Laser ablation driving experimental device under microgravity condition and experimental method thereof

Abstract

The invention discloses a laser ablation driving experimental device under a microgravity condition and an experimental method thereof. The experimental device comprises an optical platform; the vacuum falling tower assembly is arranged on the optical platform, and the experimental sample does free falling motion in the vacuum falling tower assembly; the laser is arranged on the optical platform, and a laser beam emitted by the laser is used for ablating and driving the experimental sample; the sample following assembly is arranged on the optical platform, is positioned between the vacuum falling tower assembly and the laser and is used for changing the light path of the laser beam emitted by the laser so that the laser beam is continuously focused on the experimental sample; and the recording piece is mounted at the top of the vacuum falling tower assembly. An experiment mode different from the previous experiment mode is adopted, during an experiment, an experiment sample is in a free falling body state without any constraint and is in a weightless state in the vacuum falling tower assembly, the sample following assembly and the experiment sample fall at the same acceleration, and it can be guaranteed that the laser direction and position are consistent with those of the weightless experiment sample; and the completeness and accuracy of the shot experiment phenomenon are ensured.

Description

Technical Field

[0001] This invention relates to the field of drop tower experiments, specifically to a laser ablation-driven experimental device and method under microgravity conditions. Background Technology

[0002] Space debris, due to its prolonged state of being out of control, is often subject to complex rotational or even free-tumbling motions due to factors such as solar radiation pressure and gravitational gradients. Because of its extremely complex motion patterns, direct on-orbit capture is difficult. Therefore, despinning treatment is necessary before direct capture to control its attitude.

[0003] The principle of laser ablation-driven technology is to irradiate the target surface with a high-energy pulsed laser, instantly ablating, vaporizing, and plasmaizing it, thereby generating a high-speed back jet and thus a driving impulse. The principle of laser-driven despinning technology is to control the size, position, and energy density of the laser irradiation fragments to generate an impulse deviating from the target's center of mass, thereby generating a control torque that can change the target's rotational state and thus control its attitude. Laser-driven despinning technology has advantages such as long-distance non-contact operation, precise control of the despinning torque, no loss in the despinning process itself, and almost no damage to the target. The research and application of this technology rely on the study of the dynamic behavior of laser-ablated targets on the ground and the laser-driven despinning process and its laws.

[0004] Currently, ground-based despinning experiments can only be conducted by fixing the target to a rotating base and capturing its dynamic response through built-in sensors or an external camera driven by lasers. Under the constraint of the base, the target can only rotate around a single axis and is affected by gravity and base drag, causing the experimental results to deviate from the unconstrained microgravity conditions in real space. Furthermore, this method is only applicable to regular targets with known rotation axes. The other two axes of rotation and the three-axis displacement must be tested using methods developed in a microgravity-free environment.

[0005] Methods for conducting microgravity experiments on the ground mainly involve drop tower systems or using methods such as air levitation and magnetic levitation to counteract gravity. However, due to the large size and weight of lasers and their inability to withstand the acceleration and impact of descent, conventional drop towers are unsuitable for this type of experiment. If air levitation or magnetic levitation were used, the disturbance force on the target would be too large, overwhelming the minute driving force generated by the laser ablation drive. Furthermore, none of these technologies have currently been applied to laser ablation-driven ground experiments. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention designs a laser ablation-driven experimental device under microgravity conditions, comprising: an optical platform; a vacuum drop tower assembly disposed on the optical platform, wherein the experimental sample undergoes free fall within the vacuum drop tower assembly; a laser disposed on the optical platform, wherein the laser beam emitted by the laser is used to ablate and drive the experimental sample; a sample tracking assembly disposed on the optical platform and located between the vacuum drop tower assembly and the laser, wherein the laser beam emitted by the laser is used to change the optical path so that it is continuously focused on the experimental sample; and a recording device mounted on top of the vacuum drop tower assembly.

[0007] Preferably, the sample following component includes: a vertical displacement slide rail, disposed on the optical platform and located between the vacuum drop tower component and the laser; an optical path changing component, mounted on the vertical displacement slide rail, used to change the optical path of the laser beam emitted by the laser so that it is continuously focused on the experimental sample; and a slide rail buffer layer, mounted at the bottom of the vertical displacement slide rail.

[0008] Preferably, the optical path changing component includes: a vertical displacement platform, mounted on a vertical displacement slide rail, which moves freely with the experimental sample; two reflectors, one mounted on the vertical displacement platform and the other mounted on the vertical displacement slide rail at a position flush with the optical path of the laser beam emitted by the laser, the two reflectors working together to change the optical path of the laser beam emitted by the laser; and a focusing lens, mounted on the vertical displacement platform, used to focus the laser beam emitted by the laser, whose optical path has been changed by the reflectors, onto the experimental sample.

[0009] Preferably, there are two recording devices, with the other recording device mounted on a vertical displacement platform and subject to free fall along with the vertical displacement platform.

[0010] Preferably, the distance between the vertical displacement slide rail and the vacuum drop tower assembly is adjustable.

[0011] Preferably, the vacuum drop tower assembly includes: a vacuum drop tower, set on an optical platform, in which the experimental sample undergoes free fall, and a recording device installed at the top of the vacuum drop tower; a drop tower release mechanism, installed at the top of the vacuum drop tower, for temporarily fixing the experimental sample; and an inner buffer layer, installed at the bottom of the vacuum drop tower.

[0012] Preferably, an optical window is provided on the side of the vacuum drop tower, and the optical window is positioned opposite to the sample tracking component.

[0013] Preferably, the experimental apparatus further includes a signal trigger, and the vacuum drop tower assembly, sample tracking assembly, laser, and recording device are all connected to the signal trigger. The signal trigger is used to control the opening and closing of the vacuum drop tower assembly, sample tracking assembly, laser, and recording device.

[0014] Based on the same design concept, this invention provides a laser ablation-driven experimental method under microgravity conditions, comprising the following steps: setting up a vacuum drop tower assembly, a sample tracking assembly, and a laser on an optical platform according to experimental requirements, wherein the sample tracking assembly is located between the vacuum drop tower assembly and the laser; installing a recorder on top of the vacuum drop tower assembly; and connecting the vacuum drop tower assembly, sample tracking assembly, laser, and recorder to a signal trigger; adjusting the sample tracking assembly to ensure the optical path of the laser beam emitted by the laser meets experimental requirements; installing the experimental sample inside the vacuum drop tower assembly and evacuating the interior of the vacuum drop tower assembly; setting the laser output parameters and signal delay of the signal trigger according to experimental requirements; activating the signal trigger, causing the vacuum drop tower assembly to release the experimental sample, which then undergoes free fall within the assembly; the sample tracking assembly alters the optical path of the laser beam emitted by the laser to continuously focus on the experimental sample; and the recorder records data from the free fall process of the experimental sample; and finally, reading the data recorded by the recorder to complete the experiment.

[0015] Preferably, adjusting the sample following assembly to ensure that the optical path of the laser beam emitted by the laser meets the experimental requirements includes the following steps: adjusting two mirrors to change the optical path of the laser beam emitted by the laser, ensuring that the optical path of the laser beam emitted by the laser remains stable when the vertical displacement platform moves up and down; adjusting the focusing lens to ensure that the optical path of the laser beam emitted by the laser meets the experimental requirements.

[0016] Compared with the closest prior art, the beneficial effects of the present invention are as follows:

[0017] 1. In the experiment, the experimental sample is in free fall within the vacuum drop tower assembly, without any constraints affecting its six degrees of freedom motion, and is in a state of weightlessness. The sample following assembly falls with the same acceleration as the experimental sample. The sample following assembly is used to change the optical path of the laser beam emitted by the laser so that it is continuously focused on the experimental sample. This ensures that the laser direction and position are consistent with the weightless experimental sample, thus ensuring that the experimental phenomena captured are complete and accurate.

[0018] 2. The vertical displacement platform of the present invention can move along the vertical displacement slide rail at a set acceleration, and has a deceleration buffer device at the end, so as to keep it falling together with the sample. The line connecting the reflector and the focusing lens is perpendicular to the vacuum drop tower assembly and points to the experimental sample, which can guide the laser beam emitted by the horizontally incident laser to a position at the same height as the experimental sample and focus it on the experimental sample, so that the laser continuously acts on the experimental sample in a weightless falling state, thereby ensuring the completeness and accuracy of the experimental phenomena captured. Attached Figure Description

[0019] Figure 1 This is a side view schematic diagram of the experimental apparatus of the present invention.

[0020] Figure 2 This is a top view schematic diagram of the experimental apparatus of the present invention.

[0021] Figure label:

[0022] 1- Drop tower release mechanism, 2- Experimental sample, 3- Vacuum drop tower, 4- Optical window, 5- Buffer layer inside the drop tower, 6- Vertical displacement slide rail, 7- Vertical displacement platform, 8- Reflector, 9- Focusing lens, 10- Recording device, 11- Slide rail buffer layer, 12- Laser, 13- Optical platform. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] like Figures 1-2 As shown, this invention provides a laser ablation-driven experimental device under microgravity conditions, comprising: a vacuum drop tower assembly, a sample tracking assembly, an experimental sample 2, a recording device 10, a laser 12, and an optical platform 13. The vacuum drop tower assembly, the sample tracking assembly, and the laser 12 are all mounted on the optical platform 13, with the sample tracking assembly positioned between the vacuum drop tower assembly and the laser 12. The experimental sample 2 is placed inside the vacuum drop tower assembly and undergoes free fall within it. The sample tracking assembly is used to change the optical path of the laser beam emitted by the laser 12, ensuring it is continuously focused on the experimental sample 2. The recording device 10 is mounted on top of the vacuum drop tower assembly. The vacuum drop tower assembly has an effective drop distance of 5 meters and provides approximately 1 second of free fall time. During the experiment, the experimental sample was in free fall within the vacuum drop tower assembly, with no constraints affecting its six degrees of freedom motion, and was in a state of weightlessness. The sample following assembly fell with the same acceleration as the experimental sample. The sample following assembly was used to change the optical path of the laser beam emitted by the laser so that it was continuously focused on the experimental sample. This ensured that the laser direction and position were consistent with the weightless experimental sample, thus ensuring that the experimental phenomena captured were complete and accurate.

[0025] Preferably, the sample tracking component includes: a vertical displacement slide rail 6, an optical path changing component, and a slide rail buffer layer 11. The vertical displacement slide rail 6 is disposed on the optical platform 13 and between the vacuum drop tower assembly and the laser 12. The optical path changing component and the slide rail buffer layer 11 are both mounted on the vertical displacement slide rail 6, wherein the slide rail buffer layer 11 is mounted at the bottom of the vertical displacement slide rail 6. The optical path changing component is used to change the optical path of the laser beam emitted by the laser 12 so that it is continuously focused on the experimental sample 2.

[0026] Preferably, the optical path changing component includes: a vertical displacement platform 7, a reflector 8, and a focusing lens 9. The vertical displacement platform 7 is mounted on the vertical displacement slide rail 6 and moves freely with the experimental sample 2. There are two reflectors 8, one mounted on the vertical displacement platform 7 and the other mounted on the vertical displacement slide rail 6, aligned with the optical path of the laser beam emitted by the laser 12. The two reflectors 8 work together to change the optical path of the laser beam emitted by the laser 12. The focusing lens 9 is mounted on the vertical displacement platform 7 and is used to focus the laser beam emitted by the laser 12, whose optical path has been changed by the reflector 8, onto the experimental sample 2. The focusing lens has a focal length of 1000mm, and the spot size can be controlled by adjusting the distance as needed. The vertical displacement platform 7 can move along the vertical displacement slide rail at a set acceleration, and has a deceleration buffer device at the end, so as to keep it falling together with the sample. The line connecting the reflector 8 and the focusing lens 9 is perpendicular to the vacuum drop tower assembly and points to the experimental sample 2. It can guide the laser beam emitted by the horizontally incident laser 12 to a position at the same height as the experimental sample 2 and focus it on the experimental sample 2, so that the laser can continuously act on the experimental sample 2 which is in a weightless falling state.

[0027] Preferably, there are two recording devices 10, with the other recording device 10 mounted on the vertical displacement platform 7 and undergoing free fall motion with the vertical displacement platform 7. There is one recording device 10 at the top of the vacuum drop tower assembly and one on the vertical displacement platform 7. The recording device 10 on the displacement platform, falling with the experimental sample 2, records the attitude changes of the experimental sample 2 under laser drive. The recording device 10 at the top of the vacuum drop tower assembly records the motion of the experimental sample 2 in the laser drive direction. A common 400 frame rate camera is sufficient to meet the recording needs of the experiment.

[0028] Preferably, the distance between the vertical displacement slide rail 6 and the vacuum drop tower assembly is adjustable. The laser spot size can be adjusted by changing the distance between the vertical displacement slide rail 6 and the vacuum drop tower assembly, thereby adjusting the horizontal distance L between the focusing lens 9 and the experimental sample 2.

[0029] Preferably, the vacuum drop tower assembly includes: a drop tower release mechanism 1, a vacuum drop tower 3, and an inner buffer layer 5. The drop tower release mechanism 1 is installed at the top of the vacuum drop tower 3, and the inner buffer layer 5 is disposed at the bottom of the vacuum drop tower 3. The experimental sample 2 is installed at the bottom of the drop tower release mechanism 1, and after being released by the drop tower release mechanism 1, the experimental sample 2 undergoes free fall motion within the vacuum drop tower 3. The recording device 10 is installed at the top of the vacuum drop tower 3. The height of the vacuum drop tower 3 is 5 meters, providing 1 second of microgravity time.

[0030] Preferably, the side of the vacuum drop tower 3 is provided with an optical window 4, which is positioned opposite to the sample tracking component.

[0031] Preferably, the experimental apparatus further includes a signal trigger. The vacuum drop tower assembly, the sample tracking assembly, the laser 12, and the recording device 10 are all connected to the signal trigger. The signal trigger is used to control the opening and closing of the vacuum drop tower assembly, the sample tracking assembly, the laser 12, and the recording device 10. The drop tower release mechanism 1, the vertical displacement platform 7, the laser 12, and the recording device 10 are controlled by the signal trigger. By controlling the delay time of the trigger signal, the experimental sample 2, the vertical displacement platform 7, the laser 12, and the recording device 10 are linked according to experimental requirements. The signal trigger is a common experimental device, and the drop tower release mechanism can also be similar to conventional drop tower experimental equipment.

[0032] This invention provides a laser ablation-driven experimental method under microgravity conditions, comprising the following steps: A vacuum drop tower assembly, a sample tracking assembly, and a laser 12 are all positioned on an optical platform 13 according to experimental requirements. The sample tracking assembly is located between the vacuum drop tower assembly and the laser 12. A recording device 10 is installed on top of the vacuum drop tower assembly, and the vacuum drop tower assembly, sample tracking assembly, laser 12, and recording device 10 are connected to a signal trigger. The sample tracking assembly is adjusted so that the optical path of the laser beam emitted by the laser 12 meets the experimental requirements. The laser has an energy of 8J and a repetition rate of 20Hz, and can continuously apply 20 pulses during the descent. The experimental sample 2 is installed inside the vacuum drop tower assembly, and a vacuum is evacuated inside the assembly. The output parameters of the laser 12 are set according to the experimental requirements, and the signal delay of the signal trigger is set. The activation signal trigger releases experimental sample 2 from the vacuum drop tower assembly. Sample 2 undergoes free fall within the assembly. The sample follows the assembly, altering the path of the laser beam emitted by laser 12 to ensure continuous focus on sample 2. Recorder 10 records data from sample 2 during its free fall. Reading the data recorded by recorder 10 completes the experiment.

[0033] Preferably, adjusting the sample following assembly to ensure the optical path of the laser beam emitted by the laser 12 meets experimental requirements includes the following steps: adjusting the two reflectors 8 to change the optical path of the laser beam emitted by the laser 12, ensuring that the optical path of the laser beam emitted by the laser 12 remains stable while the vertical displacement platform 7 moves up and down; and adjusting the focusing lens 9 to ensure the optical path of the laser beam emitted by the laser 12 meets experimental requirements.

[0034] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0035] Furthermore, the terms "upper" and "lower" 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 "upper" or "lower" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this application, unless otherwise expressly specified and limited, the terms "installation," "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, an electrical connection, or a connection that allows communication between components; 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the pending application of the present invention.

Claims

1. A laser ablation-driven experimental device under microgravity conditions, characterized in that, include: Optical platform; The vacuum drop tower assembly is set on the optical platform, and the experimental sample undergoes free fall motion inside the vacuum drop tower assembly; A laser is mounted on the optical platform, and the laser beam emitted by the laser is used to ablate and drive the experimental sample. A sample tracking component is disposed on the optical platform and located between the vacuum drop tower component and the laser, and is used to change the optical path of the laser beam emitted by the laser so that it is continuously focused on the experimental sample; A recording device is installed on top of the vacuum drop tower assembly.

2. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 1, characterized in that, The sample tracking component includes: A vertical displacement slide rail is disposed on the optical platform and located between the vacuum drop tower assembly and the laser; An optical path changing component, mounted on the vertical displacement slide rail, is used to change the optical path of the laser beam emitted by the laser so that it is continuously focused on the experimental sample; A slide rail buffer layer is installed at the bottom of the vertical displacement slide rail.

3. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 2, characterized in that, The optical path alteration component includes: A vertical displacement platform is mounted on the vertical displacement slide rail and moves in free fall along with the experimental sample. There are two reflectors. One reflector is mounted on the vertical displacement platform, and the other reflector is mounted on the vertical displacement slide rail at a position flush with the optical path of the laser beam emitted by the laser. The two reflectors work together to change the optical path of the laser beam emitted by the laser. A focusing mirror, mounted on the vertical displacement platform, is used to focus the laser beam emitted by the laser whose optical path has been changed by the reflecting mirror onto the experimental sample.

4. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 3, characterized in that, The number of recording devices is two, with the other recording device mounted on the vertical displacement platform and undergoing free fall motion with the vertical displacement platform.

5. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 2, characterized in that, The distance between the vertical displacement slide rail and the vacuum drop tower assembly is adjustable.

6. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 1, characterized in that, The vacuum drop tower assembly includes: A vacuum drop tower is set on the optical platform. The experimental sample undergoes free fall inside the vacuum drop tower, and a recording device is installed on the top of the vacuum drop tower. A drop tower release mechanism is installed on top of the vacuum drop tower to temporarily fix the experimental sample. A buffer layer is installed at the bottom of the vacuum drop tower.

7. The laser ablation-driven experimental apparatus under microgravity conditions as described in claim 6, characterized in that, An optical window is provided on the side of the vacuum drop tower, and the optical window is positioned opposite the sample tracking component.

8. The laser ablation-driven experimental apparatus under microgravity conditions as described in any one of claims 1-7, characterized in that, The experimental apparatus also includes a signal trigger. The vacuum drop tower assembly, the sample tracking assembly, the laser, and the recording device are all connected to the signal trigger. The signal trigger is used to control the opening and closing of the vacuum drop tower assembly, the sample tracking assembly, the laser, and the recording device.

9. A laser ablation-driven experimental method under microgravity conditions, characterized in that, Includes the following steps: The vacuum drop tower assembly, sample tracking assembly, and laser are all set up on the optical platform according to the test requirements. The sample tracking assembly is located between the vacuum drop tower assembly and the laser. The recording device is installed on top of the vacuum drop tower assembly, and the vacuum drop tower assembly, sample tracking assembly, laser, and recording device are connected to the signal trigger. Adjust the sample tracking components to ensure that the optical path of the laser beam emitted by the laser meets the experimental requirements; The experimental sample was installed inside the vacuum drop tower assembly, and the inside of the vacuum drop tower assembly was evacuated. Set the output parameters of the laser according to the experimental requirements, and set the signal delay of the signal trigger. The activation signal trigger releases the experimental sample from the vacuum drop tower assembly. The experimental sample undergoes free fall within the vacuum drop tower assembly. The sample follows the assembly to change the optical path of the laser beam emitted by the laser so that it is continuously focused on the experimental sample. The recorder records the data of the experimental sample during the free fall process. Read the data recorded in the log file to complete the experiment.

10. The laser ablation-driven experimental method under microgravity conditions as described in claim 9, characterized in that, The adjustment of the sample tracking component to ensure that the optical path of the laser beam emitted by the laser meets the experimental requirements includes the following steps: Adjusting the two mirrors to change the optical path of the laser beam emitted by the laser requires ensuring that the optical path of the laser beam emitted by the laser remains stable as the vertical displacement platform moves up and down. Adjust the focusing lens to ensure that the optical path of the laser beam emitted by the laser meets the experimental requirements.

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