Thermal cycle peel resistant fusion reactor antenna radiation belt structure and method of making

Abstract

The application discloses a kind of anti-thermal cycle peeling fusion reactor antenna radiation band structure and preparation process thereof, it is related to nuclear fusion technical field, fusion reactor antenna radiation band structure includes: metal matrix layer, intermediate buffer layer and metal conductive layer, intermediate buffer layer is coated in the outer surface of metal matrix layer, metal conductive layer is coated in the outer surface of intermediate buffer layer;Between intermediate buffer layer and metal conductive layer, between intermediate buffer layer and metal matrix layer, respectively form continuous solid solution interdiffusion zone to realize full metallurgical bonding.The anti-thermal cycle peeling fusion reactor antenna radiation band structure of the embodiment of the application, intermediate buffer layer can be isolated between metal matrix layer and metal conductive layer, can improve the anti-thermal fatigue performance of fusion reactor antenna radiation band structure, avoid producing microcracks and the like, and can avoid leading to the radio frequency conductivity reduction of metal conductive layer, and, high-strength bonding between dissimilar metals can be realized.

Description

Technical Field

[0001] This invention relates to the field of nuclear fusion technology, and in particular to a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping and a fabrication process for the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping. Background Technology

[0002] In magnetic confinement fusion devices, the ion cyclotron range of frequencies (ICRF) system is the core means of achieving plasma-assisted heating. The ICRF antenna radiating strip, as a key component directly radiating high-power radio frequency waves, operates in extremely harsh environments: on the one hand, due to the "skin effect" of high-frequency current, its outer surface must possess extremely high radio frequency conductivity; on the other hand, facing the high-temperature plasma, the radiating strip must withstand intense radiative heat flux and alternating Lorentz forces under strong magnetic fields. Therefore, the radiating strip must possess excellent surface conductivity, strong structural rigidity, and efficient active cooling capabilities.

[0003] Currently, the engineering community commonly uses a process of electroplating a pure copper layer onto an austenitic stainless steel substrate to manufacture antenna radiating strips, with cooling channels also machined inside the substrate as needed. However, as fusion devices operate with longer pulses and higher parameters, the traditional full-surface copper plating process has revealed insurmountable failure defects under extreme service conditions. On the one hand, austenitic stainless steel (approximately 16 × 10⁻⁶ / K) and pure copper (approximately 17.5 × 10⁻⁶ / K) have different coefficients of thermal expansion. Under frequent high and low temperature thermal cycling, huge alternating thermal shear stress will accumulate at the interface of dissimilar metals. Since the traditional coating and the substrate are only physically and mechanically bonded (the bonding strength is usually less than 50 MPa), microcracks are easily generated under the long-term coupling effect of thermal stress and electromagnetic oscillation, which can lead to local peeling or even large-area delamination. This will not only directly cause radio frequency arcing, but the detached debris will also seriously contaminate the vacuum chamber and cause plasma rupture. On the other hand, under long-term high-temperature operation, impurities such as iron and chromium in the stainless steel substrate can easily diffuse across the physical interface into the surface pure copper. This not only precipitates brittle intermetallic compounds at the interface, deteriorating the mechanical properties, but also drastically reduces the radio frequency conductivity of the surface oxygen-free copper, resulting in a decrease in antenna radio frequency transmission efficiency and local abnormal temperature rise, indicating room for improvement. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping. This fusion reactor antenna radiation strip structure can improve the thermal fatigue resistance of the fusion reactor antenna radiation strip structure, avoid the generation of microcracks, and prevent the reduction of radio frequency conductivity of the metal conductive layer. Moreover, it can achieve high-strength bonding between dissimilar metals.

[0005] According to an embodiment of the present invention, a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping is applicable to an ICRF antenna and includes: a metal substrate layer, an intermediate buffer layer, and a metal conductive layer. The intermediate buffer layer covers the outer surface of the metal substrate layer, and the metal conductive layer covers the outer surface of the intermediate buffer layer. The intermediate buffer layer is in contact with both the metal conductive layer and the metal substrate layer to form continuous solid solution interdiffusion bands between the intermediate buffer layer and the metal conductive layer, and between the intermediate buffer layer and the metal substrate layer, respectively, to achieve full metallurgical bonding.

[0006] According to an embodiment of the present invention, the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping utilizes an intermediate buffer layer covering the outer surface of a metal substrate layer and a conductive metal layer covering the outer surface of the intermediate buffer layer. This allows the intermediate buffer layer to isolate the metal substrate layer and the conductive metal layer, preventing the accumulation of large alternating thermal shear stress within the fusion reactor antenna radiation strip structure due to the difference in thermal expansion coefficients between the two layers. This improves the thermal fatigue resistance of the fusion reactor antenna radiation strip structure, prevents the formation of microcracks, and avoids impurities in the metal substrate layer. The mineral elements diffuse across the physical interface between the metal matrix layer and the metal conductive layer into the metal conductive layer, thereby avoiding the precipitation of brittle intermetallic compounds that would lead to deterioration of mechanical properties and reduce the radio frequency conductivity of the metal conductive layer. Moreover, continuous solid solution interdiffusion bands are formed between the intermediate buffer layer and the metal conductive layer, and between the intermediate buffer layer and the metal matrix layer, to achieve full metallurgical bonding. The tensile strength can reach more than 200 MPa, which is a significant improvement compared to the 50 MPa of the existing technology. This enables high-strength bonding between dissimilar metals and helps to improve the overall structural strength.

[0007] According to some embodiments of the present invention, a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping is provided in the metal substrate layer, wherein the distance between the inner wall surface of the cooling channel and the outer surface of the metal substrate layer is D, and satisfies: D≥5mm.

[0008] According to some embodiments of the present invention, the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping has multiple cooling channels, and the multiple cooling channels are arranged in an array inside the metal substrate layer.

[0009] According to some embodiments of the present invention, the cross-sectional structure of the cooling channel for the fusion reactor antenna radiation strip resistant to thermal cycling stripping is U-shaped, semi-circular, circular, or elliptical.

[0010] According to some embodiments of the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping, the metal substrate layer is constructed as a stainless steel substrate layer, the stainless steel substrate layer is made of non-magnetic austenitic stainless steel material, the thickness of the stainless steel substrate layer is L1, and satisfies: 18mm≤L1≤30mm; and / or, the metal conductive layer is constructed as a copper conductive layer, the copper conductive layer is made of oxygen-free copper material, the thickness of the copper conductive layer is L2, and satisfies: 1mm≤L2≤5mm; and / or, the intermediate buffer layer is constructed as a nickel-based buffer layer, the nickel-based buffer layer is made of high-plasticity pure nickel or low-alloyed nickel-based material, the thickness of the nickel-based buffer layer is L3, and satisfies: 0.2mm≤L3≤1.5mm.

[0011] According to some embodiments of the present invention, in the thermal cycling stripping resistant fusion reactor antenna radiation band structure, the thickness of the metal conductive layer is greater than the radio frequency skin depth of the ICRF antenna at the operating frequency; and / or, the thickness of the continuous solid solution interdiffusion band is L4, and satisfies: 2μm≤L4≤20μm.

[0012] According to some embodiments of the present invention, the fusion reactor antenna radiation strip structure is constructed as a multi-segment bent structure and includes a radiation strip water tank segment, a first horizontal plate segment, a first bent segment, a vertical plate segment, a second bent segment, and a second horizontal plate segment that are bent and connected in sequence. Grounding points are provided on both sides of the second horizontal plate segment.

[0013] This invention also proposes a fabrication process for a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping.

[0014] According to the fabrication process of the thermally resistant fusion reactor antenna radiation strip structure of the present invention, the fabrication process of the fusion reactor antenna radiation strip is used to fabricate the thermally resistant fusion reactor antenna radiation strip structure as described in any of the above embodiments, and includes: fabricating the metal substrate layer having cooling channels; activating the outer surface of the metal substrate layer; sequentially coating the outer surface of the metal substrate layer with the intermediate buffer layer and the metal conductive layer to form a composite component; subjecting the composite component to high-temperature vacuum degassing treatment and hot isostatic pressing treatment to combine the composite components to form a composite component; and performing flaw detection and surface treatment on the composite component to form a finished product.

[0015] According to the fabrication process of the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping of the present invention, the hot isostatic pressing process includes: placing the component to be composited in a hot isostatic pressing device and holding it at a first temperature range and a first pressure for a first duration, so that the intermediate buffer layer is bonded to the metal conductive layer and the metal substrate layer respectively.

[0016] According to the fabrication process of the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping of the present invention, the fabrication of the metal substrate layer with cooling channels includes: machining the cooling channels on the metal substrate layer using a machine tool, and sealing the cooling channels by welding a sealing cover plate to the cooling channels to seal the cooling channels.

[0017] The fabrication process of the thermally resistant stripping fusion reactor antenna radiating strip structure has the same advantages as the aforementioned thermally resistant stripping fusion reactor antenna radiating strip structure compared to the prior art, and will not be elaborated here.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the thermal cycling-resistant stripping fusion reactor antenna radiation strip structure according to an embodiment of the present invention. Figure 2 This is a partial cross-sectional view of the thermal cycling stripping resistant fusion reactor antenna radiation strip structure according to an embodiment of the present invention; Figure 3 yes Figure 2 A magnified view of a section at point A in the middle; Figure 4 This is a flowchart of the fabrication process of a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to an embodiment of the present invention.

[0020] Figure label: Fusion reactor antenna radiation strip structure 100 resistant to thermal cycling stripping 1. Metal substrate layer; 2. Intermediate buffer layer; 3. Conductive metal layer; 4. Continuous solid solution interdiffusion zone; 5. Cooling channel. Radiation zone water tank section 6, first horizontal plate section 7, first bend section 8, vertical plate section 9, second bend section 10, second horizontal plate section 11, grounding point 12. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] 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," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention 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 the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means three or more.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of three components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The following is for reference. Figures 1-3 The thermal cycling-resistant fusion reactor antenna radiation strip structure 100 described in this embodiment of the invention can improve the thermal fatigue resistance of the fusion reactor antenna radiation strip structure 100, avoid the generation of microcracks, and prevent the reduction of radio frequency conductivity of the metal conductive layer. Moreover, it can achieve high-strength bonding between dissimilar metals.

[0025] like Figures 1-3 As shown, a thermally resistant fusion reactor antenna radiation strip structure 100 according to an embodiment of the present invention is applicable to ICRF antennas and includes: a metal substrate layer 1, an intermediate buffer layer 2, and a metal conductive layer 3.

[0026] An intermediate buffer layer 2 is coated on the outer surface of the metal substrate layer 1, and a metal conductive layer 3 is coated on the outer surface of the intermediate buffer layer 2. The intermediate buffer layer 2 is in contact with the metal conductive layer 3 and the metal substrate layer 1 respectively, so as to form a continuous solid solution interdiffusion zone 4 between the intermediate buffer layer 2 and the metal conductive layer 3 and between the intermediate buffer layer 2 and the metal substrate layer 1 to achieve full metallurgical bonding.

[0027] Specifically, the thermal cycling stripping-resistant fusion reactor antenna radiation strip structure 100 is suitable for ICRF antennas. ICRF antennas are used to couple the high power generated by the radio frequency transmitter into the plasma and heat the plasma through the ion cyclotron resonance mechanism. This is a key auxiliary heating method to maintain the steady-state operation of the fusion reactor. The fusion reactor antenna radiation strip structure 100 is the core component of the ICRF antenna that directly faces the plasma and undertakes the transmission of radio frequency energy. The fusion reactor antenna radiation strip structure 100 includes a metal substrate layer 1 and a metal conductive layer 3. The metal substrate layer 1 serves as the base structure of the fusion reactor antenna radiation strip structure 100 and is the skeleton of the fusion reactor antenna radiation strip structure 100, which is used to provide structural strength. The metal conductive layer 3 is used to reduce radio frequency loss and ensure efficient current flow.

[0028] It should be noted that the metal substrate layer 1 and the metal conductive layer 3 are used for different purposes. In practice, the metal substrate layer 1 and the metal conductive layer 3 can be made of different metal materials to reduce radio frequency loss.

[0029] Simultaneously, the fusion reactor antenna radiation strip structure 100 also includes an intermediate buffer layer 2. The intermediate buffer layer 2 is wrapped around the outer surface of the metal substrate layer 1, and a metal conductive layer 3 is wrapped around the outer surface of the intermediate buffer layer 2. This allows the intermediate buffer layer 2 to be positioned between the metal substrate layer 1 and the metal conductive layer 3, thus separating them and facilitating stress transition between them. This prevents stress from occurring due to the different thermal expansion coefficients of the metal substrate layer 1 and the metal conductive layer 3, even when they are made of different materials. The radiation strip structure 100 accumulates huge alternating thermal shear stress inside, which can prevent microcracks, local peeling or even large-area detachment of the fusion reactor antenna radiation strip structure 100 under the long-term coupling effect of thermal stress and electromagnetic oscillation. It can also prevent impurity elements in the metal substrate layer 1 from diffusing into the metal conductive layer 3 across the physical interface between the metal substrate layer 1 and the metal conductive layer 3. This can prevent the precipitation of brittle intermetallic compounds at the physical interface between the two, which would lead to deterioration of mechanical properties. It can also prevent the reduction of radio frequency conductivity of the metal conductive layer 3, and prevent the decrease of radio frequency transmission efficiency and local abnormal temperature rise of the ICRF antenna.

[0030] It should be noted that the intermediate buffer layer 2 is used to transition between the metal substrate layer 1 and the metal conductive layer 3. That is, when selecting the material of the intermediate buffer layer 2, the material of the intermediate buffer layer 2 is different from the material of the metal substrate layer 1 and the material of the metal conductive layer 3, so as to ensure that the intermediate buffer layer 2 can reliably isolate and transition between the metal substrate layer 1 and the metal conductive layer 3.

[0031] Furthermore, the metal substrate layer 1, the intermediate buffer layer 2, and the metal conductive layer 3 are sequentially coated, so that the intermediate buffer layer 2 can contact the metal conductive layer 3 and the metal substrate layer 1 respectively, so as to form continuous solid solution interdiffusion bands 4 between the intermediate buffer layer 2 and the metal conductive layer 3, and between the intermediate buffer layer 2 and the metal substrate layer 1, to achieve full metallurgical bonding. That is, when the intermediate buffer layer 2 is placed between the metal substrate layer 1 and the metal conductive layer 3, the inner surface of the intermediate buffer layer 2 can be opposite to the metal substrate layer 1 and the outer surface can be opposite to the metal conductive layer 3, thereby allowing the intermediate buffer layer 2 to form continuous solid solution interdiffusion bands 4 with the metal substrate layer 1 and the metal conductive layer 3 respectively.

[0032] In other words, a continuous solid solution interdiffusion band 4 can be formed at the physical interface between the intermediate buffer layer 2 and the metal substrate layer 1. The continuous solid solution interdiffusion band 4 between the intermediate buffer layer 2 and the metal substrate layer 1 is formed by the convergence and uniform dispersion of elements in the intermediate buffer layer 2 diffusing towards the metal substrate layer 1 and elements in the metal substrate layer 1 diffusing towards the intermediate buffer layer 2 at the physical interface between the intermediate buffer layer 2 and the metal substrate layer 1. By forming this continuous solid solution interdiffusion band 4, the full metallurgical bonding between the intermediate buffer layer 2 and the metal substrate layer 1 can be achieved, that is, the tight bonding between the intermediate buffer layer 2 and the metal substrate layer 1 can be achieved.

[0033] Furthermore, a continuous solid solution interdiffusion band 4 can be formed between the intermediate buffer layer 2 and the metal conductive layer 3 at their physical interface. The continuous solid solution interdiffusion band 4 between the intermediate buffer layer 2 and the metal conductive layer 3 is formed by the convergence and uniform dispersion of elements in the intermediate buffer layer 2 diffusing towards the metal conductive layer 3 and elements in the metal conductive layer 3 diffusing towards the intermediate buffer layer 2 at their physical interface. By forming this continuous solid solution interdiffusion band 4, the intermediate buffer layer 2 and the metal conductive layer 3 can be fully metallurgically bonded, thus achieving a tight bond between the intermediate buffer layer 2 and the metal conductive layer 3. This allows for the formation of a high-strength bond between dissimilar metals without a macroscopic physical interface, with a tensile strength exceeding 200 MPa, which is beneficial for improving the overall structural strength.

[0034] The thermally resistant fusion reactor antenna radiation strip structure 100 according to an embodiment of the present invention, by covering the outer surface of the metal substrate layer 1 with an intermediate buffer layer 2 and the outer surface of the metal conductive layer 3 with the intermediate buffer layer 2, allows the intermediate buffer layer 2 to isolate the metal substrate layer 1 and the metal conductive layer 3. This avoids the accumulation of huge alternating thermal shear stress inside the fusion reactor antenna radiation strip structure 100 due to the difference in thermal expansion coefficients between the metal substrate layer 1 and the metal conductive layer 3, thereby improving the thermal fatigue resistance of the fusion reactor antenna radiation strip structure 100. This avoids the formation of microcracks and prevents impurity elements in the metal substrate layer 1 from diffusing into the metal conductive layer 3 across the physical interface between the metal substrate layer 1 and the metal conductive layer 3. This also prevents the precipitation of brittle intermetallic compounds that would lead to deterioration of mechanical properties and a decrease in the radio frequency conductivity of the metal conductive layer 3. Furthermore, continuous solid solution interdiffusion bands 4 are formed between the intermediate buffer layer 2 and the metal conductive layer 3, and between the intermediate buffer layer 2 and the metal substrate layer 1, respectively, to achieve full metallurgical bonding. This enables high-strength bonding between dissimilar metals and improves the overall structural strength.

[0035] In some embodiments, a cooling channel 5 is provided in the metal substrate layer 1, and the distance between the inner wall surface of the cooling channel 5 and the outer surface of the metal substrate layer 1 is D, which satisfies: D≥5mm.

[0036] Specifically, a cooling channel 5 is provided within the metal substrate layer 1. The cooling channel 5 allows coolant to flow through, forming a flow path for the coolant. By placing the cooling channel 5 inside the metal substrate layer 1, it is positioned within the fusion reactor antenna radiation strip structure 100. This allows the coolant to flow within the cooling channel 5, cooling the fusion reactor antenna radiation strip structure 100 from within, thus removing the heat generated by radio frequency ohmic heat and neutron / particle irradiation. This maintains the temperature of the fusion reactor antenna radiation strip structure 100 within a safe range. Furthermore, the cooling channel 5 is located at the innermost part of the fusion reactor antenna radiation strip structure 100, protecting it from damage or failure due to collisions or friction with external structures, ensuring the reliable operation of the cooling channel 5. The coolant can be water or similar substances.

[0037] Furthermore, the distance between the inner wall of the cooling channel 5 and the outer surface of the metal substrate layer 1 is D, and D is not less than 5mm. For example, D can be 5mm, 6mm, or 7mm, etc. That is, the distance between the inner wall of the cooling channel 5 and the outer surface of the metal substrate layer 1 cannot be too close. If the distance is too close, it means that the thickness of the metal substrate layer 1 is small. If the thickness is small, the pressure bearing capacity of the metal substrate will be insufficient, which will cause the surface of the metal substrate layer 1 to bulge and deform due to the pressure in the cooling channel 5. Thus, by reasonably designing the distance between the inner wall of the cooling channel 5 and the outer surface of the metal substrate layer 1, the thickness and strength of the metal substrate layer 1 can be guaranteed, as well as the pressure bearing capacity of the metal substrate layer 1.

[0038] Understandably, the distance between the inner wall of the cooling channel 5 and the outer surface of the metal substrate layer 1 should not be too far. If the distance is too far, it may cause an excessive surface temperature difference in the fusion reactor antenna radiation strip structure 100, which may lead to cracking, peeling and other problems due to thermal stress.

[0039] In some embodiments, there are multiple cooling channels 5, and the multiple cooling channels 5 are arranged in an array inside the metal substrate layer 1.

[0040] Specifically, the cooling channels 5 are used to guide the coolant to flow inside the fusion reactor antenna radiation strip structure 100 to cool the fusion reactor antenna radiation strip structure 100. Multiple cooling channels 5 can be configured, that is, the number of cooling channels 5 can be two, three or more. Thus, multiple cooling channels 5 can simultaneously cool the fusion reactor antenna radiation strip structure 100, thereby improving the reliability of cooling the fusion reactor antenna radiation strip structure 100. Moreover, the multiple cooling channels 5 are arrayed inside the metal substrate layer 1, that is, the multiple cooling channels 5 are neatly arranged inside the metal substrate layer 1, so that multiple cooling channels 5 can simultaneously cool the fusion reactor antenna radiation strip structure 100 at multiple locations, thereby improving the uniformity of cooling the fusion reactor antenna radiation strip structure 100.

[0041] In some embodiments, the cross-sectional structure of the cooling channel 5 is U-shaped, semi-circular, circular, or elliptical.

[0042] Specifically, the cooling channel 5 is used to provide a flow path for the coolant. The cross-section of the cooling channel 5 is constructed as U-shaped, semi-circular, circular, or elliptical, etc., so that the cooling channel 5 has a certain inner diameter to ensure the reliability of the coolant flow inside it. Furthermore, by designing the cross-section of the cooling channel 5, the inner diameter of the cooling channel 5 can be designed to avoid the inner diameter of the cooling channel 5 being too small. If the inner diameter of the cooling channel 5 is too small, it will lead to high flow resistance and uneven flow velocity of the coolant, which will result in poor cooling effect on the fusion reactor antenna radiation strip structure 100.

[0043] In such Figure 1 and Figure 2 In the embodiment shown, the cross-section of the cooling channel 5 is U-shaped.

[0044] In some embodiments, the metal substrate layer 1 is constructed as a stainless steel substrate layer, which is made of non-magnetic austenitic stainless steel material, and the thickness of the stainless steel substrate layer is L1, satisfying: 18mm≤L1≤30mm; and / or, the metal conductive layer 3 is constructed as a copper conductive layer, which is made of oxygen-free copper material, and the thickness of the copper conductive layer is L2, satisfying: 1mm≤L2≤5mm; and / or, the intermediate buffer layer 2 is constructed as a nickel-based buffer layer, which is made of high-plasticity pure nickel or low-alloy nickel-based material, and the thickness of the nickel-based buffer layer is L3, satisfying: 0.2mm≤L3≤1.5mm.

[0045] Specifically, the metal substrate layer 1 serves as the base structure of the fusion reactor antenna radiation strip structure 100, providing structural strength. The metal substrate layer 1 is constructed as a stainless steel substrate layer, meaning that the metal substrate layer 1 is made of stainless steel. Stainless steel has superior yield strength, tensile strength, and high-temperature creep resistance. By using stainless steel to make the metal substrate layer 1, it can simultaneously withstand thermal stress, electromagnetic force, and the internal pressure of the cooling channel 5. It is also convenient to process and form complex cooling channels 5 inside the metal substrate layer 1. Furthermore, the stainless steel substrate layer can be made of non-magnetic austenitic stainless steel, allowing magnetic field lines to penetrate freely without distorting the magnetic field configuration or interfering with the plasma magnetic field.

[0046] The thickness of the stainless steel substrate layer is L1, and L1 is between 18mm and 30mm. For example, L1 can be 18mm, 20mm or 25mm, etc. This can avoid the stainless steel substrate layer being too thick or too thin. If it is too thin, the strength of the stainless steel substrate layer will be low, and the strength and pressure bearing capacity of the metal substrate layer 1 cannot be guaranteed. If it is too thick, it will lead to uneven temperature, increased thermal stress and increased difficulty in processing the cooling channel 5.

[0047] Furthermore, the metal conductive layer 3 is used to reduce radio frequency loss and ensure efficient current flow. The metal conductive layer 3 is constructed as a copper conductive layer, which means that the metal conductive layer 3 is made of copper material. Copper material has high conductivity and low resistivity. By making the metal conductive layer 3 of copper material, the radio frequency current mainly flows in the copper conductive layer, which can effectively reduce radio frequency loss. Moreover, the copper conductive layer is made of oxygen-free copper material, which is the structural copper with the highest conductivity, so that the conductivity can be improved while reducing radio frequency loss.

[0048] The thickness of the copper conductive layer is L2, and L2 is between 1mm and 5mm. For example, L2 can be 1mm, 2mm or 4mm, etc. This can avoid the copper conductive layer being too thick or too thin. If it is too thin, the radio frequency current will penetrate the copper conductive layer to the stainless steel substrate layer, and the radio frequency loss will increase. If it is too thick, it will cause thermal stress cracking or peeling.

[0049] Furthermore, the intermediate buffer layer 2 serves to separate the metal substrate layer 1 and the metal conductive layer 3. The intermediate buffer layer 2 is constructed as a nickel-based buffer layer, meaning it is made of nickel. Nickel, stainless steel, and copper all have a face-centered cubic crystal structure with the same lattice type. Under the thermal cycling and transient thermal shock conditions of the fusion reactor, the nickel-based buffer layer can absorb the thermal mismatch stress caused by the difference in thermal expansion coefficients between copper and stainless steel through plastic deformation, delaying the initiation and propagation of thermal fatigue cracks, thereby improving the thermal fatigue life of the fusion reactor antenna radiation strip structure 100. The nickel-based buffer layer can also reduce the diffusion flux of iron and chromium elements from stainless steel to the copper conductive layer, reducing the formation of brittle intermetallic compounds. This helps maintain the radio frequency conductivity of the copper conductive layer and reduces the release of impurity gases originating from within the material under fusion vacuum conditions. The nickel-based buffer layer uses high-plasticity pure nickel or low-alloy nickel-based materials, with the nickel content in the low-alloy nickel-based materials not less than 99%.

[0050] The thickness of the nickel-based buffer layer is L3, and L3 is between 0.2mm and 1.5mm. For example, L3 can be 0.2mm, 0.5mm or 1mm, etc. This avoids L3 being too large or too small. If it is too small, the effect of isolating the stainless steel substrate layer and the copper conductive layer will be poor, and if it is too large, it will lead to material waste.

[0051] In some embodiments, the thickness of the metal conductive layer 3 is greater than the radio frequency skin depth of the ICRF antenna at the operating frequency; and / or, the thickness of the continuous solid solution interdiffusion band 4 is L4, and satisfies: 2μm≤L4≤20μm.

[0052] Specifically, when the ICRF antenna is working, the radio frequency current does not flow uniformly across the entire cross-section of the fusion reactor antenna radiation strip structure 100, but is concentrated in a very thin layer on its surface. The thickness of this layer is called the skin depth. In this way, the thickness of the metal conductive layer 3 is greater than the radio frequency skin depth of the ICRF antenna at the operating frequency, so as to ensure that the radio frequency current flows reliably in the copper conductive layer, reliably reduce the radio frequency loss, and by increasing the thickness of the metal conductive layer 3, machining allowance and anti-plasma physical sputtering consumption allowance can be reserved during the bonding process of the metal conductive layer 3 and the nickel-based buffer layer.

[0053] Furthermore, continuous solid solution interdiffusion zones 4 are formed between the intermediate buffer layer 2 and the metal conductive layer 3, and between the intermediate buffer layer 2 and the metal substrate layer 1, respectively. That is, the intermediate buffer layer 2 can form a continuous solid solution interdiffusion zone 4 with the metal conductive layer 3 and the metal substrate layer 1, respectively. The continuous solid solution interdiffusion zone 4 between the intermediate buffer layer 2 and the metal conductive layer 3 is formed when the elements in the nickel-based buffer layer and the elements in the copper conductive layer diffuse towards each other simultaneously. The continuous solid solution interdiffusion zone 4 between the intermediate buffer layer 2 and the metal substrate layer 1 is formed when the elements in the nickel-based buffer layer and the elements in the stainless steel substrate layer diffuse towards each other simultaneously. This makes the stainless steel substrate layer, the nickel-based buffer layer and the copper conductive layer all atomic-level fully metallurgical bonding interfaces, and there is no precipitation of brittle intermetallic compounds.

[0054] The thickness of the continuous solid solution interdiffusion zone 4 is set to L4, and L4 is between 2μm and 20μm. For example, L4 can be 2μm, 5μm or 10μm, etc. This can avoid the thickness of the continuous solid solution interdiffusion zone 4 being too large or too small.

[0055] It should be noted that by forming an atomic-level all-metallurgical bonding interface, the tensile strength of the copper / nickel interface is not less than 200 MPa and the shear strength is not less than 120 MPa, which can effectively improve the interface peel resistance of the fusion reactor antenna radiation strip structure 100 under the action of alternating electromagnetic force.

[0056] In some embodiments, the fusion reactor antenna radiation strip structure 100 is constructed as a multi-segment bent structure and includes a radiation strip water tank segment 6, a first horizontal plate segment 7, a first bent segment 8, a vertical plate segment 9, a second bent segment 10, and a second horizontal plate segment 11 that are bent and connected in sequence. Grounding points 12 are provided on both sides of the second horizontal plate segment 11.

[0057] Specifically, such as Figure 1 As shown, the fusion reactor antenna radiation strip structure 100 includes a radiation strip tank section 6, a first horizontal plate section 7, a first bent section 8, a vertical plate section 9, a second bent section 10, and a second horizontal plate section 11. This allows the fusion reactor antenna radiation strip structure 100 to be constructed as a multi-segment structure with multiple radiation strips. By setting multiple radiation strips, impedance matching and reduction of local electric fields can be achieved. Furthermore, by constructing the fusion reactor antenna radiation strip structure 100 as a multi-segment bent structure, the radiation strip tank section 6, the first horizontal plate section 7, the first bent section 8, the vertical plate section 9, the second bent section 10, and the second horizontal plate section 11 are sequentially bent and connected, making the fusion reactor antenna radiation strip structure 100 U-shaped and a single integrated structure. This improves the overall strength and operational reliability of the fusion reactor antenna radiation strip structure 100.

[0058] In the multi-layer structure of the fusion reactor antenna radiation belt structure 100, the cooling channels 5 are evenly arranged along the center line of each section, and the two ends of the cooling channels 5 are connected to the inlet and outlet water outlets set on the radiation belt water tank section 6 respectively.

[0059] Furthermore, it should be noted that there are gaps between each radiation strip in the fusion reactor antenna radiation strip structure 100. Ideally, the radio frequency current flows only on the surface of each radiation strip. However, in reality, there is displacement current between adjacent radiation strips, and the current at both ends of the radiation strip is distorted, generating stray radiation and reducing coupling efficiency. Grounding points 12 are provided on both sides of the second horizontal plate segment 11, so that grounding points 12 can be set on the fusion reactor antenna radiation strip structure 100 to suppress parasitic current and ensure that the radio frequency current flows according to the design path. This can avoid the decrease in coupling efficiency, the increase of impurities, and local overheating. Moreover, setting two grounding points 12 can further reduce the edge electric field and improve the suppression effect of parasitic current.

[0060] The present invention also proposes a fabrication process for a fusion reactor antenna radiation strip structure 100 resistant to thermal cycling stripping.

[0061] like Figure 4 As shown, the fabrication process of the thermally resistant fusion reactor antenna radiating strip structure 100 according to the present invention is used to fabricate the thermally resistant fusion reactor antenna radiating strip structure 100 of any of the above embodiments, and the fabrication process includes: S10: Prepare a metal substrate layer 1 with cooling channels 5.

[0062] Specifically, the fabrication process of the fusion reactor antenna radiation strip structure 100 resistant to thermal cycling stripping is used to fabricate the fusion reactor antenna radiation strip structure 100 resistant to thermal cycling stripping. This process can be used to fabricate the fusion reactor antenna radiation strip structure 100 resistant to thermal cycling stripping. For example, the fusion reactor antenna radiation strip structure 100 can be fabricated by machining or other methods. First, a metal substrate layer 1 with cooling channels 5 needs to be fabricated. A metal conductive layer 3 covers the outer surface of an intermediate buffer layer 2, and the intermediate buffer layer 2 covers the outer surface of the metal substrate layer 1. That is, the metal substrate layer 1 is located at the innermost part of the fusion reactor antenna radiation strip structure 100. When fabricating the fusion reactor antenna radiation strip structure 100, the metal substrate layer 1 can be fabricated first, so that the intermediate buffer layer 2 and the metal conductive layer 3 can be sequentially covered on the outer surface of the metal substrate layer 1.

[0063] Furthermore, the metal substrate layer 1 is provided with cooling channels 5. During the preparation of the metal substrate layer 1, cooling channels 5 need to be machined inside the metal substrate layer 1. For example, cooling channels 5 can be machined inside the metal substrate layer 1 by milling or other means, thereby forming a metal substrate layer 1 with cooling channels 5.

[0064] S20: The outer surface of the metal substrate layer 1 is activated, and the intermediate buffer layer 2 and the metal conductive layer 3 are sequentially coated on the outer surface of the metal substrate layer 1 to form the composite component.

[0065] Specifically, the outer surface of the metal substrate layer 1 is activated, that is, the surface of the metal substrate layer 1 facing the intermediate buffer layer 2 is activated to facilitate the tight bonding between the metal substrate layer 1 and the intermediate buffer layer 2. After the activation treatment is completed, the intermediate buffer layer 2 and the metal conductive layer 3 can be sequentially coated on the outer surface of the metal substrate layer 1. That is, the intermediate buffer layer 2 is coated on the outer surface of the metal substrate layer 1, and then the metal conductive layer 3 is coated on the outer surface of the intermediate buffer layer 2, thereby forming the composite component to be formed.

[0066] Before activating the metal substrate layer 1, a leak test and a pressure test can be performed on the metal substrate layer 1 with cooling channels 5. The requirement is that the overall leakage rate is less than 1.0 × 10⁻⁶. - ¹ 0 The pressure is measured at Pa·m³ / s. After introducing high-pressure water at 1.5 times the working pressure into the cooling channel 5 and maintaining the pressure for 30 minutes, there is basically no leakage and the cooling channel 5 does not undergo plastic yield deformation. Through leak detection and pressure resistance tests, the metal substrate layer 1 that does not meet the requirements can be removed in advance to ensure the reliability of the final fusion reactor antenna radiation strip structure 100. After the leak detection and pressure resistance tests are completed, the outer surface of the stainless steel substrate layer that has passed the test can be activated. The activation treatment may include mechanically grinding the outer surface of the stainless steel substrate layer to make its surface roughness no greater than 0.8μm, so as to facilitate subsequent atomic-level diffusion bonding. After grinding, ultrasonic cleaning can be performed in sequence with acetone and anhydrous ethanol to thoroughly remove the oil and oxide film on the outer surface of the stainless steel substrate layer.

[0067] Furthermore, the process of sequentially coating the outer surface of the metal substrate layer 1 with an intermediate buffer layer 2 and a metal conductive layer 3 includes: coating the outer surface of the activated stainless steel substrate layer with pure nickel foil, or pre-depositing high-purity nickel using a plasma spraying process as an intermediate buffer layer 2, and then applying a pre-processed copper conductive layer with a design allowance on its outer side. The copper conductive layer can be an oxygen-free copper outer sheath, thereby forming the composite component to be assembled.

[0068] S30: The composite components are subjected to high-temperature vacuum degassing and hot isostatic pressing to bond them together to form a composite component.

[0069] Specifically, after the composite component is formed, it can be subjected to high-temperature vacuum degassing and hot isostatic pressing to form a composite component. The composite component can be placed in an environment with a specific temperature and pressure so that the intermediate buffer layer 2 in the composite component can be combined with the metal substrate layer 1 and the metal conductive layer 3 to form a composite component.

[0070] The high-temperature vacuum degassing process includes: placing the assembled component to be composited in a vacuum degassing furnace, and subjecting it to high-temperature baking and vacuum degassing at a temperature of 200℃ to 300℃. The vacuum level of the internal metal interlayer of the component to be composited is greater than 1.0 × 10⁻⁶. - At ³Pa, an electron beam is used to perform full penetration sealing welding on all assembly joints of the external oxygen-free copper outer casing, thereby obtaining a composite component with the internal high vacuum state.

[0071] S40: Perform flaw detection and surface treatment on the composite components to form the finished product.

[0072] Specifically, flaw detection of the composite components is to inspect them to remove those that do not meet the requirements. Then, the composite components that pass the flaw detection can be surface treated to form a finished product, which can form the fusion reactor antenna radiation strip structure 100.

[0073] The flaw detection of composite components includes: performing ultrasonic C-scan non-destructive testing (NDT) on the composite components after they come out of the furnace, verifying the metallurgical bonding rate of the copper / nickel and nickel / stainless steel interfaces point by point, ensuring that the effective bonding rate reaches more than 99%, and that the area of ​​a single unbonded area does not exceed 10 mm², and the distance between adjacent unbonded areas is not less than 50 mm.

[0074] Surface treatment of composite components that have passed flaw detection includes: removing the edge process allowance of the composite component by precision CNC machining, trimming the composite component to the three-dimensional shape and size of the ICRF antenna physical design, and then electrolytically polishing or precision mechanically polishing the outer surface of the outermost oxygen-free copper outer sheath to make its surface roughness not exceed 0.4μm, so as to improve the surface withstand voltage under radio frequency high voltage conditions and reduce the probability of radio frequency arcing.

[0075] Furthermore, a final vacuum leak rate test can be performed before the final product is formed to ensure its reliability. This final vacuum leak rate test involves connecting the composite component, after all processing steps have been completed, to an ultra-high vacuum testing system and using a helium mass spectrometer leak detector to perform a final leak rate test. The testing conditions and criteria are: using helium as the tracer gas, under room temperature and operating pressure differential conditions, the overall vacuum leak rate of the composite component should be less than 1.0 × 10⁻⁶. - ¹ 0 Pa·m³ / s, finished products that meet this leakage rate index are considered to maintain effective isolation between the internal cooling channel 5 and the external service vacuum environment after undergoing HIP composite and machining, and are suitable for reliable service under the ultra-high vacuum conditions of fusion devices.

[0076] In this invention, such as Figure 4 As shown, hot isostatic pressing includes: S31: The component to be composited is placed in a hot isostatic pressing device and kept at a first temperature range and a first pressure for a first duration, so that the intermediate buffer layer 2 is bonded to the metal conductive layer 3 and the metal substrate layer 1 respectively.

[0077] The hot isostatic pressing equipment can be a HIP equipment, with a first temperature range of 850°C to 920°C, a first pressure range of 100MPa to 150MPa, and a first duration of 2 to 4 hours.

[0078] For example, hot isostatic pressing (HIP) treatment of the composite component includes: placing the component in a HIP device and holding it at 850°C to 920°C and 100MPa to 150MPa for 2 to 4 hours to achieve diffusion bonding, thereby achieving a full metallurgical bond between the stainless steel substrate layer, the nickel-based buffer layer, and the copper conductive layer. Specifically, this includes the following sub-steps: ① Synchronous heating and pressurization stage: Place the component to be composited in the working chamber of the HIP equipment, introduce high-purity argon gas as the pressure transmission medium, and simultaneously heat and pressurize at a slow rate not exceeding 3℃ / min until the system temperature reaches 850℃ to 920℃ and the pressure reaches 100MPa to 150MPa.

[0079] ② Thermal Insulation and Pressure Holding Interdiffusion Stage: Under the aforementioned isostatic pressure conditions, thermal insulation and pressure holding are maintained for 2 to 4 hours. During this stage, the isotropic static pressure forces the microscopic protrusions at the copper, nickel, and stainless steel interfaces to undergo severe plastic deformation and close bonding. Under the effect of high-temperature thermal activation, the interfacial metal atoms undergo cross-interfacial lattice-depth interdiffusion, completely eliminating microscopic porosity and achieving full metallurgical bonding of the three layers. Since the solid wall thickness of the inner wall surface of the cooling channel 5 is not less than 5 mm from any outer surface edge of the stainless steel substrate layer, under the action of 150 MPa isostatic pressure, the structural stiffness provided by the solid wall thickness is sufficient to withstand the compressive stress load, allowing the cooling channel 5 to maintain its original design dimensions and cross-sectional shape during the HIP process.

[0080] ③ In-furnace cooling and depressurization stage: After the composite is completed, the temperature is first reduced to 600℃ at a rate not exceeding 2℃ / min, and then depressurized simultaneously and continued to be cooled to room temperature in the furnace. The extremely low cooling rate is intended to fully release the residual thermal stress caused by the difference in the thermal expansion coefficients of the three layers of materials and prevent microcracks from forming at the interface during the cooling stage.

[0081] In this invention, such as Figure 4 As shown, the preparation of the metal substrate layer 1 with cooling channels 5 includes: S11: The cooling channel 5 is machined on the metal substrate layer 1 using a machine tool, and the sealing cover is welded to the cooling channel 5 by welding process to seal the cooling channel 5.

[0082] Specifically, when preparing the metal substrate layer 1 with cooling channels 5, a machine tool can be used to process the cooling channels 5 on the metal substrate layer 1. For example, a CNC machine tool can be used to process the cooling channels 5 on the stainless steel substrate layer, so that the stainless steel substrate layer can have cooling channels 5. The use of a CNC machine tool can improve processing efficiency. Then, a sealing cover plate can be welded to the cooling channels 5 through a welding process, so that the sealing cover plate can seal the cooling channels 5 to prevent coolant leakage. The welding method can also improve the connection strength and improve the reliability of sealing the cooling channels 5.

[0083] It should be noted that the method of processing the cooling channel 5 and the method of sealing the cooling channel 5 are not limited to those described in this application, and can be flexibly selected according to the actual situation.

[0084] For example, the following describes the specific implementation process of preparing a stainless steel substrate layer with cooling channels 5 and achieving a three-layer full metallurgical composite of copper / nickel / stainless steel through HIP, using the traditional machining and sealing process to prepare a simple straight-plate fusion reactor antenna radiation strip structure 100. The process is verified by numerical calculation.

[0085] ①Target Structure The dimensions of the straight section are: length 300mm, width 220mm, and total thickness after composite assembly is approximately 24mm. Cooling channel 5: U-shaped cross section, width 8.0mm, machining depth 14.0mm, spacing 20mm.

[0086] ② Material preparation The list of materials to be prepared is shown in Table 1 below.

[0087] Table 1 Material Preparation List

[0088] ③ Specific preparation process steps A. Processing of cooling channels in stainless steel substrate and preparation of composite components a. Precision machining of cooling channels 5 A five-axis CNC machining center was used to mill a straight cooling channel 5 on the back side of the 316L stainless steel substrate (i.e. the side that will not be directly bombarded by plasma). The cross-section of the cooling channel 5 is U-shaped (groove width 8mm, groove depth 14mm, bottom fillet radius R=4mm), the spacing of the cooling channels 5 is 20mm, and the surface roughness of the inner wall of the cooling channel 5 is Ra=2.8μm.

[0089] b. Vacuum electron beam sealing After attaching the matching 316L stainless steel sealing cover (6.0mm thick, the same material as the stainless steel base layer) above the cooling channel 5, the entire assembly is placed inside the vacuum electron beam welding chamber at a depth of 5.0×10 mm.- Under a vacuum of 2 Pa, a deep penetration electron beam is used to perform fully enclosed straight-line welding along the edge of the cooling channel 5. The welding parameters are: accelerating voltage 150kV, beam current 45mA, welding speed 8mm / s. The weld design ensures that the partition (width ≥8mm) between adjacent cooling channels 5 is completely covered to prevent water leakage.

[0090] Initial leak detection and pressure test of the stainless steel substrate Helium mass spectrometry was used to detect leaks in the stainless steel substrate after sealing. The overall leakage rate was controlled below 1.0×10-10 Pa·m³ / s. Then, 6.0 MPa high-pressure water was introduced for a 30-minute pressure holding test to confirm that there was no leakage in the stainless steel substrate and no plastic yielding deformation in the cooling channel 5. Each cooling channel 5 was independently purged with air using special tooling, and the pressure change of adjacent cooling channels 5 was detected to confirm that there was no cross-leakage.

[0091] B. Assembly and vacuum degassing sealing a. Interface deep activation treatment The outer surface of the stainless steel substrate layer that passed the initial inspection was mechanically ground to achieve a roughness of Ra≤0.8μm; then it was sequentially degreased with acetone ultrasonically (10 minutes), rinsed with anhydrous ethanol, and vacuum dried (80℃, 2 hours); then it was activated by ion bombardment in a vacuum chamber (500V, 2mA / cm², 10 minutes).

[0092] b. Coated nickel-based buffer layer and copper conductive layer A 0.5mm thick pure nickel foil is tightly wrapped around the outer surface of the activated stainless steel substrate as an intermediate buffer layer 2. Then, an oxygen-free copper outer sleeve (1.5mm thick) pre-processed according to the shape of the stainless steel substrate is tightly fitted on the outside, completely covering the stainless steel substrate.

[0093] c. High-temperature degassing and sealing The assembled composite components were placed in a vacuum degassing furnace and baked at 250°C for 4 hours until the vacuum level inside the metal interlayer was better than 5.0 × 10⁻⁶. - At 4 Pa, electron beam welding was used to perform full penetration sealing welding on all assembly joints of the outer oxygen-free copper outer sheath, resulting in a composite component with the interior in a high vacuum state.

[0094] C.HIP All-Metallurgical Composite Treatment a. Synchronous heating and pressurization stage The component to be composited is placed in the working chamber of the HIP device, and high-purity argon gas is introduced. The temperature and pressure are simultaneously increased at a rate of 2℃ / min until the system temperature reaches 880℃ and the pressure reaches 150MPa.

[0095] b. Thermal insulation and pressure maintenance interdiffusion stage Holding the material at 880℃ and 150MPa for 3 hours, the isotropic static pressure forces the microscopic protrusions at the flat interface to undergo plastic deformation; the high temperature drives the interfacial lattice diffusion of Cu, Ni, and Fe atoms, achieving a full metallurgical bond between the three layers of copper / nickel / stainless steel. The solid wall thickness of the cooling channel 5, 6.0mm from the outer surface of the stainless steel substrate (distance from the bottom of the cooling channel 5 to both side surfaces), is sufficient to withstand the external static pressure, ensuring that the dimensions and cross-sectional shape of the cooling channel 5 do not deform.

[0096] c. Cooling and depressurization stage with the furnace The temperature was reduced to 600℃ at a rate of 1.5℃ / min, and then simultaneously depressurized and continued to cool to room temperature in the furnace, so that the nickel-based buffer layer could undergo sufficient microscopic plastic deformation to release thermal stress and prevent microcracks from forming at the interface.

[0097] D. Precision molding and finished product inspection Interface non-destructive testing The composite components were subjected to full-coverage ultrasonic C-scan flaw detection to confirm that the effective bonding rate of the copper / nickel and nickel / stainless steel interfaces was greater than 99.5%, with no macroscopic unbonded areas and the area of ​​a single unbonded area ≤ 5 mm².

[0098] b. Precision machining and surface polishing The process allowance is removed by precision CNC milling and the final shape is adjusted to the final size. The outermost oxygen-free copper surface (especially the front heated surface) is then precision mechanically polished or electrolytically polished to achieve a surface roughness of Ra≤0.4μm, thereby eliminating the risk of tip discharge under high radio frequency voltage.

[0099] c. Final inspection for extremely high vacuum leak rate of finished product The finished product was then connected to an ultra-high vacuum testing platform for final helium mass spectrometry leak detection, and the overall leak rate stabilized at 1.0 × 10⁻⁶. - ¹ 0 At a pressure below Pa·m³ / s, each cooling channel 5 was independently pressurized with helium to confirm that there was no cross-leakage.

[0100] ④ Performance Calculation and Verification A. Calculation of composite interface strength Based on the Arrhenius equation, the diffusion coefficient D of nickel in copper is:

[0101] in: : Pre-exponential factor, taken for the diffusion of nickel in copper 1.1×10⁻⁴ m² / s; : Diffusion activation energy, taken as Q = 230 kJ / mol; : Ideal gas constant, taken as R = 8.31 J / (mol·K); In this embodiment, the process temperature is taken as T=880+273.15=1153.15K.

[0102]

[0103] According to Fick's law, the diffusion depth at the nickel / copper interface can be approximately expressed as:

[0104] Where t is the heat preservation time in this example, which is taken as t=3h=10800s;

[0105] Calculation results show that after HIP treatment at 880℃ for 3 hours, the atomic diffusion depth at the nickel / copper interface is approximately 6.7 μm. This generally indicates that a high-quality metallurgical bond has formed at the nickel / copper interface, and the strength of the nickel / copper interface will approach the strength of the softer parent material. In this embodiment, the oxygen-free copper is in a fully annealed state, and its typical room temperature mechanical properties are as follows: tensile strength

[0106] Yield strength

[0107] Considering the integrity of the microstructure at the nickel / copper interface, and taking the effective adhesion rate η = 99.5%, and taking the tensile strength of annealed oxygen-free copper as 220 MPa, calculate the tensile strength of the nickel / copper interface:

[0108] Based on the fourth strength theory, the estimated shear strength of the composite interface in this embodiment is:

[0109] B. Calculation of thermal cycle life of composite interfaces Thermal cycle life based on the Coffin-Manson low-cycle fatigue model Plastic strain amplitude caused by thermal cycling The relationship between them is:

[0110] in: : Fatigue ductility coefficient, taken as for copper / nickel / steel composite interfaces 0.5; Fatigue ductility index, taken as c=-0.6; The amplitude of plastic strain generated by the nickel-based buffer layer during each thermal cycle.

[0111] Thermal cycling condition: room temperature 20℃ 350℃ .

[0112] Since the nickel-based buffer layer is situated between the stainless steel substrate and the copper conductive layer, its thermal mismatch strain is caused by the combined effects of constraints from both sides. The equivalent thermal mismatch strain is:

[0113] This strain is borne by both the elastic and plastic deformation of the nickel-based buffer layer. Pure nickel has a yield strength of approximately 150 MPa, an elastic modulus of 200 GPa, and an elastic limit strain of... Therefore, the plastic strain amplitude is:

[0114] Substituting into the Coffin-Manson formula: Second-rate.

[0115] The above calculations serve only as a theoretical quantitative demonstration of the fusion reactor antenna radiation strip structure 100 of this invention. The actual strength data of the composite interface and the actual service life may be affected by the heating and cooling rates, the ambient temperature field, and the thermal dynamic evolution of material parameters. Therefore, the above values ​​should not be regarded as a limiting guarantee of the absolute life of the product, but should be regarded as the scientific support for this invention.

[0116] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example 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.

[0117] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A fusion reactor antenna radiation strip structure resistant to thermal cycling stripping, characterized in that, The fusion reactor antenna radiation strip structure is suitable for ICRF antennas and includes: The metal substrate layer (1), the intermediate buffer layer (2) and the metal conductive layer (3) are provided, wherein the intermediate buffer layer (2) covers the outer surface of the metal substrate layer (1) and the metal conductive layer (3) covers the outer surface of the intermediate buffer layer (2); The intermediate buffer layer (2) is in contact with the metal conductive layer (3) and the metal substrate layer (1) respectively, so as to form a continuous solid solution interdiffusion band (4) between the intermediate buffer layer (2) and the metal conductive layer (3), so that the continuous solid solution interdiffusion band (4) covers the intermediate buffer layer (2), and another continuous solid solution interdiffusion band (4) is formed between the intermediate buffer layer (2) and the metal substrate layer (1), and the other continuous solid solution interdiffusion band (4) covers the metal substrate layer (1) to achieve full metallurgical bonding.

2. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 1, characterized in that, The metal substrate layer (1) is provided with a cooling channel (5), and the distance between the inner wall of the cooling channel (5) and the outer surface of the metal substrate layer (1) is D, which satisfies: D≥5mm.

3. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 2, characterized in that, There are multiple cooling channels (5), and the multiple cooling channels (5) are arranged in an array inside the metal substrate layer (1).

4. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 2, characterized in that, The cross-sectional structure of the cooling channel (5) is U-shaped, semi-circular, circular or elliptical.

5. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 1, characterized in that, The metal substrate layer (1) is constructed as a stainless steel substrate layer. The stainless steel substrate layer is made of non-magnetic austenitic stainless steel material. The thickness of the stainless steel substrate layer is L1, and satisfies: 18mm≤L1≤30mm. And / or, the metal conductive layer (3) is constructed as a copper conductive layer, the copper conductive layer is made of oxygen-free copper material, the thickness of the copper conductive layer is L2, and satisfies: 1mm≤L2≤5mm; And / or, the intermediate buffer layer (2) is constructed as a nickel-based buffer layer, the nickel-based buffer layer is made of high-plasticity pure nickel or low-alloy nickel-based material, the thickness of the nickel-based buffer layer is L3, and satisfies: 0.2mm≤L3≤1.5mm.

6. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 1, characterized in that, The thickness of the metal conductive layer (3) is greater than the radio frequency skin depth of the ICRF antenna at the operating frequency; And / or, the thickness of the continuous solid solution interdiffusion zone (4) is L4, and satisfies: 2μm≤L4≤20μm.

7. The fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 1, characterized in that, The fusion reactor antenna radiation strip structure is constructed as a multi-segment bent structure, including a radiation strip water tank segment (6), a first horizontal plate segment (7), a first bent segment (8), a vertical plate segment (9), a second bent segment (10), and a second horizontal plate segment (11) that are bent and connected in sequence. Grounding points (12) are provided on both sides of the second horizontal plate segment (11).

8. A fabrication process for a fusion reactor antenna radiation strip structure resistant to thermal cycling stripping, characterized in that, The fabrication process is used to fabricate the thermally resistant fusion reactor antenna radiation strip structure according to any one of claims 1-7, and includes: Prepare the metal substrate layer (1) with cooling channels (5); The outer surface of the metal substrate layer (1) is activated, and the intermediate buffer layer (2) and the metal conductive layer (3) are sequentially coated on the outer surface of the metal substrate layer (1) to form the composite component. The components to be composited are subjected to high-temperature vacuum degassing and hot isostatic pressing to bond them together to form a composite component. The composite component is subjected to flaw detection and surface treatment to form a finished product.

9. The fabrication process of the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 8, characterized in that, The hot isostatic pressing process includes: The composite component is placed in a hot isostatic pressing device and kept at a first temperature range and a first pressure for a first duration, so that the intermediate buffer layer (2) is bonded to the metal conductive layer (3) and the metal substrate layer (1) respectively.

10. The fabrication process of the fusion reactor antenna radiation strip structure resistant to thermal cycling stripping according to claim 8, characterized in that, The preparation of the metal substrate layer (1) having cooling channels (5) includes: The cooling channel (5) is machined on the metal substrate layer (1) using a machine tool, and a sealing cover is welded to the cooling channel (5) by welding process to seal the cooling channel (5).

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