JP2002006054A - Radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detector, which can obtain incident position information of radiation rays with high accuracy without increasing the number of measurement circuits. SOLUTION: The detector comprises a plurality of electrode wires 2 that are individually and electrically insulated to be placed so as to cross a measured object area (1), delay elements 5 that connect in sequence an end of each couple of the wires 2 which is set an arbitrary number of these wires 2, measurement circuits 3 that are individually connected to each couple of the wires 2 that is connected to be divided by these delayed elements 5, delay elements 5 that connect in sequence the other end of the wires 2 which are individually selected from each couple of the wires 2, measurement circuits 3 that are individually connected to each couple of the wires 2 by these elements 5, dead time generating circuits 6 that are connected to these circuits 3 and measure a first signal, and a signal processing circuit 4 that specifies a wire 2 which is connected to this generating circuit 6 and generates the signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation detector used in medical facilities, nuclear facilities, and the like, and more particularly to a radiation detector having a radiation incident position detecting function.

[0002]

2. Description of the Related Art Conventionally, a radiation incident position has been measured using a divided scintillator, a scintillation fiber bundle, or a multi-wire ionization chamber. For a split scintillator or scintillation fiber bundle, a method has been established to reduce the number of photodetectors required by devising the method of extracting scintillation light. Since all the electrodes have the same potential, the integration of the electrode wires is not performed. Therefore, it is necessary to prepare the same number of measurement circuits as the number of electrode wires.

FIG. 6 shows a configuration example of a conventional radiation detection apparatus of this type. In FIG. 6, the electrode wires 2 that are each insulated and fixed to the detector container 1 are connected to a signal processing circuit 4 via a measuring circuit 3. The potential fluctuation of the electrode wire 2 that has detected the radiation is converted into an appropriate electric signal by the measurement circuit 3, and the radiation incident position information is obtained by the signal processing circuit 4.

[0004]

In the above-described conventional radiation detecting apparatus, if the accuracy of the radiation incident position information is to be improved, the number of electrode lines increases, the number of necessary measuring circuits increases, and the power consumption increases. And increase the price, and reduce the reliability of the system.

Accordingly, an object of the present invention is to provide a radiation detecting apparatus capable of obtaining radiation incident position information with high precision without increasing the number of measuring circuits connected to the electrode wires.

[0006]

According to a first aspect of the present invention, a plurality of electrode wires, each of which is electrically insulated so as to cross an area to be measured, and an arbitrary number of the electrode wires, are set. A delay element having one end connected sequentially, a measuring circuit connected to each set of electrode lines connected and divided by the delay element, and one of the electrode lines selected from each set. A delay element for sequentially connecting the other ends of the connected electrode lines, and one set for each set of the electrode lines connected by the delay element.
A measuring circuit connected to each of the measuring circuits; a dead time generating circuit connected to the measuring circuit and the measuring circuit for measuring only a first signal; and a signal connected to the dead time generating circuit and specifying an electrode line which generates a signal. And a processing circuit.

According to the present invention, one electrode wire is provided for each of the plurality of electrode wires.
By simply providing a plurality of measurement circuits, it is possible to distinguish between a signal that has arrived directly and a signal that has arrived by way of detour, and specify the electrode line that has generated the signal.

According to a second aspect of the present invention, an arbitrary number of a plurality of electrode lines which have a signal delay function and are electrically insulated so as to cross an area to be measured are set as one set, and one of the sets is used as one of the sets. And a measuring circuit connected to the other end of each set of electrode wires selected one by one from each set of the electrode wires, and a measuring circuit connected to the measuring circuit and the measuring circuit. The configuration includes a dead time generation circuit that measures only the first signal, and a signal processing circuit that is connected to the dead time generation circuit and specifies an electrode line that has generated a signal. According to the present invention, the same operation and effect as those of the first aspect of the present invention can be obtained, and at the same time, the complexity and the manufacturing cost of the configuration for connecting the delay elements can be avoided.

According to a third aspect of the present invention, there are provided a plurality of electrode wires which are provided electrically insulated so as to cross an area to be measured, and a rectifying element having a cathode connected to both ends of each of the electrode wires. A measuring circuit connected to the anode of the rectifying element at one end with an arbitrary number of the electrode wires as one set; and a rectifier at the other end of the electrode wires selected one by one from each set of the electrode wires. The configuration includes a measurement circuit connected to the anode of the element, and a signal processing circuit that is connected to the measurement circuit and specifies an electrode line that generates a signal. According to the present invention, the same effect as the above two inventions can be obtained without requiring a dead time generation circuit.

[0010]

FIG. 1 shows the configuration of a radiation detecting apparatus according to a first embodiment of the present invention. That is, the electrode wires 2 which are provided electrically insulated from each other across the area to be measured are attached inside the detector container 1. One set of an arbitrary number of electrode wires 2 is sequentially connected by a delay element 5. Further, the other ends of the electrode lines 2 selected one by one from each set of an arbitrary number of electrode lines 2 are connected to different delay elements 5.
Connect sequentially. One measuring circuit 3 having an input resistance larger than the electric resistance of the electrode line 2 is connected to each set of the electrode lines 2 connected and divided by the delay element 5.

Also, each of the sets of electrode wires 2 selected one by one from each set of electrode wires 2 and connected by the delay element 5 has a measuring circuit 3 having an input resistance larger than the electrical resistance of the electrode wires 2. Are connected one by one. On the output side of each measuring circuit 3, a dead time generating circuit 6 and a signal processing circuit 4 for obtaining the electrode line 2 which has generated a signal from the output of the measuring circuit 3 are connected.

In the radiation detecting apparatus having such a configuration, the potential of the electrode wire 2 that has detected radiation changes. Since the input resistance of the measuring circuit 3 is larger than the resistance of the electrode wire 2, it is almost constant regardless of whether the incident position of the radiation is near the center or near the end of the electrode wire 2. A signal of the specified magnitude is obtained.

Since the integrated signal lines 2 of each set are connected by the delay element 5, as shown in FIG. 4, the signal A1 from the electrode line 2 that has detected radiation reaches the measuring circuit 3 earliest. . Therefore, triggered by the arrival of the first signal, the dead time generation circuit 6 generates a measurement prohibition signal, which is input to the signal processing circuit 4 and the signals A other than the first signal A1 arrived.
2, A3 and A4 are not used for signal processing. Thus, the electrode wire 2 that has detected the radiation is specified. As described above, according to the present embodiment, it is possible to reduce the number of measurement circuits of a radiation detection device configured using a large number of electrode wires 2.

Next, a second embodiment of the present invention will be described with reference to FIG. That is, the electrode wire 7 is made of a material having a delay function. The electrode lines 7 having a delay function are combined and integrated in the same manner as in the first embodiment, and connected to the measurement circuit 3.

The radiation detecting apparatus of the present embodiment can detect radiation by the same operation as the radiation detecting apparatus of the first embodiment. Further, since the mounting of the delay element 5 becomes unnecessary, the reliability of the detector is increased by simplifying the detector structure, and the cost is reduced.

Next, a third embodiment of the present invention will be described with reference to FIG. That is, the rectifying element 8 of the delay element 5
Is mounted in a direction such that conduction occurs when a current flows from the measurement circuit 3 to the electrode wire 2. The grouping and integration of the electrode wires 2 is the same as that of the first embodiment, and is connected to the measurement circuit 3. The dead time generation circuit 6 is not used, and all signals from the measurement circuit 3 are input to the signal processing circuit 4.

In the radiation detecting apparatus having such a configuration, since the electrode wires 2 are connected by the rectifying element 8, the signal wraparound as shown in FIG. 4 is eliminated. Therefore, as shown in FIG. 5, the signal A1 reaches only the measuring circuit 3 connected to the electrode line 2 that has detected radiation in the shortest way.

The radiation detecting apparatus of the present embodiment can detect radiation by the same operation as the radiation detecting apparatus of the first embodiment, and has high reliability because the detector structure is simplified. It is expensive and cheap.

[0019]

As described above, according to the present invention, it is possible to specify an electrode line which has detected radiation with a small number of measuring circuits. Thus, high-precision radiation incident position information can be obtained without increasing the number of measurement circuits.

[Brief description of the drawings]

FIG. 1 is a diagram showing a radiation detection apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a radiation detection apparatus according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating a radiation detection apparatus according to a third embodiment of the present invention.

FIG. 4 is a view for explaining the operation of the radiation detecting apparatus according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the operation of the radiation detection apparatus according to the third embodiment of the present invention.

FIG. 6 is a diagram showing a conventional radiation detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Detector container, 2 ... Electrode wire, 3 ... Measurement circuit, 4 ... Signal processing circuit, 5 ... Delay element, 6 ... Dead time generation circuit, 7 ...
Electrode lines having a delay function, 8: rectifying elements, A1: signals from the electrode lines that have detected radiation, A2, A3, A4: signals passing through the delay elements.

Claims (3)

[Claims] 1. A delay element for electrically connecting a plurality of electrode wires, each of which is electrically insulated so as to cross an area to be measured, and one end of which is sequentially connected to one set of any number of the electrode wires. And a measuring circuit connected to each set of the electrode lines connected and divided by the delay element, and the other end of the electrode line selected one by one from each set of the electrode lines is sequentially connected. A delay element, a measurement circuit connected to each set of the electrode lines connected by the delay element, and a dead time generation circuit connected to the measurement circuit and the measurement circuit and measuring only the first signal. A signal processing circuit that is connected to the dead time generation circuit and specifies an electrode line that has generated a signal. 2. An arbitrary number of a plurality of electrode wires each having a signal delay function and being electrically insulated so as to cross an area to be measured are connected to one end of each set. Measuring circuit, a measuring circuit connected to the other end of each set of electrode wires selected one by one from each set of the electrode wires, and only the first signal connected to the measuring circuit and the measuring circuit. A radiation detection apparatus comprising: a dead time generation circuit for measuring; and a signal processing circuit connected to the dead time generation circuit and for specifying an electrode line that has generated a signal. 3. A plurality of electrode wires, each of which is electrically insulated so as to cross an area to be measured, a rectifying element having a cathode connected to both ends of each of the electrode wires, A measuring circuit connected to the anode of the rectifying element at one end as an arbitrary number as one set, and connected to the anode of the rectifying element at the other end of the electrode wire selected one by one from each set of the electrode wires. A radiation detection apparatus comprising: a measurement circuit that is connected to the measurement circuit; and a signal processing circuit that is connected to the measurement circuit and specifies an electrode line that generates a signal.