Fluorescence-based detector performance detection method and device

Abstract

The invention relates to the technical field of radiation monitoring, in particular to a detector performance detection method and device based on fluorescence. The method comprises the following steps: arranging a blue light LED detection circuit in the detector; through the arrangement of the blue light LED detection circuit, an optical signal higher than a background environment is input to the detector; the detector receives the optical signal and outputs a measurement electric signal through signal conversion; and processing the electric signal to obtain a measurement signal of the detector, performing ratio calculation on the measurement signal and the optical signal, and determining whether the detection efficiency and the performance of the detector are normal or not. The device comprises a detector, an electric signal processing unit and a radiation monitor, and a blue light LED detection circuit is arranged in the detector. The method can be used for detecting the performance of the detector, ensures that the detector is in a normal working state, and is good in safety.

Description

Technical Field

[0001] The present invention relates to the field of radiation monitoring technology, and in particular to a fluorescence-based detector performance detection method and device. Background Art

[0002] Nuclear power plants are equipped with various radiation monitors for radioactivity monitoring, which involve photoelectric detectors based on the principle of luminescence detection. During the operation of this type of detector, it is impossible to detect the detector performance and verify the detector detection efficiency. Some detectors use built-in sources to check the detector performance.

[0003] The method of using an embedded source to check the performance of the detector is as follows: by embedding a radioactive source in the detector or adding a source detection device, the radioactive source is exposed to the sensitive area of ​​the detector directly or through a specific method. The radioactive source decays and produces gamma rays that act on the detector. The photoelectric detector detects the gamma rays and converts them into actual measurement output through an electronic circuit. By comparing the ratio of the activity of the radioactive source to the measurement output of the detector, it is determined whether the detector performance has declined.

[0004] However, the method of using an embedded source to check the performance of the detector introduces the problem of safety management of the radioactive source. At present, there is no good detector performance detection method that can detect this type of detector. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a fluorescence-based detector performance detection method and device, which can be used to detect the detector performance, ensure that the detector is in a normal working state, and have good safety.

[0006] The present invention provides a fluorescence-based detector performance detection method, comprising the following steps:

[0007] Step 1: Set up a blue light LED detection circuit inside the detector;

[0008] Step 2: Input a light signal higher than the background environment to the detector through the set blue light LED detection circuit;

[0009] Step 3: The detector receives the optical signal and outputs a measurement electrical signal through signal conversion;

[0010] Step 4: Process the electrical signal to obtain the measurement signal of the detector.

[0011] The ratio of the measurement signal to the optical signal is calculated to determine whether the detection efficiency and performance of the detector are normal.

[0012] In a specific embodiment of the present invention, in step 2, the optical signal is 1 to 100 kHz.

[0013] In a specific embodiment of the present invention, the photomultiplier tube inside the detector receives the light signal and outputs a measurement electrical signal through signal conversion.

[0014] In a specific embodiment of the present invention, in step 4, the method for processing the electrical signal is:

[0015] Amplify the received electrical signal;

[0016] The amplified electrical signal is screened and processed to improve the signal-to-noise ratio, filter out noise signals, and retain the real measurement signal;

[0017] The identified signal is subjected to waveform conversion to form a standard waveform signal.

[0018] In a specific embodiment of the present invention, the step 2 further includes:

[0019] When blue light detection is required, the PWM output frequency, duty cycle and detection time set in advance are read, PWM is initialized and output, and detection begins;

[0020] In step 4, after the detection is completed, the blue light output is turned off to put the detector in a normal state.

[0021] In a specific embodiment of the present invention, the detector is a plastic scintillator detector or a sodium iodide detector.

[0022] In a specific embodiment of the present invention, in step 4, if the detector can normally output an electrical signal and after subsequent processing it is determined that the electrical signal is at a normal level, it can be determined that the performance of the detector is normal.

[0023] In a specific embodiment of the present invention, the optical signal is 20-80 kHz.

[0024] The present invention provides a detector performance detection device based on fluorescence, comprising a detector, an electrical signal processing unit and a radiation monitor;

[0025] A blue light LED detection circuit is arranged in the detector.

[0026] In a specific embodiment of the present invention, the light emission frequency of the blue light LED detection circuit is 1 to 100 kHz.

[0027] Compared with the prior art, the fluorescence-based detector performance detection method and device of the present invention have the following beneficial effects:

[0028] (1) The fluorescence-based detector detection method can normally verify the detector performance status and confirm that the detector is in normal working condition.

[0029] (2) The fluorescence-based detector detection method can detect the detection efficiency of the detector, confirm the linear performance of the detector, prepare to judge the fault status of the detector, and issue a warning and replace it in time.

[0030] (3) The fluorescence-based detector detection method can reduce the radiation source safety management risk introduced by the embedded source in the detector setting. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It represents the flow chart of fluorescence detection by the detector;

[0032] Figure 2 Represents the detector blue light LED detection diagram. DETAILED DESCRIPTION

[0033] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0034] Usually, the detector works in a low background environment for a long time, so the electrical signal output by the detector after signal conversion is at a low level, and it is impossible to determine whether there is a problem with the detector's electronic circuit. Therefore, it is necessary to test the performance of the detector.

[0035] The embodiment of the present invention discloses a method for detecting detector performance based on fluorescence, such as Figure 1 As shown, the following steps are included:

[0036] Step 1: Set up a blue light LED detection circuit inside the detector;

[0037] The detector is a plastic scintillator detector or a sodium iodide detector.

[0038] Plastic scintillator detectors are mainly composed of plastic scintillator, photomultiplier tube (PMT) and other components.

[0039] Plastic scintillator is a solid solution of organic scintillating material in plastic. When radioactive rays irradiate the plastic scintillator, the electrons in the scintillator are excited to produce scintillation light, which is then received by the photomultiplier tube and converted into electrical signals, thereby realizing the detection of radiation.

[0040] The working principle of sodium iodide detectors is based on the scintillation principle. When a sodium iodide crystal is irradiated by radiation (such as gamma rays or neutrons), the crystal absorbs the radiation energy and releases photons. After multiple reflections in the crystal, these photons are received by a photomultiplier tube or photodiode and converted into an electrical signal. By measuring the intensity of this electrical signal, the intensity and type of radiation can be determined.

[0041] Step 2: Input a light signal higher than the background environment to the detector through the set blue light LED detection circuit;

[0042] The optical signal is 1 to 100 kHz, preferably 20 to 80 kHz.

[0043] When blue light detection is required, the PWM output frequency, duty cycle and detection time set in advance are read, PWM is initialized and output, and detection begins, that is, blue light output is turned on;

[0044] Step 3: The detector receives the optical signal and outputs a measurement electrical signal through signal conversion;

[0045] When the selected detector is a plastic scintillator detector or a sodium iodide detector, the light signal is received by the photomultiplier tube of the detector and a measurement electrical signal is output through signal conversion.

[0046] Step 4: Process the electrical signal to obtain the measurement signal of the detector.

[0047] The method for processing electrical signals is:

[0048] Amplify the received electrical signal to facilitate subsequent electronic circuit processing;

[0049] The amplified electrical signal is screened and processed to improve the signal-to-noise ratio, filter out noise signals, and retain the real measurement signal;

[0050] The identified signal is converted into a waveform to form a standard waveform signal for easy subsequent processing and identification.

[0051] The ratio of the measurement signal to the optical signal is calculated to determine whether the detection efficiency and performance of the detector are normal.

[0052] The ratio calculation is performed by a radiation monitor, and a program can be set in the radiation monitor. The program contains a specific algorithm, which compares the counting level of the detector with the counting level of light of the frequency set by the program to determine whether the detection efficiency and performance of the detector are normal.

[0053] like Figure 2 As shown in the figure, the front-end processing unit of the radiation monitor processes, calculates and makes logical judgments on the standard electrical signals output by the detector after being amplified, identified and formed. At the same time, it provides the detector with a specific working high voltage to meet the working conditions of the detector.

[0054] The front-end processing unit interacts with the external LRP via RS485.

[0055] RS485: specific communication protocol mechanism;

[0056] External LRP: unit for external signal and logic processing.

[0057] If the detector can output electrical signals normally and after subsequent processing it is determined that the electrical signals are at a normal level, then it can be judged that the performance of the detector is normal.

[0058] After the detection is completed, turn off the blue light output to put the detector in normal state.

[0059] The detection principle of the present invention is:

[0060] 1. The blue LED detection circuit normally generates a specific frequency light signal;

[0061] 2. The light signal acts on the fluorescent component of the photodetector;

[0062] 3. After the fluorescent component receives the light signal, it converts the light signal into an electrical signal through the photoelectric effect;

[0063] 4. The electrical signal is processed by the back-end electronic circuit to obtain the measurement output signal of the detector;

[0064] Check whether the detector measurement output signal is normal, check the ratio of the detector measurement output signal to the light signal of a specific frequency generated by the blue light LED and other information, determine the detector efficiency response, and determine whether the detector performance is normal.

[0065] The embodiment of the present invention also discloses a fluorescence-based detector performance detection device, including a detector, a signal processing unit and a radiation monitor;

[0066] A blue light LED detection circuit is arranged in the detector.

[0067] The light emission frequency of the blue light LED detection circuit is 1-100kHz to ensure that the detection device is stable and reliable.

[0068] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0069] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fluorescence-based detector performance detection method, characterized in that: The following steps are involved: Step 1: Set up a blue light LED detection circuit inside the detector; Step 2: Input a light signal higher than the background environment to the detector through the set blue light LED detection circuit; Step 3: The detector receives the optical signal and outputs a measurement electrical signal through signal conversion; Step 4: Process the electrical signal to obtain the measurement signal of the detector. The ratio of the measurement signal to the optical signal is calculated to determine whether the detection efficiency and performance of the detector are normal.

2. The fluorescence-based detector performance detection method according to claim 1, characterized in that: In the step 2, the optical signal is 1 to 100 kHz.

3. The fluorescence-based detector performance detection method according to claim 1, characterized in that: The photomultiplier tube inside the detector receives the light signal and outputs a measurement electrical signal through signal conversion.

4. The fluorescence-based detector performance detection method according to claim 1, characterized in that: In step 4, the method for processing the electrical signal is: Amplify the received electrical signal; The amplified electrical signal is screened and processed to improve the signal-to-noise ratio, filter out noise signals, and retain the real measurement signal; The identified signal is subjected to waveform conversion to form a standard waveform signal.

5. The fluorescence-based detector performance detection method according to claim 3, characterized in that: The step 2 also includes: When blue light detection is required, the PWM output frequency, duty cycle and detection time set in advance are read, PWM is initialized and output, and detection begins; In step 4, after the detection is completed, the blue light output is turned off to put the detector in a normal state.

6. The fluorescence-based detector performance detection method according to claim 1, characterized in that: The detector is a plastic scintillator detector or a sodium iodide detector.

7. The fluorescence-based detector performance detection method according to claim 1, characterized in that: In step 4, if the detector can output electrical signals normally and the electrical signals are determined to be at a normal level after subsequent processing, it can be determined that the performance of the detector is normal.

8. The fluorescence-based detector performance detection method according to claim 2, characterized in that: The optical signal is 20 to 80 kHz.

9. A fluorescence-based detector performance detection device, characterized in that: It includes a detector, an electrical signal processing unit and a radiation monitor; A blue light LED detection circuit is arranged in the detector.

10. The fluorescence-based detector performance detection method according to claim 1, characterized in that: The light emission frequency of the blue light LED detection circuit is 1 to 100 kHz.

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