KR102663201B1 - Apparatus for radiation measurement and operation method thereof - Google Patents

Abstract

A detector system for radioactive material according to the present disclosure includes a detector module including a semiconductor detector for measuring the count of radiation and a scintillator detector for acquiring a radiation spectrum, controlling the detector module, collecting data from the detector module, and receiving It includes a main module for transmitting data to a data processing unit, and the data processing unit for processing data collected by the detector module and the main module to obtain a final dose.

Description

Radiation measurement device and method of operation of the device {APPARATUS FOR RADIATION MEASUREMENT AND OPERATION METHOD THEREOF}

The present invention relates to portable radiation monitoring equipment that can be worn by individuals, and to equipment that can analyze the spectrum while measuring low to high doses using two radiation detectors. Radiation monitoring is for low dose and high dose depending on the range of dose rate. In general, low dose refers to a dose range from nSv/h to hundreds of uSv/h, and high dose refers to a dose range from hundreds of uSv/h to Sv/h.

In order to use the spectroscopy function in radiation monitoring equipment, a scintillation detector must be used. When using a scintillation detector, it has a fixed volume, so when the radiation dose increases, an overlap phenomenon occurs and the detector becomes saturated and cannot measure radiation anymore. Therefore, when measuring the dose rate using a scintillation detector, there are limitations in measuring the dose rate. For example, a 5cm (D) x 5cm (H) scintillation detector can measure a radiation dose of about 100uSv/h or less. If the detector volume is small, the amount of incident radiation is small, so the amount of radiation that can be measured increases. Equipment that measures high doses ranging from tens of mSv/h to 1Sv/h or more generally uses gas sensors or semiconductor sensors to measure high doses. However, in the case of equipment that can measure high doses, the radiation spectrum cannot be obtained, making quantitative analysis based on nuclide information or energy difficult. Radiation spectrum refers to a spectrograph according to the energy of radiation incident on the detector. Since each radionuclide has a specific energy, analyzing the energy spectrum allows the measured nuclide to be known, and the nuclide dose can be quantitatively analyzed through spectrum analysis. However, in the case of gas sensors or semiconductor sensors, it is impossible to obtain information related to nuclides because they simply count rather than obtain energy information of radiation.

Scintillation detectors include NaI(Tl), CsI, CeBr3, and LaBr3, and semiconductor detectors include PIN and SiPM, which can be selected and used depending on energy resolution or dose rate to be measured.

As described above, when using a scintillation detector, the energy spectrum of radiation can be obtained, through which nuclides can be analyzed and quantitative analysis can be performed to calculate the radiation dose at a certain level. Using a scintillator detector, radiation doses can be measured from a few nSv/h to hundreds of uSv/h. However, at high doses, if the detector is saturated due to the overlap phenomenon, radiation cannot be measured and dose cannot be measured.

Therefore, a system that measures the dose rate and analyzes nuclides in a low dose environment using a scintillation detector, but cannot analyze nuclides in a high dose environment, is needed to measure the dose rate and alert the user.

If the dose rate exceeds the set range, an alarm must be immediately issued so that users can evacuate from the high dose area. Therefore, when providing dose information using a scintillation detector, information on high doses is also needed.

A detector system according to an embodiment of the present disclosure includes a detector module including a semiconductor detector that measures the count of radiation and a scintillator detector that acquires a radiation spectrum, controls the detector module, collects data from the detector module, and collects the received data. It includes a main module for transmitting to the data processing unit, and a data processing unit for processing data collected from the detector module and the main module to obtain the final dose. The operating method of the detector system includes the data processing unit using a scintillator detector to detect radioactive Obtaining a first output signal measured for, the data processing unit obtaining a second output signal measured for the radioactive material using a semiconductor detector, the data processing unit determining the first dose from the first output signal, , determining a second dose from the second output signal, and obtaining a final dose based on the first dose and the second dose.

In the method of operating a detector system according to an embodiment of the present disclosure, the step of obtaining the final dose includes the data processing unit determining whether the first dose is greater than or equal to a predetermined first threshold dose, and the data processing unit determining whether the first dose is If it is less than the first threshold dose, determining the final dose as the first dose, and if the first dose is greater than or equal to the first threshold dose, the data processing unit determines the final dose as the second dose. .

A method of operating a detector system according to an embodiment of the present disclosure includes determining the final dose as a second dose, determining whether the final dose is greater than or equal to a predetermined second critical dose, and determining whether the final dose is greater than the second critical dose. In the same case, it includes the step of outputting an alarm indicating that the radiation dose is high.

In the step of acquiring the final dose of the method of operating the detector system according to an embodiment of the present disclosure, the data processing unit calculates the first dose, the second dose, the absolute value of the difference between the first dose and the second dose, and a predetermined third dose. It includes selecting one of six final dose determination methods based on the threshold dose and a predetermined fourth threshold dose and obtaining the final dose based on the selected final dose determination method.

Additionally, a program for implementing the method of operating the detector system as described above may be recorded on a computer-readable recording medium.

The detector system of the present disclosure can be used in both low-dose and high-dose environments while acquiring energy spectrum and analyzing nuclides using a scintillator detector. Additionally, since the detector of the present disclosure provides dose rate information regardless of low dose or high dose, there is no need to provide a separate detector depending on the environment.

1 shows a detector module according to one embodiment of the present disclosure.
Figure 2 shows a main module according to an embodiment of the present disclosure.
Figure 3 is a block diagram showing a detector system according to an embodiment of the present disclosure.
Figure 4 is a block diagram showing a data processing unit according to an embodiment of the present disclosure.
Figure 5 is a flowchart illustrating a method of selecting a final dose according to an embodiment of the present disclosure.

This invention is a collaborative research technology development project of Korea Electric Power Corporation (KEPCO), and is a study on the development of radiation exposure scenario evaluation technology for workers to build a realistic platform for response management of serious nuclear accidents.

Hereinafter, a preferred embodiment of the calibration method of the device for measuring the nuclide concentration of radioactive material according to the present disclosure will be described in detail based on the attached drawings. Advantages and features of the disclosed embodiments and methods for achieving them will become clear by referring to the embodiments described below in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the present disclosure is complete and to those skilled in the art to which the present disclosure pertains. It is only provided to fully inform the user of the scope of the invention.

Terms used in this specification will be briefly described, and the disclosed embodiments will be described in detail.

The terms used in this specification are general terms that are currently widely used as much as possible while considering the functions in the present disclosure, but this may vary depending on the intention or precedent of a technician working in the related field, the emergence of new technology, etc. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the relevant invention. Therefore, the terms used in this disclosure should be defined based on the meaning of the term and the overall content of this disclosure, rather than simply the name of the term.

In this specification, singular expressions include plural expressions, unless the context clearly specifies the singular. Additionally, plural expressions include singular expressions, unless the context clearly specifies plural expressions.

When it is said that a part "includes" a certain element throughout the specification, this means that, unless specifically stated to the contrary, it does not exclude other elements but may further include other elements.

Additionally, the term “unit” used in the specification refers to a software or hardware component, and the “unit” performs certain roles. However, “wealth” is not limited to software or hardware. The “copy” may be configured to reside on an addressable storage medium and may be configured to run on one or more processors. Thus, as an example, “part” refers to software components, such as object-oriented software components, class components, and task components, processes, functions, properties, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and “parts” may be combined into smaller numbers of components and “parts” or may be further separated into additional components and “parts”.

According to one embodiment of the present disclosure, “unit” may be implemented with a processor and memory. The term “processor” should be interpreted broadly to include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, etc. In some contexts, “processor” may refer to an application-specific integrated circuit (ASIC), programmable logic device (PLD), field programmable gate array (FPGA), etc. The term “processor” refers to a combination of processing devices, for example, a combination of a DSP and a microprocessor, a combination of a plurality of microprocessors, a combination of one or more microprocessors in combination with a DSP core, or any other such combination of configurations. It may also refer to

The term “memory” should be interpreted broadly to include any electronic component capable of storing electronic information. The terms memory include random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), erasable-programmable read-only memory (EPROM), electrical may refer to various types of processor-readable media, such as erasable PROM (EEPROM), flash memory, magnetic or optical data storage, registers, etc. A memory is said to be in electronic communication with a processor if the processor can read information from and/or write information to the memory. The memory integrated into the processor is in electronic communication with the processor.

Below, with reference to the attached drawings, embodiments will be described in detail so that those skilled in the art can easily implement them. In order to clearly explain the present disclosure in the drawings, parts unrelated to the description are omitted.

Radioactive waste, especially decommissioned waste, is generated in large quantities and is packaged in large containers that extend up to the size of containers or containers of various sizes for other purposes. Therefore, when the decommissioning waste generated during the decommissioning of a nuclear power plant is packaged and disposed of in various sizes, a non-destructive measuring device capable of analyzing nuclides and concentrations is used regardless of the size of the container.

1 shows a detector module according to one embodiment of the present disclosure. Figure 2 also shows a main module according to an embodiment of the present disclosure.

The detector system 1 may include at least one of a detector module 10, a main module 20, and a data processing unit 30. Referring to FIG. 1, the detector module 10 may include a semiconductor detector 11 that measures the count of radiation and a scintillator detector 12 that acquires a radiation spectrum. The semiconductor detector 11 may be located close to the scintillator detector 12. The semiconductor detector 11 may be formed on the same surface 15 as the scintillator detector 12. Accordingly, when the scintillator detector 12 is directed toward the radioactive material, the semiconductor detector 11 may also be directed toward the radioactive material.

The scintillator detector 12 of the detector system may be a detector using an HPGe scintillator with excellent energy resolution. The scintillator detector 12 is equipped with a collimator 13 to limit the basic effective field of view of the scintillator detector 12. The basic effective field of view may be the field of view of the scintillation detector 12 without the collimator 13 installed. The collimator 13 may be mounted on the scintillator detector 12 to shield background radiation. In the present disclosure, the field of view of the scintillation detector 12 limited by the collimator 13 is defined as the effective field of view of the detector. In general, the collimator 13 can be made of tungsten or lead to maximize the effect of radiation shielding.

The detector system according to the present disclosure uses a scintillator detector 12 for nuclide analysis and has a semiconductor detector 11, so it can be used even in a high dose environment. The detector system according to the present disclosure integrates the semiconductor detector 11 and the scintillator detector 12, so that it can be used in both low-dose and high-dose environments, while providing users with various information such as nuclide analysis and quantitative analysis using the energy spectrum. can do.

Referring to FIG. 2 , detector system 1 may include a main module 20 . The main module 20 may control the detector module 10 and collect data from the detector module 10 . Additionally, the main module 20 may transmit the received data to the data processing unit 30.

The main module 20 may include a processor 210 and memory 220. The processor 210 may execute instructions stored in the memory 220. The main module 20 may be implemented in hardware or software. The main module 20 can be implemented with only hardware to perform the corresponding function. However, it is not limited to this, and the main module 20 may be implemented as a general-purpose processor 210, and the general-purpose processor 210 of the main module 20 may be implemented to execute a program stored in the memory 220.

Figure 3 is a block diagram showing a detector system according to an embodiment of the present disclosure.

Detector system 1 may include a data processing unit 30. The data processing unit 30 may include a processor and memory, similar to the main module 20 shown in FIG. 2. The data processing unit 30 may be implemented as an embedded program or an independent program. The data processing unit 30 may be a different device from the main module 20. The data processing unit 30 may be located in a different space from the main module 20. The data processing unit 30 can communicate with the main module 20 wired or wirelessly. Portable radiation monitoring equipment may include a detector module 10 and a main module 20. Vast amounts of data collected from portable radiation monitoring equipment can be processed in the data processing unit 30.

However, it is not limited to this, and the data processing unit 30 may be the same device as the main module 20. That is, the portable radiation monitoring equipment may include a detector module 10, a main module 20, and a data processing unit 30.

The main module 20 may largely include an electronic circuit for the semiconductor detector 11, an electronic circuit for the scintillator detector 12, and a data collection module 26.

The main module 20 may include a signal processing circuit 21. The signal processing circuit 21 may include a filter to remove noise from the signal of the semiconductor detector 11. Additionally, the signal processing circuit 21 can set the zero point of the signal of the semiconductor detector 11. Additionally, the signal processing circuit 21 can adjust the reference voltage of the signal of the semiconductor detector 11 to a value desired by the designer. Accordingly, the signal obtained from the semiconductor detector 11 and the signal obtained from the scintillator detector 12 may have the same reference voltage.

The output signal of the signal processing circuit 21 may be input to the digital signal converter 22. The digital signal converter 22 can convert the output signal of the signal processing circuit 21 from an analog signal to a digital value.

The digital value output from the digital signal converter 22 may be transmitted to the data collection module 26. The data collection module 26 may accumulate and store the counts of the semiconductor detector 11.

The circuitry for the scintillator detector 12 may include a high voltage circuit 27. The high voltage circuit 27 can generate high voltage electrical energy from the electrical energy of the power circuit 28. The high voltage circuit 27 can transmit high voltage electrical energy to the scintillator detector 12.

The output signal of the scintillator detector 12 may be transmitted to the amplifier circuit 23. The amplification circuit 23 can amplify the output signal of the scintillator detector 12. The amplified signal can be transmitted to the signal processing circuit 24. The signal processing circuit 24 can remove noise from the amplified signal and adjust the reference voltage. Accordingly, the signal obtained from the semiconductor detector 11 and the signal obtained from the scintillator detector 12 may have the same reference voltage.

The output signal of the signal processing circuit 24 may be input to the digital signal converter 25. The digital signal converter 25 can convert the output signal of the signal processing circuit 24 from an analog signal to a digital value.

The digital value output from the digital signal converter 25 may be transmitted to the data collection module 26. Data collection module 26 may ultimately collect data and generate a spectrum. Spectra can be displayed graphically. The horizontal axis of the graph may be a unit of energy (keV), and the vertical axis may be a count. The count may be the number of times radiation is incident on the detector. Radioactive materials can emit radiation of a specific energy, and the detector system 1 can generate a spectrum of the number of times radiation is detected for each energy. Additionally, the data collection module 26 may include data that may generate a spectrum without generating a spectrum. Data from which a spectrum can be generated may be counts by energy.

The data collection module 26 may transmit the accumulated and stored counts of the semiconductor detector 11 and the spectrum of the scintillator detector 12 to the data processing unit 30.

The signal processing circuits 21 and 24 may include a filter circuit for noise removal and a circuit for adjusting the reference voltage. The digital signal converter 25 is a circuit that converts analog signals into digital signals and may have a resolution of ADC 10 bits or more.

Figure 4 is a block diagram showing a data processing unit according to an embodiment of the present disclosure.

Detector system 1 may include a data processing unit 30. The data processing unit 30 may obtain the final dose by processing data collected from the detector module and the main module.

The data processing unit 30 may include a communication module 31 and a data processing module 300. The communication module 31 may be configured to perform wired or wireless communication with the main module 20. The communication module 31 may be of optional configuration. For example, if the main module 20 and the data processing unit 30 are provided in the same device, the communication module 31 may not be used.

The data processing unit 30 may perform a step of acquiring a first output signal measured for radioactive material using the scintillator detector 12. The first output signal may be data related to counts or spectra obtained from the scintillator detector 12. Additionally, the data processing unit 30 may perform a step of obtaining a second output signal measured for radioactive material using the semiconductor detector 11. The second output may be data related to counts obtained from the semiconductor detector 11.

More specifically, the data collection unit 32 may analyze packets of data received from the communication module 31. The data collection unit 32 can separate data from the scintillator detector 12 and the semiconductor detector 11. That is, the data collection unit 32 can separate the first output signal and the second output signal. For example, when the data collection module 26 transmits the first output signal and the second output signal to the data processing unit 30, it may also transmit a detector flag. The detector flag may indicate whether the data was generated based on the scintillator detector 12 or the semiconductor detector 11. For example, if the detector flag is '0', it may indicate that data was generated based on the semiconductor detector 11. That is, when the detector flag is '0', the data processing unit 30 may determine that the data is the second output signal. Additionally, when the detector flag is '1', it may indicate that data was generated based on the scintillator detector 12. That is, when the detector flag is '1', the data processing unit 30 can determine that the data is the first output signal.

However, it is not limited to this, and when the detector flag is '1', it may indicate that data was generated based on the semiconductor detector 11. Additionally, when the detector flag is '0', it may indicate that data was generated based on the scintillator detector 12. The data collection unit 32 may determine whether the received data was generated based on the semiconductor detector 11 or the scintillator detector 12 based on the detector flag.

The data processing unit 30 may perform steps of determining a first dose from a first output signal and determining a second dose from a second output signal. As already described, the first output signal is a signal generated from the scintillation detector 12 and may be data related to counts or spectra. Additionally, the first output signal is a signal generated from the semiconductor detector 11 and may be data related to the count. Below, the process of determining the first dose and the second dose will be described.

The data collection unit 32 may transmit the first output signal of the scintillation detector 12 to the spectrum analysis unit 33 based on the detector flag. The first output signal of the scintillator detector 12 may be transmitted to the spectrum analysis unit 33 module. The spectrum analysis unit 33 may transmit the collected spectrum to the nuclide analysis/quantitative analysis unit 34 module. The nuclide analysis/quantitative analysis unit 34 can determine whether nuclides are present by analyzing the spectrum. Additionally, the nuclide analysis/quantitative analysis unit 34 can perform quantitative analysis according to the energy of the nuclide if there is a nuclide. That is, the nuclide analysis/quantitative analysis unit 34 can generate a graph related to the spectrum. The horizontal axis of the graph may be about the size of energy (keV), and the vertical axis may be counts. Additionally, the spectrum analysis unit 33 may transmit the collected spectrum to the dose weight calculation unit 35 for each energy. The dose weight calculation unit 35 for each energy can check the dose weight information for each energy of the spectrum. For example, dose weight information for each energy can be given as a function such as W(e). Here, W(e) may be dose weight information. Also, e may be energy.

The scintillator dose rate calculation unit 36 can calculate the first dose according to energy. For example, the scintillator dose rate calculation unit 36 can calculate the first dose using the following equation.

D = W(e) * C

Here, D is the first dose at the corresponding energy, W(e) is the dose weight at the corresponding energy, and C may be a count corresponding to the energy. The unit of dose may be Sv/h.

The data collection unit 32 may transmit the second output signal of the semiconductor detector 11 to the semiconductor detector count unit 38 based on the detector flag. The semiconductor detector count unit 38 may obtain a count by receiving the second output signal of the semiconductor detector 11. The semiconductor detector count unit 38 may extract a count from the second output signal.

The dose rate calculator 39 may calculate the second dose by multiplying the predetermined weight by the count of the semiconductor detector 11. The predetermined weight may be a value selected based on the semiconductor detector 11. Additionally, the dose rate calculation unit 39 may calculate the second dose by further using the sensitivity of the semiconductor detector 11 and the dose calculation vector. For example, using a calibration source, each dose is irradiated to the detector to collect the count rate, and the relationship between the irradiation dose and the count rate is created into an equation and used as a vector.

As already described, the data processing module 300 may obtain the first dose and the second dose using the first output signal of the scintillator detector 12 and the second output signal of the semiconductor detector 11, respectively. Let the dose obtained using the data from the semiconductor detector 11 be referred to as the second dose, and the dose rate obtained using the data from the scintillator detector 12 be referred to as the first dose. The final dose display unit 37 may determine one of the first dose and the second dose as the final dose according to a predetermined algorithm. Additionally, the final dose display unit 37 can display the final dose and, if necessary, generate an alarm according to the dose to the user.

Figure 5 is a flowchart illustrating a method of selecting a final dose according to an embodiment of the present disclosure.

The data processing module 300 may select the final dose based on the following process. The data processing module 300 may perform step 40 of calculating the dose for each detector. More specifically, the data processing module 300 may acquire the first dose (Dsc) of the scintillator detector 12. Additionally, the data processing module 300 may acquire the second dose (Dsi) of the semiconductor detector 11. The data processing module 300 may perform the step of obtaining a final dose based on the first dose and the second dose. More specifically, the data processing module 300 may perform the following operations to obtain the final dose.

The data processing unit 30 may perform step 41 of determining whether the first dose (Dsc) of the scintillator detector 12 is greater than or equal to the first threshold dose (Th1). If the first dose (Dsc) of the scintillator detector 12 is greater than or equal to the first threshold dose (Th1), the data processing unit 30 determines the final dose (Df) as the second dose (Dsi) of the semiconductor detector 11. Step 42 can be performed.

Additionally, when the first dose Dsc is less than the first threshold dose Th1, the data processing unit 30 may perform step 43 of determining the final dose Df as the first dose Dsc.

As described above, the data processing module 300 may determine the final dose (Df) based on the predetermined first critical dose (Th1). However, it is not limited to this, and the data processing module 300 can determine the final dose (Df) using the method below.

The data processing module 300 determines six final doses based on the first dose, the second dose, the absolute value of the difference between the first dose and the second dose, the predetermined third critical dose, and the predetermined fourth critical dose. You can follow the steps to choose one of the methods. The six final dose determination methods may include a first determination method, a second determination method, a third determination method, a fourth determination method, a fifth determination method, and a sixth determination method. The data processing module 300 may perform the step of obtaining the final dose based on the selected final dose determination method.

The data processing module 300 may obtain a predetermined third threshold dose and a fourth threshold dose from memory. The third threshold dose may be less than or equal to the first threshold dose (Th1). The fourth critical dose may be greater than or equal to the first critical dose (Th1). The data processing module 300 may determine the final dose (Df) using the first determination method, the second determination method, the third determination method, and the fourth determination method. The data processing module 300 may obtain the final dose by comparing the first dose (Dsc) and the second dose (Dsi) with the third critical dose and the fourth critical dose and selecting one method from a plurality of methods. . The data processing module 300 compares the first dose (Dsc) and the second dose (Dsi) with the third threshold dose and the fourth threshold dose to determine the first determination method, the second determination method, the third determination method, and the fourth One of the decision methods, the fifth decision method, and the sixth decision method can be selected. In addition, the data processing module 300 determines one of the third determination method, the fourth determination method, the fifth determination method, and the sixth determination method based on the absolute value of the difference between the first dose and the second dose. You can select . Hereinafter, the first decision method, the second decision method, the third decision method, the fourth decision method, the fifth decision method, and the sixth decision method will be described in detail.

(First decision method)

The data processing module 300 may use the first determination method when the first dose (Dsc) and the second dose (Dsi) are less than the third threshold dose. That is, the data processing module 300 performs the step of determining the final dose (Df) as the first dose (Dsc) when the first dose (Dsc) and the second dose (Dsi) are less than the third threshold dose. You can. The first decision method may not consider the absolute value of the difference between the first dose and the second dose.

(second decision method)

Additionally, the data processing module 300 may use the second determination method when the first dose (Dsc) is greater than or equal to the fourth critical dose. That is, when the first dose (Dsc) is greater than or equal to the fourth critical dose, the data processing module 300 may determine the final dose (Df) as the second dose (Dsi). When the first dose (Dsc) is greater than or equal to the fourth threshold dose, the data processing module 300 determines the final dose (Df) as the second dose (Dsi), regardless of the value of the second dose (Dsi). You can. The second determination method may not consider the absolute value of the difference between the first dose and the second dose.

(Third decision method)

When the first dose (Dsc) is less than the third threshold dose and the second dose (Dsi) is greater than or equal to the third threshold dose, the data processing module 300 calculates the first dose (Dsc) and the second dose (Dsi). ) can be obtained. If the first absolute value is greater than or equal to the predetermined threshold difference (ThDiff), the data processing module 300 may determine the first dose (Dsc) as the final dose (Df).

(4th decision method)

If the first dose (Dsc) is less than the third threshold dose, the second dose (Dsi) is greater than or equal to the third threshold dose, and the first absolute value is less than the predetermined threshold difference, the data processing module 300 generates the final dose. The dose (Df) can be determined as follows.

Df = w1 * Dsc + w2 * Dsi

Here, w1 and w2 may be weights that are real numbers of predetermined amounts. w1 can be larger than w2. w1 + w2 = 1. w1 = 1 - (ThDiff - Abs1)/(2 * ThDiff).

The third and fourth decision methods can also be applied when the first dose (Dsc) is less than the third critical dose and the second dose (Dsi) is greater than or equal to the fourth critical dose.

(5th decision method)

When the first dose (Dsc) is greater than or equal to the third threshold dose and is less than the fourth threshold dose, the data processing module 300 processes the first dose (Dsc) and the second dose (Dsi). The second absolute value (Abs2) of the difference value can be obtained. If the second absolute value is greater than or equal to the predetermined threshold difference (ThDiff), the data processing module 300 may determine the average of the first dose (Dsc) and the second dose (Dsi) as the final dose (Df). That is, Df= (Dsc + Dsi)/2.

The data processing module 300 determines that the first dose (Dsc) is greater than or equal to the third critical dose and is less than the fourth critical dose, and the data processing module 300 determines the first dose (Dsc) and the second dose (Dsi). The second absolute value (Abs2) of the difference value can be obtained.

(6th decision method)

If the first dose (Dsc) is greater than or equal to the third threshold dose and is less than the fourth threshold dose, and the second absolute value is less than the predetermined threshold difference, the data processing module 300 sets the final dose (Df) as follows. You can decide.

Df = w3 * Dsc + w4 * Dsi

Here, w3 and w4 may be weights that are real numbers of predetermined amounts. w3 + w4 = 1. w3 = 1/2 - (ThDiff - Abs2)/(2 * ThDiff).

The fifth and sixth determination methods can be applied regardless of whether the value of the second dose (Dsi) is greater than or equal to the third threshold dose and the fourth threshold dose.

By selecting one of the first decision method, the second decision method, the third decision method, the fourth decision method, the fifth decision method, and the sixth decision method, the data processing module 300 achieves high accuracy. The final dose (Df) can be determined.

In addition, after determining the final dose (Df) as the second dose (Dsi) or in the same manner as above, a step 44 of determining whether the final dose (Df) is greater than or equal to the predetermined second critical dose (Th2) is performed. You can. If the final dose (Df) is greater than or equal to the second threshold dose (Th2), the data processor 30 may perform step 45 of outputting an alarm indicating that the radiation dose is high. Alarms can be output as sound or video. Users can easily see that an alarm has been created. As shown in FIG. 5, when the final dose (Df) is determined to be the first dose (Dsc), the data processing unit 30 determines whether the final dose (Df) is greater than or equal to the predetermined second threshold dose (Th2). Step 44 may not be performed. Therefore, the data processing unit 30 can significantly save processing performance. In particular, when the predetermined period is fast as described below, the data processing unit 30 can focus processing power on the process of obtaining the first dose and the second dose.

The detector system 1 can acquire the first dose and the second dose at predetermined intervals. For example, the predetermined period may be 0.1 to 3 seconds. Since the detector system 1 acquires the first dose, the second dose, and the final dose in such a fast cycle, it can quickly inform the user whether radioactivity has been excessively measured.

The detector system 1 of the present disclosure may use a semiconductor detector 11 in combination with a scintillator detector 12. Therefore, the detector system 1 can collect and analyze the spectrum in a low-dose environment and calculate the dose considering energy while recognizing nuclides. Additionally, the detector system 1 can calculate the dose even in a high dose environment and provide the final dose to the user.

The detector system 1 of the present disclosure may use a scintillator detector 12 at low doses and a semiconductor detector 11 at high doses. Additionally, the detector system 1 may use the data processing unit 30 to select one of the first dose and the second dose calculated based on signals obtained from the two detectors as the final dose.

The range of dose that a typical detector can normally display can be determined by the type and size of the detector. However, the detector system 1 of the present disclosure can perform spectrum analysis while greatly expanding the range of doses that can be normally displayed by including different detectors. Additionally, an alarm generation procedure according to the dose can be performed.

Hereinafter, the operation of the scintillation detector 12 included in the detector system 1 according to an embodiment of the present disclosure will be further described.

Referring to FIG. 1, the scintillator detector 12 is equipped with a collimator 13 to limit the basic effective field of view of the scintillator detector 12. The basic effective field of view may be the field of view of the scintillation detector 12 without the collimator 13 installed. The collimator 13 may be mounted on the scintillator detector 12 to shield background radiation. In the present disclosure, the field of view of the scintillation detector 12 limited by the collimator 13 is defined as the effective field of view of the detector. In general, the collimator 13 can be made of tungsten or lead to maximize the effect of radiation shielding.

The position of the collimator 13 and the relative position of the measurement target container of the scintillator detector 12 can determine the useful field of view (UFOV) of the detector system 1. For example, when the collimator 13 advances forward with respect to the scintillator detector 12, the viewing angle 14 of the scintillator detector 12 may become narrow. Therefore, the effective field of view of the detector system 1 may be narrowed. Additionally, when the collimator 13 retreats back with respect to the scintillator detector 12, the viewing angle 14 of the scintillator detector 12 can be widened. Therefore, the effective field of view of the detector system 1 can be widened. In the present disclosure, the viewing angle 14 of the scintillation detector 12 determined by the position of the collimator 13 is referred to as the effective field of view of the detector.

In addition, even if the position between the collimator 13 and the scintillator detector 12 is fixed, if the scintillator detector 12 is far from the container to be measured, detection is possible over a wide area, so the effective field of view of the detector system 1 is wide. You can lose. In addition, even if the position between the collimator 13 and the scintillator detector 12 is fixed, detection is possible in a narrow area if the scintillator detector 12 is close to the container to be measured, so the effective field of view of the detector system 1 is narrow. You can lose. In the present disclosure, the viewing angle determined by the position between the collimator 13 and the scintillator detector 12 may be referred to as the effective field of view of the detector. The effective field of view of the detector system 1 can be adjusted by moving the detector module 10 in the x-axis and y-axis to adjust the relative distance between the measurement object container and the scintillator detector 12.

The effective field of view of detector system 1 may limit the detection efficiency of detector system 1. Here, the detection efficiency of the detector system 1 can be determined by the ratio of signal and noise. For example, detection efficiency can represent the ratio of signal to noise.

In the present disclosure, detector system 1 can use the relationship between sensitivity and uniformity to determine the effective field of view of detector system 1. That is, the relationship between sensitivity and uniformity may be a figure of merit (FOM) for determining the effective field of view (UFOV) of the detector system 1.

The detection efficiency of a detector system using UFOV, determined using sensitivity and uniformity, can be verified through calculation of minimum detection activity (MDA).

As already explained, the viewing angle 14 of the scintillation detector 12 determined by the position of the collimator 13 is called the effective field of view of the detector. According to the present disclosure, the detection efficiency of the detector system 1 can be maximized by adjusting the effective field of view of the detector.

The detection efficiency of the detector system 1 can be expressed as the ratio between signal and noise (i.e., signal-to-noise ratio (SNR)). In other words, the detection efficiency of the detector system 1 may mean the ratio of the amount of radiation received in the area of the container to be measured among the radiation detected by the detector system 1. The detection efficiency of the detector system 1 may refer to the ratio of the amount of radiation detected by the detector system 1 excluding the amount of radiation received from the external area of the container to be measured. In the present disclosure, detection efficiency may have the same meaning as sensitivity.

In particular, the detection efficiency of the radiation measurement device included in the detector system 1 can generally be expressed as MDA (minimum detectable activity) based on the correlation between the radiation to be measured and background radiation.

MDA is defined as the formula below.

(Equation 1)

Here, B is the background radiation dose and K is the abscissas of Gaussian distribution, and Equation 1 can be simplified as Equation 2 below.

(Equation 2)

is denoted branching of interested peak,

t is measurement time

is energy peak efficiency (=efficiency of detector)

The position between the scintillator detector 12 and the collimator 13 and the position between the scintillator detector 12 and the measurement target container can determine the area where the scintillator detector 12 receives a signal from the measurement target container. That is, the position between the scintillator detector 12 and the collimator 13 and the position between the scintillator detector 12 and the measurement target container can determine a useful field of view (UFOV). In addition, the position between the scintillator detector 12 and the collimator 13 and the position between the scintillator detector 12 and the measurement target container are the efficiency of the detector ( ) can be determined. The efficiency of the detector may refer to the amount of radiation that the scintillation detector 12 receives among the radiation emitted by the container to be measured. The wider the viewing angle of the scintillation detector 12, the more radiation it will receive, so the efficiency of the detector can increase as the viewing angle becomes wider. In addition, since it receives a lot of radiation and reacts sensitively to the radiation emitted by the measurement target container, the efficiency of the detector in the present disclosure may have the same meaning as sensitivity. Sensitivity can be proportional to the amount of radiation collected by the detector.

The accuracy of measurement may correspond to intrinsic uniformity (IU). If the container to be analyzed is too large, the detector system 1 cannot analyze the container to be analyzed at once. Therefore, the detector system 1 can measure the vessel to be analyzed by dividing it into a plurality of correction volumes. It can be assumed that the radiation inside the container to be analyzed is uniformly distributed. Uniformity may indicate the degree to which radiation signals measured for each of a plurality of correction volumes are uniform. As already explained, since the radiation inside the container to be analyzed is assumed to be uniformly distributed, the fact that the scintillator detector 12 measured radiation signals uniformly for all correction volumes indicates that the measurement accuracy of the scintillator detector 12 is high. It can mean something.

Uniformity (IU) can be defined as Equation 3.

(Equation 3)

Here, max and min may be the maximum and minimum of the radiation signal (activity) measured in the measurement target container or correction volumes. Activity may be related to a radiation signal or concentration of radioactive material. The scintillator detector 12 can measure radiation signals for the same radioactive object multiple times or measure radiation signals for several parts of the same radioactive object to obtain max and min values. Here, the radioactive object may be a container to be measured. The first uniformity and the second uniformity, which will be described below, can be obtained by Equation 3.

There may be a conflict between maximizing sensitivity, which corresponds to the efficiency of the detector, and measurement accuracy. This is because the high efficiency of the detector means that the viewing angle is large, and the scintillator detector 12 receives a lot of radiation from the outside of the measurement object container. That is, the scintillator detector 12 measures even the radiation that is not emitted from the measurement target container.

The detector system 1 uses sensitivity (detector efficiency) and uniformity (IU) to determine the effective field of view of the scintillator detector 12. Sensitivity (detector efficiency) and uniformity (IU) may be a figure of merit (FOM) for determining the effective field of view. Additionally, the detector system 1 uses a method to determine the effective field of view of the detector that minimizes FOM. As already described, the effective field of view (UFOV) of the detector system 1 can be determined by the effective field of view of the detector.

In order to set the effective field of view (UFOV) of the detector system 1 that maximizes the detection efficiency of the detector system 1, the detector system 1 can perform the following procedure. The detection efficiency of detector system 1 can be achieved by minimizing MDA.

The viewing angle 14 of the scintillator detector 12 is an angle that limits the measurement range of the scintillator detector 12, and can be determined based on the degree of protrusion of the collimator 13.

The main module controls the collimator 13 to change the viewing angle 14 of the scintillator detector 12 from more than 40 degrees to less than 160 degrees, and can calculate the efficiency (sensitivity) and uniformity (IU) of the detector. The main module can graph the efficiency and uniformity of the detector according to viewing angle. The horizontal axis of the graph represents the viewing angle 14 of the scintillator detector 12. The left vertical axis of the graph represents the efficiency (sensitivity) of the detector. Additionally, the vertical axis on the right side of the graph represents the uniformity of the detector.

As already explained, sensitivity and uniformity may have a conflicting relationship. Therefore, as the viewing angle 14 increases in the graph, sensitivity may increase and uniformity may decrease.

The main module can match a sensitivity of 1.0e^(-6) with a uniformity of 0 to obtain a graph. Additionally, the main module can match a sensitivity of 1.0 with a uniformity of 25 to obtain a graph. Accordingly, the main module can display sensitivity and uniformity in one graph. The main module can define the viewing angle (14) at the point where sensitivity and uniformity meet as the effective field of view of the optimal detector. For example, the main module may determine the optimal effective field of view of the scintillator detector 12 to be 140 degrees.

The present disclosure described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible without departing from the technical spirit of the present disclosure. It will be clear to a person with ordinary knowledge.

Claims (4)

A detector module including a semiconductor detector that measures the count of radiation and a scintillator detector that acquires a radiation spectrum;
a main module for controlling the detector module, collecting data from the detector module, and transmitting the received data to a data processing unit; and
In a method of operating a detector system including the data processing unit for processing data collected from the detector module and the main module to obtain a final dose,
Obtaining, by the data processing unit, a first output signal measured for radioactive material using the scintillator detector;
obtaining, by the data processing unit, a second output signal measured for the radioactive material using the semiconductor detector;
determining, by the data processor, a first dose from the first output signal and a second dose from the second output signal; and
Obtaining a final dose based on the first dose and the second dose,
The step of obtaining the final dose is,
The data processing unit determining whether the first dose is greater than or equal to a predetermined first threshold dose;
If the first dose is less than the first critical dose, the data processor determines the final dose as the first dose; and
The data processor includes determining the final dose as the second dose when the first dose is greater than or equal to the first threshold dose,
not outputting an alarm when the final dose is determined to be the first dose;
When the final dose is determined to be the second dose, determining whether the final dose is greater than or equal to a predetermined second critical dose;
not outputting an alarm when the final dose is less than the second threshold dose; and
When the final dose is greater than or equal to the second threshold dose, outputting an alarm indicating a high radiation dose.
delete delete A detector module including a semiconductor detector that measures the count of radiation and a scintillator detector that acquires a radiation spectrum;
a main module for controlling the detector module, collecting data from the detector module, and transmitting the received data to a data processing unit; and
In a method of operating a detector system including the data processing unit for processing data collected from the detector module and the main module to obtain a final dose,
Obtaining, by the data processing unit, a first output signal measured for radioactive material using the scintillator detector;
obtaining, by the data processing unit, a second output signal measured for the radioactive material using the semiconductor detector;
determining, by the data processor, a first dose from the first output signal and a second dose from the second output signal; and
Obtaining a final dose based on the first dose and the second dose,
The step of obtaining the final dose is,
The data processing unit determines six final doses based on the first dose, the second dose, the absolute value of the difference between the first dose and the second dose, the predetermined third critical dose, and the predetermined fourth critical dose. selecting one of the decision methods; and
Obtaining the final dose based on the selected final dose determination method,
The six final dose determination methods include a first determination method, a second determination method, a third determination method, a fourth determination method, a fifth determination method, and a sixth determination method,
The data processing unit determines six final doses based on the first dose, the second dose, the absolute value of the difference between the first dose and the second dose, the predetermined third critical dose, and the predetermined fourth critical dose. The steps in choosing one of the decision methods are:
Comparing the first dose and the second dose with at least one of the third predetermined threshold dose and the fourth predetermined threshold dose to select one of the first determination method and the second determination method step; and
The first dose and the second dose are compared with at least one of the predetermined third threshold dose and the predetermined fourth threshold dose, and the absolute value of the difference between the first dose and the second dose is determined by a predetermined value. Selecting one of the third decision method, the fourth decision method, the fifth decision method, and the sixth decision method by comparing the threshold difference.