodiment is shown.

[0062] Figure 5 A flowchart of an online distributed optical fiber radiation dose measurement method according to an example embodiment is shown.

[0063] Figure 6 A schematic diagram of an online distributed optical fiber radiation dose measurement method according to an example embodiment is shown.

[0064] Figure 7 A block diagram of a computing device according to an example embodiment is shown. DETAILED DESCRIPTION

[0065] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the several views and, thus, description of the same elements will not be repeated.

[0066] Moreover, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the

[0067] The block diagrams in the drawings show only the functionality and arrangement of physical blocks, these can not necessarily correspond to physical entities in an implementation. That is, these blocks can be implemented in software, or in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0068] The flow diagrams in the drawings show example sequences of operations, not necessarily to be understood as necessarily including all operations and steps, nor necessarily to be performed in the order described. For example, some operations / steps can be performed in different order, or combined or partially combined, and the actual order can vary from case to case.

[0069] It should be understood that although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0070] The user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation portal for user to choose authorization or refusal.

[0071] Those skilled in the art can understand that the drawings are only schematic views of the example embodiments, and the modules or flows in the drawings are not necessarily essential for implementing the present application, and therefore cannot be used to limit the protection scope of the present application.

[0072] Nuclear technology has made outstanding contributions to the economic development and social benefits of all mankind in many fields. Due to the characteristics of the rays, if not controlled, it will cause great harm to personnel and the environment. Therefore, in the research and application of nuclear technology, the monitoring of nuclear radiation dose in space for the protection of personnel and the environment has become the key.

[0073] At present, there are many different measurement techniques for measuring radiation dose at home and abroad, mainly including ionization chamber dosimeters, thermoluminescence dosimeters, gel dosimeters and film dosimeters. Among them, the ionization chamber dosimeter has problems such as angle dependence and ion recombination, and can only measure the dose at a single point; the thermoluminescence dosimeter needs to be calibrated and cannot measure the dose in real time and high resolution; the polymer gel dosimeter is not suitable for popularization and use due to its complex operation process, long time consumption and high price; the film dosimeter also has problems such as high cost and inability to measure in real time. These methods and devices cannot realize online, rapid and high spatial resolution measurement of radiation dose.

[0074] Optical fiber sensors have the advantages of small size, light weight, flexible structure, and resistance to electromagnetic interference due to their physical and chemical properties. In the process of radiation measurement, they can be flexibly arranged, transmit signals while measuring signals, and realize long-distance monitoring of various physical quantities.

[0075] By applying optical frequency domain reflectometry (OFDR), the swept frequency laser emitted by the narrow linewidth swept frequency laser interferes with the Rayleigh scattering signal reflected by the optical fiber under certain conditions to produce mixing. Then the sensing information along the optical fiber to be measured is obtained by detection and calculation. OFDR technology can measure distances up to kilometers, with high detection sensitivity. And because the frequency domain signal is analyzed, high spatial resolution can be achieved while obtaining a large dynamic range.

[0076] To this end, the present application proposes an online distributed optical fiber radiation dose measurement device, method and computer program product, which can realize fast and high spatial resolution measurement of radiation dose, and has low test cost, and can be widely applied to various research and application scene spatial radiation dose tests. According to the embodiment, the design scheme of the present application fully utilizes the characteristics of light structure flexibility, which can be flexibly arranged in the measurement environment according to the needs of measurement, so that the device can be set in a wide range of measurement and complex test environment structure, and is more flexible and efficient. The test optical fiber selects a radiation-sensitive doped single-mode optical fiber, which improves the test precision, and improves the radiation sensitivity or the reusability of the optical fiber through annealing or other methods, further saves the cost, so that the radiation test device can be more widely applied. Since the optical signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature, high pressure or complex electromagnetic environment, the stability of the test and the reliability of the data information are guaranteed; by applying the optical frequency and reflection technology, the spatial resolution of the test optical fiber can reach micron level, the test distance can reach kilometer level, and the information points measured on the optical fiber can be greatly reflected, which greatly improves the measurement precision, sensitivity and real-time radiation monitoring range.

[0077] Before describing the embodiments of the present application, some terms or concepts related to the embodiments of the present application are explained.

[0078] The example embodiments of the present application will be described below with reference to the accompanying drawings.

[0079] Figure 1 A schematic diagram of an online distributed optical fiber radiation dose measurement device according to an example embodiment is shown.

[0080] Referring to Figure 1, the device for spatial distribution measurement of radiation dose comprises a reference laser generating unit 01, a test unit 02, a comparison unit 03 and a data acquisition and analysis unit 04, wherein the reference laser generating unit 01 is used to generate reference laser and transmit the reference laser to the test unit 02 and the comparison unit 03. The test unit 02 comprises a test optical fiber, which is used to receive the reference laser from the reference laser generating unit 01, apply the reference laser to test the test optical fiber arranged in a radiation field, and output a first beat frequency time domain signal to the data acquisition and analysis unit 04; the comparison unit 03 is used to receive the reference laser from the reference laser generating unit 01, and output a first clock trigger signal to the data acquisition and analysis unit 04; the data acquisition and analysis unit 04 is used to perform data acquisition and data analysis calculation on the first beat frequency time domain signal of the test unit 02 according to the first clock trigger signal from the comparison unit 03, to obtain the radiation dose in the radiation field where the test optical fiber is located. Wherein, the test optical fiber is a radiation sensitive optical fiber, the test optical fiber is fixed in the radiation field according to the path to be measured, the test optical fiber interacts with the radiation, corresponding defects are generated in the test optical fiber, and the reference laser conducted by the test optical fiber is lost.

[0081] According to some embodiments, the reference laser generating unit 01 can generate a stable and known characteristic reference laser signal, which provides a standard light source for the whole system, and ensures that the test unit 02 and the comparison unit 03 receive the same laser input. The test unit 02 comprises a section of optical fiber placed in the radiation field, which is used to detect the influence of the radiation field on the characteristics of the optical fiber. The test unit 02 receives the reference laser from the reference laser generating unit 01, and uses this light source to detect the changes of the optical fiber in the radiation field, which are reflected in the form of optical signals and converted into electrical signals, i.e. the first beat frequency time domain signal, which is transmitted to the data acquisition and analysis unit 04.

[0082] According to some embodiments, the arrangement of the test optical fiber can be arranged in a specific shape according to different application scenarios, which can adopt different shapes such as ring shape, side-by-side shape, three-dimensional bending shape, etc. For example, in the distribution measurement in astronauts' bodies, the optical fiber can be placed in the space suit to measure the radiation dose at different positions of the space suit; in the application of radiotherapy, the optical fiber can be laid in the irradiation field or on / in the patient's body to measure the dose distribution in the irradiation field or on / in the patient's body.

[0083] According to some embodiments, the comparison unit 03 receives the same reference laser as the test control group but is not exposed to the radiation field, generates a first clock trigger signal for synchronizing and calibrating the data acquisition of the test unit 02. The data acquisition and analysis unit 04 is responsible for receiving the signals of the test unit 02 and the comparison unit 03 and processing and analyzing them. The first beat frequency time domain signal is obtained from the test unit 02, and the first clock trigger signal is obtained from the comparison unit 03, and then the information of the two is combined to finally obtain the radiation dose value of the position where the test optical fiber is located. The scheme of the present application takes advantage of the high sensitivity and anti-electromagnetic interference capability of optical fiber sensing technology, and can accurately measure the radiation dose in a complex environment. In addition, the distributed characteristics enable the device to monitor the radiation dose distribution in a larger range, and can be widely used in various research and application scenarios for radiation dose testing.

[0084] According to some embodiments, the design scheme of the present application can measure the length of the test optical fiber to reach the order of kilometers, and due to the light weight and flexible structure of the optical fiber, the optical fiber can be arranged flexibly in the measurement environment according to the needs of the measurement. The light signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature, high pressure or complex electromagnetic environment. At the same time, the spatial resolution of the optical frequency domain reflection technology along the optical fiber to be measured can reach the order of microns, which can greatly reflect the information points measured on the optical fiber.

[0085] Figure 2 Fig. 1 shows a schematic diagram of a test optical fiber in an online distributed optical fiber radiation dose measurement device according to an example embodiment.

[0086] Referring to Figure 2 Fig. 1 shows a schematic diagram of a test optical fiber in an online distributed optical fiber radiation dose measurement device according to an example embodiment. The radiation-sensitive optical fiber includes a radiation-sensitive doped single-mode optical fiber, including a core, a cladding, and a coating layer. The coating layer is a radiation-sensitive material, including but not limited to lead, gold, and lithium. The core is made of quartz material, and 0-10wt% of a doping element is added to the quartz material. The doping element includes but is not limited to phosphorus and aluminum.

[0087] According to some embodiments, the test optical fiber is selected from a radiation-sensitive doped single-mode optical fiber (commonly doped with phosphorus and aluminum), and a radiation-sensitive material (such as lead, gold, and lithium, with a thickness of 0-0.05 cm) is used as the optical fiber coating layer. The core of the optical fiber is doped with 0-10wt% of a corresponding element in quartz material. For example, the core diameter of the optical fiber is 10μm, the cladding diameter is 125μm, and the coating layer diameter is 250μm. When the optical fiber is exposed to radiation, defects related to the corresponding doping elements will be generated in the optical fiber, thereby changing the Rayleigh scattering signal generated in the optical fiber and achieving the purpose of radiation dose measurement.

[0088] According to some embodiments, the test optical fiber is improved in radiation sensitivity and reusability by laser annealing. The test optical fiber can also be improved in radiation sensitivity or reusability of the optical fiber by laser annealing or other methods, further reducing the cost of equipment use.

[0089] According to some embodiments, when the test optical fiber is applied in a low-dose radiation environment, the optical fiber coating layer can be selected or doped with a radiation-sensitive material (such as lead, gold, etc.) as a coating layer to improve the radiation sensitivity of the optical fiber.

[0090] According to some embodiments, one end of the radiation-sensitive optical fiber is connected to the device, and the other end of the test optical fiber is knotted and fixed in the radiation field according to the required measurement path. Knotting can reduce the end face scattering of the optical fiber in the measurement results of the device. The optical fiber path is arranged according to the specific position to be measured. The optical fiber should cover the area of interest as much as possible and avoid unnecessary interference sources. This method is suitable for situations where a large range of areas need to be monitored for radiation dose, such as near nuclear power plants, medical radiation therapy devices, industrial radiation sources, etc. Distributed measurement can provide spatial distribution information of the radiation field, which is of great significance for evaluating and managing radiation safety.

[0091] According to some embodiments, the device further comprises an optical fiber sensor for acquiring temperature information of the test optical fiber. The physical properties (such as refractive index) of the optical fiber will change with temperature, so temperature compensation is crucial to ensure the accuracy of radiation dose measurement. By monitoring the temperature in real time, the radiation dose measurement data can be corrected to eliminate errors caused by temperature changes.

[0092] According to some embodiments, the optical fiber sensor can be integrated in the radiation-sensitive optical fiber, or a separate temperature sensing optical fiber can be installed near the test optical fiber. This way, the temperature of the environment where the test optical fiber is located can be monitored in real time. A separate optical fiber can also be arranged next to the radiation-sensitive optical fiber for temperature detection. Although this increases the complexity of the system, it also provides higher flexibility and redundancy.

[0093] Figure 3 A device structure diagram of an online distributed optical fiber radiation dose measurement according to an example embodiment is shown.

[0094] Referring to Figure 3 , a device for online distributed optical fiber radiation dose measurement according to an example embodiment is shown, wherein the reference laser generating unit 01 comprises a tunable laser for generating the reference laser and inputting the first beam splitter, and the first beam splitter divides the reference laser into two paths and inputs them into the test unit 02 and the comparison unit 03, respectively.

[0095] According to some embodiments, the tuning laser emits swept laser, i.e. the reference laser, wherein the light source of the reference laser is a tunable laser light source selected according to the radiation sensitive band of the fiber to be measured, has a narrow line width to meet the coherent detection condition, and the tuning laser has a large scanning frequency and a fast scanning speed so as to make the measurement system achieve a high spatial resolution, and the light source has a good linearity so that the spatial resolution of the system approaches the theoretical value.

[0096] According to some embodiments, the first beam splitter divides the reference laser from the tuning laser into two paths and sends them to the test unit 02 and the comparison unit 03 respectively. The purpose of this is to ensure that the two units receive reference laser with the same characteristics, thereby ensuring the comparability and accuracy of the measurement results.

[0097] According to some embodiments, as shown in Figure 3 The reference laser emitted by the tuning laser enters the test unit 02 and the comparison unit 03 through the first beam splitter. In the test unit 02, the reference laser passes through the second beam splitter again and is divided into two paths, one of which is directly connected to the photodetector as the reference light, and the other of which passes through the circulator and enters the test fiber, generates Rayleigh backscattering signal, returns through the circulator, and the two signals interfere on the surface of the photodetector. In the comparison unit 03, the reference laser is again divided into two signals, one of which passes through the fiber delay and the other of which does not pass through the delay signal to generate an interference signal on the surface of the detector. This can effectively achieve accurate measurement of the radiation dose, and through the setting of the comparison unit 03, it can also effectively eliminate the influence of other factors on the measurement results, thereby improving the reliability of the measurement data.

[0098] According to some embodiments, the test unit 02 further comprises a second beam splitter, a third beam splitter, a circulator and a first photodetector, the second beam splitter is used to receive the reference laser from the reference laser generating unit 01 and divide the reference laser into two paths to input into the third beam splitter and the circulator respectively; the circulator receives the reference laser from the second beam splitter and inputs the scattered laser signal returned by the test fiber after the reference laser is input into the test fiber; the third beam splitter receives the reference laser from the second beam splitter and the scattered laser signal from the circulator, and inputs the reference laser and the scattered laser signal into the first photodetector; the first photodetector is used to convert optical signals into electrical signals, and the reference laser and the scattered laser signal interfere on the surface of the first photodetector to generate a first mixed frequency signal, and the first photodetector converts the first mixed frequency signal into a first beat frequency time domain signal and inputs it into the data acquisition and analysis unit 04.

[0099] According to some embodiments, the second beam splitter splits the reference laser from the reference laser generating unit 01 into two paths, one of which is sent to the third beam splitter, and the other is sent to the circulator. The circulator is a non-reciprocal element that allows one-way transmission of light, inputs the reference laser provided by the second beam splitter into the test optical fiber, receives the scattered laser signal returned from the test optical fiber, and sends it back to the third beam splitter. Finally, the first balanced photodetector is applied to detect the mixed signal generated by the interference of the received two signals, which is converted into an electrical signal. After filtering and amplification, the beat frequency time domain signal is obtained, that is, the first beat frequency time domain signal, and then the signal is input to the data acquisition and analysis unit 04. The test unit 02 can efficiently convert the optical signal into an electrical signal that can be used for analysis, and then help the data acquisition and analysis unit 04 to accurately calculate the radiation dose. This design is particularly suitable for occasions that require high-precision measurement, such as nuclear facilities, medical radiation therapy monitoring, etc.

[0100] According to some embodiments, the contrast unit 03 includes a fourth beam splitter, a fifth beam splitter, a fiber delay, and a second photodetector. The fourth beam splitter is used to receive the reference laser from the reference laser generating unit 01 and split the reference laser into two paths, which are input into the fifth beam splitter and the fiber delay, respectively. The fiber delay receives the reference laser from the fourth beam splitter and controls the delay output of the reference laser, and inputs the delayed reference laser into the fifth beam splitter. The fifth beam splitter receives the reference laser from the fourth beam splitter and the delayed reference laser from the fiber delay, and inputs the reference laser and the delayed reference laser into the second photodetector. The second photodetector is used to convert the optical signal into an electrical signal. The reference laser and the delayed reference laser interfere on the surface of the second photodetector to generate a second mixed signal, which is converted by the second photodetector into a first clock trigger signal and input into the data acquisition and analysis unit 04.

[0101] According to some embodiments, the fourth beam splitter splits the reference laser from the reference laser generating unit 01 into two paths, one of which is sent to the fifth beam splitter, and the other is sent to the fiber delay. The fiber delay can introduce a controllable time delay, and after the reference laser is delayed, it is sent to the fifth beam splitter. Finally, the second balanced photodetector converts it into a first clock trigger signal, and then inputs this signal into the data acquisition and analysis unit 04.

[0102] According to some embodiments, the optical fiber delay line introduces a known time delay, which simulates the propagation time of the optical signal in the test unit 02, and thus generates a first clock trigger signal in the comparison unit 03 that matches the test unit 02. This signal provides a stable time reference for synchronizing the data acquisition of the test unit 02, which helps to eliminate errors caused by time differences. The optical fiber delay line ensures that the time delay of the optical signal in the comparison unit 03 is controllable, thereby improving the stability of the system.

[0103] According to some embodiments, the first and second balanced photodetectors can effectively suppress background noise and improve the quality of the signal, ensuring that the data acquisition and analysis unit 04 receives high-quality clock trigger signals and beat frequency time domain signals.

[0104] According to some embodiments, the data acquisition and analysis unit 04 includes a data acquisition card and a computing device. The data acquisition card is used to collect the first beat frequency time domain signal from the test unit 02 according to the first clock trigger signal from the comparison unit 03, and transfer the collected time domain signal to the computing device. The computing device receives the time domain signal from the data acquisition card and performs data analysis to obtain the radiation dose in the radiation field of the test optical fiber.

[0105] According to some embodiments, in order to improve the spatial resolution, the data acquisition card needs to select a corresponding data acquisition card with high sampling rate according to the selected wavelength range and tuning rate of the light source, and use the first clock trigger signal after the delay interference of the comparison unit 03 as an external clock trigger to collect the first beat frequency time domain signal of the first photodetector and convert it into a digital signal input to the computer.

[0106] According to some embodiments, in order to meet the needs of high spatial resolution measurement, the first and second photodetectors and the data acquisition card need to select the corresponding photoelectric conversion efficiency and sampling rate according to the selected sweep range and sweep rate of the reference laser light source. And use the first clock trigger signal generated by the comparison unit 03 as the external clock of the data acquisition card to compensate for the error caused by the nonlinear sweep of the laser.

[0107] According to some embodiments, the data acquisition and analysis unit 04 is configured to: Fourier transform the collected time domain signal to the frequency domain, extract the frequency information of the time domain signal from it; According to the frequency information, the scattering points of the test optical fiber are located; Obtain the radiation-induced attenuation information of the scattering points of the test optical fiber at different positions; According to the radiation-induced attenuation information at different positions, calculate the radiation dose of the test optical fiber in the radiation field.

[0108] According to some embodiments, the data acquisition card collects data from the first beat frequency time domain signal from the test unit 02 according to the first clock trigger signal from the comparison unit 03, and transmits the collected time domain signal to the computing device. The computing device converts the collected time domain signal to the frequency domain through Fourier transform, from which the frequency information of the signal is extracted. By converting the time domain signal to the frequency domain signal, different frequency components can be more easily identified, thereby locating the scattering points in the optical fiber. Since each scattering point corresponds to a specific frequency, the location of these scattering points in the test optical fiber can be determined according to the frequency information. The radiation-induced attenuation information of the scattering points at different positions of the test optical fiber is obtained. Radiation-induced attenuation (RIA) refers to the additional loss of the optical fiber under the action of radiation. The radiation dose is calculated according to the radiation-induced attenuation information of the scattering points. Since radiation will cause an increase in the loss in the optical fiber, the radiation dose can be inferred by measuring this loss. Finally, the radiation dose of the test optical fiber in the radiation field is calculated.

[0109] Figure 4 A test result diagram of an apparatus for online distributed optical fiber radiation dose measurement is shown according to an example embodiment.

[0110] Referring to Figure 4 , a test result of an apparatus for online distributed optical fiber radiation dose measurement is shown according to an example embodiment, showing the amplitude variation of the irradiated area and the non-irradiated area along the length direction of the optical fiber. From the curve trend, it can be seen that in the first irradiated area, as the length of the optical fiber increases, the signal loss or attenuation causes the amplitude to gradually decrease, indicating that this part of the optical fiber is affected by radiation. After entering the middle non-irradiated area, the amplitude remains stable and does not change significantly, and the signal transmission is relatively smooth, indicating that this part of the optical fiber is not affected by radiation. Upon entering the second irradiated area, the amplitude continues to show a downward trend, indicating that this part of the optical fiber is also affected by radiation, similar to the case of the first irradiated area.

[0111] Figure 5 A flowchart of a method for online distributed optical fiber radiation dose measurement is shown according to an example embodiment.

[0112] Figure 6 A schematic diagram of a method for online distributed optical fiber radiation dose measurement is shown according to an example embodiment.

[0113] Referring to Figure 5 and Figure 6 , a method for online distributed optical fiber radiation dose measurement is shown, which is used for measuring the radiation dose in a radiation field using an optical fiber, the method comprising:

[0114] In S101, the reference laser is divided into two paths: one is the test path, and the other is the comparison path.

[0115] According to some embodiments, firstly, a reference laser beam is split into two paths, namely a test branch and a comparison branch, and data sources are prepared for testing and comparison benchmarks, respectively, in preparation for subsequent data analysis.

[0116] In S103, in the test branch, the reference laser is split into two branches again, one branch is used as the test branch, and the other branch is used as the first reference branch. The reference laser of the test branch is input into the test optical fiber to generate a Rayleigh backscattering signal and then returns, interfering with the reference laser of the first reference branch to generate a first beat frequency time domain signal.

[0117] According to some embodiments, in the test branch, the reference laser is again divided into two parts: the test branch and the first reference branch. The reference laser of the test branch is input into the test optical fiber. Due to the influence of radiation on the optical fiber, the Rayleigh scattering light signal transmitted in the optical fiber is attenuated more in a specific band. After this scattering signal returns, it interferes with the laser of the first reference branch, thereby generating a first beat frequency time domain signal.

[0118] In S105, in the comparison branch, the reference laser is split into two branches again, one branch is used as a delay branch, and the other branch is used as a second reference branch. After the reference laser of the delay branch is delayed, it is interfered with the reference laser of the second reference branch to generate a first clock trigger signal.

[0119] According to some embodiments, in the comparison branch, the reference laser is also divided into two parts: a delay branch and a second reference branch. After a specific delay processing, the laser in the delay branch interferes with the laser in the second reference branch, generating a first clock trigger signal, which is used for subsequent data acquisition of the first beat frequency time domain signal.

[0120] In S107, the first clock trigger signal is used to acquire data from the first beat frequency time domain signal to obtain a time domain signal, and data analysis and calculation are performed based on the time domain signal to obtain the radiation dose in the radiation field where the test optical fiber is located.

[0121] According to some embodiments, see Figure 6When radiation acts on an optical fiber, it induces changes in the atomic or molecular structure within the fiber material, leading to increased energy loss during light transmission—a phenomenon known as "radiation-induced attenuation" (RIA). The reference laser is input into the test optical fiber, generating continuously varying frequency light pulses. These pulses propagate within the fiber and interact with the fiber medium. Some of these pulses are scattered back by impurities or defects within the fiber, forming Rayleigh scattering. This scattered light encounters the undisturbed reference light on the surface of a photodetector, producing an interference effect. The first photodetector receives the mixed optical signals and converts them into electrical signals. These electrical signals are then filtered and amplified to enhance the useful signal and reduce background noise. The data acquisition card digitizes the processed electrical signals and sends them to a computer for further analysis. By analyzing the frequency and amplitude changes of the signal, the computer can calculate the temperature information of the environment in which the fiber is located and the fiber loss information caused by radiation. Finally, using known conversion factors, the fiber loss information is converted into a radiation dose value.

[0122] In S1071, the acquired time-domain signal is transformed to the frequency domain using Fourier transform, and the frequency information of the time-domain signal is extracted from it.

[0123] According to some embodiments, the acquired time-domain signal is converted into a frequency-domain signal using a Fourier transform in order to extract frequency information related to radiation dose. The Fourier transform converts the time-domain data into frequency-domain data. The time-domain data is then processed to generate a corresponding spectrum, which is then analyzed.

[0124] In S1073, the scattering point of the test optical fiber is located based on the frequency information.

[0125] According to some embodiments, the formula for locating the scattering point of the test optical fiber based on the frequency information is as follows:

[0126]

[0127] Where f0 is the obtained beat frequency time-domain signal, x is the position corresponding to the scattering point on the test optical fiber, γ is the sweep frequency speed, and v f Let f0 be the speed of light propagation in the test optical fiber. This is determined by measuring the beat frequency time-domain signal f0, combined with the known sweep velocity γ and the speed of light propagation in the optical fiber v0. f This allows us to determine the location x of the scattering point. In practical applications, the spatial resolution of the scattering point can be achieved on the micrometer scale by locating the point of scattering from the optical fiber based on the frequency information obtained from the detection.

[0128] At S1075, the radiation-induced attenuation information of the scattering points at different positions of the test optical fiber is obtained.

[0129] According to some embodiments, the radiation-induced attenuation refers to the attenuation phenomenon of the optical signal in the optical fiber due to radiation exposure. The radiation-induced attenuation information (RIA) is obtained from the position of the scattering points. Through the position information of the scattering points, the scattering signal intensity at the corresponding position can be obtained, and then the difference between the scattering signal intensities before and after radiation is calculated to obtain the attenuation RIA. Referring to the test device example in Figure 3 , the radiation-induced attenuation can be obtained by the difference between the scattering light intensities before and after the multiple measurement sections on the test optical fiber. Then, the dose distribution information is calculated according to the change in the loss measured before and after the irradiation of the test optical fiber and the known RIA coefficient of the test optical fiber.

[0130] At S1077, the radiation dose of the test optical fiber in the radiation field is calculated according to the radiation-induced attenuation information at different positions.

[0131] According to some embodiments, the formula for calculating the radiation dose of the test optical fiber in the radiation field according to the radiation-induced attenuation information at different positions is as follows:

[0132]

[0133] where D T is the required radiation dose to be measured at T temperature, c λ is the radiation sensitivity coefficient of the test optical fiber at λ wavelength, RIA (T，λ) is the measured radiation-induced attenuation amount of the test optical fiber at λ wavelength. The radiation-induced attenuation amount of the optical fiber under a certain condition is divided by its corresponding radiation sensitivity coefficient, and the radiation dose under the condition is obtained. Such a method obtains the radiation dose by calculation, realizes real-time radiation dose measurement with high spatial resolution, ensures accurate measurement of the radiation dose in the radiation field, and also provides detailed radiation distribution information through the distributed arrangement of the optical fiber, which is of great significance for radiation protection and safety management.

[0134] According to some embodiments, the temperature information T of the environment in which the optical fiber is located can be obtained according to the cross-correlation operation of the collected spectra before and after the measurement to obtain the shift amount of the spectrum. Alternatively, a temperature sensor is added during the measurement, and the radiation sensitivity coefficient c λ can be obtained under different temperature conditions, so as to improve the accuracy of the dose information.

[0135] According to some embodiments, the test optical fiber is selected according to the measurement range. According to the requirement of the measurement range, the test optical fiber is selected according to the range that needs to be covered by the optical fiber. For example, in a larger radiation field, a longer optical fiber is needed to cover the entire area. While in a small local measurement, a shorter optical fiber can be selected. According to the requirement of the measurement environment, the end of the radiation sensitive optical fiber of appropriate length is linked to the device, and the other end of the optical fiber is knotted.

[0136] According to some embodiments, the test optical fiber is selected according to the actual application and the measurement environment. The radiation sensitive optical fiber (commonly doped with phosphorus, aluminum and other elements) is selected to meet the needs of radiation dose measurement in different radiation dose, different dose rate and other complex radiation field environments.

[0137] According to some embodiments, the test optical fiber is fixed in the radiation field according to the required test path. According to the distribution of the actual radiation field and the area to be monitored, the optical fiber is fixed along the specified path. The arrangement of the optical fiber should ensure that it can contact different positions of the radiation source, so as to obtain complete radiation dose distribution information. Through the interaction between the optical fiber and the radiation, corresponding defects are generated in the optical fiber, which causes the loss of the laser transmitted by the optical fiber.

[0138] According to some embodiments, the line width, scanning frequency and scanning speed of the reference laser are selected according to the radiation sensitive band of the test optical fiber. The appropriate reference laser parameters are selected to match the radiation sensitive characteristics of the test optical fiber. Operation: according to the radiation sensitive band of the test optical fiber, the line width, scanning frequency and scanning speed of the reference laser are determined. The selection of these parameters directly affects the accuracy and sensitivity of the measurement. The reference laser has a wide scanning wavelength range, generally greater than 30nm. Among them, according to the selected optical fiber, the optional wavelength band of the reference laser includes: 1550nm wavelength as the center, 1050nm wavelength as the center or different wavelength bands in the ultraviolet visible light region, so that the corresponding optical fiber selected in the measurement of the radiation field can achieve the best measurement effect.

[0139] According to some embodiments, the design scheme of the present application can also be applied to the design and development of computer program products, so that the computer program is executed by the processor to realize the method as claimed in any one of the above, the online, fast and high spatial resolution measurement of radiation dose, and the test cost is low, which can be widely applied to various research and application scene spatial radiation dose test.

[0140] According to some embodiments, the design scheme of the present application fully utilizes the characteristics of light fiber, such as light structure, flexibility, and flexible arrangement in the measuring environment according to the needs of measurement, so that the device can be arranged in a wide range of measurement and complex test environment structure, and is more flexible and efficient. The test optical fiber is selected to be a radiation-sensitive doped single-mode optical fiber, and the radiation sensitivity or the reusability of the optical fiber is improved through annealing or other methods, thereby further saving costs, so that the radiation test device can be more widely applied. The light signal transmitted in the optical fiber can effectively measure the radiation dose information in a high-temperature high-pressure or complex electromagnetic environment, thereby ensuring the stability of the test and the reliability of the data information.

[0141] According to some embodiments, the design scheme of the present application applies optical frequency domain reflection technology, so that the spatial resolution of the test optical fiber can reach microns, the test distance can reach kilometers, the information points measured on the optical fiber can be greatly reflected, and the measurement accuracy, sensitivity and real-time radiation monitoring range are greatly improved.

[0142] Figure 7 A block diagram of a computing device according to an example embodiment of the present application is shown.

[0143] As shown in Figure 7 The computing device 30 includes a processor 12 and a memory 14. The computing device 30 can also include a bus 22, a network interface 16, and an I / O interface 18. The processor 12, the memory 14, the network interface 16, and the I / O interface 18 can communicate with each other through the bus 22.

[0144] The processor 12 can include one or more general-purpose CPUs (Central Processing Units), microprocessors, or application-specific integrated circuits, etc., for executing related program instructions. According to some embodiments, the computing device 30 can also include a high-performance display adapter (GPU) 20 for accelerating the processor 12.

[0145] The memory 14 can include a machine system readable medium in the form of volatile memory, such as a random access memory (RAM), a read-only memory (ROM), and / or a cache memory. The memory 14 is used to store one or more programs containing instructions and data. The processor 12 can read the instructions stored in the memory 14 to execute the above-mentioned method according to the embodiments of the present application.

[0146] The computing device 30 can also communicate with one or more networks through the network interface 16. The network interface 16 can be a wireless network interface.

[0147] Bus 22 can include an address bus, a data bus, a control bus, etc. Bus 22 provides a means for letting the various components perform interchange of information.

[0148] It should be noted that, in the actual implementation process, the computing device 30 can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only contain components necessary for the implementation of the embodiments of the present application, and does not necessarily contain all the components shown in the figure.

[0149] The present application also provides a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the above method. The computer readable storage medium can include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, micro-drives, and magneto-optical disks, ROM, RAM, EPROM, EEPROM, DRAM, VRAM, flash memory device, magnetic or optical cards, nanosystem (including molecular memory IC), network storage device, cloud storage device, or any type of medium or device suitable for storing instructions and / or data.

[0150] The embodiments of the present application also provide a computer program product, which includes a non-transitory computer readable storage medium storing a computer program, the computer program being operable to cause a computer to perform some or all of the steps of any one of the methods described in the above method embodiments.

[0151] Those skilled in the art can clearly understand that the technical solutions of the present application can be realized by means of software and / or hardware. The "unit" and "module" in the present specification refer to software and / or hardware that can independently complete or cooperate with other components to complete a specific function, wherein the hardware can be, for example, a field programmable gate array, an integrated circuit, etc.

[0152] It should be noted that, for the foregoing method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application.

[0153] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0154] In several embodiments of the present application, it should be understood that the disclosed apparatus can be implemented in other manners. For example, the division of the apparatus embodiments is merely an example, and for other division manners, the embodiments of the present application can be implemented in a manner of other division. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be implemented by using some interfaces, and the indirect couplings or communication connections between the apparatuses or units can be implemented in electronic, mechanical or other forms.

[0155] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0156] In addition, the functional units in each embodiment of the present application can be integrated into a processing unit, or each unit can be physically present alone, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0157] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable memory. Based on this understanding, the technical solutions of the present application essentially or the part of the prior art that contributes or the whole or part of the technical solutions can be embodied in the form of a software product, which is stored in a memory and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the embodiments of the present application.

[0158] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0159] The exemplary embodiments of the present application are specifically shown and described above. It should be understood that the present application is not limited to the detailed structure, arrangement or implementation method described herein. On the contrary, the present application is intended to cover various modifications and equivalent arrangements within the spirit and scope of the appended clauses.

Claims

1. An apparatus for online distributed optical fiber radiation dose measurement, characterized in that, The device is used for spatial distribution measurement of radiation dose, comprising: a reference laser generating unit, a testing unit, a comparison unit and a data acquisition and analysis unit, wherein, The reference laser generating unit is used for generating reference laser and transmitting to the testing unit and the comparison unit; The testing unit comprises a testing optical fiber, which is used for receiving reference laser from the reference laser generating unit and applying the reference laser to test the testing optical fiber arranged in a radiation field, and outputting a first beat frequency time domain signal to the data acquisition and analysis unit; The comparison unit is used for receiving reference laser from the reference laser generating unit and outputting a first clock trigger signal to the data acquisition and analysis unit; The data acquisition and analysis unit is used for acquiring time domain signal of the first beat frequency time domain signal of the testing unit according to the first clock trigger signal from the comparison unit, and performing data analysis and calculation according to the time domain signal to obtain radiation dose in the radiation field where the testing optical fiber is located, The testing optical fiber is a radiation sensitive optical fiber, which is fixed in the radiation field according to the path to be measured, interacts with radiation, produces corresponding defects in the testing optical fiber, and causes the reference laser conducted by the testing optical fiber to be lost, The reference laser generating unit comprises a tuning laser and a first optical splitter, The tuning laser is used for generating the reference laser and inputting the first optical splitter; The first optical splitter divides the reference laser into two paths and inputs them into the testing unit and the comparison unit respectively; The testing unit further comprises a second optical splitter, a third optical splitter, a circulator and a first photoelectric detector, The second optical splitter is used for receiving reference laser from the reference laser generating unit and dividing the reference laser into two paths and inputting them into the third optical splitter and the circulator respectively; The circulator receives reference laser from the second optical splitter and inputs the scattered laser signal returned after the reference laser is input into the testing optical fiber into the third optical splitter; The third optical splitter receives reference laser from the second optical splitter and the scattered laser signal from the circulator, and inputs the reference laser and the scattered laser signal into the first photoelectric detector; The first photoelectric detector is used for converting optical signal into electrical signal, and the reference laser and the scattered laser signal interfere on the surface of the first photoelectric detector to produce a first mixed frequency signal, which is converted into the first beat frequency time domain signal and input into the data acquisition and analysis unit; The comparison unit comprises a fourth optical splitter, a fifth optical splitter, an optical fiber delay line and a second photoelectric detector, The fourth optical splitter is used for receiving reference laser from the reference laser generating unit and dividing the reference laser into two paths and inputting them into the fifth optical splitter and the optical fiber delay line respectively; The optical fiber delay receives the reference laser from the fourth optical splitter, controls the delay output of the reference laser, and inputs the delayed reference laser into the fifth optical splitter; The fifth optical splitter receives the reference laser from the fourth optical splitter and the delayed reference laser from the optical fiber delay, and inputs the reference laser and the delayed reference laser into the second photodetector; The second photodetector is used to convert optical signals into electrical signals, and the reference laser and the delayed reference laser interfere on the surface of the second photodetector to generate a second mixed frequency signal, which is converted into the first clock trigger signal by the second photodetector and input into the data acquisition and analysis unit; The data acquisition and analysis unit includes a data acquisition card and a computing device, The data acquisition card is used to collect the first beat frequency time domain signal from the test unit according to the first clock trigger signal from the comparison unit, and transmit the collected time domain signal to the computing device; The computing device receives the time domain signal from the data acquisition card and performs data analysis to obtain the radiation dose in the radiation field where the test optical fiber is located, The data acquisition and analysis unit is configured to: perform Fourier transformation on the collected time domain signal to the frequency domain, and extract the frequency information of the time domain signal therefrom; position the scattering points of the test optical fiber according to the frequency information; obtain the radiation-induced attenuation information of the scattering points of the test optical fiber at different positions; calculate the radiation dose of the test optical fiber in the radiation field according to the radiation-induced attenuation information at different positions.

2. The apparatus of claim 1, wherein, The radiation-sensitive optical fiber includes a radiation-sensitive doped single-mode optical fiber, including a core, a cladding, and a coating layer, wherein the coating layer is a radiation-sensitive material, including but not limited to lead, gold, and lithium; the core adopts quartz material, and 0-10wt% of a doping element is added to the quartz material, the doping element including but not limited to phosphorus and aluminum.

3. The apparatus of claim 1, wherein, Further comprising: an optical fiber sensor for acquiring temperature information of the test optical fiber.

4. A method of online distributed optical fiber radiation dose measurement, characterized by, The method is used for measuring the radiation dose in a radiation field by using an optical fiber, and the method includes: dividing the reference laser into two paths, one as a test branch and the other as a comparison branch; in the test branch, the reference laser is divided into two branches again, one as a test branch and the other as a first reference branch, the reference laser of the test branch is input into the test optical fiber to generate Rayleigh backscattering signals, and then returned to interfere with the reference laser of the first reference branch to generate a first beat frequency time domain signal; in the comparison branch, the reference laser is divided into two branches again, one as a delay branch and the other as a second reference branch, the reference laser of the delay branch is delayed, and then interferes with the reference laser of the second reference branch to generate a first clock trigger signal; in the comparison branch, the reference laser is divided into two branches again, one as a delay branch and the other as a second reference branch, the reference laser of the delay branch is delayed, and then interferes with the reference laser of the second reference branch to generate a first clock trigger signal; According to the first clock trigger signal, a time domain signal is obtained by data acquisition of the first beat frequency time domain signal, and a radiation dose in a radiation field where the test optical fiber is located is obtained by data analysis and calculation according to the time domain signal: The acquired time domain signal is subjected to Fourier transformation to a frequency domain, and frequency information of the time domain signal is extracted therefrom; According to the frequency information, a scattering point of the test optical fiber is positioned; Radiation-induced attenuation information of the scattering point of the test optical fiber at different positions is obtained; According to the radiation-induced attenuation information at different positions, a radiation dose of the test optical fiber in the radiation field is calculated.

5. The method of claim 4, wherein, The formula for positioning the scattering point of the test optical fiber according to the frequency information is as follows: wherein, is the obtained beat frequency time domain signal, is the position corresponding to the scattering point on the test optical fiber, and γ is the sweep speed, is the propagation speed of light in the test optical fiber.

6. The method of claim 5, wherein, The formula for calculating the radiation dose of the test optical fiber in the radiation field according to the radiation-induced attenuation information at different positions is as follows: wherein, D is the radiation dose to be measured at temperature T, β is the radiation sensitivity coefficient of the test optical fiber at wavelength λ, D is the radiation dose to be measured at temperature T, D is the radiation dose to be measured at temperature T, 7. The method of claim 4, wherein, The optional laser wavelength band of the reference laser includes: 1550nm wavelength as the center, 1050nm wavelength as the center, or different wavelength bands in the ultraviolet-visible light region.

8. The method of claim 4, wherein, The test optical fiber is improved in radiation sensitivity and reusability by laser annealing.

9. A computing device, comprising: It comprises: a processor; and a memory storing a computer program, which, when executed by the processor, causes the processor to execute the method according to any one of claims 4-8.

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