High-voltage microcell laser heating device for synchrotron radiation test

Abstract

The invention belongs to the technical field of optical equipment, and discloses a high-voltage microcell laser heating device for synchrotron radiation test, which comprises a sample heating light path part, an illumination light path part and a radiation test part, the heating light path part sequentially comprises an infrared laser, a reflecting mirror, a dichroscope, an objective lens, a carbon reflecting mirror and a diamond anvil cell press; the radiation test light path part sequentially comprises a carbon reflector, an objective lens, a dichroscope, a spectroscope I, a reflector, a lens, a filter, a spectroscope II and a spectrograph. High-pressure laser heating and synchrotron radiation testing under the same device are achieved through arrangement of different light paths, amorphous carbon serves as a substrate, silver is plated on the surface of the substrate after polishing to serve as a mirror surface, a carbon reflecting mirror is manufactured, and the material of the substrate of the amorphous carbon has no diffraction peak, so that no interference is caused to X-ray diffraction signals; the problems that a reflecting mirror in front of a sample blocks X-rays in the testing process of a synchrotron radiation experiment and remote light focusing is caused in the online testing process are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical equipment, and particularly relates to a high-pressure micro-area laser heating device for synchrotron radiation testing. Background Art

[0002] Under high-temperature and high-pressure environments, the energy of the thermodynamic system changes, and the atomic arrangement of materials changes, often forming new structures or undergoing peculiar chemical reactions. Therefore, high-temperature and high-pressure technology is a common means of studying material science and a commonly used technology for developing and preparing new functional materials. The synchrotron radiation testing technology is a powerful means for characterizing new materials and new structures under high temperature and high pressure. However, there are still many problems to be solved in high-temperature and high-pressure in-situ testing on synchrotron radiation.

[0003] Common high-pressure devices include diamond anvil presses, which can achieve a maximum pressure of 1 TPa, far higher than the pressure that can be generated by large cavity presses. In addition, since diamond has excellent transmittance to light in multiple bands, it is easy to conduct relevant test characterizations of visible light, infrared light, and X-rays. Therefore, diamond anvil presses are more widely used in experimental tests. The common heating methods of diamond anvil presses are external heating and laser heating. The external heating method is to heat through the resistance wire surrounding the diamond anvil, and the temperature is controlled by controlling the current. This method heats both the diamond anvil and the sample simultaneously. Limited by the thermal stability of diamond itself, the heating temperature is lower than 1200 K. The laser heating technology heats the sample by focusing high-power laser on the sample, avoiding heating the diamond anvil, so a high temperature above 4000 K can be achieved. However, the high-pressure laser heating system for ordinary laboratories cannot be directly used for synchrotron radiation testing.

[0004] The existing patent CN114062346A discloses an in-situ high-pressure laser heating system, which heats the upper top surface and the lower bottom surface of the sample through two upper and lower subsystems, determines the molten state of the sample through a combined Raman system, and measures the real-time temperature of the heating area through blackbody radiation. However, this system cannot remotely adjust the optical path through key components such as an electric control objective lens, and X-rays cannot pass through in the optical path direction where the laser is incident on the sample, and X-ray testing cannot be synchronously achieved at the same time. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem of synchronization between the high-pressure laser heating system and radiation testing in the prior art.

[0006] To achieve the above purpose, the present invention provides a high-pressure micro-area laser heating device for synchrotron radiation testing, including a heating optical path part, an imaging optical path part, and a radiation testing optical path part; The heating optical path part sequentially includes an infrared laser, a reflecting mirror, a dichroic mirror, an objective lens, a carbon reflecting mirror, and a diamond anvil press; The radiation test optical path part sequentially includes a carbon reflecting mirror, an objective lens, a dichroic mirror, a spectroscope I, a reflecting mirror, a lens, a filter, a spectroscope II, and a spectrometer.

[0007] Specifically, the imaging optical path part includes white light emitted by an LED light source passing through a dichroic mirror, a spectroscope I, an objective lens, and a carbon reflecting mirror in sequence and being reflected into the sample chamber; the illumination light scattered by the sample chamber passes through a carbon reflecting mirror, an objective lens, a dichroic mirror, a spectroscope I, a reflecting mirror, a lens, a filter, a spectroscope II, and a CCD camera in sequence.

[0008] Specifically, the working distance of the objective lens is 6 cm, and it is achromatic in the infrared laser bands of 500 - 800 nm and 1064 nm.

[0009] Specifically, the carbon reflecting mirror uses amorphous carbon as the substrate material, and the substrate material has no X-ray diffraction peak. The surface is polished and silver-plated to form a mirror surface.

[0010] Specifically, the coating of the reflecting mirror is Ag, and the reflectivity is greater than 95% at a wavelength of 1064 nm.

[0011] Specifically, the objective lens is fixed on a displacement stage, the displacement stage and the carbon reflecting mirror are fixed on a bracket, the bracket is installed on an electric displacement stage, and the displacements of the objective lens and the carbon reflecting mirror are controlled by the electric displacement stage.

[0012] Specifically, the wavelength of the infrared laser is 1064 nm, the maximum power of a single path is 100 W, and two beams of laser are symmetrically focused on the front and back sides of the sample.

[0013] Specifically, the spectrometer of the spectral acquisition device is configured with a grating with a focal length of 300 mm, the grating ruling is 600 lines / mm; the detector is an X-ray area detector, and the pixel size is 100 μm × 100 μm.

[0014] Beneficial effects: 1. The present invention uses amorphous carbon as the substrate, polishes it, and silver-plates its surface to form a mirror surface to make a carbon reflecting mirror. The substrate material of this reflecting mirror has less absorption of hard X-rays, and most X-rays can pass through the reflecting mirror. In addition, the substrate material of amorphous carbon has no diffraction peak, so it does not interfere with the X-ray diffraction signal. Therefore, the present invention solves the problem that the reflecting mirror in front of the sample blocks X-rays during the synchrotron radiation experiment test, and realizes the synchronization of high-pressure laser heating and radiation test under the same device.

[0015] 2. The present invention uses two beams of infrared laser to heat the two sides of the sample respectively, making the temperature of the sample more uniform in the depth direction.

[0016] 3. The present invention mounts an amorphous carbon mirror on an electrically controlled mirror mount and mounts an achromatic objective lens on an electric displacement stage. In this way, the angles or positions of the carbon mirror and the objective lens can be remotely adjusted by a motor at any time according to requirements, and the functions of remote sample alignment and focusing can be achieved by the motor. Therefore, the present invention solves the problem of debugging the laser heating device in synchrotron radiation experimental tests.

[0017] 4. The present invention mounts both the carbon mirror and the objective lens on a metal bracket and fixes them on an electric displacement stage with a large stroke. When other equipment needs to be placed near the sample, the electric displacement stage can be controlled to move the carbon mirror and the objective lens away from the sample, leaving enough space for other equipment. Therefore, the present invention solves the problem of compatibility of the laser heating device with other equipment in terms of space.

[0018] 5. The present invention uses an objective lens that is achromatic in the visible light band and the incident laser infrared band, meeting the high-quality imaging requirements when the working distance > 6 cm, and solving the imaging problem of the objective lens of the laser heating device at a long working distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a high-pressure micro-area laser heating device provided by the present invention; Figure 2 is a fitting curve of the radiation spectrum of the sample provided by the present invention and the blackbody radiation formula.

[0020] Reference numerals: 1 - infrared laser, 2 - LED light source, 3 - mirror, 4 - dichroic mirror, 5 - beam splitter I, 6 - electric displacement stage, 7 - bracket, 8 - objective lens, 9 - displacement stage, 10 - carbon mirror, 11 - cooling device, 12 - diamond anvil press, 13 - lens, 14 - filter, 15 - CCD camera, 16 - spectrometer, 17 - detector, 18 - beam splitter II. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The application principle of the present invention will be further described below with reference to the drawings and specific embodiments.

[0023] Please refer to Figure 1 , a high-pressure micro-area laser heating device for synchrotron radiation testing includes: Heating optical path: The laser beams emitted by two infrared lasers 1 reach the dichroic mirror 4 (the dichroic mirror 4 can reflect infrared laser and transmit visible light) after passing through the reflecting mirror 3. After being reflected by the dichroic mirror 4 and transmitting visible light, they are focused by the objective lens 8, reflected by the carbon reflecting mirror 10 and then reach the sample in the diamond anvil press 12, thereby heating the sample. Two infrared lasers are used to heat the front and back sides of the sample simultaneously to ensure the temperature uniformity of the sample in the depth direction. The heat of the high-temperature sample will be conducted to the entire high-pressure device. The high-pressure device consists of the cooling device 11 and the diamond anvil press 12. The cooling device 11 is provided with the diamond anvil press 12.

[0024] The imaging optical path shares part of the optical path with the heating optical path; Imaging optical path: The white light emitted by two LED light sources 2 enters the objective lens 8 through the beam splitter I 5 and the dichroic mirror 4, and then is focused and reflected by the carbon reflecting mirror 10 into the sample chamber. The illumination light scattered by the sample chamber passes through the carbon reflecting mirror 10, the objective lens 8, the dichroic mirror 4, the beam splitter I 5, the reflecting mirror 3, the lens 13 and the filter 14, and finally is reflected by the beam splitter II 18 to the CCD camera 15 for imaging.

[0025] Radiation test optical path: The radiation light (X-ray) emitted by the high-temperature sample enters the objective lens 8 through the carbon reflecting mirror 10, and then passes through the dichroic mirror 4 and the beam splitter I 5 in parallel, and then is reflected by the reflecting mirror 3 to the lens 13. The lens 13 focuses the radiation light into the filter 14. The filter 14 filters out the infrared laser scattered by the sample. The filtered radiation light passes through the beam splitter II 18 and reaches the spectrometer 16. The spectrometer 16 collects the radiation spectrum for temperature fitting (see Figure 2 ). Its radiation light enters the spectrometer 16 through two paths. Because the temperatures of the front and back sides of the sample are different, the temperatures are measured separately.

[0026] Among them, the imaging optical path and the radiation test optical path share part of the optical path.

[0027] The working distance of the objective lens 8 is 6 cm, and it is achromatic in the 500 - 800 nm and 1064 nm bands, and meets the requirements of the working distance and imaging at the same time.

[0028] The distance between the objective lens 8 and the sample can be adjusted by the electric displacement stage 6, and the carbon reflecting mirror 10 is adjusted by the electric mirror mount to change the position of the focused laser.

[0029] The carbon reflecting mirror 10 uses amorphous carbon as the base material, and silver is plated on its surface after polishing as the mirror surface. The absorption of high-energy X-rays by carbon is small, so the incident X-rays can pass through the carbon reflecting mirror 10 and irradiate the sample, and the X-ray signal coming out of the sample can also penetrate the opposite carbon reflecting mirror 10 and reach the detector 17. In addition, since amorphous carbon has no diffraction peaks, it does not interfere with the X-ray diffraction signal of the sample.

[0030] During the synchrotron radiation experiment, sometimes other devices such as a microscope or a cryostat need to be placed near the sample. At this time, the part of the laser heating device close to the sample needs to be movable and away from the sample stage. The objective lens 8 is fixed on the displacement stage 9, the displacement stage 9 and the carbon mirror 10 are fixed on the bracket 7, and the bracket 7 is installed on the electric displacement stage 6. By moving the electric displacement stage 6, the position of the bracket 7 is controlled, so as to control the positions of the objective lens 8, the displacement stage 9 and the carbon mirror 10, so that they can be away from the sample stage when needed.

[0031] Some of the devices used are selected according to the following parameters or models: Infrared laser 1: wavelength 1064 nm, maximum power 100 W; LED light source 2: divergence angle less than 3°; mirror 3: coated with Ag, reflectivity of 1064 nm laser > 95%; dichroic mirror 4: reflects 1064 nm laser and transmits visible light of 500 - 700 nm; cooling device 11: made of copper, cooled by circulating water; diamond anvil press 12: symmetric press, anvil material is diamond; lens 13: focal length 750 mm; filter 14: filters light with a wavelength of 1064 nm; CCD camera 15: pixel size 25 μm × 25 μm; spectrometer 16: focal length 300 mm, grating with 600 lines; detector 17: X-ray detector is a surface detector, pixel size 100 μm × 100 μm.

[0032] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-voltage micro-area laser heating device for synchrotron radiation testing, characterized in that: It includes a heating optical path part, an imaging optical path part and a radiation testing optical path part; The heating optical path part includes an infrared laser, a reflector, a dichroic mirror, an objective lens, a carbon reflector and a diamond anvil press in sequence; The radiation test optical path part includes a carbon reflector, an objective lens, a dichroic mirror, a beam splitter I, a reflector, a lens, a filter, a beam splitter II, and a spectrometer in sequence.

2. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The imaging optical path includes white light emitted by an LED light source, which is reflected to a sample cavity through a dichroic mirror, a beam splitter I, an objective lens, and a carbon reflector in sequence; and illumination light scattered by the sample cavity is reflected to a sample cavity through a carbon reflector, an objective lens, a dichroic mirror, a beam splitter I, a reflector, a lens, a filter, a beam splitter II, and a CCD camera in sequence.

3. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The working distance of the objective lens is 6cm and it is achromatic in the 500-800nm ​​and 1064nm infrared laser bands.

4. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The carbon reflector uses amorphous carbon as the base material, and the base material has no X-ray diffraction peak. The surface is polished and silver-plated to form a mirror surface.

5. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The reflector is coated with Ag, and its reflectivity is greater than 95% at a wavelength of 1064nm.

6. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The objective lens is fixed on the translation stage, the translation stage and the carbon reflector are fixed on the bracket, the bracket is installed on the electric translation stage, and the displacement of the objective lens and the carbon reflector is controlled by the electric translation stage.

7. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The wavelength of the infrared laser is 1064nm, the maximum power is 100W, and the two lasers are symmetrically focused on the front and back sides of the sample.

8. The high-voltage micro-area laser heating device for synchrotron radiation testing according to claim 1, characterized in that: The spectrometer of the spectrum acquisition device is equipped with a grating with a focal length of 300 mm and a grating line of 600 lines / mm; the X-ray detector is a surface detector with a pixel size of 100 μm×100 μm.

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