By Topic

Plasma Science, IEEE Transactions on

Issue 6  Part 2 • Date Dec. 2006

Filter Results

Displaying Results 1 - 22 of 22
  • Table of contents

    Page(s): C1 - 2553
    Save to Project icon | Request Permissions | PDF file iconPDF (35 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Plasma Science publication information

    Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (36 KB)  
    Freely Available from IEEE
  • Radial Variation of Refractive Index, Plasma Frequency and Phase Velocity in Laser Induced Air Plasma

    Page(s): 2554 - 2560
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (554 KB) |  | HTML iconHTML  

    Laser-induced breakdown spectroscopy (LIBS) is a nonintrusive technique that needs no sample preparation and even recently, quantitative measurements were done without the need for calibration standards. Much research has been done on the laser induced air plasma to study the spatial variation of plasma parameters in the axial direction of the laser beam. In this paper, we report investigation on the radial variation of the refractive index, plasma frequency, and phase velocity of a plasma during laser induced breakdown of air. The results show that the radial variations of the plasma frequency and refractive index are caused by the radial electron density gradient of the plasma. The radial variation of the electron density shows a noticeable depletion at the center of the focus which results in plasma phase velocities greater than the speed of light. Further from the plasma core the electron density diminishes to ambient density at the edges of the plasma. The mean full-width at half maximum (FWHM) for these plasma profiles was found to be about 1.2 mm. The results further reveal that the plasma has a concave parabollic electron density and a convex parabollic refractive index profile near the center of the laser axis, i.e., around a diameter of 0.5 mm View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modulational Instability of a Self-Guided Laser in a Magnetized Plasma Channel

    Page(s): 2561 - 2567
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (165 KB) |  | HTML iconHTML  

    A self-guided laser propagating in a plasma channel in the direction of static magnetic field is unstable to a plasma wave perturbation comoving with the laser with its group velocity. The plasma wave amplitude has a radial profile with a maximum on the axis. As the plasma wave propagates, it causes focusing of the part of the laser that propagates with the electron density trough and defocusing of the part moving with the crest. This creates an axial gradient in the intensity of the laser, exerting a ponderomotive force on the electrons that drive the plasma wave, which leads to the growth of the instability. The growth rate is enhanced as laser frequency approaches the electron cyclotron frequency. The azimuthal magnetic fields have weaker effect on the modulational instability View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of Impurities on the Exclusive Parameters of Plasma-Focus Dena

    Page(s): 2568 - 2571
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (154 KB)  

    Fusion performance of a plasma-focus is negatively affected by the presence of impurities that originated from the countereffect of the current sheath and the electrodes, which lower the plasma temperature and dilute the reacting deuterons. The experimental results of the Filippov-type plasma-focus Dena (90 kJ, 25 kV, and 288 muF) demonstrate the profound influence of anode insert materials on the exclusive parameters of the device. The spike depth, the average of the second derivative of current Vimp, and the hot spots are the parameters that clearly display the effect of impurities on the pinch structure and consequently the radiations emitted from the compressed region View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hydrodynamic Investigations of Intense Subpicosecond Laser–Matter Interaction

    Page(s): 2572 - 2578
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (535 KB) |  | HTML iconHTML  

    A model for the interaction of a short laser with matter is presented. The model is based on the solution of wave-propagation equations in a medium with complex dielectric constant. The model is coupled with multigroup radiation hydrodynamics to take into account the space and time evolution of plasma parameters. The complete code is used to analyze various experiments with laser pulse duration varying from 150 fs to 5 ps and laser intensity varying from 1012 W/cm2 to 1017 W/cm2. The model is also used to study the enhancement in absorption with prepulse View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of Voltage Distribution Among Three Electrodes on Microdischarge Characteristics in AC-PDP With Long Discharge Path

    Page(s): 2579 - 2587
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1897 KB) |  | HTML iconHTML  

    The effect of the three-electrode voltage distribution on the microdischarge characteristics of an ac-PDP with a long discharge path (400 mum) is investigated. It is found that the auxiliary pulse applied to the address electrode, which participates in the trigger discharge, plays a key role in lowering the sustain voltage in the long discharge path by both providing the priming particles to generate the main discharge and accumulating more wall charges with the proper polarity to help the next discharge. In particular, the amplitude and width of the auxiliary pulse are very important parameters in a large sustain gap structure, as they are related to both the electron channeling that bridges the long discharge path and the accumulation of wall charges on the sustain electrodes. Thus, the effect of the width and amplitude of the auxiliary short pulse on the discharge characteristics, such as a low sustain voltage, the luminance, and luminous efficiency, are extensively investigated. As a result, the existence of a proper width and amplitude for the auxiliary pulse to lower the sustain voltage is observed, thereby also improving the luminous efficiency View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Generation of Surface-Treating Plasma by a Superadiabatic Compression Ballistic Plasmatron

    Page(s): 2588 - 2593
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (186 KB) |  | HTML iconHTML  

    The concept of fast high-temperature surface processing (FHTSP) different materials by using compressed homogeneous dense plasma, produced by superadiabatic gas compression in a ballistic plasmatron (BP), is developed. The theory of the superadiabatic compression BP was developed and the experimental installation was created. It is shown that dense plasma can be generated with unique parameters: the temperature more than 10000 K under the compression pressure up to 1000 atm. This plasma is capable of emitting the powerful radiation flux providing the surface energy density up to 80 J/cm2. This radiation flux can be used for surface treatment. The advantages of new technology are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spatial and Temporal Evolution of Laser-Generated Microplasmas

    Page(s): 2594 - 2599
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    A study of the evolution of microplasmas produced on aluminum alloy surface at ambient air pressure by 266-nm 10-ns laser pulses with energies of 3 to 100 muJ (2 to 68 GW/cm2) is carried out. Gated photography with a minimum width of 5 ns is used to investigate the plasma evolution. Plasma emission and plasma distances from the sample surface are investigated as a function of time. Pulse energy has a strong effect on plasma emission particularly at short delay times. The experimental results are compared with a simplified model of plume expansion View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Characterization of Carbon Powder Produced by a Microwave-Plasma Torch at Atmospheric Pressure

    Page(s): 2600 - 2605
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (855 KB)  

    Carbon powder synthesized by an atmospheric microwave-plasma torch is characterized in terms of the mixture ratio of argon to nitrogen in torch gas. Methane as a source of carbon atoms was directly injected into the microwave-plasma torch. The samples deposited on the inner wall of a discharge tube were analyzed by the X-ray diffraction, field-emission scanning electron microscope, field-emission transmission electron microscope, and Fourier transform infrared (FTIR). The synthesized samples showed thornbush-shaped, fingerprintlike, and onionlike structures. It was identified from FTIR data that the samples contain functional groups of very weak C-N, C=N, and CequivN View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of Low-Pressure Microwave Discharges on Pyrogen Bioactivity

    Page(s): 2606 - 2610
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (184 KB) |  | HTML iconHTML  

    The effect of microwave discharge on pyrogen bioactivity has been studied in different oxygen- and hydrogen-containing mixtures with the aim of identifying the crucial depyrogenation agent. According to the obtained biological results and their comparison with properties of the plasma determined by means of optical emission spectroscopy and Langmuir probe measurements, it has been found that under experimental conditions tested, depyrogenation is not greatly affected by UV radiation or charged particles but is considerably accelerated by the presence of atomic hydrogen View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • In Situ Studies of Emission Characteristics of the DC Thermal Arc Plasma Column During Synthesis of Nano-AlN Particles

    Page(s): 2611 - 2617
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB) |  | HTML iconHTML  

    The growth process of nanoparticles and nanowires of AlN by thermal-plasma-assisted gas phase condensation reaction has been investigated by optical emission spectroscopy. The concentrations of the reacting precursors in the plasma have been correlated to the crystalline phases of nanoparticles of AlN found from X-ray diffraction analysis. The size and morphology of the nanoparticles have been studied by transmission electron microscope investigations of as-synthesized powder at a set of reactor parameters, which included arc current, reactor pressure, and standoffs of the arc column. An attempt has been made to correlate the growth of AlN to that of the precursor density present in the plasma reaction zone View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Killing of Red Tide Organisms in Sea Enclosure Using Hydroxyl Radical-Based Micro-Gap Discharge

    Page(s): 2618 - 2623
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (935 KB) |  | HTML iconHTML  

    A pilot-scale experiment for killing red tide organisms in a sea enclosure was done in Bohai Sea off Dalian City, China, in August 2003. With the physical method of micro-gap gas discharge, an OHmiddot solution of 24.3 mg/L was produced by the ionization of O2 in air and H2O at gas state and then dissolved into one part of seawater. When the OHmiddot concentration was 0.68 mg/L in the sea enclosure, the total kill efficiencies of 26 kinds of red tide organisms reached 99.8%, in which the bacterium and vibrio were reduced below the detection limit, meanwhile Gonyaulax cysts and Prei. Cysts with the cell crust were decreased to under the test limit. In addition, the content of chlorophyll-a was decreased below the test limit. The dissolved oxygen saturation of seawater was greatly increased to 430%. Therefore, the treatment of red tide using OHmiddot radicals is a kind of advanced oxidation technology, which realizes zero pollution, zero emission, and zero residual View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Degradation of Organic Contaminant by Using Dielectric Barrier Discharge Reactor Immersed in Wastewater

    Page(s): 2624 - 2629
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (187 KB) |  | HTML iconHTML  

    Dielectric barrier discharge (DBD) was applied to the degradation of an organic contaminant in wastewater. When electrical discharge occurs, the DBD reactor produces oxidative species (ozone) and emits ultraviolet light. For the purpose of using both ozone and ultraviolet light for the degradation of the organic contaminant, the DBD reactor was immersed in the wastewater. The DBD reactor for this paper consisted of a quartz cylinder and a coaxial ceramic tube inside of which a steel rod was placed. High voltage was connected to the steel rod inside of the ceramic tube, and the wastewater was grounded. In this case, the wastewater acted not only as an electrode but also as the cooling medium for the DBD reactor. The performance of this DBD reactor system was evaluated with a simulated wastewater formed with distilled water and an azo dye (Acid Red 27) as the organic contaminant. The experimental results showed that this system was able to completely degrade the organic contaminant within 20 min at typical experimental condition. The energy requirement for the degradation of the organic contaminant was found to be 0.654 kJ/mg View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inactivation Effects of PEF on Horseradish Peroxidase (HRP) and Pectinesterase (PE)

    Page(s): 2630 - 2636
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    The effect of pulsed electric fields (PEFs) applied on the enzymes horseradish peroxidase (HRP) and pectinesterase (PE), which widely exist in vegetable and fruit juices, was investigated using chambers with paralleled plane electrode and coaxial cylinder electrode, respectively. The experimental results show that the relative activity of HRP and PE decreased after PEF treatment. Inactivation effect of HRP and PE increased with the increase of the applied electric strength and the number pulses. HRP activity decreased 14.4% and 16.7% in the parallel-plane chamber and the coaxial cylinder chamber, respectively, at 207 pulses of 25 kV/cm, while a 17 (coaxial) and 16.46 (plane) reduction, respectively, was attained for PE under the same experimental condition. Inactivation effect of HRP and PE in the chamber with coaxial-cylinder-electrode configuration was better than the parallel-plane electrode. The circular-dichroism analysis showed that PEF treatment caused a loss of alpha-helix and change of the secondary-conformation structure of HRP enzyme. The fluorescence intensity of both enzymes also changed after PEF treatment, indicating that conformation changes occur in the local structure of the enzyme molecule View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental Study of Laser-Initiated Radiofrequency-Sustained High-Pressure Plasmas

    Page(s): 2637 - 2651
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1090 KB)  

    Experiments are performed using 193-nm ultraviolet laser preionization of a seed gas in atmospheric pressure range argon and nitrogen to initiate a discharge that is sustained by 13.56-MHz radiofrequency (RF) power using efficient inductive wave coupling. High-density (4.5times1012/cm3 line average density) large-volume (~500 cm3) 760-torr argon plasma is initiated and maintained for more than 400 ms with 2.2 kW of net RF power coupled to the plasma. Using the same technique, a 50-torr nitrogen plasma with line average electron density of 3.5times1011/cm3 is obtained. The nitrogen plasma volume of 1500 cm3 is initiated by the laser and maintained by a net RF power of 3.5 kW for 350 ms. Measurements of the time-varying plasma impedance and optimization of the RF matching for the transition from laser-initiated to RF-sustained plasma are carried out. Both laser-initiated plasmas provide much larger plasma volumes at lower RF power densities than can be obtained by RF alone. Millimeter wave interferometry is used to determine the electron density and the total electron-neutral collision frequency. A new diagnostic technique based on interferometry is developed to evaluate the electron temperature in high-pressure plasmas with inclusion of the neutral heating. Broadband plasma emission spectroscopy is used to illustrate the changes in the ionized species character immediately after the laser pulse and later during the RF pulse View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power Flow in a Magnetically Insulated Recyclable Transmission Line for a Z-Pinch-Driven Inertial-Confinement-Fusion Energy System

    Page(s): 2652 - 2668
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (900 KB) |  | HTML iconHTML  

    Power flow in a recyclable transmission line (RTL) for a z-pinch-driven inertial-confinement fusion energy (IFE) system is studied. In a magnetically insulated transmission line, plasma forms by explosive emission on the cathode but emission from the anode does not occur. However, in an RTL, the large linear current density that flows in the electrodes at small radius near the load resistively heats the anode surface, leading to anode plasma formation and ion emission. If the impedance of the RTL is too small, large ion current losses can occur and large electron flow currents can be launched into the z-pinch load region. If only the boundary current drives the z-pinch load, then these large electron flow currents can introduce a polarity effect with more bound current in the anode than the cathode. While being mindful of the IFE system requirement to maintain a small RTL inductance, these problems are avoided by choosing the line impedance at the load end of the RTL to be well above the effective impedance of the imploding load. In this case, the ion current losses are tolerable and the electron flow current is negligibly small. For the present baseline design with a peak current of 60 MA driving a 100-ns implosion, these power flow constraints require a gap of order 2 mm or more at the load end of the RTL View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical Simulation on Performance of Disk MHD Generator in the Closed-Loop Experimental Facility

    Page(s): 2669 - 2677
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (678 KB) |  | HTML iconHTML  

    A time dependent two-dimensional numerical simulation has been carried out in order to clarify the magnetohydrodynamic (MHD) flow behavior and performance of a disk MHD generator installed in a new closed-loop experimental facility at the Tokyo Institute of Technology. The numerical investigation is not limited to the generator channel only, but also includes an inlet duct and a downstream 90deg-bend diffuser. A set of possible generator inlet-outlet pressure ratio (PR) was selected, and the influence on flow physics and generator performance was examined. Maximum enthalpy extraction (EE) ratio was obtained at high PR. In this case, an oblique shock wave appeared in the 90deg-bend diffuser for both non-MHD and MHD flow regimes. The EE, however, did not vary monotonically with the PR. Rather a local minimum point for the EE was observed at moderate PR. In this case, either an oblique shock wave or a normal shock wave would appear in the generator channel depending upon whether the flow was in the non-MHD or MHD regime. The results predicted in the present simulation are valuable and important for setting the working gas conditions and evaluating generator performance in the closed-loop power generation experiment View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Special issue on megagauss magnetic fields: Production and application

    Page(s): 2678
    Save to Project icon | Request Permissions | PDF file iconPDF (460 KB)  
    Freely Available from IEEE
  • 2006 Index

    Page(s): 2679 - 2736
    Save to Project icon | Request Permissions | PDF file iconPDF (607 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Plasma Science Information for authors

    Page(s): C3
    Save to Project icon | Request Permissions | PDF file iconPDF (35 KB)  
    Freely Available from IEEE
  • Affiliate Plan of the IEEE Nuclear and Plasma Sciences Society

    Page(s): C4
    Save to Project icon | Request Permissions | PDF file iconPDF (16 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)