Electron beam irradiation apparatus

Abstract

To provide an electron beam irradiation apparatus capable of reliably shielding X-rays secondarily generated during electron beam irradiation.SOLUTION: An electron beam irradiation apparatus 1 comprises: an electron beam source 11 which has an electron beam generation unit 2 that generates an electron beam EB, a housing 3 that accommodates the electron beam generation unit 2, and a window 4 that is provided in the housing 3 and emits the electron beam EB; a first shielding body 13 which is formed of a material that attenuates X-rays and surrounds the housing 3 via a space; and a second shielding body 14 which is formed of a material that attenuates X-rays and surrounds the first shielding body 13 via a space.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electron beam irradiation device. [Background technology]

[0002] An electron beam irradiation device is a device that irradiates an object with an electron beam, and is used for applications such as drying ink on the object, sterilizing the object, modifying the object, etc. Patent Document 1 describes an electron beam irradiation device that includes a feed mechanism that feeds a web (film-like object), an electron beam source that emits an electron beam to the web fed by the feed mechanism, and a shielding chamber that houses the electron beam source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-520319 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electron beam irradiation device, it is common that piping for evacuation, piping for circulating a coolant, wiring for a power supply, etc. extend from the electron beam source to the outside. Therefore, in the electron beam irradiation device described in Patent Document 1, in order to reliably shield X-rays that are generated secondarily during irradiation of the electron beam, the shielding chamber must be enlarged. Note that such X-rays are generated by the interaction of the electron beam with each member constituting the window part of the electron beam source, the gas existing outside the window part, the target object, etc.

[0005] An object of the present invention is to provide an electron beam irradiation apparatus capable of reliably blocking X-rays that are generated secondarily during irradiation with electron beams. [Means for solving the problem]

[0006] The electron beam irradiation device of the present invention is [1] "an electron beam irradiation device comprising: an electron beam generating unit that generates an electron beam; a housing that houses the electron beam generating unit; an electron beam source provided in the housing and having a window portion through which the electron beam is emitted; a first shielding body formed of a material that attenuates X-rays and surrounds the housing via a space; and a second shielding body formed of a material that attenuates X-rays and surrounds the first shielding via a space."

[0007] In the electron beam irradiation device described in [1] above, the housing of the electron beam source is surrounded by a first shield, and the first shield is surrounded by a second shield. This allows the first shield to attenuate X-rays at a position close to the X-ray generation region near the window of the electron beam source, while the second shield can attenuate X-rays that are difficult to attenuate by the first shield alone due to the presence of piping, wiring, etc. Therefore, the electron beam irradiation device described in [1] above can reliably shield X-rays that are generated secondarily during irradiation of electron beams.

[0008] The electron beam irradiation device of the present invention may be [2] "the electron beam irradiation device according to the above [1], further comprising a wall supporting the electron beam source and having an opening formed therein that accommodates at least a part of the window, the first shielding body surrounding the housing on the wall, and the second shielding body surrounding the first shielding on the wall." According to the electron beam irradiation device described in [2], X-rays generated in a region outside the window of the electron beam source can be attenuated by the wall before being attenuated by the first shielding body and the second shielding body, so that X-rays generated secondarily during irradiation of the electron beam can be more reliably shielded.

[0009] The electron beam irradiation device of the present invention may be the electron beam irradiation device according to [1] or [2] above, further comprising: piping and wiring extending from the electron beam source to the outside; the first shielding body has a first passage opening through which at least one of the piping and the wiring passes; the second shielding body has a second passage opening through which at least one of the piping and the wiring passes; and the first passage opening and the second passage opening have a positional relationship in which they are not visible to each other. According to the electron beam irradiation device according to [3], X-rays passing through the first passage opening of the first shielding body are unlikely to reach the second passage opening of the second shielding body, so that the piping and wiring can be drawn out from the electron beam source to the outside while maintaining the shielding property of X-rays during irradiation of electron beams.

[0010] The electron beam irradiation device of the present invention may be the electron beam irradiation device described in [3] above, further comprising a cover structure attached to the second shielding body so as to cover the second passage port from the outside, the cover structure having a passage through which at least one of the piping and the wiring passes, the passage extending in a serpentine shape from the second passage port to the outside. According to the electron beam irradiation device described in [4], X-rays that have reached the second passage port of the second shielding body are less likely to leak from the passage to the outside, thereby improving the shielding property of X-rays during irradiation of electron beams.

[0011] The electron beam irradiation device of the present invention may be [5] "the electron beam irradiation device described in the above [3] or [4], in which an exhaust unit is provided in a portion of the piping located in a region between the first shield and the second shield, and a portion of the second shield facing the exhaust unit is openable and closable." According to the electron beam irradiation device described in [5], maintenance of the exhaust unit can be performed by opening the portion of the second shield facing the exhaust unit to the outside.

[0012] The electron beam irradiation device of the present invention may be [6] "the electron beam irradiation device according to any one of the above [1] to [6], in which a part of the electron beam source is located in a region between the first shield and the second shield, and a part of the second shield facing the part of the electron beam source is openable and closable." According to the electron beam irradiation device according to [6], maintenance of the electron beam source can be performed by opening the part of the second shield facing the part of the electron beam source to the outside.

[0013] The electron beam irradiation device of the present invention may be [7] "the electron beam irradiation device according to the above [6], in which the part of the electron beam source is an opening / closing part of the housing." According to the electron beam irradiation device according to [7], by opening the part of the second shield facing the opening / closing part of the housing to the outside, maintenance inside the housing can be performed via the opening / closing part.

[0014] The electron beam irradiation device of the present invention may be [8] "the electron beam irradiation device according to the above [6] or [7], in which the part of the electron beam source is a power supply unit that supplies power to the electron beam generating unit." According to the electron beam irradiation device according to [8], the part of the second shield facing the power supply unit can be opened to the outside to perform maintenance on the power supply unit. Effect of the Invention

[0015] According to the present invention, it is possible to provide an electron beam irradiation device capable of reliably blocking X-rays that are generated secondarily during irradiation with electron beams. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a cross-sectional view of an electron beam irradiation apparatus according to an embodiment. [Diagram 2] FIG. 2 is a perspective view of the electron beam source shown in FIG. [Diagram 3] FIG. 3 is a perspective view of the internal structure of the electron beam source shown in FIG. 2. [Figure 4]4 is a cross-sectional view of the electron beam source taken along line IV-IV shown in FIG. 2. [Diagram 5] FIG. 3 is a perspective view of the window unit shown in FIG. 2. [Figure 6] FIG. 6 is a plan view of the window unit shown in FIG. 5. [Figure 7] 7 is a cross-sectional view of the window unit taken along line VII-VII shown in FIG. 5. [Figure 8] FIG. 2 is a configuration diagram of the electron beam irradiation device shown in FIG. [Figure 9] 9 is a cross-sectional view of the cover structure taken along line IX-IX shown in FIG. 8. [Figure 10] FIG. 9 is a perspective view of the panel shown in FIG. 8. [Figure 11] 11 is a cross-sectional view of a portion of the panel taken along line XI-XI shown in FIG. 10. [Figure 12] FIG. 13 is a perspective view of an electron beam irradiation unit of a modified example of an electron beam irradiation apparatus. [Figure 13] FIG. 11 is a cross-sectional view of a modified example of an electron beam irradiation device. [Figure 14] FIG. 11 is a cross-sectional view of a modified example of an electron beam irradiation device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted. [Configuration of electron beam irradiation equipment]

[0018] As shown in FIG. 1, the electron beam irradiation device 1 includes an electron beam irradiation unit 10 and an object support unit 50. The electron beam irradiation unit 10 includes an electron beam source 11, a first wall (wall) 12, a first shield 13, and a second shield 14. The object support unit 50 includes a support portion 51 and a second wall 52. Hereinafter, the direction in which the electron beam irradiation unit 10 and the object support unit 50 are arranged is referred to as the Z-axis direction, a direction perpendicular to the Z-axis direction is referred to as the X-axis direction, and a direction perpendicular to both the Z-axis direction and the X-axis direction is referred to as the Y-axis direction. In this embodiment, the Z-axis direction is a vertical direction, but the Z-axis direction may be a direction other than the vertical direction. That is, in this embodiment, each of the X-axis direction and the Y-axis direction is a horizontal direction, but each of the X-axis direction and the Y-axis direction may be a direction other than the horizontal direction.

[0019] The electron beam source 11 has an electron beam generation unit 2, a housing 3, and a window 4. The electron beam generation unit 2 generates an electron beam EB. The housing 3 contains the electron beam generation unit 2. The window 4 is provided in the housing 3. The window 4 emits the electron beam EB emitted from the electron beam generation unit 2. In this embodiment, the window 4 is provided in a portion of the housing 3 on the object support unit 50 side, and emits the electron beam EB toward the object support unit 50 side.

[0020] The first wall 12 is disposed on the object support unit 50 side with respect to the electron beam source 11. The first wall 12 has a pair of surfaces 12a, 12b. The surface 12a is the surface opposite to the object support unit 50. The surface 12b is the surface on the object support unit 50 side. A first opening (opening) 12c is formed in the first wall 12. The first opening 12c is a through hole that opens on both sides of the first wall 12 in the Z-axis direction. The electron beam source 11 is attached to the first wall 12 with the window 4 disposed in the first opening 12c. In other words, the first wall 12 supports the electron beam source 11 with the first opening 12c housing the window 4. The first wall 12 is formed of a material that attenuates X-rays, for example, a metal.

[0021] The first shielding body 13 surrounds the housing 3 of the electron beam source 11 via a space. In this embodiment, the first shielding body 13 surrounds the housing 3 on the first wall portion 12. As an example, the first shielding body 13 is a box-shaped structure attached to the surface 12a of the first wall portion 12. The first shielding body 13 is formed of a material that attenuates X-rays, such as a metal.

[0022] The second shielding body 14 surrounds the first shielding body 13 via a space. In this embodiment, the second shielding body 14 surrounds the first shielding body 13 on the first wall portion 12. As an example, the second shielding body 14 is a box-shaped structure attached to the surface 12a of the first wall portion 12. The second shielding body 14 is formed of a material that attenuates X-rays, such as a metal.

[0023] The support unit 51 supports the object S. In this embodiment, the support unit 51 is configured with an actuator 511 and a support base 512. In this embodiment, the support base 512 on which the object S is placed is moved in the X-axis direction by the actuator 511.

[0024] The second wall 52 is disposed on the electron beam irradiation unit 10 side with respect to the support 51. The second wall 52 has a pair of surfaces 52a, 52b. The surface 52a is the surface on the electron beam irradiation unit 10 side. The surface 52b is the surface on the opposite side to the electron beam irradiation unit 10. The second wall 52 has a second opening 52c. The second opening 52c is a through hole that opens on both sides of the second wall 52 in the Z-axis direction. The second opening 52c faces the first opening 12c. That is, the window 4 and the object S directly face each other through the first opening 12c and the second opening 52c. In this embodiment, the second wall 52 is a part of a housing that houses the support 51. The second wall 52 is formed of a material that attenuates X-rays, such as a metal. [Electron beam source configuration]

[0025] As shown in Figures 2, 3 and 4, the electron beam source 11 has the above-mentioned electron beam generating unit 2, a housing 3 and a window portion 4. The electron beam generating unit 2 is an elongated filament unit with its longitudinal direction in the Y-axis direction. The housing 3 is a cylindrical vacuum vessel with a center line parallel to the Y-axis direction. The window portion 4 is airtightly attached to a flange portion 31 that defines an opening 3a in the housing 3. The opening 3a is an elongated opening with its longitudinal direction in the Y-axis direction, and faces the electron beam generating unit 2 in the Z-axis direction. A connection port 32 is provided on the part of the housing 3 opposite the opening 3a to which a pipe 17 (see Figure 8) for evacuating the space within the housing 3 is connected.

[0026] The electron beam source 11 further includes a rail member 5, a pair of holding members 6 and 7, and a power supply unit 8. The rail member 5 is an elongated member with the Y-axis direction as the longitudinal direction, and holds the electron beam generating unit 2 inside the housing 3. The cross-sectional shape of the rail member 5 perpendicular to the Y-axis direction is a C-shape that opens to the window portion 4 side. The pair of holding members 6 and 7 are cylindrical members each having a center line parallel to the Y-axis direction, and hold both ends of the rail member 5 inside the housing 3. The holding member 6 is attached to the power supply unit 8. The holding member 7 is attached to the inner surface of the housing 3 via an insulating member (not shown). One end of the housing 3 in the Y-axis direction is hermetically sealed by the power supply unit 8. The other end of the housing 3 in the Y-axis direction is hermetically sealed by the opening / closing unit 33. In the electron beam source 11, the electron beam generating unit 2 can be inserted and removed from the rail member 5 by opening the cover 33a of the opening / closing unit 33.

[0027] The housing 3, rail member 5, and pair of holding members 6, 7 are each formed of a conductive material such as metal. The housing 3 is at ground potential. The rail member 5 and pair of holding members 6, 7 are at cathode potential. The rail member 5 functions as an enclosing electrode that encloses the electron beam generating unit 2. The electron beam generating unit 2 is supplied with a high voltage (electric power) from a power supply unit 8. Wiring 19 (see FIG. 8) for supplying a high voltage to the electron beam generating unit 2 is connected to the power supply unit 8.

[0028] The electron beam generating unit 2 has a main frame 21, a filament 22, a subframe 23, a power supply line 24, a connecting member 25, a grid electrode 26, and an insulating member 27. The main frame 21 is an elongated member with the Y-axis direction as its longitudinal direction. The cross-sectional shape of the main frame 21 perpendicular to the Y-axis direction is a U-shape that opens on the window portion 4 side. The filament 22 extends in the Y-axis direction inside the main frame 21. The filament 22 is made of a high-melting point metal material (e.g., a material containing tungsten), and emits electrons when heated by passing electricity through it.

[0029] The subframe 23 is disposed on the opposite side of the mainframe 21 to the window portion 4. The subframe 23 is an elongated member with its longitudinal direction in the Y-axis direction. The cross-sectional shape of the subframe 23 perpendicular to the Y-axis direction is a U-shape that opens on the opposite side to the window portion 4. The power supply line 24 extends in the Y-axis direction inside the subframe 23. The mainframe 21 and the subframe 23 are connected to each other by a connecting member 25.

[0030] The grid electrode 26 is disposed on the window portion 4 side with respect to the main frame 21. The grid electrode 26 is an elongated member whose longitudinal direction is in the Y-axis direction, and faces the filament 22 in the Z-axis direction. The grid electrode 26 is attached to the connecting member 25 via an insulating member 27. The grid electrode 26 is a sheet-like member having a plurality of through holes arranged two-dimensionally along a plane perpendicular to the Z-axis direction.

[0031] In the electron beam generating unit 2 configured as described above, the filament 22 is heated by energization, and in this state, a negative high voltage of, for example, "-tens of kV to -hundreds of kV" is applied to the filament 22. As a result, electrons are emitted from the filament 22. At this time, a voltage of, for example, the potential of the filament 22 plus "+100V to +150V" is applied to the grid electrode 26. As a result, an electric field is formed that draws out the electrons while suppressing their diffusion, and the electrons emitted from the filament 22 are emitted as an electron beam EB toward the window portion 4 via the grid electrode 26.

[0032] 5, 6 and 7, the window portion 4 has a support member 41, a sealing member 42, a window foil 43 and a pressing member 44. The support member 41 has a pair of surfaces 41a, 41b. The surface 41a is the surface on the electron beam generating unit 2 side and is the surface that contacts the flange portion 31 of the housing 3 (see FIG. 4). The surface 41b is the surface opposite the electron beam generating unit 2. The support member 41 is formed from a metal material with high thermal conductivity (for example, a material containing copper) into a plate shape with the Y-axis direction as the longitudinal direction and the Z-axis direction as the thickness direction.

[0033] The support member 41 is formed with a recess 411, a plurality of through holes 412, a pair of flow paths 413, and a groove 414. The recess 411 opens to the surface 41a, and is formed in an elongated shape with the Y-axis direction as the longitudinal direction when viewed from the Z-axis direction. The plurality of through holes 412 are formed in the bottom of the recess 411, and are arranged two-dimensionally along a plane perpendicular to the Z-axis direction. The pair of flow paths 413 extend in the Y-axis direction on both sides of the recess 411 in the X-axis direction. The pair of flow paths 413 are connected to a pipe 18 (see FIG. 8) for supplying a cooling liquid, and the cooling liquid flows through the pipe 18. The groove 414 opens to the surface 41b, and extends in an annular shape so as to surround the plurality of through holes 412 when viewed from the Z-axis direction.

[0034] The sealing member 42 is an annular elastic member (for example, an O-ring) and is disposed along the groove 414. A pair of portions of the sealing member 42 extending in the Y-axis direction overlap with a pair of flow paths 413 when viewed from the Z-axis direction.

[0035] The window foil 43 is disposed on the surface 41b of the support member 41 so as to cover the multiple through holes 412 and the sealing member 42. The window foil 43 is in contact with the support member 41 and is thermally connected to the support member 41. The window foil 43 is made of a material (e.g., beryllium, titanium, or aluminum) that is highly transparent to the electron beam EB, and is formed into a film shape with the Y-axis direction as the longitudinal direction and the Z-axis direction as the thickness direction.

[0036] The pressing member 44 is a frame-shaped member having an opening 44a. The pressing member 44 is arranged on the surface of the window foil 43 opposite to the support member 41 so as to overlap the sealing member 42 and not overlap the multiple through holes 412 when viewed from the Z-axis direction. The pressing member 44 is formed in a frame shape with the Y-axis direction as the longitudinal direction and the Z-axis direction as the thickness direction, by a metal material (e.g., a material containing copper) having high thermal conductivity. The region between the support member 41 and the window foil 43 is airtightly sealed by fastening the support member 41 and the pressing member 44 to each other with a fastening member (not shown) such as a bolt. Note that the fastening member for fastening the support member 41 and the pressing member 44 to each other may be provided separately from the fastening member for attaching the window portion 4 to the flange portion 31 of the housing 3, or may be provided as a fastening member for attaching the window portion 4 to the flange portion 31 of the housing 3.

[0037] The pressing member 44 is formed with a flow path 441 and a plurality of branch flow paths 442. The flow path 441 extends in the Y-axis direction on one side of the opening 44a in the X-axis direction. A pipe 18 (see FIG. 8) for supplying a cooling gas is connected to the flow path 441, and the cooling gas is made to flow. The plurality of branch flow paths 442 are aligned in the Y-axis direction, branch off from the flow path 441, and open on the side of the opening 44a. The cooling gas supplied to the flow path 441 is blown onto the window foil 43 via each branch flow path 442. As an example, an inert gas (e.g., nitrogen) is used as the cooling gas.

[0038] In the window section 4 configured as above, the electron beam EB emitted from the electron beam generating section 2 passes through the multiple through holes 412 of the support member 41, transmits through the window foil 43, and passes through the opening 44a of the pressing member 44. In this manner, the window section 4 emits the electron beam EB emitted from the electron beam generating section 2 to the object supporting unit 50 side (see FIG. 1). At this time, heat is generated in the support member 41, the window foil 43, and the pressing member 44 due to the incidence of the electron beam EB, but the cooling liquid flows through the pair of flow paths 413 of the support member 41 and the cooling gas is blown onto the window foil 43 from each branch flow path 442 of the pressing member 44, thereby dissipating heat from the window section 4 and suppressing deterioration of the sealing member 42 due to heat.

[0039] In addition, in Figures 2, 3 and 4, when viewed from the Z-axis direction, the side surface 31a of the flange portion 31 of the housing 3 coincides with the side surface 41c of the support member 41 and the side surface 44b of the pressing member 44 (see Figure 4), but when viewed from the Z-axis direction, the side surface 31a of the flange portion 31 of the housing 3 may be located outside the side surface 41c of the support member 41 and the side surface 44b of the pressing member 44. [Structure of the first and second shields]

[0040] As shown in FIG. 8, the first shield 13 has a first portion 131 and a second portion 132. The first portion 131 is an elongated box-shaped body with the Y-axis direction as the longitudinal direction, and surrounds the housing 3 of the electron beam source 11 through a space. More specifically, the first portion 131 surrounds the housing 3 through a space with the power supply unit 8 and the opening / closing unit 33 exposed from both ends in the Y-axis direction. The first portion 131 is attached to the first wall portion 12. The second portion 132 is a box-shaped body with a length in the Y-axis direction shorter than that of the first portion 131, and is attached to the wall portion of the first portion 131 on the opposite side to the first wall portion 12. The first portion 131 is formed with a first passage opening 13a. The first passage opening 13a is an opening (including a through hole, a notch, etc.) formed in a wall portion constituting the first portion 131. The second portion 132 is formed with a first passage opening 13b. The first passage opening 13b is an opening (including a through hole, a notch, etc.) formed in a wall portion that constitutes the second portion 132.

[0041] The second shielding body 14 is an elongated box whose longitudinal direction is the Y-axis direction, and surrounds the first shielding body 13 through a space. The second shielding body 14 is attached to the first wall portion 12. The second shielding body 14 is formed with a second passage opening 14a. The second passage opening 14a is an opening (including a through hole, a notch, etc.) formed in a wall portion constituting the second shielding body 14. The first passage opening 13a and the second passage opening 14a have a positional relationship in which they cannot be seen through each other. That is, some member is present on a line segment connecting an arbitrary point in the first passage opening 13a and an arbitrary point in the second passage opening 14a. Alternatively, the second passage opening 14a is not included in the area obtained by projecting the first passage opening 13a onto the second shielding body 14 side, and the first passage opening 13a is not included in the area obtained by projecting the second passage opening 14a onto the first shielding body 13 side. Similarly, the first passage opening 13b and the second passage opening 14a are in a positional relationship where they cannot be seen through to each other. That is, some member exists on a line segment connecting an arbitrary point in the first passage opening 13b and an arbitrary point in the second passage opening 14a. Alternatively, the area where the first passage opening 13b is projected onto the second shielding body 14 does not include the second passage opening 14a, and the area where the second passage opening 14a is projected onto the first shielding body 13 does not include the first passage opening 13b.

[0042] A cover structure 16 is attached to the second shielding body 14 so as to cover the second passage opening 14a from the outside. The cover structure 16 has a passage 16a. In this embodiment, the cover structure 16 is a box body attached to the second shielding body 14 at a corner between the first wall portion 12 and the second shielding body 14 so as to cover the second passage opening 14a from the outside, and is made of a material that attenuates X-rays, such as a metal.

[0043] As shown in Fig. 9, the cover structure 16 is an elongated box-shaped body with the Y-axis direction as the longitudinal direction. The cover structure 16 has a pair of wall portions 161, 162 facing each other in the Z-axis direction, a pair of wall portions 163, 164 facing each other in the Y-axis direction, and a wall portion 165 (shown by a two-dot chain line in Fig. 9) facing the second shielding body 14 in the X-axis direction. The second passage opening 14a covered by the cover structure 16 is located near the wall portion 163 in the Y-axis direction. A third passage opening 16b is formed in the wall portion 164. The third passage opening 16b is an opening (including a through hole, a notch, etc.) formed in the wall portion 164.

[0044] When viewed from the X-axis direction, a wall portion 166 and a wall portion 167 are disposed between the second passage opening 14a and the third passage opening 16b. The wall portion 166 is provided upright on the wall portion 162 so as to be spaced apart from the wall portion 161 and in contact with the second shielding body 14 and the wall portion 165. The wall portion 167 is provided upright on the wall portion 161 so as to be spaced apart from the wall portion 162 and in contact with the second shielding body 14 and the wall portion 165. This causes the passage 16a to extend in a serpentine manner from the second passage opening 14a to the third passage opening 16b within the cover structure 16. In other words, the cover structure 16 has a crank structure, and the passage 16a extends in a serpentine manner from the second passage opening 14a to the outside.

[0045] As shown in Fig. 8, the piping 17 for evacuating the space in the housing 3 passes through an area in the first part 131 of the first shield 13, an area in the second part 132 of the first shield 13, a first passage opening 13b of the first shield 13, an area between the first shield 13 and the second shield 14, a second passage opening 14a of the second shield 14, and a passage 16a of the cover structure 16, and extends from the electron beam source 11 to the outside. An exhaust unit 17A is provided in a portion of the piping 17 located in the area between the first shield 13 and the second shield 14. The exhaust unit 17A includes devices for evacuating the space in the housing 3, such as a main pump, a vacuum gauge, and various valves. The piping 17 drawn to the outside is connected to an auxiliary pump for maintaining the back pressure of the main pump of the exhaust unit 17A.

[0046] The piping 18 for supplying the cooling liquid and the cooling gas to the window portion 4 passes through the area in the first portion 131 of the first shield 13, the first passage opening 13a of the first shield 13, the area between the first shield 13 and the second shield 14, the second passage opening 14a of the second shield 14, and the passage 16a of the cover structure 16, and extends from the electron beam source 11 to the outside. Of the piping 18 drawn out to the outside, the piping for supplying the cooling liquid to the window portion 4 is connected to a supply source of the cooling liquid. Of the piping 18 drawn out to the outside, the piping for supplying the cooling gas to the window portion 4 is connected to a supply source of the cooling gas. Although the piping 18 is shown as a single piping in Figs. 8 and 9, it includes a piping for supplying the cooling liquid to the window portion 4 and a piping for supplying the cooling gas to the window portion 4.

[0047] Wiring 19 for supplying a high voltage to the electron beam generating unit 2 (see FIG. 1) passes through the region between the first shield 13 and the second shield 14, the second passage opening 14a of the second shield 14, and the passage 16a of the cover structure 16, and extends from the electron beam source 11 to the outside. The wiring 19 drawn out to the outside is connected to a high-voltage power supply.

[0048] The multiple sections 14A, 14B, 14C, and 14D of the second shielding body 14 are each detachable as a panel 140. That is, in the second shielding body 14, the sections 14A, 14B, 14C, and 14D are each openable and closable. The section 14A faces the exhaust unit 17A and the power supply unit 8 in the X-axis direction. The section 14B faces the exhaust unit 17A and the power supply unit 8 in the Y-axis direction. The section 14C faces the exhaust unit 17A and the power supply unit 8 in the Z-axis direction. The section 14D faces the opening / closing section 33 of the housing 3 in the Y-axis direction. In this embodiment, the wall section 161 and the wall section 165 of the cover structure 16 are also each detachable.

[0049] As shown in FIG. 10 and FIG. 11, the panel 140 has a panel body 141 and a pair of handles 142. The panel body 141 includes an inner layer 141a, an intermediate layer 141b, and an outer layer 141c. The inner layer 141a and the outer layer 141c are formed of a metal material having higher rigidity than the intermediate layer 141b. The intermediate layer 141b is formed of a metal material having higher X-ray shielding properties than the inner layer 141a and the outer layer 141c. As an example, the inner layer 141a and the outer layer 141c are each formed of stainless steel, and the intermediate layer 141b is formed of lead. As an example, the thickness of each of the inner layer 141a, the intermediate layer 141b, and the outer layer 142c is about several mm. According to such a panel 140, it is possible to ensure both rigidity and X-ray shielding properties while suppressing exposure of lead to the outside. In addition, the walls of the first shielding body 13 and the cover structure 16 may have the same layer structure as the panel 140.

[0050] Each handle 142 includes a mounting base 142a and a handle portion 142b. The handle portion 142b is fixed to the mounting base 142a. Each handle 142 is attached to the panel body 141 from the outside by a plurality of screws 143. More specifically, a plurality of through holes 145 are formed in the mounting base 142a so as to correspond to a plurality of screw holes 144 formed in the outer layer 141c, and each screw 143 is screwed into the corresponding screw hole 144 through the corresponding through hole 145, thereby attaching the handle 142 to the panel body 141. Each screw hole 144 is formed only in the outer layer 141c, and is not formed in the intermediate layer 141b. In this way, since the intermediate layer 141b formed of a material having high X-ray shielding properties does not have the screw hole 144, leakage of X-rays through the screw hole 144 can be suppressed. Moreover, by screwing each screw 143 into the screw hole 144 of the outer layer 141c through the through hole 145 of the mounting base 142a, it is possible to reduce the load applied to each screw 143. Note that in order to reliably form the multiple screw holes 144, the outer layer 141c may be thicker than the inner layer 141a. [Action and Effects]

[0051] In the electron beam irradiation device 1, the housing 3 of the electron beam source 11 is surrounded by a first shielding body 13, and the first shielding body 13 is surrounded by a second shielding body 14. As a result, the first shielding body 13 attenuates X-rays at a position close to the X-ray generation region in the vicinity of the window portion 4 of the electron beam source 11, while the second shielding body 14 attenuates X-rays that are difficult to attenuate by the first shielding body 13 alone due to the presence of pipes 17, 18 and wiring 19, etc. Thus, the electron beam irradiation device 1 can reliably shield X-rays that are secondarily generated during irradiation of the electron beam EB.

[0052] In the electron beam irradiation device 1, the first wall 12 supports the electron beam source 11 with the first opening 12c housing the window 4. The first shielding body 13 surrounds the housing 3 on the first wall 12, and the second shielding body 14 surrounds the first shielding body 13 on the first wall 12. This allows X-rays generated in a region outside the window 4 of the electron beam source 11 to be attenuated by the first wall 12 before being attenuated by the first shielding body 13 and the second shielding body 14, so that X-rays generated secondarily during irradiation with the electron beam EB can be more reliably shielded.

[0053] In the electron beam irradiation device 1, the first passage opening 13a of the first shield 13 and the second passage opening 14a of the second shield 14 are in a positional relationship where they cannot see each other. Similarly, the first passage opening 13b of the first shield 13 and the second passage opening 14a of the second shield 14 are in a positional relationship where they cannot see each other. This makes it difficult for X-rays that have passed through the first passage openings 13a and 13b of the first shield 13 to reach the second passage opening 14a of the second shield 14. Therefore, the pipes 17 and 18 can be drawn out from the electron beam source 11 to the outside while maintaining the X-ray shielding property during irradiation with the electron beam EB.

[0054] In the electron beam irradiation device 1, a cover structure 16 is attached to the second shield 14 so as to cover the second passage opening 14a from the outside, and a passage 16a extends in a serpentine shape from the second passage opening 14a to the outside in the cover structure 16. This makes it difficult for X-rays that have reached the second passage opening 14a of the second shield 14 to leak out from the passage 16a, thereby improving the shielding properties of X-rays during irradiation with the electron beam EB.

[0055] In the electron beam irradiation device 1, the portions 14A, 14B, and 14C of the second shield 14 facing the exhaust unit 17A can be opened and closed by attaching and detaching the panel 140. This makes it possible to perform maintenance on the exhaust unit 17A by removing the panel 140 and exposing the portions 14A, 14B, and 14C to the outside.

[0056] In the electron beam irradiation device 1, a portion 14D of the second shield 14 facing the opening / closing unit 33 of the housing 3 can be opened and closed by attaching and detaching a panel 140. This allows maintenance inside the housing 3 (for example, replacement of the electron beam generating unit 2) to be performed via the opening / closing unit 33 by removing the panel 140 and opening the portion 14D to the outside.

[0057] In the electron beam irradiation device 1, the portions 14A, 14B, and 14C of the second shield 14 facing the power supply unit 8 can be opened and closed by attaching and detaching the panel 140. This makes it possible to perform maintenance of the power supply unit 8 (for example, attaching and detaching the wiring 19) by removing the panel 140 and exposing the portions 14A, 14B, and 14C to the outside.

[0058] In the electron beam irradiation device 1, the wall portion 161 and the wall portion 165 are also detachable from the cover structure 16. This makes it possible to check the layout of the pipes 17, 18 and the wiring 19, etc., by removing at least one of the wall portion 161 and the wall portion 165 to open the passage 16a to the outside. [Variations]

[0059] The present invention is not limited to the above embodiment. For example, a part of the electron beam source 11 other than the opening / closing unit 33 and the power supply unit 8 may be located in the area between the first shielding body 13 and the second shielding body 14, and a part of the second shielding body 14 facing the part of the electron beam source 11 may be openable and closable. In this case, the maintenance of the electron beam source 11 can be performed by opening the part of the second shielding body 14 facing the part of the electron beam source 11 to the outside. In addition, the second shielding body 14 may be such that a part (at least one part) of the second shielding body 14 is openable and closable. In addition, the electron beam irradiation device 1 does not need to include the cover structure 16. In addition, it is sufficient that at least a part of the window part 4 is disposed in the first opening 12c of the first wall part 12.

[0060] Furthermore, a portion of the second shielding body 14 may be openable and closable by means other than the removable panel 140 (for example, an openable and closable door). As an example, as shown in Fig. 12, the second shielding body 14 may have a plurality of semi-cylindrical covers 148 telescopically arranged between a pair of walls 146, 147 erected on the first wall portion 12 so as to face each other. In the second shielding body 14 shown in Fig. 12, a portion of the second shielding body 14 can be opened and closed by sliding each cover 148 on the first wall portion 12 between the pair of walls 146, 147.

[0061] In addition, the support section 51 of the object support unit 50 may support the object S, and the shape of the object S is not particularly limited. As an example, as shown in FIG. 13 and FIG. 14, the support section 51 may have at least one feed roller 513 that feeds the film-like object S. In the object support unit 50 shown in FIG. 13, a portion of the film-like object S that extends between a pair of feed rollers 513 faces the second opening 52c of the second wall section 52 in the Z-axis direction. In the object support unit 50 shown in FIG. 14, a portion of the film-like object S that is located on one feed roller 513 faces the second opening 52c of the second wall section 52 in the Z-axis direction. As an example, when the electron beam irradiation device 1 is used for drying ink on the object S, it is preferable that the portion of the object S that is irradiated with the electron beam EB is placed in an inert gas atmosphere in order to promote drying of the ink. Therefore, as shown in FIG. 14, in order to prevent an inert gas (e.g., nitrogen) from escaping from the area where the portion of the object S is irradiated with the electron beam EB exists, a cover 514 surrounding the portion of the object S that is irradiated with the electron beam EB may be attached to the second wall portion 52. [Explanation of symbols]

[0062] 1...electron beam irradiation device, 2...electron beam generating section, 3...housing, 4...window section, 11...electron beam source, 12...first wall section (wall section), 12c...first opening (opening), 13...first shielding body, 13a, 13b...first passage port, 14...second shielding body, 14a...second passage port, 16...cover structure, 16a...passageway, 17, 18...piping, 17A...exhaust unit, 19...wiring, 140...panel (part), EB...electron beam.

Claims

1. an electron beam source including an electron beam generating unit that generates an electron beam, a housing that houses the electron beam generating unit, and a window that is provided in the housing and through which the electron beam is emitted; a first shielding body formed of a material that attenuates X-rays and surrounding the housing via a space; a second shield formed of a material that attenuates X-rays and surrounding the first shield via a space.

2. a wall portion supporting the electron beam source and having an opening formed therein and accommodating at least a portion of the window portion; the first shield surrounds the housing on the wall portion, The electron beam irradiation apparatus according to claim 1 , wherein the second shield surrounds the first shield on the wall portion.

3. The electron beam source further includes piping and wiring extending from the electron beam source to the outside, a first passage opening through which at least one of the piping and the wiring passes is formed in the first shielding body; a second passage opening through which at least one of the piping and the wiring passes is formed in the second shielding body; The electron beam irradiation device according to claim 1 , wherein the first passage opening and the second passage opening are positioned so as not to be visible to each other.

4. a cover structure attached to the second shield so as to cover the second passage opening from the outside, the cover structure has a passage through which at least one of the piping and the wiring passes, The electron beam irradiation device according to claim 3 , wherein the passageway extends from the second passage opening to the outside in a serpentine manner.

5. an exhaust unit is provided in a portion of the pipe located in a region between the first shield and the second shield, The electron beam irradiation apparatus according to claim 3 , wherein a portion of the second shield facing the exhaust unit is openable and closable.

6. a portion of the electron beam source is located in a region between the first shield and the second shield, The electron beam irradiation apparatus according to claim 1 , wherein a portion of the second shield facing the part of the electron beam source is openable and closable.

7. The electron beam irradiation device according to claim 6 , wherein the portion of the electron beam source is an opening / closing portion of the housing.

8. The electron beam irradiation apparatus according to claim 6 , wherein the part of the electron beam source is a power supply unit that supplies power to the electron beam generating unit.

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