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Plasma Science, IEEE Transactions on

Issue 6 • Date June 2009

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Displaying Results 1 - 25 of 50
  • Table of contents

    Publication Year: 2009 , Page(s): C1 - 710
    Save to Project icon | Request Permissions | PDF file iconPDF (55 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Plasma Science publication information

    Publication Year: 2009 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (38 KB)  
    Freely Available from IEEE
  • Atmospheric-Pressure Plasmas: Science and Applications

    Publication Year: 2009 , Page(s): 711 - 713
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    Freely Available from IEEE
  • Low-Temperature Plasmas for Medicine?

    Publication Year: 2009 , Page(s): 714 - 725
    Cited by:  Papers (113)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (986 KB) |  | HTML iconHTML  

    Can low-temperature plasma technology play a role in medicine? This is a question that many investigators today are trying hard to give a positive answer to. It did not quite start out this way. Almost two decades ago, few ldquocuriousrdquo electrical engineers and physicists with the help of few ldquobraverdquo biologists/microbiologists asked themselves more basic questions: What happens to biological cells if they were exposed to low-temperature plasma? Will they die? Will they survive? If they survive, will they come out the same or somehow ldquoinjuredrdquo? If injured, will they be able to repair the damage and recover? What kind of damage? Which plasma agent causes the damage? etc. As will be shown in this paper, some of these fundamental questions have been partially or fully answered, but until today, a complete picture has yet to emerge. This is good and not so good. It is good because if we already knew all the answers, we would not be looking forward to a more exciting research. It is not so good because after all these years, we are still quite a ways from an implementable medical application. In this review paper, the present state of knowledge regarding the effects of cold plasma on bacteria cells (prokaryotes) and on eukaryotic cells (such as mammalian cells) will be presented. As medical applications where low-temperature plasma is showing signs of success, blood coagulation and wound healing will be described. View full abstract»

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  • Review: Engineering Particles Using the Aerosol-Through-Plasma Method

    Publication Year: 2009 , Page(s): 726 - 739
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1323 KB) |  | HTML iconHTML  

    For decades, plasma processing of materials on the nanoscale has been an underlying enabling technology for many ldquoplanarrdquo technologies, particularly virtually every aspect of modern electronics from integrated-circuit fabrication with nanoscale elements to the newest generation of photovoltaics. However, it is only recent developments that suggest that plasma processing can be used to make ldquoparticulaterdquo structures of value in fields, including catalysis, drug delivery, imaging, higher energy density batteries, and other forms of energy storage. In this paper, the development of the science and technology of one class of plasma production of particulates, namely, aerosol-through-plasma (A-T-P), is reviewed. Various plasma systems, particularly RF and microwave, have been used to create nanoparticles of metals and ceramics, as well as supported metal catalysts. Gradually, the complexity of the nanoparticles, and concomitantly their potential value, has increased. First, unique two-layer particles were generated. These were postprocessed to create unique three-layer nanoscale particles. Also, the technique has been successfully employed to make other high-value materials, including carbon nanotubes, unsupported graphene, and spherical boron nitride. Some interesting plasma science has also emerged from efforts to characterize and map aerosol-containing plasmas. For example, it is clear that even a very low concentration of particles dramatically changes plasma characteristics. Some have also argued that the local-thermodynamic-equilibrium approach is inappropriate to these systems. Instead, it has been suggested that charged- and neutral-species models must be independently developed and allowed to ldquointeractrdquo only in generation terms. View full abstract»

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  • Non-Self-Sustained Atmospheric Pressure Glow Discharges Maintained by the DC Helium Glow Discharge

    Publication Year: 2009 , Page(s): 740 - 749
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1214 KB) |  | HTML iconHTML  

    The possibilities of obtaining large-volume non-self-sustained atmospheric pressure glow discharge with the help of the self-sustained normal dc glow discharge in helium are demonstrated. The latter plays the role of ldquoplasma electroderdquo for the main discharge in a neighboring chamber in the three-electrode configuration. Electrical parameters of the non-self-sustained discharge for different voltage sign combinations of electrodes are presented. Conditions of discharge transfer from one chamber section to another are under investigations. The spatial profiles of potential at different discharge currents are determined. It is shown that larger volumetric plasma can be generated in the anode-cathode-anode configuration. View full abstract»

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  • Conductivity of a Lightning-Channel Corona Sheath During Return Stroke

    Publication Year: 2009 , Page(s): 750 - 758
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (297 KB) |  | HTML iconHTML  

    A generalized lightning traveling current source (GTCS) return-stroke model has been used to examine the conductivity of the lightning-channel corona sheath surrounding a thin channel core. A model of lightning channel consisting of the charged corona sheath and the narrow high-conducting central core conducting the main current flow is assumed. A strong electric field, in a prevalent radial direction, has been created during the return stroke between the channel core and the outer channel sheath containing the negative channel charge. The return-stroke process is modeled with the positive charge coming from the channel core discharging the negative leader charge. The channel corona-sheath model that predicts the charge motion in the corona sheath is used to derive the expressions of the channel sheath conductivity during the return stroke. This model can be viewed as the generalization of the corona-sheath model proposed by Maslowski and Rakov in 2006. According to this model, the corona sheath consists of two zones, zone 1 (inner zone containing a net positive charge) and zone 2 (outer zone containing negative charge), respectively. Gauss' law, the charge conservation law, and the point form of Ohm's law are combined to form the differential equation which is analytically solved, yielding the expression for the sheath conductivity in zones 1 and 2. The expressions of the radial electric fields, the current densities, and the conductivities in zones 1 and 2 are derived using the GTCS return-stroke model. The measurements of the electric field in the immediate vicinity of the lightning channel by Miki in 2002 enabled the calculation of the channel sheath parameters. It is shown that the maximum radii of zones 1 and 2 at 2 m above ground are less than 1.5 and 6 cm, respectively. The minimum value of the channel sheath conductivity, about 10 muS/m , is obtained between zones 1 and 2 during the return stroke. The theoretical considerations given in this paper can be - - also applied to other types of ldquoengineeringrdquo return-stroke models. View full abstract»

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  • An Atmospheric-Pressure Glow-Discharge Plasma Jet and Its Application

    Publication Year: 2009 , Page(s): 759 - 763
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (168 KB) |  | HTML iconHTML  

    An atmospheric-pressure glow-discharge plasma jet driven by a transformer of 1 : 500 and an alternating current of 50 Hz is presented. Discharge characteristics are investigated by oscillograph observations, and it is verified no risk of arcing. The stable glow discharge is deemed to benefit from the transformer's inductance. The electric characteristics and the plasma parameters are studied. The jet is employed in CO2 reforming of CH4 to syngas (H2, CO). It brings out higher conversion ability than other plasmas such as dielectric barrier discharge and corona discharge, which is due to its special design and special plasma characteristic. View full abstract»

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  • Electron Swarm Coefficients in \hbox {CO}_{2} \hbox {N}_{2} and \hbox {CO}_{2} \hbox {O}_{2} Mixtures

    Publication Year: 2009 , Page(s): 764 - 772
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (932 KB) |  | HTML iconHTML  

    The electron swarm coefficients (i.e., drift velocity, longitudinal diffusion coefficient, and effective ionization coefficient) have been measured using a time-resolved pulsed Townsend technique in O2, N2, and CO2 and their mixtures CO2-N2 and CO2-O2, with CO2 shares of 20%, 50%, and 80%. Simultaneously, these swarm data have been calculated from an adequate multiterm solution of the Boltzmann equation, using previously validated sets of electron-molecule collision cross sections. We have found good agreement between measurements and calculations, both for the pure gases and mixtures, particularly for the case of the calculated mean electron drift velocity Wm, which takes into account the effects of longitudinal diffusion and effective ionization. An effort has been placed in covering as high an E/N range as possible (0.01 Td up to 1000 Td) on specific electron swarm data such as transverse and longitudinal characteristic energies, which are also needed for a better understanding of the electrohydrodynamic and kinetic behavior of nonthermal atmospheric pressure electrical discharges. View full abstract»

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  • Plasma Flow Characteristics in a Spray-Type Dielectric Barrier Discharge Reactor

    Publication Year: 2009 , Page(s): 773 - 784
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2372 KB) |  | HTML iconHTML  

    A numerical simulation on the spray-type dielectric barrier discharge (DBD) is carried out for a mixture gas of nitrogen (N2) and sulfur hexafluoride (SF6) at atmospheric pressure to understand the electrical characteristics and the plasma flow dynamics that depend on design parameters and operating conditions. A 2-D axi-symmetric nonuniform grid is employed in the simulation code consisting of the following three numerical modules: 1) discharge module; 2) flow module; and 3) reaction calculation module. Through the coupling of these modules, the discharge and plasma flow characteristics are interactively calculated for discharge properties and behaviors of charged and neutral particles in the N2/SF6 plasma, including 26 species interacting among them by 59 reactions. As a result of numerical simulations, the effects of the spray hole and the gas flow on the plasma flow characteristics are discussed in the spray-type DBD reactor. The existence of a spray hole in the grounded barrier/electrode plate induces strong electric fields along the spray hole barrier wall, and these high fields trigger a localized discharge similar to the surface discharge. The localized discharge spreads out in the discharge region toward the powered electrode barrier and gives the discharge current a pulsed shape according to the group behavior of a high-density electron to eventually produce a high-density fluorine atom in both the spray hole and spray regions. When the spray hole radius decreases, the fluctuations of hole-induced electric field also decreases, accompanied by the reduced production of average densities of the electron and the fluorine atom. However, the reduced spray hole size enhances the advective velocity along the hole axis, and therefore, the overall fluorine atom density over the substrate surface is increased. With increasing inlet gas flow velocity, the localized discharges occur more frequently because of electric potent- - ial formation by interacting among meta-stable species and ions to enhance the fluorine atom production. The fast advective velocity also enlarges the radial distributions of effluent rate and fluorine atom density in the spray region and on the substrate surface due to the transport of neutral particles. View full abstract»

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  • On the Nature of Picosecond Runaway Electron Beams in Air

    Publication Year: 2009 , Page(s): 785 - 789
    Cited by:  Papers (22)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (286 KB) |  | HTML iconHTML  

    Results of experiments on the generation of picosecond runaway electron (RE) beams in air gaps with a strongly nonuniform electric field distribution are discussed. The mechanism and conditions for the field emission initiation of beams of this type and possible reasons for the limitation of the beam duration are considered. REs are supposed to be the dominant factor in the development of an ionization wave in the gap. Estimates of the mean velocity of propagation of the ionization wave are given. View full abstract»

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  • Measurement of Metastable Atom Populations Along an Argon Plasma Column Generated at Atmospheric Pressure

    Publication Year: 2009 , Page(s): 790 - 796
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (228 KB) |  | HTML iconHTML  

    This paper describes a procedure for experimental determination of metastable and resonant populations along a surface wave argon plasma column at atmospheric pressure. As modeling work progresses extensively, an experimental database is necessary to confirm these models. Obtained results, within the range of values reported in literature, indicate that densities of metastable and resonant levels grow along the plasma column for positions near the energy coupler device, where the energy of the surface wave which creates discharge is the highest. This behavior is also found for electron density and temperature; however, it is not the same for gradient. Therefore, at atmospheric pressure, populations of 4s levels are not only controlled by collision with electrons from ground state, but the dissociative recombination mechanism is also important, in agreement with results found by other authors using collisional-radiative models. View full abstract»

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  • Design of a Microwave Microplasma Source at Atmospheric Pressure

    Publication Year: 2009 , Page(s): 797 - 808
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (562 KB) |  | HTML iconHTML  

    This paper studies two linear resonator sources, which use a continuous 2.45-GHz microwave excitation to produce stable microplasmas, in air and in argon, at atmospheric pressure. The discharges are produced and sustained within the 50-200-mum gap created between two metal electrodes with either 6 or 14 mm in length. Particular attention is given to the design and optimization of the sources (in terms of frequency tuning and power coupling), following a complementary approach based on simulations and experiments. Optical-emission-spectroscopy diagnostics allow one to deduce the rotational, vibrational, and excitation gas temperatures and the electron density (using Stark broadening measurements of the Hbeta line-emission profile). View full abstract»

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  • Development of a Barrier Discharge in Air in Highly Nonhomogeneous Electric Field Caused by the Residual Dielectric Surface Charges

    Publication Year: 2009 , Page(s): 809 - 815
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (333 KB) |  | HTML iconHTML  

    The prebreakdown phases of a barrier discharge in a short gap in atmospheric-pressure air are investigated by numerical modeling. A highly nonhomogeneous electric field caused by residual charges deposited on the dielectric surfaces is taken into account. The simulation results of barrier discharge radiation are compared with experimental data. View full abstract»

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  • Microwave-Frequency Effects on Microplasma

    Publication Year: 2009 , Page(s): 816 - 822
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (885 KB) |  | HTML iconHTML  

    Capacitively coupled microplasma generation becomes more efficient at microwave frequencies. Helium and argon microplasmas are characterized using excitation frequencies of 450 MHz, 900 MHz, and 1.8 GHz. These microplasmas are tested at both atmospheric pressure and 0.4 torr. We have experimentally determined the microplasma's electrical impedance, which consists of bulk plasma resistance and capacitive sheath reactance. These two parameters were measured by fitting theoretical power reflection coefficients to experimental forward and reflected microwave power as a function of frequency. Microplasma resistance decreases with increasing frequency, showing that the generation of free electrons depends on the driving frequency. In addition, the reactive sheath impedance and the microwave electrode voltage also decrease with an increase of frequency. A 3-D microplasma simulation shows that a narrower sheath width exists for higher frequency microplasma, and this is responsible for reducing the reactive impedance and the peak-to-peak electrode voltage. At higher microwave frequency, the decreased electrode voltage reduces both the plasma potential and the ion kinetic energy losses, thus increasing the electron density. View full abstract»

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  • Ring Opening of Aromatic Polymers by Remote Atmospheric-Pressure Plasma

    Publication Year: 2009 , Page(s): 823 - 831
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (447 KB) |  | HTML iconHTML  

    An atmospheric-pressure oxygen and helium plasma was used to treat the surfaces of polyetheretherketone, polyphenylsulfone, polyethersulfone, and polysulfone. Water-contact-angle measurements, mechanical pull tests, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy were used to analyze the change in polymer properties. Plasma treatment converted all the materials from a hydrophobic to a hydrophilic state in a few tenths of a second. The adhesive bond strength was increased from 1.1 to 3.8 plusmn 1.0 MPa for polyetheretherketone and from 0.6 to 1.3 plusmn 0.2 MPa for polyphenylsulfone. XPS revealed that plasma treatment oxidizes between 7% and 27% of the aromatic carbon atoms on the polymer surfaces and converts them into aldehyde and carboxylic acid groups. The degree of oxidation was highest for polyetheretherketone, where the fraction of surface carbon atoms attributable to carbonyl (ketone and aldehyde) and carboxylic acid groups increased from 5% to 11% and from 0% to 19%, respectively. It is concluded that the O atoms generated in the atmospheric-pressure plasma oxidize and open the aromatic rings available on the polymer chains and that this is responsible for the increased adhesion. View full abstract»

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  • Supershort Avalanche Electron Beams in Discharges in Air and Other Gases at High Pressure

    Publication Year: 2009 , Page(s): 832 - 838
    Cited by:  Papers (19)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (246 KB) |  | HTML iconHTML  

    In this paper, the generation of supershort avalanche electron beams (SAEBs) from the plasmas of nanosecond diffuse discharges in air and other gases at atmospheric pressure was investigated. It is shown that, in the mode of SAEB generation, the plasma in the discharge gap with an inhomogeneous electric field can be produced in a time no greater than 100 ps with the charged-particle density sufficient to force out the electric field from the discharge-gap region occupied by the dense plasma. It is demonstrated that decreasing the voltage pulsewidth in the discharge gap (to ~100-ps FWHM) reduces the optimum gap for SAEB generation. It is also found that the difference in electron path toward the foil center and the foil edge affects the SAEB current pulsewidth. For lower voltages across the gap (~25 kV), the SAEB pulsewidth at half maximum is ~200 ps. View full abstract»

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  • Optical Emission Characteristics of Atmospheric-Pressure Nonequilibrium Microwave Discharge and High-Frequency DC Pulse Discharge Plasma Jets

    Publication Year: 2009 , Page(s): 839 - 845
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (298 KB) |  | HTML iconHTML  

    With an aim to understand the mechanism of surface processing by atmospheric-pressure nonequilibrium discharge plasma jets, we measured the vibrational and rotational temperatures in the plasmas by means of optical emission spectroscopy (OES) measurement method. This paper focuses on the OES measurement method using a torch-shaped atmospheric-pressure nonequilibrium discharge plasma jet power supply consisting of a microwave (2.45-GHz) generator and a high-frequency (5.0-10-kHz) dc pulse power supply, using a gas mixture of Ar (8.0 L/min) and N2 (0.1-0.5 L/min) as the discharge plasma gas, and changing the flow rate of N2 gas at the input power of 100-150 W. Upon comparing vibrational and rotational temperatures (0.18-0.27 eV) determined from the OES measurement method using two types of atmospheric-pressure nonequilibrium discharge plasma jets, results indicate that the microwave discharge plasma jet has considerably low vibrational and rotational temperatures. View full abstract»

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  • AC/DC/Pulsed-Power Modulator for Corona-Plasma Generation

    Publication Year: 2009 , Page(s): 846 - 851
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (387 KB) |  | HTML iconHTML  

    Gas-cleaning techniques using nonthermal plasma are slowly introduced into industry nowadays. In this paper, we present a novel power modulator for the efficient generation of large-volume corona plasma. No expensive high-voltage components are required. Switching is done at an intermediate voltage level of 1 kV with standard thyristors. Detailed investigations on the modulator and a wire-plate corona reactor will be presented. In a systematic way, modulator parameters have been varied. Furthermore, reactor parameters, such as the number of electrodes and the electrode-plate distance, have been varied systematically. The yield of O radicals was determined from the measured ozone concentrations at the exhaust of the reactor. View full abstract»

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  • Spatially Resolved Measurements of Argon Metastable (1{\rm s}_{5}) Density in a High Pressure Microdischarge Using Diode Laser Absorption Spectroscopy

    Publication Year: 2009 , Page(s): 852 - 858
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (745 KB) |  | HTML iconHTML  

    Tunable diode laser absorption spectroscopy was employed to measure the spatially resolved density of argon metastables (1s5) in a high-pressure direct-current argon microdischarge. Analysis of absorption lineshapes provided the gas temperature. The metastable density peaked near the cathode and decayed rapidly in the bulk plasma. The metastable density increased with increasing pressure but decreased with increasing discharge current. Neutral gas heating and the resulting drop in gas density were responsible for the metastable density decrease with increasing current. View full abstract»

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  • Vacuum UV Radiation of a Plasma Jet Operated With Rare Gases at Atmospheric Pressure

    Publication Year: 2009 , Page(s): 859 - 865
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (431 KB) |  | HTML iconHTML  

    The vacuum ultraviolet (VUV) emissions from 115 to 200 nm from the effluent of an RF (1.2 MHz) capillary jet fed with pure argon and binary mixtures of argon and xenon or krypton (up to 20%) are analyzed. The feed gas mixture is emanating into air at normal pressure. The Ar2 excimer second continuum, observed in the region of 120-135 nm, prevails in the pure Ar discharge. It decreases when small amounts (as low as 0.5%) of Xe or Kr are added. In that case, the resonant emission of Xe at 147 nm (or 124 nm for Kr, respectively) becomes dominant. The Xe2 second continuum at 172 nm appears for higher admixtures of Xe (10%). Furthermore, several N I emission lines, the O I resonance line, and H I line appear due to ambient air. Two absorption bands (120.6 and 124.6 nm) are present in the spectra. Their origin could be unequivocally associated to O2 and O3. The radiance is determined end-on at varying axial distance in absolute units for various mixtures of Ar/Xe and Ar/Kr and compared to pure Ar. Integration over the entire VUV wavelength region provides the integrated spectral distribution. Maximum values of 2.2 mW middotmm-2middotsr-1 are attained in pure Ar and at a distance of 4 mm from the outlet nozzle of the discharge. By adding diminutive admixtures of Kr or Xe, the intensity and spectral distribution is effectively changed. View full abstract»

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  • Decontamination of Surfaces From Extremophile Organisms Using Nonthermal Atmospheric-Pressure Plasmas

    Publication Year: 2009 , Page(s): 866 - 871
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (385 KB) |  | HTML iconHTML  

    We showed that nonthermal dielectric barrier discharge (DBD) plasma compromises the integrity of the cell membrane of Deinococcus radiodurans, an extremophile organism. In samples of D. radiodurans, which were dried in a laminar flow hood, we observe that DBD plasma exposure resulted in a six-log reduction in CFU (colony-forming unit) count after 30 min of treatment. When the Deinococcus radiodurans cells were suspended in distilled water and treated, it took only 15 s to achieve a four-log reduction of CFU count. View full abstract»

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  • An Application of AC Glow Discharge Stabilized by Fast Air Flow for Water Treatment

    Publication Year: 2009 , Page(s): 872 - 876
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (410 KB) |  | HTML iconHTML  

    A scheme for a plasma-solution reactor on the basis of a glow discharge stabilized by a fast air flow is suggested as a novel water treatment technique. The discharge ignition voltage is about 2.7 kV, and the input power can be as low as 3 W. It is found that plasma is generated in pulsed mode where the duration of each individual pulse is 15-20 mus. A maximal destruction rate of methylene blue dye of 3.27 times 10-9mol/l middots has been received in an acidic medium at a discharge power level of 6 W. A comparison of the efficiency of plasma interaction in different solutions has been carried out. The chemical effectiveness of the plasma treatment decreases with an increase of solution pH. It is shown that the developed glow discharge two phase reactor can be effectively used for destruction of water pollutants. View full abstract»

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  • Antimicrobial Effects of UV and VUV Radiation of Nonthermal Plasma Jets

    Publication Year: 2009 , Page(s): 877 - 883
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (599 KB) |  | HTML iconHTML  

    Radio-frequency-driven plasma jets in argon at atmospheric pressure have been shown to emit a significant amount of UV and VUV radiation. There is an increasing interest in the use of UV and VUV photons in many fields of research and in industry, in particular for life-science applications. In order to study the antimicrobial effect of plasma-emitted UV and VUV radiation, microbiological tests and plasma diagnostics are combined. In particular, quantitative values of irradiance are estimated. The VUV emission of the plasma jet is dominated by the emission of argon excimer (Ar2). The recorded spectra between 115 and 180 nm also include several atomic emission lines of nitrogen and oxygen. The UV emissions are due to molecular bands of NO, OH, and N2. The best antimicrobial effect is observed by means of direct plasma treatment. UV and VUV emissions have a lower effect, and there is no difference observed between these two components. View full abstract»

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  • Conversion of Nitrous Oxide by Positive Pulsed Corona Discharge

    Publication Year: 2009 , Page(s): 884 - 889
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (319 KB) |  | HTML iconHTML  

    The conversion of nitrous oxide in a positive pulsed corona discharge (PPCD) was studied using two stainless-steel corona reactors with the inner high-voltage electrode made of metal wire (0.3 mm in diameter). The length of the active zone was 0.75 m (reactor R1) or 0.45 m (reactor R2). In the experiments with 5% of oxygen (reactor R1), the overall conversion of N2O (to oxygen, nitrogen, and NOx) considerably decreased, which was about 50% smaller than that in argon alone under the same conditions. The presence of a small amount of oxygen in the gas, containing N2O, allowed us to carry out the process using a considerably lower initial concentration of nitrous oxide. For the initial N2O concentration below 1%, it was observed that the corona discharge is not stable and changes into a spark discharge. When the N2O conversion was carried out in argon and oxygen (5% by volume), the conversion of N2O to NOx was 11.7% for the initial N2O concentration of 2%. The influence of oxygen in Ar + N2O (10%) on the overall conversion and conversion of N2O to NOx was also investigated. The increase of oxygen concentration from 5% to 45% resulted in a decrease of the overall N2 O conversion and its conversion to NOx . PPCD could have been unstable and changed into a spark discharge when the N2O concentration was low. View full abstract»

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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)