JPH08248140A - Radiation measuring system - Google Patents

Abstract

PURPOSE: To obtain a radiation measuring system in which photoelectric conversion circuits whose number corresponds to the number of scintillator detectors are not required so as to be made low-cost, which can reduce the time and labor of calibration operation and which can ensure the continuity of measurement. CONSTITUTION: A radiation measuring system comprises a measuring system in which respective optical delay lines 19a1 to 19bs delay respective beams of light so as to be given to photoelectric conversion circuits 13a, 13b at mutually different timings and in which respective delay circuits 16a1 to 16b2 delay outputs of the photoelectric conversion circuits so as to be given to simultaneous counting circuits 17a, 17b at an identical timing. In addition, the radiation measuring system is provided with a plurality of optical fibers 14, for calibration, by which respective scintillator detectors 11a, 11b can be connected individually and by which the beams of light to be outputted from the connected scintillator detectors are transmitted individually and with a plurality of optical delay lines 19, for calibration, by which the beams of light to be transmitted by the respective optical fibers for calibration are delayed individually so as to be sent out to the photoelectric conversion circuits.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation measuring system for measuring radiation according to an optical signal generated by a scintillator detector upon incidence of radiation.

[0002]

2. Description of the Related Art Conventionally, in the field of radiation measurement, a radiation measurement system has been widely used for measuring radiation according to a signal input from a radiation detector upon incidence of radiation.

FIG. 14 is a block diagram showing the configuration of this type of radiation measuring system. In this radiation measurement system, a plurality of radiation detectors 120 including a detection element 121 such as NaI (Tl) and a measurement electronic circuit 122 are individually connected to a signal processing unit 125 via a metal cable 124.

Here, in each radiation detector 123, the radiation energy is converted into an electric signal by the detection element 121 and the measurement electronic circuit 122, and an analog pulse train, a DC current value or a digitally processed signal is passed through the metal cable 124. A detection signal in the form of a pulse train is given to the signal processing unit 125.

The signal processing unit 125 includes the radiation detectors 12
Based on the detection signal received from 3, the radiation energy instruction and alarm output are executed.

Another radiation measuring system of this type uses a multiplex transmission unit. FIG. 15 is a block diagram showing the configuration of such a radiation measurement system. Compared to the system shown in FIG. 14, this radiation measuring system uses a multiplex transmission unit 13 for detecting signals output from each radiation detector 123 via a metal cable 124.
1, the multiplex transmission unit 131 multiplexes each detection signal to the signal processing unit 132 by multiplex transmission.

By the way, for such a radiation measuring system, recently, instead of a radiation detector, a small size, high sensitivity,
Those using a scintillator detector having the advantage of separation from an electric circuit are disclosed in JP-A-3-242590 and JP-A-6-59044. FIG. 16 is a block diagram showing the configuration of such a radiation measurement system. In this radiation measuring system, a plurality of scintillator detectors 11 are individually connected to a signal processing circuit 18 via a measuring optical fiber 12 and a photoelectric conversion circuit 13.

Similarly, a radiation measuring system using the scintillator detector 11 is described in "Atomic Energy Society of Japan""19
94 Spring Annual Meeting "(March 29-31, 1994, at:
Presented at University of Tsukuba (Program number M)
47). In this radiation measuring system, each scintillator detector 11 sends an optical output from each end portion to each optical delay line 19 corresponding to the radiation energy through each measuring optical fiber 12. Each optical delay line 19 delays the optical output and sends it individually to the photoelectric conversion circuit 13,
Each photoelectric conversion circuit 13 photoelectrically converts an optical output into an electric signal and individually sends it to the delay circuit 16.

Each delay circuit 16 delays each electric signal so as to be synchronized with the electric signal sent from the other delay circuit, and sends it to the coincidence counting circuit 17.

When the coincidence counting circuit 17 simultaneously receives the respective electric signals transmitted from the respective delay circuits 16, it outputs a counting output signal to the signal processing circuit 18.

The signal processing circuit 18 outputs a radiation energy instruction or alarm based on the count output signal.

[0012]

However, in the radiation measuring system as described above, when the scintillator detector 11 as shown in FIG. 16 is used in place of the radiation detector 123 of the system shown in FIG. 14, scintillator detection is performed. Since the photoelectric conversion circuit 13 is required in correspondence with the number of the devices 11, there is a problem that the price is greatly increased.

Further, in the system shown in FIG. 14, the detection signal output from the radiation detector 123 is the measurement electronic circuit 1.
Since it is processed at 22, the traceability of the detection sensitivity is secured by the radiation source calibration, and the radiation detector 12
It is possible to calibrate the radiation measurement system by calibrating 3 individual items.

On the other hand, when the scintillator detector 11 is used, the characteristics of the radiation measuring system are determined by combining the characteristics of the scintillator detector 11 and the measuring optical fiber 12, and therefore the radiation of the scintillator detector 11 alone is calibrated. Since the measurement system cannot be calibrated, it is necessary to calibrate the detection sensitivity of the entire radiation measurement system using the radiation source. Therefore, when a significant deviation is found in the calibration work, the scintillator detector 11 and the measuring optical fiber 1
It is necessary to further investigate and adjust which of the two or later measurement systems is abnormal, and the calibration work is troublesome. Further, during the calibration work, it is usually impossible to perform measurement, and there is a problem that the continuity of measurement is impaired.

The present invention has been made in consideration of the above-mentioned circumstances, and the number of photoelectric conversion circuits corresponding to the number of scintillator detectors is not required, the cost can be reduced, and the labor of the calibration work can be reduced. Another object of the present invention is to provide a radiation measurement system capable of ensuring the continuity of measurement.

[0016]

According to a first aspect of the present invention, there is provided a plurality of scintillator detectors having both ends, which generate light corresponding to radiation energy and output the light from the both ends. A plurality of measuring optical fibers that individually transmit the light output from each of the scintillator detectors, and a plurality of optical delay lines that individually delay and transmit the light transmitted by each of the measuring optical fibers, , A plurality of photoelectric conversion circuits for individually photoelectrically converting the light sent from each of the optical delay lines to generate an electric signal and outputting the electric signal, and an electric signal sent from each of the photoelectric conversion circuits, When a plurality of delay circuits that individually delay the same scintillator detector so as to cancel the delayed time are sent and an electric signal sent from each of the delay circuits is received at the same time, count A plurality of coincidence counting circuits for transmitting force signals, and a signal processing circuit for outputting the radiation energy instruction signal based on the count output signals transmitted from the respective coincidence counting circuits, each scintillator detector A plurality of calibration optical fibers that individually transmit the light output from the connected scintillator detector, and individually delay the light transmitted by each calibration optical fiber. A radiation measuring system comprising a plurality of calibration optical delay lines that are sent to the photoelectric conversion circuit.

The invention according to claim 2 has a plurality of scintillators which have both ends, generate light corresponding to radiation energy and output the light from the both ends, and which are connected in series with each other. A detector, a plurality of measurement optical fibers that individually transmit the light output from each of the scintillator detectors, and photoelectrically convert the light transmitted by each of the measurement optical fibers to generate an electrical signal. Then, a plurality of photoelectric conversion circuits that output this electric signal and the electric signals sent from each of the photoelectric conversion circuits are individually delayed so as to cancel the delayed time with respect to the same scintillator detector, and then sent. A plurality of delay circuits, and a plurality of coincidence counting circuits for transmitting count output signals when the electric signals transmitted from the respective delay circuits are simultaneously received, and a count transmitted from the respective coincidence counting circuits. A signal processing circuit that outputs an instruction signal of the radiation energy based on a force signal, and enables each of the scintillator detectors to be individually connected, and individually outputs the light output from the connected scintillator detectors. A radiation measurement system comprising a plurality of calibration optical fibers to be transmitted, and a plurality of calibration optical delay lines for individually delaying the light transmitted by each of the calibration optical fibers and sending out to the photoelectric conversion circuit. is there.

Further, the invention according to claim 3 is the radiation measuring system according to claim 1 or 2, wherein the multiplex transmission means for multiplex transmission of the output of the signal processing circuit, and the multiplex transmission means. And a higher-level signal processing unit that executes a predetermined process based on the output multiplexed and transmitted by the radiation measurement system.

According to a fourth aspect of the present invention, in the radiation measuring system according to the second aspect, a high output light source for generating high output light having an emission wavelength different from the light output of each scintillator detector, An optical coupler which is provided between any one of the scintillator detectors and the photoelectric conversion circuit, and which guides the high output light generated by the high output light source to the measurement optical fiber, and the high output light source. A plurality of filters provided in the preceding stage of each photoelectric conversion circuit so as to shield each photoelectric conversion circuit from high output light by, and provided between each scintillator detector and each filter, for the measurement A plurality of branch lines for branching the light passing through the optical fiber from the measurement optical fiber, and detecting the high output light of the high output light source branched from each of the branch lines, and detecting the A radiation measuring system comprising a scene auxiliary unit using a high output light as a power source.

Further, the invention according to claim 5 is the radiation measuring system according to claim 2, wherein the scintillator detectors are individually provided at substantially the same measurement points, have both ends, and are provided with radiation energy. A plurality of standby scintillator detectors that generate light correspondingly and output this light from both ends and are connected in series with each other, and the light output from each standby scintillator detector are individually generated by the photoelectric converter. A plurality of standby system measurement optical fibers transmitted to the conversion circuit, a standby system optical switch capable of opening and closing the connection between each standby system measurement optical fiber and the photoelectric conversion circuit, and each measurement optical fiber A normal-use optical switch capable of opening and closing the connection between the photoelectric conversion circuit and the output of the photoelectric conversion circuit or the output of the signal processing circuit and a predetermined reference value are compared, and the output is more than the reference value. When large, the conventional system optical switch to an open state and a switching control from the closed state, a radiation measuring system comprising a standby switching means for the controlling closed and switching the standby optical switch from the open state.

[0021]

Therefore, in the invention according to claim 1, a plurality of scintillator detectors generate light corresponding to radiation energy and output the light from both ends, and a plurality of measuring optical fibers detect each scintillator. The light output from each device is individually transmitted, the multiple optical delay lines individually delay the light transmitted by each optical fiber for measurement, and then the multiple optical delay circuits output from each optical delay line. The generated light is individually photoelectrically converted to generate an electric signal, the electric signal is transmitted, and a plurality of delay circuits delay the electric signal transmitted from each photoelectric conversion circuit with respect to the same scintillator detector. The signals are individually delayed so as to cancel out the time, and when a plurality of coincidence counting circuits simultaneously receive the electric signals transmitted from the respective delay circuits, the counting output signals are transmitted, and the signal processing circuits cause the same clocks. Since it has a measurement system that outputs an instruction signal of radiation energy based on the count output signal sent from the circuit, each optical delay line delays each light and gives it to the photoelectric conversion circuit at different timings. , Each delay circuit delays the output of the photoelectric conversion circuit and gives it to the coincidence counting circuit at the same timing, so that the number of photoelectric conversion circuits corresponding to the number of scintillator detectors is not required and the price is reduced. be able to.

Further, each scintillator detector can be individually connected, and a plurality of calibration optical fibers for individually transmitting the light output from the connected scintillator detectors and the calibration optical fibers are transmitted. Since a plurality of calibration optical delay lines that individually delay the light and send it to the photoelectric conversion circuit are provided, the labor of the calibration work can be reduced and the continuity of the measurement can be ensured.

Further, in the invention according to claim 2, a plurality of scintillator detectors connected in series with each other generate light corresponding to radiation energy and output the light from both ends thereof for a plurality of measurement purposes. The optical fiber individually transmits the light output from each scintillator detector, and a plurality of photoelectric conversion circuits individually photoelectrically convert the light transmitted by each measurement optical fiber to generate an electrical signal. An electric signal is sent out, and a plurality of delay circuits send the electric signal sent out from each photoelectric conversion circuit by individually delaying them so as to cancel the time delayed with respect to the same scintillator detector. When the counting circuit simultaneously receives the electric signal sent from each delay circuit, it sends a counting output signal, and the signal processing circuit outputs the radiation energy based on the counting output signal sent from each simultaneous counting circuit. Since each scintillator detector connected in series provides its optical output to the photoelectric conversion circuit at different timings because it has a measurement system that outputs an instruction signal, each delay circuit delays the output of the photoelectric conversion circuit. Since they are applied to the coincidence counting circuit at the same timing, the price can be reduced without requiring the photoelectric conversion circuits of the number corresponding to the number of scintillator detectors, similarly to the operation corresponding to claim 1. it can.

Further, similarly to the invention according to claim 1,
Since the plurality of calibration optical fibers and the plurality of calibration optical delay lines are provided, the same operation as the operation corresponding to claim 1 can be achieved.

Further, in the invention corresponding to claim 3, the multiplex transmission means multiplexes the output of the signal processing circuit corresponding to claim 1 or 2, and the higher-order signal processing unit,
Since the predetermined process can be executed based on the output multiplexed by the multiplex transmission means, the same action as the action corresponding to claim 1 or claim 2 can be achieved.

In the invention according to claim 4, the high-output light source generates high-output light having an emission wavelength different from the optical output of each scintillator detector according to claim 2, and the optical coupler has a high output. High output light generated by the output light source is guided to the measurement optical fiber, multiple filters shield each photoelectric conversion circuit from the high output light from the high output light source, and multiple branch lines pass through the measurement optical fiber. Light from the measuring optical fiber is branched, the field auxiliary unit detects the high output light of the high output light source branched from each branch line, and the detected high output light is used as a power source. In addition to the function, the power cable for the field auxiliary unit is unnecessary, and the system can be simplified.

Further, the invention according to claim 5 is individually provided at substantially the same measurement points as the scintillator detectors according to claim 2, and light is generated corresponding to the radiation energy and both ends of this light are generated. Output from the unit, and a plurality of standby system scintillator detectors, which are connected in series with each other, a plurality of standby system optical fibers for individually transmitting the light output from each standby system scintillator detector to the photoelectric conversion circuit, A standby system optical switch that can open and close the connection between each standby measurement optical fiber and the photoelectric conversion circuit, and a standby system optical switch that can open and close the connection between each measurement optical fiber and the photoelectric conversion circuit. The standby system switching means compares the output of the photoelectric conversion circuit or the output of the signal processing circuit with a predetermined reference value, and when the output is greater than the reference value, the normal system optical switch is switched from the closed state to the open state. And switch control Since the standby system optical switch is controlled to switch from the open state to the closed state, in addition to the action corresponding to claim 2, even when an abnormal value is detected due to a failure in the regular system measurement loop, a missing measurement is made. To prevent the situation
The measurement can be continuously performed, and the photoelectric conversion circuit can be protected especially when external light enters due to breakage of the measurement loop or the like.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the arrangement of a radiation measuring system according to the first embodiment of the present invention. In this radiation measuring system, both ends of a scintillator detector 11a are individually connected to photoelectric conversion circuits 13a and 13b via measuring optical fibers 12a1 and 12a2, an optical switch section 15 and optical delay lines 19a1 and 19a2.

Similarly, both ends of the scintillator detector 11b are individually connected to the photoelectric conversion circuits 13a and 13b via the measuring optical fibers 12b1 and 12b2, the optical switch section 15 and the optical delay lines 19b1 and 19b2.

On the other hand, the two calibration optical fibers 14 laid from the radiation source calibration room (not shown) are individually connected to the common photoelectric conversion circuits 13a and 13b via the optical switch section 15 and the optical delay line 19. ing.

The photoelectric conversion circuits 13a and 13b are connected to a metal cable having a branch portion, and the metal cable is connected to the delay circuits 16, 16a1, 16a2, 16b1 and 1 from the branch portion, respectively.
It is connected to 6b2. Each delay circuit 16 is connected to the coincidence counting circuit 17, each delay circuit 16a1 and 16a2 is connected to the coincidence counting circuit 17a, and each delay circuit 16b1 and 16b2 is connected to the coincidence counting circuit 17b. Each coincidence counting circuit 1
7, 17a and 17b are connected to a common signal processing circuit 18.

Here, each scintillator detector 11a, 1
1b is for converting the radiation energy into light and individually measuring optical fibers 12a1, 12a2, 12b1, 12 from both ends.
It has a function to output to b2.

Optical fibers 12a1, 12a2, 12 for measurement
b1 and 12b2 individually guide the optical outputs of the scintillator detectors 11a and 11b to the optical switch unit 15.

On the other hand, each calibration optical fiber individually guides the optical output given from the radiation source calibration chamber to the optical switch section.

The optical switch section 15 has optical switches individually corresponding to the measuring optical fibers 12a1, 12a2, 12b1 and 12b2 and the calibration optical fibers 14, and the measuring optical fibers 12a1, 12a2 and 12b1. , 12b2 and the optical fibers 14 for calibration are provided to the optical delay lines 19, 19a1, 19a via the optical switches individually.
2, 19b1 and 19b2. Each optical switch can be opened and closed individually by the operator's setting operation.

Each optical delay line 19, 19a1, 19a
2, 19b1 and 19b2 individually delay each optical output given from the optical switch unit 15 and send them to the photoelectric conversion circuits 13a and 13b in order to make the photoelectric conversion circuit common. , 13b has a function of making the timings of the respective optical outputs different from each other. Each optical delay line 19, 19a1, 19a2,
19b1 and 19b2 are the scintillator detectors 11a and 11b.
Among the optical outputs given from b through the optical switch unit 15, two optical outputs corresponding to one scintillator detector 11a are delayed so as to have a time difference τa with each other, and the two optical outputs corresponding to the other scintillator detector 11b are delayed. It is delayed so that it has τb. Also, τ
a and τb are different values.

The photoelectric conversion circuits 13a and 13b have a function of photoelectrically converting the optical outputs sent from the respective optical delay lines 19, 19a1, 19a2, 19b1 and 19b2 into electric signals and sending the electric signals to a metal cable. .

The metal cable is a photoelectric conversion circuit 13a, 1
The electric signal sent from 3b is branched at the branching portion and given to the delay circuits 16, 16a1, 16a2, 16b1 and 16b2 in parallel.

Each delay circuit 16, 16a1, 16a2, 16b
1, 16b2 have individually settable delay times, and have a function of individually delaying an electric signal given from each metal cable and giving it to the coincidence counting circuits 17, 17a, 17b. Identical scintillator detector 11a
Since each electric signal corresponding to each optical output of (11b) is simultaneously given to the coincidence counting circuit 17a (17b) corresponding to the scintillator detector 11a (11b), it is delayed so as to cancel the above-mentioned time difference τa or time difference τb. The time is set.

Each coincidence counting circuit 17, 17a, 17b is
When the respective electric signals sent from the delay circuits 16, 16a1, 16a2, 16b1 and 16b2 are simultaneously received, the count output signal is sent to the signal processing circuit 18.

The signal processing circuit 18 includes a coincidence counting circuit 17,
A function of outputting a radiation energy instruction corresponding to each scintillator detector 11a, 11b and the radiation source calibration chamber based on the count output signal sent from 17a, 17b, and a function capable of outputting an alarm. I have

Next, the operation of the radiation measuring system configured as described above will be described using the abbreviated block diagram of FIG. 2 and the time chart of FIG.

The optical output generated by the scintillator detector 11a is, as shown in FIG. 3A, measured optical fibers 12a1 and 12a2 from one end and the other end of the scintillator detector 11a, respectively. Are output to the optical delay lines 19a1 and 19a2 individually, and the output of one of the optical delay lines 19a1 is shown in FIG. 3B, and the output of the other optical delay line 19a2 is shown in FIG. 3C. As described above, the signals are individually delayed so as to have a time difference τa and are sent to the photoelectric conversion circuits 13a and 13b.

The photoelectric conversion circuits 13a and 13b photoelectrically convert the optical output to generate an electric signal, respectively, as shown in FIGS.
, These two electrical signals have a time difference τ from each other.
Send them to the metal cables with a attached.

The two electric signals sent to the metal cable are branched into two, and four delay circuits 16a1, 1 are provided.
It is sent to 6a2, 16b1 and 16b2.

Here, four delay circuits 16a1, 16a2,
Of the 16b1 and 16b2, the two delay circuits 16a1 and 16b1 connected to one photoelectric conversion circuit 13a are individually connected to the one and the other coincidence counting circuits 17a and 17b, and are connected to the other photoelectric conversion circuit 13b. Two delay circuits 16
a2 and 16b2 are one and the other simultaneous counting circuits 17a and 17b.
Individually connected to.

The two delay circuits 16a1 and 16a2 connected to one coincidence counting circuit 17a have a time difference τ from each other.
The delay times t1 and t2 are individually set so as to have a. However, t1 = τa + t2.

As a result, of the outputs from both ends of the scintillator detector 11a, the one that arrives earlier in the delay circuit by the time difference τa is delayed by the delay time t1 in the delay circuit 16a1 as shown in FIG. 3 (f). It is delayed by (= τa + t2) and given to the coincidence counting circuit 17a. Of the outputs from both ends of the scintillator detector 11a, the one that arrives at the delay circuit later by the time difference τa is delayed by the delay time t2 in the delay circuit 16a2 and the simultaneous counting is performed, as shown in FIG. 3 (g). It is supplied to the circuit 17a.

Therefore, the coincidence counting circuit 17a simultaneously receives the electric signals from the two delay circuits 16a1 and 16a2 corresponding to the outputs of both ends of the scintillator detector 11a, and counts the electric signals, as shown in FIG. ), The count output signal is sent to the signal processing circuit 18.

The signal processing circuit 18 outputs a radiation energy instruction based on the count output signal.

The above-mentioned four delay circuits 16a1 and 1a1
Of 6a2, 16b1 and 16b2, the other simultaneous counting circuit 17
In the two delay circuits 16b1 and 16b2 connected to b, the delay times t3 and t4 are individually set so as to have a time difference τb different from τa. However, t3 = τb + t
It is 4.

As a result, of the outputs from both ends of the scintillator detector 11a, the one that arrives at the delay circuit earlier by the time difference τa is delayed by the delay time t3 in the delay circuit 16b1.
The one delayed by (= τb + t4) is given to the coincidence counting circuit 17b, and the one arriving at the delay circuit later by the time difference τb is delayed by the delay time t4 in the delay circuit 16b2 and given to the coincidence counting circuit 17b.

However, the delay circuit 16 for these τ b
The electric signals passing through b1 and 16b2 are given to the coincidence counting circuit 17b at different timings because one of the total delay times is τb + t4 and the other is τa + t4. ), It is not counted.

That is, each of the coincidence counting circuits 17a and 17b
Counts the respective electric signals simultaneously given to the predetermined scintillator detector 11a, but does not count the respective electric signals given to the other scintillator detector 11b at different timings.

In this way, the photoelectric conversion circuits 13a and 13b are
Even if the above is standardized, each scintillator detector 11
The electric signals can be discriminated and counted according to the outputs of a and 11b.

Further, in this embodiment, the calibration optical fiber 14 is laid from the radiation source calibration room for instrument calibration. Therefore, at the time of calibration, the scintillator detector 11a can be calibrated by removing the scintillator detector 11a from the measurement optical fibers 12a1 and 12a2 and connecting it to the calibration optical fiber 14 in the source calibration chamber. Moreover, by attaching the reference light source to the measuring optical fibers 12a1 and 12a2 from which the scintillator detector 11a is removed, the measuring optical fibers 12a1 and 12a2, the optical switch section 15, the optical delay lines 19a1 and 19a2, the photoelectric conversion circuit 13a, 1
3b, delay circuits 16a1 and 16a2, and simultaneous counting circuits 17
It is possible to calibrate the measurement system including a and the signal processing circuit 18. The reference light source is, for example, as shown in FIG. 4, a container 41 having optical connectors 42 at both ends.
And a transmissive member 43 provided between the optical connectors 42 for transmitting the emission wavelength of the scintillator, and provided in the container 41 to stably generate a constant amount of light and a constant wavelength of light.
A device including an optical pulse generator 44 that gives this light to the transmitting member 43 can be used. This optical pulse generator 44
A light emitting diode or a scintillator composed of a temperature controller and a radiation source is used as the light source.

Furthermore, at the time of calibrating the radiation source, the optical switch of the measurement system from which the scintillator detector 11a is removed is turned off, and the optical switch of the calibration optical fiber 14 which is normally off is turned on. , Source calibration can be performed without affecting other measurement channels.

As described above, according to the first embodiment, the optical delay lines 19a1, 19a2, 19b1 and 19b2 individually delay the respective optical outputs provided from the optical switch section 15 so that the timings are different from each other. Photoelectric conversion circuit 1
3a and 13b, and the delay circuits 16a1 and 16a2 individually delay the outputs of the photoelectric conversion circuits 13a and 13b so as to cancel the delay times of the optical delay lines 19a1 and 19a2, and simultaneously send them to the coincidence counting circuit 17a. Therefore, the photoelectric conversion circuit can be shared, and
The cost can be reduced without the number of photoelectric conversion circuits corresponding to the number of scintillator detectors.

Further, according to the first embodiment, the scintillator detector 11a is connected to the measuring optical fiber 12 during calibration.
The scintillator detector 1 is detached from a1 and 12a2 and connected to the calibration optical fiber 14 in the radiation source calibration room.
1a can be calibrated, and by attaching the reference light source 31 to the measuring optical fiber 13 from which the scintillator detector 11a has been removed, the measuring optical fiber 12a1,
12a2, optical switch unit 15, optical delay line 19a1,
19a2, photoelectric conversion circuits 13a and 13b, each delay circuit 16
a1, 16a2, each coincidence counting circuit 17a and signal processing circuit 1
Since the measurement system composed of 8 can be calibrated, even if an abnormal value is shown, the calibration location can be easily identified, and the labor of the calibration work can be reduced.

Further, according to the first embodiment, the optical switch of the measuring system from which the scintillator detector 11a is removed is turned off, and the optical switch of the calibration optical fiber which is normally off is turned on. , Source calibration can be performed without affecting other measurement channels.
It is possible to ensure continuity of measurement.

Next explained is a radiation measuring system according to the second embodiment of the invention.

FIG. 5 is a block diagram showing the construction of this radiation measuring system. The same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted. Only different parts will be described here.

That is, the system of this embodiment simplifies the configuration of the system shown in FIG. 1. Specifically, as compared with the system shown in FIG. 1, the scintillator detectors 11a and 11b are connected in series with each other. In addition, the optical delay lines 19a1 to 19b2 of the measurement system are omitted. The optical delay lines 19a1 to 19b2 are not necessary because the scintillator detectors 11a and 11b are connected in series so that the timings of the optical outputs given to the photoelectric conversion circuits 13a and 13b are naturally different. And omitted.

As a result, each scintillator detector 11
When the light outputs generated by a and 11b are sent out from both ends thereof, each light output is given to the photoelectric conversion circuits 13a and 13b with a time difference from each other as described above. At this time, the time difference between the light outputs sent from one end and the other end of the scintillator detector 11a is defined as τa, and each light sent from the one end and the other end of the other scintillator detector 11b is set. Assuming that the output time difference is τb,
In each of the delay circuits 16a1 to 16b2, these time differences τa and τb
Are canceled out individually, and the measurement is performed via the coincidence counting circuits 17a and 17b.

In the calibration, by replacing one of the scintillator detectors 11a and 11b with, for example, the scintillator detector 11a and the reference light source 31, the scintillator detector 11a is replaced with the scintillator detector 11a in the same manner as described above. Corresponding photoelectric conversion circuits 13a, 13b, delay circuits 16a1, 16
It is possible to calibrate the measurement system including the a2, each coincidence counting circuit 17a, and the signal processing circuit 18.

Further, the reference light source 31 is removed and one scintillator detector 11a is attached, and the other scintillator detector 11b is removed and the reference light source 31 is attached, whereby the photoelectric conversion circuit corresponding to the other scintillator detector 11b. 13a, 13b, delay circuits 16b1, 16
It is possible to calibrate the measurement system including b2, each coincidence counting circuit 17b and the signal processing circuit 18.

In the radiation source calibration room, the scintillator detector 11a (11b) is installed in the calibration optical fiber 1 as described above.
4 is attached to the scintillator detector 1
1a (11b) is calibrated.

As described above, according to the second embodiment, as compared with the first embodiment, the scintillator detectors 11a and 11a are provided.
By connecting b in series, the optical delay line 19a1
To 19b2 are reduced, and the measurement optical fibers 12a1 to 12a
The amount of b2 used can be reduced.

Next explained is a radiation measuring system according to the third embodiment of the invention.

FIG. 6 is a block diagram showing the configuration of this radiation measuring system. The same parts as those in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted. Only different parts will be described here.

That is, the system of this embodiment is capable of transmitting the output of the system shown in FIG. 1 to the higher-level signal processing circuit 52 provided in the central operating room or the like, and specifically, shown in FIG. Compared to the system, the signal processing unit 53 as an I / F connected to the subsequent stage of the signal processing circuit 18
And a multiplex transmission circuit 51 for transmitting the output of the signal processing unit 53 by time division multiplexing, and an upper signal processing circuit 52 for processing the output of the multiplex transmission circuit 51. The multiplex transmission circuit 51 and the signal processing circuit 52 are connected to each other by an optical fiber or a coaxial cable.

Here, as described above, it is assumed that the measurement or calibration is executed and the signal processing circuit 18 outputs the radiation energy instruction.

The signal processing unit 53 converts the output of the signal processing circuit 18 to the multiplex transmission circuit 51 according to the input specifications of the multiplex transmission circuit 51 and outputs it. The multiplex transmission circuit 51 time-division-processes the output of the signal processing unit 53 and outputs it to the higher-level signal processing circuit 52. Upper signal processing circuit 5
2 receives the time-divided and transmitted output and executes a predetermined process.

As described above, according to the third embodiment, as compared with the first embodiment, the output of the signal processing circuit 18 is provided in the central operating room or the like via the signal processing unit 53 and the multiplex transmission circuit 51. It can be transmitted to the higher-level signal processing circuit 52.

Further, according to the third embodiment, when the multiplex transmission circuit 51 is an existing one, it is possible to simplify the system because of easy connection and to reduce the amount of cable used by multiplex transmission. You can

Next explained is a radiation measuring system according to the fourth embodiment of the invention.

FIG. 7 is a block diagram showing the configuration of this radiation measuring system. The same parts as those in FIG. 5 are designated by the same reference numerals and detailed description thereof will be omitted. Only different parts will be described here.

That is, the system of this embodiment is capable of transmitting the output of the system shown in FIG. 5 to the higher-level signal processing circuit 52 provided in the central operation room or the like, and specifically, shown in FIG. Compared to the system, a signal processing unit 53 connected to the subsequent stage of the signal processing circuit 18, a multiplex transmission circuit 51 for transmitting the output of this signal processing unit 53 by time division multiplexing, and an output of this multiplex transmission circuit 51. And a higher-level signal processing circuit 52 for processing The multiplex transmission circuit 51 and the signal processing circuit 18 are connected to each other by an optical fiber or a coaxial cable.

Here, as described above, it is assumed that the measurement or calibration is executed and the signal processing circuit 18 outputs the radiation energy instruction.

The signal processing unit 53 converts the output of the signal processing circuit 18 to the multiplex transmission circuit 51 according to the input specifications of the multiplex transmission circuit 51 and outputs it. The multiplex transmission circuit 51 time-division-processes the output of the signal processing unit 53 and outputs it to the higher-level signal processing circuit 52. Upper signal processing circuit 5
2 receives the time-divided and transmitted output and executes a predetermined process.

As described above, according to the fourth embodiment, as compared with the second embodiment, the output of the signal processing circuit 18 is provided in the central operation room or the like via the signal processing unit 53 and the multiplex transmission circuit 51. It can be transmitted to the higher-level signal processing circuit 52.

According to the fourth embodiment, when the multiplex transmission device having the multiplex transmission circuit 51 is an existing one,
It is possible to simplify the system because it can be easily connected to the existing one and reduce the amount of cable used by multiplex transmission.

Next explained is a radiation measuring system according to the fifth embodiment of the invention.

FIG. 8 is a block diagram showing the configuration of this radiation measuring system, and FIG. 9 is a schematic diagram showing the partial configuration of this radiation measuring system. The same parts as in FIG. Detailed description thereof is omitted, and only different parts will be described here.

That is, the system of this embodiment is different from the system shown in FIG. 5 in that a field auxiliary unit that does not require a power cable is provided. Specifically, as compared with the system shown in FIG. 5, a scintillator detector is used. The high output light source 72 that generates high output light having a different emission frequency from the light outputs of 11a and 11b, and the high output light source 72 that is provided between the optical switch unit 15 and the photoelectric conversion circuit 13a. The optical coupler 71 that guides the output light to the measuring optical fiber 12a1, the optical coupler 71, the photoelectric conversion circuit 13a, and the photoelectric conversion circuit 13b are provided between the optical coupler 71 and the photoelectric conversion circuit 13b. Between the filter 76 that shields the photoelectric conversion circuits 13a and 13b, between the scintillator detector 11a and the optical switch unit 15, and between the scintillator detector 11b and the optical switch unit 15. Respectively provided, the measuring optical fiber 1
2a1 and 12a2 are used for measuring the optical fiber 12a1,
A branch line 73 for branching from 12a2, and a scintillator detector 11 branched from this branch line 73
Field auxiliary unit 7 which detects the light output of a and 11b and the high output light of the high output light source 72 by the photodetector 75 and uses it as a power source
4 and.

Here, the high power light source 72 generates high power light in the infrared region, for example.

The filter 76 includes the scintillator detector 11
The wavelengths of the light outputs of a and 11b are used as transmission wavelengths and the lights of other wavelengths are shielded. Specifically, as shown in FIG. 10, the scintillation light of the scintillator detectors 11a and 11b is output. It transmits a wavelength of several 100 nm and blocks high output light having other wavelengths.

As a result, the high output light generated by the high output light source 72 travels through the optical coupling section 71 toward the scintillator detectors 11a and 11b and the photoelectric conversion circuit 13a in the measuring optical fiber.

At this time, the high-output light traveling toward the photoelectric conversion circuit 13a is blocked by the filter 76. on the other hand,
The high output light that has traveled toward the scintillator detectors 11 a and 11 b is branched by the branch line 73, and part of the light travels to the site auxiliary unit 74.

In the field auxiliary unit 74, this high output light is detected by the photodetector 75, and the detected high output light is converted into a power supply for operation by using, for example, the photovoltaic effect.

As a result, the field auxiliary unit 74 can execute a predetermined operation without providing a power cable.

As described above, according to the fifth embodiment, the high-power light generated by the high-power light source 72 is guided to the field auxiliary unit 74 through the measurement optical fibers 12a1 and 12a2, and the field auxiliary unit 74 causes Since the high output light is converted into a power source, the power cable for the field auxiliary unit is not required and the system can be simplified.

Next explained is a radiation measuring system according to the sixth embodiment of the invention.

FIG. 11 is a block diagram showing the configuration of this radiation measuring system. The same parts as those in FIG. 5 are designated by the same reference numerals and detailed description thereof will be omitted, and only different parts will be described here.

That is, the system of this embodiment is a redundant version of the system shown in FIG.
In addition to the system shown in, each scintillator detector 11m1,
11 m 2 are connected in series to each other, and photoelectric conversion circuits 13 a, 13 are provided from the measurement optical fiber 91 via the optical switch unit 15.
A failure level monitoring circuit 93 for forming a standby system measurement loop connected to b and monitoring the output of the signal processing circuit 18
And an optical switch control circuit 92 which is controlled by the failure level monitoring circuit 93 to individually turn on / off each optical switch of the optical switch section 15. Each scintillator detector 11 also included in the system shown in FIG.
Measurement optical fiber 1 in which a and 11b are connected in series with each other
The measurement loop connected from 2a1 and 12a2 to the photoelectric conversion circuits 13a and 13b via the optical switch unit 15 is referred to as a regular system measurement loop.

Here, as described above, it is assumed that the measurement or calibration is executed and the signal processing circuit 18 outputs the radiation energy instruction.

The failure level monitoring circuit 93 monitors the output of the signal processing circuit 18, and as shown in FIG. 12, determines whether or not the radiation energy instruction deviates from a predetermined range between the upper limit value and the lower limit value. When the determination result indicates that the determination result shows a deviation from a predetermined range, an optical switch switching command to the effect that the ON state of the regular system is the OFF state and the OFF state of the standby system is the ON state is sent to the optical switch control circuit 92.

Upon receiving this optical switch switching command, the optical switch control circuit 92 switches the normal system optical switch from the ON state to the OFF state, and switches the standby system optical switch from the OFF state to the ON state. The switching time of the optical switch is generally 100 msec or less in the case of the mechanical type.

As described above, when an abnormal value is detected in the regular system measurement loop due to a failure or the like, it is possible to switch to the standby system measurement loop and continuously perform the measurement.

As described above, according to the sixth embodiment, as compared with the second embodiment, the standby system measurement loop is added, and the fault level monitoring circuit 93 monitors the output of the signal processing circuit 18 for abnormality. At this time, the measurement system is switched from the normal system to the standby system via the optical switch control circuit 92 and the optical switch unit. Therefore, even when an abnormal value is detected due to a failure in the normal system measurement loop, Preventing a missing state,
The measurement can be performed continuously.

Next explained is a radiation measuring system according to the seventh embodiment of the invention.

FIG. 13 is a block diagram showing the structure of this radiation measuring system. The same parts as those in FIG. 5 are designated by the same reference numerals and detailed description thereof will be omitted. Only different parts will be described here.

That is, the system of this embodiment is a modification of the system shown in FIG.
Compared to the system shown in FIG. 2, the failure level monitoring circuit 93 is omitted, and when the outputs of the photoelectric conversion circuits 13a and 13b are higher than the determination value, the optical switch switching command is issued.
A measuring circuit 94 is provided for sending to the second.

As described above, it is assumed that the photoelectric conversion circuits 13a and 13b output electric signals to the delay circuits 16a1 to 16b2 when the measurement or calibration is performed.

The measuring circuit 94 uses the photoelectric conversion circuit 13
The outputs of a and 13b are monitored, and as shown in FIG. 13, it is determined whether the electric signal is higher than the determination value.
When the electric signal is higher than the determination value, an optical switch switching command is sent to the optical switch control circuit 92 instructing the ON state of the regular system to be the OFF state and the OFF state of the standby system to be the ON state.

The optical switch control circuit 92 has the same configuration as described above.
When this optical switch switching command is received, the optical switch of the regular system is switched from the ON state to the OFF state, and the optical switch of the standby system is switched from the OFF state to the ON state.

As described above, when an abnormal value is detected in the regular system measurement loop due to a failure or the like, it is possible to switch to the standby system loop and continuously perform the measurement.

As described above, according to the seventh embodiment, as compared with the second embodiment, the standby system measurement loop is added, and the measurement circuit 94 monitors the outputs of the photoelectric conversion circuits 13a and 13b to detect an abnormality. At this time, the measurement system is switched from the normal system to the standby system via the optical switch control circuit 92 and the optical switch unit 15. Therefore, even when an abnormal value is detected due to a failure or the like in the normal system measurement loop. , It is possible to prevent the missing state and continuously perform the measurement.

Further, according to the present embodiment, the external light is converted into the photoelectric conversion circuits 13a and 13b by switching the external light, especially when the external light enters due to breakage of the measuring loop.
The photoelectric conversion circuit can be protected without intruding into.

Besides, the present invention can be variously modified and implemented without departing from the scope of the invention.

[0112]

As described above, according to the first aspect of the present invention, a plurality of scintillator detectors generate light corresponding to radiation energy and output the light from both ends, thereby producing a plurality of measurement light beams. The fiber individually transmits the light output from each scintillator detector, and the plurality of optical delay lines individually delay and transmit the light transmitted by each measurement optical fiber. The light sent out from the optical delay line is individually photoelectrically converted to generate an electric signal, and this electric signal is sent out. A plurality of delay circuits detect the electric signal sent out from each photoelectric conversion circuit by the same scintillator detection. When the multiple coincidence counting circuits simultaneously receive the electric signals transmitted from each delay circuit, the count output signals are transmitted and the signal processing times are delayed. However, since it has a measurement system that outputs an instruction signal of radiation energy based on the count output signal sent from each coincidence counting circuit, each optical delay line delays each light and outputs the photoelectric signals at different timings. While each delay circuit delays the output of the photoelectric conversion circuit and supplies it to the coincidence counting circuit at the same timing while supplying it to the conversion circuit, the price does not require the number of photoelectric conversion circuits corresponding to the number of scintillator detectors. It is possible to provide a radiation measurement system that can be manufactured at low cost.

Further, each scintillator detector can be individually connected, and a plurality of calibration optical fibers individually transmitting the light output from the connected scintillator detectors and the calibration optical fibers are transmitted. Since a plurality of calibration optical delay lines that individually delay the light and send it to the photoelectric conversion circuit are provided, the labor of the calibration work can be reduced and the continuity of measurement can be ensured.

According to the second aspect of the present invention, the plurality of scintillator detectors connected in series with each other generate light corresponding to the radiation energy and output the light from both ends thereof to obtain a plurality of light beams for measurement. The optical fiber individually transmits the light output from each scintillator detector, and a plurality of photoelectric conversion circuits individually photoelectrically convert the light transmitted by each measurement optical fiber to generate an electrical signal. An electric signal is sent out, and a plurality of delay circuits send the electric signal sent out from each photoelectric conversion circuit by individually delaying them so as to cancel the time delayed with respect to the same scintillator detector. When the counting circuit simultaneously receives the electric signals sent from the respective delay circuits, it sends the counting output signal, and the signal processing circuit outputs the radiation energy based on the counting output signal sent from the simultaneous counting circuit. Since it has a measurement system that outputs the indicated signal, each scintillator detector connected in series gives each optical output to the photoelectric conversion circuit at different timing, while each delay circuit delays the output of the photoelectric conversion circuit. As described in claim 1, a radiation measuring system which can reduce the price without requiring the photoelectric conversion circuits corresponding to the number of scintillator detectors is provided. it can.

Further, as in the first aspect of the invention, since a plurality of calibration optical fibers and a plurality of calibration optical delay lines are provided, the same effect as that of the first aspect can be obtained.

Further, according to the invention of claim 3, the multiplex transmission means multiplexes the output of the signal processing circuit of claim 1 or 2, and the higher-order signal processing unit multiplexes by the multiplex transmission means. Since the predetermined processing can be executed based on the output that is output, the effect of claim 1 or claim 2 can be obtained.

According to the invention of claim 4, the high output light source generates high output light having an emission wavelength different from the optical output of each scintillator detector of claim 2, and the optical coupler outputs the high output light source. Guide the high-power light generated in the optical fiber for measurement,
Multiple filters shield each photoelectric conversion circuit from the high output light from the high output light source, multiple branch lines branch the light passing through the measurement optical fiber from the measurement optical fiber, and the field auxiliary unit branches each branch line. The high output light of the high output light source branched from is detected, and the detected high output light is used as a power source. Therefore, in addition to the effect of claim 2, the power cable for the field auxiliary unit is not required, and the system is simplified. A radiation measurement system that can be achieved can be provided.

Further, according to the invention of claim 5, the scintillator detectors of claim 2 are individually provided at substantially the same measurement points, generate light corresponding to the radiation energy, and emit the light from both ends. A plurality of standby system scintillator detectors that output and are connected in series with each other, a plurality of standby system measurement optical fibers that individually transmit the light output from each standby system scintillator detector to the photoelectric conversion circuit, and each standby system A standby system optical switch that can open and close the connection between the system measurement optical fiber and the photoelectric conversion circuit, and a normal system optical switch that can open and close the connection between each measurement optical fiber and the photoelectric conversion circuit, The standby system switching means compares the output of the photoelectric conversion circuit or the output of the signal processing circuit with a predetermined reference value, and when the output is larger than the reference value, switches the service optical switch from the closed state to the open state. Control and standby system light Since the switch is controlled to switch from the open state to the closed state, in addition to the action corresponding to claim 2, even when an abnormal value is detected due to a failure or the like in the regular system measurement loop, the measurement state is lost. It is possible to provide a radiation measurement system that can prevent this from occurring and continuously perform measurement, and can protect the photoelectric conversion circuit especially when external light enters due to breakage of the measurement loop.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a radiation measurement system according to a first embodiment of the present invention,

FIG. 2 is a block diagram for explaining the operation of the embodiment.

FIG. 3 is a time chart for explaining the operation in the embodiment.

FIG. 4 is a cross-sectional view showing the calibration of the reference light source in the embodiment.

FIG. 5 is a block diagram showing a configuration of a radiation measurement system according to a second embodiment of the present invention,

FIG. 6 is a block diagram showing the configuration of a radiation measurement system according to a third embodiment of the present invention,

FIG. 7 is a block diagram showing the configuration of a radiation measurement system according to a fourth embodiment of the present invention,

FIG. 8 is a block diagram showing a configuration of a radiation measurement system according to a fifth embodiment of the present invention,

FIG. 9 is a schematic diagram showing a partial configuration of the radiation measurement system in the example.

FIG. 10 is a filter characteristic diagram for explaining the operation in the embodiment.

FIG. 11 is a block diagram showing the configuration of a radiation measurement system according to a sixth embodiment of the present invention,

FIG. 12 is a block diagram for explaining an operation in the embodiment.

FIG. 13 is a block diagram showing the configuration of a radiation measurement system according to a seventh embodiment of the present invention,

FIG. 14 is a block diagram showing a configuration of a conventional radiation measurement system,

FIG. 15 is a block diagram showing a configuration of a conventional radiation measurement system,

FIG. 16 is a block diagram showing a configuration of a conventional radiation measurement system,

FIG. 17 is a block diagram showing the configuration of a conventional radiation measurement system.

[Explanation of symbols]

11a, 11b ... Scintillator detectors, 12a1, 12a
2, 12b1, 12b2 ... Measuring optical fibers, 13a, 13
b ... Photoelectric conversion circuit, 14 ... Calibration optical fiber, 15 ... Optical switch section, 16, 16a1, 16a2, 16b1, 16b2 ...
Delay circuit, 17, 17a, 17b ... Simultaneous counting circuit, 18
... Signal processing circuit.

Claims (5)

[Claims] 1. A plurality of scintillator detectors having both ends, each of which generates light corresponding to radiation energy and outputs the light from the both ends, and a light output from each of the scintillator detectors. A plurality of measuring optical fibers to be transmitted to the optical fiber, a plurality of optical delay lines for individually delaying and transmitting the light transmitted by each of the measuring optical fibers, and a plurality of optical delay lines to be individually transmitted. A plurality of photoelectric conversion circuits that generate an electric signal by photoelectrically converting the electric signal, and the electric signals sent from the photoelectric conversion circuits are offset by the delayed time with respect to the same scintillator detector. A plurality of delay circuits for individually delaying and sending, and a plurality of simultaneous counting circuits for sending a count output signal when receiving the electrical signals sent from the respective delay circuits at the same time. A signal processing circuit that outputs the radiation energy instruction signal based on a count output signal sent from each of the coincidence counting circuits, each of the scintillator detectors can be individually connected, and the connected scintillator A plurality of calibration optical fibers for individually transmitting the light output from the detector, and a plurality of calibration light for individually delaying the light transmitted through each of the calibration optical fibers and sending out to the photoelectric conversion circuit. A radiation measuring system comprising a delay line. 2. A plurality of scintillator detectors having both ends, generating light corresponding to radiation energy, outputting the light from the both ends, and connected in series with each other, and each of the scintillator detectors. A plurality of measuring optical fibers that individually transmit the light output from the optical fiber, and a plurality of optical fibers that individually photoelectrically convert the light transmitted by each of the measuring optical fibers to generate an electrical signal and transmit the electrical signal. The photoelectric conversion circuit of, the plurality of delay circuits for individually delaying and transmitting the electric signal sent from each of the photoelectric conversion circuits so as to cancel the delayed time with respect to the same scintillator detector, A plurality of coincidence counting circuits for transmitting count output signals when simultaneously receiving electric signals transmitted from the delay circuit, and the radiation based on the count output signals transmitted from the coincidence counting circuits. And a signal processing circuit for outputting an energy instruction signal, wherein each of the scintillator detectors can be individually connected, and a plurality of calibration optical fibers that individually transmit the light output from the connected scintillator detectors And a plurality of calibration optical delay lines for individually delaying the light transmitted through each of the calibration optical fibers and sending it to the photoelectric conversion circuit. 3. The radiation measurement system according to claim 1, wherein the multiplex transmission means for multiplex-transmitting the output of the signal processing circuit and the multiplex-transmitted output by the multiplex transmission means are used. A radiation measurement system, comprising: a higher-level signal processing unit that executes a predetermined process. 4. The radiation measuring system according to claim 2, wherein one of the high-power light source that generates high-output light having an emission wavelength different from the light output of each scintillator detector, and each scintillator detector. And an optical coupler provided between the photoelectric conversion circuit and the high output light generated by the high output light source to the optical fiber for measurement, and each photoelectric conversion from the high output light by the high output light source. A plurality of filters provided in the preceding stage of each photoelectric conversion circuit so as to shield the circuit, provided between the scintillator detector and each filter, for measuring the light passing through the measurement optical fiber A plurality of branch lines for branching from the optical fiber and high output light of the high output light source branched from each of the branch lines are detected, and the detected high output light is used as a power source. Radiation measurement system characterized in that an auxiliary unit. 5. The radiation measurement system according to claim 2, wherein the scintillator detectors are individually provided at substantially the same measurement points, have both ends, and generate light corresponding to radiation energy. A plurality of standby system scintillator detectors that output light from both ends and are connected in series with each other, and a plurality of standby systems that individually transmit the light output from each standby system scintillator detector to the photoelectric conversion circuit. A measuring optical fiber, a standby optical switch capable of opening and closing the connection between each standby measuring optical fiber and the photoelectric conversion circuit, and a connection between each measuring optical fiber and the photoelectric conversion circuit A normal-use optical switch capable of opening and closing, comparing the output of the photoelectric conversion circuit or the output of the signal processing circuit with a predetermined reference value, and when the output is larger than the reference value, the normal-use optical switch Radiation measurement system characterized in that a standby switching means from the closed state to open and the state switching control, to control the closed state and switching the standby optical switch from the open state.