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[IEEE 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Greifswald (2018.9.23-2018.9.28)] 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - A Novel Vacuum Interruption Contact Design for High Current DC Vacuum Circuit Breaker
摘要: The vacuum interruption contact structure affect the insulation and breaking performance of DC vacuum circuit breaker directly. A novel vacuum interruption contact system with axial magnetic field (AMF)-double transversal magnetic field (TMF) is investigated for high current interruption in DC vacuum circuit breaker in this paper. It consists of one AMF cup-shaped contact and two concentric TMF contacts, which the internal contact is a disk-shaped structure and the external contact is a cup-shaped structure. The so-called novel TMF-TMF-AMF contact structure has the merits of having a very high axial magnetic flux density at large current condition, and producing rotation Lorentz force for metal vapor arc caused during interruption process. Its performance is compared with that of traditional TMF contact, traditional AMF contact and TMF-AMF contacts using three-dimensional finite-element method and the comparison results verify the validity of this proposed interruption contact structure design.
关键词: Lorentz force,vacuum interruption,finite element method,Axial magnetic flux density,metal vapor arc
更新于2025-09-23 15:23:52
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[IEEE 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Greifswald (2018.9.23-2018.9.28)] 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) - Two Dimensional Distribution of Metallic (Cu) Vapor in a Forced Vacuum Arc Extinction by LIF
摘要: It is important to observe the metallic vapor dissipation after interrupting a vacuum arc, for getting a deeper understanding of dielectric recovery processes, especially for DC interruptions. The object of this paper is to obtain two dimensional density distribution of copper vapor in a forced vacuum arc extinction. The method of laser-induced fluorescence (LIF) using a pulse laser with a central wavelength at 324.8 nm was adopted here. Meanwhile, an ICCD was used to capture the 510.6 nm fluorescence signal with an exposure time of 50 ns. The fluorescence can be distinguished from 125 μs (the moment of arc extinction) to 375 μs with a time interval of 25 μs. As a result, we could obtain the relative density distribution of ground-state copper metal vapor after the arc extinction. The results show that on the condition of CuCr25 contacts the metal vapor was evenly distributed in the gap and rapidly spread over time. The density of the copper vapor between the contacts dropped to less than 10% of the initial stage 200 μs after arc extinction. On the contrary, on the condition of CuCr50, higher copper metal vapor density at the moment of arc extinction was observed. It seems that the higher Cr content in the Cu-Cr contacts will lead to producing more metal vapor around current zero.
关键词: laser-induced fluorescence,copper metal vapor,vacuum arc
更新于2025-09-23 15:22:29
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Metal Vapor Lasers
摘要: The milestones in the development of researches connected with metal vapor lasers, which have been carried out at V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, since its first days are considered. Some of the most interesting fundamental and applied results are presented. A fairly extensive list of related works, published mainly in the past twenty years, is given.
关键词: brightness amplifier,active thermal insulation,active impurity generator,optical pumping,metal vapor lasers,laser efficiency,metal halides,active optical systems,inner reactor
更新于2025-09-23 15:19:57
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In situ chemical composition analysis of a tungsten-inert-gas austenitic stainless steel weld measured by laser-induced breakdown spectroscopy
摘要: The chemical composition of a weld metal determines the resulting solidification mode of stainless steel and the consequent weld metal quality. In this work tungsten inert gas (TIG) welding of EN grade 1.4435 austenitic stainless steel was monitored using laser-induced breakdown spectroscopy (LIBS) for the in situ measurement of chemical composition changes. This research aims to prototype a real-time chemical composition analysis system for welding applications and prove the feasibility of such quality control loop. LIBS was used to investigate in situ the monitoring of metal vaporization during TIG welding. We found Mn vapor formation above the weld pool and subsequent condensation of Mn on the weld metal surface using LIBS. Post-weld line scans were conducted by LIBS on various welds produced with different welding currents. Local changes of Ni and Mn were observed at higher welding currents. The results are in good agreement with the literature and proved that LIBS can be used in situ to inspect the TIG welding process.
关键词: LIBS,In situ measurement,Metal vapor,Welding,Austenitic stainless steel
更新于2025-09-23 15:19:57
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The Studies of Plasma Torch Processes by Laser Beam Welding
摘要: The manufacturing of significant products with help of laser beam welding technologies requires higher stability characteristics of such technologies; this explains the necessity to run on-line testing procedures of through pro-melting process. This type of testing can be carried out by the registration of plasma streams that occur under a work piece by through pro-melting [i.e. metal undergoes an intensive laser beam thermal processing].
关键词: collectors of charged particles,plasma,informational-measuring system,plasma torch,analog-to-digital converter,ionization of metal vapor,welding of small thickness products,laser beam welding,through pro-melting
更新于2025-09-16 10:30:52
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[IEEE 2019 20th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Erlagol (Altai Republic), Russia (2019.6.29-2019.7.3)] 2019 20th International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices (EDM) - Matching Line for Increasing of Radiation Power of Metal Vapor Lasers
摘要: The methods of increasing the radiation power of metal vapor lasers has been considered. The results of the using different types of discharge circuits are presented. The use of matching line with the peaking capacitor and the autotransformer provides additional time delay between current and voltage of the gas discharge tube. It allowed increasing in the radiation power by a factor of 1.5 and the laser pumping efficiency to ~ 1.6%. Dependences of the radiation power in the direct discharge scheme and in the scheme with matching line are represented.
关键词: pump source,metal vapor lasers,self-terminating lasers,gas discharge tube,discharge circuit,efficiency of pumping,matching line,peaking capacitor,Active optical system,pumping,radiation power
更新于2025-09-12 10:27:22
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Nucleation mechanism of metal-vapor atoms on photochromic diarylethene surface with a low glass transition temperature
摘要: Metal pattern formation on organic surfaces is essential in organic electronics. Selective metal-vapor deposition using photochromic diarylethene (DAE) is a promising method to prepare ?ne metal patterns by maskless evaporation. Metal-vapor atoms are adsorbed, di?used, and then desorbed from the colorless surface with a low glass transition temperature. We, however, found that metal deposition started at a speci?c time (deposition-threshold time, tth) even on the colorless surface by continuous evaporation. tth was investigated using a quartz crystal microbalance. We elucidated that metal-nucleation sites were generated by chemical reactions between metal atoms and surface DAE molecules. The number of nucleation sites increases during metal evaporation and when the sites are located in the di?usion range of surface metal atoms, metal-atom nucleation for ?lm-formation starts. This is the origin of tth. This result would provide important knowledge for the preparation of electrodes for organic devices based on selective metal-vapor deposition.
关键词: organic electronics,nucleation mechanism,photochromic diarylethene,quartz crystal microbalance,metal-vapor deposition
更新于2025-09-10 09:29:36