KR101702832B1 - Multi-SCA Data Logger for Radiotracer - Google Patents

Abstract

The present invention relates to an apparatus for collecting and processing detection signals from a plurality of multi-channel radiation detectors.
In the present invention,
A detector control unit for setting a setting for operating the radiation detector and receiving the measurement data from the radiation detector, a data collecting unit for collecting and delivering the measurement data received by the detector control unit, and setting information for operating the radiation detector to the detector control unit A multi-SCA gamma ray radiotracer data acquisition device is disclosed that includes an operation unit that transmits and receives measurement data from a data acquisition unit.
According to the present invention, it is possible to realize an electric collimator function by selectively and simultaneously measuring only the energy of a specific region of the gamma ray energy reaching the detector, and the latest radioisotope engineering application such as multi- It can be used for research on measurement technology.

Description

Multi-SCA Gamma Radiotracer Data Acquisition System Multi-SCA Data Logger for Radiotracer

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus for collecting and processing radiation detection signals, and more particularly, to an apparatus for collecting and processing detection signals classified by energy regions from a plurality of radiation detectors.

It is inevitable to use a number of radiation detectors to detect the flow characteristics of fluids in engineering systems using radioisotopes. Recent trends in related research include analyzing gamma-ray spectra generated by the interaction of gamma rays emitted from radioactive tracers with process fluid media, or identifying and capturing different radionuclides simultaneously to determine the behavior of multi-phase fluids Visible detection techniques are being studied.

Since there is no commercially available gamma ray measurement system that is specially designed for the engineering application of radioisotope tracers, each laboratory has been conducting experiments using a gamma ray detection system developed by itself. However, most of these systems have a single channel analyzer (SCA) type that sets only a specific gamma ray energy region and measures only the detection value corresponding to this region, and it is a multiphase flow measurement system requiring measurement and analysis of a gamma ray spectrum Is very limited in its use.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems described above by providing a gamma ray spectrometer which measures a plurality of gamma-ray spectral data measured every several tens of milliseconds (10-3 second SCA gamma-ray radiotracer data acquisition device capable of collecting and processing radiation.

According to an aspect of the present invention, there is provided a Multi-SCA gamma ray radiotracer data collection apparatus including a detector controller for supplying an operation voltage for operating a radiation detector, and receiving measurement data from the radiation detector, A data collecting unit for collecting and transmitting the measurement data received by the detector control unit and an operation unit for transmitting setting information for operating the radiation detector to the detector control unit and receiving the measurement data from the data collecting unit .

The Multi-SCA gamma ray radiotracer data collection device may include one to nine detector control units, which include an interface unit for connection with the data collection unit, a radiation detector operation unit for receiving the radiation detector operation through the interface unit And a detector connection unit connected to the radiation detector to supply an operation voltage and to receive measurement data. The detector unit may include a detector connected to the radiation detector and configured to operate the radiation detector.

And the detector control may comprise one to four detector connections, the detector connection comprising an HV supply for supplying an operating voltage to the radiation detector, an analog signal processor for processing an analog metrology signal from the radiation detector, And an ADC for converting an output signal of the analog signal processing unit into a digital signal and transmitting the digital signal to the control unit.

According to another aspect of the present invention, there is provided a multi-SCA gamma ray radiotracer data collection method comprising: setting a radiation detector operating voltage; acquiring a gamma spectrum for a radiotracer to be measured; A relative efficiency measurement step of the radiation detector, a data acquisition time interval setting step, and a data acquisition step.

The radiation detector operating voltage setting step may include a step of applying a voltage to the radiation detector that increases by a predetermined magnitude by a predetermined period, measuring a coefficient value for each cycle, and comparing the measured coefficient value have.

In addition, the operation voltage selection step may include a step of extracting a specific interval within which a variation of the count value is within a certain range, and a step of selecting an intermediate value of the applied voltage corresponding to the extracted interval as an operation voltage.

In addition to a physical collimator using a lead shield, it is possible to realize an electrical collimator function by measuring only the energy of a specific region of the gamma ray energy reaching the detector, and it has an effect of realizing the latest radioactive It can be applied to the study of isotopic engineering applications and new technologies. In addition, up to four independent SCA channels can be set for each detector to simultaneously measure radioactive tracers emitting gamma rays of different energies.

It is also possible to quantitatively detect and analyze scattering gamma ray spectral changes due to the chemical composition of the process medium. In addition, for a large number of dozens of detectors, it is possible to automatically set the applied voltage for the photomultiplier tube of the radiation detector, which must be performed for a long time each time according to the change of the cable length and measurement condition, Can be remarkably shortened.

FIG. 1 is a conceptual diagram of a Multi-SCA gamma ray radiotracer data acquisition system including a Multi-SCA gamma ray radiotracer data acquisition apparatus and a plurality of radiation detectors according to an embodiment of the present invention.
2 is a block diagram showing the structure of a detector control unit according to an embodiment of the present invention.
3 is a block diagram showing the configuration of the detector connection portion.
4 is a flowchart illustrating a method of collecting multi-SCA gamma ray radiotracer data according to an exemplary embodiment of the present invention.
Fig. 5 is a view showing an example of a coefficient value depending on the operating voltage HV. Fig.
6 is a flowchart illustrating a method of automatically setting an operating voltage of a radiation detector according to an embodiment of the present invention.
FIG. 7 is a graph showing the energy seen when a predetermined operating voltage is applied to the gamma-ray detector and the count value at each energy step. FIG.
FIG. 8 is a graph showing the gamma spectrum of gamma-ray energy at a measurement time using data measured by the Multi-SCA gamma-ray radiotracer data collection method according to an embodiment of the present invention, And the results of counting gamma rays are shown in time zones.
9 is a view showing an embodiment in which the Multi-SCA gamma ray radiotracer data collection device according to the present invention is applied to measure the flow inside a digestion tank of a sewage treatment facility.

In the following description, well-known functions or constructions are not described in detail to avoid unnecessarily obscuring the subject matter of the present invention.

Although the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, But should be understood to include all modifications, equivalents, and alternatives.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

FIG. 1 is a conceptual diagram of a Multi-SCA gamma ray radiotracer data acquisition system including a Multi-SCA gamma ray radiotracer data acquisition apparatus and a plurality of radiation detectors according to an embodiment of the present invention.

Referring to FIG. 1, the Multi-SCA gamma ray radiotracer data acquisition apparatus 100 is connected to up to 36 radiation detectors 140a to 140d to collect measurement data.

The Multi-SCA gamma ray radiotracer data collection apparatus 100 according to an embodiment of the present invention may include an operation unit 110, a data collection unit 120, and a plurality of detector control units 130a to 130i.

The operation unit 110 performs necessary settings for operation of the Multi-SCA gamma ray radiotracer data acquisition apparatus 100 and transmits necessary signals to the data collection unit 120 and the detector control units 130a to 130i according to the settings have. In addition, the operation unit 110 may process the collected data and extract necessary information. The main functions of the other operation unit 110 include a function of automatically setting a high voltage (HV) plateau of the radiation detectors 140a to 140d and a relative efficiency measurement function, a gamma spectrum acquisition for setting a threshold Function, a multi-single channel analyzer (M-SCA) mode and a multichannel analyzer (MCA) mode setting function according to time.

The data collection unit 120 collects measurement results from the plurality of detector control units 130a to 130i and transmits the measurement results to the operation unit 110. [ At this time, the data collecting unit 120 and the plurality of detector controllers 130a to 130i can perform data communication using the VME bus.

The detector controllers 130a to 130h may output an operating voltage (HV plateau) for the radiation detectors 140a to 140d according to the setting information from the operating unit 110. [ In addition, the detector controllers 130a to 130i may process measured data from the radiation detectors 140a to 140d, convert the measured data into digitized data, and transmit the digitized data to the data collecting unit 120.

2 is a block diagram showing the structure of a detector controller 130a to 130i according to an embodiment of the present invention.

Referring to FIG. 2, the detector controllers 130a to 130i may include a control unit 132, an interface unit 134, and a maximum of four detector connection units 136a to 136d.

The interface unit 134 has a function of transmitting measurement data in connection with the data collecting unit 120 or receiving the setting information of the operating unit 110 via the data collecting unit 120 and delivering it to the control unit 132 can do.

The control unit 132 receives setting information from the operation unit 110 and can set an operation voltage for the radiation detectors 140a to 140d and also has a setting for processing an analog signal from the radiation detectors 140a to 140d can do.

The detector connections 136a through 136d may serve to supply operating voltages to the radiation detectors 140a through 140d and to receive metering data coming from the radiation detectors 140a through 140d.

3 is a block diagram showing the configuration of the detector connection portion.

3, the detector connections 136a through 136d may include an analog signal processor 311, an analog-to-digital converter (ADC) 313, and an HV supplier 315.

The HV supply 315 may supply operating power for the radiation detectors 140a through 140d according to the settings of the operating unit 110. [

The analog signal processing unit 311 may perform filtering and amplification of measurement results from the radiation detectors 140a to 140d.

The ADC 313 may convert the input analog signal into a digital signal and transmit the digital signal to the control unit 132.

The Multi-SCA gamma ray radiotracer data acquisition apparatus 100 according to an exemplary embodiment of the present invention has a maximum of nine detector controllers 130a to 130i and each of the detector controllers 130a to 130i has a maximum of four radiation detectors 140a To 140d. Therefore, the Multi-SCA gamma ray radiotracer data acquisition apparatus 100 can collect measurement data by connecting up to 36 radiation detectors 140a to 140d. Each of the radiation detectors 140a through 140d may generate gamma ray spectral detection data of 1024 channels at least every 10msec.

4 is a flowchart illustrating a method of collecting multi-SCA gamma ray radiotracer data according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the Multi-SCA gamma radiotracer data acquisition apparatus 100 may first set an operation voltage HV to be used by the radiation detectors 140a to 140d (S400).

The NaI (Tl) scintillation detector, which is mainly used for the radioactive tracer experiment, is composed of a NaI (Tl) scintillator for absorbing radiation and a photo multiplier tube for converting light emitted from the scintillator into an electric signal. PMT), and a high voltage can be applied to operate the PMT. However, the measured value may vary depending on the applied operating voltage. In the case of measuring the coefficient value to determine the operating voltage, it can be counted in the entire energy range except the low energy part for electrical noise removal, not only within a specific area of interest.

5 is a diagram showing an example of a coefficient value which varies depending on the operating voltage (HV).

Referring to FIG. 5, as the voltage increases, a coefficient value increases and a plateau 510 where the coefficient value does not change is generated. The operation unit 110 can detect a portion where the coefficient value does not largely change and set the voltage at this time to the operation voltage for the radiation detector. The change of the coefficient value according to the voltage as shown in FIG. 5 is not affected by the kind of the radioactive tracer but is influenced by the measurement efficiency of the radiation detectors 140a to 140d and the cable condition. Therefore, even if the same radioactive tracer is used, The operating voltage must be separately determined for each of the radiation detectors 140a to 140d. However, manual operation of determining the operating voltage of a plurality of radiation detectors becomes a last operation and can be a waste of time in testing in a laboratory. Therefore, in the present invention, the work for determining the operating voltage can be automatically performed.

6 is a flowchart illustrating a method of automatically setting an operating voltage of a radiation detector according to an embodiment of the present invention.

Referring to FIG. 6, the operation unit 110 of the multi-SCA gamma ray radiotracer data acquisition apparatus according to the present invention applies a voltage to a connected radiation detector while increasing the radiation detector by a predetermined period (S610). Then, the coefficient value is measured for each cycle (S620). Finally, the measured voltage value is compared to select the operating voltage (S630). In this case, a criterion for selecting the operating voltage is to extract a specific section within which a variation of the count value is within a certain range (for example, a variation of 0.1%), and an intermediate value of the applied voltage corresponding to the extracted section may be selected as an operating voltage have.

5, assuming that the change amount of the coefficient value between the a voltage 520 and the b voltage 530 is 0.1%, the operation unit 110 may multiply the a voltage and the b voltage section (A + b) / 2, which is an intermediate value between the a voltage and the b voltage, can be selected as the operating voltage.

After setting the radiation detector operating voltage in the above-described manner, the gamma ray spectrum of the energy of the radioactive tracer to be measured is acquired and the region of interest is set (S410).

In radioactive tracer experiments, radioactive isotopes with emission gamma-ray energy and half-life suitable for the experimental environment are selected and used. For example, a radioactivity tracer experiment with a small reactor in a laboratory scale (the material of the reactor is acrylic and the reactor diameter is about 20 cm) can use Tc-99m with 140 keV emission energy and a half-life of 6 hours, The radioactive tracer experiment to measure the flow of the digestion tank is composed of a high-density material such as stainless steel in the outer wall of the digester and piping, and Sc-46 (emitting gamma ray energy of 0.889 and 1.121 MeV And a half-life of 83.8 days).

However, it is necessary to confirm the gamma ray spectrum measured by the radiation detector since each radioisotope emits different energy gamma rays.

7 is a graph showing the energy when the selected operating voltage is applied to the gamma ray detector and the count value at each energy step.

Referring to FIG. 7, a photopeak (710) appears in which the coefficient value is maximized in the vicinity of a specific energy except for the noise region of low energy. Since the photopeak regions shown by each radioisotope may be different when a plurality of radioisotopes are mixed, it is possible to measure various radioisotopes by measuring only the regions corresponding to the photopeak.

Therefore, in this step S410, a gamma ray spectrum showing a coefficient value for the energy of each radioisotope is obtained, and a region including the photopeak 710 is set as a region of interest. In this case, the region of interest may be the number of the gamma energy ranges to be measured (multi-SCA), the threshold value, the size of the energy range to be measured, and the like.

Next, the relative efficiency of the radiation detector can be measured (S430). The luminous efficiency of the scintillator constituting the detector and the operating voltage of the radiation detector are different for each radiation detector and different coefficients can be displayed even if the same radiation source is used. Therefore, by measuring the relative efficiency of the radiation detector and correcting it, accurate data can be obtained. Relative detection efficiency can be measured based on measurements obtained by positioning multiple detectors at the same distance from the radiation source and measuring the radiation signal over a period of time. Alternatively, one of the detectors used in the experiment may be selected, and the measured values of the other detectors may be calculated as a ratio and used as a relative detection efficiency.

Next, the Multi-SCA gamma ray radiotracer data acquisition apparatus can set a data acquire time interval (S440) that requires acquisition of data a plurality of times. This may vary from experiment to experiment. When measuring the flow of fluid moving at high speed, it is possible to measure the radiation every several tens of msec, and when measuring the flow inside the digestion tank of the sewage treatment facility, the radiation can be measured every several minutes.

Finally, measurement data can be acquired (S450).

FIG. 8 is a graph showing the relationship between gamma spectra and gamma-ray spectra of gamma-ray spectra of gamma-ray spectra obtained at a measurement time using data measured by the Multi-SCA gamma-ray radiotracer data collection method according to an embodiment of the present invention. In the time domain.

Referring to FIG. 8, measurement data at a measurement instant is obtained by the Multi-SCA gamma ray radiotracer data collection method described above to obtain a spectrum as shown in FIG. At this time, the x-axis 510 represents measured energy and the y-axis 520 is a value obtained by counting the number of measured gamma rays in a specific energy band. A radiation detector can divide a specific energy range into 1024 channels and count the number of gamma rays entering each channel. The Multi-SCA gamma ray radiotracer data acquisition system can operate up to 36 radiation detectors. In addition, even in the presence of radioactive isotopes that emit radiation of different energies, all radiation signals in the region of interest can be selectively counted. 8 illustrates three areas of interest 830, 840, and 850. In FIG.

Referring to FIG. 8, gamma ray count results (860, 870, 880) corresponding to a specific region of interest may be displayed in a time zone.

9 is a view showing an embodiment in which the Multi-SCA gamma ray radiotracer data collection device according to the present invention is applied to measure the flow inside a digestion tank of a sewage treatment facility.

Referring to FIG. 9, a large number of radiation detectors are required to measure the flow of digestion tank in the sewage treatment facility, and data must be collected while operating the same. The multi-SCA gamma ray radiotracer data collection device according to the present invention can operate up to 36 radiation detectors simultaneously in the above example. At this time, the operating voltage for each radiation detector can be set automatically to greatly reduce the preparation time for the test. It is also possible to measure the flow efficiently and efficiently by setting the same time interval for data acquisition for all connected radiation detectors and simultaneously collecting data from the radiation detector attached to the digester.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Only. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (8)

A Multi-SCA gamma radiotracer data acquisition device for controlling a plurality of radiation detectors and collecting detection data,
A detector controller configured to perform setting for operating the plurality of radiation detectors and to receive measurement data from the plurality of radiation detectors;
A data collector for collecting and transmitting the measurement data received by the detector controller; And
And an operation unit which transmits setting information including an operating voltage for operating each of the plurality of radiation detectors to the detector control unit and receives and processes the measurement data from the data collecting unit,
The operating unit
A control unit configured to control the plurality of radiation detectors to apply a voltage increasing by a predetermined magnitude in a predetermined period,
The measurement data coming from the plurality of radiation detectors is received through the detector control unit for each cycle,
For each of the plurality of radiation detectors, a cycle section in which the change of the measurement data is within a predetermined range,
And setting the operating voltage for each of the plurality of radiation detectors based on the voltage applied in the period.
Multi-SCA gamma ray radio tracer data acquisition device. The multi-SCA gamma radiotracer data collection system of claim 1,
1 to 9 detector controls;
Multi-SCA gamma ray radio tracer data acquisition device. The apparatus according to claim 1,
An interface unit for performing connection with the data collection unit;
A control unit configured to set the radiation detector to operate according to setting information for operating the radiation detector received through the interface unit; And
A detector connection unit connected to the radiation detector for supplying power for operation and receiving measurement data;
A multi-SCA gamma ray radiotracer data acquisition device. The method of claim 3,
Wherein,
Measuring relative detection efficiency between the radiation detectors based on measurement data from a plurality of radiation detectors located at the same distance from the radiation source,
Multi-SCA gamma ray radio tracer data acquisition device. The apparatus according to claim 3,
An HV supply for supplying power to the radiation detector;
An analog signal processing unit for processing an analog measurement signal coming from the radiation detector; And
An ADC for converting an output signal of the analog signal processing unit into a digital signal and transmitting the digital signal to the control unit;
A multi-SCA gamma ray radiotracer data acquisition device. A Multi-SCA gamma radiotracer data acquisition method of a Multi-SCA gamma ray radiotracer data acquisition device for controlling a plurality of radiation detectors and collecting detection data,
An operating voltage setting step for each of the plurality of radiation detectors;
Obtaining a gamma spectrum for a radioactive tracker to be measured and setting a region of interest;
Measuring relative efficiency with respect to each of the plurality of radiation detectors;
A data acquisition time interval setting step; And
Data acquisition step; Lt; / RTI >
Wherein the operating voltage setting step for each of the plurality of radiation detectors comprises:
Applying a voltage to the plurality of radiation detectors, the voltage increasing by a constant magnitude in a predetermined period;
Measuring detection data for each cycle for each of the plurality of radiation detectors; And
Comparing the measured detection data for each of the plurality of radiation detectors with each other, and extracting a period section in which the variation of the detected data for each period is within a predetermined range; And
And setting the operating voltage based on the voltage applied in the extracted period.
Multi-SCA gamma ray radio tracer data collection method. The method according to claim 6,
Measuring a relative efficiency between each of the plurality of radiation detectors,
Positioning the plurality of radiation detectors at the same distance from the radiation source; And
Measuring a relative measurement efficiency of each of the plurality of radiation detectors based on measurement data obtained by measuring a radiation signal for a predetermined period of time;
Wherein the multi-SCA gamma-ray radiotracer data collection method comprises:

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