Reactor structure material heavy ion irradiation in-situ internal friction measuring device and method

Abstract

The invention relates to the technical field of irradiation measurement, in particular to a reactor structure material heavy ion irradiation in-situ internal friction measuring device and method.The reactor structure material heavy ion irradiation in-situ internal friction measuring device comprises a vacuum chamber (1) provided with a heavy ion beam flow pipeline connector (9), an irradiation sample (12) is arranged in the vacuum chamber (1) through a sample clamp (3), a heating laser (6) can heat the irradiation sample (12), and the heavy ion beam flow pipeline connector (9) is arranged in the vacuum chamber (1); the accelerated heavy ion beam can irradiate an irradiation area on the irradiation sample (12) through the heavy ion beam pipeline interface (9); the laser displacement detector (7) is used for measuring the displacement change of the irradiation sample (12); and the temperature measuring device (8) is used for measuring and monitoring the temperature of an irradiation area on the irradiation sample (12) in real time and outputting a signal to the temperature control system. In-situ measurement of the mechanical property of the material in a heavy ion irradiation experiment process in a high-temperature environment is realized, and the change of the mechanical property of the material is intuitively measured.

Description

Technical Field

[0001] The invention relates to the technical field of irradiation measurement, and in particular to a device and method for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation. Background Art

[0002] Fuel assembly structural materials are the most important structural materials in the reactor. They are used to load the nuclear fuel core and maintain the structural integrity of the fuel rods. Their main functions are to prevent the escape of fission products, avoid corrosion of the fuel by the coolant, and effectively conduct heat energy. They are in the worst working environment and receive the highest radiation damage dose. In addition to good mechanical properties, corrosion resistance, heat resistance, and economy, fuel assembly structural materials must also have excellent radiation resistance and be able to maintain mechanical properties such as strength and toughness after being irradiated by strong neutron flux. The performance of fuel assembly structural materials is one of the main factors that determine the design and performance of the reactor, and is also a key factor in the service life of the fuel assembly and even the safety and reliability of the reactor operation.

[0003] For the core structural materials of high-power reactors, traditional austenite and martensite / ferrite steels are difficult to meet the performance requirements of high-temperature strength under complex working conditions such as high temperature and irradiation. In the process of developing advanced radiation-resistant structural materials, if various fast neutron sources are directly used to study and evaluate the irradiation performance of materials, due to the extremely complex conditions in the reactor, how to measure the evolution of the mechanical properties of the core structural materials during irradiation has always been a difficulty in the research and development of reactor structural materials, especially the lack of data on the change process of mechanical properties during irradiation. Measurements under in-pile irradiation conditions are limited by factors such as the reactor operation plan and the strong radioactivity caused by neutron irradiation, which brings great difficulties to the design of experiments and data measurement. In addition, the reactor irradiation dose rate is low, and it takes at least several years of irradiation time to carry out high-dose irradiation. In addition, due to the strong radioactivity caused by neutron irradiation, it takes several years of cooling time to test the mechanical properties after irradiation. According to current assessments, it takes 30 years for a new nuclear energy structural material to be developed and put into practical use, during which multiple irradiation tests are required. However, with the gradual closure of material test reactors around the world, the cost of neutron irradiation material testing has also increased year by year, which has seriously restricted the development of nuclear energy structural materials. At present, my country is in a critical period of developing advanced nuclear energy such as demonstration reactors, and the mechanical property evaluation of radiation-resistant structural materials has become a bottleneck in the development of advanced structural materials.

[0004] Both neutrons and heavy ions produce atomic displacements of materials through collisions. Therefore, in the process of developing reactor materials that can withstand high-dose irradiation, accelerator heavy ion irradiation simulation is an important and effective method. Since the irradiation temperature, dose rate and other parameters of accelerator heavy ion irradiation are relatively easy to control, it is more conducive to studying the mechanism of irradiation damage by changing the parameters. Accelerator heavy ion irradiation can be used to monitor the mechanical properties of materials in situ. At present, there are very limited means for online monitoring of changes in mechanical properties during irradiation. There are only limited means such as the combination of accelerator and transmission electron microscope, and online tensile / creep measurement of accelerator irradiation. Due to the limitation of the field of view of the electron microscope, the accelerator and transmission electron microscope system can only conduct microscopic damage mechanism research and cannot monitor the changes in the macroscopic mechanical properties of the material during the irradiation process. Accelerator irradiation online tensile / creep measurement can only measure the macroscopic creep properties of the material, and cannot obtain the microstructure and change information of the material during the irradiation process.

[0005] The internal friction measurement technology can obtain the elastic modulus and damping value by measuring the dynamic strain of the material under dynamic stress, and obtain the characteristic internal friction spectrum of the microstructure change process in the material by changing the parameters such as frequency, amplitude, temperature, and aging time. Since the internal friction spectrum is highly sensitive to the solid microstructure and defects (such as point defects, dislocations, etc.) and the interactions between them, in addition to intuitively measuring the changes in the mechanical properties of the material, the internal friction peak can also be used to study the type, concentration, and dynamic diffusion process of irradiation defects, as well as obtain information on the irradiation conditions and other aspects of the material's irradiation embrittlement and defect evolution. By measuring the internal friction spectrum of the material during the irradiation process, the evolution information of the mechanical properties and microscopic defects of the material during the irradiation process can be obtained.

[0006] Internal friction measurement principle: Even if a vibrating solid is completely isolated from the outside world, its mechanical vibration energy will gradually decay. This energy loss caused by internal reasons of the material is called internal friction. Because the dissipation of mechanical vibration energy is completed through internal mechanisms, this property of the material strongly depends on the microstructure and defects of the material, and is also closely related to the physical parameters of the external environment.

[0007] Internal friction can usually be measured using the free decay method or the forced vibration method.

[0008] Free decay method: After the vibration of the sample is excited, the excitation stress is removed and the sample is allowed to vibrate freely. Due to the internal friction of the sample, the amplitude of the free vibration will gradually decay. By measuring the amplitude and vibration frequency of the free decay, the internal friction value and relative modulus value of the sample can be obtained.

[0009] Forced vibration method: Sinusoidal stress is applied to the sample. Due to internal friction, the strain of the sample lags behind the stress, and a phase difference appears between the applied stress and the strain of the sample. The internal friction value of the sample can be obtained by measuring this phase difference.

[0010] To accurately measure the vibration attenuation process or stress / strain phase difference of the sample, the sample cannot contact or interact with surrounding objects during vibration. In addition, the internal friction value is usually closely related to temperature, and the temperature needs to be accurately measured and controlled during the measurement process. There are currently many methods for measuring internal friction, and there are also methods for measuring internal friction during proton irradiation, but there are still some problems in measuring the internal friction of materials during high-dose radiation damage:

[0011] (1) Internal friction measurement during high-dose irradiation: Reference (Journal of Alloys and Compounds 310 (2000) 102–106) has reported on in-situ internal friction measurement of samples during proton irradiation. Protons have a large range in the material and use a high-energy proton beam to enable protons to penetrate the entire sample and measure internal friction during irradiation. However, the proton irradiation dose rate is low (usually 10 -12 particle / cm 2 / s beam current, the dose rate is about 10 -3 dpa / hour), to produce a damage dose equivalent to that of the reactor material during its service life (tens to hundreds of dpa), the required beam time is very long, and it is not realistic to study the evolution of material properties during the formation of high-dose irradiation damage. According to Chinese patent application documents (application publication number: CN107204211A and application publication number: CN101788453A), high-dose irradiation damage is usually achieved by heavy ion irradiation, but the current high-dose heavy ion irradiation method is not able to use the existing heavy ion irradiation technology to measure internal friction during irradiation because the heavy ion irradiation depth is relatively shallow (within ten microns), and the sample morphology and installation method do not meet the requirements of internal friction measurement.

[0012] (2) Temperature measurement and control: According to the Chinese patent application document (application publication number: CN110567877A), for the current internal friction measurement technology, the sample needs to be heated by radiation heating, and the heater cannot be in contact with the sample. Generally, the heater is evenly distributed around the sample to form a uniform thermal radiation field, and the sample temperature is determined by measuring the temperature of the thermal radiation field. When the heavy ion energy is high and the beam current is strong, the irradiation beam can also become one of the heat sources (for example, the heating power formed by a beam with a current intensity of 50 MeV and microamperes reaches tens of watts), thereby affecting the temperature of the irradiated area on the sample (especially for thin samples, the beam power has a very large impact). In addition, during the irradiation process, the beam intensity may change, resulting in changes in the temperature of the irradiated area. Therefore, it is necessary to accurately measure the temperature of the irradiated area during the irradiation process and the internal friction measurement process in order to achieve accurate control of the temperature of the irradiated area. Therefore, it is necessary to directly and accurately measure the temperature at the irradiation position using a non-contact method, and the heating method does not affect the temperature measurement. The existing internal friction measurement methods cannot meet this requirement. Summary of the invention

[0013] In view of the problems existing in the prior art, the purpose of the present invention is to provide an in-situ internal friction measurement device and method for heavy ion irradiation of reactor structural materials, which is used for in-situ online measurement of the mechanical properties and microscopic defect states of the materials during the irradiation process. Since the internal friction technology spectrum is highly sensitive to solid microstructures and defects (such as point defects, dislocations, etc.) and the interactions between them, in addition to being able to intuitively measure the changes in the mechanical properties of materials in real time, the internal friction peak can also be used to study the types, concentrations, and kinetic diffusion processes of irradiation defects, as well as to obtain information on irradiation conditions and other aspects of material irradiation embrittlement and defect evolution.

[0014] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0015] A heavy ion irradiation in-situ internal friction measurement device for reactor structural materials, comprising a vacuum chamber provided with a heavy ion beam pipeline interface, an irradiated sample being arranged inside the vacuum chamber through a sample fixture, a heating laser being able to heat the irradiated sample, and an accelerated heavy ion beam being able to irradiate an irradiation area on the irradiated sample through the heavy ion beam pipeline interface, and also comprising a laser displacement detector for measuring the displacement change of the irradiated sample and a temperature measuring device for measuring and real-time monitoring the temperature of the irradiated area on the irradiated sample and outputting a signal to a temperature control system.

[0016] Furthermore, the vacuum chamber is provided with at least one vacuum exhaust port and a vacuum gauge installation interface, and a mechanical pump, a molecular pump and an ion pump are used to evacuate the chamber. After the vacuum reaches the irradiation requirement, the molecular pump and the mechanical pump are turned off, and the ion pump is used to maintain the vacuum, so as to avoid the vibration of the vacuum system equipment during operation affecting the internal friction measurement.

[0017] Furthermore, a fixed base is provided inside the vacuum chamber, a force loading system is provided on the fixed base, a sample fixture is provided on the force loading system, and the irradiated sample is arranged inside the vacuum chamber through the sample fixture.

[0018] Furthermore, the force loading system is also provided with an excitation coil, which generates a periodically changing magnetic field by controlling the current loaded on the excitation coil, thereby driving the sample fixture to deform and drive the irradiated sample to vibrate periodically.

[0019] Furthermore, the heating laser adopts a high-power semiconductor laser, and a laser stack formed by merging multiple high-power semiconductor lasers is used to obtain high-power output and uniform heating effect.

[0020] Furthermore, the vacuum chamber is provided with an optical window interface flange, a water cooling table is provided inside, a reflective laser absorption target is provided on the water cooling table, the heating laser is installed outside the vacuum chamber through the optical window interface flange, the laser beam emitted by the heating laser passes through the optical window and irradiates the back of the irradiated sample to heat the irradiated sample, the laser beam reflected from the back of the irradiated sample irradiates the reflective laser absorption target, and the reflective laser absorption target is cooled by the water cooling table.

[0021] Furthermore, the laser beam emitted by the heating laser is a rectangular beam, the beam width is consistent with the width of the middle part (the thinner part in the middle) of the irradiated sample, and the beam length is greater than the length of the irradiated area on the irradiated sample.

[0022] Furthermore, the middle part of the irradiated sample is a long strip of irradiation area and deformation area, and the two ends are clamp fixing areas. The thickness of the irradiation area is less than 1 / 5 of the thickness of the clamp fixing area, so that the heavy ion irradiation depth is more than 5% of the thickness of the irradiation area, and the area of ​​the irradiation area is more than 1% of the total deformation area of ​​the irradiated sample.

[0023] Furthermore, the sample fixture is made of ceramic material, has heat insulation and insulating properties, can be used for the installation of samples irradiated by the torsion pendulum method and can draw out the current generated by the heavy ion beam irradiation on the irradiated sample for beam measurement.

[0024] Furthermore, the vacuum chamber is provided with at least three observation windows for installing a temperature measuring device and a laser displacement detector; the vacuum chamber is also provided with at least one signal and power input and output interface.

[0025] Furthermore, the temperature measuring device includes a two-color infrared thermometer and an infrared thermal imager, which simultaneously measure the temperature of the irradiated sample through the observation window. The two-color infrared thermometer measures the average temperature of the irradiated area on the irradiated sample. The measured temperature is fed back by a temperature controller to control the power of the heating laser, thereby achieving precise temperature control of the irradiated area on the irradiated sample; the infrared thermal imager measures the temperature distribution of the irradiated area on the irradiated sample.

[0026] Furthermore, the laser displacement detector projects the laser through the observation window to the irradiated area on the irradiated sample and receives the reflected light, measures the change of the laser frequency caused by the movement of the irradiated sample, calculates the displacement change of the irradiated sample in real time, and realizes the strain measurement of the irradiated sample excited by vibration under high temperature and complex electromagnetic conditions during heavy ion beam irradiation.

[0027] Furthermore, the heating laser emits laser light of a specific wavelength, and the laser wavelength is different from the measurement wavelength of the two-color infrared thermometer, so as to avoid affecting the temperature measurement of the two-color infrared thermometer.

[0028] Furthermore, it also includes an electrical system, which includes an electric control cabinet, a voltage-stabilized power supply, a power amplifier, a high-speed AD acquisition board and a motor driver, and is responsible for providing power of various levels to the entire measuring device, power amplification of the excitation coil control signal, laser displacement detector signal processing and motor movement.

[0029] Furthermore, a method for measuring the in-situ internal friction of reactor structural materials by heavy ion irradiation using the above device comprises the following steps:

[0030] Step 1, fixing the irradiated sample to be measured on the sample fixture, then installing the sample fixture on the force loading system, and applying tension to the irradiated sample through the force loading system;

[0031] Step 2, irradiating the irradiation area on the irradiation sample by using the heavy ion beam pipeline interface after acceleration;

[0032] Step 3, by controlling the current loaded on the exciting coil installed on the force loading system, a periodically changing magnetic field is generated, and the sample fixture is driven to drive the irradiated sample to perform periodic vibration;

[0033] Step 4, irradiating the irradiated sample with a high-power heating laser through a vacuum optical window to heat the irradiated sample, and measuring the temperature of the irradiated sample during heavy ion irradiation through an optical glass and a temperature measuring device installed on the observation window;

[0034] Step 5, measuring the strain of the irradiated sample during vibration during heavy ion irradiation through a laser displacement detector and an observation window;

[0035] Step 6, by measuring the strain of the irradiated sample, comparing the stress-strain curve to calculate the internal friction, elastic modulus and dose-internal friction spectrum, to achieve in-situ internal friction measurement of the irradiated sample during heavy ion irradiation.

[0036] Furthermore, the measurement and control software is used to realize the automatic operation of the entire equipment, including the acquisition and calculation of irradiation dose, the generation of vibration excitation signals, the reading of strain signals and the deformation of samples. The internal friction, elastic modulus and dose-internal friction spectrum of the irradiated samples are calculated by comparing the stress-strain curves.

[0037] The beneficial effects of the present invention are as follows:

[0038] 1. Realized the in-situ measurement of the mechanical properties of materials during heavy ion irradiation experiments in high temperature environments;

[0039] 2. The changes in the mechanical properties of materials can be measured visually during the irradiation process;

[0040] 3. Through the analysis of the internal friction spectrum, the types, concentrations and kinetic diffusion processes of the irradiation defects generated during the material irradiation process can be obtained, and the information on the effects of irradiation conditions such as temperature and irradiation dose on the irradiation embrittlement and defect evolution of the material can be obtained. This provides a scientific basis for a deep understanding of the changes in mechanical properties during the irradiation process and the development of excellent radiation-resistant materials, and provides strong technical support for the development of excellent reactor radiation-resistant fuel assembly structural materials;

[0041] 4. It can realize in-situ internal friction measurement under heavy ion irradiation conditions of 300℃ to 1000℃, and can achieve 10 -2 ~10 2 Hz frequency range, 10 -6 ~10 -4 Vibration excitation and measurement in the strain range. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a heavy ion irradiation in-situ internal friction measurement device for reactor structural materials described in a specific embodiment of the present invention;

[0043] Figure 2 yes Figure 1 A schematic diagram of a top view structure;

[0044] Figure 3 It is a structural schematic diagram of an irradiated sample described in a specific embodiment of the present invention;

[0045] Figure 4 yes Figure 3 Side view of

[0046] Figure 5It is a structural schematic diagram of an irradiated sample and a sample fixture described in a specific embodiment of the present invention;

[0047] Figure 6 yes Figure 5 Side view of

[0048] In the above drawings, 1. vacuum chamber; 2. fixed base; 3. sample fixture; 4. force loading system; 5. exciting coil; 6. heating laser; 7. laser displacement detector; 8. temperature measuring device; 9. heavy ion beam pipeline interface; 10. reflected laser absorption target; 11. signal and power input and output interface; 12. irradiated sample; 13. observation window. DETAILED DESCRIPTION

[0049] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0050] The present invention provides an in-situ internal friction measurement device for reactor structural materials by heavy ion irradiation, comprising a vacuum chamber 1 provided with a heavy ion beam pipeline interface 9, an irradiated sample 12 being arranged inside the vacuum chamber 1 through a sample fixture 3, a heating laser 6 being capable of heating the irradiated sample 12, and the accelerated heavy ion beam being capable of irradiating an irradiation area on the irradiated sample 12 through the heavy ion beam pipeline interface 9, and further comprising a laser displacement detector 7 for measuring the displacement change of the irradiated sample 12 and a temperature measuring device 8 for measuring and real-time monitoring the temperature of the irradiated area on the irradiated sample 12 and outputting a signal to a temperature control system.

[0051] A heavy ion irradiation in-situ internal friction measurement device for reactor structural materials includes a vacuum chamber, an irradiated sample and a fixture, a temperature control system, and an internal friction measurement system. The overall structure of the device is as follows Figure 1 and Figure 2 shown.

[0052] (1) Vacuum chamber

[0053] The vacuum chamber 1 is evacuated by mechanical pump, molecular pump and ion pump. When the vacuum degree reaches the irradiation requirement, the molecular pump and mechanical pump are turned off, and the ion pump is used to maintain the vacuum to prevent the vibration of the vacuum system equipment during operation from affecting the internal friction measurement. The vacuum chamber 1 is placed on a three-dimensional shock-absorbing platform to prevent other vibration sources in the surrounding environment from affecting the internal friction measurement.

[0054] The vacuum chamber 1 has at least one vacuum pumping port and a vacuum gauge installation interface. The vacuum pumping port is used to extract the gas in the vacuum chamber 1, and the vacuum gauge installation interface provides a flange interface for installing a vacuum gauge, so as to measure the vacuum degree of the vacuum chamber 1. There is at least one heavy ion beam pipeline interface 9 directly in front of the vacuum chamber 1, which is connected to the heavy ion beam transmission vacuum pipeline (heavy ion beam pipeline for short) through a vacuum flange, and is used to transmit and irradiate the accelerated heavy ion beam to the surface of the irradiated sample 12. The irradiated sample 12 is irradiated with a heavy ion beam, because heavy ion irradiation is the only experimental means to quickly achieve high-dose irradiation. Through the high irradiation dose rate of heavy ions (usually reaching more than 1dPa / hour), a high irradiation dose can be achieved in a short time, and the internal friction change process of the irradiated sample 12 during the large irradiation dose can be measured.

[0055] The vacuum chamber 1 has at least three observation windows 13 for installing a temperature measuring device 8 (including a two-color infrared thermometer and an infrared thermal imager) and a laser displacement detector 7. The vacuum chamber 1 has at least one optical window interface flange for installing an optical window and a heating laser 6. The optical window is mounted on the flange, the heating laser 6 is also mounted on the flange, and the laser of the heating laser 6 is emitted into the vacuum chamber 1 through the optical window outside the optical window. The vacuum chamber 1 has at least one signal and power input and output interface.

[0056] (II) Irradiation specimens and fixtures

[0057] Design of irradiated specimen: The irradiated area and deformation area in the middle of the irradiated specimen 12 are in the shape of long strips, and the thickness is much smaller than the clamp fixing areas on both sides. The thickness of the irradiated area is less than 1 / 5 of the thickness of the clamp fixing area. Figure 3 and Figure 4 As shown, the heavy ion irradiation depth is made to be more than 5% of the thickness of the irradiated area, the area of ​​the irradiated area accounts for as large a proportion of the area of ​​the total deformation area as possible, and the area of ​​the irradiated area is more than 1% of the total deformation area on the irradiated sample 12. Due to the shallow depth of heavy ion irradiation, heavy ions with energies of several mega-electron volts to tens of mega-electron volts are usually used for irradiation, and the irradiation depth is usually within ten microns. For conventional irradiated samples used for internal friction measurement, the effective volume of the irradiated area accounts for a very small proportion, making it difficult to accurately measure the changes in internal friction during irradiation. Using Figure 3 and Figure 4 The design of the irradiated sample 12 shown is such that the area of ​​the irradiated region accounts for as large a proportion of the area of ​​the total deformation region as possible, so as to meet the requirements of internal friction measurement. For example, for a stainless steel sample irradiated with 70 MeV iron ions, the irradiation depth of the heavy ions in the irradiated region is about 6 microns, and the thickness of the thin area in the middle of the irradiated sample 12 does not exceed 120 microns.

[0058] like Figure 5 and Figure 6 As shown, the sample fixtures 3 located at both ends of the irradiated sample 12 are ceramic fixtures, which have heat insulation and insulating properties. They can be used to install the irradiated sample 12 using the torsion pendulum method and directly lead the current generated by the heavy ion beam irradiation on the irradiated sample 12 to the beam measurement equipment for beam measurement through the metal contacts on the sample fixture 3 that are in contact with the irradiated sample 12 for beam measurement.

[0059] (III) Temperature control system

[0060] A plurality of observation windows 13 are also provided on the upper front of the vacuum chamber 1 of the device. The temperature measuring device 8 measures and monitors the temperature of the irradiated area on the irradiated sample 12 in real time through the observation windows 13. The temperature measuring device 8 outputs the measured temperature signal to the temperature control system.

[0061] Sample heating: A high-power semiconductor heating laser 6 is installed on the optical window interface flange at the rear side of the sample fixture 3 to achieve heating of the irradiated sample 12. The heating laser 6 uses a high-power semiconductor laser, and directly obtains high-power output and uniform heating effect by combining multiple semiconductor lasers into a laser stack. The semiconductor laser emits a laser of a specific wavelength (the laser wavelength avoids the measurement wavelength range of the two-color infrared thermometer to avoid affecting the measurement of the sample temperature), and obtains a high heating power density and a uniform heating effect after homogenization and beam expansion. The heating laser 6 is installed on the optical window interface flange at the rear side of the irradiated sample 12. Outside the optical window, the laser beam emitted by the heating laser 6 is a rectangular beam, the beam width is consistent with the width of the middle part (the thinner part in the middle) of the irradiated sample 12, and the length is greater than the length of the heavy ion irradiation area on the irradiated sample 12. The heating laser beam passes through the optical window and irradiates the back of the irradiated sample 12 to heat the irradiated sample 12. The maximum temperature on the irradiated sample 12 can reach 1000°C. The laser beam reflected from the back of the irradiated sample 12 irradiates the reflective laser absorption target 10 on the other side of the rear side of the irradiated sample 12. The reflective laser absorption target 10 is installed on a water-cooled table and cooled by the water-cooled table.

[0062] Temperature measurement and control: A plurality of observation windows 13 are provided on the upper front of the vacuum chamber 1, and the temperature measuring device 8 measures and monitors the temperature of the irradiated area on the irradiated sample 12 in real time through the observation windows 13. The temperature on the irradiated sample 12 is measured simultaneously by a two-color infrared thermometer and an infrared thermal imager. The two-color infrared thermometer measures the average temperature of the irradiated area on the irradiated sample 12, and the measured temperature is fed back by the temperature controller to control the power of the heating laser 6, so as to realize accurate temperature control of the irradiated area on the irradiated sample 12. The infrared thermal imager measures the temperature distribution of the irradiated area on the irradiated sample 12.

[0063] Temperature measurement and control system: The temperature measurement and control system consists of an infrared thermometer, a temperature controller and a heating laser 6. The infrared thermometer, the temperature controller and the heating laser 6 are all installed outside the vacuum chamber 1. The infrared thermometer measures the temperature of the irradiated area on the irradiated sample 12 and outputs a temperature signal to the temperature controller. The temperature controller calculates the output power of the heating laser by the PID algorithm based on the sample temperature and the set temperature, and outputs an analog control signal to the heating laser 6 to change the output power of the heating laser 6 to achieve heating and temperature control of the irradiated sample 12.

[0064] (IV) Internal friction measurement system

[0065] The internal friction measurement is carried out using the torsion pendulum method. The internal friction measurement system is mainly composed of an excitation system, a laser displacement detection system, an electrical system, measurement and control software, a vacuum extraction system, and a heavy ion beam transmission vacuum pipeline.

[0066] A fixed base 2 is installed at the bottom center of the vacuum chamber 1, and a force loading system 4, an excitation system, an irradiated sample 12, and a sample fixture 3 are installed on the fixed base 2. The force loading system 4 uses the excitation coil 5 of the excitation system to control the current loaded on the excitation coil 5 to generate a periodically changing magnetic field, which can drive the sample fixture 3 to deform and drive the irradiated sample 12 to vibrate periodically.

[0067] The laser displacement detection system is installed on the observation window 13 in front of the vacuum chamber 1. The laser displacement detection system uses a laser displacement detector 7, which projects the laser through the observation window 13 to the irradiation area on the surface of the irradiated sample 12 and receives the reflected light, and measures the change of the laser frequency caused by the movement of the irradiated sample 12, and calculates the displacement change of the irradiated sample 12 in real time, so as to realize the strain measurement of the irradiated sample 12 excited by vibration under high temperature and complex electromagnetic conditions during heavy ion beam irradiation.

[0068] The electrical system mainly includes electrical components such as electric control cabinet, voltage-stabilized power supply, power amplifier, high-speed AD acquisition board and motor driver. It is mainly responsible for providing power supply of various levels to the entire measuring device, power amplification of the excitation coil control signal, laser displacement detector signal processing and motor movement.

[0069] The measurement and control software is mainly used to realize the automatic operation of the whole equipment, including the acquisition and calculation of irradiation dose, the generation of vibration excitation signal, the reading of strain signal and the deformation of sample. By comparing the stress-strain curve, the internal friction, elastic modulus and dose-internal friction spectrum are calculated, and the in-situ internal friction measurement of the irradiated sample 12 during heavy ion irradiation is realized, with a measurement accuracy better than 10 -4 Magnitude.

[0070] The present invention provides a method for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation, comprising the following steps:

[0071] Step 1, fix the irradiated sample 12 to be measured on the sample fixture 3, then install the sample fixture 3 on the force loading system 4, and apply tension to the irradiated sample 12 through the force loading system 4;

[0072] Step 2, irradiating the irradiation area on the irradiation sample 12 through the heavy ion beam pipeline interface 9 after acceleration of the heavy ion beam;

[0073] Step 3, by controlling the current loaded on the exciting coil 5 installed on the force loading system 4, a periodically changing magnetic field is generated, and the sample fixture 3 is driven to drive the irradiated sample 12 to perform periodic vibration;

[0074] Step 4, irradiating the irradiated sample 12 with a high-power heating laser through a vacuum optical window, thereby heating the irradiated sample 12, and measuring the temperature of the irradiated sample 12 during heavy ion irradiation through an optical glass and a temperature measuring device 8 installed on an observation window 13;

[0075] Step 5, measuring the strain of the irradiated sample 12 during vibration during heavy ion irradiation through the laser displacement detector 7 and the observation window 13;

[0076] Step 6, by measuring the strain of the irradiated sample 12, comparing the stress-strain curve to calculate the internal friction, elastic modulus and dose-internal friction spectrum, the in-situ internal friction measurement of the irradiated sample 12 during the heavy ion irradiation process is achieved.

[0077] Example

[0078] In this embodiment, a heavy ion irradiation in-situ internal friction measurement device for reactor structural materials adopts Figure 1 and Figure 2 The structure shown in FIG. 1 is a structure in which the irradiated sample 12 and the sample holder 3 are arranged as follows: Figure 3-Figure 6 The structure shown. The measurement process is as follows:

[0079] First, fix the irradiated sample 12 to be measured on the sample fixture 3, and then install the sample fixture 3 on the force loading system 4, and apply tension to the irradiated sample 12 through the force loading system 4. The accelerated heavy ion beam is used to irradiate the irradiation area on the irradiated sample 12 through the heavy ion beam pipeline interface 9. The current loaded on the excitation coil 5 is controlled by the excitation coil 5 installed on the force loading system 4 to generate a periodically changing magnetic field, and the sample fixture 3 is driven to drive the irradiated sample 12 to vibrate periodically. The high-power heating laser emitted by the heating laser 6 is irradiated on the irradiated sample 12 through the optical window set on the vacuum chamber 1, so as to heat the irradiated sample 12. The temperature of the irradiated sample 12 during heavy ion irradiation is measured by the optical glass and temperature measuring device 8 installed on the observation window 13. The strain of the irradiated sample 12 during vibration during heavy ion irradiation is measured by the laser displacement detector 7 and the observation window 13. The whole equipment is operated automatically through the measurement and control software, including the acquisition and calculation of irradiation dose, the generation of vibration excitation signal, the reading of strain signal and the deformation of sample. The internal friction, elastic modulus and dose-internal friction spectrum of irradiated sample 12 are calculated by comparing the stress-strain curve, and the in-situ internal friction measurement of irradiated sample 12 under heavy ion irradiation conditions of 300℃ to 1000℃ is achieved. For centimeter-level irradiated samples, 10 -2 ~10 2 Hz frequency range, 10 -6 ~10 -4 Vibration excitation and measurement in the strain range.

[0080] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A heavy ion irradiation in-situ internal friction measurement device for reactor structural materials, characterized in that: The invention comprises a vacuum chamber (1) provided with a heavy ion beam pipeline interface (9); an irradiated sample (12) is arranged inside the vacuum chamber (1) via a sample fixture (3); a heating laser (6) is capable of heating the irradiated sample (12); an accelerated heavy ion beam is capable of irradiating an irradiated area on the irradiated sample (12) via the heavy ion beam pipeline interface (9); and the invention also comprises a laser displacement detector (7) for measuring the displacement change of the irradiated sample (12) and a temperature measuring device (8) for measuring and real-time monitoring the temperature of the irradiated area on the irradiated sample (12) and outputting a signal to a temperature control system.

2. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 1, characterized in that: The vacuum chamber (1) is provided with at least one vacuum exhaust port and a vacuum gauge installation interface, and a mechanical pump, a molecular pump and an ion pump are used to evacuate the vacuum. After the vacuum reaches the irradiation requirement, the molecular pump and the mechanical pump are turned off, and the ion pump is used to maintain the vacuum, so as to avoid the vibration of the vacuum system equipment during operation affecting the internal friction measurement.

3. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 1, characterized in that: A fixed base (2) is provided inside the vacuum chamber (1), a force loading system (4) is provided on the fixed base (2), a sample fixture (3) is provided on the force loading system (4), and an irradiated sample (12) is arranged inside the vacuum chamber (1) via the sample fixture (3).

4. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation as claimed in claim 3, characterized in that: The force loading system (4) is also provided with an exciting coil (5), which generates a periodically changing magnetic field by controlling the current loaded on the exciting coil (5), thereby driving the sample fixture (3) to deform and drive the irradiated sample (12) to vibrate periodically.

5. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 1, characterized in that: The heating laser (6) adopts a high-power semiconductor laser, and a laser stack formed by merging a plurality of high-power semiconductor lasers is used to obtain a high-power output and a uniform heating effect.

6. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 5, characterized in that: The vacuum chamber (1) is provided with an optical window interface flange, a water cooling table is provided inside, and a reflective laser absorption target is provided on the water cooling table. The heating laser (6) is installed outside the vacuum chamber (1) through the optical window interface flange. The laser beam emitted by the heating laser (6) passes through the optical window and irradiates the back of the irradiated sample (12) to heat the irradiated sample (12). The laser beam reflected from the back of the irradiated sample (12) irradiates the reflective laser absorption target, and the reflective laser absorption target is cooled by the water cooling table.

7. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 6, characterized in that: The laser beam emitted by the heating laser (6) is a rectangular beam, the beam width is consistent with the width of the middle part of the irradiated sample (12), and the beam length is greater than the length of the irradiated area on the irradiated sample (12).

8. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 1, characterized in that: The middle part of the irradiated sample (12) is a long strip irradiation area and a deformation area, and the two ends are clamp fixing areas. The thickness of the irradiated area is less than 1 / 5 of the thickness of the clamp fixing area, so that the heavy ion irradiation depth is more than 5% of the thickness of the irradiated area, and the area of ​​the irradiated area is more than 1% of the total deformation area of ​​the irradiated sample (12).

9. The heavy ion irradiation in-situ internal friction measurement device for reactor structural materials according to claim 1, characterized in that: The sample fixture (3) is made of ceramic material and has heat insulation and insulating properties, and can be used to install a sample (12) irradiated by a torsion pendulum method and to draw out the current generated by heavy ion beam irradiation on the irradiated sample (12) for beam measurement.

10. The heavy ion irradiation in-situ internal friction measurement device for reactor structural materials according to claim 1, characterized in that: The vacuum chamber (1) is provided with at least three observation windows (13) for installing a temperature measuring device (8) and a laser displacement detector (7); the vacuum chamber (1) is also provided with at least one signal input and output interface (11) and at least one power supply input and output interface (11).

11. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 10, characterized in that: The temperature measuring device (8) comprises a two-color infrared thermometer and an infrared thermal imager. The two-color infrared thermometer and the infrared thermal imager simultaneously measure the temperature of the irradiated sample (12) through the observation window (13). The two-color infrared thermometer measures the average temperature of the irradiated area on the irradiated sample (12). The measured temperature is fed back through a temperature controller to control the power of the heating laser (6), thereby achieving accurate temperature control of the irradiated area on the irradiated sample (12). The infrared thermal imager measures the temperature distribution of the irradiated area on the irradiated sample (12).

12. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 10, characterized in that: The laser displacement detector (7) projects laser light through the observation window (13) onto an irradiated area on the irradiated sample (12) and receives reflected light, measures changes in laser frequency caused by the movement of the irradiated sample (12), and calculates the displacement changes of the irradiated sample (12) in real time, thereby achieving strain measurement of the irradiated sample (12) excited by vibration under high temperature and complex electromagnetic conditions during heavy ion beam irradiation.

13. The device for measuring in-situ internal friction of reactor structural materials by heavy ion irradiation according to claim 11, characterized in that: The heating laser (6) emits laser light of a specific wavelength, the wavelength of the laser light being different from the measurement wavelength of the two-color infrared thermometer, thereby avoiding affecting the temperature measurement of the two-color infrared thermometer.

14. The heavy ion irradiation in-situ internal friction measurement device for reactor structural materials according to claim 4, characterized in that: It also includes an electrical system, which includes an electric control cabinet, a voltage-stabilized power supply, a power amplifier, a high-speed AD acquisition board and a motor driver, and is responsible for providing power of various levels to the entire measuring device, power amplification of the excitation coil control signal, laser displacement detector signal processing and motor movement.

15. A method for measuring the in-situ internal friction of a reactor structural material subjected to heavy ion irradiation according to any one of claims 1 to 14, characterized in that: The following steps are involved: Step 1, fixing the irradiated sample (12) to be measured on the sample fixture (3), then installing the sample fixture (3) on the force loading system (4), and applying a tensile force to the irradiated sample (12) through the force loading system (4); Step 2, irradiating the irradiation area on the irradiation sample (12) with the accelerated heavy ion beam through the heavy ion beam pipeline interface (9); Step 3, by controlling the current loaded on the exciting coil (5) installed on the force loading system (4), a periodically changing magnetic field is generated, and the sample fixture (3) drives the irradiated sample (12) to perform periodic vibration; Step 4, irradiating the irradiated sample (12) with a high-power heating laser through a vacuum optical window, thereby heating the irradiated sample (12), and measuring the temperature of the irradiated sample (12) during heavy ion irradiation through an optical glass and a temperature measuring device (8) installed on an observation window (13); Step 5, measuring the strain of the irradiated sample (12) during vibration during heavy ion irradiation through the laser displacement detector (7) and the observation window (13); Step 6, by measuring the strain of the irradiated sample (12), comparing the stress-strain curve to calculate the internal friction, elastic modulus and dose-internal friction spectrum, to achieve in-situ internal friction measurement of the irradiated sample (12) during heavy ion irradiation.

16. The measuring method according to claim 15, characterized in that: The entire device is automatically operated through measurement and control software, including the acquisition and calculation of irradiation dose, generation of vibration excitation signals, reading of strain signals and sample deformation. The internal friction, elastic modulus and dose-internal friction spectrum of the irradiated sample (12) are calculated by comparing stress-strain curves.

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