JP2024078978A - Electron beam irradiation device, protective cover for object to be irradiated with electron beam, and method for protecting object to be irradiated with electron beam - Google Patents

Abstract

[Problem] To provide an electron beam irradiation device capable of protecting an object to be irradiated with electron beams, a protective cover for protecting the object in the electron beam irradiation device, and a method for protecting the object in the electron beam irradiation device. [Solution] An electron beam irradiation device 1 includes an irradiation chamber 4, an apparatus main body 3 for irradiating an electron beam to an object to be irradiated in the irradiation chamber 4 through an irradiation window 30, and a protective cover 6 for protecting the object to be irradiated. The protective cover 6 includes a covering material 7 that is permeable to electron beams and covers the object to be irradiated, and a fixing tool 8 that is placed on the covering material 7 along the outer periphery of the covering material 7. The portion of the covering material 7 on which the fixing tool 8 is placed is pressed against a mounting table 5 by the fixing tool 8, and the fixing tool 8 has an internal flow path 80 through which a cooling fluid flows, an inlet 81 for introducing the cooling fluid into the internal flow path 80, and an outlet 82 for discharging the cooling fluid from the internal flow path 80. [Selected Figure] FIG.

Description

The present invention relates to an electron beam irradiation device, a protective cover for an object to be irradiated with electron beams, and a method for protecting an object to be irradiated with electron beams.

As shown in FIG. 6, an electron beam irradiation device generally includes an apparatus main body 111 that generates an electron beam, and an irradiation chamber 112 in which the apparatus main body 111 is installed. The apparatus main body 111 generates electrons by heating a filament in a vacuum, accelerates the electrons to form an electron beam, and emits the electron beam from an irradiation window 113 to irradiate an electron beam-irradiated object (also referred to as "irradiated object" in this disclosure) 110 arranged opposite the irradiation window 113 in the irradiation chamber 112. The irradiation window 113 is covered with a metal foil (window foil) 114 through which the electron beam can pass, and this metal foil 114 functions as a boundary between the inside of the apparatus main body 111 in a vacuum state and the inside of the irradiation chamber 112 in an atmospheric pressure state.

The metal foil 114 in the irradiation window 113 is exposed to the electron beam and absorbs some of the energy of the electron beam, causing the temperature to rise. The metal foil 114 is made of, for example, titanium, but if it generates excessive heat due to electron beam irradiation, it will deform due to a decrease in strength or break due to deterioration. For this reason, an electron beam irradiation device has been proposed that includes a cooler 115 for blowing a cooling gas such as air or nitrogen gas onto the metal foil 114 in the irradiation window 113 to cool the metal foil (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 8-278399

The cooling gas blown onto the metal foil 114 of the irradiation window 113 may be reflected by hitting the metal foil 114 and may hit the irradiated object 110 arranged opposite the irradiation window 113 with force. The irradiated object 110 may move when the cooling gas hits it. In addition, if the irradiated object 110 is a lightweight object such as a powder or granular material, the irradiated object 110 may fly off. In addition, the scattered irradiated object 110 may hit the metal foil 114 of the irradiation window 113, which may damage the metal foil 114. In addition, dust in the irradiation chamber 112 may adhere to the irradiated object 110 due to convection of the cooling gas reflected by the metal foil 114. In addition, when the irradiated object 110 is a powder or granular material, the powder or granular material 110 is usually placed in the irradiation chamber 112 in a bag. In this case, the thermal expansion of the air contained in the powder and granules due to electron beam irradiation may cause individual particles or powder to break through the bag, causing the irradiated object 110 to scatter.

The present invention has been made in consideration of the above circumstances, and aims to provide an electron beam irradiation device capable of protecting an object to be irradiated with an electron beam, a protective cover for protecting an object to be irradiated in an electron beam irradiation device, and a method for protecting an object to be irradiated in an electron beam irradiation device.

The first aspect of the present invention relates to an electron beam irradiation device comprising at least an irradiation chamber having a mounting table on which an object to be irradiated with electron beams is placed, and an apparatus main body that generates an electron beam and irradiates the electron beam from an irradiation window portion to the object to be irradiated with the electron beam in the irradiation chamber. The electron beam irradiation device of the present invention further comprises a protective cover provided on the mounting table to protect the object to be irradiated with the electron beam, the protective cover comprising a covering material that is permeable to the electron beam and covers the object to be irradiated with the electron beam, and at least one stationary tool that is placed on the covering material so as to follow at least a portion of the outer periphery of the covering material, the portion of the covering material on which the stationary tool is placed is pressed against the mounting table by the stationary tool, and the stationary tool has an internal flow path through which a cooling fluid for cooling the stationary tool flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path.

The second aspect of the present invention relates to a protective cover provided on a mounting table for protecting an electron beam irradiated object in an electron beam irradiation device that irradiates an electron beam to an electron beam irradiated object placed on the mounting table. The protective cover of the present invention comprises a covering material that is permeable to the electron beam and covers the electron beam irradiated object, and at least one stationary device that is placed on the covering material along at least a portion of the outer periphery of the covering material and presses the covering material toward the mounting table, and the stationary device has an internal flow path through which a cooling fluid for cooling the stationary device flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path.

The third aspect of the present invention relates to a method for protecting an electron beam irradiated object placed on a mounting table in an electron beam irradiation device that irradiates an electron beam to the electron beam irradiated object placed on the mounting table. The method for protecting an electron beam irradiated object of the present invention is characterized in that the object is covered with a covering material that is permeable to the electron beam, at least one stationary tool is placed on the covering material so as to follow at least a portion of the outer periphery of the covering material, the covering material is pressed against the mounting table, and a cooling fluid is circulated inside the stationary tool to cool the stationary tool.

According to the present invention,

FIG. 2 is a schematic diagram of an electron beam irradiation device. FIG. 2 is an enlarged schematic diagram of a main part of FIG. 1 . FIG. 2 is a plan view of the protective cover of FIG. 1 . FIG. 13 is a plan view of a protective cover according to a modified example. FIG. 13 is a plan view of a protective cover according to a modified example. FIG. 1 is a schematic diagram of a conventional electron beam irradiation device.

The electron beam irradiation device according to the embodiment of the present invention will be described in detail below with reference to the drawings. Figs. 1 to 3 show a schematic configuration of the electron beam irradiation device 1 of this embodiment. The electron beam irradiation device 1 irradiates an irradiated object 2 with an electron beam to, for example, improve the material properties of the irradiated object 2, add functions, sterilize, or otherwise disinfect the irradiated object 2. The electron beam irradiation device 1 includes at least an apparatus main body 3 that generates electron beams to be irradiated to the irradiated object 2, an irradiation chamber 4 that includes a mounting table 5 on which the irradiated object 2 is placed, and a protective cover 6 that is provided on the mounting table 5 in the irradiation chamber 4 and protects the irradiated object 2.

The object 2 to be irradiated with the electron beam is not particularly limited, and examples include electric wires, optical cables, wires, rubber hoses, tubes, films, sheets, powders, and the like.

The device main body 3 generates an electron beam and irradiates the electron beam on the irradiated object 2. With the inside of the device main body 3 depressurized by a vacuum pump, the device main body 3 generates electrons by heating a filament, accelerates the electrons to form an electron beam, and emits the electron beam from the irradiation window 30 to the outside of the device main body 3. The structure of the device main body 3 is not particularly limited as long as it is capable of generating the above-mentioned electron beam and irradiating the electron beam on the irradiated object 2, and may be a scanning type or a non-scanning type.

The irradiation window 30 is a part of the device body 3 that opens in the irradiation chamber 4, and the area below the irradiation window 30 is the electron beam irradiation area. The irradiation window 30 is covered with a metal foil (window foil) 31. The metal foil 31 is a thin metal sheet that allows electron beams to pass through in the thickness direction, and can be made of titanium, for example. It is preferable that the thickness of the metal foil 31 is as thin as possible to suppress the energy loss of the electron beam passing through the metal foil 31, but since the metal foil 31 is the boundary between the inside of the device body 3 in a vacuum state and the inside of the irradiation chamber 4 in an atmospheric pressure state and functions as a pressure boundary, the thickness of the metal foil 31 is designed to be thick enough to withstand a pressure difference of 1 atmosphere.

The electron beam irradiation device 1 is not particularly limited, but preferably further includes a cooler 10 that cools the irradiation window portion 30 with a cooling gas. The cooler 10 includes a nozzle 100 for spraying the cooling gas onto the metal foil 31 of the irradiation window portion 30, and a duct 101 for circulating the cooling gas supplied from a cooling gas supply source (not shown) to the nozzle 100.

The metal foil 31 of the irradiation window 30 is exposed to the electron beam, and as a result, its temperature rises as it absorbs part of the energy of the electron beam. If it generates excessive heat due to the electron beam irradiation, it may deform due to a decrease in strength or become damaged due to deterioration. For this reason, a cooler 10 is provided in the device body 3 to blow a cooling gas such as air or nitrogen gas onto the metal foil 31 of the irradiation window 30 to cool the metal foil 31.

The irradiation chamber 4 is made of a lead-based metal to prevent the electron beam from leaking out of the chamber. The irradiation chamber 4 is, for example, a rectangular box, and a mounting table 5 is provided on the bottom wall 40 inside the chamber. The irradiation chamber 4 also has an apparatus main body 2 provided above the mounting table 5 such that the irradiation window 30 and the mounting table 5 are positioned opposite each other.

The mounting table 5 includes a top plate 50 and one or more legs 51, and the irradiated object 2 can be placed on the top surface of the top plate 50. The top surface of the top plate 50 is flat. The top plate 50 is preferably provided with a cooling means for cooling the top plate 50, for example by introducing and discharging cooling water into the top plate 50, although it is not particularly limited thereto. The mounting table 5 is preferably movably installed on the bottom wall 40 of the irradiation chamber 4, although it is not particularly limited thereto.

The protective cover 6 is provided on the mounting table 5 in the irradiation chamber 4 so as to cover the irradiated object 2. The protective cover 6 includes a covering material 7 that covers the irradiated object 2, and at least one fixing device 8 that is placed on the covering material 7 so as to follow at least a portion of the outer periphery of the covering material 7.

The covering material 7 prevents the cooling gas reflected by the metal foil 31 of the irradiation window portion 30 from coming into contact with the irradiated object 2 when the cooling gas is blown onto the metal foil 31. The covering material 7 also protects foreign matter such as dust in the irradiation chamber 4 from adhering to the irradiated object 2. The covering material 7 also protects the irradiated object 2 from being scattered from the mounting table 5 due to the blowing of the cooling gas described above or other factors.

The covering material 7 allows the electron beam to pass through in the thickness direction. Therefore, even if the irradiated object 2 on the mounting table 5 is covered with the covering material 7, the irradiated object 2 can be irradiated with the electron beam. In addition, the covering material 7 has heat resistance because it generates heat when irradiated with the electron beam. In addition, the covering material 7 has durability that can withstand the cooling gas being blown onto it without being damaged because the cooling gas reflected by the metal foil 31 of the irradiation window portion 30 may hit the covering material 7 with force. In addition, the covering material 7 is not particularly limited, but is preferably flexible. Since the covering material 7 has flexibility and can be flexibly deformed, the height of the covering material 7 (the vertical distance H from the upper surface of the mounting table 5 to the uppermost position of the covering material 7 shown in FIG. 2) can be easily changed according to the height of the irradiated object 2 even if the height of the irradiated object 2 on the mounting table 5 changes. In addition, when the irradiated object 2 is, for example, a powder or granular material, there is a risk that individual grains or powder of the irradiated object 2 may fly off from the mounting table 5 and collide with the coating material 7. Therefore, although there is no particular limitation, the coating material 7 is preferably durable enough to withstand the collision of the irradiated object 2 without being damaged. In addition, although there is no particular limitation, the coating material 7 is preferably made of an inexpensive material.

From the above viewpoint, the covering material 7 can be made of an aluminum sheet, for example, a thin aluminum foil. The covering material 7 can also be made of a metal sheet made of a material other than aluminum, for example, a titanium sheet, preferably a thin titanium foil, or it can be made of a sheet (or film) made of a material other than metal, although it has poor heat resistance, and the material is not particularly limited. Furthermore, the covering material 7 does not necessarily have to be in the form of a flexible sheet, but may be in the form of a plate that is hard and does not easily deform, and the shape is not particularly limited.

Because the covering material 7 is exposed to the electron beam, it absorbs some of the energy of the electron beam, causing the temperature to rise. It is preferable that the thickness of the covering material 7 is as thin as possible in order to suppress the energy loss of the electron beam passing through the covering material 7 and to suppress the temperature rise caused by the irradiation of the electron beam by the covering material 7. The thickness of the covering material 7 is set appropriately depending on the material, but when the covering material 7 is made of aluminum, it is preferable that the thickness is, for example, 11 μm or more and 17 μm or less. Aluminum foil can be used as the aluminum covering material 7 having a thickness of 11 μm or more and 17 μm or less, and aluminum foil is generally easy to obtain and inexpensive, which allows costs to be reduced.

The covering material 7 has the fixing device 8 placed along at least a portion of the outer periphery, and the portion on which the fixing device 8 is placed is pressed from above against the mounting table 5 by the fixing device 8. As a result, the covering material 7 remains in a fixed location on the mounting table 5, specifically, in the location covering the irradiated object 2.

The fixing device 8 is not particularly limited, but is preferably made of a rust-resistant metal such as stainless steel. The shape of the fixing device 8 in plan view is not particularly limited as long as it can press a portion of the coating material 7 against the mounting table 5 from above around the irradiated object 2.

However, from the viewpoints of stably placing the covering material 7 on the mounting table 5 by the mounting device 8 and making the storage space for the irradiated object 2 between the covering material 7 and the mounting table 5 as closed as possible, the mounting device 8 preferably has a frame shape in a plan view that is placed on the covering material 7 along the entire outer periphery of the covering material 7 and arranged around the irradiated object 2. The shape of the mounting device 8 in a plan view may be a circular frame, an elliptical frame, a rectangular frame, or any other polygonal frame, as long as it can surround the periphery of the irradiated object 2 and position the irradiated object 2 in the open area inside.

The size of the stationary device 8 in a plan view is not particularly limited, but is preferably smaller than the size of the irradiation area of the electron beam irradiated from the irradiation window 30 of the device body 3 to the mounting table 5 in a plan view. In other words, the stationary device 8 is sized to fit inside the irradiation area of the electron beam irradiated from the irradiation window 30 of the device body 3 to the mounting table 5 in a plan view. If the size of the stationary device 8 in a plan view is larger than the size of the irradiation area of the electron beam irradiated to the mounting table 5 in a plan view, the stationary device 8 can be prevented from being exposed to the electron beam and the stationary device 8 can be prevented from generating heat due to the electron beam irradiation, but the stationary device 8 may become too large, which may make it inefficient to manufacture and carry the protective cover 6. If the size of the stationary device 8 in a plan view is smaller than the size of the irradiation area of the electron beam irradiated to the mounting table 5 in a plan view, the protective cover 6 can be efficiently manufactured and carried.

If the size of the mounting device 8 in a plan view is smaller than the size of the irradiation area of the electron beam irradiated on the mounting table 5 in a plan view, the mounting device 8 will be exposed to the electron beam and will generate heat due to the electron beam irradiation. However, this problem can be solved by circulating a cooling fluid inside the mounting device 8, as described below.

The shape (outer shape) of the stationary device 8 in a cross section parallel to the vertical direction can be various shapes such as a circle, a rectangle, or other polygonal shapes, but it is preferable to make it rectangular, for example, so that the lower surface of the stationary device 8 facing the covering material 7 can be made flat. By making the lower surface of the stationary device 8 flat, a portion of the covering material 7 can be pressed against the mounting base 5 over a wide area by the surface, and the covering material 7 can be stably placed on the mounting base 5. As described later, the covering material 7 is fixed to the stationary device 8 by a fixing means 9 such as double-sided tape, and the portion of the stationary device 8 facing the covering material 7 and fixed to the covering material 7 has a flat lower surface, so that the stationary device 8 can be firmly fixed to the covering material 7.

Regarding the height of the mounting device 8 (the vertical distance h between the lowest position (the lower surface in this embodiment) and the highest position (the upper surface in this embodiment) when the mounting device 8 is placed on the mounting table 5 shown in FIG. 2), if the height of the mounting device 8 is too high, the electron beam irradiated to the inner peripheral surface of the mounting device 8 will be reflected and irradiated onto the irradiated object 2, and the amount of electron beam irradiated onto the irradiated object 2 will be greater than the intended amount. Therefore, the height of the mounting device 8 is not particularly limited, but is preferably 3 cm or less.

The fixture 8 has a hollow pipe shape and has an internal flow path 80 through which the cooling fluid flows. The fixture 8 also has an inlet 81 connected to one end of the internal flow path 80 for introducing the cooling fluid into the internal flow path 80, and an outlet 81 connected to the other end of the internal flow path 80 for discharging the cooling fluid from the internal flow path 80, so that the cooling fluid can be introduced into and discharged from the internal flow path 80. The inlet 81 and the outlet 81 are connected to a fluid tank (not shown) installed outside the irradiation chamber 4, and the cooling fluid stored in the fluid tank is circulated by driving a pump (not shown), and the cooling fluid cools the fixture 8 by heat exchange with the fixture 8 when it passes through the inside of the fixture 8. The cooling fluid is not particularly limited as long as it can cool the fixture 8, but is preferably a liquid, and more preferably cooling water such as tap water.

The fixing device 8 is not particularly limited, but preferably the covering material 7 is fixed by a fixing means 9. By fixing the covering material 7 to the fixing device 8 by the fixing means 9, the protective cover 6 can be easily carried, and the protective cover 6 can be easily installed on the mounting table 5 so as to cover the covering material 2.

The fixing means 9 is not particularly limited, but is preferably provided on the portion of the fixing device 8 facing the covering material 7, and in this embodiment, on the underside facing the covering material 7. By providing the fixing means 9 on the portion of the fixing device 8 facing the covering material 7, the fixing means 9 is covered by the fixing device 8 and is hidden under the fixing device 8 in a plan view so as not to be exposed. As a result, the fixing means 9 is less likely to be irradiated with the electron beam because it is blocked by the fixing device 8, and the fixing means 9 can be prevented from being damaged or its quality reduced due to deterioration caused by the effects of electron beam irradiation.

The fixing means 9 is not particularly limited as long as it can fix the covering material 7 to the mounting device 8, but by using double-sided tape, adhesive, or pressure-sensitive adhesive as the fixing means 9, the covering material 7 can be easily fixed to the mounting device 8 and the covering material 7 can be easily removed from the mounting device 8. Other fixing means 9 may be welding or a clip that clamps the outer periphery of the covering material 7 and is integrally provided on the mounting device 8.

The covering material 7 may be fixed by the fixing means 9 over the entire length of the stationary device 8, or the covering material 7 may be fixed by the fixing means 9 over a portion of the entire length. In this embodiment, the covering material 7 is fixed by the fixing means 9 over the entire length (entire circumference) of the stationary device 8, which has a frame shape in a plan view.

In the electron beam irradiation device 1 of this embodiment described above, when the object to be irradiated 2 placed on the mounting table 5 is irradiated with electron beams, a protective cover 6 is provided on the mounting table 5 to protect the object to be irradiated. A specific protection method is to irradiate the object to be irradiated 2 with electron beams while covering the object to be irradiated 2 with a covering material 7 that is permeable to electron beams, place at least one fixing tool 8 on the covering material 7 so as to follow at least a portion of the outer periphery of the covering material 7, and press the covering material 7 toward the mounting table 5 to fix the covering material 7 on the mounting table 5, and cool the fixing tool 8 by circulating a cooling fluid inside the fixing tool 7 during irradiation with the electron beam.

In the electron beam irradiation device 1 of this embodiment, the irradiated object 2 on the mounting table 5 is irradiated with electron beams while the irradiated object 2 is covered with the covering material 7. Therefore, even if the cooling gas blown onto the metal foil 31 of the irradiation window portion 30 by the cooler 10 is reflected by the metal foil 31 and flows toward the irradiated object 2 on the mounting table 5, the cooling gas is blocked by the covering material 7 and prevented from striking the irradiated object 2 with force. Therefore, there is no risk that the irradiated object 2 will move on the mounting table 5 due to the impact of the cooling gas, or that the irradiated object 2 will fly off the mounting table 5 if the irradiated object 2 is a lightweight object such as a powder or granular material. As a result, the irradiated object 2 can be irradiated with electron beams under the desired irradiation conditions. In addition, there is no risk that the scattered irradiated object 2 will hit the metal foil 31 of the irradiation window portion 30, damaging the metal foil 31. Furthermore, even if foreign matter such as dust in the irradiation chamber 4 is scattered due to convection of the cooling gas reflected by the metal foil 31, there is no risk of the foreign matter adhering to the irradiated object 2.

When the irradiated object 2 is a powder or granular material, the powder or granular material 2 is usually placed on the mounting table 5 in a bag. In this case, there is a risk that the irradiated object 2 will scatter as individual grains or powder break through the bag due to thermal expansion of the air contained in the powder or granular material caused by electron beam irradiation. However, the coating material 7 of the protective cover 6 prevents the irradiated object 2 from scattering, so the irradiated object 2 is scattered only within a specified range on the mounting table 5. Therefore, even in this case, there is no risk of the irradiated object 2 scattering and hitting the metal foil 31 of the irradiation window portion 30, causing damage to the metal foil 31.

In addition, in the electron beam irradiation device 1 of this embodiment, the fixing device 8 of the protective cover 6 is cooled by a cooling fluid during electron beam irradiation. Since the fixing device 8 is exposed to the electron beam, the temperature rises by absorbing part of the energy of the electron beam, and if it generates excessive heat due to electron beam irradiation, it will deform due to a decrease in strength or become damaged due to deterioration. Since the fixing device 8 continues to be cooled by the cooling fluid during electron beam irradiation, deformation and damage can be suppressed, and repeated use is possible.

In addition, in the electron beam irradiation device 1 of this embodiment, the fixing device 8 and the covering material 7 are fixed by the fixing means 9. Therefore, the protective cover 6 is easy to carry. Furthermore, the fixing means 9 is provided on the part of the fixing device 8 that faces the covering material 7 (the underside in this embodiment). Therefore, the fixing means 9 can be prevented from being exposed to the electron beam, and the fixing means 9 can be prevented from being damaged or degraded in quality due to deterioration caused by the effects of electron beam irradiation. Note that the fixing means 9 is also cooled by the cooling fluid circulating inside the fixing device 8, so that the fixing means 9 can be prevented from being damaged or degraded in quality due to deterioration caused by cooling.

In addition, in the electron beam irradiation device 1 of this embodiment, the bottom surface of the fixing device 8 facing the coating material 7 is flat. Therefore, the fixing device 8 can press a portion of the coating material 7 against the mounting table 5 over a wide area, and the coating material 7 can be stably placed on the mounting table 5. Furthermore, when double-sided tape, adhesive, or pressure-sensitive adhesive is used as the fixing means 9, the fixing device 8 can be firmly fixed to the coating material 7 by providing the fixing means 9 on the flat bottom surface of the fixing device 8.

In addition, in the electron beam irradiation device 1 of this embodiment, the fixing device 8 has a frame shape in a plan view that is placed on the coating material 7 so as to follow the entire circumference of the outer edge of the coating material 7. Therefore, the fixing device 8 can stably fix the coating material 7 on the mounting table 5, and the storage space for the irradiated object 2 between the coating material 7 and the mounting table 5 can be made as closed as possible.

In addition, in the electron beam irradiation device 1 of this embodiment, the size of the mounting device 8 in a plan view is smaller than the size of the irradiation area of the electron beam irradiated from the irradiation window portion 30 of the device body 3 to the mounting table 5 in a plan view. Therefore, the protective cover 6 can be efficiently manufactured and carried.

In addition, in the electron beam irradiation device 1 of this embodiment, the height of the fixing device is 3 cm or less. Therefore, it is possible to prevent the electron beam irradiated to the inner peripheral surface of the fixing device 8 from being reflected and irradiated to the irradiated object 2, and it is possible to prevent the dose of the electron beam irradiated to the irradiated object 2 from being greater than the intended dose.

In addition, in the electron beam irradiation device 1 of this embodiment, the coating material 7 is flexible. Therefore, by coating the irradiated object 2 with the coating material 7 while leaving some slack at the top, the height of the coating material 7 can be easily changed according to the height of the irradiated object 2, and coating materials 2 of various heights can be coated.

In addition, in the electron beam irradiation device 1 of this embodiment, the covering material 7 is made of aluminum foil. This makes it possible to provide the covering material 7 with heat resistance, durability, and flexibility, and because it is thin, it is possible to reduce the energy loss of the electron beam when it passes through the covering material 7.

The above describes the embodiments of the electron beam irradiation device, protective cover, and method for protecting an irradiated object of the present invention, but the electron beam irradiation device, protective cover, and method for protecting an irradiated object of the present invention are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of this disclosure.

For example, in the above-described embodiment, the fixing device 8 has a frame shape in plan view that is placed on the covering material 7 so as to follow the entire circumference of the outer periphery of the covering material 7, but the fixing device 8 does not necessarily have to have a shape that allows it to be placed on the covering material 7 so as to follow the entire circumference of the outer periphery of the covering material 7. The fixing device 8 may have a shape that allows it to be placed on the covering material 7 so as to follow a portion of the outer periphery of the covering material 7, for example, as shown in FIG. 4, a shape that allows it to be placed on the covering material 7 so as to follow three of the outer periphery (four sides) of the covering material 7 (a U-shape in plan view), or, although not shown, a shape that allows it to be placed on the covering material 7 so as to follow two orthogonal sides of the outer periphery (four sides) of the covering material 7 (an L-shape in plan view).

For example, in the above-described embodiment, the covering material 7 is fixed on the mounting table 5 by one mounting device 8, but the number of mounting devices 8 does not necessarily have to be one, and may be multiple. For example, as shown in FIG. 5, there may be two mounting devices 8. In FIG. 5, the two mounting devices 8 each have a shape that extends linearly in a plan view. Each mounting device 8 is placed on the covering material 7 so as to be along one of the four outer periphery edges (four sides) of the covering material 7. Note that in FIG. 5, the two mounting devices 8 are placed on the covering material 7 along two parallel sides of the outer periphery (four sides) of the covering material 7, but they may be placed on the covering material 7 along two perpendicular sides of the outer periphery (four sides) of the covering material 7. Also, in FIG. 5, three stationary devices 8 that extend linearly in a plan view may be prepared, and each may be placed on the covering material 7 along one of the outer periphery (four sides) of the covering material 7 (along a total of three sides), or four stationary devices 8 that extend linearly in a plan view may be prepared, and each may be placed on the covering material 7 along one of the outer periphery (four sides) of the covering material 7 (along a total of four sides). Alternatively, two stationary devices 8 that are L-shaped in a plan view may be prepared, and each may be placed on the covering material 7 along two mutually perpendicular sides of the outer periphery (four sides) of the covering material 7 (along a total of four sides).

For example, in the above-described embodiment, the fixing device 8 and the covering material 7 are fixed by the fixing means 9, but the fixing device 8 and the covering material 7 do not necessarily need to be fixed by the fixing means 9, and the fixing device 8 may simply be placed on the covering material 7.

As described above, the electron beam irradiation device of the present invention includes the electron beam irradiation device described in the following item 1 in order to solve the problem of this disclosure.

Item 1. An electron beam irradiation device including at least an irradiation chamber having a mounting table on which an object to be irradiated with an electron beam is placed, and an apparatus main body that generates an electron beam and irradiates the electron beam from an irradiation window portion to the object to be irradiated with the electron beam in the irradiation chamber,
a protective cover provided on the mounting table to protect the object to be irradiated with the electron beam,
the protective cover comprises a coating material that is permeable to the electron beam and that covers the object to be irradiated with the electron beam, and at least one fixing tool that is placed on the coating material so as to follow at least a portion of an outer periphery of the coating material;
a portion of the covering material on which the fixing tool is placed is pressed against the mounting table by the fixing tool;
The stationary tool has an internal flow path through which a cooling fluid for cooling the stationary tool flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path, in an electron beam irradiation device.

The electron beam irradiation device of the present invention also includes the electron beam irradiation device described in the following item 2 as a preferred embodiment of the electron beam irradiation device described in the above item 1.

Item 2. The electron beam irradiation device according to item 1, wherein the fixing device is provided with a fixing means for fixing the coating material to the fixing device at a portion facing the coating material.

The present invention also includes the electron beam irradiation device described in the following item 3 as a preferred embodiment of the electron beam irradiation device described in the above item 2.

Item 3. The lower surface of the fixing tool facing the covering material is flat,
3. The electron beam irradiation device according to claim 2, wherein the fixing means is provided on a lower surface of the fixing tool.

The present invention also includes the electron beam irradiation device described in the following item 4 as a preferred embodiment of the electron beam irradiation device described in the above items 2 and 3.

Item 4. The electron beam irradiation device according to item 2 or 3, wherein the fixing means is an adhesive, a pressure sensitive adhesive, or a double-sided tape.

The present invention also includes the electron beam irradiation device described in the following item 5 as a preferred embodiment of the electron beam irradiation device described in items 1 to 4 above.

Item 5. The electron beam irradiation device according to any one of items 1 to 4, wherein the mounting device has a frame shape in a plan view that is placed on the coating material so as to follow the entire circumference of the outer edge of the coating material, and the mounting device is disposed around the object to be irradiated with the electron beam.

The present invention also includes the electron beam irradiation device described in the following item 6 as a preferred embodiment of the electron beam irradiation device described in items 1 to 5 above.

Item 6. The electron beam irradiation device according to any one of items 1 to 5, wherein the size of the mounting device in a plan view is smaller than the size of the irradiation area of the electron beam irradiated from the irradiation window of the device body to the mounting table in a plan view.

The present invention also includes the electron beam irradiation device described in the following item 7 as a preferred embodiment of the electron beam irradiation device described in items 1 to 6 above.

Item 7. The electron beam irradiation device according to any one of items 1 to 6, wherein the height of the mounting device is 3 cm or less.

The present invention also includes the electron beam irradiation device described in the following item 8 as a preferred embodiment of the electron beam irradiation device described in items 1 to 7 above.

Item 8. The electron beam irradiation device according to any one of items 1 to 7, wherein the covering material is flexible.

The present invention also includes the electron beam irradiation device described in the following item 9 as a preferred embodiment of the electron beam irradiation device described in items 1 to 8 above.

Item 9. The electron beam irradiation device according to any one of items 1 to 8, wherein the covering material is made of metal.

The present invention also includes the electron beam irradiation device described in the following item 10 as a preferred embodiment of the electron beam irradiation device described in the above items 8 and 9.

Item 10. The electron beam irradiation device according to item 8 or 9, wherein the covering material is made of aluminum foil.

The present invention also includes the electron beam irradiation device described in the following item 11 as a preferred embodiment of the electron beam irradiation device described in items 1 to 10 above.

Item 11. The electron beam irradiation device according to any one of items 1 to 10, further comprising a cooler that cools the irradiation window portion with a cooling gas.

The protective cover of the present invention also includes the protective cover described in item 12 below in order to solve the problems of this disclosure.

Item 12. In an electron beam irradiation apparatus that irradiates an electron beam to an object to be irradiated with an electron beam placed on a mounting table, a protective cover is provided on the mounting table to protect the object to be irradiated with the electron beam,
a coating material that is transparent to the electron beam and that covers the object to be irradiated with the electron beam; and at least one fixing tool that is placed on the coating material along at least a portion of an outer periphery of the coating material and presses the coating material against the mounting table;
The fixed device is a protective cover having an internal flow path through which a cooling fluid for cooling the fixed device flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path.

The method for protecting an object irradiated with electron beams of the present invention also includes the method for protecting an object irradiated with electron beams described in item 13 below in order to solve the problems of this disclosure.

Item 13. In an electron beam irradiation apparatus that irradiates an electron beam to an object to be irradiated with an electron beam placed on a mounting table, a method for protecting the object to be irradiated with an electron beam, the method comprising:
covering the object to be irradiated with the electron beam with a covering material that is permeable to the electron beam;
At least one fixing tool is placed on the coating material so as to be along at least a portion of the outer periphery of the coating material, and the coating material is pressed against the mounting table;
A method for protecting an object to be irradiated with electron beams, comprising the steps of: circulating a cooling fluid through the inside of the fixing fixture to cool the fixing fixture.

REFERENCE SIGNS LIST 1 Electron beam irradiation device 2 Irradiated object 3 Device body 4 Irradiation chamber 5 Mounting table 6 Protective cover 7 Covering material 8 Fixed material 9 Fixing means 10 Cooler 80 Internal flow path 81 Inlet 82 Outlet 30 Irradiation window 31 Metal foil

Claims (13)

An electron beam irradiation apparatus including at least an irradiation chamber having a mounting table for mounting an object to be irradiated with an electron beam, and an apparatus main body that generates an electron beam and irradiates the electron beam from an irradiation window portion to the object to be irradiated with the electron beam in the irradiation chamber,
a protective cover provided on the mounting table to protect the object to be irradiated with the electron beam,
the protective cover comprises a coating material that is permeable to the electron beam and that covers the object to be irradiated with the electron beam, and at least one fixing tool that is placed on the coating material so as to follow at least a portion of an outer periphery of the coating material;
a portion of the covering material on which the fixing tool is placed is pressed against the mounting table by the fixing tool;
The stationary tool has an internal flow path through which a cooling fluid for cooling the stationary tool flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path, in an electron beam irradiation device. The electron beam irradiation device according to claim 1, wherein the fixing device is provided with a fixing means for fixing the coating material to the fixing device at a portion facing the coating material. The fixing tool has a flat lower surface facing the covering material,
The electron beam irradiation device according to claim 2 , wherein the fixing means is provided on a lower surface of the fixing tool. The electron beam irradiation device according to claim 2 or 3, wherein the fixing means is an adhesive, a pressure sensitive adhesive, or a double-sided tape. The electron beam irradiation device according to claim 1, wherein the mounting tool has a frame shape in a plan view that is placed on the coating material so as to follow the entire circumference of the outer edge of the coating material, and the mounting tool is disposed around the object to be irradiated with the electron beam. The electron beam irradiation device according to claim 1, wherein the size of the mounting device in a plan view is smaller than the size of the irradiation area of the electron beam irradiated from the irradiation window of the device body to the mounting table in a plan view. The electron beam irradiation device according to claim 1, wherein the height of the mounting device is 3 cm or less. The electron beam irradiation device according to claim 1, wherein the covering material is flexible. The electron beam irradiation device according to claim 1, wherein the covering material is made of metal. The electron beam irradiation device according to claim 8 or 9, wherein the covering material is made of aluminum foil. The electron beam irradiation device according to claim 1, further comprising a cooler that cools the irradiation window portion with a cooling gas. In an electron beam irradiation apparatus that irradiates an electron beam to an object to be irradiated with an electron beam placed on a placement table, a protective cover is provided on the placement table to protect the object to be irradiated with the electron beam,
a coating material that is transparent to the electron beam and that covers the object to be irradiated with the electron beam; and at least one fixing tool that is placed on the coating material along at least a portion of an outer periphery of the coating material and presses the coating material against the mounting table;
The fixed device is a protective cover having an internal flow path through which a cooling fluid for cooling the fixed device flows, an inlet for introducing the cooling fluid into the internal flow path, and an outlet for discharging the cooling fluid from the internal flow path. 1. An electron beam irradiation apparatus for irradiating an electron beam irradiation target placed on a mounting table with an electron beam, comprising:
covering the object to be irradiated with the electron beam with a covering material that is permeable to the electron beam;
At least one fixing tool is placed on the coating material so as to be along at least a portion of the outer periphery of the coating material, and the coating material is pressed against the mounting table;
A method for protecting an object to be irradiated with electron beams, comprising the steps of: circulating a cooling fluid through the inside of the fixing fixture to cool the fixing fixture.

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