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Plasma Science, IEEE Transactions on

Issue 10  Part 1 • Date Oct. 2010

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Displaying Results 1 - 25 of 47
  • Table of contents

    Page(s): C1 - 2505
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    Freely Available from IEEE
  • IEEE Transactions on Plasma Science publication information

    Page(s): C2
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  • Special Issue on Pulsed Power Science and Technology

    Page(s): 2506
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  • Detailed Simulation of the CYGNUS Rod Pinch Radiographic Source

    Page(s): 2507 - 2513
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1312 KB) |  | HTML iconHTML  

    In this paper, we present the results from particle-in-cell simulations of the nominally 2-MV 40-kA CYGNUS radiographic machine using a standard rod pinch diode. The rod pinch electron-beam diode consists of a small-diameter high-atomic-number anode extending through a thin cathode aperture. A significant shot-to-shot variation of the photon spectrum emerging from the anode can introduce an error in interpreting the radiograph. We present the results from these integrated simulations of the electron and photon generation and quantify the sensitivities on the photon distribution. View full abstract»

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  • Electrostatic Field Simulation Study of Nanoparticles Suspended in Synthetic Insulating Oil

    Page(s): 2514 - 2519
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    Electrostatic field simulations have been performed to investigate the effect of barium strontium titanate (BST) nanoparticle suspensions on electric fields within synthetic oil dielectrics. We predict that by physically integrating nanoparticles of high dielectric constants into the breakdown regime, the self-break jitter in rep-rate oil switches might be reduced. The simulations show that the nanoparticle suspensions generate nonlinear and random electric field enhancements within the oil dielectric and also on the electrode surfaces. The BST nanoparticles have been modeled as perfect spheres which have an approximate dielectric constant of 2000. The oil in the simulation was given a dielectric constant of 2.33 and the electrodes are modeled as perfect electrical conductors with no field enhancements. A comparison is made between simulated electric fields on the surface of the cathode with increasing nanoparticle concentration, radius, and distance from cathode. Effects on capacitance with increasing nanoparticle concentration and radii are also investigated. All electrostatic simulations were performed with CST EM Studio. Preliminary experimental electric field breakdown data are included to validate simulation results. View full abstract»

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  • A Method for Numerically Modeling a Power-Conditioning System With an Electroexplosive Opening Switch

    Page(s): 2520 - 2530
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    Due to the complex relationship between the current history through an electroexplosive opening switch (EEOS) and the switch impedance, numerical modeling methods are required to understand the dynamic switch and circuit behavior of inductive energy storage systems incorporating EEOSs. A method for numerically modeling a compact pulsed-power system consisting of a high-current source, an inductive energy store, an EEOS, and a resistive load is developed. Previous models of switch resistance are extended to recognize restrike conditions and enable modeling of system operation after restrike. In addition, the model is developed such that either a transformer or an uncoupled inductor can be implemented as the inductive energy storage component. The required circuit equations are derived, and a technique to model the dynamic circuit resistance utilizing the time derivatives of circuit currents is described. Thus, a unique modeling method, which is entirely user definable and compatible with a variety of numerical processing software, is developed. Detailed descriptions of the system under consideration, the modeling method, and modeling constraints are provided. The equations describing the switch resistance and circuit response are derived. An example simulation in which restrike occurs is presented, and modeling results are compared to experimentally measured data. View full abstract»

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  • Pulsed Current-Mode Supply of Dielectric Barrier Discharge Excilamps for the Control of the Radiated Ultraviolet Power

    Page(s): 2531 - 2538
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    UV excimer lamps are efficient narrowband sources of UV radiation with applications in various domains. The issue of controlling the UV emission by means of the power supply associated with such lamps favors pulsed current-controlled generators. After having established the previous statements, we propose a dedicated power converter topology which implements the needed performances. The analysis of the degrees of freedom of this structure shows the capability of this pulsed supply to realize the control of both the pulses' current energy and of the mean power transferred to the lamp. Actual experimental realizations and measurement are presented and the feasibility and the performances of the proposed solutions are established. View full abstract»

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  • An In-depth Investigation of the Effect of Oil Pressure on the Complete Statistical Performance of a High-pressure Flowing Oil Switch

    Page(s): 2539 - 2547
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    A high-pressure flowing oil dielectric switch was developed for high-performance, high-voltage switching. It was evaluated by a team at the University of Missouri-Columbia. The switch was designed to produce a continuous train of nanosecond-rise electrical impulses, with a peak output power ranging up to several gigawatts, and at repetition frequencies ranging up to several kilohertz. High-pressure flowing oil was proposed for the switching medium as a means of enabling the rapid recovery of the insulating properties of the dielectric following electrical breakdown. The switch was developed for self-breakdown operation, with an anticipated lifetime of greater than 107 switching cycles. An experimental study of the statistical performance of the high-pressure flowing oil switch was conducted over a range of oil pressures from 0.5 to10 MPa, oil flow, peak modulator charge voltages from 12.5 to 25.0 kV, gap separations from 0.50 to 1.00 mm, and at an oil flow rate of 20 Lpm. The switch was designed for self-breakdown operation at repetition frequencies of up to 100 Hz, though the experiment was conducted at 2 Hz. The breakdown electric field strength was found to follow a Weibull probability density function. The effect of increased oil pressure was to flatten the distribution with an asymmetric negative skew. The peak charge voltage was found to have virtually no effect on normal breakdown. The gap separation produced the largest effects observed, resulting in an increase in the average breakdown electric field strength with decreased gap separation, and a decrease in variance with increasing gap separation. View full abstract»

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  • Optimal Design of a Grid-Cathode Structure in a Spherically Convergent Beam Fusion Device by Response-Surface Methodology Combined With Experimental Design

    Page(s): 2548 - 2553
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    To apply fusion energy through a spherically convergent beam fusion (SCBF) device as a portable neutron source, neutron production is very important. The rate of production is greatly dependent upon the ion current, which is closely related to the potential-well structure within a grid cathode. In this paper, we propose a design method by varying the cathode-ring sizes to produce an optimal grid-cathode structure in an SCBF device. The optimization is based on response-surface methodology (RSM); however, full factorial design is also applied to increase the precision of optimization and reduce experiment iteration in the application of RSM. The finite-element method, combined with the flux-corrected transport algorithm, is employed to calculate the ion current. From the optimized model, a higher ion current is calculated, resulting in a deeper potential well. View full abstract»

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  • A 6-MV Pulser to Drive Horizontally Polarized EMP Simulators

    Page(s): 2554 - 2558
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    L-3 Pulse Sciences (L-3 PS) is fabricating a 6-MV biconic pulse generator to drive a horizontally polarized dipole electromagnetic pulse simulator antenna at the Naval Air Systems Command, Pax River. The L-3 PS pulser, i.e., the horizontal fast rise electromagnetic pulser (HFREMP), will replace the Maxwell Laboratories ML-5 pulser. The HFREMP project is funded through the Central Test and Evaluation Investment Program (CTEIP). The CTEIP was established by the United States Department of Defense (DoD) to provide joint initiatives, avoid unwarranted duplication of capability, and increase interoperability through capability improvement projects for the DoD Major Ranges and Test Facility Bases. Like the Physics International Fast Risetime EMP Simulator (FEMPS) 2000, which drives an identical antenna at the Centre d'Etudes de Gramat, France, the HFREMP uses two stages of pulse compression. In fact, output capacitors, output switches, intermediate capacitors, and intermediate switches all use the same type of design as the FEMPS 2000. The Marx generator is of a different lower inductance design, and where FEMPS 2000 has a 2.7-MV Marx pulser in only one side, the HFREMP has a 3-MV pulser in each side of the 150- bicone that is the central part of the antenna. When the HFREMP drives the existing Pax River antenna, which is a variable height antenna (30-18 m), it will produce a 60- to 117.5-kV/m peak at the reference sensor with a waveform similar to that of the ML-5, which produces 47-92 kV/m. The HFREMP has also been considered to drive a bounded wave antenna of a different design, which is a fixed height antenna (30 m), producing at the reference sensor a peak field of over 80 kV/m and a wider more smoothly decaying pulse. The design of the HFREMP is described and compared with the designs of ML-5 and FEMPS 2000. Predictions of its performance into both types of antennas are presented. View full abstract»

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  • Stability of Injection of a Subnanosecond High-Current Electron Beam and Dynamic Effects Within Its Rise Time

    Page(s): 2559 - 2564
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    The stability of the injection of short electron beams and the dynamic processes that occur during their transport were experimentally studied. Beams of energy 200-300 keV, current of 1-1500 A, and duration of 0.05-3 ns with a current rise time of 30-300 ps were formed in a cold-cathode electrode gap. The distribution of the accelerating electric field was highly nonuniform. The cases of vacuum and air insulation of the electron diode were considered. The shortest beams with currents of a few amperes were generated in the mode of continuous acceleration of electrons in atmospheric air. For measuring beam currents, special collector probes were used which ensured a picosecond resolution. View full abstract»

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  • Optimal Design of a 3.5-kV/11-kW DC–DC Converter for Charging Capacitor Banks of Power Modulators

    Page(s): 2565 - 2573
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (944 KB) |  | HTML iconHTML  

    For the generation of short high-power pulses in many applications, power modulators based on capacitor discharge are used, where the peak power is drawn from the input capacitor bank. In order to continuously recharge the energy buffer during operation at a lower average power, usually, power supplies connected to the mains are used. Due to the worldwide variation in mains voltages and the desired ability to adapt the capacitor voltage of the modulator, the power supply has to support a wide input and output voltage range, whereby the supply should draw a sinusoidal current from the mains due to EMI regulations. Additionally, depending on the modulator concept, a galvanic isolation also has to be provided. In order to achieve the mentioned specifications for the considered power supply, a combination of an ac-dc and a dc-dc converter is proposed, whereas the mains voltage is rectified by a three-phase buck-boost converter to 400 Vdc, and thereafter, an isolated dc-dc converter charges the input capacitor bank of the power modulator up to 3.5 kV. This paper focuses on the basic operation and the design of the 3.5-kV/11-kW isolated dc-dc converter, which includes transformer design, efficiency-volume optimization, and component selection. In this paper, compared with the well-known flyback converter, the proposed full-bridge-based topology results in a much higher efficiency and power density. View full abstract»

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  • An FDTD Interaction Scheme of a High-Intensity Nanosecond-Pulsed Electric-Field System for In Vitro Cell Apoptosis Applications

    Page(s): 2574 - 2582
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    A finite-difference time-domain analysis of a high-intensity nanosecond-pulsed electric-field (nsPEF) system, composed of a pulse-forming line (PFL) and a universal electroporation cuvette, is described. The simulation scheme is based on interactions of 1-D transmission-line equations for the PFL and 3-D Maxwell's curl equations for the cuvette volume. Simulations incorporate system adjustment to facilitate maximum transfer of electrical energy from the PFL to the cuvette medium. Experimental validation of the voltage across the cuvette electrodes through the laboratory-constructed nsPEF system with an energy density of ~1 J/cm3 reveals an overall agreement with some discrepancies. The distribution profiles of the transient field inside the cell suspension area during the excitation of 5-kV 10-ns pulses would adequately account for the feasibility of using an integrated model as a design benchmark for the interaction physics of the generated nanosecond pulses and culture vessel. The observed nsPEF effects on cells include increased transmembrane potentials across organelle membranes without permanently damaging the cell membrane, increasing the probability of electric field interactions with intracellular structures. View full abstract»

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  • Modes of Generation of Runaway Electron Beams in He,  \hbox {H}_{2} , Ne, and \hbox {N}_{2} at a Pressure of 1–760 Torr

    Page(s): 2583 - 2587
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    In this paper, the characteristics of runaway electron beams downstream of a foil anode were studied at a pressure of helium, hydrogen, neon, and nitrogen of 1-760 torr. High-voltage pulses (~150 and ~250 kV) with pulse rise times of ~300 and ~500 ps were applied to the tubular cathode-plane anode gap. It is shown that the highest amplitudes of a supershort avalanche electron beam (SAEB) of 100-ps pulse duration are attained in helium, hydrogen, and nitrogen at pressures of ~60, ~30, and ~10 torr, respectively. It is demonstrated that further decreasing the pressure changes the mode of generation of runaway electron beam and increases the beam current amplitude and the voltage pulse duration across the gap. It is found that increasing the pressure of helium, hydrogen, and nitrogen to hundreds of torr decreases the delay time between the instants the voltage pulse is applied to the gap and the SAEB is generated, as well as the maximum voltage across the gap. View full abstract»

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  • High-Performance Pulsed-Power Generator Controlled by FPGA

    Page(s): 2588 - 2592
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    The high reliability, high repetition rate, high performance, and compactness of pulsed-power generators are required for industrial applications. Also, the control of a pulsed-power generator becomes more complicated with increasing functions. An all-solid-state pulsed-power generator can be controlled by using a field-programmable gate array (FPGA). The pulsed-power generator consists of a charger, a magnetic pulse compression circuit, and a controller using the FPGA. The performance characteristics of the pulsed-power generator, such as the variable firing interval from shot to shot and the diagnosis of incorrect operation, are easily achieved by rewriting the programming of the Verilog hardware description language on the FPGA. View full abstract»

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  • High Pulsed Power Sources for Broadband Radiation

    Page(s): 2593 - 2603
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    This paper explains the design and production of two autonomous ultrawideband (UWB) radiation sources. These sources consist of a high-gain broadband antenna that is driven by one of two subnanosecond pulsed power sources. Each source is made up of a Marx generator and a pulse-forming device based on the use of a gaseous spark gap. The first source combines a four-stage 200-kV/34-J Marx generator with a coaxial pulse-forming line. Its main characteristics are an output voltage of 100 kV, a 250-ps rise time, a subnanosecond pulse duration, and a repetition rate of about 40 Hz. The second pulsed source is a ten-stage subnanosecond Marx generator that delivers pulses in the 250-kV/1.5-J range, with a 300-ps rise time and a subnanosecond pulse duration at a pulse repetition rate of 350 Hz. Probes were produced based on capacitive line dividers to measure both the temporal characteristics and the high-voltage (HV) amplitude of the pulses delivered by the pulsed power sources. The antenna, combined with these two pulsed sources, is a traveling-wave antenna called the Valentine antenna. Some mechanical modifications were made to the antenna to improve its dielectric strength. First, a 3-D model of the antenna was created on time-domain electromagnetic software to study the influence of these modifications on its main radiating characteristics. Its high gain and its capability to radiate short pulses without dispersion allow us to achieve a high measured figure of merit (the maximum value of far-field peak-to-peak electric field strength multiplied by the distance). A new method called the Instantaneous Electromagnetic Field Measurement by Signature of a Neutral Object (MICHELSON) method is used to measure the very intense electromagnetic fields that are radiated. The incident field is diffracted by a special small-dimension target. The diffracted field is measured by a conventional low-power UWB antenna. The target that is used has small dimensions, and no cables are used - - in the field region; thus, the electromagnetic interference that is generated and undergone by the measurement device is considerably limited. The figure of merit that is measured is 436 kV. View full abstract»

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  • A High-Power High-Voltage Power Supply for Long-Pulse Applications

    Page(s): 2604 - 2610
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    This paper describes a concept and a physical demonstration of a high-efficiency small-size low-cost 100-kV 100-kW high-voltage (HV) power supply (HVPS) designed for long-pulse applications (units of milliseconds to dc operation). Key technology includes a modular HV converter with energy-dosing inverters that run at about 50 kHz and have demonstrated an efficiency of 97.5% across a wide range of operating conditions. The inverters' output voltages are phase shifted, which yields a low ripple of 1% and a slew rate of 3 kV/μs combined with less than 10 J of stored energy at the maximum voltage. Modular construction allows easy tailoring of HVPS for specific needs. Owing to high efficiency, small size is achieved without water cooling. Controls provide standard operating features and advanced digital processing capabilities, along with easiness of accommodating application-specific requirements. HVPS design and testing are detailed. It is shown that the ripple factor is inversely proportional to the number of modules squared. Experimental current and voltage waveforms indicate virtually lossless switching for widely varying load in the full range of the line input voltages and fair agreement with circuit simulations. The overall efficiency is as high as 95% at full load and greater than 90% at 20% load, with a power factor that is typically greater than 93%. View full abstract»

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  • Impulse-Breakdown Characteristics of Polymers Immersed in Insulating Oil

    Page(s): 2611 - 2619
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (415 KB) |  | HTML iconHTML  

    Surface discharges along oil-immersed solids used as insulators and supports in high-voltage pulsed-power equipment can lead to catastrophic system failures. To achieve reliable compact pulsed-power systems, it is important to quantify the electrical fields at which surface flashover, or other types of breakdown event, will occur for different dielectric materials. This paper reports the observed behavior of samples of polypropylene, lowdensity polyethylene, ultrahigh-molecular-weight polyethylene, Rexolite, and Torlon, which were subjected to impulse voltages of peak amplitude of 350 kV and a rise time of 1 μs. The cylindrical samples were located between pairs of electrodes immersed in insulating oil. Breakdown events were studied under both nonuniformand uniform-field conditions, with sample lengths being chosen so that the breakdown events occurred on the rising edge of the impulse. Ultrahigh-molecular-weight polyethylene showed the highest average breakdown field, which is 645 kV/cm, in uniform fields, and the corresponding breakdown field was reduced to ~400 kV/cm in the nonuniform fields. Weibull plots of the various sets of results are presented, providing comparative data for system designers for the appropriate choice of dielectric materials to act as insulators for high-voltage pulsed-power machines. View full abstract»

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  • Genesis: A 5-MA Programmable Pulsed-Power Driver for Isentropic Compression Experiments

    Page(s): 2620 - 2626
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    Enabling technologies are being developed at Sandia National Laboratories to improve the performance and flexibility of compact pulsed-power drivers for magnetically driven dynamic materials properties research. We have designed a modular system that is capable of precision current pulse shaping through the selective triggering of pulse-forming components into a disk transmission line feeding a strip line load. The system is composed of 240 200-kV 60-kA modules in a low-inductance configuration that is capable of producing 250-350 kbar of magnetic pressure in a 1.75-nH 20-mm-wide strip line load. The system, called Genesis , measures approximately 5 m in diameter and is capable of producing shaped currents that are greater than 5 MA. This performance is enabled through the use of a serviceable solid-dielectric insulator system which minimizes the system inductance and reduces the stored energy and operating voltage requirements. Genesis can be programmed by the user to generate precision pulse shapes with rise times of 220-500 ns, allowing characterization of a range of materials from tungsten to polypropylene. This paper provides an overview of the Genesis design, including the use of genetic optimization to shape currents through selective module triggering. View full abstract»

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  • High-Power Ultrafast Current Switching by a Silicon Sharpener Operating at an Electric Field Close to the Threshold of the Zener Breakdown

    Page(s): 2627 - 2632
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    A new principle of high-power ultrafast current switching by Si sharpener based on a successive breakdown of the series-connected structures has been experimentally implemented and theoretically studied. A voltage pulse with an amplitude of 180 kV and a rise time of 400 ps was applied to a semiconductor device containing 44 series-connected diode structures located in a 50- transmission line. Due to a sharp nonuniformity of the applied voltage distribution across the length of the device, the structures operate in the successive breakdown mode. Each successive structure breaks down with a shorter time interval as the electromagnetic shockwave builds. In the experiments in a 50- transmission line, we have obtained 150-kV output pulses having a 100-ps rise time. The maximum current and voltage rise rates amount to 30 kA/ns and 1.5 MV/ns, respectively. In the numerical simulations, the ionization rate of the process-induced deep-level centers, as well as the band-to-band tunneling, is taken into account. The calculations show that, at a reverse voltage rise rate across the structure of over 10^13  V/s, the electric fields that are close to the threshold of the Zener breakdown can be achieved even if the structure contains deep-level centers with a concentration of 1011 to 1012 cm-3. View full abstract»

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  • All-Solid-State Repetitive Pulsed-Power Generator Using IGBT and Magnetic Compression Switches

    Page(s): 2633 - 2638
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    By utilizing power semiconductor switches, especially high-voltage insulated gate bipolar transistors (IGBTs), as main switches, Marx modulators have demonstrated many advantages such as variable pulse length and pulse-repetition frequency, snubberless operation, and inherent redundancy. However, the relatively slow turn-on speed of the IGBT influences the pulse rise time of the Marx modulator. In this paper, a newly developed all-solid-state pulsed-power generator is proposed. This generator consists of a Marx modulator based on discrete IGBTs and a magnetic pulse-sharpening circuit, which is employed to compress the rising edge of the Marx output pulse. The experimental results are presented with a maximum voltage of 20 kV, a rise time of 200 ns, a pulse duration of 500 ns (full-width at half-maximum), and a repetition rate of 5 kHz on a 285- resistive load. The output power of the generator is 2.5 kW, and the average power in one pulse is 1 MW. The design methods of the IGBT drive circuits and the parameter calculation of the magnetic pulse-sharpening circuit are introduced in detail in this paper. The factors influencing the performance of the generator are also discussed. View full abstract»

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  • Energy Efficiency Improvement of Nitric Oxide Treatment Using Nanosecond Pulsed Discharge

    Page(s): 2639 - 2643
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    Pulsed streamer discharge plasmas, one type of nonthermal plasma, have been used to treat exhaust gases. Since a pulsewidth of applied voltage has a strong influence on the energy efficiency of the removal of pollutants, the development of a short-pulse generator is of paramount importance for practical applications. In this paper, a nanosecond (ns) pulse generator which has a 5-ns pulse duration in output pulsed voltage is developed, and NO-removal experiments using ns pulsed discharge were conducted. The experimental results of the NO removal showed 100% of NO-removal ratio at 7 pps of pulse repetition rate and the extremely high energy efficiency, which is 0.43 mol/kWh (12.9 g-NO/kWh) for NO removal (initial NO concentration = 200 ppm; gas flow = 2.0 l/min ). The result of deriving energy efficiency for NO removal indicated that the ns pulsed discharge has great advantage in energy efficiency for NO removal to the conventional discharge methods. By this research, the utility of the ns pulse plasma process was proven, and the influence of shorter pulse duration on NO-removal energy efficiency was confirmed. View full abstract»

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  • Mechanisms of Impulse Breakdown in Liquid: The Role of Joule Heating and Formation of Gas Cavities

    Page(s): 2644 - 2651
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    The impulse dielectric behavior of insulating liquids is of significant interest for researchers and engineers working in the field of design, construction, and operation of pulsed power systems. Analysis of the literature data on transformer oils shows that potentially there are several different physical processes that could be responsible for dielectric breakdown by submicrosecond and microsecond impulses. While for short submicrosecond impulses ionization (plasma streamer) is likely to be the main breakdown mechanism, for longer impulses, the thermal effects associated with Joule heating start to play an important role. This paper provides a theoretical analysis of the latter mechanism in dielectric liquids of different degrees of purity stressed with high-voltage (HV) impulses with duration sufficient to cause local heating, evaporation, and formation of prebreakdown gas bubbles. The proposed model is based on the assumption that dielectric breakdown is developed through percolation channels of gas bubbles, and the criterion of formation of these percolation chains is obtained. To test the developed model, the breakdown field-time characteristics have been calculated for the liquid with chemical composition close to that of transformer oils but with known thermodynamic characteristics (n-hexane). Its dielectric strength has been obtained as a function of externally applied pressure and temperature. The analytical results show good agreement when compared with the experimental data available in the literature. View full abstract»

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  • Overview of Self-Magnetically Pinched-Diode Investigations on RITS-6

    Page(s): 2652 - 2662
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    The electron-beam-driven self-magnetically pinched diode is a candidate for future flash X-ray radiographic sources. As presently fielded on Sandia Laboratories' six-cavity Radiographic Integrated Test Stand (RITS-6), the diode is capable of producing sub 3-mm radiation spot sizes and greater than 350 rads of hard X-rays at 1 m. The diode operates between 6 and 7 MV with a slowly decreasing impedance that falls from approximately 65 to 40 Ω during the main pulse. Sensitivity in diode operation is affected by the interaction of evolving plasmas from the cathode and anode, which seem to limit stable diode operation to a narrow parameter regime. To better quantify the diode physics, high-resolution time-resolved diagnostics have been utilized which include plasma spectroscopy, fast-gated imaging, X-ray p-i-n diodes, X-ray spot size, and diode and accelerator current measurements. Data from these diagnostics are also used to benchmark particle-in-cell simulations. An overview of results from experiments and simulations is presented. View full abstract»

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  • A New Type Rotating Arc Gap Switch and Its Arc Velocity Characteristics

    Page(s): 2663 - 2668
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    A rotating arc gap (RAG) switch controlled by an axial magnetic field is designed and built to meet the requirements of high voltage, high current, large charge transfers, slight electrode erosion, and long lifetime. The electrodes are in a coaxial cylinder configuration. The shape of the electrodes is optimized to make the electric field well distributed. Therefore, the arc initiates randomly on the electrode. After the gap is triggered, a self-generated magnetic field exists while the arc current flows through the coils which are placed both at the top and bottom of the switch and in series with the inner electrode. The resultant magnetic field is mainly in the axial direction and forms a mirror machinelike configuration. This makes the rotating arc move to the middle of the electrode, no matter where it ignites, and avoid damage to the insulator of the switch body. B-dot probes are used to measure the arc velocity. The experimental current is a trapezoidlike waveform and is generated by a time-sequence discharge power supply. The current value is in the range of 17-72 kA, and the magnetic induction values are in the range of 0.104-0.628 T. The arc velocity in different magnetic field strength is obtained by changing the coil number. The results are compared with other RAG switches. The relationship between arc velocity and the current and magnetic field is obtained from the experimental data. The result shows that the arc velocity in this switch is primarily determined by the magnetic field. This research supplements the arc velocity characteristics of a self-induced driven arc in the high-current range. View full abstract»

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

 

 

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