Dual-channel multi-branch gated crystal spectrometer

Abstract

The present invention discloses a dual-channel multi-branch gated crystal spectrometer, comprising a box body, wherein the front end of the box body is provided with an upper incident hole and a lower incident hole, and the rear end is provided with a diffraction outlet; a beam splitter plate is fixedly mounted on the front of the box body through a bracket, and the beam splitter plate is provided with an upper row of slits and a lower row of slits; an upper crystal assembly is fixedly mounted on the upper end of the box body, and the number of the upper crystal assemblies corresponds to the number of slits in the upper row of slits; a lower crystal assembly is fixedly mounted on the lower end of the box body, and the number of the lower crystal assemblies corresponds to the number of slits in the lower row of slits. The beneficial effect is: a symmetrical dual-channel multi-branch spectrometer assembly front end is adopted, and spatially resolved measurement is realized by coupling an array-type multi-branch slit plate. A two-dimensional rotating adjustment seat design is adopted at the rear end, which is convenient for coupling with a recording system. Combined with a gated X-ray framing camera recording system, spectral measurements of multiple time points, multiple spectral bands, and spatial resolution can be simultaneously realized in a single-shot experiment.

Description

Technical Field

[0001] The invention relates to a crystal spectrometer, in particular to a dual-channel multi-branch gated crystal spectrometer. Background Art

[0002] Plasma parameter diagnosis based on spectroscopy is crucial for experimental research on laser-plasma interactions in the fields of high energy density physics, inertial confinement fusion, laboratory astrophysics, etc. However, in laser ablation experiments, the state evolution of the plasma often changes dynamically with time and space. When using a crystal spectrometer for X-ray spectral diagnosis, it is required not only to have high spectral resolution, but also to have time (ps level) and space (μm level) resolution. Therefore, the spectral diagnostic system is required not only to achieve high spectral resolution, but also to have spatial resolution, and to be easily and effectively coupled with the time-resolved recording system.

[0003] Laser ablation experiments based on large scientific facilities have limited resources and high experimental costs. They also require obtaining as many different state parameters as possible in a single shot, such as temperature, density, degree of ionization, or different parameter intervals of the same parameter. This can be achieved by measuring X-ray emission or absorption spectra of different materials at different times and in different spectral bands. However, this also poses more stringent requirements and challenges on how to achieve spectral measurements at multiple times, multiple spatial points, and multiple spectral bands in a single experiment.

[0004] In the prior art, X-ray spectroscopy diagnosis is usually achieved through a crystal spectrometer. Traditional crystal spectrometers are designed based on the Bragg diffraction theory 2dsinθ=nλ. Where d is the crystal plane spacing, θ is the diffraction angle, λ is the diffraction wavelength, and n is the diffraction order. The traditional planar crystal spectrometer has a simple structure. Depending on the measurement range, the instrument is separately configured with crystals of different specifications and recording surfaces at different angles. This results in a crystal spectrometer that can only meet the needs of a specific measurement range and is difficult to couple with other recording systems with high temporal and spatial resolution.

[0005] Therefore, it is urgent to develop a spectral measurement device that can simultaneously achieve multiple time points, multiple spectral bands, and spatial resolution in a single-shot experiment. Summary of the invention

[0006] In view of this, the present invention provides a dual-channel multi-branch gated crystal spectrometer, aiming to solve the technical requirements raised by the background technology.

[0007] To achieve the above purpose, the technical solution of the present invention is as follows:

[0008] A dual-channel multi-branch gated crystal spectrometer, the key of which is to include:

[0009] A box body of rectangular structure, wherein the front end of the box body is provided with an upper incident hole and a lower incident hole symmetrically arranged up and down, and the middle part of the rear end of the box body is provided with a diffraction outlet;

[0010] A beam splitter plate, which is fixedly mounted on the front of the box body through a bracket, and the beam splitter plate is provided with an upper row of slits and a lower row of slits;

[0011] An upper crystal assembly, which is fixedly mounted on the upper end of the box body, the number of the upper crystal assemblies corresponds to the number of the slits in the upper row of slits, the light emitted by the light source in front of the beam splitter can pass through the upper row of slits and the upper incident hole in sequence, and be incident on the upper crystal assembly, and after the incident light is diffracted by the upper crystal assembly, the diffracted light can be emitted from the diffraction outlet; and

[0012] The lower crystal assembly is fixedly mounted at the lower end of the box body. The number of the lower crystal assemblies corresponds to the number of the slits in the lower row. The light emitted by the light source in front of the beam splitter can pass through the lower row of slits and the lower incident hole in sequence and be incident on the lower crystal assembly. After the incident light is diffracted by the lower crystal assembly, the diffracted light can be emitted from the diffraction outlet.

[0013] Preferably, the upper row of slits, upper incident hole, upper crystal assembly and diffraction outlet constitute a first channel, the lower row of slits, lower incident hole, lower crystal assembly and diffraction outlet constitute a second channel, the first channel and the second channel are arranged symmetrically up and down, and a shielding assembly is installed inside the box body, and the shielding assembly is arranged in the middle position in the height direction of the box body.

[0014] Preferably, a supporting base plate is fixedly installed inside the box body, a supporting tube extending backwards is installed on one side of the supporting base plate, the supporting tube is used to install the collimating laser pen, and adjusting screws are distributed circumferentially of the supporting tube.

[0015] Preferably, the upper crystal assembly includes a crystal seat and a crystal piece, the crystal seat has a locking plate and a protrusion extending downward from the lower side of the locking plate, the crystal piece is fixedly installed in the protrusion, the upper end of the box body is provided with a strip hole, the protrusion is installed in the strip hole, both ends of the locking plate exceed the ends of the protrusion, and the exceeding part is fixed to the upper end of the box body by screws.

[0016] Preferably, the protrusion is provided with a rectangular mounting channel which passes through the protrusion along its length direction, the lower end of the rectangular mounting channel is open, and the lower end of the rectangular mounting channel is provided with a supporting step, the crystal piece is supported on the supporting step through a gasket, and the locking plate is threadedly connected with a locking screw, and the locking screw is used to fix the crystal piece on the supporting step.

[0017] Preferably, the beam splitter is a rectangular plate, which is parallel to the front end of the box body; the number of the upper row of slits, the upper crystal assembly, the lower row of slits and the lower crystal assembly are all 3 groups.

[0018] Preferably, a two-dimensional rotation adjustment seat and a gated recording system are sequentially mounted at the rear end of the box body, the gated recording system has a recording surface, and the two-dimensional rotation adjustment seat can drive the box body to rotate around the center line of the recording surface in a manual or automatic control manner.

[0019] The beneficial effects of the present invention are:

[0020] 1. The symmetrical dual-channel multi-branch spectrometer and the dedicated crystal box design can effectively expand the spectrum measurement range. Combined with the use of the gated recording system, it can simultaneously realize the spectrum measurement of multiple time points, multiple spectral segments and spatial resolution in a single-shot experiment.

[0021] 2. Through dual-channel multi-branch spectroscopy, combined with the compact design of internal shielding components, it can not only achieve miniaturization and space saving, but also achieve the effect of multiple shielding of high-energy X-rays, super-hot electrons and ions that directly penetrate the front end of the recording surface, which can effectively improve the signal-to-noise ratio.

[0022] 3. At the front end of the dual-channel multi-branch spectrometer component, spatially resolved measurement is achieved by coupling an array-type multi-branch slit plate.

[0023] 4. A two-dimensional rotating adjustment seat design is adopted at the rear end of the dual-channel multi-branch spectrometer component, which is convenient for coupling with the gated recording system and for realizing the spectrometer attitude adjustment and target aiming.

[0024] 5. Compared with the traditional crystal spectrometer, the present invention adopts multi-imaging slit and dual-channel design to achieve three-dimensional resolution measurement of time, space and spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the three-dimensional structure of the dual-channel multi-branch gated crystal spectrometer of the present invention;

[0026] Figure 2 This is a reference diagram of the use status of a dual-channel multi-branch gated crystal spectrometer;

[0027] Figure 3 A partial exploded schematic diagram showing the assembly structure of the upper crystal component 5;

[0028] Figure 4 is a cross-sectional view of the upper crystal assembly 5;

[0029] Figure 5 This is a diagram of experimental measurement results based on the Shenguang III prototype laser;

[0030] Figure 6 (a)-(c) are the spectra of Ti in the 4400-5800 eV range at 0.6, 0.85, and 1.2 ns, respectively. Figure 6(d) is the spectral line distribution diagram after the signal is normalized with the intensity corresponding to the He-α line energy value of Ti, 4749 eV, at the position r=0 μm. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with embodiments and drawings.

[0032] The directions "up, down, front, and back" mentioned in this embodiment are as follows: Figure 1 The coordinates shown are for reference only.

[0033] like Figure 1 As shown in FIG. 1 , a dual-channel multi-branch gated crystal spectrometer mainly includes a box body 1, a beam splitter 3, an upper crystal assembly 5 and a lower crystal assembly 6. The box body 1 is a rectangular structure with a hollow interior. The front end of the box body 1 is provided with an upper incident hole 1a and a lower incident hole 1b. Figure 2 It can be seen that a diffraction outlet 1c is provided in the middle of the rear end of the box body 1, and the upper incident hole 1a and the lower incident hole 1b are arranged symmetrically up and down relative to the center line of the diffraction outlet 1c. The beam splitter 3 is fixedly mounted on the front of the box body 1 through the bracket 4. The beam splitter 3 is a rectangular plate and is parallel to the front end of the box body 1. Two rows of slits are provided on the beam splitter 3, namely, the upper row of slits 3a and the lower row of slits 3b. Similarly, the upper row of slits 3a and the lower row of slits 3b are also arranged symmetrically up and down relative to the center line of the diffraction outlet 1c.

[0034] The upper crystal assembly 5 is fixedly mounted on the upper end of the box body 1, and the lower crystal assembly 6 is fixedly mounted on the lower end of the box body 1. The number of the upper crystal assemblies 5 is consistent with the number of slits in the upper row of slits 3a, and the number of the lower crystal assemblies 6 is consistent with the number of slits in the lower row of slits 3b. In this embodiment, the number of the upper row of slits 3a, the upper crystal assembly 5, the lower row of slits 3b and the lower crystal assembly 6 are all 3 groups. In addition, different numbers of branch groups can also be set according to needs, such as: 2 groups, 4 groups, 5 groups, 6 groups, etc.

[0035] Based on the above structural layout of the crystal spectrometer, its working principle is as follows:

[0036] Please refer to Figure 2, an X-ray light source 8 is arranged in front of the crystal spectrometer, which is generally generated by the interaction between a strong laser and a target to form a plasma process, and a gated recording system 9 is arranged at the rear end. The strong light emitted by the X-ray light source 8 is divided into six paths by two rows of 1mm long and 50μm wide slits of the beam splitter 3, three paths in each of the upper and lower channels, wherein the upper three groups of light sequentially pass through the upper incident hole 1a and are incident on the upper crystal component 5, after diffraction by the upper crystal component 5, they are emitted from the diffraction outlet 1c, and then recorded by the gated recording system 9 at the rear end. Similarly, the lower three groups of light sequentially pass through the lower incident hole 1b and are incident on the lower crystal component 6, after diffraction by the lower crystal component 6, they are emitted from the diffraction outlet 1c, and then recorded by the gated recording system 9 at the rear end. It can be seen from this that the use of a symmetrical dual-channel multi-branch crystal spectrometer can effectively expand the spectrum measurement range, and combined with the use of a gated recording system, it can simultaneously realize multi-time point, multi-spectral, and spatially resolved spectral measurements in a single-shot experiment.

[0037] Based on the above principles, this embodiment conducts verification tests based on the Shenguang III prototype laser. The experiment uses four lasers at the top and bottom, each laser beam is 800J / 1ns square wave, acting on a horizontally placed multi-layer material target (CH / Au / Ti / CH) to generate X-ray light sources of different spectral bands. In a single shot experiment, the dual-channel multi-branch gated crystal spectrometer measured a total of 6 different time periods and two spectral ranges, corresponding to two materials Ti and Au, and the spatial resolution was 60μm spectral experimental data. The experimental measurement results are shown in the figure. Figure 5 As shown, the spatially resolved Ti emission spectra of the three lower branches of the lower channel in the 4400-6000 eV range at three times of 0.6ns, 0.85ns, and 1.2ns are measured on the upper side; the spatially resolved Au emission spectra of the three upper branches of the upper channel in the 3200-3600 eV range at three times of 0.4ns, 0.65ns, and 0.9ns are measured below the recording surface.

[0038] After wavelength calibration and spatial position calibration of the Ti spectra at 0.6ns, 0.85ns, and 1.2ns, the results are as follows: Figure 6 (a)-(c) are shown. The spectrum line at r = 0 μm position is taken out after the signal is normalized with the corresponding intensity of the Ti-Heα line energy value 4749 eV, as shown in Figure 6 As shown in (d), the signal-to-noise ratio is evaluated by the spectral line intensity of the energy value of 4749 eV. The signal-to-noise ratios of the three spectral lines are all greater than 10:1. This shows that the dual-channel multi-branch gated crystal spectrometer used in this embodiment not only obtains spectra at multiple time points, different bands, and spatial resolution in a single-shot experiment, but also has a high spectral signal-to-noise ratio, which can reach more than 10:1.

[0039] like Figure 2As shown, the upper row of slits 3a, the upper incident hole 1a, the upper crystal assembly 5 and the diffraction outlet 1c constitute the first channel, and the lower row of slits 3b, the lower incident hole 1b, the lower crystal assembly 6 and the diffraction outlet 1c constitute the second channel. The first channel and the second channel are arranged symmetrically in the height direction of the box body. A shielding assembly 2 is installed inside the box body 1, and the shielding assembly 2 is arranged in the middle position in the height direction of the box body 1. With such a design, the strong light used for spectral measurement is directed obliquely to the crystal for diffraction, and the high-energy X-rays and super-hot electrons and ions that pass directly through the recording surface can be effectively shielded by the shielding assembly 2. Due to the complex use environment of laser ablation experiments, high-energy X-rays, electrons and ions from the laser-target interaction zone are prone to form stray background signals, which directly affect the signal-to-noise ratio of spectral data, increase the uncertainty of experimental results, and even make experimental data unavailable in severe cases. Therefore, such a design not only takes into account the compact design and miniaturization design of the crystal spectrometer, but also can effectively improve the signal-to-noise ratio of the signal.

[0040] Furthermore, the shielding assembly 2 includes a lead sheet 2b and an aluminum or plastic shell 2a sleeved on the outside of the lead sheet 2b, wherein the lead sheet 2b is a rectangular sheet and is longitudinally arranged in the middle of the box body 1. Such a design helps to better shield high-energy X-rays and super-hot electrons and ions that penetrate directly.

[0041] In this embodiment, a supporting base plate 10 is fixedly installed inside the box body 1, and a supporting tube 11 extending backward is installed on one side of the supporting base plate 10. The supporting tube 11 is used to install a collimating laser. The supporting tube 11 is circumferentially distributed with adjusting screws 12 installed along its radial direction. By turning the adjusting screws 12, the laser beam can be collimated.

[0042] In this embodiment, before the formal experiment, the micro laser in the support tube is used to aim the device, and the shielding component 2 is placed after the aiming is completed.

[0043] In this embodiment, please refer to Figure 3The upper crystal assembly 5 includes a crystal seat 5a and a crystal piece 5b. The crystal seat 5a has a locking plate 5a2 and a protrusion 5a1 extending downward from the lower side of the locking plate 5a2. The crystal piece 5b is fixedly installed in the protrusion 5a1. The upper end of the box body 1 is provided with a rectangular strip hole 1d. The protrusion 5a1 is installed in the strip hole 1d. The two ends of the locking plate 5a2 exceed the ends of the protrusion 5a1, and the exceeding part is fixed to the upper end of the box body 1 by screws e. In the prior art, the main reason for limiting the on-site operation of the crystal spectrometer experiment is the on-site aiming and the installation and removal of the crystal. The most vulnerable part of the crystal spectrometer is the crystal or the crystal box. The crystal is fragile and easily deformed by the ambient temperature, humidity, etc., and it needs to be stored in a drying cabinet. The traditional crystal spectrometer needs to install and remove the crystal separately before and after each experiment. The risk of crystal damage is high, and the process is time-consuming, which is not convenient for rapid aiming, installation and storage operations at the experimental site. Therefore, by adopting the design of this embodiment, the upper crystal assembly 5 is constructed as a detachable integrated structure, which has the advantage of being easy to install, adjust and remove.

[0044] Furthermore, Figure 6 As shown, the protrusion 5a1 is provided with a rectangular installation channel a running through the length direction thereof, the lower end of the rectangular installation channel a is open, and the lower end of the rectangular installation channel a is provided with a support step b, the crystal piece 5b is supported on the support step b through a gasket c, and a locking screw 5c is threadedly connected to the locking plate 5a2, and the locking screw 5c is used to fix the crystal piece 5b on the support step b. With such a design, the crystal piece can also be replaced and installed by loosening and tightening the locking screw 5c.

[0045] For example Figure 2 As shown, the rear end of the box body 1 is sequentially installed with a two-dimensional rotation adjustment seat 7 and a gated recording system 9, the gated recording system 9 has a recording surface 9a, and the two-dimensional rotation adjustment seat 7 can drive the box body 1 to rotate horizontally and translate up and down around the center line of the recording surface 9a in a manual or automatic control manner. With such a design, when the crystal spectrometer is actually used, it can be rotated and adjusted according to the recording system, which is convenient for coupling with the gated recording system, and can also facilitate the spectrometer posture adjustment and target aiming, which has the advantage of convenient and fast use of the spectrometer.

[0046] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention, and such changes all fall within the scope of protection of the present invention.

Claims

1. A dual-channel multi-branch gated crystal spectrometer, characterized in that: include: A box body (1) of rectangular structure, wherein the front end of the box body (1) is provided with an upper incident hole (1a) and a lower incident hole (1b) symmetrically arranged up and down, and the middle part of the rear end of the box body (1) is provided with a diffraction outlet (1c); A beam splitter plate (3) fixedly mounted on the front of the box body (1) via a bracket (4), wherein the beam splitter plate (3) is provided with an upper row of slits (3a) and a lower row of slits (3b); An upper crystal assembly (5) is fixedly mounted on the upper end of the box body (1); the number of the upper crystal assemblies (5) corresponds to the number of the slits in the upper row of slits (3a); the light emitted by the light source in front of the beam splitter (3) can sequentially pass through the upper row of slits (3a) and the upper incident hole (1a) and be incident on the upper crystal assembly (5); after the incident light is diffracted by the upper crystal assembly (5), the diffracted light can be emitted from the diffraction outlet (1c); as well as A lower crystal component (6) is fixedly mounted at the lower end of the box body (1); the number of the lower crystal components (6) corresponds to the number of the slits in the lower row of slits (3b); the light emitted by the light source in front of the beam splitter (3) can pass through the lower row of slits (3b) and the lower incident hole (1b) in sequence and be incident on the lower crystal component (6); after the incident light is diffracted by the lower crystal component (6), the diffracted light can be emitted from the diffraction outlet (1c).

2. The dual-channel multi-branch gated crystal spectrometer according to claim 1, characterized in that: The upper row of slits (3a), the upper incident hole (1a), the upper crystal assembly (5) and the diffraction outlet (1c) constitute a first channel, and the lower row of slits (3b), the lower incident hole (1b), the lower crystal assembly (6) and the diffraction outlet (1c) constitute a second channel. The first channel and the second channel are arranged symmetrically up and down. A shielding assembly (2) is installed inside the box body (1), and the shielding assembly (2) is arranged in the middle position of the box body (1) in the height direction.

3. The dual-channel multi-branch gated crystal spectrometer according to claim 2, characterized in that: The shielding assembly (2) comprises a lead sheet (2b) and an aluminum or plastic shell (2a) sleeved on the outside of the lead sheet (2b); the lead sheet (2b) is arranged inside the box body (1) along the vertical direction.

4. The dual-channel multi-branch gated crystal spectrometer according to claim 1, characterized in that: A supporting base plate (10) is fixedly installed inside the box body (1), a supporting tube (11) extending backwards is installed on one side of the supporting base plate (10), the supporting tube (11) is used to install a collimating laser pen, and adjusting screws (12) are distributed around the supporting tube (11).

5. The dual-channel multi-branch gated crystal spectrometer according to claim 1, characterized in that: The upper crystal assembly (5) comprises a crystal seat (5a) and a crystal plate (5b); the crystal seat (5a) has a locking plate (5a2) and a protrusion (5a1) extending downward from the lower side of the locking plate (5a2); the crystal plate (5b) is fixedly mounted in the protrusion (5a1); a strip hole (1d) is provided at the upper end of the box body (1); the protrusion (5a1) is mounted in the strip hole (1d); both ends of the locking plate (5a2) exceed the ends of the protrusion (5a1), and the exceeding part is fixed to the upper end of the box body (1) by screws.

6. The dual-channel multi-branch gated crystal spectrometer according to claim 5, characterized in that: The protruding portion (5a1) is provided with a rectangular installation channel (a) penetrating along its length direction, the lower end of the rectangular installation channel (a) is open, and the lower end of the rectangular installation channel (a) is provided with a supporting step (b), the crystal piece (5b) is supported on the supporting step (b) through a gasket (c), and a locking screw (5c) is threadedly connected to the locking plate (5a2), and the locking screw (5c) is used to fix the crystal piece (5b) on the supporting step (b).

7. The dual-channel multi-branch gated crystal spectrometer according to claim 1, characterized in that: The beam splitter (3) is a rectangular plate, which is parallel to the front end of the box body (1); The number of the upper row of slits (3a), the upper crystal assembly (5), the lower row of slits (3b) and the lower crystal assembly (6) is three groups.

8. The dual-channel multi-branch gated crystal spectrometer according to claim 1, characterized in that: A two-dimensional rotation adjustment seat (7) and a gated recording system (9) are sequentially mounted on the rear end of the box body (1); the gated recording system (9) has a recording surface (9a); and the two-dimensional rotation adjustment seat (7) can drive the box body (1) to rotate horizontally and translate vertically around the center line of the recording surface (9a) in a manual or automatic control manner.

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