A kind of energy dissipation compensator

Abstract

This invention provides an energy dissipation compensator, comprising: a vacuum structure with an upper and lower corrugated plate inside, providing a vacuum environment; a mechanical structure supporting the vacuum structure, having a transmission mechanism connected to the upper and lower corrugated plates, the transmission mechanism including an upper and lower inlet beam transmission mechanism installed at the upper and lower parts of the vacuum structure near the inlet end, and an upper and lower outlet beam transmission mechanism installed at the upper and lower parts of the vacuum structure near the outlet end; and a control system configured to drive the transmission mechanism, thereby moving the upper and lower corrugated plates and adjusting the distance between them. This invention uses four stepper motors in linkage to adjust the gap and angle between the two corrugated plates to compensate for electron beam energy dissipation, and even when the grating ruler reading head is damaged, a rotary encoder is used as position feedback to still adjust the energy dissipation compensator.

Description

Technical Field

[0001] This invention relates to the field of free-electron lasers, and more specifically to an energy dissipation compensator for free-electron laser devices, particularly for X-ray free-electron laser devices. Background Technology

[0002] X-ray free-electron lasers have become an essential high-tech infrastructure for developed countries vying for the technological high ground in the 21st century. They provide cutting-edge research tools such as high-resolution imaging, ultrafast process exploration, and advanced structure analysis for multiple disciplines including physics, chemistry, life sciences, materials science, and energy science. They can simultaneously meet the experimental needs of matter, single molecules, ultra-intense and ultra-short single-particle imaging, as well as extreme photophysics.

[0003] The Shanghai Hard X-ray Free Electron Laser Facility (SHINE) operates in a superconducting continuous wave mode. Unlike room-temperature accelerators, superconducting accelerators have a much larger beam aperture and a very weak wake field effect. In room-temperature accelerators, the energy dissipation introduced by electron beam compression is mainly eliminated by the combined effect of the phase and longitudinal wake field of the accelerating section. However, the longitudinal wake field effect of superconducting structures is very weak, and the bundle length of the electron beam after magnetic compression is less than 10 micrometers. Compensating for electron beam energy dissipation by changing the RF phase of the accelerator is not only extremely inefficient but also wastes a significant amount of the effective acceleration gradient. Therefore, the tail of the main accelerator needs an energy dissipation compensator to compensate for electron beam energy chirp.

[0004] The dechirper is a device that precisely controls the longitudinal wake intensity of the beam through a pair of flat, pleated structures parallel to the beam direction, thereby controlling the energy dissipation at the accelerator exit. To eliminate the transverse quadrupole wake component, at least two dechirpers (one horizontal and one vertical) are required in combination.

[0005] At the end of the SHINE linear accelerator, three pairs (six sets in total) of energy dissipators are required. The phase shift of each pair of energy dissipators needs to be set to an even multiple of π. Ideally, the energy dissipators should be superimposed to achieve a zero phase shift. The energy dissipation compensator requirements for the SHINE project are as follows:

[0006] Each energy dissipation compensator has a 2m long pleated structure with an adjustable gap range of 0.5mm to 28mm, a pleat width of 0.25mm ± 0.013mm, a pleat depth of 0.5mm ± 0.025mm, a period length of 0.5mm ± 0.025mm, a beam direction spacing of 5mm ± 0.05mm between pleated plate modules, a flatness of <50μm for the 2m long pleated plate, and an ultimate vacuum of <1×10⁻⁶. -6Pa. Among these technical specifications, the dimensional specifications of the corrugated plate are relatively high; at the same time, in terms of motion control, the four transmission mechanisms are required to move synchronously and independently for fine-tuning; in addition, as the position feedback electronic component of motion control, the grating ruler may be affected by radiation and "freeze" during the process of the electron beam passing through the energy dissipation compensator, causing the GAP of the energy dissipation compensator to be unable to be adjusted. A solution needs to be found to improve the safety and reliability of motion control, so there are certain difficulties and challenges in the research and development.

[0007] Research indicates that current energy dissipation compensators, such as those from the US LCLS II and South Korea's PAL, can compensate for electron beam energy dissipation by altering the intensity and wavelength of the wake field. However, these current compensators cannot effectively adjust the gap (GAP) and taper between the two beams when the grating ruler malfunctions. Currently, there is no energy dissipation compensator that can simultaneously meet the requirements of the SHINE project. Specifically, the SHINE project requires a 2m pleated structure length, while the energy dissipation compensator from Pohang Accelerator Laboratory (PAL) in South Korea has a 1m pleated structure length, thus failing to meet the requirement. Furthermore, the energy dissipation compensator from Stanford University's Linear Accelerator Coherent Light Source II (LCLS II) only allows adjustment of the taper using two stepper motors closer to the vacuum chamber and adjustment of the GAP using two motors closer to the center of the vacuum chamber. It does not mention an automatic fine-tuning maintenance mode for the beams or the overall movement of the two beam centers. Therefore, the US LCLS energy dissipation compensator does not meet the requirements of the SHINE project. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides an energy dissipation compensator that can compensate for electron beam energy dissipation when the grating ruler malfunctions.

[0009] To achieve the above objectives, the present invention provides an energy dissipation compensator, comprising:

[0010] A vacuum structure with an upper and lower corrugated plate inside its cavity, configured to provide a vacuum environment for the upper and lower corrugated plates;

[0011] A mechanical structure, configured to support a vacuum structure, has transmission mechanisms connected to an upper pleated plate and a lower pleated plate. The number of transmission mechanisms is four, including an inlet upper beam transmission mechanism and an inlet lower beam transmission mechanism installed on the upper and lower parts of the vacuum structure near the inlet end, respectively; and an outlet upper beam transmission mechanism and an outlet lower beam transmission mechanism installed on the upper and lower parts of the vacuum structure near the outlet end, respectively.

[0012] The control system is configured to drive the transmission mechanism in the mechanical structure, thereby moving the upper and lower pleated plates of the vacuum structure and adjusting the size of the gap GAP between the upper and lower pleated plates.

[0013] The mechanical structure includes a bracket, an adjusting base mounted on the bracket, a vertical plate mounted on the adjusting base, and the transmission structure mounted on the vertical plate. The inlet upper beam transmission mechanism and the outlet upper beam transmission mechanism, as well as the inlet lower beam transmission mechanism and the outlet upper beam transmission mechanism, are symmetrically arranged about the upper and lower sides of the vacuum structure. The inlet upper beam transmission mechanism and the inlet lower beam transmission mechanism, as well as the outlet upper beam transmission mechanism and the outlet lower beam transmission mechanism, are symmetrically arranged about the left and right sides.

[0014] Each transmission mechanism includes a stepper motor and a reducer mounted on the vertical plate. The stepper motor is connected to the reducer via a coupling. The reducer is connected to a ball screw via a key. The ball screw is connected to a slide via its nut. The slide is threaded to a vacuum support connection structure. The vacuum support connection structure is threaded to an upper beam or a lower beam. The upper beam is fixedly connected to an upper pleated plate, and the lower pleated plate is fixedly connected to a lower beam.

[0015] The control system includes a master station control cabinet and a slave station control box connected to each other. The slave station control box includes a motor driver and is connected to the stepper motor through the motor driver. The slave station control box is also connected to a grating ruler reading head and a rotary encoder.

[0016] Each transmission mechanism is equipped with a grating ruler and a grating ruler reading head that are opposite each other. The grating ruler is fixed relative to the vertical plate, and the grating ruler reading head is connected to the transmission mechanism. The rotary encoder is installed on the ball screw of each transmission mechanism. The grating ruler reading head serves as a closed-loop position sensor. The rotary encoder serves as a redundant monitoring position sensor when the grating ruler reading head is working normally and as a closed-loop position sensor when the grating ruler reading head is damaged.

[0017] The slave control box is electrically connected to the photoelectric minimum limit switch, the electromechanical minimum limit switch, the electromechanical maximum limit switch, and the photoelectric maximum limit switch. Each transmission mechanism is fixed with the photoelectric minimum limit switch, the electromechanical minimum limit switch, the electromechanical maximum limit switch, and the photoelectric maximum limit switch by screws. Each transmission mechanism is also equipped with a shielding cover.

[0018] The master station control cabinet includes a master station controller, a touch screen connected to the master station controller, an Ethernet network module and an EtherCAT communication module, and a photoelectric conversion module and an optical fiber module connected in sequence to the Ethernet network module; the slave station control cabinet includes a slave station controller, an Ethernet network module and an EtherCAT communication module connected to the slave station controller, a motor driver and an I / O module connected to the Ethernet network module, the Ethernet network module being connected in sequence to the photoelectric conversion module and the optical fiber module, and the motor driver being connected to a stepper motor.

[0019] The master station control cabinet is connected to multiple slave station control boxes, and the slave station control boxes are connected to each other via Ethernet and EtherCAT to form network redundancy.

[0020] Both the upper and lower pleated plates are equipped with minimum limit hard stops.

[0021] The vacuum structure includes a left end vacuum chamber, a main vacuum chamber, and a right end vacuum chamber connected in sequence via CF150 connecting flanges, and an upper beam, an upper pleated plate, a lower pleated plate, and a lower beam disposed within the cavity formed by the left end vacuum chamber, the main vacuum chamber, and the right end vacuum chamber. The upper beam is fixedly connected to the upper pleated plate, and the lower pleated plate is fixedly connected to the lower beam. The upper beam and the lower beam are symmetrically positioned vertically within the vacuum structure with the central axis of the vacuum structure as the axis of symmetry.

[0022] The energy dissipation compensator of this invention uses four stepper motors in tandem to adjust the gap (GAP) between the two corrugated plates and the taper between the two main beams. Each motor can also move independently to fine-tune the main beams. By adjusting the spacing between the corrugated metal plates, the groove depth, length, and period, the intensity and wavelength of the wake field generated by the corrugated structure can be adjusted, thereby compensating for electron beam energy dissipation. Furthermore, the energy dissipation compensator of this invention can also achieve overall movement of the centers of the two main beams by simultaneously moving all four electrodes in center mode.

[0023] Furthermore, this invention provides an energy dissipation compensator that uses a grating ruler as a closed-loop position sensor. A rotary encoder serves as a redundant monitoring position sensor when the grating ruler reading head is working normally and as a closed-loop position sensor when the grating ruler reading head is damaged. Therefore, when the grating ruler is damaged by beam radiation, in an emergency of physical beam adjustment, the grating ruler can be shielded via a software interface, and the rotary encoder can be switched to the closed-loop position sensor via software operation. This allows for the adjustment of the energy dissipation compensator's GAP (Gap Up) even when the grating ruler reading head is damaged, thus still enabling adjustment of the energy dissipation compensator. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of an energy dissipation compensator according to an embodiment of the present invention.

[0025] Figure 2 It is an installation diagram of the mechanical and vacuum structure of the energy dissipation compensator.

[0026] Figure 3 This is a schematic diagram of the transmission mechanism of the energy dissipation compensator.

[0027] Figure 4 This is a schematic diagram of the vacuum structure of the energy dissipation compensator.

[0028] Figure 5 This is a cross-sectional view of the end section of the vacuum structure of the energy dissipation compensator.

[0029] Figure 6 This is a cross-sectional view of the vacuum support connection structure.

[0030] Figure 7A and Figure 7B This is a schematic diagram of the pleated structure of the energy dissipation compensator, in which... Figure 7A and Figure 7B It shows two different perspectives.

[0031] Figure 8 This is a three-dimensional structural diagram of the pleated plate of the energy dissipation compensator.

[0032] Figure 9 This is a schematic diagram of the layout of the limit switch and the grating ruler.

[0033] Figure 10 It is a block diagram of the control system.

[0034] Figures 11A-11D This is a schematic diagram of the four control modes of the energy dissipation compensator of the present invention.

[0035] Figure 12 Is it like this? Figure 3 The diagram shows the structural schematic of the transmission mechanism of the energy dissipation compensator.

[0036] Figure label:

[0037] 1-Bracket; 2, 3, 5, 7-Transmission mechanism; 4-Upright plate; 6-Vacuum structure; 8-Adjustable base; 9-Slave control cabinet; 10-Cable; 11-Master control cabinet; 12-Maximum limit stop; 13-Rotary encoder; 14-Ball screw; 15-Optical scale; 16-Shielding cover; 17-Optical scale reading head; 18-Optical scale reading head connector; 19-Left guide rail; 20-Reducer; 21-Photoelectric minimum limit switch; 22-Electromechanical minimum limit switch; 23-Stepper motor; 24-Coupling; 25-Electromechanical maximum limit switch; 26-Photoelectric maximum limit switch. 27-Right guide rail, 28-Lifting lug, 29-Left end vacuum chamber, 30-CF150 connecting flange, 31-Vacuum body support, 32-Inlet CF flange module, 33-Main vacuum chamber, 34-CF blind flange module, 35-Outlet CF flange module, 36-Right end vacuum chamber, 37-CF blind flange, 38-Ion pump, 39-C assembly flange, 40-Upper corrugated plate, 41, 42-Minimum limit hard stop, 43-Lower corrugated plate, 44-Lower beam, 45-Upper beam, 46-Vacuum support connection structure, 47-Slide block, 48-Screw, 49-Key, 50-Nut Detailed Implementation

[0038] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0039] The technical solution adopted in this invention is as follows: by adjusting the spacing between metal plates with pleated structures, the depth, length and period of the grooves can be adjusted to adjust the intensity and wavelength of the tail field generated by the pleated structure, thereby achieving the purpose of compensating for electron beam energy dissipation.

[0040] like Figure 1 and Figure 2 and Figure 9 The diagram illustrates a dissipation compensator according to a preferred embodiment of the present invention, placed on the horizontal ground of a tunnel of an X-ray free electron laser device. It includes a mechanical structure, a vacuum structure 6, and a control system. The vacuum structure 6 has an upper corrugated plate 40 and a lower corrugated plate 43 within its inner cavity, primarily used to provide a vacuum environment for the upper and lower corrugated plates 40 and 43. The mechanical structure is configured to support the vacuum structure 6 and has a transmission mechanism connected to the upper and lower corrugated plates 40 and 43. The control system drives the transmission mechanism in the mechanical structure, thereby moving the upper and lower corrugated plates 40 and 43 of the vacuum structure 6 and adjusting the distance GAP between them.

[0041] The mechanical structure includes a bracket 1, an adjusting base 8 mounted on the bracket 1, a vertical plate 4 mounted on the adjusting base 8, and transmission structures 2, 3, 5, and 7 mounted on the vertical plate 4. The bracket is placed on a horizontal ground to support the adjusting base 8. It adopts a hollow top plate design to facilitate the overall transportation of the two-layer mechanism (i.e., the bracket 1, the adjusting base 8, and its upper part) by a mobile hydraulic trolley.

[0042] The vacuum structure 6 is fixed to the adjusting base 8 via a vertical plate 4 and multiple transmission structures 2, 3, 5, and 7 mounted on the vertical plate 4, allowing the adjusting base 8 to adjust the height of the vacuum structure 6. Specifically, the vacuum structure 6 has an inlet end and an outlet end, where the inlet and outlet refer to the entry and exit of the beam, and the beam flows from... Figure 1 The vacuum structure 6 enters from the left and exits from the right; there are four transmission structures 2, 3, 5 and 7, including an inlet upper beam transmission mechanism 3 and an inlet lower beam transmission mechanism 2 installed on the upper and lower parts of the vacuum structure 6 near the inlet end, and an outlet upper beam transmission mechanism 5 and an outlet lower beam transmission mechanism 7 installed on the upper and lower parts of the vacuum structure 6 near the outlet end. The upper beam transmission mechanisms 3 and 5 and the lower beam transmission mechanisms 2 and 7 are respectively connected to the upper beam 45 and the lower beam 44 of the vacuum structure 6 to drive the upper pleated plate 40 connected to the upper beam 45 and the lower pleated plate 43 connected to the lower beam 44. Among them, the inlet upper beam drive mechanism 3 and the outlet upper beam drive mechanism 5, and the inlet lower beam drive mechanism 2 and the outlet upper beam drive mechanism 7 are arranged symmetrically about the vacuum structure 6. Furthermore, the inlet upper beam drive mechanism 3 and the inlet lower beam drive mechanism 2 at the inlet and the outlet upper beam drive mechanism 5 and the outlet lower beam drive mechanism 7 at the outlet are arranged symmetrically about the left and right. Due to the physical requirements of the accelerator, the electron beam moves along the central axis of the vacuum structure 6, and the upper pleated plate 40 and the lower pleated plate 43 must move simultaneously to realize the opening and closing of the GAP. Therefore, the drive mechanisms must be arranged symmetrically.

[0043] The four transmission structures 2, 3, 5, and 7 have the same structure. The following explanation uses the entrance upper beam transmission mechanism 3 as an example. Figure 3 and Figure 12As shown, the entrance upper beam transmission mechanism 3 includes a stepper motor 23, a reducer 20, and a left guide rail 19 and a right guide rail 27 mounted on the vertical plate 4. The left guide rail 19 and the right guide rail 27 are connected to a slide 47 for the slide 47 to slide. The left guide rail 19 and the right guide rail 27 are used to support and guide the moving parts such as the slide 47 to perform reciprocating linear motion in a given direction. The stepper motor 23 is connected to the reducer 20 through a coupling 24. The reducer 20 is connected to a ball screw 14. The ball screw 14 is connected to the reducer 20 through a key 49. The ball screw 14 is connected to the slide 47 through its nut 50. The slide 47 is threadedly connected to a vacuum support connection structure 46. The vacuum support connection structure 46 is threadedly connected to the upper beam 45 or the lower beam 44. Therefore, when the transmission mechanism is working, when the stepper motor 23 is controlled to run, the torque is first transmitted to the reducer 20 through the coupling 24, then the reducer 20 transmits the torque to the ball screw 14, and finally the ball screw 14 drives the upper beam 45 and the lower beam 44, which in turn drives the upper pleated plate 40 and the lower pleated plate 43 fixed on the upper beam 45 and the lower beam 44 to move.

[0044] The reducer 20 is self-locking, has a reduction ratio of 1:60, and a mechanical backlash of 10 arc minutes, resulting in a y-direction error of 2.3 μm for the ball screw 14. The ball screw 14 is a BNF2505 model with a lead of 5 mm, a precision class of C1, and a positioning accuracy error of 3.5 μm. It is connected to the reducer 20 via a standard flat key. These parameter settings all contribute to improving the repeatability and positioning accuracy of the motion.

[0045] The upper beam transmission mechanism 3 at the entrance is equipped with a shielding cover 16 for radiation protection of the grating ruler 15 and the reading head 17. The outer layer of the shielding cover 16 is made of lead, the middle layer is made of polyethylene, and the innermost layer is made of lead. The top of the vertical plate 4 is equipped with a lifting lug 28 for hoisting and transferring the energy dissipation compensator. Each transmission structure on the vertical plate 4 has a maximum limit hard stop 12 fixed relative to the vertical plate 4 on the side away from the vacuum structure 6.

[0046] like Figures 4-6 As shown, the vacuum structure 6 includes a left end vacuum chamber 29, a main vacuum chamber 33, and a right end vacuum chamber 36 connected in sequence via a CF150 connecting flange 30, and an upper beam 45, an upper pleated plate 40, a lower pleated plate 43, and a lower beam 44 disposed within the cavity formed by the left end vacuum chamber 29, the main vacuum chamber 33, and the right end vacuum chamber 36. The upper beam 45 is fixedly connected to the upper pleated plate 40, and the lower pleated plate 43 is fixedly connected to the lower beam 44. The upper beam and the lower beam are symmetrically positioned vertically within the vacuum structure 6 with the central axis of the vacuum structure 6 as the axis of symmetry.

[0047] Minimum limiting hard blocks 41 and 42 are installed between the upper pleated plate 40 and the lower pleated plate 43. The minimum limiting hard blocks 41 and 42 are preferably located at the entrance and exit of the upper pleated plate 40 or the lower pleated plate 43. This achieves the minimum limitation of the distance between the upper pleated plate 40 and the lower pleated plate 43.

[0048] The structural parameters of the upper pleated plate 40 and the lower pleated plate 43, such as the spacing between the pleated plates, the depth of the grooves, and the period, are appropriately selected as needed, thereby controlling the intensity and wavelength of the longitudinal tail field based on the principle of adjusting the free-electron laser tail field according to the pleated structure. Combined with... Figure 7A , Figure 7B and Figure 8 In this embodiment, the geometric parameters of the upper pleated plate 40 and the lower pleated plate 43 are shown in Table 1.

[0049] Table 1. Geometric parameters of the upper pleated plate 40 and the lower pleated plate 43

[0050] parameter Design value Half gap a 0.25mm Folding period p 0.5mm Depth h 0.5mm pleat width t 0.25mm Minimum spacing g of pleated plates 0.5mm pleated electrode width w 12.7mm Length L of the pleated electrode plate 2m

[0051] The ends of the left end vacuum chamber 29 and the right end vacuum chamber 36 are tightly connected to an external beam vacuum pipe (not shown) to ensure a vacuum environment.

[0052] The main vacuum chamber 33 is provided with a vacuum body support 31 whose bottom is fixedly connected to the adjustment base 8. The lower end of the vacuum body support is specifically connected to the adjustment base 8 through four screws.

[0053] An inlet CF flange module 32, corresponding to one of the transmission mechanisms, is installed on the upper and lower sides of the main vacuum chamber 33 near the inlet end. An outlet CF flange module 35, corresponding to one of the transmission mechanisms, is installed on the upper and lower sides of the main vacuum chamber 33 near the outlet end. The inlet CF flange module 32 and the outlet CF flange module 35 are connecting flange modules, configured to connect the main vacuum chamber 28 and the vacuum support connection structure 46. The vacuum support connection structure 46 connects one of the upper beam 45 and the lower beam 44 and one of the transmission mechanisms. Figure 6 As shown, the corrugated pipes around the vacuum support connection structure 46 are adjustable, and the upper beam 45 and lower beam 44 are hoisted through the vacuum support connection structure 46. Each beam requires two vacuum support connection structures 46 for hoisting, and they are symmetrically arranged near the inlet end and near the outlet end.

[0054] Thus, the mechanical structure supports the vacuum structure 6 and connects and fixes the upper beam 45 and lower beam 44 within the vacuum structure 6.

[0055] The main vacuum chamber 33 is equipped with vertically opposed CF blind flange modules 34 and front-to-back opposed CF assembly flanges 39 in the middle. The left end vacuum chamber 29 and the right end vacuum chamber 36 are each equipped with a CF blind flange 37 and an ion pump 38. The CF blind flange modules 34, CF blind flanges 37, and CF assembly flanges 39 are used to seal the main vacuum chamber (the flanges need to be opened when installing the internal beams of the vacuum chamber), and the ion pump 38 is used to evacuate the vacuum structure 6.

[0056] like Figure 9 and Figure 10 As shown, the control system includes a master station control cabinet 11 and a slave station control chassis 9 connected to each other. The slave station control chassis 9 includes a motor driver and is connected to the stepper motor 23 via the motor driver. The slave station control chassis 9 is also electrically connected to the grating ruler reading head 17, the rotary encoder 13, the photoelectric minimum limit switch 21, the electromechanical minimum limit switch 22, the electromechanical maximum limit switch 25, and the photoelectric maximum limit switch 26. The energy dissipation compensator uses the grating ruler reading head as a closed-loop position sensor, and the rotary encoder serves as a redundant monitoring position sensor when the grating ruler reading head is working normally. When the grating ruler reading head 17 is damaged by beam radiation, in an emergency of physical beam adjustment, the grating ruler can be shielded through the software interface, and the software operation can switch the rotary encoder as the closed-loop position sensor to adjust the GAP value of the energy dissipation compensator.

[0057] Please see again Figure 3 Each transmission mechanism is equipped with a photoelectric minimum limit switch 21, an electromechanical minimum limit switch 22, an electromechanical maximum limit switch 25, and a photoelectric maximum limit switch 26, all secured by screws.

[0058] Therefore, electromechanical maximum limit switches, electromechanical minimum limit switches, photoelectric maximum limit switches, and photoelectric maximum four limit switches are installed at the upper and lower inlet and outlet of the energy dissipation compensator. When the gap (GAP) exceeds the tolerance (exceeding the maximum or minimum limit position), the photoelectric limit switches first provide position protection, followed by the electromechanical limit switches. Furthermore, combined with the aforementioned maximum limit hard stop 12 and minimum limit hard stops 41 and 42, when the gap exceeds the maximum limit and the programmed soft limit, electromechanical maximum limit switches, and photoelectric maximum limit switches fail, the mechanical maximum hard limit switches provide protection at the maximum limit position, ensuring the gap reaches the maximum limit position. When the gap exceeds the minimum limit and the programmed soft limit, electromechanical minimum limit switches, and photoelectric minimum limit switches fail, mechanical minimum hard stops installed on the two corrugated plates provide minimum gap (GAP) position protection, ensuring the gap reaches the minimum limit position.

[0059] Each transmission mechanism is provided with an optical grating ruler 15 and an optical grating ruler reading head 17 that are opposite to each other. The optical grating ruler 15 and the optical grating ruler reading head 17 are preferably located on the side of one of the left guide rail 19 and the right guide rail 27. The optical grating ruler 15 is fixed relative to the vertical plate 4, and the optical grating ruler reading head 17 is connected to the transmission mechanism through the optical grating ruler reading head connector 18. The optical grating ruler reading head 17 moves up and down with the transmission mechanism, so the optical grating ruler reading head 17 is set to output the displacement of the transmission structure.

[0060] Each ball screw of the transmission mechanism is equipped with a rotary encoder 13. Thus, the control system uses a grating ruler 15 as a position sensor in the closed-loop feedback. Simultaneously, the rotary encoders 13 and grating rulers 15 mounted on the four ball screws 14 form redundant protection. The grating rulers are installed near the main beam (to more accurately reflect the beam's displacement), and are close to the electron beam, making them susceptible to radiation (ionizing radiation, electromagnetic radiation). The rotary encoders are mounted on the ball screws, further away from the electron beam, and are less affected by radiation (ionizing radiation, electromagnetic radiation). Generally, the grating ruler is used as the position feedback element for closed-loop control. The rotary encoder can monitor the four position values ​​of the beam, but it does not participate in closed-loop control. If the grating ruler is exposed to radiation, it may "freeze," causing the grating ruler reading to change. However, this changes may conform to the motion control logic in the program, posing a potential safety hazard. Therefore, a difference comparison is made between the output position value of the rotary encoder and the feedback value of the grating ruler. Once the difference exceeds a set value, the grating ruler is disabled, and the output result of the rotary encoder is used as the closed-loop position sensor. This protects the GAP movement in the software and prevents out-of-tolerance phenomena.

[0061] Therefore, four sets of grating rulers at the four transmission mechanism positions act as position sensors to monitor the values ​​at the left end, right end, left end, and right end of the upper beam, respectively. When the upper and lower beams remain parallel to the central axis of the vacuum body, the values ​​of the four sets of grating rulers are the same. If there are differences in the readings of the four sets of grating rulers, it means that the upper and lower beams are not parallel. This is because the upper and lower beams move synchronously up and down relative to the central axis of the vacuum body (i.e., adjust GAP), requiring the upper and lower beams to always remain parallel. Therefore, the slave controller controls the stepper motor to adjust the displacement of the four ends of the upper and lower beams to keep them parallel.

[0062] Please see again Figure 1The master control cabinet 11 and the slave control chassis 9 are connected by a cable 10, which powers the slave control chassis 9 and enables EtherCAT (Ethernet Control Automation Technology) communication. The master control cabinet 11 is connected to multiple slave control chassis 9, and the slave control chassis 9 are connected to each other via Ethernet and EtherCAT to form network redundancy.

[0063] The main station control cabinet 11 includes a main station controller, a touch display connected to the main station controller, an Ethernet network module and an EtherCAT communication module, and a photoelectric conversion module and an optical fiber module connected in sequence to the Ethernet network module.

[0064] The master station controller is configured to control the motion of the transmission system, provide an operating interface to the touchscreen display, communicate with external remote devices, and communicate with the slave station control chassis 9. The slave station controllers themselves control the movement of the four transmission mechanisms of the energy dissipation compensator; the master station controller is used to uniformly send commands to multiple slave station controllers and read information from them; the slave station controllers control the energy dissipation compensator's information, and the master station controller is also used to communicate with external remote devices. The touchscreen display is configured to send operation commands and display the status information of the energy dissipation compensator. The Ethernet network module supports the Ethernet protocol and can be used for TCP / IP communication with external remote devices. The EtherCAT network module supports the EtherCAT communication protocol and can be used for communication between the master station controller and slave station controllers, between slave station controllers and motor drivers, I / O modules, etc. The photoelectric conversion module is used to convert electrical signals into optical signals or vice versa. The fiber optic module is used to transmit optical signals. This is because EtherCAT and Ethernet communication are not suitable for long-distance transmission and cannot be used for communication with external remote devices; therefore, when communicating with external remote devices, it is necessary to convert electrical signals into optical signals.

[0065] The slave control cabinet 9 includes a slave controller, an Ethernet network module and an EtherCAT communication module connected to the slave controller, a motor driver and an I / O module connected to the Ethernet network module. The Ethernet network module is sequentially connected to a photoelectric conversion module and an optical fiber module. The motor driver is connected to a stepper motor. Each motor driver drives one stepper motor; a total of four stepper drivers are required to drive the stepper motors of the inlet upper beam drive mechanism 3, the inlet lower beam drive mechanism 2, the outlet upper beam drive mechanism 5, and the outlet lower beam drive mechanism 7, respectively. The I / O module is used to write limit switch digital values ​​to the slave controller or read external signals (e.g., water flow signals). The Ethernet network module supports the Ethernet protocol and can be used to communicate with external remote devices. The master control cabinet 11 is connected to the EtherCAT network module of the slave control cabinet 9. The EtherCAT network module supports the EtherCAT communication protocol and can be used for communication between the master controller and the slave controller, between the slave controller and the driver, and the I / O module. The photoelectric conversion module converts electrical signals into optical signals or vice versa. Fiber optic modules are used to transmit optical signals.

[0066] Therefore, the master station control cabinet first sends an execution command to the slave station control cabinet; then the slave station control cabinet controls the motor's movement by controlling the driver and forming a closed-loop control with the absolute position grating ruler; finally, the motor adjusts the distance GAP between the upper and lower pleated plates inside the vacuum structure through the transmission mechanism, thereby changing the intensity and wavelength of the longitudinal wake field, thus achieving the purpose of compensating for electron beam energy dispersion.

[0067] The following is combined Figures 11A-11D The four operating modes of the energy dissipation compensator are described below:

[0068] (1) Gap mode

[0069] like Figure 11A As shown, by controlling the transmission mechanisms 3 and 5 to drive the upper pleated plate 40 to move and controlling the transmission mechanisms 2 and 7 to drive the lower pleated plate 43 to move, the gap GAP can be increased or decreased.

[0070] (2) Center Model

[0071] like Figure 11B As shown, when the foundation experiences slight subsidence, the upper pleated plate 40 can be moved by controlling transmission mechanisms 3 and 5, and the lower pleated plate 43 can be moved upward by controlling transmission mechanisms 2 and 7, thereby achieving the upward movement of the center of the entire GAP.

[0072] (3) Taper mode

[0073] like Figure 11C As shown, taking the inlet of vacuum structure 6 as the reference, Taper = Taper1 + Taper2. Taper1 = the value of the upper grating ruler at the outlet (i.e., grating 3) - the value of the upper grating ruler at the inlet (i.e., grating 1). Taper2 = the value of the lower grating ruler at the outlet (i.e., grating 4) - the value of the lower grating ruler at the inlet (i.e., grating 2). By changing the values ​​of the upper and lower grating rulers at the outlet, Taper can be increased or decreased; that is, the inlet size remains unchanged while the outlet size is changed. When the gap is already at its maximum, a positive Taper cannot be input to further increase Taper; when the gap is at its minimum, a negative Taper cannot be input to further decrease Taper.

[0074] In addition, a torque protection value is set in the control system. If the real-time torque value exceeds the torque protection value, the motor will stop moving to prevent the upper and lower corrugated plates from deforming and developing a large taper due to collision with the hard stop. Specifically, the torque value of each stepper motor is monitored online (the torque value can be read through the driver module), and then a torque protection value is set in the software program logic. If the real-time torque value of any of the four stepper motors exceeds the torque protection value, the motor will stop moving, thereby protecting the upper and lower corrugated plates.

[0075] (4) Maintenance Mode

[0076] like Figure 11D As shown, during beam operation, the grating ruler is affected by radiation, and one of the transmission structures of the energy dissipation compensator exceeds the tolerance. The deviation can be corrected by selecting the maintenance mode. The stepper motor of the individual transmission structure is driven by the slave controller to adjust the upper and lower pleated plates to keep them parallel.

[0077] In summary, combining Figure 4 , Figure 5 Figure 7 Figure 9 and Figure 10 The working process of the energy dissipation compensator of the present invention is as follows: The energy dissipation compensator of the present invention sends an execution command to the slave control box 9 through the master station control cabinet 11; then the slave control box 9 controls the movement of the stepping electrode 23 by controlling the electrode driver and forming a closed loop with the grating ruler; finally, the stepping electrode 23 adjusts the distance between the upper and lower pleated plates in the vacuum body through the transmission mechanism, thereby controlling the intensity and wavelength of the longitudinal tail field, so as to achieve the purpose of compensating for electron beam energy dissipation.

[0078] While specific embodiments of the present invention have been described above, they are not intended to limit the scope of the invention. They are merely illustrative examples. Other changes can be made to these embodiments without departing from the essence of the invention. Therefore, the scope of protection of the present invention is defined by the appended claims.

Claims

1. An energy dissipation compensator, characterized in that, include: A vacuum structure with an upper and lower corrugated plate inside its cavity, configured to provide a vacuum environment for the upper and lower corrugated plates; A mechanical structure, configured to support a vacuum structure, has four transmission mechanisms connected to an upper pleated plate and a lower pleated plate. These transmission mechanisms include an inlet upper beam transmission mechanism and an inlet lower beam transmission mechanism installed on the upper and lower parts of the vacuum structure near the inlet end, respectively; and an outlet upper beam transmission mechanism and an outlet lower beam transmission mechanism installed on the upper and lower parts of the vacuum structure near the outlet end, respectively. The control system is configured to drive the transmission mechanism in the mechanical structure, thereby driving the upper and lower pleated plates to move and adjusting the size of the gap between the upper and lower pleated plates. The mechanical structure includes a bracket, an adjustment base mounted on the bracket, a vertical plate mounted on the adjustment base, and the transmission mechanism mounted on the vertical plate. The inlet upper beam transmission mechanism and the outlet upper beam transmission mechanism, as well as the inlet lower beam transmission mechanism and the outlet upper beam transmission mechanism, are symmetrically arranged about the upper and lower sides of the vacuum structure. The inlet upper beam transmission mechanism and the inlet lower beam transmission mechanism, as well as the outlet upper beam transmission mechanism and the outlet lower beam transmission mechanism, are symmetrically arranged about the left and right sides.

2. Claim 1. The energy dissipation compensator according to claim 1, characterized in that, Each transmission mechanism includes a stepper motor and a reducer mounted on the vertical plate. The stepper motor is connected to the reducer via a coupling. The reducer is connected to a ball screw via a key. The ball screw is connected to a slide via its nut. The slide is threaded to a vacuum support connection structure. The vacuum support connection structure is threaded to an upper beam or a lower beam. The upper beam is fixedly connected to an upper pleated plate, and the lower pleated plate is fixedly connected to a lower beam.

3. The energy dissipation compensator according to claim 2, characterized in that, The control system includes a master station control cabinet and a slave station control box connected to each other. The slave station control box includes a motor driver and is connected to the stepper motor through the motor driver. The slave station control box is also connected to a grating ruler reading head and a rotary encoder.

4. The energy dissipation compensator according to claim 3, characterized in that, Each transmission mechanism is equipped with a grating ruler and a grating ruler reading head that are opposite each other. The grating ruler is fixed relative to the vertical plate, and the grating ruler reading head is connected to the transmission mechanism. The rotary encoder is installed on the ball screw of each transmission mechanism. The grating ruler reading head serves as a closed-loop position sensor. The rotary encoder serves as a redundant monitoring position sensor when the grating ruler reading head is working normally and as a closed-loop position sensor when the grating ruler reading head is damaged.

5. The energy dissipation compensator according to claim 3, characterized in that, The slave control box is electrically connected to the photoelectric minimum limit switch, the electromechanical minimum limit switch, the electromechanical maximum limit switch, and the photoelectric maximum limit switch. Each transmission mechanism is fixed with the photoelectric minimum limit switch, the electromechanical minimum limit switch, the electromechanical maximum limit switch, and the photoelectric maximum limit switch by screws. Each transmission mechanism is also equipped with a shielding cover.

6. The energy dissipation compensator according to claim 3, characterized in that, The master station control cabinet includes a master station controller, a touch screen connected to the master station controller, an Ethernet network module and an EtherCAT communication module, and a photoelectric conversion module and an optical fiber module connected in sequence to the Ethernet network module; the slave station control cabinet includes a slave station controller, an Ethernet network module and an EtherCAT communication module connected to the slave station controller, a motor driver and an I / O module connected to the Ethernet network module, the Ethernet network module being connected in sequence to the photoelectric conversion module and the optical fiber module, and the motor driver being connected to a stepper motor.

7. The energy dissipation compensator according to claim 3, characterized in that, The master station control cabinet is connected to multiple slave station control boxes, and the slave station control boxes are connected to each other via Ethernet and EtherCAT to form network redundancy.

8. The energy dissipation compensator according to claim 1, characterized in that, Both the upper and lower pleated plates are equipped with minimum limit hard stops.

9. The energy dissipation compensator according to claim 1, characterized in that, The vacuum structure includes a left end vacuum chamber, a main vacuum chamber, and a right end vacuum chamber connected in sequence via CF150 connecting flanges, as well as an upper beam, an upper pleated plate, a lower pleated plate, and a lower beam disposed within the cavity formed by the left end vacuum chamber, the main vacuum chamber, and the right end vacuum chamber. The upper beam and the lower beam are symmetrically positioned vertically within the vacuum structure with the central axis of the vacuum structure as the axis of symmetry.

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