JPH0617093Y2 - Fluorescent glass dosimeter element - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention relates to a fluorescent glass dosimeter element used for controlling radiation dose, and in particular, one fluorescent dosimeter TECHNICAL FIELD The present invention relates to a fluorescent glass dosimeter element capable of separately measuring multi-quality radiation using a glass element for use.

(Prior Art) In general, as a fluorescent glass dosimeter element, a glass element for a fluorescent dosimeter made of phosphate glass containing silver ions is used. This glass element emits fluorescence when excited by ultraviolet rays having a wavelength of 300 to 400 nm after being activated by exposure to radiation, but the fluorescence intensity at this time is proportional to the amount of radiation exposure, so it is necessary to detect this fluorescence intensity. The radiation dose can be measured by.

In this way, in measuring the radiation dose, after selectively extracting the ultraviolet rays of the predetermined wavelength by passing the light projected from the ultraviolet excitation light source through the optical filter, the rectangular parallelepiped glass element for the fluorescence dosimeter is placed on one surface. It is incident almost vertically.
Here, the glass element for a fluorescence dosimeter that receives an ultraviolet ray of a predetermined wavelength emits fluorescence, and the fluorescence emitted at this time is taken out from a direction perpendicular to the incident direction of the ultraviolet ray and a predetermined wavelength range through an optical filter. After passing the light of (1), photoelectric conversion is performed by a photomultiplier tube to obtain an electric signal of a level substantially proportional to the fluorescence intensity, and the fluorescence intensity, and thus the radiation dose, is measured from the level of this electric signal.

By the way, conventionally, in the case of separately measuring the radiation dose of multi-quality using the above glass element for a fluorescence dosimeter, as shown in FIG. 6, a plurality of glass elements 1a to 1d are provided as a set of supporting frames. A plastic case, which is individually loaded at a predetermined position of the bodies 2 and 3, and then a filter for separately measuring multi-radiation radiation is individually attached to facing positions on one surface or both surfaces of the glass elements 1a to 1d. (Not shown). Then, after entering the ultraviolet excitation light, each glass element 1a
By detecting the fluorescence emitted from 1d through a filter and performing an appropriate calculation with a microcomputer or the like, the multi-ray quality such as X
The radiation dose of rays such as gamma rays, gamma rays, beta rays and neutron rays is separately measured (Japanese Patent Laid-Open Nos. 64-86087 and 1-167690).

(Problems to be solved by the invention) However, as described above, the fluorescent glass dosimeter element using the plurality of glass elements 1a to 1d has no problem in separating and measuring multi-ray radiation. The following points are problematic.

Even if each glass element is manufactured under the same manufacturing conditions, there is some variation in the fluorescence detection sensitivity with respect to the radiation dose for each manufacturing lot. Therefore, when a plurality of glass elements 1a to 1d are used, the glass elements of different production lots are naturally likely to be mixed, and the radiation dose measurement accuracy is lowered due to the variation in the sensitivity between the production lots, and the reliability is improved. There is a problem that lacks.

Further, usually, a plurality of glass elements 1a to 1d are sequentially loaded at a predetermined position of one of the support frames 2. At this time, as the number of glass elements increases, the number of assembling steps increases, and accordingly, the assembling process increases. The time becomes longer and the work efficiency is significantly reduced.

Further, the glass elements 1a to 1d are finished by polishing. However, as described above, if the number of glass elements is large, the polishing cost increases accordingly, and the glass elements 1a to 1d
Since both d are small in shape, handling during polishing is inconvenient.

The present invention has been made in view of the above circumstances, and is a fluorescent glass capable of simplifying the assembling steps and polishing work, and capable of separating and measuring multi-radiation radiation with high accuracy with uniform fluorescence detection sensitivity. It is intended to provide a dosimeter element.

[Means for Solving the Problems] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an integrated unit at a facing position of a plurality of filters used for separating and measuring multi-quality radiation. The glass element for fluorescence dosimeter is arranged so as to straddle the plurality of filters.

(Operation) The present invention takes the above-described means, and by providing one glass element for a fluorescence dosimeter across a plurality of filters, glass of different manufacturing lots as in the conventional case It is possible to reliably separate and measure multi-ray radiation with uniform fluorescence detection sensitivity without mixing elements, and since it handles one glass element for a fluorescence dosimeter, the number of steps such as assembly and polishing is reduced. It can be significantly reduced.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. First, as the glass element for a fluorescent glass dosimeter, a glass element having a length corresponding to a plurality of conventional glass elements, for example, a glass element equivalent to four glass elements is integrally manufactured, and the four glass elements are replaced. That is, one glass element 11 having the same function as four glass elements is used. The glass element 11 is a glass composition obtained by adding 0.3% by weight of silver metaphosphate to a polymer composed of 60% by weight of aluminum metaphosphate, 20% by weight of sodium metaphosphate and 20% by weight of sodium orthophosphate. For example, 10 × 7 × 3 mm or 34 × 10 × 7 mm
It is obtained by polishing into a rectangular parallelepiped.

Reference numerals 12 and 13 denote a pair of supporting frame bodies for holding the glass element 11. One of the supporting frame bodies 12 is at a position corresponding to the conventional four glass element mounting portions, more specifically, for the time being. For example, four opening portions 14a, 1 having an area sufficiently smaller than the area of one side surface of each of the glass elements at the facing position of the four glass elements when arranged.
4b, 14c, 14d are formed, and element holding protrusions 15, ... Are provided in the vertical direction from the outer peripheral edge portion of the frame body except for the portion which becomes the fluorescence output optical path of the glass element 11.
Therefore, the projection 15 is formed on the glass element holding support frame 12,
By fitting the glass elements 11 inside, one glass element 1 corresponding to the conventional four glass elements is provided.
1 can be held. Further, the other support frame 1
3 has a role of accommodating and holding one support frame body 12 holding the glass element 11, and specifically, a plurality of openings 16a, 16b, 16c, 16d are formed similarly to the support frame body 12, Moreover, both ends of the frame body 13 in the longitudinal direction are bent in the same direction to provide U-shaped portions 17, 17, and the U-shaped portions 17, 17 are provided corresponding to the openings 16a, 16b, 16c, 16d. Notches 18 on the surface of 17
a to 18d are provided. Furthermore, this support frame 1
A numbered hole 19 for optically reading the type of glass element and the ID code of the operator is provided at one end of 3.

The pair of supporting frames 12 and 13 holding the glass element 11 as described above is the plastic case 20 shown in FIG.
Is stored in. The plastic case 20 includes, for example, a tin slit filter 21a having a porosity of 20% and a thickness of 1 mm.
The tin filter 21b, the aluminum filter 21c having a thickness of 1 mm, the resin filter 21d having a thickness of 12 mg / cm ^{2 and} the like are attached in a positional relationship corresponding to the openings 14a, 14b, 14c and 14d, respectively.

Therefore, according to the fluorescent glass dose system element thus configured, the energy dependence of the sensitivity of the glass element 11 to γ-rays and X-rays when radiated through each filter is as shown in FIG. . Curve A is the sensitivity curve of the glass element 11 when covered with the tin slit filter 21a, curve B is the sensitivity curve of the glass element 11 covered with the tin filter 21b, and curve C is the aluminum filter 2
The sensitivity curve of the glass element 11 covered with 1c, curve D is the sensitivity curve of the glass element 11 covered with the resin filter 21d.

The glass element 11 having the sensitivity characteristic of the curve A exhibits a uniform dose response to the γ-ray and X-ray energies, so that the γ-ray and X-ray dose evaluation can be performed. As shown in FIG. 4, a curve H showing the sensitivity ratio between the glass element 11 coated with the tin filter and the glass element 11 coated with the resin filter 21d is 60 to 20.
The energy of hard X-ray of 0 KeV can be evaluated,
The energy of soft X-rays of 25 to 60 KeV can be evaluated by the curve J showing the sensitivity ratio between the glass element 11 covered with the aluminum filter and the glass element 11 covered with the tin filter. Further, the aluminum filter 21c having a thickness of 1 mm has a property of transmitting neutron rays and low energy γ rays of 200 KeV or less well.

Further, β-rays can be detected by the glass element 11 covered with the resin filter 21d, and mixed γ-rays are obtained by the glass element 11 covered with the tin slit filter 21a and subtracted to obtain the β-ray dose. it can.
Therefore, the fluorescence amount of the glass element 11 at the time of passing each of these filters is sequentially read, and the number hole 19 such as the type of the glass element 11 supported by the support frames 12 and 13 and the ID code of the operator is optically read. By further performing arithmetic processing with a microcomputer etc. attached in the reading device,
X-ray, β-ray, γ-ray and neutron ray can be automatically separated and measured.

Therefore, according to the configuration of the embodiment as described above, conventionally, a plurality of glass elements have been used to separate and measure multi-ray radiation, but a plurality of filters are used instead of the plurality of glass elements. One glass element 11 which is an integrated body so as to straddle
By using, there is no need to worry about mixing glass elements from different manufacturing lots as before, and multi-ray radiation can be separated and measured with uniform fluorescence detection sensitivity, and the reliability of the obtained measurement results can be improved. Can be greatly improved. Further, assembling work for loading the glass elements into the support frames 12 and 13 is performed, but at this time, in the conventional case, the glass elements are loaded while positioning one by one, which is very complicated and a lot of work is required. take time. On the other hand, when one glass element 11 is mounted so as to straddle a plurality of filters, the shape of the one glass element 11 is large, so that it is not only convenient to handle but also the glass element 11 Is very easy to position and very easy to assemble. Moreover,
By reducing the number of glass elements, the polishing cost for polishing the glass elements can be significantly reduced.

In addition, in the said Example, several filter 21a-.
Although 21d are arranged at equal intervals, for example, as shown in FIG. 5, a part without a filter may be provided between a plurality of filters. Further, the support frames 12 and 13 do not have to be in the form shown in the drawings, for example, a bag-shaped support frame is made in advance, and the glass element 11 is inserted from the opening side at one longitudinal end of the support frame. But it's okay. Needless to say, various filters are used depending on the radiation quality to be separated and measured. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[Effects of the Invention] As described above, according to the present invention, the assembling can be simplified and the polishing cost can be reduced, and highly uniform radiation detection sensitivity with high uniformity can be obtained with uniform fluorescence detection sensitivity. It is possible to provide a fluorescent glass dosimeter element that can be separately measured.

[Brief description of drawings]

1 to 4 are shown for explaining one embodiment of the fluorescent glass dosimeter element according to the present invention, and FIG. 1 is an exploded perspective view showing the relationship between the glass element and the supporting frame, FIG. 2 is a sectional view of a case for accommodating a support frame holding a glass element, FIGS. 3 and 4 are views for explaining the relationship between radiation energy and sensitivity for each filter, and FIG. 5 is for the present invention. FIG. 6 is a view showing another arrangement example of filters as another embodiment, and FIG. 6 is an exploded perspective view showing a relationship between a glass element and a support frame for explaining a conventional example. 11 ... Fluorescence dosimeter glass element, 12, 13 ... One set of support frames, 14a-14d, 16a-16d ... Opening, 18a-18d ... Notch, 19 ... Number hole, 20
...... Case, 21a to 21d ...... Filter.

Claims (1)

[Scope of utility model registration request] 1. A glass element for a fluorescence dosimeter as an integrated body is arranged across a plurality of filters at facing positions of a plurality of filters used for separating and measuring multi-quality radiation. Fluorescent glass dosimeter element characterized by.