JP7397307B2 - Electron beam irradiation device - Google Patents

Description

The present invention relates to an electron beam irradiation device.

For example, the electron beam irradiation device described in Patent Document 1 includes a casing having an opening window through which the electron beam from the electron beam generating section passes, and a casing that is provided so as to close the opening window and transmitting the electron beam. The device includes a window foil that transmits light from the inside of the body to the outside of the casing, and a removable protective cover that covers the outside of the window foil. During normal use of the electron beam irradiation device, the protective cover is removed from the casing, and the object to be irradiated is irradiated with the electron beam emitted to the outside of the casing through the window foil.

Patent No. 6343154

In the above-described electron beam irradiation device, if electron beam irradiation is performed while forgetting to remove the protective cover, the protective cover may be irradiated with the electron beam and the protective cover may be damaged.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an electron beam irradiation device that can suppress damage to a protective cover.

An electron beam irradiation device that solves the above problems includes: an electron beam generation section that generates an electron beam; a housing section that has an opening window section through which the electron beam passes; A window foil that transmits an electron beam from the inside of the casing to the outside of the casing, a removable protective cover that covers the outside of the window foil, and whether or not the protective cover is in an attached state. and a control unit that, based on the detection result of the detection unit, permits emission of the electron beam through the window foil on the condition that the protective cover is not attached. .

According to this configuration, if the protective cover is forgotten to be removed, the control section receives the detection result of the detection section and does not permit emission of the electron beam. Therefore, damage to the protective cover due to irradiation of the protective cover with the electron beam can be suppressed.

The electron beam irradiation apparatus described above includes a notification section that provides notification based on the detection result of the detection section.
According to this configuration, the notification section can make notifications based on the detection results of the detection section. This makes it easier for the operator to recognize whether electron beam emission is permitted or not, thereby improving work efficiency.

The electron beam irradiation device described above includes a shielding body for surrounding the electron beam generating section and the housing section and blocking the outflow of the electron beam to the outside, and the detecting section is provided outside the shielding body. There is.

According to this configuration, since the detection section is provided outside the shield, the detection section is not exposed to the electron beam irradiation inside the shield, and as a result, the detection section is not exposed to the electron beam irradiation condition. Damage to the detection unit due to this can be suppressed.

According to the electron beam irradiation device of the present invention, damage to the protective cover can be suppressed.

FIG. 1 is a schematic configuration diagram of an electron beam irradiation device in an embodiment. FIG. 2 is a schematic configuration diagram showing main parts of an electron beam irradiation device in the same form. FIG. 3 is a schematic configuration diagram showing an electron beam emission site in an electron beam irradiation device of the same type. FIG. 2 is a schematic configuration diagram showing an electron beam irradiation device in a state in which a protective cover of the same type is attached. FIG. 7 is a schematic configuration diagram showing an electron beam irradiation device with a protective cover attached in a modified example.

Hereinafter, one embodiment of an electron beam irradiation device will be described with reference to the drawings. Note that in the drawings, a part of the configuration may be exaggerated or simplified for convenience of explanation. Furthermore, the dimensional ratio of each part may also differ from the actual size.

The electron beam irradiation device 10 of this embodiment shown in FIG. 1 is a scanning type electron beam irradiation device. The electron beam irradiation device 10 includes a filament 11 made of, for example, tungsten that emits thermionic electrons. The filament 11 corresponds to an electron beam generating section that generates the electron beam e. The filament 11 emits electrons by heating itself based on the power supply from the filament power supply 12. The filament 11 is provided on the upper end side of the acceleration tube 13.

The acceleration tube 13 has a cylindrical shape with a closed upper end where the filament 11 is placed. The accelerating tube 13 has a plurality of accelerating electrodes 14 arranged in parallel in the axial direction of the accelerating tube 13. The accelerating electrode 14 generates an electric field that converges the electrons emitted from the filament 11 and accelerates them downward based on the power supply from the accelerating electrode power source 15. That is, in the accelerating tube 13, the electric field generated at the accelerating electrode 14 causes an electron flow directed downward in the tube axis direction, that is, an electron beam e. A scanning tube 16 is connected to the acceleration tube 13 at its lower end. The acceleration tube 13 and the scanning tube 16 communicate with each other through an internal space 17, and the electron beam e advances from the accelerating tube 13 toward the scanning tube 16 in the internal space 17. Note that the scanning tube 16 corresponds to a housing portion of the electron beam irradiation device 10.

The scanning tube 16 has a shape that is narrow at the upper end and widens toward the bottom. The scan tube 16 is provided with a scan coil 18 at its narrow upper end. The scanning coil 18 deflects the direction of the electron beam e generated by the accelerator tube 13 based on the energization thereof, that is, scans the electron beam e.

As shown in FIGS. 1, 2, and 3, a substantially rectangular opening window 19, for example, is provided at the lower end of the scanning tube 16, that is, at the end on the emission side. A substantially rectangular window foil 20 is attached. The window foil 20 of this embodiment is made of extremely thin metal foil, and more specifically, the window foil 20 of this embodiment is made of a titanium-based metal material. The window foil 20 has a shape that is one size larger than the opening window portion 19, and is provided so as to close the opening window portion 19.

The window foil 20 is fixed in such a manner that it is sandwiched between the lower end of the scanning tube 16 and a mounting frame 19a fixed to the peripheral edge of the open window section 19. The mounting frame 19a is fixed to the lower end of the scanning tube 16 by bolts or the like (not shown). The mounting frame 19a is formed with an opening 19b through which the electron beam e transmitted through the window foil 20 passes.

The window foil 20 seals the opening window portion 19 while allowing the electron beam e to pass therethrough. In other words, the internal space 17 spanning the acceleration tube 13 and the scanning tube 16 is configured as a closed space. The internal space 17 is kept in a vacuum state, for example, by driving a vacuum pump 21 connected to the scanning tube 16, at least during the period when the electron beam e is generated.

In the constituent members of the electron beam irradiation device 10 described above, at least the filament 11, the acceleration tube 13, and the scanning tube 16 are surrounded by a shield S as shown in FIG. Note that in FIG. 1, illustration of the shield S is omitted for convenience of explanation. The shield S is for blocking the outflow of the electron beam e to the outside, and the shield S of this embodiment is formed of a lead-based metal material.

The shield S includes a first structure S1 in which a filament 11, an acceleration tube 13, and a scanning tube 16 are arranged, and a second structure S2 that covers an opening Sa of the first structure S1. The second structure S2 is configured to be detachable from the first structure S1. In a state where the first structure S1 and the second structure S2 are connected, the electron beam e emitted from the electron beam irradiation device 10 is prevented from flowing out of the shielding body S.

The filament power source 12, accelerating electrode power source 15, scanning coil 18, and vacuum pump 21 described above are controlled by a control device 22. The control device 22 adjusts the output of the electron beam e through the power supplies 12 and 15, controls the scanning of the electron beam e through the scanning coil 18, and controls the internal space 17 of the acceleration tube 13 and the scanning tube 16 through the vacuum pump 21. Perform vacuum adjustment.

Note that the control device 22 is one or more processors that execute various processes according to a computer program (software), or one such as an application-specific integrated circuit (ASIC) that executes at least some of the various processes. It may be configured as a circuitry that includes one or more dedicated hardware circuits, or a combination thereof. A processor includes a CPU and memory, such as RAM and ROM, where the memory stores program codes or instructions configured to cause the CPU to perform processing. Memory or computer-readable media includes any available media that can be accessed by a general purpose or special purpose computer.

The electron beam e emitted through the window foil 20 attached to the opening window portion 19 is irradiated onto an irradiated object 24 transported in the transport direction x by a transport device 23, for example, and the irradiated object 24 is subjected to a predetermined process. I do. In this case, the electron beam irradiation device 10 is arranged such that the longitudinal direction of the substantially rectangular opening window 19 faces the direction y perpendicular to the transport direction of the transport device 23, and the electron beam irradiation device 10 is arranged so that the longitudinal direction of the approximately rectangular opening window 19 faces the direction y perpendicular to the transport direction y of the transport device 23. A predetermined scan of e is performed, and a substantially rectangular irradiation area A corresponding to the opening window portion 19 is irradiated. The effect of irradiating the object 24 with the electron beam e can be expected to be, for example, improving the properties of the material, adding functionality, and sterilizing/sterilizing the material.

Next, the protective cover 30 for protecting the window foil 20 will be explained.
As shown in FIG. 4, the electron beam irradiation device 10 includes a protective cover 30 that is detachable from the mounting frame 19a.

FIG. 4 shows the electron beam irradiation device 10 with the protective cover 30 attached. The protective cover 30 has a shape that is slightly larger than the opening 19b of the mounting frame 19a. The protective cover 30 is fixed to the mounting frame 19a with bolts B so as to close the opening 19b. That is, when the protective cover 30 is attached to the mounting frame 19a, the protective cover 30 covers the outside of the window foil 20. As a result, the window foil 20 cannot be contacted from the outside by the protective cover 30, and damage to the window foil 20 due to contact from the outside can be prevented. Note that a handle 31 is provided on the surface of the protective cover 30. Further, the surface of the protective cover 30 is painted in an easily visible color (for example, yellow).

The electron beam irradiation device 10 includes a detection unit 32 that detects whether the protective cover 30 is in an attached state. The detection unit 32 of this embodiment is a mechanical sensor, and is installed on the outer surface of the first structure S1 of the shield S. On the other hand, the protective cover 30 is provided with an extension part 33 that extends through the opening Sa of the first structure S1 to the detection part 32 on the outside of the first structure S1. The detecting section 32 is configured such that the tip of the extending section 33 can be inserted into the detecting section 32 . Then, the detection unit 32 detects the attachment state of the protective cover 30 based on whether the tip of the extension portion 33 is inserted. The detection unit 32 outputs a signal to the control device 22. Based on the detection result of the detection unit 32, the control device 22 allows output of the electron beam e from the filament 11 on the condition that the protective cover 30 is not attached.

Further, the electron beam irradiation device 10 includes a notification section 34 that notifies that the protective cover 30 is in an attached state based on the detection result of the detection section 32. The notification unit 34 of this embodiment operates under the control of the control device 22. The notification unit 34 includes at least one of a display, a speaker, and an indicator light, and indicates to the worker that the protective cover 30 is attached by an indication on the display, sound output from the speaker, or lighting of the indicator light. to notify that there is a

The operation of this embodiment will be explained.
As shown in FIG. 4, when the electron beam irradiation device 10 is not used, the second structure S2 is removed from the first structure S1 and the opening Sa of the first structure S1 is opened, and the protective cover 30 is Attach it to the mounting frame 19a with bolts B. Thereby, the outside side of the window foil 20 is covered with the protective cover 30.

Also, at this time, the tip of the extending portion 33 of the protective cover 30 is inserted into the detection portion 32 . Thereby, the detection unit 32 detects that the protective cover 30 is in the attached state. Then, a detection signal from the detection unit 32 is output to the control device 22, and the control device 22 performs control based on the detection signal so as not to permit output of the electron beam e from the filament 11. This prevents the electron beam e from being emitted with the protective cover 30 attached.

Also, an example of the operation of the notification section 34 will be explained. In a situation where the detection unit 32 detects that the protective cover 30 is attached, when the operator performs an operation to output the electron beam e, it is detected that the protective cover 30 is attached to the display. It performs operations such as displaying information, outputting sound from speakers, or lighting up indicator lights. This notifies the operator that the protective cover 30 is in the attached state.

When using the electron beam irradiation device 10, as shown in FIG. 2, after removing the protective cover 30 from the mounting frame 19a, the opening Sa of the first structure S1 is closed with the second structure S2. In this state, the detection unit 32 detects that the protective cover 30 is not attached, and the control device 22 allows output of the electron beam e from the filament 11 based on the detection signal from the detection unit 32. .

The effects of this embodiment will be explained.
(1) The electron beam irradiation device 10 includes a detection unit 32 that detects whether or not the protective cover 30 is attached, and a condition that the protective cover 30 is not attached based on the detection result of the detection unit 32. and a control device 22 that permits output of the electron beam e from the filament 11. According to this configuration, when the protective cover 30 is attached, the control device 22 that receives the detection result of the detection section 32 does not permit output of the electron beam e. Therefore, damage to the protective cover 30 caused by irradiation of the electron beam e to the protective cover 30 that has been forgotten to be removed can be suppressed.

(2) The electron beam irradiation device 10 includes a notification section 34 that notifies that the protective cover 30 is in an attached state based on the detection result of the detection section 32. According to this configuration, the notification unit 34 can notify the operator that the protective cover 30 is in the attached state. This makes it easier for the operator to recognize that the protective cover 30 is in the attached state, which means that the emission of the electron beam e is not permitted, and it is possible to improve work efficiency.

(3) The electron beam irradiation device 10 includes a shield S that surrounds the filament 11, the acceleration tube 13, and the scanning tube 16 and blocks the electron beam e from flowing out. The detection unit 32 is provided outside the shielding body S. According to this configuration, since the detecting section 32 is provided outside the shielding body S, the detecting section 32 can be configured not to be exposed to the irradiation condition of the electron beam e inside the shielding body S, and as a result, Damage to the detection unit 32 due to irradiation with the electron beam e can be suppressed.

This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- In the above embodiment, the detection section 32 is provided outside the shield S, but the present invention is not limited to this, and the detection section 32 may be provided inside the shield S as shown in FIG. In the configuration shown in FIG. 5, the detection unit 32 is provided on the inner surface of the first structure S1 of the shield S. Further, the detection unit 32 is provided inside a shield box 40 for shielding the electron beam e. In this way, by surrounding the detection unit 32 with the shield box 40, the detection unit 32 is prevented from being irradiated with the electron beam e, and as a result, damage to the detection unit 32 due to the irradiation with the electron beam e is prevented. can be suppressed.

- The material used for the window foil 20 is not limited to the above embodiment, and materials other than titanium-based metal materials may be used.
- The material used for the shield S is not limited to the above embodiment, and concrete or the like other than lead-based metal materials may be used.

- The detection unit 32 may be a magnetic sensor other than a mechanical sensor, for example. As an example of a configuration in which the detection section 32 is a magnetic sensor, a sensor magnet is provided at the tip of the extension section 33, and the sensor magnet approaches the detection section 32 when the protective cover 30 is attached to the mounting frame 19a. composition.

- The notification unit 34 of the above embodiment notifies that the protective cover 30 is in the attached state based on the detection result of the detection unit 32, but is not limited to this, and notifies that the protective cover 30 is in the non-attached state ( In other words, it may be configured to notify that the emission of the electron beam e is permitted.

- In the electron beam irradiation device 10 of the above embodiment, the opening direction of the opening window portion 19 was configured to be downward, that is, the traveling direction of the electron beam e was set to be downward. It may be.

- Applied to a scanning type electron beam irradiation device 10 that forms an electron beam e from electrons emitted from a single filament 11 and scans it with a scanning coil 18 to irradiate the irradiation area A, but it corresponds to the irradiation area. The present invention may also be applied to an area type electron beam irradiation device using a plurality of filaments and omitting a scanning coil.

The technical ideas that can be understood from the above embodiment and modification examples will be described.
(a) In the electron beam irradiation device, the notification section notifies that the protective cover is in an attached state based on the detection result of the detection section.

According to this configuration, the notification section can notify the operator that the protective cover is in the attached state.

10...Electron beam irradiation device 11...Filament (electron beam generation part)
16...Scanning tube (housing part)
19...Opening window portion 20...Window foil 22...Control device (control unit)
30... Protective cover 32... Detection section 34... Notification section e... Electron beam S... Shielding body

Claims (3)

an electron beam generating section that generates an electron beam;
a housing having an opening window through which the electron beam passes;
a window foil that is provided to cover the opening window and allows the electron beam to pass from the inside of the casing to the outside of the casing;
a removable protective cover that covers the exterior side of the window foil;
a detection unit that detects whether the protective cover is in an attached state;
a control unit that permits emission of the electron beam through the window foil on the condition that the protective cover is not attached, based on the detection result of the detection unit;
Electron beam irradiation equipment equipped with The electron beam irradiation apparatus according to claim 1, further comprising a notification section that provides notification based on the detection result of the detection section. comprising a shielding body for surrounding the electron beam generating section and the housing section and blocking the outflow of the electron beam to the outside;
The electron beam irradiation device according to claim 1 or 2, wherein the detection section is provided outside the shield.