2008 IEEE 35th International Conference on Plasma Science最新文献_第10页

High power CW klystrons for fusion experiments 核聚变实验用大功率连续波速调管

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590953

A. Beunas, F. Kazarian

{"title":"High power CW klystrons for fusion experiments","authors":"A. Beunas, F. Kazarian","doi":"10.1109/PLASMA.2008.4590953","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590953","url":null,"abstract":"On TORE SUPRA (TS) located in Cadarache, the Lower Hybrid Current Drive (LHCD) 3.7 GHz system is being upgraded* in the frame of the CIMES project. Since the end of 2001, several technological components have been under manufacturing or have been installed. Particularly, a new high power CW klystron has been successfully developed and tested at Thales Electron Devices (TED) for CEA Cadarache. The main required performances are to deliver at 3.7 GHz, 700kW minimum output power on a matched load with a 44% efficiency, and 620kW minimum output power on a 1.4:1 VSWR all phases with a 38% efficiency, this latter case corresponding to the shot mode on plasma. The klystron has been factory tested up to 700 kW in CW operation on a matched load, without any difficulty. This operating point has been achieved at 73.1 kV and 20.7 A, with an efficiency of 47% and a gain of 52 dB. Power variation is less than 0.15 dB over the specified 5 MHz bandwidth. No instabilities were observed during tests. The power dissipated in the two klystron body cooling circuits is about 16.5 kW. The overall RF losses are estimated at 15 kW, which means that the beam losses are quite low, at 1.5 kW to be compared to the 1500 kW beam power. As a result, the temperatures of the output cavity noses are kept below 110 degC at 700 kW. Ten 1000s 700 kW shots were applied to the klystron with remarkably stable thermal and RF performances. On a mismatched load (1.4:1 VSWR), the tube has delivered 620 kW min, any phase, with an efficiency of 40%. As expected, a slight temperature rise of the output cavity noses (about 20degC) was observed, when compared to operation on a matched load at the same output power. In the diode mode, at full beam power, the measured temperatures of the collector inner wall are lower than 220degC. These results demonstrate that this new 3.7 GHz 700kW CW klystron has been designed with large thermal safely margins, which will ensure high operational reliability on the TORE SUPRA facility, but also good manufacturing yield during the serial production recently started at TED.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85043558","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

Nonlinear dynamics of fluctuations in the presence of sheared parallel and perpendicular flows in a magnetized laboratory plasma 磁化实验室等离子体中存在平行和垂直剪切流时波动的非线性动力学

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590642

M. Gilmore, L. Yan, S. Xie, C. Watts, A. Lynn

{"title":"Nonlinear dynamics of fluctuations in the presence of sheared parallel and perpendicular flows in a magnetized laboratory plasma","authors":"M. Gilmore, L. Yan, S. Xie, C. Watts, A. Lynn","doi":"10.1109/PLASMA.2008.4590642","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590642","url":null,"abstract":"Laboratory experiments are described which utilize a set of concentric bias rings to affect the velocity (flow) shear in the linear HELCAT (HELicon-CAThode) device at the University of New Mexico. HELCAT is 4 m long, 0.5 in diameter, with B0 les 2.2 kG, and utilizes two plasma sources: an RE helicon at one end of the device, and a thermionic cathode at the other. With increasing ring bias, relative to the vacuum chamber wall, it is found that both axial and azimuthal flow shear change by only a small amount in magnitude, but move inward to the plasma core from the wall. As bias is increased, drift waves decrease in magnitude and are eventually fully suppressed, then the Kelvin-Helmholtz (K-H) mode is destabilized. It appears that the azimuthal flow shear is mainly responsible for suppression of drift modes, while the azimuthal shear is the primary driver of the K-H instability. While bias applied to rings at any radii suppresses drift fluctuations with nearly equal effectiveness, the K-H mode is more easily excited by biasing at the plasma edge. Fluctuations show increasingly chaotic and intermittent behavior as bias increases, up to V ~ 10 kTe/e, when the chaos disappears, as indicated by a rapid drop in correlation dimension, and very bursty behavior. Additionally, detached edge \"blobs\" are observed in cathode plasmas, but appear to be absent from helicon discharges, even when other operating parameters (magnetic field, background pressure) are identical. Experimental results and comparisons with theory are described.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82086597","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

Nonideal effects in the operation of a paraxial diode with gas cell focusing 带气池聚焦的近轴二极管工作中的非理想效应

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590791

D. Welch, N. Bruner, D. Rose, K. Hahn, B. Oliver

引用次数: 0

Improving germination rate of soybeans as a biofuel resource 提高大豆作为生物燃料资源的发芽率

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590820

N. Parsi, S. Gyawali, N. Boriraksantikul, P. Kirawanich, N. Islam, M. Pathan, D. Sleper

{"title":"Improving germination rate of soybeans as a biofuel resource","authors":"N. Parsi, S. Gyawali, N. Boriraksantikul, P. Kirawanich, N. Islam, M. Pathan, D. Sleper","doi":"10.1109/PLASMA.2008.4590820","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590820","url":null,"abstract":"Summary form only given. Improvements in plant quality, root strength and seed germination through different means has been the subject of research for many. For example, low intensity and extreme low frequency magnetic field on sunflower and wheat seeds germination have produced positive effect. In this study different variety of soybean seeds have been exposed to electromagnetic and magnetic fields using an anechoic chamber and Helmholtz's Coil. The objective was to determine changes in the germination rate, if any, as a function of frequency, field intensity and duration of exposure. Soybean was chosen because, compared to other bio-fuel resources, it produces the maximum energy per gram and any increase in germination due to EM or magnetic field exposure would result in a greater production of this important asset. Experiments were conducted with four different varieties of soybean seeds namely Magellan, Maverick, SS97-6946 and Williams82. Results show that at 128 Watts, 100 MHz frequency and with exposure time of 10 minutes, only one variety of soybeans (Magellan) had a seven percent increase in the germination rate and was statistically significant. With an increase in the number of seeds per batch, the percent increase of germination for Magellan got down to five while for the other three types there was no change. There was statistical significance for germination of Magellan even for this experiment. Experiments were also conducted with the seeds in magnetic field of strengths 1G 5G and 10 G and exposure durations of 1 min, 5 min, 10 min and 20 min. Positive effect with 5 and 10 G field strength is reported. The number of seeds used in the magnetic field experiments was 25 and germination rate increase was again seen in the Magellan variety. This was further analyzed through statistical analysis which showed that for 5 G and 10 G field strengths the germination rate was significant.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79813534","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

Compact low current X-pinch based EUV source for lithography 用于光刻的紧凑低电流x捏点EUV源

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590704

S. Hassan, E. Clark, A. Gopal, S. Minardi, C. Petridis, J. Chatzakis, G. Androulakis, M. Tatarakis, E. Baronova, V. Vikhrev, P. Lee

引用次数: 0

Growth of high power laser ripple in plasma and its effects on upper hybrid wave excitation: Relativistic effects 等离子体中高功率激光纹波的生长及其对上层混合波激发的影响:相对论效应

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590995

T. Gill, N. S. Saini, R. Mahajan

引用次数: 0

Subnanosecond rise time of high voltage pulses in ferrite loaded coaxial line 铁氧体负载同轴线路中高压脉冲的亚纳秒级上升时间

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4591189

O. Kovalchuk, V. O. Kutenkov, I. Romanchenko, V. Rostov

引用次数: 1

Feasibility study of atmospheric pressure plasma treatments of HEPG-2 and SK-HEP-1 cancer cells 常压等离子体治疗HEPG-2和SK-HEP-1癌细胞的可行性研究

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590921

B. Gweon, D. Kim, S. Moon, W. Choe, Sukhyun Song, Daeyun Kim, J. Shin

{"title":"Feasibility study of atmospheric pressure plasma treatments of HEPG-2 and SK-HEP-1 cancer cells","authors":"B. Gweon, D. Kim, S. Moon, W. Choe, Sukhyun Song, Daeyun Kim, J. Shin","doi":"10.1109/PLASMA.2008.4590921","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4590921","url":null,"abstract":"Summary form only given. A feasibility study of plasma cancer cell treatment was performed using a pin-type plasma jet. A 50 kHz AC power was used to generate the plasma in the ambient air assisted by the helium flow. The plasma gas temperature was maintained at the room temperature of 25degC to eliminate the thermal damages to the cell. The liver cancer cells of HEPG-2 and SK-HEP-1 were used as the treatment samples. The sample cells were prepared on the fibronectin coated slide glass for the sake of convenience of the microscopic observation process. The input voltage and the treatment time were controlled in the range of (750-1000) V and (30-120) s, respectively. After the plasma treatments, the sample cells were stained with the viability assay (ethidium homodimer and calcein AM) to make discrimination between live and dead cells. Then, the microscopy scan was performed from the plasma center up to about 1 cm. The necrotized cells as well as a void or cell free zone appeared starting at the input voltage of 800 V and the treatment time of 60 s, . The necrotized zone and the void were well matched to the plasma profile. Normal liver cell, THLE-2, was then treated for comparison with the liver cancer cells.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77816678","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

MHz pulsed power by semiconductor devices 半导体器件的兆赫脉冲功率

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4591188

Weihua Jiang, T. Yokoo, K. Saiki, K. Hisayama, K. Narita, Ken Takayama, M. Wake, N. Shimizu

{"title":"MHz pulsed power by semiconductor devices","authors":"Weihua Jiang, T. Yokoo, K. Saiki, K. Hisayama, K. Narita, Ken Takayama, M. Wake, N. Shimizu","doi":"10.1109/PLASMA.2008.4591188","DOIUrl":"https://doi.org/10.1109/PLASMA.2008.4591188","url":null,"abstract":"Pulsed power generators with repetition rates on the order of MHz have been developed by using semiconductor opening switch (SOS), static induction thyristor (SIThy), and silicon carbide junction field-effect-transistor (SiC-JFET). A compact SOS circuit based on inductive energy storage has been developed. It uses semiconductor switches for forward and reverse current control of the SOS diodes, instead of commonly used magnetic switch. The repetition rate has reached 500 kHz (burst) for output voltage pulse of 10 kV and pulse width of 15 ns (FWHM). A full-bridge switching unit using SIThy has been developed and tested for bipolar square voltage pulse generation of plusmn 2 kV for a 100-Omega load, at repetition rate of 1 MHz (burst). A stacked SiC-JFET switching unit consists of 4 devices (2S x 2P) has been operated for 2 kV and 20 A at repetition rate up to 5 MHz (burst). Important issues on switching characteristics, such as rise- time, heat loading, and balance between devices have been studied. The MHz-repetitive power modulators are expected to have various applications in the future, especially for high- energy accelerators and biological treatment.","PeriodicalId":6359,"journal":{"name":"2008 IEEE 35th International Conference on Plasma Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82221534","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 DARHT II Accelerator beam position monitor system DARHT II加速器光束位置监测系统

2008 IEEE 35th International Conference on Plasma Science Pub Date : 2008-06-15 DOI: 10.1109/PLASMA.2008.4590860

J. Johnson, C. Ekdahl, W. Broste

引用次数: 0