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CN-121978744-A - Method for compensating angular response of radiation detection chip

CN121978744ACN 121978744 ACN121978744 ACN 121978744ACN-121978744-A

Abstract

The invention relates to a method for compensating angular response of a radiation detection chip, which comprises the following steps of 1, testing counting rate of each channel deposition of an array SiPM (silicon single crystal particulate) when gamma rays are at different incidence angles, 2, constructing a linear equation set according to standard dose rate values and the counting rate of each channel of the array SiPM when the gamma rays are at different incidence angles obtained in the 1, 3, solving the linear equation set in the 2 to obtain an angular response correction matrix, and 4, correcting the angular response of the chip according to the angular response correction matrix in the 3. The invention realizes the angular response compensation of the thin-layer scintillator radiation detection chip to the directional dose rates of different incidence angles, and solves the problem of measurement deviation of the radiation detection chip caused by the change of the incidence angle of the radiation source.

Inventors

  • XIAO SIMIN
  • LUO ZHIPING
  • LI XINGLONG
  • LI SHIYAO
  • WU JIANHUA
  • WANG CHUANGAO
  • LIU YANG
  • QIN QIAN
  • YUAN GUOJUN
  • HUANG XIAOPENG

Assignees

  • 中国原子能科学研究院

Dates

Publication Date
20260505
Application Date
20251212

Claims (10)

  1. 1. A method for compensating for angular response of a radiation detection chip, comprising the steps of: Step 1, testing the counting rate of each channel deposition of the array SiPM when gamma rays are at different incidence angles; Step 2, constructing a linear equation set according to the standard dose rate value and the counting rate of each channel of the array SiPM at different incidence angles obtained in the step 1; step 3, solving the linear equation set in the step2 to obtain an angular response correction matrix; and 4, correcting the angular response of the chip according to the angular response correction matrix in the step 3.
  2. 2. A method for compensating for angular response of a radiation detection chip as defined in claim 1, wherein in step 1, a simulation software is used to simulate the count rate of each channel deposition of an array SiPM for different angles of incidence of gamma rays.
  3. 3. A method for compensating for an angular response of a radiation detection chip as defined in claim 2, wherein said simulation software is GEANT4 software.
  4. 4. A method for compensating for angular response of a radiation detection chip as defined in claim 1, wherein the number of channels of the array SiPM is m.
  5. 5. A method for compensating for an angular response of a radiation detection chip as defined in claim 1, wherein in step 1, said gamma rays are incident at an angle ranging from 0 DEG to 90 deg.
  6. 6. The method for compensating the angular response of a radiation detection chip of claim 4, wherein in step 1, the different incident angles are arranged in a gradient manner according to a set variation interval, and the number of the incident angles is m×m.
  7. 7. A method for compensating for the angular response of a radiation detection chip as defined in claim 1, wherein in step 1, the radiation source sets 662keV unienergy gamma rays of Cs-137 as the incident source.
  8. 8. The method for compensating for the angular response of a radiation detection chip of claim 4, wherein in step 2, the system of linear equations is: Where H is the standard dose rate value, ε ij is the calibration coefficient, and N ij (θ) is the count rate of ij channels of the SiPM array at the incident angle θ.
  9. 9. The method for compensating the angular response of a radiation detection chip of claim 1, wherein in step 3, the matrix elements of the angular response correction matrix are calibration coefficients of corresponding channels of the array type SiPM.
  10. 10. A method for compensating for the angular response of a radiation detection chip as recited in claim 9, wherein in step 3, the angular response correction matrix is as follows: Wherein, the For correction coefficients, i is the X-axis channel number of the matrix SiPM, j is the Y-axis channel number of the SiPM, For the corrected count rate of channels ij, To test the count rate of the resulting channels ij.

Description

Method for compensating angular response of radiation detection chip Technical Field The invention belongs to the technical field of radioactive ray radiation dose measurement, and particularly relates to a method for compensating the angular response of a radiation detection chip. Background The radiation detection chip adopts a thin-layer scintillator as a gamma ray probe, the gamma rays react with the scintillator to generate fluorescent photons, siPM (silicon photomultiplier) collects the fluorescent photons and then generates pulses through a signal amplifying circuit, the number of the generated pulses is in direct proportion to the directional dose rate value, and the directional dose rate of a place can be measured by measuring the number of the pulses generated by the SiPM. However, since the thin-layer scintillator is different from the spherical scintillator, the angular response of the thin-layer scintillator is poor, and the number of pulses generated by gamma rays incident at different angles is inconsistent. Therefore, when the radiation detection chip is used for measuring directional dose rate by equipment such as an accelerator, the dose rate deviation caused by different angles of incidence is larger, and therefore, the array SiPM is adopted, and the angular response compensation of the radiation detection chip is realized by correcting the energy deposited on each channel of the SiPM by gamma rays with different angles of incidence. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide a method for compensating the angular response of a radiation detection chip, which realizes the angular response compensation of a thin-layer scintillator radiation detection chip to different incidence angle directional dose rates and aims to fundamentally solve the problem of measurement deviation of the radiation detection chip caused by the incidence angle change of a radiation source. To achieve the above object, an embodiment of the present invention provides a method for compensating an angular response of a radiation detection chip, including the steps of: Step 1, testing the counting rate of each channel deposition of the array SiPM when gamma rays are at different incidence angles; Step 2, constructing a linear equation set according to the standard dose rate value and the counting rate of each channel of the array SiPM at different incidence angles obtained in the step 1; step 3, solving the linear equation set in the step2 to obtain an angular response correction matrix; and 4, correcting the angular response of the chip according to the angular response correction matrix in the step 3. Further, in the method for compensating the angular response of the radiation detection chip as described above, in step 1, the counting rate of each channel deposition of the array SiPM at different incidence angles of the gamma rays is simulated and tested by using simulation software. As an alternative embodiment, the simulation software is GEANT4 software. Further, in a specific embodiment, the number of channels of the array SiPM is m×m, as described above for the method of compensating the angular response of the radiation detection chip. Further, in a specific embodiment, the method for compensating the angular response of the radiation detection chip as described above, in step 1, the incident angle of the gamma ray ranges from 0 ° to 90 °. As an alternative embodiment, the different incident angles are arranged in a gradient manner according to a set change interval, and the number of the incident angles is m×m. Further, in a specific embodiment, the method for compensating the angular response of a radiation detection chip as described above, in step 1, the radioactive source sets 662keV monoenergetic gamma rays of Cs-137 as the incident source. Further, in a specific embodiment, the method for compensating the angular response of the radiation detection chip as described above, in step 2, the system of linear equations is: Where H is the standard dose rate value, ε ij is the calibration coefficient, and N ij (θ) is the count rate of ij channels of the SiPM array at the incident angle θ. Further, in the method for compensating the angular response of the radiation detection chip as described above, in step 3, the matrix elements of the angular response correction matrix are calibration coefficients of the corresponding channels of the array SiPM. Further, in a specific embodiment, the method for compensating the angular response of the radiation detection chip as described above, in step 3, the angular response correction matrix is as follows: Wherein, the For correction coefficients, i is the X-axis channel number of the matrix SiPM, j is the Y-axis channel number of the SiPM,For the corrected count rate of channels ij,To test the count rate of the resulting channels ij. The invention has the beneficial effects that the invention realizes the method