JP2001242298A - Charged particle beam irradiation device and X-ray irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged-particle beam irradiation device and an X-ray irradiation device capable of preventing generation of ozone caused by charged- particle beam irradiation or X-ray irradiation. SOLUTION: In this charged-particle beam irradiation device, a gas container in which gas including no oxygen is filled is installed on an irradiation route of a charged-particle beam, and the charged-particle beam irradiated from a charged-particle beam irradiation part is irradiated onto an object to be irradiated through the gas container. In this X-ray irradiation device, a similar gas container is also installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charged particle beam irradiation apparatus and an X-ray irradiation apparatus, and more particularly to a charged particle beam irradiation apparatus and an X-ray irradiation apparatus used for sterilizing an object to be irradiated.

[0002]

2. Description of the Related Art Fig. 4 shows the future prospect of the electron beam irradiation service business by Yutaka Yamase (23rd Japan Isotope
FIG. 1 is a schematic view of an electron beam irradiation apparatus having a conventional structure, which is disclosed in the General Meeting of the Radiation Congress, A304, 1998). FIG.
As shown in (1), the electron beam irradiation apparatus 100 includes an electron beam generator 1, an electron beam transporter 2, and an electron beam emitter 3, and is supported by a support 4. The electron beam generator 1 is composed of an electron accelerator, and electrons generated by the electron beam generator 1 are guided to an electron beam irradiation unit 3 through an electron beam transport unit 2 formed of a beam duct. The insides of the electron beam generator 1, the electron beam transporter 2, and the electron beam irradiator 3 are maintained in a high vacuum state. The electron beam irradiator 3 is provided with an electromagnet, changes the direction of the electron beam 6 by controlling the magnetic field, and scans the electron beam 6 emitted from the electron beam irradiator 3. A window 5 is provided on the bottom surface of the electron beam irradiation unit 3, and an electron beam 6 is irradiated to the irradiation target 7 through the window 5. The irradiation target 7 is placed on a base 8 such as a conveyor and moves. The irradiation target 7 is, for example, a medical tool, food, or the like. By irradiating the irradiation target 7 with the electron beam 6, the irradiation target 7 can be sterilized.

[0003]

However, in the electron beam irradiation apparatus 100 shown in FIG. 4, the distance between the window 5 and the base 8 is set so that the irradiation target 7 having different sizes can be irradiated with the electron beam 6. Must be large enough. Therefore, a space filled with air always exists between the irradiation target 7 and the window 5, and the electron beam 6 passes through the air. The electron beam 6 used for sterilization processing or the like is usually
Because of high energy of several tens kW to about 100 kW,
The electron beam 6 collides with oxygen in the air to generate ozone. In particular, when the height of the irradiation target 7 is low, the distance between the window 5 and the irradiation target 7 increases, and the amount of generated ozone increases.

[0004] Such ozone has an adverse effect on the human body and oxidizes the metal part of the electron beam irradiation apparatus. Therefore, it is necessary to separately arrange ozone treatment equipment to collect and treat the generated ozone. However, in order to treat such ozone, expensive ozone treatment equipment and the like are required, which hinders the use of the electron beam irradiation apparatus 100 as a general-purpose sterilization apparatus.

[0005] Therefore, the present invention is directed to a charged particle beam irradiation and X-ray irradiation.
It is an object of the present invention to provide an inexpensive charged particle beam irradiation apparatus and an X-ray irradiation apparatus which prevent generation of ozone due to irradiation with rays.

[0006]

Accordingly, as a result of diligent research, the present inventors have arranged a gas containing no oxygen between the window and the irradiation object, and the charged particle beam or X-ray passes through the gas. By doing so, it has been found that collision between charged particle beam or X-ray and oxygen in the air can be prevented, and generation of ozone can be suppressed, and the present invention has been completed.

That is, the present invention relates to a charged particle beam irradiation apparatus for generating a charged particle beam and irradiating the irradiated object with a charged particle beam generator, and a charged particle beam generated by the charged particle beam generator. A charged particle beam irradiation unit that irradiates the irradiation target with the irradiation target through a window, and a base unit on which the irradiation target is placed, and between the window and the irradiation target, a gas containing no oxygen is contained. A charged particle beam irradiation apparatus, comprising: a charged first gas container, wherein the charged particle beam emitted from the window is irradiated to the irradiated object through the first gas container. It is. Thus, by arranging the first gas container in the irradiation path of the charged particle beam, the collision between the charged particle beam in the irradiation path and oxygen in the air can be significantly reduced, and the cause of adverse effects on the human body, etc. Generation of ozone can be suppressed. As a result, the ozone treatment equipment required in the conventional charged particle beam irradiation apparatus becomes unnecessary, and the price and size of the charged particle beam irradiation apparatus can be reduced. Note that the charged particles include electrons, protons, positrons, ions, and the like.

[0008] Further, a beam stop portion arranged to absorb the charged particle beam transmitted through the stage portion, and a gas containing no oxygen arranged between the stage portion and the beam stop portion is filled. A second gas container, and the charged particle beam transmitted through the base portion may be applied to the beam stop portion through the second gas container. Thus, by arranging the second gas container, it is possible to significantly reduce the collision between the charged particle beam transmitted through the irradiation target and the base and the oxygen in the air, and suppress the generation of ozone. Can be.

It is preferable that the first gas container and / or the second gas container are filled with an inert gas. Helium gas, nitrogen gas, argon gas and the like can be used as the inert gas.

[0010] The first gas container may extend and contract so that the length of the charged particle beam irradiation direction of the first gas container is substantially equal to the distance between the window portion and the object to be irradiated. As described above, by expanding and contracting the first gas container in accordance with the size of the irradiation target, collision of the charged particle beam in the irradiation path of the charged particle beam with oxygen in the air is reduced as much as possible, and generation of ozone is reduced. Can be suppressed. Further, there is no need to prepare a plurality of first gas containers having different heights corresponding to the size of the irradiation object, and the charged particle beam irradiation apparatus can be provided at low cost.

The side wall of the first gas container has a bellows structure.
Preferably, the gas container expands and contracts. By using such a structure, the height of the first gas container can be easily controlled by the gas filling amount.

The present invention also relates to an X-ray irradiating apparatus for generating X-rays and irradiating the object with X-rays. The X-ray generating unit and the X-rays generated by the X-ray generating unit are irradiated through a window. A first gas including an X-ray irradiator that irradiates an irradiating body, and a pedestal section on which the irradiating body is placed, wherein a gas containing no oxygen is filled between the window and the irradiating body; An X-ray irradiation apparatus comprising a container, wherein the object to be irradiated is irradiated with the X-ray radiated from the window through the first gas container. By arranging the first gas container in the X-ray irradiation path in this way, it is possible to significantly reduce the collision between the X-rays in the irradiation path and oxygen in the air, which may cause adverse effects on the human body. Ozone generation can be suppressed.

[0013] Further, a beam stop portion arranged to absorb the X-rays transmitted through the base portion and an oxygen-free gas disposed between the base portion and the beam stop portion are filled. A second gas container may be provided, and the X-rays transmitted through the base may pass through the second gas container and enter the beam stop. By arranging the second gas container in this way, it is possible to significantly reduce the collision between the X-ray transmitted through the irradiation target and the pedestal and oxygen in the air, thereby suppressing the generation of ozone. it can.

Preferably, the first gas container and / or the second gas container is filled with an inert gas.

The first gas container may expand and contract so that the length of the first gas container in the X-ray irradiation direction is substantially equal to the distance between the window and the irradiation object.

The side wall of the first gas container has a bellows structure, and the first gas container has a side wall depending on the amount of gas charged in the first gas container.
Preferably, the gas container expands and contracts.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a schematic diagram of an electron beam irradiation apparatus 100 according to the first embodiment of the present invention. 4 indicate the same or corresponding parts. In the electron beam irradiation apparatus 100 according to the present embodiment, in addition to the conventional structure, the window 5 of the electron beam irradiation unit 3 and the irradiation target 7
And a first gas container 10 is provided. A second gas container 13 and a beam stopping unit 14 are provided below the irradiation target 7. The irradiation direction of the electron beam 6 is controlled by the control unit 9.

An electron beam irradiation apparatus 10 according to the present embodiment
In the case of 0, before the irradiation of the electron beam 6, the first gas container 10 selected according to the size of the irradiation target 7 is placed between the window 5 of the electron beam irradiation unit 3 and the irradiation target 7. Is held by, for example, a support. The size of the first gas container 10 is such that the space between the window 5 and the irradiation target 7 is substantially occupied by the first gas container 10 and the irradiation path of the electron beam 6 irradiated from the electron beam irradiation unit 3 Most are selected to be in the first gas container 10.

The first gas container 10 has an entrance window 11 on the upper surface and an exit window 12 on the bottom surface. The entrance window 11 and the exit window 12 are formed of, for example, a metal thin film such as an aluminum thin film or a titanium thin film so that the electron beam 6 is easily transmitted and has heat resistance. On the other hand, the first gas container 10
In addition to a metal film, a plastic or the like can be used on the side surface of. The first gas container 10 is a closed container, and is filled with a gas containing no oxygen. In particular, here, the first gas container 10 is filled with an inert gas such as helium gas.
In addition, in order to cool the entrance window 11 and the exit window 12,
The gas filled in the gas container 10 may be circulated.

When the irradiation target 7 is thin, the electron beam 6 passes through the irradiation target. Therefore, in such a case, the beam stopping unit 14 is provided below the irradiation target 7. The electron beam 6 that has passed through the irradiation target 7 is
Stop colliding with. The bremsstrahlung X-ray generated when the high-energy electron beam 6 stops is transmitted to the beam stopping unit 14.
Is absorbed by In the electron beam irradiation apparatus 100 having such a configuration, it is preferable to provide the second gas container 13 below the irradiation target 7. The second gas container 13 has the same structure as the first gas container 10 described above, and the gas filled in the container is the same as the first gas container 10.

In order to reduce the amount of bremsstrahlung X-rays, the vicinity of the surface of the beam stop portion 14 on which the electron beam 6 is incident is formed of a material having a small atomic weight such as carbon. It is preferable to use a material having a large atomic weight such as lead.

As described above, in the electron beam irradiation apparatus 100 according to the present embodiment, the first gas container 10 and the second gas container 13 filled with the inert gas are provided in the irradiation path of the electron beam 6. The electron beam 6 emitted from the window 5 of the electron beam irradiator 3 passes through the inert gas. Therefore, collision between the electron beam 6 and oxygen in the air in the irradiation path can be significantly reduced, and generation of ozone can be suppressed. Therefore, ozone treatment equipment, which is indispensable in the conventional electron beam irradiation apparatus, becomes unnecessary, and the cost and size of the electron beam irradiation apparatus can be reduced.

If the electron beam 6 does not pass through the irradiation object 7, the thickness of the irradiation object 7 is large.
3. It is not necessary to provide the beam stop unit 14. Further, as a method of irradiating the electron beam 6, any of divergent beam scan irradiation and parallel beam scan irradiation may be used.
In this embodiment, the case of irradiating an electron beam has been described.However, in an apparatus using another charged particle such as a proton, a positron, or an ion, by using such a configuration, the charged particle and the air Ozone generated by collision with oxygen can be significantly reduced.

Embodiment 2 FIG. FIG. 2 is a schematic diagram of an electron beam irradiation apparatus 100 according to the second embodiment of the present invention. 4 indicate the same or corresponding parts. In the electron beam irradiation apparatus 100 according to the present embodiment, a telescopic gas container 15 is used instead of the first gas container 10 used in the first embodiment. The telescopic gas container 15 is held in an extensible state by, for example, a support.

The telescopic gas container 15 has an entrance window 1 on the upper surface.
1. The bottom surface becomes the exit window 12, the entrance window 11, the exit window 12
Is formed from a metal thin film such as an aluminum thin film or a titanium thin film. On the other hand, the side surface is a bellows which can be expanded and contracted, and a plastic material other than a metal film can be used for the material of the side surface. A gas supply source 17 is connected to the telescopic gas container 15 via a pipe 16. A gas that does not contain oxygen is supplied from the gas supply source 17 and is filled in the telescopic gas container 15. Here, an inert gas such as helium gas is supplied. The telescopic gas container 15 expands and contracts according to the gas supply amount.

The height of the irradiation target 7 (the length in the electron beam irradiation direction) is detected by the irradiation target detection unit 18 and the window 5 is detected.
The distance between the object and the irradiation target 7 is obtained. Based on the distance thus obtained, the inert gas is supplied from the gas supply source 17, and the height of the telescopic gas container 15 is adjusted to be substantially equal to the distance.

As described above, in the first embodiment, it is necessary to prepare a plurality of first gas containers 10 corresponding to the size of the irradiation target 7, but in the second embodiment, the first gas containers 10 are required. Since the height of the telescopic gas container 15 can be adjusted according to the size of the irradiation body 7, there is no need to prepare a plurality of containers. Accordingly, the electron beam irradiation apparatus 100 can be supplied at low cost, and can quickly respond even when the irradiation target 7 is changed.

In this embodiment, the side wall of the telescopic gas container 15 has a bellows structure which can be expanded and contracted. For example, the side wall is formed of a thin film of vinyl or the like, and a spring is wound around the side wall.
A structure in which the side wall expands and contracts in the height direction may be used. In such a structure, when an inert gas is supplied to the telescopic gas container 15, the container extends in the height direction. Conversely, when the inert gas is discharged, the spring contracts, and the container contracts in the height direction.

Embodiment 3 FIG. 3 is a schematic diagram of an X-ray irradiation device 200 according to the third embodiment of the present invention. FIG.
The same reference numerals indicate the same or corresponding parts. In the X-ray irradiation apparatus 200 according to the present embodiment, the electron beam is converted into X-rays by providing the existing X-ray converter 19 in the electron beam irradiation apparatus 100 according to the first embodiment. In particular,
A cooling means is provided between the electron beam irradiation unit 3 and the first gas container 10, and the X-ray converter 1 made of heavy metal such as lead is provided.
9 are provided. The electron beam 6 incident on the X-ray converter 19 is converted into an X-ray 20 and is irradiated on the irradiation target 7. X
The irradiation of the line 20 enables the irradiation target 7 to be sterilized or the like.

In the X-ray irradiation apparatus 200 shown in FIG.
First gas container 1 filled with an inert gas
0, a second gas container 13 is provided. Therefore, X
The X-rays 20 emitted from the ray converter 19 pass through the inert gas filled in the first gas container 10. The X-rays 20 transmitted through the irradiation target 7 pass through the inert gas filled in the second gas container 13 and are absorbed by the beam stopping unit 14.

As described above, in the X-ray irradiation apparatus 200 shown in FIG. 3, the X-ray 20 is irradiated with the first gas container 1 filled with the inert gas.
0, since it passes through the second gas container 13, the collision between the X-rays 20 in the irradiation path and oxygen in the air can be greatly reduced, and the generation of ozone can be suppressed. Therefore, the conventional X
The ozone treatment equipment required for the X-ray irradiator becomes unnecessary, and the X-ray irradiator can be reduced in cost and size.

The X-ray irradiation device 200 shown in FIG.
As in the first embodiment, the first gas container 10 is selected in accordance with the type of the irradiation target 1. However, instead of the first gas container 10, a telescopic type as in the second embodiment is used. A gas container 15 can also be used.

[0033]

As is apparent from the above description, the charged particle beam irradiation apparatus according to the present invention can reduce the collision between charged particles and oxygen and suppress the generation of ozone which has a bad influence on the human body. it can.

Further, in the X-ray irradiation apparatus according to the present invention,
Similarly, collision between X-rays and oxygen can be reduced, and generation of ozone can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an electron beam irradiation apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of an electron beam irradiation apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram of an X-ray irradiation device according to a third embodiment of the present invention.

FIG. 4 is a schematic view of a conventional electron beam irradiation apparatus.

[Explanation of symbols]

1 electron beam generating section, 2 electron beam transporting section, 3 electron beam irradiating section, 4 support section, 5 window section, 6 electron beam, 7 irradiated object,
8 units, 9 control unit, 10 first gas container, 11 entrance window, 12 exit window, 13 second gas container, 14 beam stop unit, 15 telescopic gas container, 16 piping, 17
Gas supply source, 18 irradiated object detection unit, 19 X-ray converter, 20 X-ray, 100 electron beam irradiation device, 200 X
Line irradiation equipment.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G21K 5/02 G21K 5/02 X 5/04 5/04 E

Claims (10)

[Claims] 1. A charged particle beam irradiation apparatus for generating a charged particle beam and irradiating an object to be irradiated with a charged particle beam, and a charged particle beam generated by the charged particle beam generator through a window A charged particle beam irradiating unit for irradiating the irradiation target; and a pedestal unit on which the irradiation target is placed. Further, a gas containing no oxygen is filled between the window and the irradiation target. A charged particle beam irradiating apparatus, wherein the charged particle beam radiated from the window portion is irradiated to the irradiated object through the first gas container. 2. The method according to claim 1, further comprising: a beam stop arranged to absorb the charged particle beam transmitted through the base, and a gas containing no oxygen disposed between the base and the beam stop. The charged particle beam having passed through the base portion is irradiated to the beam stop portion through the second gas container, the charged gas beam having a filled second gas container. Charged particle beam irradiation device. 3. The charged particle beam irradiation apparatus according to claim 1, wherein the first gas container and / or the second gas container is filled with an inert gas. 4. The apparatus according to claim 1, wherein the length of the first gas container in the charged particle beam irradiation direction expands and contracts so as to be substantially equal to a distance between the window and the irradiation target. 3. The charged particle beam irradiation device according to 2. 5. The side wall of the first gas container has a bellows structure, and the first gas container has a first side wall depending on an amount of gas filled therein.
The charged particle beam irradiation apparatus according to claim 4, wherein the gas container expands and contracts. 6. An X-ray for generating X-rays and irradiating the irradiation target with the X-rays
An X-ray irradiator, an X-ray generator, an X-ray irradiator that irradiates an X-ray generated by the X-ray generator to a target through a window, and a table on which the target is mounted. Further comprising a first gas container filled with a gas containing no oxygen between the window and the object to be irradiated, wherein the X-rays radiated from the window are filled with the first gas. An X-ray irradiation apparatus characterized in that the object to be irradiated is irradiated through a container. 7. A beam stop portion arranged to absorb the X-rays transmitted through the base portion, and filled with an oxygen-free gas disposed between the base portion and the beam stop portion. The X-ray irradiation according to claim 6, further comprising a second gas container provided, wherein the X-ray transmitted through the base portion passes through the second gas container and is incident on the beam stopping portion. apparatus. 8. The X-ray irradiation apparatus according to claim 6, wherein the first gas container and / or the second gas container is filled with an inert gas. 9. The apparatus according to claim 6, wherein a length of the first gas container in the X-ray irradiation direction is expanded and contracted so as to be substantially equal to a distance between the window and the irradiation object. 3. The X-ray irradiation device according to claim 1. 10. The first gas container according to claim 9, wherein a side wall of the first gas container has a bellows structure, and the first gas container expands and contracts according to an amount of gas filled in the first gas container. X-ray irradiator.