Vacuum最新文献

{"title":"Optimizing and well-Controlled Grayscale Electron Beam lithography for planar dual-blazed grating fabrication","authors":"Liang Liu ,&nbsp;Xiaodong Zhang ,&nbsp;Jingyuan Zhu ,&nbsp;Siyu Dong ,&nbsp;Zeyong Wei ,&nbsp;Zhanshan Wang ,&nbsp;Xinbin Cheng","doi":"10.1016/j.vacuum.2025.114540","DOIUrl":"10.1016/j.vacuum.2025.114540","url":null,"abstract":"<div><div>The blazed grating is a commonly used spectral component in spectroscopic imaging systems, but its operating bandwidth is limited by diffraction efficiency. Dual-blazed gratings, with varying blazed angles in different regions, offer a solution for wider bandwidth. However, fabricating such gratings faces the challenges in processing different angles and matching wavefronts. Grayscale electron beam lithography (g-EBL) presents a flexible method for manufacturing dual-blazed gratings with high efficiency and precise wavefronts compared to other techniques. Despite its advantages, the detailed process remains underdiscussed. This paper outlines a detailed g-EBL process for creating planar dual-blazed gratings. By optimizing grating layout and exposure doses, two blazed-angle gratings (1.8° and 3.5°) were accurately produced with consistent alignment in center height. The resulting dual-blazed grating exhibited 53 % average diffraction efficiency in 0.4–1.05 μm and less than 0.2 wv Peak-to-Valley wavefront aberration. This method establishes a universal approach for crafting dual-blazed gratings using g-EBL techniques.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114540"},"PeriodicalIF":3.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491578","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":"Study on growth mechanism of InAs array nanowires on two different patterned substrates","authors":"Xiaoye Wang ,&nbsp;Xiaoguang Yang ,&nbsp;Tao Yang","doi":"10.1016/j.vacuum.2025.114539","DOIUrl":"10.1016/j.vacuum.2025.114539","url":null,"abstract":"<div><div>Si/SiO₂ patterned substrates are usually employed to assist the positioning growth of array nanowires, but the detailed growth mechanism has not been thoroughly investigated. In this work, two completely different methods were adopted to fabricate Si/SiO₂ patterned substrates, and the InAs array nanowires grown on them via MOCVD presented some distinct growth results. By deeply analyzing the different processes and structures of the two methods for preparing patterned substrates, the different growth mechanisms of the two array nanowires were studied. Moreover, the method of preparing Si/SiO₂ patterned substrates using Si₃N₄ as a transition layer can further reduce the diameter of naonholes and solve the problem that the diameter of nanoholes of the Si/SiO₂ patterned substrates prepared by the traditional method is difficult to be further reduced.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114539"},"PeriodicalIF":3.8,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144472151","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":"Characterization of on-state resistance of electrically-triggered vacuum surface flashover switch","authors":"Yingjie Fu ,&nbsp;Bingyang Feng ,&nbsp;Mingtian Ye ,&nbsp;Luokang Dong ,&nbsp;Shenyi Qin ,&nbsp;Zhengzheng Liu ,&nbsp;Mengbing He","doi":"10.1016/j.vacuum.2025.114531","DOIUrl":"10.1016/j.vacuum.2025.114531","url":null,"abstract":"<div><div>The electrically triggered vacuum surface flashover switch (VSFS) has the advantages of high-speed conduction, fast insulation recovery, compact size, and simple construction, making it well-suited for high voltage and high-power conversion applications. The on-state resistance, as a critical parameter of the VSFS, directly influences the output efficiency and lifetime of the pulse power system. In this paper, a theoretical model of the VSFS on-state resistance is proposed, and the effect of different phases of channel development on the on-state resistance is also investigated. Specifically, it covers the channel expansion and channel resistivity decline during three distinct developmental phases, the establishment of vacuum-stream channel, the resistance collapse of vacuum-stream channel, and the on state. The theoretical model demonstrates that increasing the operating voltage can effectively expand the channel width, and the channel voltage in the on-state is negative to the channel resistivity. Finally, the variation trend of the VSFS on-state resistance under square wave and exponential decay conditions was calculated using experimental waveforms, and the experimental results are consistent with the theoretical analysis.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114531"},"PeriodicalIF":3.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480862","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 metamagnetic transition in nanosized FeRh structures","authors":"A. Lengyel ,&nbsp;M.A. Gracheva ,&nbsp;A.I. Chumakov ,&nbsp;D. Bessas ,&nbsp;Sz Sajti ,&nbsp;A. Deák ,&nbsp;Z. Zolnai ,&nbsp;G.Z. Radnóczi ,&nbsp;Z.E. Horvath ,&nbsp;G. Hegedűs ,&nbsp;D.G. Merkel","doi":"10.1016/j.vacuum.2025.114533","DOIUrl":"10.1016/j.vacuum.2025.114533","url":null,"abstract":"<div><div>Nanosized iron-rhodium islands of various sizes have been successfully prepared on MgO substrate by masked molecular beam epitaxy. Nuclear scattering of nanofocused synchrotron radiation was used to map the islands, and in-situ measure their magnetic states and metamagnetic phase transition. The findings demonstrated a pronounced size dependency in the metamagnetic behavior of the FeRh, as the size of the islands decreased, the metamagnetic phase transition changes until finally it disappears completely at certain threshold size. This suppression effect suggests that finite-size scaling plays a significant role in determining the magnetic characteristics of FeRh at the nanoscale. These results provide insight into the fundamental mechanisms behind size-dependent magnetic phase transitions in FeRh nanostructures, which likely arise due to increased surface-to-volume ratios, altered atomic coordination, and oxidation-based effects.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114533"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144472152","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":"Vacuum system of the HEPS storage ring","authors":"Haiyi Dong,&nbsp;Ping He,&nbsp;Qi Li,&nbsp;Dizhou Guo,&nbsp;Xujian Wang,&nbsp;Yongsheng Ma,&nbsp;Baiqi Liu,&nbsp;Tao Huang,&nbsp;Lei Zhang,&nbsp;Fei Sun,&nbsp;Tianfeng Liu,&nbsp;Pilong Tian,&nbsp;Yuchen Yang,&nbsp;Qi Yang,&nbsp;Pengcheng Wang,&nbsp;Jiaming Liu,&nbsp;Shunming Liu,&nbsp;Xiaoyang Sun,&nbsp;Bangle Zhu,&nbsp;Biao Tan,&nbsp;Saike Tian","doi":"10.1016/j.vacuum.2025.114520","DOIUrl":"10.1016/j.vacuum.2025.114520","url":null,"abstract":"<div><div>HEPS (High Energy Photon Source) is a 4th generation ring-based light source with a beam energy of 6 GeV and a beam current intensity of 200 mA. The HEPS accelerator consists of a linac, a booster, a storage ring, and three transport lines connecting the linac, booster, and storage ring. The storage ring serves as the core region of HEPS. In this paper, the characteristics of the storage ring vacuum system are reviewed, and the designs and fabrication approaches for some key vacuum components are detailed. The main challenges include the extrusion of thin-walled CuCrZr vacuum chambers and the application of NEG (Non Evaporable Getters) coatings on their inner surfaces. These are used to mitigate substantial heat loads induced by synchrotron radiation along the vacuum chamber walls and provide an effective pumping speed for conductance-limited vacuum pipes with an inner diameter of 22 mm. The installation of the storage ring vacuum system started in November 2023, and finished in July 2024. Vacuum sectors were in-situ baked and activated for NEG films in the vacuum chambers, an average static pressure of 3 × 10⁻⁸Pa has been reached, which is better than the specification. These results confirm the feasibility of the storage ring vacuum system, covering aspects from the design and fabrication of components such as vacuum chambers, RF shielding bellows, and photon absorbers to processes like NEG coating via magnetron sputtering, installation, and in-situ activation of NEG films. After more than 20 days of conditioning, the beam current of the HEPS storage ring reached 12 mA, marking a milestone progress in the HEPS accelerator. At present, the accumulated beam dose is about 30 Ah (Jan.2025), the vacuum system performs well, the dynamic pressure of the storage ring is expected to decrease with the increase of accumulated beam dose.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114520"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335648","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":"Aerodynamic heating distribution of the inner wall in an evacuated tube structure","authors":"Yongbao Wang ,&nbsp;Xiaolei Zhang ,&nbsp;Zhengyang Zhang ,&nbsp;Yunjing Nie ,&nbsp;Zhaoliang Li","doi":"10.1016/j.vacuum.2025.114530","DOIUrl":"10.1016/j.vacuum.2025.114530","url":null,"abstract":"<div><div>To investigate the distribution of Aerodynamic Heating (AH) on ultra-high-speed Evacuated Tube Structures (ETS), a 2D fluid simulation model utilizing the overset grid method was developed. The model comprehensively considered the internal track heat source and fluid-solid coupling heat transfer analysis. The distribution of AH on the inner wall was studied, taking into account various factors, including vacuum level, blocking ratio, train speed and operating time intervals. The results reveal that the radiation from the internal heat source can impact AH along the height of the ETS. Meanwhile, vacuum degree exhibit only limited effects on temperature rise in the tube. On the other hand, blocking ratio and train speed are identified as major factors significantly influencing AH, the residual temperature can rise 55 K. Furthermore, the number of train operations is a linear increasing with the residual temperature. If effective cooling measures are not implemented, the increased residual temperature can have an impact on the tube.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114530"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491577","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":"Synchronization effect through incorporation of trace elements (B and La) to enhance high-temperature oxidation performance of Ti6Al4V fabricated via additive manufacturing","authors":"Lvjun Zhou ,&nbsp;Can Guo ,&nbsp;An Li ,&nbsp;Chen Yu ,&nbsp;Chenlu Yan ,&nbsp;Xiaochong Liang","doi":"10.1016/j.vacuum.2025.114535","DOIUrl":"10.1016/j.vacuum.2025.114535","url":null,"abstract":"<div><div>The superiority of additively manufactured titanium alloys on the preparation of exotic components makes it extensively applied to aero-engine applications. However, the most significant challenges of aero-engine titanium alloys are the prolonged exposure to high-temperature oxidation. Improving the high temperature oxidation performance is urgently required. This study explores the effect of 0.2 wt% B and 0.1 wt% La element co-doping on the microstructure of additively manufactured Ti6Al4V, and investigates its oxidation behavior and the stability of its mechanical properties after oxidation at high temperatures (600 °C–700 °C) for 96 h. The experimental results demonstrate the synergistic effect of the co-doping of the two elements: grain refinement reduced from 1.13 ± 0.26 μm to 0.51 ± 0.12 μm and high temperature oxidation performance was significantly enhanced. Moreover, the La₂O₃ in the samples effectively prevents the grain extension at high temperatures for short durations and consequently stabilizes the mechanical performance.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114535"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144472153","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":"Nb-N solid solution strengthening in (FeCoNiCuNb)Nx high-entropy alloy nitride films","authors":"Yantao Li ,&nbsp;Xianting Yang ,&nbsp;Yefeng Zhou ,&nbsp;Jun Liang ,&nbsp;Yu Ni ,&nbsp;Yurong Zhou ,&nbsp;Deming Huang ,&nbsp;Xin Jiang ,&nbsp;Donglin Ma","doi":"10.1016/j.vacuum.2025.114536","DOIUrl":"10.1016/j.vacuum.2025.114536","url":null,"abstract":"<div><div>High-entropy alloy films composed of 3d transition metals exhibit excellent plasticity, but their strength and wear resistance remain inferior to refractory-metal-based HEA systems. In this paper, a small amount of Nb atoms were introduced into the FeCoNiCu system, and (FeCoNiCuNb)N_x high-entropy alloy nitride films (HENFs) were prepared by reactive magnetron sputtering. The results show that N atoms combine with Nb and Nb-N is uniformly distributed in the film without segregation. With the introduction of N atoms, the film structure still maintains FCC structure, and the grains are refined, and the amorphous region at the grain interface is observed with the high-resolution image. Due to the solid solution strengthening effect, the hardness of the (FeCoNiCuNb)N_x HENFs reaches a maximum of 9.48 GPa and the wear rate reaches a minimum of 1.01 × 10⁻⁶ mm/N·m. Polarization and electrochemical impedance spectrum measurements revealed that all HENFs show good corrosion resistance comparable to the 304 stainless steel in 3.5 wt% NaCl solution. The Nb-N strengthened (FeCoNiCuNb)N_x HENFs can effectively improve the wear resistance without loss of corrosion resistance, which provides a feasible method for the strengthening of 3d transition metals family high-entropy alloy films.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114536"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335646","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":"Crystallographic dependence of ultrafast laser induced crack generation in single-crystal sapphire","authors":"Liu Tongwei,&nbsp;Tang Haoxing,&nbsp;Dong Xin,&nbsp;Yang Dingkun,&nbsp;Luo Zhiyong","doi":"10.1016/j.vacuum.2025.114528","DOIUrl":"10.1016/j.vacuum.2025.114528","url":null,"abstract":"<div><div>Crack generation is a bottleneck in the processing of sapphire crystals using ultrafast laser. This paper aims to investigate the influence of crystal orientation on the laser-induced crack generation in single-crystal sapphire at the atomic scale. A molecular dynamics model of sapphire crystal irradiated by ultrafast laser was constructed, and the influence of crystal orientation on atomic number density and pressure was analyzed. The results show that smaller interplanar spacing enhances the material's resistance to damage, resulting in a faster stabilization rate of atomic number density within the crystal. The relationship among stress wave propagation speed, interplanar spacing and the direction of crack initiation in sapphire crystals was explored. It was found that crystal orientations with lower stress wave propagation speeds are more prone to crack generation. Laser induced sapphire crystal crack generation experiments were conducted, and the results showed that cracks were most likely to occur along the (10-10) direction, followed by the (01-01) direction, and the (1–100) direction exhibited the least susceptibility when laser irradiation on the C-plane of sapphire crystals. The research of this article will provide theoretical and technological guidance for suppressing the generation of laser-induced cracks in sapphire crystals.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114528"},"PeriodicalIF":3.8,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335645","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":"Gas-refractometry-based high resolution continuous measurements in a medium vacuum","authors":"Dong Fan ,&nbsp;Detian Li ,&nbsp;Zhenhua Xi ,&nbsp;Kun Liu ,&nbsp;Wenjie Jia ,&nbsp;Yongjun Cheng ,&nbsp;Wenxi Zhang","doi":"10.1016/j.vacuum.2025.114524","DOIUrl":"10.1016/j.vacuum.2025.114524","url":null,"abstract":"<div><div>While an optical vacuum pressure standard (OVPS) using gas refractometry accurately offers a wide pressure measurement range, the measurement accuracy in the medium vacuum range is restricted by various factors. In this study, an optical vacuum pressure standard based on the refractive index measurement of gas in a Fabry-Perot (FP) cavity was developed. The measurement pressures from OVPS and the capacitance diaphragm gauge (CDG) were compared in the medium vacuum range of 4 Pa∼130 Pa. The relative differences between the two measurements ranged from 0.01 % to 0.835 %, with reproducibility relative differences ranging from 0.0323 % to 1.19 %. These results were achieved using argon gas properties. Furthermore, a high-gain, low-noise frequency measurement system based on a rubidium atomic clock frequency reference was constructed to realize the accurate measurement of beat frequency, and the argon pressure resolution was verified to be less than 5 mPa. Finally, this paper also considered the factors influencing the uncertainty of medium vacuum measurements and proposed corresponding solutions. The uncertainty of the OVPS was evaluated to be [(31 mPa)²+(77 × 10⁻⁶<em>p</em>)²]^1/2 (<em>k</em> = 2).</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"240 ","pages":"Article 114524"},"PeriodicalIF":3.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365317","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}