Preparation method of substrate-free radioactive isotope source and preparation method of isotope battery
By preparing a solute layer between the intermediate layer and the substrate and utilizing the concentration gradient migration method, the problem of oxidation contamination in the preparation of substrate-free radioisotope sources was solved, realizing a self-supported isotope source with high cleanliness and high tritium uptake, thus improving the performance and production efficiency of isotope batteries.
Patent Information
- Application Number
- CN202511653855.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-11
- Publication Date
- 2026-03-17
AI Technical Summary
In the preparation of substrate-free radioisotope sources, the dissolution transition layer stage of existing technologies is prone to oxidative contamination, which leads to a decrease in the tritium storage performance of the thin film and makes it difficult to prepare self-supporting isotope sources with high surface cleanliness.
The solute atom concentration gradient migration method is adopted. A solute layer is prepared between the intermediate layer and the substrate. The solute atom concentration gradient is used for transfer, which causes the mixed layer to cyclically shrink and expand, pulverize and separate, forming a self-supporting loading layer and avoiding contamination of the solution.
It improves the success rate and integrity of self-supporting thin film preparation, enhances the tritium absorption of the isotope source, and increases the power of the isotope battery, making it suitable for mass production.
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Figure CN121687597A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of isotope battery, in particular, to a preparation method of a substrate-free radioactive isotope source and a preparation method of an isotope battery. BACKGROUND
[0002] Nuclear battery, also known as radioactive isotope battery, is a device that converts the energy released by radioactive isotope decay into electrical energy. In 1913, British physicist Moseles designed the first isotope battery using a beta radiation source, and since then, numerous branches have been developed in the past century. Isotope battery can continuously release energy during the decay process and is not affected by the outside world. Among them, isotope battery can work continuously for several years, several decades or even hundreds of years according to the half-life of the radioactive source. Compared with ordinary chemical batteries and solar cells, isotope batteries have unique advantages such as stable and reliable operation, no need for human intervention, high energy density, and long-term stable power supply, making them have important applications in aerospace, national defense, extreme environments (such as deep sea, space, desert), and medical fields.
[0003] Isotope batteries can be divided into several categories. According to the conversion method, isotope batteries can be divided into thermal conversion type and non-thermal conversion type. Among them, thermal conversion type isotope batteries mainly use the heat energy of isotopes such as plutonium 238 to generate electricity, which is generally used in military and aerospace fields; and non-thermal conversion type isotope batteries rely on isotope decay to generate electricity. Due to its weak radioactivity, it has been widely used in civilian fields and has great development prospects. For example, in the direct conversion type isotope battery, the alpha or beta particles emitted by the radiation source are injected into the semiconductor material to generate a large number of electron-hole pairs through ionization. If these electron-hole pairs are generated or drift into the depletion layer in the conversion device (usually pn junction or pin junction), they will be separated and move directionally under the action of the built-in electric field, which will connect the external circuit and generate current. Compared with alpha radiation voltage effect, beta radiation voltage effect nuclear battery has smaller irradiation damage to the conversion device and longer stable power supply time, so it has more broad application prospects. The beta radiation voltage effect isotope battery is composed of a radiation source, an electrode, and a semiconductor conversion device. Among them, the beta particle radiation source is the core component of the isotope battery. The thickness of the radiation source varies according to the radioactivity intensity of the material itself, and the thickness is between 300 nm and 2000 nm. Generally, the radioactive material is deposited on the surface of a metal or semiconductor substrate to prepare it. In the preparation process, the thickness of the substrate should be as small as possible to reduce the absorption intensity of the beta rays. Using a thin film radioactive material without substrate as the source is undoubtedly one of the best methods. This structure without substrate is called a self-supporting structure.
[0004] At present, most of the self-supporting structure radioactive sources are prepared by dissolving the sacrificial layer method, mainly including the following steps: a thin film material which can be dissolved in water or other solvents is plated between the substrate and the radioactive material, the sample is placed in a container containing water or solvent to float, and after the intermediate layer is dissolved, the self-supporting structure radioactive source is obtained. However, as a radioactive source, the tritium will cause the oxidation pollution to be deepened and the hydrogen storage performance of the film to be doubled when the hydrogen absorption film directly contacts the solution during the dissolving transition layer stage. How to prepare a self-supporting isotope source with high surface cleanliness is a technical problem to be solved by those skilled in the art. SUMMARY
[0005] The present application aims to at least solve one of the technical problems in the related art. To this end, the embodiments of the present application propose a method for preparing a substrate-free radioactive isotope source, which can separate the substrate and the isotope source to obtain a substrate-free isotope source.
[0006] The method for preparing a substrate-free radioactive isotope source of the present application comprises the following steps:
[0007] S1: preparing an intermediate layer on the surface of the substrate, the intermediate layer comprising solvent atoms and solute atoms;
[0008] S2: preparing a solute layer on the surface of the intermediate layer, the solute layer comprising the solute atoms;
[0009] S3: heating the intermediate layer and / or the substrate, the solute atoms migrating to the intermediate layer to obtain a mixed layer;
[0010] S4: preparing a loading layer on the surface of the mixed layer;
[0011] S5: transferring to a radioactive isotope source loading device, the mixed layer being pulverized, the loading layer being separated from the substrate, and the loading layer absorbing the radioactive element to obtain a substrate-free radioactive isotope source.
[0012] According to the preparation method of the substrate-free radioisotope source, the solute atoms are transferred according to the concentration gradient, so that the mixed layer is cyclically shrunk and expanded to be powdered, thereby preparing the substrate-free loading layer, i.e., obtaining the isotopic source with a self-supporting structure, the thin film of the isotopic source has high integrity, and the success rate of the self-supporting thin film preparation is effectively increased. Compared with the traditional preparation method of the substrate-free radioisotope source (a soluble intermediate layer is prepared between the substrate and the isotopic source, the assembly including the substrate and the isotopic source is placed in a solution to dissolve the intermediate layer, so as to separate the substrate and the isotopic source), the isotopic source prepared by the method can effectively avoid pollution of the dissolving solution, i.e., the pollution of nitrogen, carbon, oxygen and other impurities to the thin film is reduced, so that the tritium absorption amount of the isotopic source is effectively increased, and the power of the isotopic battery is increased. The preparation method of the substrate-free isotopic source has high success rate, good thin film integrity and high thin film tritium absorption amount, and can be used for batch preparation.
[0013] Optionally, the concentration of the solute atoms in the intermediate layer gradually decreases in the direction from the solute layer to the substrate.
[0014] Optionally, before the step S1 operation, the method further comprises a step S0 of substrate pretreatment: ultrasonic cleaning of the substrate, blow drying, and plasma cleaning.
[0015] Optionally, the heating temperature of the step S3 is 100-250 degrees Celsius.
[0016] Optionally, the thickness of the solute layer is 10-20 nm.
[0017] Optionally, the substrate is prepared by any one of magnetron sputtering, thermal evaporation deposition, electron beam deposition, electroplating and chemical vapor deposition.
[0018] Optionally, the intermediate layer and / or the solute layer are prepared by any one of magnetron sputtering, ion implantation, thermal evaporation deposition, electron beam deposition, electroplating and chemical vapor deposition.
[0019] Optionally, the loading layer is prepared by any one of magnetron sputtering, thermal evaporation deposition, laser deposition, chemical vapor deposition and electron beam deposition.
[0020] Optionally, the material of the solvent atoms is at least one of silicon, germanium and tin; and / or
[0021] The material of the solute atoms is lithium; and / or
[0022] The material of the loading layer is at least one of titanium, scandium, vanadium, magnesium, lanthanum and zirconium.
[0023] The method for preparing the isotope battery of the present application comprises the method for preparing the substrate-free radioisotope source described above. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 is a schematic diagram of the assembly preparation process in the embodiment of the present application.
[0025] Reference signs: 1 - substrate, 2 - intermediate layer, 3 - solute layer, 4 - loading layer, 5 - mixed layer. DETAILED DESCRIPTION
[0026] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.
[0027] The method for preparing the substrate-free radioisotope source of the embodiment of the present application is described below with reference to the accompanying drawings. As shown in the drawings, the substrate-free radioisotope source of the embodiment of the present application comprises the following steps: Figure 1
[0028] S1: preparing an intermediate layer 2 on the surface of a substrate 1, the intermediate layer 2 comprising solvent atoms and solute atoms;
[0029] S2: preparing a solute layer 3 on the surface of the intermediate layer 2, the solute layer 3 comprising the solute atoms;
[0030] S3: heating the intermediate layer 2 and / or the substrate 1, the solute atoms migrating to the intermediate layer 2 to obtain a mixed layer 5;
[0031] S4: preparing a loading layer 4 on the surface of the mixed layer 5;
[0032] S5: transferring to a radioisotope source loading device, the mixed layer being pulverized, the loading layer 4 being separated from the substrate 1, and the loading layer 4 absorbing the radioactive element to obtain the substrate-free radioisotope source.
[0033] According to the preparation method of the substrate-free radioisotope source of the specific embodiment of the present application, the solute atoms are transferred according to the concentration gradient, so that the mixed layer 5 is cyclically shrunk and expanded to be powdered, thereby preparing the substrate-free loading layer 4, that is, obtaining the isotopic source with a self-supporting structure, the thin film of which has high integrity, and the success rate of the self-supporting thin film preparation is effectively increased. Compared with the conventional preparation method of the substrate-free radioisotope source (a soluble intermediate layer is prepared between the substrate and the isotopic source, and the assembly including the substrate and the isotopic source is placed in a solution to dissolve the intermediate layer, thereby separating the substrate and the isotopic source), the isotopic source prepared by the present application can effectively avoid the pollution of the dissolving solution, that is, reduce the pollution of nitrogen, carbon, oxygen and other impurities to the thin film, thereby effectively increasing the tritium absorption amount of the isotopic source, and further improving the power of the isotopic battery. The preparation method of the substrate-free isotopic source of the present application has high success rate, good thin film integrity and high thin film tritium absorption amount, and can be used for batch preparation.
[0034] The substrate-free radioisotope source of the embodiment of the present application includes the following steps:
[0035] S0: ultrasonic cleaning of the substrate, drying, and plasma cleaning to remove other impurities on the surface, such as grease, oxide layer, etc., to improve the adhesion and flatness of the deposited coating to the substrate 1, prevent peeling during the preparation of the intermediate layer 2, and finally prepare a self-supporting radioactive source with low surface roughness.
[0036] In some specific embodiments, the substrate is prepared by any one of magnetron sputtering, thermal evaporation deposition, electron beam deposition, electroplating and chemical vapor deposition.
[0037] S1: preparing the intermediate layer 2 on the surface of the substrate 1, the intermediate layer 2 including solvent atoms and solute atoms. Specifically, as shown in Figure 1 After the intermediate layer 2 is prepared on the substrate 1, the solute atom concentration in the intermediate layer 2 is higher than that of the substrate 1, and the solute atoms in the intermediate layer 2 will continuously diffuse into the substrate 1, so that the intermediate layer 2 is in a shrinking state.
[0038] In some embodiments, the concentration of the solute atoms in the intermediate layer 2 gradually decreases in the direction from the solute layer 3 to the substrate 1. Specifically, in the intermediate layer 2, the solute atoms at the high concentration position continuously diffuse to the solute atoms at the low concentration position, so that the solute atoms at the high concentration position are in a shrinkage state and the solute atoms at the low concentration position are in an expansion state, while the solute atoms in the solute layer 3 continuously diffuse to the high concentration position and the solute atoms at the low concentration position continuously diffuse to the substrate 1. That is, the solute atoms in the solute layer 3 successively diffuse to the high concentration position, the low concentration position and the substrate 1, and in the process of diffusion of the solute atoms, the intermediate layer 2 continuously cycles shrinkage and expansion, so that the intermediate layer 2 can be deformed and pulverized.
[0039] In some embodiments, the intermediate layer 1 is prepared by any one of magnetron sputtering, ion implantation, thermal evaporation deposition, electron beam deposition, electroplating and chemical vapor deposition.
[0040] In some embodiments, the material of the solvent atoms is at least one of silicon, germanium and tin.
[0041] In some embodiments, the material of the solute atoms is lithium.
[0042] S2: preparing a solute layer 3 on the surface of the intermediate layer 2, the solute layer 3 comprising solute atoms. Specifically, as shown in FIG. 2, the solute atoms in the solute layer 3 can diffuse into the intermediate layer 2, so that the intermediate layer 2 is expanded, while the solute atoms in the intermediate layer 2 diffuse into the substrate 2, so that the intermediate layer 2 is shrunk. Figure 1
[0043] In some embodiments, the solute layer 3 is prepared by any one of magnetron sputtering, ion implantation, thermal evaporation deposition, electron beam deposition, electroplating and chemical vapor deposition.
[0044] In some embodiments, the thickness of the solute layer is 10-20 nm, so that the solute atoms in the solute layer can diffuse in the intermediate layer for a long enough path, increase the cycle times of expansion and shrinkage of the intermediate layer, and accelerate the pulverization of the mixed layer.
[0045] S3: heating the intermediate layer 2 and / or the substrate 1, and the solute atoms migrate to the intermediate layer 2 to obtain a mixed layer 5. Specifically, as shown in FIG. 3, in the process of heating the intermediate layer 2 and / or the substrate 1, the solute atoms in the solute layer 3 continuously diffuse into the intermediate layer 2, so as to obtain the mixed layer 5. Figure 1
[0046] In some specific embodiments, the heating temperature in step S3 is 100 degrees Celsius to 250 degrees Celsius to avoid the solute layer 3 from liquefying due to excessive temperature, thereby affecting the diffusion effect, while ensuring that the atoms in the solute layer 3 diffuse fully into the intermediate layer 2.
[0047] S4: Prepare a loading layer 4 on the surface of the hybrid layer 5. Specifically, in order to obtain an ultrathin loading layer 4, a corresponding substrate is required to prepare the loading layer 4.
[0048] In some specific embodiments, the loading layer 4 is prepared by magnetron sputtering, thermal evaporation deposition, laser deposition, chemical vapor deposition, or electron beam deposition.
[0049] In some specific embodiments, the material of the loading layer 4 is at least one of titanium, scandium, vanadium, magnesium, lanthanum, and zirconium.
[0050] S5: The mixture is transferred to a radioactive isotope source loading device. The mixing layer 5 is pulverized, and the loading layer 4 separates from the substrate 1. After absorbing the radionuclide, the loading layer 4 yields a substrate-free radioactive isotope source. Specifically, after the loading layer 4 is loaded, the mixing layer 5 continuously contracts and expands in cycles, that is, the mixing layer 5 continuously deforms until it is pulverized. After the mixing layer 5 is pulverized, the loading layer 4 separates from the substrate 1, resulting in a self-supporting loading layer 4.
[0051] The method for preparing the isotope battery of the present invention includes the above-described method for preparing a substrate-free isotope source.
[0052] Example 1
[0053] Silicon is used as the solvent atom and lithium is used as the solute atom.
[0054] The preparation process of the substrate-free isotope source is as follows:
[0055] Step 1: After ultrasonically cleaning the silicon with acetone alcohol, dry it with cold air, and then bombard the silicon with argon plasma to obtain a clean surface.
[0056] Step 2: Using a lithium target with a purity of 99.99% and a silicon target with a purity of 99.99%, a silicon-lithium composite coating with a thickness of 100nm-200nm is deposited on the surface of a silicon substrate using multi-target co-sputtering technology in magnetron sputtering. The deposition vacuum degree is 5.0×10-4Pa, the Ar2 flow rate is 10sccm-30sccm, the deposition temperature is 100-250℃, the deposition bias voltage is 0V-200V, the deposition pressure is 0.1Pa-1Pa, and the deposition time is 30min-60min. During the deposition process, the power of the silicon and lithium targets is decreased and increased over time to prepare a coating with a concentration gradient. The lithium target is sputtered using DC (or RF) with the power increasing from 50W to 100W at a rate of 1W / 5min-5W / 5min; the silicon target is sputtered using RF with the power increasing from 200W to 100W at a rate of 1W / 5min-5W / 5min.
[0057] In addition, in the second step, lithium ions can be implanted onto the silicon surface using ion implantation technology, resulting in a lithium ion concentration gradient distribution at a depth of 100 nm to 200 nm on the silicon surface. The implantation energy is approximately 5–200 keV, and the implantation dose is approximately 1 × 10⁻⁶. 11 -1×10 16 / cm 2 Incident angle 0-45°.
[0058] Step 3: Deposit a lithium film with a thickness of 10nm-20nm on the surface of the silicon-lithium interlayer, heat the substrate to 100℃-250℃, and hold for 1min-5min to allow lithium in the lithium film to diffuse into the silicon-lithium interlayer. This process can cause the silicon-lithium interlayer to expand.
[0059] Step 4: A titanium film with a thickness of 500 nm to 1000 nm was prepared on the surface of the silicon-lithium interlayer using radio frequency magnetron sputtering technology. A titanium target with a purity of 99.999% was used, and the deposition vacuum was 5.0 × 10⁻⁶. -4 Pa, Ar2 flow rate 30 sccm, deposition temperature 100℃-200℃, deposition bias voltage 0-200V, deposition pressure 0-1Pa, deposition time 4-8h, after coating, wait for the sample temperature to drop to room temperature.
[0060] Step 5: Remove the coated sample and quickly transfer it to a sealed tritium absorption device, then evacuate to 10°C. -4 Pa, the sample is heated to 400℃-700℃ and held for 0.5h-2h to allow the silicon-lithium interlayer to fully expand and contract and then completely pulverize. Then, the titanium film is loaded according to the tritium absorption process.
[0061] Step 6: After the tritium absorption is complete, wait for the temperature inside the chamber to drop to room temperature, take out the sample, use tweezers to pick up and remove the tritium absorption layer on the surface, and you will get a complete self-supporting tritium titanium film.
[0062] This invention proposes a method for preparing a substrate-free isotope source, which can effectively solve the problem of surface contamination of radioactive sources. Example 1 mainly utilizes the small atomic radius, large diffusion coefficient, and low activation energy of lithium, as well as the principle that silicon undergoes nearly 400% deformation during lithium storage and release, leading to alloy pulverization. In other words, during the activation of the titanium film under high-temperature conditions, the concentration difference in the silicon-lithium interlayer causes lithium ion migration, resulting in cyclic contraction and expansion of the silicon-lithium interlayer. The silicon-lithium interlayer, with its high residual stress, continuously deforms. As the holding time increases, the silicon-lithium interlayer gradually transforms into a powdery structure and peels off from the upper film and lower substrate. The upper titanium film then becomes a self-supporting film structure and undergoes subsequent tritium absorption. After tritium absorption, a self-supporting tritium-titanium radioactive source can be directly obtained.
[0063] Example 2
[0064] Germanium is used as the solvent atom and lithium is used as the solute atom.
[0065] The preparation process of the substrate-free isotope source is as follows:
[0066] Step 1: After ultrasonically cleaning germanium with acetone and alcohol, dry it with cold air, and then bombard the germanium with argon plasma to obtain a clean surface.
[0067] Step 2: Using a lithium target with a purity of 99.99% and a germanium target with a purity of 99.99%, a germanium-lithium composite coating with a thickness of 100nm-200nm was deposited on the substrate surface using multi-target co-sputtering technology in magnetron sputtering. The deposition vacuum degree was 5.0×10⁻⁶. - 4 The Ar2 flow rate was 10-30 sccm, the deposition temperature was 100-250℃, the deposition bias was 0-200V, the deposition pressure was 0.1Pa-1Pa, and the deposition time was 30-60 min. During deposition, the power of the germanium and lithium targets was decreased and increased over time to prepare a coating with a concentration gradient. The lithium target was sputtered using DC (or RF) sputtering, with power increasing from 50W to 100W at a rate of 1W / 5min to 5W / 5min. The germanium target was sputtered using DC (or RF) sputtering, with power increasing from 200W to 100W at a rate of 1W / 5min to 5W / 5min. Additionally, in the second step, lithium ions could be implanted into the germanium surface using ion implantation technology, resulting in a lithium ion concentration gradient distribution at a depth of 100nm-200nm. The implantation energy was approximately 5-200keV, and the implantation dose was approximately 1×10⁻⁶. 11 -1×10 16 / cm 2 Incident angle 0-45°.
[0068] Step 3: Deposit a lithium film with a thickness of 10nm-20nm on the surface of the germanium-lithium interlayer, heat the substrate to 100℃-250℃, and hold for 1min-5min to allow lithium in the lithium film to diffuse into the germanium-lithium interlayer. This process can cause the germanium-lithium interlayer to expand.
[0069] Step 4: A titanium film with a thickness of 500 nm to 1000 nm was prepared on the surface of the silicon-lithium interlayer using radio frequency magnetron sputtering technology. A titanium target with a purity of 99.999% was used, and the deposition vacuum was 5.0 × 10⁻⁶. -4 Pa, Ar2 flow rate 30 sccm, deposition temperature 100℃-200℃, deposition bias voltage 0-200V, deposition pressure 0.1-1Pa, deposition time 4-8h, after coating, wait for the sample temperature to drop to room temperature.
[0070] Step 5: Remove the coated sample and quickly transfer it to a sealed tritium absorption device, then evacuate to 10°C. -4 Pa, the sample is heated to 400℃-700℃ and held for 0.5h-2h. The lithium content in the germanium-lithium interlayer increases and decreases in cycles, so that the germanium-lithium interlayer fully expands and contracts and is completely pulverized. Then, the titanium film is loaded according to the tritium absorption process.
[0071] Step 6: After the tritium absorption is complete, wait for the temperature inside the chamber to drop to room temperature, take out the sample, use tweezers to pick up and remove the tritium absorption layer on the surface, and you will get a complete self-supporting tritium titanium film.
[0072] The technical effects achieved by using germanium as a solvent atom are the same as those achieved by using silicon as a solvent atom, and will not be elaborated here.
[0073] Example 3
[0074] Tin is used as the solvent atom and lithium is used as the solute atom.
[0075] The preparation process of the substrate-free isotope source is as follows:
[0076] Step 1: After ultrasonically cleaning the tin with acetone and alcohol, dry it with cold air, and then bombard the tin with argon plasma to obtain a clean surface.
[0077] Step 2: Using a lithium target with a purity of 99.99% and a tin target with a purity of 99.99%, a lithium-tin composite coating with a thickness of 100nm-200nm is deposited on the substrate surface using multi-target co-sputtering technology in magnetron sputtering. The deposition vacuum level is 5.0×10⁻⁶. - 4The Ar2 flow rate was 10 sccm-30 sccm, the deposition temperature was 100-250℃, the deposition bias was 0V-200V, the deposition pressure was 0.1Pa-1Pa, and the deposition time was 30min-60min. During the deposition process, the power of the tin target and the lithium target was decreased and increased over time to prepare a coating with a concentration gradient. The lithium target was sputtered by DC (or RF) with the power increasing from 50W to 100W at a rate of 1W / 5min-5W / 5min. The tin target was sputtered by DC (or RF) with the power increasing from 200W to 100W at a rate of 1W / 5min-5W / 5min.
[0078] Step 3: Deposit a lithium film with a thickness of 10nm-20nm on the surface of the tin-lithium interlayer, heat the substrate to 100℃-150℃, and hold for 1min-5min to allow lithium in the lithium film to diffuse into the tin-lithium interlayer. This process can cause the tin-lithium interlayer to expand.
[0079] In addition, in the second step, lithium ions can be implanted onto the silicon surface using ion implantation technology, resulting in a lithium ion concentration gradient distribution at a depth of 100nm-200nm on the tin surface. The implantation energy is approximately 5–200 keV, and the implantation dose is approximately 1×10⁻⁶. 11 -1×10 16 / cm 2 Incident angle 0-45°. Step 4: Prepare a 500nm-1000nm thick titanium film on the surface of the tin-lithium interlayer using radio frequency magnetron sputtering technology, using a titanium target with a purity of 99.999%, and a deposition vacuum of 5.0 × 10⁻⁶. -4 Pa, Ar2 flow rate 30 sccm, deposition temperature 100℃-200℃, deposition bias voltage 0-200V, deposition pressure 0.1-1Pa, deposition time 4-8h, after coating, wait for the sample temperature to drop to room temperature.
[0080] Step 5: Remove the coated sample and quickly transfer it to a sealed tritium absorption device, then evacuate to 10°C. -4 Pa, the sample is heated to 400℃-700℃ and held for 0.5-2h. The lithium content in the tin-lithium interlayer increases and decreases in cycles, so that the germanium-lithium interlayer fully expands and contracts and is completely pulverized. Then, the titanium film is loaded according to the tritium absorption process.
[0081] Step 6: After the tritium absorption is complete, wait for the temperature inside the chamber to drop to room temperature, take out the sample, use tweezers to pick up and remove the tritium absorption layer on the surface, and you will get a complete self-supporting tritium titanium film.
[0082] The technical effects achieved by using tin as a solvent atom are the same as those achieved by using silicon as a solvent atom, and will not be elaborated here.
[0083] Example 4
[0084] In this invention, at least two of silicon, germanium, and tin can be used as solvent atoms. For example, silicon and germanium can be used as solvent atoms; silicon and tin can be used as solvent atoms; or silicon, germanium, and tin can be used as solvent atoms. The preparation process is the same as that in Example 1, and will not be repeated here.
[0085] In the description of this invention, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0087] In this invention, unless otherwise explicitly 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 them; 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0088] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" of the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0089] In this invention, 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 the invention. 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.
[0090] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.
Claims
1. A method of manufacturing a substrateless radioisotope source, characterized by, The method comprises the following steps: S1: preparing an intermediate layer on the surface of a substrate, the intermediate layer comprising solvent atoms and solute atoms; S2: preparing a solute layer on the surface of the intermediate layer, the solute layer comprising the solute atoms; S3: heating the intermediate layer and / or the substrate, the solute atoms migrating to the intermediate layer to obtain a mixed layer; S4: preparing a loading layer on the surface of the mixed layer; S5: transferring to a radioactive isotope source loading device, the mixed layer being pulverized, the loading layer being separated from the substrate, and the loading layer absorbing the radioactive isotope to obtain a substrate-free radioactive isotope source.
2. The method for preparing a substrate-free radioactive isotope source according to claim 1, wherein the concentration of the solute atoms in the intermediate layer gradually decreases in the direction from the solute layer to the substrate. Before step S1, the method further comprises step S0: substrate pretreatment, wherein the substrate is ultrasonically cleaned, dried, and plasma cleaned.
3. The method of claim 1, wherein the method further comprises: The heating temperature in step S3 is 100-250 degrees Celsius.
4. The method of claim 1, wherein the method is characterized by, The thickness of the solute layer is 10-20 nm.
5. The method of claim 1, wherein the method further comprises, 6. The method for preparing a substrate-free radioactive isotope source according to claim 1, wherein the substrate is prepared by any one of magnetron sputtering, thermal evaporation deposition, electron beam deposition, electroplating, and chemical vapor deposition.
7. The method for preparing a substrate-free radioactive isotope source according to claim 1, wherein the intermediate layer and / or the solute layer are prepared by any one of magnetron sputtering, ion implantation, thermal evaporation deposition, electron beam deposition, electroplating, and chemical vapor deposition.
8. The method for preparing a substrate-free radioactive isotope source according to claim 4, wherein the loading layer is prepared by any one of magnetron sputtering, thermal evaporation deposition, laser deposition, chemical vapor deposition, and electron beam deposition.
9. The method for preparing a substrate-free radioactive isotope source according to claim 4, wherein the material of the solvent atoms is at least one of silicon, germanium, and tin; and / or the material of the solute atoms is lithium; and / or the material of the loading layer is at least one of titanium, scandium, vanadium, magnesium, lanthanum, and zirconium. The method for preparing a substrate-free radioactive isotope source according to any one of claims 1-9. 10. A method of producing an isotopic cell, characterized by,