Liquid level control device for vacuum beam line mirror box

Abstract

The invention relates to a liquid level control device for a vacuum beam line mirror box, a first liquid level control mechanism is arranged in the vacuum beam line mirror box, the first liquid level control mechanism comprises a sliding block and a sliding block driving mechanism, in a liquid heat exchange medium of the sliding block, the sliding block driving mechanism can drive the sliding block to move up and down; and the liquid level height of the liquid heat exchange medium in the cooling tank is changed by changing the volume of the sliding block immersed in the liquid heat exchange medium, so that the purpose of adjusting the contact length or contact area of the cooling block and the liquid heat exchange medium is achieved. According to the scheme, the structure is simple, external large equipment is not needed, in addition, the liquid heat exchange medium can absorb vibration generated when the sliding block moves, and therefore the vibration influence of the scheme on the optical element is very small.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of optical technologies, and in particular, to a liquid level control device for a vacuum beamline mirror box. Background Art

[0002] A beamline mirror box is a key component in diffraction-limited light sources (such as synchrotron radiation light sources, free electron lasers, etc.). The inside of the beamline mirror box is usually a high-vacuum environment, which is used to carry and precisely adjust optical elements (such as mirrors, focusing mirrors, etc.) to control the direction and intensity of the light source beamline. To ensure the performance of the diffraction-limited light source, it is required that the optical elements in the beamline mirror box can maintain extremely high static surface shape accuracy under a high thermal load. For this reason, a cooling system is usually configured in the beamline mirror box to dissipate heat from the optical elements and prevent the optical elements from affecting their optical performance due to thermal deformation. The cooling system generally includes a cooling block, on which a coolant flow channel is provided, and the coolant flow channel is connected to a coolant circulation and transmission pipeline. The cooling block extends into a cooling groove on the upper surface of the optical element and indirectly contacts the optical element through a liquid heat transfer medium filled in the cooling groove to take away the heat generated by the optical element.

[0003] When optimizing the thermal surface shape of the optical surface of an optical element, the heat dissipation effect is generally adjusted by adjusting the contact length or contact area between the cooling block and the liquid heat transfer medium, so as to change the temperature distribution of the optical element and keep the optical surface with sufficient surface shape accuracy under the corresponding thermal load distribution.

[0004] A related technology proposes a solution of using a special-shaped cooling block to achieve continuous switching of the effective contact length or contact area, that is, the lower part of the cooling block is designed into a trapezoidal, triangular or arc shape with a wider upper part and a narrower lower part, so that the lower end of the cooling block has a continuously changing slope. By moving the cooling block up and down or changing the amount of the liquid heat transfer medium online, continuous switching of the contact length or contact area between the cooling block and the liquid heat transfer medium can be achieved.

[0005] Methods for adjusting the contact length or contact area between a cooling block and a liquid heat exchange medium are specifically as follows: There are two methods. One method is to adjust the depth of immersion of the cooling block in the liquid heat exchange medium by moving the cooling block. Considering that the cooling block is fixedly connected to the entire coolant circulation and transfer pipeline, when moving the cooling block, the entire coolant circulation and transfer pipeline needs to be moved. The designed movement control mechanism is relatively complex and is likely to introduce additional vibrations, affecting the stability of the light beam. The other method is to directly extract and inject the liquid heat exchange medium externally through devices such as pumps or syringes to control the liquid level height of the liquid heat exchange medium. However, this method must consider that the inside of the mirror box is in a high-vacuum environment, where the pressure is much lower than the external pressure. Therefore, it is relatively easy to inject the liquid heat exchange medium into the vacuum chamber. However, if the liquid heat exchange medium needs to be extracted, a rather large negative pressure must be created, that is, a pressure lower than that in the high-vacuum chamber needs to be generated, which is very difficult to achieve for devices such as pumps or syringes.

[0006] How to effectively achieve the adjustment of the contact length or contact area between the cooling block and the liquid heat exchange medium is a technical problem that needs to be studied and solved currently. Summary of the Invention

[0007] The embodiment of the present application provides a liquid level control device for a vacuum beamline mirror box, aiming to adjust the contact length or contact area between a cooling block and a liquid heat exchange medium in a high-vacuum environment and avoid some technical problems existing in the related art.

[0008] To achieve the above object, the embodiment of the present application provides a liquid level control device for a vacuum beamline mirror box, including: An optical element, on which a cooling groove is provided, and the cooling groove is filled with a liquid heat exchange medium; A cooling block, which is immersed in the liquid heat exchange medium; A first liquid level control mechanism, which includes a slider and a slider driving mechanism. The slider is immersed in the liquid heat exchange medium, and the slider driving mechanism is connected to the slider and can drive the slider to move up and down to change the volume of the slider immersed in the liquid heat exchange medium.

[0009] In the above solution, a first liquid level control mechanism is provided in the vacuum beamline mirror box. The first liquid level control mechanism includes a slider and a slider driving mechanism. The slider is in the liquid heat exchange medium, and the slider driving mechanism can drive the slider to move up and down, changing the volume of the slider immersed in the liquid heat exchange medium, and further changing the liquid level height of the liquid heat exchange medium in the cooling groove, so as to achieve the purpose of adjusting the contact length or contact area between the cooling block and the liquid heat exchange medium. This solution has a simple structure and does not require external large-scale equipment. In addition, the liquid heat exchange medium can absorb the vibrations generated when the slider moves, so this solution has a very small impact on the vibrations of the optical element.

[0010] In a possible implementation manner of an embodiment of the present application, the slider driving mechanism includes a fixed slide rail seat, a motor, a lead screw, and a nut seat. The motor is installed on the fixed slide rail seat. The lower end of the nut seat is connected to the slider. A threaded hole is provided at the upper end of the nut seat. The motor is threadedly connected to the threaded hole through the lead screw.

[0011] In a possible implementation manner of an embodiment of the present application, the first liquid level control mechanism further includes an upper and lower limit component for restricting the distance of the up and down movement of the slider.

[0012] In a possible implementation manner of an embodiment of the present application, a step is provided at the bottom of the cooling tank, such that the cooling tank has different depths; the depth below the slider is greater than the depth below the cooling block.

[0013] In a possible implementation manner of an embodiment of the present application, a second liquid level control mechanism is further included. The second liquid level control mechanism includes a compressible supplementary medium storage structure and a compression driving mechanism; the supplementary medium storage structure is filled with the liquid heat exchange medium, and the supplementary medium storage structure has a medium inlet and outlet communicating with the cooling tank; the compression driving mechanism is connected to the supplementary medium storage structure and can drive the supplementary medium storage structure to compress or restore. During the compression process of the supplementary medium storage structure, the liquid heat exchange medium is injected into the cooling tank through the medium inlet and outlet. During the restoration process of the supplementary medium storage structure, the liquid heat exchange medium in the cooling tank flows into the supplementary medium storage structure through the medium inlet and outlet.

[0014] In a possible implementation manner of an embodiment of the present application, the supplementary medium storage structure includes a funnel, a telescopic bellows, and a medium storage cavity; the upper end of the funnel is a narrow opening serving as the medium inlet and outlet, and the lower end is a wide opening; a channel connected to the narrow opening of the funnel is provided at the bottom of the cooling tank; the wide opening of the funnel is connected to the medium storage cavity through the telescopic bellows; the funnel, the telescopic bellows, and the medium storage cavity are all filled with the liquid heat exchange medium; the compression driving mechanism is connected to the medium storage cavity.

[0015] In a possible implementation manner of an embodiment of the present application, the device further includes a support plate for supporting the optical element. The optical element is arranged on the support plate, and a through hole for avoiding the supplementary medium storage structure is provided on the support plate; the second liquid level control mechanism further includes a bracket for supporting the supplementary medium storage structure, and the bracket is installed below the support plate.

[0016] In a possible implementation manner of an embodiment of the present application, a first heat insulation layer is provided at the connection between the bracket and the support plate, and a second heat insulation layer is provided at the connection between the compression driving mechanism and the medium storage cavity.

[0017] In a possible implementation manner of an embodiment of the present application, there are two first liquid level control mechanisms, symmetrically distributed on both sides of the cooling block.

[0018] In a possible implementation manner of an embodiment of the present application, the slider driving mechanisms of the two first liquid level control mechanisms are both connected to a controller, and the controller is used to control the two slider driving mechanisms to drive the sliders to move upward or downward synchronously.

[0019] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 Structural schematic diagram of a liquid level control device for a vacuum beam line mirror box provided in Embodiment 1 of the present application; Figure 2 Structural schematic diagram of an optical element provided in Embodiment 1 of the present application; Figure 3 Structural schematic diagram of a cooling block provided in Embodiment 1 of the present application; Figure 4 Structural schematic diagram of a first liquid level control mechanism provided in Embodiment 1 of the present application; Figure 5 Partial cross-sectional view of the liquid level control device when the slider is not immersed in the liquid heat exchange medium provided in Embodiment 1 of the present application; Figure 6 Partial cross-sectional view of the liquid level control device when the slider is immersed in the liquid heat exchange medium provided in Embodiment 1 of the present application; Figure 7 Structural schematic diagram of a first liquid level control mechanism provided in Embodiment 2 of the present application; Figure 8 Partial cross-sectional view of the liquid level control device provided in Embodiment 3 of the present application; Figure 9 Partial cross-sectional view of a liquid level control device provided in Embodiment 4 of the present application; Description of reference numerals in the drawings: first liquid level control mechanism 1, cooling block 2, optical element 3, liquid heat exchange medium 4, support plate 5, second liquid level control mechanism 6, fixed slide rail base 11, slider 12, motor 121, upper limit seat 122, lead screw 123, guide rail 124, nut seat 125, moving shaft 126, groove 127, lower limit stop 128, upper moving shaft 1260, lower moving shaft 1261, limit groove 1280, coolant flow channel 21, cooling plate 22, cooling groove 31, mirror body optical surface 32, support point 51, through hole 52, channel 33, funnel 61, telescopic bellows 62, medium storage cavity 63, bracket 64, first heat insulation layer 65, second heat insulation layer 66. Detailed implementation manners

[0022] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] In the description of the embodiments of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of the present application.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0025] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0026] In the embodiments of the present application, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0027] In the embodiments of the present application, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent the situations of A existing alone, A and B existing simultaneously, and B existing alone. Where A and B may be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c may represent: a existing alone, b existing alone, c existing alone, a and b existing simultaneously, a and c existing simultaneously, b and c existing simultaneously, or a, b, and c existing simultaneously, where a, b, and c may be single or multiple.

[0028] In the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Rather, the use of words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0029] The beamline mirror box is a key component in diffraction-limited light sources (such as synchrotron radiation light sources, free electron lasers, etc.). It is used to carry and precisely adjust optical elements (such as mirrors, focusing mirrors, etc.) to control the direction and intensity of the light source beamline. Generally, the beamline mirror box includes a vacuum chamber, optical elements, and a cooling mechanism. Among them, the optical elements and the cooling mechanism are both located in the vacuum chamber. The high-vacuum environment provided by the vacuum chamber can improve the coherence and stability of the beamline. The optical elements refer to devices used to control the transmission and processing of light. Their material is usually single-crystalline silicon. The side surface of the optical element is provided with an optical surface, and the upper surface of the optical element is provided with a cooling groove, which is filled with a liquid heat transfer medium with high thermal conductivity efficiency (usually indium-gallium liquid alloy). The cooling mechanism specifically includes a cooling block, a cooling block support mechanism, a coolant flow channel, and a coolant circulation and transmission pipeline. The cooling block extends into the cooling groove and is indirectly in contact with the optical element through the liquid heat transfer medium. The cooling block support mechanism is used to support the cooling block. The coolant flow channel is arranged in the cooling block, and the coolant flow channel is connected to the coolant circulation and transmission pipeline. The coolant circulation and transmission pipeline injects flowing cooling liquid (usually deionized water or liquid nitrogen) into the coolant flow channel.

[0030] For the beamline of a synchrotron radiation light source or a free electron laser, the position, resolution, etc. of the light spot will jitter and drift under the influence of thermal load and vibration of the optical element (or called the mirror body), which greatly affects the stability of the beam. Since both heat and vibration will have an adverse impact on the quality of the transmitted beam, when using a cooling mechanism to control the thermal deformation of the mirror body, the influence of the vibration of the coolant circulation and transmission pipeline on the stability of the mirror body also needs to be considered. In order to prevent the vibration of the coolant circulation and transmission pipeline from being transmitted to the mirror body through direct contact, the prior art designs the mirror body with grooves on the upper surface and injects a liquid heat transfer medium. The cooling block of the cooling mechanism is immersed in the liquid heat transfer medium in the groove. The liquid heat transfer medium can isolate the vibration of the cooling mechanism and can also serve as a heat transfer medium between the mirror body and the cooling mechanism, playing a good heat conduction role.

[0031] When optimizing the thermal surface shape of the optical surface of the mirror body, generally, the heat dissipation effect is adjusted by adjusting the contact length or contact area between the cooling block and the liquid heat transfer medium, so as to change the temperature distribution of the mirror body and make the optical surface still maintain sufficient surface shape accuracy under the corresponding thermal load distribution. For a mirror body working at multiple wavelengths, the corresponding light spot lengths are also different, so the optimal contact length or contact area with the heat transfer medium is also different. Using the traditional segmented cooling method not only has a very complex structure, but also cannot achieve continuous switching of the effective contact length or contact area for the continuously covered light spot length, making it difficult to effectively control the thermal deformation of the optical surface of the mirror body.

[0032] A related technology proposes to adopt a scheme of using a special-shaped cooling block to achieve continuous switching of the effective contact length or contact area, that is, designing the lower part of the cooling block into a trapezoidal, triangular or arc shape with a wider upper part and a narrower lower part, so that the lower end of the cooling block has a continuously changing slope. By moving the cooling block up and down or changing the amount of liquid indium gallium alloy online, the depth of the cooling block immersed in the indium gallium alloy is changed, so as to achieve continuous switching of the contact length or contact area between the cooling block and the liquid heat exchange medium. This related technology has a simpler structure and a wider application range compared with the multi-section cooling scheme. When adopting this related technology, it is necessary to be able to effectively control the depth of the cooling block immersed in the indium gallium alloy, so as to accurately control the effective cooling length. However, this related technology does not give a specific implementation scheme. In fact, in a mirror box with a very strict high-vacuum environment and vibration requirements, it is very difficult to move the cooling block up and down or change the amount of indium gallium alloy during specific implementation.

[0033] Specifically, for adjusting the contact length or contact area between the cooling block and the liquid heat exchange medium by moving the cooling block up and down, it is necessary to consider that the cooling block is fixedly connected to the entire coolant circulation transmission pipeline. When moving the cooling block, the entire coolant circulation transmission pipeline needs to be moved. The designed moving control mechanism is relatively complex and is likely to introduce additional vibrations, affecting the stability of the light beam.

[0034] For changing the amount of liquid indium gallium alloy online to change the depth of the cooling block immersed in the indium gallium alloy and achieve the adjustment of the contact length or contact area between the cooling block and the liquid heat exchange medium, it is necessary to consider the influence of the high-vacuum environment in the mirror box. Due to the large pressure difference between the internal and external environments of the vacuum cavity of the mirror box, it is difficult to inject or suck out the indium gallium alloy into the vacuum cavity in the way of a communicating vessel. It is also very difficult to create a pressure difference inside the vacuum cavity to suck out the indium gallium alloy from the tank. Therefore, the scheme of increasing or decreasing the indium gallium alloy by creating a pressure difference to control the height of its liquid level is difficult to implement. If the extraction and release of liquid in a high-vacuum environment are realized through external equipment (such as a filtrate pump or a syringe), for a high-vacuum environment, if a negative pressure is to be generated, it is necessary to rely on corresponding equipment to create a lower pressure to form a negative-pressure environment before the liquid inside can be pumped out, which is very difficult to achieve. Even if the generation of negative pressure is realized through a corresponding filtrate pump, the vibration generated by the pump group will also interfere with the entire mirror box system, resulting in a decrease in the spot quality. If liquid is poured into the high-vacuum cavity in the atmospheric environment, due to the very large internal and external pressure difference, the liquid will be instantaneously pressed into the vacuum cavity and splashed violently, and at the same time, the vacuum degree inside the vacuum cavity will also decrease. Therefore, additional equipment is needed to control the injection speed of the liquid, which suddenly increases the complexity of the entire device.

[0035] Therefore, how to effectively control the height of the indium gallium alloy liquid level in a vacuum environment is the difficulty for the true realization of such a continuous switching scheme of the effective contact length / area.

[0036] An embodiment of the present application provides a liquid level control device for a vacuum beam line mirror box, aiming to adjust the contact length or contact area between a cooling block and a liquid heat exchange medium in a high-vacuum environment and avoid some technical problems existing in the related art.

[0037] The following will detail the technical solutions provided by each embodiment of the present application in conjunction with the accompanying drawings.

[0038] Embodiment 1 Please refer to Figures 1-6 , Figure 1 , which is a schematic structural diagram of a liquid level control device for a vacuum beam line mirror box provided in Embodiment 1 of the present application, Figure 2 , which is a schematic structural diagram of an optical element provided in Embodiment 1 of the present application, Figure 3 , which is a schematic structural diagram of a cooling block provided in Embodiment 1 of the present application, Figure 4 , which is a schematic structural diagram of a first liquid level control mechanism provided in Embodiment 1 of the present application, Figure 5 , which is a partial cross-sectional view of the liquid level control device when the slider is not immersed in the liquid heat exchange medium provided in Embodiment 1 of the present application, Figure 6 , which is a partial cross-sectional view of the liquid level control device when the slider is immersed in the liquid heat exchange medium provided in Embodiment 1 of the present application. In this embodiment, the liquid level control device includes an optical element 3, a cooling block 2, and a first liquid level control mechanism 1. Among them, a cooling groove 31 is provided on the optical element 3, and the cooling groove 31 is filled with a liquid heat exchange medium 4; the cooling block 2 is immersed in the liquid heat exchange medium 4; the first liquid level control mechanism 1 includes a slider 12 and a slider driving mechanism. The slider 12 is immersed in the liquid heat exchange medium 4, and the slider driving mechanism is connected to the slider 12 and can drive the slider 12 to move up and down to change the volume of the slider 12 immersed in the liquid heat exchange medium 4.

[0039] As Figure 2 shown, in this embodiment, a mirror body optical surface 32 is provided on the front surface of the optical element 3, and a cooling groove 31 for accommodating the liquid heat exchange medium 4 is provided on the upper surface. As an example, the length of the cooling groove 41 is 320 mm, the width is 5 mm, and the groove depth

[0040] is Figure 3 15 mm.

[0040] As Figure 3 shown, in this embodiment, the cooling block 2 specifically includes a cooling plate 22 and a coolant flow channel 21. The coolant flow channel 21 is provided on the upper side of the cooling plate 22. The coolant flow channel 21 has an inlet and an outlet for cooling liquid, which are used to connect the coolant circulation transmission pipeline. The circulating cooling liquid flows into the coolant flow channel from the inlet to absorb the heat transferred by the cooling plate 22, and then flows out from the outlet and reflows into the coolant circulation transmission pipeline to achieve circulating heat dissipation.

[0041] As Figure 3 shown, in this embodiment, the lower part of the cooling plate 22 is provided with a structure that is wider at the top and narrower at the bottom. The purpose of this setting is to make the lower end of the cooling plate have a continuously changing slope, and by changing the depth of the cooling plate immersed in the liquid heat exchange medium, the continuous switching of the effective contact length with the liquid heat exchange medium is realized.

[0042] As Figure 4 shown, in this embodiment, the slider driving mechanism specifically includes a fixed slide rail seat 11, a motor 121, a lead screw 123 and a nut seat 125. The motor 121 is installed on the fixed slide rail seat 11. The lower end of the nut seat 125 is connected to the slider 12. The upper end of the nut seat 125 is provided with a threaded hole, and the motor 121 is threadedly connected to the threaded hole through the lead screw 123. Through the transmission of the lead screw 123 and the threaded seat 125, the rotational motion of the motor 121 can be converted into a linear motion to drive the slider 12 to move linearly in the vertical direction. When the slider 12 moves upward, the volume of the slider 12 immersed in the liquid heat exchange medium 4 decreases, the liquid level of the liquid heat exchange medium 4 drops, and further the contact length / area between the cooling plate 22 and the liquid heat exchange medium 4 decreases; when the slider 12 moves upward, the volume of the slider 12 immersed in the liquid heat exchange medium 4 increases, the liquid level of the liquid heat exchange medium 4 rises, and further the contact length / area between the cooling plate 22 and the liquid heat exchange medium 4 increases.

[0043] As Figure 4 shown, a groove 127 for avoiding the lead screw is further provided on the lower side of the above-mentioned threaded hole.

[0044] As Figure 4 shown, a guide rail 124 cooperating with the nut seat is further provided on the above-mentioned fixed slide rail seat to facilitate the up and down movement of the nut seat 125 along the guide rail 124.

[0045] In this embodiment, the first liquid level control mechanism 1 further includes an upper and lower limit component for limiting the up and down movement distance of the slider 12. As Figure 4 shown, the upper and lower limit component specifically includes: a moving shaft 126 provided on the nut seat 125, a lower limit stop block 128 provided on the fixed slide rail seat 11 for cooperating with the moving shaft 126, an upper limit seat 122 provided on the fixed slide rail seat 11 for cooperating with the upper surface of the nut seat 125. The upper limit seat 122 has a hole for the lead screw 123 to pass through. Pressure-sensitive resistor sheets connected to the control system are attached to the upper surface of the lower limit stop block 128 and the lower surface of the upper limit seat 122.

[0046] As Figure 1As shown, in this embodiment, there are two first liquid level control mechanisms 1, symmetrically distributed on both sides of the cooling block 2. The slider drive mechanisms of the two first liquid level control mechanisms 1 are both connected to the controller, and the controller is used to control the two slider drive mechanisms to drive the sliders to move upward or downward synchronously.

[0047] In a possible implementation, the optical element 3 is made of single crystal silicon, placed laterally, and operates at a wavelength of 2nm - 4.5nm. The size of the mirror body is 350mm × 60mm × 60mm, and the length of the cooling groove 31 is 320mm, and the width is 5mm, and the groove depth is

[0048] 15mm. The cooling block 2 is inserted into the cooling groove 31, and the heat of the light spot absorbed on the optical surface 32 of the mirror body is transferred to the cooling plate 2 through the liquid heat transfer medium 4 as the heat conduction medium. The circulating cooling water passes through the cooling water flow channel 21 above the cooling block 2 for heat exchange to take away the heat in the area of the light spot on the optical surface 32 of the mirror body. According to the previous calculation and optimization, at a wavelength of 2nm, the optimal effective cooling length of the cooling block 2 is 78mm, and at a wavelength of 4.5nm, the optimal effective cooling length is 141mm. In order to ensure that the cooling block 2 covers all the optimal effective cooling lengths at wavelengths of 2nm - 4.5nm, the long side of the trapezoidal cooling plate 22 is 150mm, that is, the overall length

[0049] of the cooling block 2, the short side is 50mm, the thickness of the cooling plate 22 is 4mm, made of oxygen-free copper, and the surface of the cooling plate 22 is plated with a nickel layer. In the first liquid level control mechanism 1, the threaded thickness of the nut seat 125 cooperating with the lead screw 123 is 2.5mm, the thickness of the upper limit seat 122 is 1.5mm, and the length of the lead screw 123 is 21.5mm, which is greater than the groove depth of the cooling groove 31, the thickness of the nut seat 125, and the thickness of the upper limit seat 122, ensuring that the slider 12 has sufficient stroke. The length of the slider 12 is 80mm, and the total length 2 of the two sliders 12 on both sides and the length of the cooling block 2 are less than the length of the cooling groove 31, ensuring that the slider 12 and the cooling block 2 will not collide in the cooling groove 31. The effective height , preventing the cooling block from being submerged by the liquid heat exchange medium 4 and losing the liquid level adjustment ability. The thickness of the part of the slider 12 intended to be immersed in the liquid heat exchange medium 4 is 4 mm, which is less than the width of the cooling tank 31 , and the flatness of the side surface of the slider 12 is 0.01 mm. The height of the groove 127 below the nut seat 125 on the slider 12 is 18 mm, which is the same as the thickness of the nut seat 125 , the thickness of the upper limit seat 122 and the sum is greater than the length of the lead screw . To prevent the slider 12 from interfering with the elbow pipe (i.e., the circulating coolant pipe, not shown in the figure) connected to the cooling water flow channel 21 of the cooling block 2 during the upward movement, the distance ΔH between the upper end face of the cooling tank 31 and the lower end face of the outside of the cooling water flow channel 21 is 17.5 mm, which is greater than the effective height of the slider 12 ; the distance ΔL between the side surface of the fixed slide rail seat 11 and the side surface of the cooling block 2 is 33 mm, which is greater than the outer bending radius of 29 mm of the elbow pipe connected to the coolant flow channel 21. The fixed slide rail seat 11 is fixed on the support fixture of the optical element 3 through a clamping mechanism.

[0050] The upper surface of the lower limit stop block 128 and the lower surface of the upper limit seat 122 are both mounted with piezoresistive chips connected to the control system. When the two end motors 121 are started synchronously, the sliders 12 on both sides move downward along the guide rail 124 under the action of the control system. When the moving shaft 126 touches the piezoresistive chip on the upper surface of the lower limit stop block 128, the control system receives relevant signals and stops the motor from rotating, and the slider stops moving. The maximum downward stroke of the slider 12 can reach a position 0.2 mm above the bottom surface of the cooling tank 31. When the control system controls the motor 121 to rotate in the reverse direction, the slider 12 moves upward. When the slider touches the piezoresistive chip on the lower surface of the upper limit seat 122, the control system also stops the motor from rotating after receiving the signal. The material of the slider 12 can be 316L stainless steel, and the surface is plated with pure nickel to better resist the corrosion of the liquid heat exchange medium 4 (InGa alloy). The remaining components of the liquid level control device can all be made of 316L stainless steel.

[0051] As Figure 5 shown, initially, a certain amount of liquid heat exchange medium 4 is added to the cooling tank 31. At this time, the interface height of the liquid heat exchange medium 4 is 7 mm, the cooling block 2 is immersed in the liquid heat exchange medium by 2 mm, and the effective cooling length of the cooling block 2 is 70 mm. Under the synchronous drive of the two side motors 121, the slider 12 moves downward by 6.5 mm. The distance between the bottom surface of the moved slider 12 and the bottom surface of the cooling tank 31 is 0.5 mm, and the limit stroke is not reached. As Figure 6 shown, during the movement of the slider 12, the liquid heat exchange medium 4 extruded below accumulates upward, causing the liquid level to gradually rise, and the effective cooling length After the slider 12 moves down 6.5 mm, the liquid level of the liquid heat exchange medium in the cooling groove 31 rises by 8 mm as a whole, just reaching the top of the groove. At this time, the effective cooling length becomes the length of cooling block 2 , i.e. 150mm. The effective cooling length in the process is adjusted The range is 70mm-150mm, including the effective cooling length required to adjust at the wavelength of 2nm-4.5nm The variation range, i.e. 78mm-141mm, meets the requirements of thermal deformation control of optical surfaces at wavelengths of 2nm-4.5nm.

[0052] The related technologies rarely involve the extraction and release measures of liquids in vacuum environments, especially in high vacuum environments. This is mainly because there are few liquids with extremely low saturated vapor pressures, and most liquids are difficult to exist stably in high vacuum environments. Another reason is that the extraction of liquids is generally done by generating negative pressure through devices such as pumps or syringes, and the liquid is sucked out under the action of this pressure. For high vacuum environments, if negative pressure is to be generated, it is necessary to rely on corresponding equipment to create a lower pressure to form a negative pressure environment before the liquid inside can be extracted. This is difficult to achieve. Even if negative pressure is generated by the corresponding filtrate pump, the vibration generated by the pump group will interfere with the entire mirror box system, resulting in a decrease in the quality of the light spot. If liquid is poured into a high vacuum chamber in an atmospheric environment, due to the large pressure difference between the inside and outside, the liquid will be instantly pressed into the vacuum chamber and violent splashing will occur, and the vacuum degree in the vacuum chamber will also decrease. Therefore, additional equipment is required to control the speed of liquid injection, which sharply increases the complexity of the entire device.

[0053] The solution of the embodiment of the present application does not need to adopt the method of creating negative pressure, nor does it need to move the optical element mirror body and cooling mechanism. It only changes the volume of the slider immersed in the liquid heat exchange medium 4 by adjusting the height of the slider 12 up and down to achieve free control of the liquid level of the liquid heat exchange medium 4 in the side groove of the reflector in a high vacuum environment. Then, the effective cooling length of the cooling block 2 can be freely changed in a high vacuum environment, so that the cooling adjustment device for thermal deformation of the optical surface 32 of the mirror body of the optical element 3 can be better suitable for continuously changing light spots. The solution has a simple structure and does not require large external equipment. Because the liquid heat exchange medium 4 can absorb the vibration generated when the slider 12 moves, the solution has a very small effect on the vibration of the optical element 3. In addition to the height adjustment of the liquid level of the liquid heat exchange medium 4 in the cooling groove 31 of the beam line optical element 3, it can also be used for other devices that require liquid level adjustment in a high vacuum environment.

[0054] Example 2 See also Figure 7 , Figure 7A schematic structural diagram of a first liquid level control mechanism provided for Embodiment 2 of the present application. In this embodiment, the upper and lower limit components specifically include: a limit groove 1280, an upper moving shaft 1260, and a lower moving shaft 1261. The limit groove 1280 is a strip-shaped slot hole provided on both side surfaces of the fixed slide rail base 11; the upper moving shaft 1260 is provided on both side surfaces of the nut seat 125 and is used to cooperate with the top end of the limit groove 1280; the lower moving shaft 1261 is provided on both side surfaces of the nut seat 125 and is used to cooperate with the bottom end of the limit groove 1280. Pressure-sensitive resistor sheets connected to the control system are attached to the inner surfaces of the top end and the bottom end of the limit groove 1280.

[0055] Compared with Embodiment 1, the main difference in Embodiment 2 is that: the guide rail structure between the fixed slide rail base 11 and the slider 12 is cancelled, and symmetric limit grooves 1280 and corresponding moving shafts are used to restrict the degrees of freedom of the slider 12 other than the vertical direction, which has a smaller processing difficulty compared with the guide rail structure. The moving shafts are bolt-connected to the upper part of the slider 12 and symmetrically arranged, which is convenient for installation and disassembly. When the upper moving shaft 1260 moves to the extreme position at the top end of the limit groove 1280, the control system stops the rotation of the motor 121 after detecting the signal of the pressure-sensitive resistor, and the slider 12 just completely disengages from the cooling tank 31; when the lower moving shaft 1261 moves to the extreme position at the bottom end of the limit groove 1280, the control system stops the rotation of the motor 121 after detecting the signal of the pressure-sensitive resistor, and the maximum downward stroke of the slider 12 can reach a position 0.2 mm above the bottom surface of the cooling tank 31, which is the same as that in Embodiment 1.

[0056] For the introduction of other structures of Embodiment 2, reference can be made to the relevant descriptions of the previous Embodiment 1, which will not be elaborated here.

[0057] Embodiment 3 Please refer to Figure 8 , Figure 8 A partial cross-sectional view of the liquid level control device provided for Embodiment 3 of the present application. In this embodiment, a step is provided at the bottom of the cooling tank 31, so that the cooling tank 31 has different depths; the depth below the slider 12 is greater than the depth below the cooling block 2.

[0058] Compared with Embodiment 1, the main difference in Embodiment 2 is that: the depths of the cooling tank 31 below the slider 12 and below the cooling block 2 are not equal, and the groove depth below the slider 12 is greater. The purpose of this setting is that the adjustable liquid level height of the slider 12 is related to the distance that the slider 12 can move. As the groove depth below the slider 12 increases, the space for the slider 12 to move in the vertical direction increases, which means that the range of the effective cooling length that the slider 12 can adjust increases, and the applicable range of the entire device is increased. Since the cooling block 2 is a non-movable component, there is no additional requirement for the groove depth below it, and it can be appropriately reduced, which not only reduces the processing amount and processing difficulty during the machining of the mirror body, but also increases the bending stiffness of the mirror body.

[0059] As an example, the groove depth of the cooling tank 31 under the slider 12 is 15 mm, and the groove depth of the cooling block 2 is 11 mm.

[0060] For the introduction of other structures of Embodiment 3, reference may be made to the relevant descriptions of Embodiment 1 above, and details will not be elaborated here.

[0061] Embodiment 4 Please refer to Figure 9 , Figure 9 FIG. is a partial cross-sectional view of a liquid level control device provided for Embodiment 4 of the present application. In this embodiment, the liquid level control device further includes a second liquid level control mechanism 6, and the second liquid level control mechanism 6 includes a compressible supplementary medium storage structure and a compression driving mechanism (not shown in the figure); the supplementary medium storage structure is filled with a liquid heat exchange medium 4, and the supplementary medium storage structure has a medium inlet and outlet communicating with the cooling tank 31; the compression driving mechanism is connected to the supplementary medium storage structure and can drive the supplementary medium storage structure to compress or restore. During the compression process of the supplementary medium storage structure, the liquid heat exchange medium 4 is injected into the cooling tank 31 through the medium inlet and outlet. During the restoration process of the supplementary medium storage structure, the liquid heat exchange medium 4 in the cooling tank 31 flows into the supplementary medium storage structure through the medium inlet and outlet.

[0062] As Figure 9 shown, the supplementary medium storage structure includes a funnel 61, a telescopic bellows 62, and a medium storage cavity 63; the upper end of the funnel 61 is a narrow opening serving as the medium inlet and outlet, and the lower end is a wide opening; a channel 33 connected to the narrow opening of the funnel 61 is provided at the bottom of the cooling tank 31; the wide opening of the funnel 61 is connected to the medium storage cavity 63 through the telescopic bellows 62; the funnel 61, the telescopic bellows 62, and the medium storage cavity 63 are all filled with the liquid heat exchange medium 4; the compression driving mechanism is connected to the medium storage cavity 63.

[0063] In a possible implementation manner of the embodiment of the present application, the liquid level control device further includes a support plate 5 for supporting the optical element 3, the optical element 3 is disposed on the support plate 5, and a through hole 52 for avoiding the supplementary medium storage structure is provided on the support plate 5; the second liquid level control mechanism 6 further includes a bracket 64 for supporting the supplementary medium storage structure, and the bracket 64 is installed below the support plate 5.

[0064] In a possible implementation manner of the embodiment of the present application, a first heat insulation layer 65 is provided at the connection between the bracket 64 and the support plate 5, and a second heat insulation layer 66 is provided at the connection between the compression driving mechanism and the medium storage cavity 63, so as to prevent the heat absorbed by the optical element 3 from being conducted to the clamping mechanism of the optical element 3 by the liquid heat exchange medium 4, causing thermal deformation of the relevant components of the clamping mechanism and affecting the adjustment accuracy.

[0065] The embodiments of the present application are mainly directed to the optical element 3 with a relatively large spot size range. The effective cooling length of this type of optical element 3 requires a relatively large adjustment range. Therefore, the change range of the liquid level height of the liquid heat exchange medium 4 is also relatively large. It is difficult to significantly increase the liquid level height only by pressing down the slider 12. A second liquid level control mechanism 6 needs to be added on the basis of the first liquid level control mechanism 1. The second liquid level control mechanism 6 mainly consists of a funnel 61, a telescopic bellows 62, and a medium storage cavity 63. A channel 33 with a diameter of 2 mm is machined below the center of the cooling tank 31 for the inflow and outflow of the liquid heat exchange medium 4. The size of this channel needs to be minimized as much as possible to avoid interfering with the heat transfer structure of the mirror body. The medium inlet and outlet at the upper end of the funnel 61 are connected to the lower end of the channel 33 by interference fit or bolt connection. The funnel 61, the telescopic bellows 62, and the medium storage cavity 63 can be connected by welding to increase the sealing performance of the device. The support point 51 of the support plate 5 is used to support the optical element 3. The support plate 5 is machined with a through hole 52 below the position of the channel 33 for placing the funnel 61. The upper bracket 64 is welded to the surface of one end of the telescopic bellows 62 close to the optical element 3 to fix one end of the telescopic bellows 62. Zirconia ceramic thermal insulation layers are added below the medium storage cavity 63 and between the support plate 5 and the bracket 64 to prevent the liquid heat exchange medium 4 from conducting the heat absorbed by the optical element 3 to the clamping mechanism of the optical element 3, causing thermal deformation of the relevant components of the clamping mechanism and affecting the adjustment accuracy. The bracket 64 and the first thermal insulation layer 65 are fixed to the support plate 5 by bolts. Initially, the funnel 61, the telescopic bellows 62, and the medium storage cavity 63 are all filled with the liquid heat exchange medium 4. A compression driving mechanism (not shown in the figure, acting on the second thermal insulation layer 66) is arranged below the medium storage cavity 63. The compression driving mechanism includes a motor, and the motor is connected to the control system. When the liquid level of the liquid heat exchange medium 4 needs to rise, the motor below pushes the medium storage cavity 63 upward. At this time, the telescopic bellows 62 is compressed, and the excess liquid heat exchange medium 4 is squeezed into the cooling tank 31 of the optical element 3 through the channel 33, realizing the increase of the liquid level of the liquid heat exchange medium 4. When the liquid level of the liquid heat exchange medium 4 reaches the appropriate position under the action of the second liquid level control mechanism 6, the motor stops moving, and then the first liquid level control mechanism 1 is used to finely adjust the liquid level to obtain the final reasonable effective cooling length . Similarly, when the liquid level of the liquid heat exchange medium 4 needs to drop, the compression driving mechanism below pulls the medium storage cavity 63 downward. At this time, the telescopic bellows 62 is stretched, and the excess liquid heat exchange medium 4 in the cooling tank 31 flows downward through the channel 33 under the action of gravity, causing the liquid level of the liquid heat exchange medium 4 to drop. It should be noted that the inner surfaces of the funnel 61, the telescopic bellows 62, and the medium storage cavity 63 can be plated with an anti-corrosion coating when necessary to avoid being corroded and damaged in the case of long-term contact with the liquid heat exchange medium 4.

[0066] The above is a specific description of the preferred embodiment of the present application. However, the present application is not limited to the above-mentioned embodiments. Those skilled in the art can make various equivalent deformations or substitutions without departing from the spirit of the present application, and these equivalent deformations or substitutions are all included within the scope defined by the claims of the present application.

Claims

1. A liquid level control device for a vacuum beam line mirror box, characterized in that Comprising: An optical element, on which a cooling groove is provided, and the cooling groove is filled with a liquid heat exchange medium; A cooling block, which is immersed in the liquid heat exchange medium; A first liquid level control mechanism, which includes a slider and a slider driving mechanism. The slider is immersed in the liquid heat exchange medium, and the slider driving mechanism is connected to the slider and can drive the slider to move up and down to change the volume of the slider immersed in the liquid heat exchange medium.

2. The device according to claim 1, wherein The slider driving mechanism includes a fixed slide rail seat, a motor, a lead screw and a nut seat. The motor is installed on the fixed slide rail seat. The lower end of the nut seat is connected to the slider, and a threaded hole is provided at the upper end of the nut seat. The motor is threadedly connected to the threaded hole through the lead screw.

3. The device according to claim 2, characterized in that, The first liquid level control mechanism further includes an upper and lower limit assembly for limiting the distance of the up and down movement of the slider.

4. The device according to claim 1, characterized in that, Steps are provided at the bottom of the cooling groove, so that the cooling groove has different depths; the depth below the slider is greater than the depth below the cooling block.

5. The device according to claim 1, characterized in that, It further includes a second liquid level control mechanism, which includes a compressible supplementary medium storage structure and a compression driving mechanism; the supplementary medium storage structure is filled with the liquid heat exchange medium, and the supplementary medium storage structure has a medium inlet and outlet communicating with the cooling groove; the compression driving mechanism is connected to the supplementary medium storage structure and can drive the supplementary medium storage structure to compress or restore. During the compression process of the supplementary medium storage structure, the liquid heat exchange medium is injected into the cooling groove through the medium inlet and outlet. During the restoration process of the supplementary medium storage structure, the liquid heat exchange medium in the cooling groove flows into the supplementary medium storage structure through the medium inlet and outlet.

6. The device according to claim 5, characterized in that The supplementary medium storage structure includes a funnel, a telescopic bellows and a medium storage cavity; the upper end of the funnel is a narrow opening serving as the medium inlet and outlet, and the lower end is a wide opening; a channel connected to the narrow opening of the funnel is provided at the bottom of the cooling groove; the wide opening of the funnel is connected to the medium storage cavity through the telescopic bellows; the funnel, the telescopic bellows and the medium storage cavity are all filled with the liquid heat exchange medium; the compression driving mechanism is connected to the medium storage cavity.

7. The device according to claim 6, wherein The device further includes a support plate for supporting the optical element. The optical element is arranged on the support plate, and a through hole for avoiding the supplementary medium storage structure is provided on the support plate; the second liquid level control mechanism further includes a bracket for supporting the supplementary medium storage structure, and the bracket is installed below the support plate.

8. The device according to claim 7, characterized in that, A first heat insulation layer is provided at the connection between the bracket and the support plate, and a second heat insulation layer is provided at the connection between the compression driving mechanism and the medium storage cavity.

9. The device according to claim 1, wherein There are two first liquid level control mechanisms, symmetrically distributed on both sides of the cooling block.

10. The device according to claim 9, characterized in that The slider driving mechanisms of the two first liquid level control mechanisms are both connected to a controller, and the controller is used to control the two slider driving mechanisms to drive the sliders to move up or down synchronously.

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