Vacuum最新文献

{"title":"Design and fabrication of a low-activation lithium target for BNCT","authors":"Kai-Yu Ou ,&nbsp;Yuntao Song ,&nbsp;Ji-Chao Wang ,&nbsp;Nengbin Liu ,&nbsp;Xiaolong Wang ,&nbsp;Xiancai Meng ,&nbsp;Lizheng Liang ,&nbsp;Ping Liu","doi":"10.1016/j.vacuum.2026.115154","DOIUrl":"10.1016/j.vacuum.2026.115154","url":null,"abstract":"<div><div>The lithium target is a key component located at the end of the accelerator beamline or target station, serving as a bridge between the accelerator output and neutron production. To address the heat dissipation challenges of the lithium target and to reduce its radioactivity and maintenance frequency, this study comparatively evaluated the post-irradiation activation behavior of Ag–Cu and Ge–Cu filler metals. A low-activation Ge–Cu filler was ultimately selected to investigate the brazing process between CuCrZr and 316L stainless steel. Detailed analyses of the microstructure and mechanical properties of the CuCrZr/Cu–Ge/316L joints were performed. Furthermore, a finned, water-cooled lithium target with an inclined geometry was designed through finite element simulation, and a prototype of the inclined lithium target was successfully fabricated using the optimized process.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115154"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of 100 MeV Ag7+ ion irradiation on photoluminescence and dielectric properties of bilayer structured Au/GeO2 thin films for optoelectronics applications","authors":"Mahendra Singh Rathore ,&nbsp;Anand Y. Joshi ,&nbsp;Srinivasa Rao Nelamarri","doi":"10.1016/j.vacuum.2026.115169","DOIUrl":"10.1016/j.vacuum.2026.115169","url":null,"abstract":"<div><div>The effects of 100 MeV Ag⁷⁺ ions irradiation on tailoring the physical, photoluminescence, and dielectric properties of bilayer Au/GeO₂ thin films have been investigated. GeO₂ and Au thin films were grown onto silicon substrates using E-beam evaporation. Eventually, the prepared films were irradiated at different ion fluences ranging from 1 × 10¹² to 1 × 10¹³ ions/cm². The results reveal the grain growth and nucleation of nanoparticles upon irradiation. Rutherford backscattered spectroscopy measurements were performed to identify the elemental composition and film thickness, which was around 110 nm. The chemical composition and oxidation state of elements were examined using X-ray photoelectron spectroscopy. The bandgap energy of films varies from 2.0 to 2.33 eV with irradiation. The films irradiated at 1 × 10¹² and 1 × 10¹³ ions/cm² show intense UV and blue PL emission, respectively. The dielectric constant and dielectric loss obtained were around 76.5 and 191 at 15 kHz, respectively, from the film irradiated at 1 × 10¹³ ions/cm². The maximum AC conductivity value is exhibited in the high-frequency range (10⁴ to 10⁶ Hz). The photometric properties were evaluated from an illumination study. Varying S/P ratios of irradiated films shows the potential usefulness in blue and yellowish LEDs, and also considers the potential applications of Au/GeO₂ in optoelectronic devices.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115169"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Requirements, design, and challenges of the HIAF vacuum system","authors":"J. Meng ,&nbsp;J.C. Yang ,&nbsp;C. Luo ,&nbsp;W.S. Yang ,&nbsp;W.J. Xie ,&nbsp;Z. Chai ,&nbsp;G.D. Shen ,&nbsp;J.X. Wu ,&nbsp;C.C. Li ,&nbsp;J.L. Liu ,&nbsp;J.Q. Jiao ,&nbsp;X.J. Lin ,&nbsp;N.F. Wei ,&nbsp;Y.P. Wan ,&nbsp;Y.M. Gao ,&nbsp;X.R. Zhu ,&nbsp;X.L. Ma ,&nbsp;K.X. Zhong ,&nbsp;R.P. Zhang ,&nbsp;X.P. Zhang","doi":"10.1016/j.vacuum.2026.115162","DOIUrl":"10.1016/j.vacuum.2026.115162","url":null,"abstract":"<div><div>The High Intensity heavy ion Accelerator Facility (HIAF) is the world's first heavy ion research device that integrates superconducting linear, synchronous acceleration, and storage rings. Its vacuum system is critical for the stable transport of high intensity beams and long-term reliable operation. This paper systematically presents the technical challenges, key innovations, and engineering achievements of the nearly 2-km-long HIAF vacuum system. To reduce the eddy current effect caused by rapidly changing magnetic fields, the Booster Ring (BRing) magnetic vacuum chamber innovatively adopts a titanium alloy-lined ultra-thin-walled (wall thickness 0.3 mm) structure based on the combination of 3D printing and Non-Evaporable Getter (NEG) coating technology. This type of vacuum chamber accounts for 60% of the BRing. In addition, by optimizing the outgassing process and chamber structure of the built-in components, an average pressure of 4.7 × 10⁻¹⁰ Pa was achieved, representing the world's largest room temperature ultra-thin-walled vacuum system; Faced with the challenge of limited installation space for the Spectrometer Ring (SRing) electronic-cooling system, an integrated solution combining sputter ion pumps, built-in titanium wire evaporation, and NEG coating was implemented. The system ultimately achieved an average pressure of 1.0 × 10⁻⁹ Pa; For the high radiation area of the High energy Fragment Separator (HFRS), a self-developed split type sealing flange is used to achieve remote disassembly and reliable sealing of pipelines, maintaining a pressure of 2.5 × 10⁻⁶ Pa; In addition, a 3 mm ultra-thin integrated baking jacket has been developed, achieving precise high-temperature baking of complex vacuum systems. The design of the HIAF vacuum system was initiated in 2018, following multiple iterations and process validations, its large-scale installation was launched in March 2024. Full integration of the system was achieved by September of the same year, completed the entire installation and commissioning process within a six-month period. The vacuum performance of each subsystem ultimately exceeded the design specifications, providing a new technological path and engineering paradigm for the design and construction of future large-scale accelerator vacuum systems.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115162"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146161661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure evolution and mechanical properties of 5B70 Al alloy induced by micro-arc oxidation","authors":"Mingjin wu ,&nbsp;Lixin Wang ,&nbsp;Yao Xie ,&nbsp;Chaoyu Han ,&nbsp;Libin Ren ,&nbsp;Ping Zhu ,&nbsp;Chunyin Deng ,&nbsp;Zhongbing Chen ,&nbsp;Shuhui Wu ,&nbsp;Li Lu ,&nbsp;Jia Yang","doi":"10.1016/j.vacuum.2026.115175","DOIUrl":"10.1016/j.vacuum.2026.115175","url":null,"abstract":"<div><div>This study focused on the structural heterogeneity of ceramic film formed during micro-arc oxidation (MAO) and its influence on mechanical properties. Using 5B70 Al alloy as the substrate, a systematic investigation was conducted to compare the microstructural features and mechanical performance between the edge transition zone around discharge pores and the ceramic region between pores. The results indicated that the edge transition zone, affected by localized high-temperature discharges, exhibited amorphous/sub-grain structures accompanied by the precipitation of ZrO₂ particles and structural defects. In contrast, the inter-pore ceramic region features fine and dense grains with a high density of dispersed Al₃Sc nanoparticles. Nanoindentation tests revealed that the inter-pore ceramic region demonstrated higher hardness and elastic modulus, whereas the edge transition zone showed reduced local fracture toughness due to microcracks and coarse particle-induced stress concentrations. This study elucidated the coupled mechanism between reinforcement phase evolution and discharge behavior in regulating film properties, providing theoretical guidance for optimizing the MAO process and enhancing the overall performance of ceramic films.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115175"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146161641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structurally ordered glucose-derived carbon coatings enabling enhanced Cu–C interfacial thermal transport in 3D copper foams","authors":"Junlei Qi,&nbsp;Yong Xia,&nbsp;Zhenyu Ye,&nbsp;Jian Cao,&nbsp;Yaotian Yan","doi":"10.1016/j.vacuum.2026.115170","DOIUrl":"10.1016/j.vacuum.2026.115170","url":null,"abstract":"<div><div>As modern electronic systems advance toward compact architectures and intensified power densities, managing heat generation and dissipation has become a central challenge affecting both device stability and functional reliability. In this study, a carbon-coated three-dimensional (3D) porous copper foam composite (CFCC) was synthesized using a combined hydrothermal and annealing process to enhance heat dissipation. Optimization studies revealed that the combination of 6 g glucose with a 600 °C annealing treatment produced the most favorable coating quality. Consequently, the CFCC exhibited an in-plane thermal conductivity of 16.3 W m⁻¹ K⁻¹ and a thermal diffusivity of 28.5 mm² s⁻¹, representing 39.3% and 122.7% increases over pristine copper foam, respectively. Infrared thermography confirmed significantly improved heat spreading, with the optimized composite maintaining the lowest steady-state temperature (145.8 °C) under a constant 160 °C heat load.</div><div>Microstructural and mechanistic investigations indicate that the improved heat-transfer capability originates from the higher ordering of the carbon domains, the decrease in structural defects, and the strengthened Cu–C interfacial interactions. These factors collectively reduce phonon scattering, extend the phonon mean free path, and minimize interfacial thermal resistance, enabling effective three-dimensional heat conduction. Overall, the integrated hydrothermal–annealing strategy presents a controllable, scalable, and cost-effective approach for producing high-quality carbon coatings on porous metal substrates, offering substantial promise for advanced thermal management in next-generation high-power electronic systems.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115170"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brazing-induced microstructural effects on galvanic corrosion of AA4343/AA3xxx multi-layered alloys","authors":"Qiaoling Wang ,&nbsp;Menghao Jiang ,&nbsp;Zhikang Yang ,&nbsp;Zhipeng Yuan ,&nbsp;Yilu Zhang ,&nbsp;Datian Cui ,&nbsp;Yiyou Tu ,&nbsp;Ting Yuan ,&nbsp;Fang Liu ,&nbsp;Liang Huang ,&nbsp;Jin Peng ,&nbsp;Zenglei Ni ,&nbsp;Wenyi Huo","doi":"10.1016/j.vacuum.2026.115165","DOIUrl":"10.1016/j.vacuum.2026.115165","url":null,"abstract":"<div><div>Galvanic corrosion limits the durability of multi-layered aluminum alloys in automotive heat exchangers, particularly in chloride-containing environments. This study investigated brazing-induced microstructural effects on the corrosion behavior of AA4343/AA3xxx/AA4343 multi-layered aluminum sheets, addressing interlayer and particle/matrix galvanic interactions. Using immersion tests in 3.5 wt% NaCl, electrochemical measurements, and thorough microstructural characterization, the results show that α-Al(Fe,Mn)Si particles act as cathodic sites, initiating pitting at particle/matrix interfaces, while grain boundary Al₄Cu₂Mg₈Si₇ (Q phase) precipitates undergo Mg dissolution and Cu enrichment, forming cathodic paths that promote intergranular corrosion. Brazing exacerbates corrosion by enhancing Si diffusion and Cu segregation at the clad/core interface, increasing galvanic coupling and intensifying both pitting and intergranular attack. These findings elucidate the synergistic roles of intermetallic particles, grain boundary phases, and brazing-induced microstructures in localized corrosion. This work provides critical insights for optimizing alloy composition, brazing processes, and service life prediction and advances the design of corrosion-resistant aluminum heat exchangers for new energy vehicles.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115165"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146193213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-principles study of the mechanical and thermal properties of borates MBO3 (M = Sc, Al, Ga) under high pressure","authors":"Hao Wu ,&nbsp;He Ma ,&nbsp;Xudong Zhang ,&nbsp;Lijia Chen ,&nbsp;Xiaoming Wang ,&nbsp;Haonan Li","doi":"10.1016/j.vacuum.2026.115160","DOIUrl":"10.1016/j.vacuum.2026.115160","url":null,"abstract":"<div><div>First-principles calculations have been systematically employed to investigate the mechanical and thermal properties of trigonal MBO₃ (M = Sc, Al, Ga) under hydrostatic pressure up to 25 GPa. At ambient conditions, AlBO₃ possesses the highest stiffness and hardness but exhibits brittleness, in contrast to the most ductile yet mechanically softest ScBO₃, with GaBO₃ displaying intermediate character. With increasing pressure, the elastic moduli of AlBO₃ and GaBO₃ initially increase before softening, while those of ScBO₃ decrease continuously, indicating distinct mechanical responses. Notably, AlBO₃ undergoes a brittle-to-ductile transition around 15 GPa. Overall, pressure enhances ductility and elastic anisotropy but reduces material hardness. Regarding thermal properties, the lattice thermal conductivity increases with pressure for all compounds, whereas the Debye temperature shows a unique decrease only for ScBO₃. These results elucidate the critical structure-property relationships in MBO₃ borates under extreme pressure, offering valuable theoretical guidance for their targeted application in high-pressure environments.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"248 ","pages":"Article 115160"},"PeriodicalIF":3.9,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146161642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic properties and hysteresis behavior of a mixed-spin (3/2, 1) ovalene like structure: A Monte Carlo study","authors":"H. Kerrai ,&nbsp;D. Bokpe ,&nbsp;M. Mouhib ,&nbsp;O. Mennaoui ,&nbsp;S. Elhadfi ,&nbsp;J. Chenouf ,&nbsp;E.M. Jalal ,&nbsp;H. Saadi ,&nbsp;R. El Mrabet ,&nbsp;A. El Fadl ,&nbsp;T.D. Oke","doi":"10.1016/j.vacuum.2026.115171","DOIUrl":"10.1016/j.vacuum.2026.115171","url":null,"abstract":"<div><div>Ovalene is a polycyclic aromatic hydrocarbon (PAH) characterized by a planar structure and high chemical stability, which confer unique electronic properties and make it a promising candidate for nanoscale applications. In this work, Monte Carlo simulations were employed to investigate the hysteresis behavior and magnetic properties of an ovalene-like nanostructure within the framework of a mixed-spin <span><math><mrow><mo>(</mo><mn>3</mn><mo>/</mo><mn>2</mn><mo>,</mo><mspace></mspace><mn>1</mn><mo>)</mo></mrow></math></span> Blume–Capel model. The ground-state phase diagrams as functions of various physical parameters were examined. The effects of the exchange coupling and single-ion anisotropy on the phase diagrams and magnetic properties were analyzed. The results indicated that the system exhibited compensation behavior as well as first- and second-order phase transitions. Furthermore, the influence of temperature, crystal field, and exchange interaction on the hysteresis cycles was investigated. Multiple hysteresis loop behaviors were observed for specific physical parameters, originating from the competition among anisotropy, temperature, and the longitudinal magnetic field.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115171"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of long-term thermal exposure at 600°C on the tensile properties of SiCf/Ti60 composites","authors":"Zhicong Gan,&nbsp;Yumin Wang,&nbsp;Lina Yang,&nbsp;Qiuyue Jia,&nbsp;Mushi Li,&nbsp;Yuming Zhang,&nbsp;Xu Kong,&nbsp;Rui Yang","doi":"10.1016/j.vacuum.2026.115157","DOIUrl":"10.1016/j.vacuum.2026.115157","url":null,"abstract":"<div><div>In this study, the tensile properties of SiC_f/Ti60 composites under hot isostatic pressing (HIP) and 600 °C/100h states were investigated. The properties of thermal exposure SiC_f/Ti60 composites were reduced by about 34 MPa compared to the properties of HIP composites with good thermal stability. The results show that SiC_f/Ti60 composites have good matrix and interfacial thermal stability. The average grain size of matrix α-Ti in both states was 3.4-3.6 μm, the texture of α-Ti was &lt;0001&gt;//AD and &lt;10-10&gt;//AD, and the polar densities ranged from 6.9 to 7.4 to 2.7-3.1, respectively. The thickness of the interfacial reaction layer in both states was about 0.38-0.43 μm, the interfacial thickness increased slowly, and the silicon content fraction at the interface remains virtually unchanged. The interfacial silicide volume fraction is similar. About 58.2 MPa reduced the residual compressive stress of SiC fibers after thermal exposure. In summary, SiC_f/Ti60 composites exhibit excellent microstructure, mechanical properties, and thermal stability, enabling long-term operation in a 600 °C vacuum environment.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115157"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth temperature optimization for high-quality InAs/GaSb Type-II superlattices grown by MBE towards high-performance long-wavelength infrared detection","authors":"Rong Yan,&nbsp;Yuhao Chen,&nbsp;Zhenfei Xing,&nbsp;Jing Yu,&nbsp;Bingfeng Liu,&nbsp;Weiqiang Chen,&nbsp;Lidan Lu,&nbsp;Lianqing Zhu","doi":"10.1016/j.vacuum.2026.115083","DOIUrl":"10.1016/j.vacuum.2026.115083","url":null,"abstract":"<div><div>In response to the critical material requirements in the field of long-wavelength infrared detection, this study systematically investigates the effect of growth temperature on the material quality and interfacial properties of long-wavelength superlattices. By growing InAs/GaSb type-II superlattice samples at different temperatures (360°C–460 °C), a variety of characterization techniques including atomic force microscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were employed to systematically analyze the influence of temperature on surface morphology, crystal quality, strain state, and interfacial chemical stability. The results indicate that the sample grown at 380 °C exhibits clear atomic step-flow morphology, low root-mean-square roughness (0.262 nm), sharp interfaces, and excellent period uniformity, demonstrating that this temperature represents the optimal condition for achieving high-quality layered growth of superlattices. This study provides a reliable process window and theoretical foundation for the high-quality superlattice materials required for high-performance long-wavelength infrared detectors.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"247 ","pages":"Article 115083"},"PeriodicalIF":3.9,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}