2007 IEEE 34th International Conference on Plasma Science (ICOPS)最新文献_第2页

Design of a Compact Coaxial Magnetized Plasma Gun for Laboratory Studies of Plasma Relaxation 用于等离子体弛豫实验室研究的紧凑同轴磁化等离子体枪的设计

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346234

Y. Zhang, A. Lynn, C. Watts, M. Gilmore, S. Hsu

{"title":"Design of a Compact Coaxial Magnetized Plasma Gun for Laboratory Studies of Plasma Relaxation","authors":"Y. Zhang, A. Lynn, C. Watts, M. Gilmore, S. Hsu","doi":"10.1109/PPPS.2007.4346234","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346234","url":null,"abstract":"Summary form only given. We discuss the design of a compact coaxial magnetized plasma gun and its associated systems in detail. The plasma gun will be used for experimental studies of plasma relaxation to be conducted in the HELCAT facility at UNM. These studies will advance our knowledge of basic plasma physics in the areas of magnetic relaxation and space and astrophysical plasmas, including the evolution of active galactic jets. The gun will be powered by a 120 muF ignitron switched capacitor bank which is operated in a range of 5 ~ 10kV. High pressure gas will be puffed into an annular gap between the inner and outer coaxial electrodes. The applied high voltage ionizes the gas and creates a radial current sheet. The ~ 100kA discharge current generates toroidal flux and an external applied magnetic field provides poloidal flux. The axial JxB force ejects plasma out of the gun. If the JxB force exceeds the magnetic tension of the poloidal flux by a sufficient amount then a detached magnetized plasma will be formed. We plan to study the evolution of this plasma \"bubble\" as it interacts with a preexisting lower pressure background plasma.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115475082","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

Comparison of Antibacterial Effect in at Mosphericpressure Plasmas Excited with Fast-Rising Voltage Pulse 快升电压脉冲激励大气压等离子体抑菌效果的比较

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345581

T. Akitsu, H. Murayama, K. Katayama-Hirayama

{"title":"Comparison of Antibacterial Effect in at Mosphericpressure Plasmas Excited with Fast-Rising Voltage Pulse","authors":"T. Akitsu, H. Murayama, K. Katayama-Hirayama","doi":"10.1109/PPPS.2007.4345581","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345581","url":null,"abstract":"Summary form only given. Antibacterial effect was studied in cold plasmas excited by fast-rising voltage pulse. The antibacterial effect was measured on the basis of total mortality and temporal dependence of survived population of micro-organism: spore forming bacteria of Bacillus genera and Aspergillus niger. Control characteristics and antibacterial effect is compared with another type of cold plasma excited by pulse-modulated high-frequency. Notable results in this experiment: 1. Control scheme of plasma homogeneity using fast rising voltage pulse and pulse-modulated high frequency. 2. Antibacterial effect was compared in different experimental conditions using carrier materials, for helium/oxygen mixture and helium/nitrogen mixture. In helium/nitrogen mixture, primary sterilization effect resulted by UV:NO-gamma emitted by NO radical. Antibacterial effect of atmospheric-pressure Townsend-tvpe discharge was evaluated, for Geobacillus stearothermophilus, coated on filter-paper carrier at 6.8x10 CFU. Total sterilization time varied from 30 to 150 sec. around hot-spot, near the discharge region, and 900 sec. around cold-spot. Typical measurement for the shortest D-time constant leveled 10 sec./decade. 3. Antibacterial effect for Bacillus atrophaeus spores at 3.8 x 106 CFU showed total sterilization time, 300 sec. around hot-spot and 900 sec. for cold-spot. Experimental comparison of antibacterial effect is tested using Aspergillus niger spores. Relative strength of the antibacterial effect is discussed for the helium/nitrogen and nitrogen base atmospheric pressure plasma discharge.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116739820","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

Modeling of a Single Element Pulsed Ring-Down Antenna for Implementation in a Phased Array System 相控阵系统中单元件脉冲衰荡天线的建模

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346122

D. Belt, J. Walter, J. Mankowski, J. Dickens

{"title":"Modeling of a Single Element Pulsed Ring-Down Antenna for Implementation in a Phased Array System","authors":"D. Belt, J. Walter, J. Mankowski, J. Dickens","doi":"10.1109/PPPS.2007.4346122","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346122","url":null,"abstract":"Summary form only given. A pulsed ring-down phased array antenna provides substantial energy deposition in the far field region in addition to a broad range main beam with scanning capabilities. This allows remote neutralization of Improvised explosive devices (IEDs) at far field distances and in virtually any direction. The pulsed ring-down antenna operates by charging the single element antenna with a high potential source and closing a switch to develop transient wave reflections on the antenna which then propagate in air. The performance of a pulsed ring-down phased arrav is highly contingent upon the design and performance of the individual antenna elements within the array. Such factors as operating voltage, antenna capacitance, material losses, antenna geometry and closing switch conductance characteristics must be examined for optimal performance to be achieved. By utilizing the Comsol RF module transient analysis functions, we are able to characterize the various parameters beginning with a monopole and a dipole pulsed ring-down antenna operating in the hundreds of MHz range. We have examined and compared the results achieved from the experimental setup to the simulation model in order to better characterize the individual components of the antenna. We have also examined the discrepancies between an ideal closing switch and the experimental setup closing switch, which dramatically affects the far field range of the antenna. We have examined the material properties of the antenna to improve losses and increase system capacitance allowing an increase in the number of RF cycles per antenna discharge. With the results presented, an accurate model of pulsed ring-down antennas is available and will allow future development of more complex geometries that will improve the operation of pulsed ring- down phased array.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116896716","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: 4

Simulating Hypersonic Atmospheric Conditions in a Laboratory Setting using a 6-in-Diameter Helicon Source 使用直径6英寸的螺旋源在实验室环境中模拟高超声速大气条件

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345529

K. Lemmer, A. Gallimore, T.B. Smith, S. Nguyen, D. R. Austin, D. Morris, C. Davis, J. Zagel

引用次数: 3

Simple, Noninvasive and Wide-Band Current and Voltage Sensors for Use with Coaxial Cables 用于同轴电缆的简单，无创和宽带电流和电压传感器

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345675

R. Kumar, B. M. Novae, I. Smith

引用次数: 4

Active Gate Control for Current Balancing in Paralleled IGBT Modules in a Solid State Modulator 固态调制器中并联IGBT模块电流平衡的有源门控制

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346097

D. Bonis, J. Biela, J. Kolar

引用次数: 4

Discrete Pulse Forming Lines for a Compact Pulsed Power Generator 小型脉冲电源发生器的离散脉冲形成线

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345726

L. Caballero B., P. Smith

{"title":"Discrete Pulse Forming Lines for a Compact Pulsed Power Generator","authors":"L. Caballero B., P. Smith","doi":"10.1109/PPPS.2007.4345726","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345726","url":null,"abstract":"Summary form only given. A new design for a 1 MA pulsed power supply to drive a z-pinch is being developed in Oxford. The new design avoids the use of very high voltage Marx generators and water pulse forming lines that are usually used in such designs. It should also be far more reliable and capable of a much higher repetition rate, particularly if the z-pinch channel is preionised using a laser instead of using wires. Thus such a generator would be ideal as a driver for relatively small z-pinches that could act as, for example, a high intensity soft X-ray source. The basic idea is to use many very low impedance pulse forming lines or networks, connected in parallel/series combinations that are DC charged and switched simultaneously on to the z-pinch load. The lines/networks are constructed using either specially shaped tiles of barium titanate ceramics or by using conventional HV ceramic capacitors mounted in such a way as to generate quite square pulses at impedances down to 1Omega or below. This paper will describe the preliminary' tests on a PFN built using 13, 60 kV ceramic capacitors (C = 4 nF). The line impedance is just 0.8 Omega. It has been found that, provided there is sufficient difference in the inductance on either side of the network connections, it will behave as a pulse forming network and produce pulse rise-times of 30 ns with a pulse width of 200 ns or more. At a 50 kV charge such lines will deliver 50 kA into a short circuit so that 20 such lines operating in parallel can deliver the 1 MA required. It is, of course, very important that each line is switched virtually simultaneously and the results of work exploring this issue will be included. So far it has teen possible to synchronise the switch firing jitter to 20 ns without the need to use optical coupling or other techniques to aid the synchronization. Finally the design and testing of a 4 line cross device will be discussed which is a preliminary test generator that is being built prior to construction of a 20 line, 1 MA generator.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125855792","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

A Hybrid Solid State Induction Modulator for klystrons 一种用于速调管的混合固态感应调制器

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346244

J.R.L. Cassel, M. Nguyen, E. Cook, C. Brooksby

引用次数: 1

Interaction Mechanism of a Field Emission Based Terahertz Generator 基于场发射的太赫兹发生器的相互作用机理

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345539

P. Lu, M. Lina

引用次数: 0

A Plasma Microwave Barrier That Opens in Microseconds 在微秒内打开的等离子体微波屏障

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345683

I. Alexeff, T. Anderson, E. Farshi, N. Karnam, E. P. Pradeep, N.R. Pulsani

{"title":"A Plasma Microwave Barrier That Opens in Microseconds","authors":"I. Alexeff, T. Anderson, E. Farshi, N. Karnam, E. P. Pradeep, N.R. Pulsani","doi":"10.1109/PPPS.2007.4345683","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345683","url":null,"abstract":"Summary form only given. Plasma barriers are used to protect sensitive microwave apparatus from potentially damaging electronic warfare signals. Unfortunately, the characteristic decay time of the plasma after power turn-of is typically many milliseconds, so the opening time of such a barrier generally is predicted also to be many milliseconds. However, we have found both experimentally and theoretically that we can open such a barrier on a time scale of microseconds. We do this by increasing the plasma density rather than waiting for it to decay. We have two layers of plasma. We produce a standing wave between the two layers that results in microwave transmission, analogous to the transmission found in an optical Fabry-Perot Resonator. The secret lies in the boundary layer behavior of the plasma. Once microwave cutoff occurs, one would expect the plasma behavior to be static. What actually occurs is that at microwave cut-off, the reflection is in phase with the incident wave, in analogy to an open coaxial line. (The electron and displacement currents are equal, but out-of-phase.) As the plasma density further increases, the reflection smoothly changes from in-phase to 180 degrees out-of-phase, in analogy to a shorted coaxial line. (The electron current is much greater than the displacement current.).","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123435193","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