Reflection type time resolution single crystal X-ray diffraction target device

Abstract

The invention discloses a reflective time-resolved single-crystal X-ray diffraction target device, which comprises a laser shock loading target assembly for simulating shock compression and unloading stretching processes in a high-speed impact or detonation process under the drive of an externally loaded laser beam; the backlight X-ray target assembly is used for carrying out transient imaging on a lattice structure in the single crystal sample and evolution of defects through reflective diffraction; the X-ray imaging assembly is used for detecting and imaging the reflective diffraction pattern; a detection probe assembly; the method has the characteristics of nanosecond-level time resolution and sensitive atomic-scale crystal structure, and has ultrahigh time and space resolution capability; the method has the advantages that pulse X-ray beams are utilized efficiently, the requirement for collimation of the X-ray beams is lowered, single-shot measurement is achieved more easily, and the signal-to-noise ratio does not need to be increased through repeated measurement; compared with a transmission-type diffraction structure, the device has the advantages that the requirement for the thickness of a single crystal sample is lowered, and the success rate of sample preparation is increased.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal X-ray diffraction diagnosis, and in particular to a reflection-type time-resolved single crystal X-ray diffraction target device. Background Art

[0002] Traditional single crystal X-ray diffractometers mainly use collimated quasi-monochromatic X-rays to impinge on the surface of single crystal samples, and obtain the reflection diffraction pattern of single crystal samples by rotating the sample and the detector. This technology is limited by the brightness of collimated X-rays and the mechanical rotation speed, and usually does not have time resolution capability. It can only characterize the crystal structure and structural defects of stationary single crystals, making it difficult to expand its application field to the study of structural property changes of crystal materials under high-speed motion, high strain rate deformation, rapid heating, strong light, electricity, magnetism and other pulse stimulations. Summary of the invention

[0003] The main purpose of the present invention is to provide a reflective time-resolved single crystal X-ray diffraction target device, aiming to solve the existing technical problems.

[0004] To achieve the above object, the present invention provides a reflection-type time-resolved single crystal X-ray diffraction target device, comprising:

[0005] Laser shock loading target components, including ablation layer and single crystal sample, simulate the shock compression and unloading stretching process during high-speed impact or detonation driven by external loading laser beam;

[0006] Backlit X-ray target assembly, which generates a non-collimated X-ray point source driven by an external diagnostic laser beam, and performs transient imaging of the lattice structure and defect evolution inside the single crystal sample through reflection diffraction;

[0007] X-ray imaging components for detecting and imaging reflection diffraction patterns;

[0008] Detection probe assembly, used for coupling laser interferometry velocity measurement and radiation temperature measurement diagnosis;

[0009] Wherein, the backlit X-ray target assembly and the X-ray imaging assembly are distributed on the same side of the sample.

[0010] Furthermore, the backlit X-ray target assembly comprises:

[0011] The backlit X-ray target generates plasma by interacting with the focused diagnostic pulse laser. With the target point as the center, it emits quasi-monochromatic characteristic X-rays to the surrounding space, forming reflective diffraction on the surface of the single crystal sample.

[0012] The backlit X-ray target holder is used to shield the X-rays generated by the backlit X-ray target.

[0013] Furthermore, the X-ray imaging assembly comprises:

[0014] Shielding layer, used to filter out stray X-rays, low-energy X-rays, and other charged particles that interfere with the X-ray imaging plate.

[0015] X-ray imaging plate, used to image reflection X-ray diffraction patterns.

[0016] Furthermore, the shielding layer includes a hydrocarbon material shielding layer and a metal film shielding layer.

[0017] Furthermore, it also includes an X-ray shielding assembly for blocking and weakening the background interference on the diffraction image caused by the X-ray beam generated by the backlit X-ray target assembly and the laser shock loading target assembly. The X-ray imaging assembly and the backlit X-ray target assembly are on the same side of the single crystal sample.

[0018] Furthermore, the X-ray shielding assembly includes a shielding cover for weakening the background caused by low-energy X-ray secondary particles or rays generated by the loaded pulse laser on the X-ray imaging plate.

[0019] Furthermore, the X-ray shielding assembly also includes a reflective detection box for fixing the X-ray imaging assembly and shielding the interference of stray X-rays on the X-ray imaging plate.

[0020] Furthermore, it also includes a hollow carved marker arranged on the backlit X-ray target, which is used to ensure the accuracy of the diagnostic light of the backlit X-ray target in the backlit X-ray target assembly during laser target shooting.

[0021] Furthermore, the hollow engraved marker is two hollow equilateral triangles arranged at intervals, and the middle position of the two hollow equilateral triangles serves as the center position of the diagnostic light aiming target for diagnostic light positioning.

[0022] Furthermore, it also includes a sample target holder for solidifying the specific positions of the backlit X-ray target assembly and the laser shock loading target assembly in the reflective diffraction configuration, providing target holder support for the pulse laser shock loading process and the diagnostic laser focusing to generate a plasma light source.

[0023] The beneficial effects of the present invention are embodied in:

[0024] The present invention has the characteristics of nanosecond time resolution and atomic scale crystal structure sensitivity, and has ultra-high time and space resolution capabilities;

[0025] The present invention has the characteristics of efficiently utilizing pulsed X-ray beams, reducing the requirements for the collimation of X-ray beams, and thus more easily realizing single-shot measurement without the need to improve the signal-to-noise ratio through repeated measurements;

[0026] The present invention has the advantage of being compatible with traditional shock wave measurement technology, provides a universal adapter interface for laser interferometer velocimeters, radiation temperature measuring instruments, etc., and effectively realizes technical compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the present invention;

[0028] Figure 2 for Figure 1 Schematic diagram of the cross-section structure along AA;

[0029] Figure 3 It is a schematic diagram of the structural relationship between the sample target holder, the backlit X-ray target assembly and the laser shock loading target assembly of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a backlit X-ray target stand and a backlit X-ray target of the present invention.

[0031] Description of reference numerals:

[0032] 1. Shielding cover; 2. Reflective detection box; 3. Detection probe assembly; 4. Sample target holder; 5. Backlit X-ray target assembly; 6. Laser shock loading target assembly; 7. X-ray imaging assembly; 8. Target rod; 9. Backlit X-ray target holder; 10. Backlit X-ray target. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] See also Figure 1-3 The present invention provides a reflective time-resolved single crystal X-ray diffraction target device.

[0035] The laser shock loading target assembly 6 includes two parts: the ablation layer and the single crystal sample. The externally loaded pulsed laser beam generates a laser-driven shock wave by interacting with the ablation layer. The shock wave propagates toward the single crystal sample to realize the shock loading and dynamic unloading process of the sample, which is used to simulate the shock compression and unloading stretching process in the high-speed impact or detonation process.

[0036] The backlit X-ray target assembly 5 includes three parts: a foil-shaped metal backlit target and a backlit target bracket. After the external diagnostic pulsed laser beam is focused, it interacts with the foil-shaped metal backlit target to generate high-temperature plasma. The ionized metal particles generate characteristic X-rays through energy level transitions. The X-rays are spherically divergent with the interaction area between the diagnostic laser pulse and the foil-shaped metal backlit target as the center. In the reflective diffraction target device, the backlit X-ray target assembly and the X-ray imaging assembly are respectively arranged on the same side of the single crystal sample. After the spherically divergent pulsed X-rays are incident on the sample, reflective diffraction occurs. By adjusting the timing relationship between the diagnostic pulsed laser beam and the loading pulsed laser beam, time-resolved structural detection of the single crystal material in the impact compression and unloading tension stages is achieved.

[0037] X-ray shielding assembly. In the reflective diffraction target device, the X-ray imaging assembly and the backlit X-ray target assembly are on the same side of the single crystal sample. Therefore, the X-ray beam generated by the backlit X-ray target assembly will cause extremely strong interference to the diffraction image. In addition, the low-energy X-rays generated by the laser shock loading target assembly will also cause strong interference to the diffraction image. Therefore, the X-ray shielding assembly is mainly used to block and weaken the X-ray beam generated by the backlit X-ray target assembly, while ensuring that the X-ray photons generated by the reflective diffraction can be directly imaged on the X-ray imaging plate, thereby weakening the interference of the X-rays generated by the laser shock loading target assembly on the diffraction image.

[0038] The X-ray imaging assembly 7 includes two parts: an X-ray filter group and an X-ray imaging plate. In the reflective diffraction target device, the X-ray imaging assembly and the backlight X-ray target assembly are on the same side of the single crystal sample. Therefore, the function of the X-ray filter group is to further weaken the interference of low-energy X-rays, electron beams generated by the photoelectric effect, X-ray fluorescence, etc. on the diffraction image detection on the basis of the X-ray shielding assembly, so that the diffraction image can be clearly presented on the X-ray imaging plate.

[0039] Detection probe assembly 3, in order to dynamically monitor the impact compression and dynamic stretching process generated by the laser impact loading assembly in the sample, the present invention introduces a fiber optic interface, which is coupled to the free interface of the single crystal sample through a five-dimensional adjustable lens group; when the sample interface moves due to the impact loading, the Doppler frequency shifted light beam generated by the sample interface is coupled into the fiber optic structure again through the lens group, providing a universal adapter interface for the laser interferometer velocimeter. At the same time, the interface can collect the luminous signal on the sample surface to achieve the measurement of thermodynamic states such as radiation temperature.

[0040] The above-mentioned components are specifically as follows: the reflective time-resolved single crystal X-ray diffraction target device includes a shielding cover 1, which is used to weaken the background caused by secondary particles or rays such as low-energy X-rays generated by the loaded pulse laser on the X-ray imaging plate; a reflective detection box 2, which is used to fix the X-ray imaging component and shield the interference of stray X-rays on the X-ray imaging plate; a detection probe component 3, including a shielding window, a five-dimensional adjustable lens and an FC / APC optical fiber interface, the shielding window is used to prevent the sputtering generated by laser target shooting from being coated on the lens, the five-dimensional adjustable lens is used to adjust the spatial relationship of the light beam collected by the optical fiber interface originating from or reflected from a certain point on the sample interface, and the FC / APC interface is used to couple a standard FC / APC optical fiber connector to realize laser interference speed measurement and radiation temperature measurement of the sample interface during the impact loading process. Diagnosis such as; a sample target holder 4, which is used to solidify the specific positions of the backlight X-ray target assembly 9 and the laser shock loading target assembly 6 in the reflective diffraction configuration, and provide a target holder support for the impact loading process of the pulsed laser and the diagnosis of the laser focusing to produce a plasma light source, such as Figure 3 As shown; the backlit X-ray target assembly 5 includes a backlit X-ray target stand 9 and a backlit X-ray target 10. The backlit X-ray target 10 generates plasma by interacting with the focused diagnostic pulse laser, and emits quasi-monochromatic characteristic X-rays to the surrounding space with the target point as the center of the circle, forming reflective diffraction on the surface of the single crystal sample. At the same time, the backlit X-ray target stand 9 shields the X-rays generated by the backlit X-ray target, so that it cannot be directly imaged on the X-ray imaging plate, thereby improving the signal-to-noise ratio of the X-ray reflective diffraction pattern, as shown in FIG. Figure 4 As shown; a laser shock loading target assembly 6, including an ablation layer and a single crystal sample, the ablation layer generates a shock wave by interacting with the beam-smoothed loading pulse laser, thereby realizing the shock loading process of the single crystal sample; an X-ray imaging assembly 7, including a shielding layer and an X-ray imaging plate, the shielding layer is mainly used to filter out stray X-rays, low-energy X-rays, and other charged particles that interfere with the X-ray imaging plate, including a hydrocarbon material shielding layer and a metal film shielding layer, and the X-ray imaging plate is mainly used to image the reflection X-ray diffraction pattern.

[0041] The technical principle of the present invention is as follows: a group of pulsed lasers are used to ablate the ablation layer on the surface of the sample to generate shock waves, and the impact loading and unloading process is realized in the single crystal sample; after a certain time delay, another group of pulsed lasers are used to interact with the X-ray backlight target assembly to generate a quasi-monochromatic X-ray point source; the quasi-monochromatic X-ray pulses are spherically diverged from the target point of the backlight target assembly and incident on the surface of the single crystal sample, and a reflective X-ray diffraction process occurs; the X-ray imaging assembly and the backlight target assembly are distributed on the same side of the sample, and the intensity distribution of the X-ray photons that undergo reflective diffraction is imaged to obtain the X-ray diffraction pattern of the single crystal material during the laser loading or unloading process; a detection probe assembly is arranged on another group of the sample, and the movement process of the interface / surface of the single crystal sample during the impact loading and unloading process is monitored through a standard optical fiber external laser interferometer velocimetry device, so as to achieve quantitative characterization of the impact loading pressure.

[0042] Specifically, an external laser optical path system provides two groups of time-synchronized high-energy pulsed lasers, one group of laser pulses is used as diagnostic light, and the other group of laser pulses is used as loading light. When in use, the loading light acts on the single crystal sample through the laser shock loading target assembly 6 to generate a shock compression process, and the diagnostic light acts on the backlight X-ray target assembly 5 to generate quasi-monochromatic pulsed X-rays, which enter the X-ray imaging assembly 7 through reflection diffraction to form an image, and are used to perform transient X-ray diffraction imaging of the single crystal material in the shock compression or unloading stretching process. The backlight X-ray target holder in the backlight X-ray target assembly 5 will block the X-rays generated by the backlight X-ray target from being directly imaged on the X-ray imaging assembly 7 without reflection, thereby improving the signal-to-noise ratio of the reflection diffraction diagnosis, and the shielding cover 1 and the reflective detection box 2 will block the low-energy X-rays generated by the laser shock loading target assembly 6 and the low-energy X-rays generated by the stray laser from generating a background on the X-ray imaging assembly 7. The detection probe assembly 3 will achieve laser interferometry velocimetry and radiation temperature measurement and other diagnoses of the rear interface of the sample by coupling an external optical fiber.

[0043] Specifically, as a specific mode of the external optical path system, the external optical path system can select the Shenguan II device, and use the four north or four south pulse lasers of its target chamber as diagnostic light, and the ninth pulse laser of the ninth device as loading light. When in use, the wavelength of the loading light is 351nm, the pulse waveform is within 10ns and adjustable, and the laser energy output is more than 1000J; the diagnostic light generates pulsed X-rays through synchronous focusing and the backlight X-ray target assembly 5, which is used to perform transient X-ray diffraction diagnosis on single crystal samples at a specific delay time. The wavelength of the diagnostic light is 351nm, the pulse width is 1ns, the energy of each diagnostic light is about 250J, and the total energy of the four diagnostic lights is about 1000J. It should be noted that the reflective time-resolved single crystal X-ray diffraction target device can be placed in a vacuum environment such as a vacuum target chamber when in use to reduce the influence of air and external light, and can be positioned in a vacuum environment through a supporting device such as a target rod 8 to provide a stable working environment.

[0044] In one embodiment, in order to ensure the accuracy of the diagnostic light of the backlit X-ray target 10 in the backlit X-ray target assembly 5 during laser target shooting, a hollow engraved marker on the metal foil is used to mark the center of the diagnostic light target, such as Figure 4 As shown, the diagnostic light targeting position can be determined by the marked diagnostic light targeting center.

[0045] Furthermore, the hollow carved marker is two hollow equilateral triangles set at intervals, and the middle position of the two hollow equilateral triangles can be used as the center position of the diagnostic light aiming target for diagnostic light positioning.

[0046] In one embodiment, in order to ensure long-term use and not affect diagnosis, the sample target holder 4 and the backlight X-ray target holder 9 are made of tantalum or tantalum-tungsten alloy. Specifically, both can be made of Ta10W alloy.

[0047] It should be noted that the detection probe assembly 3, as an adjustment mechanism for the position or relative position of the optical lens or optical fiber interface, can be implemented in various ways in the prior art, such as the public document with patent number CN200962162Y and the name of five-dimensional adjustment mechanism. Its specific working principle and specific structure will not be further described in this embodiment.

[0048] In summary, the reflective time-resolved single crystal X-ray diffraction target device of the present invention has the following beneficial effects: 1) high timing synchronization accuracy, the timing control accuracy between the driving light and the pulsed X-ray can be controlled within nanoseconds; 2) good time resolution, the X-ray pulse width can usually reach nanoseconds or even sub-nanoseconds; 3) sensitive to microstructural changes at the atomic scale, the measurement accuracy of the lattice constant or crystal plane spacing can reach 0.01 nanometers; 4) the X-ray diffraction spectrum can be directly obtained through a single measurement, and there is no need to improve the signal-to-noise ratio through multiple repeated measurements, which saves a lot of samples and experimental times; 5) without hindering the implementation of time-resolved X-ray diffraction diagnosis for powder crystals, the laser interferometry velocimetry diagnosis and interface radiation temperature diagnosis of the rear interface of the powder crystal can be taken into account.

[0049] In addition, in response to the material research needs in the fields of explosion mechanics and armor protection, the present invention has achieved a breakthrough in time resolution, making it possible to study the lattice structure deformation and damage evolution of single crystal materials under external forces such as dynamic compression and tension; at the same time, the requirements for the incident X-rays are reduced from a collimated beam to a point divergent beam, greatly improving the utilization efficiency of the X-ray beam; using a reflective diffraction configuration, the thickness requirement for single crystal samples is reduced compared to a transmission diffraction configuration, thereby improving the success rate of sample preparation.

[0050] It should be noted that if the embodiments of the present invention involve directional indications such as up, down, left, right, front, back, etc., then the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0051] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, "multiple" refers to more than two. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A reflective time-resolved single crystal X-ray diffraction target device, characterized in that: include, The laser shock loading target assembly (6), including the ablation layer and the single crystal sample, is driven by an external loading laser beam to simulate the shock compression and unloading stretching process in the high-speed impact or detonation process; A backlit X-ray target assembly (5) generates a non-collimated X-ray point light source under the drive of an external diagnostic laser beam, and performs transient imaging of the lattice structure and defect evolution inside the single crystal sample through reflection diffraction; An X-ray imaging component (7) for detecting and imaging the reflection diffraction pattern; A detection probe assembly (3) for coupling laser interferometry velocity measurement and radiation temperature measurement diagnosis; Wherein, the backlit X-ray target assembly (5) and the X-ray imaging assembly (7) are distributed on the same side of the sample.

2. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 1, characterized in that: The backlit X-ray target assembly (5) comprises: The backlit X-ray target (10) generates plasma by interacting with the focused diagnostic pulse laser, emitting quasi-monochromatic characteristic X-rays to the surrounding space with the target point as the center, and forming reflection diffraction on the surface of the single crystal sample; The backlight X-ray target stand (9) is used for shielding X-rays generated by the backlight X-ray target.

3. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 1, characterized in that: The X-ray imaging assembly (7) comprises: Shielding layer, used to filter out stray X-rays, low-energy X-rays, and other charged particles that interfere with the X-ray imaging plate. X-ray imaging plate, used to image reflection X-ray diffraction patterns.

4. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 3, characterized in that: The shielding layer comprises a hydrocarbon material shielding layer and a metal film shielding layer.

5. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 1, characterized in that: It also includes an X-ray shielding assembly for blocking and weakening the background interference on the diffraction image caused by the X-ray beam generated by the backlit X-ray target assembly and the laser shock loading target assembly. The X-ray imaging assembly and the backlit X-ray target assembly are on the same side of the single crystal sample.

6. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 5, characterized in that: The X-ray shielding assembly comprises a shielding cover (1) for weakening the background caused by low-energy X-ray secondary particles or rays generated by the loaded pulse laser on the X-ray imaging plate.

7. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 5, characterized in that: The X-ray shielding component also includes a reflective detection box (2) which is used to fix the X-ray imaging component and shield the interference of stray X-rays on the X-ray imaging plate.

8. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 2, characterized in that: It also includes a hollow carved marker disposed on the backlit X-ray target (10) for ensuring the accuracy of the diagnostic light of the backlit X-ray target (10) in the backlit X-ray target assembly (5) during laser target shooting.

9. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 8, characterized in that: The hollow carved marker is two hollow equilateral triangles arranged at intervals, and the middle position of the two hollow equilateral triangles serves as the center position of the diagnostic light aiming target for diagnostic light positioning.

10. The reflection-type time-resolved single crystal X-ray diffraction target device according to claim 1, characterized in that: The invention also comprises a sample target stand (4) for solidifying the specific positions of the backlit X-ray target assembly (5) and the laser shock loading target assembly (6) in the reflective diffraction configuration, and providing target stand support for the shock loading process of the pulsed laser and the plasma light source generated by focusing the diagnostic laser.

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