JPS5811590B2 - thermoluminescent dosimeter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoluminescent dosimeter for measuring radiation exposure dose, and the present invention relates to a thermoluminescent dosimeter that measures radiation exposure dose, and automatically measures a card holding a thermoluminescent material while the card is housed in a case for protecting the thermoluminescent material. This provides a configuration to do this.

When a thermoluminescent dosimeter element (hereinafter referred to as an element) exposed to radiation is heated, thermoluminescence is emitted from the element in accordance with the exposure dose.

The radiation exposure dose can be determined by converting this thermoluminescence into a current using a photomultiplier tube and integrating it, and by measuring this integrated value or by counting the number of photons of thermoluminescence.

1 and 2 show elements used in the thermoluminescence dosimeter of the present invention.

In FIG. 1 and FIG. 2, 1 is a case body, and protrusions 2 and 3 are formed on this case body 1.
A cover plate 4 is fixed to the upper surface of 3 to form a case with one end open.

5 is a notch formed between the protrusions 2 and 3, and 6 is the protrusion 2.
A protrusion 7 formed at the end of the case body 1 is an information reading section formed integrally with the case body 1. A large number of holes 8 are formed in the information reading section 7, and by closing any hole 8, Personal code etc. are recorded.

Reference numeral 9 denotes a card housed in the case, and a plurality of holes 10 are formed in the card 9, and a thermoluminescent material 11 is housed in the holes 10.

Reference numeral 12 indicates an engaging claw formed on the card 9, and reference numeral 13 indicates a recess formed in the card 9. When the card 9 is inserted into the case, the engaging claw 12 engages with the notch and the card 9 is inserted into the case. is kept inside the case.

FIGS. 3, 4, and 5 show a magazine that stores a large number of the elements shown in FIG. 1.

In FIGS. 3 to 5, reference numeral 14 designates a magazine whose top surface is open and whose interior is partitioned by a partition wall 15, and a hole 16 is formed in the bottom surface of this magazine 14.

17 is a protruding piece provided at a corner of each compartment 18 of the magazine 14, and 19 is a rack formed on a side surface of the magazine 14.

The element 20 shown in FIG. 1 is attached to the magazine 1 with the information reading section 7 side facing down, as shown by broken lines in FIGS. 4 and 5.
4 into each compartment 18.

FIG. 6 schematically shows the entire thermoluminescent dosimeter of the present invention.

In FIG. 6, reference numeral 21 denotes a board, and guide plates 22 and 22' for guiding the magazine 14 are fixed to this board 21.

23.23' is a spring having one end fixed to the guide plate 22.22' and the other end supporting rollers 24, 24'; the rollers 24, 24' are formed on the guide plates 22, 22'. Guide plate 22゜22' through window 25.25'
It protrudes inward and presses the magazine 14 against one side wall of the guide plate 22, 22' by the elastic force of the spring 23, 23'.

26 is a pulse motor, and a ramp wheel 28 is fixed to a rotating shaft 27 of this pulse motor 26.

This gear 28 meshes with the rack 19 of the magazine 14.

Reference numeral 29 is a disk fixed to the rotating shaft 27, and a plurality of holes 30 are formed at equal intervals in the disk 2-9.

Reference numerals 31 and 32 denote a light emitting diode and a phototransistor, respectively, which are arranged opposite to each other with the disk 29 in between, and the number of holes 30 in the disk 29 is also 8 for the number of strokes of the gear 28, which is 8.
If the pulse motor 26 rotates by the commanded number of pulses without making a mistake, the number of holes 30 is detected by the light emitting diode 31 and the phototransistor 32, and the magazine 14 is transferred at a predetermined pitch. is what is detected.

33.34.35 is a light emitting diode, 36°37.38
is a phototransistor, and the magazine 14 is inserted into the guide plate 22 by the light emitting diode 33 and the phototransistor 36, and the gear 28 and the rack 19 of the magazine 14 are connected to each other.
The end of the magazine 14 is detected by the light emitting diode 34 and the phototransistor 37, and the light emitting diode 35 and the phototransistor 38 detect whether the element 20 is housed in the magazine 14. When the light emitting diode 35 and phototransistor 38 detect that no element 20 is stored, the pulse motor 26 continues to rotate and transports the magazine 14 until the next element 20 is detected. be.

Further, when the magazine 14 is transferred to the end, the end of the magazine 14 is detected by the light emitting diode 34 and the phototransistor 37, and the rotation of the pulse motor 26 is stopped.

39 is a pulse motor, and a gear 41 is attached to a rotating shaft 40 of this pulse motor 39.

42 is a sliding rod, and the above-mentioned gear 41 is attached to this sliding rod 42.
A rack 43 is formed that meshes with the rack.

Reference numeral 44 denotes a push-up plate provided at the upper end of the slide rod 42. When the pulse motor 39 rotates in one direction, the slide rod 42 rises, and the push-up plate 44 is inserted into the hole 16 formed at the bottom of the magazine 14. inserted, pushes up one element 20, and this element 2
0 from the magazine 14.

45 is a disc fixed to the rotating shaft 40 of the pulse motor 39, and this disc 45 has a notch 46 formed therein.

Reference numerals 47 and 48 indicate light emitting diodes, and 49 and 50 indicate phototransistors.These light emitting diodes 47 and 48 and phototransistors 49 and 50 detect whether or not the sliding rod 42 has moved by a specified amount.

In FIG. 6, reference numeral 51 denotes a heating measurement section.Next, the structure of this heating measurement section 51 will be explained with reference to FIGS. 6, 7, and 8.

In FIG. 7, 52 is a plate-shaped main housing supported by support legs 53, 53', and guide rods 54, 54' are implanted in this main housing 52.

Reference numeral 55 denotes a plate-shaped sub-housing that is guided by the guide rods 54, 54' and overlapped with the main housing 52. The sub-housing 55 is fixed to the main housing 52 with screws 56, 56'.

57 and 58 are supports attached to the main housing 52, and the support 57 has the light emitting diodes 33 to 3.
5 is supported, and the phototransistors 36 to 38 are supported on the support body 58.

59 is a condenser tube fixed to the main housing 52, 60 is a heat lamp attached to this condenser tube 59, 61 is a photomultiplier tube provided in the sub housing 55, and 62 is a photomultiplier tube of this photomultiplier tube 61. The support piece 63 is attached to the housing 52.5.
A roller 64 is rotatably supported on this plate 63, and a coiled spring 6 is attached to this roller 64.
5 is wound.

66° is a clamping rod that is slidably supported by a bearing 71 attached to the main housing 52. The coiled spring 65 is attached to the upper end of this clamping rod 66, and the coiled spring 65 causes the clamping rod 66 to is biased downward.

67 is a pulse motor fixed to the main housing 52, and a rotating shaft 68 of this pulse motor 67 has a pullout 69 fixed thereto.

The pulse motor 67 serves as a driving source for extracting the card 9 from inside the case body 1 of the element 20 and transporting the card 9.

70 is a microswitch, and this microswitch 70 is turned OFF when the sub housing 55 is removed from the main housing 52, stopping the supply of high voltage to the photomultiplier tube 61; This prevents strong external light from entering the photomultiplier tube 61 and damaging the photomultiplier tube 61 when the housing 55 is removed.

Next, the internal structure of the heating measuring section 51 will be explained with reference to FIG. 8.

In FIG. 8, 72 is a vertical groove formed on the mounting surface side of the sub-housing 55 of the main housing 52, and 73 is this vertical groove 72.
The engagement release plate 73 is an engagement release plate fixed to the upper side of the element 20, and a protrusion 74 that is inserted into the notch 5 of the main body case 1 of the element 20 is formed on this engagement release plate 73.

75 is a lamp attached to the wall surface of the vertical groove 72.

76 is a horizontal groove formed in the main housing 52, and a card drive plate 77 is slidably supported in this horizontal groove 76.

Reference numeral 78 denotes an engaging protrusion formed at one end of the card driving plate 77, and this engaging protrusion 78 engages with the recess 13 of the card 9 of the element 20.

Reference numeral 79 denotes a filter attached to the card drive plate 77. This filter 79 is made of carbon film or the like and is used to check the power of the heating lamp 60.

Reference numeral 80 denotes a calibration light source attached to the card drive plate 77. This calibration light source 80 is a light source such as luminous paint, and is used to adjust the sensitivity of the photomultiplier tube 61 and the measurement circuit (not shown). .

81.82°, 83.84.85 are small holes formed in the card drive plate 77.

Reference numeral 86 denotes a support metal fitting that supports the roller 87, and the roller 87 comes into contact with the card drive plate 77.

Reference numeral 88 denotes a member provided on the wall surface of the horizontal groove 76. Small holes 89, 90, 91°92 are formed in this member 88, and a phototransistor is attached.

Next, the element 20 stored in the magazine 14 is extracted,
The outline of the operation of transferring to the heating measuring section will be explained with reference to FIG.

When the slide rod 42 rises, the push-up plate 44 provided at its tip is inserted into the hole 16 on the bottom of the magazine 14, and the element 2
0 from the magazine 14.

At this time, a clamping rod 66 energized by a coiled spring 65 is in self-contact on the upper surface of the element 20, and the element 20 is held by the clamping rod 66.
It is transferred into the vertical groove 72 of the main housing 52 while being held between the push-up plate 44 and the push-up plate 44 .

When the element 20 is further moved upward, the element 20 comes into contact with the upper side of the vertical groove 72, and the information in the information reading section 7 of the element 20 is read here.

At this time, the protrusion 74 enters the notch 5 of the element 20, the engagement between the engagement claw 12 of the card 9 of the element 20 and the notch 5 is released, and the engagement protrusion 78 of the card drive plate 77 is released. It engages with the recess 13 of the card 9.

Here, the card driving plate 77 is moved, the card 9 is pulled out and inserted into the horizontal groove 76, and each thermoluminescent material 11 of the card 9 is sequentially transferred along the optical axis of the heating measuring section and sequentially measured.

After the measurement is completed, the card 9 is stored in the case body 1 of the element 20, and the element 20 is lowered and stored in the magazine 14.

Next, details of each part in FIG. 8 will be explained in conjunction with FIGS. 9 to 13.

FIG. 9 shows a cross section taken along line A-A' in FIG.

In FIG. 9, 93 is a hole formed in the main housing 52, into which the lamp 75 is inserted.

94 is a printed circuit board for mounting the lamp 75;
Reference numeral 95 is a reflector plate of the lamp 75, 96 is a small hole formed in the sub-housing 55, and a light sensor 97 is arranged at the back of this small hole 96.

98 is a printed circuit board on which the optical sensor 97 is mounted.

The information reading section 7 of the element 20 is interposed between the lamp 75 and the optical sensor 97, and the optical sensor 9 detects whether the light from the lamp 75 reaches the optical sensor 97 through the hole 8 of the information reading section 7.
7, and various information can be read.

FIG. 10 shows a cross section taken along line B-B' in FIG.

A rib 99 is provided within the horizontal groove 76 formed in the main housing 52.
is formed, and the card 9 is transferred within the horizontal groove 76 at the bottom of the rib 99.

100.101 are holes formed in the main housing 52 and the sub housing 55, respectively, and these holes 100.101
A light emitting diode 102 and a phototransistor 1 are installed inside.
03 is inserted.

104 and 105 are printed circuit boards on which the light emitting diode 102 and phototransistor 103 are mounted.

The light emitting diode 102 and the phototransistor 103
By this, damage or presence of the thermoluminescent material 11 held on the card 9 is detected.

FIG. 11 shows a cross section taken along line CC' in FIG.

In FIG. 11, reference numeral 59 is the light condensing tube, and a conical through hole 106 is formed in the condensing tube 59, and an infrared transmitting filter 10 is provided at one end of the through hole 106.
7 is installed.

60 is the heating lamp, and this heating lamp 60 is equipped with a reflecting mirror 108.

The heating lamp 60 is placed at the other end opening of the condenser tube 59, and is pressed and fixed by a ring plate 110 via an O-ring 109.

Numeral 111 is a screw for integrally attaching the ring plate 110 and the condenser tube 59 to the main housing 52.

A seat 112 is attached to a hole in the sub-housing 55, and a light glass 113 is inserted into the center hole of the seat 112.

The photomultiplier tube 61 is screwed to the dust 112.

In FIG. 11, the filter 79 provided on the card drive plate 77 is located between the infrared transmission filter 107 and the light glass 113.

The above infrared transmission filter 107 and light glass 113
In between, thermoluminescent material 11 held on card 9
When transported, the thermoluminescent material 11 is heated by light from the heating lamp 60 and becomes thermoluminescent.

This thermoluminescence enters the photomultiplier tube 61 via the light glass 113 and is converted into an electric current.

FIG. 12 shows a cross section taken along the line DD' in FIG.

In FIG. 12, 114 is a rack provided on the card drive plate 77. This rack 114 meshes with the hour wheel 69, and the card drive plate 77 is slid by the rotation of the pulse motor 67.

FIG. 13 shows a cross section taken along line E-E' in FIG.

A phototransistor 115 is mounted within a member 88 attached to the main housing 52.

116 is a light emitting diode inserted into the hole 117 of the sub-housing 55, and 118 and 119 are printed circuit boards on which the phototransistor 115 and the light emitting diode 116 are mounted, respectively.

The light emitting diode 116 and the phototransistor 115
Accordingly, it is detected whether or not the card drive plate 77 is stopped at a predetermined position.

Next, the operation of the present invention will be explained.

6 and 8 show the magazine 14 inserted from the outside.

When such a magazine 14 is inserted, the magazine 14
Since the rack 19 and both cars 28 mesh with each other, and the light from the light emitting diode 33 is blocked by the magazine 14,
Insertion of the magazine 14 is detected by the phototransistor 36.

At this point, when the start switch (not shown) is closed,
The pulse motor 39 rotates a predetermined number of pulses, and the sliding rod 42
, push up the element 20 in the magazine 14, and push up the element 20 in the magazine 14.
0 into the vertical groove 72 of the main housing 52, and
(Fig. 14).

At this time, it is detected that the notch 46 of the disk 45 is rotated to be located between the light emitting diode 48 and the phototransistor 50, and that the element 20 has been pushed up to its normal position.

As shown in FIG. 14, when the element 20 is transferred to the upper end of the vertical groove 72, the protrusion 74 is inserted into the notch 5 of the element 20, and the engaging claw 12 of the card 9 and the notch 5 are engaged. Missing,
Furthermore, the engaging protrusion 78 of the card drive plate 77 engages with the recess 13 of the card 9.

Further, when the element 20 is moved to the position shown in FIG. 14, the lamp 75 in FIG.

Next, the heating lamp 60 shown in FIG.
It is checked whether the heating is being performed normally.

Next, the pulse motor 67 shown in FIG. 12 rotates by the commanded number of pulses, and the card 1 drive plate 77 moves to pull out the card 9 from the case body 1 and transfer the card 9 into the horizontal groove 76. The calibration light source 80 provided on the card drive plate 77 is moved to the optical axis of the heating measurement position (15th
figure).

At this time, the small hole 81 of the card drive plate 77 matches the small hole 91, and it is detected by the light emitting diode 116 and phototransistor 115 shown in FIG. 13 whether or not the card drive plate 77 has been correctly fed.

Note that while the card 9 is being transferred to the position shown in FIG. 15, the leftmost one of the plurality of thermoluminescent materials 11 provided on the card 9 is connected to the light emitting diode 102 and the phototransistor shown in FIG. 103, and the presence or absence of this leftmost thermoluminescent material 11 and the presence or absence of damage are detected.

As shown in FIG. 15, when the calibration light source 80 reaches the optical axis of the heating measurement position, the amount of light emitted by the calibration light source 80 is measured by the photomultiplier tube 61, and the sensitivity of the photomultiplier tube 61 is checked. It is done.

Next, when the pulse motor 67 rotates by the commanded number of pulses, the card driving plate 77 and the card 9 are further transferred as shown in FIG. 16, and the leftmost thermoluminescent material 11 of the card 9 is heated to the measuring position. Position it along the optical axis.

At this time, the small hole 91 of the small hole 82 of the card driving plate 77 coincides with the small hole 91, and it is detected whether the card driving plate 77 has been transferred correctly.

Furthermore, while the card drive plate 77 is being transferred to the position shown in FIG.
It is detected by a light emitting diode 102 and a phototransistor 103 shown in FIG.

In the state shown in FIG. 16, the heating lamp 60 is turned on, the leftmost thermoluminescent material 11 of the card 9 is heated, and the thermoluminescent material 11 emits thermoluminescence through the light glass 113 shown in FIG. The radiation enters the photomultiplier tube 61, is converted into a current, this current is integrated, and the integrated value is detected to measure the radiation exposure dose.

In this way, when the measurement of the thermoluminescent material 11 on the leftmost side of the card 9 is completed, the card drive plate 77 is further transferred, and the second thermoluminescent material 11 from the left is located along the optical axis, and is also exposed to radiation. Exposure dose is measured.

In this case, the small hole 83 and the small hole 91 of the card driving plate 77 detect whether or not the card driving plate 77 has been transferred normally. Presence and presence of damage are detected.

Similarly, the third and fourth thermoluminescent materials 11 are sequentially measured.

When the measurement of the four thermoluminescent materials 11 on the card 9 is completed, the pulse motor 67 reversely rotates by the commanded number of pulses, returning the card drive plate 77 and the card 9 to the state shown in FIG. It is stored inside the case body 1.

At this time, it is detected that the small hole 92 is unshielded by the card drive plate 77 and the card drive plate 77 has returned to its normal position.

In addition, even during the return, the thermoluminescent material 1 is
1 is detected.

Next, the pulse motor 39 shown in FIG. 6 rotates by the commanded number of pulses to lower the sliding rod 42 and move the element 20
It is lowered to the position shown in the figure and stored in the magazine 14.

At this time, the notch 46 of the disc 45 attached to the rotating shaft 40 of the pulse motor 39 rotates to the optical axis of the light emitting diode 47 and the phototransistor 49, and the sliding rod 42 descends to its normal position. is detected.

Next, the pulse motor 31 rotates by the commanded number of pulses to advance the magazine 14 one pitch.

At this time, one hole 30 of the disc 290 attached to the rotating shaft 27 of the pulse motor 31 is located on the optical axis of the light emitting diode 31 and the phototransistor 32, and it is detected that the magazine 14 has been fed at a regular pitch. .

Thereafter, the second, third, etc. elements 20 are sequentially measured in the same manner as described above, and when the measurement of the last element 20 is completed, the rear end of the magazine 14 is connected to the light emitting diode 34 and the phototransistor 37. out of the optical axis of the magazine 14.
It is detected that the magazine 14 has been sent to the final position, and the pulse motor 26 rotates in reverse until the magazine 14 is removed from the optical axis of the light emitting diode 33 and the phototransistor 36, that is, the gear 28 and the magazine 140 rack 19 are removed. Until then, the magazine 14 is driven by the pulse motor 26.

By taking this magazine 14 out and inserting another magazine in the same way, it is possible to measure a large number of elements in the same way.

FIG. 17 shows a portion of a pulse motor 39 in another embodiment of the present invention.

In this embodiment, a metal fitting 12 is attached to the rotating shaft 40 of the pulse motor 39.
0 is fixed, a gear 41 is rotatably supported on the rotating shaft 40, and one end of the spring 121 is connected to the metal fitting 120.
At the same time, the other end of the spring 121 is fixed to the gear 4.
1.

In this way, when the gear 41 is connected to the rotating shaft 40 via the spring 121, even if there is some error in the position between the pulse motor 39 and the upper end of the vertical groove 72 in the main housing 52, the pulse motor By rotating 39 extra, the spring 121 can absorb the positional error, eliminating the need for accurate positional adjustment between the main bousing 52 and the pulse motor 39, and also absorbing variations in the dimensions of the element 200. be.

The thermoluminescence dosimeter of the present invention has the above-described configuration, and there is no need to take out the thermoluminescence dosimeter card built into the protective case from the protective case beforehand, and it can be measured while the card is inside the protective case. can do.

Therefore, since there is no need to take the card out of the case, it is not only possible to measure a large number of elements very efficiently, but when the card is removed manually, the material is contaminated due to contact with the thermoluminescent material, and the measurement can be carried out easily. Sensitivity may change, noise may occur during measurement, and if the material is exposed to external light when taken out, the material is sensitive to light, which may cause errors in measured values. In the configuration according to the present invention, since the card is automatically removed inside the device, such inconvenience does not occur at all, and measurement can be performed with extremely high reliability.

Further, the structure for transferring elements according to the present invention has the following features.

By forcibly holding and pressing the element, transferring it to the vertical hole in the housing and ejecting it from the vertical hole, and forcibly removing the card from the case body and inserting it into the case body, there is no friction or the like on the element or card. Reliable operation can be guaranteed even if there is resistance.

Furthermore, by having a configuration in which the card is pulled out into the horizontal hole after transferring the element to the vertical hole, it is possible to disengage the card from the case body simply by transferring the element to the end of the vertical hole, and it is possible to disengage the card from the case body using a solenoid or the like. There is no need to provide a separate lock release mechanism, which not only simplifies the structure, but also
High operational reliability can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a thermoluminescent dosimeter element used in the thermoluminescent dosimeter of the present invention, FIG. 2 is an exploded perspective view of the same, FIG. 3 is a top view of a magazine containing the thermoluminescent dosimeter element, and FIG. The figures are a sectional view taken along the line AA' in FIG. 3, FIG. 5 is a sectional view taken along the line BB' in FIG. 3, FIG. 6 is a schematic diagram of a thermoluminescence dosimeter according to an embodiment of the present invention, and FIG. 8 is a sectional view of the main part of the thermoluminescence dosimeter, FIG. 9 is a sectional view taken along line A-A' in FIG. 8, and FIG. B-B in the diagram
'Cross-sectional view, Figure 11 is the CC' cross-sectional view of Figure 8, Figure 12 is
The figure is a sectional view taken along line DD' in Figure 8, and Figure 13 is a cross-sectional view taken along line E-D in Figure 8.
E' sectional view, FIG. 14 is a sectional view of the main part of the thermoluminescence dosimeter when the element is transferred, FIGS. 15 and 16 are sectional views of the main part of the thermoluminescence dosimeter when the card is transferred, and FIG. The figure is a sectional view of a main part of an element transfer mechanism in another embodiment of the present invention. 1...Case body, 5...Notch, 7
...Information reading section, 8...hole, 9...
... Card, 11 ... Thermoluminescence material, 12 ... Engagement claw, 13 ... Recess, 1
4... Magazine, 19... Rack, 2
0...Element, 26...Pulse motor,
27...Rotating shaft, 28...Gear, 29
... Disk, 30 ... Hole, 31 ... Light emitting diode, 32 ... Phototransistor,
33-35... Light emitting diode, 36-38...
...Phototransistor, 39...Pulse motor, 40... Rotating shaft, 41...
Gear, 42...Sliding rod, 43...Rack, 45...Disc, 46...Notch, 4
7.48... Light emitting diode, 49.50...
... Phototransistor, 51 ... Heat measurement section, 52 ... Main housing, 55 ... Sub-nozzling, 60 ... Heat lamp, 61 ...・
... Photomultiplier tube, 65 ... Coiled spring, 66 ... Holding rod, 67 ... Pulse motor, 68 ... Rotating shaft, 69...Gear, 72...Vertical groove, 73...Engagement release plate, 74...Protrusion, 76...Horizontal groove, 77
... Card drive plate, 78 ... Engaging protrusion, 79 ... Filter, 80 ... Calibration light source, 81 to 85 ... Small hole, 89-92...
...Small hole, 106...Through hole, 107...
...Infrared transmission filter.

Claims (1)

[Claims] 1. A thermoluminescent dosimeter element formed by engaging and holding a card holding a thermoluminescent material in a case body;
A magazine for storing the plurality of thermoluminescence dosimeter elements, a magazine transfer means for transporting the magazine, and an element for pinching and pressing the thermoluminescence dosimeter elements to extract them from the magazine and transfer them to a vertical hole in the housing. a transporting means, an engagement release means for disengaging the card from the case body, a card transporting means for engaging the card and transporting the card to a horizontal hole in the housing, and a card transporting means for transporting the card into the horizontal hole. a heating means for heating the thermoluminescent material of the card, and a photoelectric conversion means for converting the thermoluminescence emitted from the thermoluminescent material into an electrical signal, and the thermoluminescent dosimeter element is pressed and extracted from the magazine. The card is taken out and transferred to a vertical hole in the housing, and the thermoluminescence dosimeter element is pressed in the vertical hole to act on the disengagement means to disengage the card from the case body, and A thermoluminescent dosimeter, wherein the card is engaged with a card transfer means.