Variable-diameter beam scraping device

Abstract

The invention provides a variable-diameter beam scraping device used in an electron linear accelerator, which comprises a circular tube module structure, and the structure can realize axial movement under the driving of a motor; comprising a corrugated pipe structure which is welded with a circular pipe module; comprising a gear transmission structure which can convert axial movement of a circular tube module into rotation of an internal gear; comprising a movable baffle structure which can convert the rotation of a driven bevel gear into the change of the aperture. The beam scraping device has the advantages that the variable-diameter beam scraping device is arranged inside the corrugated pipe, and the driving mechanism is arranged outside the corrugated pipe, so that the vacuum state of the beam scraping device during working is met. Secondly, by means of the axial flexibility of the corrugated pipe, external movement is achieved to drive the internal hole diameter to change.

Description

Technical Field

[0001] The present invention relates to a device for controlling the transverse size of an electron beam in an electron linear accelerator. Background Art

[0002] In an electron linear accelerator, as a device for controlling the transverse size of the beam, the performance of the beam scraper directly affects the transverse quality of the beam. With the development of free electron laser devices towards high energy density and multi-mode operation, the limitations of traditional fixed-aperture beam scrapers have become increasingly prominent. On the one hand, the fixed aperture cannot adapt to the dynamic adjustment requirements of different energy beams. For example, the utility model patent with publication number CN202135392U discloses a beam scraper for an electron linear accelerator tube, and another invention patent with publication number CN11537107A discloses a water-cooled detachable eight-way temperature-measuring beam scraper for an irradiating linear electron accelerator. These patents are all research carried out on traditional fixed-aperture beam scrapers. Another invention patent with publication number CN110719684A discloses an approximately circular adjustable beam slit device. The variable diameter method of this invention is achieved by the expansion and combination of a regular quadrilateral. The variable diameter of this invention is installed by the way of two front and rear baffles approaching each other, but at this time the axial dimension will become larger. If the axial dimension of the beam scraper is too long, it may lead to an increase in energy spread, that is, particles at different longitudinal positions have energy differences due to space charge effects or electromagnetic field changes. There are also variable diameter design schemes, which mostly rely on complex drive mechanisms in the vacuum chamber, with too large structural dimensions and difficult to meet the space constraints of free electron laser devices.

[0003] Therefore, a variable-aperture beam scraper is needed, which can realize dynamic adjustment of the aperture by driving an internal mechanism under the condition of high-vacuum sealing. The present invention combines the external placement of the drive mechanism, bellows sealing and gear transmission to solve the problem that the beam scraper in the traditional scheme cannot change its diameter. And while realizing the variable diameter function, the overall axial dimension of the beam scraper is ensured to be the same as that of the traditional fixed-aperture beam scraper, meeting the installation space for beam scraper replacement. Summary of the Invention

[0004] A variable-aperture beam scraper includes a round tube module, a bellows, a cover plate, a housing, a driving bevel gear, a driven bevel gear, a spur gear, a rack, a rack connecting rod, a transmission shaft, a deep groove ball bearing, a front baffle, and a moving baffle. The bellows is nested outside the housing and the cover plate. The cover plate and the housing are connected together by welding and are concentric. The six identical moving baffles are installed in the hexagonal chute of the housing and the straight slot of the front baffle. The front baffle is connected to the driven bevel gear by a key. A regular hexagonal chute is opened inside the housing. The driving bevel gear is coaxially connected to the spur gear through the transmission shaft. The transmission shaft is fixed on the inner wall of the housing by the deep groove ball bearing. The rack is welded to the round tube module through the rack connecting rod.

[0005] For the beam scraper according to the present invention, optionally, the overall axial dimension of the invented beam scraper is 112 mm.

[0006] For the beam scraper according to the present invention, optionally, the aperture diameter of the beam scraper can achieve a dimensional change from 0 mm to 12 mm.

[0007] For the beam scraper according to the present invention, optionally, a regular hexagon chute is provided inside the housing, and six moving baffles and the rear baffle are engaged together through the regular hexagon chute.

[0008] For the beam scraper according to the present invention, optionally, six straight notches evenly distributed in a circular pattern are provided on the front baffle, and six moving baffles are engaged on the straight notches. Compared with the prior art, the beneficial effects of the present application are as follows: The advantage of this invention is that the beam scraper and the transmission mechanism are nested inside the corrugated pipe. While achieving variable aperture diameter, the axial dimension of the entire beam scraper is more compact, and it can be adapted to the installation in narrow spaces. At the same time, the beam scraper of the present application can achieve continuous change of the aperture diameter size from 0 mm to 12 mm. The variable-aperture beam scraper can flexibly adjust the size of the aperture of the beam scraper to adapt to different beam parameters, so as to cope with different application scenarios. Description of the Drawings Referring to the embodiments shown in the following drawings, the advantages of the present invention will be more clearly understood: Figure 1 It is an overall external view of a variable-aperture beam scraper.

[0009] Figure 2 It is the front baffle of the beam scraper variable-aperture structure in a variable-aperture beam scraper.

[0010] Figure 3 It is the cooperation of the front baffle and six moving baffles of the beam scraper variable-aperture structure in a variable-aperture beam scraper.

[0011] Figure 4 It is the housing of the beam scraper variable-aperture structure in a variable-aperture beam scraper.

[0012] Figure 5 It is a schematic diagram of the cooperation of six moving baffles and the housing in a variable-aperture beam scraper.

[0013] Figure 6 It is a schematic diagram of the installation of the front baffle, six moving baffles and the housing in a variable-aperture beam scraper.

[0014] Figure 7 It is a gear transmission mechanism in a variable-aperture beam scraper.

[0015] Figure 8 It is a cover plate in a variable-aperture beam scraper.

[0016] Figure 9 It is an internal sectional view after the cover plate and the outer shell in a variable-diameter scraping beam device are matched.

[0017] Figure 10 It is an installation schematic diagram of the circular tube module and the gear transmission mechanism in a variable-diameter scraping beam device.

[0018] Figure 11 It is a mating position diagram of the circular tube module and the outer shell in a variable-diameter scraping beam device.

[0019] Figure 12 It is a schematic diagram inside the bellows in a variable-diameter scraping beam device.

[0020] The list of components represented by each label is as follows: 1A. Bellows a; 1B. Bellows b; 2. Circular tube module; 3. Front baffle; 4. Key; 5. Straight notch; 6. Moving baffle; 7. Outer shell; 8. Regular hexagon chute; 9. Bearing seat; 10. Chute; 11. Driven bevel gear; 12. Keyway; 13. Driving bevel gear; 14. Deep groove ball bearing; 15. Transmission shaft; 16. Straight gear; 17. Rack; 18. Rack connecting rod; 19. Cover plate; 20. Accelerator pipe. Specific embodiments

[0021] The following further elaborates on the present application through specific embodiments in conjunction with the accompanying drawings, so that those skilled in the art can understand the technical solution and specific implementation steps of the present application. It should be noted that in the following embodiments, many details are described to enable a better understanding of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0022] Figure 1This is a schematic diagram of an embodiment of the present invention and an external view schematic diagram of a variable-diameter beam scraper. It includes corrugated pipe a1A, corrugated pipe b1B, and a circular pipe module 2. During operation, the circular pipe module 2 is connected to an external driving mechanism (not shown in the figure). Through the external driving mechanism, the circular pipe module 2 can be moved horizontally to provide driving force for the transmission system inside the corrugated pipe. The two sides of the circular pipe module 2 are respectively welded to the corrugated pipe a1A and the corrugated pipe b1B. The corrugated pipes are made of 316 stainless steel. The left end of the corrugated pipe a1A is welded to the cover plate 19, and the right end of the corrugated pipe b1B is welded to the housing 7. The inside of the corrugated pipe is in a vacuum state. When the circular pipe module 2 moves axially, at this time, the corrugated pipe a1A and the corrugated pipe b1B will also elongate or compress axially. When the circular pipe module 2 moves to the leftmost state, the corrugated pipe a1A is in a compressed state, and the corrugated pipe b1B is in an elongated state. At this time, the aperture of the beam scraper is 12 mm, and the variable-diameter baffle is in a fully unfolded state. When the circular pipe module 2 moves 5 mm to the right, at the middle position of the beam scraper of the circular pipe module 2, both corrugated pipes are in an initial state. At this time, the inscribed circle diameter of the through-hole of the beam scraper is 6 mm. When the circular pipe module 2 moves another 5 mm to the right, the circular pipe module 2 moves to the rightmost state. The corrugated pipe a1A is in an elongated state, and the corrugated pipe b1B is in a compressed state. The variable-diameter baffle is in a fully closed state. Therefore, when the circular pipe module 2 moves axially by 10 mm, a change in the inscribed circle diameter of the through-hole of the beam scraper of 12 mm can be achieved.

[0023] Figure 12 This is a schematic diagram of the inside of the corrugated pipe, including the circular pipe module 2, the housing 7, the chute 10, and the cover plate 19. There is a rack link 18 on the circular pipe module 2 and it is connected thereto. As Figure 10 shown (a schematic diagram of hiding the corrugated pipe, the cover plate 19, and the housing 7 under the overall appearance structure), the rack link 18 is connected to the rack 17. The rack link 18 realizes the connection of the internal and external transmission of the housing 7 through the chute 10 on the housing 7 and the cover plate 19. When the circular pipe module 2 moves axially, the movement of the rack 17 can be driven through the rack link 18. The rack 17 meshes with the spur gear 16. As Figure 7 .

[0024] Figure 7It is a schematic diagram of the gear transmission mechanism inside the housing 11, including a driven bevel gear 11, a keyway 12, a driving bevel gear 13, a deep groove ball bearing 14, a transmission shaft 15, a spur gear 16, a rack 17, and a rack connecting rod 18. When the rack 17 moves, the spur gear 16 will rotate along with it, and transmit the power to the driving bevel gear 13 coaxially installed with the spur gear 16 through the transmission shaft 15. The driving bevel gear 13 transmits the power to the driven bevel gear 11. The transmission ratio of the rack 17 to the spur gear 16 is 1 / 17, and the transmission ratio of the driving bevel gear 13 to the driven bevel gear 11 is 17 / 70. The driven bevel gear 11 cooperates with the front baffle 3 in the scraper diameter reducing mechanism through the key 4 and the keyway 12. When the circular tube module 2 moves 1mm, the six movable baffles 6 of the scraper will move in the straight slot 5 and the regular hexagonal slide 8, and the through hole of the scraper achieves a diameter change of 1mm, such as Figure 10 shown.

[0025] Figure 11 Schematic diagram of the transmission mechanism and the diameter-changing mechanism inside the housing 7. Figure 2 The front baffle plate 3 in the diameter reducing mechanism is shown, on which six straight slots 5 are evenly and circumferentially distributed, and six movable baffle plates 6 cooperate with the straight slots 5, as shown in FIG. Figure 4 The shell 7 is shown, and a regular hexagonal slot 8 is opened inside the shell 7. Figure 5 Cooperate with the other side of the movable baffle 6, such as Figure 6 FIG. 1 is a schematic diagram of the installation of the front baffle 3, the six movable baffles 6 and the housing 7, as shown in FIG. Figure 11 It is a schematic diagram of the installation of the transmission mechanism, the front baffle 3, the six movable baffles 6, and the outer shell 7.

[0026] Figure 9 is a cross-sectional view of the interior of the housing 7, Figure 8 1 is a schematic diagram of the cover plate 19. The cover plate 19 and the housing 7 are mounted together by welding, and the cover plate 19 is pressed against the front baffle plate 3 to fix the internal structure of the entire housing 7. Figure 12 This is a schematic diagram after installation.

[0027] As described above, after the power is transmitted to the driven bevel gear 11, the front baffle plate 3 is connected to it through the key 4, and the front baffle plate 3 leads the six movable baffle plates 6 to slide synchronously through the straight slot 5 to realize the change of the aperture size, thereby realizing the axial movement outside the vacuum and driving the scraper beam diameter change inside the vacuum.

[0028] The above embodiments of the invention are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can better understand and use the present invention.

Claims

1. A variable diameter beam scraper, comprising a round tube module, a bellows, a cover plate, a housing, an active bevel gear, a driven bevel gear, a spur gear, a rack, a rack connecting rod, a transmission shaft, a deep groove ball bearing, a front baffle, and a movable baffle, characterized in that: The bellows is nested outside the shell and the cover plate, the cover plate and the shell are connected together by welding and are concentric, the six identical movable baffles are installed in the hexagonal slide groove of the shell and the straight groove of the front baffle, the front baffle is connected to the driven bevel gear through a key, a regular hexagonal slide groove is opened inside the shell, the active bevel gear is coaxially connected to the spur gear through a transmission shaft, the transmission shaft is fixed to the inner wall of the shell through a deep groove ball bearing, and the rack is welded to the round tube module through a rack connecting rod.

2. The variable diameter beam scraper according to claim 1, characterized in that: The overall axial dimension of the invented beam scraper is 112 mm.

3. The variable diameter beam scraper according to claim 1, characterized in that: The aperture of the beam scraper can vary in size from 0mm to 12mm.

4. The variable diameter beam scraper according to claim 1, characterized in that: A regular hexagonal sliding groove is provided inside the shell, and the six movable baffles are matched with the shell through the regular hexagonal sliding groove.

5. The variable diameter beam scraper according to claim 1, characterized in that: The front baffle plate is provided with six straight slots which are evenly distributed in a circumference, and the six movable baffle plates are matched with the straight slots.

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