2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)最新文献

{"title":"Electron probe micro analysis and surface resistance measurement investigation of copper chrome coatings on vacuum circuit breaker ceramic surfaces following switching operations","authors":"I. Gramberg, M. Kurrat, D. Gentsch","doi":"10.1109/DEIV.2012.6412460","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412460","url":null,"abstract":"Vacuum Interrupters (VIs) are designed for a long operating life. Even after a large number of switching operations they should still provide good arc extinction and be able to withstand high voltages. Switching operations produce substantial masses of metal vapor that condense on the inner component parts of the VI. The Vis are equipped with shields to protect the ceramic surfaces from being coated by metal vapor. Since the first VI was put into service, a large number of shield designs have been developed. If the shield design consists of a floating shield with two end-shields, there are two gaps between these shields. These gaps are necessary for insulation when the VI is in the open position, but during the switching operation metal vapor can flow through these gaps and coat the ceramics. If the deposited area on the alumina ceramics reaches a critical value, the dielectric performance of the VI can become reduced. Standard VIs have been tested with a floating shield and two end shields, that did not overlap the floating shield. The VIs were assembled at the Institute's high power test facility to perform switching operations at different current intensities. After opening the VIs, the coated ceramics were examined. It became clear that, the more switching operations were performed, the darker the deposited layers became. Electron Probe Micro Analysis (EPMA) is a method for surface investigations which was used here to obtain a very detailed view of the thickness of the deposited layers. With EPMA it is possible to detect very thin layers in the range of nanometers. Several coated ceramic surfaces of VIs that had been switched with different current intensities were investigated. In order to provide a better understanding of how strongly different deposited layers can affect the dielectric performance of the VI, surface resistance measurements were carried outdone. These were performed with a high resistance meter, which is able to measure up to 1016Ω using a 1 kV voltage source.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116760372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of residual charge after a forced extinguishing of the vacuum arc","authors":"A. Klajn","doi":"10.1109/DEIV.2012.6412499","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412499","url":null,"abstract":"The paper presents results of an experimental and theoretical analysis concerning the observation of the post-arc phenomena in plasma after the forced extinguishing of a diffuse arc in vacuum. Examination applied, among other things, evaluation of the residual charge. Experiments were performed in laboratory conditions using a de-mountable vacuum chamber equipped with Cu flat contact system. The switched-off arc current had the form of a half-wave with amplitudes of 400 A and 600 A and frequency of 30 Hz. The source of this current was a capacitor bank, loaded before each switching process. The voltage of loaded capacitor was in range of few hundreds Volts, so the examined arc was low voltage and diffuse one. The forced extinguishing had been realised by the counter-pulse current with falling rate in range 2÷90 A/μs. The measurements of post-arc plasma was performed using retarding field analyser (RFA), witch worked in electron separation mode, measuring ion current. The ion current after extinguishing of the arc was the basis to evaluation of the residual charge. The peak post-arc current was the range (2-7) A and residual charge (10-30) μC in the tested conditions. The results could be used in modelling of post-arc phenomena in vacuum.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115399948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microthruster based on a low voltage vacuum spark","authors":"S. Gorbunov, V. Paperny, K. N. Pukhilas","doi":"10.1109/DEIV.2012.6412601","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412601","url":null,"abstract":"Experimental studies of thrust characteristics of a small-size low voltage vacuum spark with liquid (InGa) cathode are present. It is shown that the view of the signal in the time-of-flight measurements depends strongly on the interelectrode gap, namely, the three ion components are present with the gap of 9 mm. The thrust of the plasma source depends on the interelectrode gap length and increase by 1.5 times with application of a permanent circular magnet. The thrust attains of P = 0.8 μNs with the stored energy of 0.1 J so that we may estimate the thrust to power ratio as 8 μNs/J as well as efficiency of the thruster η = PV/CU02 ≈ 12% at U0 = 250 V. Taking in mind the very small size, rather low mass that is about of 50 g, as well as the simple design of the source, we may conclude that it is a promising one as a thruster for the microsatellites.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122968129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gyrotron heating of vacuum arc plasma for high charge state metal ion beam generation","authors":"G. Yushkov, A. Vodopyanov, A. Nikolaev, I. Izotov, K. Savkin, S. Golubev, E. Oks","doi":"10.1109/DEIV.2012.6412592","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412592","url":null,"abstract":"High charge state heavy metal ion beams have been formed by high power microwave heating of vacuum arc plasma confined in magnetic traps. Two types of magnetic traps were investigated, one a simple mirror configuration and the other a cusp configuration with inherent “minimum-B” structure. Pulsed high power (>;100 kW) gyrotrons with frequency 37.5 GHz and 75 GHz were used for heating the vacuum arc plasma injected into the traps. Two different approaches were used for injecting the metal plasma - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. High charge state heavy metal ion beams were extracted from the heated plasma.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125286121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On breaking capacity of the CuCr25 composite material produced with electron-beam cladding","authors":"A. Schneider, S. Popov, V. Durakov, B. Dampilon, S. Z. Dehonova, A. Batrakov","doi":"10.1109/DEIV.2012.6412505","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412505","url":null,"abstract":"The copper chromium composite coatings produced by the electron beam cladding in the vacuum on the copper substrate and electrical contacts CuCr25 produced by solid-phase sintering in a hydrogen atmosphere have been investigated. The copper chromium composite coatings produced by the electron beam cladding showed higher values of breaking capacity compared with the sintered contact material.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126380961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface charge characteristics on insulators in vacuum under DC voltage","authors":"Feng Li, Meng Wang, Yingmin Dai, Lin Chen, Jing Ren","doi":"10.1109/DEIV.2012.6412462","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412462","url":null,"abstract":"Accumulation of insulator surface charge with DC loaded in vacuum is studied with electrostatic capacitive probe by measuring the surface charge of insulators of various roughnesses at different applied voltages and loading time. The measurement results indicate that the average surface charge density is affected by the structure of electrode and grows with the increment of the magnitude and duration of the applied voltage. It is concluded that the increment of insulator surface roughness would enhance the collection of surface charge, but it may bring the higher energy level trap center to suppress the accumulation of surface charge. The accumulation and decay of surface charge is affected with the pressure and surface charge on insulator is positive with negative DC voltage in vacuum.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129941423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dependence of asperity depth on secondary electron emission coefficient","authors":"S. Fujita, T. Iwao, M. Yumoto","doi":"10.1109/DEIV.2012.6412444","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412444","url":null,"abstract":"Surface discharges at the solar array on the spacecrafts are originated from electrification. Now, estimation of the electrical potential of the spacecraft by electrification is carried out. But, the reliability of the calculated results depends on the accuracy of the physical properties. One of the desired property is the secondary electron emission coefficient (SEEC): δ (The number of secondary electrons/Primary electrons). In this study, SEEC was obtained down to 200 eV using the original irradiation system. In the preliminary experiment using the Au sample, the magnitude of the maximum δ was 1.6 which was obtained around the primary electron energy Ep≈800 e V. It is reported that roughness on surface materials by atomic oxygen (AO) in the low earth orbit increase remarkably. Thus, the authors tried to make asperity forming island structures by evaporating Au. AFM (Atomic Force Microscope) was used for observing the surface geometry. The result showed that the height of several tens nanometers was able to be controlled. The magnitude of SEEC of evaporated sample increased compared with the untreatment sample.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128560933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emission and postemission of charged particles in vacuum at low values of an external electric field","authors":"N. V. Tatarinova","doi":"10.1109/DEIV.2012.6412441","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412441","url":null,"abstract":"It is known, that the presence of oxide films and nonmetallic inclusions on a high-voltage electrode surface considerably reduce a vacuum gap electric strength. One of this phenomenon causes is electric charge occurrence in them, which one increases an external electric field strength. The charged particles postemission existence after external voltage switching-off is explained by such charge influence. In this report the experiment data, in which one the increase of an electric charge on an electrode surface after external voltage switching-off was watched, are represented. It is demonstrated, that at low external field strength it is impossible to explain this phenomenon by a field emission processes. Prebreakdown currents appearance and behavior of a charge in nonmetallic films mechanisms are considered by processes in pores or pore typed defects, i.e. by poroemission processes.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130961217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase transitions in vacuum arcs in the context of liquid metal arc sources","authors":"A. Anders, J. Slack","doi":"10.1109/DEIV.2012.6412514","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412514","url":null,"abstract":"Arc sources using liquid cathode material could enable very high rate deposition of metal and metal compounds of cathode materials of low melting point. Of special interest are cathodes of zinc, cadmium, tin, and indium as they can be used to deposit high quality transparent conducting oxide films. Phase transitions are briefly reviewed using phase diagrams and vapor pressure curves, and preliminary experiments are reported using a crucible designed to hold the solid or liquid cathode material. Liquid zinc showed evidence of boiling, and liquid tin emitted less and smaller macroparticles than the same source using solid tin.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128681733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cold emission of negative ions from the graphite with the rough surface","authors":"D. Sinelnikov, V. Kurnaev, N. Mamedov, A. P. Popov","doi":"10.1109/DEIV.2012.6412455","DOIUrl":"https://doi.org/10.1109/DEIV.2012.6412455","url":null,"abstract":"The negative ions fraction in the low field emission as function of cathode temperature, residual gas composition and pressure is analyzed. Simultaneous mass analysis of emitted negative ions and residual gas during cathode heating is carried out. The intensity of the emitted negative ions increases linearly with partial pressure of various gases in the range 10-5-10-7 Torr. A simple model based on secondary negative ion emission of adsorbed atoms under positive ion bombardment of cathode is proposed.","PeriodicalId":130964,"journal":{"name":"2012 25th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122481478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}