CD-CH composite polymer spherical cap in double-cone collision ignition and its preparation method

Abstract

The present invention provides a CD-CH composite polymer spherical cap for use in double-cone collision ignition and a preparation method thereof. The preparation method comprises: preparing a CD polymer hollow sphere using a microfluidic method; depositing a CH film on the CD polymer hollow sphere to form a CD-CH composite polymer hollow sphere; cutting the CD-CH composite polymer hollow sphere using a laser tail cutting method; and peeling the cut CD-CH composite polymer spherical cap from the CD-CH composite polymer hollow sphere using a sharp-ended tool along the cut contour to obtain a CD-CH composite polymer spherical cap for use in double-cone collision ignition. The present invention solves the problems of difficult precise control of the CH layer thickness and difficulty in cutting and sampling the spherical cap during the preparation of the CD-CH composite polymer spherical cap, thereby achieving high-precision and batch production of CD-CH composite polymer spherical caps.

Description

Technical Field

[0001] The present invention relates to the technical field of laser fusion ignition components, and in particular to a CD-CH composite polymer spherical cap in double-cone collision ignition and a preparation method thereof. Background Art

[0002] Energy is the most fundamental element required for human survival and development, and a crucial material foundation for social progress and economic development. Controlled nuclear fusion is considered a "clean" and "efficient" new energy source due to its high reaction energy, abundant fuel reserves, safe operation, and environmental friendliness.

[0003] An important part of achieving controlled nuclear fusion is to laser ablate the carbon-deuterium (CD) spherical cap to form deuterium-deuterium collisions to produce neutrons. However, in order to avoid background interference from neutrons in the ablation area, the experiment needs to deposit a carbon-hydrogen (CH) layer on the CD spherical cap to remove the impact on the detection of colliding neutrons. Since the spherical cap produced by microfluidics is a whole hollow sphere, the CD hollow sphere needs to be cut when it is assembled on the target holder. In addition, when the CD spherical cap is fixed to deposit the CH layer, since the lower spherical cap is difficult to achieve uniform deposition, usually only the upper spherical cap can be used for the experiment. This also poses a key problem for the experiment: cutting the CD spherical cap and retaining the upper layer.

[0004] Ultra-precision machining can be used for cutting materials, utilizing a tool servo system to achieve precise cutting of the material being processed. Other cutting techniques include UV laser machining. However, these cutting methods all present certain challenges. For example, ultra-precision machining is limited by tool path constraints, resulting in complex and time-consuming systems and difficulty in cutting hollow spherical crowns. UV laser machining also generates significant thermal effects that can damage the material, causing black edges, cracks, and bubbles around the cut surface.

[0005] Femtosecond laser processing technology is recognized by the industry as a true "high-resolution" and "cold processing" technology. Femtosecond laser is an ultrashort pulse laser, in which only a small portion of the beam energy in the spot can reach the threshold intensity to cause multiphoton absorption. Therefore, it has a high spatial resolution and can accurately locate the area of ​​action, showing great advantages in the field of fine processing. In addition, the thermal effect generated by femtosecond laser processing is very small, and the processed material has advantages such as no heat-affected zone and microcracks. It can be used for cutting CD spherical crowns and can maximize the quality of the processed area. However, when using femtosecond laser to cut CD spherical crowns, the laser beam during cutting creates a pressure difference between the inside and outside of the hollow spherical crown, and the upper spherical crown is very easy to fly off, greatly reducing the utilization rate of the material.

[0006] Currently, there is an urgent need for a method to prepare a CD-CH composite polymer spherical cap in double-cone collision ignition, so as to avoid the problem that the CD spherical cap with CH deposited on the upper layer is blown away by the airflow during the laser cutting process and cannot be retained, making sampling difficult.

[0007] After searching, we found:

[0008] A Chinese invention patent application, publication number CN112935709A, discloses a femtosecond laser processing method and system for polymer spherical caps in double-cone collision ignition. The specific process includes depositing and growing a polymer film on micro-steel balls on a steel mesh substrate; positioning the machine vision focus on the surface of the micro-steel ball film using a mobile platform; cutting the spherical cap film from the micro-steel balls as a whole; gently rubbing the cut spherical cap film from the micro-steel balls using a cotton swab; placing the peeled spherical cap film flat on a glass slide, and modifying the spherical cap edge using a femtosecond laser. However, the patent still has the following problems: it only describes a single polymer spherical shell with a deposited film. In the hollow sphere cutting process, since there is no steel ball, there is no bonding force between the steel ball and the polymer. As a result, the spherical shell will be blown away as long as there is airflow during laser cutting. Summary of the Invention

[0009] In view of the defects in the prior art, the purpose of the present invention is to provide a CD-CH composite polymer spherical cap for double-cone collision ignition and a preparation method thereof, which can solve the problems of the difficulty in preparing and sampling the CD-CH composite polymer spherical cap in the prior art.

[0010] According to one aspect of the present invention, a method for preparing a CD-CH composite polymer spherical cap in a double-cone collision ignition is provided, the method comprising:

[0011] CD polymer hollow spheres were prepared using a microfluidic method;

[0012] depositing a CH film on the CD polymer hollow sphere to form a CD-CH composite polymer hollow sphere;

[0013] Cutting the CD-CH composite polymer hollow spheres by laser tail cutting;

[0014] The cut CD-CH composite polymer spherical cap is peeled off from the CD-CH composite polymer hollow sphere by using a tool with a sharp end to pry it apart along the cutting contour, thereby obtaining the CD-CH composite polymer spherical cap in the double-cone collision ignition.

[0015] Furthermore, the CD polymer hollow spheres are prepared by a microfluidic method, wherein:

[0016] The microfluidic method involves three phases of liquid, namely an inner water phase, an intermediate oil phase and an outer water phase. The intermediate oil phase is a CD polymer material, the inner water phase is ultrapure water, and the outer water phase is an aqueous solution containing a surfactant.

[0017] Furthermore, a CH film is deposited on the CD polymer hollow spheres, wherein: the CH film is deposited by chemical vapor deposition, and the raw material for chemical vapor deposition is N-type polyparaxylene; during deposition, a throttle plate is provided between the vacuum pump and the through hole of the deposition chamber to increase the deposition speed of the N-type polyparaxylene.

[0018] Furthermore, a CH film is deposited on the CD polymer hollow spheres, wherein the temperature of the cracking furnace is 630-670°C, the temperature of the evaporation chamber is 170-180°C, and the temperature of the cold trap is -95--105°C.

[0019] Furthermore, before cutting the CD-CH composite polymer hollow spheres using the laser tail-leaving cutting method, the method further includes: measuring and recording the diameter of each CD-CH composite polymer hollow sphere, so that when the prepared CD-CH composite polymer spherical caps are subsequently assembled into a double-cone ignition collision target, a pair of spherical caps are on the same spherical surface.

[0020] Furthermore, the CD-CH composite polymer hollow spheres are cut by a laser tail cutting method, wherein a femtosecond laser or a picosecond laser is used; the laser has a wavelength of 650-1030 nm, a power of 1-3 W, and a pulse width of 50 fs-200 ps.

[0021] Furthermore, the CD-CH composite polymer hollow spheres are cut by using a laser tail cutting method, wherein the laser tail cutting is achieved by controlling the cutting pattern, the cutting pattern is a circle with a notch, the circle diameter is 700-900 μm, and the notch angle is 1° to 3°.

[0022] Furthermore, the CD-CH composite polymer hollow sphere is cut by the laser tail cutting method, wherein: the laser tail cutting is achieved by controlling the laser on delay and off delay, the on-off delay range is 200-700 μs, and the off delay range is 300-900 μs, and the cut pattern is a complete circle with a diameter of 700-900 μm.

[0023] Furthermore, the CD-CH composite polymer hollow spheres are cut by a laser tail cutting method, wherein a laser cutting processing platform positions the CD-CH composite polymer hollow spheres through a microscope, and an alignment accuracy is below 10 μm.

[0024] According to another aspect of the present invention, a CD-CH composite polymer spherical cap for double-cone collision ignition is provided, and the spherical cap is prepared by the above method.

[0025] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0026] The CD-CH composite polymer spherical cap and preparation method for double-cone collision ignition provided by the present invention combine the advantages of microfluidics, chemical vapor deposition, and tail-leaving laser cutting. Chemical vapor deposition can precisely control the thickness of the CH layer in the CD-CH composite polymer hollow sphere. Because the mass of the CD-CH composite polymer hollow spherical cap is too small, the laser tail-leaving cutting method can effectively prevent the CD-CH composite polymer hollow spherical cap from being blown away by the airflow during the cutting process. After cutting, the adhered parts are separated using pointed tweezers or other tools. This method solves the problem of difficulty in cutting and sampling the CD-CH composite polymer hollow spherical cap. Furthermore, due to the precise control of the laser tail, the tail size is sufficiently small. After peeling, the CD-CH polymer tail can be completely detached due to the rigidity of the spherical cap, without any residual CD-CH polymer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0028] Figure 1 Schematic diagram of laser tail cutting of a hollow spherical cap of a CD-CH composite polymer in one embodiment of the present invention;

[0029] Figure 2 Schematic diagram of the process for preparing a CD-CH composite polymer spherical cap according to one embodiment of the present invention;

[0030] Figure 3 A schematic structural diagram of a chemical vapor deposition apparatus according to an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the appearance of CD-CH composite polymer hollow spheres in one embodiment of the present invention;

[0032] Figure 5 Schematic cross-sectional view of CD-CH composite polymer hollow spheres according to one embodiment of the present invention;

[0033] Figure 6 Schematic diagram of the appearance of a CD-CH composite polymer hollow spherical crown in one embodiment of the present invention;

[0034] In the figure: 1 is a CD-CH composite polymer hollow sphere, 2 is a net for placing the CD-CH composite polymer hollow sphere, 3 is a laser, 4 is a laser beam, 5 is a path of laser tail cutting, 6 is a CH layer, and 7 is a CD layer. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0036] The preparation method of CD-CH composite polymer spherical cap in double cone collision ignition provided by one embodiment of the present invention is as follows: Figure 1-2 ,include:

[0037] S1, preparation of CD polymer hollow spheres using microfluidic method;

[0038] S2, depositing a layer of CH thin film on the CD polymer hollow sphere to form CD-CH composite polymer hollow spheres, such as Figure 4 The cross-sectional diagram of CD-CH composite polymer hollow sphere is shown in Figure 5 As shown, in the CD-CH composite polymer hollow sphere, the CH layer 6 is formed on the surface of the CD layer 7;

[0039] S3, using the laser tail cutting method to cut the CD-CH composite polymer hollow spheres; according to the shape of the spherical cap, the cutting path should be a circle. Laser tail cutting means leaving an adhesion area (tail) during cutting, so that the actual cutting path forms a circle with a gap;

[0040] S4, peeling the cut CD-CH composite polymer spherical cap from the CD-CH composite polymer hollow sphere along the cutting contour to obtain the CD-CH composite polymer spherical cap in the double cone collision ignition, as shown in FIG. Figure 6 As shown, the CH layer 6 is formed on the CD layer 7 in the CD-CH composite polymer spherical cap.

[0041] In some embodiments, in step S1, the microfluidic method involves three phases of liquid, namely an inner water phase, an intermediate oil phase and an outer water phase, the intermediate oil phase is a CD polymer material, the inner water phase is ultrapure water, and the outer water phase is an aqueous solution containing a surfactant, thereby preparing CD polymer hollow spheres of a certain thickness.

[0042] In some embodiments, in step S2, a CH thin film is deposited by chemical vapor deposition, and the raw material for chemical vapor deposition is N-type polyparaxylene; the equipment used for chemical vapor deposition is such as Figure 3As shown, during deposition, a throttle plate is placed between the vacuum pump and the through-hole in the deposition chamber to reduce the diameter of the through-hole. This prevents the vacuum pump from pumping away too much of the lighter N-type parylene gas, thereby increasing the deposition rate of N-type parylene. Based on the physical and chemical properties of the raw materials, the cracking furnace temperature is preferably 630-670°C, the evaporation chamber temperature is 170-180°C, and the cold trap temperature is -95--105°C.

[0043] In the process of depositing CH thin films by chemical vapor deposition, the thickness of the CH polymer layer can be controlled by the quality of the raw materials put in, thereby precisely regulating the thickness of the CH layer in the CD-CH composite polymer hollow spheres. The CH thin film layer prepared by chemical vapor deposition has the advantage of a dense structure.

[0044] Continue to refer to Figure 1 The prepared CD-CH composite polymer hollow sphere 1 is transferred to the net 2 for placing CD-CH composite polymer hollow spheres, and fixed in the culture dish through the mesh of the net. The diameter of the mesh is slightly smaller than the diameter of the CD-CH composite polymer hollow sphere 1 to prevent the CD-CH composite polymer hollow sphere 1 from rolling. The bottom of the CD-CH composite polymer hollow sphere 1 is adhered with double-sided tape to further prevent it from rolling.

[0045] In order to ensure that the pair of spherical caps are on the same spherical surface during subsequent assembly, before cutting the CD-CH composite polymer hollow sphere using the laser tail-leaving cutting method, the following steps are also included: measuring and recording the diameter of each CD-CH composite polymer hollow sphere, and selecting a pair of spherical caps with the same diameter to assemble them into a double-cone ignition collision target during subsequent assembly so that the pair of CD-CH composite polymer spherical caps are on the same spherical surface.

[0046] Continuing with the figure, above the CD-CH composite polymer hollow sphere 1, the laser 3 generates a laser beam 4, and cuts along the laser tail cutting path 5. In some embodiments, the laser tail cutting is achieved by controlling the cutting pattern. The cutting pattern is a circle with a notch, and no cutting is performed at the notch position. The notch position is the adhesion site after cutting. Preferably, the diameter of the circle is 700-900 μm, and the angle of the notch is 1° to 3°.

[0047] Since the actual laser light cannot be turned on and off immediately, for example, if the light is turned on a little late, the laser head has moved but the light has not yet turned on, that is, there is a switching delay, so that the notch position can be avoided. Similarly, when the light is turned off, the light is off but the laser head is still moving, that is, there is a light-off delay, which can also avoid cutting at the notch position. In some other embodiments, the CD-CH composite polymer hollow sphere is cut using a laser tail cutting method, wherein: the laser tail cutting is achieved by controlling the laser light on delay and light off delay. Depending on the size of the notch, the switching delay range is 200-700μs, and the light off delay range is 300-900μs. The cut pattern is a complete circle with a diameter of 700-900μm, so that the notch position can be avoided.

[0048] In some embodiments, the CD-CH composite hollow polymer spheres are cut using a laser tail-leaving cutting method, wherein: a femtosecond laser or picosecond laser is used to minimize the impact of thermal effects during laser cutting on the CD-CH composite polymer sphere cap; the laser wavelength and pulse width are determined based on the required cutting precision. Due to the small size of the cut, the higher the precision, the better. The laser power must ensure that the cut is complete without causing severe burning. Preferably, the laser wavelength is 650-1030 nm, the power is 1-3 W, and the pulse width is 50 fs-200 ps. The laser cutting processing platform uses a microscope to position the CD-CH composite hollow polymer spheres with an alignment accuracy of less than 10 μm, ensuring that the center of the laser-cut pattern is aligned with the center of the CD-CH composite hollow polymer sphere, thereby ensuring the uniformity of the CD-CH composite sphere cap.

[0049] After laser cutting, gently pry the CD-CH composite polymer cap from the CD-CH composite polymer hollow sphere with a tool (e.g., a sharp-tipped tweezer). The exfoliated CD-CH composite polymer cap should be soaked in alcohol and ultrasonically cleaned for 10-20 minutes to ensure a clean surface.

[0050] In the above embodiment, since the mass of the hollow spherical cap of the CD-CH composite polymer is too small, the laser tail-leaving cutting method can prevent the CD-CH composite polymer hollow spherical cap from being blown away by the airflow during the cutting process. After cutting, the adhering parts can be separated using pointed tweezers or other tools, making the spherical shell easy to peel off. This method solves the problem of difficult cutting and sampling of the hollow spherical cap of the CD-CH composite polymer. Moreover, due to the precise control of the laser tail, the tail size is sufficiently small. After peeling, due to the rigidity of the spherical cap, the CD-CH polymer tail can be completely detached, and no CD-CH polymer residue will remain.

[0051] In a preferred embodiment, the method for preparing a CD-CH composite polymer spherical cap in a double-cone collision ignition process is described as follows:

[0052] The first step, such as Figure 2 As shown in (a), the microfluidic method was used to prepare Figure 4 The CD polymer hollow spheres shown in the figure have three phases of liquid in microfluidics, namely, an inner water phase, an intermediate oil phase and an outer water phase; wherein, the intermediate oil phase is a CD polymer material, the inner water phase is ultrapure water; and the outer water phase is an aqueous solution containing a surfactant, thereby preparing CD polymer hollow spheres with a thickness of 30 μm.

[0053] Step 2: Figure 2 As shown in (b), the CD polymer hollow ball is first fixed on the net and then placed in the culture dish. At the same time, there is double-sided tape on the culture dish to make the CD polymer hollow ball better adhere to the culture dish, thereby preventing the CD polymer hollow ball from rolling. The CD polymer hollow ball is placed in the culture dish as shown in (b). Figure 3 In the deposition chamber of the chemical vapor deposition device shown, deposition is performed in four steps. Each time, 15 g of N-type polyparaxylene is placed in the evaporation chamber. Then, the vacuum pump is turned on to maintain the entire chamber in a vacuum state. At the same time, the cold trap is turned on. Finally, the heating device is turned on to first allow the cracking furnace to reach 650°C and then the evaporation chamber to reach 175°C. This allows the solid N-type polyparaxylene to be vaporized and crystallized into a CH film in the deposition chamber at room temperature, which is coated on the CD polymer hollow spheres to form CD-CH polymer hollow spheres. The thickness of the CH layer is 29 μm.

[0054] Step 3: Figure 2 As shown in (c), the CD-CH composite polymer hollow spheres are cut using a laser tail-leaving cutting method, thereby separating the CD-CH composite polymer cap from the CD-CH composite polymer hollow spheres. First, a steel mesh with a deposited CH layer and affixed CD-CH composite polymer hollow spheres is secured to a laser cutting platform. A camera is then used to locate the center of the hollow sphere and align it with the center of the cutting pattern. The alignment accuracy of the laser platform is less than 10μm. The laser wavelength is 1030 nm, the pulse width is 50 fs, and the power is 1.8W. The diameter of the desired cap is 766μm, so the cutting path is a circle with a diameter of 766μm and a 1-degree gap. This separates the caps while preventing the lighter caps from being blown away by the equipment's airflow during the cutting process. The tail-leaving laser cutting path can be directly completed by setting it after drawing the laser cutting pattern; it can also be completed by controlling the light-on and light-on delay method, where the cutting pattern is set to a complete circle with a diameter of 766μm, the light-on delay is modulated to 500μs, and the light-off delay is modulated to 200μs.

[0055] Step 4: Figure 2As shown in (d), the cut CD-CH composite polymer spherical cap is gently peeled off from the CD-CH composite polymer hollow sphere using pointed tweezers. After peeling, the CD-CH composite polymer spherical cap is placed in alcohol and then ultrasonically cleaned for 20 minutes to remove any residue left during laser cutting.

[0056] Correspondingly, another embodiment of the present invention provides a CD-CH composite polymer spherical cap for double-cone collision ignition, which is prepared by the above method.

[0057] The CD-CH composite polymer spherical cap and preparation method thereof in the double-cone collision ignition in the above-mentioned embodiment combine the advantages of microfluidics technology, chemical vapor deposition technology and tail-leaving laser cutting technology, thereby ensuring that the CD-CH composite polymer hollow spherical cap will not be blown away during the cutting process and the spherical shell can be easily peeled off. This solves the problems of difficult precise control of the CH layer thickness and difficulty in cutting and sampling the spherical cap in the preparation of the CD-CH composite polymer spherical cap, achieves high precision, and can prepare CD-CH composite polymer spherical caps in batches.

[0058] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various modifications or variations within the scope of the claims without affecting the essence of the present invention. The above preferred features may be used in any combination as long as they do not conflict with each other.

Claims

1. A method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition, characterized in that: include: CD polymer hollow spheres were prepared using a microfluidic method; Depositing a layer of CH thin film on the CD polymer hollow sphere to form CD-CH composite polymer hollow spheres; wherein: the CH thin film is deposited by chemical vapor deposition; The CD-CH composite polymer hollow spheres are cut by a laser tail cutting method; the laser tail cutting is achieved by controlling the cutting pattern, the cutting pattern is a circle with a notch, and the notch position is not cut, and the notch position is the adhesion site after cutting; the laser tail cutting is achieved by controlling the laser light on delay and light off delay; Use a sharp-ended tool to peel off the cut CD-CH composite polymer spherical cap from the CD-CH composite polymer hollow sphere along the cutting contour to obtain the CD-CH composite polymer spherical cap in the double-cone collision ignition; The CD-CH composite polymer hollow spheres are cut by a laser tail cutting method, wherein: a femtosecond laser or a picosecond laser is used; the laser wavelength is 650-1030 nm, the power is 1-3 W, and the pulse width is 50 fs-200 ps; The switching delay range is 200-700μs, the light-off delay range is 300-900μs, and the cut pattern is a notched circle with a diameter of 700-900μm.

2. The method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 1, characterized in that: The CD polymer hollow spheres are prepared by a microfluidic method, wherein: The microfluidic method involves three phases of liquid, namely an inner water phase, an intermediate oil phase and an outer water phase. The intermediate oil phase is a CD polymer material, the inner water phase is ultrapure water, and the outer water phase is an aqueous solution containing a surfactant.

3. The method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 1, characterized in that: A CH film is deposited on the CD polymer hollow spheres, wherein the raw material for chemical vapor deposition is N-type parylene; during deposition, a throttle plate is arranged between the vacuum pump and the through hole of the deposition chamber to increase the deposition speed of the N-type parylene.

4. The method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 3, characterized in that: A CH film is deposited on the CD polymer hollow spheres, wherein the temperature of the cracking furnace is 630-670°C, the temperature of the evaporation chamber is 170-180°C, and the temperature of the cold trap is -95--105°C.

5. The method for preparing the CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 1, characterized in that: Before cutting the CD-CH composite polymer hollow spheres using the laser tail cutting method, the method further includes: measuring and recording the diameter of each CD-CH composite polymer hollow sphere, so that when the prepared CD-CH composite polymer spherical caps are subsequently assembled into a double-cone ignition collision target, a pair of spherical caps are on the same spherical surface.

6. The method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 1, characterized in that: The CD-CH composite polymer hollow spheres are cut by a laser tail cutting method, wherein the circular diameter is 700-900 μm and the notch angle is 1°-3°.

7. The method for preparing a CD-CH composite polymer spherical cap in double-cone collision ignition according to claim 1, characterized in that: The CD-CH composite polymer hollow spheres are cut by the laser tail cutting method, wherein the laser cutting processing platform positions the CD-CH composite polymer hollow spheres through a microscope, and the alignment accuracy is below 10 μm.

8. A CD-CH composite polymer spherical cap for double cone collision ignition, characterized in that: The method according to any one of claims 1 to 7 is used for preparation.

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