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

{"title":"Field emission characteristics of mixture films of nano-structure amorphous graphite and carbon nanotubes","authors":"Zhanling Lu, Binglin Zhang, N. Yao, Xinyue Zhang, Bingxian Ma, Zhiqin Fan","doi":"10.1109/IVESC.2004.1414242","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414242","url":null,"abstract":"The mixture film of nano-structure graphite and carbon nanotubes was fabricated on titanium coated ceramic substrate by microwave plasma chemical vapor deposition system (MPCVD). The source gas was a mixture of H/sub 2/ and CH/sub 4/ with flow rates of 100 sccm and 12 sccm, respectively. During the deposition, the total pressure of 6.0 KPa, substrate temperature of 850/spl deg/C and microwave power of 1500W were kept for 2 hours. The surface morphology and the nano-structure of the film were examined using field emission scanning electron microscopy, X-ray diffraction, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. Field emission of the film were carried out in a vacuum chamber with base pressure of below 5/spl times/10/sup -5/Pa. The initial turn-on field was 0.6V//spl mu/m and 1.7 mA/cm/sup 2/ of current density at 1.7 V//spl mu/m was obtained. The stability of the emission was tested by maintaining the electric field at 1.8 V//spl mu/m. The experiments indicate that the film is an efficient and stable cathode material at low electric field.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"64 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":"128851220","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":"Preparation of nano-structure amorphous carbon film and its field emission properties","authors":"Xinyue Zhang, Zhanling Lu, Binglin Zhang, N. Yao, Bingxian Ma, Yongmei Zhao","doi":"10.1109/IVESC.2004.1414243","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414243","url":null,"abstract":"Nano-structure amorphous carbons films were fabricated on n-Si(111) substrates coated with titanium by microwave plasma chemical vapor deposition (MPCVD) system. The source gas was a mixture of H/sub 2/ and CH/sub 4/ with the flow rates of 100 sccm and 16 sccm, respectively. During the deposition, the total pressure of 6.0 KPa, substrates temperature of 830/spl deg/C and microwave power of 1700W which were kept for 4 hours. The surface morphology and the nano-structure of the films were tested by field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman scattering spectroscopy and X-ray photoelectron spectroscopy (XPS). The results show that the film consists of carbon grain size of no more than 100 nm and the main component was amorphous carbon with the mixture of sp/sup 2/ and sp/sup 3/ bond. Field emission of as-deposited film was then measured at a vacuum of below 5/spl times/10/sup -5/Pa. It was found that the initial turn-on field was very low, which was about 0.6 V//spl mu/m; the current density of 2.5mA/cm/sup 2/ was obtained under an electric field of 3.7 V//spl mu/m. The emission sites density was estimated to be more than 10/sup 4//cm/sup 2/ at electric field of 3.7V//spl mu/m. All these characteristics indicate that such deposited nano-structure amorphous carbon film is an efficient cold cathode material.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"96 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":"116298378","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 way of depressing and eliminating the ion noise in microwave tubes","authors":"H. Gong, Y. Gong, Wenxiang Wang, Changjian Tang","doi":"10.1109/IVESC.2004.1414248","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414248","url":null,"abstract":"Ion noise is an important figure of merit in microwave tube. It behaves manifest as a relaxation oscillation of phase. In this paper, we used hybrid model to analyze the noise phenomena and the way of depressing and eliminating the ion noise. To reduce the ion noise, besides the commonly way such as improving the vacuum degree and electronic beam focus level, another more practicability technique of adding electrode ring in tube is discussed and the numeric simulation (PIC) proved it is a well method.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"5 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":"127055515","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":"Influences of light illumination on (Cs,O) activated GaAs photocathode","authors":"Li Min, D. Xiaoqing, Du Yujie, Chang Benkang, Fu Rongguo, Gao Ping","doi":"10.1109/IVESC.2004.1414232","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414232","url":null,"abstract":"Some experiments were made on the effects of light illumination on the (Cs,O) activated GaAs(110) photocathode in previous work. It was observed that if the GaAs photocathode activated without illumination were illuminated by light of proper intensities, its photosensitivity would increase to a new maximum in several minutes and that too intensive illumination could decrease the photosensitivity on the contrary. We also made a stability and recovery study of GaAs photocathodes under varies intensities illumination, which was sealed in image intensifier and placed in UHV chamber respectively, with the help of the self-developed spectral response testing instruments. We found that when the photocathode sealed in the image intensifier illuminated by light of weak intensities, the photosensitivity first increased to a new maximum and then decreased. After removing the light for several hours, the photosensitivity can be recovered itself. Contrast to the weak illumination case, the photosensitivity of photocathode under intensive illumination would decrease monotonously and could not be recovered. By another experiment on photocathode that had been activated successfully in the UHV chamber, we found some new phenomena. Monotonous degradation is produced not only by intensive illumination, but also by weak illumination. Furthermore, photosensitivity after illuminating was unrecoverable. One of the most important phenomena observed by us was that the intensity of pressure in UHV system varied with the intense of illumination. The more intense the illumination was, the more intense would be the pressure in vacuum chamber in the several minutes of beginning. In this paper, the phenomena above-mentioned are analyzed and discussed. It is suggested that excess minority carrier induced by incident photons would damage the surface composition and structure of (Cs,O) activated GaAs photocathode. According to our research, an effective solution to increase photoemission stability is put forward. In our discussion the dipole model is strongly supported.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"12 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":"132439547","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":"Effect of helical slow-wave structure parameter variations on TWT cold-test characteristics","authors":"Li Shi, Liu Wei, Su Xiao-bao, Yin He-jun","doi":"10.1109/IVESC.2004.1414289","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414289","url":null,"abstract":"In this paper, the quasi-periodic boundary conditions in the computer code MAFIA is used to determine the effect on dispersion and on-axis interaction impedance of helical slow-wave structure and the finite element method software-ANSYS is used to simulate the helix pressure distortion. The result is that, with the variations of axial width and height of the helical tape, only a slight effect in the phase velocity, but more effect in the interaction impedance. There is a best point on both axial width and height of the helical tape for the interaction impedance. Both dispersion and on-axis interaction impedance are increased with helix deformation, in which the radial relative deformation is less then 1%. While radial relative deformation is more then 1%, the on-axis interaction impedance is decreased.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"16 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":"115215186","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":"74cm (29\") PF CPT with medium differentiating rate used for digital TV","authors":"Wang Jian-Ping, Niu Shao-Mei, Tao Ding-Yuan, Ding Wen-Hui, Yang Jia-Lin","doi":"10.1109/IVESC.2004.1414290","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414290","url":null,"abstract":"This article briefly introduces the technology characteristics of 74cm (29\") PF CPT with medium differentiating rate used for digital TV technology by Caihong, analyzes and discusses the application foreground of this technology.","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":"115969417","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":"Cathode electronics and microwave tubes manufacturers in China","authors":"Fujiang Liao, T. Yan, Ji Li, Honglai Zhang, J. Wang","doi":"10.1109/IVESC.2004.1413949","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1413949","url":null,"abstract":"The history of vacuum electron sources developed in China was briefly reviewed in this paper. The state of the art of the microwave tubes and the cathode application in these devices made in Beijing Vacuum Electronics Research Institute (BVERI), Institute of Electronics, Chinese Academy of Science (IECAS), Nanjing Sanle Group Ltd. Corporation and Guoguang Electric Group Corporation Ltd. were presented. Finally, the research plans in electron source field were also introduced.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"60 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":"121677226","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":"Cathode life test facility - historical review","authors":"L. Dressman, R. Warnick, A. Qualls","doi":"10.1109/IVESC.2004.1414169","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414169","url":null,"abstract":"Summary form only given. The cathode life test facility (CLTE) has performed real-time life testing of various thermionic cathode types since 1980. The facility originated at Rome Laboratories, Griffiss AFB. In 1992, it was moved to it present location at NSWC Crane, Crane Indiana. Since its inception, the facility has accumulated approximated 4 million total life test hours on cathodes of at least eighteen different types. Historically, the most popular cathodes under test have include reservoir cathodes, designated MK (Siemens), RV and V (CPI), and impregnated cathodes, Designated M (Semicon and Hughes), TM (CPI) and MMM (CPI). In addition, smaller numbers of more exotic cathode types have also been tested. Most cathodes are life tested at loadings of 1, 2, and 4 A/cm/sup 2/ in continuous emission mode. However, a number of cathode (e.g. cathode with 10 A/cm/sup 2/) have been tested with applied filament power only, due to limitation on the test stations available. A summary of the cathodes tested over the entire life of facility is given and the result obtained is compared. Test vehicle configuration and methods of data collection and analysis are reviewed. Emphasis is placed on comparing different cathodes by type and loading. The usefulness of data is discussed.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"9 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":"127778669","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 first indicator based on liquid metal multiple tip field emitter","authors":"E. O. Popov, A. Pashkevich, A.V. Vitugov","doi":"10.1109/IVESC.2004.1414244","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414244","url":null,"abstract":"Liquid metal multiple tip (LMMT) electron emitter was created by pulling liquid metal (indium gallium eutectic) through holes in a nuclear membrane of polyethylene terephtalate (Popov et al., 2001), The track membranes presently employed in selective clean-up filters are obtained by bombarding a film with heavy ions having energy of several tens of megaelectron volts. After irradiation, the film is illuminated by ultraviolet light and subjected to chemical etching. These membranes are produced by cyclotron of Physico-technical Institute. Liquid metal multiple tip field emitters have some advantages in comparison with solid-state field emitters and explosive electron emitters: unlimited life expectancy, large current densities (>100 mA per sq. cm), practically unlimited surface, stable emission in poor vacuum (10/sup -4/ Torr) (Popov et al., 2002). In this work, we report about use of LMMT field emitter on the base of polyethylene terephtalate film with 3 /spl mu/m-diameter holes as the simplest light indicator. The design of the indicator consists of flat accelerating grid and phosphor glass as collecting electrode. The work stability, surface distribution, longlife are discussed in paper.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"72 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":"115734422","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":"Cathode in pulse magnetron for MW grade high power","authors":"Zhang Cui-wei","doi":"10.1109/IVESC.2004.1414260","DOIUrl":"https://doi.org/10.1109/IVESC.2004.1414260","url":null,"abstract":"This paper introduced the diode test of a new type of oxide cathode of nickel sponge and the noticeable superiority when it was used for pulsed magnetron of 2.6MW. For the former, although common vacuum simulated diode with the space of 10mm between cathode and anode has simple structure ,the anode current of test diode was still measured up to 1.2A and 1.32A correspond to No.1 and No.2 new type of cathode. Otherwise, the pulsed emission current of the new type of cathode should be in range of 7.4 /spl sim/ 7.8A/cm/sup 2/for pulsed magnetron of 2.6MW high power. Three assembled pulsed magnetron of 2.6MW high power show that their output are more then 2.6MW specified value at Va=45 /spl sim/ 46KV and Ia=110A. In the condition of different duty cycle such as /spl tau/=4/spl mu/s f=122Hz and as /spl tau/=4/spl mu/s, f=250Hz, to measure beam meterage of complete machine with this magnetron show that current envelope is very good and operation is very stead. Beam meterage satisfies demand. In the case of specified operating status at Va=45KV and pulsed current 110A,beam meterage is up to 823Ld, more then the specified value of complete machine -700Ld and can satisfy applied need. Spectral shape is also satisfactory, which is monitored by means of AV4023B type of frequency spectrograph. The magnetron requires of heat load of the new type oxide cathode being very strict. So life test conducted carefully with 2.1MW magnetron first, 7 /spl sim/ 8 h a day, at /spl tau/=:2/spl mu/s, la=110A and P=2.1MW and continued 50 hours. During the whole operation, its performance and stabilization are perfect. The cathode has not obvious the phenomena of evaporation and sputter as well as virtual current. Later, life test conducted with No.2 tube, /spl tau/ 4/spl mu/s, Ia=110A and P=2.6MW, 7 /spl sim/ 8 hours a day and continued 23 hours 45 minutes. The test still keep on.","PeriodicalId":340787,"journal":{"name":"IVESC 2004. The 5th International Vacuum Electron Sources Conference Proceedings (IEEE Cat. No.04EX839)","volume":"46 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":"123584408","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}