JPS59116567A - Glass dosimeter - Google Patents

Abstract

PURPOSE:To achieve a higher accuracy and a shorter measuring time by varying an input level into detector while using a plurality of collimation glasses with a subdivided measuring range to enable the measurement of the detector in the maximum sensitivity. CONSTITUTION:An ultraviolet ray source 1 and a power source 10 are operated to radiate the ultraviolet rays with the wavelength of 300-400nm. Four of collimation glasses 7I, 7II...7IV are measured sequentially and memorized at each range thereof. Then, sample glasses 6I, 6II...6VI are initially measured at such a high level as 1,000 roentgen and compared with level values previously memorized to screen the range at which measurement should be made. Remeasurement is done at a specified range and the results thereof are compared with input of the collimation glasses at the corresponding range to determine a dose value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a glass wire for measuring the amount of radiation exposure of glass.

[Technical Background of the Invention] A conventional glass dosimeter holds a sample and a reference glass for relative evaluation side by side in a sample holder, and passes light from an ultraviolet light source through a condensing lens and a visible light blocking filter to the sample and the sample. The reference glass is irradiated to generate fluorescent light, and the emitted light is detected by a fluorescence detection device f2, and the exposure dose of the sample is measured by comparing it with that of the reference glass.

[Problems with the background technology] Conventional glass dosimeters have only one reference glass;
A dose value close to the center of the measurement range is selected and used. For this reason, the low dose side of the measurement range or the high line i 1141i! There was a tendency for the relative error to become larger in the second case.

Moreover, the glass sample to be measured is transparent with polished edges, and no changes in the upper side of the appearance are observed even after irradiation with gamma rays or X-rays, so it is possible to estimate the exposure dose before measurement. First, for verification purposes, it was necessary to cover the entire range with something close to the median of the measurement range, which caused problems with measurement accuracy.

Since the sample size is small and the fluorescence emitted when externally irradiated is weak, a photoelectron multiplier layer is generally used as the O/C button device. Then, the sample crow to be measured was exposed to a wide range of roentgen from 01 to 2000 (! Even if a photomultiplier tube is used, the detection input is insufficient, so the voltage applied to the photomultiplier tube is increased to improve sensitivity.However, in order to stabilize the operation of the photomultiplier tube, a certain 1 hour It is desirable to apply pressure, and when the voltage is made variable, it is stable from the start up and the waiting time is safe, but it has the drawback that it takes 2 hours to stabilize.

[Object of the Invention] An object of the present invention is to provide a glass wire gauge having a wide wire angle and an improved measuring viscosity.

[Summary of the Invention] The first aspect of the present invention is to use a plurality of comparison glasses for relative evaluation.
1lil The relative error was reduced by using C2 to press the foot range in sections.

The second aspect of the present invention is that the dosimeter is equipped with a means for reducing the input to the fluorescence detection device when measuring a high radiation active sample, thereby reducing the measurement sensitivity in the high dose range f2, and (Secondly, it is possible to perform measurements in the highest sensitivity state.

[Embodiments of the invention] Hereinafter, details of the present invention will be explained with reference to illustrated embodiments.

(1) is an ultraviolet light source such as a high-pressure mercury vapor discharge lamp, +2
), (81, (4) is a one-layer neutral density filter, a condensing lens, and a visible light processing filter facing this ultraviolet light source (1), (5) is a neutral density filter (2),
It has a plurality of filter holding parts facing the ultraviolet light source (1) through a condensing lens (8) and a visible light blocking filter (4), and moves in the direction S2 intersecting the optical axis of the light source (1). long holder, (6+), (6m),..., (6
v+) is held on the - side C2 of this holder (5), and as the holder (5) moves, the UV light source (5) sequentially moves to face the ultraviolet light source (1). , (8) is a fluorescence detection device facing the ultraviolet light source (1) via this holder (5), and (9) is a C two intermediary device between this fluorescence detection device (8) and the holder (6). The ultraviolet filter [ν"filter, oO] is the fluorescence detection device (8)ζ
The constant-voltage DC galvanic etchant, t,'l) that supplies the two-side constant voltage is an amplifier that amplifies the output signal of the fluorescence detection device (8), (]2
1 is the output of this amplifier (11) (radiation % after receiving g)
This is a display device that displays the closing date.

If exposed to 7° rays or The radiation of gamma rays or X-rays (f - as shown,
Measuring range 0.1-3000 Roentgen 0.1-10
C2 corresponding known doses of Roentgen (range 1), 10 to 100 Roentgen (range If), 100 to 1000 Roentgen (range ill), and 1000 to 3000 Roentgen (range ■), respectively, were irradiated.

The neutral density filter (2) is configured to be detachable and is used only when measuring a sample with a high dose, for example, 1000 Roentgens or more, to reduce the intensity of the ultraviolet rays emitted by the sample C. By the way, in the past, in the case of a high dose range, measurements were taken by lowering the voltage applied to the detection device (8).
Since the interposition C2 of this filter (2) sets the attenuation rate to the joining level of other ranges (two combinations), it is possible to measure a wide dose range while setting the detection device (8) at the optimum sensitivity level.

The above-mentioned detection device (8) - "A photoelectric conversion element, which has a built-in photomultiplier tube, operates based on a constant voltage of direct current supplied from the power source (10), and outputs an electrical signal, such as a voltage, in response to the fluorescence. Then, about 15 minutes after the start of operation, a stable measurement condition g+2 is obtained.Then, the output of this detection device (8) is amplified by the amplifier 01), and the output is displayed on the display (19).

Next, the measurement procedure of this device will be explained. First, operate the ultraviolet light source (1) and the power supply, and
Cena 12+2R reminds me. Next is the second, fermented, non-L glass (6+), (6m).

...((5VI), first measure at a high level of 1000 Roentgen, then compare with the memorized values of each level to determine in which range the measurement should be made, and then repeat the measurement at the specified range. By adding 6111 and comparing the result with the input of the reference glass of that range, the linearity value (X-ray) is determined.Furthermore, the holder (5) can hold six sample glasses.

In this way, the measurement accuracy of this sensor can be improved by subdividing the measurement range and using an algebraic matching method.1,-! In addition, since the input level to the detection device (8) is variable, it is possible to measure the detection device at its highest sensitivity and condition, improving the accuracy and shortening the 6I time period.

In addition, since Verification 2 Solas finely divides the 0111 constant range, it is possible to improve the measurement accuracy of th, which is large in number, but in the present invention C2, it is only necessary to have two or more, and even in this case, the measurement accuracy is improved compared to the conventional method. The error becomes smaller.

Furthermore, as a means of varying the input to the detection device, in addition to the above-mentioned dimming of the ultraviolet light source, the fluorescence emitted from the glass may be dimmed; for example, an aperture may be attached to the lens of the detection device. .

[Effects of the Invention] The first aspect of the present invention is a glass dosimeter that irradiates glass exposed to radiation with two ultraviolet rays to generate fluorescence, detects the emitted string wave of the fluorescence, and measures the exposed radiation pair. Since the measurement range was divided into sections using a plurality of reference glasses for relative evaluation, the measurement accuracy was improved in other words, the specific yield accuracy with respect to the reference glasses.

The second aspect of the present invention is that in the above-mentioned glass dosimeter, the input of the fluorescence detection device is made variable (2), so that it is possible to measure the fluorescence detection device in its highest sensitivity state.
Improved accuracy and shortened measurement time 0

[Brief explanation of the drawing]

Figure 51 is an explanatory diagram of an embodiment of the crow line meter of the present invention.
FIG. 2 is a graph showing subdivision levels of the measurement range of the reference glass. (1)...UV light source (2)--Dark filter (3)...Condensing lens (4)--Visible light blocking filter (5)...Holder (6+), (6m) , (6i), (6u), (
6V), (6Yl)...sample glass (c), (7
n), (7m), (7+v)... matching crow (8
)...Detection device (9)...Ultraviolet blocking filter 00)...Power supply C1J...Amplifier (1
2)...Display device agent Patent attorney Inoue - Male Figure 1 Figure 2 Dose (X-ray 2)

Claims (2)

[Claims] (1) In a dosimeter that measures the exposure dose by irradiating ultraviolet rays onto glass exposed to radiation to generate fluorescence and detecting the emission intensity of this fluorescence, multiple reference glasses for relative evaluation are used. A glass dosimeter with a special feature of having separate measurement ranges. (2) Dosimeter C2, which measures the exposure dose by irradiating glass-e exposed to radiation with ultraviolet rays to generate fluorescence and measuring the exposure dose by detecting the emission intensity of this fluorescence, is used when measuring high-dose samples. A glass dosimeter characterized by being equipped with a means for reducing input to a detection device.