Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)最新文献_第10页

One microsecond Pulse-width Annular Beam Relativistic Klystron Operating at 500 MW 一微秒脉宽环形束相对论速调管工作在500毫瓦

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589112

M. Fazio, W. B. Haynes, B. Carlsten, R.M. Stingfield

{"title":"One microsecond Pulse-width Annular Beam Relativistic Klystron Operating at 500 MW","authors":"M. Fazio, W. B. Haynes, B. Carlsten, R.M. Stingfield","doi":"10.1109/PLASMA.1994.589112","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.589112","url":null,"abstract":"This paper describes the experimental development of a long pulse high current, annular beam relativistic klystron amplifier. The desired performance parameters are 1 GW output power and 1 {mu}s pulse length with an operating frequency of 1.3 GHz. the electron beam voltage and current are nominally 600 kV and 5 kA. Peak powers approaching 500 MW have been achieved in pulses of 1 {mu}s nominal baseline-to-baseline duration. The half power pulse width is 0.5 {mu}s. These pulses contain an energy of about 160 J. The rf output terminates abruptly just before the highest parts of the beam voltage and current pulses are reached. The cause of the premature termination of the rf pulse has not been definitely determined. Experimental observations indicate that the rf pulse termination could be the result of the output cavity gap voltage being too high, causing electron reflection at the gap and rf breakdown across the gap. To reduce the output gap voltage, a new output cavity has been designed with a much lower shunt impedance and a loaded Q of 4. Current experimental results and theoretical design considerations for this class of tube are discussed.","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124628217","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}

引用次数: 2

Wave Excitation With Helical Antennas 螺旋天线的波激发

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588747

M. E. Light, F.F. Chen

引用次数: 0

The Role Of Potential Hills And Reflexing Electrons In The Operation Of A Plasma Opening Switch 势丘和反射电子在等离子体开断开关工作中的作用

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589001

R. Kares

引用次数: 0

Theory Of The Plasma-sheath Transition And The Bohm Criterion 等离子体鞘层跃迁理论及玻姆判据

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589048

K. Riemann

引用次数: 9

Numerical Modelling Of Ozone Production In A Pulsed Homogeneous Oxygen Discharge 脉冲均匀氧放电中臭氧生成的数值模拟

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588757

J. Nilsson, J.F. Eninger

引用次数: 1

Limiter Biasing Experiments On The Stor-m Tokamak storm托卡马克上的限制器偏置实验

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588913

W. Zhang, C. Xiao, L. Zhang, A. Hirose

{"title":"Limiter Biasing Experiments On The Stor-m Tokamak","authors":"W. Zhang, C. Xiao, L. Zhang, A. Hirose","doi":"10.1109/PLASMA.1994.588913","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.588913","url":null,"abstract":"Liniiter biasiiig experiments has been carried out on the STOR-51 tokaiiiak. The liiniter consists of eight stainless steel scgiiieiits in a sandwich structure with equal number of segments on hotli sides of a ceramic base. In the experiments reported here, all four segments on one side are connected togct1ic.r to form a limiter and can be biased either positively (1120 lr, 25 A) or nega.tively (-380 V, -40 A) with respect to tlie tokamak chamber. The segments on the other side are used to measure the plasma floating potential and its fluctuations ( V J ) in the scrape-off-layer (SOL). A movable Langmuir probe at the outer board measures those quantities in both SOL and at the edge (./a < 1) regions. It has been found that floating potential fluctuations in the SOL region depend mainly on the polarity of the limiter potential, not the potential gradient. The potential fluctuations in the SOL were strongly suppressed with a positive limiter potential and enhanced dramatically with a negative limiter potential, despite observations that the potential profile was steeper in the SOL region during negative biasing. The behaviour of Vf may be related to the interchange-flute instability with dissipation caused by fluctuating currents flowing through the Langmuir sheath potential near the surface of the limiter'. At the plasma edge the suppression of the fluctuations is always accompanied by a steeper potential profile, which indicates that the rotational shear layer may be the cause for fluctuation suppression inthat region. Despite different behaviours of Vf during the positive and negative bias, improved confinement has been observed for both bias polarities. The improved confinement is characterized by significant density increase (100% for positive bias and 80% for negative bias) and sudden drop in H, radiation level.","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"251 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132677733","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}

引用次数: 0

The Electrical Boundary Layer And Current Transfer Between A Thermal Plasma And A Plane Electrode 热等离子体与平面电极之间的电边界层与电流传递

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589052

E. Meeks, M. Cappelli

引用次数: 0

Two Dimensional Time Dependent Modeling Of Optically Switched GaAs 光开关砷化镓的二维时间相关建模

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589053

P. Stout, M. Kushner

{"title":"Two Dimensional Time Dependent Modeling Of Optically Switched GaAs","authors":"P. Stout, M. Kushner","doi":"10.1109/PLASMA.1994.589053","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.589053","url":null,"abstract":"The advantages of high power photoconductive semiconductor switches (PCSS) such as high hold-off voltage and fast rise times have motivated significant development efforts. However, observations of lock-on, non-uniformities in the electric field, and filamentation of current flow across the device when switching at high fields have raised concerns about the scaling of PCSS to higher currents. To investigate these issues, a two dimensional time dependent computer model of GaAs PCSS has been developed with the motivation of understanding filament formation. The model solves the continuity equations for electrons and holes, conservation equations for trapping sites, the energy equation for the lattice. Poisson`s equation, and a circuit equation. Physical effects in the model include band-to-band impact ionization, trap impact ionization, photoionization, and negative differential resistance. The physical devices investigated with the model are based on the Bulk Optical Semiconductor Switch (BOSS) developed by Schoenbach. In this talk a description of the model will be presented followed by consequences of switch geometries, gain mechanisms, and non-uniform injection and illumination on the operation of the device.","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128930248","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}

引用次数: 1

Three Dimensional Simulations Of The Lanl Large Orbit Gyrotron Using Isis On The Connection Machine 利用Isis在连接机上对Lanl大轨道回旋管进行三维仿真

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589076

R. Kares, V. Thomas, M.E. Jones

引用次数: 0

Buried Ceramic Layer Formation In Glass And Silicon Using Plasma Source Ion Implantation 等离子体源离子注入在玻璃和硅中形成埋藏陶瓷层

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588985

J. Booske, L. Zhan, R. Cooper, J. Shohet, K. Shenai, D. Dallman, M.J. Goeckner, R. Breun, W. Hitchon, E. Wickesberg, R. Speth, J. Jacobs, G. Was

引用次数: 0