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Plasma Science, IEEE Transactions on

Issue 6 • Date Dec. 2007

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Displaying Results 1 - 25 of 29
  • Table of contents

    Publication Year: 2007 , Page(s): C1 - 1685
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    Freely Available from IEEE
  • IEEE Transactions on Plasma Science publication information

    Publication Year: 2007 , Page(s): C2
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    Freely Available from IEEE
  • Editorial

    Publication Year: 2007 , Page(s): 1686 - 1690
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    Freely Available from IEEE
  • Simulation of Gas-Phase Kinetics in CHF3:H2: O2 Mixtures

    Publication Year: 2007 , Page(s): 1691 - 1703
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (441 KB) |  | HTML iconHTML  

    A gas-phase reaction model for and mixtures was developed. Self-consistent electron impact cross-section set for was introduced. The original total and partial dissociation cross sections were received. A developed gas-phase kinetic scheme was tested on the experimental data. An important role of the chain reactions in the kinetics of F and H atoms and radicals was revealed. View full abstract»

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  • Inducing Mechanism of Electrohydrodynamic Flow by Surface Barrier Discharge

    Publication Year: 2007 , Page(s): 1704 - 1709
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (424 KB) |  | HTML iconHTML  

    An asymmetric surface-barrier discharge induces a unidirectional gas flow of several meters per second near the electrodes. The mechanism of how the discharge induces the gas flow is investigated experimentally by changing the electrode configuration from asymmetric to symmetric. The peak values of the discharge current and the discharge patterns depend on the polarity of the applied voltage in the asymmetric electrode configuration. When the exposed electrode is an anode (negative-going cycle), positive streamers extend over the dielectric above the buried electrode, and relatively large discharge current pulses flow. The momentum transfer from positive ions to neutral molecules occurs at the head of the streamers, where the electric field is strongest. Thus, the surrounding air is pushed with the extension of the streamers. When the exposed electrode is a cathode (positive-going cycle), a weak light emission is uniformly observed above the buried electrode. This light emission results from the electron impact excitation of gas molecules; thus, it does not indicate movements of the positive ions. Therefore, the momentum transfer during the negative-going cycle is dominant, and the unidirectional gas flow is induced in the direction of the extension of positive streamers. View full abstract»

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  • On the Dynamics of the Plasma Entry and Guiding in a Straight Magnetized Filter of a Pulsed Vacuum Arc

    Publication Year: 2007 , Page(s): 1710 - 1716
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (230 KB) |  | HTML iconHTML  

    In this paper, a study of the plasma jet generated in a pulsed copper vacuum arc along a straight magnetized filter is presented. The ion saturation current and the plasma potential at different radial and axial positions and magnetic field intensities were measured using electrostatic probes. A theoretical model was developed to understand the dynamics of the plasma entry and guiding in the filter. This model takes into account magnetic field variations and Gaussian ion radial profiles. An analysis of the experimental results with the theoretical model shows that, in our device, as the magnetic field intensity increases along the filter, the plasma motion evolves from a radial compression with a low rotational velocity at the filter entrance to a rotating jet guided along the duct. View full abstract»

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  • Flow Dynamics of Ions Generated by Laser-Blow-Off of LiF-C Film

    Publication Year: 2007 , Page(s): 1717 - 1723
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (210 KB) |  | HTML iconHTML  

    The flow dynamics of ejected ions generated by the laser-blow-off of a multicomponent LiF-C thin film deposited on a quartz substrate has been studied using the charge collector probe technique. The spatial distributions of ions were analyzed in different ambient environments ranging from high vacuum to 0.2 mbar of argon pressure and at various laser fluences varying from 2.8 to 26 J/cm2. In vacuum, a double peak structure was observed in the temporal profile of the ion signal at low laser fluence, which slowly transformed into a single peak with increasing laser fluence. The observed plume splitting in vacuum as well as in background gas is interpreted by the formation of ions by two different mechanisms that can produce two different velocity distributions. Present findings at a large collector to target distance, d = 70 mm was found to be consistent with our previously reported optical emission spectroscopic results at a relatively small distance (d = 12 mm). View full abstract»

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  • Switching Characteristics of Large-Aperture Electro-Optical Switches With Plasma Electrodes Part I—Model

    Publication Year: 2007 , Page(s): 1724 - 1728
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (455 KB) |  | HTML iconHTML  

    Optical switches with plasma-electrode Pockels cells (PEPCs) are important elements for large-aperture multipass laser amplifiers in inertial-confinement fusion. In this paper, we present a fluid model for a one-pulse process of the PEPC, in which the preionization discharge and the stable discharge plasma are achieved in one pulse. Multiple species including electrons, atomic ions, molecular ions, excited atoms and excited molecules and the energy exchange between the electrons and other species are considered in the model. Under the same condition of discharge, the calculation for two-specie and five-species are implemented and the results showed that the density of electrons in the stable glow discharge of the PEPC by the model of five species is 2%~3% higher than that of the two species model. View full abstract»

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  • Switching Characteristics of Large-Aperture Electro-Optical Switches With Plasma Electrodes Part II—Comparison With Experiment

    Publication Year: 2007 , Page(s): 1729 - 1732
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB) |  | HTML iconHTML  

    The large-aperture optical switches with plasma-electrode Pockels cell (PEPC) are important elements for the multipass laser amplifiers in the inertial-confinement fusion. In this paper, an optical switch of the PEPC driven by one-pulse process (OPP) is simulated by using a fluid model developed in a previous paper. We computationally study the physical processes of the discharge evolvements and discharge fading away in the large-aperture PEPC switches driven by the OPP. Charging on the surfaces of potassium dihydrogen phosphate crystal in the discharge determines the switching characteristics of the PEPC. The simulation results nearly coincide with the experimental measurement. View full abstract»

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  • Fundamentals of Capacitance Property in Tokamak

    Publication Year: 2007 , Page(s): 1733 - 1737
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (138 KB) |  | HTML iconHTML  

    The capacity of tokamak plasma is derived using a coaxial-torus capacitor property. The value of this capacitance is significant for tokamaks and dramatically high for the International Thermonuclear Experimental Reactor. Therefore, tokamak plasma will play important roles in time varying regimes (like current ramp-up), transient regimes, edge related phenomena, and many other different. This quantity may be incorporated in circuit equations and transport codes for use in exact simulations of plasma behavior. Because this capacitance property of tokamak produces a radial electric field, it would be of considerable interest. View full abstract»

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  • Investigation of a Dynamic Corona to Normal Glow Transition in a Neon Gas Diode

    Publication Year: 2007 , Page(s): 1738 - 1742
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (215 KB) |  | HTML iconHTML  

    The development of the spatial distribution of the emitted lights from a gas diode during the positive corona to normal glow discharge transition is investigated. The diode consists of a rod anode and a cylinder cathode and is filled with neon at a pressure of 1.33 mbar. Investigations are performed both in the dynamic and stationary regimes. In the dynamic regime, the slowly increasing voltage is applied to the diode, and the time development of the emitted light from the different positions in the diode is measured. In the stationary regime, the slowly increasing applied voltage is restituted with the stepping voltage, which allowed a series of stationary regimes with different values of current to be established (from 5 nA to 10 muA). The intensity of the emitted light from the different positions in the diode along the diode axes is measured by a scanning technique, starting from the anode up to the space behind the cathode with a 0.1-mm precision. These distributions are compared with the corresponding photographic records of the emitted lights from the diode to confirm the spatial distributions of the emitted lights. The results of these investigations show that the light emission for the smallest detected current (from 5 to 100 nA) is ordinate near the anode surface and that this kind of discharge should be defined as the positive corona. With the increase in the current, the conduction channel to the cathode is made because of the discharge transfer from the corona to the normal glow for current values of about 1 muA. The real-time measurement shows that, in the present condition, corona appears and vanishes in about 2 ms and that the transition to the stationary normal glow is about 10 ms. The increase in the emitted light that was detected corresponds to the second and third stages of the normal glow discharge formation in the gas diode when the initial breakdown channel appears, grows, and changes up to the final stationary discharge regime. View full abstract»

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  • Optimization of Quasi-Optical Launchers for Multifrequency Gyrotrons

    Publication Year: 2007 , Page(s): 1743 - 1746
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (408 KB) |  | HTML iconHTML  

    Recent techniques that were developed for the synthesis of mode converters in quasi-optical launchers for single-frequency gyrotrons have been applied to the optimization of launchers for multifrequency gyrotrons. Using those techniques, a significant performance enhancement of a multifrequency launcher can be obtained. View full abstract»

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  • Mirror Design for Use in Gyrotron Quasi-Optical Mode Converters

    Publication Year: 2007 , Page(s): 1747 - 1757
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (457 KB) |  | HTML iconHTML  

    An iterative planar- and cylindrical-based mirror design procedure is discussed for use in a gyrotron quasi-optical mode converter. The planar-based mirrors were designed using the iterative Katsenelenbaum-Semenov phase corrector procedure with an input beam obtained from a planar phase reconstruction. Many improvements were made to the design procedure including the use of an advanced phase unwrapping technique. The more robust design procedure resulted in smooth mirror surfaces. It was found that the fraction of power coupled between the target beam and the output of the planar-based mirrors measured in a cold test setup was 0.982. A similar design process was used for a cylindrical-based mirror pair. This design was performed using a simulated output of the launcher. It was found that the fraction of power coupled between the target beam and the theoretical output of the system was 0.990. The fraction of power coupled between the target beam and the phase-reconstructed beam at the output of the second mirror was 0.961. By using a cylindrical phase reconstruction, it was found that the reason for the slightly degraded performance of the cylindrical-based mirrors tested in the low power test setup was due to inaccuracies in modeling the field radiated from the launcher. These inaccuracies are presumed to come from impurities in the mode generator. The techniques discussed in this article can be used to improve the efficiency of quasi-optical mode converters and thus improve the operation of gyrotrons. View full abstract»

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  • Magnetically Assisted Transferred Plasma Torch Applied to Vitrification of Ceramic Clay

    Publication Year: 2007 , Page(s): 1758 - 1765
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (790 KB) |  | HTML iconHTML  

    A new magnetically assisted transferred plasma torch (MA-TPT) was specially developed for the treatment of ceramic clay and harmful substances. The electrical plasma source consists mainly of a power buck converter and an alternating magnetic field, which allow sustaining a highly efficient plasma discharge at different arc lengths. The interaction of the electric arc with the magnetic field produces a broadening arc effect on the anode, enhancing the heat fluxes to the ceramic clay. Electrical and thermal characterization of the plasma torch showed that high thermal efficiency is easily reached with the current plasma configuration. In turn, the characterization tests of the vitrified clay revealed that the final vitrified product presents good chemical stability. View full abstract»

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  • Analysis on Discharge Modes in AC Plasma Display Panel With Sustain Gap of 200 μm

    Publication Year: 2007 , Page(s): 1766 - 1774
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1800 KB) |  | HTML iconHTML  

    The Vt close-curve measurement shows that there exists a surface (X-Y) discharge contour in spite of a large sustain gap of 200 mum greater than a barrier rib height of 125 mum. This indicates that there are two different discharge modes, i.e., one mode is to produce the surface discharge, and the other is to produce the surface discharge including the plate gap discharge. The two discharge modes are examined and analyzed based on the Vt close-curve movement on the cell voltage plane. The two discharge modes show the different discharge characteristics such as the sustain voltage level, Vt close-curve behavior, luminance, and luminous efficiency. In addition, the spatial wall charge, electron density behaviors, and their current flows as a function of time are investigated in detail using the numerical analysis. View full abstract»

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  • High Luminous Efficacy Characteristics of Long Gap Structure AC Plasma Display Panel With Self-Ignition Electrodes

    Publication Year: 2007 , Page(s): 1775 - 1780
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (449 KB) |  | HTML iconHTML  

    A long gap structure alternating current plasma display panel (ac PDP) with ignition electrodes is suggested, and its luminous characteristics are investigated. The operation voltages of the long gap structure PDP can be reduced with the help of ignition electrodes. Luminance and luminous efficacy are improved compared with those of an ac PDP with electrodes having the conventional short discharge gap. The luminance and luminous efficacy of the suggested structure can be further improved by applying address auxiliary pulses synchronized with the sustain pulses. The detailed current waveform analysis suggests that the application of address auxiliary pulse changes the discharge current ratio between the long gap electrodes to the ignition electrodes. By increasing the address auxiliary pulse voltage to a certain extent, the luminous efficacy increased along with the discharge current ratio. It has been also observed that when the width of the long gap discharge electrode is increased, the dynamic voltage margin increased accordingly. View full abstract»

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  • Two-Dimensional and Three-Dimensional Simulation of DC Plasma Torches

    Publication Year: 2007 , Page(s): 1781 - 1786
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB) |  | HTML iconHTML  

    Two-dimensional modeling of non-transferred dc plasma torches have been performed using an axis symmetric geometrical configuration and boundary conditions. A control volume approach and SIMPLER algorithm is used to solve the governing equations for mass, momentum, and energy conservation coupled with the electric and magnetic fields. The results are compared with the ones obtained in 3-D simulation works of the authors. Results show substantial difference in control parameters as calculated from the two simulations, owing to local attachment of the arc over the anode surface. View full abstract»

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  • The Delay and Jitter Characteristics of Laser-Triggered Multistage Switch: A Parametric Study

    Publication Year: 2007 , Page(s): 1787 - 1790
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (165 KB) |  | HTML iconHTML  

    The dependence of delay and jitter of a 200-kV laser-triggered multistage multichannel switch on the experimental parameters is reported. The experimental results are explained by a 0-D model in which the delay of the laser-triggered gap is calculated by a ldquo2-2rdquo model and the delay of the self-fired gaps is calculated by Martin's formula. The delay and the jitter decrease with the increase of energy of laser pulse, voltage, and pressure or the decrease of the percentage SF6 in SF6-N2 in mixtures. The delay of 200-kV switch is less than 28 ns, and the jitter is less than 1 ns. View full abstract»

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  • Loss Characteristics of a Magnetic Core for Pulsed Power Applications

    Publication Year: 2007 , Page(s): 1791 - 1796
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (796 KB) |  | HTML iconHTML  

    A low-inductance circuit has been fabricated in order to investigate loss characteristics of the magnetic cores under fast pulse magnetization. The B-H curves have been derived from the measured voltage and current waveforms, and the losses of the magnetic cores have been derived using a novel method to determine time to saturation. The derived B-H curves show the following characteristics: a high ratio of unsaturated to saturated permeability (muun/musat), a maximum flux swing of about 2.5 T, a high ratio of remanent flux density to saturation magnetic flux density (Br/Bs), and a low core loss. Furthermore, the core loss increases as the charging energy increases for a fixed capacitance, which means that the core loss is inversely proportional to the time to saturation, whereas the percentile core loss decreases as the charging energy increases. The hysteresis loss is proportional to frequency, and the eddy current loss can be neglected for the used core. The dissipated energy during core saturation is consistently 3.0% of the charging energy for each frequency, which indicates that the core is saturated and behaves as an air core. View full abstract»

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  • Time History and Spectra of the Light Emitted by Multimegavolt Water Switches

    Publication Year: 2007 , Page(s): 1797 - 1804
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (921 KB) |  | HTML iconHTML  

    We study the physics of water switching at 4 to 5 MV as part of Sandia's Z-Refurbishment program. We present time histories of the light emitted by two sets of water switches and correlate the light emission to the accelerator power pulse. Framing camera images demonstrate how the initial "bushy" streamers collapse to narrow current channels at late time. Spectroscopy of the water switches indicates that the early-time streamers are already hot-dense blackbodies with temperatures between 7000 K and 9000 K. Late time hydrogen emission lines allow estimates of electron densities at that time ranging from 0.2 to 2 times 1018/cm3. View full abstract»

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  • A Note on the Possibility of Generating a Dense Dusty Plasma Liquid

    Publication Year: 2007 , Page(s): 1805 - 1808
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (94 KB) |  | HTML iconHTML  

    Recently, there has been interest in the properties of strongly coupled dusty plasmas in the liquid phase. Here, we consider theoretically a possible way to generate and detect a dense dusty plasma liquid. The idea is to use noble metal submicron dust particles and detect the dust by scattering at the surface plasmon resonance frequency of the dust. Parameters that may be relevant to possible laboratory dusty plasma experiments are discussed. View full abstract»

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  • Special issue on Laser and Plasma Accelerators (August 2008)

    Publication Year: 2007 , Page(s): 1809
    Save to Project icon | Request Permissions | PDF file iconPDF (120 KB)  
    Freely Available from IEEE
  • Special issue on Advances in Plasma Processing for Semiconductor Manufacturing

    Publication Year: 2007 , Page(s): 1810
    Save to Project icon | Request Permissions | PDF file iconPDF (114 KB)  
    Freely Available from IEEE
  • 2007 Index IEEE Transactions on Plasma Science Vol. 35

    Publication Year: 2007 , Page(s): 1811 - 1845
    Save to Project icon | Request Permissions | PDF file iconPDF (412 KB)  
    Freely Available from IEEE
  • Leading the field since 1884 [advertisement]

    Publication Year: 2007 , Page(s): 1846
    Save to Project icon | Request Permissions | PDF file iconPDF (217 KB)  
    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Plasma Sciences focuses on plasma science and engineering, including: magnetofluid dynamics and thermionics; plasma dynamics; gaseous electronics and arc technology.

 

 

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Steven J. Gitomer, Ph.D.
Senior Scientist, US Civilian Research & Development Foundation
Guest Scientist, Los Alamos National Laboratory
1428 Miracerros Loop South
Santa Fe, NM  87505  87505  USA
tps-editor@ieee.org
Phone:505-988-5751
Fax:505-988-5751 (call first)