A high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator

Abstract

This invention discloses a high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator (RFQ), belonging to the field of particle accelerator testing technology. The device includes a leveling system, a measurement platform, and a control system. The leveling system is equipped with multiple test fixtures with adjustable spacing along the axial direction and a lifting mechanism for fixing and automatically leveling the RFQ cavity. Two measurement platforms are respectively arranged at both ends of the leveling system, each equipped with a rope traction mechanism with micro-perturbation blocks. The control system integrates a measurement control industrial computer, a network analyzer, and other units to synchronously control the automatic leveling of the cavity, the movement of the micro-perturbation blocks, and frequency sweep testing. It automatically acquires and calculates multiple parameters such as resonant frequency, quality factor, field distribution, phase, and mode spectrum in a single setup. This invention combines leveling, automated measurement, and integrated control, improving the efficiency, accuracy, and repeatability of RFQ cavity cold-state testing compared to the cumbersome, low-precision, and poorly versatile nature of traditional testing methods.

Description

Technical Field

[0001] This invention relates to the field of particle accelerator testing technology, and in particular to a high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator. Background Technology

[0002] A radio frequency quadrupole (RFQ) accelerator is a commonly used linear accelerator structure that focuses and accelerates an ion beam at low energy levels using quadrupole electrodes. The electromagnetic parameters of the RFQ cavity, such as resonant frequency, field strength distribution, and phase, are crucial to its acceleration performance. Before an RFQ is put into high-power operation, cold-state testing is typically required. This involves measuring and verifying the cavity's resonant characteristics and field distribution under low-power RF conditions without a beam. Cold-state testing effectively reveals issues such as resonant frequency drift caused by manufacturing tolerances and assembly deviations, non-uniform electric field distribution within the accelerating cavity, and coupling of unwanted modes. By tuning and correcting the test results, the effects of these factors on the uniformity and stability of the accelerating field can be compensated, ensuring that the cavity's electromagnetic performance meets design requirements under actual operating conditions.

[0003] Existing RFQ cold-state testing methods often require multiple independent measurement processes and manual adjustments. Specifically, a network analyzer is typically used to measure the resonant frequency and quality factor of the cavity, while the "bead traction" method or moving probe is used to measure the axial field strength distribution. Different coupling ports or probes are used to identify resonant modes. However, each measurement usually requires separate equipment and procedures, making the operation cumbersome. Furthermore, the cavity needs to be disassembled and reassembled multiple times between different measurement items, which can easily introduce cumulative errors and affect the accuracy of the test results.

[0004] Furthermore, to obtain reliable data, the cavity needs to be precisely aligned and leveled before testing. Current technology typically uses manual leveling by adjusting shims or bolts at both ends of the cavity, a method with limited accuracy and poor repeatability. It is difficult to restore the same testing conditions after each disassembly and reassembly, making it difficult to guarantee the consistency of test results across different batches and complicating subsequent tuning and correction work.

[0005] Meanwhile, there are also issues with the compatibility of different RFQ cavities with the test platform. RFQ cavities come in various structural forms, such as four-bar or four-piece types, and vary in length. Existing test platforms often require custom-made support fixtures for each type of cavity, lacking versatility, which not only increases testing costs and time but also limits the applicability of the test platform. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator, so as to solve the problems existing in the background art.

[0007] This invention provides the following technical solution: a high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator, comprising: The leveling system is used to assemble the RFQ cavity to be tested. It includes a support platform, multiple test fixtures and multiple lifting mechanisms. The test fixtures are used to fix and position the RFQ cavity to be tested. The multiple test fixtures are slidably assembled on the support platform through linear guide rail modules and can be adjusted along the cavity axis to adapt to RFQ cavities of different lengths. The lifting mechanisms are assembled at the bottom of the support platform and are used to adjust the height of the cavity to keep the cavity axis horizontal. Two measurement platforms are respectively arranged at both ends of the leveling system. Each measurement platform includes a field probe positioning mechanism. A rope is suspended on the field probe positioning mechanism. The rope passes through the RFQ cavity to be measured and is suspended between the two measurement platforms. A micro-disturbance block is set on the rope for moving inside the cavity to collect electromagnetic field distribution information. The control system is electrically connected to the lifting mechanism of the leveling system and the field probe positioning mechanism of the measurement platform, respectively. It is used to control the lifting mechanism to automatically level the cavity, control the field probe positioning mechanism to drive the rope to move the micro-perturbation block along the cavity axis, and simultaneously control the radio frequency measurement unit to perform frequency sweep test and collect radio frequency response data during the movement of the micro-perturbation block, calculate and output the radio frequency parameters of the RFQ cavity under test.

[0008] Preferably, the measurement platform further includes a platform base, a horizontal adjustment support plate, a three-dimensional adjustment block, and a three-dimensional fine-tuning platform; the platform base, horizontal adjustment support plate, three-dimensional adjustment block, and three-dimensional fine-tuning platform are assembled and connected sequentially from bottom to top; The horizontal adjustment support plate is detachably installed on the platform base by screws and nuts, and the height of the horizontal adjustment support plate is adjusted by turning the nuts. The field probe positioning mechanism is mounted on the three-dimensional fine-tuning platform.

[0009] Preferably, the three-dimensional adjustment block includes a base plate and a first limiting block disposed around the base plate. A first threaded push rod is threadedly connected to the first limiting block. The first threaded push rod abuts against the side of the base plate and is used to adjust the left-right and front-back positions of the base plate. The three-dimensional adjustment block also includes a second limiting block disposed on two sides of the base plate. A second threaded push rod is threadedly connected to the second limiting block. The bottom of the second threaded push rod is rotatably connected to the top surface of the base plate and is used to adjust the height of the base plate.

[0010] Preferably, the three-dimensional fine-tuning platform includes a base and a first slider, a second slider, and a third slider connected in sequence, wherein the first slider is slidably mounted on the base, the second slider is slidably mounted on the first slider, and the third slider is slidably mounted on the second slider. The second slider has an L-shaped structure, with one side sliding and slidably assembled with the first slider to the left and right, and the other side sliding and slidably assembled with the third slider to the right and down. A first adjusting rod is provided on the base, one end of which is connected to a first slider to push the first slider to move back and forth on the base. A second adjusting rod is provided on the first slider, one end of which is connected to a second slider to push the second slider to move left and right on the first slider. A third adjusting rod is provided on the second slider, one end of which is connected to a third slider to push the third slider to move up and down on the second slider.

[0011] Preferably, the field probe positioning mechanism includes pulleys and tensioning pulleys; the number of pulleys is four, two of which are set on one measuring platform and the other two are set on another measuring platform, so that the rope is supported by two pulleys at each end of the RFQ cavity; The rope passes through the RFQ cavity and is suspended on pulleys at both ends, forming a closed loop structure; the tensioning pulley abuts against the rope and is used to adjust the tension of the rope.

[0012] Preferably, the field probe positioning mechanism further includes a traction wheel, which is connected to a rope and is also connected to a servo motor for driving the traction wheel to rotate, so that the rope drives the micro-disturbance block to move axially inside the RFQ cavity.

[0013] Preferably, each of the lifting mechanisms includes a servo motor, a reducer, and a lead screw lifting assembly; The lead screw lifting assembly includes a lead screw and a lead screw nut. The servo motor drives the lead screw to rotate through a reducer. The lead screw nut is connected to a support platform for supporting the end of the cavity. The servo motor has a built-in encoder for real-time feedback of the height position of the support platform. The control system controls the servo motors at both ends in a closed loop according to the height difference between the two ends of the cavity until the height difference between the two ends is within the predetermined tolerance range, so that the axis of the cavity reaches a horizontal state.

[0014] Preferably, the test fixture includes a support base and a clamping mechanism; The support base includes a T-shaped seat that is slidably fitted on the top of the support base for supporting the cylindrical outer shell or flange portion of the cavity. The clamping mechanism is used to fix the cavity onto the support base; the support base is connected to the leveling system via a linear guide rail and is used to slide along the cavity axis to adjust the spacing between the support bases.

[0015] Preferably, the support base is provided with a fine-tuning mechanism for making fine adjustments to the height and lateral position of the cavity; The fine-tuning mechanism includes fixed blocks on both sides of the support base and bolts threaded onto the fixed blocks. One end of the bolt abuts against the T-shaped seat, which is used to push the T-shaped seat to move laterally on the support base. The fine-tuning mechanism also includes an adjuster mounted on a T-shaped seat, which is connected to the clamping mechanism and is used to adjust the height of the clamping mechanism.

[0016] Preferably, the control system includes a control unit cabinet, and a measurement and control industrial computer, a network data switch, a power system, and a network analyzer installed in the control unit cabinet; The measurement and control industrial computer communicates with the network analyzer through the network data switch, and the power system is used to supply power to each electrical component; the measurement and control industrial computer controls the servo motors of the lifting mechanism and the field probe positioning mechanism through the servo drive module, and controls the network analyzer to perform frequency sweep test through the network data switch; When the perturbation block moves to each preset position, the measurement and control industrial computer triggers the network analyzer to collect the transmission characteristic data at that position, and stores the perturbation block position information in association with the radio frequency response data.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention achieves closed-loop automatic adjustment of the height at both ends of the RFQ cavity by coordinating a servo motor, reducer, and lead screw lifting assembly in a lifting mechanism, along with real-time position feedback from the encoder built into the servo motor. Simultaneously, the control system precisely controls the servo motor's movement based on the height difference between the two ends of the cavity or the tilt sensor signal until the cavity axis reaches the preset level tolerance range. Compared to the traditional manual shim or bolt leveling method, this not only significantly improves the leveling accuracy but also ensures the consistency of the cavity's posture height before each test, effectively avoiding differences in measurement conditions caused by manual leveling errors, thereby improving the repeatability and stability of the measurement results. 2. The test fixture of this invention adopts a support base structure that can slide along the axial direction. The spacing between the support bases can be flexibly adjusted through the set linear guide rail module to adapt to RFQ cavities of different lengths. In addition, the support base is equipped with a fine adjustment mechanism, which can make fine adjustments to the height and lateral position of the cavity after it is fixed to ensure that the cavity axis is precisely aligned with the field probe guide rail. At the same time, the fixture is also equipped with a positioning reference, which can quickly restore the previously calibrated position when the cavity is reinstalled after multiple disassemblies and reassemblies, realizing a high repeatability positioning function. Furthermore, this fixture structure is suitable for RFQ cavities of different structures such as four-bar or four-piece, and has good universal adaptability. It solves the problem that traditional test platforms need to customize special fixtures for each cavity, reducing test costs and cycle time. 3. This invention employs a structure with two measurement platforms positioned at opposite ends of the leveling system. A closed-loop traction system is formed by suspending the micro-perturbation block via ropes. Four pulleys, along with tension and traction wheels, ensure a stable movement path for the ropes within the RFQ cavity. A servo motor drives the traction wheels, causing the micro-perturbation block to move smoothly along the cavity axis. Simultaneously, the measurement platform itself possesses precise three-dimensional fine-tuning capabilities, enabling precise calibration of the field probe positioning mechanism to ensure the micro-perturbation block always moves along the cavity axis. Compared to traditional measurements where the micro-perturbation block sags due to gravity or deviates from the axis, this significantly improves the accuracy of field distribution measurements. 4. This invention integrates leveling control, probe movement control, and RF measurement control into a single control system. The measurement control industrial computer controls the lifting mechanism and traction servo motor through a servo drive module, and controls the vector network analyzer to perform frequency sweep testing through a network data switch. Data acquisition is triggered synchronously when the micro-perturbation block moves to each preset position. The micro-perturbation block position information is associated with and stored with the RF response data, realizing an integrated synchronous control mechanism. This allows multiple key RF parameters such as the cavity's resonant frequency, quality factor, axial field strength distribution, phase change, and resonant mode spectrum to be acquired simultaneously in a single clamping and operation. This achieves true multi-parameter coupled measurement. Compared with the traditional method that requires step-by-step measurement and multiple disassembly and assembly, this invention shortens the test time, avoids the cumulative errors introduced by step-by-step measurement and multiple disassembly and assembly, and ensures the inherent consistency and comparability of the test data. 5. This invention integrates the leveling system, measurement platform, and measurement control industrial computer, network data switch, and network analyzer in the control system to form an integrated measurement and control system with automatic leveling, automatic measurement, and synchronous data acquisition and processing capabilities. It realizes fully automated testing from the moment the cavity is installed. The operator only needs to install the RFQ cavity to be tested on the test fixture and start the system. The control system can automatically complete all steps such as cavity leveling, micro-disturbance block movement control, frequency sweep test synchronization, data acquisition and storage, parameter calculation and analysis, and test report generation without manual intervention. This not only reduces the technical threshold and labor intensity of operators, but also avoids the uncertainty caused by human operation, ensures the standardization and normalization of each test process, and achieves a dual improvement in testing efficiency and data reliability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall testing equipment of the present invention.

[0019] Figure 2 This is a schematic diagram of the RFQ cavity installation according to the present invention.

[0020] Figure 3 This is a schematic diagram of the measurement platform of the present invention.

[0021] Figure 4 This is a schematic diagram of the three-dimensional adjustment block of the present invention.

[0022] Figure 5 This is a schematic diagram of the three-dimensional fine-tuning platform of the present invention.

[0023] Figure 6 This is a schematic diagram of the lifting mechanism of the present invention.

[0024] Figure 7 This is a schematic diagram of the test fixture of the present invention.

[0025] Figure 8 This is a schematic diagram of the control system of the present invention.

[0026] Figure 9 This is a schematic diagram showing the test state of the present invention.

[0027] The attached figures are labeled as follows: 1. Leveling system; 11. Support platform; 12. Test fixture; 121. Support base; 1211. T-shaped base; 122. Clamping mechanism; 123. Fixing block; 124. Bolt; 125. Adjuster; 13. Lifting mechanism; 131. First servo motor; 132. Reducer; 133. Screw lifting assembly; 134. Support table; 2. Measurement platform; 21. Field probe positioning mechanism; 211. Rope; 212. Micro-disturbance block; 213. Pulley; 214. Tensioner wheel; 215. Traction wheel; 216. Second servo motor; 22. Platform base; 23. Horizontal adjustment support plate; 231. Screw; 232. Nut; 24. Three-dimensional adjustment stop; 241. Base plate; 242. First limit block; 243. First threaded top rod; 244. Second limit block; 245. Second threaded top rod; 25. Three-dimensional micro-adjustment platform; 251. Base; 252. First slider; 253. First adjusting rod; 254. Second slider; 255. Second adjusting rod; 256. Third slider; 257. Third adjusting rod; 3. Control system; 31. Control unit cabinet; 32. Network analyzer; 33. Measurement and control industrial computer; 34. Network data switch; 35. Power supply system; 4. RFQ cavity. Detailed Implementation

[0028] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0029] The invention provides a high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator, such as... Figure 1 As shown, the system includes a leveling system 1, a measurement platform 2, and a control system 3. The control system 3 coordinates the collaborative work of the leveling system 1 and the measurement platform 2. The leveling system 1, measurement platform 2, and control system 3 work together to form an automated testing device. Specifically, the leveling system 1 provides stable, level support; the measurement platform 2 collects field distribution data; and the control system 3 coordinates the timing of actions of each mechanism, data acquisition, and processing to ensure the automated operation of the entire testing process.

[0030] like Figure 2 As shown, the leveling system 1 is used to assemble the RFQ cavity 4, so that the RFQ cavity 4 is horizontally fixed on the ground or a certain device.

[0031] In this embodiment, the leveling system 1 includes a support platform 11, a plurality of test fixtures 12 that are slidably mounted on the support platform 11 via slide rails, and a plurality of lifting mechanisms 13 disposed at the bottom of the support platform 11.

[0032] The test fixture 12 is used to fix and precisely position the RFQ cavity 4. For example... Figure 3As shown, the test fixture 12 includes multiple support seats 121 mounted on the leveling system 1 and a lockable clamping mechanism 122. In this embodiment, test fixtures 12 are respectively provided at both ends of the RFQ cavity 4, and support points can also be added in the middle of the RFQ cavity 4 as needed to support the weight of the long RFQ cavity 4.

[0033] Furthermore, the support base 121 includes a T-shaped seat 1211 slidably mounted on the top of the support base 121, and a slider is provided at the bottom of the support base 121. The slider cooperates with the linear guide rail laid on the support platform 11, so that the test fixture 12 can slide along the RFQ cavity 4 axis to adjust the spacing.

[0034] Specifically, the support base 121 is also equipped with locking bolts. After the support base 121 slides to the target position, tightening the locking bolts can fix the support base 121 on the linear guide rail. The spacing of each test fixture 12 can be flexibly adjusted according to the actual length of the RFQ cavity 4 to adapt to RFQ cavities 4 of different lengths. The adjustment range can reach 0.5m to 5m.

[0035] Furthermore, the support base 121 is also equipped with a fine-tuning mechanism for making minor adjustments to the height and lateral position of the RFQ cavity 4. The fine-tuning mechanism includes fixing blocks 123 on both sides of the support base 121 and bolts 124 threaded onto the fixing blocks 123. One end of the bolt 124 abuts against the T-shaped seat 1211 to push the T-shaped seat 1211 to move laterally on the support base 121.

[0036] This embodiment employs a two-stage fine-tuning mechanism to precisely adjust the orientation of the RFQ cavity 4. Lateral fine-tuning is achieved by tightening bolts 124, specifically as follows: tightening the left bolt 124 pushes the T-shaped seat 1211 to the right; tightening the right bolt 124 pushes the T-shaped seat 1211 to the left. Through the cooperation of the two bolts 124, the T-shaped seat 1211 can be precisely adjusted to the desired lateral position.

[0037] The fine-tuning mechanism also includes an adjuster 125 rotatably mounted on the T-shaped seat 1211. The adjuster 125 is connected to the clamping mechanism 122 and is used to adjust the height of the clamping mechanism 122.

[0038] In this embodiment, the clamping mechanism 122 is a threaded rod that is adapted to the threaded hole at the bottom of the RFQ cavity 4 for threaded assembly of the RFQ cavity 4. The adjuster 125 includes a nut adapted to the threaded rod and a rotary bearing. The nut is rotatably mounted on the T-shaped seat 1211 via the rotary bearing and is threadedly connected to the clamping mechanism 122. By rotating the nut, the threaded rod moves up and down, thereby changing the height of the clamped part of the RFQ cavity 4. Through the coordination of lateral and height fine-tuning, the axis of the RFQ cavity 4 can be precisely aligned with the rope traction direction of the measuring platform 2.

[0039] See appendix Figure 2 and Figure 4 As shown, two lifting mechanisms 13 are installed below each end of the support platform 11. Each lifting mechanism 13 includes a first servo motor 131, a reducer 132, and a lead screw lifting assembly 133. The lead screw lifting assembly 133 includes a lead screw and a lead screw nut. The first servo motor 131 drives the lead screw to rotate through the reducer 132. The lead screw nut is connected to a support platform 134, which is used to support the end flange or support part of the RFQ cavity 4. By controlling the rotation of the first servo motor 131, the support platform 134 can be precisely raised and lowered in the vertical direction, thereby adjusting the height of that end of the RFQ cavity 4.

[0040] It can be explained here that the first servo motor 131 has a built-in high-precision encoder for real-time feedback on the height position of the support platform 134. When the height at one end changes, the control system 3 compares it with the height feedback at the other end and drives the first servo motor 131 to adjust until the height difference between the two ends is within the predetermined tolerance range, thereby making the axis of the RFQ cavity 4 horizontal.

[0041] In a preferred embodiment, a tilt sensor may also be installed on the RFQ cavity 4 to monitor the longitudinal tilt angle of the RFQ cavity 4; when the tilt angle is not zero, the control system 3 may finely adjust the height at both ends accordingly to further ensure that the RFQ cavity 4 is completely horizontal.

[0042] The lifting mechanism 13 employs a transmission scheme consisting of a first servo motor 131, a reducer 132, and a lead screw lifting assembly 133 to improve load-bearing capacity, positioning accuracy, and response speed. The encoder built into the first servo motor 131 provides real-time feedback on the actual height of the support platform 134. The control system 3 calculates the height difference between the two ends of the RFQ cavity 4 by comparing the feedback values ​​from the encoders at both ends. When the height difference exceeds a preset threshold, the control system 3 calculates the required adjustment amount for each end according to a PID control algorithm and outputs pulse signals to drive the first servo motor 131 until the height difference between the two ends is less than the threshold.

[0043] If a tilt sensor is configured, the control system 3 simultaneously reads the tilt angle data from the tilt sensor and fuses it with the height difference data to further improve the leveling accuracy. After leveling is completed, the control system 3 keeps the current position of the first servo motor 131 locked to prevent changes in attitude due to external forces or vibrations.

[0044] like Figure 1 , Figure 9As shown, there are two measurement platforms 2, which are respectively arranged at both ends of the leveling system 1. Both measurement platforms 2 are equipped with field probe positioning mechanisms 21. A rope 211 is suspended between the two field probe positioning mechanisms 21. A micro-disturbance block 212 is suspended on the rope 211. The micro-disturbance block 212 is tested by the rope 21 through the RFQ cavity 4.

[0045] In this embodiment, as Figure 5 , Figure 6 As shown, both measurement platforms 2 also include a platform base 22, a horizontal adjustment support plate 23, a three-dimensional adjustment block 24, and a three-dimensional fine-tuning platform 25.

[0046] The platform base 22, the horizontal adjustment support plate 23, the three-dimensional adjustment block 24, and the three-dimensional fine-tuning platform 25 are assembled and connected in sequence from bottom to top. The horizontal adjustment support plate 23 is detachably installed on the platform base 22 by means of screws 231 and nuts 232. The screws 231 stand at the four corners of the platform base 22, and the nuts 232 are used to support the horizontal adjustment support plate 23. The height of the horizontal adjustment support plate 23 can be adjusted by turning the nuts 232.

[0047] By tightening the nuts 232 at the four corners, the height of each of the four corners of the horizontal adjustment support plate 23 can be adjusted independently, thereby achieving a coarse adjustment of the overall levelness of the horizontal adjustment support plate 23. This can compensate for unevenness of the ground or platform base 22 itself.

[0048] The top of the three-dimensional adjustment block 24 is detachably equipped with a three-dimensional fine-tuning platform 25. The field probe positioning mechanism 21 is mounted on the three-dimensional fine-tuning platform 25. The three-dimensional adjustment block 24 and the horizontal adjustment support plate 23 can be used to adjust the three-dimensional fine-tuning platform 25 so that the micro-disturbance block 212 on the field probe positioning mechanism 21 reaches the target position.

[0049] Furthermore, the three-dimensional adjustment block 24 includes a base plate 241 and first limiting blocks 242 disposed around the base plate 241. Each first limiting block 242 is threadedly connected to a first threaded push rod 243, which abuts against the side of the base plate 241 to adjust the left-right and front-back positions of the base plate 241, thereby adjusting the left-right and front-back positions of the three-dimensional fine-tuning platform 25, and thus adjusting the position of the rope 211 and the micro-disturbance block 212 on the rope 211. The three-dimensional adjustment block 24 also includes second limiting blocks 244 disposed on two sides of the base plate 241. Each second limiting block 244 is threadedly connected to a second threaded push rod 245, the bottom of which is rotatably connected to the top surface of the base plate 241 to adjust the height of the base plate 241, thereby adjusting the height of the three-dimensional fine-tuning platform 25, and thus adjusting the height of the rope 211 and the micro-disturbance block 212 on the rope 211.

[0050] The three-dimensional adjustment stop 24 uses a graded adjustment method to achieve coarse adjustment of the three-dimensional fine-tuning platform 25. There are eight first threaded push rods 243, two on each side, which abut against the sides of the base plate 241 from the front, back, left, and right directions. When the first threaded push rod 243 is rotated in a certain direction, it pushes the base plate 241 to move in the opposite direction, thereby adjusting the position of the base plate 241 in the X and Y directions in the horizontal plane. There are two second threaded push rods 245, which are rotatably connected to the top surface of the base plate 241 from above via a second limiting block 244. By synchronously rotating the two second threaded push rods 245, the height of the base plate 241 can be raised or lowered, achieving coarse adjustment in the Z direction. This allows the three-dimensional fine-tuning platform 25 to be quickly adjusted to near the target position.

[0051] Furthermore, such as Figure 7 As shown, the three-dimensional fine-tuning platform 25 includes a base 251 and a first slider 252, a second slider 254 and a third slider 256 connected in sequence. The first slider 252 is slidably mounted back and forth on the base 251, the second slider 254 is slidably mounted left and right on the first slider 252, and the third slider 256 is slidably mounted up and down on the second slider 254.

[0052] It is worth noting that the second slider 254 has an L-shaped structure, with one side slidingly assembled with the first slider 252 from left to right, and the other side slidingly assembled with the third slider 256 from top to bottom.

[0053] A first adjusting rod 253 is provided on the base 251. One end of the first adjusting rod 253 is connected to a first slider 252 to push the first slider 252 to move back and forth on the base 251. A second adjusting rod 255 is provided on the first slider 252. One end of the second adjusting rod 255 is connected to a second slider 254 to push the second slider 254 to move left and right on the first slider 252. A third adjusting rod 257 is provided on the second slider 254. One end of the third adjusting rod 257 is connected to a third slider 256 to push the third slider 256 to move up and down on one side of the second slider 254.

[0054] The three-dimensional fine-tuning platform 25 adopts a three-stage slider stacked structure, combined with precision adjustment rods, to achieve micron-level precision positioning. The first adjustment rod 253, second adjustment rod 255, and third adjustment rod 257 preferably use micrometer heads or precision lead screws with a pitch of 0.25mm-0.5mm, which, in conjunction with the dial, can achieve adjustment accuracy of 0.01mm or even 0.001mm. During operation, coarse adjustment is first performed using the three-dimensional adjustment stop 24 to bring the micro-disturbance block 212 near the target position. Then, fine-tuning is performed using the three adjustment rods of the three-dimensional fine-tuning platform 25 to ensure that the micro-disturbance block 212 is precisely located on the axis of the RFQ cavity 4. The L-shaped structure of the second slider 254 ensures that the movements in the three directions are independent and do not interfere with each other, guaranteeing the stability and accuracy of the adjustment.

[0055] In this embodiment, the field probe positioning mechanism 21 further includes pulleys 213 and tensioning pulleys 214. There are four pulleys 213, with two at each end of the RFQ cavity 4. The rope 211 passes through the RFQ cavity 4 and is suspended from the pulleys 213 at both ends, forming a quadrilateral structure. Below one of the pulleys 213, there is a tensioning pulley 214 for tensioning the rope 211 and a traction pulley 215. The tensioning pulley 214 abuts against the rope 211 to adjust the tension of the rope 211. The traction pulley 215 is sleeved with the rope 211 and is also connected to a second servo motor 216 to drive the traction pulley 215 to rotate, so that the rope 211 drives the micro-disturbance block 212 to move inside the RFQ cavity 4, thereby testing and obtaining the electromagnetic field distribution information inside the RFQ cavity 4.

[0056] It can be explained here that pulley 213 and tensioning wheel 214 are mounted on three-dimensional adjustment block 24, and second servo motor 216 and traction wheel are mounted on three-dimensional fine-tuning platform 25 to adjust the position of rope 211 and micro-disturbance block 212 on rope 211.

[0057] Rope 211 is made of high-strength materials with low creep and low coefficient of thermal expansion, such as aramid fiber or metallized polyester fiber, to ensure length stability under long-term use and tension. Four pulleys 213 are located above and below both ends of the RFQ cavity 4, forming an approximately rectangular closed-loop path for rope 211. Tensioning pulley 214 applies constant tension through an elastic element (such as a spring or gas spring) to ensure that rope 211 is always taut, eliminating slack and vibration. Traction pulley 215 is directly connected to the second servo motor 216, which has a built-in high-precision encoder to precisely control the rotation angle and speed of traction pulley 215. When the second servo motor 216 drives the traction pulley to rotate forward or backward, rope 211 is driven by friction, thereby dragging micro-disturbance block 212 to move smoothly axially inside the RFQ cavity 4. By controlling the speed and running time of the second servo motor 216, the moving speed and position of the micro-disturbance block 212 can be precisely controlled. The moving speed can be steplessly adjusted within the range of 0.1mm / s to 100mm / s, and the positioning accuracy can reach ±0.1mm.

[0058] The perturbation block 212 can be made of different materials and shapes depending on the measurement requirements. For electric field distribution measurement, a small-diameter dielectric sphere or metal sphere is typically used; for magnetic field distribution measurement, a small ring or magnetic core is used. The size selection of the perturbation block 212 must meet the perturbation condition, that is, its volume is small enough not to significantly affect the electromagnetic field distribution within the RFQ cavity 4, while simultaneously generating a sufficiently large frequency offset for measurement. In this embodiment, the perturbation block 212 is preferably a polytetrafluoroethylene sphere with a diameter of 3mm-8mm, suspended from the rope 211 by a thin thread. The suspension point is located at the geometric center of the perturbation block 212 to ensure balance during movement.

[0059] like Figure 8 As shown, the control system includes a control unit cabinet 31, and a network analyzer 32, a measurement and control industrial computer 33, a network data switch 34, and a power system 35, all housed within the control unit cabinet 31.

[0060] The control system 3 of the test platform is centrally installed in the control unit cabinet 31, which is used to coordinate the work of the leveling system 1, the field probe positioning mechanism 21 and the radio frequency measurement unit.

[0061] The measurement and control industrial computer 33 is implemented using an industrial control computer or a programmable logic controller (PLC) with built-in corresponding software algorithms. It controls the servo motors of the lifting mechanism 13 and the field probe positioning mechanism 21 via a servo drive module, and communicates with the network analyzer 32 via the network data switch 34, enabling command control and data exchange with the network analyzer 32. The power supply system 35 provides a stable and clean power supply to all electrical components.

[0062] Network analyzer 32 is a vector network analyzer used to perform radio frequency sweep tests. Its output is connected to the feed port or coupled antenna of RFQ cavity 4 via a directional coupler, and its input receives signals from a probe or another coupled port. Under the control of measurement and control computer 33, network analyzer 32 scans the excitation frequency within a predetermined frequency range and records the parameter response data of RFQ cavity 4.

[0063] The network data switch 34 is a high-speed Ethernet switch that enables real-time data exchange between the measurement and control industrial computer 33 and the network analyzer 32.

[0064] The power supply system 35 includes a voltage regulator, a filter, and multiple DC / DC modules, which provide the required voltage to the industrial control computer 33, the network analyzer 32, the servo driver, etc., and have overload and short circuit protection functions.

[0065] like Figure 9 As shown, the collaborative process of each unit during the testing process is as follows: Leveling: The measurement and control industrial computer 33 controls the first servo motor 131 through the servo drive module and reads the encoder signal of the first servo motor 131 in real time through the position feedback module, thereby obtaining the current height position of both ends of the RFQ cavity 4. The measurement and control industrial computer 33 executes the cavity leveling program: when a height deviation is detected at both ends of the RFQ cavity 4, the adjustment amount is calculated according to the pre-set control strategy (such as PID algorithm), and control signals are output to drive the first servo motors 131 at both ends to rotate until the cavity tilt angle is close to zero or the height difference between the two ends is less than the threshold. After leveling is completed, the measurement and control industrial computer 33 locks the current position of the first servo motor 131 to ensure that the attitude of the RFQ cavity 4 remains stable during the measurement process.

[0066] Multi-parameter measurement: After automatic cavity alignment, the measurement control industrial computer 33 performs multi-parameter measurements according to the predetermined test procedure. First, the measurement control industrial computer 33 sends a command to the network analyzer 32 through the network data switch 34, instructing it to scan the excitation frequency within a predetermined frequency range. The network analyzer 32 performs a frequency sweep test. When scanning past the resonant frequency of the RFQ cavity 4, it measures a clear resonant peak and the corresponding phase change curve, and transmits the acquired scattering parameter data to the measurement control industrial computer 33 in real time through the network data switch 34 for storage and backup.

[0067] Simultaneously, the measurement and control industrial computer 33, in a manner synchronized with or sequential with the frequency scan, controls the field probe positioning mechanism 21 to drive the micro-scratching block 212 to move axially along the RFQ cavity 4 via the servo drive module. At each predetermined position point, after confirming that the micro-scratching block 212 has reached the preset position based on encoder feedback, the measurement and control industrial computer 33 keeps it stable and immediately triggers the network analyzer 32 to collect transmission characteristic data at that position via the network data switch 34. The network analyzer 32 returns the collected data to the measurement and control industrial computer 33, which associates and stores the position information of the micro-scratching block 212 with the RF response data. This cycle of micro-scratching block movement and data acquisition continues until all measurement points along the entire length of the RFQ cavity 4 are covered. Through the above multi-point scanning process, the electric field intensity distribution and relative phase distribution data along the axial direction of the RFQ cavity 4 are obtained.

[0068] Data Analysis and Report Generation: Based on the frequency sweep and field distribution measurement results, the measurement and control industrial computer 33 calculates and analyzes the key RF parameters of the RFQ cavity 4. The frequency response data provided by the network analyzer 32 is used to determine parameters such as the resonant frequency and quality factor of the RFQ cavity 4; combined with the data measured by the micro-perturbation block 212 at various locations, the distribution curve of the field strength along the axial direction inside the RFQ cavity 4 is plotted, and the axial electric field distribution non-uniformity index is calculated. The phase measurement of the micro-perturbation block 212 at different locations reflects the change of the electromagnetic field phase along the cavity axis, and the measurement and control industrial computer 33 uses this to determine whether there is an abnormal field phase gradient in the RFQ cavity 4. By analyzing each resonant peak in the frequency response curve, the measurement and control industrial computer 33 can also identify different modes of the RFQ cavity 4: based on the design parameters, the frequency position and field distribution characteristics of the target accelerating mode can be expected, the measured main resonant peak is matched with it, and the resonant peaks of other frequencies are determined to be non-target modes. If the target mode frequency deviates from the design value or the field distribution does not meet the uniformity requirements, it indicates that the RFQ cavity 4 may have manufacturing deviations or improper tuning, requiring readjustment. After the test, the measurement and control industrial computer 33 automatically generates a test report containing the cavity resonant frequency, field strength distribution curve, phase distribution, and modal analysis results.

[0069] In the specific implementation process, the steps for performing a cold test on the RFQ cavity 4 using the test platform of the present invention are as follows: S1: Place the RFQ cavity 4 to be tested into the test fixture 12 on the leveling system 1, adjust the spacing of the support base 121 according to the length of the RFQ cavity 4 and fix it.

[0070] S2: Adjust the RFQ cavity 4 using the fine-tuning mechanism on the test fixture 12 to make it roughly horizontal and aligned with the probe guide rail. Then start the measurement control industrial computer 33. The system first automatically drives the lifting mechanism 13 to make precise adjustments to both ends of the RFQ cavity 4 until the RFQ cavity 4 is completely horizontal and its posture is stable.

[0071] S3: The measurement and control industrial computer 33 controls the vector network analyzer 32 to perform radio frequency sweep test on the RFQ cavity 4, and at the same time drives the field probe positioning mechanism 21 to move the micro-disturbance block 212 to multiple measurement positions and collect data according to the preset program.

[0072] The entire testing process was completed automatically without human intervention. After the test, the measurement and control industrial computer 33 generated a test report containing the resonant frequency, field strength distribution curve, phase distribution, and modal analysis results of the RFQ cavity 4. Compared with traditional manual adjustment and step-by-step measurement, the test platform of this invention significantly shortens the testing time and improves the consistency and reliability of the test results. This platform allows for more convenient debugging and optimization of the RFQ cold model, ensuring that the final delivered RFQ accelerator RFQ cavity 4 meets the design specifications and performance requirements.

[0073] Several points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection" and "linkage" should be interpreted broadly, and can be mechanical or electrical connection, or internal connection between two components, or direct connection. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationship. When the absolute position of the described object changes, the relative positional relationship may change.

[0074] The above description is only a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. Any equivalent modifications or changes made by those skilled in the art based on the content disclosed in the present invention should be included within the scope of protection set forth in the claims.

Claims

1. A high-precision cold-state testing device for multiple parameters of a radio frequency quadrupole accelerator, characterized in that, include: The leveling system is used to assemble the RFQ cavity to be tested. It includes a support platform, multiple test fixtures and multiple lifting mechanisms. The test fixtures are used to fix and position the RFQ cavity to be tested. The multiple test fixtures are slidably assembled on the support platform through linear guide rail modules and can be adjusted along the cavity axis to adapt to RFQ cavities of different lengths. The lifting mechanisms are assembled at the bottom of the support platform and are used to adjust the height of the cavity to keep the cavity axis horizontal. Two measurement platforms are respectively arranged at both ends of the leveling system. Each measurement platform includes a field probe positioning mechanism. A rope is suspended on the field probe positioning mechanism. The rope passes through the RFQ cavity to be measured and is suspended between the two measurement platforms. A micro-disturbance block is set on the rope for moving inside the cavity to collect electromagnetic field distribution information. The control system is electrically connected to the lifting mechanism of the leveling system and the field probe positioning mechanism of the measurement platform, respectively. It is used to control the lifting mechanism to automatically level the cavity, control the field probe positioning mechanism to drive the rope to move the micro-perturbation block along the cavity axis, and simultaneously control the radio frequency measurement unit to perform frequency sweep test and collect radio frequency response data during the movement of the micro-perturbation block, calculate and output the radio frequency parameters of the RFQ cavity under test. The measurement platform also includes a platform base, a horizontal adjustment support plate, a three-dimensional adjustment block, and a three-dimensional fine-tuning platform; the platform base, horizontal adjustment support plate, three-dimensional adjustment block, and three-dimensional fine-tuning platform are assembled and connected sequentially from bottom to top; The horizontal adjustment support plate is detachably installed on the platform base by screws and nuts, and the height of the horizontal adjustment support plate is adjusted by turning the nuts. The field probe positioning mechanism is mounted on the three-dimensional fine-tuning platform.

2. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: The three-dimensional adjustment block includes a base plate and a first limiting block disposed around the base plate. A first threaded push rod is threadedly connected to the first limiting block. The first threaded push rod abuts against the side of the base plate and is used to adjust the left-right and front-back positions of the base plate. The three-dimensional adjustment block also includes a second limiting block disposed on two sides of the base plate. A second threaded push rod is threadedly connected to the second limiting block. The bottom of the second threaded push rod is rotatably connected to the top surface of the base plate and is used to adjust the height of the base plate.

3. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: The three-dimensional fine-tuning platform includes a base and a first slider, a second slider, and a third slider connected in sequence. The first slider is slidably assembled on the base, the second slider is slidably assembled on the first slider, and the third slider is slidably assembled on the second slider. The second slider has an L-shaped structure, with one side sliding and slidably assembled with the first slider to the left and right, and the other side sliding and slidably assembled with the third slider to the right and down. A first adjusting rod is provided on the base, one end of which is connected to a first slider to push the first slider to move back and forth on the base. A second adjusting rod is provided on the first slider, one end of which is connected to a second slider to push the second slider to move left and right on the first slider. A third adjusting rod is provided on the second slider, one end of which is connected to a third slider to push the third slider to move up and down on the second slider.

4. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: The field probe positioning mechanism includes pulleys and tensioning pulleys; there are four pulleys, two of which are set on one measuring platform and the other two are set on another measuring platform, so that the rope is supported by two pulleys at each end of the RFQ cavity; The rope passes through the RFQ cavity and is suspended on pulleys at both ends, forming a closed loop structure; the tensioning pulley abuts against the rope and is used to adjust the tension of the rope.

5. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 4, characterized in that: The field probe positioning mechanism also includes a traction wheel, which is connected to a rope and is also connected to a servo motor to drive the traction wheel to rotate, so that the rope drives the micro-disturbance block to move axially inside the RFQ cavity.

6. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: Each of the aforementioned lifting mechanisms includes a servo motor, a reducer, and a lead screw lifting assembly; The lead screw lifting assembly includes a lead screw and a lead screw nut. The servo motor drives the lead screw to rotate through a reducer. The lead screw nut is connected to a support platform for supporting the end of the cavity. The servo motor has a built-in encoder for real-time feedback of the height position of the support platform. The control system controls the servo motors at both ends in a closed loop according to the height difference between the two ends of the cavity until the height difference between the two ends is within the predetermined tolerance range, so that the axis of the cavity reaches a horizontal state.

7. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: The test fixture includes a support base and a clamping mechanism; The support base includes a T-shaped seat that is slidably fitted on the top of the support base for supporting the cylindrical outer shell or flange portion of the cavity. The clamping mechanism is used to fix the cavity onto the support base; the support base is connected to the leveling system via a linear guide rail and is used to slide along the cavity axis to adjust the spacing between the support bases.

8. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 7, characterized in that: The support base is equipped with a fine-tuning mechanism for making minor adjustments to the height and lateral position of the cavity; The fine-tuning mechanism includes fixed blocks on both sides of the support base and bolts threaded onto the fixed blocks. One end of the bolt abuts against the T-shaped seat, which is used to push the T-shaped seat to move laterally on the support base. The fine-tuning mechanism also includes an adjuster mounted on a T-shaped seat, which is connected to the clamping mechanism and is used to adjust the height of the clamping mechanism.

9. The high-precision cold-state testing equipment for multiple parameters of a radio frequency quadrupole accelerator according to claim 1, characterized in that: The control system includes a control unit cabinet, and a measurement and control industrial computer, a network data switch, a power system, and a network analyzer installed in the control unit cabinet; The measurement and control industrial computer communicates with the network analyzer through the network data switch, and the power system is used to supply power to each electrical component; the measurement and control industrial computer controls the servo motors of the lifting mechanism and the field probe positioning mechanism through the servo drive module, and controls the network analyzer to perform frequency sweep test through the network data switch; When the perturbation block moves to each preset position, the measurement and control industrial computer triggers the network analyzer to collect the transmission characteristic data at that position, and stores the perturbation block position information in association with the radio frequency response data.

Images