Method and apparatus for designing an energy slit for a thermal load leveling type particle accelerator

Abstract

This invention provides a method and apparatus for designing energy slits in a heat-homogenizing particle accelerator. The energy slit design method includes: constructing a three-dimensional coordinate system based on electron beam propagation characteristics; discretizing the front face of the energy slit blocking block in the electron beam propagation direction into a trapezoidal sawtooth array comprising multiple trapezoidal blocking units; obtaining the energy deposition distribution characteristics of the electron beam through a three-dimensional energy deposition field model of the electron beam, thereby determining the initial geometric parameters of the trapezoidal sawtooth array; establishing an inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density; obtaining the energy deposition distribution characteristics while maintaining a constant height of the trapezoidal blocking units in the trapezoidal sawtooth array; and adjusting the initial geometric parameters of the trapezoidal sawtooth array to achieve gradient dilution of the central energy and heat load homogenization within the entire trapezoidal sawtooth array range.

Description

Technical Field

[0001] This invention relates to the fields of particle accelerators and quantum material property measurement technology, and in particular to a method and apparatus for designing energy slits in a heat-load homogenization type particle accelerator. Background Technology

[0002] In the field of quantum material property measurement, particle accelerators are used to provide highly stable and coherent terahertz (THz) light sources to achieve precise characterization of quantum material properties. The energy slit device is a key beam optics component in the dispersive band of a particle accelerator. Its core function is to intercept electrons with large energy dispersion at the tail end through a physical aperture, thereby optimizing beam energy dispersion and protecting downstream equipment. In existing technologies, the blocking components (blocks) of the energy slit device are typically made of highly thermally conductive metal materials (such as oxygen-free copper), and their geometry is mostly a simple cuboid shape. A mechanical device drives the relative movement of the two cuboid blocks on the left and right sides, thereby changing the opening width of the central slit.

[0003] Electron beams exhibit a typical Gaussian distribution in the transverse space, while possessing specific penetration depth and energy deposition characteristics in the longitudinal direction. Existing cuboid baffle designs suffer from a fundamental contradiction between "geometric homogeneity" and "beam non-uniformity": due to the lack of transverse differential matching, the traditional flat endface results in a "double superposition" of transverse Gaussian peaks and longitudinal deposition peaks in the beam center region. This superposition effect causes a dramatic increase in local peak power density within a very small volume of the baffle, leading to a severe imbalance between energy deposition and heat dissipation. The resulting enormous instantaneous thermal stress, under conditions of limited thermal diffusion, can easily trigger metal material erosion, thermal fatigue cracking, and even structural failure, seriously threatening the accelerator's vacuum environment and operational stability.

[0004] It is evident that the single geometric structure in the existing technology can no longer meet the interception requirements of high-power, Gaussian distributed beams. There is an urgent need for an energy slit design method and device that can adjust geometric parameters according to the beam power density distribution, achieve uniform distribution of electron heat deposition, and optimize the electromagnetic tail field to ensure beam stability. Summary of the Invention

[0005] In view of the above, in order to at least partially solve at least one of the aforementioned technical problems, the present invention provides a method and apparatus for designing energy slits in a heat-load homogenization type particle accelerator. The technical solution is as follows:

[0006] According to one aspect of the present invention, a method for designing an energy slit in a heat-load homogenized particle accelerator is provided, comprising: constructing a three-dimensional coordinate system based on electron beam propagation characteristics; discretizing the front face of the energy slit blocking block in the electron beam propagation direction into a trapezoidal sawtooth array comprising multiple trapezoidal blocking units; obtaining the energy deposition distribution characteristics of the electron beam through a three-dimensional energy deposition field model of the electron beam, thereby determining the initial geometric parameters of the trapezoidal sawtooth array; establishing an inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density; obtaining the energy deposition distribution characteristics while keeping the height of the trapezoidal blocking units in the trapezoidal sawtooth array constant; and adjusting the initial geometric parameters of the trapezoidal sawtooth array to achieve gradient dilution of the central energy and heat load homogenization within the entire trapezoidal sawtooth array range.

[0007] According to an embodiment of the present invention, the geometric parameters of the trapezoidal sawtooth array include the base width of the trapezoidal blocking unit, the base angle, and the spacing between the trapezoidal blocking units.

[0008] According to an embodiment of the present invention, the trapezoidal blocking unit is configured to taper along a direction perpendicular to the electron beam, such that the width of the bottom edge of the trapezoidal blocking unit is greater than the width of the top edge, and the thermal shock over a large area is dispersed and homogenized by the spacing between adjacent trapezoidal blocking units.

[0009] According to an embodiment of the present invention, the bottom corner tilt angle With local electron beam power density The inverse covariant relation function can be expressed as:

[0010] ;

[0011] in, Let i be a dimensionless constant that includes total power, material properties, and safety factor, and let i, j, and k represent the mesh element indices of the 3D mesh along the three orthogonal coordinate axes X, Y, and Z, respectively. This represents the position coordinates in a three-dimensional coordinate system.

[0012] According to an embodiment of the present invention, the inverse covariance function of the bottom angle tilt angle and the local electron beam power density is mapped onto a discrete trapezoidal blocking unit, and the ideal tilt angle of the trapezoidal blocking unit is calculated. If the calculated ideal tilt angle is between the minimum process angle and the maximum process angle, the calculated ideal tilt angle is taken as the actual bottom angle tilt angle.

[0013] If the calculated ideal tilt angle is less than the minimum process angle, then the minimum process angle is used as the actual bottom tilt angle; if the calculated ideal tilt angle is greater than the maximum process angle, then the maximum process angle is used as the actual bottom tilt angle.

[0014] According to an embodiment of the present invention, the first The width of the base of each trapezoidal blocking unit Rate of change of local electron beam power density If they are inversely proportional, then:

[0015] ;

[0016] Where K is the proportionality coefficient, P represents the electron beam power density, and Z is the coordinate of the electron beam propagation direction. k Indicates the first The characteristic position of each trapezoidal blocking unit.

[0017] According to an embodiment of the present invention, an inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density is established based on the characteristics of the transverse Gaussian distribution and the longitudinal penetration distribution of the electron beam.

[0018] According to another aspect of the present invention, an energy slit device obtained by the above-described design method is provided, comprising two opposing blocking blocks, each blocking block having a plurality of trapezoidal blocking units arranged continuously on its inner surface along the electron beam direction. The energy slit device is applied to a particle accelerator to improve the thermal safety margin of the particle accelerator. Attached Figure Description

[0019] The objects, features, and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0020] Figure 1 This is a flowchart illustrating the energy slit design method for a heat load homogenization type particle accelerator according to an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the structure of the heat load homogenization type particle accelerator energy slit device according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the inverse covariant mapping matching between the bottom angle of the trapezoidal blocking unit and the longitudinal energy deposition distribution of the electron beam in an embodiment of the present invention.

[0023] Figure 4 Monte Carlo simulation cloud diagram of the longitudinal energy deposition characteristics of the electron beam inside the blocking block material in an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram comparing the internal temperature distribution of the blocking block material under steady-state conditions between the heat load homogenizing type particle accelerator energy slit device and the traditional smooth end face energy slit device according to an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the longitudinal tail field impedance of the energy slit device of the heat load homogenization type particle accelerator according to an embodiment of the present invention. Detailed Implementation

[0026] This invention provides a heat load homogenization type particle accelerator energy slit design method and device. Addressing the technical challenge of energy slit device failure due to heat accumulation under high beam power, it proposes a three-dimensional dissipation homogenization structure design based on a discretized trapezoidal sawtooth array, achieving heat load homogenization through precise matching of geometric topology and energy deposition distribution.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0028] In this embodiment of the invention, a method for designing energy slits in a heat-homogenized particle accelerator is provided, such as... Figure 1 As shown, the particle accelerator energy slit design method includes the following operations or steps:

[0029] S1: Construct a three-dimensional coordinate system based on electron beam propagation characteristics;

[0030] S2: Discretize the front face of the energy slit blocking block in the direction of electron beam propagation into a trapezoidal sawtooth array including multiple trapezoidal blocking units;

[0031] S3: Obtain the energy deposition distribution characteristics of the electron beam through the three-dimensional energy deposition field model of the electron beam, thereby determining the initial geometric parameters of the trapezoidal sawtooth array;

[0032] S4: Establish the inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density;

[0033] S5: Obtain the energy deposition distribution characteristics while keeping the height of the trapezoidal blocking unit in the trapezoidal sawtooth array constant;

[0034] S6: Adjust the initial geometric parameters of the trapezoidal sawtooth array to achieve gradient dilution of the central energy and homogenization of the heat load within the trapezoidal sawtooth array range.

[0035] Specifically, the initial operating parameters of the particle accelerator must first be determined, such as electron beam power, electron beam spot size, and electron beam energy. Modeling of the electron beam energy deposition characteristics is also necessary to obtain information on the three-dimensional heat source distribution.

[0036] Regarding the construction of the system coordinate system and the definition of the geometric parameter space: In step S1, the electron beam propagation characteristics include the electron beam propagation direction, the energy dispersion direction, and the non-dispersion direction, and a three-dimensional coordinate system is constructed accordingly; for example, a three-dimensional Cartesian coordinate system can be constructed, where the Z-axis of the three-dimensional coordinate system is the electron beam propagation direction, the Y-axis is the energy dispersion direction (i.e., the adjustment direction of the slit), and the X-axis is the non-dispersion direction.

[0037] According to an embodiment of the present invention, the geometric parameters of the trapezoidal sawtooth array include the base width, height, base angle, and spacing between the trapezoidal blocking units. The trapezoidal blocking units are configured to taper along a direction perpendicular to the electron beam, such that the base width of each trapezoidal blocking unit is greater than its top width. Combined with the spacing between adjacent trapezoidal blocking units, the thermal shock over a large area is dispersed and homogenized.

[0038] In step S2, the front face of the energy slit blocking block is discretized into N trapezoidal blocking units arranged continuously along the Z-axis, where N is a positive integer. For example, N can be a positive integer greater than 5, or N can be a positive integer greater than 10. The value of N can be adjusted according to the actual application. For any... A trapezoidal blocking element is defined, and the geometric parameter vector set of the trapezoidal blocking element is defined. for:

[0039] =[ , , , (1);

[0040] H represents the height of the trapezoidal blocking unit. For the first The height of each trapezoidal blocking unit, i.e., the projected height of the trapezoidal blocking unit along the Y-axis, is a constant for the entire array; B represents the width of the base of the trapezoidal blocking unit. For the first The width of the bottom edge of each trapezoidal blocking unit, that is, the width of the bottom edge of the trapezoidal blocking unit at... The projected width on the axis. D represents the spacing between the trapezoidal blocking units. For the first The lateral spacing between each trapezoidal blocking unit and its adjacent trapezoidal blocking unit. θ represents the base angle of the trapezoidal blocking unit. For the first The bottom angle of the trapezoidal blocking unit, that is, the angle between the inclined surface of the trapezoidal blocking unit and the Z-axis direction, is the angle of the bottom angle of the trapezoidal blocking unit. The bottom angle of each trapezoidal blocking unit The range of values ​​for θ is: min ≤ ≤θ max θ min and θ max These are the minimum and maximum process angles, respectively.

[0041] According to the three-dimensional energy deposition field model of the electron beam, the thermal load distribution of the electron beam is determined by both the transverse power flux distribution and the longitudinal energy deposition distribution.

[0042] (1) Regarding the transverse power flux function:

[0043] Assuming the incident electron beam follows a Gaussian distribution in the X and Y axes, its power density function is... Represented as:

[0044] (2);

[0045] Among them, P total Let σ be the total power of the electron beam. x With σ y X and Y are the standard deviations of the beam spot along the X and Y axes, respectively. X0 and Y0 are the center coordinates on the transverse plane (i.e., the two-dimensional transverse plane perpendicular to the direction of electron beam propagation) in the three-dimensional coordinate system. i Let Y be the center coordinate of the i-th grid cell in the X-axis direction, and Y be the center coordinate of the i-th grid cell in the X-axis direction. j Let be the center coordinates of the j-th grid cell in the Y-axis direction.

[0046] (2) Regarding the longitudinal energy deposition distribution function:

[0047] The energy loss rate S(Z) of electrons within the energy slit barrier material (e.g., oxygen-free copper, graphite) is not uniform. A normalized depth dose distribution function f(ξ) is introduced, where ξ is the normalized penetration depth of the electron along the incident path, ξ = Z / R. max R max This represents the maximum range of electrons within the energy slit baffle material.

[0048] When an electron beam is incident, according to the principle of geometric projection, the longitudinal power density inside the blocking block material along the Z-axis is... (Z) undergoes the following tensor transformation:

[0049] (3);

[0050] in, The term is the geometric dilution factor. This represents the energy loss rate of electrons along the actual incident path. This represents the normalized depth dose distribution of electrons along the actual incident path, when When the tilt decreases (becomes more severe), Reduced, resulting in lower longitudinal power density (Z) is significantly reduced, and the distribution of energy deposition in the Z-axis direction is stretched.

[0051] According to embodiments of the present invention, an inverse covariant relationship between a trapezoidal sawtooth array and the local electron beam power density is established based on the characteristics of the transverse Gaussian distribution and the longitudinal penetration distribution of the electron beam, involving geometric-physical inverse covariant matching. The core concept lies in using spatially varying geometric parameters. Longitudinal power density to offset spatial variation To achieve equal peak heat flux density control within the entire trapezoidal sawtooth array range.

[0052] To obtain the complete volumetric power density in three-dimensional space, the power density in the transverse plane needs to be multiplied by the power density in the longitudinal plane to obtain the three-dimensional equation for the local electron beam power density:

[0053] The allowable limiting volumetric peak thermal power density of the material is set as P. max To prevent localized thermal failure, the following must be satisfied:

[0054] (4);

[0055] By combining the above equations, an analytical solution for the bottom angle-power density inverse mapping is constructed. This is achieved by neglecting higher-order nonlinear fluctuations in the depth dose distribution function f(ξ) curve and taking its peak characteristic ξ. peak Under approximate conditions, the optimal base angle slope distribution function satisfy:

[0056] (5);

[0057] This leads to the inverse covariant control equation over the continuous domain, and the bottom angle of the trapezoidal blocking element is then determined. With local electron beam power density The inverse covariant relation function can be expressed as:

[0058] (6);

[0059] in, Let i, j, and k be dimensionless constants that include total power, material properties, and safety factor, and let i, j, and k represent the mesh element indices of the 3D mesh along the three orthogonal coordinate axes X, Y, and Z, respectively. This represents the position coordinates in a three-dimensional coordinate system. This demonstrates that the sine of the base angle is inversely proportional to the local power density. Considering the actual manufacturing difficulty, each trapezoidal blocking unit adopts a constant-angle trapezoid.

[0060] like Figure 3As shown, (a) displays the energy deposition distribution curve of the electron beam within the baffle material at longitudinal depth, and (b) displays the matching curves of the bottom angle of the trapezoidal baffle units at each longitudinal depth to achieve homogenization. Depth d refers to the total length of the energy slit along the beam direction. It can be seen that by using a small bottom angle in the peak heat load region and a large bottom angle in the low power region, the volumetric power density within the baffle material is homogenized. For example, in the longitudinal depth range of 0.6 dE / dz to 1 dE / dz relative power deposition, each baffle unit uses a small bottom angle range of 20 to 40 degrees; in the longitudinal depth range of less than 0.6 dE / dz relative power deposition, a bottom angle greater than 40 degrees is used; and in the longitudinal depth range of less than 0.2 dE / dz relative power deposition, a large bottom angle range of 60 to 80 degrees is used. The bottom angle is... With local electron beam power density The inverse covariant relation function is mapped onto discrete trapezoidal blocking elements, and the ideal tilt angle of each trapezoidal blocking element is calculated.

[0061] According to an embodiment of the present invention, the first The width of the base of each trapezoidal blocking unit Rate of change of local electron beam power density If they are inversely proportional, then:

[0062] (7);

[0063] Where K is the proportionality coefficient, P represents the electron beam power density, and Z is the coordinate of the electron beam propagation direction. k For the first The characteristic position of each trapezoidal blocking unit.

[0064] In practical engineering implementation, the above-mentioned optimal base angle and tilt angle distribution function will be applied. Mapped onto discrete trapezoidal blocking units. For the first... The geometric parameters at characteristic locations of a trapezoidal blocking unit are determined according to the following steps:

[0065] First, discretize the tilt angle and calculate the... If the calculated ideal tilt angle at the characteristic position of a trapezoidal blocking unit is between the minimum process angle and the maximum process angle, then the calculated ideal tilt angle is taken as the actual bottom angle tilt angle. If there is no solution for the calculated ideal tilt angle or the calculated ideal tilt angle is extremely small, less than the minimum process angle, then the minimum process angle is taken as the actual bottom angle tilt angle; if the calculated ideal tilt angle is greater than the maximum process angle, then the maximum process angle is taken as the actual bottom angle tilt angle.

[0066] Further verification of the effective interception thickness is required;

[0067] The base width of the trapezoidal blocking unit It needs to be matched with the local beam gradient, and is usually set to... Rate of change of local power density Inversely proportional.

[0068] Through the generated geometric parameter vector set It can transform the originally concentrated extremely high heat load into a uniform heat source with nonlinear stretching along the Z-axis by adaptively adjusting the size and number of trapezoidal barrier units, thereby achieving the design goal of the target heat load.

[0069] Furthermore, a collaborative verification of the electromagnetic tail field impedance envelope is performed;

[0070] To prevent the spacing between discrete trapezoidal blocking units and local bottom angle The combination of these factors introduces a high-frequency tail field, requiring the generation of a set of geometric parameter vectors. Apply electromagnetic boundary envelope smoothness constraints. Define the spatial envelope surface of the vertices of the trapezoidal sawtooth array, and iteratively fine-tune the spacing between adjacent trapezoidal blocking elements. This ensures that the envelope surface satisfies the slowly varying transmission characteristics of high-frequency electromagnetic waves. The longitudinal loss factor and transverse shunt impedance of the array structure are verified to be below the safety thresholds specified by accelerator beam dynamics. If the impedance exceeds the limit, the process returns to the previous steps, and the structure is readjusted by introducing a smoothing penalty function until both the thermodynamic steady-state peak and the electromagnetic wake impedance reach optimal convergence.

[0071] Another embodiment of the present invention also provides a heat-homogenized particle accelerator energy slit device obtained by the above-described design method, such as... Figure 2 As shown, the energy slit device includes two opposing blocking blocks. Each blocking block has multiple trapezoidal blocking units arranged continuously on its inner surface along the electron beam direction, forming a trapezoidal sawtooth array. More specifically, the trapezoidal sawtooth arrays of the two blocking blocks are positioned on opposite sides of the electron beam propagation direction. Under the premise that the height of each trapezoidal blocking unit in the trapezoidal sawtooth array is constant, the electron beam energy deposition distribution characteristics are obtained, and the geometric parameters of the trapezoidal sawtooth array are adjusted. For example, at least one of the three parameters—the base width of each trapezoidal blocking unit, the base angle, and the spacing between adjacent blocking units—is adjusted to achieve gradient dilution of the central energy and homogenization of the heat load within the entire trapezoidal sawtooth array range. Figure 2 As shown, both the left and right blocking blocks have trapezoidal sawtooth arrays. There are several trapezoidal blocking units. The base width of the first trapezoidal blocking unit is B1, the base width of the second trapezoidal blocking unit is B2, the base width of the third trapezoidal blocking unit is B3, and so on, with the base width of the last trapezoidal blocking unit being... The base angle of the first trapezoidal blocking unit is θ1, the base angle of the second trapezoidal blocking unit is θ2, the base angle of the third trapezoidal blocking unit is θ3, and so on, with the base angle of the last trapezoidal blocking unit being... The distance between the first and second trapezoidal blocking units is D1, the distance between the second and third trapezoidal blocking units is D2, the distance between the third and fourth trapezoidal blocking units is D3, and so on, with the distance between the last trapezoidal blocking unit and the previous trapezoidal blocking unit being... Each blocking block is provided with a connecting part for connection and fixation to a drive mechanism, etc., so that the relative distance between the two blocking blocks can be adjusted. The energy slit device of the present invention is used in particle accelerators to improve the thermal safety margin during particle accelerator operation.

[0072] The energy slit device designed using the heat load homogenization type particle accelerator energy slit design method of this invention has undergone performance verification in the quantum material property measurement subsystem of the Hefei National Laboratory's integrated air-ground quantum precision measurement experimental facility. The electron beam parameters are as follows: incident electron beam center energy of 70 MeV, beam power up to 10 kW. The beam current follows a Gaussian distribution in the transverse cross-section with a standard deviation of 0.425 mm. The blocking block material is, for example, high thermal conductivity oxygen-free copper as the main material, with a density of 8.96 g / cm³, a thermal conductivity of approximately 400 W / (m·K), and a melting point of 1084 °C. To effectively cut off electrons in this energy region while considering installation space, the effective blocking length of the blocking block along the electron beam direction (Z-axis direction) is set to 50 mm. The cooling medium is deionized water, with a constant inlet water temperature of 20 °C. The flow velocity in the cooling channel is set to 3 m / s, corresponding to a forced convection heat transfer coefficient of 13679 W / (m²·K). Based on the above operating conditions, the energy slit device of this invention was adopted. A series of discretized trapezoidal blocking units were arranged along the Z-axis on the inner sides of the left and right blocking blocks (the side facing the electron beam). A steady-state thermal field distribution comparison analysis was conducted using multiphysics simulation software under the same 10kW heat source and cooling boundary conditions. The steady-state thermal field distribution of the energy slit device with the conventional structure and the energy slit device proposed in this invention were compared. Figure 5The image shows comparative data on the temperature distribution along the electron beam direction at the front end of the energy slit. As shown by the red solid line, the heat load distribution of a conventional flat-end face energy slit device is extremely uneven, exhibiting a typical needle-like characteristic. The temperature rises sharply after incidence, forming an extremely high sharp peak at a depth of approximately 4.3 mm, with a local thermal peak of approximately 1350 Kelvin (K). Figure 4 The Monte Carlo simulation shows a high degree of agreement with the peak energy deposition location, confirming a dramatic heat accumulation at this point. This localized thermal peak far exceeds the safe range; in actual operation, such an extreme temperature rise would lead to material softening or even localized melting. After the peak, the temperature rapidly decays to a low level, indicating that the material in the latter half is not effectively utilized. However, the temperature distribution curve of the energy slit device of this invention is as follows: Figure 5 As shown by the blue curve, a significant homogenization characteristic is observed. Compared to the red curve, the highest temperature value represented by the blue curve is significantly lower, approximately 650 Kelvin, representing a temperature peak reduction of about 50%, indicating that the heat homogenization effect is satisfactory. This means that under the same cooling conditions, the thermal safety margin is greatly improved. The top of the blue curve is broad and flat, with very gentle slopes for both its ascent and descent. This uniform temperature distribution greatly reduces the thermal stress gradient within the material, effectively preventing the propagation of microcracks caused by uneven thermal expansion and contraction, such as... Figure 6 As shown, the tail field impedance across the entire frequency band is far below the safe impedance threshold (10). 5 The requirement of Ω will not cause beam instability.

[0073] Unlike traditional energy slit block structures with smooth end faces that suffer from beam power density mismatch and surface heat accumulation due to geometric uniformity, the heat load homogenization particle accelerator energy slit design method and device of this invention achieves active heat load homogenization by constructing a trapezoidal sawtooth array with a bottom angle inversely mapped to the local power density. The core of this method lies in configuring a smaller bottom angle in the high-flux region at the center of the electron beam based on an "inverse covariance" mechanism, significantly increasing the effective longitudinal deposition depth of energy within the material through geometric projection effects. While maintaining the axial dimension constraints of the component, the longitudinal volume dissipation capacity of the block is fully utilized, resulting in a more uniform energy deposition density across the entire array, thus eliminating local hot spots that lead to structural failure at their physical source. This effectively overcomes the heat load carrying capacity bottleneck of a single material, transforming the high-gradient concentrated temperature field of traditional structures into a low-gradient uniformly distributed field, significantly reducing the thermal stress concentration factor within the material, effectively suppressing surface erosion and thermal fatigue failure under high-power conditions, and significantly improving the power carrying capacity threshold without altering the material system, thereby significantly extending the service life of the energy slit device. In addition, while maintaining the thermodynamic stability of the material, the tail field impedance is controlled at a safe level, ensuring the stability of the electron beam transmission in the high-power particle accelerator.

[0074] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. It should be noted that implementations not illustrated or described in the drawings or the main text of the specification are forms known to those skilled in the art and have not been described in detail. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing an energy slit in a heat-load homogenizing particle accelerator, characterized in that, include: A three-dimensional coordinate system is constructed based on the characteristics of electron beam propagation. The front face of the energy slit blocking block in the direction of electron beam propagation is discretized into a trapezoidal sawtooth array comprising multiple trapezoidal blocking units. The energy deposition distribution characteristics of the electron beam are obtained by using a three-dimensional energy deposition field model of the electron beam, thereby determining the initial geometric parameters of the trapezoidal sawtooth array; Establish an inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density; While maintaining a constant height of the trapezoidal blocking units in the trapezoidal sawtooth array, the characteristics of energy deposition distribution are obtained; The initial geometric parameters of the trapezoidal sawtooth array are adjusted to achieve gradient dilution of the central energy and homogenization of the heat load within the entire trapezoidal sawtooth array range.

2. The energy slit design method for a heat-equalizing particle accelerator according to claim 1, characterized in that, The geometric parameters of the trapezoidal sawtooth array include the base width of the trapezoidal blocking unit, the base angle, and the spacing between the trapezoidal blocking units.

3. The energy slit design method for a heat-equalizing particle accelerator according to claim 2, characterized in that, The trapezoidal blocking unit is configured to taper along a direction perpendicular to the electron beam, such that the width of the bottom edge of the trapezoidal blocking unit is greater than the width of the top edge. Combined with the setting of the spacing between adjacent trapezoidal blocking units, the thermal shock over a large area is dispersed and homogenized.

4. The energy slit design method for a heat-equalizing particle accelerator according to claim 2, characterized in that, The bottom angle With local electron beam power density The inverse covariant relation function can be expressed as: ； in, Let i be a dimensionless constant that includes total power, material properties, and safety factor, and let i, j, and k represent the mesh element indices of the 3D mesh along the three orthogonal coordinate axes X, Y, and Z, respectively. This represents the position coordinates in a three-dimensional coordinate system.

5. The energy slit design method for a heat-equalizing particle accelerator according to claim 4, characterized in that, The inverse covariant relationship function between the bottom angle tilt angle and the local electron beam power density is mapped onto the discrete trapezoidal blocking unit. The ideal tilt angle of the trapezoidal blocking unit is calculated. If the calculated ideal tilt angle is between the minimum process angle and the maximum process angle, the calculated ideal tilt angle is taken as the actual bottom angle tilt angle.

6. The energy slit design method for a heat-equalizing particle accelerator according to claim 4, characterized in that, If the calculated ideal tilt angle is less than the minimum process angle, then the minimum process angle shall be used as the actual bottom tilt angle. If the calculated ideal tilt angle is greater than the maximum process angle, then the maximum process angle will be used as the actual bottom tilt angle.

7. The energy slit design method for a heat-equalizing particle accelerator according to claim 2, characterized in that, No. The width of the base of each trapezoidal blocking unit Rate of change of local electron beam power density If they are inversely proportional, then: ； Where K is the proportionality coefficient, P represents the electron beam power density, and Z is the coordinate of the electron beam propagation direction. k Indicates the first The characteristic position of each trapezoidal blocking unit.

8. The energy slit design method for a heat-equalizing particle accelerator according to claim 1, characterized in that, Based on the characteristics of the transverse Gaussian distribution and longitudinal penetration distribution of the electron beam, an inverse covariant relationship between the trapezoidal sawtooth array and the local electron beam power density is established.

9. An energy slit device obtained using the design method according to any one of claims 1 to 8, characterized in that, It includes two opposing blocking blocks, and the inner surface of each blocking block has a series of trapezoidal blocking units arranged continuously along the direction of the electron beam.

10. The energy slit device according to claim 9, characterized in that, It is applied to particle accelerators to improve their thermal safety margin.

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