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CN-121721689-B - Light leakage detection method and device for alpha and beta surface pollution detector

CN121721689BCN 121721689 BCN121721689 BCN 121721689BCN-121721689-B

Abstract

The invention discloses a light leakage detection method and a light leakage detection device for an alpha and beta surface pollution detector, which relate to the technical field of radiation monitoring and sensing; calculating the ratio of the blue light intensity component to the sum of the red light intensity component and the green light intensity component, judging light leakage according to the ratio and a preset dynamic threshold parameter, and triggering an alarm and shielding current detection data if the natural light leakage is judged. The invention is characterized in that the light-emitting spectrum of the ZnS (Ag) scintillator is concentrated in a blue light wave band, and natural light is full-wave band continuous spectrum, and the precise and rapid distinction between a light leakage signal and a real nuclear radiation signal is realized by analyzing the proportion relation of RGB color components. The method effectively solves the technical problem that the traditional hardware shielding method cannot identify micropore light leakage, and has the advantages of high detection sensitivity, quick response and strong anti-interference capability.

Inventors

  • ZHANG XIANGLIN
  • WANG HONGTAO
  • JIN LEI
  • YAN YONGJIE
  • Bu Mengni
  • CHEN HAOHAN
  • LUO DANNI

Assignees

  • 陕西卫峰核电子有限公司

Dates

Publication Date
20260508
Application Date
20260227

Claims (8)

  1. 1. The light leakage detection method of the alpha and beta surface pollution detector is characterized by comprising the following steps of: step 1, acquiring optical signals in a detection cavity by using a sensor to obtain intensity components of three color channels comprising red light, green light and blue light; step 2, calculating the ratio of the intensity component of the blue light to the sum of the intensity components of the red light and the green light according to the intensity components of the three color channels; step 3, judging the light leakage of the detector according to the ratio and a preset dynamic threshold parameter; Wherein the dynamic threshold parameter is adaptively adjusted according to the ambient light intensity, and the method comprises the following steps: Obtaining the dynamic threshold parameter by utilizing a pre-stored illumination-threshold mapping table or an illumination-threshold fitting formula according to the acquired ambient light intensity, wherein the illumination-threshold fitting formula is as follows: ; in the formula, As a function of the dynamic threshold value parameter, As a result of the initial threshold value, For the intensity of the ambient light, For the reference light intensity to be a reference light intensity, For adjusting the coefficient; and 4, responding to the natural light leakage as a judging result, triggering an alarm device and shielding the current detection data of the detector.
  2. 2. The method of claim 1, wherein the sensor comprises an RGB sensor, a multichannel spectrum sensor, or a photodiode array with filters.
  3. 3. The method for detecting light leakage of the α, β surface contamination detector according to claim 1, wherein the step 3 comprises: step 3.1, comparing the ratio with the dynamic threshold parameter; and 3.2, combining the intensity components of the three color channels according to the comparison result to obtain the judgment result.
  4. 4. The method for detecting light leakage of the α, β surface contamination detector according to claim 3, wherein the step 3.2 comprises: When B/(r+g) < k, and the intensity component of the red light and the intensity component of the green light are not lower than the preset ratio of the intensity component of the blue light, the determination result is natural light leakage; When B/(R+G) is not less than k, and the intensity component of the red light and the intensity component of the green light are both lower than a preset noise threshold value, the judgment result is that the scintillator emits light; wherein B represents the intensity component of blue light, R represents the intensity component of red light, G represents the intensity component of green light, and k represents the dynamic threshold parameter.
  5. 5. The method for detecting light leakage of an α, β surface contamination detector according to claim 4, wherein the predetermined ratio is 20%.
  6. 6. The method for detecting light leakage of an α, β surface contamination detector according to claim 4, wherein the noise threshold is 3 times the standard deviation of dark noise of the sensor.
  7. 7. An α, β surface contamination detector light leakage detection apparatus, adapted to the α, β surface contamination detector light leakage detection method according to any one of claims 1 to 6, comprising: The sensor is used for collecting the light signals in the detection cavity and obtaining the intensity components of three color channels comprising red light, green light and blue light; The microprocessor is used for calculating the ratio of the intensity component of the blue light to the sum of the intensity components of the red light and the green light according to the intensity components of the three color channels, judging the light leakage of the detector according to the ratio and a preset dynamic threshold parameter, responding to the judging result to be natural light leakage, generating a control signal and shielding the current detection data of the detector; and the alarm device is used for sending out an alarm according to the received control signal when the judging result is that the natural light leaks.
  8. 8. The light leakage detection device for alpha and beta surface contamination detector according to claim 7, The communication interface between the sensor and the microprocessor is an I2C, SPI or UART interface, and the signal output interface between the microprocessor and the alarm device is a GPIO, PWM or wireless transmission interface.

Description

Light leakage detection method and device for alpha and beta surface pollution detector Technical Field The invention belongs to the technical field of radiation monitoring and sensing, and particularly relates to a light leakage detection method and device for an alpha and beta surface pollution detector. Background In the field of nuclear radiation monitoring, alpha and beta surface pollution detectors are core equipment for detecting radioactive substances, and the performance of the alpha and beta surface pollution detectors is directly related to the accuracy of nuclear safety monitoring. Such detectors are typically composed of a plastic scintillator, a photomultiplier tube and a closed detection chamber, wherein the scintillator surface is coated with a ZnS (Ag) (silver activated zinc sulfide) phosphor layer sensitive to alpha and beta particles and covered with an extremely thin (typically 1-2 μm) aluminum film window in front of it. The working principle is that when the radioactive particles pass through an aluminum film window with the thickness of 1-2 mu m, the energy is converted into fluorescent photons by a scintillator, and the fluorescent photons are converted into electric signals by a PMT (photomultiplier tube) and then the alpha and beta particles are distinguished through pulse amplitude analysis. However, the performance of the detector is highly dependent on the light tightness, and the ultra-thin aluminum film with protection and sealing functions is extremely easy to generate micropore breakage due to mechanical stress, chemical corrosion or environmental temperature and humidity change in practical use, once the aluminum film is broken, visible light (such as sunlight or indoor illumination) in the environment directly penetrates through and irradiates the scintillator to be received by the photomultiplier, so that interference pulses similar to real radioactive signals are generated. The background noise and false signal caused by light leakage can seriously interfere with the judgment of real radioactive pollution, so that the monitoring data is distorted, and potential threat is formed to nuclear safety. Currently, the main approach to the problem of light leakage is to use hardware shielding, such as adding a physical light shield to the detector or using a narrow band filter that only allows certain wavelengths (e.g., blue light) to pass through. Although the methods can weaken the influence of the ambient light to a certain extent, the methods have the defects that firstly, the detection sensitivity of the micropore light leakage signal is insufficient, weak ambient light interference is difficult to capture, secondly, the ambient light and the scintillator fluorescent signal are highly overlapped on the frequency domain, the prior separation technology is easy to produce misjudgment, and finally, the PMT is easy to saturate under the strong light environment to cause signal distortion, so that the measurement accuracy is influenced. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a light leakage detection method and device for an alpha and beta surface pollution detector. The technical problems to be solved by the invention are realized by the following technical scheme: the invention provides a light leakage detection method of an alpha and beta surface pollution detector, which comprises the following steps: step 1, acquiring optical signals in a detection cavity by using a sensor to obtain intensity components of three color channels comprising red light, green light and blue light; step 2, calculating the ratio of the intensity component of the blue light to the sum of the intensity components of the red light and the green light according to the intensity components of the three color channels; step 3, judging the light leakage of the detector according to the ratio and a preset dynamic threshold parameter; and 4, responding to the natural light leakage as a judging result, triggering an alarm device and shielding the current detection data of the detector. The invention provides a light leakage detection device of an alpha and beta surface pollution detector, which is suitable for the light leakage detection method of the alpha and beta surface pollution detector, and comprises the following steps: The sensor is used for collecting the light signals in the detection cavity and obtaining the intensity components of three color channels comprising red light, green light and blue light; The microprocessor is used for calculating the ratio of the intensity component of the blue light to the sum of the intensity components of the red light and the green light according to the intensity components of the three color channels, judging the light leakage of the detector according to the ratio and a preset dynamic threshold parameter, responding to the judging result to be natural light leakage, generating a control signal and shie