IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)最新文献

{"title":"Research of the field emission of fractal blades patterns of large length","authors":"Y. Gulyaev, V.N. Koro, Y. Grigorev, G. A. Rehen","doi":"10.1109/IVESC.2004.1414140","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414140","url":null,"abstract":"The looking up of effective, cost-effective (cold) sources of intensive beam couplings is one of actual problems of modern vacuum micro- and nanoelectronics. As far as it is known, the difficulties of deriving of large absolute values of a current of field emission are connected to extremely small values of the effective area of emission component, which forms 10/sup -6/ to 10/sup -8/ part from the area of a cathodic substrate. One of methods of increasing of the effective area of emission is the transferring from regular bivariate tips of gratings to surface patterns blade or planar-end configuration with extended fractal boundaries. Apparently, that substantial surface micro- and nanostructure from this or that fraction can be referred to natural fractals. As it was shown, field emission properties of close set film and monolithic carbon patterns on conductive substrates can be essentially improved by a simple vacuum discharge converting 2D pattern with mean values of a period 65-70 nm, altitude 7-8 nm, and radius of curvature of tops 2-3 nm, in discontinuous branching.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117337445","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":"Thermal analysis of electron gun with grid control in pulsed TWT","authors":"L. Xiaofeng, Wang Junyi, Xu Hui","doi":"10.1109/IVESC.2004.1414186","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414186","url":null,"abstract":"Summary form only given. The design of electron optical system of electron gun with grid control in pulsed TWT has been completed. During the cathode of grid control electron gun, shadow grid and control grid are radiated, it is necessary to further analyze change of electrode temperature and displacement with the help of CAD technique. Selected material of support piece and integrative heating cathode are analyzed by calculation. These conclusions are gained such as the variation of cathode surface temperature in the range of 10/spl deg/C, the highest temperature of shadow grid to be radiated at 707 /spl deg/C, the temperature of mat edging being lower and the highest surface temperature of control grid at 193/spl deg/C-far below the surface temperature of shadow grid. After cathode heat balance, each electrode will produce expand and displacement so it will result in change of original gap each electrode. By means of CAD analysis, cathode, shadow grid and control grid will produce displacement of 0.06mm ,0.036mm and 0.00875mm respectively when they come under the influence of thermal radiation. So assembling size of electron gun with grid control can be obtained by means of modifying electron optical size. Tests of temperature and displacement of electron gun with grid control are measuring surface temperature each electrode with the aid of micro-optical thermal detector and axial displacement each electrode with the aid of tool microscope. And the assembled electron gun is sealed in glass shell through exhaust. Test data are corresponding with calculating results of CAD.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115498961","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":"CAD design for multi-beam klystron broad BW power output system","authors":"Fuzhi Zhang","doi":"10.1109/IVESC.2004.1414262","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414262","url":null,"abstract":"The outstanding specifications of klystron are high output power, high gain, high reliability, but its transient band width (BW) is narrow, so its applications are limited. To broad the BW of klystron, double gap cavity, several gap cavity, traveling wave klystron and multi-beam klystron (MBK) have been invented. In them the MBK has low working voltage, broad transient BW, so it gets more and more attention. According to microwave theory and electron-magnet filed theory, the final BW of klystron is limited in the BW of group collection segment and BW of power output segment. Usually the BW of group collection segment is broader than the BW of power output segment, the MBK's group collection segment has more broad BW. So the key problem of broad klystron's BW is how to broad the BW of power output system. So people invented double cavity, several cavity distribution cavity structure, overlap model output, output cavity add filter and so on. The structures of output cavity add filter is simple and easy to be made. Many MBK use this structure. In past when people design this structure, first split this problem into two parts, one is output cavity design, the other is filter design; use many approximate conditions, use microwave circuit method to design it, the result can't be accurate then to make cold test model, many times change, many times test, after many periods the results can be use on the practice klystron. The working cycle is long, the efficient is low. At recent times, many microwave compute software appears and get more and more mature, such as MAFIA, HFSS program. Use these software people can simulate the electro-magnet filed in microwave tubes, also can compute the interaction and energy interchange of cell and field. In practice people use these software can quickly get the better design ,greatly improve the design level, short the design time. In this text ,use MAFIA HFSS compute the single cavity, double gap cavity, single cavity add filter structure, double gap cavity add filter (13 /spl sim/ 18GHz), from the compute results, we can see that the double cavity add filter is better than other structure. And analysis all the factors of this structure. Then made a cold-test model, the test results is basically according to the compute results, It has 2.5% cold-test BW. In practice klystron this structure has 1.6% hot-test BW (Ku band, 20kW). In this text conclusion of CAD design in broad BW is made. Also discuss some skills and problems of using the software.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115447987","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":"Two-dimensional numerical simulation for gun of TWT","authors":"Liu Wei, Li Shi, Shen Bin, Yin He-jun","doi":"10.1109/IVESC.2004.1414293","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414293","url":null,"abstract":"Summary form only given. This paper presents the numerical simulation method by software MAFIA, TAU and EGUN to calculate the electron-gun of traveling-wave tube. The simulation result are good consistency with part experiment data. The average calculation precise may be less than 5%. It proves that these electro-magnetic software are capable of simulating the electron-gun, making some research for computer simulation to satisfy practical engineering design demand in computation precise. The calculation time is compared for these software.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"230 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131618426","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":"Stable high electron emission from LiNbO/sub 3/single crystal","authors":"M. Yin, Y. Ren, Dejie Li","doi":"10.1109/IVESC.2004.1414282","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414282","url":null,"abstract":"A sample of LiNbO/sub 3/ single crystal Z-cut slice is stimulated by a high negative voltage submicrosecond pulse to obtain the emission. When the pulse voltage exceeds a threshold, which is 800V in the experiment, we observe a stable high electron emission from the sample's surface. The threshold is irrelevant to the driving frequency and the anode voltage. Below the threshold the electron emission density increases with the anode voltage, above the threshold the electron emission density varies very little with the anode voltage. The electron emission density reached a peak value of 50A/cm, when the driving pulse V/sub p-p/ is 900V. The emission current is not synchronized with the driving signal. When the frequency of the driving voltage is 10 kHz, the frequency of the emission current is only 1 Hz. The frequency of the emission current further decreases, as the driving frequency decreases.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116840642","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":"The design of a photonic bandgap wideband filter 2.4GHz","authors":"L. Shi, D. Lou","doi":"10.1109/IVESC.2004.1414274","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414274","url":null,"abstract":"This paper presents a novel one dimensional (1D) 2.4GHz photonic bandgap (PBG) microstrip structure filter. This device consists of a 50/spl Omega/z microstrip transmission line and a PBG ceramic substrate. The filter exhibits a well-defined stopband. The novel filter is simulated with 3D full wave electromagnetic analysis using HFSS (high-frequency structure simulator). At last several filters with different parameters of periodic lattice are compared. The design and simulation facilitate further research on the structural design and optimization.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116933296","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":"Grid-controlled electron gun of multi-beam klystron at TM220 mode","authors":"Li Dongfeng, Z. Yilin, Zhai Jianguo, Ke Yuhai, Xie Jisheng","doi":"10.1109/IVESC.2004.1414258","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414258","url":null,"abstract":"Long life high performance grid-controlled electron gun has been great extensive used in multi-beam klystron. High performance grid-controlled electron gun is the base of modern high power and broadband multi-beam klystron. We developed a tight and efficient electron gun; its perveance can be more than 0.5 micro-perveance of only one cathode.The whole electron gun has 28 independent small cathodes. The total of whole gun's perveance can be more than 18 micro-perveance. The characteristics of the gun are given in this article.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130696166","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":"The study of travelling-wave tube cold-test characteristics by three-dimensional simulation code","authors":"Zhao-Jun Zhu, Zhengxiang Luo, B. Jia","doi":"10.1109/IVESC.2004.1414266","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414266","url":null,"abstract":"The 3D simulation code of Ansoft HFSS and CST Microwave Studio has been used to simulate the cold-test characteristics of four helix slow-wave circuits. The simulation result shows good agreement with the measurement.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121453999","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":"Spindt-type cathodes with aligned carbon nanotube emitters","authors":"M. Ding, Xinghui Li, Guodong Bai, Jinjun Feng, Fuquan Zhang, Fujiang Liao","doi":"10.1109/IVESC.2004.1414156","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414156","url":null,"abstract":"Two kinds of Spindt-type cathode arrays with vertically aligned carbon nanotubes (CNTs) emitters were fabricated. One process involved direct growth of CNTs from the bottom of each micro-cell and the other process was to grow CNTs on Mo tips in Spindt-type cathode arrays. The former had fairly good consistent emitters with a number of CNTs, whereas the latter showed a few or single CNTs in micro-sized cells could be formed.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"173 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122070245","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":"A brief history of the development of vacuum electron devices in China","authors":"Keqian Zhang, Fujiang Liao","doi":"10.1109/IVESC.2004.1413945","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1413945","url":null,"abstract":"2004 is the year of the 100th anniversary of the invention of vacuum electron device and also the discovery of oxide coated cathode. One hundred years ago, in 1904, the first vacuum electron device, diode was invented by John Ambrase Fleming, and the oxide coated cathode had been invented by A. Wehnelt in 1903. Later, in 1906, purring a control grid into the Fleming diode, the triode was invented by Lee de Forest. Detection and amplification was realized by means of vacuum electron devices. This leads the way to the earlier steps of signal processing, transmission and detection. Wireless telecommunication, broadcasting and other applications systems were then developed and extended rapidly all over the world,. including China, which was just under the transition from an empire to a republic. In this paper, a brief history of the development of vacuum electron devices in China is presented. The current state of art is described.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115470630","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}