JP3014225B2 - Radiation dose reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation dose reading device for reading a dose of a fluorescent glass dosimeter for measuring a radiation exposure dose, and more particularly to estimating a radiation quality (energy) and a radiation incident direction together with the dose. The present invention relates to a radiation dose reading device capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, as an example of a radiation dose reading device of this type, that is, a radiation dose reading device capable of estimating a radiation incident direction together with a dose, see JP-A-3-10228.
There is one shown in Japanese Patent Publication No. In this method, the fluorescence intensity distribution of a glass element is measured using a movable diaphragm.

[0003]

However, the conventional techniques described above have the following disadvantages. (1) A complicated mechanism and a control device are required to move the diaphragm. (2) It is necessary to repeat the movement of the diaphragm and the measurement in accordance with the number of divisions of the measurement area, and it takes several times as long as a normal dose measurement. The present invention does not use complicated mechanisms and control devices,
It is an object of the present invention to provide a radiation dose reading device capable of estimating a radiation quality and an incident direction by a short measurement.

[0004]

In order to achieve the above object, a first aspect of the present invention is to excite a fluorescent glass element which has been irradiated with ionizing radiation with ultraviolet light, and to detect the fluorescence of the fluorescent glass element at that time. in radiation dose reading device for reading a radiation amount by fluorescence intensity generated from the surface, the
The fluorescent glass element is placed in close proximity to the fluorescent detection surface.
And receives the fluorescent light of the fluorescent glass element.
Divide into multiple sections, and select the fluorescence intensity for each section.
And the fluorescence intensity distribution on the light receiving surface is detected from each detected value.
It is a radiation dose reading device equipped with a detector that emits radiation.

[0005] In order to achieve the above object, an invention according to claim 2 is a fluorescent glass irradiated with ionizing radiation.
The device is excited by ultraviolet light, and the fluorescent glass
Reads radiation dose based on fluorescence intensity generated from light detection surface
In the radiation dose reading device, the fluorescent glass element
Fluorescent light from the fluorescent glass element
And an optical system for imaging and multiplying
The multiplied fluorescence is received, and this light receiving surface is divided into multiple sections.
And then detect the fluorescence intensity for each divided section.
Detector for detecting the fluorescence intensity distribution of the light receiving surface from the output value
And a radiation dose reading device comprising:

[0006]

According to the invention corresponding to claim 1 or 2 , the fluorescent light of the fluorescent glass element is received on the light receiving surface, the fluorescence intensity is detected for each arbitrary section of the light receiving surface, and the light receiving surface is detected from each detected value. Since it has a detector that detects the fluorescence intensity distribution of
It is possible to estimate the beam quality and the incident direction by a short measurement without using a complicated mechanism and a control device.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a first embodiment of the present invention, in which a fluorescent glass element 1, an objective lens 2, a photocathode 3, an electron multiplier plate 4, a phosphor screen 5, an eyepiece 6, and a detector are included. Constituting CCD device (solid-state image sensor) 7 etc.
Area sensor .

[0008] The operation of the radiation dose reading apparatus thus configured will be described. The fluorescence generated from the fluorescent glass element 1 by the excitation of the ultraviolet rays is imaged on the photoelectric surface 3 through the objective lens 2. Photoelectrons are emitted from the photocathode 3 in accordance with the brightness of the image, and this electron image is enhanced several thousand times or more when passing through an electron multiplying plate 4 constituting a detector, which will be described later. 5 and becomes an optical image again. As a result, the incident light that has been enhanced by several tens of thousands is imaged on the CCD image pickup device 7 through the eyepiece 6, and is read by a known fluorescent intensity reading means (not shown), and the resulting fluorescence intensity distribution is not shown. It is input to a known estimating means to estimate the radiation quality (energy) and the incident direction.

As shown in FIG. 2, the electron multiplying plate 4 has a large number (approximately one million) of channels 45 formed of glass capillaries having a diameter of 12 to 20 μm and having an electron multiplying function.
It is bundled and sliced thinly. 1 channel 1
The book acts as an independent electron multiplier.

FIG. 3 is a diagram for explaining the principle of multiplication of the channel 45 of the electron multiplying plate 4 by the incident electron 4.
Zeros are drawn by the potential gradient of the power supply (VD) 41 and collide with the channel wall 42. At this time, output electrons 43 multiplied by several thousand times come out due to secondary electrons emitted from the wall surface. . The electron multiplying plate 4 includes a large number of the channels described above.

In such a configuration, the fluorescence obtained from the fluorescent glass element 1 is multiplied by the electron multiplier plate 4 and the light receiving surface is divided into a plurality of sections, and the fluorescence intensity is increased for each of the divided sections. Each of them is detected, and the fluorescence intensity distribution on the light receiving surface is detected from each detected value. Since the thus-obtained fluorescence intensity distribution is electrically divided in the CCD image pickup device 7 to perform signal processing, it is not necessary to use a diaphragm and a control device required conventionally. Since the fluorescence intensity distribution can be measured at once, the measurement time required for estimating the radiation quality and the incident direction can be greatly reduced.

In the above-described embodiment, the electron multiplier plate 4,
Although the objective lens 2 and the eyepiece 5 are used, the above-described objective lens 2 and the eyepiece 6 are unnecessary if the area sensor has a light receiving surface having a size equal to or larger than the fluorescence detection surface of the fluorescent glass element 1. It is. Also, the fluorescent glass element 1, the photocathode 3, the electron multiplying plate 4, the phosphor screen 5, the CC of FIG.
Detection is possible even when the D imaging element 7 is in close contact.
Further, if the detection sensitivity of the area sensor is improved, the electron multiplying plate 4 becomes unnecessary, and the detection can be performed only by bringing the fluorescent glass element 1 of FIG.
It is possible to further reduce the size of the entire device.

[0013]

According to the present invention, the fluorescence of the glass element is received on the light receiving surface, the fluorescence intensity is detected for each of the arbitrary sections of the light receiving surface, and the fluorescence intensity distribution of the light receiving surface is detected from each detected value. Since the detector is provided, it is possible to provide a radiation dose reading device capable of estimating the radiation quality and the incident direction by a short-time measurement without using a complicated mechanism and a control device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a radiation dose reading device according to the present invention.

FIG. 2 is a diagram showing a configuration of the electron multiplier plate of FIG.

FIG. 3 is a view for explaining the principle of multiplication of the electron multiplication plate of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fluorescent glass element, 2 ... Objective lens, 3 ... Photocathode, 4
... Electron multiplication plate, 5 ... Phosphor screen, 6 ... Eyepiece, 7
... CCD imaging device.

Claims (3)

(57) [Claims] 1. A radiation dose reading apparatus for exciting a fluorescent glass element irradiated with ionizing radiation with ultraviolet rays and reading a radiation dose based on a fluorescent intensity generated from a fluorescence detection surface of the fluorescent glass element at the time, wherein the fluorescent glass It is disposed in close proximity to the fluorescence detection surface of the element, receives the fluorescence of the fluorescent glass element, divides this light-receiving surface into a plurality of sections, detects the fluorescence intensity for each of the divided sections, A radiation dose reader comprising a detector for detecting a fluorescence intensity distribution on the light receiving surface from a detected value. 2. A fluorescent glass which has been irradiated with ionizing radiation.
The fluorescent element is excited by ultraviolet light,
The radiation dose is read based on the fluorescence intensity generated from the fluorescence detection surface.
In the radiation dose reading device, the fluorescent glass element is disposed so as to face the fluorescent detection surface of the fluorescent glass element,
Optical system for imaging and multiplying fluorescence from optical glass elements
And the fluorescent light image-multiplied by the optical system is received.
The light surface is divided into multiple sections, and the fluorescence intensity is
Each is detected, and the fluorescence intensity of the light receiving surface is calculated from each detected value.
A radiation dose reading device comprising: a detector for detecting cloth . 3. The method of claim 2, wherein said detector comprises an area sensor.
Item 3. The radiation dose reading device according to Item 1 or 2.