2007 IEEE 34th International Conference on Plasma Science (ICOPS)最新文献_第8页

Growth of Gaussian Spikes on Gaussian Laser Beam in a Plasma with Relativistic Nonlinearity 具有相对论非线性的等离子体中高斯激光束高斯尖峰的生长

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346088

A. Singh, T. Gill

引用次数: 0

Coordinated Observations of High Power Interactions with the High Latitude Ionosphere 与高纬度电离层高功率相互作用的协调观测

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346307

P. Bernhardt, B. Watkins, B. Bristow

{"title":"Coordinated Observations of High Power Interactions with the High Latitude Ionosphere","authors":"P. Bernhardt, B. Watkins, B. Bristow","doi":"10.1109/PPPS.2007.4346307","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346307","url":null,"abstract":"The High Frequency Active Auroral Research Program (HAARP) transmitter in central Alaska changes the properties of the F-region with transmissions of high power radio waves that reflect in the ionosphere. Simultaneous measurements of radar scatter from plasma waves, radar scatter from field aligned irregularities, and radio wave spectra near the HF pump wave frequency provide a clear picture of the radio wave interactions. The HAARP F-region diagnostics are (1) Modular IJHF Ionospheric Radar (MURI), (2) Dual Auroral Radar Network (SuperDARN), and (3) Stimulated Ionospheric 1 {missions Radio Receiving Array (SIKRRA). The MUIR incoherent scatter plasma line spectra are produced by Langmuir waves driven by the HF pump. The plasma line is initially intense with a decay associated with formation of field aligned irregularities (FAFs) that absorb the electromagnetic HF before reaching the reflection altitude. Consequently the growth of SuperDARN radar backscatter from FAI is coincident with the decay of the HF induced plasma lines, the independent SIERRA diagnostic of stimulated electromagnetic emissions (SHE) measured with ground receivers show a decay of a down-shifted spectral feature associated and a formation of a weak broad continuum. The temporal history of the radar and SEE data are being analyzed to provide a complete understanding of nonlinear interactions of high power EiM wave in the ionospheric over HAARP.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"12 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":"123623772","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

A Laser Triggered High Pressure Gas Switch for Microwave Compression 微波压缩用激光触发高压气体开关

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345493

K. Gan, Tianhui lie, Peng Zhang, L. Shan, Heping Hu, Ming Li

{"title":"A Laser Triggered High Pressure Gas Switch for Microwave Compression","authors":"K. Gan, Tianhui lie, Peng Zhang, L. Shan, Heping Hu, Ming Li","doi":"10.1109/PPPS.2007.4345493","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345493","url":null,"abstract":"Summary form only given. Microwave compression is very effective approach to get high power microwave output. Microwave compression system includes primary microwave generation system, resonation cavity and switches. The self breakdown gas switch is applied in our microwave compression experimental system, although the microwave compression system can output very high power microwave pulse, but the fluctuation of the power of the output microwave pulse is very large, furthermore, it operates unstable, the main reason of the fluctuation is the difference of the onset electrical field of the high pressure gas breakdown. In order to get almost same microwave power output and operate reliably, a laser triggered high-pressure gas switch was proposed to replace the self-breakdown high-pressure gas switch in the microwave compression system. The laser triggered high pressure gas switch uses the fourth double frequency light of the 1064um laser to trigger the high pressure N;/SF6 gas in the rectangular resonator, and then rectangular resonator radiate the high power microwave. The design of the laser triggered high pressure gas switch is described in detail and the its experimental results were also discussed in the article, and finally, the we discuss the difference of the laser triggered gas switch in RF field and DC field.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"49 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":"121951422","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

2D R-Z Simulations for SPHINX Experiments - Numerical Study of Axial Inhomogeneities in the Ablation Process of Wire Arrays SPHINX实验的二维R-Z模拟-导线阵列烧蚀过程中轴向不均匀性的数值研究

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345701

J. Grunenwald, F. Hamann, H. Calamy

{"title":"2D R-Z Simulations for SPHINX Experiments - Numerical Study of Axial Inhomogeneities in the Ablation Process of Wire Arrays","authors":"J. Grunenwald, F. Hamann, H. Calamy","doi":"10.1109/PPPS.2007.4345701","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345701","url":null,"abstract":"Summary form only given. On shot #543 the SPHINX machine based on microsecond LTD technology was used to implode a nested tungsten wire array with 140-74 mm outer-inner diameters, 144-90 (outer-inner) 4 mum W wires and 5 cm height. The maximum current was 4.2 MA and the implosion time (time of maximum of first X-ray peak) was 783 ns. An axial inhomogeneity of the implosion occurs in this shot and impacts the radiation output. Shot #543 was interesting because visible 2D images clearly show the formation of a precursor pinch growing from the anode to the cathode, creating a big upper bubble. This effect is seen on many shots even with aluminum wires but is less impressive that the one observed on shot #543. In this presentation we try to explain this phenomenon by a continuous variation of wire ablation velocity from the anode to the cathode (Vabl=Vabl(z)) using the model\" that links the mass rate and the inverse of Vabl(z). As a consequence, if Vabl(anode) is higher, the precursor pinch will appear first near the anode and then will grow from bottom to top and if Vabl(cathode) is lower, the wire ablation will end sooner so the implosion will start sooner as well. Numerical simulations of this shot presented here was done with Marple2D (Fortran version), a 2D(r,z) MHD code developed by IMM (Moscow). These MHD simulations allow us to quantify possible variations of Vabl(z) in order to fit experimental results. 2D simulations are shown, a relation between Vabl and the physical velocity of the plasma front is given and the implementation in this code of the mass injection law is explained. The link between Er(z) (radial electric field) and Vabl(z) and the issue of simulating in the proper way the interaction between the precursor plasma and the inner array are also discussed.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"30 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":"125983459","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

Improved Method for Embedded Object Detection and Reconstruction Through Near-Field Pulse Imaging Techniques 基于近场脉冲成像技术的嵌入式目标检测与重建改进方法

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345758

S. Tantong, B. Camps-Raga, P. Kirawanich, N. Islam

{"title":"Improved Method for Embedded Object Detection and Reconstruction Through Near-Field Pulse Imaging Techniques","authors":"S. Tantong, B. Camps-Raga, P. Kirawanich, N. Islam","doi":"10.1109/PPPS.2007.4345758","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345758","url":null,"abstract":"Summary form only given. Near-field imaging offers certain advantages over other methods, specifically in data reconstruction. Because of its short ranges, the near-field experimental setup and antennas for measurements require very little space as compared to larger far-field distances for similar image reconstruction methods. In this paper we describe the application of a near-field, frequency-synthesized microwave pulse, for the detection, imaging and reconstruction of an embedded object. Specifically, we present an alternate detection technique, called single-probe detection and reconstruction (SPDR), which uses a single probe to reconstruct an object's shape and determine its location in two dimensions. The experimental setup of the near-field system consists of a rotating platform and a planar-scanning probe. This setup involves both cylindrical and planar scanning of the target and the processing of the reflected data collected at the single probe detection system. As compared to our previous techniques for which shape reconstruction was only possible when the object was placed at the center of the platform, this new technique provides reconstruction regardless of the location of the object. Once the data has been received and recorded, it is then processed for object reconstruction through time-domain analysis and an in-house developed code.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"206 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":"124629821","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

High-Voltage Generator of Microsecond Pulses 微秒脉冲高压发生器

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345883

I. Vintizenko, A. Mashchenko, V. Yu

{"title":"High-Voltage Generator of Microsecond Pulses","authors":"I. Vintizenko, A. Mashchenko, V. Yu","doi":"10.1109/PPPS.2007.4345883","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345883","url":null,"abstract":"The engineering design, calculations, and computer simulations for the high-voltage generator (HVG) intended for the production of microsecond output voltage pulses of rectangular form at a high repetition rate are presented. The original ideas are suggested for the high-voltage generator. The output pulse is produced by the discharge of several synchronized magnetic pulsed generator (MPG) lines. The application of the saturation chokes with increased linkage values in the several lines of the MPG last compression stage makes possible the delay in switching on to the winding of the high-voltage transformer (HVT). The superposition of the output pulses of several MPG lines enables the formation of the rectangular output pulse of required duration and amplitude at the load. In order to reduce the discharging inductance for getting a steep pulse front, to decrease the weight and dimensions and the possible cost, the HVT is designed according to the principle of linear induction accelerators induction system with multiple-turn windings. Application of magnetic elements allows one to achieve a high pulse repetition rate. Conducted simulation allowed us to determine the elements that limit output parameters, to correct their characteristics, and to adjust the HVG elements for obtaining the pulses of required characteristics: voltage, current, and duration. The proposed concept of the High-Voltage Generator makes possible the realization of up to 1 MV, 1-5 kA, 1 mus, 1 kHz pulse parameters. The quantity of pulses continuously produced at 1 kHz repetition rate is determined by the primary storage capacity, which depends on concrete requirements and can reach several thousands. Such parameters are unique and can be obtained at relatively low weight, size, and cost characteristics. The proper choice of parameters of the last MPG stage elements allows for creating output pulses of special forms: linearly increasing or linearly falling down. Such generators can be applied as modulators for high-power microwave devices of O-and M-types.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"61 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":"124702578","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

From Submicrosecond to Subnanosecond Pulses - Entering a New Domain of Electric Field-Cell Interactions 从亚微秒到亚纳秒脉冲——进入电场-细胞相互作用的新领域

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345780

K. Schoenbach, S. Xiao, J. T. Camp, T. Heeren, J. Kolb, J.A. White, M. Migliaccio, R. Joshi, R. Nuccitelli, S. Beebe, C. Baum, S. Altunc

{"title":"From Submicrosecond to Subnanosecond Pulses - Entering a New Domain of Electric Field-Cell Interactions","authors":"K. Schoenbach, S. Xiao, J. T. Camp, T. Heeren, J. Kolb, J.A. White, M. Migliaccio, R. Joshi, R. Nuccitelli, S. Beebe, C. Baum, S. Altunc","doi":"10.1109/PPPS.2007.4345780","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4345780","url":null,"abstract":"Summary form only given. By reducing the duration of electrical pulses from microseconds into the nanosecond range, the electric field-cell interactions shift increasingly from the plasma (cell) membrane to subcellular structures. Yet another domain of pulsed electric field interactions with cell structures and functions opens when the pulse duration is reduced to values such that membrane charging becomes negligible, and direct electric field-molecule effects determine the biological mechanisms. For mammalian cells, this holds for a pulse duration of less than one nanosecond. In addition to entering a new domain of electric field-cell interactions, entering the subnanosecond temporal range will allow us to use near-field-focusing, wideband antennas, rather than needle or plate electrodes, to generate large pulsed electric fields with reasonable spatial resolution in tissue. Modeling results indicate that electric field intensities of tens (up to perhaps hundreds) of kV/cm with a spatial resolution of a few mm can be generated with prolate-spheroidal reflectors with TEM wave-launching structures, and using state-of-the-art pulsed power technology. In order to study the biological effect of subnanosecond pulses, we have developed a sub-ns pulse generator capable of delivering 250 kV into a high impedance load. The pulse width is approximately 600 ps with a voltage rise of up to 1 MV/ns. The pulses have been applied to B16 (murine melanoma) cells, and the plasma membrane integrity was studied by means of trypan blue exclusion. The results show that temporary nanopores in the plasma membrane are generated, allowing the uptake of drugs or nanoparticles without affecting the viability of the cells.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"10 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":"124810034","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 Laser Trigger System for ZR ZR激光触发系统

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4345944

D. Bliss, W. T. Clark, K. LeChien, J. Maenchen, M. Savage, M. Sceiford, B. Stoltzfus, K. Struve, W. Stygar, J. Woodworth, D. Dalton, P. Wakeland

引用次数: 4

Effects of the Reflector Design on the Flash Lamps Developed for the LMJ 反射镜设计对LMJ闪光灯的影响

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346087

L. Courtois, B. Cassany, P. Eyl, P. Patelli, A. Roques, J. Mexmain, F. Andrieu

{"title":"Effects of the Reflector Design on the Flash Lamps Developed for the LMJ","authors":"L. Courtois, B. Cassany, P. Eyl, P. Patelli, A. Roques, J. Mexmain, F. Andrieu","doi":"10.1109/PPPS.2007.4346087","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346087","url":null,"abstract":"Summary form only given. When operating the LIL, which is the prototype of the LMJ, we have observed an unexpected behaviour of several flash lamps after a few hundreds of shots. A whitening appeared near the anode, constituted of a deposition of SiO2 molecule in the inner part of the quartz tube. An investigation of the performance of these lamps was performed in terms of the emitted spectrum. We have shown that the pollution is not yet enough to affect the pumping efficiency of the lamp: the emitted light is only diffused. Nevertheless, because we need to guarantee their behaviour for thousands of shots, we recently started experiments in order to understand the whitening, and to intent to suppress it. In this paper, we present these studies. In particular, we show that the reflector design has a strong influence on the plasma formation inside the lamp. Photographs of the lamp discharge indicate that the geometry of the system lamp-reflector influences the homogeneity of the plasma. We think that regions where there are high plasma densities contribute to the whitening. We are carrying-on experiments with a full-scale LMJ amplifier prototype to test the new reflector design.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"7 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":"129881229","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

High Voltage Capillary Discharge System for Excitation of Soft X-ray Laser 软x射线激光的高压毛细管放电激励系统

2007 IEEE 34th International Conference on Plasma Science (ICOPS) Pub Date : 2007-06-17 DOI: 10.1109/PPPS.2007.4346273

Y. Sakai, T. Komatsu, M. Watanabe, A. Okino, E. Hotta

{"title":"High Voltage Capillary Discharge System for Excitation of Soft X-ray Laser","authors":"Y. Sakai, T. Komatsu, M. Watanabe, A. Okino, E. Hotta","doi":"10.1109/PPPS.2007.4346273","DOIUrl":"https://doi.org/10.1109/PPPS.2007.4346273","url":null,"abstract":"Summary form only given. Characteristics of high voltage capillary discharge system for the excitation of capillary discharge soft X-ray laser, which has a high step-up ratio of discharge voltage to the charging voltage of primary capacitors, will be reported. The discharge system consists of a 2.2 muF LC inversion generator, a 2:54 step-up transformer, a 3 nF water capacitor, a self triggered gap switch and a load capillary. The LC generator and the pulse transformer are connected through a low stray inductance transmission line of about 400 nH. In addition, the chamber, in which the step-up transformer is set, is filled with 2 atm SF6 gas to increase dielectric strength. Consequently, leakage inductance of pulse transformer is decreased to about 300 nH. The low inductance, which exists between the primary LC generator and the secondary water capacitor, enables the water capacitor to be charged within 2.5 mus without saturation of the core of pulse transformer or much energy loss through the water. With this new system, the obtained step-up ratio of the water capacitor voltage to the initial charging voltage of a capacitor used in the LC generator is about 35. Therefore, when the charging voltage of primary capacitor is 20 kV, the charging voltage of 3 nF water capacitor reaches 700 kV. With this high voltage capillary discharge system, discharge current can be increased to generate high-density and high-temperature long plasma column in order to shorten the wavelength of the laser to EUV range.","PeriodicalId":446230,"journal":{"name":"2007 IEEE 34th International Conference on Plasma Science (ICOPS)","volume":"84 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":"128713350","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