JP2018054468A - Radiation measurement apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a spectrum corresponding to a dose rate having undergone a time constant process to be displayed, in a radiation measuring device such as a survey meter.SOLUTION: A dose rate D(n) is obtained by multiplying a spectrum (original spectrum) S(n,i) by a G(E) function, and undergoes a time constant process. A dose rate Dτ(n) having undergone the time constant process is displayed. The spectrum S(n,i) also undergoes the time constant process. A spectrum Sτ(n,i) having undergone the time constant process is displayed. Two time constant processes are executed in accordance with the same time constant τ. Instead of the time constant process, a movement average process can be applied. A spectrum after the multiplication of the G(E) function may undergo the time constant process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radiation measurement apparatus and method, and more particularly to processing of an energy spectrum.

  Various devices such as survey meters, monitoring posts, and personal dosimeters are known as radiation measuring devices. For example, a survey meter is used in measuring a dose rate from an object. Specifically, in the survey meter, an energy spectrum (hereinafter simply referred to as “spectrum”) is generated based on a detection signal obtained by detecting radiation. The spectrum is composed of a plurality of count values corresponding to a plurality of energy channels. The spectrum is multiplied by a G (E) function, that is, a plurality of count values are multiplied by a plurality of correction coefficients, and a dose rate is obtained as the sum of the multiplication results (the unit is, for example, Sv / h or Gy / h). Various functions are known as G (E) functions. In the survey meter, a specific G (E) function corresponding to the dose rate to be obtained and the energy characteristic of the detector is stored. The G (E) function can also be called an energy correction function or an energy compensation function.

  Generally, since the dose rate changes drastically with time, the dose rate subjected to the time constant processing is displayed for display for the convenience of reading. The time constant process is a process having an integral action, and is a smoothing process in the time axis direction. If the time constant is increased, the displayed dose rate usually changes slowly. Conversely, if the time constant is reduced, the displayed dose rate usually changes quickly. That is, the response speed (statistical accuracy and readability) can be changed by operating the time constant. Examples of other smoothing processes include a moving average process.

  Some survey meters display spectra. In such a survey meter, when the start button is operated in a state where the measurement time is preset, a count value (integrated value) is obtained for each energy channel. After the measurement time has elapsed, a spectrum that is a distribution of a plurality of count values is displayed in non-real time. It is also possible to display the spectrum in the growth process until the end of the measurement time. However, a radiation measurement apparatus that displays in real time a spectrum that dynamically changes while performing radiation measurement (increase / decrease in the count rate for each energy channel) has not yet been realized.

  Patent Document 1 describes a radiation measurement device for confirming the soundness of a steam generator in a nuclear reactor facility. In such an apparatus, a low energy count rate and a high energy count rate are required based on the spectrum. It seems that time constant processing is applied to the high energy count rate. However, Patent Document 1 does not describe time constant processing for the spectrum itself.

JP 2014-2335014 A

  An object of the present invention is to generate a spectrum that dynamically changes and whose response can be manipulated. Alternatively, when displaying a measurement value that has been smoothed while performing radiation measurement, a spectrum that matches the measurement value is displayed. Alternatively, a new display mode of a spectrum subjected to time constant processing is realized.

  The radiation measuring apparatus according to the present invention includes a spectrum generating means for generating a spectrum based on a signal obtained by detecting radiation, and a smoothing process in the time axis direction for the count value for each energy channel in the spectrum. Spectrum smoothing means for applying and thereby generating a smoothed spectrum.

  According to the above configuration, a smoothed spectrum is generated by the smoothing process on the spectrum. In the smoothed spectrum, the count value dynamically changes for each energy channel as the energy distribution of the detected radiation changes over time (the count value is the count result for each energy channel, and the concept is counting Rate, dose, dose rate, etc.). The count value for each energy channel not only increases but also decreases. The smoothing process is a process of smoothing the change in the count value in units of energy channels, and is, for example, a time constant process for the count value, a moving average process, or the like. According to the display of the smoothed spectrum, it is easier to read the form as compared to the case where the instantaneous spectrum that changes every moment is displayed as it is. The smoothed spectrum is a new display mode, and is expected to be used or applied in the future. When time constant processing is employed as the smoothing processing, the smoothed spectrum is a time constant processed spectrum. The smoothed spectrum is usually displayed as it is, but it may be displayed after being processed. The smoothed spectrum may be stored in memory. The spectrum read from the memory may be smoothed.

  The spectrum is preferably generated by a multi-channel analyzer (MCA). It usually has hundreds or thousands of energy channels. Alternatively, a plurality of count values corresponding to a plurality of energy channels may be obtained by using a plurality of wave height discriminators or the like, and thereby a virtual spectrum may be configured. In that case, for example, three or more energy channels, preferably 10 or more energy channels are set.

  Desirably, it includes means for calculating a smoothed dose rate based on the spectrum, and the time condition for calculating the smoothed dose rate is the same as the time condition for generating the smoothed spectrum. The time condition for performing the time constant process is a time constant, and the time condition for performing the moving average process is a moving average period.

  Preferably, the smoothed dose rate is a dose rate after time constant processing, the smoothing processing is time constant processing, the smoothed spectrum is a spectrum after time constant processing, and the smoothed dose rate is The time constant that is the time condition for the calculation and the time constant that is the time condition for generating the smoothed spectrum are the same. According to this configuration, it is possible to simultaneously display the time constant processed spectrum together with the time constant processed dose rate. In that case, since the same time constant is used in the two time constant processes, the responsiveness of both can be made uniform, and a spectrum suitable for the displayed dose rate can be displayed. In other words, a dose rate suitable for the displayed spectrum can be displayed. That is, a certain consistency can be given to the relationship between the numerical value and the waveform.

  Preferably, the spectrum generating means includes means for generating an original spectrum based on the signal, and means for generating a corrected spectrum by applying a G (E) function to the original spectrum, The spectrum smoothing unit generates a smoothed corrected spectrum as the smoothed spectrum by applying the smoothing process to the corrected spectrum. Instead of performing time constant processing on the dose rate calculated by applying the G (E) function to the original spectrum, time constant processing is performed on the original spectrum, and thereby obtained. A time constant processed dose rate may be obtained by applying a G (E) function to the time constant processed spectrum. That is, the order of time constant processing and application of the G (E) function may be switched.

  Preferably, the display includes a display that displays the corrected spectrum, a graph showing the G (E) function, and one or more display elements selected from the smoothed spectrum. It should be noted that the display of the graph indicating the G (E) function and the display of the spectrum multiplied by the G (E) function are understood to be independent features that are not allowed in conventional devices.

  Preferably, it includes means for generating a bar graph composed of a plurality of bars whose heights change based on the smoothed spectrum. In this configuration, a smoothed spectrum is processed to generate a bar graph. In the first place, the spectrum can be said to be a bar graph, but each bar here corresponds to an energy class, that is, multiple energy channels, and the bar height is the sum or average of multiple counts in each energy class. Corresponding to If the time constant is relatively small and the change in the smoothed spectrum is relatively severe, or if you want to capture the distribution of the count rate roughly across the energy axis, express the smoothed spectrum as a bar graph. For example, the spectrum can be moderated by effectively smoothing or averaging the energy direction.

  The radiation measurement method according to the present invention includes a step of generating a spectrum composed of a plurality of count values corresponding to a plurality of energy channels based on a signal obtained by detection of radiation, and a time axis direction for the plurality of count values. The method includes generating a time constant processed spectrum by time constant processing and displaying the time constant processed spectrum while detecting the radiation.

  Preferably, the method includes a step of calculating a time constant processed dose rate by time constant processing in a time axis direction with respect to a dose rate calculated based on the spectrum, the time constant processed dose rate and the time constant processed spectrum Are displayed at the same time. Preferably, the same time constant is used for the time constant processing for the spectrum and the time constant processing for the dose rate.

  You may make it implement | achieve the said method by the function of a program. Such a program is installed in an information processing apparatus that processes radiation measurement data via a portable storage medium or a network. Such an information processing apparatus can be considered as a kind of radiation measurement apparatus.

  According to the present invention, it is possible to display a spectrum that is a dynamically changing spectrum and whose responsiveness can be manipulated. Alternatively, it is possible to display a spectrum having a mode suitable for the case where the calculation value subjected to the smoothing process is displayed while performing the radiation measurement. Alternatively, a new display mode of a spectrum subjected to time constant processing can be realized.

1 is a block diagram showing a first embodiment of a radiation measuring apparatus according to the present invention. It is a figure for demonstrating a time constant process. It is a figure which shows an example of the spectrum after a time constant process. It is a figure which shows the change of a display content. It is a block diagram which shows the principal part of 2nd Embodiment. It is a figure which shows the multiplication of a G (E) function. It is a block diagram which shows the principal part of 3rd Embodiment. It is a figure which shows the example of a display in case a moving average process is applied. It is a figure which shows the bar graph produced | generated from the spectrum after a time constant process. It is a figure which shows application of a some time constant.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

(1) First Embodiment FIG. 1 shows a first embodiment of a radiation measuring apparatus according to the present invention. This radiation measuring apparatus is, for example, a survey meter. It is a portable device that measures radiation from an object, environmental radiation, and the like. The present invention may be applied to other radiation measurement apparatuses. The radiation measured in this embodiment is gamma rays. Other radiation may be measured.

  In FIG. 1, the survey meter includes a detector 10, a signal processing circuit 12, and a calculation unit 14. In the figure, illustration of a battery and a power supply unit is omitted. The computing unit 14 is preferably composed of one or more processors that perform a program operation. All or part of the calculation unit 14 may be configured by an information processing device (computer).

  In this embodiment, the detector 10 includes a scintillator 16 and a photomultiplier tube 18. The scintillator 16 is made of a material that generates scintillation light by the incidence of γ rays. The scintillation light is detected by a photomultiplier tube 18 as a photodetector. An electrical signal (charge signal or current signal) is output from the photomultiplier tube 18. A high voltage is applied to the photomultiplier tube 18 for its operation. A semiconductor detector or the like may be used as the detector 10. As the detector 10, it is desirable to use a detector that generates an electrical signal corresponding to radiation energy.

  The signal processing circuit 12 includes a preamplifier 20, a waveform shaping circuit 22, and an A / D converter 24 in the illustrated example. Still other circuits may be provided. In the signal processing circuit 12, the input electric signal is amplified by the preamplifier 20, and a detection pulse is output from the preamplifier 20. The detected pulse is processed in the waveform shaping circuit 22. The waveform shaping circuit 22 may be configured by a shaping amplifier. The analog output pulse of the waveform shaping circuit 22 is converted into digital data representing the peak value (amplitude value) by the A / D converter 24. The digital data is sent to the calculation unit 14. In the present embodiment, the calculation unit 14 constitutes the main body of the survey meter, and the detector 10 and the signal processing circuit 12 constitute a portable probe in the survey meter. The main body and the probe are connected by a cable. The main functions of the calculation unit 14 may be provided on the probe side.

  The individual blocks constituting the calculation unit 14 are realized by software functions in this embodiment. Each block may be constituted by a dedicated processor that performs its function. The MCA (multi-channel analyzer) 26 functions as a spectrum generation unit. Specifically, counting is performed for each individual energy channel based on the input digital data string. In the MCA 26, a spectrum (energy spectrum) S (n, i) is generated. Here, n represents time (or an index indicating a display order to be described later), and i represents an energy channel. The spectrum S (n, i) generated at each time can also be referred to as an instantaneous spectrum or an original spectrum. For example, the spectrum S (n, i) is sequentially generated every second. Data representing this is sent to the dose rate calculation unit 30 and the time constant processing unit 38. Since the spectrum S (n, i) is generated every unit time, the count value for each energy channel constituting the spectrum S (n, i) can be considered as a count rate.

  The time constant setting unit 34 functions as time constant setting means. The time constant setting unit 34 is a module that sets a time constant τ as a parameter to be given to the time constant processing units 36 and 38. The time constant τ may be set based on user designation, or the time constant τ may be adaptively automatically set according to some condition such as a standard deviation or a dispersion value obtained from a spectrum. The time constant process is a process for obtaining an output value by performing a time constant operation on an input value.

  The dose rate calculation unit 30 functions as a dose rate calculation means. Specifically, the spectrum S (n, i) is multiplied by the G (E) function (coefficient sequence) stored in the memory 32, and the dose rate D (i) is obtained as the sum of the multiplication results. It is. The dose rate D (i) calculated from the instantaneous spectrum S (n, i) can also be referred to as the instantaneous dose rate. A plurality of functions may be applied to the spectrum S (n, i) stepwise for energy compensation and energy correction.

  The time constant processing unit 36 functions as first time constant processing means for dose rate. Specifically, the input dose rate D (n) is subjected to time constant processing according to the time constant τ, and the time constant processed dose rate Dτ (n) is calculated. The time constant process is a process with an integral action, and the time constant processed dose rate Dτ (n) can be said to be a dose rate smoothed in time. A calculation formula representing the time constant processing will be described later. Data indicating the time constant processed dose rate Dτ (n) is sent to the display 42 via the display processing unit 40. The display processing unit 40 has an image synthesis function and the like, and has a function of generating an image to be displayed on the screen of the display 42.

  The time constant processing unit 38 functions as a second time constant processing unit for spectrum. The time constant processing unit 38 performs time constant processing on the input spectrum S (n, i) to generate a time constant processed spectrum Sτ (n, i). It can also be referred to as a smoothed spectrum. Specifically, a time constant process is performed on the count value for each energy channel in the spectrum S (n, i). The time constant process is a smoothing process in the time axis direction as described above. The time constant as the time condition in the time constant processing for the spectrum is the same as the time constant as the time condition in the time constant processing for the dose rate, and both are τ. Data representing the time constant processed spectrum Sτ (n, i) is sent to the display 42 via the display processing unit 40. A modification in which the time constants used in the two time constant processes are different is also conceivable.

  The display 42 is constituted by a liquid crystal display, for example. On the display 42, the time constant processed dose rate Dτ (n) as a numerical display and the time constant processed spectrum Sτ (n, i) as a waveform display are displayed simultaneously and in real time. The time constant processed dose rate Dτ (n) increases and decreases with time, and its responsiveness depends on the time constant τ. Similarly, the count value of each energy channel in the time constant processed spectrum Sτ (n, i) also increases and decreases with time, and its responsiveness depends on the time constant τ.

  Increasing the time constant τ delays the time response, and the displayed dose rate Dτ (n)) and spectrum Sτ (n, i) change relatively slowly. If the time constant is reduced, the time response is accelerated, and the displayed dose rate Dτ (n) and spectrum Sτ (n, i) change relatively quickly. Since a common time constant is used for the two time constant processes, the responsiveness of numerical display and waveform display can be made uniform. It is also possible to display a correct spectrum in a sense corresponding to the displayed dose rate. The display update rate is 1 second, for example. You may comprise so that a display update rate can be variably set.

  As will be described later, a moving average process may be used instead of the time constant process. The concept of smoothing processing includes time constant processing, moving average processing, and the like. The concept of moving average processing includes weighted moving average processing. Other smoothing processes may be used. Although not shown in FIG. 1, a memory for storing a spectrum and a dose rate is provided. You may make it perform a time constant process with respect to the spectrum and dose rate which were read from memory. For example, a plurality of instantaneous spectra may be stored in a memory in time series order and read out sequentially to calculate and display a spectrum and dose rate processed by time constant.

  FIG. 2 shows the function of the time constant. The horizontal axis is the time axis, and the vertical axis indicates the dose rate as the indicated value. In the original waveform before the time constant processing, the dose rate changes stepwise. Reference numeral 44 indicates a time constant processing result when the time constant is 3 seconds, and reference numeral 46 indicates a time constant processing result when the time constant is 30 seconds. Reading accuracy is improved by lengthening (increasing) the time constant. Further, the change of the indicated value can be quickly read by shortening (decreasing) the time constant. These are advantages obtained in the same way in the time constant processed spectrum display described below.

  FIG. 3 shows a display example in the survey meter. The display example includes a time constant processed spectrum 48, a time constant processed dose rate 50, and a time constant indicator 52. The time constant indicator 52 represents a common time constant applied in the time constant processing of the dose rate and the time constant processing of the spectrum. It is a fixed value or a variable value. While the radiation measurement is performed, the dynamically changing display content is observed. If the instantaneous spectrum is displayed as it is, its form usually changes drastically, so that it is difficult to read it, but according to the present embodiment, the spectrum 48 after time constant processing is displayed. So easy to read. The responsiveness of the spectrum 48 and the responsiveness of the dose rate 50 are aligned, and when both are observed at the same time, there is no sense of incongruity caused by a relative time shift. In such a meaning, it is possible to display numerical values and waveforms that have a correct relationship in terms of time. Incidentally, the vertical axis in the time constant processed spectrum 48 in FIG. 3 is the count rate. It is possible to make it another unit.

  Note that a display mode for displaying only one of the time constant processed spectrum 48 and the time constant processed dose rate 50 may be provided. Further, a display mode for displaying the instantaneous spectrum and the instantaneous dose rate before performing the time constant processing may be provided. Furthermore, a mode for enlarging and displaying a part of the spectrum 48 may be provided.

  FIG. 4 illustrates a change in display content. When the dose rate becomes high while maintaining the time constant, the display content 54 changes to the display content 56. On the other hand, when the time constant is switched in a situation where the dose rate does not change, the display content 54 changes to the display content 58.

  Hereinafter, the time constant processing in the time constant processing unit 36 and the time constant processing unit 38 shown in FIG. 1 will be further described using mathematical expressions.

For example, the following equation is used in the time constant processing (time constant calculation) for the dose rate:

  Here, n is an index indicating the order (time, display order), D (n) represents the instantaneous dose rate (the unit is, for example, Sv / h or Gy / h), and dT (n) is the instantaneous It is a measurement time for obtaining a spectrum (for example, 1 second), τ is a time constant (unit is second), and Dτ (n) is an nth time constant processed dose rate. X is a weight.

On the other hand, in the time constant processing (time constant calculation) for the spectrum, for example, the following equation is used.

  Here, i is an energy channel, and S (n, i) represents the n-th instantaneous spectrum, specifically, a count value for each energy channel i counted per unit time (which is actually For example, counting rate [s-1]). τ ′ is a time constant, and Sτ (n, i) represents a time constant processed spectrum, specifically, a time constant processed count value for each energy channel i displayed n-th. X ′ is a weight.

  In obtaining the time constant processed dose rate, the order of the multiplication of the G (E) function (energy compensation function) and the time constant processing can be switched.

This will be described below. As described with reference to FIG. 1, D (n) is the sum of the results of multiplying the instantaneous spectrum S (n, i) (that is, the count value sequence) by the G (E) function (that is, the coefficient sequence). Defined. That is, it is as follows.

  Time constant processing based on the above equation (1) is performed on D (n), and a time constant processed dose rate Dτ (n) is obtained.

On the other hand, D ′ (n) below is a time constant processed dose rate obtained by multiplying the already described time constant processed spectrum Sτ (n, i) by the G (E) function.

When the above D (n) is expanded using Equations (1), (2), (3), and (4), the result is as follows.
Here, X = X ′ and τ = τ ′ are assumed.

  In the above equation (5), if Dτ (0) = D'τ (0) = 0, Dτ (1) = D'τ (1) when n = 1, and for any n, Dτ (n) = Dτ '(n) holds. Although the configuration of FIG. 1 is for obtaining Dτ, the configuration may be modified to obtain D′ τ. That is, the time constant-calculated spectrum Sτ (n, i) output from the time constant processing unit 38 in FIG. 1 is input to the dose rate calculation unit, and the time constant processed dose rate D′ τ is obtained as its output. It may be. In the case of adopting such a configuration, there is an advantage that a single time constant processing unit may be provided. Of course, when the time delay in the calculation becomes a problem, it is desirable to adopt the configuration shown in FIG.

(2) Second Embodiment FIG. 5 shows a second embodiment. The same reference numerals are given to the same components as those shown in FIG. 1, and the description thereof is omitted. In FIG. 5, the detector and the signal processing circuit are not shown. Hereinafter, the calculation unit 14A will be described.

  In the second embodiment, a spectrum processing unit 60 is added in the calculation unit 14A. It is a kind of spectrum generating means in the sense of generating a spectrum to be subjected to time constant processing. Specifically, the spectrum processing unit 60 is a waveform calculator that multiplies the instantaneous spectrum S (n, i) by a G (E) function. The already explained dose rate calculation unit 30 has a function of multiplying the instantaneous spectrum S (n, i) by the G (E) function and a function of obtaining the sum of the multiplication results, and only the former function is provided. It is also possible to understand that what is provided is the spectrum processing unit 60. Therefore, the dose rate calculation unit 30 can also be used as the spectrum processing unit 60.

  A spectrum S ′ (n, i) after correction (after compensation) is output from the spectrum processing unit 60. The spectrum S ′ (n, i) is sent to the time constant processing unit 62 and the display processing unit 40. The time constant processing unit 62 performs time constant processing on the input corrected spectrum S ′ (n, i), and generates the result. This is displayed on the display 42.

  In the second embodiment, the display unit 42 can also display a graph representing the corrected instantaneous spectrum S ′ (n, i) and G (E) function before the time constant processing. By observing them, information based on the displayed dose rate and spectrum can be confirmed. It is desirable that the display element to be displayed can be selected by the user in accordance with the measurement purpose and usage status. The instantaneous spectrum S (n, i) and the spectrum Sτ (n, i) before correction subjected to time constant processing may be displayed. The corrected spectrum S′τ (n, i) subjected to time constant processing is obtained by multiplying the spectrum Sτ (n, i) subjected to time constant processing by the G (E) function. Also good.

  FIG. 6 schematically shows a process of obtaining a corrected spectrum 68 by applying a G (E) function 66 to the instantaneous spectrum 64. The vertical axis of the corrected spectrum 68 represents the dose rate for each energy channel. In the second embodiment, it is possible to display a corrected spectrum 68, a G (E) function (actually a graph representing the function) 66, and the like. Of course, it is also possible to display a corrected spectrum that has been subjected to time constant processing and generated by performing time constant processing on the corrected spectrum 68.

(3) Third Embodiment FIG. 7 shows a third embodiment. The same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. Also in FIG. 7, the detector and the signal processing circuit are not shown.

  In the calculation unit 14B of the third embodiment, a moving average processing unit 70 for dose rate is provided instead of the time constant processing unit for dose rate, and the spectrum is replaced with the time constant processing unit for spectrum. A moving average processing unit 72 is provided. The average period setting unit 73 sets an average period t that is commonly used in two moving average processes. The average period t is designated by the user or automatically set. The average period t may be dynamically variably set. Also in the third embodiment, a common time condition is set in the two smoothing processes, and specifically, a common average period is set in the two moving average processes.

  Also in the third embodiment, since the temporally smoothed spectrum is displayed, it is possible to facilitate the reading thereof. That is, it is possible to select a spectrum display that prioritizes temporal response and a spectrum display that prioritizes readability. In particular, when displaying a smoothed spectrum and a smoothed dose rate, it is possible to make both responsiveness uniform and to match both in time.

  FIG. 8 shows a display example in the third embodiment. On the display screen, a moving average processed spectrum 75, a moving average processed dose rate 74 and an average period indicator 76 are displayed. Note that the concept of moving average processing includes weighted moving average processing and the like.

(4) Description of Modified Examples As shown in FIG. 9, a bar graph 78 may be generated based on the smoothed spectrum and displayed. The horizontal axis of the bar graph 78 represents the energy of radiation, and the vertical axis of the bar graph 78 represents the count value (counting rate). The entire energy range is divided into a plurality of sections. The bar graph 78 includes a plurality of bars 78a corresponding to a plurality of sections. Each bar 78a corresponds to a plurality of energy channels, and the height of each bar 78a represents the sum or average of a plurality of count values counted in the plurality of energy channels.

  According to such a display of the bar graph 78, the same advantages as those obtained by reducing the energy resolution can be obtained. That is, since the change in the count rate averaged for each section is displayed, it becomes easy to read the change in the count rate over the entire energy. If you want to read detailed changes, you can select spectral display. In addition, you may comprise so that the magnitude | size of an area can be variably set. When the energy increment in the multi-channel analyzer can be variably set, the display mode shown in FIG. 9 can be easily realized by adjusting the increment. Other graphs (a line graph, a voiceprint chart, etc.) may be displayed instead of the bar graph. Further, a three-dimensional smoothed spectrum may be displayed by adding a time axis to the smoothed spectrum.

  As shown in FIG. 10, a plurality of different time constants τ1, τ2 may be applied to the plurality of energy ranges 80, 82. For example, a time constant smaller than other energy ranges may be set for an energy range of particular interest. However, when performing such processing, it is desirable to employ a display format that allows the user to recognize the time constant applied to each energy range.

  According to each embodiment described above, real-time display of a smoothed dose and spectrum can be realized while measuring radiation. By displaying not only the smoothed dose but also the smoothed spectrum, the target radiation can be analyzed from the viewpoint of energy. By changing the time condition such as the time constant, it is possible to realize measurement giving priority to statistical accuracy or responsiveness. In addition, after measuring by designating measurement time, you may comprise so that the dose and spectrum smoothed based on the measurement data may be displayed. The configuration of each embodiment may be applied to a radiation measurement device (for example, a monitoring post or a dust monitor) other than the survey meter.

10 detectors, 12 signal processing circuits, 14 calculation units, 26 MCA (multichannel analyzer), 30 dose rate calculation units, 34 time constant setting units, 36 time constant processing units, 38 time constant processing units.

Claims (11)

Spectrum generating means for generating a spectrum based on a signal obtained by detection of radiation;
Spectrum smoothing means for applying a smoothing process in the time axis direction to the count value for each energy channel in the spectrum, thereby generating a smoothed spectrum;
A radiation measuring apparatus comprising: The apparatus of claim 1.
Means for calculating a smoothed dose rate based on the spectrum;
The time condition for calculating the smoothed dose rate and the time condition for generating the smoothed spectrum are the same.
A radiation measuring apparatus characterized by that. The apparatus of claim 2.
The smoothed dose rate is the dose rate after time constant processing,
The smoothing process is a time constant process,
The smoothed spectrum is a spectrum after time constant processing,
The time constant that is the time condition for calculating the smoothed dose rate and the time constant that is the time condition for generating the smoothed spectrum are the same.
A radiation measuring apparatus characterized by that. The apparatus of claim 2.
A display for displaying the smoothed dose rate and the smoothed spectrum;
A radiation measuring apparatus characterized by that. The apparatus of claim 1.
The spectrum generating means includes
Means for generating an original spectrum based on the signal;
Means for generating a corrected spectrum by applying a G (E) function to the original spectrum;
Including
The spectrum smoothing unit generates a smoothed corrected spectrum as the smoothed spectrum by applying the smoothing process to the corrected spectrum.
A radiation measuring apparatus characterized by that. The apparatus of claim 5.
A display that displays the corrected spectrum, a graph showing the G (E) function, and one or more display elements selected from the smoothed spectrum;
A radiation measuring apparatus characterized by that. The apparatus of claim 1.
Means for generating a bar graph comprising a plurality of bars of varying heights based on the smoothed spectrum;
A radiation measuring apparatus characterized by that. The apparatus of claim 1.
The smoothing process is a time constant process or a moving average process.
A radiation measuring apparatus characterized by that. Generating a spectrum composed of a plurality of count values corresponding to a plurality of energy channels based on a signal obtained by detection of radiation; and
Generating a time constant processed spectrum by time constant processing in the time axis direction for the plurality of count values;
Displaying the time constant processed spectrum while detecting the radiation;
A radiation measurement method comprising: The method of claim 9, wherein
Furthermore, a step of calculating a time constant processed dose rate by a time constant processing in a time axis direction with respect to a dose rate calculated based on the spectrum,
In the displaying step, the time constant processed dose rate and the time constant processed spectrum are displayed simultaneously.
The radiation measuring method characterized by the above-mentioned. The method of claim 10, wherein:
The same time constant is used in the time constant processing for the spectrum and the time constant processing for the dose rate,
The radiation measuring method characterized by the above-mentioned.