JPS6223269B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gamma ray pulse height spectrum analysis processing method, and in particular, a gamma ray pulse height spectrum analysis method suitable for use when continuously measuring and analyzing gamma ray pulse height spectra online using a computer. This relates to a wave height analysis processing method.

An example of a conventional method of this type is shown in FIG. A pulse signal processing system that processes pulse signals from the line detector 1; 3 a multiplex wave height analyzer connected to the pulse signal processing system 2; 4 a central processing unit of a computer including memory (hereinafter referred to as a computer); ), 5 is an output device of the computer 4, and this output device 5 is a device for outputting the analysis processing results, such as a system typewriter, line printer, or magnetic tape device.
The multiple wave height analyzer 3 and the output device 5 are connected to the computer 4 online.

On the other hand, the computer 4 includes a controller 4a that controls the operation mode of the multiplex wave height analyzer 3, a buffer area 4b that uses a specific area of memory to store the spectrum data transferred from the multiplex wave height analyzer 3, and Batsuhua area 4
The buffer area 4c includes a spectrum analysis processing section 4c for analyzing the spectrum data stored in the buffer area 4b and a buffer area 4d similar to the buffer area 4b for storing analysis results.

The operation of the device configured in this way will be explained. First, gamma ray information is converted into a pulse electric signal by the gamma ray detector 1, and the output thereof is converted by the pulse signal processing system 2 into a pulse waveform suitable for measuring the gamma ray pulse height spectrum. The number and peak value of these pulses correspond to the number and energy of gamma rays emitted. Then, this γ-ray pulse is accumulated in the memory of the multiple pulse height analyzer 3 for a certain period of time from the start of the measurement to the stop of the measurement. Here, the memory of this multiple pulse height analyzer 3 is divided into multiple channels according to the pulse height value (for Ge (Li) detector, normally 2048 to 8192 channels are used). The frequency of input pulses is stored for each channel in correspondence with . In this way, what is obtained by integrating for a certain period of time is the γ-ray pulse height spectrum, which consists of the measurement or integration time and the count value for each channel. This spectrum has a gentle distribution (baseline) with a steep slope, as shown in Figure 2, which is an explanatory diagram showing an example of γ-ray pulse height spectrum data, with the number of channels on the horizontal axis and the count value on the vertical axis. It is characterized by a mixture of peaks. In FIG. 2, A indicates the baseline, B indicates the detected peak, C indicates the peak below the detection limit, and D indicates the baseline statistical error.

The γ-ray pulse height spectrum data in the memory of the multiplex pulse height analyzer 3 is transferred online to the computer 4 and analyzed, and the analysis results are outputted by the output device 5.

Next, the operation of this computer 4 will be explained. This computer 4 controls, by a built-in controller 4a, the start and stop of measurement by the multiplex pulse height analyzer 3, the transfer of the γ-ray pulse height spectrum data in the memory to the computer, and the erasure of the data in the memory after the transfer. In the case of continuous measurement, the above series of operations is repeated. The spectrum data transferred to the computer 4 is stored in the buffer area 4b, and the spectrum analysis processing unit 4c calculates the channel position of the peak in the spectrum and the total count value, and calculates the gamma ray energy, intensity, and nuclide that emits the gamma ray. Calculate the amount and concentration of each. Here, the presence or absence of a peak is determined by comparing the statistical error between the peak count value and the baseline count value in the vicinity thereof. The analysis processing results obtained in this way are stored in the buffer area 4d.

However, since the conventional method is configured as described above, in order to increase the sensitivity and accuracy of peak detection, multiple wave height Although the measurement time of the analyzer must be lengthened,
In this case, the analysis results obtained are average values over a long period of time, which has the disadvantage that short-term fluctuations in the amount or concentration of each nuclide cannot be ascertained.

In view of the above points, the present invention was made to solve such problems.The purpose of the present invention is to be able to analyze both short-time wave height spectrum data and long-time integrated spectrum data, and to analyze nuclide in a short time. It is an object of the present invention to provide a gamma ray pulse height spectrum analysis processing method that can perform highly sensitive nuclide analysis over a long period of time while monitoring fluctuations in the amount or concentration.

In order to achieve the objective in this way, the present invention
Means for creating long-term integrated spectrum data by repeatedly integrating short-time wave height spectral data read at fixed intervals for a specified number of times, and integrating spectral data instead of analyzing wave height spectral data every time repeated integration is completed. The central processing unit is equipped with a means for performing an analysis process, and is capable of analyzing both short-time wave height spectral data and long-time integrated spectral data. An example will be explained in detail.

FIG. 3 is a block diagram showing an embodiment of the gamma ray pulse height spectrum analysis processing method according to the present invention. In FIG. 3, the same numbers as in FIG. 1 indicate corresponding parts, 4e is an adder, 4f is a buffer area similar to 4b for storing long-term integrated spectrum data, and 4g is a short-time wave height spectrum. A selector is used to specify which of the buffer area 4b that stores data and the buffer area 4f that stores the long-term integrated spectrum data is to be analyzed. After repeating the analysis process for a specified number of times, it is provided with a function to select and control whether or not to analyze and process the long-term integrated spectrum data in the buffer area 4f.

Next, the operation of the embodiment shown in FIG. 3 will be explained. First, from the γ-ray detector 1 to the pulse signal processing system 2
The waveform conversion and integration operations of the system leading to the multiplex wave height analyzer 3 via the waveform converter 3 are the same as in FIG. 1, and therefore their explanations will be omitted here.

Now, the present invention is implemented as follows.
The short-time wave height spectrum data stored in the buffer area 4b is added for each channel to the immediately preceding integrated spectrum data already stored in the buffer area 4f by an adder 4e.
The results are updated and stored in buffer area 4f as long-term integrated spectrum data.
This integration is repeated a specified number of times. On the other hand, the wave height spectrum data stored in the buffer area 4b is analyzed in the same manner as in FIG. 1, and the results are outputted via the buffer area 4d, and the spectrum data in the buffer area 4b is erased.

On the other hand, the operation mode controller 4a of the multiple wave height analyzer 3 sends a signal to the selector 4g once for a series of operations that repeat the above control, and this signal is counted and stored in the selector 4g. The above operation is repeated a specified number of times.

When the specified number of times is reached, a command is sent from the selector 4g to the spectrum analysis processing unit 4c, and instead of analyzing the wave height spectrum data from the buffer area 4b, the spectrum analysis processing unit 4c executes the command from the selector 4g. The long-term integrated spectrum data in the buffer area 4f is analyzed. Note that handling of the processing results is the same as in the case of FIG.

With the above processing method, the long-term integrated spectrum data of the buffer area 4f becomes the result of integrating the short-time wave height spectrum data of the buffer area 4b over a specified number of long periods, and the peaks below the detection limit shown in Fig. 2 are integrated over a long period of time. This is a value that is sufficiently detected during spectrum analysis processing.

In the above embodiment, the case where long-term integrated spectrum data is stored in the buffer area 4f of the computer main body was explained as an example.
The present invention is not limited to this, but it is assumed that the data is sequentially stored in the disk memory, and the buffer area 4f is used to add the wave height spectrum data once.
It is also possible to reduce the storage capacity to the amount necessary for the rotation. In this case, when analyzing a long-time integrated spectrum, spectrum data is transferred from the disk memory to the buffer area 4b. In this case, the selector 4g also controls the transfer of long-term integrated spectrum data from the disk memory to the buffer area 4b.

As explained above, according to the present invention, spectral data is integrated inside a computer, and the spectral data integrated over a long period of time can be analyzed separately from the spectral data integrated over a short period of time, so that the following effects can be achieved. is obtained.

That is, first, information regarding short-term changes in the amount or concentration of each nuclide can be obtained, and
The average amount or average concentration of each nuclide over a long period of time can be obtained with high sensitivity. Second, since the results of analyzing and processing spectrum data every short period of time are always output, even if a system abnormality occurs, the missing measurement time can be shortened.

As described above, the present invention has significant effects compared to conventional methods of this type, and is unique as a gamma-ray pulse height spectrum analysis processing method.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing an example of a conventional gamma-ray pulse height spectrum analysis processing method, and Figure 2 is a block diagram showing an example of a conventional gamma-ray pulse height spectrum analysis processing method.
FIG. 3 is a block diagram showing an embodiment of the gamma ray pulse height spectrum analysis processing method according to the present invention. 1...γ-ray detector, 2...pulse signal processing system, 3...
Multiple wave height analyzer, 4...Central processing unit, 4a...Controller, 4b...Buffer area, 4c...Spectrum analysis processing section, 4d...Buffer area, 4e
...Adder, 4f...Buffer area, 4g...Selector, 5...Output device.

Claims (1)

[Claims] 1. The output of the gamma ray detector that measures the gamma ray pulse height spectrum is repeatedly input online as short-time pulse height spectrum data to the central processing unit via the pulse signal processing system and multiple pulse height analyzer, and the central processing unit In the method of continuously analyzing the gamma ray pulse pulse height spectrum by repeatedly processing the wave height spectrum data, the short time wave height spectrum data read at fixed time intervals are repeatedly integrated a specified number of times to obtain long time integrated spectrum data. and a means for performing an analysis process on the integrated spectrum data in place of the analysis process on the wave height spectrum data every time the repeated integration is completed. A gamma ray pulse height spectrum analysis processing method, characterized in that analysis processing can be performed on both integrated spectrum data.