A vacuum arc-extinguishing chamber radiation field hazard evaluation method based on energy spectrum distortion correction

Abstract

The application discloses a kind of vacuum arc-extinguishing chamber radiation field hazard evaluation methods based on energy spectrum distortion correction, belong to high voltage test and radiation detection protection technical field.It includes the following steps: step S1, obtain the geometric parameters of vacuum arc-extinguishing chamber, and calculate the space reference measured energy spectrum;Step S2, according to the space observation angle, the equivalent penetration thickness factor of X-ray in the main shield of vacuum arc-extinguishing chamber is calculated, and the space direction related shield self-absorption attenuation matrix is constructed based on the equivalent penetration thickness factor of X-ray in the main shield of vacuum arc-extinguishing chamber.The application provides a kind of vacuum arc-extinguishing chamber radiation field hazard evaluation method based on energy spectrum distortion correction, through external energy spectrum measurement and spectral reconstruction, and the direct table calculation of each tissue dose of human body based on international standard conversion coefficient, realizes the three-dimensional, accurate, fast quantitative evaluation to the actual exposure hazard of human body under specific high pressure working condition.

Description

Technical Field

[0001] This invention relates to a method for assessing the radiation field hazards of a vacuum interrupter based on energy spectrum distortion correction, belonging to the field of high voltage testing and radiation detection and protection technology. Background Technology

[0002] Currently, during the aging, type testing, and routine inspection of high-voltage vacuum circuit breakers, field-induced electron emission at the microscopic protrusions between the electrodes generates bremsstrahlung radiation and characteristic X-rays by bombarding the anode with a large number of high-energy electrons. To ensure the safety of testing personnel, conventional X-ray dosimeters are primarily used to monitor radiation levels on-site. Low-energy soft X-rays have weak penetrating power and mainly damage human skin. High-energy hard X-rays, on the other hand, have strong penetrating power and can directly damage deep hematopoietic organs and internal organs.

[0003] However, traditional dosimeters can only measure a total dose rate and cannot distinguish the energy distribution of radiated photons, leading to significant assessment errors. Furthermore, using a single macroscopic radiation dose threshold as the basis for alarms, without considering the absorption characteristics of human tissue for different energy rays, creates blind spots in the protection against highly penetrating hard X-rays. Additionally, existing radiation calculation methods and dose assessment models are generally based on the ideal assumption of "point sources propagating in isotropic media." However, the vacuum interrupter has a complex geometry, and the physical penetration thickness of X-rays varies significantly at different spatial observation angles when penetrating the shield, resulting in strong anisotropy in the spatial radiation field. Not only are the dose rates different in each direction, but the energy distribution of the spectrum also undergoes drastic distortion with spatial angle. Using traditional single response matrices and isotropic inverse square models can lead to over-protection in certain directions, resulting in wasted space, while insufficient protection in other directions can cause safety hazards. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a method for assessing the radiation field hazards of a vacuum interrupter based on energy spectrum distortion correction. By measuring and reconstructing the external energy spectrum and directly calculating the dose of various human tissues based on international standard conversion coefficients, a three-dimensional, accurate, and rapid quantitative assessment of the actual radiation hazards to the human body under specific high-pressure conditions is achieved.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction includes the following steps: Step S1: Obtain the geometric parameters of the vacuum interrupter and calculate the measured energy spectrum of the space reference. Step S2: Calculate the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter based on the spatial observation angle. Construct a spatially related shield self-absorption attenuation matrix based on the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter. Then, based on the shield self-absorption attenuation matrix, reconstruct the three-dimensional spatial dynamic distortion energy spectrum of the entire space surrounding the vacuum interrupter, which varies with the spatial observation angle. Step S3: Calculate the effective dose equivalent rate of the human body at any polar coordinate in space using a three-dimensional spatial integral model of the full-energy spectrum. Step S4: Compare with the set safe dose limit, use a nonlinear numerical optimization algorithm to perform boundary inverse solution of the effective dose equivalent rate of the human body under the spatial observation angle in each direction of space, output a non-centrosymmetric three-dimensional safety envelope surface, and calculate the maximum allowable residence time of the target area under the current working conditions.

[0006] Furthermore, in step S1, obtaining the geometric parameters of the vacuum interrupter and calculating the measured energy spectrum of the space reference specifically includes the following steps: Step S11: Obtain the normal wall thickness d0 of the main shield of the vacuum interrupter and the attenuation coefficient μ of the shield material. s (E); Step S12: Set up an X-ray detector at a reference distance r0 from the vacuum interrupter. At this time, the spatial observation angle θ = θ0 of the X-ray detector relative to the center plane of the contact gap is θ. Combine the response signal measured by the X-ray detector and the background energy spectrum of the environment, perform background subtraction to obtain the net measured energy spectrum M at the spatial observation angle θ. i (θ0), the net measured energy spectrum M i (θ0) is used as the measured energy spectrum of the space reference.

[0007] Furthermore, the net measured energy spectrum M i The expression for (θ0) is as follows:

[0008] Where θ0 is the reference observation angle; N meas_i (θ0) represents the total number of photons measured by the detector in the i-th energy channel, N bg_i (θ0) represents the total count of background photons collected by the detector in the i-th energy channel, t meas t represents the measured energy spectrum acquisition time. bg The time for collecting the background energy spectrum.

[0009] Furthermore, the formula for calculating the equivalent penetration thickness factor of the X-rays within the main shield of the vacuum interrupter is as follows:

[0010] Where, d eff(θ) is the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter, d0 is the normal wall thickness of the main shield of the vacuum interrupter, and θ is the spatial observation angle.

[0011] Furthermore, the shield's self-absorption attenuation matrix A(E) j The expression for ,θ) is as follows:

[0012] Where, μ s (E j ) represents the attenuation coefficient matrix of the shielding material as a function of energy, d0 represents the normal wall thickness of the main shielding of the vacuum interrupter, and θ represents the spatial observation angle.

[0013] Furthermore, in step S2, based on the self-absorption attenuation matrix of the shield, the three-dimensional spatial dynamic distortion energy spectrum of the entire space surrounding the vacuum interrupter, which varies with the spatial observation angle, is reconstructed. This specifically includes the following steps: Net measured energy spectrum M i (θ0) is incorporated into the first kind of Fredholm integral equation to construct an improved joint iterative model, the expression of which is as follows:

[0014] Wherein, Φ (E j ,θ) represents the three-dimensional dynamic distortion energy spectrum; R ij These are elements of the system energy response matrix; A(E j Let θ be the energy of the shield pair under any spatial observation angle θ. j The self-absorption attenuation matrix elements of X-rays; A(E j (θ0) is the reference observation angle θ0, and the energy of the shield is E. j The self-absorption attenuation matrix elements of X-rays.

[0015] Furthermore, in step S3, the effective dose equivalent rate of the human body at any polar coordinate in space is calculated using a three-dimensional spatial integral model of the full-energy spectrum, specifically including the following steps: Step S31: Extract the photon energy distribution of the three-dimensional dynamic distortion energy spectrum Φ (E,θ); Step S32: Call the database in the external radiation protection dose conversion coefficient standard; Step S33: Multiply the photon fluence of each energy segment under different spatial observation angles with the corresponding red bone marrow dose conversion coefficient, integrate and accumulate within the full energy spectrum, and combine with the air attenuation coefficient related to the full energy spectrum energy to calculate the human effective dose equivalent rate H (r,θ) at any spatial coordinate (r,θ).

[0016] Furthermore, the formula for calculating the effective dose equivalent rate H(r,θ) in the human body is as follows:

[0017] Wherein, Φ (E j ,θ) represents the three-dimensional dynamic distortion energy spectrum, h marrow (E j Energy E j The corresponding red bone marrow dose conversion factor, μ air (E j ) is the air attenuation coefficient related to the full-energy spectrum, r is the distance between the X-ray detector and the vacuum interrupter at each spatial observation angle θ, and r0 is the reference distance between the X-ray detector and the vacuum interrupter at the reference observation angle θ0.

[0018] Furthermore, in step S4, by comparing with the set safe dose limit, a nonlinear numerical optimization algorithm is used to perform boundary inverse kinematics on the effective dose equivalent rate of the human body under the spatial observation angle in each direction, outputting a non-centrosymmetric three-dimensional safety envelope surface, and calculating the maximum allowable residence time of the target area under the current working conditions, specifically including the following steps: The effective dose equivalent rate H(r,θ) for humans is compared with the safe dose equivalent rate limit H. safe Comparison, using H(r,θ)- H safe = 0 is used as the objective function to solve the inverse problem and find the root, thus obtaining the minimum safe operating radius r under each spatial observation angle θ. min (θ); The minimum safe operating radius r under each spatial observation angle θ min Connect (θ) to output a non-centrosymmetric three-dimensional safe envelope surface; Let the maximum permissible absorbed dose limit for a single operator be D. limit Calculate the maximum permissible dwell time T of the current operator relative to the actual physical distance L of the vacuum interrupter center.

[0019] Furthermore, the expression for the maximum permissible dwell time T is as follows:

[0020] Among them, D limit The maximum permissible absorbed dose limit for a single operation; L is the actual physical distance of the current operator relative to the center of the vacuum interrupter; θ is the spatial observation angle; h marrow (E j Energy E j The corresponding red bone marrow dose conversion coefficient; r0 is the reference distance between the X-ray detector and the center of the vacuum interrupter at the reference observation angle θ0.

[0021] By adopting the above technical solution, the present invention has the following beneficial effects: 1. This invention introduces the shield self-absorption attenuation matrix as a nonlinear penalty operator and incorporates an iterative spectrum resolution algorithm to accurately correct the energy spectrum distortion caused by the complex geometry of the vacuum interrupter, restore the true X-ray photon fluence and energy distribution in the entire space and at all angles, and solve the measurement distortion problem caused by neglecting angle-related attenuation in traditional methods from the source, making the evaluation benchmark more reliable.

[0022] 2. This invention differs from the traditional ideal model of point source and isotropic propagation. Based on the equivalent penetration thickness factor, this invention constructs a spatially related attenuation model, which fully characterizes the penetration and dose differences of X-rays at different observation angles, generates a three-dimensional dynamic distortion energy spectrum, and truly reflects the non-uniform and asymmetric distribution characteristics of the radiation field of the vacuum interrupter. The accuracy of the radiation field description is improved by an order of magnitude.

[0023] 3. This invention fully utilizes the spatial attenuation effect of the shielding on X-rays at different observation angles, and extracts the distribution of low-energy soft X-rays and high-energy hard X-rays with angle distortion based on measured energy spectra. Combining the absorption characteristics of different human tissues to different energy rays, it directly calculates organ equivalent dose using internationally standardized fluence-dose conversion factors, no longer relying on a single total dose threshold. This accurately identifies the risk of damage to deep hematopoietic organs and internal organs by highly penetrating hard X-rays at specific spatial angles, completely eliminating blind spots in traditional protection.

[0024] 4. This invention uses a nonlinear numerical optimization algorithm to solve for the safe operating radius in each direction and outputs a non-centrosymmetric three-dimensional safety envelope surface that matches the radiation field distribution. This avoids the waste of local space and insufficient local protection caused by traditional uniform protection. Under the premise of ensuring the absolute safety of test personnel, it maximizes the use of test site space and improves the rationality of on-site operation layout.

[0025] 5. This invention combines standard dose limits with precisely calculated spatial dose rates to directly output the maximum permissible dwell time at the target location, upgrading radiation hazard monitoring from single-point qualitative monitoring to full-space quantitative control. This provides a scientific basis for on-site operation duration planning and personnel rotation arrangements, reducing the risk of long-term cumulative radiation exposure. Attached Figure Description

[0026] Figure 1 This is a flowchart of a method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction, according to the present invention. Figure 2 This is a schematic diagram of the installation of the X-ray detector of the present invention. Detailed Implementation

[0027] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0028] like Figure 1 As shown, this embodiment provides a method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction, including the following steps: Step S1: Obtain the geometric parameters of the vacuum interrupter and calculate the measured energy spectrum of the space reference. Specifically: Step S11: Obtain the normal wall thickness d0 of the main shield of the vacuum interrupter and the attenuation coefficient μ of the shield material. s (E).

[0029] Step S12: At the reference distance from the vacuum interrupter, record the spatial observation angle of the X-ray detector relative to the center plane of the contact gap. Combine the response signal measured by the X-ray detector and the background energy spectrum of the environment, perform background subtraction to obtain the net measured energy spectrum under the spatial observation angle, and use the net measured energy spectrum as the spatial reference measured energy spectrum.

[0030] like Figure 2 As shown, in this embodiment, an X-ray detector 2 with a vertical collimator is installed outside the 126 kV vacuum interrupter 1 (with a set reference distance r0 = 1 m). At this time, the spatial observation angle θ = θ0 of the X-ray detector 2 relative to the center plane of the contact gap of the vacuum interrupter 1 is calculated. The normal wall thickness d0 of the main shield of the vacuum interrupter 1 and the attenuation coefficient matrix μ of the shield material as a function of energy are extracted in advance. s (E).

[0031] High pressure is applied to the vacuum interrupter for aging. The response signal measured by the X-ray detector and the environmental background energy spectrum are combined to perform environmental background subtraction, thereby obtaining the net measured energy spectrum M at the spatial observation angle θ0. i (θ0), the net measured energy spectrum M i (θ0) is used as a reference, and the net measured energy spectrum M i The expression for (θ0) is as follows:

[0032] Where, N meas_i (θ0) represents the total number of photons measured by the detector in the i-th energy channel, N bg_i (θ0) represents the total count of background photons collected by the detector in the i-th energy channel, t meas t represents the measured energy spectrum acquisition time. bg The time for collecting the background energy spectrum.

[0033] Step S2: Based on the spatial observation angle, calculate the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter. Based on this equivalent penetration thickness factor, construct a spatially related shield self-absorption attenuation matrix. Then, based on this shield self-absorption attenuation matrix, incorporate it as a nonlinear penalty operator into an iterative spectral resolution algorithm containing the energy response matrix of the X-ray detector system. Solve the first kind of Friedholm integral equation to reconstruct the three-dimensional dynamic distortion energy spectrum of the entire space surrounding the vacuum interrupter, which varies with the spatial observation angle θ. Specifically: Existing analytical methods often neglect the spatial anisotropy caused by the structure of the shield inside the vacuum interrupter. This embodiment introduces a self-absorption attenuation operator based on three-dimensional geometry. Since the shield is cylindrical, the physical equivalent penetration thickness factor d of X-rays emitted at different angles θ within the shield varies. eff (θ) is:

[0034] Where d0 is the normal wall thickness of the main shield of the vacuum interrupter, and θ is the spatial observation angle (i.e., the X-ray emission angle).

[0035] Based on the equivalent penetration thickness factor d within the main shield of the vacuum interrupter eff (θ), construct the spatially related shield self-absorption attenuation matrix A(E) j ,θ), the shield's self-absorption attenuation matrix A(E j The expression for ,θ) is as follows:

[0036] Where, μ s (E j ) is the attenuation coefficient matrix of the shield material as a function of energy, d0 is the normal wall thickness of the main shield of the vacuum interrupter, and θ is the spatial observation angle (i.e., the exit angle of X-rays).

[0037] Since the measured energy spectrum is obtained at a single predetermined angle θ0, in order to deduce the radiation field in the whole space, this embodiment incorporates the above operator into the first kind of Friedholm integral equation to construct an improved joint iterative model. The expression of the joint iterative model is as follows:

[0038] Among them, R ij Let Φ be an element of the system energy response matrix, representing the probability that an incident photon of energy j will generate a count in energy channel i; Φ (E j The three-dimensional spatial dynamic distortion energy spectrum at any angle θ around the vacuum interrupter is obtained as the objective; A(E jLet θ be the energy of the shield pair under any spatial observation angle θ, and let E be the energy of the shield pair. j The self-absorption attenuation matrix elements of X-rays; A(E j (θ0) is the reference observation angle θ0, and the energy of the shield is E. j The self-absorption attenuation matrix elements of X-rays.

[0039] This implementation utilizes an improved Richardson-Lucy (RL) iterative algorithm to obtain the net measured energy spectrum M. i Using (θ0) as a reference, the true incident photon fluence spectrum Φ(E) across the entire space, varying with the spatial observation angle θ, is derived in reverse. j The method (θ) solves the problem that the traditional point source assumption cannot describe the angle distortion of high-energy rays caused by the shield.

[0040] Step S3: This embodiment abandons the traditional empirical formula of inverse square ratio for point sources and uses a three-dimensional spatial integral model of the full-energy spectrum to calculate the effective dose equivalent rate of the human body at any polar coordinate in space. Specifically: Step S31: Extract the photon energy distribution of the three-dimensional spatial dynamic distortion energy spectrum Φ (E,θ); Step S32: Call the database in the external radiation protection dose conversion coefficient standard; Step S33: Multiply the photon fluence of each energy segment under different spatial observation angles with the corresponding red bone marrow dose conversion coefficient, integrate and accumulate over the full energy spectrum, and combine with the air attenuation coefficient related to the full energy spectrum energy to calculate the human effective dose equivalent rate H(r,θ) at any spatial coordinate (r,θ). The formula for calculating the human effective dose equivalent rate H(r,θ) is as follows:

[0041] Wherein, Φ (E j ,θ) represents the three-dimensional dynamic distortion energy spectrum, h marrow (E j Energy E j The corresponding red bone marrow dose conversion factor, in pSv·cm 2 μ air (E j ) is the air attenuation coefficient related to the full-energy spectrum; r is the distance from the X-ray detector to the center of the vacuum interrupter at each spatial observation angle θ; and r0 is the reference distance from the X-ray detector to the center of the vacuum interrupter at the reference observation angle θ0.

[0042] Step S4: Compare with the set safe dose limits, use a nonlinear numerical optimization algorithm to perform boundary inverse kinematics on the effective dose equivalent rate of the human body under spatial observation angles in various directions, output a non-centrosymmetric three-dimensional safety envelope surface, and calculate the maximum allowable residence time of the target area under the current operating conditions. Specifically: The system incorporates the nationally mandated safe dose equivalent rate limit H for specific work areas. safe Since the above transcendental equation contains r 2 The denominator contains an exponentially decaying term with respect to r, making direct algebraic solution impossible. A nonlinear numerical optimization algorithm (such as the Newton-Raphson iteration method) is employed to calculate the value in the one-dimensional direction of each spatial observation angle θ, using H(r, θ) - H... safe = 0 is used as the objective function to solve the inverse problem and find the roots, thus obtaining the precise minimum safe operating radius r under each spatial observation angle θ. min (θ), the specific calculation formula is as follows:

[0043] Among them, H safe The specified safe dose equivalent rate limit; h marrow (E j Energy E j The corresponding red bone marrow dose conversion factor, in pSv·cm 2 μ air (E j ) is the air attenuation coefficient related to the full-energy spectrum; r is the distance from the X-ray detector to the center of the vacuum interrupter at each spatial observation angle θ; and r0 is the reference distance from the X-ray detector to the center of the vacuum interrupter at the reference observation angle θ0.

[0044] Then, the inverse solution is used to find the root: First, we ignore the exponential attenuation effect of air on X-rays (i.e., A direct algebraic analytical solution can be derived, which can be used as the initial approximation r for the iteration. (0) (θ):

[0045] Among them, H safe The specified safe dose equivalent rate limit.

[0046] With the above initial value r (0) Starting from (θ), the solution is obtained by inverse problem-solving according to the following explicit iterative formula:

[0047] Where, f(r) (k) (θ)) is the objective function value at the k-th iteration, expressed as:

[0048] f(r (k) (θ) is the objective function f(r) (k) The first derivative of (θ) with respect to distance is used. The calculation is repeated using the above formula until the convergence condition is met. (ε can be chosen according to actual needs), at this time the output r (k+1) (θ) represents the precise minimum safe operating radius r under the spatial observation angle θ. min (θ).

[0049] Because the shielding thickness is smallest and radiation is strongest on the central plane of the vacuum interrupter contact gap (θ≈0), while the penetration thickness increases in an anticosine series in the polar directions (where θ is larger), radiation is largely absorbed. Therefore, r in each direction... min Connecting (θ) will output a non-centrosymmetric three-dimensional secure envelope surface that extends outward from the center and contracts inward at the poles.

[0050] Let D be the maximum permissible absorbed dose limit for a single operation as specified in the national standard. limit Calculate the maximum permissible dwell time T of the current operator relative to the actual physical distance L of the vacuum interrupter center. The calculation formula is as follows:

[0051] Among them, D limit The maximum permissible absorbed dose limit for a single operation is given in μSv; L is the actual physical distance of the current operator relative to the center of the vacuum interrupter; θ is the spatial observation angle; h marrow (E j Energy E j The corresponding red bone marrow dose conversion factor, in pSv·cm 2 r0 is the reference distance between the X-ray detector and the center of the vacuum interrupter at the reference observation angle θ0.

[0052] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions 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 assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction, characterized in that, Includes the following steps: Step S1: Obtain the geometric parameters of the vacuum interrupter and calculate the measured energy spectrum of the space reference. Step S2: Calculate the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter based on the spatial observation angle. Construct a spatially related shield self-absorption attenuation matrix based on the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter. Then, based on the shield self-absorption attenuation matrix, reconstruct the three-dimensional spatial dynamic distortion energy spectrum of the entire space surrounding the vacuum interrupter, which varies with the spatial observation angle. Step S3: Calculate the effective dose equivalent rate of the human body at any polar coordinate in space using a three-dimensional spatial integral model of the full-energy spectrum. Step S4: Compare with the set safe dose limit, use a nonlinear numerical optimization algorithm to perform boundary inverse solution of the human effective dose equivalent rate under the spatial observation angle in each direction of space, output a non-centrally symmetric three-dimensional safety envelope surface, and calculate the maximum allowable residence time of the target area under the current working conditions. In step S2, based on the self-absorption attenuation matrix of the shield, the three-dimensional spatial dynamic distortion energy spectrum of the entire space surrounding the vacuum interrupter, which varies with the spatial observation angle, is reconstructed. This specifically includes the following steps: The net real measured energy spectrum M i (θ0) into the first kind Fredholm integral equation, and an improved joint iteration model is constructed, and the expression of the improved joint iteration model is as follows: where Φ (E j ,θ) is the three-dimensional dynamic distortion spectrum. R ij are the system energy response matrix elements; A(E j , θ) is a self-absorption attenuation matrix element of the shield for X-rays of energy E j at an arbitrary observation angle θ; and A(E j , θ0) is a self-absorption attenuation matrix element of the shield for X-rays of energy E j at a reference observation angle θ0. In step S4, by comparing the set safe dose limit, a nonlinear numerical optimization algorithm is used to perform boundary inverse kinematics on the effective dose equivalent rate of the human body under the spatial observation angle in each direction, outputting a non-centrosymmetric three-dimensional safety envelope surface, and calculating the maximum allowable residence time of the target area under the current working conditions. Specifically, the steps are as follows: The effective dose equivalent rate H(r,θ) for humans is compared with the safe dose equivalent rate limit H. safe Comparisons are made using H(r, θ)-H safe = 0 is used as the objective function to solve the inverse problem and find the root, thus obtaining the minimum safe operating radius r under each spatial observation angle θ. min (θ); The minimum safe operating radius r under each spatial observation angle θ min Connect (θ) to output a non-centrosymmetric three-dimensional safe envelope surface; Let the maximum permissible absorbed dose limit for a single operator be D. limit Calculate the maximum allowable dwell time T of the current operator relative to the actual physical distance L of the vacuum interrupter center; The expression for the maximum permissible dwell time T is as follows: Among them, D limit The maximum permissible absorbed dose limit for a single operation; L is the actual physical distance of the current operator relative to the center of the vacuum interrupter; θ is the spatial observation angle; h marrow (E j Energy E j The corresponding red bone marrow dose conversion coefficient; r0 is the reference distance between the X-ray detector and the center of the vacuum interrupter at the reference observation angle θ0.

2. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 1, characterized in that, In step S1, the geometric parameters of the vacuum interrupter are obtained, and the measured energy spectrum of the space reference is calculated. This specifically includes the following steps: Step S11: Obtain the normal wall thickness d0 of the main shield of the vacuum interrupter and the attenuation coefficient μ of the shield material. s (E); Step S12: Set up an X-ray detector at a reference distance r0 from the vacuum interrupter. At this time, the spatial observation angle θ = θ0 of the X-ray detector relative to the center plane of the contact gap is θ. Combine the response signal measured by the X-ray detector and the background energy spectrum of the environment, perform background subtraction to obtain the net measured energy spectrum M at the spatial observation angle θ. i (θ0), the net measured energy spectrum M i (θ0) is used as the measured energy spectrum of the space reference.

3. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 2, characterized in that, The net measured energy spectrum M i The expression for (θ0) is as follows: Where θ0 is the reference observation angle; N meas_i (θ0) represents the total number of photons measured by the detector in the i-th energy channel, N bg_i (θ0) represents the total count of background photons collected by the detector in the i-th energy channel, t meas t represents the measured energy spectrum acquisition time. bg The time for collecting the background energy spectrum.

4. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 1, characterized in that, The formula for calculating the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter is as follows: Where, d eff (θ) is the equivalent penetration thickness factor of X-rays within the main shield of the vacuum interrupter, d0 is the normal wall thickness of the main shield of the vacuum interrupter, and θ is the spatial observation angle.

5. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 1, characterized in that, The shielding cover has a self-absorption attenuation matrix A(E) j The expression for ,θ) is as follows: Where, μ s (E j ) represents the attenuation coefficient matrix of the shielding material as a function of energy, d0 represents the normal wall thickness of the main shielding of the vacuum interrupter, and θ represents the spatial observation angle.

6. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 1, characterized in that, In step S3, the effective dose equivalent rate of the human body at any polar coordinate in space is calculated using a full-spectrum three-dimensional spatial integral model, which specifically includes the following steps: Step S31: Extract the photon energy distribution of the three-dimensional dynamic distortion energy spectrum Φ (E,θ); Step S32: Call the database in the external radiation protection dose conversion coefficient standard; Step S33: Multiply the photon fluence of each energy segment under different spatial observation angles with the corresponding red bone marrow dose conversion coefficient, integrate and accumulate within the full energy spectrum, and combine with the air attenuation coefficient related to the full energy spectrum energy to calculate the human effective dose equivalent rate H (r,θ) at any spatial coordinate (r,θ).

7. The method for assessing the radiation field hazard of a vacuum interrupter based on energy spectrum distortion correction according to claim 6, characterized in that, The formula for calculating the effective dose equivalent rate H(r,θ) in the human body is as follows: Wherein, Φ (E j ,θ) represents the three-dimensional dynamic distortion energy spectrum, h marrow (E j Energy E j The corresponding red bone marrow dose conversion factor, μ air (E j ) is the air attenuation coefficient related to the full-energy spectrum, r is the distance between the X-ray detector and the vacuum interrupter at each spatial observation angle θ, and r0 is the reference distance between the X-ray detector and the vacuum interrupter at the reference observation angle θ0.

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