JPH02163688A - Multinuclide separation type radiation measuring device - Google Patents

Abstract

PURPOSE:To satisfactorily execute multinuclide separation measurement by providing a multichannel waveheight analyzing circuit and a recording part to store multinuclide energy spectrum data. CONSTITUTION:A multinuclide separation type radiation measuring device is composed of a detector 10 to detect radiation, multichannel waveheight analyzing circuit 18, counting circuit 20, storing part 22 and control part 24. Radiation measurement is executed in the circuit 18 by using an (n)-types of nuclide standard sample, for which the possibility of separation measurement is left, and the energy spectrum data is recorded. Next, when the plural nuclides to be separately measured is designated, the control part 24 reads the energy spectrum data from the storing part 22 and the coefficient value of another nuclide mixture rate, which is a correcting value, is calculated. When the radiation quantity of a certain nuclide is separately measured, the channel is selected by the circuit 18, however, the correcting value is simultaneously calculated and outputted as well. Thus, this arithmetic of the correcting value is automatically executed by selecting and designating the plural nuclide to be separately measured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a multi-nuclide separation type radiation measuring device, particularly in the field of analysis/inspection and environmental measurement, which separates the radiation dose of multiple nuclides for each nuclide. This invention relates to a multi-nuclide separation type radiation measuring device for measurement.

[Prior art] In in vivo and in vitro tests, many types of nuclides (
By measuring the amount or behavioral state of specific nuclides, for example, blood component tests and in-vivo function tests are performed.Also, for environmental pollution measurements, radioactive materials from nuclear facilities, etc. are used. The radiation of multiple nuclides present in the released liquid and air is being measured and monitored.

FIG. 3 shows the circuit of this type of conventional device,
A single pulse height analysis circuit 12 is connected to a detection unit 10 that detects radiation emitted from each nuclide. In this example, it is possible to separately measure three nuclides A, B, and C, and for this purpose, the three windows (channels) are set to match the radiation energy of the nuclides A, B, and C. single wave height analysis circuits 12a, 12b, 12
C is provided.

This single pulse height analysis circuit 12 is provided with three counting circuits 14a, 14b, and 14c, and each counting circuit 14 measures the radiation of each nuclide.

In this case, since the radiation of the nuclide to be measured is mixed with the radiation of other nuclides, it is necessary to correct the measured value, and this correction is performed by the microcomputer control section 16.

That is, before the actual measurement, a standard sample of the three nuclides is prepared, a pre-measurement is performed for each nuclide for correction, and in this pre-measurement, the mixing ratio of each nuclide is determined by the microcomputer control unit 16. Calculate and memorize. Then, the count values obtained by each counting circuit 14 are corrected based on this mixing ratio. Note that conventionally, there are devices for measuring 5 nuclides in addition to the 3-nuclides Katsura.

In this way, the radiation of multiple nuclides can be separated and accurately determined for each nuclide, which can be used for various tests on animals, humans, etc., and for monitoring environmental contamination of soil, vegetables, fruits, fish, etc. be able to.

[Problems to be Solved by the Invention] However, conventional devices can only separate 3 or 5 nuclides, which limits the number of nuclides that can be separated and measured, and it is difficult to separate and measure many nuclides. had the following inconveniences:

That is, in the microcomputer control section 16,
Only the correction values calculated by calculating the mixing ratio of other nuclides for each of the 3 or 5 nuclides that are known in advance are stored, so when measuring nuclides other than the 3 or 5 nuclides that have been selected, a new Correction values must be memorized and set for the nuclides combined.

Furthermore, in this case, standard samples (radiation sources) for all the nuclides to be newly combined must be prepared, which is a problem in that the work is complicated and the frequency of handling the radiation sources increases.

Purpose of the Invention The present invention has been made in view of the above-mentioned conventional problems.The purpose of the present invention is to eliminate the limitation of measurable nuclides, easily perform separate measurements of many nuclides, and to be able to perform corrections for It is an object of the present invention to provide a multi-nuclide separation type radiation measurement device that can reduce the degree of use of a necessary radiation source.

[Means for Solving the Problems] In order to achieve the above object, multi-nuclide separation type radiation according to the present invention! ! j! The measurement device includes a detector that detects radiation;
A multichannel wave height analysis circuit that analyzes the wave height of radiation of various energies incident on this detector in multiple channels, a counting circuit that measures radiation through this multichannel wave height analysis circuit, and multiple nuclides measured using a standard sample. A storage unit that stores energy spectrum data, and a mixture ratio of the radiation dose of other nuclides mixed into the measured value of the separated measurement nuclide is calculated from the energy spectrum data of multiple nuclides input to this storage unit, and the above-mentioned count is calculated based on this mixture ratio. The present invention is characterized in that it includes a control unit that corrects a measured value of the circuit.

[Operation: According to the above configuration, radiation is first measured by a multi-channel pulse height analysis circuit using a standard sample of n nuclides that may be separated and measured, and the energy vector is measured]
・Store the file data in the storage unit.

Next, if you specify multiple nuclides to be separated and measured,
The control unit reads the energy spectrum data (count values) of specified other nuclides for each nuclide from the storage unit, and uses this data to calculate the coefficient value of the other nuclide mixing ratio, which is a correction value, for each nuclide to be separated and measured. Calculate.

When separately measuring the radiation dose of a certain nuclide,
A channel (window) for measuring the nuclide is selected in the multi-channel wave height analysis circuit, but at the same time, a correction value for the radiation dose of this nuclide is also calculated and output. This is automatically performed by selecting and specifying multiple nuclides to be separated and measured.

[Embodiment j] Hereinafter, a preferred embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a circuit schematically showing a multi-nuclide separation type radiation measuring device. are applicable.

This detector 10 includes a multichannel pulse height analysis circuit 1
This multi-channel pulse height analysis circuit 18 is capable of detecting radiation in all energy ranges, and has tens or hundreds of channels in which energy is divided into predetermined widths. Therefore, when measuring radiation of a predetermined nuclide, it is sufficient to select a channel width corresponding to the energy width thereof, and by changing the channel width, it is possible to satisfactorily determine the radiation dose of multiple nuclides.

A counting circuit 20, a storage section 22, and a control section 24 are connected to the multichannel pulse height analysis circuit 18, and the control section 24 controls the counting circuit 20 and the storage section 22. First, radiation measurement is performed for each energy by the counting circuit 20 using a standard sample of multiple nuclides, and the energy spectrum data of the multiple nuclides obtained thereby is stored in the storage unit 22.

At the same time, the control unit 24 automatically performs control to correct the radiation dose of other nuclides mixed into the measured value of the separated and measured nuclide based on the energy spectrum data. That is, a theoretical formula regarding multiple nuclides to be separated and measured is calculated based on the energy spectrum data, and the mixing ratio of other nuclides to the nuclides to be separated and measured is determined. Then, a correction coefficient value is calculated from this mixing ratio, and a process is performed in which this correction coefficient value is multiplied by the measured value obtained by the counting circuit 2°. Note that this control section 24 also controls channel width selection of the multichannel pulse height analysis circuit 18.

The control section 24 and the storage section 22 can be replaced by a personal computer having a CRT display. Accordingly, the storage section 22 can be a floppy sheet, and data files can be stored on this, and the data can be displayed on the screen. The operator can calculate the mixing ratio while looking at the data.

The embodiment has the above configuration, and its operation will be explained below.

First, a pre-measurement is performed to input energy spectrum data in advance for the standard Zambuflu (radiation source) of n nuclides that may be measured, and the energy spectrum data obtained in this pre-measurement is stored in the storage unit 22. Filed.

In this way, if you memorize the data for n nuclides, you can store the data for new nuclides in the same manner as before.
Standard samples are not used when making the determination.

Figure 2 shows energy spectra for three nuclides: A nuclide (e.g. 125I), B nuclide (e.g. I), and C nuclide (e.g. 60Co), and the energy spectra are memorized by measuring standard samples. That will happen. According to this, radiation of the B nuclide mixes into the i01 constant channel width 100A of the A nuclide, radiation of the A nuclide mixes into the measurement channel width 100B of the B nuclide, and furthermore, the radiation of the A nuclide mixes into the 11111 constant channel width 100C of the C nuclide. It is understood that radiation of A and B nuclides is mixed in.

When performing separate measurements, you will need to specify multiple nuclides to be separated and measured.
The control unit 24 reads the energy spectrum data of other nuclides in the channel width (multichannel pulse height analysis circuit 18) set for each nuclide from the pig stored in the storage unit 22. Then, based on this energy spectrum data, the mixing ratio of other nuclides in the measurement channel width of the nuclide to be separated and measured is calculated, and this mixing ratio calculation is performed for all the specified nuclides.

In this way, the correction coefficient for the nuclide to be separated and measured is derived from the mixing ratio of other nuclides, and this correction coefficient is set for each nuclide.

In the case of Figure 2 above, for the A nuclide, the correction coefficient corresponds to the mixing ratio of the B nuclide radiation, for the B nuclide, the correction coefficient corresponds to the mixing ratio of the A nuclide radiation, and for the C nuclide, the correction coefficient corresponds to the mixing ratio of the A and B nuclide. A correction coefficient corresponding to the mixing ratio of radiation is set.

Therefore, if we perform separation 1 (Pj determination) for each nuclide,
The radiation dose corrected for the influence of other nuclides is determined n1, and separation measurements can be performed satisfactorily.

[Effects of the Invention] As explained above, according to the present invention, the present invention includes a multi-channel pulse height analysis circuit and a storage section that stores energy spectrum data of a large number of nuclides, and specifies a signal based on the stored energy spectrum data. M 1 (II
Since the radiation of other nuclides mixed into the radiometer dpj value of each nuclide for fixed nuclides is corrected, it is possible to eliminate the limitation of nuclides that can be quantified, and it is possible to perform separate measurements of many nuclides effectively. It becomes possible to do so.

Furthermore, if the energy spectrum data is stored as a p+ constant in the standard sample, it is possible to easily calculate and set the mixing ratio (correction coefficient) for a nuclide group based on a new combination. Therefore, it is possible to reduce the frequency of use of a standard sample, which is a radiation source, which is necessary when performing separate measurements on new nuclides as in the past, and it is also possible to reduce radiation exposure as much as possible.

[Brief explanation of the drawing]

@Figure 1 is a circuit block diagram schematically showing an embodiment of the multi-nuclide separation type radiation 3Pj determination device according to the present invention, and FIG. 2 is a graph diagram showing the energy spectrum of multiple nuclides stored in the device of FIG. 1. FIG. 3 is a circuit block diagram schematically showing a conventional device. 10...Detector 12...Single pulse height analysis circuit 14.20...Counting circuit 1G...Microcomputer control section 18...
Multi-channel pulse height analysis circuit 22... Storage section 24... Control section.

Claims (1)

[Claims] (1) A detector that detects radiation, a multichannel wave height analysis circuit that analyzes the wave height of radiation of various energies incident on the detector in multiple channels, and a counting circuit that measures radiation via this multichannel wave height analysis circuit. a storage unit that stores energy spectrum data of multiple nuclides measured using standard samples; and a storage unit that stores energy spectrum data of multiple nuclides input to this storage unit, and determines the radiation dose of other nuclides mixed into the measured value of the separated measurement nuclide. A multi-nuclide separation type radiation measuring device, comprising: a control section that calculates a mixing ratio and corrects the measurement value of the counting circuit based on the mixing ratio.