JPH1039034A - Scintillator sheet for measurement of radiation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate treatment, preparation and disposal treatment of a specimen by measuring a great amount of filter type specimens and disk type specimens as a bunch thereof, to execute continuous measurement and to reduce the measuring time. SOLUTION: A long holding tape or a holding sheet is formed such that a solid/liquid reversible scintillator 2 having a solid and liquid reversibility is covered and held thereby. The holding tape is a doubled tape constituted such that it covers the scintillator 2 from both of the faces thereof. The doubled tape is openable such that a specimen can be inserted thereto and it can be deformed so as to be used as a cassette type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scintillator sheet for measuring radiation. More specifically, the present invention relates to a scintillator sheet for radiation measurement capable of continuously and efficiently measuring the radioactivity of many samples.

[0002]

2. Description of the Related Art Radioisotopes that are used in a wide range of fields such as medicine, biology, pharmacy, agriculture, engineering, and life science, and are used for today's academic research and industrial development,
It shows excellent characteristics when used as a tracer, and has sensitivity and simplicity that are incomparable with other analytical and quantitative techniques. In particular, analysis and quantification techniques that use radioisotopes as tracers include analysis of biological metabolic functions, determination of the molecular structure of biological substances, hormones,
In the field of life sciences, such as quantification of trace metabolites such as enzymes, analysis of genetic information, quantification of residual amount of drug, and determination of drug efficacy and appropriate amount, it has been established as an indispensable means used in daily life science.

There are various kinds of samples such as gas, liquid and solid, and also various shapes and properties.
As a method for separating and analyzing these various samples, recently, molecular filters, filter papers, especially disk-shaped filter papers, and the like have come to be widely used.

[0004] In the case of soft beta radiation measurement, since many measurement samples are mixed with a liquid scintillator or are immersed in the liquid scintillator for measurement, processing of the sample and the container after the measurement is a problem. That is, the series of handling is complicated, and not only the sample but also the liquid scintillator becomes radioactive waste. Therefore, waste disposal including containers has become a new problem.

In a method in which a disc-shaped sample (a sample trapped on a filter or filter paper, hereinafter simply referred to as a sample) is placed in a sample dish and measured by a gas flow counter,
Soft beta rays are self-absorbed by the sample and cannot be measured or cannot be measured accurately.

[0006] Incidentally, a solid-liquid reversible scintillator is known. Since this scintillator can penetrate the heat-applied liquefied disk-shaped sample or coat and solidify it, it is convenient for handling the sample during measurement and disposal. The problem of self-absorption does not occur. It is desired that the use of such a solid-liquid reversible scintillator facilitates measurement of the disk-shaped sample.

As seen in recent remarkable researches on life science, there is a demand for a sample preparation / measurement technology for easily and quickly processing a large amount of samples, and in particular, for mechanically and continuously processing and measuring. Have been. It is also necessary to respond to a demand for making a large group of samples collectively measured to facilitate information processing.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical background and achieves the following objects.

An object of the present invention is to provide a scintillator sheet for radiation measurement which can measure a large number of filter-like samples and disk-like samples as a group.

Another object of the present invention is to provide a scintillator sheet for radiation measurement which is easy to prepare for measurement.

Still another object of the present invention is to provide a scintillator sheet for radiation measurement that can be easily disposed of.

Still another object of the present invention is to provide a scintillator sheet for radiation measurement which can continuously measure a large number of samples in a group to shorten the sample preparation time.

Still another object of the present invention is to provide a radiation measurement scintillator sheet capable of continuously measuring a large number of samples in a group and automatically processing measurement data.

Still another object of the present invention is to provide a scintillator sheet for radiation measurement which is simple and quick by utilizing a solid and liquid reversible scintillator.

Still another object of the present invention is to provide a scintillator sheet for radiation measurement which can be easily and quickly and continuously machine-measured and machine-measured by utilizing a solid and liquid reversible scintillator.

[0016]

The scintillator sheet for radiation measurement according to the first aspect of the present invention is a holder for holding the scintillator for radiation measurement, and covers and holds a scintillator whose liquid phase and solid phase are reversible. As long as the holding tape.

The scintillator sheet for radiation measurement according to the second aspect of the present invention is characterized in that, in the first aspect, the holding tape is a double tape formed so as to cover the scintillator from both sides.

The radiation measuring scintillator sheet of the third invention is characterized in that, in the second invention, the double tape is openable and closable so that a sample can be inserted.

The radiation measuring scintillator sheet of the fourth invention is characterized in that, in the second invention, the double tape has an edge which is closed after the sample is inserted.

In a fifth aspect of the present invention, the scintillator sheet for radiation measurement according to the fourth aspect is characterized in that the scintillator is discontinuously held by the holding tape.

According to a sixth aspect of the present invention, in the radiation measuring scintillator sheet according to the first aspect, the scintillator is continuously formed as a continuous long tape.

The scintillator sheet for radiation measurement of the present invention 7 comprises a sheet layer and a scintillator layer joined to the sheet layer and formed of a scintillator for radiation measurement, wherein the scintillator has a reversible liquid phase and solid phase. The sheet layer does not pass through the scintillator and is impermeable.

The radiation measuring scintillator sheet according to the eighth aspect of the present invention is a set of a large number of sheets. Each of the sheets comprises a sheet layer and a scintillator layer joined to the sheet layer and formed of a radiation measuring scintillator. The liquid phase and the solid phase of the scintillator are reversible, and the sheet layer does not pass through the scintillator and is impermeable.

[0024] In the scintillator sheet for radiation measurement of the present invention 9, in the above invention 1 or 2, the sheet layer is composed of two front and back layers, and the scintillator layer is sandwiched between the two front and back layers.

[0025]

In the scintillator sheet for radiation measurement according to the present invention, the scintillator is held by a long holding tape. The scintillator held by the holding tape is eventually covered by the holding tape. A radioactive sample is bonded to the scintillator. The heat applied during the measurement causes the solid-phase scintillator to be liquefied and permeate or surround the sample evenly, so that the total amount of radioactivity can be accurately detected without causing self-absorption. The scintillator sheet is a two-layer structure composed of a sheet layer and a scintillator layer.

The tape is continuously pulled out from the end in sequence and continuously passed through the measuring instrument. The samples pass through the detector of the measuring device in the order in which they are arranged. One group of samples is measured in numerical order and recorded with addresses in the recording unit of the measuring device. The data recorded in this way is convenient for automatic analysis.

The scintillator can be formed as a continuous long tape. A long tape-shaped sample can be continuously bonded to a long tape-shaped scintillator, and a sample that continuously flows down as a liquid is continuously attached to a tape-shaped filter paper that moves at a constant speed. This can be joined or joined with a long tape-shaped scintillator. When such a continuous scintillator is used, for example, it is convenient for measurement of a dynamic sample which is generated due to a temporal change in radiation dose. When a sample is intermittently or discontinuously joined or united to a scintillator formed intermittently, that is, discontinuously, it is convenient for measurement of a discontinuous sample.

It is very easy to discard the prepared sample. This is because the scintillator is solidified again when it is wound up and processed again. Complete encapsulation is not required. The sample and the scintillator attached to the base layer such as filter paper are hardly powdered, and are almost never scattered in the air because they are covered by the covering layer.

The two-layer structure is a set or set of many sheets. In this case, a large number of sheets can be made into a cassette, stacked in a box, continuously taken out, and machine-processed.

[0030]

Next, embodiments of the present invention will be described.

(Embodiment 1) FIG. 1 shows Embodiment 1 of a scintillator sheet for radiation measurement according to the present invention. FIG. 1 shows a state in which the sample has already been attached to the scintillator sheet for radiation measurement and preparation for measurement has been completed. The sample sheet in the ready state for measurement comprises a holding tape 1 and a scintillator continuum 2a as a scintillator 2.

The holding tape 1 holds the scintillator 2. The scintillator continuous body 2a is formed in a long tape shape. The scintillator continuum 2a uses a membrane filter base layer. The scintillator continuum 2a includes a scintillator such as an organic light emitting body.

The scintillator continuum 2a is heat-fusible, and its solid and liquid phases are reversible. That is, the solid-liquid reversible scintillator tape 2a is liquefied by a rise in temperature and solidified by a fall in temperature.

The holding tape 1 can be formed as a double tape so as to cover the front and back surfaces of the scintillator 2. In this case, as shown in FIG.
Are provided with edges 3 on both sides or one side. On one side of this edge 3, the double part of the holding tape 1 is formed so that it can be separated from each other. That is, the holding tape 1 is formed to be freely opened and closed. The other side of one side edge 3 is closed from the beginning.

On one side, which is closed from the beginning, feed holes 4 for intermittent feed can be provided at a constant pitch. The openable and closable edge 3 is fitted after the sample is inserted. A feed hole 5 for intermittent feed can also be provided on one side edge that is closed in this way. The long holding tape 1 can be wound around the core 6.

The scintillator is continuous and therefore
When the scintillators are also continuously distributed, the sample S can be continuously joined and adhered. In this case, it is convenient for measurement of a sample prepared by continuously flowing down as a liquid. For example, it is convenient for measurement of a dynamic sample which is generated due to a change in radioactivity over time.

FIG. 2 shows the holding tape 1a with the holding tape 1 opened. The holding tape 1a
It is wound around another winding core 6a. In this open state, the scintillator 2 is exposed. The sample is attached to the exposed surface of the scintillator 2. At the time of measurement, the tape is folded so as to form the double tape shown in FIG. 1 and rewound as shown in FIG.

Before the start of the measurement, the scintillator in the solid phase or the scintillator is changed to the liquid phase by heating as described later.
The liquefied scintillator uniformly surrounds the sample so that the scintillator and the sample are homogeneously mixed.

(Embodiment 2) FIG. 3 shows Embodiment 2 of a scintillator sheet for radiation measurement according to the present invention. The sample has not yet been attached to the scintillator sheet for radiation measurement shown in FIG. The scintillator 2 according to the second embodiment includes a large number of scintillator forming disks 2a. The holding tape 1 is the same as the holding tape 1 of the first embodiment in that the holding tape 1 has an edge 3, a feed hole 4 and a feed hole 5.

The scintillator forming disk 2a has a reversible solid and liquid phase. In other words, the solid-liquid reversible scintillator forming disk 2a is liquefied by a rise in temperature and solidified by a fall in temperature.

FIG. 4 shows a state where the sample is inserted into the holding tape 1. The opening and closing of the holding tape 1 for inserting a sample is as described in the first embodiment. The sample is attached to the sample attachment 9. Various forms of the sample adhering body 9 are actually used. The sample attachment 9 shown in FIG. 4 is formed of a disk-shaped portion 7 and a branch portion 8. The disk-shaped part 7 and the branch part 8 are integral. For example, the disc-shaped portion 7 is pressed against the floor with the left finger, the branch portion 8 is pulled with the right finger, the back surface of the disc-shaped portion 7 is strongly pressed against the floor by friction, and the radioactive material on the floor is disc-shaped. Wipe and adhere on the back side of part 7 (this is an internationally defined wiping method). Other examples of the sample adhering body 9 include a disk-shaped one (molecular filter) and a spoon-shaped one.

When the sample adhered body 9 to which the radioactive substance is adhered is inserted into the holding tape 1, the disc-shaped portion 7 of the sample adhered body 9 is overlapped with the disc-shaped scintillator 2.

(Embodiment of Measuring Apparatus) The sample sheet prepared as described in Embodiments 1 and 2 and wound around the core 6 is
It is rotatably supported. The holding tape 1 can be fed at a constant speed by the feed rotary wheel 11 having a pin-type gear or the like. A gear-shaped pin fits into the edge 3 of the holding tape 1 and performs intermittent feeding at a constant pitch.

The number of rotations of the rotating wheel 11 corresponds to the sample number. During the feeding between the beginning of feeding and the rotating wheel 11 for feeding,
A heater 12 and a cooler 13 are provided. Cooler 1
3 is arranged ahead of the heater 12 in the feed direction. A sample tray 14 is arranged on the destination side. The sent holding tape 1 is stored in the sample pan 14 and discarded or processed together with the sample pan.

A detection device 15 is arranged in the middle of the transmission path ahead of the cooler 13. The detection device 15 is two photomultiplier tubes. The incident sides of the two photomultiplier tubes on which photons enter are opposed to each other, and are also opposed to the front and back surfaces of the holding tape 1. The detection device 15 uses a unit that counts only fluorescence emitted from a specific region of the scintillator 2, that is, fluorescence emitted in a direction in which the photomultiplier tubes on both sides are opposed to each other. The coincidence circuit 16 is provided to prevent noise detection.

The photon amount of the sample of the sample number corresponding to the rotation speed of the feed rotary wheel 11 of the feed device is recorded in correspondence with each sample. Also, the temporal change of a group of related continuous samples can be graphed immediately after measurement.

(Embodiment 3) FIGS. 6 and 8 show card type and cassette type scintillator sheets 51. FIG. The scintillator sheet 51 has a two-layer structure,
2 and a scintillator layer 53. The sheet layer is preferably light-transmissive for fluorescence. As described above, the scintillator layer 53 has reversibility. The sheet layer 53 has non-permeability that does not melt when the scintillator layer 53 is melted and does not pass through the melted scintillator.

The scintillator sheet 51 may have any shape such as a square, a rectangle, and an ellipse. A scintillator layer 53 is joined to a substantially central region of the scintillator sheet 51.
Many such scintillator sheets 51 are prepared,
It forms an aggregate and is sold as a set. Many scintillator sheets 51 are stacked before measurement. Each scintillator sheet 51 is handled as a cassette or a cartridge, is stacked and stored in one box,
Each sheet is taken out and introduced into the measuring instrument.

As shown in FIG. 8, the peripheral edge of the scintillator sheet 51 can be bordered by a relatively hard edge film or paper. Such edging can provide the scintillator sheet 51 with the mechanical strength required for mechanical processing.

[Brief description of the drawings]

FIG. 1 is an oblique projection view showing a first embodiment of a scintillator sheet for radiation measurement of the present invention.

FIG. 2 is an oblique axis projection view showing a state in which the holding tape of the first embodiment is opened.

FIG. 3 is an oblique projection view showing Embodiment 2 of the scintillator sheet for radiation measurement of the present invention.

FIG. 4 is an oblique axis projection view showing a state in which a radiation measurement scintillator sheet according to a second embodiment of the present invention is ready for measurement.

FIG. 5 is a circuit diagram showing an embodiment of a measuring device.

FIG. 6 is a plan view showing Embodiment 3 of the scintillator sheet for radiation measurement of the present invention.

FIG. 7 is a front view of FIG. 6;

FIG. 8 is a sectional view showing a modification of the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Holding tape 2 ... Scintillator 3 ... Edge 4 ... Feeding hole 5 ... Feeding hole 6 ... Core 7 ... Disk-shaped part 8 ... Branch part 11 ... Feeding rotary wheel 12 ... Heating device 13 ... Cooler 15 ... Detector

Claims (9)

[Claims] A scintillator for holding a radiation measurement scintillator, wherein the scintillator is formed as a long holding tape to cover and hold a scintillator whose liquid phase and solid phase are reversible. Sheet. 2. The scintillator sheet for radiation measurement according to claim 1, wherein the holding tape is a double tape formed so as to cover the scintillator from both sides. 3. The scintillator sheet according to claim 2, wherein the double tape is openable and closable so that a sample can be inserted. 4. The scintillator sheet for radiation measurement according to claim 2, wherein the double tape has an edge closed after the sample is inserted. 5. The scintillator sheet for radiation measurement according to claim 4, wherein said scintillator is discontinuously held by said holding tape. 6. The scintillator sheet for radiation measurement according to claim 1, wherein the scintillator is formed continuously as a continuous long tape. 7. A scintillator layer comprising a sheet layer and a scintillator layer bonded to the sheet layer and formed of a scintillator for radiation measurement, wherein the scintillator has a liquid phase and a solid phase which are reversible. Non-permeable, non-permeable scintillator sheet for radiation measurement. 8. A set of a large number of sheets, each sheet comprising a sheet layer and a scintillator layer formed of a scintillator for radiation measurement joined to the sheet layer, wherein the scintillator is a liquid phase and a solid phase. A scintillator sheet for radiation measurement, wherein the phase is reversible, and the sheet layer is impermeable to the scintillator. 9. The scintillator sheet for radiation measurement according to claim 7, wherein the sheet layer comprises two front and back layers, and the scintillator layer is sandwiched between the two front and back layers.