Temperature stress detection system and detection method based on Bragg grating fiber sensor

Abstract

The invention discloses a temperature stress detection system based on a Bragg grating fiber sensor. The temperature stress detection system comprises a plasma generation system and a temperature strain measurement system, according to the plasma generation system, a helicon wave plasma generator is arranged in an irradiation chamber, and working gas is provided for a plasma generation area in the irradiation chamber; spreading the helicon wave plasma to the sample to be detected in the irradiation chamber along the axial direction; the temperature strain measurement system comprises a strain gauge measurement acquisition instrument, a Bragg grating demodulator, a strain gauge measurement acquisition instrument and a thermocouple measurement acquisition instrument which are used for detecting a to-be-measured sample; and the temperature and strain measurement system is used for detecting the temperature and strain of the to-be-tested sample during the irradiation test. The invention discloses a temperature stress detection system and detection method based on a Bragg grating fiber sensor, which realize in-situ measurement under a plasma irradiation condition and have the functions of strong anti-electromagnetic interference capability, strong expandability and wide application range.

Description

Technical Field

[0001] This invention relates to the field of materials testing technology, specifically to a temperature stress detection system and method based on a Bragg grating fiber optic sensor. Background Technology

[0002] In magnetic confinement fusion devices, high-heat-load materials such as tungsten-copper alloys are widely used in critical components such as the first wall and divertors. Under conditions of high heat flux density, high-energy particle bombardment, and strong electromagnetic field coupling, these materials experience significant temperature gradients, thermal stress, and thermal fatigue damage. Therefore, high-precision, in-situ, and real-time measurement of the temperature and stress of these materials under plasma irradiation conditions is a crucial technical means to evaluate their service performance and failure mechanisms.

[0003] In existing technologies, material temperature measurement mainly employs thermocouples, infrared thermometry, or embedded resistance sensors; strain measurement primarily relies on resistance strain gauges. Furthermore, research has explored the use of fiber Bragg grating (FBG) sensors for structural health monitoring or strain / temperature detection in high-temperature environments. For example, existing FBG detection schemes include: directly attaching or embedding single or multiple Bragg grating fibers onto the surface of the structure under test; retrieving temperature or strain through grating wavelength drift; and using dual gratings or reference gratings for temperature compensation in some engineering applications. In fusion-related research, there are also reports of using FBGs for structural monitoring in vacuum, high-temperature, or irradiated environments, but these are mostly concentrated on static thermal structures or non-plasma conditions, and the objects being measured are mostly simple block or plate-like structures.

[0004] In summary, the existing technology has at least the following shortcomings: 1. Difficulty adapting to plasma irradiation environments. Traditional electrical sensors are susceptible to plasma electromagnetic noise, bias voltage, and particle bombardment, resulting in insufficient measurement stability and reliability.

[0005] 2. Severe coupling between temperature and strain signals. A single FBG sensor is sensitive to both temperature and strain, and existing solutions lack an effective temperature compensation structure design for plasma irradiation conditions.

[0006] 3. Not applicable to tube-type tungsten-copper alloy structures. Existing testing methods are mostly designed for solid or simple structures, making it difficult to perform multi-point, in-situ measurements on tube-type tungsten-copper alloy blocks that are internally cooled and subjected to non-uniform heating.

[0007] 4. Lack of system integration with plasma-driven conditions. In existing technologies, sensing systems are often not integrated with plasma generation, bias loading, and cooling systems, making it difficult to conduct material performance testing under real fusion simulation conditions. Summary of the Invention

[0008] This invention overcomes the shortcomings of the prior art and provides a temperature stress detection system and method based on a Bragg grating fiber optic sensor, which realizes in-situ measurement under plasma irradiation conditions and has the functions of strong anti-electromagnetic interference capability, strong scalability, and wide applicability.

[0009] To achieve the above objectives, the technical solution adopted by this invention is as follows: a temperature stress detection system based on a Bragg grating fiber optic sensor, comprising: a plasma generation system and a temperature strain measurement system; the plasma generation system includes an irradiation chamber, in which a helical wave plasma generator is disposed and provides working gas to the plasma generation region within the irradiation chamber; a helical wave plasma is generated within the irradiation chamber, which is externally equipped with an applied magnetic field; the helical wave plasma is propagated axially to the sample to be tested within the irradiation chamber; thereby driving the injection and permeation of the working gas substance into the sample to be tested; the temperature strain measurement system includes a strain gauge measurement and acquisition instrument, a Bragg grating demodulator, a strain gauge measurement and acquisition instrument, and a thermocouple measurement and acquisition instrument for detecting the sample to be tested; the temperature strain measurement system is used to detect the temperature and strain of the sample to be tested during irradiation testing.

[0010] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a second Bragg grating fiber connected to a Bragg grating demodulator; The second Bragg grating fiber is placed in a groove one opened on the sample to be tested, and the second Bragg grating fiber is fixed in the groove one with ceramic glue. The strain generated by the sample to be tested during irradiation is measured by a Bragg grating demodulator.

[0011] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a chiller, which is connected to a copper tube inserted into the sample under test via a water-cooling pipeline. The chiller and the water-cooling pipeline provide coolant to the copper tube in the sample under test to provide cooling energy to the sample under test during irradiation.

[0012] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a bias power supply, which is electrically connected to the sample under test via a cable.

[0013] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a fixing through hole in the sample to be tested, one end of the Bragg grating fiber is fixed to the sample to be tested by ceramic tape, and the fiber of the Bragg grating fiber makes contact with the sample to be tested. The first Bragg grating fiber is connected to the Bragg grating demodulator via cable to measure the temperature of the sample under test during irradiation and to perform temperature compensation on the second Bragg grating fiber.

[0014] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a strain gauge, which is attached to the sample to be tested and connected to a strain gauge measurement and acquisition instrument via a cable, for measuring the strain generated when the sample to be tested is irradiated.

[0015] In a preferred embodiment of the present invention, the temperature strain measurement system further includes a thermocouple, a ceramic tube is sleeved around the thermocouple, and the thermocouple with the ceramic tube sleeved is embedded in a test hole opened on the sample to be tested; the thermocouple is connected to a thermocouple measurement and acquisition instrument via a cable for measuring the temperature of the sample to be tested during irradiation.

[0016] In a preferred embodiment of the present invention, the sample to be tested is installed inside a vacuum chamber in front of the helical wave plasma beam.

[0017] In a preferred embodiment of the present invention, the plasma generation system further includes a quartz tube installed at the tail end of the irradiation chamber and a helical wave plasma antenna surrounding the outside of the quartz tube; the helical wave plasma antenna is electrically connected to the radio frequency power supply through a matching device and is used to excite the formation of helical wave plasma under the action of an external axial magnetic field. The tail end of the quartz tube is connected to a mass flow meter and a gas cylinder via a stainless steel gas tube; the gas cylinder is supplied to the plasma generation area by adjusting the gas flow rate of the working gas through the mass flow meter. A DC power supply provides DC power to the electromagnetic coil to generate an axial magnetic field in the plasma generation region to support the formation and propagation of helical wave plasma. The bottom of the irradiation chamber is connected to a vacuum pump assembly to provide the vacuum environment required for plasma discharge.

[0018] In a preferred embodiment of the present invention, a detection method for a temperature stress detection system based on a Bragg grating fiber sensor is implemented using a temperature stress detection system based on a Bragg grating fiber sensor, comprising: a sample installation stage, a device vacuum and measurement system preparation stage, and a sample irradiation detection stage. The sample installation stage includes: installing the sample to be tested inside the vacuum chamber in front of the helical wave plasma beam; connecting the copper tube passing through the sample to a chiller via a cooling pipe; connecting the sample to a bias power supply via a cable; and connecting the strain gauge, thermocouple, Bragg grating fiber 2, and Bragg grating fiber 1 installed on the sample to the strain gauge measurement and acquisition instrument, Bragg grating demodulator, strain gauge measurement and acquisition instrument, and thermocouple measurement and acquisition instrument, respectively, thus completing the installation before the temperature stress detection system is tested. The preparation phase of the device vacuum and measurement system includes: based on the installed temperature stress detection system, debugging and calibrating the plasma generation system and the temperature strain measurement system respectively; The commissioning and calibration of the plasma generation system includes: Turn off the mass flow meter, turn on the vacuum pump group, and when the vacuum in the irradiation chamber meets the requirements, start plasma discharge to calibrate the temperature strain system; open the gas cylinder, turn on the mass flow meter to control the argon flow rate to 50 sccm, and turn on the DC power supply to adjust the current to 100A.

[0019] The debugging and calibration of the temperature strain measurement system includes: Turn on the bias power supply and adjust it to 200V. Turn on the chiller, and then turn on the Bragg grating demodulator, strain gauge measurement and acquisition instrument and thermocouple measurement and acquisition instrument in sequence. Once the readings stabilize, the preparation of the measurement system is complete. The sample irradiation detection stage includes: starting plasma discharge and measuring temperature strain based on the debugged and calibrated plasma generation system and temperature strain measurement system.

[0020] This invention addresses the deficiencies in the technical background, and the beneficial technical effects of this invention are: A temperature stress detection system and method based on a Bragg grating fiber optic sensor is disclosed, which enables in-situ measurement under plasma irradiation conditions and features strong anti-electromagnetic interference capability, strong scalability, and wide applicability.

[0021] 1. This invention integrates Bragg grating fiber, strain gauge and thermocouple into a plasma irradiation device, which can simultaneously acquire material temperature and strain data under real plasma bombardment and bias loading conditions, and realize in-situ measurement under plasma irradiation conditions.

[0022] 2. By setting up two Bragg grating optical fibers, one for temperature measurement and the other for strain measurement, the influence of temperature drift on strain measurement is effectively reduced, thus helping to improve the accuracy of temperature-strain decoupling and compensation.

[0023] 3. The tube-type structure for internal cooling can accurately reflect the thermo-mechanical coupling response characteristics of key components of the fusion device.

[0024] 4. Fiber optic sensors are unaffected by the electromagnetic environment of plasma, significantly improving the stability of the measurement system under strong electromagnetic and particle irradiation conditions, exhibiting strong anti-electromagnetic interference capabilities and high measurement reliability.

[0025] 5. This invention is not only applicable to tungsten-copper alloy materials, but can also be extended to the testing of material properties in other fusion candidate materials or high-energy particle irradiation environments. It has strong scalability and a wide range of applications. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Figure 1 This is a schematic diagram of the temperature stress detection system based on a Bragg grating fiber optic sensor in a preferred embodiment of the present invention; Figure 2 This is a side view of the sensor mounting module in a temperature stress detection system based on a Bragg grating fiber optic sensor according to a preferred embodiment of the present invention. Figure 3 This is an axial view of the sensor mounting module in a temperature stress detection system based on a Bragg grating fiber optic sensor according to a preferred embodiment of the present invention. The components include: 1. Quartz tube; 2. Helical wave plasma antenna; 3. Temperature strain measurement system; 4. Bragg grating demodulator; 5. Strain gauge measurement and acquisition instrument; 6. Thermocouple measurement and acquisition instrument; 7. Irradiation chamber; 8. Bias power supply; 9. Chiller; 10. Vacuum pump group; 11. Electromagnetic coil; 12. DC power supply; 13. Gas cylinder; 14. Mass flow meter; 15. Matching device; 16. Radio frequency power supply; 17. Sample to be tested; 18. Strain gauge; 19. Ceramic tube; 20. Thermocouple; 21. Copper tube; 22. Bragg grating fiber 1; 23. Bragg grating fiber 2. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams, which are only used to illustrate the basic structure of the present invention and therefore only show the components relevant to the present invention.

[0029] It should be noted that if directional indicators (such as up, down, bottom, top, etc.) are involved in the embodiments of the present invention, these directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature. Unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0030] Example 1, as Figures 1-3 As shown, a temperature stress detection system based on a Bragg grating fiber optic sensor includes: a plasma generation system and a temperature strain measurement system.

[0031] The plasma generation system includes an irradiation chamber 7, within which a helical wave plasma generator is installed, supplying working gas to the plasma generation region. An external magnetic field is applied to the irradiation chamber 7 to generate helical wave plasma, which propagates axially to the sample 17 within the irradiation chamber 7, driving the injection and permeation of the working gas into the sample 17. The sample 17 is mounted inside the vacuum chamber 7, directly in front of the helical wave plasma beam. The working gas is either argon or deuterium.

[0032] The temperature strain measurement system includes a strain gauge 18, a thermocouple 20, a second Bragg grating fiber 23, and a first Bragg grating fiber 22, all mounted on the sample 17 to be tested. It also includes a strain gauge measurement and acquisition instrument 3, a Bragg grating demodulator 4, a strain gauge measurement and acquisition instrument 5, and a thermocouple measurement and acquisition instrument 6, all connected to the strain gauge 18, thermocouple 20, second Bragg grating fiber 23, and first Bragg grating fiber 22, respectively. The temperature strain measurement system is used to detect the temperature and strain of the sample 17 during irradiation testing.

[0033] In Example 2, based on Example 1, a second Bragg grating fiber 23 is placed in a groove 1 on the sample 17 to be tested, and the second Bragg grating fiber 23 is fixed in the groove 1 with ceramic adhesive. The second Bragg grating fiber 23 of the temperature strain measurement system is connected to the Bragg grating demodulator 4. The strain generated by the sample 17 to be tested during irradiation is measured by the Bragg grating demodulator 4.

[0034] Specifically, the chiller 9 of the temperature strain measurement system is connected to the copper tube 21 inserted inside the sample 17 through a water-cooling pipeline. The chiller 9 and the water-cooling pipeline provide coolant to the copper tube 21 inside the sample 17 to provide cold energy to the sample 17 during the irradiation process.

[0035] Specifically, the bias power supply 8 of the temperature strain measurement system is electrically connected to the sample 17 under test via a cable. The bias power supply 8 is used to increase the energy of the plasma bombardment of the sample 17 under test.

[0036] Specifically, the Bragg grating fiber 22 of the temperature strain measurement system is inserted into a fixed through hole in the sample 17 to be tested. One end of the Bragg grating fiber 22 is fixed to the sample 17 to be tested with ceramic tape, and the fiber of the Bragg grating fiber 22 is in contact with the sample 17 to be tested. The Bragg grating fiber 22 is connected to the Bragg grating demodulator 4 through a cable to measure the temperature of the sample 17 to be tested during irradiation and to perform temperature compensation for the second Bragg grating fiber 23.

[0037] Specifically, the strain gauge 18 of the temperature strain measurement system is attached to the sample 17 to be tested, and the strain gauge 18 is connected to the strain gauge measurement and acquisition instrument 5 via a cable to measure the strain generated when the sample 17 is irradiated.

[0038] Specifically, the thermocouple 20 of the temperature strain measurement system is covered with a ceramic tube 19, and the thermocouple 20 covered with the ceramic tube 19 is embedded in the test hole opened on the sample 17 to be tested; the thermocouple 20 is connected to the thermocouple measurement and acquisition instrument 6 through a cable to measure the temperature of the sample 17 under irradiation.

[0039] In Example 3, based on Example 1 or Example 2, the plasma generation system further includes a quartz tube 1 installed at the tail end of the irradiation chamber 7, and a helical wave plasma antenna 2 surrounding the outside of the quartz tube 1. The helical wave plasma antenna 2 is electrically connected to the radio frequency power supply 16 through a matching device 15, and is used to excite the formation of helical wave plasma under the action of an external axial magnetic field. The tail end of the quartz tube 1 is connected to a mass flow meter 13 and a gas cylinder 13 through a stainless steel gas pipe. The gas cylinder 13 adjusts the gas flow rate of the working gas through the mass flow meter 14 to provide working gas to the plasma generation area. The DC power supply 12 provides DC power to the electromagnetic coil 11 to form an axial magnetic field in the plasma generation area to support the formation and propagation of the helical wave plasma. A vacuum pump group 10 is connected to the bottom of the irradiation chamber 7 to provide the vacuum environment required for plasma discharge. However, it is not limited to this. In other embodiments, the plasma generation system can also adopt other existing structures and use the temperature stress detection system of this invention to connect and set with the sample 17 to realize the temperature stress detection of the sample 17.

[0040] Example 4: A detection method for a temperature stress detection system based on a Bragg grating fiber optic sensor, implemented using any one of Examples 1 to 3, includes: a sample installation stage, a device vacuum and measurement system preparation stage, and a sample irradiation detection stage.

[0041] The sample installation stage includes: installing the sample to be tested 17 inside the vacuum chamber 7, directly in front of the helical wave plasma beam; connecting the copper tube 21 passing through the sample to be tested 17 to the chiller 9 through the cooling pipe; connecting the sample to be tested 17 to the bias power supply 8 through the cable; and connecting the strain gauge 18, thermocouple 20, Bragg grating fiber 23, and Bragg grating fiber 22 set on the sample to be tested 17 to the strain gauge measurement and acquisition instrument 3, the Bragg grating demodulator 4, the strain gauge measurement and acquisition instrument 5, and the thermocouple measurement and acquisition instrument 6, respectively, to complete the installation before the temperature stress detection system is tested.

[0042] The preparation phase of the device vacuum and measurement system includes: based on the installed temperature stress detection system, debugging and calibrating the plasma generation system and the temperature strain measurement system respectively; The commissioning and calibration of the plasma generation system includes: Turn off the mass flow meter 14, turn on the vacuum pump group 10, and when the vacuum in the irradiation chamber 7 meets the requirements, start plasma discharge to calibrate the temperature strain system; turn on the gas cylinder 13, turn on the mass flow meter 14 to control the argon flow rate to 50 sccm, and turn on the DC power supply 12 to adjust the current to 100A.

[0043] The debugging and calibration of the temperature strain measurement system includes: Turn on the bias power supply 8 and adjust the bias power supply to 200V. Turn on the chiller 9, and then turn on the Bragg grating demodulator 4, strain gauge measurement and acquisition instrument 5 and thermocouple measurement and acquisition instrument 6 in sequence. The preparation of the measurement system is complete after the readings stabilize.

[0044] The sample irradiation detection stage includes: starting plasma discharge and measuring temperature strain based on the debugged and calibrated plasma generation system and temperature strain measurement system.

[0045] Example 5 illustrates the irradiation temperature stress detection of a tube-type tungsten-copper alloy block using a 13.56MHz radio frequency power supply at 1kW, with argon as the working gas.

[0046] The experiment was divided into three stages: the first stage was the sample installation stage; the second stage was the preparation of the device vacuum and measurement system; and the third stage was the start of the plasma discharge to conduct sample irradiation experiments and detect the temperature stress changes of the sample.

[0047] In the first stage, the sample 17 to be tested is installed inside the vacuum chamber 7, directly in front of the helical wave plasma beam. The copper tube 21 inside the sample is connected to a chiller 9 via a water pipe to provide cooling for the sample during irradiation. The sample 17 is connected to a bias power supply 8 via a cable to increase the energy of the plasma bombardment of the sample.

[0048] High-temperature resistant ceramic adhesive was used to fix the Bragg grating fiber 23 inside the front groove above the sample 17, and all grating areas were bonded to the sample. The strain generated when the sample 17 was irradiated was measured by connecting it to the Bragg grating demodulator 4 via cable.

[0049] The Bragg grating fiber 12 is inserted into the through-hole on the side of the sample 17 and fixed to the sample 17 with a high-temperature resistant ceramic adhesive end, so that the other part of the Bragg grating fiber 12 is in contact with the sample 17 but not fixed. The Bragg grating demodulator 4 is connected by cable to measure the temperature of the sample 17 during irradiation and to perform temperature compensation on the Bragg grating fiber 23.

[0050] Strain gauge 18 is attached above the sample 17 to be tested, and strain gauge measurement and acquisition instrument 5 is connected by cable to measure the strain generated when the sample 17 is irradiated.

[0051] A ceramic tube 19 is used to insulate and isolate the voltage of the bias power supply 8 outside the thermocouple 20. The thermocouple 20 with the ceramic tube 19 is inserted into the rear half-hole of the sample 17 to be tested, and the temperature of the sample 17 under irradiation is measured by connecting it to the thermocouple measuring and acquisition instrument 6 via a cable.

[0052] The second stage involves preparing the vacuum and measurement systems. Mass flow meter 14 is turned off, and vacuum pump group 10 is turned on. Once the vacuum in irradiation chamber 7 meets the requirements, plasma discharge is initiated to calibrate the temperature strain system. Gas cylinder 13 is opened, mass flow meter 14 is turned on to control the argon flow rate to 50 sccm, and DC power supply 12 is turned on and the current is adjusted to 100A.

[0053] To prepare the measurement system, turn on the bias power supply 8 and adjust it to 200V. Turn on the chiller 9, and then turn on the Bragg grating demodulator 4, strain gauge measurement and acquisition instrument 5, and thermocouple measurement and acquisition instrument 6 in sequence. Once the readings stabilize, the preparation of the measurement system is complete.

[0054] The third stage begins with plasma discharge for temperature strain measurement. The RF power supply 16 is turned on and adjusted to 100W. Simultaneously, the matching device 15 is adjusted to complete the helical wave plasma ignition. Then, the RF power supply 16 and matching device 15 are adjusted simultaneously. While maintaining the stability of the helical wave plasma, the power is increased to 1kW. At this point, a significant argon plasma beam bombardment of the sample 17 is observed. Simultaneously, the Bragg grating fiber 22 is affected by temperature; the grating expands due to heat, changing its period and increasing the center wavelength of the reflected light by Δλ. B1 The Bragg grating fiber 23 is simultaneously affected by temperature and stress, causing the center wavelength of the reflected light to increase by Δλ. B2 The Bragg grating demodulator 4 is connected via cable, and the Bragg grating demodulator 4 demodulates the change Δλ in the center wavelength of the reflected light. B This allows for the calculation of temperature and stress changes during the irradiation of the sample 17. Strain gauge 18 and thermocouple 20 are connected to strain gauge measurement and acquisition instrument 5 and thermocouple measurement and acquisition instrument 6 respectively via cables, enabling a direct display of strain and temperature records.

[0055] Data processing for optical fiber temperature and stress measurement using Bragg gratings. The formula for the temperature sensitivity of the grating is: ΔT = K T Δλ B ΔT is the temperature change in the grating region, K. T Δλ is a parameter used to measure the sensitivity of a grating to temperature. B Δλ is the center wavelength of the light reflected from the grating. This is based on Δλ measured using fiber-22 of the Bragg grating. B1 Substituting into the formula yields ΔT.

[0056] The strain sensitivity formula for the grating is: Δε z =K S Δλ B ,Δε z This indicates the strain magnitude of the grid region. K S It is a parameter used to measure the sensitivity of a grating to temperature. Since the Bragg grating fiber 23 is affected by both temperature and stress, the Δλ measured by the Bragg grating fiber 22 is used to measure this sensitivity. B1 As a temperature compensation, the wavelength change data Δλ measured by the Bragg grating fiber 23 is used. B2 Subtract the wavelength change Δλ caused by temperature variation B1 This yields the wavelength change Δλ that is truly caused by strain. B21 Substituting into the formula yields Δε. z Therefore, temperature stress detection of the sample under plasma irradiation conditions can be performed using Bragg grating optical fibers.

[0057] Working principle: like Figures 1-3As shown, a temperature stress detection system and method based on a Bragg grating fiber optic sensor enables in-situ measurement under plasma irradiation conditions. This system features strong anti-electromagnetic interference capabilities, high scalability, and wide applicability. The invention integrates a Bragg grating fiber, strain gauge, and thermocouple into a plasma irradiation device, enabling simultaneous acquisition of material temperature and strain data under real plasma bombardment and bias loading conditions, thus achieving in-situ measurement under plasma irradiation. By using two Bragg grating fibers, one for temperature measurement and the other for strain measurement, the influence of temperature drift on strain measurement is effectively reduced, improving the accuracy of temperature-strain decoupling and compensation. For internally cooled tube-type structures, this system accurately reflects the thermo-mechanical coupling response characteristics of key components in fusion devices, making it suitable for tube-type tungsten-copper alloy structures with high heat loads. The fiber optic sensor is unaffected by the plasma electromagnetic environment, significantly improving the stability of the measurement system under strong electromagnetic and particle irradiation conditions, exhibiting strong anti-electromagnetic interference capabilities and high measurement reliability. This invention is not only applicable to tungsten-copper alloy materials, but can also be extended to the testing of material properties in other fusion candidate materials or high-energy particle irradiation environments. It has strong scalability and a wide range of applications.

[0058] The above specific embodiments are specific support for the concept proposed in this invention, and should not be used to limit the scope of protection of this invention. Any equivalent changes or modifications made on the basis of this technical solution in accordance with the technical concept proposed in this invention shall still fall within the scope of protection of this invention.

Claims

1. A temperature stress detection system based on a Bragg grating fiber sensor, comprising: Plasma generation system and temperature strain measurement system; characterized in that: The plasma generation system comprises an irradiation chamber (7) provided with a spiral wave plasma generator inside and providing working gas to a plasma generation area inside the irradiation chamber (7); the spiral wave plasma is generated in the irradiation chamber (7) provided with an external magnetic field; the spiral wave plasma is propagated axially to the sample (17) to be measured inside the irradiation chamber (7); and the injection and penetration of substances in the working gas into the sample (17) are driven. The temperature strain measurement system comprises a strain gauge measurement collector (3) for detecting the sample (17) to be measured, a Bragg grating demodulator (4), a strain gauge measurement collector (5), and a thermocouple measurement collector (6); and the temperature strain measurement system is used for detecting the temperature and strain of the sample (17) to be measured during irradiation test.

2. The Bragg grating fiber sensor based temperature stress detection system of claim 1, wherein: The temperature strain measurement system further comprises a Bragg grating fiber two (23) connected with the Bragg grating demodulator (4); The Bragg grating fiber two (23) is arranged in a groove one formed in the sample (17) to be measured, and is fixed in the groove one by ceramic glue; and the strain of the sample (17) to be measured during irradiation is measured by the Bragg grating demodulator (4).

3. The Bragg grating fiber sensor based temperature stress detection system of claim 2, wherein: The temperature strain measurement system further comprises a water chiller (9) in communication with a copper pipe (21) penetrating the sample (17) to be measured through a water cooling pipeline; the copper pipe (21) in the sample (17) to be measured is provided with cooling liquid by the water chiller (9) and the water cooling pipeline, so as to provide cold energy for the sample (17) to be measured during irradiation.

4. The Bragg grating fiber sensor based temperature stress detection system of claim 3, wherein: The temperature strain measurement system further comprises a bias power supply (8) electrically connected with the sample (17) to be measured through a cable.

5. The Bragg grating fiber sensor based temperature stress detection system of claim 4, wherein: The temperature strain measurement system further comprises a Bragg grating fiber one (22) penetrating a fixed through hole formed in the sample (17) to be measured; one end of the Bragg grating fiber one (22) is fixed on the sample (17) to be measured by ceramic tape; and the fiber body of the Bragg grating fiber one (22) movably contacts the sample (17) to be measured; The Bragg grating fiber one (22) is connected with the Bragg grating demodulator (4) through a cable, so as to measure the temperature of the sample (17) to be measured during irradiation and compensate the temperature of the Bragg grating fiber two (23).

6. The Bragg grating fiber sensor based temperature stress detection system of claim 4, wherein: The temperature strain measurement system further comprises a strain gauge (18) attached to the sample (17) to be measured; the strain gauge (18) is connected with the strain gauge measurement collector (5) through a cable, so as to measure the strain of the sample (17) to be measured during irradiation.

7. The Bragg grating fiber sensor based temperature stress detection system of claim 4, wherein: The temperature strain measurement system further comprises a thermocouple (20); a ceramic tube (19) is sleeved on the thermocouple (20); the thermocouple (20) sleeved with the ceramic tube (19) is embedded in a test hole formed in the sample (17) to be measured; and the thermocouple (20) is connected with the thermocouple measurement collector (6) through a cable, so as to measure the temperature of the sample (17) to be measured during irradiation.

8. The Bragg grating fiber sensor based temperature stress detection system of claim 6, wherein: The sample (17) to be measured is installed inside the vacuum chamber (7) in front of the helicon plasma beam.

9. The Bragg grating fiber sensor based temperature stress detection system of claim 7, wherein: The plasma generating system further comprises a quartz tube (1) installed at the tail end of the irradiation chamber (7), and a helicon plasma antenna (2) surrounding the outside of the quartz tube (1); the helicon plasma antenna (2) is electrically connected with the radio frequency power supply (16) through the matching device (15), and is used for exciting the helicon plasma under the action of the applied axial magnetic field; The tail end of the quartz tube (1) is connected with the mass flow meter (13) and the gas cylinder (13) through the stainless steel gas pipe; the gas cylinder (13) adjusts the gas flow of the working gas through the mass flow meter (14), and provides the working gas to the plasma generating area; The direct current power supply (12) provides direct current for the electromagnetic coil (11), which is used for forming the axial magnetic field in the plasma generating area to support the formation and propagation of the helicon plasma; The bottom of the irradiation chamber (7) is connected with the vacuum pump set (10) for providing the vacuum environment required by the plasma discharge; The working gas is argon or deuterium.

10. A detection method of a temperature stress detection system based on a Bragg grating fiber sensor, characterized by: The temperature stress detection system based on the Bragg grating fiber sensor is realized by the temperature stress detection system based on the Bragg grating fiber sensor in any one of claims 1-8, including: a sample installation stage, a device vacuum and measurement system preparation stage, and a sample irradiation detection stage. The sample installation stage includes: installing the sample (17) to be measured inside the vacuum chamber (7) in front of the helicon plasma beam; connecting the copper pipe (21) passing through the sample (17) to be measured with the cooling water machine (9) through the cooling pipe; connecting the sample (17) to be measured with the bias power supply (8) through the cable; and connecting the strain gauge (18), the thermocouple (20), the Bragg grating fiber two (23), and the Bragg grating fiber one (22) arranged on the sample (17) to be measured with the strain gauge measurement and collection instrument (3), the Bragg grating demodulator (4), the strain gauge measurement and collection instrument (5), and the thermocouple measurement and collection instrument (6) respectively, to complete the installation of the temperature stress detection system before detection; The device vacuum and measurement system preparation stage includes: based on the installed temperature stress detection system, the plasma generating system and the temperature strain measurement system are respectively debugged and calibrated; The calibration of the plasma generating system includes: closing the mass flow meter (14), opening the vacuum pump set (10), and starting the plasma discharge to calibrate the temperature strain system when the vacuum of the irradiation chamber (7) meets the requirements; opening the gas cylinder (13), opening the mass flow meter (14) to control the argon flow to be 50sccm, and opening the direct current power supply (12) to adjust the current to 100A; The calibration of the temperature strain measurement system includes: opening the bias power supply (8) to adjust the bias power supply to 200V, opening the cooling water machine (9), and then sequentially opening the Bragg grating demodulator (4), the strain gauge measurement and collection instrument (5), and the thermocouple measurement and collection instrument (6); after the readings are stable, the preparation of the measurement system is completed. The sample irradiation detection stage includes: based on the debugging and calibrated plasma generating system and temperature strain measurement system, starting the plasma discharge, and carrying out temperature strain measurement.

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