KR102619779B1 - A threshold voltage level determining device using multichannel analysis and a method thereof - Google Patents

Abstract

A method of determining a screening voltage using a screening voltage determination device includes determining pulse coefficients for each channel by applying multi-channel analysis to an electric pulse signal input from a neutron detector; and determining a screening voltage for removing noise from the electric pulse signal input from the neutron detector using the pulse coefficient for each channel.

Description

Screening voltage determination device using multi-wave height analysis and its operating method {A THRESHOLD VOLTAGE LEVEL DETERMINING DEVICE USING MULTICHANNEL ANALYSIS AND A METHOD THEREOF}

It concerns the determination of screening voltage.

A neutron detector can be used to detect neutrons leaking from the core. A neutron detector can detect neutrons using a neutron reactive material. For example, a neutron detector uses the principle that when a nuclear fission product generated through a nuclear reaction between a neutron and a reactant transfers energy to another material (e.g., a gaseous material in the detector, etc.), electrons are removed from the material, thereby generating neutrons. Presence can be detected.

Signals from neutrons as well as other radiation can be detected from the neutron detector. In a neutron detector, a wave height separator may be used to detect only signals resulting from neutrons. The wave separator can distinguish neutrons from other particles by using the fact that the amount of electrons generated in the detector varies depending on the incident radiation energy.

In addition, because the wave separator detects based on the differences between neutrons and other particles, the detection accuracy may be affected by complex phenomena that occur during the particle collision process or environmental changes. To compensate for this, the accuracy of the detector itself must be increased or calibration work must be performed.

For this purpose, a number of methods, such as Korean Patent No. 10-1189957, have been proposed. In this way, the wave separator plays an important role in a neutron detector, but various technologies and supplementary work are required to improve its performance.

In order to solve the above problem, this specification discloses a method of determining the screening voltage of the wave height separator using a multi-channel wave height analysis device.

In order to solve the above problem, this specification describes a method of determining a screening voltage using a screening voltage determining device according to an embodiment. This method includes determining pulse coefficients for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector, and using the pulse coefficient for each channel to remove noise from the electric pulse signal input from the neutron detector. It may be configured to include the step of determining a screening voltage.

Additionally, this specification describes a screening voltage determination device according to an embodiment. A screening voltage determination device according to an embodiment includes a multi-channel wave height analyzer that determines the pulse coefficient for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector, and a multi-channel wave height analyzer that determines the pulse coefficient for each channel from the neutron detector. It may include a screening voltage determination unit that determines a screening voltage for removing noise (electrical noise and surrounding radiation excluding neutrons) from the input electrical pulse signal.

Additionally, in order to solve the above-described problem, this specification discloses a computer program for performing the above-described method and a computer-readable recording medium on which the program is recorded.

According to the technical content proposed in this specification, the operator can omit the procedure of counting pulses while changing the wave separator voltage.

Additionally, the operator can simply connect a multi-channel wave height analysis device to accumulate data and then convert it into a characteristic curve to determine the screening voltage.

Accordingly, the worker's workload can be reduced, work time can be reduced, and reliability of results can be improved through automation.

The present disclosure may be readily understood by combination of the following detailed description and accompanying drawings, where reference numerals refer to structural elements.
1 is a diagram conceptually illustrating an off-air neutron flux monitoring system according to an embodiment.
FIG. 2A is a conceptual diagram showing the configuration of a controller according to an embodiment.
FIG. 2B is a diagram showing an example of an amplified electrical pulse signal.
FIG. 2C is a diagram illustrating an example of separating noise from an amplified pulse signal by applying a selection voltage.
Figure 2D is a diagram showing the resulting TTL pulse.
Figure 3 is a diagram showing a method of setting a screening voltage according to an embodiment.
4 to 5 are diagrams illustrating the steps of obtaining coefficient values for each predetermined voltage.
Figure 6 is an example of the characteristic curve of the BF ₃ proportional counter obtained through counting work for each voltage.
FIG. 7 is a block diagram of a screening voltage determiner 700 according to an embodiment.
FIG. 8 is a diagram illustrating a method by which the screening voltage determiner 700 determines a screening voltage using multi-channel wave height analysis according to an embodiment.
FIG. 9 is a graph showing coefficient values determined for each channel as a result of the selection voltage determiner 700 analyzing the electrical pulse signal received from the neutron detector for a predetermined period of time.
Figure 10 is a graph showing a characteristic curve and selection voltage according to one embodiment. do
Figure 11 is a diagram explaining an embodiment of applying a multi-channel wave height analyzer to existing equipment.

Hereinafter, various embodiments will be described in detail with reference to the drawings. The embodiments described below may be modified and implemented in various different forms. In order to more clearly explain the characteristics of the embodiments, detailed descriptions of matters widely known to those skilled in the art to which the following embodiments belong will be omitted.

Meanwhile, in this specification, when a configuration is said to be “connected” to another configuration, this includes not only the case of being “directly connected,” but also the case of being “connected with another configuration in between.” Additionally, when a configuration “includes” another configuration, this means that, unless specifically stated to the contrary, it does not exclude other configurations but may further include other configurations.

Additionally, terms including ordinal numbers such as 'first' or 'second' used in this specification may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

An ex-core neutron flux monitoring system (ENFMS) according to an embodiment can measure neutron flux leaking outside the reactor vessel using a neutron detector installed on the outside of the reactor core.

Each reactor type may have different channel and/or range configurations. For example, the values below may vary depending on the reactor type.

- WEC(NIS): Source Range, Intermediate Range, Power Range

- OPR-1000, APR1400: Start-up Channel, Control Channel, Safety Channel

However, since the basic measurement concept is similar, the monitoring system disclosed in this specification can be applied according to the above properties to apply to the desired nuclear reactor type. Hereinafter, an off-road neutron flux monitoring system according to an embodiment is disclosed.

1 is a diagram illustrating the concept of an off-road neutron flux monitoring system according to an embodiment. The description will be made with reference to FIG. 1 . The core 110 is located within the containment building 100. The extra-furnace neutron flux monitoring system may be configured to include a neutron detector 210 and a controller 220 installed outside the core. The neutron detector 210 and the controller 220 may be connected by wire. When the neutron detector 210 and the controller 220 are connected by a cable, the cable box 230 and/or junction box 240 may be used to improve manageability.

The neutron detector 210 may be located near the reactor core 110 or may be installed on the outside of the reactor core 110. The neutron detector 210 can measure the neutron flux leaking to the outside of the reactor vessel.

A plurality of neutron detectors 210 may be installed around the core 110. For example, when two neutron detectors 210 are installed, the neutron detectors 210 may be installed symmetrically with respect to the core 110. When four neutron detectors 210 are installed, the neutron detectors 210 may be installed at an angle of 90 degrees to each other with the core 110 as a reference point. Alternatively, the neutron detectors 210 may be installed to be symmetrical to each other at an arbitrary angle other than an angle of 90 degrees. In this way, when n number of neutron detectors 210 are installed, the neutron detectors 210 can be installed at an angle of 360/n degrees to each other with the core 110 as a reference point.

The controller 220 avoids damage from neutron flux, gamma rays, etc. leaking from the core 110, and for the convenience of controller maintenance (if installed near the core, it is very difficult for operators to access). Alternatively, it may be located at a considerable distance from the neutron detector 210. For example, the controller 220 may be located in a separate building from the containment building where the core 110 is located.

The system including the controller 220 may be named an off-furnace neutron flux monitoring system. For example, only the controller 220 may be referred to as an off-air neutron flux monitoring system. Alternatively, the system including the neutron detector 210 and the controller 220 may be called an off-furnace neutron flux monitoring system. Meanwhile, the off-furne neutron flux monitoring system may also be called an off-furnace measurement system.

In one embodiment, the neutron flux monitoring range of the off-road neutron flux monitoring system may be up to 200% FP assuming an accident in the source area. For example, a neutron detector can monitor neutron flux in the source region up to 200% FP, assuming an accident. Additionally, the off-air neutron flux monitoring system can provide output (e.g., electrical signal) proportional to the output change rate. Additionally, the off-road neutron flux monitoring system can transmit safety grade signal signals to the power plant protection system. Additionally, the off-furnace neutron flux monitoring system can transmit a control grade signal to the nuclear reactor control system. Additionally, the off-furnace neutron flux monitoring system can provide source region neutron flux audible signals to the controller and/or core (e.g., main control room and reactor containment building).

An off-air neutron flux monitoring system can monitor the output of a nuclear power plant and provide output signals to the reactor monitoring and protection system. Below, we will describe how an off-air neutron flux monitoring system monitors the output of a nuclear power plant.

Neutrons generated when a nuclear fission phenomenon occurs in the nuclear fuel of the reactor core 110 may leak outside the core. At this time, mainly fast neutrons are leaked to the outside of the furnace. Leaked neutrons may be incident into the neutron detector 210 installed outside the furnace. When fast neutrons are incident into the neutron detector 210, the fast neutrons may be decelerated into thermal neutrons by the moderator material surrounding the outside of the detector. As an external moderator of the neutron detector 210, a resin that has little deformation at temperature can generally be used. Here, resin is a material containing elements such as hydrogen-carbon-oxygen-silicon. The external moderator slows down fast neutrons and allows them to flow into the detector as thermal neutrons.

Thermal neutrons can generate energy by reacting with nuclear reactants inside the detector. For this purpose, the nuclear reactive material inside the detector may be composed of nuclides that can capture neutrons, such as uranium-235 and boron-10. For example, when tritium and neutrons collide, helium and alpha particles are generated, and when neutrons collide with B-10 (nuclear reaction), lithium and alpha particles are generated, releasing energy. When neutrons and uranium-235 undergo a nuclear reaction, nuclear fission products are generated and energy can be released.

The generated energy transfers energy to the gaseous material inside the detector, thereby generating electrons. For example, there may be a gaseous substance inside the detector that receives energy and generates electrons. For example, argon gas can be used, which can generate electrons from the energy generated.

The generated electrons are captured by the electrode by the high voltage applied to the detector anode and can be measured as an electrical signal. The size of the electrical signal at this time is proportional to the number of thermal neutrons incident on the detector. And, the number of incident neutrons is proportional to the number of neutrons (neutron flux) leaked to the outside of the reactor through nuclear fission within the reactor core. That is, the electrical signal generated by the neutron detector 210 is proportional to the reactor output.

As described above, the detected electrical signal can be classified into a pulse signal, a mean square voltage (MSV) signal, and a current signal, depending on the detector type. The signals can be used separately depending on the purpose and function of the off-road neutron flux monitoring system. The off-air neutron flux monitoring system may consist of at least one channel. For example, the off-furnace neutron flux monitoring system may include at least one of a starting channel used when operating a nuclear reactor, a control channel used for controlling and monitoring the nuclear reactor, and a safety channel used for protecting the nuclear reactor. Examples of starting channels used when operating a nuclear reactor include the BF ₃ proportional counter or the wide-area fission box, which can be operated using pulse signals. For example, the BF ₃ proportional counter can generate a neutron voltage pulse by the B-10 interaction of the neutron and the proportional counter. Examples of control channels used for the purpose of controlling and monitoring nuclear reactors include decompensated ion ionization chambers and wide-area nuclear fission chambers, which can be operated using current signals. Examples of safety channels used to protect nuclear reactors include wide-area nuclear fission boxes, which can be operated by combining pulse signals, MSV signals, and current signals.

As described above, the off-furnace neutron flux monitoring system according to one embodiment may use a pulse signal among electrical signals. As described above, the electrical pulse signal generated by a nuclear reaction inside the neutron detector 210 can be transmitted to the controller 220. Hereinafter, a pulse signal processing method of the controller 220 according to an embodiment will be described.

FIG. 2A is a conceptual diagram showing the configuration of a controller according to an embodiment. The controller 220 according to one embodiment may be configured to include a pre-amplifier 221, a main amplifier 222, a wave height selector 223, a TTL pulse generator 224, and a pulse counting circuit 225.

The electrical pulse signal applied from the neutron detector 210 may be amplified through the pre-amplifier 221 and then amplified through the main amplifier 222. If the pulse signal generated from the neutron detector 210 is too small to be processed by the controller 220, the pulse signal is processed to a level that can be processed by the controller 220 using the pre-amplifier 221 and/or the main amplifier 222. The size of can be amplified. Figure 2b shows an example of an amplified electrical pulse signal.

Depending on the embodiment, at least one of the pre-amplifier 221 and the main amplifier 222 may be omitted when implementing the controller 220. For example, if the pulse signal input from the neutron detector 220 is sufficiently strong, the amplification procedure may be omitted.

A wave discriminator (Discriminator, 223) removes noise from the pulse of the amplified signal. To increase the accuracy of reactor output monitoring, noise must be removed. The pulse signal applied from the neutron detector 210 to the controller 220 may contain various noise signals. In addition to neutrons, there may be noise such as ambient radiation, noise generated when the neutron detector 210 reacts to radiation generated inside the neutron detector 210, or electrical noise flowing into the neutron detector 210 or the cable.

The wave height selector 223 may compare the amplitude of the amplified pulse signal with the selection voltage. The wave height selector 223 may determine whether the amplitude of the amplified pulse signal is higher than, equal to, or lower than the selection voltage. A conceptual example of this is shown in Figure 2C. FIG. 2C is a diagram illustrating an example of separating noise from an amplified pulse signal by applying a selection voltage.

The wave height selector 223 may use the voltage value of the comparator as a selection voltage. The amplitude of the pulse signal caused by neutrons varies, but the amplitude level tends to be higher than that of the noise signal. Therefore, it is necessary to appropriately determine the level of the selection voltage to properly remove noise. As will be described later, in order to properly remove noise, a characteristic curve can be taken through the TTL pulse coefficient according to the change in the screening voltage, and the screening voltage can be determined through the curve.

The Transistor-Transistor Logic (TTL) pulse generator 224 may generate TTL pulses depending on the input. The TTL pulse generator 224 may generate a pulse indicating 1 if the amplitude of the amplified pulse signal is higher than the selection voltage according to the selection result of the wave height selector 223, and 0 if the amplitude of the amplified pulse signal is not higher than the selection voltage. An example of this is shown in Figure 2d.

The pulse counting circuit 225 processes the TTL pulse signal and measures the number of neutrons. For example, the number of neutrons can be obtained by counting the number of pulses generated.

As described above, it is necessary to appropriately determine the level of the selection voltage so that the wave height selector 223 properly removes noise. Hereinafter, a method of taking a characteristic curve through the TTL pulse coefficient according to the change in the selection voltage and determining the selection voltage through the curve will be described.

Figure 3 is a diagram showing a method of setting a screening voltage according to an embodiment. Referring to FIG. 3, a method of setting a screening voltage of an off-furnace neutron flux monitoring system according to an embodiment will be described. The method of setting the screening voltage of the off-air neutron flux monitoring system can be performed in two steps: obtaining a coefficient value for each screening voltage candidate (S310) and determining the screening voltage (S320). Here, the selection voltage candidate refers to a voltage that can be determined as the selection voltage. Typically, at least one voltage value that can be specified between the lowest voltage and the highest voltage can be determined as a selection voltage candidate.

Referring to FIG. 4, the step of obtaining coefficient values for each selection voltage candidate will be described in more detail. The wave height selector 223 may determine a coefficient value according to the selection voltage candidate by performing a step of determining a selection voltage candidate (S410) and a step of counting the TTL signal for a predetermined time for the determined selection voltage candidate (S420).

For example, the wave height selector 223 may count TTL signals for a plurality of candidate selection voltage values. In the step of determining a selection voltage candidate (S410), the wave height selector 223 uses a potentiometer (variable resistor) to select at least one voltage among the voltages specified for each minimum resolution interval available from the minimum available voltage to the maximum available voltage. It can be decided as a voltage candidate. Additionally, the wave height selector 223 may count the TTL signal for each determined selection voltage candidate.

Another embodiment will be described with reference to FIG. 5 . The wave height selector 223 may determine whether a selection voltage candidate exists (S510). Here, the selection voltage candidate refers to a selection voltage candidate for which counting has not yet been performed. The wave height selector 223 may sequentially specify selection voltage candidates in order of a predetermined resolution interval (e.g., minimum available resolution), starting from the minimum available voltage to the maximum available voltage. Then, the wave height selector 223 may determine the specified selection voltage candidate as a selection voltage candidate for counting the TTL signal (S520). Next, the wave height selector 223 may count the TTL signal for a predetermined time for the corresponding selection voltage candidate. Next, the wave height selector 223 may count the TTL signal for the next selection voltage candidate for which counting has not progressed, and may stop counting the TTL signal if the next selection voltage candidate does not exist.

For example, in a state where a source or nuclear fuel that generates neutrons is loaded in the core, the wave height selector 223 sets the voltage as low as possible as a candidate selection voltage value using a potency meter, and then uses a counter and a timer to set the voltage as low as possible. TTL pulse signals can be counted for a specific time. The wave height selector 223 can change the selection voltage candidate by slightly increasing the voltage again and then count the TTL pulse signal for the same time using a counter and timer. By repeating the above operation, the wave selector 223 can perform counting for each selection voltage candidate until the TTL pulse signal according to the selection voltage candidate is no longer counted.

Referring again to FIG. 3, the step of determining the selection voltage using the coefficient value determined for each selection voltage candidate (S320) may be performed by numerical analysis of the coefficient result. For example, the measured coefficient value can be displayed on an XY graph (X axis = selection voltage level, Y axis = measurement coefficient value). For example, the coefficient results may be displayed graphically as shown in FIG. 6 . Figure 6 is an example of the characteristic curve of the BF ₃ proportional counter obtained through counting work for each voltage. As shown in FIG. 6, the value of the selection voltage can be determined as the value of the point where the section due to noise in the graph intersects the X-axis by extending it in a straight line.

For example, the wave height separator may determine the x-intercept value of the first-order equation specified by the minimum selection voltage candidate and its coefficient value, the minimum selection voltage candidate next voltage and its coefficient value as the selection voltage.

Alternatively, the wave height separator may determine the x-intercept value of the linear equation specified by the minimum selection voltage candidate and its coefficient value, the nth largest voltage from the minimum selection voltage candidate and its coefficient value as the selection voltage. Here, n may be a value specified by the user.

Meanwhile, if there are a plurality of neutron detectors 210, the above-described work may have to be performed for each neutron detector. In addition, since the TTL pulse signal must be counted for a certain period of time for each individual counting voltage, a considerable amount of time is consumed. Accordingly, in the case of a wide-area nuclear fission box with a low detector sensitivity or a new nuclear power plant (initial core) with a low leakage neutron flux, it may take several days to perform the procedure. In addition, because a frequency counter consisting of a single channel is used, there is a problem of having to repeat the same operation to measure the screening voltage of 2 to 3 detectors per channel of the external measuring instrument.

Hereinafter, a method of determining the selection voltage of the selection voltage determiner to solve the above-mentioned problem will be described. The screening voltage determiner according to one embodiment may determine the screening voltage using a multi-channel wave height analyzer (Multichannel Analyzer, MCA).

In one embodiment, the screening voltage determiner can measure the amplitude of pulses in multiple channels simultaneously by employing a multi-channel crest analyzer. The multi-channel wave height analyzer has the same effect as applying the wave height separator 223 described above simultaneously to each of a plurality of channels. For example, the screening voltage determiner is a multi-channel wave height analyzer that measures the amplitude of each input pulse in real time, stores the accumulated coefficient value according to the amplitude range, and determines the screening voltage to be applied to the wave height sorter from the stored data. You can.

For example, the detector characteristic curve described above with reference to FIG. 6 is a concept that integrates the coefficient values for pulses with an amplitude greater than the wave height selector voltage, so the amplitude of all pulses is measured in real time through a multi-channel wave height analysis method and the amplitude The coefficient values according to can be accumulated and then converted into a detector characteristic curve.

FIG. 7 is a block diagram of a screening voltage determiner 700 according to an embodiment. This will be explained with reference to FIG. 7 . The screening voltage determiner 700 according to an embodiment may be configured to include an amplifying unit 710, a multi-channel wave height analysis unit 720, an integrating unit 730, and a screening voltage determining unit 740.

The amplification unit 710 may amplify a pulse signal coming from the outside to an amplitude that can be analyzed. For example, the amplification unit 710 amplifies the pulse signal input from the neutron detector 210 to an amplitude that can be analyzed by the multi-channel wave analysis unit 720. If the amplitude of the input electric pulse has a sufficient magnitude or the multi-channel wave height analysis unit 720 performs an amplification function, employment of the amplification unit 710 may be omitted.

The multi-channel wave height analysis unit 720 can measure the amplitude of each amplified pulse in real time and store the coefficient value. The integration unit 730 may accumulate the coefficient values determined by the multi-channel wave height analysis unit 720 for each amplitude and store them for each amplitude.

As described above, the screening voltage determination unit 740 may determine the screening voltage of the wave height separator using the coefficient values accumulated and stored for each amplitude.

Referring to FIG. 8, a method of determining a screening voltage using multi-channel wave height analysis of the screening voltage determiner 700 according to an embodiment will be described in more detail. FIG. 8 is a diagram illustrating a method by which the screening voltage determiner 700 determines a screening voltage using multi-channel wave height analysis according to an embodiment.

First, the selection voltage determiner 700 may determine a coefficient value for each channel of each amplitude based on the amplitude of the pulse measured for each of the plurality of channels (S810). For example, the screening voltage determiner 700 may count the number of occurrences for each amplitude of the pulse signal appearing in the electrical pulse signal input from the neutron detector during the reference time. For example, the screening voltage determiner 700 may count 10 for the amplitude of the value a when the amplitude of the value a appears 10 times during a predetermined time, and the amplitude of the value b when the amplitude of the value b appears 15 times. You can count 15 for .

An example of this is shown in Figure 9. FIG. 9 is a graph showing coefficient values determined for each channel as a result of the selection voltage determiner 700 analyzing the electrical pulse signal received from the neutron detector for a predetermined period of time. In the graph of FIG. 9, the X-axis represents the amplitude of the pulse signal, and the Y-axis represents the pulse count value according to the corresponding amplitude. Here the amplitude corresponds to the selection voltage. In a multi-channel wave height analyzer, a predetermined process can be performed to match the channel that is the subject of classification to the selection voltage. This will be described later.

Next, the selection voltage determiner 700 may determine the cumulative coefficient value for each channel by accumulating coefficient values determined for each plurality of channels (S820). For example, the screening voltage determiner 700 can convert all coefficient values measured above the corresponding amplitude for each amplitude into a detector characteristic curve by integrating them. For example, the equation below can be used for this purpose.

Here, Y(i) represents the coefficient value corresponding to the spectrum i channel, and S(i) represents the cumulative coefficient value to be displayed in the characteristic curve X-axis i channel.

Using the above conversion equation, the detector characteristic curve 1010 of FIG. 10 can be obtained. Figure 10 is a graph showing a characteristic curve and selection voltage according to one embodiment. Detector characteristic curve 1010 in FIG. 10 corresponds to detector characteristic curve 610 in FIG. 6 .

The method of determining the sorting voltage described with reference to FIGS. 3 to 6 uses a method of counting the voltage of the wave height sorter one by one while changing the variable resistance in appropriate steps (e.g., increasing by 0.2 Vdc), so resolution is limited due to issues of time and cost. There are some parts where it is difficult to increase. On the other hand, by using the method of adopting the multi-channel wave height analysis described with reference to FIG. 8, it is possible to obtain a characteristic curve graph with high resolution (e.g. Range 10Vdc, 0.02Vdc for 512 Ch).

Next, the selection voltage determiner 700 may determine the selection voltage by generating detection characteristic data based on the cumulative coefficient values of multiple channels (S830). For example, the screening voltage determiner 700 may designate two points corresponding to noise in the detector characteristic curve 1010 of FIG. 10 and generate a graph 1020 representing the screening voltage using the fitting equation below. . As described above, the selection voltage determiner 700 may determine the x-intercept value specified by the equation below as the selection voltage.

Here, a represents the slope constant, b represents the attenuation constant, and c represents the offset.

Hereinafter, an embodiment of installing and applying a multi-channel wave height analyzer to existing equipment as shown in FIG. 1 will be described. Figure 11 is a diagram explaining an embodiment of applying a multi-channel wave height analyzer to existing equipment. In one embodiment, a multi-channel wave height analyzer may be directly connected to the controller 220 of FIG. 1.

This will be explained with reference to FIG. 11. First, connect a multi-channel wave height analyzer to the neutron detector output pulse (S1110). If the amplitude of the neutron detector output pulse is low and amplification is required, a multi-channel wave height analyzer can be connected to the rear end of the amplifier. For example, a multi-channel wave height analyzer can be connected to the rear end of the main amplifier 222 of the controller 220.

Next, connect communication between the multi-channel wave height analyzer and the user terminal (S1120). For example, in order to measure data generated from a multi-channel wave height analyzer and control the multi-channel wave height analyzer, a communication connection can be established between the multi-channel wave height analyzer and a user terminal (e.g., user computer or computer). At this time, the communication method may be USB communication, LAN communication, RS-232, or RS-488 communication.

Next, the output data of the multi-channel wave height analyzer is modified (S1130). The output of the multi-channel wave height analyzer may be composed of channels on the X-axis and coefficients on the Y-axis, as shown in the graph of FIG. 9. The X-axis conversion constant can be set so that the X-axis channel corresponds to the selection voltage candidate. For example, if the voltage range of the ADC of a multi-channel wave height analyzer is 0~10Vdc and the number of channels is 512, the conversion constant can be 10Vdc / 512 Ch = 0.0195 Vdc/Ch. The X-axis channel of the characteristic curve that determines the final analyzer voltage can be multiplied by the corresponding conversion constant to display the X-axis. The value entered in the above equation is only an example and may vary depending on the performance and specifications of the multi-channel wave height analyzer. Modification of output data of the multi-channel wave height analyzer can be performed using the built-in functions of the multi-channel wave height analyzer or using a user terminal connected to it.

Next, calibrate the amplitude of the multi-channel wave height analyzer (S1140). This can be performed by inputting the amplitude correction value into the multi-channel wave height analyzer, using the built-in function of the multi-channel wave height analyzer, or using a user terminal connected to it.

Typically, the wave height selector of an off-air neutron flux monitoring system compares the amplitude of the pulse input from the main amplifier. However, multi-channel wave analyzers may have their own amplification function. In this case, the amplitude of the pulse measured by the multi-channel wave height analyzer is the result of applying self-amplification to the result amplified through the amplifier of the off-road neutron flux monitoring system, so it becomes higher than the amplitude of the pulse actually input to the wave height separator. Therefore, in the case of a multi-channel wave height sorter with its own amplification function, calibration of the measured values is necessary.

Therefore, in order to accurately determine the screening voltage of the wave height separator, it must be converted to the same magnitude as the pulse amplitude input to the wave height separator. This procedure can be performed simply as follows: Using a pulse signal generator or a separate pulse signal generator to check the off-air neutron flux monitoring system, the tester outputs a pulse signal with a certain amplitude to the main amplifier input terminal. The tester measures the amplitude of the pulse at the rear of the main amplifier using an oscilloscope, etc. The tester removes the oscilloscope and connects a multi-channel wave height analyzer to remeasure. At this time, the voltage value of the amplitude of the measured channel is checked using the X-axis conversion constant described above. A correction value can be derived using the simple equation below so that the voltage value of the amplitude confirmed in the multi-channel wave height analyzer becomes the amplitude value measured on the oscilloscope and reflected in the multi-channel wave height analyzer setup program.

Here, the actual pulse amplitude size is a value obtained at the rear of the main amplifier using an oscilloscope, etc., and the measured pulse amplitude size is a value obtained from a multi-channel wave height analyzer.

Among the constants described above, the conversion constant is a value that can be determined in advance because it is a value that depends on the specifications of the multi-channel wave height analyzer, and in the case of the calibration constant, it is a value that depends on the off-road neutron flux monitoring system and the multi-channel wave height analyzer and can be acquired through testing. You can.

Next, the screening voltage can be determined using the set multi-channel wave height analyzer (S1150). Since the multi-channel wave height analyzer has been connected to the off-road neutron flux monitoring system through the previous steps, and the settings of the multi-channel wave height analyzer have been completed, spectrum measurement can be performed through the multi-channel wave height analyzer to generate spectrum data as shown in Figure 9. . Additionally, the measured spectrum data can be converted into the detector characteristic curve 1010 of FIG. 10. In addition, the extension line 1020 can be determined by using the two points corresponding to the noise of the detector characteristic curve 1010, and the screening voltage can be determined by identifying the extension 1020 and the contact value (intercept value) of the X axis. , you can also display the results.

Hereinafter, a method of determining a screening voltage using a screening voltage determining device according to another embodiment will be described. This method includes determining pulse coefficients for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector, and using the pulse coefficient for each channel to remove noise from the electric pulse signal input from the neutron detector. It may be configured to include the step of determining a screening voltage.

The multi-channel analysis can be performed by simultaneously determining whether an amplitude value exists in the electric pulse signal input from the neutron detector for multiple channels.

Additionally, the pulse coefficients for each channel are accumulated to determine the cumulative coefficient value for each channel, and the selection voltage may be determined based on the cumulative coefficient value. Here, a screening voltage characteristic graph may be determined based on the cumulative coefficient value, and the screening voltage may be determined based on the screening voltage characteristic graph.

The selection voltage characteristic graph is shown to the user, two coordinate values on the selection voltage characteristic graph are input from the user, and the selection voltage is calculated using a selection voltage formula representing a straight line connecting the two input coordinate values. can be decided. Here, the X-intercept value of the selection voltage formula may be determined as the selection voltage value.

Hereinafter, a screening voltage determination device according to another embodiment will be described. A screening voltage determination device according to an embodiment includes a multi-channel wave height analyzer that determines the pulse coefficient for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector, and a multi-channel wave height analyzer that determines the pulse coefficient for each channel from the neutron detector. It may include a screening voltage determination unit that determines a screening voltage for removing noise from the input electric pulse signal.

The multi-channel analysis can be performed by simultaneously determining whether an amplitude value exists in the electric pulse signal input from the neutron detector for multiple channels. A cumulative coefficient value for each channel is determined by accumulating the pulse coefficients for each channel, and the selection voltage may be determined based on the cumulative coefficient value. Here, a screening voltage characteristic graph may be determined based on the cumulative coefficient value, and the screening voltage may be determined based on the screening voltage characteristic graph.

The selection voltage characteristic graph is shown to the user, two coordinate values on the selection voltage characteristic graph are input from the user, and the selection voltage is calculated using a selection voltage formula representing a straight line connecting the two input coordinate values. can be decided. Here, the X-intercept value of the selection voltage formula may be determined as the selection voltage value.

Additionally, the channel value of the multi-channel wave height analysis unit may be preprocessed to correspond to a voltage value that can be set as a screening voltage. In addition, the screening voltage determination device further includes an amplifier, and the electric pulse signal applied to the multi-channel wave height analysis unit is amplified through the amplifier, using the output value of the amplifier and the value identified by the multi-channel wave height analysis unit. Thus, calibration of the multi-channel wave height analysis unit can be performed. Calibration can be performed by using a calibration constant using Equation 3 described above.

The devices, systems, and methods of performing the same described in this disclosure may be implemented with hardware components, software components, and/or a combination of hardware components and software components. Additionally, the present disclosure may be provided in the form of a computer program stored in a computer-readable storage medium so as to perform methods of operating devices and systems. Additionally, the present disclosure can be written as a program that can be executed on a computer, and can be implemented in a general-purpose digital computer that operates such a program using a computer-readable storage medium.

Such computer-readable storage media include read-only memory (ROM), random-access memory (RAM), flash memory, CD-ROMs, CD-Rs, CD+Rs, CD-RWs, CD+RWs, and DVD-ROMs. , DVD-Rs, DVD+Rs, DVD-RWs, DVD+RWs, DVD-RAMs, BD-ROMs, BD-Rs, BD-R LTHs, BD-REs, magnetic tapes, floppy disks, magneto-optical data storage devices, It may be an optical data storage device, a hard disk, or a solid-state disk (SSD), capable of storing instructions or software, related data, data files, and data structures, and attached to a processor or computer so that the processor or computer can execute the instructions. It can be any device capable of providing instructions or software, associated data, data files, and data structures.

Although the embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements can be made by those skilled in the art using the basic concept of the present invention as defined in the following claims. The form also falls within the scope of the present invention.

Claims (15)

In the screening voltage determination method using a screening voltage determination device,
Determining pulse coefficients for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector; and
Determining a screening voltage for removing noise from the electric pulse signal input from the neutron detector using the pulse coefficient for each channel,
The cumulative coefficient value for each channel is determined by accumulating the pulse coefficients for each channel,
A screening voltage determination method wherein the screening voltage is determined based on the cumulative coefficient value.
According to paragraph 1,
The multi-channel analysis is a screening voltage determination method performed by simultaneously determining whether an amplitude value exists in an electric pulse signal input from the neutron detector for multiple channels.
delete According to paragraph 1,
A screening voltage characteristic graph is determined based on the cumulative coefficient value,
A screening voltage determination method in which the screening voltage is determined based on the screening voltage characteristic graph.
According to paragraph 4,
The selection voltage characteristic graph is shown to the user,
Receive two coordinate values on the selected voltage characteristic graph from the user,
A selection voltage determination method in which the selection voltage is determined using a selection voltage formula representing a straight line connecting the two input coordinate values.
According to clause 5,
A screening voltage determination method in which the X-intercept value of the screening voltage formula is determined as the screening voltage value.
In the screening voltage determination device,
A multi-channel wave height analysis unit that determines pulse coefficients for each channel by applying multi-channel analysis to the electric pulse signal input from the neutron detector; and
A screening voltage determination unit that determines a screening voltage for removing noise from the electric pulse signal input from the neutron detector using the pulse coefficient for each channel,
The cumulative coefficient value for each channel is determined by accumulating the pulse coefficients for each channel,
A screening voltage determination device wherein the screening voltage is determined based on the cumulative coefficient value.
In clause 7,
The multi-channel analysis is a screening voltage determination device that is performed by simultaneously determining whether an amplitude value exists in the electric pulse signal input from the neutron detector for multiple channels.
delete In clause 7,
A screening voltage characteristic graph is determined based on the cumulative coefficient value,
A screening voltage determination device wherein the screening voltage is determined based on the screening voltage characteristic graph.
According to clause 10,
The selection voltage characteristic graph is shown to the user,
Receive two coordinate values on the selected voltage characteristic graph from the user,
A selection voltage determination device in which the selection voltage is determined using a selection voltage formula representing a straight line connecting the two input coordinate values.
According to clause 11,
A screening voltage determination device in which the X-intercept value of the screening voltage formula is determined as the screening voltage value.
According to clause 12,
A screening voltage determination device in which the channel value of the multi-channel wave height analysis unit is preprocessed to correspond to a voltage value that can be set as a screening voltage.
According to clause 13,
The selection voltage determination device further includes an amplifier,
The electric pulse signal applied to the multi-channel wave height analysis unit is amplified through the amplifier,
A screening voltage determination device in which calibration of the multi-channel wave height analysis unit is performed using the output value of the amplifier and a value identified by the multi-channel wave height analysis unit.
A computer program recorded on a computer-readable recording medium for performing the method of claim 1.