JP2003121550A - Radiation detector, apparatus and system for radiation measurement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray detector, an apparatus and a method for X-ray measurement wherein X-rays can be detected with satisfactory accuracy without having to re-conduct, the calibration processing operation, even when the X-ray detector is replaced. SOLUTION: A data storage means which stores data on a calibration value used to calculate an X-ray measured value from a detection signal is installed at the X-ray detector 100, which detects the X-rays so as to output the detection signal. As the data storage means, a memory 105a inside a microcomputer 105 can be used. At the X-ray measuring apparatus 200, which calculates and outputs the X-ray measured value on the basis of the detection signal to be output from the X-ray detector 100, a microcomputer 204 which functions as a calibration-value-data readout means used to read out the data on the calibration value stored, in the memory 105a in the X-ray detector 100 and as a calculation means used to calculate the X-ray measured value, on the basis of the detection signal and on the basis of the data on the calibration value is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation detector, a dose measuring device and a dose measuring system for measuring the dose of radiation such as X-rays.

[0002]

2. Description of the Related Art Conventionally, as a radiation measuring system of this type, a radiation detector for detecting radiation and a radiation measuring device for calculating and outputting a measured value of radiation based on a detection signal of the radiation detector are combined. Things are known. In this dosimetry system, the detection signal output from the detector that detects the radiation is sent to the radiation measurement device via the communication cable, and the radiation measurement device calculates the measured value such as the radiation dose from the detection signal and displays it. And output to. Here, in the radiation detector, there are variations in conversion efficiency from radiation to a detection signal which is an electric signal, and variations in the amplifier in the detector, and the intensity of radiation (dose rate)
It has been difficult to make a radiation detector with a constant sensitivity characteristic, which is the magnitude of the detection signal for. Therefore, it is necessary to calibrate the measured value of the radiation calculated by the radiation measuring apparatus by some method. Therefore, conventional radiation measurement systems so far have an adjustment function that measures standard radiation in a state in which a radiation detector and a radiation measurement device are combined in advance and adjusts so that a correct radiation measurement value is output. , Had it in the radiation measuring device.

[0003]

However, when the radiation measuring device is provided with the adjusting function as in the conventional radiation measuring system, the combination of the radiation detector and the radiation measuring device is determined. was there.
Therefore, when only the radiation detector is replaced, it is necessary to perform a calibration process for measuring standard radiation again in a state where the replaced radiation detector and the radiation measuring apparatus are combined.

The present invention has been made in view of the above problems, and an object thereof is to be able to accurately measure radiation without recalibration even if the radiation detector is replaced. A radiation measuring device and a radiation measuring system are provided.

[0005]

In order to achieve the above-mentioned object, the invention of claim 1 is a radiation detector for detecting radiation and outputting a detection signal, and measuring the radiation value from the detection signal. It is characterized in that it is provided with a data storage means for storing the data of the calibration value used in the calculation. In this radiation detector, even when the radiation detector combined with the radiation measuring device is replaced, the calibration value data stored in the data storage means of the radiation detector is read out to the radiation measuring device side, and the calibration value data is read. The radiation measurement value can be accurately calculated based on the detection signal output from the radiation detector.

According to a second aspect of the present invention, in the radiation detector according to the first aspect, the calibration value data storage means is composed of a memory of a microcomputer. In this radiation detector, the calibration value data can be easily stored as a digital signal in the memory of the microcomputer as the calibration value data storage means. Further, since the calibration value data stored in the microcomputer can be read out as a digital signal to the radiation measuring apparatus side, digital signal processing for calculating the radiation measurement value based on the calibration value data and the detection signal. Will be easier. Further, since the memory of the microcomputer is used as the calibration value data storage means, the microcomputer can also be used for other control in the radiation detector.

The invention according to claim 3 is a radiation measuring apparatus for calculating and outputting a measured value of radiation based on a detection signal output from the radiation detector, wherein the radiation detector according to claim 1 or 2 A calibration value data reading means for reading the calibration value data stored in the data storage means, and a calculating means for calculating a radiation measurement value based on the detection signal and the calibration value data. It is what In this radiation measuring apparatus, even when the radiation detector is replaced, the calibration value data reading means reads the calibration value data stored in the data storage means of the radiation detector, and the calibration value data and the radiation detector are read. The measurement value of the radiation can be accurately calculated by the calculation means based on the detection signal output from the.

The invention of claim 4 is a radiation measuring system for measuring radiation, wherein the radiation detector of claim 1 or 2, the radiation measuring device of claim 3 and the radiation measuring device to the radiation measuring device. And a communication cable for sending the detection signal and the calibration value data. In this radiation measurement system, even when the radiation detector connected to the radiation measurement device via a communication cable is replaced, the calibration value data stored in the data storage means of the radiation detector is transferred to the radiation measurement device side via the communication cable. The radiation measurement value can be accurately calculated based on the calibration value data and the detection signal sent from the radiation detector to the radiation measurement device via the communication cable. Even when the radiation measuring device is installed in a place away from the radiation detector and where the risk of radiation exposure is low, the detection signal and calibration value data can be reliably transmitted from the radiation detector to the radiation measuring device via the communication cable. be able to.

In addition to the values of irradiation dose [C / kg, X-ray (R)], absorbed dose, [Gray (Gy), rad] values, and dose equivalents are included in the measured values of the radiation. The values of [sievert (Sv), rem] and the like are also included. Further, it may be a dose rate value which is a value per unit time.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an X-ray measurement system as a radiation measurement system for measuring the dose of X-rays will be described below with reference to the drawings. FIG. 2 is an external view of the X-ray measurement system according to this embodiment. The X-ray measurement system 10 includes an X-ray detector 100 as a radiation detector, an X-ray measurement device 200 as a radiation measurement device, an X-ray detector 100 and an X-ray measurement device 2.
It is configured using a communication cable 300 that connects with 00. The X-ray detector 100 detects X-rays and outputs a detection signal. The X-ray measuring apparatus 200 is the X-ray detector 10
The value of the X-ray dose (irradiation dose or absorbed dose in air) is calculated based on the detection signal output from 0 and displayed on the display unit 201. The case of displaying the irradiation dose will be described below. The communication cable 300 is for transmitting and receiving the detection signal and the calibration value data between the X-ray detector 100 and the X-ray measuring apparatus 200.

FIG. 1 is a block diagram showing a schematic configuration of an internal circuit of the X-ray detector 100. In the X-ray detector 100, the X-ray sensor element 101 composed of a diode element is used for X-ray
The line is detected, the sensor output signal is amplified by the purine amplifier 120, and then input to the V / F conversion circuit 103. The V / F conversion circuit 103 generates a pulse train whose repeating period changes according to the amplitude of the sensor output signal input from the purine amplifier 120. V / F conversion circuit 103
The pulse signal output from the signal passes through the buffer circuit 104 and is output as a detection signal. In addition, the X-ray detector 10
0 is equipped with a one-chip type microcomputer 105, and the memory 1 in this microcomputer 105
Reference numeral 05a is used as a data storage means for storing the data of the calibration value used when calculating the value of the X-ray irradiation dose from the detection signal in the X-ray measuring apparatus 200. Memory 105 in this microcomputer 105
The data of the calibration value is stored in a as digital information, and is stored in the internal memory 105a based on the calibration value data acquisition command signal transmitted from the external X-ray measuring apparatus 200 via the communication cable 300. The calibration value data that has been recorded is transmitted to the X-ray measurement apparatus 200. The microcomputer 105 also outputs control data for setting the 0-point level on the input side of the V / F conversion circuit 103. This control data is converted into an analog signal by the D / A conversion circuit 106, and the V / F conversion circuit 10
3 is applied as an offset voltage on the input side, whereby the 0-point level is set.

FIG. 3 is a block diagram showing a schematic configuration of an internal circuit of the X-ray measuring apparatus 200. In the X-ray measuring apparatus 200, the X-ray detector 100 is connected to the communication cable 300.
The detection signal (pulse signal) sent via the buffer circuit 202 is input to the pulse control circuit 203 through the buffer circuit 202. The pulse control circuit 203 turns on the X-ray detection based on the detection signal (pulse signal) received from the X-ray detector 100.
Generate a signal and an overload signal. These X-ray detection ON signal (S2) and overload signal (S3)
Is input to the microcomputer 204 as a main control unit together with the detection signal (S1). The X-ray detection ON signal (S2) has a predetermined level (for example, the V / F
This signal is output when an X-ray larger than 1 mV) is detected on the input side of the conversion circuit. Further, the overload signal (S3) is at an excessive level (for example, the V
This signal is output when the input side of the / F conversion circuit 103 detects an X-ray of 10 V or more).

Further, the microcomputer 204 described above
Is also used as a calibration value data reading means for reading the calibration value data stored in the memory 105a of the microcomputer 105 of the X-ray detector 100. The reading of the calibration value data is performed by transmitting a calibration value data acquisition command signal from the microcomputer 204 to the microcomputer 105 of the X-ray detector 100 via the communication cable 300 prior to the X-ray dose measurement. . The calibration value data received from the X-ray detector 100 is temporarily stored in the memory 204a in the microcomputer 204 and read out from the memory 204a for use when calculating the X-ray measurement value.

In the microcomputer 204, X
The pulses of the detection signal (S1) input from the line detector 100 are counted, and the dose of the X-ray is calculated based on the count result and the data of the calibration value acquired from the microcomputer 105 of the X-ray detector 100. The value is calculated. The calculated X-ray dose value is sent to the display drive circuit 205 as a digital signal, and the measured X-ray dose value is displayed on the display 201 by the display drive circuit 205.

As described above, according to this embodiment, the X-ray detector 1
By storing the calibration value data in 00, X
When the X-ray detector 100 and the X-ray measuring apparatus 200 are used in combination, the calibration value data in the X-ray detector 100 can be read out and used to calculate the X-ray dose value. Therefore, even when the X-ray detector 100 is replaced, the radiation can be accurately measured without performing the calibration process again. In addition, even if an X-ray detector having a detection characteristic different from that currently used, such as an X-ray detector using an X-ray sensor element having a higher sensitivity than that of the present, is developed in the future. If the combined calibration value is stored in the X-ray detector, the X-ray measuring device 200 can be used.
Can be used as is in combination with.

FIGS. 4 (a) and 4 (b) are explanatory views showing how the measured values are corrected when the X-ray detectors having different sensitivity characteristics are exchanged. In FIG. 4A, the X-ray irradiation dose is 1000 mR, the sensitivity of the X-ray detector 100A is 1.0, and the calibration value is 1. Therefore,
The X-ray detector 100A outputs a detection signal S1 corresponding to 1000 mR, and the X-ray measurement apparatus 200 detects the detection signal S1.
The value (1000) calculated from 1 is multiplied by the calibration value 1, and the true value (1000 mR) of the X-ray irradiation dose is displayed on the display unit 201.
Is displayed in. On the other hand, as shown in FIG. 4B, when the X-ray detector 100B having a sensitivity of 0.5 is replaced, 2 is stored as the calibration value. Then, the X-ray detector 100B outputs a detection signal S1 ′ that apparently corresponds to 500 mR, and the X-ray measuring apparatus 200 multiplies the value (500) calculated from the detection signal S1 ′ by the calibration value 2 to calculate the X-ray The true value (1000 mR) of the irradiation dose is displayed on the display device 201.

Further, according to the present embodiment, the X-ray measuring apparatus 200 has no factor of manufacturing error (fluctuation) and, for example, a standard signal generated by a reference oscillation circuit (not shown) built in the apparatus is simulated. It can be adjusted by adding it as a signal to the input side of the pulse control circuit 203. Therefore, the step of measuring standard radiation in a state where the X-ray detector and the X-ray measuring apparatus are combined and adjusting so that a correct measurement value of the radiation is output, which is performed in the case of the conventional apparatus, becomes unnecessary,
The number of manufacturing steps can be reduced.

Further, according to the present embodiment, the X-ray detector 1
Even when the X-ray measuring device 200 is installed in a place away from the exposure risk 00, which is less likely to be exposed to radiation, the data of the detection signal and the calibration value is surely transmitted from the X-ray detector 100 to the X-ray measuring device 200 via the communication cable 300. Can be sent to.

In the above embodiment, the case of measuring X-rays has been described, but the present invention can be applied to the case of measuring other radiation such as gamma rays, and similar effects can be obtained.

[0020]

According to the first to fourth aspects of the present invention, by storing the calibration value data in the radiation detector,
When the radiation detector and the radiation measuring device are used in combination, the calibration value data in the radiation detector can be read out and used to calculate the radiation measured value. Therefore, even if the radiation detector is replaced, there is an effect that the radiation can be accurately measured without performing the calibration process again.

In particular, according to the second aspect of the invention, the calibration value data can be easily stored as a digital signal, and the digital signal processing for calculating the radiation measurement value in the radiation measuring apparatus becomes easy. Furthermore,
There is an effect that the microcomputer used as the calibration value data storage means can also be used for other control in the radiation detector.

In particular, according to the invention of claim 4, even when the radiation measuring apparatus is installed in a place away from the radiation detector where the risk of radiation exposure is small, the detection signal and the data of the calibration value are emitted from the radiation detector. There is an effect that it can be reliably sent to the measuring device via a communication cable.

[Brief description of drawings]

FIG. 1 is a block diagram showing an internal circuit of an X-ray detector that constitutes an X-ray measurement system according to an embodiment of the present invention.

FIG. 2 is an external view showing a schematic configuration of the X-ray measurement system.

FIG. 3 is a block diagram showing an internal circuit of an X-ray measurement apparatus which constitutes the X-ray measurement system.

4 (a) and 4 (b) are explanatory views showing a manner of correcting an irradiation dose value of X-ray when the X-ray detector in the X-ray measurement system is replaced.

[Explanation of symbols]

10 X-ray measurement system 100 X-ray detector 101 X-ray sensor element 102 preamplifier 103 V / F converter 104 buffer circuit 105 Microcomputer 106 D / A converter 200 X-ray measuring device 201 display 202 buffer circuit 203 pulse control circuit 204 microcomputer 205 Display drive circuit 300 communication cable

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G088 EE11 EE30 FF02 FF19 GG21                       JJ09 JJ33 JJ36 KK20 KK29                       LL26

Claims (4)

[Claims] 1. A radiation detector for detecting radiation and outputting a detection signal, comprising data storage means for storing calibration value data used when calculating a measurement value of radiation from the detection signal. A radiation detector characterized by. 2. The radiation detector according to claim 1, wherein the calibration value data storage means is constituted by a memory in a microcomputer. 3. A radiation measuring device for calculating and outputting a measured value of radiation based on a detection signal output from the radiation detector, wherein the radiation measuring device stores the data in the data storing means of the radiation detector. A radiation measuring device, comprising: a calibration value data reading unit for reading data of a calibration value stored therein; and a calculating unit for calculating a radiation measurement value based on the detection signal and the calibration value data. . 4. A radiation detector according to claim 1 or 2, a radiation measuring device according to claim 3, and a communication cable for sending the detection signal and the calibration value data from the radiation detector to the radiation measuring device. A radiation measurement system, which is configured by combining and.