JP2012002816A - Environmental radiation measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmental radiation measuring apparatus which can measure a wide range of environmental radiations from a natural radiation level to a high radiation level with high accuracy, enables reduction of the size and weight, and can reduce the manufacturing cost, using a semiconductor radiation detecting element.SOLUTION: An environmental radiation measuring apparatus comprises: a support body 6 having multiple supporting surfaces disposed at an equal distance making a predetermined base point as a center; one or multiple semiconductor radiation detecting elements 12 provided on the respective support surfaces of the support body 6; measuring means 14 and 19 which are electrically connected with the respective semiconductor radiation detecting elements 12 and measure measurement values caused by incidence of radiations to respective semiconductor radiation detecting elements 12 individually or collectively; and data processing means for determining and outputting output information based on the measurement values by the measuring means and conditioning information stored by a memory.

Description

  The present invention relates to an apparatus for measuring environmental radiation.

  As a conventional radiation measuring apparatus for measuring environmental radiation, for example, a plurality of sub-detectors having high sensitivity to radiation coming from the front are provided on the four outer peripheral sides of the direction switching unit on which the radiation detection unit is mounted. Some are arranged so that the front faces outward, the direction of incident radiation is specified from their count ratio, the turntable is rotated, and the front of the radiation detector is directed in that direction (for example, (See Patent Document 1).

  In addition, a rotatable support member is attached to the main body supporting the radiation detector, and the movable support member is moved upward so that it can be moved by a wheel attached to the lowermost part of the main body. Some have been made (see, for example, Patent Document 2).

  Further, a radiation detection means using a semiconductor is known (see, for example, Patent Document 3 or 4).

JP 2005-265471 A JP 2003-057347 A International Publication WO2002 / 063340 Pamphlet JP 2009-246073 A

The environmental radiation dose meter described in Patent Document 1 is complicated in structure, takes time for operation, is large, and is expensive to manufacture.
Patent Document 2 only describes the configuration of the environmental radiation dose meter for transportation, and does not describe the specific structure of the radiation detector.
In addition, radiation detectors using conventional semiconductors as described in Patent Documents 3 and 4 are less sensitive than NaI (Tl) scintillation detectors and are not suitable for use in environmental radiation measurement devices. Has been.

  In view of the above-mentioned problems of the prior art, the present invention uses a semiconductor radiation detection element, which has been conventionally unsuitable, from a natural radiation level (on the order of 0.01 μGy / h) to a high dose level ( An object of the present invention is to provide an environmental radiation measuring apparatus capable of measuring a wide range of environmental radiation up to 100 mGy / h) with high accuracy, and which can be reduced in size and weight and can reduce manufacturing costs.

According to the present invention, the above problem is solved as follows.
(1) A support body having a plurality of support surfaces in which the environmental radiation measurement device is arranged at an equal distance around a predetermined reference point, and one or a plurality of radiations provided on each support surface of the support body A semiconductor device for detection, and a measuring means that is electrically connected to each of the semiconductor elements for radiation detection, and measures measurement values caused by incidence of radiation on each of the semiconductor elements for radiation detection, or a plurality of measurement values collectively And data processing means for determining and outputting the output information based on the measurement value of the measurement means and the condition setting information stored in the memory.

With such a configuration, even if each semiconductor element for radiation detection has poor sensitivity, a plurality of them are provided on a plurality of support surfaces arranged at equal distances around a predetermined reference point. The radiation incident on the space formed by the semiconductor element can be accurately caught, and the environmental radiation can be measured with high accuracy over a wide measurement range.
In addition, even if multiple semiconductor elements are gathered together, the individual semiconductor elements are small, so the overall measuring device can be reduced in size and weight, not only reducing manufacturing costs, but also being excellent in portability and during radiation disasters. It can be installed urgently.
Furthermore, by installing it around the reactor facility, the radiation environment around the reactor facility can be monitored over time during normal times and when disasters occur, and the radiation exposure dose of the residents around the facility can be estimated and the cause of the disaster clarified. And so on.

  (2) In the above item (1), the support body has at least four support surfaces provided on the front and rear, left and right outer surfaces and one support surface provided on the upper surface.

  With such a configuration, it is possible to form a three-dimensional space having the simplest structure in which semiconductor elements for radiation detection are arranged on the entire outer periphery except the bottom surface, simplify the structure, and reduce manufacturing costs. it can.

  (3) In the above item (1) or (2), the measurement means is one or more radiation detection semiconductor elements for each support surface, or predetermined measurement values of a plurality of radiation detection semiconductor elements. It is assumed that a sub-measuring unit that measures the above and a main measuring unit that adds the measurement values of all the sub-measuring units are provided.

  With such a configuration, when a very large amount of radiation is incident on the radiation detecting semiconductor element, it is possible to reduce as much as possible the number of erroneous measurements.

  (4) In any one of the above items (1) to (3), a radiation filter that covers the entire support surface of the support body provided with the semiconductor element for radiation detection and prevents entry of radiation having a predetermined energy level or less. And provided on the support.

  With such a configuration, detection of radiation with a low energy level can be discarded and an averaging process can be performed.

  (5) In any of the above items (1) to (4), a transmitter is connected to the data processing means so that the output data of the data processing means can be transmitted from the transmitter.

  With this configuration, environmental radiation measurement device data can be received at a remote location, so multiple environmental radiation measurement devices can be installed at remote locations to collect a wide range of environmental radiation at one location. Status monitoring.

  According to the present invention, environmental radiation can be measured with high accuracy over a wide measurement range by using a semiconductor radiation detection element that has been conventionally unsuitable, and can be reduced in size and weight. It is possible to provide an environmental radiation measurement apparatus that can reduce the cost.

It is the disassembled perspective view which looked at one Embodiment of this invention from diagonally forward. It is a vertical front view which shows a case and a radiation filter longitudinally in the center. It is a front view of one board | substrate. It is a block diagram which shows an electric system with a block.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1 and FIG. 2, this environmental radiation measurement apparatus has a horizontal circular base plate 1, a plurality of spacers 2 and fixing screws 3 on the base plate 1, and is spaced upward from the base plate 1. Thus, a support body 6 comprising a circular support plate 4 having a smaller diameter than the base plate 1 and a rectangular parallelepiped support frame 5 provided at the center of the upper surface of the support plate 4 is provided.

  The support frame 5 includes four support columns 7 whose lower ends are fixed to the support plate 4 with fixing screws, and four horizontal rods 8 that connect the upper ends of the support columns 7 so as to form a square in plan view. Yes. Note that the lower portions of the columns 7 may be connected to each other with a horizontal surface (not shown) similar to the horizontal surface 8.

  A square substrate 9 is attached to the upper surface of the support frame 5, and a vertically long rectangular substrate 10 is attached to the front, rear, left and right side surfaces of the support frame 5 by screwing four corners with fixing screws 11. Yes.

The upper surface of the substrate 9 and the outer side surface of the square portion (see the two-dot chain line in FIG. 3) whose upper side is one side from the upper end of each substrate 10 are surfaces other than the bottom surface of the regular cube.
Accordingly, each of the surfaces forms a support surface disposed at an equal distance around the reference point when the center O of the regular cube is determined as the reference point.

  Four radiation detecting semiconductor elements (hereinafter simply referred to as “semiconductor elements”) 12 are arranged in the same pattern of two vertically and two horizontally on the upper surface of the substrate 9 which is a supporting surface and on the outer surface of the square portion of each substrate 10. It is fastened.

  Each semiconductor element 12 is obtained by forming an electrode on a plate-like silicon semiconductor by aluminum vapor deposition or the like. When a reverse bias voltage is applied to the semiconductor element 12, a depletion layer is formed inside the semiconductor, and the dose is measured by counting electrons and holes generated by the interaction of γ radiation incident on this region. It has become.

  As shown in FIG. 3, at the lower part of each substrate 10 except for the square portion, four semiconductor elements 12 fixed to each substrate 10 are electrically connected with printed wirings 13 (or lead wires), A counter block 14 having four counters 14a for counting the number of pulses generated in response to radiation incidence from the semiconductor element 12 is provided.

  An auxiliary substrate 15 is attached below the substrate 10 on the front surface (or the rear surface or side surface) of the support frame 5, and four semiconductor elements 12 provided on the substrate 9 are electrically connected to the four semiconductor elements 12 via the lead wires 16. There is provided a counter block 14 having four counters 14a for counting the number of pulses generated from each semiconductor element 12 corresponding to the incidence of radiation.

  A control box 17 is detachably provided at the center of the upper surface of the base plate 1, and as shown in FIG. 4, all 20 counters 14 a for counting the measurement values of the semiconductor elements 12 are provided in the control box 17. Are connected to each other via a lead wire 18 and act to add up the measured values of the counters 14a, a memory 20 for storing various condition setting information, measured values of the CPU 19, and stored in the memory 20 The data processing means 21 for determining and outputting the output information based on the condition setting information, and the transmission connected to the data processing means 21 for converting the output data of the data processing means 21 into a radio wave for transmission A machine 22, a power source 23 for supplying power to each of the above-mentioned electric and electronic components, and the like are provided.

  In this embodiment, 20 counters 14a constitute sub-measurement means for measuring the measurement values of each semiconductor element 12, and the CPU 19 serves as main measurement means for adding up the measurement values of all the sub-measurement means. None, the measuring means is formed by the sub-measuring means and the main measuring means.

  The condition setting information stored in the memory 20 includes, for example, a count value, a unit time length to be counted, a radiation dose rate, a device-specific correction value, and the like.

    As shown in FIG. 2, the lead wire 18 is led from each counter block 14 to the control box 17 through a vertical insertion hole 24 formed in the center of the support plate 4.

  In the center of the support plate 4, an upward step 4a having a diameter larger than the diagonal line in plan view of the support frame 5 is provided, and the upper end of the upward step 4a is closed with an upper surface plate 25a. The lower end of the cylindrical radiation filter 25 is tightly fitted.

The radiation filter 25 is for preventing the entry of radiation having a predetermined energy level (for example, 50 keV) or less, and is made of, for example, copper. In order to change the energy level of the radiation that prevents entry, the thickness and material of the radiation filter 25 may be changed as appropriate.
In addition, the radiation filter 25 may be omitted, or may be provided integrally with an exterior case 26 described below.

The outside of the radiation filter 25 is further covered with a cylindrical outer case 26 whose upper end is closed with an upper surface plate 26a.
The outer case 26 is detachably attached to the base plate 1 by fixing an enlarged flange 26 b provided at the lower end to the outer peripheral edge of the base plate 1 with a fixing screw 27.

  Since this environmental radiation measuring apparatus is configured as described above, when radiation that is higher than a predetermined energy level passes through the radiation filter 25 and enters one of the semiconductor elements 12, the semiconductor element 12 A pulse is generated in response to the incidence of the radiation, and the pulse is counted by each counter 14a which is a sub-measurement means.

  If a large amount of radiation exceeding the counting limit of the counting circuit is incident on each semiconductor element 12, there is a possibility that only a value smaller than the count value to be counted is counted. For this reason, the size of the semiconductor element is suppressed so that the semiconductor element falls within the counting limit of the counting circuit even when a radiation number corresponding to a high dose rate (100 mGy / h) is incident. In this way, it is possible to reduce as much as possible the erroneous measurement.

  The counts counted by the counters 14a are all added and output by the CPU 19 which is the main measuring means. At this time, since each count is added up as a numerical value, there is no fear of the erroneous measurement as described above in the counter 14a.

  The output data of the CPU 19 is processed by the data processing means 21 based on the condition setting information stored in the memory 20, and the output data is converted into radio waves by the transmitter 22 and transmitted.

The output data converted into radio waves and transmitted can be received at a remote place by a receiver.
Therefore, by installing multiple environmental radiation measurement devices at points distant from each other and receiving output data transmitted from each environmental radiation measurement device at one location, a wide range of environmental radiation is collected at one location to monitor the condition can do.

  As is clear from the above, according to the present invention, even if each semiconductor element for radiation detection has insufficient sensitivity, a plurality of supports are arranged at equal distances around a predetermined reference point. By providing on the surface, it is possible to accurately capture the radiation incident in the space formed by these semiconductor elements, and it is possible to measure the environmental radiation with high accuracy over a wide measurement range.

  In addition, even if a plurality of semiconductor elements 12 are gathered together, the individual semiconductor elements 12 may be small, so that the overall measurement apparatus can be reduced in size and weight, not only reducing the manufacturing cost, but also being excellent in portability, It can be installed urgently during a radiation disaster.

  Furthermore, by installing it around the reactor facility, the radiation environment around the reactor facility can be monitored over time during normal times and when disasters occur, and the radiation exposure dose of the residents around the facility can be estimated and the cause of the disaster clarified. And so on.

  Since the support 6 has at least four support surfaces provided on the front, back, left, and right side surfaces and one support surface provided on the upper surface, the semiconductor element 12 is disposed on the entire outer periphery except the bottom surface. In addition, a three-dimensional space having the simplest structure can be formed, the structure can be simplified, and the manufacturing cost can be reduced.

  When the radiation filter 25 is provided, detection of radiation with a low energy level can be discarded and an averaging process can be performed.

The present invention is not limited to the above embodiment, and can be implemented in the following modified modes.
(1) In the above-described embodiment, the support surface of the support 6 is five surfaces including the front, back, left, and right side surfaces and the upper surface. For example, each surface of a regular octahedron, each surface of another regular polyhedron, or mirror ball It can also be each side.
(2) In the above embodiment, four radiation detecting semiconductor elements 12 are arranged on one supporting surface, but the number of semiconductor elements 12 arranged on each supporting surface is one or It can be a plurality other than four. However, it is desirable to reduce the number of semiconductor elements 12 arranged on one support surface.
(3) In the above embodiment, the measurement value of one semiconductor element 12 is counted by one counter 14a which is a sub-measurement unit. For example, one counter 14a is used to count one measurement value. The measurement values of the four semiconductor elements 12 disposed on the support surface are collectively measured, or the measurement values of the plurality of semiconductor elements 12 disposed on the plurality of support surfaces are collectively measured. Also good.
(4) As shown by a two-dot chain line in FIG. 2, a solar cell 28 is provided on the upper surface plate 26 a of the outer case 26 or on other parts, and the power source 23 is charged by the solar cell 28. Good.

DESCRIPTION OF SYMBOLS 1 Base plate 2 Spacer 3 Fixing screw 4 Support plate 4a Upward step part 5 Support frame 6 Support body 7 Support column 8 Recumbent pad 9 9, Substrate 11 Fixing screw 12 Semiconductor element 13 for radiation detection Printed wiring 14 CPU (sub measurement means)
15 Auxiliary board 16 Lead wire 17 Control box 18 Lead wire 19 CPU (Main measuring means)
20 Memory 21 Data Processing Means 22 Transmitter 23 Power Supply 24 Insertion Hole 25 Radiation Filter 25a Top Plate 26 Exterior Case 26a Top Plate 26b Expanding Flange 27 Fixing Screw 28 Solar Cell

Claims (5)

A support having a plurality of support surfaces arranged equidistantly around a predetermined reference point;
One or a plurality of radiation detecting semiconductor elements provided on each supporting surface of the support;
A measurement means that is electrically connected to each of the radiation detection semiconductor elements, and that measures measurement values resulting from the incidence of radiation on each of the radiation detection semiconductor elements, or a plurality of measurement values collectively,
An environmental radiation measurement apparatus comprising: a data processing unit that determines and outputs output information based on a measurement value of the measurement unit and condition setting information stored in a memory.   2. The environmental radiation measuring apparatus according to claim 1, wherein the support has at least four support surfaces provided on the front, rear, left and right side surfaces and one support surface provided on the upper surface.   The measurement means includes one or a plurality of radiation detection semiconductor elements for each support surface, or a sub measurement means for measuring measurement values of a plurality of predetermined radiation detection semiconductor elements, and all of the sub measurement means. The environmental radiation measuring apparatus according to claim 1, further comprising main measuring means for adding up the measurement values.   The radiation filter according to any one of claims 1 to 3, wherein the support is provided with a radiation filter that covers the entire support surface of the support provided with the semiconductor element for radiation detection and prevents entry of radiation having a predetermined energy level or less. Environmental radiation measurement equipment.   The environmental radiation measuring apparatus according to claim 1, wherein a transmitter is connected to the data processing means so that output data of the data processing means can be transmitted from the transmitter.

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