Ion beam processing apparatus and method with adjustable beam energy

Abstract

The application discloses a kind of beam energy adjustable ion beam processing device, including base, support, negative electrode plate, positive electrode plate, diaphragm and electric energy control module, the middle part of base is equipped with circular through-hole, one end of negative electrode plate and positive electrode plate is fixed on base, and negative electrode plate and positive electrode plate are enclosed into cylindrical ion beam passage, diaphragm is fixed on base by support, diaphragm is equipped with conical passage, the big end of conical passage is aligned with the one end of cylindrical ion beam passage away from circular through-hole, and small end faces outward, the positive and negative poles of electric energy control module are connected with negative electrode plate and positive electrode plate respectively by wire.It also discloses a kind of beam energy adjustable ion beam processing method.This beam energy adjustable ion beam processing device and method have the advantages of reducing machine tool acceleration and deceleration adjustment frequency, meeting large-span removal amount adjustment requirements, improving processing efficiency and precision, and reducing the demand for machine tool dynamic performance.

Description

Technical Field

[0001] This invention relates to the field of optical element processing equipment technology, and specifically to an ion beam processing apparatus and method with adjustable beam energy. Background Technology

[0002] In the field of high-end optics, the surface accuracy of optical components directly determines the performance of optical imaging systems, laser weapon devices, and extreme ultraviolet lithography systems. To meet the manufacturing requirements of such optical components at the nanometer or even picometer level, ion beam polishing equipment is often used in the final stage of ultra-precision manufacturing to correct surface errors of the optical components. Ultra-precision ion beam polishing technology achieves atomic-scale material removal through ion sputtering: when a high-energy ion beam bombards the surface of the optical component, surface atoms are sputtered after reaching the sputtering threshold, macroscopically manifesting as a material removal profile with a Gaussian shape. This non-contact manufacturing process has many advantages, such as picometer-level material removal resolution, linear relationship of material removal rate over time, and stability without damage, and has become a recognized ultra-high precision processing method in the modern optical manufacturing field.

[0003] To correct millimeter-level dimensional errors on the surface of optical components, theoretically, the diameter of the generated ion beam should be smaller than the spatial wavelength of that error, and the smaller the beam diameter, the stronger the correction capability for spatial errors in that frequency band. Since the removal function generated by a small-sized ion beam has a large aspect ratio, this places higher demands on the dynamic performance of the machine tool.

[0004] Currently, a method to reduce the dynamic performance requirements of machine tools during ion beam shaping is to add a hypothetical additional removal material layer to the workpiece surface during the dwell time calculation stage. This method optimizes the dynamic performance of the machine tool by increasing the total material removal of the workpiece, but it inevitably increases the time of the ion beam polishing process. Especially for small ion beam diameters, the removal function has extremely high peak efficiency but weak volumetric removal rate. Existing machine tools struggle to meet the frequent acceleration and deceleration requirements and the need for large-scale removal adjustment during ion beam shaping. Adding even a few nanometers of additional removal layer will multiply the ion beam shaping time. Furthermore, with the increase in the overall processing time, the entire shaping process becomes highly uncertain. Long-term ion beam shaping places more stringent demands on the stability of the ion source, and excessive addition of an additional removal layer increases the possibility of surface deterioration. Furthermore, in existing ion beam polishing equipment, the energy of the ion beam remains constant throughout the entire ion beam shaping process, and the contour of material removed per unit time remains constant. The processing energy of the ion beam cannot be dynamically adjusted during the processing, and the final processing effect depends on the surface shape error distribution of the actual optical element, making it difficult to meet the requirements of ion beam for effective correction of surface shape errors of ultra-high precision optical elements.

[0005] Chinese patent document with application number 201910340903.7 discloses an ion beam energy control device, which includes: an inlet end and an outlet end, the inlet end for ion beam injection and the outlet end for ion beam emission; a plurality of electrode pairs, each electrode pair including a first electrode and a second electrode arranged opposite to each other, both the first electrode and the second electrode being rod-shaped, and the space between the first electrode and the second electrode for the ion beam to pass through; at least one of the electrode pairs forms a first electrode group, and a voltage applied to the first electrode group causes the ion beam to deflect in a first direction; at least one of the electrode pairs forms a second electrode group, and a voltage applied to the second electrode group causes the ion beam to deflect in a second direction, the second direction being opposite to the first direction. This ion beam energy control device has many advantages in terms of electrode shape, electrode layout, and beam current adjustment. However, the purpose of this ion beam energy control device in changing the direction of the ion beam is to reduce energy pollution and avoid the loss of ion beam energy. In other words, it cannot adjust the ion beam energy, cannot control the removal effect by controlling the ion beam energy, and is difficult to integrate with machine tools to reduce the acceleration and deceleration adjustment frequency of the machine tool, meet the adjustment requirements of large-span removal volume, improve processing efficiency and quality, and reduce the dynamic performance requirements of the machine tool. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an ion beam processing device and method with adjustable beam energy that reduces the acceleration and deceleration adjustment frequency of the machine tool, meets the requirements of large-span removal amount adjustment, improves processing efficiency and quality, and reduces the dynamic performance requirements of the machine tool.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] An ion beam processing apparatus with adjustable beam energy includes a base, a support, a negative electrode plate, a positive electrode plate, an aperture, and a power control module. The base has a circular through-hole in its center. One end of each of the negative and positive electrode plates is fixed to the base, forming a cylindrical ion beam channel. The aperture is fixed to the base by the support and contains a conical channel. The conical channel is coaxial with the cylindrical ion beam channel, and the larger end of the conical channel is aligned with the end of the cylindrical ion beam channel furthest from the circular through-hole. The small end faces outward and is used to emit an ion beam to process the surface of the optical element to be processed. The positive and negative terminals of the power control module are connected to the negative electrode plate and the positive electrode plate respectively through wires. It is used to control the on and off frequency of the negative electrode plate and the positive electrode plate. The negative electrode plate and the positive electrode plate are used to generate a potential difference in the cylindrical ion beam channel when energized, so as to deflect the passing ion beam. The negative electrode plate is used to absorb the deflected ions. The conical channel is used to intercept the ion beam passing through the cylindrical ion beam channel to obtain the ion beam diameter that meets the actual processing requirements.

[0009] As a further improvement to the above technical solution:

[0010] The power control module includes a DC power supply box, an electronic switch, and a control unit. The positive electrode plate is connected to the positive terminal of the DC power supply box via the electronic switch, the negative electrode plate is connected to the negative terminal of the DC power supply box, and the control unit is connected to the electronic switch.

[0011] Both the negative electrode plate and the positive electrode plate are housed within a bracket, and the bracket has wire passage windows on both sides.

[0012] Insulating pads are provided between the negative electrode plate and the positive electrode plate and the base.

[0013] The insulating pad is a ceramic pad.

[0014] The cone angle of the conical channel is 60° to 80°, and the diameter of the cylindrical ion beam channel is larger than that of the circular through-hole.

[0015] The base, bracket, negative electrode plate, positive electrode plate, and aperture are all made of graphite material.

[0016] An ion beam processing method with adjustable beam energy is disclosed, using the aforementioned ion beam processing apparatus. The circular through-hole is connected to an ion source, the small end of the tapered channel is aligned with the surface to be processed of an optical element on a machine tool, and the power control module is connected to the machine tool. The ion beam processing method with adjustable beam energy includes the following steps:

[0017] S1. Detect the error morphology distribution of the surface to be processed of the optical element;

[0018] S2. Based on the error morphology distribution of the surface to be processed of the optical element, obtain the processing path of the ion beam processing device relative to the optical element and the amount to be removed at each processing point on the processing path.

[0019] S3. Based on the amount to be removed at each processing point along the processing path, obtain the speed at which the ion beam processing device passes through each processing point along the processing path and the on / off frequency of the negative electrode plate and the positive electrode plate.

[0020] S4. The ion source emits an ion beam into the cylindrical ion beam channel at a constant power, and the ion beam processing device processes each processing point sequentially along the processing path relative to the optical element. The power control module obtains the position of the ion beam processing device relative to the optical element in real time, and makes the ion beam processing device pass through each processing point according to the speed and power-on / off frequency corresponding to each processing point obtained in S3.

[0021] As a further improvement to the above technical solution:

[0022] In S3, the speed at which the ion beam processing device passes through each processing point along the processing path is divided into three tiers from smallest to largest: the first tier, the second tier, and the third tier. When the speed of the ion beam processing device at the processing point is in the first tier, the switching frequency of the corresponding negative and positive electrode plates is 0, meaning the ion beam processing device emits all the ion beams emitted by the ion source. When the speed of the ion beam processing device at the processing point is in the second tier, the switching frequency of the corresponding negative and positive electrode plates is 0.5, meaning the ion beam processing device emits half of the ion beams emitted by the ion source. When the speed of the ion beam processing device at the processing point is in the third tier, the switching frequency of the corresponding negative and positive electrode plates is 0.33, meaning the ion beam processing device emits one-third of the ion beams emitted by the ion source.

[0023] In S3, a dwell speed threshold V is set. When the passing speed of the ion beam processing device corresponding to the processing point is equal to or less than V, the switching frequency of the corresponding negative electrode plate and positive electrode plate is 0. Even if the ion beam processing device passes through all the ion beams emitted by the ion source, when the passing speed of the ion beam processing device corresponding to the processing point is greater than V, the passing speed of the ion beam processing device corresponding to the processing point is adjusted to V. The switching frequency of the corresponding negative electrode plate and positive electrode plate is determined according to V.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] The ion beam processing apparatus and method of the present invention, which allows for adjustable beam energy, utilizes an electrical control module to energize the negative and positive electrode plates when the ion beam passes through a cylindrical ion beam channel. This generates an electric field within the cylindrical ion beam channel, deflecting the passing ion beam. The deflected ions are absorbed by the negative electrode plate. When the negative and positive electrode plates are not energized, no electric field is generated within the cylindrical ion beam channel, and the passing ion beam remains undeflected, exiting entirely through the small port of the conical channel. In other words, undeflected ions are intercepted by the conical channel after passing through the cylindrical ion beam channel, obtaining an ion beam diameter that meets the actual processing requirements. Thus, by controlling the on / off frequency of the negative and positive electrode plates, the ion beam energy (or ion beam intensity) passing through the cylindrical ion beam channel per unit time can be adjusted, thereby regulating the ion beam energy emitted from the small port of the conical channel to the surface of the optical element to be processed. In other words, by controlling the on / off frequency of the deflection electric field within a fixed time period, the energy of the ion beam can be regulated. Compared to existing processing methods that use constant ion beam energy to irradiate the workpiece surface, firstly, given the different amounts to be removed at each processing point, high ion beam energy can be used at processing points with large amounts to be removed, while low ion beam energy can be used at processing points with small amounts to be removed, thus reducing the frequency of machine tool acceleration and deceleration adjustments. It's even possible to maintain a uniform speed for the machine tool in some or all sections of the processing path (i.e., ensuring the ion beam processing device travels at the same speed through some or all processing points). Secondly, for adjacent processing points with large differences in the amount to be removed (i.e., a large difference in the amount to be removed between adjacent processing points), the machine tool speed can be adjusted to a small extent (i.e., the speed of the ion beam processing device passing through the processing point can be adjusted to a large extent), while the ion beam energy can be adjusted to a large extent, or only the ion beam energy can be adjusted without adjusting the machine tool speed, thereby enabling the machine tool to meet the adjustment requirements for large-span removal during ion beam shaping. Thirdly, by using a combination of ion beam energy adjustment and machine tool speed adjustment, the dynamic performance requirements of the machine tool are reduced, improving processing efficiency and quality. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the main cross-section of the ion beam processing apparatus with adjustable beam energy according to the present invention.

[0027] Figure 2 This is a three-dimensional structural schematic diagram of the ion beam processing device with adjustable beam energy according to the present invention.

[0028] Figure 3 This is a schematic diagram of the processing path on the optical element of the ion beam processing device with adjustable beam energy of the present invention.

[0029] Figure 4 This is a simulation diagram of the ion beam passing through the ion beam processing device with adjustable beam energy of the present invention without deflection.

[0030] Figure 5 This is a simulation diagram of the ion beam deflection in the ion beam processing apparatus with adjustable beam energy of the present invention.

[0031] The labels in the diagram represent:

[0032] 1. Base; 11. Circular through hole; 12. Insulating pad; 2. Bracket; 21. Wire passage window; 3. Negative electrode plate; 4. Positive electrode plate; 5. Aperture; 6. Power control module; 61. DC power supply box; 62. Electronic switch; 63. Control unit; 7. Cylindrical ion beam channel; 8. Conical channel; 9. Optical element; 91. Processing path; 92. Processing point. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Example 1:

[0038] Figures 1 to 5This invention illustrates an embodiment of an ion beam processing apparatus with adjustable beam energy. The apparatus includes a base 1, a support 2, a negative electrode plate 3, a positive electrode plate 4, an aperture 5, and a power control module 6. The base 1 has a circular through-hole 11 in its center. One end of both the negative electrode plate 3 and the positive electrode plate 4 are fixed to the base 1, forming a cylindrical ion beam channel 7 between them. The aperture 5 is fixed to the base 1 via the support 2. A conical channel 8 is provided within the aperture 5, coaxial with the cylindrical ion beam channel 7, and the larger end of the conical channel 8 is aligned with the cylindrical ion beam channel 7. The end of the ion beam channel 7 furthest from the circular through-hole 11 is aligned with the smaller end facing outwards to emit an ion beam to process the surface to be processed of the optical element 9. The positive and negative electrodes of the power control module 6 are connected to the negative electrode plate 3 and the positive electrode plate 4 respectively through wires to control the on and off frequency of the negative electrode plate 3 and the positive electrode plate 4. The negative electrode plate 3 and the positive electrode plate 4 generate electrical energy in the cylindrical ion beam channel 7 when energized, causing the passing ion beam to deflect. The negative electrode plate 3 absorbs the deflected ions. The conical channel 8 is used to intercept the ion beam passing through the cylindrical ion beam channel 7 to obtain the ion beam diameter that meets the actual processing requirements.

[0039] When using this adjustable beam energy ion beam processing device, the circular through-hole 11 is connected to the ion source, the small end of the tapered channel 8 is aligned with the surface to be processed of the optical element 9 on the machine tool, and the power control module 6 is connected to the machine tool. The specific process is as follows:

[0040] The first step is to detect the error morphology distribution of the surface to be processed of the optical element 9;

[0041] The second step is to obtain the processing path 91 of the ion beam processing device relative to the optical element 9 based on the error morphology distribution of the surface to be processed of the optical element 9 (e.g., ...). Figure 3 (as shown) and the amount to be removed at each processing point 92 on the processing path 91;

[0042] The third step is to obtain the speed at which the ion beam processing device passes through each processing point 92 along the processing path 91 and the on / off frequency of the negative electrode plate 3 and the positive electrode plate 4, based on the amount to be removed at each processing point 92 on the processing path 91.

[0043] Fourth, the ion source emits an ion beam into the cylindrical ion beam channel 7 at a constant power, and the ion beam processing device processes each processing point 92 sequentially along the processing path 91 relative to the optical element 9. The power control module 6 obtains the position of the ion beam processing device relative to the optical element 9 in real time, and makes the ion beam processing device pass through each processing point 92 according to the speed and power-on / off frequency corresponding to each processing point 92 obtained in S3.

[0044] As the ion beam passes through the cylindrical ion beam channel 7, the power control module 6 energizes the negative electrode plate 3 and the positive electrode plate 4, thereby generating an electric field in the cylindrical ion beam channel 7. This electric field deflects the passing ion beam (e.g., ...). Figure 5 As shown), the deflected ions are absorbed by the negative electrode plate 3; when the negative electrode plate 3 and the positive electrode plate 4 are not energized, no electric field is generated in the cylindrical ion beam channel 7, and the passing ion beam is not deflected (as shown). Figure 4 As shown, all ions are emitted through the small port of the conical channel 8. That is, undeflected ions are intercepted by the conical channel 8 after passing through the cylindrical ion beam channel 7 to obtain the ion beam diameter that meets the actual processing requirements. In this way, by controlling the on and off frequency of the negative electrode plate 3 and the positive electrode plate 4, the ion beam energy (or ion beam intensity) passing through the cylindrical ion beam channel 7 per unit time can be adjusted, thereby adjusting the ion beam energy emitted from the small port of the conical channel 8 to the surface to be processed of the optical element 9. That is, by controlling the on and off frequency of the deflection electric field within a fixed time, the energy of the ion beam can be adjusted. Compared to existing processing methods that use constant ion beam energy to irradiate the workpiece surface, firstly, given the different amounts to be removed at each processing point 92, high ion beam energy processing can be performed at processing points 92 with large amounts to be removed, while low ion beam energy processing can be performed at processing points 92 with small amounts to be removed, thus reducing the frequency of machine tool acceleration and deceleration adjustments. It is even possible to make the machine tool move at a uniform speed in some or all sections of the processing path 91 (i.e., to make the ion beam processing device move at the same speed through some or all processing points 92). Secondly, for adjacent processing points 92 with large differences in the amount to be removed (i.e., a large difference in the amount to be removed between adjacent processing points 92), the machine tool speed can be adjusted to a small extent (i.e., the speed of the ion beam processing device passing through processing points 92 can be adjusted to a large extent), while the ion beam energy can be adjusted to a large extent, or only the ion beam energy can be adjusted without adjusting the machine tool speed, thereby enabling the machine tool to meet the adjustment requirements for large-span removal amounts during ion beam shaping. Thirdly, by adopting a combined approach of ion beam energy adjustment and machine tool speed adjustment, the dynamic performance requirements of the machine tool are reduced, improving processing efficiency and accuracy.

[0045] Furthermore, in this embodiment, the power control module 6 includes a DC power supply box 61, an electronic switch 62, and a control unit 63. The positive electrode plate 4 is connected to the positive terminal of the DC power supply box 61 through the electronic switch 62, the negative electrode plate 3 is connected to the negative terminal of the DC power supply box 61, and the control unit 63 is connected to the electronic switch 62.

[0046] Furthermore, such as Figure 1 and Figure 2As shown, in this embodiment, both the negative electrode plate 3 and the positive electrode plate 4 are housed within the bracket 2, and wire passage windows 21 are provided on both sides of the bracket 2. The bracket 2 protects the negative electrode plate 3 and the positive electrode plate 4, and the wire passage windows 21 allow wires between the negative electrode plate 3 and the positive electrode plate 4 and the power control module 6 to pass through. Preferably, the cross-sections of both the negative electrode plate 3 and the positive electrode plate 4 are semi-circular.

[0047] Furthermore, in this embodiment, an insulating pad 12 is provided between the negative electrode plate 3 and the positive electrode plate 4 and the base 1. Preferably, the insulating pad 12 is a ceramic pad.

[0048] Furthermore, in this embodiment, the cone angle of the conical channel 8 is 60° to 80°, and the diameter of the cylindrical ion beam channel 7 is larger than that of the circular through-hole 11. Preferably, the cone angle of the conical channel 8 is 70°.

[0049] Furthermore, in this embodiment, the base 1, the bracket 2, the negative electrode plate 3, the positive electrode plate 4, and the aperture 5 are all made of graphite material.

[0050] The base 1 serves as the carrier for the adjustable beam energy ion beam processing device, used to fix the device above the ion source. During use, the negative electrode plate 3 and the positive electrode plate 4 are connected to an external power source, forming a parallel electric field approximately perpendicular to the negative electrode plate 3. The potential energy of the ion beam within this deflection region is converted into kinetic energy, and the ion beam exhibits deflection and acceleration effects as it passes through this electric field. By adjusting the switching frequency of the electronic switch 62, the application period and duration of the deflection electric field can be controlled, thereby controlling the deflection effect on the ion beam and adjusting the processing energy. The inlet aperture (inner diameter of the large-diameter end) of the tapered channel 8 can be adjusted according to the aperture of the circular through-hole 11, the aperture of the cylindrical ion beam channel 7, and its length. The outlet aperture of the tapered channel 8 needs to be selected based on the error wavelength of the optical element 9 to be corrected.

[0051] Example 2:

[0052] An ion beam processing method with adjustable beam energy is disclosed, using the ion beam processing apparatus with adjustable beam energy described in Example 1. An ion source is connected to a circular through-hole 11, and the small end of a tapered channel 8 is aligned with the surface to be processed on the optical element 9 of the machine tool. An electrical control module 6 is connected to the machine tool. The ion beam processing method with adjustable beam energy includes the following steps:

[0053] S1. Detect the error morphology distribution of the surface to be processed of the optical element 9;

[0054] S2. Based on the error morphology distribution of the surface to be processed of the optical element 9, obtain the processing path 91 of the ion beam processing device relative to the optical element 9 and the amount to be removed at each processing point 92 on the processing path 91.

[0055] S3. Based on the amount to be removed at each processing point 92 on the processing path 91, obtain the speed at which the ion beam processing device passes through each processing point 92 along the processing path 91 and the on / off frequency of the negative electrode plate 3 and the positive electrode plate 4.

[0056] S4. The ion source emits an ion beam into the cylindrical ion beam channel 7 at a constant power, and the ion beam processing device processes each processing point 92 sequentially along the processing path 91 relative to the optical element 9. The power control module 6 obtains the position of the ion beam processing device relative to the optical element 9 in real time, and makes the ion beam processing device pass through each processing point 92 according to the speed and power-on / off frequency corresponding to each processing point 92 obtained in S3.

[0057] As the ion beam passes through the cylindrical ion beam channel 7, the power control module 6 energizes the negative electrode plate 3 and the positive electrode plate 4, thereby generating an electric field in the cylindrical ion beam channel 7. This electric field deflects the passing ion beam (e.g., ...). Figure 5 As shown), the deflected ions are absorbed by the negative electrode plate 3; when the negative electrode plate 3 and the positive electrode plate 4 are not energized, no electric field is generated in the cylindrical ion beam channel 7, and the passing ion beam is not deflected (as shown). Figure 4As shown, all ions are emitted through the small port of the conical channel 8. That is, undeflected ions are intercepted by the conical channel 8 after passing through the cylindrical ion beam channel 7 to obtain the ion beam diameter that meets the actual processing requirements. In this way, by controlling the on and off frequency of the negative electrode plate 3 and the positive electrode plate 4, the ion beam energy (or ion beam intensity) passing through the cylindrical ion beam channel 7 per unit time can be adjusted, thereby adjusting the ion beam energy emitted from the small port of the conical channel 8 to the surface of the optical element 9 to be processed. Compared to existing processing methods that use constant ion beam energy to irradiate the workpiece surface, firstly, given the different amounts to be removed at each processing point 92, high ion beam energy processing can be performed at processing points 92 with large amounts to be removed, while low ion beam energy processing can be performed at processing points 92 with small amounts to be removed, thus reducing the frequency of machine tool acceleration and deceleration adjustments. It is even possible to make the machine tool move at a uniform speed in some or all sections of the processing path 91 (i.e., to make the ion beam processing device move at the same speed through some or all processing points 92). Secondly, for adjacent processing points 92 with large differences in the amount to be removed (i.e., a large difference in the amount to be removed between adjacent processing points 92), the machine tool speed can be adjusted to a small extent (i.e., the speed of the ion beam processing device passing through processing points 92 can be adjusted to a large extent), while the ion beam energy can be adjusted to a large extent, or only the ion beam energy can be adjusted without adjusting the machine tool speed, thereby enabling the machine tool to meet the adjustment requirements for large-span removal amounts during ion beam shaping. Thirdly, by adopting a combined approach of ion beam energy adjustment and machine tool speed adjustment, the dynamic performance requirements of the machine tool are reduced, improving processing efficiency and accuracy.

[0058] Further, in this embodiment, in S3, the speed of the ion beam processing device passing through each processing point 92 along the processing path 91 is divided into a first echelon (e.g., 0-2000 mm / min), a second echelon (e.g., 2000-4000 mm / min), and a third echelon (e.g., 4000-6000 mm / min) in ascending order. When the speed of the ion beam processing device corresponding to the processing point 92 is in the first echelon, the on / off frequency of the corresponding negative electrode plate 3 and positive electrode plate 4 is 0, even if the ion beam processing device passes through the first echelon, the speed of the ion beam processing device is divided into a first echelon (e.g., 0-2000 mm / min), a second echelon (e.g., 2000-4000 mm / min), and a third echelon (e.g., 4000-6000 mm / min). The processing device emits the entire ion beam through the ion source. When the speed of the ion beam processing device passing through processing point 92 is in the second tier, the switching frequency of the corresponding negative electrode plate 3 and positive electrode plate 4 is 0.5, which means that half of the ion beam emitted by the ion beam processing device passes through the ion source. When the speed of the ion beam processing device passing through processing point 92 is in the third tier, the switching frequency of the corresponding negative electrode plate 3 and positive electrode plate 4 is 0.33, which means that one-third of the ion beam emitted by the ion beam processing device passes through the ion source. This method uses a combination of ion beam energy regulation and machine tool speed regulation (speed regulation of the ion beam processing device passing through processing point 92) to reduce the dynamic performance requirements of the machine tool and improve processing efficiency, accuracy, and quality.

[0059] Example 3:

[0060] Another ion beam processing method with adjustable beam energy is performed using the ion beam processing apparatus with adjustable beam energy described in Example 1. An ion source is connected to a circular through-hole 11, and the small end of a tapered channel 8 is aligned with the surface to be processed of the optical element 9 on the machine tool. The power control module 6 is connected to the machine tool. The ion beam processing method with adjustable beam energy includes the following steps:

[0061] S1. Detect the error morphology distribution of the surface to be processed of the optical element 9;

[0062] S2. Based on the error morphology distribution of the surface to be processed of the optical element 9, obtain the processing path 91 of the ion beam processing device relative to the optical element 9 and the amount to be removed at each processing point 92 on the processing path 91.

[0063] S3. Based on the amount to be removed at each processing point 92 on the processing path 91, obtain the speed at which the ion beam processing device passes through each processing point 92 along the processing path 91 and the on / off frequency of the negative electrode plate 3 and the positive electrode plate 4.

[0064] S4. The ion source emits an ion beam into the cylindrical ion beam channel 7 at a constant power, and the ion beam processing device processes each processing point 92 sequentially along the processing path 91 relative to the optical element 9. The power control module 6 obtains the position of the ion beam processing device relative to the optical element 9 in real time, and makes the ion beam processing device pass through each processing point 92 according to the speed and power-on / off frequency corresponding to each processing point 92 obtained in S3.

[0065] In S3, a dwell speed threshold V (e.g., 700 mm / min) is set. When the passing speed of the ion beam processing device corresponding to processing point 92 is equal to or less than V, the switching frequency of the corresponding negative electrode plate 3 and positive electrode plate 4 is 0. Even if the ion beam processing device passes through all the ion beams emitted by the ion source, when the passing speed of the ion beam processing device corresponding to processing point 92 is greater than V, the passing speed of the ion beam processing device corresponding to processing point 92 is adjusted to V. The switching frequency of the corresponding negative electrode plate 3 and positive electrode plate 4 is determined according to V. In this way, the machine tool can move at a constant speed in some or all sections of the processing path 91, that is, the speed of the ion beam processing device passing through some or all processing points 92 is the same, which greatly reduces the requirements for the dynamic performance of the machine tool.

[0066] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. An ion beam processing apparatus with adjustable beam energy, characterized in that: The system includes a base (1), a bracket (2), a negative electrode plate (3), a positive electrode plate (4), an aperture (5), and a power control module (6). The base (1) has a circular through-hole (11) in the middle. One end of both the negative electrode plate (3) and the positive electrode plate (4) is fixed to the base (1). The negative electrode plate (3) and the positive electrode plate (4) together form a cylindrical ion beam channel (7). The aperture (5) is fixed to the base (1) via the bracket (2). A conical channel (8) is provided inside the aperture (5). The conical channel (8) is coaxial with the cylindrical ion beam channel (7), and the larger end of the conical channel (8) is aligned with the end of the cylindrical ion beam channel (7) away from the circular through-hole (11), while the smaller end faces outwards. This is used to emit an ion beam to process the surface of the optical element (9) to be processed. The positive and negative terminals of the power control module (6) are connected to the negative electrode plate (3) and the positive electrode plate (4) respectively through wires. The power control module (6) is used to control the on and off frequency of the negative electrode plate (3) and the positive electrode plate (4) and obtain the position of the ion beam processing device relative to the optical element (9) in real time, so that the ion beam processing device passes through each processing point (92) according to the speed and on and off frequency corresponding to each processing point (92). The negative electrode plate (3) and the positive electrode plate (4) are used to generate a potential difference in the cylindrical ion beam channel (7) when energized, so that the passing ion beam is deflected. The negative electrode plate (3) is used to absorb the deflected ions. The conical channel (8) is used to intercept the ion beam passing through the cylindrical ion beam channel (7) to obtain the ion beam diameter that meets the actual processing requirements.

2. The ion beam processing apparatus with adjustable beam energy according to claim 1, characterized in that: The power control module (6) includes a DC power supply box (61), an electronic switch (62) and a control unit (63). The positive electrode plate (4) is connected to the positive terminal of the DC power supply box (61) through the electronic switch (62), the negative electrode plate (3) is connected to the negative terminal of the DC power supply box (61), and the control unit (63) is connected to the electronic switch (62).

3. The ion beam processing apparatus with adjustable beam energy according to claim 1, characterized in that: The negative electrode plate (3) and the positive electrode plate (4) are both located inside the bracket (2), and the bracket (2) has wire passage windows (21) on both sides.

4. The ion beam processing apparatus with adjustable beam energy according to claim 1, characterized in that: An insulating pad (12) is provided between the negative electrode plate (3) and the positive electrode plate (4) and the base (1).

5. The ion beam processing apparatus with adjustable beam energy according to claim 4, characterized in that: The insulating pad (12) is a ceramic pad.

6. The ion beam processing apparatus with adjustable beam energy according to claim 1, characterized in that: The cone angle of the conical channel (8) is 60°~80°, and the diameter of the cylindrical ion beam channel (7) is larger than that of the circular through hole (11).

7. The ion beam processing apparatus with adjustable beam energy according to any one of claims 1 to 6, characterized in that: The base (1), bracket (2), negative electrode plate (3), positive electrode plate (4) and aperture (5) are all made of graphite material.

8. A method for ion beam processing with adjustable beam energy, characterized in that, The ion beam processing method is performed using an ion beam processing apparatus with adjustable beam energy as described in any one of claims 1 to 7. The circular through-hole (11) is connected to an ion source, the small end of the tapered channel (8) is aligned with the surface to be processed of the optical element (9) on the machine tool, and the power control module (6) is connected to the machine tool. The ion beam processing method with adjustable beam energy includes the following steps: S1. Detect the error morphology distribution of the surface to be processed of the optical element (9); S2. Based on the error morphology distribution of the surface to be processed of the optical element (9), obtain the processing path (91) of the ion beam processing device relative to the optical element (9) and the amount to be removed at each processing point (92) on the processing path (91); S3. Based on the amount to be removed at each processing point (92) on the processing path (91), obtain the speed at which the ion beam processing device passes through each processing point (92) along the processing path (91) and the on / off frequency of the negative electrode plate (3) and the positive electrode plate (4). S4. The ion source emits an ion beam into the cylindrical ion beam channel (7) at a constant power, and the ion beam processing device processes each processing point (92) sequentially along the processing path (91) relative to the optical element (9). The power control module (6) obtains the position of the ion beam processing device relative to the optical element (9) in real time, and makes the ion beam processing device pass through each processing point (92) according to the speed and power-on / off frequency corresponding to each processing point (92) obtained in S3.

9. The ion beam processing method with adjustable beam energy according to claim 8, characterized in that: In S3, the speed of the ion beam processing device passing through each processing point (92) along the processing path (91) is divided into three echelons: the first echelon, the second echelon, and the third echelon, in ascending order. When the speed of the ion beam processing device corresponding to the processing point (92) is in the first echelon, the switching frequency of the corresponding negative electrode plate (3) and positive electrode plate (4) is 0, which means that the ion beam processing device emits all the ion beams through the ion source. When the speed of the ion beam processing device corresponding to the processing point (92) is in the second echelon, the switching frequency of the corresponding negative electrode plate (3) and positive electrode plate (4) is 0.5, which means that the ion beam processing device emits half of the ion beams through the ion source. When the speed of the ion beam processing device corresponding to the processing point (92) is in the third echelon, the switching frequency of the corresponding negative electrode plate (3) and positive electrode plate (4) is 0.33, which means that the ion beam processing device emits one-third of the ion beams through the ion source.

10. The ion beam processing method with adjustable beam energy according to claim 8, characterized in that: In S3, a dwell speed threshold V is set. When the passing speed of the ion beam processing device corresponding to the processing point (92) is equal to or less than V, the on / off frequency of the corresponding negative electrode plate (3) and positive electrode plate (4) is 0, so that the ion beam processing device passes through all the ion beams emitted by the ion source. When the passing speed of the ion beam processing device corresponding to the processing point (92) is greater than V, the passing speed of the ion beam processing device corresponding to the processing point (92) is adjusted to V. The on / off frequency of the negative electrode plate (3) and positive electrode plate (4) corresponding to the processing point (92) is determined according to V.

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