A method for preparing a U-shaped self-supporting target film

Abstract

The present invention belongs to the field of nuclear reaction measurement technology, and specifically relates to a method for preparing a U-shaped self-supporting target film, comprising the following steps: step S1, preparing a target film by using a substrate material; step S2, demolding; step S3, clamping the opening of the U-shaped target frame by a clamping device to scoop up the film, so that the target film is fixed on the U-shaped target frame; step S4, using the "point breaking method" to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film. The present invention breaks through the fixed thinking of those skilled in the art and creatively conceives of clamping the open end of the U-shaped target frame with a clamping device, which greatly reduces the difficulty of scooping up the film and improves the success rate. The open end of the U-shaped target frame is closed by using a clamping device to turn it into a closed target frame. The method for preparing a U-shaped self-supporting target film provided by the present invention has high efficiency in preparing a U-shaped self-supporting target film, and the success rate of scooping up the film is nearly 100%, especially solving the technical defect that the success rate of the traditional scooping method is no more than 20%.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear reaction measurement, and particularly relates to a method for preparing a U-shaped self-supporting target film. Background Art

[0002] U-shaped self-supporting target membranes are an important target membrane in nuclear reaction measurement and nuclear technology application research. For example, medical cyclotrons require the use of U-shaped self-supporting carbon stripping membranes as a stripper for the extranuclear charge of heavy ions to obtain a higher charge state. This type of target membrane is usually fixed on a U-shaped open target frame. Compared with ordinary target membranes fixed on annular or mouth-shaped closed target frames, the preparation of U-shaped target membranes is more difficult. In particular, the success rate of film scooping after rinsing is extremely low, resulting in a significant increase in the material and time costs of preparing U-shaped target membranes. Therefore, a method for preparing U-shaped self-supporting target membranes with a high success rate is needed. Summary of the Invention

[0003] In view of the existing problem of preparing a U-shaped self-supporting target film, the present invention aims to provide a method for preparing a U-shaped self-supporting target film with high preparation efficiency and a preparation success rate of nearly 100%.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is a method for preparing a U-shaped self-supporting target film, comprising the following steps:

[0005] Step S1, preparing a target film using a substrate material;

[0006] Step S2, demolding;

[0007] Step S3, clamping the opening of the U-shaped target frame with a clamping device to scoop up the film so that the target film is fixed on the U-shaped target frame;

[0008] Step S4, using the “point breaking method” to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film.

[0009] Furthermore, in step S1, the substrate material is glass, a release agent is coated on the surface of the glass, and the target film of a desired thickness is prepared on the surface of the glass coated with the release agent; the target film is a carbon release film or a boron film.

[0010] Furthermore, in the step S2, the demolding is to demold the target film attached to the substrate material in deionized water, and the demolding agent is betaine or cesium iodide.

[0011] Furthermore, in step S3, when the clamping device clamps the U-shaped target frame, the clamping device completely covers the opening of the U-shaped target frame, and the clamping device forms a closed end of the opening of the U-shaped target frame.

[0012] Furthermore, in step S3, the contact between the clamping device and the opening of the U-shaped target frame and the target frames at both ends of the opening edge is "line contact", and the contact line is set parallel to the target frames at the opening edge of the U-shaped target frame.

[0013] Furthermore, the thickness of the clamping end of the clamping device is less than 0.4 mm.

[0014] Furthermore, the thickness of the clamping end of the clamping device is 0.1-0.2 mm, which is the thickness at the contact position between the clamping device and the U-shaped target frame.

[0015] Furthermore, the point breaking method is to use a needle-shaped tool with a diameter of micrometer order to puncture the contact between the target film and the clamping device, so that the target film and the clamping device are peeled off, and the needle puncture interval is no more than 200 μm.

[0016] Furthermore, the thickness of the carbon stripping film is 5 μg / cm 2 -200 μg / cm 2 .

[0017] Furthermore, the thickness of the boron film is 50 μg / cm 2 -250μg / cm 2 .

[0018] The beneficial effects of the present invention are:

[0019] 1. In the traditional U-shaped self-supporting target film preparation method, since the closed end (the port opposite to the open end) has a relatively good clamping point, those skilled in the art are always accustomed to clamping the closed end of the U-shaped target frame with a clamping device (similar to a "ticket clip") to perform the film scooping operation. Since the target film thickness is only a few tens of μg / cm 2 , the opening size is large (relative to the target frame size), and when the closed end is clamped to scoop up the film, it is difficult for the target film to adhere to the edge of the target frame at the open end. In more than 80% of cases, after being scooped out, the target film will sink and break at the opening, and the success rate of scooping up the film is less than 20%, and the time cost is high. The present invention breaks through the fixed thinking pattern of those skilled in the art, and creatively thinks of clamping the open end of the U-shaped target frame with a clamping device, which greatly reduces the difficulty of scooping up the film and improves the success rate. The clamping device is used to close the open end of the U-shaped target frame to turn it into a closed target frame. The method for preparing a U-shaped self-supporting target film provided by the present invention has high efficiency in preparing a U-shaped self-supporting target film, and the success rate of scooping up the film is nearly 100%, especially solving the technical defect that the success rate of the traditional film scooping method is no more than 20%.

[0020] 2. The point breaking method is creatively used to break the peeling film in contact with the clamping device, saving material, labor and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of a method for preparing a U-shaped self-supporting target film described in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and examples.

[0023] The present invention provides a method for preparing a U-shaped self-supporting target film, comprising the following steps:

[0024] Step S1, preparing a target film using a substrate material;

[0025] Step S2, demolding;

[0026] Step S3, clamping the opening of the U-shaped target frame with a clamping device to scoop up the film so that the target film is fixed on the U-shaped target frame;

[0027] Step S4, using the "point breaking method" to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film.

[0028] In step S1, the substrate material is glass, a release agent is coated (or evaporated) on the glass surface, and a target film of a desired thickness is prepared on the surface of the glass coated (or evaporated) with the release agent; the target film is a carbon stripping film or a boron film.

[0029] In step S2 , the target film attached to the substrate material is removed in deionized water, and the removal agent is betaine or cesium iodide.

[0030] In step S3, when the clamping device clamps the U-shaped target frame, the clamping device must at least completely cover the opening of the U-shaped target frame, and the clamping device forms a closed end of the opening of the U-shaped target frame.

[0031] In step S3, the contact between the clamping device and the opening of the U-shaped target frame and the target frames at both ends of the opening edge is approximately "line contact", and the contact line is set parallel to the target frames at the opening edge of the U-shaped target frame.

[0032] The thickness of the clamping end of the clamping device is less than 0.4 mm, and the "clamping end" refers to the part of the clamping device that "covers the opening of the U-shaped target frame".

[0033] The thickness of the clamping end of the clamping device is 0.1-0.2 mm, which is the thickness at the contact position between the clamping device and the U-shaped target frame.

[0034] The point breaking method uses a needle-shaped tool with a diameter of micrometers to pierce the contact between the target film and the clamping device, so that the target film and the clamping device are peeled off, and the needle puncture spacing is no more than 200μm.

[0035] The thickness of the carbon release film is 5 μg / cm 2 -200 μg / cm2 .

[0036] The thickness of the boron film is 50 μg / cm 2 -250μg / cm 2 .

[0037] Example 1

[0038] In medical cyclotrons, U-shaped self-supporting target membranes (carbon stripping membranes) are often used as stripping agents to strip extranuclear charges from heavy ions. Medical cyclotrons typically utilize hundreds or even thousands of these membranes. The low success rate of membrane removal during the preparation of these membranes has been a persistent but unresolved challenge in the field.

[0039] The present invention provides a method for preparing a U-shaped self-supporting target film (the target film is a carbon peeling film), the method comprising the following steps:

[0040] Step S1, preparing a target film using a substrate material, specifically includes:

[0041] (Step 1.1) Using cleaned glass as a substrate, the glass surface is coated with betaine or evaporated with cesium iodide as a release agent;

[0042] (Step 1.2) Prepare a 1 μg / cm thick film on a glass surface coated or evaporated with a release agent using a carbon arc method. 2 carbon film;

[0043] (Step 1.3) On the carbon film obtained in (Step 1.2), a carbon stripping film (DLC stripping film) of the desired thickness was prepared using a double 90-degree elbow filtered cathode vacuum pulse arc device. The thickness of the carbon stripping film was 5 μg / cm 2 .

[0044] Step S2, demolding;

[0045] The prepared carbon stripping film attached to the substrate is stripped in deionized water. When stripping, the substrate is first placed on a support frame with a slope of 20-30 degrees, and then deionized water is injected into the container where the support frame is located at a flow rate of 0.03-0.05L / min. The deionized water is slowly raised to gradually soak the carbon stripping film and dissolve the stripping agent to strip the film. Using this method for stripping, the film is not easy to break.

[0046] Step S3: Clamp the opening of the U-shaped target frame with a clamping device to scoop up the film so that the target film is fixed on the U-shaped target frame.

[0047] The clamping device grips the opening of the U-shaped target frame and performs a film scooping operation, securing the carbon stripping film to the U-shaped target frame. During scooping, the clamping device is positioned perpendicular to the water surface to remove the carbon stripping film from the water. When the clamping device grips the U-shaped target frame, the contact between the clamping device and the opening of the U-shaped target frame and the target frames at both ends of the opening are approximately "line contact." The contact line is parallel to the target frames at the opening edge of the U-shaped target frame, forming a closed target frame with the U-shaped target frame. The clamping device completely covers the opening of the U-shaped target frame and the target frames at both ends of the opening edge, and the thickness of the clamping end of the clamping device is 0.2mm.

[0048] Step S4, using the "point breaking method" to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film.

[0049] After step S3, the target film is dried and then separated from the clamping device and the carbon stripping film using the "point breaking method" to obtain the desired U-shaped self-supporting target film. The point breaking method mainly uses a needle-shaped tool with a diameter of micrometers to pierce the contact line between the carbon stripping film and the clamping device, thereby separating the carbon stripping film and the clamping device. The needle puncture interval is 150 micrometers.

[0050] This method is highly efficient in preparing U-shaped, self-supporting target films. It overcomes the technical drawback of conventional film retrieval methods, which typically have a success rate of less than 20%. The method provided by the present invention achieves a nearly 100% success rate. Furthermore, the prepared target film is a carbon release film (DLC release film), which has a longer lifespan and reduces the cost of accelerator film replacement.

[0051] Example 2

[0052] On the basis of Example 1, another embodiment provided by the present invention is to prepare a U-shaped self-supporting target film (the target film is a carbon peeling film), the thickness of the contact line between the clamping device and the U-shaped target frame is 0.3 mm, and the thickness of the carbon film is 2 μg / cm 2 , carbon peeling film (DLC peeling film) thickness 100μg / cm 2 The thickness of the clamping end of the clamping device is 0.1 mm, and the needle-punching spacing used in the point-breaking method is 100 μm.

[0053] Example 3

[0054] Based on Example 1, another example provided by the present application is to prepare a U-shaped self-supporting target film (the target film is a carbon stripping film), the thickness of the contact line between the clamping device and the U-shaped target frame is 0.3 mm, and the thickness of the carbon stripping film (DLC stripping film) is 200 μg / cm 2 The thickness of the clamping end of the clamping device is 0.2 mm, and the needle-punching spacing used in the point-breaking method is 90 μm.

[0055] Example 4

[0056] The present invention provides a method for preparing a U-shaped self-supporting target film (the target film is a boron film), the method comprising the following steps:

[0057] Step S1, preparing a target film using a substrate material, specifically includes:

[0058] (Step 1.1) Using cleaned glass as a substrate material, the glass surface is coated with betaine as a release agent;

[0059] (Step 1.2) Boron film was deposited discontinuously on the glass surface coated with release agent by using focused fine-tuning electron bombardment method (5 μg / cm 2 Cooling 10min), the boron film thickness is 60μg / cm 2 ;

[0060] Step S2, demolding;

[0061] The prepared boron film attached to the substrate is stripped in deionized water. When stripping, the substrate is first placed on a support frame with a slope of 20-30 degrees, and then deionized water is injected into the container where the support frame is located at a flow rate of 0.02-0.03L / min. The deionized water is slowly raised to gradually soak the boron film and dissolve the stripping agent to strip the film. Using this method for stripping, the film is not easy to break.

[0062] Step S3: Clamp the opening of the U-shaped target frame with a clamping device to scoop up the film so that the target film is fixed on the U-shaped target frame.

[0063] The clamping device grips the opening of the U-shaped target frame and performs a film scooping operation, securing the boron film to the U-shaped target frame. During scooping, the clamping device is held perpendicular to the water surface to remove the boron film from the water. When the clamping device grips the U-shaped target frame, the contact between the clamping device and the opening of the U-shaped target frame and the target frames at both ends of the opening is approximately "line contact." The contact line is parallel to the target frames at the opening edge of the U-shaped target frame, forming a closed target frame with the U-shaped target frame. The clamping device completely covers the opening of the U-shaped target frame and the target frames at both ends of the opening edge, and the thickness of the clamping end of the clamping device is 0.2mm.

[0064] Step S4, using the "point breaking method" to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film.

[0065] After step S3, the target film is dried and then separated from the clamping device and the boron film using the "point breaking method" to obtain the desired U-shaped self-supporting target film. The point breaking method mainly uses a needle-shaped tool with a diameter of micrometers to pierce the contact line between the boron film and the clamping device, thereby separating the boron film and the clamping device. The needle puncture interval is 150 micrometers.

[0066] The method is highly efficient in preparing a U-shaped self-supporting target film, and in particular, it overcomes the technical drawback of conventional film-fishing methods, which have a success rate of no more than 20%. The method provided by the present invention can achieve a film-fishing success rate of nearly 100%. In addition, the prepared target film is a boron film.

[0067] Example 5

[0068] Based on Example 4, another example provided by this application is to prepare a U-shaped self-supporting target film (the target film is a boron film), and the thickness of the boron film is 100 μg / cm 2 The thickness of the clamping end of the clamping device is 0.3 mm, and the point-breaking needle-punching spacing used is 90 μm.

[0069] Example 6

[0070] Based on Example 4, another example provided by this application is to prepare a U-shaped self-supporting target film (the target film is a boron film), and the thickness of the boron film is 250 μg / cm 2 The thickness of the clamping end of the clamping device is 0.2 mm, and the needle-punching spacing used in the point-breaking method is 120 μm.

[0071] Example 7

[0072] Based on Example 4, another example provided by this application is to prepare a U-shaped self-supporting target film (the target film is a boron film), and the thickness of the boron film is 200 μg / cm 2 The thickness of the clamping end of the clamping device is 0.1 mm, and the point-breaking needle-punching spacing used is 150 μm.

[0073] The method described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the scope of the technical innovation of the present invention.

Claims

1. A method for preparing a U-shaped self-supporting target film, comprising the following steps: Step S1, preparing a target film using a substrate material; Step S2, demolding; Step S3, clamping the opening of the U-shaped target frame with a clamping device to scoop up the target film so that the target film is fixed on the U-shaped target frame; when the clamping device clamps the U-shaped target frame, the clamping device completely covers the opening of the U-shaped target frame, and the clamping device forms a closed end of the opening of the U-shaped target frame; Step S4, using the "point breaking method" to disconnect the clamping device from the target film to obtain the desired U-shaped self-supporting target film.

2. The method for preparing a U-shaped self-supporting target film according to claim 1, wherein: In the step S1, the substrate material is glass, a release agent is coated on the surface of the glass, and the target film of a desired thickness is prepared on the surface of the glass coated with the release agent; the target film is a carbon release film or a boron film.

3. The method for preparing a U-shaped self-supporting target film according to claim 1, wherein: In the step S2, the film removal is to remove the target film attached to the substrate material in deionized water, and the film removal agent is betaine or cesium iodide.

4. The method for preparing a U-shaped self-supporting target film according to claim 1, wherein: In step S3, the contact between the clamping device and the opening of the U-shaped target frame and the target frames at both ends of the opening edge is "line contact", and the contact line is set parallel to the target frames at the opening edge of the U-shaped target frame.

5. The method for preparing a U-shaped self-supporting target film according to claim 4, wherein: The thickness of the clamping end of the clamping device is less than 0.4 mm.

6. The method for preparing a U-shaped self-supporting target film according to claim 5, wherein: The thickness of the clamping end of the clamping device is 0.1-0.2 mm, which is the thickness at the contact position between the clamping device and the U-shaped target frame.

7. The method for preparing a U-shaped self-supporting target film according to claim 1, wherein: The point breaking method is to use a needle-shaped tool with a diameter of micrometer order to puncture the contact between the target film and the clamping device, so that the target film and the clamping device are peeled off, and the needle puncture interval is no more than 200 μm.

8. The method for preparing a U-shaped self-supporting target film according to claim 2, wherein: The thickness of the carbon release film is 5 μg / cm 2 -200 μg / cm 2 .

9. The method for preparing a U-shaped self-supporting target film according to claim 2, wherein: The thickness of the boron film is 50 μg / cm 2 -250μg / cm 2 .

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