JP2003167097A - Planar radiation source and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that a conventional planar radiation source by drop drying has a severe problem in its uniformity, an organic film has uniformity but it is impossible to have arbitrary concentration gradient, and further as both are not suitable for mass production, but a single matter, they are expensive and have a problem in homogeneity in radiation sources. <P>SOLUTION: The homogeneous radiation sources can be easily manufactured by performing the printing with the printer ink including a radioactive isotope, whereby the radiation sources suitable for mass production, and capable of having arbitrary shape and concentration gradient can be provided in a state of breaking away from a conventional method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radioactivity standard radiation source manufacturing technique in the field of nuclear engineering.

[0002]

2. Description of the Related Art A radioactive surface radiation source is usually used for checking the operation and calibration of a large area measuring device such as a hand foot cross monitor (radiation contamination inspection device for limbs and clothes) and a gate monitor. An example thereof is shown in FIG. These radiation sources are prepared by dropping a radioactive solution onto a filter paper and an aluminum plate on which etch pits (fine holes) have been formed, drying and then surface polishing. Alternatively, it has been manufactured by mixing it with an epoxy resin and a plastic such as polyethylene and then stretching it thinly. The small disk in the lower left of FIG. 1 is a point source for reference.

FIG. 2 is an image of the radioactivity distribution of the planar radiation source shown in FIG. 1 taken by an image plate. The square portion on the upper right is the result of the measurement of the planar radiation source prepared by dropping the radiation source. As described above, in the planar radiation source prepared by dropping, the density is not uniform although it is planar.

[0004]

Therefore, the conventional dripping and drying method has a significant problem in uniformity, and
In the organic film, uniformity was obtained, but it was impossible to give an arbitrary concentration gradient. In addition, neither is suitable for mass production, it is expensive because it is a single item.
There was also a problem with the homogeneity of the radiation sources.

[0005]

Means for Solving the Problems The present invention is different from the conventional manufacturing method as described above, and is suitable for mass production, and has an arbitrary shape and an arbitrary concentration gradient.
By printing the ink of the printer mixed with the radioactive isotope, it is possible to prepare a uniform radiation source despite its simplicity.

[0006]

EXAMPLE An example of a planar radiation source distribution is shown in FIG.
Here, a radioactive substance is mixed in the yellow ink, and the color tone is divided by 1% from 1 to 10% density, and further 100% density is printed. 1000, 1E4, and 1E5 are images printed in other colors, and other reds with different densities by one digit
By mixing radioactive materials in blue and black dyes, it is possible to easily deal with logarithmic scales. FIG. 4 shows the result of imaging the radioactivity distribution of FIG. 3 with an imaging plate.
In this example, the radioactive substances are not mixed with the dyes other than yellow, so the logarithmic scale part is not completed, but any shape and concentration gradient, and even the letters are clearly imaged as part of the radiation source. .

In order to simplify the handling of the surface radiation source, the surface radiation source should be rubbed on its surface during normal use.
The hermeticity needs to be maintained. Also, the radiation source is α
Since charged particles such as rays or β rays are emitted, charge-up occurs in a non-conductive state, which causes discharge and changes in the charged particle emission rate from the surface of the radiation source. Therefore, by covering the printed surface with an aluminum-coated thin plastic cover, coating and charge-up prevention can be performed.

Alternatively, it is possible to provide sealing property and conductivity by printing with a water-soluble ink from the back side of a paper laminated with vinyl coated with aluminum on one side in advance and applying a back plate to the printed surface. At this time, the mass of the substance covering the surface of the radiation source must be a thickness equal to or less than the half-value transmission value (about several tens of mg) corresponding to the energy of the β-ray, especially in the case of the β-ray source.

In order to calibrate the position resolution and sensitivity of an X-ray film and an imaging plate which is widely used as a substitute for the X-ray film, a grid-like pattern at regular intervals or a contour index type surface radiation source having a density gradient is printed. It is prepared and lightly sprayed with a synthetic rubber adhesive on one surface thereof so as to have a weak tackiness, so that it can be directly attached to the surface of an X-ray film or an imaging plate to easily perform a position resolution test or sensitivity calibration.

[0010]

As described above, compared to the conventional methods and products, it is possible to supply a radioactive surface radiation source that is extremely inexpensive and uniform, and the utilization method thereof is a radioactive concentration gradient or a precise pattern. By drawing, the position resolution or sensitivity can be directly and easily performed.

[Brief description of drawings]

FIG. 1 is a conventional planar radiation source.

FIG. 2 is a result of imaging the radioactivity distribution of the planar radiation source of FIG. 1 with an image plate.

FIG. 3 is an example of a test pattern in which radioactivity is added to a yellow dye.

FIG. 4 is a result of imaging the radioactivity distribution of the planar radiation source of FIG. 3 with an image plate.

Claims (9)

[Claims] 1. A method for producing a planar radiation source, which comprises mixing a radioisotope in ink of a printer and printing the mixture at an arbitrary concentration. 2. A radiation source characterized by mixing a radioisotope with ink of a printer. 3. A planar radiation source characterized by being printed at an arbitrary density with ink of a printer containing a radioactive isotope. 4. The surface according to claim 3, wherein the printed surface is covered with an electric conductor or a film-like plastic to which the electric conductor is adhered so as to have sealing property and surface electric conductivity. Radiation source. 5. The surface radiation source according to claim 4, wherein the conductor is aluminum, and the plastic is vinyl. 6. Sealing is achieved by printing with the water-soluble ink from the back side of a paper laminated with a film-like plastic which is previously coated with a conductor on one side, and by sticking the printed surface to a back plate and fixing it. The planar radiation source according to claim 3, wherein the surface has electrical conductivity. 7. The on-plane radiation source according to claim 6, wherein the conductor is aluminum and the plastic is vinyl. 8. The surface radiation source is provided with a weak adhesive property and is attached to a film plastic so that it can be directly used as a charged particle emission rate and γ ray emission rate standard. Item 2. The planar radiation source according to Item 3. 9. The on-plane radiation source according to claim 8, wherein the weak tackiness is obtained by adhering an adhesive.