Online distributed optical fiber radiation dose measurement device and method and computer equipment

Abstract

The invention provides an online distributed optical fiber radiation dose measurement device and method and computing equipment, the device is used for spatial distribution measurement of radiation dose, the device comprises a reference laser generation unit, a test unit, a comparison unit and a data acquisition and analysis unit, 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 invention, rapid and high-spatial-resolution measurement of the radiation dose can be realized, the test cost is low, and the method can be widely applied to radiation dose tests of various research and development and application scene spaces.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear radiation measurement, and in particular to an apparatus, method and computer equipment for online distributed optical fiber radiation dose measurement. Background Art

[0002] Nuclear technology has been developed and has irreplaceable applications in many fields, making outstanding contributions to the economic development and social benefits of all mankind. However, due to the characteristics of radiation itself, if it is not controlled, it will cause great harm to personnel and the environment. Therefore, in the research and development and application of nuclear technology, monitoring the distribution of nuclear radiation dose has become the key to protect personnel and the environment.

[0003] At present, there are many different measurement technologies for radiation dose measurement at home and abroad, mainly including: ionization chamber dosimeter, thermoluminescence dosimeter, gel dosimeter and film dosimeter. Among them, ionization chamber dosimeter has problems such as angle dependence and ion recombination, and can only measure single-point dose; thermoluminescence dosimeter requires cumbersome calibration to measure radiation, and cannot perform real-time high-resolution dose measurement; polymer gel dosimeter is not suitable for promotion and use due to its complex operation, long time consumption and high price; film dosimeter also has problems such as high cost and inability to measure in real time. These methods and devices cannot achieve online, fast and high spatial resolution measurement of radiation dose.

[0004] To this end, a technical solution is needed that can achieve fast, high spatial resolution measurement of radiation dose while also being widely applicable to radiation dose distribution measurement in various research and development and application scenarios with the advantage of low cost. Summary of the invention

[0005] The present invention aims to provide an apparatus, method and computer program product for online distributed optical fiber radiation dose measurement, which can achieve fast and high spatial resolution measurement of radiation dose and can also be widely used in spatial radiation dose monitoring in various research and development and application scenarios with the advantage of low cost.

[0006] According to one aspect of the present invention, there is provided an online distributed optical fiber radiation dose measurement device, which is used for measuring the spatial distribution of radiation dose, and comprises: a reference laser generating unit, a testing 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 the reference laser to the testing unit and the comparing unit;

[0008] The test unit includes a test optical fiber, which is used to receive the reference laser from the reference laser generating unit and use the reference laser to test the test optical fiber arranged in the radiation field, and output a first beat frequency time domain signal to the data acquisition and analysis unit;

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

[0010] The data acquisition and analysis unit is used 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 a radiation field according to a path to be measured. The test optical fiber interacts with the radiation, causing corresponding defects in the test optical fiber, causing loss of the reference laser transmitted by the test optical fiber.

[0012] According to some embodiments, the radiation-sensitive optical fiber includes a radiation-sensitive doped single-mode optical fiber, including a core, a cladding, and a coating, wherein the coating is a radiation-sensitizing material, including but not limited to lead, gold, and lithium; the core is made of quartz material, and 0-10wt% of doping elements are added to the quartz material, and the doping elements include but are not limited to: phosphorus and aluminum.

[0013] According to some embodiments, the device further comprises: an optical fiber sensor, wherein the optical fiber sensor is used to obtain temperature information of the test optical fiber.

[0014] According to some embodiments, the reference laser generating unit comprises: a tunable laser and a first beam splitter,

[0015] The tunable laser is used to generate the reference laser and input the reference laser into the first beam splitter;

[0016] The first beam splitter splits the reference laser into two paths and inputs them into the test unit and the comparison unit respectively;

[0017] The test unit further includes: a second beam splitter, a third beam splitter, a circulator and a first photodetector,

[0018] The second beam splitter is used to receive the reference laser from the reference laser generating unit and split the reference laser into two paths, which are input to the third beam splitter and the circulator respectively;

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

[0020] 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 to the first photodetector;

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

[0022] The comparison unit includes: a fourth optical splitter, a fifth optical splitter, an optical fiber delay device and a second photodetector,

[0023] The fourth optical splitter is used to receive the reference laser from the reference laser generating unit and split the reference laser into two paths, which are input to the fifth optical splitter and the optical fiber delay device respectively;

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

[0025] The fifth beam splitter receives the reference laser from the fourth beam splitter and the delayed reference laser from the fiber delay device, and inputs the reference laser and the delayed reference laser to the second photodetector;

[0026] 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 mixing signal, and the second photodetector converts the second mixing signal into the first clock trigger signal and inputs it into the data acquisition and analysis unit;

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

[0028] The data acquisition card is used to collect data of 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 as follows:

[0031] The collected time domain signal is transformed into the frequency domain through Fourier transform, and the frequency information of the time domain signal is extracted therefrom;

[0032] Positioning the scattering point of the test optical fiber according to the frequency information;

[0033] Obtaining radiation induced attenuation information of the scattering points of the test optical fiber at different positions;

[0034] The radiation dose of the testing 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 invention, there is provided an online distributed optical fiber radiation dose measurement method, the method being used to measure the radiation dose in a radiation field using an optical fiber, the method comprising:

[0036] The reference laser is divided into two paths, one 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 branch is used as a test branch, and the other branch is used as a 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, and interferes with the reference laser of the first reference branch to generate a first beat frequency time domain signal;

[0038] In the comparison branch, the reference laser is again divided into two branches, 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 interferes with the reference laser of the second reference branch to generate a first clock trigger signal;

[0039] According to the first clock trigger signal, data is collected on the first beat frequency time domain 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 in the radiation field where the test optical fiber is located:

[0040] Transforming the collected time domain signal into the frequency domain through Fourier transform, and extracting the frequency information of the time domain signal therefrom;

[0041] Positioning the scattering point of the test optical fiber according to the frequency information;

[0042] Obtaining radiation induced attenuation information of the scattering points of the test optical fiber at different positions;

[0043] The radiation dose of the testing 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, 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 speed, and 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] Among them, D T is the radiation dose to be measured at temperature T, c λ is the radiation sensitivity coefficient of the test optical fiber at wavelength λ, RIA (T，λ) To measure the radiation induced attenuation of the test optical fiber at wavelength λ at temperature T.

[0050] According to some embodiments, the optional laser wavelength bands of the reference laser include: a wavelength centered at 1550 nm, a wavelength centered at 1050 nm, or different wavelength bands in the ultraviolet and visible light regions.

[0051] According to some embodiments, the test optical fiber is laser annealed to improve radiation sensitivity and reusability.

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

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

[0054] According to another aspect of the present invention, there is provided a non-transitory computer-readable storage medium having computer-readable instructions stored thereon, and when the instructions are executed by a processor, the processor is caused to execute any of the above methods.

[0055] According to the embodiments of the present invention, the design scheme of the present invention gives full play to the advantages of optical fiber, such as light weight, flexible structure, and the ability to be flexibly arranged in the measurement environment according to measurement needs, so that the device can be arranged and tested over a large range in the irradiation test environment structure in a more flexible and efficient manner. The test optical fiber uses radiation-sensitive doped single-mode optical fiber to improve the test accuracy, and improves the radiation sensitivity or reusability of the optical fiber through annealing or other methods, further saving costs, so that the radiation test device can be widely used. The optical signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature and high pressure or complex electromagnetic environments, ensuring the stability of the test and the reliability of the data information; by applying optical frequency domain reflection technology, the positioning accuracy of the optical signal of the test optical fiber can be improved to the micron level, and the test distance can reach the kilometer level, which greatly improves the measurement accuracy, sensitivity and real-time radiation monitoring range.

[0056] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

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

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

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

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

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

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

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

[0065] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted.

[0066] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solution of the present invention can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring various aspects of the present invention.

[0067] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0068] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0069] It should be understood that although the terms first, second, third, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another component. Therefore, the first component discussed below can be referred to as the second component without departing from the teachings of the present inventive concept. As used herein, the term "and / or" includes any one of the associated listed items and all combinations of one or more.

[0070] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0071] Those skilled in the art will appreciate that the drawings are merely schematic diagrams of example embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing the present invention, and therefore cannot be used to limit the protection scope of the present invention.

[0072] Nuclear technology has been developed and has irreplaceable applications in many fields, making outstanding contributions to the economic development and social benefits of all mankind. Due to the characteristics of radiation itself, if it is not controlled, it will cause great harm to personnel and the environment. Therefore, in the research and development and application of nuclear technology, monitoring the 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 technologies for radiation dose measurement at home and abroad, mainly including: ionization chamber dosimeter, thermoluminescence dosimeter, gel dosimeter and film dosimeter. Among them, ionization chamber dosimeter has problems such as angle dependence and ion recombination, and can only measure single-point dose; thermoluminescence dosimeter requires cumbersome calibration to measure radiation, and cannot perform real-time high-resolution dose measurement; polymer gel dosimeter is not suitable for promotion and use due to its complex operation process, long time consumption and high price; film dosimeter also has problems such as high cost and inability to measure in real time. These methods and devices cannot achieve online, fast and high spatial resolution measurement of radiation dose.

[0074] Due to its physical and chemical properties, optical fiber sensors have the advantages of small size, light weight, flexible structure, and anti-electromagnetic interference. When used in the radiation measurement process, they can be flexibly arranged, transmit signals while measuring them, and monitor a variety of physical quantities over long distances.

[0075] By applying the optical frequency domain reflectometry (OFDR) technology, the swept laser emitted by the narrow linewidth swept laser interferes with the Rayleigh scattered 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 through detection and calculation. The OFDR technology can measure distances up to kilometers and has high detection sensitivity. And because of the analysis of frequency domain signals, a large dynamic range can be obtained while achieving high spatial resolution.

[0076] To this end, the present invention proposes an online distributed optical fiber radiation dose measurement device, method and computer program product, which can realize the rapid and high spatial resolution measurement of radiation dose, and the test cost is low, and can be widely used in radiation dose tests in various research and development and application scenarios. According to the embodiment, the design scheme of the present invention gives full play to the characteristics of optical fiber light weight and flexible structure, and can be flexibly arranged in the measurement environment according to the measurement needs, so that the device can be set up in a large-scale measurement and complex test environment structure, which is more flexible and efficient. The test optical fiber uses radiation-sensitive doped single-mode optical fiber to improve the test accuracy, and improves the radiation sensitivity or the reusability of the optical fiber by annealing or other methods, further saving costs, so that the radiation test device can be more widely used. Since the optical signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature and high pressure or complex electromagnetic environment, the stability of the test and the reliability of the data information are guaranteed; by applying optical frequency and reflection technology, the spatial resolution of the test optical fiber can reach the micron level, and the test distance can reach the kilometer level, which can largely reflect the information points measured on the optical fiber, greatly improving the measurement accuracy, sensitivity and the range of real-time radiation monitoring.

[0077] Before describing the embodiments of the present invention, some terms or concepts involved in the embodiments of the present invention are explained.

[0078] Exemplary embodiments of the present invention are described below with reference to the accompanying drawings.

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

[0080] See also Figure 1, the figure shows an apparatus for measuring radiation dose of online distributed optical fiber according to an exemplary embodiment, the apparatus is used for measuring the spatial distribution of radiation dose, and 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 for generating a reference laser and transmitting it to the test unit 02 and the comparison unit 03. The test unit 02 comprises a test optical fiber, which is used for receiving a reference laser from the reference laser generating unit 01 and applying the reference laser to test 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 04; the comparison unit 03 is used for receiving a reference laser from the reference laser generating unit 01 and outputting a first clock trigger signal to the data acquisition and analysis unit 04; the data acquisition and analysis unit 04 is used for performing 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, and obtaining the radiation dose in the radiation field where the test optical fiber is located. The test optical fiber is a radiation-sensitive optical fiber, which is fixed in a radiation field according to a path to be measured. The test optical fiber interacts with the radiation, causing corresponding defects in the test optical fiber, causing loss of the reference laser transmitted by the test optical fiber.

[0081] According to some embodiments, the reference laser generating unit 01 is capable of generating a stable reference laser signal with known characteristics, providing a standard light source for the entire system, and ensuring that the test unit 02 and the comparison unit 03 receive the same laser input. The test unit 02 includes a section of optical fiber placed in a 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 in the optical fiber in the radiation field. These changes will be reflected in the form of optical signals and the optical signals will be converted into electrical signals, namely 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, and can adopt different shapes such as ring, side-by-side, three-dimensional bending, etc. For example, when measuring the distribution inside the astronaut's body, the optical fiber can be placed inside the space suit to measure the radiation dose at different positions of the space suit; in radiotherapy applications, it can be laid out in the irradiation field or on the patient's body surface / body to measure the dose distribution in the irradiation field or on the patient's body surface / body.

[0083] According to some embodiments, the comparison unit 03 serves as a test control group, receives the same reference laser but is not exposed to the radiation field, and 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. Then, the information of the two is combined to finally obtain the radiation dose value at the location of the test optical fiber. The scheme of the present invention utilizes the advantages of high sensitivity and anti-electromagnetic interference ability 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 large range, and can be widely used in radiation dose testing in various research and development and application scenarios.

[0084] According to some embodiments, the test optical fiber measurement length in the design of the present invention can reach the kilometer level, and because the optical fiber is light and flexible in structure, the optical fiber can be flexibly arranged in the measurement environment according to the measurement needs. The optical signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature and high pressure or complex electromagnetic environments. At the same time, the spatial resolution of the optical frequency domain reflection technology along the optical fiber to be tested can reach the micron level, which can largely reflect the information points measured on the optical fiber.

[0085] Figure 2 A schematic diagram of a test optical fiber in a device for online distributed optical fiber radiation dose measurement according to an exemplary embodiment is shown.

[0086] See also Figure 2 , the figure 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, wherein the coating layer is a radiation sensitizing material, including but not limited to lead, gold, and lithium; the core is made of quartz material, and 0-10wt% of doping elements are added to the quartz material, and the doping elements include but are not limited to: phosphorus and aluminum.

[0087] According to some embodiments, the test optical fiber uses a radiation-sensitive doped single-mode optical fiber (commonly doped with phosphorus and aluminum), and uses a radiation-sensitizing material (such as lead, gold, lithium, etc., with a thickness of 0-0.05 cm) as the optical fiber coating. The optical fiber core is doped with 0-10wt% of the corresponding element in the quartz material. For example, the optical fiber core diameter is 10μm, the cladding diameter is 125μm, and the coating 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, so that the Rayleigh scattering signal generated in the optical fiber changes, thereby achieving the purpose of radiation dose measurement.

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

[0089] According to some embodiments, when the test optical fiber is used in a low-dose radiation environment, the optical fiber coating layer may be selected or doped with radiation-sensitive materials (such as lead, gold, etc.) as a coating layer to enhance 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 path to be measured. Knotting can reduce the end-face scattering of the optical fiber end in the measurement results of the device. The optical fiber path is arranged according to the specific location 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 radiation dose monitoring of a large area is required, such as nuclear power plants, near medical radiotherapy equipment, industrial radiation sources and other places. Distributed measurement can provide spatial distribution information of the radiation field, which is of great significance for the assessment and management of radiation safety.

[0091] According to some embodiments, the device further comprises: an optical fiber sensor, which is used to obtain temperature information of the test optical fiber. The physical properties of the optical fiber (such as the refractive index) will change with the change of temperature. Therefore, temperature compensation is essential to ensure the accuracy of radiation dose measurement. By real-time monitoring of temperature, the radiation dose measurement data can be corrected to eliminate the error caused by temperature change.

[0092] According to some embodiments, the optical fiber sensor can be integrated into the radiation sensitive optical fiber, or an independent temperature sensing optical fiber can be installed near the test optical fiber. In this way, the temperature of the environment in which the test optical fiber is located can be monitored in real time. Alternatively, a separate optical fiber can 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 structural diagram of an apparatus for online distributed optical fiber radiation dose measurement according to an exemplary embodiment is shown.

[0094] See also Figure 3 , the figure shows an apparatus for online distributed optical fiber radiation dose measurement according to an example embodiment, wherein the reference laser generating unit 01 comprises: a tunable laser and a first beam splitter, the tunable laser is used to generate the reference laser and input it into the first beam splitter; the first beam splitter splits 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 tunable laser emits a 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 optical fiber to be measured, and has a narrow linewidth to meet the coherent detection conditions, and the tunable laser has a large scanning frequency and a fast scanning speed so that the measurement system achieves high spatial resolution, and the light source has a good linearity so that the spatial resolution of the system is close to the theoretical value.

[0096] According to some embodiments, the first beam splitter splits the reference laser from the tuned laser into two paths, which are respectively transmitted to the test unit 02 and the comparison unit 03. This is to ensure that the two units receive reference lasers with the same characteristics, thereby ensuring the comparability and accuracy of the measurement results.

[0097] According to some embodiments, Figure 3 As shown, the reference laser emitted by the tuned laser passes through the first beam splitter and enters the test unit 02 and the comparison unit 03 respectively. Among them, in the test unit 02, it 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 passes through the circulator to enter the test optical fiber, generating a Rayleigh backscattering signal and returning through the circulator, and the two signals interfere on the surface of the photodetector. In the comparison unit 03, the reference laser is divided into two signals again, one of which is delayed by the optical fiber and generates an interference signal with the other signal that has not been delayed on the detector surface. It can effectively achieve accurate measurement of 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 credibility of the measurement data.

[0098] According to some embodiments, the test unit 02 also includes: a second beam splitter, a third beam splitter, a circulator and a first photodetector, wherein the second beam splitter is used to receive the reference laser from the reference laser generating unit 01 and split the reference laser into two paths and input them 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 after the reference laser is input into the test optical fiber into the third beam splitter; the third beam splitter receives the reference laser from the second beam splitter and the scattered laser signal of the circulator, and inputs the reference laser and the scattered laser signal into the first photodetector; 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 mixing signal, and the first photodetector converts the first mixing signal into the 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 divides the reference laser from the reference laser generating unit 01 into two paths, one path is sent to the third beam splitter, and the other path is sent to the circulator. The circulator is a non-reciprocal element that allows unidirectional transmission of light. The reference laser provided by the second beam splitter is input into the test optical fiber, and the scattered laser signal returned from the test optical fiber is received, and then it is sent back to the third beam splitter. Finally, the first balanced photodetector is used to detect the mixed signal generated by the interference of the two signals, and converts it 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 is obtained, and then this signal is input into 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, thereby helping the data acquisition and analysis unit 04 to accurately calculate the radiation dose. This design is particularly suitable for occasions requiring high-precision measurement, such as nuclear facilities, medical radiotherapy monitoring and other fields.

[0100] According to some embodiments, the comparison unit 03 includes: a fourth beam splitter, a fifth beam splitter, a fiber delay device and a second photodetector, wherein the fourth beam splitter is used to receive the reference laser from the reference laser generating unit 01 and divide the reference laser into two paths and input them into the fifth beam splitter and the fiber delay device respectively; the fiber delay device receives the reference laser from the fourth beam splitter, controls the delayed 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 of the fiber delay device, and inputs the reference laser and the delayed reference laser into the second photodetector; the second photodetector is used to convert an 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 mixing signal, and the second photodetector converts the second mixing signal into the first clock trigger signal and inputs it into the data acquisition and analysis unit 04.

[0101] According to some embodiments, the fourth optical splitter divides the reference laser from the reference laser generating unit 01 into two paths, one path is sent to the fifth optical splitter, and the other path is sent to the optical fiber delay device. The optical fiber delay device can introduce a controllable time delay, and after delaying the reference laser, it is sent to the fifth optical 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, by introducing a known time delay through the optical fiber delay device, the optical fiber delay device can simulate the propagation time of the optical signal in the test unit 02, thereby generating a first clock trigger signal matching the test unit 02 in the comparison unit 03. 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 device 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, improve signal quality, and ensure 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, wherein the data acquisition card is used to perform data acquisition on 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 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.

[0105] According to some embodiments, in order to improve the spatial resolution capability, the data acquisition card needs to select a corresponding data acquisition card with a high sampling rate for data acquisition according to the selected light source tuning wavelength range and tuning rate, and use the first clock trigger signal after delayed 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 for input into a computer.

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

[0107] According to some embodiments, the data acquisition and analysis unit 04 is configured to: transform the collected time domain signal into the frequency domain through Fourier transform, and extract the frequency information of the time domain signal therefrom; locate 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; and calculate the radiation dose of the test optical fiber in the radiation field according to the radiation induced attenuation information at different positions.

[0108] According to some embodiments, the data acquisition card performs data acquisition on 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 acquired time domain signal to the computing device. The computing device converts the acquired time domain signal into the frequency domain through Fourier transform, and extracts the frequency information of the signal therefrom. By converting the time domain signal into 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 position of these scattering points in the test optical fiber can be determined based on the frequency information. The radiation-induced attenuation information of the scattering points of the test optical fiber at different positions is obtained. Radiation-induced attenuation (RIA) refers to the additional loss generated by the optical fiber under the action of radiation. The radiation dose is calculated based on the radiation-induced attenuation information of the scattering points. Since radiation causes 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 schematic diagram showing test results of an apparatus for online distributed optical fiber radiation dose measurement according to an example embodiment is shown.

[0110] See also Figure 4 , the figure shows the test results of an online distributed optical fiber radiation dose measurement device according to an example embodiment, showing the amplitude changes in the irradiated area and the non-irradiated area along the length of the optical fiber. Observing the trend of the curve, it can be seen that: in the first irradiated area, as the length of the optical fiber increases, the signal is lost or attenuated, and the amplitude gradually decreases, indicating that this part of the optical fiber is affected by radiation. After entering the middle non-irradiated area, the amplitude remains stable without significant changes, and the signal transmission is relatively smooth, indicating that this section of the optical fiber is not affected by radiation. Entering the second irradiated area again, the amplitude continues to show a downward trend, indicating that this part of the optical fiber is also affected by radiation, similar to the situation in the first irradiated area.

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

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

[0113] See also Figure 5 as well as Figure 6 , the figure shows a method for online distributed optical fiber radiation dose measurement, the method is used to measure the radiation dose in the radiation field using optical fiber, the method comprises:

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

[0115] According to some embodiments, first, a reference laser beam is divided into two branches, namely a test branch and a comparison branch, to prepare data sources for testing and as a comparison benchmark, respectively, in preparation for subsequent data analysis.

[0116] In S103, in the test branch, the reference laser is again divided into two branches, one branch is used as a test branch, and the other branch is used as a 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 returned, 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: a test branch and a first reference branch. The reference laser of the test branch is input into the test optical fiber. Since the optical fiber is affected by radiation, the attenuation of the Rayleigh scattered light signal transmitted in the optical fiber increases in a specific band. After returning, this scattered signal 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 again divided into two branches, 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 interferes 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 process, the laser of the delay branch interferes with the laser of the second reference branch to generate a first clock trigger signal for subsequent data acquisition of the first beat frequency time domain signal.

[0120] In S107, the first clock trigger signal is used to perform data acquisition on 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 a radiation dose in a radiation field where the test optical fiber is located.

[0121] According to some embodiments, see Figure 6When radiation acts on the optical fiber, it will cause changes in the atomic or molecular structure of the optical fiber material, resulting in increased energy loss during light transmission, which is called "radiation induced attenuation" (RIA). The reference laser is input into the test optical fiber to form a continuously changing frequency light pulse. These light pulses will propagate in the optical fiber and interact with the optical fiber medium. Some light pulses will be scattered back by impurities or defects in the optical fiber to form Rayleigh scattered light. This part of the scattered light meets the undisturbed reference light on the surface of the photodetector, producing an interference effect. The first photodetector receives the mixed optical signal and converts it into an electrical signal. Subsequently, these electrical signals are filtered and amplified to enhance the useful signal and reduce background noise. The data acquisition card is responsible for digitizing the processed electrical signal and sending it to the computer for further analysis. By analyzing the frequency and amplitude changes of the signal, the computer can solve the temperature information of the environment in which the optical fiber is located and the optical fiber loss information caused by radiation. Finally, the optical fiber loss information is converted into a radiation dose value using a known conversion coefficient.

[0122] In S1071, the collected time domain signal is transformed into the frequency domain through Fourier transformation, and the frequency information of the time domain signal is extracted therefrom.

[0123] According to some embodiments, the collected time domain signal is converted into a frequency domain signal by Fourier transform, so as to extract frequency information related to the radiation dose. The time domain data is converted into frequency domain data by Fourier transform. The time domain data is processed to generate a corresponding spectrum, and the generated spectrum is analyzed.

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

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

[0126]

[0127] Wherein, 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 speed, and v f is the propagation speed of light in the test optical fiber. By measuring the beat frequency time domain signal f0, combined with the known sweep frequency speed γ and the propagation speed v of light in the optical fiber f , we can get the position x of the scattering point. In practical application scenarios, the point where the optical fiber scatters is located based on the frequency information obtained by detection, and the spatial resolution of the scattering point position can reach the micron level.

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

[0129] According to some embodiments, the radiation-induced attenuation refers to the attenuation of optical signals in optical fibers due to radiation exposure. Radiation-induced attenuation (RIA) information is obtained from the position of the scattering point. The intensity of the scattering signal at the corresponding position can be obtained through the position information of the scattering point, and then the difference in the intensity of the scattering signal before and after radiation is calculated to obtain the attenuation RIA. Figure 3 In the example of the test device, the radiation induced attenuation can be obtained by measuring the difference in scattered light intensity before and after multiple measurement sections on the test optical fiber. The dose distribution information is then calculated based on the loss change measured before and after the test optical fiber is irradiated 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] Among them, D T is the radiation dose to be measured at temperature T, c λ is the radiation sensitivity coefficient of the test optical fiber at wavelength λ, RIA (T，λ) To measure the radiation-induced attenuation of the test optical fiber at the wavelength λ. By measuring the radiation-induced attenuation of the optical fiber under specific conditions and dividing it by its corresponding radiation sensitivity coefficient, the radiation dose under the conditions can be obtained. This method obtains the radiation dose by calculation, realizes real-time radiation dose measurement with high spatial resolution, and can provide detailed radiation distribution information through distributed optical fibers while ensuring accurate measurement of the radiation dose in the radiation field, 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 by performing cross-correlation calculation on the spectra collected before and after the measurement to obtain the offset of the spectrum. Alternatively, a temperature sensor is added during the measurement process to obtain the radiation sensitivity coefficient c under different temperature conditions. λ , which can improve the accuracy of dosage information.

[0135] According to some embodiments, a test optical fiber of a suitable length is selected according to the measurement range. A test optical fiber of a suitable length is selected according to the requirements of the measurement range, and the measurement range determines the area that the optical fiber needs to cover. For example, in a larger radiation field, a longer optical fiber is required to cover the entire area. When measuring a small local area, a shorter optical fiber can be selected. According to the requirements of the measurement environment, one end of a radiation-sensitive optical fiber of a suitable length is selected to be connected to the device, and the other end of the optical fiber is knotted.

[0136] According to some embodiments, the test optical fiber selects the corresponding radiation sensitive optical fiber (commonly used optical fiber doped with elements such as phosphorus and aluminum) according to the measurement environment in actual applications to meet the needs of radiation dose measurement under different radiation doses, different dose rates and other complex radiation field environments.

[0137] According to some embodiments, the test optical fiber is fixed in the radiation field according to the path to be tested. The optical fiber is fixed along the specified path according to the distribution of the actual radiation field and the area to be monitored. The arrangement of the optical fiber should ensure that it can contact different positions of the radiation source 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, causing the laser conducted by the optical fiber to be lost.

[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. Appropriate reference laser parameters are selected to match the radiation-sensitive characteristics of the test optical fiber. Operation: Determine the line width, scanning frequency and scanning speed of the reference laser according to the radiation-sensitive band of the test optical fiber. 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, the reference laser segment is different according to the selected optical fiber. The optional laser bands of the reference laser include: 1550nm wavelength as the center, 1050nm wavelength as the center or different bands in the ultraviolet visible light region, so that the corresponding optical fiber selected for the corresponding radiation field in the measurement can achieve the best measurement effect.

[0139] According to some embodiments, the design scheme of the present invention can also be applied to the design and development of computer program products, so that when the computer program is executed by the processor, the method as described in any of the above items is implemented, and the radiation dose is measured online, quickly, and with high spatial resolution. Moreover, the testing cost is low, and it can be widely used in radiation dose testing in various research and development and application scenarios.

[0140] According to some embodiments, the design scheme of the present invention gives full play to the characteristics of optical fiber, which is light in weight and flexible in structure, and can be flexibly arranged in the measurement environment according to the measurement needs, so that the device can be set up in a large-scale measurement and complex test environment structure, which is more flexible and efficient. The test optical fiber uses radiation-sensitive doped single-mode optical fiber, and improves the radiation sensitivity or reusability of the optical fiber through annealing or other methods, further saving costs, so that the radiation test device can be more widely used. The optical signal transmitted in the optical fiber can effectively measure the radiation dose information in high temperature and high pressure or complex electromagnetic environment, ensuring the stability of the test and the reliability of the data information.

[0141] According to some embodiments, the design of the present invention applies optical frequency domain reflection technology so that the spatial resolution of the test optical fiber can reach the micron level, and the test distance can reach the kilometer level. It can reflect the information points measured on the optical fiber to a large extent, greatly improving the measurement accuracy, sensitivity and the range of real-time radiation monitoring.

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

[0143] like Figure 7 As shown, computing device 30 includes processor 12 and memory 14. Computing device 30 may also include bus 22, network interface 16, and I / O interface 18. Processor 12, memory 14, network interface 16, and I / O interface 18 may communicate with each other via bus 22.

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

[0145] The memory 14 may include a machine system readable medium in the form of a 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 including instructions and data. The processor 12 can read the instructions stored in the memory 14 to execute the above-mentioned method according to the embodiment of the present invention.

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

[0147] The bus 22 may include an address bus, a data bus, a control bus, etc. The bus 22 provides a path for exchanging information between components.

[0148] It should be noted that, in the specific implementation process, the computing device 30 may also include other components necessary for normal operation. In addition, those skilled in the art may understand that the above device may only include components necessary for implementing the embodiments of this specification, and need not include all components shown in the figure.

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

[0150] An embodiment of the present invention also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute part or all of the steps of any method recorded in the above method embodiments.

[0151] Those skilled in the art can clearly understand that the technical solution of the present invention can be implemented with the help of software and / or hardware. "Unit" and "module" in this specification refer to software and / or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a field programmable gate array, an integrated circuit, etc.

[0152] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0153] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0154] In the several embodiments provided by the present invention, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

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

[0156] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0157] If the integrated unit is implemented 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 solution of the present invention is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the methods of various embodiments of the present invention.

[0158] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

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

Claims

1. An online distributed optical fiber radiation dose measurement device, characterized in that: The device is used for measuring the spatial distribution of radiation dose, and comprises: a reference laser generating unit, a testing unit, a comparing unit and a data acquisition and analysis unit, wherein: The reference laser generating unit is used to generate reference laser and transmit the reference laser to the testing unit and the comparing unit; The test unit includes a test optical fiber, which is used to receive the reference laser from the reference laser generating unit and use the reference laser to test the test optical fiber arranged in the radiation field, and output a first beat frequency time domain signal to the data acquisition and analysis unit; The comparison unit is used to receive the reference laser from the reference laser generating unit and output a first clock trigger signal to the data acquisition and analysis unit; The data acquisition and analysis unit is used to acquire data of the first beat frequency time domain signal of the test unit according to the first clock trigger signal from the comparison unit to obtain a time domain signal, and perform data analysis and calculation according to the time domain signal to obtain the radiation dose in the radiation field where the test optical fiber is located. The test optical fiber is a radiation-sensitive optical fiber, which is fixed in a radiation field according to a path to be measured. The test optical fiber interacts with the radiation, causing corresponding defects in the test optical fiber, causing loss of the reference laser transmitted by the test optical fiber.

2. The device according to claim 1, characterized in that The radiation sensitive optical fiber comprises a radiation sensitive doped single mode optical fiber, including a core, a cladding and a coating layer, wherein the coating layer is a radiation sensitizing material, including but not limited to lead, gold and lithium; the core is made of quartz material, and 0-10wt% of doping elements are added to the quartz material, and the doping elements include but are not limited to: phosphorus and aluminum.

3. The device according to claim 1, characterized in that Also includes: An optical fiber sensor is used to obtain temperature information of the test optical fiber.

4. The device according to claim 1, characterized in that The reference laser generating unit comprises: a tunable laser and a first beam splitter, The tunable laser is used to generate the reference laser and input the reference laser into the first beam splitter; The first beam splitter splits the reference laser into two paths and inputs them into the test unit and the comparison unit respectively; The test unit further includes: 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 and split the reference laser into two paths, which are input to the third beam splitter and the circulator respectively; The circulator receives the reference laser from the second optical splitter, and inputs the scattered laser signal returned after the reference laser is input into the test optical fiber into the third optical splitter; 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 to the first photodetector; The first photodetector is used to convert the optical signal into an electrical signal, the reference laser and the scattered laser signal interfere on the surface of the first photodetector to generate a first mixing signal, and the first photodetector converts the first mixing signal into the first beat frequency time domain signal and inputs it into the data acquisition and analysis unit; The comparison unit includes: a fourth optical splitter, a fifth optical splitter, an optical fiber delay device and a second photodetector, The fourth optical splitter is used to receive the reference laser from the reference laser generating unit and split the reference laser into two paths, which are input to the fifth optical splitter and the optical fiber delay device respectively; The optical fiber delay device receives the reference laser from the fourth optical splitter, controls the delayed output of the reference laser, and inputs the delayed reference laser into the fifth optical splitter; The fifth beam splitter receives the reference laser from the fourth beam splitter and the delayed reference laser from the fiber delay device, and inputs the reference laser and the delayed reference laser to 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 mixing signal, and the second photodetector converts the second mixing signal into the first clock trigger signal and inputs it 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 data of 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 as follows: The collected time domain signal is transformed into the frequency domain through Fourier transform, and the frequency information of the time domain signal is extracted therefrom; Positioning the scattering point of the test optical fiber according to the frequency information; Obtaining radiation induced attenuation information of the scattering points of the test optical fiber at different positions; The radiation dose of the testing optical fiber in the radiation field is calculated according to the radiation induced attenuation information at different positions.

5. A method for online distributed optical fiber radiation dose measurement, characterized in that: The method is used to measure the radiation dose in a radiation field using an optical fiber, and the method comprises: The reference laser is divided into two paths, one is a test branch and the other is a comparison branch; In the test branch, the reference laser is again divided into two branches, one branch is used as a test branch, and the other branch is used as a 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, and interferes 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 again divided into two branches, 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 interferes with the reference laser of the second reference branch to generate a first clock trigger signal; According to the first clock trigger signal, data is collected on the first beat frequency time domain 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 in the radiation field where the test optical fiber is located: Transforming the collected time domain signal into the frequency domain through Fourier transform, and extracting the frequency information of the time domain signal therefrom; Positioning the scattering point of the test optical fiber according to the frequency information; Obtaining radiation induced attenuation information of the scattering points of the test optical fiber at different positions; The radiation dose of the testing optical fiber in the radiation field is calculated according to the radiation induced attenuation information at different positions.

6. The method according to claim 5, characterized in that The formula for locating the scattering point of the test optical fiber according to the frequency information is as follows: Wherein, 0 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 speed, and v f is the propagation speed of light in the test optical fiber.

7. The method according to claim 6, characterized in that 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: Among them, D T is the radiation dose required to be measured at temperature T, c λ is the radiation sensitivity coefficient of the test optical fiber at wavelength λ, RIA (T，λ) To measure the radiation induced attenuation of the test optical fiber at wavelength λ at temperature T.

8. The method according to claim 5, characterized in that The optional laser wavelength bands of the reference laser include: Centered around 1550nm wavelength, centering around 1050nm wavelength or in different bands in the ultraviolet visible light region.

9. The method according to claim 5, characterized in that The test optical fiber is laser annealed to improve radiation sensitivity and reusability.

10. A computing device, characterized in that: include: processor; as well as A memory storing a computer program, which, when executed by the processor, enables the processor to perform the method according to any one of claims 5 to 9.

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