Partitioned focal field grating spectrometer and multi-channel parallel energy spectrum acquisition system

Abstract

This invention relates to a partitioned flat-field grating spectrometer and a multi-channel parallel energy spectrum acquisition system, comprising: an entrance collimation and light-limiting module, a partitioned flat-field concave grating module, a vacuum coupling and precision adjustment component, and a pulse-stretching framing camera. This invention uses gratings of different periods to incident signals of different wavelengths onto different microstrip cathodes, and performs high-time-resolution measurements of the spectral signals with a pulse-stretching framing camera having a time resolution better than 10 ps. Through optical path compensation and gated triggering synchronization, multi-channel time reference alignment is achieved, resulting in high spatiotemporal resolution energy spectrum data that can be synchronously compared. This effectively improves the system's time resolution and solves problems in existing technologies such as low experimental efficiency, insufficient channel isolation, difficulties in geometric matching and calibration, and easy spectral overflow and truncation.

Description

Technical Field

[0001] This invention relates to the technical field of radiation diagnostics and spectral measurement, and more specifically, to a partitioned flat focal field grating spectrometer and a multi-channel parallel energy spectrum acquisition system. Background Technology

[0002] X-ray spectral diagnostics often requires the stable and repeatable coupling of spectral images from a flat-field concave grating spectrometer to the detector's photosensitive surface. When experiments demand picosecond-level time resolution, gated detection or framing cameras are typically introduced to achieve "time window" sampling. Detection structures, such as microstrip cathode framing cameras, can provide multiple parallel effective photosensitive areas (microstrip cathodes) on the same device, providing the hardware foundation for "parallel landing of multi-channel spectral images." However, this also imposes clear constraints on the spatial position, width, and channel spacing of spectral bands in the non-dispersive direction. To achieve the goal of "parallel acquisition of multi-energy band spectral images in a single experiment," existing systems typically employ various complementary approaches: on the one hand, changing the grating or system geometry to obtain spectral image coverage of different energy bands; on the other hand, distributing radiation to multiple channels through beam splitting / reflection structures or multiple spectrometers; and also developing methods to set multiple independent scribed regions on the same substrate to form multiple non-overlapping spectral bands on the same image plane, and then performing regional acquisition of different spectral bands on the detector's photosensitive surface in conjunction with framing / gating for recording. These approaches provide a path to achieve multi-segment parallel operation, and also highlight the key issues that need to be addressed in the future: "channel isolation, geometric matching, and time synchronization".

[0003] Existing multi-band acquisition methods, when combined with slatted / gated detection, mainly face the following shortcomings:

[0004] (1) Efficiency and repeatability: Many schemes still rely on multiple experiments to switch gratings or geometries, resulting in low experimental efficiency, and repeated assembly and adjustment lead to systematic errors and reduced repeatability.

[0005] (2) Insufficient channel isolation: Multiple spectral bands are prone to overlap or edge crossing on the image plane. The superposition of stray light and scattering causes crosstalk between channels, affecting the quantitative analysis of spectral lines.

[0006] (3) Difficulty in geometric matching: When the detector is a multi-strip cathode, the center distance and width of the spectral image in the non-dispersion direction are subject to hard constraints such as "cathode center distance / gap / effective width". If there is no clear mathematical matching relationship, it is often necessary to repeatedly try to assemble and adjust, and the adaptability to different camera parameters is poor.

[0007] (4) Spectral width overflow and effective area truncation: In the dispersion direction, the effective width of a single cathode is limited (e.g., 12 mm). If the spectral width constraint is not included in the grating parameter configuration, the spectral image may exceed the effective area and be truncated, resulting in incomplete energy band coverage or resolution degradation.

[0008] (5) Complex assembly and calibration: Multi-channel structures usually increase mechanical freedom and alignment difficulty. Without an assembly / calibration process to match the geometry, the engineering implementation cost is high and the stability is insufficient.

[0009] (6) The traditional scheme uses a two-dimensional spatial resolution detector with a time resolution of only 100ps, which uses a traditional microchannel plate traveling wave gating type frame camera. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a partitioned flat focal field grating spectrometer and a multi-channel parallel energy spectrum acquisition system, which addresses the problems existing in the prior art.

[0011] The technical solution adopted by the present invention to solve its technical problem is: to construct a partitioned flat focal field grating spectrometer, comprising: an entrance collimation and light limiting module, a partitioned flat focal field concave grating module, a vacuum coupling and precision adjustment component, and a pulse stretching type stencil camera connected in sequence;

[0012] The entrance collimation and beam limiting module is located at the entrance end and is used to limit the size of the incident beam in the dispersion direction and suppress divergence in non-target directions;

[0013] The partitioned flat focal field concave grating module is used to simultaneously complete dispersion and focusing of the incident beam under grazing incidence conditions, and to image different wavelengths on the same plane image plane through independent partitioning.

[0014] The vacuum coupling and precision adjustment assembly is used to connect and adapt the partitioned flat field grating spectrometer and the framing camera in vacuum; the framing camera is a pulse-stretching framing camera with a time resolution better than 10 ps.

[0015] In the partitioned flat focal field grating spectrometer of the present invention, the partitioned flat focal field concave grating module includes: a partitioned variable line spacing concave grating;

[0016] The partitioned variable line spacing concave grating includes multiple independent diffraction marking areas and non-marking dead areas set between adjacent diffraction marking areas.

[0017] The multiple independent diffraction-defined regions are distributed sequentially along the non-dispersive direction on the surface of the grating substrate; the non-deformation dead zone is used to physically isolate the diffraction beams of adjacent diffraction-defined regions.

[0018] In the partitioned flat-field grating spectrometer of the present invention, the sum of the width of each diffraction-defined region in the non-dispersion direction and the width of the adjacent non-defined dead region is equal to the center distance between adjacent microstrip cathodes on the detection surface of the framing camera.

[0019] In the partitioned flat-field grating spectrometer of the present invention, each of the diffraction scribed regions is configured with a corresponding centerline density, incident angle and image distance according to the effective width of a single microstrip cathode of the framing camera.

[0020] In the partitioned flat focal field grating spectrometer of the present invention, each of the diffraction marking regions has an independently set variable line spacing coefficient, and each of the diffraction marking regions has an independently set blaze angle or groove depth.

[0021] In the partitioned flat-focus grating spectrometer of the present invention, the partitioned flat-focus concave grating module further includes: a partitioned light-limiting window and a grating base;

[0022] The opening of the partitioned light-limiting window corresponds one-to-one with the multiple independent diffraction-defined regions in the non-dispersion direction, and blocks the position corresponding to the non-defined dead zone.

[0023] The grating holder is used to mount the partitioned variable line spacing concave grating, and the grating holder has at least three types of adjustment degrees of freedom.

[0024] In the partitioned flat focal field grating spectrometer of the present invention, the entrance collimation and light limiting module includes: an entrance slit, a slit seat, an entrance light limiting aperture, and an inner wall extinction structure located on the inner wall of the slit seat;

[0025] The width of the inlet slit is 20 μm, and the effective length of the inlet slit is 60 mm; the inlet slit is installed inside the slit seat;

[0026] The inlet aperture is used to limit incident light divergence and reduce edge scattering;

[0027] The inner wall extinction structure is used to absorb and suppress stray light background formed by multiple scattering within the cavity.

[0028] In the partitioned flat focal field grating spectrometer of the present invention, the vacuum coupling and precision adjustment component includes: a precision adjustment mechanism and a coupling section;

[0029] The coupling section is disposed between the spectrometer outlet flange and the camera inlet flange, and the coupling section is used to vacuum connect the spectrometer outlet flange and the camera inlet flange.

[0030] The precision adjustment mechanism is located on the coupling section and is used to perform lateral micro-movement, angular micro-adjustment, and locking of the spectrometer outlet flange and the camera inlet flange.

[0031] The present invention also provides a multi-channel parallel energy spectrum acquisition system, including: the partitioned flat focal field grating spectrometer and the framing camera described above;

[0032] The framing camera is used to acquire spectral images of each channel under picosecond gating conditions, and achieves multi-channel time reference alignment through gating-triggered delay compensation to obtain high spatiotemporal resolution energy spectrum data that can be synchronously compared; the framing camera is a pulse-stretching framing camera with a time resolution better than 10 ps.

[0033] In the multi-channel parallel energy spectrum acquisition system described in this invention, the framing camera calculates the optical arrival time delay based on the geometric parameters of the partitioned focal field grating spectrometer and the center distance of the diffraction scribed region, and applies reverse electrical delay compensation to the gated trigger / delay link of each microstrip channel of the framing camera based on the optical arrival time delay.

[0034] The partitioned flat-focus grating spectrometer and multi-channel parallel energy spectrum acquisition system of the present invention have the following beneficial effects:

[0035] This invention, through the design of a partitioned flat-focus concave grating structure, enables the diffraction beams corresponding to different energy bands to be naturally separated in space, reducing crosstalk and stray light coupling between channels from the source. Furthermore, it establishes a matching relationship between the grating partition geometry and the microstrip cathode geometry of the framing camera, so that multiple spectral images are arranged in the non-dispersion direction in a manner consistent with the center distance of the microstrip cathode and fall into the corresponding effective photosensitive area.

[0036] The present invention also comprehensively sets the parameters of the partitioned flat focal field concave grating based on the constraint of the effective width of the cathode, so that the physical unfolding length of the target band in the image plane dispersion direction does not exceed the effective width of a single cathode microstrip, thereby avoiding spectral overflow and truncation.

[0037] In addition, this invention calculates or calibrates the geometric optical path difference between the edge channel and the center channel and converts it into an equivalent arrival time delay, thereby applying corresponding reverse electrical delay compensation in the framing camera. This aligns the effective exposure time windows of different energy bands, ultimately achieving wide-spectrum parallel coverage of multiple energy bands under single experimental conditions. Furthermore, it unifies the spatial separation and temporal reference alignment of the three channels under picosecond gating capability, thereby obtaining high spatiotemporal resolution energy spectrum data that can be synchronously compared.

[0038] This invention uses gratings with different periods to incident signals of different wavelengths onto different microstrip cathodes, and performs high time-resolution measurements of the spectral signals with a pulse-stretching framing camera with a time resolution better than 10 ps. Through optical path compensation and gated triggering synchronization, multi-channel time reference alignment is achieved to obtain high spatiotemporal resolution energy spectrum data that can be synchronously compared. This effectively improves the system's time resolution and solves the problems of low experimental efficiency, insufficient channel isolation, difficulty in geometric matching and calibration, and easy overflow and truncation of spectral images in the prior art. Attached Figure Description

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0040] Figure 1 This is a schematic diagram illustrating the working principle of the multi-channel parallel energy spectrum acquisition system provided by the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of the entrance collimation and light limiting module and the partitioned focal field concave grating module provided by the present invention;

[0042] Figure 3 This is a schematic diagram of the partitioned variable line spacing concave grating provided by the present invention;

[0043] Figure 4 This is a schematic diagram of the vacuum coupling and precision adjustment component provided by the present invention;

[0044] Figure 5 This is the energy spectrum obtained by the photocathode provided by the present invention. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] To address the problems existing in the prior art, this invention provides a partitioned flat-field grating spectrometer. This partitioned flat-field grating spectrometer has a partitioned flat-field concave VLS consisting of "diffraction-defined regions (diffraction-defined regions refer to areas on the grating substrate surface that have specific groove shapes and distribution patterns formed through processes such as mechanical scribing, holographic exposure, or ion beam etching) + non-scrubbing dead regions (non-scrubbing dead regions refer to smooth transition regions or interval regions on the grating substrate surface located between two adjacent diffraction-defined regions, where the grating groove structure is not fabricated, and are usually preserved as optically polished planes)". The (variable line spacing coefficient) grating structure naturally separates the diffraction beams corresponding to different energy bands in space, reducing crosstalk and stray light coupling between channels from the source. It further establishes a matching relationship between the grating partition geometry and the geometry of the microstrip cathode 402 of the framing camera 400, ensuring that multiple spectral images are arranged in the non-dispersive direction in a manner consistent with the center distance of the microstrip cathode 402 and fall into their respective effective photosensitive areas. Simultaneously, a "spectral width limited" parameter configuration method is given, with the effective width of the cathode as the boundary. This is achieved by adjusting the center line density of each diffraction scribed region and the VLS... Parameters are comprehensively configured to ensure that the physical spread length of the target band in the image plane dispersion direction does not exceed the effective width of a single cathode microstrip, thereby avoiding spectral overflow and truncation. Under the premise that each zone can be independently optimized, efficiency optimization methods such as blaze angle / groove geometry are introduced to improve the diffraction efficiency of different channels for the target energy band and suppress aberrations. Finally, a multi-channel geometric optical path difference calibration and time synchronization compensation process is proposed. The geometric optical path difference between the edge channels and the center channel is calculated or calibrated and converted into an equivalent arrival time delay. Corresponding reverse electrical delay compensation is applied to the gated trigger circuit of the 400-frame camera to align the effective exposure time windows of different energy bands, enabling comparable recording of multi-energy band spectra at the same time. Ultimately, multi-energy band wide-spectral parallel coverage is achieved under single experimental conditions, and the spatial separation and temporal reference alignment of the three channels are unified under picosecond gating capability, thereby obtaining high spatiotemporal resolution energy spectrum data that can be synchronously compared.

[0047] refer to Figure 1 In a preferred embodiment, the partitioned flat-field grating spectrometer includes: an entrance collimation and light-limiting module 10, a partitioned flat-field concave grating module 20, and a vacuum coupling and precision adjustment component 30, connected in sequence. By designing this partitioned flat-field grating spectrometer, it can be used for geometric matching coupling with a framing camera 400 to achieve parallel acquisition of multi-energy band spectral information at the same emission moment. The framing camera 400 is a pulse-stretching framing camera with a time resolution better than 10 ps.

[0048] Specifically, the entrance collimation and beam limiting module 10 is disposed at the entrance end to limit the size of the incident beam in the dispersion direction and suppress divergence in non-target directions. By utilizing the entrance collimation and beam limiting module 10, the equivalent source size of the incident beam in the dispersion direction can be limited and divergence in non-target directions can be suppressed, thereby providing a calculable lower limit of resolution and reducing stray background.

[0049] In a preferred embodiment, such as Figure 2 As shown, the entrance collimation and light-limiting module 10 includes: an entrance slit 101, a slit seat 102, an entrance light-limiting aperture 103, and an inner wall extinction structure located on the inner wall of the slit seat 102. The width of the entrance slit 101 is 20 μm, and the effective length of the entrance slit 101 is 60 mm; the entrance slit 101 is installed inside the slit seat 102. The effective length refers to the opening length of the slit in the non-dispersion direction (i.e., the light-transmitting length in the slit height direction), and its physical meaning is to limit the effective field of view range that can be received by the grating and form spectral stripes on the image plane; this parameter, together with the effective height of the grating and the length of the image stripe, determines the trade-off between light transmission, stripe uniformity, and edge stray control.

[0050] The inlet slit 101 includes a slit plate, preferably made of tungsten, molybdenum, or other high-Z materials. The slit plate is installed within a slit seat 102, which is a replaceable structure. It is connected to the spectrometer housing 104 using a metal seal or a vacuum O-ring seal. The slit seat 102 is equipped with a reference positioning surface and a limiting structure to ensure that the repeatability error after slit replacement is within the range of micrometers to tens of micrometers, thereby preventing uncontrollable drift of the energy calibration curve. Figure 2 As shown, an entrance light-limiting aperture 103 and an inner wall extinction structure are provided after the entrance slit 101. The entrance light-limiting aperture 103 is used to limit the divergence angle of the incident beam and weaken edge scattering. The aperture shape includes, but is not limited to, a rectangle or a narrow slit, and the size is based on meeting the requirements of target light transmission and stray suppression. The spectrometer housing 104 is preferably subjected to extinction treatment or covered with an inner wall extinction structure. The inner wall extinction structure can be made of a low-reflection material to reduce the background formed by multiple scattering of soft X-rays in the cavity. Among them, vacuum-compatible extinction blackening materials or surface treatments are preferred, such as Acktar series vacuum blackening coatings (VacuumBlack / Metal Velvet, etc.), black nickel / black chromium electroplating layers, anodized blackened aluminum combined with sandblasting roughening treatment, chemical blackening (such as copper oxide / nickel oxide blackening layers), and graphite / carbon-based thin film coatings, etc. The specific selection can be determined according to the vacuum venting requirements, the reflection characteristics of the soft X-ray energy range, and the availability of the process.

[0051] The partitioned focal field concave grating module 20 is used to simultaneously achieve dispersion and focusing of the incident beam under grazing incidence conditions, and to image different wavelengths on the same plane image plane through independent partitioning. By designing this partitioned focal field concave grating module, dispersion and focusing can be achieved simultaneously under grazing incidence conditions (incident angle close to 90°), and the focal field constraint is achieved through partitioned independent linear density parameters, so that different wavelengths can be imaged on the same plane image plane to adapt to planar / strip cathodes (microstrip cathode 402 on the side of the framing camera 400).

[0052] In a preferred embodiment, such as Figure 2 As shown, the partitioned flat focal field concave grating module 20 includes: a partitioned light-limiting window 201, a partitioned variable line spacing concave grating 202, and a grating base 203.

[0053] Specifically, the openings of the partitioned light-limiting window 201 correspond one-to-one with multiple independent diffraction-defined regions in the non-dispersive direction, and are blocked / shielded at positions corresponding to non-defined dead zones to suppress crosstalk caused by cross-zone illumination and dead zone reflection. The grating holder 203 is used to mount the partitioned variable-pitch concave grating 202, and the grating holder 203 has at least three degrees of freedom for adjustment. The partitioned variable-pitch concave grating 202 includes multiple independent diffraction-defined regions and non-defined dead zones disposed between adjacent diffraction-defined regions; the multiple independent diffraction-defined regions are sequentially distributed along the non-dispersive direction on the grating substrate surface; the non-defined dead zones are used to physically isolate the diffracted beams of adjacent diffraction-defined regions. By setting non-defined dead zones between adjacent diffraction-defined regions, the diffracted beams of adjacent diffraction-defined regions (which can also be defined as channels) can be physically isolated, thereby suppressing signal crosstalk and stray light between channels.

[0054] It should be noted that, Figure 1 The diagram shows the working principle of the system. The inlet limiting aperture 103, the inner wall extinction layer, and the partition limiting window 201 in front of the grating are stray suppression structures inside the spectrometer housing 104. To avoid the diagram being too crowded, they are not drawn one by one. Their actual installation positions are located in the collimation / limiting section after the inlet slit 101, on the inner wall surface of the spectrometer cavity, and at a close distance in front of the grating, respectively.

[0055] In this embodiment of the invention, to achieve multi-zone channelized illumination, a zoned light-limiting window 201 is preferably provided in front of the zoned variable-pitch concave grating 202 (or a zoned light-shielding plate can be used instead). The opening of the zoned light-limiting window 201 corresponds one-to-one with multiple independent diffraction-defined areas in the non-dispersion direction, and is blocked / shielded at the position corresponding to the non-defined dead zone to suppress crosstalk caused by cross-zone illumination and dead zone reflection, so that the illumination only acts on the diffraction-defined areas and does not illuminate the non-defined dead zones, thereby reducing inter-channel crosstalk and background rise caused by non-defined dead zone reflection. The distance between the zoned light-limiting window 201 and the zoned variable-pitch concave grating 202 can be set according to the assembly space, generally from a few millimeters to tens of millimeters, requiring that its edge does not enter the effective diffraction beam and cause hard cut-off fringes.

[0056] like Figure 2 As shown, the partitioned variable-pitch concave grating 202 is mounted on the grating holder 203, which provides at least three degrees of freedom for adjustment. These include: minute translation along the optical axis (for fine-tuning the focal plane position and compensating for image distance errors), pitch / yaw fine-tuning around the horizontal and vertical axes (for eliminating image plane tilt and channel landing point offset), and minute rotation adjustment around the optical axis (for ensuring the spectral stripe direction is strictly parallel to the long axis of the cathode microstrip). In this embodiment, the grating holder 203 preferably employs a three-point support or kinematic positioning structure and is equipped with a locking mechanism to solidify the posture after adjustment, preventing posture rebound caused by vacuuming or temperature drift. A thermal expansion difference absorption structure or symmetrical layout should be provided between the grating holder 203 and the spectrometer housing 104 to reduce the impact of temperature changes on the grating posture.

[0057] To achieve geometric separation of multi-channel spectral images in the non-dispersive direction, this invention divides the partitioned variable-spacing concave grating 202 into multiple independent diffraction etched regions along the non-dispersive direction. The sum of the width of each diffraction etched region in the non-dispersive direction and the width of its adjacent non-etched dead region is equal to the center-to-center distance between adjacent microstrip cathodes 402 on the detection surface of the framing camera 400. This dimensional matching ensures that spectral bands of different energy bands are parallel to each other in the non-dispersive direction and accurately fall within the effective photosensitive area of ​​their respective microstrip cathodes 402 in the framing camera 400.

[0058] Furthermore, in this embodiment of the invention, each diffraction pattern region is configured with a corresponding centerline density, incident angle, and image distance based on the effective width of the single microstrip cathode 402 of the framing camera 400. Each diffraction pattern region has an independently set variable line spacing coefficient, and each diffraction pattern region has an independently set blaze angle or trench depth. Similarly, the centerline density of each diffraction pattern region is also independently set.

[0059] The following example illustrates the derivation and explanation of the partitioned variable spacing concave grating 202 structure and geometric matching parameters designed in this invention.

[0060] In this embodiment, the incident angle and diffraction angle in the dispersion plane are first defined as follows: , (Relative to the grating normal), the diffraction order is taken as m=1. The spacing between the scribe lines at the center of the grating is... The corresponding centerline density is ,in, The object distance is Image distance is The coordinates of the spectral lines along the dispersion direction on the image plane are Commonly used approximate relationships when using a flat-focus field spectrometer:

[0061] (1);

[0062] (2);

[0063] In the above formula, λ is the wavelength.

[0064] Equations (1) and (2) provide a first-order mapping of wavelength-diffraction angle-image plane position. Equations (1) and (2) can be used to achieve quantitative design of the relationship between wavelength band and spectral width.

[0065] In this embodiment, the fixed geometric conditions are:

[0066] ;

[0067] The radius of curvature of the grating is:

[0068] .

[0069] The aforementioned geometric quantities can be used as constraints for subsequent spectral width calculation, off-axis optical path difference calculation, and flat focal field aberration correction.

[0070] The side-mounted structure parameters of the 400-inch split-frame camera are as follows: three gold microstrip cathodes of 402, with an effective width of each cathode. Adjacent cathode gap Therefore, the cathode center distance is:

[0071] .

[0072] The electron imaging magnification is approximately 1:1, therefore, the 22mm center-to-center distance between the cathode surfaces corresponds to approximately 22mm on the MCP (microchannel plate) surface, achieving precise geometric matching with the three microstrips (12mm wide, 10mm spacing) of the MCP. Thus, the structural design of the partitioned variable-spacing concave grating 202 in this invention must simultaneously satisfy the following:

[0073] (1) Three parallel spectral orbits with a center distance of 22 mm are formed in the non-dispersive direction;

[0074] (2) The effective spectral width of each image in the dispersion direction should be designed to be about 12 mm to match the width of a single cathode and to leave a margin for the cathode gap;

[0075] (3) The three-track spectrum image is formed into a 1:1 image by a magnetic lens and falls within the 12mm microstrip range on the MCP surface, avoiding crossband interference.

[0076] Through this structural design, the partitioned variable line spacing concave grating 202 can explicitly transform the spatial sampling scale of the 400 microstrip of the split camera into the structural boundary conditions of the grating partition through geometric matching, so that the spectral image is "separable, can be placed, and can be isolated" in space; combined with subsequent channel optical path difference compensation and gated trigger synchronization, the ability to perform high spatiotemporal resolution parallel energy spectrum measurement under single exposure is realized.

[0077] To achieve geometric separation of the three-track spectral images in the non-dispersive direction, this invention divides the partitioned variable-pitch concave grating 202 into three diffraction etched regions along the grating etched direction, namely region A, region B, and region C. Non-etched dead zones are set between adjacent diffraction etched regions to suppress crosstalk and stray light between adjacent channels, specifically as follows: Figure 3 As shown.

[0078] Geometric design of the partitioned variable-pitch concave grating 202:

[0079] Determine the grating substrate dimensions: ;

[0080] The effective width of each diffraction pattern region is taken as The width of the non-criterion dead zone between adjacent diffraction criterion regions is taken as... The total width is:

[0081] ;

[0082] The center distance between adjacent diffraction scribed regions is:

[0083] ;

[0084] Therefore, we can conclude that: This meets the matching requirements for the center distance of the three microstrip cathodes 402. It should be noted that... and The main determinants are the separation of the three spectral lines in the non-dispersive direction and the center distance of their points; while the spectral width of the spectral lines in the dispersive direction is determined by ( The constraint is determined by both the selected band endpoint and the band endpoint; the two are constraints of different dimensions.

[0085] Selection of the center line density of the partitioned variable line spacing concave grating 202:

[0086] The design logic for selecting the centerline density of the partitioned variable-pitch concave grating 202 in this invention is as follows: first, determine the energy (or wavelength) coverage range to be measured; then, under given geometric conditions, calculate the required dispersion and resolution capabilities; and finally, determine the centerline density of each partition. The variable line spacing coefficient was determined, and the image plane spectral width was ultimately checked to ensure that it could be completely covered by the effective width of the 12mm cathode.

[0087] Let the target band of a certain partition be ( ), in fixed , Below, the length occupied by this band in the image plane dispersion direction is:

[0088] (3);

[0089] (3) Where:

[0090] , ;

[0091] When the requirement is that "the spectral image falls completely within a single cathode width of 12mm", the design objective is:

[0092] .

[0093] There are generally two strategies in engineering design:

[0094] Strategy I: Fixed target band ( ), seeking satisfaction in reverse =12 mm .

[0095] Strategy II: Standards for Fixed Processing (For example, 2400 / 1200 / 600 lp / mm), then by =12mm, therefore, under this geometry, the effective target band that can be completely covered by a single exposure is ( ). The remaining bands are used as extended coverage by changing the image plane length, adjusting geometry, or acquiring data in stages. This embodiment adopts Strategy II: the target measurement bands are initially determined according to the commonly used segments of plasma soft X-rays as A: 1–5 nm, B: 5–15 nm, and C: 15–30 nm. Then, a centerline density step that is convenient for processing and efficiency optimization is selected, and the effective coverage range under the condition of a 12 mm cathode width is checked.

[0096] Based on the above principle, the center line densities of the three diffraction marking regions in this invention are as follows:

[0097]

[0098] The corresponding scribe line spacing is:

[0099]

[0100] in, The centerline density of region A, The centerline density of region B, The centerline density of region C; The spacing between the scribe lines in area A. This refers to the spacing between the scribe lines in area B. This refers to the spacing between the scribe lines in area C.

[0101] Substitute the initial target band Calculations were performed at α = 87° and q = 235 mm, yielding the following results:

[0102] Zone A (2400 lp / mm, 1–5 nm): ≈18.35 mm;

[0103] Region B (1200 lp / mm, 5–15 nm): ≈18.25 mm;

[0104] Region C (600 lp / mm, 15–30 nm): ≈12.83 mm.

[0105] Therefore, it can be seen that in fixed geometry and fixed Under these conditions, the complete bands of segments A and B cannot be fully contained in a single 12 mm cathode, while segment C is close to satisfying the requirements.

[0106] Inversely determine the effective wavelength range that satisfies a 12mm cathode width:

[0107] Maintaining three zones Unchanged, Maintain Under the condition that remains unchanged, let: ; Inversely calculate the upper limit wavelength that can be completely covered We can obtain:

[0108] Area A: Fixed λ A1 =1.00 nm, thus λ A2 ≈3.349 nm.

[0109] Area B: Fixed λ B1 =5.00 nm, thus λ B2 ≈11.076 nm.

[0110] Zone C: Fixed λ C1 =15.00 nm, thus λC2 ≈28.901 nm.

[0111] Convert wavelength to energy:

[0112] ;

[0113] The effective energy coverage range obtained for a single exposure with a spectral width not exceeding 12mm is as follows:

[0114] Zone A: 1.00–3.349nm → 1.240–0.370 keV (1240–370 eV);

[0115] Region B: 5.00–11.076nm → 0.248–0.112 keV (248–112 eV);

[0116] Region C: 15.00–28.901nm → 0.0827–0.0429 keV (82.7–42.9 eV).

[0117] The above results provide a feasible set of parameters that maintains the 2400 / 1200 / 600 processing steps while strictly meeting the 12mm spectral width constraint for a single cathode. If complete coverage of the initial target band is required under the same geometry and cathode width, strategy I needs to be used to recalculate the parameters. Or increase the effective length of the image plane.

[0118] Therefore, under the premise of meeting the 12mm spectral width constraint of a single cathode, the three regions can obtain a wide spectral coverage of approximately 42.9–1240 eV in a single exposure, while aligning each channel to the same effective exposure time window through time compensation.

[0119] Furthermore, in this embodiment of the invention, the local line density of each diffraction-defined region is set as a polynomial along the dispersive coordinate s (with the grating center as s=0), as follows:

[0120] ;

[0121] Its physical function is to correct off-axis aberrations, enabling image points of different wavelengths to be focused within the same plane (flat focal field image plane), thus adapting to the planar cathode. The three zones are designed independently. , The center line density of a certain diffraction pattern region. , , The line spacing coefficient is the variable line spacing coefficient for a certain diffraction pattern region, that is, the center line density and the variable line spacing coefficient are designed independently for each diffraction pattern region.

[0122] In this embodiment of the invention, the solution for the variable spacing coefficient is as follows: using the center wavelength of each zone... λ C The main working point is in a fixed position. , , Under α, construct the optical path function and... Expanding the series, let the key terms corresponding to defocus, coma, etc., be in λ. C The value is zero or minimum. During implementation, at least three representative wavelengths are selected within each band. λ k} (including endpoints and midpoints), for each λ k The result is obtained from the grating equation. k Then, set zero or minimum conditions for the key aberration terms to form a condition regarding... The equations are solved numerically or iteratively optimized using ray tracing to obtain the coefficients. This process ensures the focal field constraint for multi-point coplanar imaging within the band and allows consideration of the effects of effective aperture, installation errors, and manufacturing errors on aberrations. The specific values ​​depend on the selection of the optical path function, the effective illumination aperture, and the aberration weights, and usually require joint solution with ray tracing software (such as SHADOW, Zemax / OpticStudio, Code V, etc.). In the prototype stage, calibration can provide a final coefficient table as a preferred implementation method.

[0123] Furthermore, to improve the first-order diffraction efficiency, this invention employs a Littrow blaze design. The grazing incidence angle and grazing diffraction angle are defined as follows:

[0124] , ;

[0125] Grazing incidence angle refers to the acute angle between the incident ray and the tangent plane of the optical surface of the grating at the incident point; grazing diffraction angle refers to the acute angle between the outgoing ray after diffraction by the grating and the tangent plane of the optical surface of the grating at the exit point.

[0126] Define the flash angle Let be the tilt angle of the groove blazed surface relative to the grating surface. Then the near-Littrow condition can be written as:

[0127] ;

[0128] Pick ,but If we take the center wavelength of each region as the center point of the effective band, then we have:

[0129] ;

[0130] ;

[0131] .

[0132] Under the geometry and effective band definition of this embodiment, the blaze angle can be selected as:

[0133] , , .

[0134] In this embodiment of the invention, the groove refers to the groove (sawtooth / blazed groove) on the surface of the partitioned variable line spacing concave grating 202. Its geometric parameters (blazed angle, groove depth, etc.) are used to improve the first-order diffraction efficiency of the target band and suppress non-target order background.

[0135] Trench depth estimation:

[0136] For sawtooth grooves, the groove depth and line spacing With Shining Corner Approximate geometric estimation can be performed:

[0137] ;

[0138] Substituting the parameters for the three zones, the trench depths for each zone are obtained as follows:

[0139] Area A: ;

[0140] Area B: ;

[0141] Area C: .

[0142] The trench duty cycle can be preferably set between 0.45 and 0.55, and the surface coating can preferably be Au or Ni to improve the soft X-ray reflectivity. Surface roughness and slope error should be given as processing acceptance indicators to ensure spectral contrast and resolution.

[0143] In this embodiment of the invention, the parameters and resolution of the entrance slit 101 are designed as follows:

[0144] Take the slit width The geometric magnification of the slit in the image plane is approximated as:

[0145] ;

[0146] From the above relationship, the dispersion rate can be obtained and the wavelength broadening caused by the slit can be estimated:

[0147] ;

[0148] .

[0149] The corresponding resolutions calculated at the center wavelength of the three regions are as follows:

[0150] ; ; .

[0151] Resolution under slit constraints ( Approximately:

[0152] , , .

[0153] It should be noted that in practical applications, the system resolution is also affected by the source size, aberrations, diffusion of the microchannel plate 407 / fluorescent screen, and assembly and adjustment errors. The above is a calculable lower limit estimate given by the slit and first-order dispersion mapping.

[0154] In this embodiment of the invention, the vacuum coupling and precision adjustment component 30 is used to connect and adapt the partitioned flat-field grating spectrometer and the framing camera 400 in a vacuum. Preferably, the vacuum coupling and precision adjustment component 30 includes: a precision adjustment mechanism 301 and a coupling section 302; the spectrometer outlet flange 204, the coupling section 302, and the camera inlet flange 401 are arranged sequentially, the coupling section 302 is used to connect the spectrometer outlet flange 204 and the camera inlet flange 401 in a vacuum; the precision adjustment mechanism 301 is arranged on the coupling section 302, and is used to perform lateral micro-movement, angular micro-adjustment, and locking of the spectrometer outlet flange 204 and the camera inlet flange 401.

[0155] Specifically, such as Figure 4 As shown, the spectrometer outlet (spectrometer outlet flange 204) is connected to the framing camera inlet (camera inlet flange 401) via a coupling section 302 to achieve vacuum communication. The coupling section 302 preferably employs a bellows structure to provide minute pose adjustment capability while maintaining a seal. A precision adjustment mechanism 301 is provided on the outer periphery of the bellows. This precision adjustment mechanism 301 is preferably a three- or four-point symmetrical differential adjustment screw pushing mechanism. Figure 4 (Symmetrical at four points), allowing for lateral micro-movement, angular micro-adjustment, and locking of the spectrometer outlet flange 204 and camera inlet flange 401. For example... Figure 4 As shown, the coupling section 302 can also be provided with mechanical reference alignment holes or positioning pin holes, so that the reference coordinate systems of the spectrometer and the framing camera 400 can be nearly aligned during initial assembly, thereby shortening the assembly and adjustment time.

[0156] like Figure 1As shown, the multi-channel parallel energy spectrum acquisition system provided by this invention includes the aforementioned partitioned flat-field grating spectrometer and a framing camera 400. The framing camera 400 is used to acquire spectral images of each channel under picosecond gating conditions and achieves multi-channel time reference alignment through gating trigger delay compensation, thereby obtaining high spatiotemporal resolution energy spectrum data that can be synchronously compared. Preferably, the framing camera 400 calculates the optical arrival time delay based on the geometric parameters of the partitioned flat-field grating spectrometer and the center distance of the diffraction scribed regions, and applies reverse electrical delay compensation to the gating trigger / delay link of each microstrip channel of the framing camera 400 based on the optical arrival time delay. This invention utilizes the aforementioned partitioned flat-field grating spectrometer to incident signals of different wavelengths onto different microstrip cathodes using gratings of different periods, and employs a pulse-stretching framing camera with a time resolution better than 10 ps to perform high time-resolution measurements of the spectral signals. Multi-channel time reference alignment is achieved through gating trigger delay compensation, thereby obtaining high spatiotemporal resolution energy spectrum data that can be synchronously compared.

[0157] like Figure 1 As shown, the framing camera 400 includes: a microstrip cathode 402 (also known as a horizontal microstrip photocathode), which provides the small degrees of pose freedom required for assembly and adjustment via a bellows, enabling geometric alignment of the three spectral strips formed by the grating on the horizontal microstrip cathode 402. A zero-order light trap 403 is located after the microstrip cathode 402, which absorbs zero-order light that has not undergone first-order diffraction and high-intensity background, thus reducing direct and reflected crosstalk on the image plane at the source. Following the zero-order light trap 403 are sequentially arranged an anode grid 405, a magnetic solenoid / magnetic focusing coil and drift tube forming an electronic imaging and transmission channel 406, a microchannel plate 407 (MCP, responsible for gain amplification), and a CCD camera 408 (for recording the spectral stripes).

[0158] In this embodiment of the invention, the three microstrip cathodes 402 (gold cathodes) in the framing camera 400 achieve equal-size imaging matching with the subsequent microchannel microstrip structure through an approximately 1:1 electronic imaging magnification. After the three-track spectral images of the spectrometer are formed on the cathode surface, they are recorded by the camera's existing electron optics and readout links. This invention only adds the coupling structure between the optical spectrometer and the camera front end, as well as the necessary synchronous calibration steps, without changing the implementation method of the existing gated circuit and microstrip transmission structure inside the camera.

[0159] To achieve high spatiotemporal resolution energy spectrum data that can be synchronously compared under single-exposure conditions, this invention requires compensation based on the optical arrival time difference of the partitioned focal-field grating spectrometer. The calculation of the compensation amount required for the three-track optical arrival time difference and gating synchronization is as follows:

[0160] After adding the partitioned flat-field grating spectrometer, the overall optical path geometric length is approximately:

[0161] ;

[0162] The optical travel time reference is approximately:

[0163] .

[0164] The center-to-center distance of the three rails in the non-dispersive direction is 22 mm, and the off-axis distance of the outer rail relative to the center rail is y = 22 mm. The geometric path difference is estimated as follows:

[0165] ;

[0166] Substitution get:

[0167] ;

[0168] The corresponding time difference is:

[0169] .

[0170] Due to the left-right symmetry of the structure, the time delays of the two outer rails relative to the center rail can be approximately consistent under ideal symmetrical assembly; residual asynchrony caused by assembly and adjustment deviations can be compensated for in the time delay link after calibration. The gating trigger is obtained using the following formula:

[0171] ;

[0172] in, For the first The time difference introduced by the different geometric optical path lengths of each channel relative to the reference channel can be derived from... Obtained through calculation or actual measurement calibration. For fixed delay terms in cables and electronics, To enable the 400-fold frame camera The gating gate of each microstrip channel accurately captures the spectral signal corresponding to that channel, but the actual trigger time value needs to be set in the electronic control system or delay generator; This refers to the unified time zero point or the arrival time of the reference trigger signal for the entire diagnostic system; the final energy spectrum image acquired by the photocathode is as follows: Figure 5 As shown.

[0173] The multi-channel parallel energy spectrum acquisition system provided by this invention, which designs the aforementioned partitioned flat-field grating spectrometer and matches it with a framing camera 400, has the following significant advantages:

[0174] By using a partitioned, flat-field concave, variable-distance grating, three parallel spectral bands are simultaneously formed on the same image plane. These bands are then separated in the non-dispersive direction with a center-to-center distance of 22 mm, ensuring that each of the three spectral bands falls within the effective photosensitive area of ​​a gold cathode microstrip. This allows for the parallel acquisition of multi-energy band spectral information at the same emission moment. Compared to methods that require grating replacement, repeated system geometry adjustments, or multiple experiments covering different energy bands, this invention enables multi-energy band recording in a single experiment, improving measurement efficiency and reducing systematic errors caused by repeated setup and adjustment.

[0175] To ensure a stable and repeatable relationship between the optical image, cathode, and MCP, this invention uses geometric matching as a constraint in the system design: the width of each diffraction pattern and the width of the adjacent dead zone together determine the center distance of the image stripes, making it equivalent to the center distance of the microstrip cathode 402 of the framing camera; at the same time, by utilizing the camera's approximately 1:1 electronic imaging magnification, the 22mm center distance on the cathode surface is naturally mapped to 22mm on the MCP surface, thus matching the center distance of the MCP microstrip and forming a closed size-matched link, reducing the risk of crossband crosstalk and edge truncation.

[0176] In terms of band coverage and spectral width control, this invention uses the effective width of a single cathode microstrip (e.g., 12 mm) as a hard boundary to define the band endpoints and centerline density. Incident angle α and image distance The relationship between the parameters is quantitatively expressed, and under the conditions of fixed geometry and machinable linear density gradient, the upper limit of the effective band that can be completely covered by each partition is calculated inversely, giving a set of parameters for the energy coverage range of the three partitions that can be directly implemented. This configuration method ensures that the physical spread length of the spectral image in the dispersion direction does not exceed the effective area of ​​the cathode, avoiding truncation, incomplete coverage, or resolution degradation caused by spectral image overflow.

[0177] Regarding diffraction efficiency and stray light suppression, since the three diffraction marking regions are independent of each other, the blaze angle and groove geometry parameters can be set separately, so that different energy bands can maintain high efficiency in first-order diffraction. Combined with the constraints on process parameters such as groove depth, duty cycle and coating material, the spectral contrast can be further improved and the stray light background can be reduced, thereby improving the availability of multi-channel spectral data and the reliability of quantitative analysis.

[0178] Regarding time consistency, this invention provides a calculable estimation of the optical path difference in the three off-axis optical paths, yielding an arrival time offset of approximately 6.83 ps between the outer track and the center track. It also proposes a synchronization compensation method based on external delay settings and a calibration closed loop: converting the geometric optical path difference into an equivalent time delay, and applying corresponding reverse electrical delay compensation to the edge channels in the gated trigger / electrical delay link of the framing camera 400. Without altering the internal gate control circuitry of the framing camera 400, this achieves alignment of the three-channel exposure windows, enabling multi-band spectral images to be compared and analyzed under a unified time reference.

[0179] The broad-spectral parallel acquisition capability of this invention enables the acquisition of multiple energy bands of spectral lines in parallel within a single exposure, significantly improving experimental efficiency and reducing systematic errors and time costs associated with repetitive experiments. Simultaneously, the system's high spatiotemporal resolution ensures reliable comparison of spectral lines from different energy bands at the same time reference, providing high-precision transient radiation process analysis capabilities. Compared to existing technologies, this invention not only significantly improves experimental efficiency but also achieves picosecond-level temporal accuracy, meeting the demands for higher-precision diagnostics.

[0180] The following describes the assembly and adjustment method, three-track landing point calibration, and energy calibration of the multi-channel parallel energy spectrum acquisition system of the present invention.

[0181] To ensure that the three spectral images fall within the effective width of the three microstrip cathodes 402, the assembly and adjustment process is preferably carried out in the order of "geometric pre-alignment - three-track landing point calibration - focal plane optimization - strip direction calibration - energy calibration", and the final state is solidified with quantifiable acceptance criteria.

[0182] In the geometric pre-alignment stage, the mechanical center of the spectrometer exit is aligned with the geometric center of the 400mm cathode of the framing camera, and the direction of the center-to-center distance between the partitions is consistent with the direction of the center-to-center distance between the cathode microstrips. After pre-alignment, it should be observed that the three spectral bands are approximately equally spaced in the non-dispersive direction, and there is no significant overall tilt. The focus of this stage is to converge the systematic error from the centimeter level to the millimeter level so that subsequent fine-tuning can be completed within the bellows' fine-tuning range.

[0183] The three-track landing point calibration stage uses the middle channel as the reference channel. Through lateral micro-movement and yaw fine-tuning of coupling section 302, the center of the middle spectral band is aligned with the center of the middle cathode. Subsequently, while maintaining the middle channel without drift, it is verified whether the centers of the left and right spectral bands fall near the centers of the left and right cathodes respectively, and the yaw is adjusted to ensure that the center distance of the three bands matches the cathode center distance. Acceptance criteria can be defined by the minimum safety margin from the spectral boundary to the cathode gap. It is recommended to maintain a margin of not less than 1 mm between the outer boundary and the gap area to resist landing point drift caused by vacuum deformation, thermal drift, and slight vibration.

[0184] The focal plane optimization stage is achieved by slightly shifting the grating mount 203 along the optical axis. The sharpness of representative spectral lines is used as the criterion; the maximum edge sharpness of the spectral line or the minimum full width at half maximum (FWHM) of the spectral line can be used as the focusing standard. In a three-channel system, the goal should be to achieve sharpness in all three channels simultaneously, avoiding sacrificing the focusing quality of other channels for the sharpest one. If image plane tilt occurs, it can be compensated for by pitch adjustment, ensuring that the image plane and the cathode surface maintain approximately coplanar imaging within the effective area.

[0185] Strip orientation calibration is used to eliminate the angle between the spectral stripe and the long axis of the cathode microstrip. If an angle exists, the spectral image will approach the cathode gap obliquely when it expands in the dispersion direction, resulting in a decrease in effective spectral width or the risk of cross-banding. Calibration can be achieved by micro-rotating the grating mount 203 or the coupling section 302 around the optical axis to make the stripe direction parallel to the long axis of the cathode.

[0186] The energy calibration stage establishes a mapping relationship between image plane coordinates and energy. Characteristic spectral lines with known energies are preferably used as calibration benchmarks. Their image plane positions are measured on three separate spectral images, resulting in independent calibration curves for each channel. Calibration can employ physical parameter fitting or polynomial fitting methods, with residuals used to evaluate calibration quality. To ensure the comparability of multi-channel parallel measurements, consistency checks can be performed at potentially overlapping energy bands in the three channels. This ensures that the spectral line positions and intensity trends at the same energy level remain consistent across different channels, or alignment can be achieved through fixed correction terms.

[0187] The implementation and verification of the three-channel optical time synchronization of the multi-channel energy spectrum parallel acquisition system of the present invention are described below:

[0188] In three-channel parallel recording, the three spectral images originate from off-axis optical paths in space, resulting in a picosecond-level optical path difference. This causes a fixed offset in the effective exposure windows corresponding to the three cathodes on the time axis. This offset originates from the optical geometry and is a fixed systematic error. It can be estimated through theoretical calculations and eliminated through experimental calibration. Furthermore, it can be compensated for by external delay settings without changing the internal door control circuitry of the 400-frame camera.

[0189] Synchronous implementation preferably uses the middle channel as the time reference channel. First, based on the spectrometer's geometric parameters and the channel center distance, the optical path difference between the left and right channels relative to the middle channel is calculated and converted into a time difference, serving as the initial value for the delay setting. Then, closed-loop correction is performed through synchronization event calibration: a reference spectral line or signal identifiable in all three channels within the same emission event is selected, and its time position difference in the three channel outputs is compared to obtain the residual time error. This error is then written into the external delay setting for correction. This process iterates until the residual time error compensation is less than a preset threshold.

[0190] Synchronous verification can be performed under different gating amplitudes, different trigger links, and different re-assembly states to confirm the stability of the compensation value. If the compensation value drifts with cable replacement, the fixed delay item and the adjustable delay item should be managed separately: the fixed delay item is fixed through a one-time measurement, and the adjustable delay item is used to compensate for channel differences introduced by the optical path.

[0191] The operation flow and output format of the multi-channel energy spectrum parallel acquisition system of the present invention will be described below.

[0192] During system operation, soft X-rays, confined by a slit, irradiate the partitioned variable-spacing grating, forming three parallel spectral bands on the image plane for each partition (i.e., each diffraction-defined region). These three bands fall within the effective regions of the three microstrip cathodes 402 in the non-dispersive direction and expand according to energy in the dispersive direction, forming an energy spectrum distribution. The framing camera 400 records the spectral image through existing electron optics and readout links, converting the image plane coordinates to energy coordinates using energy calibration curves, and outputting three-channel energy spectrum data. If time-resolved measurements are performed, after three-channel trigger compensation, each channel can be compared for spectral intensity, aligned for spectral shape, and analyzed for evolution under a unified time reference.

[0193] This invention addresses the core objective of "parallel acquisition of multiple energy segments in a single exposure" in soft X-ray energy spectroscopy diagnostics. It provides a partitioned flat-focus grating spectrometer and a multi-channel parallel energy spectral acquisition system. The system precisely couples a partitioned flat-focus grating spectrometer based on a partitioned variable-spacing concave grating with three microstrip cathode 402 framing cameras 400. Different wavelengths of signals are incident onto different microstrip cathodes 402 using gratings with different periods. Simultaneously, the framing cameras 400, with a time resolution better than 10 ps, ​​perform high spatiotemporal resolution measurements of the spectral signals. The core innovation of this system lies in breaking down the traditional barrier of independent spectrometer and detector design. Through a "reverse constraint" systems engineering method, the inherent microstrip geometry of the framing cameras 400 is explicitly transformed into boundary conditions for the grating structure design.

[0194] To address the spatial mismatch challenge of multi-channel parallel processing, this invention constructs a partitioned grating structure with alternating "diffraction-defined regions and non-defined dead zones," and mandates that the strip period of the grating image plane be strictly conjugate to the center distance of the microstrip cathode 402 of the framing camera 400. This successfully establishes a closed geometrically matched link. This design not only achieves automatic spectral image alignment in physical space but also effectively blocks stray light crosstalk between channels using the dead zone structure, ensuring the purity and independence of each energy spectrum data path. Furthermore, to guarantee the integrity of wide spectral coverage, this paper abandons the conventional forward derivation process and establishes a reverse parameter configuration strategy using the detector's effective photosensitive width as a hard threshold. This ensures that, under single-exposure conditions, the spectral image dispersion width of each channel is always controlled within the detector's receiving limit, fundamentally avoiding the risk of spectral image overflow or edge truncation.

[0195] Furthermore, this invention addresses the unavoidable time reference deviation introduced by off-axis optical paths, further advancing synchronization accuracy to the picosecond level. Specifically, by precisely quantifying the geometric optical path difference of multiple channels and compensating for electrical delay closed-loop, systematic timing misalignments are eliminated without altering the detector hardware architecture.

[0196] This invention provides an efficient, accurate, and highly comparable diagnostic tool for laser fusion and high-energy-density physics experiments through the coordinated design of three dimensions: spatial geometry, energy dispersion, and time reference.

[0197] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0198] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0199] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0200] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A partitioned flat focal field grating spectrometer, characterized in that, include: The entrance collimation and light limiting module, the zoned focal field concave grating module, the vacuum coupling and precision adjustment components, and the pulse-stretching type split-frame camera are connected in sequence. The entrance collimation and beam limiting module is located at the entrance end and is used to limit the size of the incident beam in the dispersion direction and suppress divergence in non-target directions; The partitioned flat focal field concave grating module is used to simultaneously complete dispersion and focusing of the incident beam under grazing incidence conditions, and to image different wavelengths on the same image plane through independent partitioning; the partitioned flat focal field concave grating module includes: a partitioned variable line spacing concave grating. The partitioned variable line spacing concave grating includes multiple independent diffraction scribed regions and non-scribed dead zones disposed between adjacent diffraction scribed regions; the multiple independent diffraction scribed regions are sequentially distributed along the non-dispersion direction on the grating substrate surface; the non-scribed dead zones are used to physically isolate the diffraction beams of adjacent diffraction scribed regions; the sum of the width of each diffraction scribed region in the non-dispersion direction and the width of the adjacent non-scribed dead zone is equal to the center distance between adjacent microstrip cathodes on the detection surface of the framing camera; each diffraction scribed region is configured with a corresponding centerline density, incident angle, and image distance according to the effective width of a single microstrip cathode of the framing camera; The vacuum coupling and precision adjustment assembly is used to connect and adapt the partitioned flat-field grating spectrometer and the framing camera in vacuum; the framing camera is a pulse-stretching framing camera with a time resolution better than 10 ps; the framing camera calculates the optical arrival time delay based on the geometric parameters of the partitioned flat-field grating spectrometer and the center distance of the diffraction scribed region, and applies reverse electrical delay compensation to the gated trigger / delay link of each microstrip channel of the framing camera based on the optical arrival time delay.

2. The partitioned flat-focus grating spectrometer according to claim 1, characterized in that, Each of the diffraction marking regions has an independently set variable line spacing coefficient, and each of the diffraction marking regions has an independently set blaze angle or groove depth.

3. The partitioned flat-focus grating spectrometer according to claim 1, characterized in that, The partitioned flat focal field concave grating module also includes: a partitioned light-limiting window and a grating base; The opening of the partitioned light-limiting window corresponds one-to-one with the multiple independent diffraction-defined regions in the non-dispersion direction, and blocks the position corresponding to the non-defined dead zone. The grating holder is used to mount the partitioned variable line spacing concave grating, and the grating holder has at least three types of adjustment degrees of freedom.

4. The partitioned flat-focus grating spectrometer according to claim 3, characterized in that, The inlet collimation and light limiting module includes: an inlet slit, a slit seat, an inlet light limiting aperture, and an inner wall extinction structure located on the inner wall of the slit seat; The width of the inlet slit is 20 μm, and the effective length of the inlet slit is 60 mm; the inlet slit is installed inside the slit seat; The inlet aperture is used to limit incident light divergence and reduce edge scattering; The inner wall extinction structure is used to absorb and suppress stray light background formed by multiple scattering within the cavity.

5. The partitioned flat-focus grating spectrometer according to claim 3, characterized in that, The vacuum coupling and precision adjustment assembly includes: a precision adjustment mechanism and a coupling section; The coupling section is disposed between the spectrometer outlet flange and the camera inlet flange, and the coupling section is used to vacuum connect the spectrometer outlet flange and the camera inlet flange. The precision adjustment mechanism is located on the coupling section and is used to perform lateral micro-movement, angular micro-adjustment, and locking of the spectrometer outlet flange and the camera inlet flange.

6. A multi-channel parallel energy spectrum acquisition system, characterized in that, include: The partitioned flat-field grating spectrometer and framing camera as described in any one of claims 1-5; The framing camera is used to acquire spectral images of each channel under picosecond gating conditions, and to achieve multi-channel time reference alignment through gating-triggered delay compensation, so as to obtain high spatiotemporal resolution energy spectrum data that can be synchronously compared. The framing camera is a pulse-expanding framing camera with a time resolution better than 10 ps.

7. The multi-channel parallel energy spectrum acquisition system according to claim 6, characterized in that, The framing camera calculates the optical arrival time delay based on the geometric parameters of the partitioned focal field grating spectrometer and the center distance of the diffraction scribed area, and applies reverse electrical delay compensation to the gated trigger / delay link of each microstrip channel of the framing camera based on the optical arrival time delay.

Images