Vacuum最新文献

{"title":"Development of SLA 3D printed volumes for leak testing of LHC Hi-Lumi cryomodules at STFC","authors":"J.O.W. Poynton ,&nbsp;S. Wilde ,&nbsp;J. Bourne ,&nbsp;E. Jordan ,&nbsp;N. Templeton ,&nbsp;B. Matheson ,&nbsp;T. Capelli ,&nbsp;A. Seller","doi":"10.1016/j.vacuum.2025.114090","DOIUrl":"10.1016/j.vacuum.2025.114090","url":null,"abstract":"<div><div>Daresbury Laboratory recently completed the build of a Radio Frequency Dipole (RFD) crab cavity cryomodule for the Super Proton Synchrotron (SPS). During the build the team faced challenges leak testing welds which could not be tested in the typical evacuation method. Each cryomodule build requires 34 unique cryogenic and insulation vacuum weld configurations, most of which are repeated across multiple weld sites. Each weld must be qualified inspected and tested (visual and leak) before the build can progress.</div><div>A suite of bespoke 3D printed weld test tools and procedures have been developed with major savings to time and cost and improved quality of leak testing tooling, developing a methodology which can be adapted to many different weld configurations. All whilst maintaining a baseline leak rate of &lt;5e-12 mbar L/s at or below 1e-3 mbar. The result was a repeatable and cost-effective means of performing high-accuracy leak tests in a short timescale.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114090"},"PeriodicalIF":3.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Light-weight multi-principal element alloy Ti50V40Cr5Al5 with high strength-ductility and improved thermo-physical properties","authors":"Z. Du ,&nbsp;X. Li ,&nbsp;M. Zheng ,&nbsp;S.V. Rogozhkin ,&nbsp;A.A. Nikitin ,&nbsp;H. Pan","doi":"10.1016/j.vacuum.2025.114110","DOIUrl":"10.1016/j.vacuum.2025.114110","url":null,"abstract":"<div><div>The single-phase body-centered-cubic (BCC) multi-principal element alloys (MPEAs) have garnered attention as promising materials for extreme conditions in nuclear reactors. However, the limited ductility and high density of BCC MPEAs present challenges for practical applications. In this work, a novel light-weight single-phase BCC MPEA with high strength-ductility, Ti₅₀V₄₀Cr₅Al₅, was designed using the Δ<em>H</em>_mix-<em>δ</em>, and M-VEC under the requirement of <em>ρ</em> &lt; 6 g/cm³. The Ti₅₀V₄₀Cr₅Al₅ prepared by vacuum arc melting exhibits single-phase BCC microstructure and a low density of 5.09 g/cm³. Compared to conventional reduced activation ferritic/martensitic (RAFM) steels, the thermal expansion coefficient of this alloy is reduced by 0.19 × 10⁻⁵ K⁻¹ to 0.49 × 10⁻⁵ K⁻¹ (a decrease of 15–33 %), while its thermal conductivity increases by &gt; 1.2 W/(m·°C) (an increase of &gt;4 %) at 600 °C. Ti₅₀V₄₀Cr₅Al₅ exhibits high strength-ductility at room temperature (<em>σ</em>_y = 796 MPa, <em>ε</em>_ΤΕ = 31 %) and achieves excellent strength-ductility synergy at 25–600 °C. Its yield strength is 125–333 MPa (an increase of 26–132 %) higher than that of conventional RAFM steels, with a 7.7–35.1 % (an increase of 33–396 %) higher total elongation. With its outstanding thermo-physical properties and excellent strength-ductility synergy, Ti₅₀V₄₀Cr₅Al₅ stands out as a promising candidate for structural materials of nuclear reactors.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114110"},"PeriodicalIF":3.8,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369862","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":"Measurements of PSD and photoelectrons on NEG coated vacuum chambers exposed to synchrotron radiation at the Taiwan Light Source beamline","authors":"Gao-Yu Hsiung ,&nbsp;Chin Shueh ,&nbsp;Chia-Mu Cheng ,&nbsp;Che-Kai Chan ,&nbsp;Reza Valizadeh","doi":"10.1016/j.vacuum.2025.114112","DOIUrl":"10.1016/j.vacuum.2025.114112","url":null,"abstract":"<div><div>A 1.5 GeV Taiwan Light Source (TLS) BL19B beamline was built to measure the photon stimulated desorption (PSD)-yield (η_PSD) and the associated photoelectron yield (PEY, η_e). Three stainless steel vacuum tubes 0.5 m in length were installed in the beamline for synchrotron radiation exposure. They were coated with non-evaporable getter (NEG) films with different structures, including conductive NEG (TiZrVAg) to reduce RF surface resistance, dual NEG (dense-TiZrV/columnar-TiZrV) for higher pumping performance, and triple-layer NEG (TiZrVN/dense-TiZrV/columnar-TiZrV) in which the nitride-layer (TiZrVN) acted as a hydrogen barrier in the chamber. Both η_PSD and η_e were measured simultaneously under two conditions, namely, “non-activated NEG”, baking only the tube at 80 °C without NEG-activation and “activated NEG” where the NEG was activated after at 180 °C. The intrinsic η_PSD comprises two parts, the η_c is measured via the throughput or conductance method for non-activated NEG, hydrocarbons, and noble gases with a sticking probability of α = 0; and the η_α for the activated NEG which absorbs the gases with α &gt; 0. The results of PSD reveal a much lower intrinsic η_PSD for activated NEG than that of the non-activated NEG by a factor of 10–100 for most of the gases including H₂, CO, CO₂, CH₄, H₂O, and C₂H₆. The PEY (η_e) measurements for the NEG-tube showed higher values (&gt;0.033 electrons/photon) for the non-activated NEG and lower values (&lt;0.022 electrons/photon) for the activated NEG. Comparison showed that the triple-layer NEG tube possessed both the lowest η_PSD and η_e of all the NEG tubes. The η_e was also lower after activation of the conductive NEG tube. The simultaneous measurements of both η_PSD and η_e for the NEG-coated tubes at the beamline in this experiment are reproducible and practically convincing.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114112"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369861","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":"Controllable preparation of flaky CoxNiy for designing and fabricating a multilayer absorber with broadwidth microwave absorption at thin thickness","authors":"Peng Wang","doi":"10.1016/j.vacuum.2025.114108","DOIUrl":"10.1016/j.vacuum.2025.114108","url":null,"abstract":"<div><div>Magnetic materials, as the microwave absorber, have huge advantages due to high microwave permeability and large microwave magnetic loss. To achieve a broadband microwave absorption, magnetic Co_xNi_y alloy particles were prepared in this paper by a simple co-precipitation method of H₂C₂O₄ and a quick thermal decomposition process in vacuum, then deformed into micro-flakes by planetary ball milling method. Based on the Co_xNi_y alloy particles before and after ball milling, a three-layer absorber was designed and fabricated, with an effective absorption band of 5.4–18 GHz at a total thickness of 3.3 mm. It is found that the Co_xNi_y alloy particles show high coercive force and large microwave magnetic loss after ball milling, capable of greatly attenuating electro-magnetic (EM) waves, as a wave absorbing layer of the three-layer absorber. However, they are soft magnetic with relatively low coercive force and high microwave permeability before ball milling, allowing the incident EM waves to enter the absorbing layer when employed as an impedance matching layer. Through this study, the strategy combining the magnetic alloys before and after ball milling as well as the multilayer structure design, is feasible to achieve a broadband microwave absorption at a thin thickness, providing a simple and effective method for the broadband microwave absorption research and application.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114108"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369863","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":"Investigation of the interface deformation behavior of SiCp/Al composites via TEM in-situ tensile test","authors":"Pengru Liu ,&nbsp;Shiming Hao ,&nbsp;Haozhan Wu ,&nbsp;Sitong Cai ,&nbsp;Aiqiong Pan ,&nbsp;Jingpei Xie","doi":"10.1016/j.vacuum.2025.114106","DOIUrl":"10.1016/j.vacuum.2025.114106","url":null,"abstract":"<div><div>As a “bridge” between the matrix and reinforcement, the interface plays a crucial role in the deformation behavior of SiCp/Al composites. It is of great significance to investigate the dynamic changes of dislocations and microcracks in the deformation process of the composite interface microzone. In situ tensile specimens with special interfaces containing different thicknesses of MgAl₂O₄ reaction layers were selected. In situ tensile tests were performed using field emission transmission electron microscopy. The effect of the interface layer thickness on the tensile deformation of the composites was revealed based on the crack initiation to propagation fracture. The results showed that the cracks first emerged at the SiC/Al interface, and then extend along the MgAl₂O₄/Al interface to the interface region of the MgAl₂O₄ reaction layer with a thickness of about 40 nm, eventually fracture occurs at the interface region with 70 nm thick MgAl₂O₄ reaction layer. Suitable thickness of MgAl₂O₄ reaction layer can effectively delay the crack propagation and improve the interface bonding strength between SiC and Al. The regulation of the thickness of the MgAl₂O₄ reaction layer is crucial for the mechanical properties of SiCp/Al composites.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114106"},"PeriodicalIF":3.8,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349788","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":"Non-enzymatic photoelectrochemical sensors based on rGO/TiO2/Cu-MOFs nanostructures for simultaneous detection of glucose and lactic acid","authors":"Bairui Tao ,&nbsp;Huihui Guo ,&nbsp;XiaoQin Li ,&nbsp;Fengjuan Miao,&nbsp;Hui Li","doi":"10.1016/j.vacuum.2025.114105","DOIUrl":"10.1016/j.vacuum.2025.114105","url":null,"abstract":"<div><div>This study reports the preparation of a high-performance rGO/TiO₂/Cu-MOFs sensitive electrode through a two-step hydrothermal method. This electrode exhibits low detection limits, high sensitivity, and a straightforward fabrication process. The nanomaterials are uniformly grown on a 1 × 1 cm² nickel foam substrate, with rGO first coated and then followed by the growth of rod-shaped TiO₂ and Cu-MOFs metal particles, forming a three-dimensional spatial structure. The micromorphology, chemical composition, and state of the electrode were characterized using TEM, SEM, and other techniques. Its electrochemical performance was tested using an electrochemical workstation. Experimental results indicate that the copper ions in this electrode, due to their different valence states, can achieve highly sensitive detection of glucose and lactic acid, with sensitivities reaching as high as 1195.13 μA mM⁻¹ cm⁻² and 1157.77 μA mM⁻¹ cm⁻², respectively. Additionally, it possesses excellent anti-interference ability, stability, and reproducibility, making it a promising dual-function photoelectrochemical sensor.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114105"},"PeriodicalIF":3.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265943","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":"High-strength nanostructured copper alloys via mechanical consolidation of pure copper and Fe-Si-B glassy powers","authors":"Hongbo Zhou ,&nbsp;Haihong Jiang ,&nbsp;Li Yu ,&nbsp;Gan Ding ,&nbsp;Songlin Cai ,&nbsp;Depeng Shen ,&nbsp;Minqiang Jiang ,&nbsp;Gerhard Wilde","doi":"10.1016/j.vacuum.2025.114101","DOIUrl":"10.1016/j.vacuum.2025.114101","url":null,"abstract":"<div><div>High-strength nanostructured copper alloys were fabricated through the mechanical consolidation of pure copper and Fe-Si-B glassy powders using a two-step high-pressure torsion (HPT) process. Structural characterization by transmission electron microscopy and electron backscatter diffraction revealed that, after overall 20 HPT revolutions, 1 wt% Fe₇₈Si₉B₁₃ glassy powders can be fully decomposed and homogeneously supersaturated into the copper matrix. The resulting Cu-1 wt.% FeSiB alloy exhibited a compositionally uniform nanostructure with an average grain size of 63.3 nm and a high proportion of low-angle grain boundaries (54.2 %), achieving an ultimate tensile strength of 1246 MPa. In contrast, the addition of 5 wt% Fe₇₈Si₉B₁₃ glassy powder under the identical HPT conditions resulted in a crystal-glass composite structure with an ultimate tensile strength of 895.8 MPa. This work advances a hybrid method that integrates bottom-up particle bonding with top-down grain refinement to fabricate high-performance alloys.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114101"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143206202","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":"Editorial Board and Vacuum units","authors":"","doi":"10.1016/S0042-207X(24)00966-7","DOIUrl":"10.1016/S0042-207X(24)00966-7","url":null,"abstract":"","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113920"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182754","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":"Design and characteristic analysis of micro-cathode arc thruster using liquid metal as working medium","authors":"Tiance Liang ,&nbsp;Tianyuan Ji ,&nbsp;Haochen Ma ,&nbsp;Lu Wang ,&nbsp;Liqiu Wei","doi":"10.1016/j.vacuum.2025.114083","DOIUrl":"10.1016/j.vacuum.2025.114083","url":null,"abstract":"<div><div>The limitation associated with the application of titanium micro-cathode arc thruster (Ti-μCAT) is that the cathode working medium carried in a single space mission is insufficient. To address this issue, a μCAT using liquid metal as the working medium (LM-μCAT) was designed. The discharge characteristics and performance parameters of the LM-μCAT and Ti-μCAT were examined. The experimental results show that the LM-μCAT has higher elementary impulse, lower ion velocity, higher plasma ionization degree, and lower power consumption. Theoretical analysis indicates that the differences are caused by the surface structure and physical property parameters of the two working media. The reason for the change of elementary impulse and ion velocity is the larger average atomic mass of liquid metal. The discrepancies in plasma ionization degree and power consumption are caused by the difference between the energy proportion of metal into metal vapour and ionized metal vapour to form plasma. The change in the energy proportion is caused by the physical characteristics of the cathode and the roughness of its surface.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114083"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143265944","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":"Ion composition of beam plasma formed by electron beam evaporation of YSZ ceramic in medium vacuum","authors":"D.B. Zolotukhin,&nbsp;A.A. Andronov,&nbsp;A.V. Tyunkov,&nbsp;Yu.G. Yushkov","doi":"10.1016/j.vacuum.2025.114102","DOIUrl":"10.1016/j.vacuum.2025.114102","url":null,"abstract":"<div><div>Plasma with high content of rare-earth elements finds applications in ion implantation and surface modification technologies. Here, we have studied the mass-to-charge ion composition of multicomponent beam plasma formed by irradiation of a refractory dielectric target of zirconia ceramic partially stabilized with yttria (YSZ) by a continuous focused electron beam with energy 3–11 keV in a gas atmosphere (helium, or a mixture of helium and argon or oxygen) in the forevacuum pressure range (about 4–6 Pa). Using a quadrupole mass analyzer, we find that, at a power sufficient for intense evaporation of the target, the ion mass spectrum, in a background of residual atmosphere and operating gas ions, contains peaks of singly charged positive ions of yttrium, zirconium, and their oxides and dioxides with amplitudes comparable to those of the residual atmosphere and the operating gas, which indirectly indicates the presence of a high proportion of target material ions in the plasma. We find that signals of oxides of zirconium and yttrium ions decrease while signals of dioxides of these elements increase as the separation (along the electron beam direction) between the analyzer and the target increases. With intensive e-beam evaporation, the fraction of ions of target components surpasses the fractions of ions of all other gaseous plasma components.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"234 ","pages":"Article 114102"},"PeriodicalIF":3.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143351618","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}