JP2645196B2 - Random pulse measuring device and radiation measuring device provided with the measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random pulse measuring device and a radiation measuring device provided with the measuring device.
In particular, the present invention relates to a random pulse measuring device capable of measuring a counting rate of random pulses from a plurality of input lines and a radiation measuring device provided with the measuring device.

[0002]

2. Description of the Related Art When measuring radiation randomly emitted from a radioactive substance, usually, the radiation is detected by a detector, converted into analog pulses, and then these analog pulses are converted into an A / D converter. To convert to digital pulse,
Radiation measurement is performed by counting the digital pulses.

In order to measure such a random pulse, conventionally, a random pulse measuring device 1 as shown in FIG.
Is used.

A random pulse measuring device 1 converts an analog pulse 4 from a detector (not shown) into a digital pulse 2 by a single channel analyzer (SCA) 5 and converts the converted random pulse 2 into a digital pulse 2. The counter 3 is configured to count.

The counter 3 has a predetermined time set in advance, and measures the count value of the random pulse 2 during the predetermined time so that the count value per unit time, that is, the count rate can be measured. is there.

When measuring radiation, it is sometimes necessary to know how the above-mentioned counting rate changes with time. In such a case, a random pulse measurement as shown in FIG. Apparatus 11 is used.

The random pulse measuring device 11 converts an analog pulse 4 from a detector (not shown) into a digital pulse 2 by the SCA 5, and converts the converted random pulse 2 into a multi-channel scaler (MC).
(Referred to as S) 12.

When the random pulse 2 is actually measured, a multi-channel analyzer (hereinafter referred to as MCA) operable in various measurement modes.
Is often used, but the above-mentioned MCS 12 also uses this MCA
Is generally used.

The MCS 12 previously sets a dwell time, which is the time of one counting operation, and the number of channels, which is the number of repetitions of the counting operation, in a setting unit (not shown) in advance.
The digital pulse 2 is counted over the dwell time, and the counted value is stored in a corresponding address of the memory.

The MCS 12 is configured to repeat the above-described series of operations by the number of channels, and to store the count values corresponding to each channel at different addresses on the memory.

Therefore, the memory requires only an area corresponding to the number of channels, and also requires a header area for storing the number of channels and the number of sweeps for further repeating the entire number of channels.

The count rate of each channel can be easily obtained by dividing each count value stored in the memory by the dwell time, that is, the count time.

FIG. 4 is an example in which 23 count values counted for each dwell time are plotted with a channel plotted on the horizontal axis.

In FIG. 4, the last channel is 24 because the above header area is secured in the first channel, that is, channel 0.

FIG. 4 shows a case where the number of sweeps is set to one.

In the above description, only one input line has been described. However, in radiation measurement, there are many cases where a plurality of input lines are provided.

A case where a plurality of input lines are provided corresponds to, for example, a case where radiation emitted from a plurality of portions of a fuel rod is detected by a plurality of detectors.

Further, even when there is one detector, the case where the analog pulse 4 output from the detector is discriminated into a plurality of pulses and these discriminated pulses are sent to a plurality of input lines is also applicable.

In order to measure the time change of the count rate of the random pulse 4 of each input line in the case where there are a plurality of input lines, the random pulse measuring device 11 and the SCA 5 shown in FIG. Only in parallel.

However, the M of the random pulse measuring device 11
MCA that constitutes CS12 is very expensive,
It is very difficult to arrange the random pulse measuring devices 11 in parallel, especially when the number of input lines is large, due to an increase in space for installing power supply equipment and the like accompanying these MCAs. .

For this reason, conventionally, as shown in FIG.
The random pulse measuring device 21 which uses only one CA and saves cost and space is used.

The random pulse measuring device 21 converts an analog pulse 4 from a detector (not shown) into a digital pulse 2 by the SCA 5, and generates a pulse detection signal in the router 22 in response to the input of the converted random pulse 2. , And sequentially generates the generated pulse detection signals in a multiple multi-channel scaler (hereinafter referred to as M).
MMCS 23).
Is configured to calculate the count rate of the random pulse 4 for each of the input lines using the pulse detection signal.

The MMCS 23 also generally uses MCA.

The router 22 is provided with the same number of input units as the input lines. When a digital pulse 2 is input to each input unit, each input unit is in a triggered state.

Assuming that the number of input lines is N, for example, N input units of the router 22 are also provided.
It is checked whether or not the trigger has been applied in order from the first input section, in other words, whether or not the digital pulse 2 has been input to the input section. The input state of No. 2 is checked.

The time required to check one input section and the next input section is, for example, about 100 ns.

The router 22 determines whether a certain input unit has been triggered during the above-described examination.
It is determined that the digital pulse 2 has been input to this input unit, and a pulse detection signal is output to the MMCS 23.

The pulse detection signal 23 includes an address signal for specifying the input section and a pulse signal for notifying that the digital signal 2 is present.

The MMCS 23 is provided with a memory for storing the count value of the digital pulse 2 of each input line and an adder circuit.
The count value stored at the input address is called once, the adder circuit adds 1 to the count value to increase the count value by one, and the count value is stored again at the same address.

For example, the time when the router 22 detects that the digital pulse 2 is input to the first input unit and sends the address signal and the pulse signal to the MMCS 23,
The total time T from the so-called add-one cycle until the MMCS 23 adds the count value in response to these signals and stores the added count value in the memory is necessary for the process for counting the digital pulse 2 so to speak. It depends on the arithmetic processing capabilities of the router 22 and the MMCS 23.

In order to measure radiation using the random pulse measuring device 21, randomly emitted radiation is detected by a detector (not shown) and an analog pulse 4 is output. The output analog pulse 4 is output by the SCA 5. Convert to digital pulse 2.

As described above, the plurality of analog pulses 4 in FIG. 5 may be converted electric signals from a plurality of detectors, or may be converted electric signals that are discriminated at the same time from the same detector, for example. There is also.

The converted digital pulse 2 is input to each input unit of the router 22 of the random pulse measuring device 21.

Since the router 22 monitors the input of the digital pulse 2 from the first input unit to the N-th input unit in order, if the input unit that has been turned around is in the trigger state, , And outputs a pulse detection signal to the MMCS 23.

If the number of input lines is, for example, three, and the digital pulse 2 of each input line enters the router 22 at the timing shown in FIG.
3 will now be described.

As described above, each input section of the router 22 is triggered when the digital pulse 2 from the SCA 5 is detected.

The state excited by the trigger is a state in which the digital pulse 2 has already been received but has not been counted by the MMCS 23 yet.
The excited state does not change even if the second digital pulse 2 enters, so the second digital pulse 2 is a state where it is counted down. In this sense, the excited state is insensitive, and this time zone is insensitive. That.

The router 22 first accesses the first input unit and checks whether or not the user is in a dead state.

In FIG. 6, since the digital pulse 2a has been input and is in the insensitive state, the router 22
An address signal notifying that the digital pulse 2a has been input to the second input unit and a pulse signal notifying that the input has been input are sent to the MMCS 23.

When the address signal and the pulse signal are input, the MMCS 23 once calls the count value stored in the input address, and adds one to the count value by an adding circuit to increase the count value by one. , Is stored again at the same address.

The time from when the router 22 detects that the first input unit is in the insensitive state until the counting process of the MMCS 23 ends is T as described above.

On the other hand, the insensitive state of the first input unit immediately returns to the original state, that is, the state in which no trigger is applied after the insensitive state is detected.

The digital pulse 2a of the first input section is input to the second input section, and the digital pulse 2b is input a short while after the input section is in a dead state.

However, as can be seen from FIG. 6, when the digital pulse 2b is input, the MMCS 23 is still in the stage of counting the digital pulse 2a.
The insensitive state of the second input unit continues until the counting process of the digital pulse 2a ends. After the count processing of the digital pulse 2a is completed, the router 22 detects that the second input unit is in the insensitive state, and as described above,
23, an address signal and a pulse signal are sent.

The same processing is performed on the digital pulse 2c input to the third input section. When the router 22 finishes the processing sequentially from the first to the third, it returns to the first again to determine whether or not there is a dead state.

The first input section receives a digital pulse 2a
Although the digital pulse 11d is input immediately after the input of the MMCS, at this time, the MMCS 23 is in a dead state because the digital pulse 11a is still being counted.

Further, since the router 22 sequentially checks from the first to the third whether or not the digital pulse 2 has been input, the above-mentioned insensitive state is,
This will continue until the first input section is turned again.

That is, in the worst case, the length of the dead time is almost equal to the time T multiplied by the number of channels.

In the case shown in FIG. 6, the digital pulse 2 input to each input unit is transmitted to the MMCS2 through the router 22.
According to 3, all were counted and no countdown occurred.

[0050]

However, the following problems occur when the counting rate is large, in other words, as shown in FIG. 7, when the digital pulse 2 comes in rapidly in a short time.

Even in such a state, the conventional random pulse measuring device 21 operates in the same manner as described above.

That is, the MMCS 23 and the router 22
Performs a counting process in response to the digital pulse 2a,
Subsequently, a counting process is performed in response to the digital pulses 2b and 2c.

Then, returning to the first input section, the digital pulses 2d, 2e and 2f are counted again.

However, for example, in the second input unit, the dead state in response to the digital pulse
The digital pulse that has just entered the digital pulse 2b immediately after the end of the counting process of the digital pulse 2a jumps in this insensitive state, so that the digital pulse is not counted by the MMCS 23 but is counted down. I will.

Similarly, for example, in the third input section, the dead state in response to the digital pulse 2c continues until the counting process of the digital pulses 2a and 2b in the MMCS 23 is completed, and immediately after the digital pulse 2c, 3 The three digital pulses are not counted by the MMCS 23 but are counted down because one digital pulse jumps in the insensitive state.

As described above, since the digital pulse 2 hatched in FIG. 7 jumps into each input section in the insensitive state, it is all counted down.

Therefore, the router 22 and the MMCS2
Due to the counting processing time T in 3, the dead time occurs in each input unit of the router, and the counting accuracy of the MMCS 23 becomes extremely low.

Further, since the dead state or dead time affects each input unit, it is extremely difficult to estimate the number of digital pulses that would have been input during the dead time by stochastic processing. .

The present invention has been made in consideration of the above-mentioned circumstances, and enables digital pulses of a plurality of input lines to be provided for each input line and not to be counted down while enabling low cost and space saving. It is an object of the present invention to provide a random pulse measuring device capable of counting and a radiation measuring device provided with the measuring device.

[0060]

In order to achieve the above object, a random pulse measuring apparatus according to the present invention comprises a plurality of input lines and the same number of pulse generators as the input lines. To the respective pulse generators, the respective pulse generators send correction pulses to the router in response to the random pulses, and the router responds to the correction pulses in response to the pulses. The detection signal is sequentially sent to the MMCS, and the MMCS is configured to count the count rate of the correction pulse for each of the input lines in response to the pulse detection signal, and to change the pulse width of the correction pulse. A dead time setting unit for setting a predetermined dead time τ such that the counting rate measured by the MMCS is not affected by the dead time of the router. By adjusting each of the pulse generation units using the dead time τ and correcting the count rate of the correction pulse by the correction unit using the dead time τ, the true value of the random pulse of each of the input lines is corrected. The counting rate can be calculated for each input line.

Further, the radiation measuring apparatus according to the present invention is described in claim 2.
As described in the paragraph, the detector detects radiation and outputs a random pulse, inputs the random pulse to a plurality of input lines, and counts the input random pulses to convert the radiation into each of the input lines. In the radiation measuring device configured to be able to measure, the same number of pulse generators as the plurality of input lines are provided and random pulses from the respective input lines are input to the respective pulse generators, and the respective pulse generators are The router sends a correction pulse to the router in response to each of the random pulses, the router sequentially sends a pulse detection signal to the MMCS in response to the correction pulse, and the MMCS responds to the pulse detection signal in response to the pulse detection signal. The counting rate of the correction pulse is configured to be counted for each of the input lines, and the pulse width of the correction pulse is set to the MM. A dead time setting unit that sets a predetermined dead time τ such that the counting rate measured in S is not affected by the dead time of the router is provided, and the respective pulse generators are adjusted using the dead time τ. In addition, by correcting the count rate of the correction pulse by the correction unit using the dead time τ, the true count rate of the random pulse of each input line can be calculated for each input line. It is provided with a random pulse measuring device.

[0062]

[Action] Dead time τ when a random pulse is input
Is generated by the pulse generator, the correction pulse is counted by the MMCS, and the counted count rate is corrected by the dead time τ to obtain a true count rate. With this configuration, it is possible to count the random pulses of a plurality of input lines for each input line without counting down, while enabling low cost and space saving.

By providing the random pulse measuring device having the above-described configuration in the radiation measuring device, it is possible to count the radiation radiated at random for each input line without counting down.

[0064]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a random pulse measuring apparatus according to the present invention and a radiation measuring apparatus provided with the measuring apparatus will be described below with reference to the accompanying drawings.

The same parts as those of the prior art are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows a schematic configuration example of the random pulse measuring device 31 of the present embodiment.

The random pulse measuring device 31 of the present embodiment
Converts an analog random pulse 4 from a plurality of input lines sent from a detector (not shown) into a digital pulse 2 by the SCA 5.

Further, the random pulse measuring device 31 of this embodiment has the same number of pulse generators 32 as a plurality of input lines.
And the random pulse 2 from each input line is input to each pulse generator 32, and each pulse generator 32 sends a correction pulse 34 to the router 22 in response to each random pulse 2.
To be sent to

The router 22 sequentially sends a pulse detection signal to the MMCS 23 in response to the correction pulse 34,
The MCS 23 is configured to count the count rate of the correction pulse 34 for each input line in response to the pulse detection signal.

Further, the random pulse measuring device 31 of this embodiment sets the pulse width of the correction pulse 34 to the MMCS 23
There is provided a dead time setting unit 33 for setting a predetermined dead time τ such that the counting rate measured by the above is not affected by the dead time of the router 22.

The random pulse measuring device 31 adjusts each pulse generating section 32 using the dead time τ, and corrects the counting rate of the correction pulse 34 by the correcting section 35 using the dead time τ. Thus, the true count rate of the digital pulse 2 of each input line can be calculated for each input line.

The router has the same number of input units as input lines, and if the number of input lines is N, the number of input units is also N.

As described in the related art, the router 22 has a dead time due to the time T determined from the arithmetic processing capability of the MMCS 23 for each input unit.

That is, the digital pulse 2 _h is first input to, for example, the k-th input section of the router 22, is immediately processed, and returns from the trigger state to the original state. In this state, the next digital pulse 2 _i is _generated. It is assumed that input has been made.

Since the router 22 processes each input section in order after processing the k-th section, it takes a considerable time to return to the k-th input section.

The considerable time is defined as the time T required for processing the digital pulse 2 _{h at} the k-th input section, (k +
1) to the last Nth and from the first to (k-
1) This is the time obtained by adding the time required for processing the digital pulse input to the first input unit.

Since the time required for the counting process of each input unit is T, if a digital pulse is input to all of the N input units, the k-th input unit takes approximately NT time. You have to wait, which is the maximum dead time.

Therefore, the digital pulse 2 _i is processed after the elapse of the maximum dead time N · T and is counted by the MMCS 23, but the k-th input from the input of the digital pulse 2 _i to the elapse of the maximum dead time. All digital pulses that enter the section are ignored and no longer counted.

However, considering this in reverse, the router 22
If the time interval of the digital pulse 2 input to each input unit of the router 22 is always equal to or longer than the maximum dead time, the digital pulses input to each input unit of the router 22 can be counted without being counted down. Recognize.

The dead time setting section 33 is configured to obtain the dead time τ of each pulse generating section 32 based on the maximum dead time NT described above.

However, since the above-mentioned maximum dead time was obtained on the assumption that digital pulses were input to all the other input units before the turn to the input unit of interest again, the actual maximum dead time was actually obtained. The maximum dead time is shorter.

Therefore, the dead time setting section 33 sets N ·
In consideration of not only T but also an analysis result simulating an experimental state that may actually occur, each pulse generator 32
Is set to set the dead time τ.

Therefore, the MMCS 23 does not count the digital pulse 2 actually input to each input line, but counts the correction pulse 34 having the dead time τ.

The dead time setting section 33 may be configured so that the operator can directly input the dead time τ via an input device (not shown), or to input information from the processing capability data of the MMCS 23 or the router 22 or the above-described simulation data. It may be configured to automatically evaluate the dead time τ by using this.

The pulse generating section 32 includes a dead time setting section 33
The internal circuit is adjusted so that the output pulse width becomes τ by using τ obtained in (1).

The pulse generator 32 is preferably a retriggerable monostable multivibrator.
For example, TC74HC123AP manufactured by Toshiba is commercially available.

The correction unit 35 corrects the count rate of the correction pulse 34 output from the MMCS 23 by the dead time τ.

That is, the count rate observed in the experiment is expressed as λ
(Here, it corresponds to the count rate of the correction pulse 34), ρ is the true count rate (here, it corresponds to the count rate of the digital pulse 2), and τ is the dead time. Can be.

[0089]

Λ = ρ × EXP (−τ · ρ) (1)

Therefore, if the dead time τ and the count rate λ are known, the true count rate ρ, ie, the digital pulse 2
Can be obtained for each input line.

However, ρ cannot be easily solved from equation (1) and must be calculated by an iterative method.

In the conventional random pulse measuring device 21 shown in FIG. 5, since the dead time at each input section of the router 22 influences each other as described in the prior art, the MMCS2
Using the count rate of the digital pulse 2 of each input line output by 3, it was not possible to stochastically infer the actual count rate taking into account the digital pulse 2 that would have entered the dead time. .

However, in the present embodiment, a pulse generator 32 is provided for each input line, and a correction pulse having a pulse width of a dead time τ not affected by the dead time of the router 22 is provided from the pulse generator 32. 34, the correction pulse 34 is counted by the MMCS 23, and the count rate of the correction pulse 34 is corrected by the dead time τ to obtain the true count rate.

In other words, since the dead time occurring in the router influences each input line, it is impossible to specify the dead time of each input line. Although it is impossible to calculate the counting rate of the clock, if the dead time can be specified for each input line and the dead time does not occur in the router, the final counting rate will be the presence of the dead time. , The final count rate can be used to evaluate the true count rate stochastically.

Hereinafter, a procedure for measuring radiation using the random pulse measuring device 31 of this embodiment will be described.

The analog random pulse 4 sent from the detector or the like is digitized by the SCA 5 and sent to the pulse generator 32.

Each of the pulse generators 32 outputs the digital pulse 2
Is sent to the router 22, the correction pulse 34 having a pulse width of the dead time τ.

When the correction pulse 34 is sent from the pulse generator 32 to the router 22, a trigger is applied to the corresponding input of the router 22, and the router 22 becomes insensitive.

This is the same for any input line.

On the other hand, the router 22 checks the presence / absence of the input of the correction pulse 34 in order from the first input unit. A detection signal is generated, and this pulse detection signal, that is, an address signal and a pulse signal
Send to 23.

The MMCS 23 receiving these signals performs a counting process for the k-th input section.

After the counting process is completed, that is, k
After a lapse of time T from when the router 22 confirms that the second input unit is in the input state until the count value is stored,
The router 22 performs the same processing for the next input unit.

Here, the pulse generator 32 connected to each input unit of the router 22 sets the pulse width to the dead time τ, and the dead time τ is set to a value exceeding the maximum dead time N · T. , All the input units are in the input state before returning to the k-th input unit, and it takes N · T time to count them, and the k-th input unit has an N · T dead time. Even if this is the case, no new correction pulse 34 is input to the k-th input section during this dead time.

However, since a state in which the trigger is applied to all the input units hardly occurs at almost the same time,
In practice, a value smaller than N · T is sufficient for the dead time τ as described above.

As described above, the correction pulse 34 is not counted down at the stage of the router 22.

The count rate of the correction pulse 34 for each input line is calculated by the MMCS 23 and then sent to the correction unit 35.

The correction unit 35 calculates the true count rate for each input line based on the equation (1), and then outputs it to a memory, a printer, or the like, or displays it on a monitor.

When the random pulse measuring device 31 of this embodiment is used for a radiation measuring device, the digital pulse 2 for each input line obtained by the random pulse measuring device 31 is used.
From the true count rate, the radiation entering each detector can be measured while considering the characteristics of the SCA or the detector.

The random pulse measuring device 31 of the present embodiment
Uses a retriggerable monostable multivibrator for the pulse generator 32,
Is configured to perform the correction based on the expression (1).

However, an ordinary monostable multivibrator may be used for the pulse generator 32.

When a monostable multivibrator is used, the count rate observed in the experiment is λ (corresponding to the count rate of the correction pulse 34), and the true count rate is ρ.
Assuming that the dead time is τ (corresponding to the counting rate of the digital pulse 2 here), the following approximate expression can be generally used.

[0112]

Λ = ρ / (1 + τ · ρ) (2)

Therefore, if the dead time τ and the count rate λ are known, the true count rate ρ, ie, the digital pulse 2
Can be obtained for each input line.

A monostable multivibrator is:
For example, TC74HC221AP manufactured by Toshiba is preferably used.

Since the random pulse measuring apparatus of the present embodiment is premised on the input of the analog pulse 4, the SCA
Although SCA5 is provided, it is not necessary to provide SCA5 if a digital pulse is directly input.

[0116]

As described above, the random pulse measuring apparatus according to the present invention is provided with the same number of pulse generators as the plurality of input lines, and inputs the random pulses from the respective input lines to the respective pulse generators. Each of the pulse generators sends a correction pulse to a router in response to each of the random pulses, and the router sequentially sends a pulse detection signal to the MMCS in response to the correction pulse. The correction pulse count rate is configured to be counted for each input line in response to a pulse detection signal, and the pulse width of the correction pulse is determined by counting the count rate measured by the MMCS to the router. A dead time setting unit for setting a predetermined dead time τ not affected by the dead time is provided, and the respective pulse generators are adjusted using the dead time τ. In addition, the true counting rate of the random pulse of each input line can be calculated for each input line by correcting the counting rate of the correction pulse by the correcting unit using the dead time τ. In addition, random pulses of a plurality of input lines can be counted for each input line and without counting down while enabling low cost and space saving.

Further, the radiation measuring apparatus of the present invention detects the radiation with the detector, outputs a random pulse, inputs the random pulse to a plurality of input lines, and counts the input random pulse. In a radiation measuring apparatus configured to be capable of measuring radiation for each of the input lines, the same number of pulse generators as the plurality of input lines are provided, and random pulses from the respective input lines are input to the respective pulse generators, Each of the pulse generators sends a correction pulse to a router in response to each of the random pulses, and the router sequentially sends a pulse detection signal to the MMCS in response to the correction pulse. The correction pulse counting rate is counted for each of the input lines in response to the detection signal, and the correction pulse is counted. A dead time setting unit that sets the pulse width of the clock as a predetermined dead time τ such that the counting rate measured by the MMCS is not affected by the dead time of the router, and using the dead time τ The true count rate of the random pulse of each input line is corrected by adjusting each of the pulse generation units and correcting the count rate of the correction pulse by the correction unit using the dead time τ. Equipped with a random pulse measuring device that can calculate each time, it enables low cost and space saving, and counts the radiation entering multiple input lines for each input line without counting down. can do.

The random pulse measuring device of the present invention can be applied to all cases where the random pulses are counted in an environment where random pulses are input from a plurality of input lines.

Therefore, the random pulse measuring device of the present invention is not limited to application to a radiation measuring device, but can also be applied to an electric pulse counter and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram of a random pulse measuring device according to the present embodiment.

FIG. 2 is a block diagram showing an example of a conventional random pulse measuring device.

FIG. 3 is a block diagram showing another example of a conventional random pulse measuring device.

FIG. 4 is a graph in which the result of measuring a random pulse by the conventional random pulse measuring device shown in FIG. 3 is plotted.

FIG. 5 is a block diagram showing still another example of the conventional random pulse measuring device.

6 is a diagram showing an example in which random pulses having a low counting rate are counted by the conventional random pulse measuring device shown in FIG.

FIG. 7 is a diagram showing an example of counting random pulses with a high counting rate by the conventional random pulse measuring device shown in FIG.

[Explanation of symbols]

 5 SCA 22 Router 23 MMCS 31 Random pulse measuring device 32 Pulse generator 33 Dead time setting unit 35 Correction unit

Claims (2)

(57) [Claims] A plurality of input lines and a number of pulse generators provided to input random pulses from said input lines to said respective pulse generators, said respective pulse generators responding to said respective random pulses; The router sends a correction pulse to the router, the router sequentially sends a pulse detection signal to the MMCS in response to the correction pulse, and the MMCS calculates the counting rate of the correction pulse in response to the pulse detection signal. The configuration is such that counting is performed for each input line, and the pulse width of the correction pulse is defined as a predetermined dead time τ such that the counting rate measured by the MMCS is not affected by the dead time of the router. A dead time setting unit to be set is provided, and each of the pulse generation units is adjusted using the dead time τ, and the correction pulse is adjusted using the dead time τ. A random pulse measuring device wherein the true counting rate of the random pulse of each input line can be calculated for each input line by correcting the counting rate by a correction unit. 2. Detecting radiation with a detector, outputting a random pulse, inputting the random pulse to a plurality of input lines, and counting the input random pulse, the radiation is applied to each of the input lines. In the radiation measurement device configured to be capable of measurement, the same number of pulse generators as the plurality of input lines are provided, and random pulses from the respective input lines are input to the respective pulse generators, and the respective pulse generators are Sending a correction pulse to the router in response to each random pulse, the router sequentially sending a pulse detection signal to the MMCS in response to the correction pulse,
The MMCS is configured to count a count rate of the correction pulse for each of the input lines in response to the pulse detection signal, and to calculate a pulse width of the correction pulse by the counting measured by the MMCS. A predetermined dead time τ such that the rate is not affected by the dead time of the router
Providing a dead time setting unit to set each pulse generating unit using the dead time τ and correcting the count rate of the correction pulse by the correcting unit using the dead time τ. A radiation pulse measuring device comprising: a random pulse measuring device configured to calculate a true count rate of the random pulse of each input line for each input line.