Tuning device and superconducting accelerator

Abstract

The present invention provides a tuning device and a superconducting accelerator. The tuning device includes a mechanical tuning assembly and a connecting bracket. The mechanical tuning assembly includes an actuator and a driving mechanism. The actuator includes a first and second connected parts. The first part has a connecting arm for connecting and fixing to a liquid helium tank of a superconducting cavity, the connecting arm being used to mount the mechanical tuning assembly as a whole on the superconducting cavity. The second part has a connecting portion. The connecting bracket is connected to the connecting portion and has an extrusion portion that acts on the beam port of the superconducting cavity in a first direction. The first and second parts are eccentrically arranged and rotatably engaged. The output end of the driving mechanism is transmission-connected to the second part and drives the second part to rotate about a first axis. The first axis, the axis of the connecting portion, and the central axis of the second part are all parallel to offset displacement of the connecting portion in the second direction. The central axes of the first, second, and second parts are perpendicular to each other. The tuning device has high tuning accuracy.

Description

Technical Field

[0001] The present invention relates to the field of superconducting accelerators, and in particular to a tuning device and a superconducting accelerator. Background Art

[0002] Superconducting accelerators offer advantages such as low total energy consumption, excellent beam quality and stability, and high repetition rates, making them one of the main development directions in accelerator technology internationally. Compared to room-temperature cavities, superconducting cavities are affected by fluctuations in helium pressure, the Lorentz force, the microphone effect, beam current, and microphonic noise from surrounding equipment, causing the cavity frequency to deviate from the operating frequency (the frequency of the signal source). To maintain a stable pressure in the accelerating cavity, the incident power into the superconducting cavity must be increased. This also increases the reflected power, wasting energy and damaging the transmitter. Therefore, each accelerating cavity is equipped with a tuning device that works in conjunction with a superconducting cavity tuning control loop to compensate for and damp the effects of various noise factors inside and outside the cavity on its frequency, maintaining a constant acceleration field and stable beam operation. The superconducting cavity tuner is a crucial component of the superconducting component. Existing superconducting cavity tuners mostly use a squeezing method to effectively change the cavity frequency. The frequency of the superconducting cavity decreases when the beam port is squeezed and increases when the beam port is relaxed. The squeeze tuner does not have a significant impact on the high-order mode separation in the cavity, nor does it cause the generation of new high-order modes, so it is a common tuning method.

[0003] Due to the high quality factor of superconducting cavities, extremely precise frequency adjustment is required. Existing tuning devices suffer from insufficient tuning accuracy and susceptibility to tuning lag, making them incapable of achieving real-time tuning of superconducting cavities, thus affecting the cavity's acceleration performance. These issues are pressing technical challenges in this field. Summary of the Invention

[0004] The main technical problem solved by the present invention is to provide a tuning device with high tuning accuracy and a superconducting accelerator.

[0005] According to a first aspect, the present invention provides a tuning device for a superconducting cavity, the tuning device comprising:

[0006] The mechanical tuning assembly includes an actuator and a driving mechanism. The actuator includes a first part and a second part that are connected. The first part has a connecting arm for connecting and fixing to the liquid helium tank of the superconducting cavity. The connecting arm is used to mount the mechanical tuning assembly as a whole on the superconducting cavity. The second part has a connecting portion.

[0007] and a connecting bracket connected to the connecting portion and having an extrusion portion acting on the beam port of the superconducting cavity in a first direction;

[0008] Among them, the first part and the second part are eccentrically arranged and rotated together, the output end of the driving mechanism is transmission-connected to the second part, and drives the second part to rotate around the first axis, the first axis, the axis of the connecting part and the central axis of the second part are all parallel to offset the displacement of the connecting part in the second direction, so that the connecting part and the extrusion part move only along the first direction relative to the first part, and the first direction, the second direction and the central axes of the second part are perpendicular to each other.

[0009] In an optional embodiment, the second part includes an eccentric shaft and a first bearing; the eccentric shaft includes a main body section and two connecting sections connected to the main body section at both axial ends, the two connecting sections are coaxially arranged, and the axis of the main body section coincides with the central axis of the second part; the first bearing is sleeved on the main body section; the connecting sections constitute a connecting portion and are connected to the connecting bracket;

[0010] The first part is a second bearing that is sleeved with the first bearing and is eccentrically arranged, so that the second part as a whole rotates and deviates in the direction opposite to the displacement generated by the connecting section in the second direction.

[0011] In an optional embodiment, the distance between the axis of the main body segment and the axis of the connecting segment is 2 mm to 3 mm; and / or the distance between the axis of the first bearing and the axis of the second bearing is 2 mm to 3 mm.

[0012] In an optional embodiment, the mechanical tuning assembly further includes a third bearing, the third bearing is provided on the connecting bracket, and the connecting portion is rotatably engaged with the third bearing.

[0013] In an optional embodiment, the driving mechanism includes a driving member and a swing arm; one end of the swing arm is transmission-connected and hinged to the driving member, and the other end is transmission-connected to the connecting section, for converting the movement of the driving member into rotation of the connecting section.

[0014] In an optional embodiment, the driving mechanism further includes a ball screw pair driven by the driving member, and one end of the swing arm is hinged to the nut member of the ball screw pair.

[0015] In an optional embodiment, the number of actuators and swing arms is two, the actuator includes a first actuator and a second actuator spaced apart along the second direction; the two swing arms include a first swing arm and a second swing arm spaced apart along the second direction, the first swing arm is transmission-connected to the first actuator, the second swing arm is transmission-connected to the second actuator, the first actuator and the second actuator are respectively connected to the two ends of the connecting bracket, and the first actuator and the second actuator are both driven by a driving mechanism; the extrusion portion is used to be connected and fixed to the beam port, and the first direction is perpendicular to the second direction.

[0016] In an optional embodiment, the mechanical tuning assembly further includes a fourth bearing and a synchronization assembly;

[0017] The axial direction of the screw of the ball screw pair is the second direction, and the fourth bearing is in sliding cooperation with the screw of the ball screw pair; the first swing arm and the second swing arm are symmetrically arranged along the second direction, the first swing arm is hinged to the nut member of the ball screw pair, and the second swing arm is hinged to the fourth bearing;

[0018] The synchronization assembly includes a three-link mechanism, a first gear and a second gear; the two movable ends of the three-link mechanism are hinged to the connecting bracket to form a parallelogram linkage mechanism with the connecting bracket; the first gear is sleeved on the connecting section of the first actuator; the second gear is located between the three-link mechanism and the connecting bracket, and is sleeved on the first hinge shaft of the three-link mechanism close to the movable end of the first actuator and the connecting bracket, and the first gear is meshed with the second gear.

[0019] In an optional embodiment, along the second direction, two connecting sections of the same eccentric shaft are connected to the corresponding swing arms and the first gear respectively in a one-to-one correspondence, and the swing arms and the three-link mechanism are located on both sides of the connecting bracket.

[0020] According to a second aspect, the present invention further provides a superconducting accelerator, comprising:

[0021] a superconducting cavity with a liquid helium tank and a beam port;

[0022] The tuning device is connected to the liquid helium tank and acts on the beam port along a first direction.

[0023] According to the above-mentioned embodiment of a tuning device for a superconducting cavity, the first part can be fixed to the liquid helium tank via a connecting arm, so that the first part will not be displaced or rotated. The central axis of the second part, the axis of the connecting portion, and the first axis are all eccentrically arranged. When the second part rotates about the first axis, the connecting portion will rotate along with the second part as a whole. Because the first and second parts are eccentrically arranged and maintain a contact-type rotational fit, the first part has a positioning effect on the second part as a whole. Therefore, in the coordinate system formed by the first and second directions, the second part as a whole will still have a certain amount of overall offset and overall rotation. Therefore, by reasonably setting the relative positions of the first axis, the central axis of the second part, and the axis of the connecting portion, while the driving mechanism drives the second part as a whole to rotate about the first axis, the connecting portion will ultimately only have a displacement along the first direction, achieving the technical effect of eliminating the displacement of the connecting portion in the second direction through the two-stage eccentric structure.

[0024] The connecting bracket is connected to the connecting portion, and the extrusion portion changes position with the connecting portion, thereby changing the relative position of the extrusion portion and the beam port of the superconducting cavity in the first direction, causing the superconducting cavity to be further squeezed or released along its axial direction, reducing its axial squeezing amount, and ultimately changing the frequency of the superconducting cavity. At the same time, due to the complex movement of the second part itself, the rotation and offset of the second part under the action of the first part will cause the stroke of the connecting portion to be vectorially superimposed, ultimately eliminating the displacement of the connecting portion in the second direction, so that the connecting portion and the extrusion portion move only in the first direction. The stroke of the drive mechanism is not linearly related to the displacement of the first part in the first direction, and the stroke of the drive mechanism and the displacement of the connecting portion in the first direction can have a large amplification ratio, thereby improving the tuning accuracy of the mechanical tuning assembly along the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the overall structure of the tuning device provided in some embodiments of the present application.

[0026] Figure 2 for Figure 1 Schematic diagram of the tuning device from another perspective.

[0027] Figure 3 Schematic diagram of the assembly of the mechanical tuning component and the fast tuning component provided in some embodiments of the present application.

[0028] Figure 4 Schematic diagram of the assembly of mechanical tuning components and fast tuning components provided in some other embodiments of the present application.

[0029] Figure 5 for Figure 4 Schematic diagram from another perspective.

[0030] Figure 6 Schematic diagram of the assembly of the actuator and fast tuning component provided in some embodiments of the present application.

[0031] Figure 7 for Figure 6 Top view of .

[0032] Figure 8 for Figure 6 Explosion diagram.

[0033] Figure 9 for Figure 7 AA cross-sectional view.

[0034] Figure 10 for Figure 6 Schematic diagram of the structure of the fast tuning component in.

[0035] Figure 11An overall schematic diagram of the superconducting cavity and tuning device of a superconducting accelerator provided in some embodiments of the present application.

[0036] Figure 12 A top view of the superconducting cavity and tuning device of a superconducting accelerator provided in some embodiments of the present application.

[0037] Reference numeral: superconducting accelerator 1000 .

[0038] Tuning device 100, actuator 10, first portion 11, connecting arm 111, second portion 12, connecting portion 121, eccentric shaft 122, body section 123, connecting section 124, first bearing 125, first actuator 13, second actuator 14, drive mechanism 20, drive member 21, swing arm 22, first swing arm 221, second swing arm 222, ball screw pair 23, screw 231, nut 232, connecting bracket 3 0, extrusion portion 31, first bracket 32, second bracket 33, third bracket 34, third bearing 40, fourth bearing 50, synchronization assembly 60, three-link mechanism 61, first gear 62, second gear 63, elastic member 70, piezoelectric ceramic 81, first mounting seat 82, first plate 821, second plate 822, third plate 823, receiving groove 824, second mounting seat 83, through hole 825, guide rod 84, locking nut 85, connecting seat 86.

[0039] Superconducting cavity 200 , liquid helium tank 210 , and beam port 220 . DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0041] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0042] Component numbers used herein, such as "first" and "second," are used solely to distinguish the components being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0043] Due to the high quality factor of the superconducting cavity, the frequency needs to be adjusted very finely. However, the existing tuning device is generally a structure that directly drives the displacement in the axial direction of the superconducting cavity. The ratio of the stroke of the driving member to the displacement of the tuning device along the axial direction of the superconducting cavity can be calculated and determined. A smaller proportional relationship will lead to problems such as insufficient tuning accuracy and easy tuning lag, which cannot meet the needs of real-time tuning of the superconducting cavity. In addition, when it is necessary to improve the tuning accuracy, a gear set is often used to achieve proportional amplification. At this time, the gear set is prone to getting stuck at low temperatures, causing the tuning device to fail. At the same time, there will be a return difference in the gear structure, which will affect the acceleration effect of the superconducting cavity. The above problems are technical problems that need to be solved urgently in this field.

[0044] In order to solve the above technical problems, the present application provides a tuning device 100 for a superconducting cavity 200. Figure 1 、 Figure 3 and Figure 4 The tuning device 100 includes a mechanical tuning component and a connecting bracket 30. The mechanical tuning component includes an actuator 10 and a driving mechanism 20. The actuator 10 includes a first portion 11 and a second portion 12. The first portion 11 has a connecting arm 111 for connecting and fixing to the liquid helium tank 210 of the superconducting cavity 200. The second portion 12 has a connecting portion 121. The connecting bracket 30 is connected to the connecting portion 121, and the connecting bracket 30 has an extrusion portion 31 that acts on the beam port 220 of the superconducting cavity 200 in a first direction. The first direction is the axial direction of the superconducting cavity 200.

[0045] To ensure that the connection portion 121 moves only in the first direction, the first portion 11 and the second portion 12 are eccentrically arranged and rotatably matched. The first portion 11 can be fixed to the liquid helium tank 210 via the connecting arm 111. Therefore, the first portion 11 will not be displaced or rotated, while the second portion 12 can rotate relative to the first portion 11. The first portion 11 and the second portion 12 always maintain contact, so that the first portion 11 applies force to the second portion 12 in its radial direction to position the second portion 12. The output end of the drive mechanism 20 is connected to the second portion 12 and drives the second portion 12 to rotate about the first axis. The first axis, the axis of the connecting portion 121, and the central axis of the second portion 12 are all parallel, that is, they do not overlap. If the second portion 12 rotates about the first axis, the connecting portion 121 will rotate along with the second portion 12 as a whole, and the position and posture of the connecting portion 121 will change. At this time, because the second portion 12 does not rotate about the central axis, the posture of the outer peripheral surface of the second portion 12 and the contact position with the first portion 11 will also change. However, the first portion 11 is fixed by the liquid helium tank 210. Therefore, in the coordinate system formed by the first direction and the second direction, the second portion 12 as a whole will still have a certain amount of overall offset and overall rotation. The first direction, the second direction, and the central axis of the second portion 12 are perpendicular to each other. By properly setting the relative positions of the first axis, the central axis of the second portion 12, and the axis of the connecting portion 121, the second portion 12 can be simultaneously driven by the driving mechanism 20 to rotate about the first axis while simultaneously moving the second portion 12 in the opposite direction. This offsets the displacement of the connecting portion 121 in the second direction, allowing the connecting portion 121 and the extrusion portion 31 to move only in the first direction relative to the first portion 11. The connecting bracket 30 is connected to the connecting portion 121, and the extrusion portion 31 changes position with the connecting portion 121, thereby changing the relative position of the extrusion portion 31 and the beam port 220 of the superconducting cavity 200 in the first direction. This further compresses or releases the superconducting cavity 200 in its axial direction, reducing the amount of axial compression, and ultimately changing the frequency of the superconducting cavity 200.

[0046] Please refer to Figure 1 and Figure 2 The first direction is the X direction, the second direction is the Y direction, and the central axis of the second portion 12 extends along the Z direction.

[0047] In the technical solution disclosed in the present application, the mechanical tuning assembly is integrally mounted on the superconducting cavity 200 via the connecting arm 111. The first portion 11 is fixed relative to the superconducting cavity 200, and the second portion 12 and the extrusion portion 31 are movable relative to the superconducting cavity 200 in a first direction. Since the central axis of the second portion 12 itself, the first axis corresponding to the drive mechanism 20, and the axis of the connecting portion 121 of the connecting bracket 30 do not coincide, the connecting portion 121 rotates around the first axis under the drive of the drive mechanism 20, and the connecting portion 121 simultaneously has displacements in the first and second directions. In addition, when the second portion 12 rotates around the first axis as a whole, since the first and second portions 11 and 12 are eccentrically arranged and maintained in tension, the second portion 12 will also have a secondary offset under the action of the first portion 11, and the connecting portion 121 will ultimately also have displacements in the first and second directions during the secondary offset. In other words, looking at the connection portion 121 alone, the connection portion 121 has two forms of movement under different driving forces. The first is a position change caused by the action of the driving mechanism 20, and the second is a position change caused by the action of the first part 11. Both of the above position changes will simultaneously result in displacement in the first direction and displacement in the second direction. Therefore, the final position of the connection portion 121 is obtained by vector superposition of the two position changes. By simply properly setting the structure of the first part 11 and the relative positional relationship between the first part 11 and the second part 12, the displacement in the second direction can be eliminated after vector superposition, so that the connection portion 121 and the extrusion portion 31 only move along the first direction. In some embodiments, through a reasonable structural setting, it is even possible to make the displacement of the connection portion 121 in the first direction during the secondary offset opposite to the displacement of the connection portion 121 in the first direction driven by the driving mechanism 20, and thus the displacement of the connection portion 121 along the first direction can be reduced after vector superposition, achieving the technical effect of further amplifying the ratio.

[0048] In the technical solution of the present application, since the relationship between the stroke of the driving mechanism 20 and the displacement of the first part 11 in the first direction is not linear, and there can be a large amplification ratio between the stroke of the driving mechanism 20 and the displacement of the connecting portion 121 in the first direction, the accuracy of the tuning of the mechanical tuning component along the first direction is improved. In addition, since the accuracy and amplification ratio are improved at this time, the influence of the return difference in the structure of the driving mechanism 20 itself on the tuning of the superconducting cavity 200 can also be reduced. Compared with the solution of using a gear structure to amplify the stroke ratio relationship and improve the tuning accuracy, the mechanical tuning component using this solution effectively avoids the technical problem of the actuator 10 being stuck and unable to tune at low temperatures, thereby improving the overall stability and overall performance of the tuning device 100.

[0049] In order to improve the amplification ratio and tuning accuracy, in some embodiments, please refer to Figure 6The second portion 12 may include an eccentric shaft 122 and a first bearing 125. The eccentric shaft 122 includes a main body section 123 and two connecting sections 124 connected to the main body section 123 at either axial end. The two connecting sections 124 are coaxially arranged, and the axis of the main body section 123 coincides with the central axis of the second portion 12. In other words, the main body section 123 and the connecting sections 124 are not coaxial. The connecting sections 124 constitute the connecting portion 121. The drive mechanism 20 is in transmission connection with the connecting section 124, and the connecting bracket 30 is connected to the connecting section 124. The first bearing 125 is sleeved on the main body section 123. When the eccentric shaft 122 is driven to rotate by the driving mechanism 20, the first bearing 125 does not rotate with the eccentric shaft 122. However, since the first axis does not coincide with the axis of the main body section 123 (i.e., the central axis of the eccentric shaft 122), the position of the central axis of the eccentric shaft 122 will change. The first part 11 can be a second bearing that is sleeved on the first bearing 125 and eccentrically arranged, so that the second part 12 as a whole rotates and offsets in the opposite direction to the displacement of the connecting section 124 in the second direction, and finally offsets the displacement of the axis of the connecting section 124 in the second direction, and the connecting section 124 only moves along the first direction while rotating.

[0050] In order to effectively offset the displacement of the axis of the connecting section 124 in the second direction, in some embodiments, please refer to Figure 7 and Figure 9 , the distance between the axis of the main body section 123 and the axis of the connecting section 124 is 2 mm to 3 mm; and / or the distance between the axis of the first bearing 125 and the axis of the second bearing is 2 mm to 3 mm. By controlling at least one of the eccentricity between the main body section 123 and the connecting section 124 and the eccentricity between the axis of the first bearing 125 and the second bearing within a small and appropriate range, the probability of structural damage to the superconducting cavity 200 and the beam port 220 due to displacement of the connecting section 124 in the second direction can be effectively reduced, and the first part 11 and the second part 12 can be effectively prevented from being stuck in the fit.

[0051] Because the connecting portion 121 ultimately exhibits both translational movement along the first direction and rotational movement about its own axis, when the first portion 11 drives the connecting bracket 30 to move as a whole along the first direction, the connecting portion 121 also rotates relative to the connecting bracket 30. Therefore, to extend the service life of the connecting bracket 30, in some embodiments, the mechanical tuning assembly further includes a third bearing 40 disposed on the connecting bracket 30, with the connecting portion 121 rotatably engaged with the third bearing 40.

[0052] The present application does not limit the specific scheme for achieving tensioning and initial relative position determination of the first part 11 and the second part 12. For example, in some embodiments, the specific position in each state can be determined by coordinating the design of multiple structures of the mechanical tuning component. In some embodiments, please refer to Figure 1 and Figure 3 The drive mechanism 20 may include a drive member 21 and a swing arm 22. One end of the swing arm 22 is transmission-connected and hinged to the drive member 21, and the other end is transmission-connected to the connecting segment 124. This is used to convert the movement of the drive member 21 into rotation of the connecting segment 124, thereby achieving tensioning and determining the relative position of the first portion 11 and the second portion 12. One end of the swing arm 22 is driven by the drive member 21, causing its position to change. Since the two ends of the swing arm 22 have fixed lengths, the angle of the swing arm 22 changes, thereby causing the connecting segment 124 to move and rotate simultaneously. In some embodiments, the swing arm 22 and the connecting segment 124 may be connected by a snap fit, an interference fit, or the like.

[0053] In order to further improve the tuning accuracy and facilitate the installation and positioning of the drive mechanism 20, in some embodiments, please refer to Figure 1 and Figure 3 The drive mechanism 20 also includes a ball screw pair 23 driven by a driver 21. One end of the swing arm 22 is hingedly connected to a nut 232 of the ball screw pair 23. When the driver 21 rotates the screw 231, the nut 232 translates along the axial direction of the screw 231, thereby changing the endpoint position and angle of the swing arm 22. The driver 21 and the ball screw pair 23 are both mounted on the first portion 11 via the swing arm 22. The ball screw pair 23 is used to change the position of the swing arm 22. The high precision of the ball screw pair 23, combined with the high amplification ratio of the actuator 10 itself, further improves the tuning ratio and reduces the impact of backlash.

[0054] In the tuning device 100 provided in the present application, the tuning principle of the tuning device 100, the number of mechanical tuning components, etc. can be adaptively adjusted according to actual needs. In some embodiments, the connecting bracket 30 can be set to move horizontally along the first direction with the connecting portion 121. At this time, the displacement of the extrusion portion 31 is consistent with the displacement of the connecting portion 121. In some embodiments, the connecting bracket 30 can be a structure in which the first end is connected and fixed to the liquid helium tank 210 and the second end is connected to the connecting portion 121. This is a lever-type tuning mechanism in the relevant technology. The specific structure and principle can refer to the relevant technology and will not be described here. In some embodiments, the two ends of the connecting bracket 30 can also be connected to the superconducting cavity 200 through an actuator 10 and an extrusion portion 31 respectively, as long as the connecting bracket 30 can move horizontally along the first direction as a whole with the connecting portion 121.

[0055] Since the tuning device 100 provided by the present application can have a large amplification ratio and tuning accuracy, in some embodiments, please refer to Figure 4 To reduce damage to the structure of the superconducting cavity 200 caused by the tuning operation, the number of actuators 10 and the number of swing arms 22 are both two. The actuator 10 includes a first actuator 13 and a second actuator 14 spaced apart along the second direction. The two swing arms 22 include a first swing arm 221 and a second swing arm 222 spaced apart along the second direction. The first swing arm 221 is transmission-connected to the first actuator 13, and the second swing arm 222 is transmission-connected to the second actuator 14. The first actuator 13 and the second actuator 14 are respectively connected to two ends of a connecting bracket 30, and both the first actuator 13 and the second actuator 14 are driven by a driving mechanism 20. The extrusion portion 31 is used to be connected and fixed to the beam port 220. The first direction is perpendicular to the second direction, that is, the two ends of the connecting bracket 30 are driven by the connection portions 121 of the first actuator 13 and the second actuator 14 to move in the first direction. In the second direction, the extrusion portion 31 is located between the first actuator 13 and the second actuator 14.

[0056] In order to control the overall weight of the connecting bracket 30 so that the connecting portion 121 can smoothly drive the connecting bracket 30 to move in the first direction, in some embodiments, please refer to Figure 1 and Figure 2 The connecting bracket 30 may include a first bracket 32, a second bracket 33, and a third bracket 34. The first bracket 32 ​​and the second bracket 33 are spaced apart along the axial direction of the eccentric shaft 122. The first bracket 32 ​​and the second bracket 33 are respectively connected to the two connecting segments 124. The third bracket 34 connects the first bracket 32 ​​and the second bracket 33. In some embodiments, a plurality of weight-reducing holes may be provided on the first bracket 32 ​​and the second bracket 33.

[0057] In some embodiments, the number of the driving member 21 and the ball screw pair 23 can both be one, see Figure 3 The double-ended ball screw pair 23 is configured using a double-ended reverse-threaded lead screw 231. Specifically, one lead screw 231 has two threaded members, and the first swing arm 221 and the second swing arm 222 are articulated to the two threaded members in a one-to-one correspondence. In some embodiments, the number of drive mechanisms 20 can be two. When two actuators 10 need to move synchronously in the first direction, the two drive mechanisms 20 can be configured with identical structures and the two lead screws 231 can be coaxial, thereby forming one of the feasible synchronous drive solutions. Any other feasible technical solution can also be adopted.

[0058] When there is one actuator 10 or multiple actuators 10 are respectively driven by a corresponding driving mechanism 20 , in some embodiments, the axial direction of the lead screw 231 can be any direction within the plane formed by the first direction and the second direction.

[0059] In order to reduce the failure rate of mechanical jamming when two actuators 10 are synchronized, in some embodiments, please refer to Figure 4 and Figure 5 The axial direction of the lead screw 231 of the ball screw assembly 23 is the second direction. The mechanical tuning assembly further includes a fourth bearing 50 and a synchronization assembly 60. Along the second direction, the fourth bearing 50 slides with the lead screw 231 of the ball screw assembly 23. The first swing arm 221 and the second swing arm 222 are symmetrically arranged. The first swing arm 221 is hingedly connected to the nut 232 of the ball screw assembly 23, and the second swing arm 222 is hingedly connected to the fourth bearing 50. In other words, the first swing arm 221 is directly driven to rotate by the driver 21, and the first actuator 13 is driven by the driver 21, causing the connecting portion 121 to rotate and move only in the first direction. The synchronization assembly 60 includes a three-link mechanism 61, a first gear 62 and a second gear 63; the two movable ends of the three-link mechanism 61 are hinged with the connecting bracket 30 to form a parallelogram linkage mechanism with the connecting bracket 30, and the three-link mechanism 61, the first gear 62 and the second gear 63 move in a first direction along with the connecting portion 121 and the connecting bracket 30; the first gear 62 is sleeved on the connecting section 124 of the first actuator 13; the second gear 63 is located between the three-link mechanism 61 and the connecting bracket 30, and is sleeved near the three-link mechanism 61. At the movable end of the first actuator 13 and the first hinge shaft of the connecting bracket 30, the first gear 62 is meshed with the second gear 63. Under the action of the parallelogram linkage, the first gear 62, and the second gear 63, the first gear 62 transmits the rotation of the connecting portion 121 to the second gear 63. The second gear 63 drives the first hinge shaft to rotate, and the first hinge shaft in turn drives the connecting rod of the three-bar linkage 61 connected to the connecting bracket 30 to rotate, ultimately causing the connecting section 124 of the second actuator 14 to move along the first direction and rotate a certain angle. This application arranges one of the two actuators 10 to be directly connected to the drive member 21, and the other to achieve power transmission using the parallelogram mechanism and the meshing first gear 62 and second gear 63. Compared to a solution in which both actuators 10 are directly driven by the drive member 21, this solution reduces the failure rate of mechanical jamming when the two actuators 10 are synchronized, while also simplifying the structure and saving costs.

[0060] In order to reasonably layout and control the volume and occupied space of the entire tuning device 100, and at the same time effectively avoid interference between the driving mechanism 20 and the three-bar mechanism 61, in some embodiments, along the second direction, the two connecting sections 124 of the same eccentric shaft 122 are respectively connected one-to-one with the corresponding swing arm 22 and the first gear 62, and the swing arm 22 and the three-bar mechanism 61 are located on both sides of the connecting bracket 30.

[0061] In order to meet the tuning requirements of the superconducting cavity under different working conditions, in some embodiments, the tuning device may also include a fast tuning component. In order to provide a tuning device with a simple structure, timely tuning and high tuning accuracy, the present application has made improvements to the structure and transmission method of the tuning device. Figure 6 and Figure 7 In some embodiments, the tuning device further includes an elastic member 70 and a fast tuning assembly. The fast tuning assembly includes a piezoelectric ceramic 81, a first mounting seat 82, and a second mounting seat 83. The first mounting seat 82 is fixedly connected to the liquid helium tank of the superconducting cavity. The first mounting seat 82 and the second mounting seat 83 slide together along a first direction. The piezoelectric ceramic 81 is fixedly mounted between the first mounting seat 82 and the second mounting seat 83. The first direction is consistent with the axial direction of the piezoelectric ceramic 81. The two ends of the elastic member 70 respectively transmit force to the first mounting seat 82 and the second mounting seat 83 to adaptively adjust the spacing between the first mounting seat 82 and the second mounting seat 83 as the axial dimension of the piezoelectric ceramic 81 changes. The connecting arm 111 is connected to the second mounting seat 83, that is, the connecting arm 111 is fixedly connected to the liquid helium tank of the superconducting cavity through the first mounting seat 82.

[0062] In the above technical solution, the piezoelectric ceramic 81 in the fast tuning component has the ability to quickly respond to voltage changes and change its axial size. The first mounting seat 82 and the second mounting seat 83 slide together along the first direction, and the elastic member 70 transmits force at both axial ends to act on the first mounting seat 82 and the second mounting seat 83. Under the action of the elastic member 70, the piezoelectric ceramic 81 can be fixedly installed between the first mounting seat 82 and the second mounting seat 83. That is to say, the elastic member 70 provides a pre-tightening force for the first mounting seat 82, the second mounting seat 83 and the piezoelectric ceramic 81, so that the three are always kept in tension. When the operating frequency of the superconducting cavity needs to be adjusted, the axial dimension of the piezoelectric ceramic 81 is changed by charging and disconnecting the piezoelectric ceramic 81 or by increasing or decreasing the pressure. The elastic member 70 is compressed or adaptively extended accordingly. Since the first mounting seat 82 is fixedly connected to the liquid helium tank of the superconducting cavity, the position of the first mounting seat 82 does not change. Ultimately, the second mounting seat 83 moves axially relative to the superconducting cavity along the piezoelectric ceramic 81. The first portion is connected to the second mounting seat 83, so the mechanical tuning assembly and the connecting bracket as a whole will also undergo a certain displacement relative to the superconducting cavity, ultimately causing the extrusion portion to squeeze or relax the beam port of the superconducting cavity, thereby correspondingly adjusting the operating frequency of the superconducting cavity. Keeping the first direction consistent with the axial direction of the piezoelectric ceramic 81 effectively prevents the piezoelectric ceramic 81 from being damaged by shear force when the second mounting seat 83 is actuated. Due to the rapid response of the piezoelectric ceramic 81 and the very fine change in axial dimension, the displacement of the extrusion portion relative to the beam port of the superconducting cavity can also be very fine, thereby achieving a high level of precision in the fast tuning assembly. It is only necessary to reasonably select the elastic member 70 and the pre-tightening force of the elastic member 70 on the first mounting seat 82 and the second mounting seat 83 so that the overall rigidity of the tuning device can be improved. At the same time, when the piezoelectric ceramic 81 responds, it can easily drive the second mounting seat 83 and the connecting bracket to move as a whole to meet the requirements of response speed and tuning accuracy, and realize the role of a fast and real-time superconducting cavity tuning body, so that it meets the physical parameter requirements and ensures the acceleration effect of the superconducting cavity.

[0063] In different embodiments, the second mounting base 83 and the connecting arm 111 can be an integrally formed structure (see Figure 8 and Figure 10 ), it can also be a detachable connection structure, which is not specifically limited in this embodiment. Similarly, in different embodiments, the connecting arm and the first part can be a detachable connection structure or an integrally formed structure, which is not specifically limited in this embodiment.

[0064] The present application does not limit the scheme for achieving sliding fit between the first mounting seat 82 and the second mounting seat 83. For example, in some embodiments, the first mounting seat 82 and the second mounting seat 83 can be socketed. In other embodiments, the first mounting seat 82 and the second mounting seat 83 can also adopt a guide rail and slider scheme.

[0065] Furthermore, the elastic member 70 can act on the first mounting seat 82 by direct contact transmission, or by indirect transmission through the piezoelectric ceramic 81 with one end in contact. This is sufficient so that the first mounting seat 82, under the combined action of the elastic member 70 and the piezoelectric ceramic 81, can be adaptively adjusted relative to the second mounting seat 83. Similarly, the coordination between the second mounting seat 83 and the elastic member 70 can be referenced above and will not be elaborated upon here.

[0066] In different embodiments, the number of piezoelectric ceramics 81 can be selected based on actual needs. It is necessary that the piezoelectric ceramics 81 can relatively easily overcome the elastic force of the elastic member 70 to quickly and smoothly push the second mounting seat 83 to move relative to the first mounting seat 82. While the elastic member 70 provides tension and preload for the first mounting seat 82, the second mounting seat 83, and the piezoelectric ceramic 81, the elastic member 70 also enhances the overall strength of the fast tuning assembly. When the fast tuning assembly responds, the spacing between the first mounting seat 82 and the second mounting seat 83 is adaptively matched to the axial dimension of the piezoelectric ceramic 81, thereby improving the overall reliability and stability of the tuning device.

[0067] In order to further simplify the structure and facilitate the overall assembly of the tuning device, in some embodiments, please refer to Figure 8 A guide rod 84 is mounted on one of the first and second mounting seats 82, 83. The first and second mounting seats 82, 83 are slidably engaged with each other via the guide rod 84. The axial direction of the guide rod 84 is arranged along a first direction so that the axial direction of the guide rod 84 aligns with the axial direction of the piezoelectric ceramic 81, effectively preventing shear forces during dimensional changes of the piezoelectric ceramic 81. A locking nut 85 is provided on the guide rod 84 for locking the first and second mounting seats 82, 83. The elastic member 70 is locked to the fast tuning assembly by the locking nut 85.

[0068] In some embodiments, the elastic member 70 can be locked between the first mounting seat 82 and the second mounting seat 83, can be locked between the first mounting seat 82 and the locking nut 85, and can be locked between the second mounting seat 83 and the locking nut 85. In some embodiments, the elastic member 70 can also be locked between one of the first mounting seat 82 and the second mounting seat 83 and the piezoelectric ceramic 81.

[0069] In order to further simplify the structure of the first mounting base 82 and the second mounting base 83, and at the same time make the second mounting base 83 able to stably overcome the force of the elastic member 70 and perform adaptive adjustment of the position along with the piezoelectric ceramic 81, please refer to FIG. Figure 10 In some embodiments, the first mounting seat 82 includes a first plate 821 and a second plate 822 disposed opposite and spaced apart from each other along a first direction, and a third plate 823 connecting the first and second plates 821 and 822. A guide rod 84 connects the first plate 821, the second plate 822, and the second mounting seat 83. The second plate 822 is provided with a guide hole for the guide rod 84 to pass through. Along the axial direction of the guide rod 84, the first plate 821, the second plate 822, and the second mounting seat 83 are sequentially disposed, with the second plate 822 abutting the second mounting seat 83. This embodiment still does not limit the location of the guide rod 84. In some embodiments, the guide rod 84 can be fixedly connected to the first plate 821, in which case the guide rod extends from a side of the second mounting seat 83 facing away from the first mounting seat 82, and the lock nut 85 is located on the side of the second mounting seat 83 facing away from the first mounting seat 82. In other embodiments, the guide rod 84 can also be fixedly connected to the second mounting seat 83, in which case the lock nut 85 is located on the side of the second mounting seat 83 facing away from the first mounting seat 82. The axial direction of the piezoelectric ceramic 81 is aligned with the axial direction of the guide rod 84. The first plate 821 is provided with a receiving groove 824 that abuts one end of the piezoelectric ceramic 81. The second mounting seat 83 is provided with a raised portion that abuts the other end of the piezoelectric ceramic 81. The second plate 822 is provided with a through-hole 825 for the raised portion to pass through. The bottom of the receiving groove 824 and the top surface of the raised portion respectively abut the two end surfaces of the piezoelectric ceramic 81. Consequently, under the action of the elastic member 70 and the locking nut 85, the piezoelectric ceramic 81 is fixedly connected to the first mounting seat 82 and the second mounting seat 83. At the same time, the sidewalls of the receiving groove 824 also provide positioning and support for the piezoelectric ceramic 81. By configuring the first mounting seat 82 as a hollow structure, the installation and removal of the piezoelectric ceramic 81 can be facilitated.

[0070] In addition, in some embodiments, the protrusion may be accommodated in the through hole 825 of the second plate 822 . In this case, the sidewall of the through hole 825 may also provide certain positioning and support for the piezoelectric ceramic 81 .

[0071] In order to facilitate the installation and positioning of the elastic member 70, in some embodiments, the elastic member 70 can be sleeved on the guide rod 84, and the elastic member 70 is arranged on the side opposite to the first mounting seat 82 and the second mounting seat 83 and is locked by the locking nut 85. For example, please refer to Figure 10 and Figure 11 The guide rod 84 is fixed to the second mounting seat 83 , the guide rod 84 is slidably matched with the first mounting seat 82 and passes through the first mounting seat 82 , and the elastic member 70 is provided between the locking nut 85 and the first mounting seat 82 .

[0072] According to the required tuning method, the number of fast tuning components can be adaptively adjusted. For example, in some embodiments, the connecting bracket 30 can be set to move horizontally along the first direction with the second mounting seat 83. At this time, the displacement of the extrusion portion 31 is consistent with the displacement of the second mounting seat 83. In some embodiments, the connecting bracket 30 can be a structure in which the first end is connected and fixed to the liquid helium tank 210 and the second end is connected to the second mounting seat 83. This is a lever-type tuning mechanism in the relevant technology. The specific structure and principle can refer to the relevant technology and will not be described here. In some embodiments, the two ends of the connecting bracket 30 can also be connected to the superconducting cavity 200 respectively through a fast tuning component, so that the connecting bracket 30 can move horizontally along the first direction as a whole with the connecting portion 121.

[0073] In some embodiments, in order to reduce the damage of the tuning operation to the structure of the superconducting cavity 200, the tuning device can be configured to connect the bracket to move in a translational manner along the first direction. Figure 1 There are two fast tuning components, and the second mounting bases 83 of the two fast tuning components are respectively connected to the opposite ends of the connecting bracket so that the connecting bracket as a whole can be translated along the first direction.

[0074] In some embodiments, the fast tuning assembly may further include a connecting base 86 detachably connected to the first mounting base 82 , and the connecting base 86 is used to be connected and fixed to the liquid helium tank. That is, the first mounting base 82 is fixed to the liquid helium tank through the connecting base 86 , which facilitates subsequent use and maintenance.

[0075] Based on the same invention concept, please refer to Figure 11 and Figure 12 The present application also provides a superconducting accelerator 1000, comprising a superconducting cavity 200 and the tuning device 100 of the above embodiment. The superconducting cavity 200 has a liquid helium tank 210 and a beam port 220. The tuning device 100 is connected to the liquid helium tank 210 and acts on the beam port 220 along a first direction.

[0076] The operating principles of the tuning device 100 and superconducting accelerator 1000 are as follows: The entire tuning device 100 is secured to the exterior of the liquid helium tank 210 of the superconducting cavity 200 via a connecting bracket 30. The extrusion portion 31 of the connecting bracket 30 is connected and secured to the flange of the beam port 220 of the superconducting cavity 200. A motor drives the lead screw 231 to rotate, causing the first swing arm 221 and the second swing arm 222 to deflect inward or outward, respectively. This drives the rotation and displacement of the eccentric shaft 122 and the first bearing 125. This allows the extrusion portion 31 to push the superconducting cavity 200 in a first direction, i.e., the axial direction of the superconducting cavity 200, or to reduce the amount of superconducting extrusion.

[0077] In summary, the tuning device 100 and superconducting accelerator 1000 provided in this application have at least the following beneficial effects:

[0078] Compared with the prior art, the inventive concept of this application is to simultaneously improve the structure of the fast tuning component and the transmission scheme of the mechanical tuning component. The fast tuning response action and the mechanical tuning action do not interfere with each other and do not affect each other. Only fast tuning can be performed, only mechanical tuning can be performed, or both fast tuning and mechanical tuning can be performed at the same time. When the corresponding voltage of the piezoelectric ceramic changes and drives the second mounting base to move as a whole, the mechanical tuning component also moves as a whole with the second mounting base.

[0079] The mechanical tuning component adopts a rotating structure of an eccentric shaft and a bearing assembly, which greatly amplifies the tuning ratio. The displacement change of the connecting part in the first direction can reach the order of um when the screw rotates one circle, thereby effectively improving the tuning accuracy and reducing the impact of the return difference of the motor, screw, etc. on the tuning accuracy.

[0080] The parallelogram linkage mechanism formed by the synchronization component and the connecting bracket can keep the two actuators synchronized. Such a tuning device will have a faster response speed and can more accurately compensate for the frequency deviation of the superconducting cavity in the working state, thereby allowing the superconducting cavity to operate normally.

[0081] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art can make several simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. A tuning device, characterized in that: For a superconducting cavity, the tuning device comprises: A mechanical tuning assembly includes an actuator and a drive mechanism. The actuator includes a first portion and a second portion that are connected. The first portion has a connecting arm for fixedly connecting to the liquid helium tank of the superconducting cavity, and the connecting arm is used to mount the mechanical tuning assembly as a whole on the superconducting cavity. The second portion includes an eccentric shaft and a first bearing. The eccentric shaft includes a main body section and two connecting sections connected to the main body section at both axial ends. The two connecting sections are coaxially arranged, and the axis of the main body section coincides with the central axis of the second portion. The first bearing is sleeved on the main body section; the connecting section constitutes a connecting portion. The first portion is a second bearing sleeved on the first bearing and eccentrically arranged. and a connecting bracket connected to the connecting portion and having an extrusion portion acting on the beam port of the superconducting cavity in a first direction, wherein the first direction is the axial direction of the superconducting cavity; The first part and the second part are eccentrically arranged and rotated together, the output end of the driving mechanism is connected to the second part and drives the second part to rotate around the first axis, and the second part rotates as a whole in the opposite direction, the first axis, the axis of the connecting part and the central axis of the second part are all parallel to offset the displacement of the connecting part in the second direction, so that the connecting part and the extrusion part move only along the first direction relative to the first part, and the first direction, the second direction and the central axis of the second part are perpendicular to each other.

2. The tuning device according to claim 1, wherein The distance between the axis of the main body segment and the axis of the connecting segment is 2 mm to 3 mm; and / or the distance between the axis of the first bearing and the axis of the second bearing is 2 mm to 3 mm.

3. The tuning device according to claim 1, wherein The mechanical tuning assembly further includes a third bearing, which is disposed on the connecting bracket, and the connecting portion is rotatably engaged with the third bearing.

4. The tuning device according to any one of claims 1 to 3, wherein: The driving mechanism includes a driving member and a swing arm; one end of the swing arm is transmission-connected and hinged to the driving member, and the other end is transmission-connected to the connecting section, for converting the movement of the driving member into rotation of the connecting section.

5. The tuning device according to claim 4, wherein: The driving mechanism further includes a ball screw pair driven by the driving member, and one end of the swing arm is hinged to a nut member of the ball screw pair.

6. The tuning device according to claim 5, wherein: The number of the actuators and the number of the swing arms are both two, and the actuators include a first actuator and a second actuator spaced apart along the second direction; the two swing arms include a first swing arm and a second swing arm spaced apart along the second direction, the first swing arm is transmission-connected to the first actuator, and the second swing arm is transmission-connected to the second actuator, the first actuator and the second actuator are respectively connected to the two ends of the connecting bracket, and the first actuator and the second actuator are both driven by the driving mechanism; the extrusion portion is used to be connected and fixed to the beam port, and the first direction is perpendicular to the second direction.

7. The tuning device according to claim 6, wherein: The mechanical tuning assembly further includes a fourth bearing and a synchronization assembly; The axial direction of the screw of the ball screw pair is the second direction, and the fourth bearing is in sliding engagement with the screw of the ball screw pair; the first swing arm and the second swing arm are symmetrically arranged along the second direction, the first swing arm is hinged to the nut member of the ball screw pair, and the second swing arm is hinged to the fourth bearing; The synchronization assembly includes a three-bar linkage, a first gear and a second gear; the two movable ends of the three-bar linkage are hinged to the connecting bracket to form a parallelogram linkage with the connecting bracket; the first gear is sleeved on the connecting section of the first actuator; the second gear is located between the three-bar linkage and the connecting bracket, and is sleeved on the first hinge shaft of the three-bar linkage close to the movable end of the first actuator and the connecting bracket, and the first gear is meshed with the second gear.

8. The tuning device according to claim 7, wherein: Along the second direction, the two connecting sections of the same eccentric shaft are connected to the corresponding swing arms and the first gear respectively in a one-to-one correspondence, and the swing arms and the three-link mechanism are located on both sides of the connecting bracket.

9. A superconducting accelerator, characterized in that: include: a superconducting cavity with a liquid helium tank and a beam port; The tuning device according to any one of claims 1 to 8, wherein the tuning device is connected to the liquid helium tank and acts on the beam port along the first direction.

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