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Sample records for capacitively coupled plasma

  1. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  2. Instabilities in a capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Küllig, C., E-mail: kuellig@physik.uni-greifswald.de; Wegner, Th., E-mail: physics@thwegner.com; Meichsner, J., E-mail: meichsner@physik.uni-greifswald.de [Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

    2015-04-15

    Periodic fluctuations in the frequency range from 0.3 to 3 kHz were experimentally investigated in capacitively coupled radio frequency (13.56 MHz) oxygen plasma. The Gaussian beam microwave interferometry directly provides the line integrated electron density fluctuations. A system of two Langmuir probes measured the floating potential spatially (axial, radial) and temporally resolved. Hence, the floating potential fluctuation development is mapped within the discharge volume and provides a kind of discharge breathing and no wave propagation. Finally, it was measured the optical emission pattern of atomic oxygen during the fluctuation as well as the RF phase resolved optical emission intensity at selected phase position of the fluctuation by an intensified charge-coupled device camera. The deduced excitation rate pattern reveals the RF sheath dynamics and electron heating mechanisms, which is changing between low and high electronegativity during a fluctuation cycle. A perturbation calculation was taken into account using a global model with 15 elementary collision processes in the balance equations for the charged plasma species (O{sub 2}{sup +}, e, O{sup −}, O{sub 2}{sup −}) and a harmonic perturbation. The calculated frequencies agree with the experimentally observed frequencies. Whereby, the electron attachment/detachment processes are important for the generation of this instability.

  3. RF capacitively coupled plasma with multi-hole multi electrode

    Science.gov (United States)

    Lee, Hun Su; Lee, Yun Seong; Seo, Sang Hun; Chang, Hong Young

    2011-10-01

    In the photovoltaic industry, it is desired to make plasma discharge of high electron density for the deposition of microcrystalline silicon layer, which is a bottle-neck process in the fabrication of thin film solar cell. So multi-hole electrode instead of plane electrode is used to make capacitively coupled discharge and the deposition rate could be increased because of the plasma density increases by the increased ionization by the energetic secondary electron surrounded by sheath region. To further increase the productivity of the process, high frequency and large electrode area is demanded, however the uniformity of the process is degraded by the change. To solve the matter, the concept of dividing a multi-hole electrode into multiple multi-hole electrode is introduced in the presentation. By dividing electrode into several region and differentiating the hole configuration of each region, local hollow cathode effect can be controlled to make more uniform discharge. To verify the feasibility of the concept, an electrode of RF capacitively coupled plasma is divided and the hole configuration of each electrode. And with 13.56MHz power applied to the electrode, the spatial plasma distribution of the discharge is measured.

  4. Electron heating in capacitively coupled RF plasmas: a unified scenario

    Science.gov (United States)

    Brinkmann, Ralf Peter

    2016-02-01

    Electron heating in radio-frequency capacitively coupled plasmas (RF-CCP) is studied from first principles. The starting points are the electron equations of continuity and motion, with ionization neglected but electric and pressure forces and elastic collisions with the neutral background taken into account. Poisson’s equation self-consistently calculates the electric field; the ion density is assumed as a given. Postulating that the Debye length {λ\\text{D}} is small compared to the sheath length scale l and the applied frequency {ω\\text{RF}} is small compared to the electron plasma frequency {ω\\text{pe}} , an asymptotic expansion in the smallness parameter ε ={λ\\text{D}}/l∼ {ω\\text{RF}}/{ω\\text{pe}} is conducted. As has been demonstrated before (Brinkmann 2015 Plasma Sources Sci. Technol. 24 064002), this ansatz gives an expression—the smooth step model (SSM)—which yields (i) the space charge field in the unipolar region, (ii) the generalized Ohmic field in the ambipolar region, and (iii) a smooth interpolation for the rapid transition in between. Using the SSM and formulas for the electron density and the electron flux, expressions for the electric force and the electric power density are established which hold up to O≤ft(ε \\right) . Integrating over the sheath and taking the phase average, a representation for the total dissipated power is found as a sum of four physically distinct contributions. All terms correspond to electron heating mechanisms which are (explicitly or implicitly) already known but were so far discussed only within mutually incompatible frameworks.

  5. A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

    International Nuclear Information System (INIS)

    In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10% by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas

  6. Cleaning of optical surfaces by capacitively coupled RF discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, P. K., E-mail: praveenyadav@rrcat.gov.in; Rai, S. K.; Nayak, M.; Lodha, G. S. [X-ray Optics Section, Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore- 452013 (India); Kumar, M.; Chakera, J. A.; Naik, P. A. [Laser Plasma Laboratory, Laser Plasma Division Raja Ramanna Centre for Advanced Technology, Indore- 452013 (India); Mukherjee, C. [Mechanical and Optical Support Section, Raja Ramanna Centre for Advanced Technology, Indore- 452013 (India)

    2014-04-24

    In this paper, we report cleaning of carbon capped molybdenum (Mo) thin film by in-house developed radio frequency (RF) plasma reactor, at different powers and exposure time. Carbon capped Mo films were exposed to oxygen plasma for different durations at three different power settings, at a constant pressure. After each exposure, the thickness of the carbon layer and the roughness of the film were determined by hard x-ray reflectivity measurements. It was observed that most of the carbon film got removed in first 15 minutes exposure. A high density layer formed on top of the Mo film was also observed and it was noted that this layer cannot be removed by successive exposures at different powers. A significant improvement in interface roughness with a slight improvement in top film roughness was observed. The surface roughness of the exposed and unexposed samples was also confirmed by atomic force microscopy measurements.

  7. Control of plasma properties in capacitively coupled oxygen discharges via the electrical asymmetry effect

    OpenAIRE

    Schüngel, E; Zhang, Q-Z; Iwashita, S; J. Schulze(Universität Bochum I. Institut für Experimentalphysik, Germany); Hou, L-J; Wang, Y-N; Czarnetzki, U

    2011-01-01

    Abstract By using a combined experimental, numerical and analytical approach, we investigate the control of plasma properties via the Electrical Asymmetry Effect (EAE) in a capacitively coupled oxygen discharge. In particular, we present the first experimental investigation of the EAE in electronegative discharges. A dual-frequency voltage source of 13.56 MHz and 27.12 MHz is applied to the powered electrode and the discharge symmetry is controlled by adjusting the phase angle ? between th...

  8. Influence of finite geometrical asymmetry of the electrodes in capacitively coupled radio frequency plasma

    International Nuclear Information System (INIS)

    Capacitively coupled radio frequency (CCRF) plasmas are widely studied in last decades due to the versatile applicability of energetic ions, chemically active species, radicals, and also energetic neutral species in many material processing fields including microelectronics, aerospace, and biology. A dc self-bias is known to generate naturally in geometrically asymmetric CCRF plasma because of the difference in electrode sizes known as geometrical asymmetry of the electrodes in order to compensate electron and ion flux to each electrode within one rf period. The plasma series resonance effect is also come into play due to the geometrical asymmetry and excited several harmonics of the fundamental in low pressure CCRF plasma. In this work, a 13.56 MHz CCRF plasma is studied on the based on the nonlinear global model of asymmetric CCRF discharge to understand the influences of finite geometrical asymmetry of the electrodes in terms of generation of dc self-bias and plasma heating. The nonlinear global model on asymmetric discharge has been modified by considering the sheath at the grounded electrode to taking account the finite geometrical asymmetry of the electrodes. The ion density inside both the sheaths has been taken into account by incorporating the steady-state fluid equations for ions considering that the applied rf frequency is higher than the typical ion plasma frequency. Details results on the influences of geometrical asymmetry on the generation of dc self-bias and plasma heating are discussed

  9. Investigation of capacitively coupled argon plasma driven at various frequencies and validation of surface waves excitation

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Fattah, E., E-mail: essam29@hotmail.com [Physics Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Physics Department, College of Science, Salman bin AbdulAziz University, Al-Kharj, P.O. 83, Al-Kharj 11942 (Saudi Arabia)

    2013-01-03

    The influence of excitation frequency (13.56–96 MHz) on the characteristics of capacitively coupled argon plasma is investigated by means of Langmuir probe and a high-voltage probe. Measurements are performed in argon pressure of 40 and 60 mTorr at a fixed discharge voltage V{sub pp}=200 V. The measured electron energy distribution function EEPFs are a bi-Maxwellian type irrespective of the driving frequency and gas pressure. The electron density and temperatures show peak over frequency range of 54–72 MHz, beyond which it decreases. The non-monotonic dependences of plasma parameters with driving frequency were interpreted in terms of excited surface wave excited at the powered electrode.

  10. CHF3 Dual-Frequency Capacitively Coupled Plasma by Optical Emission Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    XU Yi-Jun; YE Chao; HUANG Xiao-Jiang; YUAN Jing; XING Zhen-Yu; NING Zhao-Yuan

    2008-01-01

    @@ We investigate the intermediate gas phase in the CHF3 13.56 MHz//2 MHz dual-frequency capacitively couple plasma (CCP) for the SiCOH low dielectric constant (low-k) film etching, and the effect of 2MHz power on radicals concentration. The major dissociation reactions of CHF3 in 13.56 MHz CCP are the low dissociation bond energy reactions, which lead to the low F and high CF2 concentrations. The addition of 2MHz power can raise the probability of high dissociation bond energy reactions and lead to the increase of F concentration while keeping the CF2 concentration almost a constant, which is of advantage to the SiCOH low-k films etching. The radical spatial uniformity is dependent on the power coupling of two sources. The increase of 2 MHz power leads to a poor uniformity, however, the uniformity can be improved by increasing 13.56 MHz power.

  11. Self-bias Dependence on Process Parameters in Asymmetric Cylindrical Coaxial Capacitively Coupled Plasma

    CERN Document Server

    Upadhyay, J; Popović, S; Valente-Feliciano, A -M; Phillips, L; Vušković, L

    2015-01-01

    An rf coaxial capacitively coupled Ar/Cl2 plasma is applied to processing the inner wall of superconducting radio frequency cavities. A dc self-bias potential is established across the inner electrode sheath due to the surface area difference between inner and outer electrodes of the coaxial plasma. The self-bias potential measurement is used as an indication of the plasma sheath voltage asymmetry. The understanding of the asymmetry in sheath voltage distribution in coaxial plasma is important for the modification of the inner surfaces of three dimensional objects. The plasma sheath voltages were tailored to process the outer wall by providing an additional dc current to the inner electrode with the help of an external dc power supply. The dc self-bias potential is measured for different diameter electrodes and its variation on process parameters such as gas pressure, rf power and percentage of chlorine in the Ar/Cl2 gas mixture is studied. The dc current needed to overcome the self-bias potential to make it ...

  12. Customized ion flux-energy distribution functions in capacitively coupled plasmas by voltage waveform tailoring

    CERN Document Server

    Schuengel, E; Hartmann, P; Derzsi, A; Korolov, I; Schulze, J

    2016-01-01

    We propose a method to generate a single peak at a distinct energy in the ion flux-energy distribution function (IDF) at the electrode surfaces in capacitively coupled plasmas. The technique is based on the tailoring of the driving voltage waveform, i.e. adjusting the phases and amplitudes of the applied harmonics, to optimize the accumulation of ions created by charge exchange collisions and their subsequent acceleration by the sheath electric field. The position of the peak (i.e. the ion energy) and the flux of the ions within the peak of the IDF can be controlled in a wide domain by tuning the parameters of the applied RF voltage waveform, allowing optimization of various applications where surface reactions are induced at particular ion energies.

  13. Reversal of the Asymmetry in a Cylindrical Coaxial Capacitively Coupled Ar/Cl2 Plasma

    CERN Document Server

    Upadhyay, J; Popović, S; Valente-Feliciano, A -M; Phillips, L; Vušković, L

    2015-01-01

    The reduction of the asymmetry in the plasma sheath voltages of a cylindrical coaxial capacitively coupled plasma is crucial for efficient surface modification of the inner surfaces of concave three-dimensional structures, including superconducting radio frequency cavities. One critical asymmetry effect is the negative dc self-bias, formed across the inner electrode plasma sheath due to its lower surface area compared to the outer electrode. The effect on the self-bias potential with the surface enhancement by geometric modification on the inner electrode structure is studied. The shapes of the inner electrodes are chosen as cylindrical tube, large and small pitch bellows, and disc-loaded corrugated structure (DLCS). The dc self-bias measurements for all these shapes were taken at different process parameters in Ar/Cl2 discharge. The reversal of the negative dc self-bias potential to become positive for a DLCS inner electrode was observed and the best etch rate is achieved due to the reduction in plasma asymm...

  14. Simulation of Main Plasma Parameters of a Cylindrical Asymmetric Capacitively Coupled Plasma Micro-Thruster using Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Amelia eGreig

    2015-01-01

    Full Text Available Computational fluid dynamics (CFD simulations of a radio-frequency (13.56 MHz electro-thermal capacitively coupled plasma (CCP micro-thruster have been performed using the commercial CFD-ACE+ package. Standard operating conditions of a 10 W, 1.5 Torr argon discharge were used to compare with previously obtained experimental results for validation. Results show that the driving force behind plasma production within the thruster is ion-induced secondary electrons ejected from the surface of the discharge tube, accelerated through the sheath to electron temperatures up to 33.5 eV. The secondary electron coefficient was varied to determine the effect on the discharge, with results showing that full breakdown of the discharge did not occur for coefficients coefficients less than or equal to 0.01.

  15. Slope and amplitude asymmetry effects on low frequency capacitively coupled carbon tetrafluoride plasmas

    Science.gov (United States)

    Bruneau, B.; Korolov, I.; Lafleur, T.; Gans, T.; O'Connell, D.; Greb, A.; Derzsi, A.; Donkó, Z.; Brandt, S.; Schüngel, E.; Schulze, J.; Johnson, E.; Booth, J.-P.

    2016-04-01

    We report investigations of capacitively coupled carbon tetrafluoride (CF4) plasmas excited with tailored voltage waveforms containing up to five harmonics of a base frequency of 5.5 MHz. The impact of both the slope asymmetry, and the amplitude asymmetry, of these waveforms on the discharge is examined by combining experiments with particle-in-cell simulations. For all conditions studied herein, the discharge is shown to operate in the drift-ambipolar mode, where a comparatively large electric field in the plasma bulk (outside the sheaths) is the main mechanism for electron power absorption leading to ionization. We show that both types of waveform asymmetries strongly influence the ion energy at the electrodes, with the particularity of having the highest ion flux on the electrode where the lowest ion energy is observed. Even at the comparatively high pressure (600 mTorr) and low fundamental frequency of 5.5 MHz used here, tailoring the voltage waveforms is shown to efficiently create an asymmetry of both the ion energy and the ion flux in geometrically symmetric reactors.

  16. Capacitively coupled hydrogen plasmas sustained by tailored voltage waveforms: excitation dynamics and ion flux asymmetry

    Science.gov (United States)

    Bruneau, B.; Diomede, P.; Economou, D. J.; Longo, S.; Gans, T.; O’Connell, D.; Greb, A.; Johnson, E.; Booth, J.-P.

    2016-08-01

    Parallel plate capacitively coupled plasmas in hydrogen at relatively high pressure (~1 Torr) are excited with tailored voltage waveforms containing up to five frequencies. Predictions of a hybrid model combining a particle-in-cell simulation with Monte Carlo collisions and a fluid model are compared to phase resolved optical emission spectroscopy measurements, yielding information on the dynamics of the excitation rate in these discharges. When the discharge is excited with amplitude asymmetric waveforms, the discharge becomes electrically asymmetric, with different ion energies at each of the two electrodes. Unexpectedly, large differences in the \\text{H}2+ fluxes to each of the two electrodes are caused by the different \\text{H}3+ energies. When the discharge is excited with slope asymmetric waveforms, only weak electrical asymmetry of the discharge is observed. In this case, electron power absorption due to fast sheath expansion at one electrode is balanced by electron power absorption at the opposite electrode due to a strong electric field reversal.

  17. Simulation of cold plasma in a chamber under high- and low-frequency voltage conditions for a capacitively coupled plasma

    Institute of Scientific and Technical Information of China (English)

    Hao Daoxin; Cheng Jia; Ji Linhong; Sun Yuchun

    2012-01-01

    The characteristics of cold plasma,especially for a dual-frequency capacitively coupled plasma (CCP),play an important role for plasma enhanced chemical vapor deposition,which stimulates further studies using different methods.In this paper,a 2D fluid model was constructed for N2 gas plasma simulations with CFD-ACE+,a commercial multi-physical software package.First,the distributions of electric potential (Epot),electron number density (Ne),N number density (N) and electron temperature (Te) are described under the condition of high frequency (HF),13.56 MHz,HF voltage,300 V,and low-frequency (LF) voltage,0 V,particularly in the sheath.Based on this,the influence of HF on Ne is further discussed under different HF voltages of 200 V,300 V,400 V,separately,along with the influence of LF,0.3 MHz,and various LF voltages of 500 V,600 V,700 V.The results show that sheaths of about 3 mm are formed near the two electrodes,in which Epot and Te vary extensively with time and space,while in the plasma bulk Epot changes synchronously with an electric potential of about 70 V and Te varies only in a small range.N is also modulated by the radio frequency,but the relative change in N is small.Ne varies only in the sheath,while in the bulk it is steady at different time steps.So,by comparing Ne in the plasma bulk at the steady state,we can see that Ne will increase when HF voltage increases.Yet,Ne will slightly decrease with the increase of LF voltage.At the same time,the homogeneity will change in both x and y directions.So both HF and LF voltages should be carefully considered in order to obtain a high-density,homogeneous plasma.

  18. Experimental observation and computational analysis of striations in electronegative capacitively coupled radio-frequency plasmas

    CERN Document Server

    Liu, Yong-Xin; Korolov, Ihor; Donko, Zoltan; Wang, You-Nian; Schulze, Julian

    2016-01-01

    Self-organized spatial structures in the light emission from the ion-ion capacitive RF plasma of a strongly electronegative gas (CF4) are observed experimentally for the first time. Their formation is analyzed and understood based on particle-based kinetic simulations. These "striations" are found to be generated by the resonance between the driving radio-frequency and the eigenfrequency of the ion-ion plasma (derived from an analytical model) that establishes a modulation of the electric field, the ion densities, as well as the energy gain and loss processes of electrons in the plasma. The growth of the instability is followed by the numerical simulations.

  19. Tailored voltage waveform capacitively coupled plasmas in electronegative gases: frequency dependence of asymmetry effects

    Science.gov (United States)

    Schüngel, E.; Korolov, I.; Bruneau, B.; Derzsi, A.; Johnson, E.; O’Connell, D.; Gans, T.; Booth, J.-P.; Donkó, Z.; Schulze, J.

    2016-07-01

    Capacitively coupled radio frequency plasmas operated in an electronegative gas (CF4) and driven by voltage waveforms composed of four consecutive harmonics are investigated for different fundamental driving frequencies using PIC/MCC simulations and an analytical model. As has been observed previously for electropositive gases, the application of peak-shaped waveforms (that are characterized by a strong amplitude asymmetry) results in the development of a DC self-bias due to the electrical asymmetry effect (EAE), which increases the energy of ions arriving at the powered electrode. In contrast to the electropositive case (Korolov et al 2012 J. Phys. D: Appl. Phys. 45 465202) the absolute value of the DC self-bias is found to increase as the fundamental frequency is reduced in this electronegative discharge, providing an increased range over which the DC self-bias can be controlled. The analytical model reveals that this increased DC self-bias is caused by changes in the spatial profile and the mean value of the net charge density in the grounded electrode sheath. The spatio-temporally resolved simulation data show that as the frequency is reduced the grounded electrode sheath region becomes electronegative. The presence of negative ions in this sheath leads to very different dynamics of the power absorption of electrons, which in turn enhances the local electronegativity and plasma density via ionization and attachment processes. The ion flux to the grounded electrode (where the ion energy is lowest) can be up to twice that to the powered electrode. At the same time, while the mean ion energies at both electrodes are quite different, their ratio remains approximately constant for all base frequencies studied here.

  20. The discharge mode transition and O(5p1) production mechanism of pulsed radio frequency capacitively coupled plasma

    Science.gov (United States)

    Liu, X. Y.; Hu, J. T.; Liu, J. H.; Xiong, Z. L.; Liu, D. W.; Lu, X. P.; Shi, J. J.

    2012-07-01

    The discharge mode transition from uniform plasma across the gas gap to the α mode happens at the rising phase of the pulsed radio frequency capacitively coupled plasma (PRF CCP). This transition is attributed to the fast increasing stochastic heating at the edge of sheath. In the second stage with the stable current and voltage amplitude, the consistency between experimental and numerical spatial-temporal 777 nm emission profile suggests that He* and He2* dominate the production of O(5p1) through dissociation and excitation of O2. Finally, the sterilization efficiency of PRF CCP is found to be higher than that of plasma jet.

  1. The discharge mode transition and O(5p1) production mechanism of pulsed radio frequency capacitively coupled plasma

    International Nuclear Information System (INIS)

    The discharge mode transition from uniform plasma across the gas gap to the α mode happens at the rising phase of the pulsed radio frequency capacitively coupled plasma (PRF CCP). This transition is attributed to the fast increasing stochastic heating at the edge of sheath. In the second stage with the stable current and voltage amplitude, the consistency between experimental and numerical spatial-temporal 777 nm emission profile suggests that He* and He2* dominate the production of O(5p1) through dissociation and excitation of O2. Finally, the sterilization efficiency of PRF CCP is found to be higher than that of plasma jet.

  2. Plasma inhomogeneities near the electrodes of a capacitively-coupled radio-frequency discharge containing dust particles

    OpenAIRE

    Tawidian, Hagop; Mikikian, Maxime; Couëdel, Lénaïc; Lecas, Thomas

    2011-01-01

    Abstract Small plasma spheroids are evidenced and analyzed in front of the electrodes of a capacitively-coupled radio-frequency discharge in which dust particles are growing. These regions are characterized by a spherical shape, a slightly enhanced luminosity and are related to instabilities induced by the presence of dust particles. Several types of behaviors are identified and particularly their chaotic appearance or disappearance and their rotational motion along the electrode p...

  3. Surface-plasma interactions in GaAs subjected to capacitively coupled RF plasmas

    CERN Document Server

    Surdu-Bob, C C

    2002-01-01

    Surface compositional changes in GaAs due to RF plasmas of different gases have been investigated by XPS and etch rates were measured using AFM. Angular Resolved XPS (ARXPS) was also employed for depth analysis of the composition of the surface layers. An important role in this study was determination of oxide thickness using XPS data. The study of surface - plasma interaction was undertaken by correlating results of surface analysis with plasma diagnosis. Different experiments were designed to accurately measure the BEs associated with the Ga 3d, Ga 2p sub 3 sub / sub 2 and LMM peaks using XPS analysis and propose identification in terms of the oxides of GaAs. Along with GaAs wafers, some reference compounds such as metallic Ga and Ga sub 2 O sub 3 powder were used. A separate study aiming the identification of the GaAs surface oxides formed on the GaAs surface during and after plasma processing was undertaken. Surface compositional changes after plasma treatment, prior to surface analysis are considered, wi...

  4. Influence of dielectric materials on uniformity of large-area capacitively coupled plasmas for N2/Ar discharges

    Science.gov (United States)

    Liang, Ying-Shuang; Zhang, Yu-Ru; Wang, You-Nian

    2016-10-01

    The effect of the dielectric ring on the plasma radial uniformity is numerically investigated in the practical 450-mm capacitively coupled plasma reactor by a two-dimensional self-consistent fluid model. The simulations were performed for N2/Ar discharges at the pressure of 300 Pa, and the frequency of 13.56 MHz. In the practical plasma treatment process, the wafer is always surrounded by a dielectric ring, which is less studied. In this paper, the plasma characteristics are systematically investigated by changing the properties of the dielectric ring, i.e., the relative permittivity, the thickness and the length. The results indicate that the plasma parameters strongly depend on the properties of the dielectric ring. As the ratio of the thickness to the relative permittivity of the dielectric ring increases, the electric field at the wafer edge becomes weaker due to the stronger surface charging effect. This gives rise to the lower ion density, flux and N atom density at the wafer edge. Thus the homogeneous plasma density is obtained by selecting optimal dielectric ring relative permittivity and thickness. In addition, we also find that the length of the dielectric ring should be as short as possible to avoid the discontinuity of the dielectric materials, and thus obtain the large area uniform plasma. Project supported by the National Natural Science Foundation of China (Grant Nos. 11335004 and 11405019) and the Important National Science and Technology Specific Project of China (Grant No. 2011ZX02403-001).

  5. Modeling of discharges in a capacitively coupled dual frequency plasma reactor

    Directory of Open Access Journals (Sweden)

    Bojarov Aleksandar

    2009-01-01

    Full Text Available In this paper we have modeled a dual frequency coupled plasma reactor (DF-CCP by using a 1d3v PIC/MCC code. The obtained results apart from their theoretical relevance have practical applications especially for development of plasma reactors and for nanoelectronics. Dual frequency plasmas are used for etching of dielectric interconnect layers with high aspect ratios (contact holes. In the DF-CCP, the density of the plasma is controlled by the high frequency, while the ion energy depends mainly on the potential drop in the sheath, which is controlled by the low frequency. The results of our simulations show the dependence of the energy of the ions arriving at the inner electrode on the voltage of the low frequency generator and how the voltage of the high frequency generator affects the ion flux on the electrode.

  6. The effects of process conditions on the plasma characteristic in radio-frequency capacitively coupled SiH4/NH3/N2 plasmas:Two-dimensional simulations

    Institute of Scientific and Technical Information of China (English)

    Liu Xiang-Mei; Song Yuan-Hong; Jiang Wei; Yi Lin

    2013-01-01

    A two-dimensional (2D) fluid model is presented to study the behavior of silicon plasma mixed with SiH4,N2,and NH3 in a radio-frequency capacitively coupled plasma (CCP) reactor.The plasma-wall interaction (including the deposition) is modeled by using surface reaction coefficients.In the present paper we try to identify,by numerical simulations,the effect of variations of the process parameters on the plasma properties.It is found from our simulations that by increasing the gas pressure and the discharge gap,the electron density profile shape changes continuously from an edge-high to a center-high,thus the thin films become more uniform.Moreover,as the N2/NH3 ratio increases from 6/13 to 10/9,the hydrogen content can be significantly decreased,without decreasing the electron density significantly.

  7. 2D fluid model analysis for the effect of 3D gas flow on a capacitively coupled plasma deposition reactor

    Science.gov (United States)

    Kim, Ho Jun; Lee, Hae June

    2016-06-01

    The wide applicability of capacitively coupled plasma (CCP) deposition has increased the interest in developing comprehensive numerical models, but CCP imposes a tremendous computational cost when conducting a transient analysis in a three-dimensional (3D) model which reflects the real geometry of reactors. In particular, the detailed flow features of reactive gases induced by 3D geometric effects need to be considered for the precise calculation of radical distribution of reactive species. Thus, an alternative inclusive method for the numerical simulation of CCP deposition is proposed to simulate a two-dimensional (2D) CCP model based on the 3D gas flow results by simulating flow, temperature, and species fields in a 3D space at first without calculating the plasma chemistry. A numerical study of a cylindrical showerhead-electrode CCP reactor was conducted for particular cases of SiH4/NH3/N2/He gas mixture to deposit a hydrogenated silicon nitride (SiN x H y ) film. The proposed methodology produces numerical results for a 300 mm wafer deposition reactor which agree very well with the deposition rate profile measured experimentally along the wafer radius.

  8. Ion species and electron behavior in capacitively coupled Ar and O2 plasma

    International Nuclear Information System (INIS)

    We investigated the change in electron density using the plasma frequency by the wave cutoff method, and the behavior of ion species with a quadrupole mass spectrometer (QMS) in pure Ar and O2 and mixed O2/Ar plasmas. The change in electron and ion density in pure Ar and O2 plasmas was evaluated while varying such process conditions as rf power and pressure. We found that electron density in a pure Ar and O2 discharge is closely correlated to loss and generation of ions. The electron densities in both pure Ar and O2 plasmas increase with rf plasma power but show different dependence on pressure due to different loss mechanism for each type of gas. The addition of Ar to an O2 plasma significantly enhances the electron density due to the rapid increase of Ar+ ions regardless of the pressure. Also, Ar addition results in more dissociation of O2, which gives more atomic O. These results indicate that the electron density calculated from the plasma frequency, measured by the wave cutoff method, is well explained by the ion behavior, as characterized by QMS

  9. Spatial evolution of the electron energy distribution function in a low-pressure capacitively coupled plasma containing argon and krypton

    International Nuclear Information System (INIS)

    The spatial evolution of the electron energy distribution function (EEDF) in the axial direction of a capacitively coupled plasma with two parallel plate electrodes is investigated using an optical emission line-ratio method for Ar/Kr discharges. When the rf power is increased from 25 to 400 W at a pressure of 400 mTorr, we observe a transition from convex EEDFs to concave ones and a sharp increase in electron density, due to an α–γ mode transition, which is believed to be caused by the high-energy electrons originating in the high-voltage sheath. We also investigate the spatial evolution of the EEDF when the pressure is increased from 45 to 500 mTorr at a power of 100 W. The EEDF is uniform at pressures below 180 mTorr and becomes non-uniform at higher pressures, owing to the decrease in the energy relaxation length of the high-energy electrons. (paper)

  10. Phase Transitions in a Capacitively Coupled Dusty Plasma with Conducting Dust

    Science.gov (United States)

    Carmona-Reyes, Jorge; Matthews, Lorin; Hyde, Truell

    2011-10-01

    Complex plasma is present in a variety of environments including planetary rings, cometary tails, interplanetary clouds and semiconductor manufacturing and fusion environments. Understanding the physics behind such complex plasmas, particularly those comprised of conducting dust, is not well understood. In this work, a GEC reference cell is employed to examine the translational and orientational order of conducting dust contained within crystal lattice structures formed in a complex plasma. The Pair Correlation function, bond orientation function and Voronoi and polygon construction diagrams are used to measure dislocations and disclinations, yielding a quantitative measure of the overall phase of the structure. The role this phase transition process plays in the melting of conducting and non-conducting 2D structures will be discussed.

  11. Numerical study of capacitive coupled HBr/Cl2 plasma discharge for dry etch applications

    Science.gov (United States)

    Gul, Banat; Ahmad, Iftikhar; Zia, Gulfam; Aman-ur-Rehman

    2016-09-01

    HBr/Cl2 plasma discharge is investigated to study the etchant chemistry of this discharge by using the self-consistent fluid model. A comprehensive set of gas phase reactions (83 reactions) including primary processes such as excitation, dissociation, and ionization are considered in the model along with 24 species. Our findings illustrate that the densities of neutral species (i.e., Br, HCl, Cl, H, and H2) produced in the reactor are higher than charged species (i.e., Cl2+, Cl-, HBr+, and Cl+). Density profile of neutral and charged species followed bell shaped and double humped distributions, respectively. Increasing Cl2 fraction in the feedback gases (HBr/Cl2 from 90/10 to 10/90) promoted the production of Cl, Cl+, and Cl2+ in the plasma, indicating that chemical etching pathway may be preferred at high Cl-environment. These findings pave the way towards controlling/optimizing the Si-etching process.

  12. Electron heating enhancement due to plasma series resonance in a capacitively coupled RF discharge: Electrical modeling and comparison to experimental measurements

    Science.gov (United States)

    Cao, Minglu; Lu, Yijia; Cheng, Jia; Ji, Linhong

    2016-09-01

    The electron heating enhancement due to the self-excitation of the plasma series resonance in capacitively coupled plasmas is revisited by a combination of an equivalent circuit model and experiments. To improve the model accuracy, measured voltage waveforms at the powered electrode are used instead of prescribing a sinusoidal voltage supply in series with a bias capacitance. The results calculated from the electrical model are consistent with the experimental measurements performed by a Langmuir probe with verification of a microwave interferometer, at pressures of 0.2 and 0.3 Torr. High harmonics occurring in the discharge currents agree with observations in previous research. The nonlinear plasma series resonance effect is found to have a notable contribution to both ohmic and stochastic heating evaluated by the electron heating efficiencies.

  13. Effect of driving voltages in dual capacitively coupled radio frequency plasma: A study by nonlinear global model

    International Nuclear Information System (INIS)

    On the basis of nonlinear global model, a dual frequency capacitively coupled radio frequency plasma driven by 13.56 MHz and 27.12 MHz has been studied to investigate the influences of driving voltages on the generation of dc self-bias and plasma heating. Fluid equations for the ions inside the plasma sheath have been considered to determine the voltage-charge relations of the plasma sheath. Geometrically symmetric as well as asymmetric cases with finite geometrical asymmetry of 1.2 (ratio of electrodes area) have been considered to make the study more reasonable to experiment. The electrical asymmetry effect (EAE) and finite geometrical asymmetry is found to work differently in controlling the dc self-bias. The amount of EAE has been primarily controlled by the phase angle between the two consecutive harmonics waveforms. The incorporation of the finite geometrical asymmetry in the calculations shift the dc self-bias towards negative polarity direction while increasing the amount of EAE is found to increase the dc self-bias in either direction. For phase angle between the two waveforms ϕ = 0 and ϕ = π/2, the amount of EAE increases significantly with increasing the low frequency voltage, whereas no such increase in the amount of EAE is found with increasing high frequency voltage. In contrast to the geometrically symmetric case, where the variation of the dc self-bias with driving voltages for phase angle ϕ = 0 and π/2 are just opposite in polarity, the variation for the geometrically asymmetric case is different for ϕ = 0 and π/2. In asymmetric case, for ϕ = 0, the dc self-bias increases towards the negative direction with increasing both the low and high frequency voltages, but for the ϕ = π/2, the dc-self bias is increased towards positive direction with increasing low frequency voltage while dc self-bias increases towards negative direction with increasing high frequency voltage

  14. The discharge mode transition and O({sup 5}p{sub 1}) production mechanism of pulsed radio frequency capacitively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. Y.; Hu, J. T.; Liu, J. H.; Xiong, Z. L.; Liu, D. W.; Lu, X. P. [National State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, HuBei 430074 (China); Shi, J. J. [College of Science, Donghua University, Shanghai 201620 (China)

    2012-07-23

    The discharge mode transition from uniform plasma across the gas gap to the {alpha} mode happens at the rising phase of the pulsed radio frequency capacitively coupled plasma (PRF CCP). This transition is attributed to the fast increasing stochastic heating at the edge of sheath. In the second stage with the stable current and voltage amplitude, the consistency between experimental and numerical spatial-temporal 777 nm emission profile suggests that He* and He{sub 2}* dominate the production of O({sup 5}p{sub 1}) through dissociation and excitation of O{sub 2}. Finally, the sterilization efficiency of PRF CCP is found to be higher than that of plasma jet.

  15. Capacitance-coupled wiper increases potentiometer life

    Science.gov (United States)

    Dimeff, J.

    1968-01-01

    Capacitively-coupled wiper reduces the friction between the sliding contact and the potentiometer element in conventional potentiometers. A small preamplifier employed close to the wiper reduces errors caused by output cable capacitance. The device is friction free with resultant low wear and has high speed and high resolution.

  16. Tuning the ITO work function by capacitively coupled plasma and its application in inverted organic solar cells

    Science.gov (United States)

    Fang, Ming; Zhang, Chunmei; Chen, Qiang

    2016-11-01

    In this paper, we investigated the performance of inverted organic solar cells (OSCs) with plasma-treated indium tin oxide (ITO) as the cathode for omitting an electron transport layer. The Ar plasma was produced by capcitively coupled plasma setup under 20 Pa chamber pressure. For the device with the structure of plasma-treated ITO/P3HT:PCBM/MoO3/Ag, a power conversion efficiency (PCE) of 3.22% was achieved, whereas PCE of 1.13% was recorded from the device fabricated with the pristine ITO. The photovoltaic performance was found to be dependent on the applied power of plasma. After analyzing by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), we concluded that the chemical component variation of ITOs surface resulted in the decrease of ITO work function, which meant that the ITO Fermi level became shallow relative to the vacuum level. The low work function of ITO should be responsible for the improvement of inverted OSCs because of the better energy level alignment between ITO and the photoactive layer.

  17. A comparative study of capacitively coupled HBr/He, HBr/Ar plasmas for etching applications: Numerical investigation by fluid model

    Energy Technology Data Exchange (ETDEWEB)

    Gul, Banat, E-mail: banatgul@gmail.com [Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad 45650 (Pakistan); Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Aman-ur-Rehman, E-mail: amansadiq@gmail.com [Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Nilore, Islamabad 45650 (Pakistan)

    2015-10-15

    Fluid model has been applied to perform a comparative study of hydrogen bromide (HBr)/He and HBr/Ar capacitively coupled plasma discharges that are being used for anisotropic etching process. This model has been used to identify the most dominant species in HBr based plasmas. Our simulation results show that the neutral species like H and Br, which are the key player in chemical etching, have bell shape distribution, while ions like HBr{sup +}, Br{sup +}, which play a dominant rule in the physical etching, have double humped distribution and show peaks near electrodes. It was found that the dilution of HBr by Ar and/or He results in an increase in electron density and electron temperature, which results in more ionization and dissociation and hence higher densities of neutral and charged species can be achieved. The ratio of positive ion flux to the neutral flux increases with an increase in additive gas fraction. Compare to HBr/He plasma, the HBr/Ar plasma shows a maximum change in the ion density and flux and hence the etching rate can be considered in the ion-assisted and in the ion-flux etch regime in HBr/Ar discharge. The densities of electron and other dominant species in HBr/Ar plasma are higher than those of HBr/He plasma. The densities and fluxes of the active neutrals and positive ions for etching and subsequently chemical etching versus physical sputtering in HBr/Ar and HBr/He plasmas discharge can be controlled by tuning gas mixture ratio and the desire etching can be achieved.

  18. Measurements of heat flux distribution toward substrate by means of the LiNbO3 interferometer, and electron density in a capacitively coupled rf discharge plasma

    International Nuclear Information System (INIS)

    Measurement of temperature by the laser interferometry method with a LiNbO3 substrate and determination of heat flux in capacitively coupled plasma (CCP) are described. This method is based on monitoring the variation on nature birefringence with temperature. The CCP is generated at 20 or 40 mm gap length, 100 mTorr argon gas pressure, and 250 cc/min gas flow with an rf input power of 100 W. The rf power is supplied to the lower electrodes through a L-type matching network containing a coupling capacitor and the upper electrode is grounded. The heat flux and electron density distribution possess the same peak characteristics around the maximal point of plasma density under the same experimental conditions. The average diffusion flux for electrons and ions can be calculated from the electron distribution and ambipolar diffusion coefficient. The axial and radial diffusion fluxes are 2.4 x 1012 and 8.1 x 1012/cm2 s, respectively. Taking account of the electrode and side area, we find that the total axial flux is 10 times larger than the radial one

  19. Highly selective etching of silicon nitride to physical-vapor-deposited a-C mask in dual-frequency capacitively coupled CH2F2/H2 plasmas

    International Nuclear Information System (INIS)

    A multilevel resist (MLR) structure can be fabricated based on a very thin amorphous carbon (a-C) layer ( congruent with 80 nm) and Si3N4 hard-mask layer ( congruent with 300 nm). The authors investigated the selective etching of the Si3N4 layer using a physical-vapor-deposited (PVD) a-C mask in a dual-frequency superimposed capacitively coupled plasma etcher by varying the process parameters in the CH2F2/H2/Ar plasmas, viz., the etch gas flow ratio, high-frequency source power (PHF), and low-frequency source power (PLF). They found that under certain etch conditions they obtain infinitely high etch selectivities of the Si3N4 layers to the PVD a-C on both the blanket and patterned wafers. The etch gas flow ratio played a critical role in determining the process window for infinitely high Si3N4/PVD a-C etch selectivity because of the change in the degree of polymerization. The etch results of a patterned ArF photoresisit/bottom antireflective coating/SiOx/PVD a-C/Si3N4 MLR structure supported the idea of using a very thin PVD a-C layer as an etch-mask layer for the Si3N4 hard-mask pattern with a pattern width of congruent with 80 nm and high aspect ratio of congruent with 5.

  20. Simple and robust method for lithium traces determination in drinking water by atomic emission using low-power capacitively coupled plasma microtorch and microspectrometer.

    Science.gov (United States)

    Zsigmond, Andreea R; Frentiu, Tiberiu; Ponta, Michaela; Frentiu, Maria; Petreus, Dorin

    2013-12-15

    A method for Li determination in drinking water using atomic emission spectrometry in a new low-power Ar capacitively coupled plasma microtorch (15 W, 0.6 L min(-1)) with a detection limit of 0.013 μg L(-1) was developed. The method is based on external calibration in the presence of a buffering solution containing 5 mg L(-1) Na, K, Ca, Mg added both to calibration standards and water samples. The statistical validation on 31 bottled drinking water samples (0.4-2140 μg L(-1) Li) using the Bland and Altman test and regression analysis has shown results similar to those obtained by the standard additions method. The buffering solution approach is simpler than the standard additions and has demonstrated good intra- and interday precision, accuracy and robustness. It was successfully applied over a wide concentration range of Li and multimineral matrix with a pooled precision of 2.5-3.5% and 99±9% accuracy.

  1. Development of a high-speed impedance measurement system for dual-frequency capacitive-coupled pulsed-plasma.

    Science.gov (United States)

    Lee, Hohyoung; Lee, Jeongbeom; Park, Gijung; Han, Yunseok; Lee, Youngwook; Cho, Gunhee; Kim, Hanam; Chang, Hongyoung; Min, Kyoungwook

    2015-08-01

    A high-speed impedance measurement system was developed, which enables the measurement of various characteristics of CW and pulsed plasmas with time resolution of less than a microsecond. For this system, a voltage and current sensor is implemented in a printed circuit board to sense the radio frequency signals. A digital board, which has a high-speed analog to digital converter and a field-programmable gate-array, is used to calculate the impedance of the signal. The final output of impedance is measured and stored with a maximum speed of 3 Msps. This sensor system was tested in a pulsed-plasma by applying it to the point between the matching box and the plasma chamber. The experimental equipment was constructed connecting the matching box, a 13.56 MHz generator, a 2 MHz generator that produced pulsed power, and a pulse-signal generator. From the temporal behavior of the measured impedance, we were able to determine the time intervals of transient states, especially of the initial active state. This information can be used to set the pulse frequency and duty for plasma processing. PMID:26329190

  2. Effects of Bias Pulsing on Etching of SiO2 Pattern in Capacitively-Coupled Plasmas for Nano-Scale Patterning of Multi-Level Hard Masks.

    Science.gov (United States)

    Kim, Sechan; Choi, Gyuhyun; Chae, Heeyeop; Lee, Nae-Eung

    2016-05-01

    In order to study the effects of bias pulsing on the etching characteristics of a silicon dioxide (SiO2) layer using multi-level hard mask (MLHM) structures of ArF photoresist/bottom anti-reflected coating/SiO2/amorphous carbon layer (ACL)/SiO2, the effects of bias pulsing conditions on the etch characteristics of a SiO2 layer with an ACL mask pattern in C4F8/CH2F2/O2/Ar etch chemistries were investigated in a dual-frequency capacitively-coupled plasma (CCP) etcher. The effects of the pulse frequency, duty ratio, and pulse-bias power in the 2 MHz low-frequency (LF) power source were investigated in plasmas generated by a 27.12 MHz high-frequency (HF) power source. The etch rates of ACL and SiO2 decreased, but the etch selectivity of SiO2/ACL increased with decreasing duty ratio. When the ACL and SiO2 layers were etched with increasing pulse frequency, no significant change was observed in the etch rates and etch selectivity. With increasing LF pulse-bias power, the etch rate of ACL and SiO2 slightly increased, but the etch selectivity of SiO2/ACL decreased. Also, the precise control of the critical dimension (CD) values with decreasing duty ratio can be explained by the protection of sidewall etching of SiO2 by increased passivation. Pulse-biased etching was successfully applied to the patterning of the nano-scale line and space of SiO2 using an ACL pattern. PMID:27483889

  3. Role of the blocking capacitor in control of ion energy distributions in pulsed capacitively coupled plasmas sustained in Ar/CF4/O2

    International Nuclear Information System (INIS)

    In plasma etching for microelectronics fabrication, the quality of the process is in large part determined by the ability to control the ion energy distribution (IED) onto the wafer. To achieve this control, dual frequency capacitively coupled plasmas (DF-CCPs) have been developed with the goal of separately controlling the magnitude of the fluxes of ions and radicals with the high frequency (HF) and the shape of the IED with the low frequency (LF). In steady state operation, plasma properties are determined by a real time balance between electron sources and losses. As such, for a given geometry, pressure, and frequency of operation, the latitude for controlling the IED may be limited. Pulsed power is one technique being investigated to provide additional degrees of freedom to control the IED. In one configuration of a DF-CCP, the HF power is applied to the upper electrode and LF power is applied to the lower electrode which is serially connected to a blocking capacitor (BC) which generates a self dc-bias. In the steady state, the value of the dc-bias is, in fact, constant. During pulsed operation, however, there may be time modulation of the dc-bias which provides an additional means to control the IED. In this paper, IEDs to the wafer in pulsed DF-CCPs sustained in Ar/CF4/O2 are discussed with results from a two-dimensional plasma hydrodynamics model. The IED can be manipulated depending on whether the LF or HF power is pulsed. The dynamic range of the control can be tuned by the dc-bias generated on the substrate, whose time variation depends on the size of the BC during pulsed operation. It was found that high energy ions can be preferentially produced when pulsing the HF power and low energy ions are preferentially produced when pulsing the LF power. A smaller BC value which allows the bias to follow the change in charged particle fluxes produces a larger dynamic range with which to control IEDs

  4. Experimental investigation of a low pressure capacitively-coupled discharge

    OpenAIRE

    Kechkar, Samir

    2015-01-01

    In this thesis, a low-pressure, capacitively-coupled plasma (CCP) was investigated using the well established techniques of actinometry, two-photon laser-induced fluorescence (TALIF), appearance potential mass spectrometry (APMS), Langmuir and hairpin probes. The behaviour of atomic oxygen density in mixtures of O2/SF6 was investigated using TALIF and a Langmuir probe. A significant five-fold increase of [O] was observed when O2 plasma was diluted with SF6 (5 - 10%). This was attributed to a ...

  5. Comparison of vacuum ultra-violet emission of Ar/CF4 and Ar/CF3I capacitively coupled plasmas

    Science.gov (United States)

    Zotovich, A.; Proshina, O.; el Otell, Z.; Lopaev, D.; Rakhimova, T.; Rakhimov, A.; de Marneffe, J.-F.; Baklanov, M. R.

    2016-10-01

    Spectra in the vacuum-ultra violet range (VUV, 30 nm-200 nm) as well as in the ultra-violet(UV) and visible ranges (UV+vis, 200 nm-800 nm) were measured from Ar/CF3I and Ar/CF4 discharges. The discharges were generated in an industrial 300 mm capacitively coupled plasma source with 27 MHz radio-frequency power. It was seen that the measured spectra were strongly modified. This is mainly due to absorption, especially by CF3I, and Ar self-trapping along the line of sight, towards the detector and in the plasma itself. The estimated unabsorbed VUV spectra were revealed from the spectra of mixtures with low fluorocarbon gas content by means of normalization with unabsorbed I* emission, at 206 nm, and CF2\\ast band (1B1(0,v‧,0){{\\to}1} A1(0,{{\\text{v}}\\prime \\prime} ,0)) emission between 230 nm and 430 nm. Absolute fluences of UV CF2\\ast emission were derived using hybrid 1-dimensional (1D) particle-in-cell (PIC) Monte-Carlo (MC) model calculations. Absolute calibration of the VUV emission was performed using these calculated values from the model, which has never been done previously for real etch conditions in an industrial chamber. It was seen that the argon resonant lines play a significant role in the VUV spectra. These lines are dominant in the case of etching recipes close to the standard ones. The restored unabsorbed spectra confirm that replacement of conventional CF4 etchant gas with CF3I in low-k etching recipes leads to an increase in the overall VUV emission intensity. However, emission from Ar exhibited the most intense peaks. Damage to low-k SiCOH glasses by the estimated VUV was calculated for blanket samples with pristine k-value of 2.2. The calculations were then compared with Fourier transform infrared (FTIR) data for samples exposed to the similar experimental conditions in the same reactor. It was shown that Ar emission plays the most significant role in VUV-induced damage.

  6. [Wireless ECG measurement system with capacitive coupling].

    Science.gov (United States)

    Aleksandrowicz, Adrian; Walter, Marian; Leonhardt, Steffen

    2007-04-01

    This paper describes a measurement system that captures an electrocardiogram (ECG) using capacitively coupled electrodes. The measurement system was integrated into an off-the-shelf office chair (so-called "Aachen SmartChair"). Whereas for classical ECG measurement adhesive is used to attach conductively coupled electrodes to bare skin, the system presented allows ECG measurement through clothing without direct skin contact. Furthermore, a ZigBee communication module was integrated to allow wireless transmission of ECG data to a PC or an ICU patient monitor. For system validation, classical ECG using conductive electrodes was obtained simultaneously. First measurement results, including variations of cloth thickness and material, are presented and some of the system-specific problems of this approach are discussed.

  7. 废轮胎粉末在高频电容耦合等离子体反应器中的热解%Treatment of Waste Tyre Powder Using a High-frequency Capacitively Coupled Plasma Reactor

    Institute of Scientific and Technical Information of China (English)

    唐兰; 黄海涛

    2005-01-01

    A high-frequency (HF) capacitively coupled plasma reactor was developed to study the pyrolysis of waste tyre powder. The main objective was to generate a plasma at medium pressure and moderate temperatures for waste tyre powder gasification. Description of the reactor setup and experimental results concerning the plasma characteristics and product gas composition were presented, and potential use of the pyrolytic char was also discussed. Plasma temperatures were found to be between 1073 K to 1773 K, and under optimum operating conditions, over 70% of the tyre feed was converted into gaseous products by the treatment process. Pyrolysed gas was a mixture of H2, CO, CH4 and other organic compounds. The pyrolytic char may be used as low cost activated carbon for treating the species with large molecular weight.

  8. Wavelet approach to artifact noise removal from Capacitive coupled Electrocardiograph.

    Science.gov (United States)

    Lee, Seung Min; Kim, Ko Keun; Park, Kwang Suk

    2008-01-01

    Capacitive coupled Electrocardiography (ECG) is introduced as non-invasive measurement technology for ubiquitous health care and appliance are spread out widely. Although it has many merits, however, capacitive coupled ECG is very weak for motion artifacts for its non-skin-contact property. There are many studies for artifact problems which treats all artifact signals below 0.8Hz. In our capacitive coupled ECG measurement system, artifacts exist not only below 0.8Hz but also over than 10Hz. Therefore, artifact noise removal algorithm using wavelet method is tested to reject artifact-wandered signal from measured signals. It is observed that using power calculation each decimation step, artifact-wandered signal is removed as low frequency artifacts as high frequency artifacts. Although some original ECG signal is removed with artifact signal, we could level the signal quality for long term measure which shows the best quality ECG signals as we can get. PMID:19163323

  9. Quantum superposition of charge states on capacitively coupled superconducting islands

    NARCIS (Netherlands)

    Heij, C.P.; Dixon, D.C.; Wal, C.H. van der; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuri

  10. Tunable capacitive coupling between two semiconductor charge qubits

    Science.gov (United States)

    Yu, Guo-Dong; Li, Hai-Ou; Cao, Gang; Xiao, Ming; Jiang, Hong-Wen; Guo, Guo-Ping

    2016-08-01

    Strong coupling between two qubits is one of the main requirements for high fidelity two-qubit logic operations. Here we experimentally investigate the capacitive coupling between two double quantum dots. A pair of open slot confinement gates is used to enhance the coupling. We find that the coupling energy J can be conveniently tuned in a broad range. Through numerical simulations, we study the effect of J on two-qubit operations. The analysis shows that our experimentally obtained J is adequate to achieve high fidelity two-qubit entanglement and logic gates.

  11. Mode transition of power dissipation and plasma parameters in an asymmetric capacitive discharge

    International Nuclear Information System (INIS)

    Electrical characteristics and plasma parameters were experimentally investigated in asymmetric capacitively coupled plasma with various argon gas pressures. At a low discharge current region, the transferred power to the plasma was proportional to the current, while the transferred power increased proportionally to square of the current at a high discharge current region. The mode transition of power dissipation occurred at the lower discharge current region with the high gas pressure. At the low radio-frequency power or low discharge current, the plasma density increased linearly with the discharge current, while at the high power or high discharge current, the rate of an increase in the plasma density depended on the gas pressures. A transition of the discharge resistance was also found when the mode transition of the power dissipation occurred. These changes in the electrical characteristics and the plasma parameters were mainly caused by the power dissipation mode transition from the plasma bulk to the sheath in the capacitive discharge with the asymmetric electrode, which has extremely high self-bias voltages. - Highlights: • Mode transition of the power dissipation in an asymmetrical capacitive discharge • Evolution of the discharge power, electrode voltage, and discharge impedance • Electron temperature and plasma density on the power dissipation mode transition

  12. Influence of addifion of electronegative gases on the properties of capacitively coupled Ar plasmas*%电负性气体的掺入对容性耦合Ar等离子体的影响*

    Institute of Scientific and Technical Information of China (English)

    洪布双; 苑涛; 邹帅; 唐中华; 徐东升; 虞一青; 王栩生; 辛煜†

    2013-01-01

    Investigation of electronegative plasmas has now been atrractive due to the advantages of negative-ion assisted etching and charge-free ion implantation in semiconductor manufacture. Langmuir electrostatic probe, as a simple, inexpensive and good spatial resolution diagnosic tool, is popularly used in investigating electronegative plasmas. In this paper, the Langmuir electrostatic probe is proposed to measure the capacitively coupled Ar plasmas with added electronegative gases, such as O2, Cl2 and SF6. The experimental results from the measurements of Ar plasmas with added electronegative gases driven by a 40.68 MHz field indicate that, with increasing flow rate of electronegative gas, high energy peak will occur in electron energy possibility function and shift towards higher energyside. The addition of electronegative gases reduces the electron density significantly as the electron temperature increases. We also calculate the electronegativity of Ar plasmas for the three kinds of electronegative gases. The preliminary interpretations of the above experimental phenomena are presented.%  本文利用朗缪尔静电探针对掺入了电负性气体O2, Cl2, SF6的由4068 MHz激发的单射频容性耦合Ar等离子体进行了诊断测量。测量结果表明:随着电负性气体流量的增加,电子能量概率分布函数出现了高能峰,高能峰且有向高能侧漂移的现象;电负性气体掺入Ar等离子体后显著降低了等离子体的电子密度;电子温度随着电负性气体流量比的增加而升高。另外,本文还测量了掺入三种电负性气体后在不同流量比下的混合气体等离子体的电负度α。对实验现象进行了初步的解释。

  13. Correlated Coulomb drag in capacitively coupled quantum-dot structures

    DEFF Research Database (Denmark)

    Kaasbjerg, Kristen; Jauho, Antti-Pekka

    2016-01-01

    We study theoretically Coulomb drag in capacitively coupled quantum dots (CQDs) -- a biasdriven dot coupled to an unbiased dot where transport is due to Coulomb mediated energy transfer drag. To this end, we introduce a master-equation approach which accounts for higher-order tunneling (cotunneling....... Interestingly, the direction of the drag current is not determined by the drive current, but by an interplay between the energy-dependent lead couplings. Studying the drag mechanism in a graphene-based CQD heterostructure, we show that the predictions of our theory are consistent with recent experiments...

  14. Effect of wettability and surface roughness on the adhesion properties of collagen on PDMS films treated by capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Juárez-Moreno, J.A. [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico); Ávila-Ortega, A. [Facultad de Ingeniería Química—UADY, Periférico Norte Kilómetro 33.5, Col. Chuburna de Hidalgo Inn, C.P. , 97203 Mérida, Yucatán (Mexico); Oliva, A.I. [Centro de Investigación y de Estudios Avanzados del IPN–Unidad Mérida, Km. 6 Antigua carretera a Progreso Apdo. Postal 73, Cordemex, 97310 Mérida, Yucatán (Mexico); Avilés, F. [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico); Cauich-Rodríguez, J.V., E-mail: jvcr@cicy.mx [Centro de Investigación Científica de Yucatán, Calle 43 No. 130, Col. Chuburna de Hidalgo C.P., 97200 Mérida, Yucatán (Mexico)

    2015-09-15

    Highlights: • Plasma treatment was used as an adhesive tool for PDMS/collagen composite preparation. • Response surface methodology was used for statistical optimization. • A microscopic roughness can also lead to a mechanical interlocking between materials. • Hydroxyl groups on the PDMS surface contribute to the enhanced chemical interactions. • PDMS/collagen composite obtained by plasma treatment exhibited higher peel strength. - Abstract: Direct chemical bonding of biomolecules to the surface of chemically inert polymers such as polydimethylsiloxane (PDMS) is not easily achieved. Therefore, pre-activation of such materials, followed by attachment of the biomolecule is necessary. This paper describes a procedure to functionalize a PDMS surface by oxygen-based plasma followed by the adhesion of collagen type I for the preparation of adhesive-free bilayer composite intended as skin substitute. Plasma treatments between 40 and 120 W for 5 to 15 min were used and the extent of surface modification was followed by contact angle, Fourier transform infrared (FTIR) spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM) and adhesion test. It was found that as the plasma power and time were increased, PDMS contact angle decreased while surface roughness increased as revealed by SEM and AFM. The formation of oxygen-containing functional groups at the surface was detected by FTIR. T-peel tests, performed on PDMS treated at 80 W/13 min and covered with collagen showed maximum peel strength of 0.1 N/mm which was 3 times higher than that measured for the untreated bilayer composite. The observed enhancement in the adhesion strength was attributed to the increased mechanical interlocking driven by the increased roughness and the formation of hydrophilic functional groups.

  15. Surface modification by nitrogen plasma immersion ion implantation into new steel 460Li–21Cr in a capacitively coupled radio frequency discharge

    Energy Technology Data Exchange (ETDEWEB)

    Bhuyan, H., E-mail: hbhuyan@fis.puc.cl [Institute of Physics, Pontificia Universidad Católica de Chile, Santiago (Chile); Mändl, S. [Leibniz-Institut für Oberflächenmodifizierung, Leipzig (Germany); Bora, B.; Favre, M.; Wyndham, E.; Maze, J.R. [Institute of Physics, Pontificia Universidad Católica de Chile, Santiago (Chile); Walczak, M. [Department of Mechanical and Metallurgical Engineering, Pontificia Universidad Católica de Chile, Santiago (Chile); Manova, D. [Leibniz-Institut für Oberflächenmodifizierung, Leipzig (Germany)

    2014-10-15

    Highlights: • Nitriding of a novel steel has been done in a RF plasma by PIII technique. • Improved hardness and wear behavior have been observed. • Hardness was improved by a factor 4 and the wear by 2 orders of magnitude. • Fast, anomalous diffusion, similar to nitrogen in expanded austenite is observed. - Abstract: A novel steel 460Li–21Cr belonging to a new generation of superferritic grade steel has been implanted with nitrogen in a low power 13.56 MHz radio frequency plasma by the plasma immersion ion implantation (PIII) technique in order to study its physical and chemical properties under different experimental conditions. We observed improved hardness and wear behavior of 460Li–21Cr steel with a layer thickness between 1.5 and 4.0 μm after 60 min implantation in the temperature range from 350 to 550 °C. The modified surface layer containing nitrogen does not show CrN in X-ray diffraction (XRD). Compared to untreated substrates, the hardness can be increased by a factor of 4, depending on the experimental conditions, and the wear behavior was also improved by two orders of magnitude. The results are very similar to those for austenitic stainless steel with a similar pronounced increase in wear resistance and plateau-like nitrogen depth profiles.

  16. Quantum superposition of charge states on capacitively coupled superconducting islands

    OpenAIRE

    Heij, C. P.; Dixon, D C; van der Wal, C H; Hadley, P.; Mooij, J.E.

    2003-01-01

    We investigate the ground state properties of a system containing two superconducting islands coupled capacitively by a wire. The ground state is a macroscopic superposition of charge states, even though the islands cannot exchange charge carriers. The ground state of the system is probed by measuring the switching current of a Bloch transistor containing one of the islands. Calculations based on superpositions of charge states on both islands show good agreement with the experiments. The abi...

  17. Capacitive-coupled Series Spoof Surface Plasmon Polaritons

    Science.gov (United States)

    Yin, Jia Yuan; Ren, Jian; Zhang, Hao Chi; Zhang, Qian; Cui, Tie Jun

    2016-04-01

    A novel method to realize stopband within the operating frequency of spoof surface plasmon polaritons (SPPs) is presented. The stopband is introduced by a new kind of capacitive-coupled series spoof SPPs. Two conventional H-shaped unit cells are proposed to construct a new unit cell, and every two new unit cells are separated by a gap with certain distance, which is designed to implement capacitive coupling. The original surface impedance matching is disturbed by the capacitive coupling, leading to the stopband during the transmission of SPPs. The proposed method is verified by both numerical simulations and experiments, and the simulated and measured results have good agreements. It is shown that the proposed structure exhibits a stopband in 9-9.5 GHz while the band-pass feature maintains in 5-9 GHz and 9.5-11 GHz. In the passband, the reflection coefficient is less than -10 dB, and the transmission loss is around 3 dB in the stopband, the reflection coefficient is -2 dB, and the transmission coefficient is less than -30 dB. The compact size, easy fabrication and good band-pass and band-stop features make the proposed structure a promising plasmonic device in SPP communication systems.

  18. Capacitively Coupled CMOS VCSEL Driver Circuits for Optical Communication

    Science.gov (United States)

    Kozlov, Victor

    This thesis presents the analysis, design and implementation of a common-cathode capacitively-coupled VCSEL driver in 65nm CMOS intended for short-reach optical interconnects. The driver consists of an AC-coupled high-frequency path and a low-frequency path that provides DC signal components. By increasing the low-frequency path bandwidth by 10 times compared to previous AC-coupled drivers allowed the on-chip coupling capacitor to be reduced to 2.1pF, occupying 3 times less area than prior art. The driver introduces capacitively-coupled two-tap emphasis to equalize the VCSEL's optical response. The VCSEL was modulated with an OMA of up to 5.1dBm and an ER of 9dB, measuring an RMS jitter of 5ps at a data rate of 15Gb/s, which represents the highest OMA and ER achieved in high-speed anode-driving LDDs. The driver could be programmed for a low-power mode, outputting 2.3dBm OMA at power consumption of only 30mW, corresponding to an energy efficiency of 2pJ/bit.

  19. Effect of electrode spacing on the density distributions of electrons, ions, and metastable and radical molecules in SiH4/NH3/N2/He capacitively coupled plasmas

    International Nuclear Information System (INIS)

    Semiconductor fabrication often requires the deposition of hydrogenated silicon nitride (SiNxHy) film using SiH4/NH3/N2/He capacitively coupled plasma (CCP) discharge. As analysis of the discharge geometry is essential to understanding CCP deposition, the effect of electrode spacing on the two-dimensional distributions of electrons, ions, and metastable and radical molecules was analyzed numerically using a fluid model. The simulation shows that the spatial variations in the ionization rates near the sheath become more obvious as the electrode spacing increases. In addition, as molecule-molecule gas-phase reactions are significantly affected by the local residence time, large electrode spacings are associated with significant volumetric losses for positive ions. Consequently, an increase of the electrode spacing leads axial density profiles of ions to change from bell shaped to double humped. However, NH4+ persistently maintains a bell-shaped axial density profile regardless of the degree of electrode spacing. We set the mole fraction of NH3 to only 1% of the total flow at the inlet, but NH4+ is the most abundant positive ion at the large electrode spacings. As the gas flow can transport the radicals around the space between the electrodes, we found that radical density distribution shifts toward the grounded electrode. The shift becomes pronounced as the electrode spacing increases. Finally, to validate our model, we compared the calculated deposition rate profile with the experimental data obtained along the wafer radius. According to our numerical results, the SiNxHy deposition rate decreases by approximately 16% when the electrode spacing increases from 9 to 20 mm

  20. Effect of electrode spacing on the density distributions of electrons, ions, and metastable and radical molecules in SiH{sub 4}/NH{sub 3}/N{sub 2}/He capacitively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ho Jun, E-mail: tiger.anima@gmail.com [Thin Film Technology Team, Samsung Electronics, Hwaseong-si 445-701 (Korea, Republic of); Yang, Wonkyun [AE R& D Center, Kyungwon Tech, Inc., Seongnam-si 463-828 (Korea, Republic of); Joo, Junghoon [Department of Materials Science and Engineering, Kunsan National University, Kunsan-si 573-701 (Korea, Republic of)

    2015-07-28

    Semiconductor fabrication often requires the deposition of hydrogenated silicon nitride (SiN{sub x}H{sub y}) film using SiH{sub 4}/NH{sub 3}/N{sub 2}/He capacitively coupled plasma (CCP) discharge. As analysis of the discharge geometry is essential to understanding CCP deposition, the effect of electrode spacing on the two-dimensional distributions of electrons, ions, and metastable and radical molecules was analyzed numerically using a fluid model. The simulation shows that the spatial variations in the ionization rates near the sheath become more obvious as the electrode spacing increases. In addition, as molecule-molecule gas-phase reactions are significantly affected by the local residence time, large electrode spacings are associated with significant volumetric losses for positive ions. Consequently, an increase of the electrode spacing leads axial density profiles of ions to change from bell shaped to double humped. However, NH{sub 4}{sup +} persistently maintains a bell-shaped axial density profile regardless of the degree of electrode spacing. We set the mole fraction of NH{sub 3} to only 1% of the total flow at the inlet, but NH{sub 4}{sup +} is the most abundant positive ion at the large electrode spacings. As the gas flow can transport the radicals around the space between the electrodes, we found that radical density distribution shifts toward the grounded electrode. The shift becomes pronounced as the electrode spacing increases. Finally, to validate our model, we compared the calculated deposition rate profile with the experimental data obtained along the wafer radius. According to our numerical results, the SiN{sub x}H{sub y} deposition rate decreases by approximately 16% when the electrode spacing increases from 9 to 20 mm.

  1. Electromechanical coupling factor of capacitive micromachined ultrasonic transducers

    Science.gov (United States)

    Caronti, Alessandro; Carotenuto, Riccardo; Pappalardo, Massimo

    2003-01-01

    Recently, a linear, analytical distributed model for capacitive micromachined ultrasonic transducers (CMUTs) was presented, and an electromechanical equivalent circuit based on the theory reported was used to describe the behavior of the transducer [IEEE Trans. Ultrason. Ferroelectr. Freq. Control 49, 159-168 (2002)]. The distributed model is applied here to calculate the dynamic coupling factor kw of a lossless CMUT, based on a definition that involves the energies stored in a dynamic vibration cycle, and the results are compared with those obtained with a lumped model. A strong discrepancy is found between the two models as the bias voltage increases. The lumped model predicts an increasing dynamic k factor up to unity, whereas the distributed model predicts a more realistic saturation of this parameter to values substantially lower. It is demonstrated that the maximum value of kw, corresponding to an operating point close to the diaphragm collapse, is 0.4 for a CMUT single cell with a circular membrane diaphragm and no parasitic capacitance (0.36 for a cell with a circular plate diaphragm). This means that the dynamic coupling factor of a CMUT is comparable to that of a piezoceramic plate oscillating in the thickness mode. Parasitic capacitance decreases the value of kw, because it does not contribute to the energy conversion. The effective coupling factor keff is also investigated, showing that this parameter coincides with kw within the lumped model approximation, but a quite different result is obtained if a computation is made with the more accurate distributed model. As a consequence, keff, which can be measured from the transducer electrical impedance, does not give a reliable value of the actual dynamic coupling factor.

  2. Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

    CERN Document Server

    Alipour Tehrani, Niloufar; Benoit, Mathieu; Dannheim, Dominik; Dette, Karola; Hynds, Daniel; Kulis, Szymon; Peric, Ivan; Petric, Marko; Redford, Sophie; Sicking, Eva; Valerio, Pierpaolo

    2015-01-01

    The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor. Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

  3. Characterization of active CMOS sensors for capacitively coupled pixel detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hirono, Toko; Gonella, Laura; Janssen, Jens; Hemperek, Tomasz; Huegging, Fabian; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn (Germany); Peric, Ivan [Institut fuer Prozessdatenverarbeitung und Elektronik, Karlsruher Institut fuer Technologie, Karlsruhe (Germany)

    2015-07-01

    Active CMOS pixel sensor is one of the most attractive candidates for detectors of upcoming particle physics experiments. In contrast to conventional sensors of hybrid detectors, signal processing circuit can be integrated in the active CMOS sensor. The characterization and optimization of the pixel circuit are indispensable to obtain a good performance from the sensors. The prototype chips of the active CMOS sensor were fabricated in the AMS 180nm and L-Foundry 150 nm CMOS processes, respectively a high voltage and high resistivity technology. Both chips have a charge sensitive amplifier and a comparator in each pixel. The chips are designed to be glued to the FEI4 pixel readout chip. The signals from 3 pixels of the prototype chips are capacitively coupled to the FEI4 input pads. We have performed lab tests and test beams to characterize the prototypes. In this presentation, the measurement results of the active CMOS prototype sensors are shown.

  4. Capacitively coupled electrical substitution for resistive bolometer enhancement

    International Nuclear Information System (INIS)

    A new electrical substitution method for resistive bolometers is proposed to operate them in a closed-loop configuration. This method was implemented and evaluated with a resistive bolometer based on metallic layers over a 120 µm thick glass membrane. Based on an electrical substitution (ES) directly at the place of the resistive sensing element, the new method allows for space savings and a simplification of the technological manufacturing while maintaining the time response improvement linked to a closed-loop operation. Compared to a previously available ES solution, this new method is applicable to all resistive bolometers. Time response and signal-to-noise ratio (SNR) were evaluated through measurements and compared for three operation configurations of the resistive bolometer: open loop, classical ES closed loop and with the proposed capacitively coupled electrical substitution (CCES) closed loop

  5. Fundamental investigations of capacitive radio frequency plasmas: simulations and experiments

    International Nuclear Information System (INIS)

    Capacitive radio frequency (RF) discharge plasmas have been serving hi-tech industry (e.g. chip and solar cell manufacturing, realization of biocompatible surfaces) for several years. Nonetheless, their complex modes of operation are not fully understood and represent topics of high interest. The understanding of these phenomena is aided by modern diagnostic techniques and computer simulations. From the industrial point of view the control of ion properties is of particular interest; possibilities of independent control of the ion flux and the ion energy have been utilized via excitation of the discharges with multiple frequencies. ‘Classical’ dual-frequency (DF) discharges (where two significantly different driving frequencies are used), as well as discharges driven by a base frequency and its higher harmonic(s) have been analyzed thoroughly. It has been recognized that the second solution results in an electrically induced asymmetry (electrical asymmetry effect), which provides the basis for the control of the mean ion energy. This paper reviews recent advances on studies of the different electron heating mechanisms, on the possibilities of the separate control of ion energy and ion flux in DF discharges, on the effects of secondary electrons, as well as on the non-linear behavior (self-generated resonant current oscillations) of capacitive RF plasmas. The work is based on a synergistic approach of theoretical modeling, experiments and kinetic simulations based on the particle-in-cell approach. (paper)

  6. Capacitive Substrate Coupling of Row–Column-Addressed 2-D CMUT Arrays

    DEFF Research Database (Denmark)

    Engholm, Mathias; Bouzari, Hamed; Jensen, Jørgen Arendt;

    2016-01-01

    the semiconductor substrate. To reduce the parasitic capacitance by 80% the bulk doping concentration should be at most 1012 cm-3. Experimental results show that the parasitic capacitance can be reduced by 87% by applying a substrate potential of 6V relative to the bottom electrodes. The depletion......Row–column-addressed CMUT arrays suffer from low receive sensitivity of the bottom elements due to a capacitive coupling to the substrate. The capacitive coupling increases the parasitic capacitance. A simple approach to reduce the parasitic capacitance is presented, which is based on depleting...... of the semiconductor substrate can be sustained for at least 10 minutes making it applicable for row–column-addressed CMUT arrays for ultrasonic imaging. Theoretically the reduced parasitic capacitance indicates that the receive sensitivity of the bottom elements can be increased by a factor of 2:1....

  7. Particle-in-Cell/Test-Particle Simulations of Technological Plasmas: Sputtering Transport in Capacitive Radio Frequency Discharges

    OpenAIRE

    Trieschmann, Jan; Schmidt, Frederik; Mussenbrock, Thomas

    2016-01-01

    The paper provides a tutorial to the conceptual layout of a self-consistently coupled Particle-In-Cell/Test-Particle model for the kinetic simulation of sputtering transport in capacitively coupled plasmas at low gas pressures. It explains when a kinetic approach is actually needed and which numerical concepts allow for the inherent nonequilibrium behavior of the charged and neutral particles. At the example of a generic sputtering discharge both the fundamentals of the applied Monte Carlo me...

  8. Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

    Science.gov (United States)

    Tehrani, N. Alipour; Arfaoui, S.; Benoit, M.; Dannheim, D.; Dette, K.; Hynds, D.; Kulis, S.; Perić, I.; Petrič, M.; Redford, S.; Sicking, E.; Valerio, P.

    2016-07-01

    The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor, where efficiencies of greater than 99% have been achieved at -60 V substrate bias, with a single hit resolution of 6.1 μm . Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

  9. Capacitive iris to adjust coupling factor between waveguide and ACS linac in J-PARC

    International Nuclear Information System (INIS)

    The beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac has been increased from 181 to 400 MeV by installing Annular-ring Coupled Structure (ACS) cavities in the maintenance period of 2013. Some of the ACS cavities require the correction of the coupling factor between waveguide and the cavity. To adjust the coupling factor, a capacitive iris in the rectangular waveguide was designed. And then, the rectangular waveguide with the capacitive iris was manufactured and installed to one of the ACS cavities. The capacitive iris corrected the coupling factor to the designed value and performed well under high-power operation. (author)

  10. Macroscopic quantum tunneling in a stack of capacitively-coupled intrinsic Josephson junctions

    Science.gov (United States)

    Koyama, Tomio; Machida, Masahiko

    2008-04-01

    A macroscopic quantum theory for the phase dynamics in capacitively-coupled intrinsic Josephson junctions (IJJ's) is constructed. We quantize the capacitively-coupled IJJ model in terms of the canonical quantization method. The multi-junction effect for the macroscopic quantum tunneling (MQT) to the first resistive branch is clarified. It is shown that the escape rate is greatly enhanced by the capacitive coupling between junctions. We also discuss the origin of the N2 -enhancement in the escape rate observed in the uniformly switching in Bi-2212 IJJ's.

  11. Relationship between the discharge mode and the spatial oxygen plasma distribution in a large size ferrite inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Jun [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Hwang, Hye Ju; Cho, Jeong Hee; Chae, Hee Sun [R and D Center for PSK-INC Corporation, Hwaseong-si 445-170 (Korea, Republic of); Kim, Dong Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-15

    The electrical characteristics and the spatial distribution of oxygen plasma according to the number of turns in ferrite inductively coupled plasmas (ferrite ICPs) are investigated. Through a new ICP model, which includes the capacitive coupling and the power loss of the ferrite material with the conventional ICP model, the variation of the oxygen discharge characteristics depending on the number of turns is simply understood by the electrical measurement, such as the antenna voltages and the currents. As the number of the turns increases, the capacitive coupling dominantly affects the spatial plasma distribution. This capacitive coupling results in a center focused density profile along the radial direction. In spite of the same discharge conditions (discharge chamber, neutral gas, and pressure), the spatial plasma distribution over 450 mm has drastic changes by increasing number of the turns. In addition, the effect of the negative species to the density profile is compared with the argon discharge characteristics at the same discharge configuration.

  12. Capacitively coupled radio-frequency discharges in nitrogen at low pressures

    KAUST Repository

    Alves, Luís Lemos

    2012-07-06

    This paper uses experiments and modelling to study capacitively coupled radio-frequency (rf) discharges in pure nitrogen, at 13.56MHz frequency, 0.11 mbar pressures and 230W coupled powers. Experiments performed on two similar (not twin) setups, existing in the LATMOS and the GREMI laboratories, include electrical and optical emission spectroscopy (OES) measurements. Electrical measurements give the rf-applied and the direct-current-self-bias voltages, the effective power coupled to the plasma and the average electron density. OES diagnostics measure the intensities of radiative transitions with the nitrogen second-positive and first-negative systems, and with the 811.5 nm atomic line of argon (present as an actinometer). Simulations use a hybrid code that couples a two-dimensional time-dependent fluid module, describing the dynamics of the charged particles (electrons and positive ions N 2 + and N 4 + ), and a zero-dimensional kinetic module, describing the production and destruction of nitrogen (atomic and molecular) neutral species. The coupling between these modules adopts the local mean energy approximation to define spacetime-dependent electron parameters for the fluid module and to work out spacetime-averaged rates for the kinetic module. The model gives general good predictions for the self-bias voltage and for the intensities of radiative transitions (both average and spatially resolved), underestimating the electron density by a factor of 34. © 2012 IOP Publishing Ltd.

  13. Capacitively coupled radio-frequency discharges in nitrogen at low pressures

    International Nuclear Information System (INIS)

    This paper uses experiments and modelling to study capacitively coupled radio-frequency (rf) discharges in pure nitrogen, at 13.56 MHz frequency, 0.1–1 mbar pressures and 2–30 W coupled powers. Experiments performed on two similar (not twin) setups, existing in the LATMOS and the GREMI laboratories, include electrical and optical emission spectroscopy (OES) measurements. Electrical measurements give the rf-applied and the direct-current-self-bias voltages, the effective power coupled to the plasma and the average electron density. OES diagnostics measure the intensities of radiative transitions with the nitrogen second-positive and first-negative systems, and with the 811.5 nm atomic line of argon (present as an actinometer). Simulations use a hybrid code that couples a two-dimensional time-dependent fluid module, describing the dynamics of the charged particles (electrons and positive ions N2+ and N4+), and a zero-dimensional kinetic module, describing the production and destruction of nitrogen (atomic and molecular) neutral species. The coupling between these modules adopts the local mean energy approximation to define space–time-dependent electron parameters for the fluid module and to work out space–time-averaged rates for the kinetic module. The model gives general good predictions for the self-bias voltage and for the intensities of radiative transitions (both average and spatially resolved), underestimating the electron density by a factor of 3–4. (paper)

  14. Radio frequency effect on the sheath capacitance in a low density plasma

    International Nuclear Information System (INIS)

    In this work we describe the use of the nonlinear properties of the sheath capacitance in a low density plasma to produce parametric amplification of RF signals in a high frequency band (H.F.). The experiment has been carried out in the Linear Mirror Device LISA of the Universidade Federal Fluminense, where a helium plasma was produced using a radio-frequency source built at UFF, with variable (10 watts to 100 watts) and frequency of 28 MHz. The experimental results shows good agreement between the theoretical model of sheat capacitance. This allows one to predict, within a limited range, the sheath capacitance variation as a function of certain plasma parameters. (author)

  15. Capacitive Coupling in Double-Circuit Transmission Lines

    Directory of Open Access Journals (Sweden)

    Zdenka Benesova

    2004-01-01

    Full Text Available The paper describes an algorithm for calculation of capacitances and charges on conductors in systems with earth wires and in double-circuit overhead lines with respect to phase arrangement. A balanced voltage system is considered. A suitable transposition of individual conductors enables to reduce the electric and magnetic fields in vicinity of overhead lines and to limit the inductive and capacitive linkage. The procedure is illustrated on examples the results of which lead to particular recommendations for designers.

  16. One-Dimensional Fluid Model for Dust Particles in Dual-Frequency Capacitively Coupled Silane Discharges

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-Mei; SONG Yuan-Hong; WANG You-Nian

    2009-01-01

    A self-consistent fluid model, which incorporates density and flux balances of electrons, ions, neutrals and nanopar ticles, electron energy balance, and Poiaaon 's equation, is employed to investigate the capacitively coupled silane discharge modulated by dual-frequency electric sources. In this discharge process, nanoparticles are formed by a successive chemical reactions of anion with silane. The density distributions of the precursors in the dust particle formation are put forward, and the charging, transport and growth of nanoparticles are simulated. In this work, we focus our main attention on the influences of the high-frequency and low-frequency voltage on nanoparticle densities, nanoparticle charge distributions in both the bulk plasma and sheath region.

  17. Macroscopic quantum effects in capacitively- and inductively-coupled intrinsic Josephson junctions

    Science.gov (United States)

    Koyama, T.; Machida, M.

    2009-03-01

    A theory for macroscopic quantum tunneling (MQT) in intrinsic Josephson junction stacks is formulated. Both capacitive and inductive couplings between junctions are taken into account. We calculate the escape rate in the switching to the first resistive branch in the quantum regime. It is shown that the enhancement of the escape rate is caused mainly by the capacitive coupling between junctions in IJJ's with small in-plane area of ~ 1μm2.

  18. Electron heating via the self-excited plasma series resonance in geometrically symmetric multi-frequency capacitive plasmas

    CERN Document Server

    Schuengel, E; Donko, Z; Korolov, I; Derzsi, A; Schulze, J

    2016-01-01

    The self-excitation of Plasma Series Resonance (PSR) oscillations plays an important role in the electron heating dynamics in Capacitively Coupled Radio Frequency (CCRF) plasmas. In a combined approach of PIC/MCC simulations and a theoretical model based on an equivalent circuit, we investigate the self-excitation of PSR oscillations and their effect on the electron heating in geometrically symmetric CCRF plasmas driven by multiple consecutive harmonics. The discharge symmetry is controlled via the Electrical Asymmetry Effect, i.e. by varying the total number of harmonics and tuning the phase shifts between them. It is demonstrated that PSR oscillations will be self-excited under both symmetric and asymmetric conditions, if (i) the charge-voltage relation of the plasma sheaths deviates from a simple quadratic behavior and if (ii) the inductance of the plasma bulk exhibits a temporal modulation. These two effects have been neglected up to now, but we show that they must be included in the model in order to pro...

  19. Experimental and simulation study of a capacitively coupled oxygen discharge driven by tailored voltage waveforms

    Science.gov (United States)

    Derzsi, Aranka; Lafleur, Trevor; Booth, Jean-Paul; Korolov, Ihor; Donkó, Zoltán

    2016-02-01

    We report experimental and particle-based kinetic simulation studies of low-pressure capacitively coupled oxygen plasmas driven by tailored voltage waveforms that consist of up to four harmonics of base frequency 13.56 MHz. Experimentally determined values of DC self-bias and electrical power deposition, as well as flux density and flux-energy distribution of the positive ions at the grounded electrode are compared with simulation data for a wide range of operating conditions. Very good agreement is found for self-bias and flux-energy distribution of the positive ions at the electrodes, while a fair agreement is reached for discharge power and ion flux data. The simulated spatial and temporal behaviour of the electric field, electron density, electron power absorption, ionization rate and mean electron energy shows a transition between sheath expansion heating and drift-ambipolar discharge modes, induced by changing either the number of harmonics comprising the excitation waveform or the gas pressure. The simulations indicate that under our experimental conditions the plasma operates at high electronegativity, and also reveal the crucial role of {{\\text{O}}2}≤ft({{a}1}{{Δ }g}\\right) singlet metastable molecules in establishing discharge behavior via the fast destruction of negative ions within the bulk plasma.

  20. Mapping Capacitive Coupling Among Pixels in a Sensor Array

    Science.gov (United States)

    Seshadri, Suresh; Cole, David M.; Smith, Roger M.

    2010-01-01

    An improved method of mapping the capacitive contribution to cross-talk among pixels in an imaging array of sensors (typically, an imaging photodetector array) has been devised for use in calibrating and/or characterizing such an array. The method involves a sequence of resets of subarrays of pixels to specified voltages and measurement of the voltage responses of neighboring non-reset pixels.

  1. Quantum Fluctuation of Mesoscopic Capacitance Coupled Circuit in a Thermal Vacuum State

    Institute of Scientific and Technical Information of China (English)

    朱爱东; 张寿; 金哲; 赵永芳; 井孝功; 千正男; 苏文辉

    2003-01-01

    The quantum fluctuations of mesoscopic capacitance-coupled circuit in thermal vacuum state are investigated by using the theory of thermal field dynamics on the basis of quantization of the mesoscopic circuit. It is shown that under a definite temperature, the fluctuations of electric charges and currents change with temperature. The higher the temperature, the more quantum noise the coupled circuit exhibits.

  2. Layout Capacitive Coupling and Structure Impacts on Integrated High Voltage Power MOSFETs

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    The switching performances of the integrated high voltage power MOSFETs that have prevailing interconnection matrices are being heavily influenced by the parasitic capacitive coupling of on-chip metal wires. The mechanism of the side-byside coupling is generally known, however, the layer-to-layer......The switching performances of the integrated high voltage power MOSFETs that have prevailing interconnection matrices are being heavily influenced by the parasitic capacitive coupling of on-chip metal wires. The mechanism of the side-byside coupling is generally known, however, the layer...... that the layer-to-layer coupling can contribute higher impacts than the well-known side-by-side coupling. Four layout structures are then proposed and implemented in a 0.18 µm partial SOI process for 100 V integrated power MOSFETs with a die area 2.31 mm2. The post-layout comparison using an industrial 2D...

  3. Evaluation of electrical capacitance tomography sensor based on the coupling of fluid field and electrostatic field

    Science.gov (United States)

    Ye, Jiamin; Wang, Haigang; Yang, Wuqiang

    2016-07-01

    Electrical capacitance tomography (ECT) is based on capacitance measurements from electrode pairs mounted outside of a pipe or vessel. The structure of ECT sensors is vital to image quality. In this paper, issues with the number of electrodes and the electrode covering ratio for complex liquid-solids flows in a rotating device are investigated based on a new coupling simulation model. The number of electrodes is increased from 4 to 32 while the electrode covering ratio is changed from 0.1 to 0.9. Using the coupling simulation method, real permittivity distributions and the corresponding capacitance data at 0, 0.5, 1, 2, 3, 5, and 8 s with a rotation speed of 96 rotations per minute (rpm) are collected. Linear back projection (LBP) and Landweber iteration algorithms are used for image reconstruction. The quality of reconstructed images is evaluated by correlation coefficient compared with the real permittivity distributions obtained from the coupling simulation. The sensitivity for each sensor is analyzed and compared with the correlation coefficient. The capacitance data with a range of signal-to-noise ratios (SNRs) of 45, 50, 55 and 60 dB are generated to evaluate the effect of data noise on the performance of ECT sensors. Furthermore, the SNRs of experimental data are analyzed for a stationary pipe with permittivity distribution. Based on the coupling simulation, 16-electrode ECT sensors are recommended to achieve good image quality.

  4. Driving frequency effects on the mode transition in capacitively coupled argon discharges

    Institute of Scientific and Technical Information of China (English)

    Liu Xiang-Mei; Song Yuan-Hong; Wang You-Nian

    2011-01-01

    A one-dimensional fluid model is employed to investigate the discharge sustaining mechanisms in the capacitively coupled argon plasmas, by modulating the driving frequency in the range of 40 kHz-60 MHz. The model incorporates the density and flux balance of electron and ion, electron energy balance, as well as Poisson's equation. In our simulation,the discharge experiences mode transition as the driving frequency increases, from the γ regime in which the discharge is maintained by the secondary electrons emitted from the electrodes under ion bombardment, to the α regime in which sheath oscillation is responsible for most of the electron heating in the discharge sustaining. The electron density and electron temperature at the centre of the discharge, as well as the ion flux on the electrode are figured out as a function of the driving frequency, to confirm the two regimes and trabetween them. The effects of gas pressure, secondary electron emission coefficient and applied voltage on the discharge are also discussed.

  5. PIC/MCC simulation of capacitively coupled discharges: Effect of particle management and integration

    Science.gov (United States)

    Sun, Anbang; Becker, Markus M.; Loffhagen, Detlef

    2016-09-01

    A PIC/MCC simulation model for the analysis of low-temperature discharge plasmas is represented which takes the common leapfrog and the velocity Verlet algorithm for the particle integration, adaptive particle management as well as parallel computing using MPI into account. Main features of the model including the impact of super particle numbers, adaptive particle management and the time step size for the different integration methods are represented. The investigations are performed for low-pressure capacitively coupled radio frequency discharges in helium and argon. Besides a code verification by comparison with benchmark simulation results in helium it is shown that an adaptive particle management is particularly suitable for the simulation of discharges at elevated pressures where boundary effects and processes in the sheath regions are important. Furthermore, it is pointed out that the velocity Verlet integration scheme allows to speed up the PIC/MCC simulations compared to the leapfrog method because it makes the use of larger time steps at the same accuracy possible.

  6. Wire-bonded through-silicon vias with low capacitive substrate coupling

    International Nuclear Information System (INIS)

    Three-dimensional integration of electronics and/or MEMS-based transducers is an emerging technology that vertically interconnects stacked dies with through-silicon vias (TSVs). They enable the realization of circuits with shorter signal path lengths, smaller packages and lower parasitic capacitances, which results in higher performance and lower costs. This paper presents a novel technique for fabricating TSVs from bonded gold wires. The wires are embedded in a polymer, which acts both as an electrical insulator, resulting in low capacitive coupling toward the substrate and as a buffer for thermo-mechanical stress

  7. Computerized Langmuir Probe Measurements in a Capacitively Coupled RF Discharge

    CERN Document Server

    Shaer, M El; Massoud, A; Mobasher, M; Wuttmann, M

    2014-01-01

    A system of automated computerized Langmuir probe measurements is used in order to determine the plasma parameters in a plasma reactor constructed for cleaning of metallic artifacts by RF discharge. A compensated probe insures the suppression of the RF interference. The probe data are collected using a commercial data acquisition unit connected to a portable computer. The raw data are processed using wavelet transforms techniques which assures the de-noising of the probe signal without distortion of the probe I-V characteristic. The first and second derivatives of the I-V characteristic are determined. The measurement of the electron density spatial distribution in the inter-electrode distance indicates a flat density profile in the middle region of the discharge.

  8. Analysis, Control and Experimental Verification of a Single-Phase Capacitive-Coupling Grid-Connected Inverter

    DEFF Research Database (Denmark)

    Dai, Ning-Yi; Zhang, Wen-Chen; Wong, Man-Chung;

    2015-01-01

    This study proposes a capacitive-coupling grid-connected inverter (CGCI), which consists of a full-bridge single-phase inverter coupled to a power grid via one capacitor in series with an inductor. The fundamental-frequency impedance of the coupling branch is capacitive. In contrast with the conv......This study proposes a capacitive-coupling grid-connected inverter (CGCI), which consists of a full-bridge single-phase inverter coupled to a power grid via one capacitor in series with an inductor. The fundamental-frequency impedance of the coupling branch is capacitive. In contrast...... with the conventional inductive-coupling grid-connected inverter (IGCI), this structure provides an alternative interface for use between a low-voltage DC microgrid and an AC grid. A comparison between the CGCI and the IGCI is performed. It is concluded that the CGCI is able to transfer active power and provide lagging...

  9. treatment of polyimide by an atmospheric pressure plasma of capacitive rf discharge for liquid crystal alignment

    International Nuclear Information System (INIS)

    Uniform planar alignment of liquid crystals is obtained by polyimide films obliquely treated by a stream of argon plasma from capacitive RF discharge at atmospheric pressure. Two liquid crystal alignment modes are discovered differing by their longitudinal or transverse orientation with respect to treatment direction. Optimum parameters of the treatment for obtaining these orientation modes are determined.

  10. Capacitively coupled nano conductors. Ratchet currents and exchange fluctuation relations

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Robert; Kohler, Sigmund [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain)

    2015-10-15

    We investigate electron transport in two quantum circuits with mutual Coulomb interaction. The first circuit is a double quantum dot connected to two electron reservoirs, while the second one is a quantum point contact in the weak tunneling limit. The coupling is such that an electron in the first circuit enhances the barrier of the point contact and, thus, reduces its conductivity. While such setups are frequently used as charge monitors, we focus on two different aspects. First, we derive transport coefficients which have recently been employed for testing generalized equilibrium conditions known as exchange fluctuation relations. These formally exact relations allow us to test the consistency of our master equation approach. Second, a biased point contact entails noise on the DQD and induces non-equilibrium phenomena such as a ratchet current. (copyright 2015 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Mathematical modeling of intrinsic Josephson junctions with capacitive and inductive couplings

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu M.; Zemlyanaya, E. V.; Sarhadov, I.; Andreeva, O.

    2012-11-01

    We investigate the current voltage characteristics (CVC) of intrinsic Josephson junctions (IJJ) with two types of couplings between junctions: capacitive and inductive. The IJJ model is described by a system of coupled sine-Gordon equations which is solved numerically by the 4th order Runge-Kutta method. The method of numerical simulation and numerical results are presented. The magnetic field distribution is calculated as the function of coordinate and time at different values of the bias current. The influence of model parameters on the CVC is studied. The behavior of the IJJ in dependence on coupling parameters is discussed.

  12. The electric field in capacitively coupled RF discharges: a smooth step model that includes thermal and dynamic effects

    Science.gov (United States)

    Brinkmann, Ralf Peter

    2015-12-01

    The electric field in radio-frequency driven capacitively coupled plasmas (RF-CCP) is studied, taking thermal (finite electron temperature) and dynamic (finite electron mass) effects into account. Two dimensionless numbers are introduced, the ratios ε ={λ\\text{D}}/l of the electron Debye length {λ\\text{D}} to the minimum plasma gradient length l (typically the sheath thickness) and η ={ω\\text{RF}}/{ω\\text{pe}} of the RF frequency {ω\\text{RF}} to the electron plasma frequency {ω\\text{pe}} . Assuming both numbers small but finite, an asymptotic expansion of an electron fluid model is carried out up to quadratic order inclusively. An expression for the electric field is obtained which yields (i) the space charge field in the sheath, (ii) the generalized Ohmic and ambipolar field in the plasma, and (iii) a smooth interpolation for the transition in between. The new expression is a direct generalization of the Advanced Algebraic Approximation (AAA) proposed by the same author (2009 J. Phys. D: Appl. Phys. 42 194009), which can be recovered for η \\to 0 , and of the established Step Model (SM) by Godyak (1976 Sov. J. Plasma Phys. 2 78), which corresponds to the simultaneous limits η \\to 0 , ε \\to 0 . A comparison of the hereby proposed Smooth Step Model (SSM) with a numerical solution of the full dynamic problem proves very satisfactory.

  13. Nanocellulose coupled flexible polypyrrole@graphene oxide composite paper electrodes with high volumetric capacitance

    Science.gov (United States)

    Wang, Zhaohui; Tammela, Petter; Strømme, Maria; Nyholm, Leif

    2015-02-01

    A robust and compact freestanding conducting polymer-based electrode material based on nanocellulose coupled polypyrrole@graphene oxide paper is straightforwardly prepared via in situ polymerization for use in high-performance paper-based charge storage devices, exhibiting stable cycling over 16 000 cycles at 5 A g-1 as well as the largest specific volumetric capacitance (198 F cm-3) so far reported for flexible polymer-based electrodes.A robust and compact freestanding conducting polymer-based electrode material based on nanocellulose coupled polypyrrole@graphene oxide paper is straightforwardly prepared via in situ polymerization for use in high-performance paper-based charge storage devices, exhibiting stable cycling over 16 000 cycles at 5 A g-1 as well as the largest specific volumetric capacitance (198 F cm-3) so far reported for flexible polymer-based electrodes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07251k

  14. The effect of electrode contact resistance and capacitive coupling on Complex Resistivity measurements

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas

    2006-01-01

    The effect of electrode contact resistance and capacitive coupling on complex resistivity (CR) measurements is studied in this paper. An equivalent circuit model for the receiver is developed to describe the effects. The model shows that CR measurements are severely affected even at relatively lo...... the contact resistance artificially increased by resistors. The results emphasize the importance of keeping contact resistance low in CR measurements....

  15. Ram seminal plasma proteins contribute to sperm capacitation and modulate sperm-zona pellucida interaction.

    Science.gov (United States)

    Luna, C; Colás, C; Casao, A; Serrano, E; Domingo, J; Pérez-Pé, R; Cebrián-Pérez, J A; Muiño-Blanco, T

    2015-03-01

    Incubation of ram spermatozoa in capacitating conditions with cAMP-elevating agents promotes a progressive time-dependent increase in the capacitated sperm subpopulation. In this study, the fertilizing capacity of ram spermatozoa (ability to bind to the zona pellucida, ZBA rate) capacitated in these conditions was determined. The results showed an increase (P ram spermatozoa. Likewise, the presence of two seminal plasma (SP) proteins able to protect sperm against cold shock (RSVP14 and RSVP20) was evidenced in both SP and the ram sperm surface, and their influence in the fertilizing ability of spermatozoa capacitated in basal medium or with cAMP-elevating agents was determined. The results verified that RSVP14 and RSVP20 act as decapacitating factors given that their addition to SP-free sperm samples previously to capacitation maintained high proportions of the noncapacitated sperm pattern with no increase in protein tyrosine phosphorylation. However, the obtained ZBA rate in the high-cAMP-containing samples was increased in the presence of RSVP20 (P < 0.05). These findings would indicate that the stimulating effect exerted by this protein on the sperm-oocyte binding occurs downstream from the cAMP generation and that the mechanisms by which RSVP20 promotes the zona pellucida binding might be independent of protein tyrosine phosphorylation.

  16. Particle-in-Cell/Test-Particle Simulations of Technological Plasmas: Sputtering Transport in Capacitive Radio Frequency Discharges

    CERN Document Server

    Trieschmann, Jan; Mussenbrock, Thomas

    2016-01-01

    The paper provides a tutorial to the conceptual layout of a self-consistently coupled Particle-In-Cell/Test-Particle model for the kinetic simulation of sputtering transport in capacitively coupled plasmas at low gas pressures. It explains when a kinetic approach is actually needed and which numerical concepts allow for the inherent nonequilibrium behavior of the charged and neutral particles. At the example of a generic sputtering discharge both the fundamentals of the applied Monte Carlo methods as well as the conceptual details in the context of the sputtering scenario are elaborated on. Finally, two in the context of sputtering transport simulations often exploited assumptions, namely on the energy distribution of impinging ions as well as on the test particle approach, are validated for the proposed example discharge.

  17. One-dimensional N-qubit system based on capacitively coupled quantum dots

    CERN Document Server

    Tanamoto, T

    2000-01-01

    Coulomb blockade effects in capacitively coupled quantum dots can be utilized for constructing a normal-state quantum computer by combining a field-effect-transistor (FET) structure. We show that the Hamiltonian for a weakly coupled quantum-dot array is reduced to that for nuclear magnetic resonance (NMR) spectroscopy. Quantum operations are carried out by applying only electrical pulse sequences, thus various error-correction methods developed in NMR spectroscopy are applicable without using magnetic fields. A measurement scheme in an N-qubit system is quantitatively estimated from a practical viewpoint.

  18. Quantum Fluctuations of Mesoscopic Damped Circuit Involving Capacitance-Inductance Coupling at a Finite Temperature

    Science.gov (United States)

    Xu, Xing-Lei; Xu, Shi-Min; Li, Hong-Qi

    2008-06-01

    The quantization of mesoscopic damped circuit involving capacitance-inductance coupling is proposed by the method of thrice linear transformation and damped harmonic oscillator quantization. The quantum fluctuations of the charges and current of each loop are calculated by thermo-field dynamics (TFD) in thermal vacuum state, thermal coherent state and thermal squeezed state, respectively. It is shown that the quantum fluctuations of the charges and current not only depend on circuit inherent parameter and coupled magnitude, but also rely on squeezed coefficients, squeezed angle, environmental temperature and damped resistance. And, because of influence of environmental temperature and damped resistance, the quantum fluctuations increase with increasing temperature and decrease with prolonging time.

  19. Capacitance of High-Voltage Coaxial Cable in Plasma Immersion Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Plasma immersion ion implantation (PIII) is an excellent technique for the surface modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the processand cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.

  20. Equidistance of branch structure in capacitively coupled Josephson junctions model with diffusion current

    Energy Technology Data Exchange (ETDEWEB)

    Shukrinov, Yu.M. [BLTP, JINR, Dubna, Moscow Region, 141980 (Russian Federation) and Physical Technical Institute, Dushanbe 734063 (Tajikistan)]. E-mail: shukrinv@theor.jinr.ru; Mahfouzi, F. [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of); Seidel, P. [Institut fuer Festkorperphysik, Friedrich-Schiller-Universitaet Jena, D-07743 Jena (Germany)

    2006-11-01

    Branch structure in current-voltage characteristics of intrinsic Josephson junctions of HTSC is studied in the framework of two models: capacitively coupled Josephson junctions (CCJJ) model and CCJJ model with diffusion current (CCJJ + DC). We investigate the coupling dependence of the branch's slopes and demonstrate that the equidistance of the branch structure in CCJJ model is broken at enough small values of coupling parameter (at {alpha} << 1). We show that the inclusion of diffusion in the tunneling current through intrinsic Josephson junctions might restore the equidistance of the branch structure. Change of the current-voltage characteristics in CCJJ + DC model under variation of the coupling and McCumber parameters and effect of boundary conditions on the branch structure is analyzed.

  1. Equidistance of branch structure in capacitively coupled Josephson junctions model with diffusion current

    Science.gov (United States)

    Shukrinov, Yu. M.; Mahfouzi, F.; Seidel, P.

    2006-11-01

    Branch structure in current-voltage characteristics of intrinsic Josephson junctions of HTSC is studied in the framework of two models: capacitively coupled Josephson junctions (CCJJ) model and CCJJ model with diffusion current (CCJJ + DC). We investigate the coupling dependence of the branch’s slopes and demonstrate that the equidistance of the branch structure in CCJJ model is broken at enough small values of coupling parameter (at α ≪ 1). We show that the inclusion of diffusion in the tunneling current through intrinsic Josephson junctions might restore the equidistance of the branch structure. Change of the current-voltage characteristics in CCJJ + DC model under variation of the coupling and McCumber parameters and effect of boundary conditions on the branch structure is analyzed.

  2. Analysis, Control and Experimental Verification of a Single-Phase Capacitive-Coupling Grid-Connected Inverter

    OpenAIRE

    Dai, Ning-Yi; Zhang, Wen-Chen; Wong, Man-Chung; Guerrero, Josep M.; Lam, Chi-Seng

    2015-01-01

    This study proposes a capacitive-coupling grid-connected inverter (CGCI), which consists of a full-bridge single-phase inverter coupled to a power grid via one capacitor in series with an inductor. The fundamental-frequency impedance of the coupling branch is capacitive. In contrast with the conventional inductive-coupling grid-connected inverter (IGCI), this structure provides an alternative interface for use between a low-voltage DC microgrid and an AC grid. A comparison between the CGCI an...

  3. Experiments on the coupling mechanisms of a compact ECR plasma source

    International Nuclear Information System (INIS)

    A compact coaxial ECR plasma source (the MPDR 610) for molecular beam applications has previously been developed and experimentally evaluated. It has been shown that the plasma source can efficiently couple electromagnetic (EM) power at 2.45 GHz, or 915 MHz excitation frequency under a variety of power and pressure conditions, and for a number of different gases. In its original design, the air filled coaxial plasma source has an open circuit capacitive gap termination of the center conductor, beyond which the EM fields are evanescent. These impressed fields create and sustain the plasma. This study attempts to reevaluate the microwave coupling structure of the plasma source. The output of the plasma source are compared for various EM coupling structures. Specifically, the capacitive gap coupling is compared to an inductive loop and helical termination of the center conductor. Measurements of the plasma source performance are made for each of these three center conductor terminations. The dependence of the plasma source output to various input parameters for these different center conductor terminations is presented

  4. Ion flux and ion distribution function measurements in synchronously pulsed inductively coupled plasmas

    International Nuclear Information System (INIS)

    Changes in the ion flux and the time-averaged ion distribution functions are reported for pulsed, inductively coupled RF plasmas (ICPs) operated over a range of duty cycles. For helium and argon plasmas, the ion flux increases rapidly after the start of the RF pulse and after about 50 μs reaches the same steady state value as that in continuous ICPs. Therefore, when the plasma is pulsed at 1 kHz, the ion flux during the pulse has a value that is almost independent of the duty cycle. By contrast, in molecular electronegative chlorine/chlorosilane plasmas, the ion flux during the pulse reaches a steady state value that depends strongly on the duty cycle. This is because both the plasma chemistry and the electronegativity depend on the duty cycle. As a result, the ion flux is 15 times smaller in a pulsed 10% duty cycle plasma than in the continuous wave (CW) plasma. The consequence is that for a given synchronous RF biasing of a wafer-chuck, the ion energy is much higher in the pulsed plasma than it is in the CW plasma of chlorine/chlorosilane. Under these conditions, the wafer is bombarded by a low flux of very energetic ions, very much as it would in a low density, capacitively coupled plasma. Therefore, one can extend the operating range of ICPs through synchronous pulsing of the inductive excitation and capacitive chuck-bias, offering new means by which to control plasma etching.

  5. Ion flux and ion distribution function measurements in synchronously pulsed inductively coupled plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Brihoum, Melisa; Cunge, Gilles; Darnon, Maxime; Joubert, Olivier [Laboratoire des Technologies de la Microelectronique CNRS, Grenoble Cedex 9, Isere 38054 (France); Gahan, David [Impedans Ltd., Dublin 17 (Ireland); Braithwaite, Nicholas St. J. [Department of Physical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)

    2013-03-15

    Changes in the ion flux and the time-averaged ion distribution functions are reported for pulsed, inductively coupled RF plasmas (ICPs) operated over a range of duty cycles. For helium and argon plasmas, the ion flux increases rapidly after the start of the RF pulse and after about 50 {mu}s reaches the same steady state value as that in continuous ICPs. Therefore, when the plasma is pulsed at 1 kHz, the ion flux during the pulse has a value that is almost independent of the duty cycle. By contrast, in molecular electronegative chlorine/chlorosilane plasmas, the ion flux during the pulse reaches a steady state value that depends strongly on the duty cycle. This is because both the plasma chemistry and the electronegativity depend on the duty cycle. As a result, the ion flux is 15 times smaller in a pulsed 10% duty cycle plasma than in the continuous wave (CW) plasma. The consequence is that for a given synchronous RF biasing of a wafer-chuck, the ion energy is much higher in the pulsed plasma than it is in the CW plasma of chlorine/chlorosilane. Under these conditions, the wafer is bombarded by a low flux of very energetic ions, very much as it would in a low density, capacitively coupled plasma. Therefore, one can extend the operating range of ICPs through synchronous pulsing of the inductive excitation and capacitive chuck-bias, offering new means by which to control plasma etching.

  6. Capacitively coupled electrolyte-conductivity sensor based on high-k material of barium strontium titanate

    OpenAIRE

    Huck, C.; Poghossian, A; Baecker, M; Chaudhuri, S.; Zander, W; Schubert, J.; Begoyan, V. K.; Buniatyan, V. V.; Wagner, Patrick Hermann; Schoening, M. J

    2014-01-01

    A miniaturized capacitively coupled contactless conductivity detection (C4D) sensor based on high-kperovskite oxide of barium strontium titanate (BST) has been implemented for the first time. The BST films(∼120 nm thick) of Ba0.25Sr0.75TiO3composition were prepared on a p-Si-SiO2-Pt structure by pulsed laserdeposition technique using BST targets fabricated by the self-propagating high-temperature synthesismethod. The Pt electrodes were buried into the SiO2layer to obtain a planar structure. F...

  7. Transient performance estimation of charge plasma based negative capacitance junctionless tunnel FET

    Science.gov (United States)

    Singh, Sangeeta; Kondekar, P. N.; Pal, Pawan

    2016-02-01

    We investigate the transient behavior of an n-type double gate negative capacitance junctionless tunnel field effect transistor (NC-JLTFET). The structure is realized by using the work-function engineering of metal electrodes over a heavily doped n+ silicon channel and a ferroelectric gate stack to get negative capacitance behavior. The positive feedback in the electric dipoles of ferroelectric materials results in applied gate bias boosting. Various device transient parameters viz. transconductance, output resistance, output conductance, intrinsic gain, intrinsic gate delay, transconductance generation factor and unity gain frequency are analyzed using ac analysis of the device. To study the impact of the work-function variation of control and source gate on device performance, sensitivity analysis of the device has been carried out by varying these parameters. Simulation study reveals that it preserves inherent advantages of charge-plasma junctionless structure and exhibits improved transient behavior as well.

  8. Seminal plasma proteins interacting with sperm surface revert capacitation indicators in frozen-thawed ram sperm.

    Science.gov (United States)

    Ledesma, Alba; Fernández-Alegre, Estela; Cano, Adriana; Hozbor, Federico; Martínez-Pastor, Felipe; Cesari, Andreína

    2016-10-01

    This study was conducted to evaluate the effects of interacting seminal plasma proteins (iSPP) obtained by AV or EE on frozen-thawed ram sperm in order to test the hypothesis whether this fraction could be sufficient to emulate the effect of complete seminal plasma (SP). Additionally, we evaluated whether these proteins have a differential effect between spermatozoa from high and low fertility rams and between breeding and non-breeding seasons. We assessed sperm motility, quality parameters (intracellular reactive oxygen species, membrane fluidity, plasma membrane permeability and mitochondrial activity) and capacitation status. The main findings from this work were: i) iSPP had no effect on sperm motility, whereas SP (AV or EE) addition produced the highest values of total motility (74.13±2.99 and 72.27±2.99 for AV and EE, respectively) and progressive motility (64.97±2.64 and 63.73±2.64 for AV and EE, respectively); ii) iSPP had no effect on sperm quality parameters (p>0.05), but whole SP improved all parameters evaluated. Moreover, SP collected by AV yielded significantly higher viability (44.60±2.87) and sperm with stable plasma membrane (44.56±2.49) comparing with the addition of SP collected by EE (35.80±2.47 and 36.67±1.71, respectively); iii) iSPP and SP collected by EE, but not by AV, reverted molecular signals of capacitation as protein tyrosine phosphorylation caused by freezing temperatures; iv) there were no effects of fertility or season in sperm quality parameters evaluated. This study demonstrated that, although the iSPP have a clear decapacitating effect, including the ability to revert cryo-capacitation indicators, they are not sufficient to emulate the effects of complete SP regarding sperm functional parameters. PMID:27570190

  9. Seminal plasma proteins interacting with sperm surface revert capacitation indicators in frozen-thawed ram sperm.

    Science.gov (United States)

    Ledesma, Alba; Fernández-Alegre, Estela; Cano, Adriana; Hozbor, Federico; Martínez-Pastor, Felipe; Cesari, Andreína

    2016-10-01

    This study was conducted to evaluate the effects of interacting seminal plasma proteins (iSPP) obtained by AV or EE on frozen-thawed ram sperm in order to test the hypothesis whether this fraction could be sufficient to emulate the effect of complete seminal plasma (SP). Additionally, we evaluated whether these proteins have a differential effect between spermatozoa from high and low fertility rams and between breeding and non-breeding seasons. We assessed sperm motility, quality parameters (intracellular reactive oxygen species, membrane fluidity, plasma membrane permeability and mitochondrial activity) and capacitation status. The main findings from this work were: i) iSPP had no effect on sperm motility, whereas SP (AV or EE) addition produced the highest values of total motility (74.13±2.99 and 72.27±2.99 for AV and EE, respectively) and progressive motility (64.97±2.64 and 63.73±2.64 for AV and EE, respectively); ii) iSPP had no effect on sperm quality parameters (p>0.05), but whole SP improved all parameters evaluated. Moreover, SP collected by AV yielded significantly higher viability (44.60±2.87) and sperm with stable plasma membrane (44.56±2.49) comparing with the addition of SP collected by EE (35.80±2.47 and 36.67±1.71, respectively); iii) iSPP and SP collected by EE, but not by AV, reverted molecular signals of capacitation as protein tyrosine phosphorylation caused by freezing temperatures; iv) there were no effects of fertility or season in sperm quality parameters evaluated. This study demonstrated that, although the iSPP have a clear decapacitating effect, including the ability to revert cryo-capacitation indicators, they are not sufficient to emulate the effects of complete SP regarding sperm functional parameters.

  10. Discontinuity of mode transition and hysteresis in hydrogen inductively coupled plasma via a fluid model

    Institute of Scientific and Technical Information of China (English)

    徐会静; 赵书霞; 高飞; 张钰如; 李雪春; 王友年

    2015-01-01

    A new type of two-dimensional self-consistent fluid model that couples an equivalent circuit module is used to in-vestigate the mode transition characteristics and hysteresis in hydrogen inductively coupled plasmas at different pressures, by varying the series capacitance of the matching box. The variations of the electron density, temperature, and the cir-cuit electrical properties are presented. As cycling the matching capacitance, at high pressure both the discontinuity and hysteresis appear for the plasma parameters and the transferred impedances of both the inductive and capacitive discharge components, while at low pressure only the discontinuity is seen. The simulations predict that the sheath plays a determi-native role on the presence of discontinuity and hysteresis at high pressure, by influencing the inductive coupling efficiency of applied power. Moreover, the values of the plasma transferred impedances at different pressures are compared, and the larger plasma inductance at low pressure due to less collision frequency, as analyzed, is the reason why the hysteresis is not seen at low pressure, even with a wider sheath. Besides, the behaviors of the coil voltage and current parameters during the mode transitions are investigated. They both increase (decrease) at the E to H (H to E) mode transition, indicating an improved (worsened) inductive power coupling efficiency.

  11. Quantum fluctuations of mesoscopic damped mutual capacitance coupled double resonance RLC circuit in thermal excitation state

    Institute of Scientific and Technical Information of China (English)

    XU Xing-Lei

    2007-01-01

    Mesoscopic damped mutual capacitance coupled double resonance circuit is quantized by the method of damped harmonic oscillator quantization. Hamiltonian is diagonalized by the method of unitary transformation. The energy spectra of this circuit are given. The quantum fluctuations of the charge and current of each loop are investigated by the method of thermofield dynamics (TFD) in thermal excitation state,thermal squeezed vacuum state,thermal vacuum state and vacuum state. It is shown that the quantum fluctuations of the charge and current are related to not only circuit inherent parameter and coupled magnitude,but also quantum number of excitation,squeezed coefficients,squeezed angle and environmental temperature. And the quantum fluctuations increase with the increase of temperature and decay with time.

  12. Theory and simulation of laser plasma coupling

    International Nuclear Information System (INIS)

    The theory and simulation of these coupling processes are considered. Particular emphasis is given to their nonlinear evolution. First a brief introduction to computer simulation of plasmas using particle codes is given. Then the absorption of light via the generation of plasma waves is considered, followed by a discussion of stimulated scattering of intense light. Finally these calculations are compared with experimental results

  13. Mass spectrometry of positive ions in capacitively coupled low pressure RF discharges in oxygen with water impurities

    Science.gov (United States)

    Stefanović, Ilija; Stojanović, Vladimir; Boulmer-Leborgne, Chantal; Lecas, Thomas; Kovacevic, Eva; Berndt, Johannes

    2016-07-01

    A capacitively coupled RF oxygen discharge is studied by means of mass spectroscopy. Mass spectra of neutral and positive species are measured in the mid plane between the electrodes at different distances between plasma and mass-spectrometer orifice. In the case of positive ions, as expected, the largest flux originates from \\text{O}2+ . However, a significant number of impurities are detected, especially for low input powers and larger distances. The most abundant positive ions (besides \\text{O}2+ ) are \\text{N}{{\\text{O}}+}, \\text{NO}2+ , {{\\text{H}}+}≤ft({{\\text{H}}2}\\text{O}\\right) , and {{\\text{H}}+}{{≤ft({{\\text{H}}2}\\text{O}\\right)}2} . In particular, for the case of hydrated hydronium ions {{\\text{H}}+}{{≤ft({{\\text{H}}2}\\text{O}\\right)}n} (n  =  1, 2) a surprisingly large flux (for low pressure plasma conditions) is detected. Another interesting fact concerns the {{\\text{H}}2}{{\\text{O}}+} ions. Despite the relatively high ammount of water impurities {{\\text{H}}2}{{\\text{O}}+} ions are present only in traces. The reaction mechanisms leading to the production of the observed ions, especially the hydrated hydronium ions are discussed.

  14. Mechanism for heating of nitrogen plasmas in an electrodeless rf capacitive discharge at medium pressures

    International Nuclear Information System (INIS)

    The possible contributions of several processes to the experimentally observed heating of nitrogen plasmas in an electarodeless rf capacitive discharge at pressures of p=2.7-67 kPa are discussed. These processes are electron-rotational, vibrational--translational (V--T), and nonresonance vibrational--vibrational (V--V) energy exchange and effects due to O2, H2O, and NO impurities in the gas. It is shown that as the pressure is decreased the heating mechanism changes from quasiequilibrium to nonequilibrium V--T heating caused by overpopulation of high vibrational levels in the ground state of the nitrogen molecule

  15. The Tuned Substrate Self-bias in a Radio-frequency Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    丁振峰; 霍伟刚; 王友年

    2004-01-01

    The radio frequency (rf) self-bias of the substrate in a rf inductively coupled plasma is controlled by means of varying the impedance of an external LC network inserted between the substrate and the ground. Experimental studies were done on the relations of the tuned substrate self-bias with varying discharge and external circuit parameters. Under a certain discharge gas pressure, the curves of tuned substrate self-bias Vtsb versus tuning capacitance Ct demonstrate jumps and hysteresises when rf discharge power is higher than a threshold. The hysteresis loop in terms of ACtcrit1 (= Ccrit1 - Ccrit2, here, Ccrit1, Ccrit2 are critical capacitance magnitudes under which the tuned substrate self-bias jumps) decreases with increasing rf discharge power, while the maximum | Vtsbimn | is achieved in the middle discharge-power region. Under a constant discharge power |Vtsb min|, Ctcrit1 and Ctcrit2 achieve their minimums in the middle gas-pressure region.When the tuning capacitance is pre-set at a lower value, Vtsb varies slightly with gas-flow rate;in the case of tuning capacitance sufficiently approaching CtcritX, Vtdb undergoes the jump and hysteresis with the changing gas-flow rate. By inserting a resistor R into the external network,the characteristics of Vtsb - Ct curves are changed with the reduced quality factor Q depending on resistance values. Based on inductive- and capacitive-coupling characteristics of inductively coupled plasma, the dependence of a plasma sheath on plasma parameters, and the impedance properties of the substrate branch, the observed results can be qualitatively interpreted.

  16. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    Science.gov (United States)

    Rahmonov, I. R.; Shukrinov, Yu. M.; Plecenik, A.; Zemlyanaya, E. V.; Bashashin, M. V.

    2016-02-01

    The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current-voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge-Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna). We demonstrate the appearance of the charge traveling wave (CTW) at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  17. Numerical Study of a System of Long Josephson Junctions with Inductive and Capacitive Couplings

    Directory of Open Access Journals (Sweden)

    Rahmonov I. R.

    2016-01-01

    Full Text Available The phase dynamics of the stacked long Josephson junctions is investigated taking into account the inductive and capacitive couplings between junctions and the diffusion current. The simulation of the current–voltage characteristics is based on the numerical solution of a system of nonlinear partial differential equations by a fourth order Runge–Kutta method and finite-difference approximation. A parallel implementation is based on the MPI technique. The effectiveness of the MPI/C++ code is confirmed by calculations on the multi-processor cluster CICC (LIT JINR, Dubna. We demonstrate the appearance of the charge traveling wave (CTW at the boundary of the zero field step. Based on this fact, we conclude that the CTW and the fluxons coexist.

  18. Analysis of ecstasy tablets using capillary electrophoresis with capacitively coupled contactless conductivity detection.

    Science.gov (United States)

    Porto, Suely K S S; Nogueira, Thiago; Blanes, Lucas; Doble, Philip; Sabino, Bruno D; do Lago, Claudimir L; Angnes, Lúcio

    2014-11-01

    A method for the identification of 3,4-methylenedioxymethamphetamine (MDMA) and meta-chlorophenylpiperazine (mCPP) was developed employing capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C(4) D). Sample extraction, separation, and detection of "Ecstasy" tablets were performed in Ecstasy tablets seized in Rio de Janeiro, Brazil, were analyzed by CE-C(4) D and compared against routine gas chromatography-mass spectrometry (GC-MS). The CE method demonstrated sufficient selectivity to discriminate the two target drugs, MDMA and mCPP, from the other drugs present in seizures, namely amphepramone, fenproporex, caffeine, lidocaine, and cocaine. Separation was performed in <90 sec. The advantages of using C(4) D instead of traditional CE-UV methods for in-field analysis are also discussed.

  19. Simulations of electromagnetic effects in high frequency capacitively coupled discharges using the Darwin approximation

    CERN Document Server

    Eremin, Denis; Brinkmann, Ralf Peter; Mussenbrock, Thomas

    2012-01-01

    The Darwin approximation is investigated for its possible use in simulation of electromagnetic effects in large size, high frequency capacitively coupled discharges. The approximation is utilized within the framework of two different fluid models which are applied to typical cases showing pronounced standing wave and skin effects. With the first model it is demonstrated that Darwin approximation is valid for treatment of such effects in the range of parameters under consideration. The second approach, a reduced nonlinear Darwin approximation-based model, shows that the electromagnetic phenomena persist in a more realistic setting. The Darwin approximation offers a simple and efficient way of carrying out electromagnetic simulations as it removes the Courant condition plaguing explicit electromagnetic algorithms and can be implemented as a straightforward modification of electrostatic algorithms. The algorithm described here avoids iterative schemes needed for the divergence cleaning and represents a fast and ...

  20. Metalless electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips.

    Science.gov (United States)

    Duarte Junior, Gerson F; Fracassi da Silva, José Alberto; Mendonça Francisco, Kelliton José; do Lago, Claudimir Lucio; Carrilho, Emanuel; Coltro, Wendell K T

    2015-08-01

    This paper describes the use of ionic solutions as sensing electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips. Initially, two channels were engraved in a PMMA holder by using a CO2 laser system and sealed with a thin adhesive membrane. PDMS electrophoresis chips were fabricated by soft lithography and reversibly sealed against the polymer membrane. Different ionic solutions were investigated as metalless electrodes. The electrode channels were filled with KCl solutions prepared in conductivity values from approximately 10 to 40 S/m. The best analytical response was achieved using the KCl solution with 21.9 S/m conductivity (2 mol/L). Besides KCl, we also tested NaCl and LiCl solutions for actuating as detection electrodes. Taking into account the same electrolyte concentration (2 mol/L), the best response was recorded with KCl solution due to its higher ionic conductivity. The optimum operating frequency (400 kHz) and the best sensing electrode (2 mol/L KCl) were used to monitor electrophoretic separations of a mixture containing K(+) , Na(+) , and Li(+) . The use of liquid solutions as sensing electrodes for capacitively coupled contactless conductivity detection measurements has revealed great performance to monitor separations on chip-based devices, avoiding complicated fabrication schemes to include metal deposition and encapsulation of electrodes. The LOD values were estimated to be 28, 40, and 58 μmol/L for K(+) , Na(+) , and Li(+) , respectively, what is comparable to that of conventional metal electrodes. When compared to the use metal electrodes, the proposed approach offers advantages regarding the easiness of fabrication, simplicity, and lower cost per device.

  1. A novel in-line frequency sensor based on coupling capacitance for X-band application

    International Nuclear Information System (INIS)

    This paper presents a novel in-line frequency sensor, based on coupling capacitance, for X-band applications. The novel frequency sensor can achieve absolute frequency measurement with a simple structure and no DC power consumption. Fabrication of the frequency sensor is completely compatible with the GaAs monolithic microwave integrated circuit process. A well-designed metal–insulator–metal capacitor is employed to couple a certain percentage of incident power and a thermoelectric power sensor is used to measure the coupled power. The sensor design is guided by HFSS simulation and a lumped circuit model. The results validate the effectiveness of the simulation and model, and show relatively good performance of the frequency sensor with simple and reliable components. The net sensitivity of the frequency sensor is about 1.43 mV (W•GHz)−1, and the measured S 11 and S 21 are better than  −14.8 dB and  −1.39 dB at X-band. (paper)

  2. Nonzero Temperature Squeezing of the Time-Dependent Harmonic Oscillator and the Applications to the Capacitive Coupled Electric Circuit

    Institute of Scientific and Technical Information of China (English)

    LIANG Mai-Lin; YUAN Bing

    2002-01-01

    A new way to calculate the nonzero temperature quantum fluctuations of the time-dependent harmonicoscillator is proposed and the properties of squeezing are exactly given. The method is applied to the capacitive coupledelectric circuit. It is explicitly shown that squeezing can appear and the squeezing parameters are related to the physicalquantities of the coupled circuit.

  3. Hybrid modeling of a capacitively coupled radio frequency glow discharge in argon: Combined Monte Carlo and fluid model

    NARCIS (Netherlands)

    Bogaerts, A.; Gijbels, R.; W. Goedheer,

    1999-01-01

    A hybrid model has been developed for a capacitively coupled rf glow discharge in argon, employed as a spectroscopic source in the field of analytical chemistry. The cell is a rather small cylinder with a very small rf-powered electrode (only 5 mm in diameter). The typical working conditions applied

  4. High and low frequency relaxation oscillations in a capacitive discharge plasma

    Institute of Scientific and Technical Information of China (English)

    Zhou Zhu-Wen; Sungjin Kim; Ji Shi-Yin; Sun Guang-Yu; Deng Ming-Sen

    2008-01-01

    Both high and low frequency relaxation oscillations have been observed in an argon capacitive discharge connected to a peripheral grounded chamber through a slot with dielectric spacers.The oscillations,observed from time-varying optical emission of the main discharge chamber,show,for example,a high frequency(46 kHz)relaxation oscillation at 100 mTorr,with an absorbed power near the peripheral breakdown,and a low frequency(2.7-3.7 Hz)oscillation,at a higher absorbed power.The high frequency oscillation is found to ignite a plasma in the slot,but usually not in the periphery.The high frequency oscillation is interpreted by using an electromagnetic model of the slot impedance,combined with the circuit analysis of the system including a matching network.The model is further developed by using a parallel connection of variable peripheral capacitance to analyse the low frequency oscillation.The results obtained from the model are in agreement with the experimental observations and indicate that a variety of behaviours are dependent on the matching conditions.

  5. Laser beam-plasma coupling in laser solenoid plasmas

    International Nuclear Information System (INIS)

    A model has been constructed to analyze the gross beam-plasma interaction in a laser solenoid plasma. The model includes a simple solution for a slab plasma response to a given laser beam, and a solution for axial beam size variations in response to arbitrary axial plasma structure. The two solutions are combined to determine the coupled behavior. Trapping of the focused laser beam where it enters the plasma is a significant problem, but can be achieved by a minimum level of imbedded field in the plasma. If the beam is trapped, it first focuses and then defocuses near the front of the bleaching wave (front of the laser heated plasma). In order to avoid divergence of the beam near the front, it is essential to have a pre-formed favorable density profile in the plasma. Such a condition is probably achieved automatically in the early stages of plasma heating. Several techniques are discussed which can be used to avert unfavorable refractive behavior (catastrophic self-focusing and defocusing)

  6. Further development and applications of capillary electrophoresis with capacitively coupled contactless conductivity detection and sequential injection analysis in analytical chemistry

    OpenAIRE

    Stojkovic, Marko

    2013-01-01

    This dissertation is based on the further development and applications of capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C4D), i. e. sequential injection analysis (SIA) applications when coupled with CE-C4D, or determination and quantification of various ions that are not or barely UV absorbed. A purpose made CE-C4D system was used for determination of the DNA fragments of different length, using additives to modify the medium and to sieve ch...

  7. Excitation dynamics in electrically asymmetric capacitively coupled radio frequency discharges: experiment, simulation, and model

    International Nuclear Information System (INIS)

    The symmetry of capacitively coupled radio frequency (CCRF) discharges can be controlled electrically by applying a fundamental frequency and its second harmonic with fixed but adjustable phase shift θ between the driving voltages to one electrode. In such a discharge a variable dc self-bias η is generated as an almost linear function of θ for 00 ≤ θ ≤ 900 via the Electrical Asymmetry Effect. The control parameter for η and the discharge symmetry is θ. Here electron dynamics in electrically asymmetric geometrically symmetric dual frequency discharges operated in argon at 13.56 and 27.12 MHz is investigated experimentally by a particle-in-cell simulation and by an analytical model. The electron dynamics is probed by the electron impact excitation rate of energetic electrons from the ground state into highly excited levels. At high pressures (collisional sheaths) the excitation dynamics is found to work differently compared with conventional CCRF discharges. Unlike in classical discharges the maxima of the time modulated excitation at the powered and grounded electrode within one low frequency period will be similar (symmetric excitation), if η is strong at θ ∼ 00, 900, and significantly different (asymmetric excitation), if η ∼ 0 V at θ ∼ 450. At low pressures (collisionless sheaths) the excitation dynamics works similar to classical discharges, i.e. the excitation will be asymmetric, if η is strong, and symmetric, if η ∼ 0 V. This dynamics is understood in the frame of an analytical model, which provides a more detailed insight into electron heating in CCRF discharges and could be applied to other types of capacitive RF discharges as well.

  8. Inter-Electrode Separation Induced Amorphous-to-Nanocrystalline Transition of Hydrogenated Silicon Prepared by Capacitively Coupled RF PE-CVD Technique

    Directory of Open Access Journals (Sweden)

    S.W. Gosavi

    2011-01-01

    Full Text Available Role of inter-electrode spacing in capacitively coupled radio frequency plasma enhanced chemical vapor deposition deposition (PE-CVD system was studied. The influence of inter-electrode separation on the structural, optical and electrical properties of the deposited films was carefully invesigated keeping all other deposition parameters constant. The results indicate that the film growth rate critically depends up on the plasma chemistry/gas phase chemistry altered by variation of inter-electrode separation. Structure and optical properties are strongly influenced by inter-electrode separation. The nanocrystallization in the material was observed for smaller inter-electrode separation, whereas higher inter-electrode separation favors amorphous structure of the deposited material. The band gap of the material was found to decrease from ~2 eV to 1.8 eV when inter-electrode separation was varied from 15 mm to 40 mm.

  9. On the self-excitation mechanisms of Plasma Series Resonance oscillations in single- and multi-frequency capacitive discharges

    CERN Document Server

    Schuengel, Edmund; Korolov, Ihor; Derzsi, Aranka; Donko, Zoltan; Schulze, Julian

    2016-01-01

    The self-excitation of plasma series resonance (PSR) oscillations is a prominent feature in the current of low pressure capacitive radio frequency (RF) discharges. This resonance leads to high frequency oscillations of the charge in the sheaths and enhances electron heating. Up to now, the phenomenon has only been observed in asymmetric discharges. There, the nonlinearity in the voltage balance, which is necessary for the self-excitation of resonance oscillations with frequencies above the applied frequencies, is caused predominantly by the quadratic contribution to the charge-voltage relation of the plasma sheaths. Using PIC/MCC simulations of single- and multi- frequency capacitive discharges and an equivalent circuit model, we demonstrate that other mechanisms such as a cubic contribution to the charge-voltage relation of the plasma sheaths and the time dependent bulk electron plasma frequency can cause the self-excitation of PSR oscillations, as well. These mechanisms have been neglected in previous model...

  10. Jet quenching in strongly coupled plasma

    CERN Document Server

    Chesler, Paul M

    2014-01-01

    We present calculations in which an energetic light quark shoots through a finite slab of strongly coupled ${\\cal N}=4$ supersymmetric Yang-Mills (SYM) plasma, with thickness $L$, focussing on what comes out on the other side. We find that even when the "jets" that emerge from the plasma have lost a substantial fraction of their energy they look in almost all respects like "jets" in vacuum with the same reduced energy. The one possible exception is that the opening angle of the "jet" is larger after passage through the slab of plasma than before. Along the way, we obtain a fully geometric characterization of energy loss in the strongly coupled plasma and show that $dE_{\\rm out}/dL \\propto L^2/\\sqrt{x^2_{\\rm stop}-L^2}$, where $E_{\\rm out}$ is the energy of the "jet" that emerges from the slab of plasma and $x_{\\rm stop}$ is the (previously known) stopping distance for the light quark in an infinite volume of plasma.

  11. Numerical simulation on coupling performance of steam flow field and electric field in capacitance sensor measuring steam wetness

    International Nuclear Information System (INIS)

    Based on the theory of dielectric polarization and hydrodynamics, using the FLUENT UDF code, the coupling performances of the steam flow field and the electric field in the capacitance sensor were numerically simulated. The standard k-ε model, wall function and SIMPLE way were used. The results show that the voltage decreases gradually from positive plate to negative plate, and the change is even; water molecule is polarized, the polarized charge appears near the plates, and there is no polarized charge in the center of sensor when the dry saturation steam flows through the capacitance sensor; the radial velocity is different from with and without electric field in the capacitance sensor, and the difference is max near the outmost plate; the electric field near the plate is smaller when there is no flow field. The results of numerical simulation match with the results of experiment. The numerical simulation model is feasibility. (authors)

  12. The effect of ambipolar electric fields on the electron heating in capacitive RF plasmas

    CERN Document Server

    Schulze, J; Derzsi, A; Korolov, I; Schuengel, E

    2016-01-01

    We investigate the electron heating dynamics in electropositive argon and helium capacitively coupled RF discharges driven at 13.56 MHz by Particle in Cell simulations and by an analytical model. The model allows to calculate the electric field outside the electrode sheaths, space and time resolved within the RF period. Electrons are found to be heated by strong ambipolar electric fields outside the sheath during the phase of sheath expansion in addition to classical sheath expansion heating. By tracing individual electrons we also show that ionization is primarily caused by electrons that collide with the expanding sheath edge multiple times during one phase of sheath expansion due to backscattering towards the sheath by collisions. A synergistic combination of these different heating events during one phase of sheath expansion is required to accelerate an electron to energies above the threshold for ionization. The ambipolar electric field outside the sheath is found to be time modulated due to a time modul...

  13. Capacitively coupled pickup in MCP-based photodetectors using a conductive metallic anode

    CERN Document Server

    Angelico, Evan; Adams, Bernhard; Elagin, Andrey; Frisch, Henry; Spieglan, Eric

    2016-01-01

    We have designed and tested a robust 20 $\\times$ 20 cm$^2$ thin metal film internal anode capacitively coupled to an external array of signal pads or micro-strips for use in fast microchannel plate photodetectors. The internal anode, in this case a 10nm-thick NiCr film deposited on a 96% pure Al$_2$O$_3$ 3mm-thick ceramic plate and connected to HV ground, provides the return path for the electron cascade charge. The multi-channel pickup array consists of a printed-circuit card or glass plate with metal signal pickups on one side and the signal ground plane on the other. The pickup can be put in close proximity to the bottom outer surface of the sealed photodetector, with no electrical connections through the photodetector hermetic vacuum package other than a single ground connection to the internal anode. Two pickup patterns were tested using a small commercial MCP-PMT as the signal source: 1) parallel 50$\\Omega$ 25-cm-long micro-strips with an analog bandwidth of 1.5 GHz, and 2) a 20 $\\times$ 20 cm$^2$ array...

  14. Measurement of bubble velocity using Capacitively Coupled Contactless Conductivity Detection (C4D) technique

    Institute of Scientific and Technical Information of China (English)

    Baoliang Wang; Ying Zhou; Haifeng Ji; Zhiyao Huang; Haiqing Li

    2013-01-01

    The feasibility of applying Capacitively Coupled Contactless Conductivity Detection (C4D) technique to measurement of bubble velocity in gas-liquid two-phase flow in millimeter-scale pipe is investigated.And,a new method,which combines the C4D technique and the principle of cross-correlation velocity measurement,is proposed for the measurement of bubble velocity.This research includes two parts.First,based on the principle of C4D,a new five-electrode C4D sensor is developed.Then,with two conductivity signals obtained by the C4D sensor,the velocity measurement of bubble is implemented according to the principle of cross-correlation.The research results indicate that the C4D technique is highly effective and anticipates a broad potential in the field of two-phase flow.Experimental results show that the fiveelectrode C4D sensor is suitable for measuring the velocity of single bubbles with a relative error of less than 5%.

  15. Heart Rate Variability Monitoring during Sleep Based on Capacitively Coupled Textile Electrodes on a Bed

    Directory of Open Access Journals (Sweden)

    Hong Ji Lee

    2015-05-01

    Full Text Available In this study, we developed and tested a capacitively coupled electrocardiogram (ECG measurement system using conductive textiles on a bed, for long-term healthcare monitoring. The system, which was designed to measure ECG in a bed with no constraints of sleep position and posture, included a foam layer to increase the contact region with the curvature of the body and a cover to ensure durability and easy installation. Nine healthy subjects participated in the experiment during polysomnography (PSG, and the heart rate (HR coverage and heart rate variability (HRV parameters were analyzed to evaluate the system. The experimental results showed that the mean of R-peak coverage was 98.0% (95.5%–99.7%, and the normalized errors of HRV time and spectral measures between the Ag/AgCl system and our system ranged from 0.15% to 4.20%. The root mean square errors for inter-beat (RR intervals and HR were 1.36 ms and 0.09 bpm, respectively. We also showed the potential of our developed system for rapid eye movement (REM sleep and wake detection as well as for recording of abnormal states.

  16. Supramolecular organization of the sperm plasma membrane during maturation and capacitation

    Institute of Scientific and Technical Information of China (English)

    Roy Jones; Peter S. James; Liz Howes; Andreas Bruckbauer; David Klenerman

    2007-01-01

    Aim: In the present study, a variety of high resolution microscopy techniques were used to visualize the organization and motion of lipids and proteins in the sperm's plasma membrane. We have addressed questions such as the presence of diffusion barriers, confinement of molecules to specific surface domains, polarized diffusion and the role of cholesterol in regulating lipid rafts and signal transduction during capacitation. Methods: Atomic force microscopy identified a novel region (EqSS) within the equatorial segment of bovine, porcine and ovine spermatozoa that was enriched in constitutively phosphorylated proteins. The EqSS was assembled during epididymal maturation. Fluorescence imaging techniques were then used to follow molecular diffusion on the sperm head. Results: Single lipid molecules were freely exchangeable throughout the plasma membrane and showed no evidence for confinement within domains. Large lipid aggregates, however, did not cross over the boundary between the post-acrosome and equatorial segment suggesting the presence of a molecular filter between these two domains. Conclusion: A small reduction in membrane cholesterol enlarges or increases lipid rafts concomitant with phosphorylation of intracellular proteins. Excessive removal of cholesterol, however, disorganizes rafts with a cessation of phosphorylation. These techniques are forcing a revision of long-held views on how lipids and proteins in sperm membranes are assembled into larger complexes that mediate recognition and fusion with the egg.

  17. Optical vibration measurements of cross coupling effects in capacitive micromachined ultrasonic transducer arrays

    Science.gov (United States)

    Leirset, Erlend; Aksnes, Astrid

    2011-05-01

    Optical vibration measurement systems are excellent tools for characterizing ultrasonic transducers. This paper presents measurements on immersed arrays of capacitive ultrasonic transducers (CMUTs) using a heterodyne interferometer. The interferometer allows measurements of vibrations from DC up to 1 GHz with a noise floor of ~1pm/√Hz. Previously CMUTs have been characterized in air. The transducer is intended for intravascular use. Therefore the CMUTs were characterized in the transparent fluids kerosene and rapeseed oil that have acoustic properties closer to blood. The optical measurements on immersed CMUTs were validated by assessing the measurement errors caused by the acousto optic effects in the fluid. When immersed there is significant cross coupling between individual CMUTs within an array. Simulations presented here indicate that this causes an acoustic wave mode that is bound to the interface between the CMUTs and the fluid. This is confirmed by measurements of the phase velocity and attenuation coefficient of this wave. The measurement results indicate that the wave exists up to a maximum frequency and that the attenuation constant increases with increasing frequency. Rapeseed oil causes a significantly larger attenuation coefficient than kerosene, which most probably is due to a considerable difference in fluid viscosities. There was a mismatch between the simulated and measured phase velocity for low frequencies. It is likely that the cause of this is coupling between the fluid CMUT interface waves and Lamb waves in the substrate of the CMUT array. Measurements performed with the heterodyne interferometer have confirmed the presence of dispersive waves bound to the surface of the transducer by directly showing their propagation along the array. The setup has also characterized the bound waves by measuring dispersion relations.

  18. Two-dimensional fluid modelling of charged particle transport in radio-frequency capacitively coupled discharges

    International Nuclear Information System (INIS)

    This paper reviews the formulation and updates some numerical procedures usually adopted in two-dimensional, time-dependent fluid models to study the transport of charged particles in radio-frequency capacitively coupled discharges. The description of charged particle transport is made by solving the continuity and momentum transfer equations for electrons and ions, coupled with Poisson's equation and the electron mean energy transport equations. Inertia terms are considered in the ion momentum transfer equations, by generalizing the earlier definition of effective electric field. The electron mean energy equations are written using specific energy transport parameters, deduced from integration over the electron energy distribution function (EEDF). The model adopts the local mean energy approximation, i.e. it computes the electron transport parameters as a function of the electron mean energy, using either a homogeneous, two-term Boltzmann equation solver or a Maxwellian EEDF. More appropriate boundary conditions for the electron and ion fluxes are used successfully. The model is solved for a GEC Cell reactor type (with 6.4 cm radius and 3.2 cm interelectrode distance) operating at frequency 13.56 MHz, pressures between 10 mTorr and 10 Torr and applied voltages from 100 to 500 V, in electropositive (helium) and electronegative (silane-hydrogen) gases or gas mixtures. The ion kinetics in silane and hydrogen is updated with respect to previous works, by further considering SiH2+, H+ and H3+ ions. In general, simulation results for some typical electrical parameters are closer to experimental measurements available than calculations reported in previous works

  19. Modeling and Characterization of the Implant Intra-Body Communication Based on Capacitive Coupling Using a Transfer Function Method

    Directory of Open Access Journals (Sweden)

    Kai Zhang

    2014-01-01

    Full Text Available Implantable devices have important applications in biomedical sensor networks used for biomedical monitoring, diagnosis and treatment, etc. In this paper, an implant intra-body communication (IBC method based on capacitive coupling has been proposed, and the modeling and characterization of this kind of IBC has been investigated. Firstly, the transfer function of the implant IBC based on capacitive coupling was derived. Secondly, the corresponding parameters of the transfer function are discussed. Finally, both measurements and simulations based on the proposed transfer function were carried out, while some important conclusions have been achieved, which indicate that the achieved transfer function and conclusions are able to help to achieve an implant communication method with the highly desirable characteristics of low power consumption, high data rate, high transmission quality, etc.

  20. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    Science.gov (United States)

    Park, Jaeyoung; Henins, Ivars

    2005-06-21

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  1. Capacitively coupled contactless conductivity detection and sequential injection analysis in capillary electrophoresis and capillary electro-chromatography

    OpenAIRE

    Mai, Thanh Duc

    2011-01-01

    This thesis focuses on the applications of capacitively coupled contactless conductivity detection (C4D) in capillary electrophoresis (CE) hybridized with high-performance liquid chromatography (HPLC), i.e. in capillary electrochromatography and pressure-assisted capillary electrophoresis, as well as on the development and applications of an extension of CE-C4D with sequential injection analysis (SIA). At first, the in-house built C4D was used for electro-chromatographic determinations of...

  2. Thermal effect and energy-level transition rule for a mesoscopic LC circuit with inductance-capacitance coupling

    Institute of Scientific and Technical Information of China (English)

    Su Jie; Wang Ji-Suo; Liang Bao-Long; Zhang Xiao-Yan

    2009-01-01

    This paper reports that the mesoscopic inductance and capacitance coupling LC circuit is quantized by means of the canonical quantization method. Using the 'invariant eigen-operator' method, it deduces the energy-level transition rule when the system is disturbed by an external electromagnetic field. At the same time, the quantum fluctuations for the system at finite temperature are examined by virtue of the generalized Hellmann-Feynman theorem.

  3. Quark Gluon Plasma as a Strongly Coupled Color-Coulombic Plasma

    OpenAIRE

    Bannur, Vishnu Mayya

    1998-01-01

    We show that the extensively studied equation of state (EOS) of strongly coupled QED plasma fits the recent lattice EOS data of gluon plasma remarkably well, with appropriate modifications to take account of color degrees of freedom and running coupling constant. Hence we conclude that the quark gluon plasma near the critical temperature is a strongly coupled color-Coulombic plasma.

  4. A parallel-architecture parametric equalizer for air-coupled capacitive ultrasonic transducers.

    Science.gov (United States)

    McSweeney, Sean G; Wright, William M D

    2012-01-01

    Parametric equalization is rarely applied to ultrasonic transducer systems, for which it could be used on either the transmitter or the receiver to achieve a desired response. An optimized equalizer with both bump and cut capabilities would be advantageous for ultrasonic systems in applications in which variations in the transducer performance or the properties of the propagating medium produce a less-than-desirable signal. Compensation for non-ideal transducer response could be achieved using equalization on a device-by-device basis. Additionally, calibration of ultrasonic systems in the field could be obtained by offline optimization of equalization coefficients. In this work, a parametric equalizer for ultrasonic applications has been developed using multiple bi-quadratic filter elements arranged in a novel parallel arrangement to increase the flexibility of the equalization. The equalizer was implemented on a programmable system-on-chip (PSOC) using a small number of parallel 4th-order infinite impulse response switchedcapacitor band-pass filters. Because of the interdependency of the required coefficients for the switched capacitors, particle swarm optimization (PSO) was used to determine the optimum values. The response of a through-transmission system using air-coupled capacitive ultrasonic transducers was then equalized to idealized Hamming function or brick-wall frequencydomain responses. In each case, there was excellent agreement between the equalized signals and the theoretical model, and the fidelity of the time-domain response was maintained. The bandwidth and center frequency response of the system were significantly improved. It was also shown that the equalizer could be used on either the transmitter or the receiver, and the system could compensate for the effects of transmitterreceiver misalignment.

  5. The electrical asymmetry effect in geometrically asymmetric capacitive radio frequency plasmas

    International Nuclear Information System (INIS)

    The electrical asymmetry effect (EAE) allows an almost ideal separate control of the mean ion energy, i>, and flux, Γi, at the electrodes in capacitive radio frequency discharges with identical electrode areas driven at two consecutive harmonics with adjustable phase shift, θ. In such geometrically symmetric discharges, a DC self bias is generated as a function of θ. Consequently, i> can be controlled separately from Γi by adjusting the phase shift. Here, we systematically study the EAE in low pressure dual-frequency discharges with different electrode areas operated in argon at 13.56 MHz and 27.12 MHz by experiments, kinetic simulations, and analytical modeling. We find that the functional dependence of the DC self bias on θ is similar, but its absolute value is strongly affected by the electrode area ratio. Consequently, the ion energy distributions change and i> can be controlled by adjusting θ, but its control range is different at both electrodes and determined by the area ratio. Under distinct conditions, the geometric asymmetry can be compensated electrically. In contrast to geometrically symmetric discharges, we find the ratio of the maximum sheath voltages to remain constant as a function of θ at low pressures and Γi to depend on θ at the smaller electrode. These observations are understood by the model. Finally, we study the self-excitation of non-linear plasma series resonance oscillations and its effect on the electron heating.

  6. Titanium oxidation by rf inductively coupled plasma

    Science.gov (United States)

    Valencia-Alvarado, R.; de la Piedad-Beneitez, A.; López-Callejas, R.; Barocio, S. R.; Mercado-Cabrera, A.; Peña-Eguiluz, R.; Muñoz-Castro, A. E.; Rodríguez-Méndez, B. G.; de la Rosa-Vázquez, J. M.

    2014-05-01

    The development of titanium dioxide (TiO2) films in the rutile and anatase phases is reported. The films have been obtained from an implantation/diffusion and sputtering process of commercially pure titanium targets, carried out in up to 500 W plasmas. The experimental outcome is of particular interest, in the case of anatase, for atmospheric pollution degradation by photocatalysis and, as to the rutile phase, for the production of biomaterials required by prosthesis and implants. The reactor employed consists in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56 MHz RF source. The process takes place at a 5×10-2 mbar pressure with the target samples being biased from 0 to -3000 V DC. The anatase phase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates placed 2 cm away from the target. The rutile phase was obtained by implantation/diffusion on targets at about 700 °C. The plasma was developed from a 4:1 argon/oxygen mixture for ~5 hour processing periods. The target temperature was controlled by means of the bias voltage and the plasma source power. The obtained anatase phases did not require annealing after the plasma oxidation process. The characterization of the film samples was conducted by means of x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy.

  7. Isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The potential of isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) was evaluated for the determination of trace amounts of uranium and thorium in silicate rocks. Compared with conventional isotope dilution methods using thermal ionization mass spectrometers, the major benefit is a large increase in sample through-put without a significant decrease in precision and accuracy. This results from direct liquid sampling at atmospheric pressure and from the capability of measuring isotope ratios on raw solutions, without chemical separation of the analytes from the matrix elements. Isotope dilution ICP-MS alleviates the need for matrix-matched standards. Further, it is insensitive to possible causes of intensity drift (e.g., clogging of the plasma/mass spectrometer interface and defocusing of the ion beam) and to chemical effects (e.g. oxide formulation). Results obtained on some international rock standards are in good agreement with recommended values. (author). 26 refs.; 1 fig., tabs

  8. Effects of microwave and oxygen plasma treatments on capacitive characteristics of supercapacitor based on multiwalled carbon nanotubes

    Science.gov (United States)

    Dulyaseree, Paweena; Yordsri, Visittapong; Wongwiriyapan, Winadda

    2016-02-01

    The effects of microwave and oxygen plasma treatments on the capacitive characteristics of a supercapacitor based on multiwalled carbon nanotubes (MWNTs) were investigated. MWNTs were heat-treated under air ambient at 500 °C for 1 h, and subsequently microwave-treated at 650 W for 70 s (m-MWNTs). Another batch of MWNTs was treated by oxygen plasma for 30 min (p-MWNTs). Pristine MWNTs, m-MWNTs, and p-MWNTs were separately used as electrode materials for supercapacitors. Their cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy results were analyzed. The p-MWNTs show the best performance with a specific capacitance of 238.23 F·g-1. The capacitance improvement is attributed to the increase in the number of oxygen-containing functional groups, as evidenced by Fourier transform-infrared spectroscopy and contact angle measurement. These results suggest that oxygen plasma treatment is a rapid and efficient method for oxygen functionalization.

  9. A Microfabricated Inductively Coupled Plasma Excitation Source

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-Qing; PU Yong-Ni; SUN Rong-Xia; TANG Yu-Jun; CHEN Wen-Jun; LOU Jian-Zhong; MA Wen

    2008-01-01

    A novel miniaturization of inductively coupled plasma(ICP)source based on printed circuit produced using micro-fabrication techniques is presented.The basic parameters of the novel ICP,including its radio frequency,power loss,size,and argon consumption are less than 1% of that for the case of atmospheric pressure ICP source.For example,at 100 Pa of argon gas pressure,the present ICP source can be ignited by using the rf power less than 3.5 W.Potential applications of the ICP is discussed.

  10. ''SensArray'' voltage sensor analysis in an inductively coupled plasma

    International Nuclear Information System (INIS)

    A commercially manufactured PlasmaVolt sensor wafer was studied in an inductively coupled plasma reactor in an effort to validate sensor measurements. A pure Ar plasma at various powers (25-420 W), for a range of pressures (10-80 mT), and bias voltages (0-250 V) was utilized. A numerical sheath simulation was simultaneously developed in order to interpret experimental results. It was found that PlasmaVolt sensor measurements are proportional to the rf-current through the sheath. Under conditions such that the sheath impedance is dominantly capacitive, sensor measurements follow a scaling law derived from the inhomogeneous sheath model of Lieberman and Lichtenberg, [Principles of Plasma Discharges and Materials Processing (Wiley, New York, 2005)]. Under these conditions, sensor measurements are proportional to the square root of the plasma density at the plasma-sheath interface, the one-fourth root of the electron temperature, and the one-fourth root of the rf bias voltage. When the sheath impedance becomes increasingly resistive, the sensor measurements deviate from the scaling law and tend to be directly proportional to the plasma density. The measurements and numerical sheath simulation demonstrate the scaling behavior as a function of changing sheath impedance for various plasma conditions.

  11. Interface and permittivity simultaneous reconstruction in electrical capacitance tomography based on boundary and finite-elements coupling method.

    Science.gov (United States)

    Ren, Shangjie; Dong, Feng

    2016-06-28

    Electrical capacitance tomography (ECT) is a non-destructive detection technique for imaging the permittivity distributions inside an observed domain from the capacitances measurements on its boundary. Owing to its advantages of non-contact, non-radiation, high speed and low cost, ECT is promising in the measurements of many industrial or biological processes. However, in the practical industrial or biological systems, a deposit is normally seen in the inner wall of its pipe or vessel. As the actual region of interest (ROI) of ECT is surrounded by the deposit layer, the capacitance measurements become weakly sensitive to the permittivity perturbation occurring at the ROI. When there is a major permittivity difference between the deposit and the ROI, this kind of shielding effect is significant, and the permittivity reconstruction becomes challenging. To deal with the issue, an interface and permittivity simultaneous reconstruction approach is proposed. Both the permittivity at the ROI and the geometry of the deposit layer are recovered using the block coordinate descent method. The boundary and finite-elements coupling method is employed to improve the computational efficiency. The performance of the proposed method is evaluated with the simulation tests. This article is part of the themed issue 'Supersensing through industrial process tomography'. PMID:27185960

  12. Branch structure of IV-characteristics in the capacitively coupled Josephson junctions model with the diffusion current

    Energy Technology Data Exchange (ETDEWEB)

    Shukrinov, Yu.M. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Physical Technical Institute, Dushanbe 734063 (Tajikistan)], E-mail: shukrinv@theor.jinr.ru; Mahfouzi, F. [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of); Seidel, P. [Institut fuer Festkorperphysik, Friedrich-Schiller-Universitaet Jena, D-07743 Jena (Germany)

    2007-09-01

    We have solved numerically a system of dynamical equations for the gauge-invariant phase differences between superconducting layers for a stack of N intrinsic junctions and obtained a total branch structure in the current-voltage characteristics (IVC) of the stack. The coupling dependence of the branch's slopes is investigated and demonstrated that the equidistance of the branch structure in capacitively coupled Josephson junctions (CCJJ) model is broken at small values of coupling parameter. Changes in the parameters of the boundary conditions and the use of periodic boundary conditions do not affect this result. In the framework of the CCJJ model with the diffusion current we simulate an experiment and obtain the IV-characteristic with equidistant branch structure at different values of model parameters.

  13. Branch structure of IV-characteristics in the capacitively coupled Josephson junctions model with the diffusion current

    Science.gov (United States)

    Shukrinov, Yu. M.; Mahfouzi, F.; Seidel, P.

    2007-09-01

    We have solved numerically a system of dynamical equations for the gauge-invariant phase differences between superconducting layers for a stack of N intrinsic junctions and obtained a total branch structure in the current-voltage characteristics (IVC) of the stack. The coupling dependence of the branch’s slopes is investigated and demonstrated that the equidistance of the branch structure in capacitively coupled Josephson junctions (CCJJ) model is broken at small values of coupling parameter. Changes in the parameters of the boundary conditions and the use of periodic boundary conditions do not affect this result. In the framework of the CCJJ model with the diffusion current we simulate an experiment and obtain the IV-characteristic with equidistant branch structure at different values of model parameters.

  14. Quantum fluctuations of mesoscopic damped double resonance RLC circuit with mutual capacitance inductance coupling in thermal excitation state

    Science.gov (United States)

    Xu, Xing-Lei; Li, Hong-Qi; Wang, Ji-Suo

    2007-08-01

    Based on the scheme of damped harmonic oscillator quantization and thermo-field dynamics (TFD), the quantization of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling is proposed. The quantum fluctuations of charge and current of each loop in a squeezed vacuum state are studied in the thermal excitation case. It is shown that the fluctuations not only depend on circuit inherent parameters, but also rely on excitation quantum number and squeezing parameter. Moreover, due to the finite environmental temperature and damped resistance, the fluctuations increase with the temperature rising, and decay with time.

  15. Quantum fluctuations of mesoscopic damped double resonance RLC circuit witn mutual capacitance-inductance coupling in thermal excitation state

    Institute of Scientific and Technical Information of China (English)

    Xu Xing-Lei; Li Hong-Qi; Wang Ji-Suo

    2007-01-01

    Based on the scheme of damped harmonic oscillator quantization and thermo-field dynamics(TFD),the quantization of mesoscopic damped double resonance RLC circuit with mutual capacitance-inductance coupling iS proposed.The quantum fluctuations of charge and current of each loop in a squeezed vacuum state are studied in the thermal excitation case.It is shown that the fluctuations not only depend on circuit inherent parameters.but also rely on excitation quantum number and squeezing parameter.Moreover.due to the finite environmental temperature and damped resistance,the fluctuations increase with the temperature rising.and decay with time.

  16. High Coupling Efficiency Generation in Water Confined Laser Plasma Propulsion

    Institute of Scientific and Technical Information of China (English)

    ZHENG Zhi-Yuan; ZHANG Yi; ZHOU Wei-Gong; LU Xin; LI Yu-Tong; ZHANG Jie

    2007-01-01

    High coupling efficiency generation in water confined laser plasma propulsion is investigated. It is found that the coupling efficiency is enhanced over thirty times in water confined ablation compared to that of direct ablation.From calculation of the ablation pressure induced by the plasma on the target surface, it is realized that high coupling efficiency is attributed to the confinement of the water layer on the plasma expansion.

  17. Fluorescence measurements of expanding strongly-coupled neutral plasmas

    CERN Document Server

    Cummings, E A; Durfee, D S; Bergeson, S D

    2005-01-01

    We report new detailed density profile measurements in expanding strongly-coupled neutral plasmas. Using laser-induced fluorescence techniques, we determine plasma densities in the range of 10^5 to 10^9/cm^3 with a time resolution limit as small as 7 ns. Strong-coupling in the plasma ions is inferred directly from the fluorescence signals. Evidence for strong-coupling at late times is presented, confirming a recent theoretical result.

  18. Stochastic properties of strongly coupled plasmas.

    Science.gov (United States)

    Morozov, I V; Norman, G E; Valuev, A A

    2001-03-01

    Stochastic properties of equilibrium strongly coupled plasmas are investigated by a molecular dynamics method. The Krylov-Kolmogorov entropy K and the dynamical memory time t(m) are calculated both for electrons and ions with mass ratios 10-10(5). Two values of K entropy for ions are discovered corresponding to electron and ion time scales. The dependence of the K entropy on the number of particles, the nonideality parameter, and the form of the interaction potential is investigated. The problem of the accuracy of molecular dynamics simulations is discussed. A universal relation between Kt(m) and the fluctuation of the total energy of the system is obtained. The relation does not depend on the numerical integration scheme, temperature, density, and the interparticle interaction potential, so that it may be applied to arbitrary dynamic systems. Transition from dynamic to stochastic correlation is treated for both electron and ion velocity autocorrelation functions, for Langmuir and ion-sound plasma wave dynamic structure factors. We point to quantum uncertainty as a physical reason which limits dynamic (Newton) correlation for times greater than t(m). PMID:11308773

  19. A capacitive-coupled ground resistivity system for engineering and environmental applications: Results of two Canadian field tests

    Energy Technology Data Exchange (ETDEWEB)

    Douma, M.; Hunter, J.A. [Geological Survey of Canada, Ottawa, Ontario (Canada); Timofeev, V.M. [All-Russian Research Inst. for Hydrogeology and Engineering Geology, Zeleny (Russian Federation); Rogozinski, A.W. [Androtex, Ltd., Mississauga, Ontario (Canada)

    1994-12-31

    Ground resistivity conditions in a variety of geological environments were measured using a technique that odes not rely on galvanic contact between the sensors and the terrain. The capacitive-coupling method converts a current applied through one pair of antennas and a voltage potential received through another set of antennas into apparent resistivity using a particular constant which is dependent upon the geometry of the antenna arrays. The method supports rapid data acquisition, and because contact resistance problems are obviated, surveys in very resistive conditions (> 10,000 ohm-m) can be conducted. Originally a Russian development, used in routine permafrost mapping along pipeline routes and at well-sites in Siberia, a version of the capacitive-coupled resistivity (CCR) system, called RUSCAN, is being developed by a Canadian firm, Androtex, Ltd. The development program is supported by the All-Russian Institute for Hydrogeology and Engineering Geology in Moscow and the Industrial Partners Program of the Geological Survey of Canada. Case studies in a variety of geological environments have been used to evaluate the new system, comparing results from electromagnetic, D.C. resistivity, drilling results, and borehole geophysics.

  20. Quantum phase transition and Coulomb blockade effect in triangular quantum dots with interdot capacitive and tunnel couplings

    Institute of Scientific and Technical Information of China (English)

    熊永臣; 王为忠; 杨俊涛; 黄海铭

    2015-01-01

    The quantum phase transition and the electronic transport in triangular quantum dot system are investigated using the numerical renormalization group method. We concentrate on the interplay between the interdot capacitive coupling V and the interdot tunnel coupling t . For small t , three dots form a local spin doublet. As t increases, due to the competition between V and t , there exist two first-order transitions with phase sequence spin-doublet-magnetic frustration phase-orbital spin singlet. When t is absent, the evolutions of the total charge on the dots and the linear conductance are of the typical Coulomb-blockade features with increasing gate voltage. While for sufficient t , the antiferromagnetic spin correlation between dots is enhanced, and the conductance is strongly suppressed for the bonding state is almost doubly occupied.

  1. Characteristic study of plasma waves by varying the applied RF frequency and electron temperature in single frequency capacitive discharges

    International Nuclear Information System (INIS)

    In low-pressure capacitive discharges, stochastic heating is the dominant electron heating mechanism which occurs due to the momentum transfer from the oscillating electron sheath edge to electrons. The existence of waves in electron density close to the sheath edge was firstly reported in literature but a comprehensive analysis of their nature has not been discussed. The evidence of wave emission with a frequency near to electron plasma frequency adjacent the sheath territory in case of collisionless plasma in single frequency capacitive discharges was detailed investigated by S Sharma et al. Here the wave properties have been studied by varying the current density amplitude J0 for a constant Radio-Frequency (RF), 27.12 MHz. The electron temperature was also constant (2.5 eV). The field reversal and ion reflection phenomena were reported. In current research work, these waves are studied by varying the frequency of applied RF and keeping other parameters constant. The wave amplitude changes with the frequency of applied RF and the presence of strong field reversal region also observed. The wave properties are also studied by varying the electron temperature Te for applied frequency 27.12 MHz by keeping all other controlling parameters constant. At low values of electron temperature i.e. ∼ 2 eV the strong field reversal emerges. The wave amplitude is also varies by changing electron temperature. (author)

  2. Shear viscosities of photons in strongly coupled plasmas

    Science.gov (United States)

    Yang, Di-Lun; Müller, Berndt

    2016-09-01

    We investigate the shear viscosity of thermalized photons in the quark gluon plasma (QGP) at weak coupling and N = 4 super Yang-Mills plasma (SYMP) at both strong and weak couplings. We find that the shear viscosity due to the photon-parton scattering up to the leading order of electromagnetic coupling is suppressed when the coupling of the QGP/SYMP is increased, which stems from the blue-shift of the thermal-photon spectrum at strong coupling. In addition, the shear viscosity rapidly increases near the deconfinement transition in a phenomenological model analogous to the QGP.

  3. Stopping Power for Strong Beam-Plasma Coupling

    Science.gov (United States)

    Gericke, Dirk O.

    2001-10-01

    The slowing down process of charged particles in plasma targets is investigated for the case of strong beam-plasma coupling. Strong beam-plasma correlations can be considered using the collision operator of the quantum Boltzmann equation. As a first step, dynamic screening is included in the first Born approximation. This approach gives good results for moderate beam-plasma coupling (Zb Γ^3/2 Bethe-formula, the standard model of the stopping power (Bethe plus Bloch corrections and Barkas terms), the Li & Petrasso formula and simulation data (MD and PIC), is given. This comparison clearly shows the advantage of the proposed model: it smoothly interpolates between the classical low velocity regime, where strong coupling effects occur, and the high velocity quantum regime, where collective modes are important. In the latter case, the experimentally proven Bethe-formula is obtained. Furthermore, it matches the simulation data for moderate as well as strong beam-plasma coupling.

  4. Capacitive deionization coupled with microbial fuel cells to desalinate low-concentration salt water.

    Science.gov (United States)

    Yuan, Lulu; Yang, Xufei; Liang, Peng; Wang, Lei; Huang, Zheng-Hong; Wei, Jincheng; Huang, Xia

    2012-04-01

    A new technology (CDI-MFC) that combined capacitive deionization (CDI) and microbial fuel cell (MFC) was developed to treat low-concentration salt water with NaCl concentration of 60mg/L. The water desalination rate was 35.6mg/(Lh), meanwhile the charge efficiency was 21.8%. Two desorption modes were investigated: discharging (DC) mode and short circuit (SC) mode. The desalination rate in the DC mode was 200.6±3.1mg/(Lh), 47.8% higher than that in the SC mode [135.7±15.3mg/(Lh)]. The average current in the DC mode was also much higher than that of the SC mode. The energy stored in the CDI cell has been reused to enhance the electron production of MFC by the discharging desorption mode (DC mode), which offers an approach to recover the electrostatic energy in the CDI cell. PMID:22364771

  5. Enhancing capacitive deionization performance of electrospun activated carbon nanofibers by coupling with carbon nanotubes.

    Science.gov (United States)

    Dong, Qiang; Wang, Gang; Wu, Tingting; Peng, Senpei; Qiu, Jieshan

    2015-05-15

    Capacitive deionization (CDI) is an alternative, effective and environmentally friendly technology for desalination of brackish water. The performance of the CDI device is highly determined by the electrode materials. In this paper, a composite of carbon nanotubes (CNTs) embedded in activated carbon nanofiber (ACF) was prepared by a direct co-electrospinning way and subsequent CO2 activation. The introduction of CNTs can greatly improve the conductivity while the CO2-mediated activation can render the final product with high porosity. As such, the hybrid structure can provide an excellent storage space and pathways for ion adsorption and conduction. When evaluated as electrode materials for CDI, the as-prepared CNT/ACF composites with higher electrical conductivity and mesopore ratios exhibited higher electrosorption capacity and good regeneration performance in comparison with the pure ACF. PMID:25595622

  6. Contactless vector network analysis using diversity calibration with capacitive and inductive coupled probes

    Directory of Open Access Journals (Sweden)

    T. Zelder

    2007-06-01

    Full Text Available Contactless vector network analysis based on a diversity calibration is investigated for the measurement of embedded devices in planar circuits. Conventional contactless measurement systems based on two probes for each measurement port have the disadvantage that the signal-to-noise system dynamics strongly depends on the distance between the contactless probes.

    In order to avoid a decrease in system dynamics a diversity based measurement system is presented. The measurement setup uses one inductive and two capacitive probes. As an inductive probe a half magnetic loop in combination with a broadband balun is introduced. In order to eliminate systematic errors from the measurement results a diversity calibration algorithm is presented. Simulation and measurement results for a one-port configuration are shown.

  7. Mode-coupling instability of monolayer complex (dusty) plasmas

    Science.gov (United States)

    Zhdanov, Sergey; Ivlev, Alexei; Morfill, Gregor

    2010-05-01

    Strongly coupled complex (dusty) plasmas give us a unique opportunity to go beyond the limits of continuous media and study various generic processes occurring in liquids or solids, in regimes ranging from the onset of cooperative phenomena to large strongly coupled systems at the most detailed kinetic (atomistic) level. On the other hand, there is certain peculiarity of the interparticle interactions in complex plasmas. This can be easily understood if we divide the complete set of elementary charges in complex plasmas into two distinct categories - a subsystem of charges bound to the microparticles, and a subsystem of free plasma charges in the surrounding wakes. Plasma wakes play the role of a "third body" in the mutual particle-particle interaction and, hence, make the pair interaction nonreciprocal. We carried out rigorous theoretical investigation of the DL wave mode coupling occurring in 2D complex plasmas due to particle-wake interactions. The analysis of the mode coupling shows that if the strength of the vertical confinement is below a certain critical value, then resonance coupling between the longitudinal in-plane mode and out-of-plane mode sets in. This results in the emergence of a hybrid mode and drives the mode-coupling instability. The universal dependence of the critical confinement frequency on plasma parameters is calculated, which allows us to specify the conditions when stable 2D highly ordered complex plasma can be formed in experiments.

  8. A Compact System of Capacitively Coupled Contactless Conductivity Detection Based on the Square Wave Excitation Signal for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    Shui Feng ZHANG; Li Shi WANG; Zhi DANG

    2006-01-01

    This paper reported a compact system of capacitively coupled contactless conductivity detection (C4D) based on the square wave excitation voltage for capillary electrophoresis, and it exhibited excellent sensitivity at the optimal frequency of 198 kHz. The feasibility and sensitivity of this detector was demonstrated by simultaneous detection of thirteen ions including alkali,alkaline earth and heavy metal ions. And the detection limits (S/N 3) were in the range of 0.2-1μmol/L for Mn2+,K+,Na+,Mg2+,Ca2+ ,Li+ ,Ba2+ ,and 7-25μmol/L for Ni2+ ,Cu2+ ,Cd2+ ,Pb2+,Co2+ ,Zn2+.

  9. Fabrication and application of a wireless inductance-capacitance coupling microsensor with electroplated high permeability material NiFe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y H; Chang, I N [Ph. D. Program in Electrical and Communications Engineering, Feng-Chia University, Taichung 40724, Taiwan (China); Chang, H C; Lai, C C, E-mail: hcchang@fcu.edu.tw [Department of Automatic Control Engineering, Feng-Chia University, Taichung 40724, Taiwan (China)

    2011-01-01

    A fully integrated wireless inductance-capacitance (LC) coupling microsensor was designed and fabricated by MEMS technology. The sensing loop was formed by connecting a deformable parallel-plated capacitor and a planar spiral inductor with a Ni(80)Fe(20) core. Polyimide and PMMA were used to isolate and package the devices. Typical dimension of the sensors was 5 x 5 mm{sup 2} x 0.77 mm. Different electroplated inductive coils (30, 40, and 60 turns) were fabricated to connect with a 4 x 4 mm{sup 2} plate capacitor in series. The LC sensing module for measuring liquid-level induced frequency responses was setup. Experimental results show that frequency response decreased as liquid level increased and sensitivity is about 7.01 kHz/cm with deviation less than 2%. Developed planar spiral inductor with high permeability magnetic core can provide a wide range of frequency variation in LC sensing applications.

  10. Development of a versatile readout and test system and characterization of a capacitively coupled active pixel sensor

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Jens; Gonella, Laura; Hemperek, Tomasz; Hirono, Toko; Huegging, Fabian; Krueger, Hans; Wermes, Norbert [Institute of Physics, University of Bonn, Bonn (Germany); Peric, Ivan [Karlsruher Institut fuer Technologie, Karlsruhe (Germany); Collaboration: ATLAS-Collaboration

    2015-07-01

    With the availability of high voltage and high resistivity CMOS processes, active pixel sensors are becoming increasingly interesting for radiation detection in high energy physics experiments. Although the pixel signal-to-noise ratio and the sensor radiation tolerance were improved, active pixel sensors cannot yet compete with state-of-the-art hybrid pixel detector in a high radiation environment. Hence, active pixel sensors are possible candidates for the outer tracking detector in HEP experiments where production cost plays a role. The investigation of numerous prototyping steps and different technologies is still ongoing and requires a versatile test and readout system, which will be presented in this talk. A capacitively coupled active pixel sensor fabricated in AMS 180 nm high voltage CMOS process is investigated. The sensor is designed to be glued to existing front-end pixel readout chips. Results from the characterization are presented in this talk.

  11. Fabrication and application of a wireless inductance-capacitance coupling microsensor with electroplated high permeability material NiFe

    Science.gov (United States)

    Chen, Y. H.; Chang, H. C.; Lai, C. C.; Chang, I. N.

    2011-01-01

    A fully integrated wireless inductance-capacitance (LC) coupling microsensor was designed and fabricated by MEMS technology. The sensing loop was formed by connecting a deformable parallel-plated capacitor and a planar spiral inductor with a Ni(80)Fe(20) core. Polyimide and PMMA were used to isolate and package the devices. Typical dimension of the sensors was 5 × 5 mm2 × 0.77 mm. Different electroplated inductive coils (30, 40, and 60 turns) were fabricated to connect with a 4 × 4 mm2 plate capacitor in series. The LC sensing module for measuring liquid-level induced frequency responses was setup. Experimental results show that frequency response decreased as liquid level increased and sensitivity is about 7.01 kHz/cm with deviation less than 2%. Developed planar spiral inductor with high permeability magnetic core can provide a wide range of frequency variation in LC sensing applications.

  12. Mesoscopic Capacitance Oscillations

    OpenAIRE

    Buttiker, Markus; Nigg, Simon

    2006-01-01

    We examine oscillations as a function of Fermi energy in the capacitance of a mesoscopic cavity connected via a single quantum channel to a metallic contact and capacitively coupled to a back gate. The oscillations depend on the distribution of single levels in the cavity, the interaction strength and the transmission probability through the quantum channel. We use a Hartree-Fock approach to exclude self-interaction. The sample specific capacitance oscillations are in marked contrast to the c...

  13. Theory and simulation of laser plasma coupling-II

    International Nuclear Information System (INIS)

    In previous lectures at the 1979 Scottish Universities' Summer School in Physics, we presented an introduction to the theory and simulation of laser plasma interactions. A representative mix of coupling processes was discussed. In this update lecture for the 1982 school, we will emphasize two specific topics which have received increased attention in the last few years: stimulated Raman scatter and the wavelength scaling of laser plasma coupling

  14. Thermal conductivity of a strongly coupled hydrogen plasma

    International Nuclear Information System (INIS)

    ''Molecular Dynamics'' simulations has been used to compute the thermal conductivity of the strongly coupled, nearly classical hydrogen plasma. The relaxation of a suitably defined heat current is significantly faster than the decay of the microscopic electric current. Electrical and thermal conductivities are not related by a simple Wiedemann-Franz law in the dense plasma

  15. Holography and screening in strongly coupled non-abelian plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Noronha, Jorge [Universidade de Sao Paulo (IF/USP), Sao Paulo, SP (Brazil). Instituto de Fisica

    2013-07-01

    Full text: In this talk I will show how the gauge/gravity duality can be used to compute the screening length of strongly coupled plasmas such as the quark-gluon plasma formed in ultrarelativistic heavy ion collisions. Predictions for the non-Abelian Debye screening length in QCD, computed using a holographic model of QCD, will be shown. (author)

  16. Effect of gas properties on the dynamics of the electrical slope asymmetry effect in capacitive plasmas: comparison of Ar, H2 and CF4

    NARCIS (Netherlands)

    Bruneau, B.; Lafleur, T.; Gans, T.; O’Connell, D.; Greb, A.; Korolov, I.; Derzsi, A.; Donko, Z.; Brandt, S.; Diomede, P.; Schüngel, E.; Schulze, J.; Economou, D. J.; Longo, S.; Johnson, E.; Booth, J. P.

    2016-01-01

    Tailored voltage excitation waveforms provide an efficient control of the ion energy (through the electrical asymmetry effect) in capacitive plasmas by varying the ‘amplitude’ asymmetry of the waveform. In this work, the effect of a ‘slope’ asymmetry of the waveform is investigated by using sawtooth

  17. Instability of Longitudinal Wave in Magnetized Strongly Coupled Dusty Plasma

    Institute of Scientific and Technical Information of China (English)

    谢柏松

    2003-01-01

    Instability of longitudinal wave in magnetized strongly coupled dusty plasmas is investigated. The dust charging relaxation is taken into account. It is found that there exists threshold of interdust distance for the instability of wave, which is determined significantly by the dust charging relaxation, the coupling parameter of high correlation of dust as well the strength of magnetic field.

  18. Driven transverse shear waves in a strongly coupled dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, P. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)], E-mail: banerjee_pintu2002@yahoo.com; Prasad, G.; Sen, A.; Kaw, P.K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2008-08-11

    The linear dispersion properties of transverse shear waves in a strongly coupled dusty plasma are experimentally studied in a DC discharge device by exciting them in a controlled manner with a variable frequency external source. The dusty plasma is maintained in the strongly coupled fluid regime with (1<{gamma}<<{gamma}{sub c}) where {gamma} is the Coulomb coupling parameter and {gamma}{sub c} is the crystallization limit. A dispersion relation for the transverse waves is experimentally obtained over a frequency range of 0.1 Hz to 2 Hz and found to show good agreement with viscoelastic theoretical results.

  19. Different modes of a capacitively coupled radio-frequency discharge in methane.

    Science.gov (United States)

    Schweigert, I V

    2004-04-16

    The transition between different regimes of a capacitevely coupled radio-frequency gas discharge in methane is studied with a combined particle-in-cell Monte Carlo collision algorithm over a wide range of gas pressure P and discharge current j. The results of this study are compared with known experimental and numerical results and summarized on a P-j phase diagram, which constitutes the areas of existence of different discharge regimes. PMID:15169290

  20. Dynamic compression of strongly coupled plasmas at megabars

    International Nuclear Information System (INIS)

    Complete text of publication follows. New experimental results on thermodynamics and electrical conductivity of shock and isoentropically compressed hydrogen and deuterium are presented. Strongly coupled plasmas at pressures achieved 18 Mbar, Coulomb coupling parameter exceeded 450, electron degeneracy parameter came up to 290 were obtained with semi-spherical explosive-driven generators. Theoretical models for description of thermodynamics of strongly coupled hydrogen are discussed, comparison of the experimental and theoretical data for strongly non-ideal hydrogen plasmas under high energy density are presented. Experimental and theoretical problems in studying of warm dense hydrogen are discussed. Problems of accurate description of weakly coupled solar plasma on basis of astrophysical observations are discussed as well.

  1. Solar terrestrial coupling through space plasma processes

    International Nuclear Information System (INIS)

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations

  2. SU-8 etching in inductively coupled oxygen plasma

    DEFF Research Database (Denmark)

    Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming;

    2013-01-01

    Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

  3. Construction of Larger Area Density-Uniform Plasma with Collisional Inductively Coupled Plasma Cells

    Institute of Scientific and Technical Information of China (English)

    OUYANG Liang; LIU Wandong; BAI Xiaoyan; CHEN Zhipeng; WANG Huihui; LI LUO Chen; JI Liangliang; HU Bei

    2007-01-01

    The plasma density and electron temperature of a multi-source plasma system composed of several collisional inductively coupled plasma (ICP) cells were measured by a double-probe. The discharges of the ICP cells were shown to be independent of each other. Furthermore, the total plasma density at simultaneous multi-cell discharge was observed to be approximately equal to the summation of the plasma density when the cells discharge separately. Based on the linear summation phenomenon, it was shown that a larger area plasma with a uniform density and temperature profile could be constructed with multi-collisional ICP cells.

  4. Characterization of stationary and pulsed inductively coupled RF discharges for plasma sterilization

    Science.gov (United States)

    Gans, T.; Osiac, M.; O'Connell, D.; Kadetov, V. A.; Czarnetzki, U.; Schwarz-Selinger, T.; Halfmann, H.; Awakowicz, P.

    2005-05-01

    Sterilization of bio-medical materials using radio frequency (RF) excited inductively coupled plasmas (ICPs) has been investigated. A double ICP has been developed and studied for homogenous treatment of three-dimensional objects. Sterilization is achieved through a combination of ultraviolet light, ion bombardment and radical treatment. For temperature sensitive materials, the process temperature is a crucial parameter. Pulsing of the plasma reduces the time average heat strain and also provides additional control of the various sterilization mechanisms. Certain aspects of pulsed plasmas are, however, not yet fully understood. Phase resolved optical emission spectroscopy and time resolved ion energy analysis illustrate that a pulsed ICP ignites capacitively before reaching a stable inductive mode. Time resolved investigations of the post-discharge, after switching off the RF power, show that the plasma boundary sheath in front of a substrate does not fully collapse for the case of hydrogen discharges. This is explained by electron heating through super-elastic collisions with vibrationally excited hydrogen molecules.

  5. Characterization of stationary and pulsed inductively coupled RF discharges for plasma sterilization

    International Nuclear Information System (INIS)

    Sterilization of bio-medical materials using radio frequency (RF) excited inductively coupled plasmas (ICPs) has been investigated. A double ICP has been developed and studied for homogenous treatment of three-dimensional objects. Sterilization is achieved through a combination of ultraviolet light, ion bombardment and radical treatment. For temperature sensitive materials, the process temperature is a crucial parameter. Pulsing of the plasma reduces the time average heat strain and also provides additional control of the various sterilization mechanisms. Certain aspects of pulsed plasmas are, however, not yet fully understood. Phase resolved optical emission spectroscopy and time resolved ion energy analysis illustrate that a pulsed ICP ignites capacitively before reaching a stable inductive mode. Time resolved investigations of the post-discharge, after switching off the RF power, show that the plasma boundary sheath in front of a substrate does not fully collapse for the case of hydrogen discharges. This is explained by electron heating through super-elastic collisions with vibrationally excited hydrogen molecules

  6. Attachment Instabilities of SF6 Inductively Coupled Plasmas under Different Coupling Intensities

    Institute of Scientific and Technical Information of China (English)

    GAO Wei; SUN Bin; DING Zhen-Feng

    2009-01-01

    Characteristics of attachment instabilities in SF6 inductively coupled plasmas are experimentally studied under different coupling intensities.Experimental results show that the instabilities only occur in H modes operating in positive feedback regions.Both the sudden mode transitions and the instabilities are influenced by the coupling intensities.With increasing absorbed power,weak and middle coupling discharges can sequently undergo sudden mode transitions and attachment instabilities.In strong coupling discharges,the sudden mode transitions disappear and only attachment instabilities exist.The strong and weak coupling discharges are the most stable and unstable,respectively.

  7. Dust acoustic instability in a strongly coupled dusty plasma

    Science.gov (United States)

    Rosenberg, M.; Kalman, G. J.; Hartmann, P.; Goree, J.

    2013-10-01

    Dusty plasmas are plasmas containing charged micron to sub-micron size dust grains (solid particulates). Because the grains can be multiply charged and are much more massive than the ions, the presence of dust can lead to novel waves such as the dust acoustic wave, which is a compressional wave that can be excited by a flow of ions that is driven by an electric field. Moreover, the large dust charge can result in strong Coulomb coupling between the dust grains, where the electrostatic energy between neighboring grains is larger than their thermal (kinetic) energy. When the coupling between dust grains is strong, but not large enough for crystallization, the dust is in the strongly coupled liquid phase. This poster theoretically investigates the dust acoustic instability, which is driven by sub-thermal ion flow, in a three-dimensional dusty plasma in the strongly coupled liquid phase. It is found that strong coupling enhances the instability. The application is to microgravity experiments with dusty plasma planned for the PK-4 and PlasmaLab instruments, which are in development for the International Space Station. Microgravity conditions enable the preparation of dust clouds under these sub-thermal ion flow conditions by avoiding the need for strong electric fields to levitate the dust grains.

  8. Investigation of ion energy and angular distributions at the wafer edge in rf capacitively coupled reactors using CFD-ACE+

    Science.gov (United States)

    Bhoj, Ananth; Roy, Abhra; Jain, Kunal; Xiong, Zhongmin

    2015-09-01

    Dual frequency capacitively coupled reactors are now commonly used in microelectronics fabrication. The extent of possible independent control of ion fluxes and ion energy and angular distribution (IEADs) by varying HF and LF signals is currently a topic of great interest. In this study, we report on investigations of IEADs in single and dual frequency CCPs, including the wafer edge refinement using CFD-ACE+. The current algorithms in CFD-ACE+ allow the determination of total power at the electrode or in the discharge. To account for the presence of two or more rf sources connected to a powered electrode, the existing numerical algorithms for power targeting were enhanced to track current at the electrode as a function of time, vary voltage and determine power as a function of frequency. The Monte Carlo transport module for heavy species in CFD-ACE+ was recently enhanced to compute IEADs in rf discharges. Results for the effect of varying power and pressure on IEADs were compared to semi-analytical models and data reported in Gahan et al.. The validated model was applied to investigate the effect of details of HF and LF signals on IEADs in Argon discharges.

  9. Application of capacitively coupled contactless conductivity as an external detector for zone electrophoresis in poly(dimethylsiloxane) chips.

    Science.gov (United States)

    Koczka, Péter I; Bodoki, Ede; Gáspár, Attila

    2016-02-01

    In this work, lab-made PDMS microfluidic chips were matched to a capacitively coupled contactless conductivity detector (C(4) D) having external in-plane electrodes (eDAQ, Australia). The advantages of this type of C(4) D are the choice to reversibly place or remove the microchip onto/from the detector and to freely variate the position of the detection (separation length) on the microchip. The thickness of the bottom layer of the PDMS chip was optimized to achieve sensitive detection during the electrophoretic separation. PDMS chips with 100 μm bottom layer used with the C(4) D platform were tested by CZE of a mixture of seven anions and different types of real samples. Using split-flow pressure sample injection and effective length of 6.5 cm, the numbers of theoretical plates were in the range of 4000-6000 (63,000-93,000/m) and the LODs amounted to 3.66-14.7 μmol/L (0.13-2.26 μg/mL) for the studied anions. PMID:26531885

  10. On plasma coupling and turbulence effects in low velocity stopping

    Energy Technology Data Exchange (ETDEWEB)

    Kurilenkov, Yu K [Unified Institute for High Temperatures of Russian Academy of Sciences, 13/19 Izhorskaya Str., 125412 Moscow (Russian Federation); Maynard, G [Laboratoire de Physique des Gaz et des Plasmas, UMR-8578, Bat. 210, Universite Paris XI, F-91405 Orsay (France); Barriga-Carrasco, M D [Laboratoire de Physique des Gaz et des Plasmas, UMR-8578, Bat. 210, Universite Paris XI, F-91405 Orsay (France); Valuev, A A [Unified Institute for High Temperatures of Russian Academy of Sciences, 13/19 Izhorskaya Str., 125412 Moscow (Russian Federation)

    2006-04-28

    The problem of stopping power (SP) for projectile ions is analysed in terms of the dielectric function and effective collision frequency for moderately dense and strongly coupled plasmas (SCP). We consider several issues regarding the calculation of stopping power for correlated ensembles of particles and oscillators. In particular, effects of group (few particle) modes, transition from positive to negative dispersion and excitation of collective modes up to suprathermal level at plasma targets are addressed. Linear SP of dense suprathermal (nonlinear) plasma targets at different levels of target plasma turbulence is estimated. The force of suprathermal plasma oscillations on the projectile ions is mostly in the nature of increased frictional drag. The results obtained show the possibility of increasing low velocity stopping (up to 'turbulent' values) in comparison with losses in equilibrium dense plasma targets. Experimental conditions to create specific turbulent targets as well as some connection between stopping phenomena and SCP transport properties are discussed briefly.

  11. Development of a low-cost inductively coupled argon plasma

    International Nuclear Information System (INIS)

    The aim of this investigation is to drastically reduce running costs of an inductively coupled plasma. This is done by reducing the argon consumption from 20 l/min to about 1 l/min. First, a sample introduction system operating on 0.1 l/min of carrier argon is described. This system ensures a high ratio of plasma argon and carrier argon even at the low total argon consumptions intended. Next, the developed low consumption plasma is presented. In the proposed design, air is blown perpendicularly against the outside of the torch. A different coil has been developed to make air-cooling efficient. Preliminary data on coupling efficiency for the air-cooled plasma are presented. A similarly low argon consumption has been achieved with water as an external coolant medium. It is concluded that a cheaper alternative to the current ICP has become available. (Auth.)

  12. Probing strongly coupled anisotropic plasmas from higher curvature gravity

    Energy Technology Data Exchange (ETDEWEB)

    Jahnke, Viktor; Misobuchi, Anderson Seigo [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil)

    2016-06-15

    We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential, and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results. (orig.)

  13. Probing strongly coupled anisotropic plasmas from higher curvature gravity

    CERN Document Server

    Misobuchi, Anderson Seigo

    2015-01-01

    We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results.

  14. Probing strongly coupled anisotropic plasmas from higher curvature gravity

    Science.gov (United States)

    Jahnke, Viktor; Misobuchi, Anderson Seigo

    2016-06-01

    We consider five-dimensional AdS-axion-dilaton gravity with a Gauss-Bonnet term and use a black brane solution displaying spatial anisotropy as the gravity dual of a strongly coupled anisotropic plasma. We compute several observables relevant to the study of the plasma, namely, the drag force, the jet quenching parameter, the quarkonium potential, and the thermal photon production. The effects of higher derivative corrections and of the anisotropy are discussed and compared with previous results.

  15. Antenna coupling study for ICWC plasma characterization in TEXTOR

    Indian Academy of Sciences (India)

    Manash Kumar Paul; A Lyssoivan; R Koch; G Van Wassenhove; M Vervier; G Bertschinger; R Laengner; B Unterberg; G Sergienko; V Philipps; T Wauters; the TEXTOR Team

    2013-01-01

    Ion cyclotron wall conditioning (ICWC) discharges, in pulsed-mode operation, were carried out in the limiter tokamak TEXTOR to explore safe operational regimes for the experimental parameters for possible ICWC-discharge cleaning in International Thermonuclear Experimental Reactor (ITER) at half field. Antenna coupling properties obtained during the ion cyclotron range of frequencies (ICRF) wall conditioning experiments performed in helium–hydrogen mixture in TEXTOR were analysed in relation to the obtained ICWC-plasma characterization results. Satisfactory antenna coupling in the mode conversion scenario along with reproducible generation of ICRF plasmas for wall conditioning, were achieved by coupling radio frequency (RF) power from one or two ICRF antennas. The plasma breakdown results obtained in the TEXTOR tokamak have been compared with the predictions of a zero-dimensional RF plasma production model. The present study of ICWC emphasizes the beneficial effect of application of an additional (along with toroidal magnetic field) stationary vertical ($B_{V} \\ll B_{T}$) or oscillating poloidal magnetic field ($B_{P} \\ll B_{T}$) on antenna coupling and relevant plasma parameters.

  16. Degenerate Wave and Capacitive Coupling Increase Human MSC Invasion and Proliferation While Reducing Cytotoxicity in an In Vitro Wound Healing Model

    OpenAIRE

    Michelle Griffin; Syed Amir Iqbal; Anil Sebastian; James Colthurst; Ardeshir Bayat

    2011-01-01

    Non-unions pose complications in fracture management that can be treated using electrical stimulation (ES). Bone marrow mesenchymal stem cells (BMMSCs) are essential in fracture healing; however, the effect of different clinical ES waveforms on BMMSCs cellular activities remains unknown. We compared the effects of direct current (DC), capacitive coupling (CC), pulsed electromagnetic field (PEMF) and degenerate wave (DW) on cellular activities including cytotoxicity, proliferation, cell-kineti...

  17. Polyakov Loops in Strongly-Coupled Plasmas with Gravity Duals

    OpenAIRE

    Noronha, Jorge

    2010-01-01

    We study the properties of the Polyakov loop in strongly-coupled gauge plasmas that are conjectured to be dual to five dimensional theories of gravity coupled to a nontrivial single scalar field. We find a gravity dual that can describe the thermodynamic properties and also the expectation value of the Polyakov loop in the deconfined phase of quenched SU(3) QCD up to $3T_c$.

  18. Capacitively-Coupled Resistivity measurements to determine frequency dependent electrical parameters in periglacial environment - theoretical considerations and first field tests.

    Science.gov (United States)

    Przyklenk, A.; Hördt, A.; Radić, T.

    2016-05-01

    Capacitively-Coupled Resistivity (CCR) is conventionally used to emulate DC resistivity measurements and may provide important information about the ice content of material in periglacial areas. The application of CCR theoretically enables the determination of both electrical parameters, i.e. the resistivity and the electrical permittivity, by analyzing magnitude and phase shift spectra. The electrical permittivity may dominate the impedance, especially in periglacial areas or regions of hydrogeological interest. However, previous theoretical work suggested that the phase shift may strongly depend on electrode height above ground, implying that electrode height must be known with great accuracy to determine electrical permittivity. Here, we demonstrate with laboratory test measurements, theoretical modelling and by analysing the Jacobian matrix of the inversion, that the sensitivity towards electrode height is drastically reduced if the electrical permittivity is frequency dependent in a way that is typical for ice. For the fist time, we used a novel broadband CCR device "Chameleon" for a field test located in one of the ridge galleries beneath the crest of Mount Zugspitze. A permanently ice covered bottom of a tunnel was examined. For the inversion of the measured spectra, the frequency dependance of the electrical parameters was parameterized in 3 different ways. A Debye Model for pure ices, a Cole-Cole Model for pure ices and a dual Cole-Cole Model including interfacial water additionally. The frequency-dependent resistivity and permittivity spectra obtained from the inversion, including low and high frequency limits, agree reasonably well with laboratory and field measurements reported in the literature.

  19. Zinc isotope discrimination effect in inductively coupled plasma mass spectrometer

    International Nuclear Information System (INIS)

    Inductively coupled plasma mass spectrometry (ICPMS) has recently been used for isotope ratio analysis. The isotope discrimination effect in the mass spectrometer is a primary factor contributing to loss of precision and accuracy in isotope ratio analysis. The discrimination effect of zinc isotopes was investigated by comparing the results obtained using a quadrupole type ICPMS with those obtained using a thermal ionization mass spectrometer

  20. AETHER: A simulation platform for inductively coupled plasma

    Science.gov (United States)

    Turkoz, Emre; Celik, Murat

    2015-04-01

    An in-house code is developed to simulate the inductively coupled plasma (ICP). The model comprises the fluid, electromagnetic and transformer submodels. Fluid equations are solved to evaluate the plasma flow parameters, including the plasma and neutral densities, ion and neutral velocities, electron flux, electron temperature, and electric potential. The model relies on the ambipolar approximation and offers the evaluation of plasma parameters without solving the sheath region. The electromagnetic model handles the calculation of the electric and magnetic fields using the magnetic vector potential. The transformer model captures the effect of the matching circuit utilized in laboratory experiments for RF power deposition. The continuity and momentum equations are solved using finite volume method. The energy, electric potential, and magnetic vector potential equations are solved using finite difference method. The resulting linear systems of equations are solved with iterative solvers including Jacobi and GMRES. The code is written using the C++ programming language, it works in parallel and has graphical user interface. The model is applied to study ICP characteristics of a plasma confined within a cylindrical chamber with dielectric walls for two different power deposition cases. The results obtained from the developed model are verified using the plasma module of COMSOL Multiphysics. The model is also applied to a plasma source configuration, and it is demonstrated that there is an overall increase in the plasma potential when current is extracted from ICP with a biased wall electrode.

  1. Calibration of a cylindrical RF capacitance probe. [for ionospheric plasma effects on Radio Astronomy Explorer 1 antenna

    Science.gov (United States)

    Mosier, S. R.; Kaiser, M. L.

    1975-01-01

    Ambient electron concentrations derived from observations with the Radio Astronomy Explorer 1 antenna capacitance probe have been compared with upper hybrid resonance measurements from the same spacecraft. From this comparison an empirical correction factor for the capacitance probe measurements has been derived. The differences between the two types of measurements is attributed to sheath effects.

  2. Fully parameterized model of a voltage-driven capacitive coupled micromachined ohmic contact switch for RF applications

    International Nuclear Information System (INIS)

    A comprehensive and completely parameterized model is proposed to determine the related electrical and mechanical dynamic system response of a voltage-driven capacitive coupled micromechanical switch. As an advantage over existing parameterized models, the model presented in this paper returns within few seconds all relevant system quantities necessary to design the desired switching cycle. Moreover, a sophisticated and detailed guideline is given on how to engineer a MEMS switch. An analytical approach is used throughout the modelling, providing representative coefficients in a set of two coupled time-dependent differential equations. This paper uses an equivalent mass moving along the axis of acceleration and a momentum absorption coefficient. The model describes all the energies transferred: the energy dissipated in the series resistor that models the signal attenuation of the bias line, the energy dissipated in the squeezed film, the stored energy in the series capacitor that represents a fixed separation in the bias line and stops the dc power in the event of a short circuit between the RF and dc path, the energy stored in the spring mechanism, and the energy absorbed by mechanical interaction at the switch contacts. Further, the model determines the electrical power fed back to the bias line. The calculated switching dynamics are confirmed by the electrical characterization of the developed RF switch. The fabricated RF switch performs well, in good agreement with the modelled data, showing a transition time of 7 µs followed by a sequence of bounces. Moreover, the scattering parameters exhibit an isolation in the off-state of >8 dB and an insertion loss in the on-state of <0.6 dB up to frequencies of 50 GHz. The presented model is intended to be integrated into standard circuit simulation software, allowing circuit engineers to design the switch bias line, to minimize induced currents and cross actuation, as well as to find the mechanical structure dimensions

  3. Magnetized strongly coupled plasmas and how to realize them in a dusty plasma setup

    CERN Document Server

    Bonitz, M; Ott, T; Löwen, H

    2013-01-01

    Strongly coupled plasmas in which the interaction energy exceeds the kinetic energy play an important role in many astrophysical and laboratory systems including compact stars, laser plasmas and dusty plasmas. They exhibit many unusual collective properties, such as liquid or crystalline behaviour, peculiar oscillation spectra and transport properties. Recently, strongly coupled plasmas were studied in the presence of a strong magnetic field by computer simulations, and strong modifications of their transport properties and oscillation spectra were observed. While strong magnetization is common in stellar systems it is practically impossible to achieve in complex plasmas due to the large mass of the dust particles. Here we discuss a recently demonstrated approach to achieve very strong "magnetization" by a rotation of the neutral gas, and we present new results for macroscopic two-dimensional systems.

  4. Modeling, fabrication and plasma actuator coupling of flexible pressure sensors for flow separation detection and control in aeronautical applications

    Science.gov (United States)

    Francioso, L.; De Pascali, C.; Pescini, E.; De Giorgi, M. G.; Siciliano, P.

    2016-06-01

    Preventing the flow separation could enhance the performance of propulsion systems and future civil aircraft. To this end, a fast detection of boundary layer separation is mandatory for a sustainable and successful application of active flow control devices, such as plasma actuators. The present work reports on the design, fabrication and functional tests of low-cost capacitive pressure sensors coupled with dielectric barrier discharge (DBD) plasma actuators to detect and then control flow separation. Finite element method (FEM) simulations were used to obtain information on the deflection and the stress distribution in different-shaped floating membranes. The sensor sensitivity as a function of the pressure load was also calculated by experimental tests. The results of the calibration of different capacitive pressure sensors are reported in this work, together with functional tests in a wind tunnel equipped with a curved wall plate on which a DBD plasma actuator was mounted to control the flow separation. The flow behavior was experimentally investigated by particle image velocimetry (PIV) measurements. Statistical and spectral analysis, applied to the output signals of the pressure sensor placed downstream of the profile leading edge, demonstrated that the sensor is able to discriminate different ionic wind velocity and turbulence conditions. The sensor sensitivity in the 0-100 Pa range was experimentally measured and it ranged between 0.0030 and 0.0046 pF Pa-1 for the best devices.

  5. Energy loss of heavy ions in strongly coupled plasmas

    International Nuclear Information System (INIS)

    We investigate the energy loss of heavy ions in strongly coupled plasmas, by performing molecular dynamics (MD) computer simulations. These studies are of interest in heavy-ion-driven inertial confinement fusion, as well as for electron cooling. We consider the non-linear behavior for strong target-ion coupling parameters, i.e. ZΓ3/2>or∼1, in non-ideal plasmas with Γ>or∼0.1 (Z is the charge number of the ion and Γ is the plasma parameter of the target). The new features that we found from our simulation results can be summarized as follows. (1) For strong ion-target coupling, the energy loss of the ions at low velocities scales with Z as Z1.5, in agreement with recent experimental and other theoretical results. This clearly deviates from the Z2 ln(const./Z) scaling of the conventional weak coupling theories. (2) The change in the Z scaling has its origin in a non-linear screening that occurs for strong coupling and is associated with an increase in the (static) screening length above the Debye-Hueckel result of the linear theory. (3) The non-linear screening is accompanied by electrons trapped by the ion into high Rydberg states, through multi-particle collisions. Compared with the case of linear coupling, this trapping causes an enhanced electron density around the ion. (4) The transient time dependence of the stopping power after switching on the ion-target interaction has characteristic time-scales that are a fraction of the plasma period. (orig.)

  6. The effects of insulin-like growth factorI (IGF I) complex from seminal plasma on capacitation, membrane integrity andDNA fragmentation in goat spermatozoa

    Institute of Scientific and Technical Information of China (English)

    Suherni Susilowati; Indah Norma Triana; Abdul Malik

    2015-01-01

    Objective:To evaluate the effects of the insulin-like growth factor I (IGF I) complex from seminal plasma on capacitation, membrane integrity and DNA fragmentation.Methods:A total of 0.5 mL of fresh semen was added to 1 mL of Bracket-Oliphant (BO) medium, and the sample was then centrifuged at a speed of 1 800 rpm for 10 minutes. The samples were analyzed before and after centrifugation for sperm viability, motility, membrane integrity and capacitation. The centrifuged samples were divided into three groups, each consisting of 3í 106spermatozoa. BO medium was added to group 1, BO ¬+ 12 ng IGF I complex medium was added to group 2, and 12 ng IGF I complex was added to group 3. Then, the samples were incubated for 15 minutes. Results:The result showed that sperm motility, viability and membrane integrity were significantly lower (P<0.05) after centrifugation. Furthermore, the sperm capacitation was significantly increased (P<0.05) after centrifugation. The percentages of sperm capacitation, membrane integrity and DNA fragmentation were significantly different (P< 0.05) in all media, including BO, BO + IGF-I complex and the IGF-I complex alone. Conclusions:Sperm quality include motility, viability and membrane integrity were lower after centrifugation. whereas DNA fragmentation after incubation in the IGF-I complex medium also was lower compared to that of specimens in the BO and BO + IGF-I complex media.

  7. Energy exchange in strongly coupled plasmas with electron drift

    Energy Technology Data Exchange (ETDEWEB)

    Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz (Iran, Islamic Republic of); International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum (Germany); Ghorbanalilu, M. [Physics Department, Shahid Beheshti University, G.C., Evin, Tehran (Iran, Islamic Republic of)

    2015-11-15

    In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam.

  8. Methane coupling in microwave plasma under atmospheric pressure

    Institute of Scientific and Technical Information of China (English)

    Changsheng Shen; Dekun Sun; Hongsheng Yang

    2011-01-01

    Methane coupling in microwave plasma under atmospheric pressure has been investigated.The effects of molar ratio n(CH4)/n(H2),flow rate and microwave power on the reaction have been studied.(1) With the decrease of n(CH4)/n(H2) ratio,methane conversion,C2 hydrocarbon yield,energy yield and space-time yield of acetylene increased,but the yield of carbon deposit decreased.(2) With the increase of microwave power,energy yield of acetylene decreased,but space-time yield of acetylene increased.(3) With the increase of flow rate,energy yield and space-time yield of acetylene increased first and then decreased.Finally,under the reaction conditions of CH4 flow rate of 700 mL/min,n(CH4)/n(H2) ratio of 1/4 and microwave power of 400 W,the energy yield and space-time yield of acetylene could reach 0.337 mmol/kJ and 12.3 mol/(s·m3),respectively.The reaction mechanism of methane coupling in microwave plasma has been investigated based on the thermodynamics of chemical reaction.Interestingly,the acetylene yield of methane coupling in microwave plasma was much higher than the maximum thermodynamic yield of acetylene.This phenomenon was tentatively explained from non-expansion work in the microwave plasma system.

  9. Free-Free Radiation in Strongly Coupled Plasmas

    Science.gov (United States)

    Weisheit, Jon; Daligault, Jerome; Murillo, Michael; Turner, Leaf

    2004-11-01

    In strongly coupled plasmas, the basic electron-ion collision events responsible for emission or absorption of free-free radiation are modified by interrelated collective effects: quasi-static ion correlations, dynamical electron correlations, and screened Coulombic interactions resulting from correlations between the positive and negative charged particle components of the plasma. We are investigating the relative importance of these different phenomena, within the context of the collision frequency formula of Boercker et al.[1] Our statistical model [2] describes the self-consistent fluctuations of a multi-component plasma, and includes quantal effects on the dynamics as well as strong coupling between species. We will present numerical results that identify plasma conditions for which strong coupling causes major changes to the electron-ion collision frequency. [1] D.B. Boercker, F.J. Rogers, H.E. DeWitt, Phys. Rev. A25, 1623 (1982). [2] J. Daligault and M.S. Murillo, Phys. Rev. E68, 015401 (2003).

  10. ICRF antenna coupling theory for a cylindrically stratified plasma

    International Nuclear Information System (INIS)

    Antenna coupling to a cyclindrical plasma is examined for the ion cyclotron range of frequencies (ICRF). A variety of antenna configurations are modelled such as a partial-turn loop, Nagoya coils, an aperture antenna, and arrays of coils. A procedure that utilizes the induction theorem is presented which replaces a general coil configuration with an equivalent representation in terms of sinusoidal current sheets. This transformation reduces the three dimensional antenna boundary value problem to that of one dimension (r, the radial coordinate) with the spatial variation in the other directions represented by complex exponentials (exp (in phi + ik/sub z/z)). As constructed, the transformation is directly applicable to axisymmetric geometries where the plasma parameters are only functions of radius. The radial variation of the plasma parameters such as the local density and temperature are approximated by a stratified model. As the number of strata are increased, the step-wise model is shown to converge to the continuous case. The plasma response is modelled by a local equivalent dielectric tensor. In the context of this model antenna-plasma coupling characteristics are compared for the various ICRF antennas

  11. Study on spatial distribution of plasma parameters in a magnetized inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong, E-mail: kwhang@snu.ac.kr [Plasma Laboratory, Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hyuk [Samsung Electronics Co., Banwol-dong, Hwaseong 445-701 (Korea, Republic of); Park, Wanjae [Tokyo Electron Miyagi Ltd., Taiwa-cho, Kurokawa-gun, Miyagi 981-3629 (Japan)

    2015-07-15

    Spatial distributions of various plasma parameters such as plasma density, electron temperature, and radical density in an inductively coupled plasma (ICP) and a magnetized inductively coupled plasma (M-ICP) were investigated and compared. Electron temperature in between the rf window and the substrate holder of M-ICP was higher than that of ICP, whereas the one just above the substrate holder of M-ICP was similar to that of ICP when a weak (<8 G) magnetic field was employed. As a result, radical densities in M-ICP were higher than those in ICP and the etch rate of oxide in M-ICP was faster than that in ICP without severe electron charging in 90 nm high aspect ratio contact hole etch.

  12. Analytical solution for a coaxial plasma gun: Weak coupling limit

    International Nuclear Information System (INIS)

    The analytical solution of the system of coupled ODE's which describes the time evolution of an ideal (i.e., zero resistance) coaxial plasma gun operating in the snowplow mode is obtained in the weak coupling limit, i.e, when the gun is fully influenced by the driving (RLC) circuit in which it resides but the circuit is negligibly influenced by the gun. Criteria for the validity of this limit are derived and numerical examples are presented. Although others have obtained approximate, asymptotic and numerical solutions of the equations, the present analytical results seem not to have appeared previously in the literature

  13. Ionization equilibrium and equation of state in strongly coupled plasmas

    International Nuclear Information System (INIS)

    Calculation of the physical properties of reacting plasmas depends on knowing the state of ionization and/or the state occupation numbers. Simple methods have often been used to estimate ionization balance in plasmas, but they are not adequate for understanding a variety of new experimental and observational measurements. Theoretical methods to determine the ionization state of partially ionized plasmas must confront the effects of density on bound states and strong ion coupling. These methods can be separated into two categories. Chemical picture methods consider the system to be composed of distinct chemical species. Consequently, it is necessary to assert the effect of the plasma environment on internal states of these species. On the other hand, physical picture methods view the plasma in terms of its fundamental constituents; i.e., electrons and nuclei, so that plasma effects on bound states are a basic component of the theory. A discussion of some work representative of both of these philosophies will be given. Some comparisons between theories and with recent helioseismic observations and shock experiments will also be given. (c) 2000 American Institute of Physics. (c)

  14. Four lectures on strongly coupled Quark Gluon Plasma

    International Nuclear Information System (INIS)

    The four lectures are divided evenly between phenomenology and theory. Lecture 1 describes the hydrodynamical treatment of the high energy heavy ion collisions: we discuss in it the appearance of the notion of the 'strongly coupled' QGP. Another phenomenological lecture is about perturbations of this expansion, by fluctuations of different types. We will in particularly argue that matter in a near-Tc situation is quite special, with an electric field imbedded in it for a long time: this situation should be described by dual-magnetohydrodynamics (DMHD). Two theoretical lectures focus on two dualities. The electric-magnetic duality, describing gradual transition from electric plasma at high-T to a magnetic-dominated plasma in the near-Tc domain. The last lecture is about applications of AdS/CFT duality, between strongly coupled N=4SYM gauge theory in 4 dimensions and string theory in the AdS5*S5 background.

  15. Coupled dust lattice modes in dust-plasma crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yaroshenko, V. V.; Ivlev, A. V.; Morfill, G. E.

    2005-07-01

    Dust lattice (DL) modes arising in strongly coupled dusty plasmas have been extensively studies in many experiments using radio-frequency discharge plasmas in the laboratory and under microgravity conditions. In the laboratory experiments, the highly negatively charged particles levitate in the sheath region of the horizontal negatively biased electrode where there is a balance between the gravitational and electrostatic forces acting in the vertical direction. If the particles are magnetized by an external field, the magnetic force can also contribute to the force balance and support particle levitation. There are a few characteristic features of the particle trapping in discharge plasma. On the one hand, the complex plasma structures reveal the anisotropy due to vertical ion flows that lead to the formation of an ion wake underneath the suspended microparticles. On the other hand, an equilibrium particle charge strongly depends on the vertical particle position in the sheath region. This introduces anisotropy of the system related to a vertical profile of the equilibrium particle charge. Finally, if the particles are magnetized, there exists a vertical non-uniformity of the magnetic moments induced by the external in homogenous magnetic field. We study the influence of all these factors on coupling of the transverse and longitudinal DL modes in a one-dimensional horizontal particle string. It is found two different ways of the reconnection of the dispersion curves for the longitudinal and transverse modes in the vicinity of their intersection point. When the particles levitate at that part of the complex plasmas, which provides a coupling coefficient to be positive, the transverse and longitudinal branches become confluent in such a way, that there is a considerable frequency gap in the vicinity of the intersection point, in which both DL modes are evanescent. This type of reconnection can be considered as a kind of the linear mode conversion. Conversely if the

  16. Experiment on dust acoustic solitons in strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Dusty plasma, which contains nanometer to micrometer sized dust particles along with electrons and ions, supports a low frequency wave called Dust Acoustic wave, analogous to ion acoustic wave in normal plasma. Due to high charge and low temperature of the dust particles, dusty plasma can easily transform into a strongly coupled state when the Coulomb interaction potential energy exceeds the dust kinetic energy. Dust acoustic perturbations are excited in such strongly coupled dusty plasma by applying a short negative pulse (100 ms) of amplitude 5 - 20 V to an exciter. The perturbation steepens due to nonlinear effect and forms a solitary structure by balancing dispersion present in the medium. For specific discharge conditions, excitation amplitude above a critical value, the perturbation is found to evolve into a number of solitons. The experimental results on the excitation of multiple dust acoustic solitons in the strongly coupled regime are presented in this work. The experiment is carried out in radio frequency discharged plasma produced in a glass chamber at a pressure 0.01 - 0.1 mbar. Few layers of dust particles (∼ 5 μm in diameter) are levitated above a grounded electrode inside the chamber. Wave evolution is observed with the help of green laser sheet and recorded in a high resolution camera at high frame rate. The high amplitude soliton propagates ahead followed by smaller amplitude solitons with lower velocity. The separation between the solitons increases as time passes by. The characteristics of the observed dust acoustic solitons such as amplitude-velocity and amplitude- Mach number relationship are compared with the solutions of Korteweg-de Vries (KdV) equation. (author)

  17. Self-diffusion in strongly coupled Yukawa systems (complex plasmas)

    CERN Document Server

    Khrapak, Sergey A; Morfill, Gregor E

    2012-01-01

    We show that the idea of mapping between the Newtonian and Brownian diffusivities proposed and tested on a class of particle systems interacting via soft and ultra-soft potentials (IPL, Gaussian core, Hertzian, and effective star-polymer) by Pond {\\it et al}., [Soft Matter {\\bf 7}, 9859 (2011)] is also applicable to the Yukawa (screened Coulomb) interaction. Some of the implications of this result with respect to self-diffusion in strongly coupled complex (dusty) plasmas are discussed.

  18. Study of plasma parameters influencing fractionation in laser ablation-inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

  19. Nonlinear Debye screening in strongly-coupled plasmas

    CERN Document Server

    Sarmah, D; Tessarotto, M

    2006-01-01

    An ubiquitous property of plasmas is the so-called Debye shielding of the electrostatic potential. Important aspects of Debye screening concern, in particular, the investigation of non-linear charge screening effects taking place in strongly-coupled plasmas, that imply a reduction of the effective charge characterizing the Debye-H\\"{u}ckel potential. These effects are particularly relevant in dusty plasmas which are characterized by high-Z particles. The investigation of the effective interactions of these particles has attracted interest in recent years especially for numerical simulations. In this work we intend to analyze the consistency of the traditional mathematical model for the Debye screening. In particular, we intend to prove that the 3D Poisson equation involved in the DH model does not admit strong solutions. For this purpose a modified model is proposed which takes into account the effect of local plasma sheath (i.e., the local domain near test particles where the plasma must be considered discre...

  20. Josephson coupling and plasma resonance in vortex crystal

    International Nuclear Information System (INIS)

    The authors consider the magnetic field dependence of the plasma resonance frequency in vortex crystal state. The authors found that low magnetic field induces a small correction to the plasma frequency proportional to the field. The slope of this linear field dependence is directly related to the average distance between the pancake vortices in the neighboring layers, wandering length. This length is determined by both Josephson and magnetic couplings between layers. At higher fields the Josephson coupling is suppressed collectively and is determined by elastic energy of the vortex lattice. Analyzing experimental data, they found that (1) the wandering length becomes comparable with the London penetration depth near Tc, (2) at small melting fields (< 20 G) the wandering length does not change much at the melting transition demonstrating existence of the line liquid phase in this field range, and (3) the self consistent theory of pancake fluctuations describes very well the field dependence of the Josephson plasma resonance frequency up to the melting point

  1. Capacitively coupled contactless conductivity detection as an alternative detection mode in CE for the analysis of kanamycin sulphate and its related substances.

    Science.gov (United States)

    El-Attug, Mohamed N; Adams, Erwin; Hoogmartens, Jos; Van Schepdael, Ann

    2011-09-01

    A method was developed to determine simultaneously kanamycin, its related substances and sulphate in kanamycin sulphate using capacitively coupled contactless conductivity detection. Kanamycin is an aminoglycoside antibiotic that lacks a strong UV-absorbing chromophore. Due to its physicochemical properties, CE in combination with capacitively coupled contactless conductivity detection was chosen. The separation method uses a BGE composed of 40 mM 2-(N-morpholino)ethanesulphonic acid monohydrate and 40 mM L-histidine, pH 6.35. A 0.6 mM N-cetyltrimethyl ammonium bromide (CTAB) solution was added as electroosmotic flow modifier in a concentration below the critical micellar concentration (CMC). Ammonium acetate 50 mg/L was used as internal standard. In total, 30 kV was applied in reverse polarity on a fused-silica capillary (65/41 cm; 75 μm id). The optimized separation was obtained in less than 6 min with good linearity (R(2)=0.9999) for kanamycin. It shows a good precision expressed as RSD on the relative peak areas equal to 0.3 and 1.1% for intra-day and inter-day precision, respectively. The LOD and LOQ are 0.7 and 2.3 mg/L, respectively. Similarly, for sulphate, a good linearity (R(2)=0.9996) and precision (RSD 0.4 and 0.6% for intra-day and inter-day, respectively) were obtained. PMID:21796785

  2. The energetic coupling of scales in gyrokinetic plasma turbulence

    CERN Document Server

    Teaca, Bogdan; Jenko, Frank

    2014-01-01

    In magnetised plasma turbulence, the couplings of perpendicular spatial scales that arise due to the nonlinear interactions are analysed from the perspective of the free-energy exchanges. The plasmas considered here, with appropriate ion or electron adiabatic electro-neutrality responses, are described by a gyrokinetic formalism in a toroidal magnetic geometry. Turbulence develops due to the electrostatic fluctuations driven by temperature gradient instabilities, respectively, ion temperature gradient (ITG) or electron temperature gradient (ETG). The analysis consists in decomposing the system into a series of scale structures, while accounting separately for contributions made by modes possessing special symmetries (e.g. the zonal flow modes). The interaction of these scales is analysed using the energy transfer functions, including a forward and backward decomposition, scale fluxes and locality functions. The comparison between the ITG and ETG cases shows that ETG turbulence has a more pronounce classical t...

  3. Strong-coupling effects in a plasma of confining gluons

    CERN Document Server

    Florkowski, Wojciech; Su, Nan; Tywoniuk, Konrad

    2015-01-01

    The plasma consisting of confining gluons resulting from the Gribov quantization of the SU(3) Yang-Mills theory is studied using non-equilibrium fluid dynamical framework. Exploiting the Bjorken symmetry and using linear response theory a general analytic expressions for the bulk and shear viscosity coefficients are derived. It is found that the considered system exhibits a number of properties similar to the strongly-coupled theories, where the conformality is explicitly broken. In particular, it is shown that, in the large temperature limit, bulk to shear viscosity ratio, scales linearly with the difference $1/3 - c_s^2$, where $c_s$ is the speed of sound. Results obtained from the analysis are in line with the interpretation of the quark-gluon plasma as an almost perfect fluid.

  4. A Review on Inductively Coupled Plasma Mass Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ramyalakshmi G

    2012-12-01

    Full Text Available Inductively coupled plasma mass spectroscopy is routinely used in many diverse research fields such as earth, environmental, life and forensic sciences and in food, material, chemical, semiconductor and nuclear industries. The high ion density and the high temperature in a plasma provide an ideal atomizer and element ionizer for all types of samples and materials introduced by a specialised devices .outstanding properties such as high sensitivity, relative salt tolerance, compound-independent element response and highest quantitation accuracy lead to the unchallenged performance of ICPMS in efficiently detecting, identifying and reliably quantifying trace element. The increasing availability of relevant reference compounds and high separation selectively extend the molecular identification capability of ICPMS hyphenated to species – specific separation techniques

  5. The energetic coupling of scales in gyrokinetic plasma turbulence

    International Nuclear Information System (INIS)

    In magnetized plasma turbulence, the couplings of perpendicular spatial scales that arise due to the nonlinear interactions are analyzed from the perspective of the free-energy exchanges. The plasmas considered here, with appropriate ion or electron adiabatic electro-neutrality responses, are described by the gyrokinetic formalism in a toroidal magnetic geometry. Turbulence develops due to the electrostatic fluctuations driven by temperature gradient instabilities, either ion temperature gradient (ITG) or electron temperature gradient (ETG). The analysis consists in decomposing the system into a series of scale structures, while accounting separately for contributions made by modes possessing special symmetries (e.g., the zonal flow modes). The interaction of these scales is analyzed using the energy transfer functions, including a forward and backward decomposition, scale fluxes, and locality functions. The comparison between the ITG and ETG cases shows that ETG turbulence has a more pronounced classical turbulent behavior, exhibiting a stronger energy cascade, with implications for gyrokinetic turbulence modeling

  6. Optoelectronic properties of Black-Silicon generated through inductively coupled plasma (ICP) processing for crystalline silicon solar cells

    Science.gov (United States)

    Hirsch, Jens; Gaudig, Maria; Bernhard, Norbert; Lausch, Dominik

    2016-06-01

    The optoelectronic properties of maskless inductively coupled plasma (ICP) generated black silicon through SF6 and O2 are analyzed by using reflection measurements, scanning electron microscopy (SEM) and quasi steady state photoconductivity (QSSPC). The results are discussed and compared to capacitively coupled plasma (CCP) and industrial standard wet chemical textures. The ICP process forms parabolic like surface structures in a scale of 500 nm. This surface structure reduces the average hemispherical reflection between 300 and 1120 nm up to 8%. Additionally, the ICP texture shows a weak increase of the hemispherical reflection under tilted angles of incidence up to 60°. Furthermore, we report that the ICP process is independent of the crystal orientation and the surface roughness. This allows the texturing of monocrystalline, multicrystalline and kerf-less wafers using the same parameter set. The ICP generation of black silicon does not apply a self-bias on the silicon sample. Therefore, the silicon sample is exposed to a reduced ion bombardment, which reduces the plasma induced surface damage. This leads to an enhancement of the effective charge carrier lifetime up to 2.5 ms at 1015 cm-3 minority carrier density (MCD) after an atomic layer deposition (ALD) with Al2O3. Since excellent etch results were obtained already after 4 min process time, we conclude that the ICP generation of black silicon is a promising technique to substitute the industrial state of the art wet chemical textures in the solar cell mass production.

  7. Heat conduction in 2D strongly-coupled dusty plasmas

    CERN Document Server

    Hou, Lu-Jing

    2008-01-01

    We perform non-equilibrium simulations to study heat conduction in two-dimensional strongly coupled dusty plasmas. Temperature gradients are established by heating one part of the otherwise equilibrium system to a higher temperature. Heat conductivity is measured directly from the stationary temperature profile and heat flux. Particular attention is paid to the influence of damping effect on the heat conduction. It is found that the heat conductivity increases with the decrease of the damping rate, while its magnitude confirms previous experimental measurement.

  8. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: · We determine methylmercury in serum and plasma using isotope dilution calibration. · Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. · Data for 50 specimens provides first reference range for methylmercury in serum. · Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with 198Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) μg L-1 could be performed with uncertainty amplification factors -1 was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were -1, 0.35 μg L-1 and 2.8 μg L-1, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; -1. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  9. Influence of plasma-etch damage on the interface states in SOI structures investigated by capacitance-voltage measurements and simulations

    Science.gov (United States)

    Jo, Yeong-Deuk; Koh, Jung-Hyuk; Ha, Jae-Geun; Kim, Ji-Hong; Cho, Dae-Hyung; Moon, Byung-Moo; Koo, Sang-Mo

    2009-12-01

    Au/SiO2/n-Si metal-oxide-silicon-on-insulator (MOSOI) capacitors were fabricated to study the damage caused by reactive ion etching (RIE) on (1 1 0) oriented silicon-on-insulator (SOI) substrates. The MOSOI capacitors with an etch-damaged SOI layer were characterized by capacitance-voltage (C-V) measurements and compared to the sacrificial oxidation treated samples and the reference samples without etching treatment. The measurements revealed that C-V curves significantly change and a negative voltage shift occurs for plasma-damaged capacitors. The simulated band diagram profiles and potential distribution of the corresponding structures indicate that the C-V shift is mainly due to the removal of a parasitic depletion capacitance (Cp) in the substrate, when the interface charges (Qf) are present at the gate oxide/SOI interface. For etch-damaged MOSOI samples, the surface roughness and the interface charges (Qf) have been found to increase by ~1.94 × 1012 cm-2 with respect to the reference devices, whereas the increase was reduced for sacrificial-oxidation treated samples, which implies a recovery from the plasma-induced etch damage on SOI structures.

  10. Transient plasma potential in pulsed dual frequency inductively coupled plasmas and effect of substrate biasing

    Science.gov (United States)

    Mishra, Anurag; Yeom, Geun Young

    2016-09-01

    An electron emitting probe in saturated floating potential mode has been used to investigate the temporal evolution of plasma potential and the effect of substrate RF biasing on it for pulsed dual frequency (2 MHz/13.56 MHz) inductively coupled plasma (ICP) source. The low frequency power (P2MHz) has been pulsed at 1 KHz and a duty ratio of 50%, while high frequency power (P13.56MHz) has been used in continuous mode. The substrate has been biased with a separate bias power at (P12.56MHz) Argon has been used as a discharge gas. During the ICP power pulsing, three distinct regions in a typical plasma potential profile, have been identified as `initial overshoot', pulse `on-phase' and pulse `off-phase'. It has been found out that the RF biasing of the substrate significantly modulates the temporal evolution of the plasma potential. During the initial overshoot, plasma potential decreases with increasing RF biasing of the substrate, however it increases with increasing substrate biasing for pulse `on-phase' and `off-phase'. An interesting structure in plasma potential profile has also been observed when the substrate bias is applied and its evolution depends upon the magnitude of bias power. The reason of the evolution of this structure may be the ambipolar diffusion of electron and its dependence on bias power.

  11. Modeling viscosity and diffusion of plasma mixtures across coupling regimes

    Science.gov (United States)

    Arnault, Philippe

    2014-10-01

    Viscosity and diffusion of plasma for pure elements and multicomponent mixtures are modeled from the high-temperature low-density weakly coupled regime to the low-temperature high-density strongly coupled regime. Thanks to an atom in jellium modeling, the effect of electron screening on the ion-ion interaction is incorporated through a self-consistent definition of the ionization. This defines an effective One Component Plasma, or an effective Binary Ionic Mixture, that is representative of the strength of the interaction. For the viscosity and the interdiffusion of mixtures, approximate kinetic expressions are supplemented by mixing laws applied to the excess viscosity and self-diffusion of pure elements. The comparisons with classical and quantum molecular dynamics results reveal deviations in the range 20--40% on average with almost no predictions further than a factor of 2 over many decades of variation. Applications in the inertial confinement fusion context could help in predicting the growth of hydrodynamic instabilities.

  12. Inductively coupled plasma mass spectrometry (ICP-MS)

    International Nuclear Information System (INIS)

    The period of investigation for the previous general remarks on the progress of ICP-MS was from January, 1991 to September, 1993. In the investigation of this time, for the object of the Chemical Abstracts from January, 1994 to September, 1996, retrieval was carried out by using the STN International. As the key words, ICP-MS, Inductively Coupled Plasma Mass Spectrometry or Inductively Coupled Plasma Mass Spectrometer was used. The number of hit was 373 in 1994, 462 in 1995, and 356 as of September, 1996, 1191 in total. The cumulative number of the papers from 1980 to 1996 is shown. It is known how rapidly the ICP-MS has pervaded as the means of analysis. In order to cope with the enormous number of papers, this time, it was decided to do the review by limiting to the papers which were published in the main journals deeply related to analytical chemistry. As to the tendency in the last three years, it is summarized as how to overcome the spectrum interference and matrix effect in the ICP-MS and the trend of using the ICP-MS as the high sensitivity detector for separation techniques. The technical basic research of the ICP-MS on spectrum interference, sample introduction method and others and the analysis of living body samples are reported. (K.I.)

  13. Dusty Plasmas - Kinetic Studies of Strong Coupling Phenomena

    Science.gov (United States)

    Morfill, Gregor

    2011-10-01

    ``Dusty plasmas'' can be found almost everywhere - in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere and in the laboratory. In astrophysical plasmas the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory there is great interest in industrial processes (e.g. etching, vapor deposition) and at the fundamental physics level - the main topic here - the study of strong coupling phenomena. Here the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and pace, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many particle systems including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10-12 to 10-9 g) precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.

  14. Complex (dusty) plasmas-kinetic studies of strong coupling phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Morfill, Gregor E.; Ivlev, Alexei V.; Thomas, Hubertus M. [Max-Planck-Institut fuer Extraterrestrische Physik, D-85740 Garching (Germany)

    2012-05-15

    'Dusty plasmas' can be found almost everywhere-in the interstellar medium, in star and planet formation, in the solar system in the Earth's atmosphere, and in the laboratory. In astrophysical plasmas, the dust component accounts for only about 1% of the mass, nevertheless this component has a profound influence on the thermodynamics, the chemistry, and the dynamics. Important physical processes are charging, sputtering, cooling, light absorption, and radiation pressure, connecting electromagnetic forces to gravity. Surface chemistry is another important aspect. In the laboratory, there is great interest in industrial processes (e.g., etching, vapor deposition) and-at the fundamental level-in the physics of strong coupling phenomena. Here, the dust (or microparticles) are the dominant component of the multi-species plasma. The particles can be observed in real time and space, individually resolved at all relevant length and time scales. This provides an unprecedented means for studying self-organisation processes in many-particle systems, including the onset of cooperative phenomena. Due to the comparatively large mass of the microparticles (10{sup -12}to10{sup -9}g), precision experiments are performed on the ISS. The following topics will be discussed: Phase transitions, phase separation, electrorheology, flow phenomena including the onset of turbulence at the kinetic level.

  15. Matrix effects in inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoshan

    1995-07-07

    The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the {open_quotes}Fassel{close_quotes} TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids.

  16. Laser studies of plasmas

    OpenAIRE

    Jacobs, Robert Michael James.; Hancock, G; Gus Hancock

    2000-01-01

    Measurement of the intrinsic properties of processing plasmas is critically important in understanding discharges so that the optimum conditions can be achieved. Several different diagnostic methods have been developed and tested.A planar probe has been used to measure the ion flux and electron temperature in both inductively coupled and capacitively coupled plasma systems, at various pressures and applied powers, using the assumption that the electron energy distribution is a Ma...

  17. Efficient laser-overdense plasma coupling via surface plasma waves and steady magnetic field generation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Universite Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilee 94200, Ivry-sur-Seine (France); Heron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Macchi, A. [Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (CNR/INO), Dipartimento di Fisica ' ' E. Fermi' ' , Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2011-10-15

    The efficiency of laser overdense plasma coupling via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed over a wide range of laser pulse intensity from 10{sup 15} to 10{sup 20} W cm{sup -2}{mu}m{sup 2} with electron density ranging from 25 to 100n{sub c} to describe the laser interaction with a grating target where a surface plasma wave excitation condition is fulfilled. The numerical studies confirm an efficient coupling with an enhancement of the laser absorption up to 75%. The simulations also show the presence of a localized, quasi-static magnetic field at the plasma surface. Two interaction regimes are identified for low (I{lambda}{sup 2} < 10{sup 17} W cm{sup -2}{mu}m{sup 2}) and high (I{lambda}{sup 2} > 10{sup 17} W cm{sup -2}{mu}m{sup 2}) laser pulse intensities. At ''relativistic'' laser intensity, steady magnetic fields as high as {approx}580 MG {mu}m/{lambda}{sub 0} at 7 x 10{sup 19} W cm{sup -2}{mu}m{sup 2} are obtained in the simulations.

  18. Hyperthermic therapy of deep seated tumors: comparison of the heating efficiencies of an annular array applicator and a capacitively coupled radiofrequency system.

    Science.gov (United States)

    Egawa, S; Tsukiyama, I; Akine, Y; Kajiura, Y; Ogino, T; Yamashita, K

    1988-03-01

    Among 82 cases of deep seated tumors treated by hyperthermia with an annular array applicator (AA) and/or a capacitively coupled 8 mHz system (CCS) combined with radiation therapy, 13 cases were treated by both devices. The efficiencies of tumor heating were compared in terms of the time required to attain 42 degrees C, the duration of heating time and the thermal dose as determined by a biological iso-effect formula for equivalent minutes at 42.5 degrees C. Temperature profiles and percent of temperature levels greater than 42 degrees C were better in the cases treated by the AA, but higher thermal doses were obtained with the CCS because longer treatment times were tolerated with the CCS than with the AA. Methods are necessary to prevent excess elevation of body temperature in the case of the AA, and to reduce superficial pain where the applicators contact the skin in the case of the CCS.

  19. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Douglas C., E-mail: douglas.baxter@alsglobal.com [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Faarinen, Mikko [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Osterlund, Helene; Rodushkin, Ilia [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Division of Geosciences, Lulea University of Technology, 977 87 Lulea (Sweden); Christensen, Morten [ALS Scandinavia AB, Maskinvaegen 2, 183 53 Taeby (Sweden)

    2011-09-09

    Highlights: {center_dot} We determine methylmercury in serum and plasma using isotope dilution calibration. {center_dot} Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. {center_dot} Data for 50 specimens provides first reference range for methylmercury in serum. {center_dot} Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with {sup 198}Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) {mu}g L{sup -1} could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 {mu}g L{sup -1} was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 {mu}g L{sup -1}, 0.35 {mu}g L{sup -1} and 2.8 {mu}g L{sup -1}, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) {mu}g L{sup -1}. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  20. Quantitative aspects of inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Bulska, Ewa; Wagner, Barbara

    2016-10-01

    Accurate determination of elements in various kinds of samples is essential for many areas, including environmental science, medicine, as well as industry. Inductively coupled plasma mass spectrometry (ICP-MS) is a powerful tool enabling multi-elemental analysis of numerous matrices with high sensitivity and good precision. Various calibration approaches can be used to perform accurate quantitative measurements by ICP-MS. They include the use of pure standards, matrix-matched standards, or relevant certified reference materials, assuring traceability of the reported results. This review critically evaluates the advantages and limitations of different calibration approaches, which are used in quantitative analyses by ICP-MS. Examples of such analyses are provided. This article is part of the themed issue 'Quantitative mass spectrometry'.

  1. Molecular Nitrogen Vibrational Temperature in an Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    康正德; 蒲以康

    2002-01-01

    Using a technique applied previously to vibrationally excited molecular nitrogen (N*2) in the region of daytime and nighttime aurora, the emission intensity of the N2 second positive band system in an inductively coupled plasma (ICP) has been analysed and the vibrational temperature of nitrogen molecules in the ICP is thus determined. The result shows that the vibrational temperature increases with the increase of the neutral gas pressure from 0.04Pa to 10Pa, then decreases with the further increase of the pressure from 10Pa to 100Pa. Also,this is explained by using the Boltzmann relation between the vibrational temperature and the concentration of the vibrationally excited N*2(X1∑+g ) molecules.

  2. Microwave power coupling in a surface wave excited plasma

    OpenAIRE

    Satyananda Kar; Lukas Alberts; Hiroyuki Kousaka

    2015-01-01

    In recent decades, different types of plasma sources have been used for various types of plasma processing, such as, etching and thin film deposition. The critical parameter for effective plasma processing is high plasma density. One type of high density plasma source is Microwave sheath-Voltage combination Plasma (MVP). In the present investigation, a better design of MVP source is reported, in which over-dense plasma is generated for low input microwave powers. The results indicate that the...

  3. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Munafò, A., E-mail: munafo@illinois.edu; Alfuhaid, S. A., E-mail: alfuhai2@illinois.edu; Panesi, M., E-mail: mpanesi@illinois.edu [Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Talbot Laboratory, 104 S. Wright St., Urbana, Illinois 61801 (United States); Cambier, J.-L., E-mail: jean-luc.cambier@us.af.mil [Edwards Air Force Base Research Laboratory, 10 E. Saturn Blvd., Edwards AFB, California 93524 (United States)

    2015-10-07

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients.

  4. A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

    International Nuclear Information System (INIS)

    The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients

  5. Strongly coupled non-Abelian plasmas in a magnetic field

    CERN Document Server

    Critelli, Renato

    2016-01-01

    In this dissertation we use the gauge/gravity duality approach to study the dynamics of strongly coupled non-Abelian plasmas. Ultimately, we want to understand the properties of the quark-gluon plasma (QGP), whose scientifc interest by the scientific community escalated exponentially after its discovery in the 2000's through the collision of ultrarelativistic heavy ions. One can enrich the dynamics of the QGP by adding an external field, such as the baryon chemical potential (needed to study the QCD phase diagram), or a magnetic field. In this dissertation, we choose to investigate the magnetic effects. Indeed, there are compelling evidences that strong magnetic fields of the order $eB\\sim 10 m_\\pi^2$ are created in the early stages of ultrarelativistic heavy ion collisions. The chosen observable to scan possible effects of the magnetic field on the QGP was the viscosity, due to the famous result $\\eta/s=1/4\\pi$ obtained via holography. In a first approach we use a caricature of the QGP, the $\\mathcal{N}=4$ s...

  6. Deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    D H Jung; B Park; J J Lee

    2004-01-01

    Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

  7. 脉冲调制磁化容性耦合放电中Ar+光谱特性研究%Study on spectral characteristics of Ar+ in the pulse-modulated magnetized capacitive coupling discharge

    Institute of Scientific and Technical Information of China (English)

    王华强; 张鹏云; 李玉洁

    2012-01-01

    Employing parallel plate pulse-modulated capacitive coupling RF discharge device in this paper, we investigated the changing regularity about electron excitation temperature and relative intensity of Ar+ optical emission spectrometry with air pressure, RF power, modulation frequency, duty cycle and magnetic field intensity using the method of optical emission spectrum diagnosis in the process of producing plasma in Ar discharge under the condition of different magnetic field intensity at low pressure (30Pa~65Pa).%本文在平行平板脉冲调制容性耦合射频放电装置中,采用光学发射谱线诊断的方法,研究了低气压(30 Pa~65 Pa)不同磁场强度条件下氩气(Ar)放电时产生等离子体过程中电子激发温度以及Ar离子的光谱线相对强度随气压、射频功率、调制频率、占空比和磁场强度大小的变化规律.

  8. Coupled neoclassical-magnetohydrodynamic simulations of axisymmetric plasmas

    Science.gov (United States)

    Lyons, Brendan C.

    2014-10-01

    Neoclassical effects (e.g., the bootstrap current and neoclassical toroidal viscosity [NTV]) have a profound impact on many magnetohydrodynamic (MHD) instabilities, including tearing modes, edge-localized modes (ELMs), and resistive wall modes. High-fidelity simulations of such phenomena require a multiphysics code that self-consistently couples the kinetic and fluid models. We present the first results of the DK4D code, a dynamic drift-kinetic equation (DKE) solver being developed for this application. In this study, DK4D solves a set of time-dependent, axisymmetric DKEs for the non-Maxwellian part of the electron and ion distribution functions (fNM) with linearized Fokker-Planck-Landau collision operators. The plasma is formally assumed to be in the low- to finite-collisionality regimes. The form of the DKEs used were derived in a Chapman-Enskog-like fashion, ensuring that fNM carries no density, momentum, or temperature. Rather, these quantities are contained within the background Maxwellian and are evolved by an appropriate set of extended MHD equations. We will discuss computational methods used and benchmarks to other neoclassical models and codes. Furthermore, DK4D has been coupled to a reduced, transport-timescale MHD code, allowing for self-consistent simulations of the dynamic formation of the ohmic and bootstrap currents. Several applications of this hybrid code will be presented, including an ELM-like pressure collapse. We will also discuss plans for coupling to the spatially three-dimensional, extended MHD code M3D-C1 and generalizing to nonaxisymmetric geometries, with the goal of performing self-consistent hybrid simulations of tokamak instabilities and calculations of NTV torque. This work supported by the U.S. Department of Energy (DOE) under Grant Numbers DE-FC02-08ER54969 and DE-AC02-09CH11466.

  9. Capillary Electrophoresis-Inductively Coupled Plasma Mass Spectrometry.

    Science.gov (United States)

    Michalke, Bernhard

    2016-01-01

    During the recent years, capillary electrophoresis (CE) has been fully established as a powerful tool in separation sciences as well as in element speciation. This road of success is based on the rapid analysis time, low sample requirements, high separation efficiency, and low operating costs of CE. Inductively coupled plasma mass spectrometry (ICP-MS) is known for superior detection and multielement capability. Consequently, the combination of both instruments is approved for analysis of complex sample types at low element concentrations which require high detection power. Also the diversity of potential applications brings CE-ICP-MS coupling into central focus of element speciation. The key to successful combination of ICP-MS as an (multi-)element selective detector for CE is the availability of a suitable and effective interface.Therefore, this chapter summarizes the most important and basic principles about coupling of capillary electrophoresis to ICP-MS. Specifically, the major requirements for interfacing are described and technical solutions are given. Such solutions include the closing of the electrical circuit from CE at the nebulization, the adoption of flow rates for efficient nebulization, the reduction of a suction flow through the capillary, caused by the nebulizer, and maintaining the high separation resolution from CE across the interface for ICP-MS detection. Additionally, detailed information is presented to determine and quantify the siphoning suction through the CE capillary by the nebulizer. Finally, two applications, namely, the manganese and selenium speciation in cerebrospinal fluid are shown as examples, providing the relevant operational parameter. PMID:27645737

  10. Aerosol detection efficiency in inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Hubbard, Joshua A.; Zigmond, Joseph A.

    2016-05-01

    An electrostatic size classification technique was used to segregate particles of known composition prior to being injected into an inductively coupled plasma mass spectrometer (ICP-MS). Size-segregated particles were counted with a condensation nuclei counter as well as sampled with an ICP-MS. By injecting particles of known size, composition, and aerosol concentration into the ICP-MS, efficiencies of the order of magnitude aerosol detection were calculated, and the particle size dependencies for volatile and refractory species were quantified. Similar to laser ablation ICP-MS, aerosol detection efficiency was defined as the rate at which atoms were detected in the ICP-MS normalized by the rate at which atoms were injected in the form of particles. This method adds valuable insight into the development of technologies like laser ablation ICP-MS where aerosol particles (of relatively unknown size and gas concentration) are generated during ablation and then transported into the plasma of an ICP-MS. In this study, we characterized aerosol detection efficiencies of volatile species gold and silver along with refractory species aluminum oxide, cerium oxide, and yttrium oxide. Aerosols were generated with electrical mobility diameters ranging from 100 to 1000 nm. In general, it was observed that refractory species had lower aerosol detection efficiencies than volatile species, and there were strong dependencies on particle size and plasma torch residence time. Volatile species showed a distinct transition point at which aerosol detection efficiency began decreasing with increasing particle size. This critical diameter indicated the largest particle size for which complete particle detection should be expected and agreed with theories published in other works. Aerosol detection efficiencies also displayed power law dependencies on particle size. Aerosol detection efficiencies ranged from 10- 5 to 10- 11. Free molecular heat and mass transfer theory was applied, but

  11. Development of the detection of trace elements and radionuclides in some environmental samples by high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS)

    International Nuclear Information System (INIS)

    Determination of long-lived radionuclides at femto gram concentration level is a challenging task in analytical techniques. Inductively coupled plasma mass spectrometry (ICP-MS)with its ability to provide the sensitive and fast multielemental analysis is one of the most suitable method for the measurements of long lived radionuclides in the trace and ultra trace concentration range in the present study the reduction of the fundamental polyatomic ions in inductively coupled plasma mass spectrometry by inserting a metal sheath between the outer surface of the torch and the work coil (shielded torch), effectively eliminate the capacitive coupling of the high surface potential of the work coil with the plasma. This resulted in a low plasma potential with respect to the sampling cone. This leads to an effective reduction of 38ArH, Co2, and 40ArO as a result of using the shielded torch system. The sensitivity and detection limit of some selected long-lived radionuclides are studied by the double focusing ICP-MS under the condition of using the shielded torch.

  12. Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Baxter, Douglas C; Faarinen, Mikko; Österlund, Heléne; Rodushkin, Ilia; Christensen, Morten

    2011-09-01

    A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with (198)Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) μg L(-1) could be performed with uncertainty amplification factors levels of 0.14 μg L(-1), 0.35 μg L(-1) and 2.8 μg L(-1), with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  13. Chemical characterization of materials by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    An Inductively Coupled Plasma Mass Spectrometer was procured for trace elemental determination in diverse samples. Since its installation a number of analytical measurements have been carried out on different sample matrices. These include chemical quality control measurements of nuclear fuel and other materials such as uranium metal. Uranium peroxide, ADU, ThO2, UO2; isotopic composition of B, Li; chemical characterization of simulated ThO2 + 2%UO2 fuel; sodium zirconium phosphate and trace metallic elements in zirconium; Antarctica rock samples and wet phosphoric acid. Necessary separation methodologies required for effective removal of matrix were indigenously developed. In addition, a rigorous analytical protocol, which includes various calibration methodologies such as mass calibration, response calibration, detector cross calibration and linearity check over the entire dynamic range of 109 required for quantitative determination of elements at trace and ultra trace level,, has been standardized. This report summarizes efforts of RACD that have been put in this direction for the application of ICP-MS for analytical measurements. (author)

  14. Uranium quantification in semen by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Todorov, Todor I; Ejnik, John W; Guandalini, Gustavo; Xu, Hanna; Hoover, Dennis; Anderson, Larry; Squibb, Katherine; McDiarmid, Melissa A; Centeno, Jose A

    2013-01-01

    In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4-7% RSD and spike recoveries were 97-100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n=10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans' semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

  15. Local cooling, plasma reheating and thermal pinching induced by single aerosol droplets injected into an inductively coupled plasma

    Science.gov (United States)

    Chan, George C.-Y.; Hieftje, Gary M.

    2016-07-01

    The injection of a single micrometer-sized droplet into an analytical inductively coupled plasma (ICP) perturbs the plasma and involves three sequential effects: local cooling, thermal pinching and plasma reheating. Time-resolved two-dimensional monochromatic imaging of the load-coil region of an ICP was used to monitor this sequence of plasma perturbations. When a microdroplet enters the plasma, it acts as a local heat sink and cools the nearby plasma region. The cooling effect is considered local, although the cooling volume can be large and extends 6 mm from the physical location of the vaporizing droplet. The liberated hydrogen, from decomposition of water, causes a thermal pinch effect by increasing the thermal conductivity of the bulk plasma and accelerating heat loss at the plasma periphery. As a response to the heat loss, the plasma shrinks in size, which increases its power density. Plasma shrinkage starts around the same time when the microdroplet enters the plasma and lasts at least 2 ms after the droplet leaves the load-coil region. Once the vaporizing droplet passes through a particular plasma volume, that volume is reheated to an even higher temperature than under steady-state conditions. Because of the opposing effects of plasma cooling and reheating, the plasma conditions are different upstream (downward) and downstream (upward) from a vaporizing droplet - cooling dominates the downstream region whereas reheating controls in the upstream domain. The boundary between the local cooling and reheating zones is sharp and is only ~ 1 mm thick. The reheating effect persists a relatively long time in the plasma, at least up to 4 ms after the droplet moves out of the load-coil region. The restoration of plasma equilibrium after the perturbation induced by microdroplet injection is slow. Microdroplet injection also induces a momentary change in plasma impedance, and the impedance change was found to correlate qualitatively with the different stages of plasma

  16. Control of electron heating and ion energy distributions in capacitive plasmas by voltage waveform tailoring based on a novel power supply and impedance matching

    Science.gov (United States)

    Berger, Birk; Franek, James; Brandt, Steven; Liese, Martin; Barthel, Matthias; Schuengel, Edmund; Koepke, Mark; Schulze, Julian

    2015-09-01

    We present a novel RF power supply and impedance matching to drive technological plasmas with customized voltage waveforms. By adjusting the individual phases and amplitudes of multiple consecutive harmonics any voltage waveform can be realized as a customized finite Fourier series. This RF supply system is easily adaptable to any technological plasma for industrial applications and allows the commercial utilization of process optimization based on voltage waveform tailoring for the first time. Here, this system is tested on a capacitive discharge based on three consecutive harmonics of 13.56 MHz in argon. The effect of changing the shape of the driving voltage waveform on the electron heating and sheath dynamics is investigated by Phase Resolved Optical Emission Spectroscopy (PROES) for different electrode gaps, pressures, and applied voltages. At low pressure the results are correlated with ion energy distribution functions measured at both electrodes. Tuning the phases between the applied harmonics results in an electrical control of the DC self-bias and the mean ion energy. A comparison with the reference case of a dual-frequency discharge reveals that using more than two consecutive harmonics significantly enlarges the control range of the mean ion energy.

  17. Non-equilibrium Plasma Dehydrogenation Coupling of Methane

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A few factors effecting the reaction of plasma dehydrocoupling of methane have been investigated. The experiment shows that plasma power load, i.e. the ratio of methane flow to plasma power, is the most important factor effecting methane dehydrocoupling. The products of the reaction are mainly acetylene, ethylene, ethane and unreacted methane etc. If oxygen with a suitable molar ratio is introduced into plasma region at a reasonable position, the selectivity of C2 hydrocarbons can be increased greatly.

  18. Equivalence of the hard-wall and kinetic-fluid models of collisionless electron heating in capacitively coupled discharges

    International Nuclear Information System (INIS)

    By re-evaluating the hard-wall collisionless electron heating model from first principles, we show that despite previous criticisms (Gozadinos et al 2001 Phys. Rev. Lett. 87 135004), this model can in general be made consistent with the requirement of radio frequency (rf) current continuity at the sheath edge, while still producing a net heating effect. In addition, we demonstrate that the hard-wall and kinetic-fluid heating models stem from the same basic physical mechanism, and are in many ways the same theory; they differ only in the spatial region where electron heating is assumed to occur, and the way in which the effective electron distribution function is determined. Fundamentally, both models predict that collisionless heating occurs because of a non-isothermal compression and expansion of the plasma electrons by an oscillating rf sheath. (paper)

  19. Development and validation of a capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C(4) D) for the analysis of amikacin and its related substances.

    Science.gov (United States)

    El-Attug, Mohamed Nouri; Adams, Erwin; Van Schepdael, Ann

    2012-09-01

    Amikacin is a semisynthetic aminoglycoside antibiotic derived from kanamycin A that lacks a strong UV absorbing chromophore or fluorophore. Due to the physicochemical properties of amikacin and its related substances, CE in combination with capacitively coupled contactless conductivity detection (CE-C(4) D) was chosen. The optimized separation method uses a BGE composed of 20 mM MES adjusted to pH 6.6 by l-histidine and 0.3 mM CTAB that was added as flow modifier in a concentration below the CMC. Ammonium acetate 20 mg.L(-1) was used as internal standard. 30 kV was applied in reverse polarity on a fused silica capillary (73/48 cm; 75 μm id). The optimized separation was obtained in less than 6 min with good linearity (R(2) = 0.9996) for amikacin base. It shows a good precision expressed as RSD on relative peak areas equal to 0.1 and 0.7% for intraday and interday, respectively. The LOD and LOQ are 0.5 mg.L(-1) and 1.7 mg.L(-1) , respectively. PMID:22965725

  20. Analysis, design and implementation of a quasi-proportional-resonant controller for multifunctional capacitive-coupling grid-connected inverter

    DEFF Research Database (Denmark)

    Ye, Tao; Dai, Ning-Yi; Lam, Chi-Seng;

    2015-01-01

    and current control characteristics differs from the conventional inductive-coupling grid-connected inverter. The direct current tracking with hysteresis pulse width modulation (PWM) was used in previous studies. However, this method suffers from widely varying switching frequency and large current ripples....... A Quasi-proportional-resonant (Quasi-PR) current controller is designed for the CGCI in this paper. Its modeling and parameter selection are studied in detail. In contrast with proportional-integration (PI) current controller, the Quasi-PR controller reduces steady-state error. It also generates a voltage...... reference for applying the carrier-based PWM to improve output waveform quality. Simulation results are provided to verify the Quasi-PR controller and comparison with the PI controller is also done. A lab-scale prototype is built. Experimental results are given to show the validity of the proposed control...

  1. Enhanced Macroscopic Quantum Tunneling in Capacitively Coupled BiPb2201 Single-Layered Intrinsic Josephson Junctions

    Science.gov (United States)

    Nomura, Yoshiki; Mizuno, Takaaki; Kambara, Hitoshi; Nakagawa, Yuya; Kakeya, Itsuhiro

    2015-01-01

    Macroscopic quantum tunneling (MQT) in an intrinsic Josephson junction (IJJ) stack of Bi1.9Pb0.1Sr1.39La0.63CuO6+δ (BiPb2201) has been investigated. For the first switch, from superconducting to the first resistive branch in current-voltage characteristics, the crossover between MQT and thermal activation (TA) takes place at 0.6 K. On the other hand, for the second switch, the MQT-TA crossover temperature is increased to 2.0 K. This result is interpreted as follows: the MQT rate of the second switch is enhanced by the charge coupling between adjacent IJJs as well as in Bi2Sr2CaCu2O8+δ. We consider that the enhancement of the MQT rate is a common feature among bismuth-cuprates with single and double CuO2 layers in their crystal structures.

  2. Advanced Burnup Method using Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hilton, Bruce A. [Idaho Natonal Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Glagolenko, Irina; Giglio, Jeffrey J.; Cummings, Daniel G

    2009-06-15

    Nuclear fuel burnup is a key parameter used to assess irradiated fuel performance, to characterize the dependence of property changes due to irradiation, and to perform nuclear materials accountability. For advanced transmutation fuels and high burnup LWR fuels that have multiple fission sources, the existing Nd-148 ASTM burnup determination practice requires input of calculated fission fractions (identifying the specific fission source isotope and neutron energy that yielded fission, e.g., U-235 from thermal neutron, U-238 from fast neutron) from computational neutronics analysis in addition to the measured concentration of a single fission product isotope. We report a novel methodology of nuclear fuel burnup determination, which is completely independent of model predictions and reactor types. The proposed method leverages the capability of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to quantify multiple fission products and actinides and uses these data to develop a system of burnup equations whose solution is the fission fractions. The fission fractions are substituted back in the equations to determine burnup. This technique requires high fidelity fission yield data, which is not uniformly available for all fission products. We discuss different means that can potentially assist in indirect determination, verification and improvement (refinement) of the ambiguously known fission yields. A variety of irradiated fuel samples are characterized by ICP-MS and the results used to test the advanced burnup method. The samples include metallic alloy fuel irradiated in fast spectrum reactor (EBRII) and metallic alloy in a tailored spectrum and dispersion fuel in the thermal spectrum of the Advanced Test Reactor (ATR). The derived fission fractions and measured burnups are compared with calculated values predicted by neutronics models. (authors)

  3. Electrochemical capacitance of a leaky nanocapacitor

    OpenAIRE

    Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We report a detailed theoretical investigation on electrochemical capacitance of a nanoscale capacitor where there is a DC coupling between the two conductors. For this ``leaky'' quantum capacitor, we have derived general analytic expressions of the linear and second order nonlinear electrochemical capacitance within a first principles quantum theory in the discrete potential approximation. Linear and nonlinear capacitance coefficients are also derived in a self-consistent manner without the ...

  4. Microwave to plasma coupling in electron cyclotron resonance and microwave ion sources (invited)

    International Nuclear Information System (INIS)

    Coupling improvements between microwaves and plasmas are a key factor to design more powerful electron cyclotron resonance and microwave ion sources. On this purpose different activities have been undertaken by the INFN-LNS ion source team and a new approach was developed. Recent experiments confirmed the simulations, demonstrating that even in presence of a dense plasma, resonant modes are excited inside the cavity and the plasma dynamics depends on their structure. An overview of the coupling issues on microwave ion sources is also given along with a discussion on alternative coupling techniques.

  5. Microwave power coupling with electron cyclotron resonance plasma using Langmuir probe

    Indian Academy of Sciences (India)

    S K Jain; V K Senecha; P A Naik; P R Hannurkar; S C Joshi

    2013-07-01

    Electron cyclotron resonance (ECR) plasma was produced at 2.45 GHz using 200 – 750 W microwave power. The plasma was produced from argon gas at a pressure of 2 × 10−4 mbar. Three water-cooled solenoid coils were used to satisfy the ECR resonant conditions inside the plasma chamber. The basic parameters of plasma, such as electron density, electron temperature, floating potential, and plasma potential, were evaluated using the current–voltage curve using a Langmuir probe. The effect of microwave power coupling to the plasma was studied by varying the microwave power. It was observed that the optimum coupling to the plasma was obtained for ∼ 600 W microwave power with an average electron density of ∼ 6 × 1011 cm−3 and average electron temperature of ∼ 9 eV.

  6. Experimental investigation on plasma parameter profiles on a wafer level with reactor gap lengths in an inductively coupled plasma

    International Nuclear Information System (INIS)

    The gap length effect on plasma parameters is investigated in a planar type inductively coupled plasma at various conditions. The spatial profiles of ion densities and the electron temperatures on the wafer level are measured with a 2D probe array based on the floating harmonic method. At low pressures, the spatial profiles of the plasma parameters rarely changed by various gap lengths, which indicates that nonlocal kinetics are dominant at low pressures. However, at relatively high pressures, the spatial profiles of the plasma parameter changed dramatically. These plasma distribution profile characteristics should be considered for plasma reactor design and processing setup, and can be explained by the diffusion of charged particles and the local kinetics

  7. Inner magnetospheric plasma interactions and coupling with the ionosphere

    OpenAIRE

    Fok,Mei-Ching/Ebihara,Yusuke/Moore,Thomas E.

    2005-01-01

    The inner magnetosphere occupies a vast volume in space containing a relatively low-density mixture of hot and cold plasmas: the ring current, plasmasphere and radiation belt. Energy is transferred from the ring current to the cold plasmas through Coulomb collisions and wave-particle interactions, producing temperature enhancements in the plasmasphere. The plasma waves generated in the plasmasphere cause pitch-angle and energy diffusion of the energetic particles. The magnetic disturbances ge...

  8. Inductively coupled plasma - mass spectrometry (ICP-MS) and inductively coupled plasma – optical emission spectrometry (IP-OES) analysis of elements in Macedonian wines

    OpenAIRE

    Ivanova, Violeta; Wiltsche, Helmar; Stafilov, Trajče; Motter, Herber; Stefova, Marina; Lankmayr, Ernst

    2013-01-01

    In this study the major, minor and trace elements in 25 Macedonian white, rose and red wines from different wine regions were determined. Analysis was performed with inductively coupled plasma - mass spectrometry (ICP-MS) and inductively coupled plasma – optical emission spectrometry (ICP-OES) for accurate determination of the concentration of 42 elements (Ag, Al, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Ho, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Pr, S, Sm, Tb, Ti, T...

  9. Application of inductively coupled plasma mass spectrometry (ICP-MS) to radioecology

    International Nuclear Information System (INIS)

    The advantages of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) over conventional radioanalytical measurements are presented and the applications of the ICP-MS technique to environmental samples are given

  10. Determination of traces of thorium in uranium by inductively coupled plasma mass spectrometry (ICP-MS)

    International Nuclear Information System (INIS)

    An analytical methodology for the determination of traces of thorium in uranium oxide by Inductively Coupled Plasma Mass Spectrometry has been developed. Recovery studies were carried out by standard addition and also by tracer technique to validate the methodology. (author)

  11. A Concept for Directly Coupled Pulsed Electromagnetic Acceleration of Plasmas

    Science.gov (United States)

    Thio, Y.C. Francis; Cassibry, Jason T.; Eskridge, Richard; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Plasma jets with high momentum flux density are required for a variety of applications in propulsion research. Methods of producing these plasma jets are being investigated at NASA Marshall Space Flight Center. The experimental goal in the immediate future is to develop plasma accelerators which are capable of producing plasma jets with momentum flux density represented by velocities up to 200 km/s and ion density up to 10(exp 24) per cu m, with sufficient precision and reproducibility in their properties, and with sufficiently high efficiency. The jets must be sufficiently focused to allow them to be transported over several meters. A plasma accelerator concept is presented that might be able to meet these requirements. It is a self-switching, shaped coaxial pulsed plasma thruster, with focusing of the plasma flow by shaping muzzle current distribution as in plasma focus devices, and by mechanical tapering of the gun walls. Some 2-D MHD modeling in support of the conceptual design will be presented.

  12. Thermo-magneto coupling in a dipole plasma

    CERN Document Server

    Yoshida, Z; Morikawa, J; Saitoh, H

    2012-01-01

    On a dipole plasma, we observe the generation of magnetic moment, as the movement of the levitating magnet-plasma compound, in response to electron-cyclotron heating and the increase of $\\beta$ (magnetically-confined thermal energy). We formulate a thermodynamic model with interpreting heating as injection of microscopic magnetic moment; the corresponding chemical potential is the ambient magnetic field.

  13. Holographic Brownian motion and time scales in strongly coupled plasmas

    NARCIS (Netherlands)

    A. Nata Atmaja; J. de Boer; M. Shigemori

    2010-01-01

    We study Brownian motion of a heavy quark in field theory plasma in the AdS/CFT setup and discuss the time scales characterizing the interaction between the Brownian particle and plasma constituents. In particular, the mean-free-path time is related to the connected 4-point function of the random fo

  14. Characterization of an inductively coupled plasma source with convergent nozzle

    Science.gov (United States)

    Dropmann, Michael; Clements, Kathryn; Edgren, Josh; Laufer, Rene; Herdrich, Georg; Matthews, Lorin; Hyde, Truell

    2015-11-01

    The inductively heated plasma generator (IPG6-B) located in the CASPER labs at Baylor University has recently been characterized for both air, nitrogen and helium. A primary area of research within the intended scope of the instrument is the analysis of material degradation under high heat fluxes such as those imposed by a plasma during atmospheric entry of a spacecraft and at the divertor within various fusion experiment. In order to achieve higher flow velocities and respectively higher heat fluxes, a new exit flange has been designed to allow the installation of nozzles with varying geometries at the exit of the plasma generator. This paper will discuss characterization of the plasma generator for a convergent nozzle accelerating the plasma jet to supersonic velocity. The diagnostics employed include a cavity calorimeter to measure the total plasma power, a Pitot probe to measure stagnation pressure and a heat flux probe to measure the local heat flux. Radial profiles of stagnation pressure and heat flux allowing the determination of the local plasma enthalpy in the plasma jet will be presented. Support from the NSF and the DOE (award numbers PHY-1262031 and PHY-1414523) is gratefully acknowledged.

  15. Velocity field measurements in an inductively coupled plasma

    International Nuclear Information System (INIS)

    With the rapid development of laser doppler anemometry, a new tool became available that proved to be quite useful for gas and particle velocity measurements under plasma conditions. The objective of the present study was to adapt this technique to measurements in an induction plasma and to obtain gas and particle velocity data in the discharge zone under different operating conditions

  16. Electron Temperature Control in Inductively Coupled Nitrogen Plasmas by Adding Argon/Helium

    Institute of Scientific and Technical Information of China (English)

    康正德; 蒲以康

    2002-01-01

    A new technique, adding argon or helium into nitrogen plasma, has been used to regulate the electron temperature in an inductively coupled plasma. The electron temperature is determined by analysing the intensity ratio of two nitrogen spectrum lines. The results show that, when the total pressure is 0.7Pa, the electron temperature increases with the increase of the He partial pressure in He/N2 plasma, but the electron temperature decreases with the increase of the Ar partial pressure in Ar/N2 plasma. The regulation effect of electron temperature is weaker in higher pressure N2/He plasma of 2.6Pa.

  17. Redox regulation of mammalian sperm capacitation

    Directory of Open Access Journals (Sweden)

    Cristian O′Flaherty

    2015-01-01

    Full Text Available Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P H for sperm capacitation. Peroxiredoxins (PRDXs are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

  18. Improvement of Uniformity of Inductively Coupled Plasma with a Cone Spiral Antenna

    Institute of Scientific and Technical Information of China (English)

    LI Lin-Sen; XU Xu; LIU Feng; ZHOU Qian-Hong; NIE Zong-Fu; LIANG Yi-Zi; LIANG Rong-Qing

    2008-01-01

    Uniformity of inductively coupled plasma (ICP) is improved with a cone spiral antenna in our experiment. Performance of the ICP with a new type of antenna is experimentally investigated, The results indicate that the uniformity of plasma density in the radial direction is obviously improved as compared to the ICP with a planar spiral antenna. Performance of ICP is analysed with the experimental results.

  19. Degenerate wave and capacitive coupling increase human MSC invasion and proliferation while reducing cytotoxicity in an in vitro wound healing model.

    Directory of Open Access Journals (Sweden)

    Michelle Griffin

    Full Text Available Non-unions pose complications in fracture management that can be treated using electrical stimulation (ES. Bone marrow mesenchymal stem cells (BMMSCs are essential in fracture healing; however, the effect of different clinical ES waveforms on BMMSCs cellular activities remains unknown. We compared the effects of direct current (DC, capacitive coupling (CC, pulsed electromagnetic field (PEMF and degenerate wave (DW on cellular activities including cytotoxicity, proliferation, cell-kinetics and apoptosis by stimulating human-BMMSCs 3 hours a day, up to 5 days. In addition, migration and invasion were assessed using fluorescence microscopy and by quantifying gene and protein expression. We found that DW had the greatest proliferative and least apoptotic and cytotoxic effects compared to other waveforms. DC, DW and CC stimulations resulted in a higher number of cells in S phase and G(2/M phase as shown by cell cycle analysis. CC and DW caused more cells to invade collagen and showed increased MMP-2 and MT1-MMP expression. DC increased cellular migration in a scratch-wound assay and all ES waveforms enhanced expression of migratory genes with DC having the greatest effect. All ES treated cells showed similar progenitor potential as determined by MSC differentiation assay. All above findings were shown to be statistically significant (p<0.05. We conclude that ES can influence BMMSCs activities, especially DW and CC, which show greater invasion and higher cell proliferation compared to other types of ES. Application of DW or CC to the fracture site may help in the recruitment of BMMSCs to the wound that may enhance rate of bone healing at the fracture site.

  20. The role of the metastable O2(b{{}^{1}}{\\Sigma}_{\\text {g}}^{+} ) and energy-dependent secondary electron emission yields in capacitively coupled oxygen discharges

    Science.gov (United States)

    Hannesdottir, H.; Gudmundsson, J. T.

    2016-10-01

    The effects of including the singlet metastable molecule O2(b{{}1}Σ\\text{g}+ ) in the discharge model of a capacitively coupled rf driven oxygen discharge are explored. We furthermore examine the addition of energy-dependent secondary electron emission yields from the electrodes to the discharge model. The one-dimensional object-oriented particle-in-cell Monte Carlo collision code oopd1 is used for this purpose, with the oxygen discharge model considering the species {{\\text{O}}2}≤ft({{\\text{X}}3}Σ\\text{g}-\\right) , {{\\text{O}}2}≤ft({{\\text{a}}1}{{Δ }\\text{g}}\\right) , {{\\text{O}}2}≤ft({{\\text{b}}1}Σ\\text{g}+\\right) , O(3P), O(1D), \\text{O}2+ , O+, O-, and electrons. The effects on particle density profiles, the electron heating rate profile, the electron energy probability function and the sheath width are explored including and excluding the metastable oxygen molecules and secondary electron emission. Earlier we have demonstrated that adding the metastable O2(a{{}1}{{Δ }\\text{g}} ) to the discharge model changes the electron heating from having contributions from both bulk and sheath heating to being dominated by sheath heating for pressures above 50 mTorr. We find that including the metastable O2(b{{}1}Σ\\text{g}+ ) further decreases the ohmic heating and the effective electron temperature in the bulk region. The effective electron temperature in the electronegative core is found to be less than 1 eV in the pressure range 50-200 mTorr which agrees with recent experimental findings. Furthermore, we find that including an energy-dependent secondary electron emission yield for \\text{O}2+ -ions has a significant influence on the discharge properties, including decreased sheath width.

  1. Capacitively Coupled Resistivity measurements to determine frequency-dependent electrical parameters in periglacial environment—theoretical considerations and first field tests

    Science.gov (United States)

    Przyklenk, A.; Hördt, A.; Radić, T.

    2016-08-01

    Capacitively Coupled Resistivity (CCR) is conventionally used to emulate DC resistivity measurements and may provide important information about the ice content of material in periglacial areas. The application of CCR theoretically enables the determination of both electrical parameters, that is, the resistivity and the electrical permittivity, by analysing magnitude and phase shift spectra. The electrical permittivity may dominate the impedance, especially in periglacial areas or regions of hydrogeological interest. However, previous theoretical work suggested that the phase shift may strongly depend on electrode height above ground, implying that electrode height must be known with great accuracy to determine electrical permittivity. Here, we demonstrate with laboratory test measurements, theoretical modelling and by analysing the Jacobian matrix of the inversion that the sensitivity towards electrode height is drastically reduced if the electrical permittivity is frequency dependent in a way that is typical for ice. For the first time, we used a novel broad-band CCR device `Chameleon' for a field test located in one of the ridge galleries beneath the crest of Mount Zugspitze. A permanently ice covered bottom of a tunnel was examined. For the inversion of the measured spectra, the frequency dependence of the electrical parameters was parametrized in three different ways: A Debye Model for pure ices, a Cole-Cole Model for pure ices and a dual Cole-Cole Model including interfacial water additionally. The frequency-dependent resistivity and permittivity spectra obtained from the inversion, including low- and high-frequency limits, agree reasonably well with laboratory and field measurements reported in the literature.

  2. Actions of low- and high-energy electrons on the phase transition between E- and H-modes in an inductively coupled plasma in Ar

    International Nuclear Information System (INIS)

    It is known that an inductively coupled plasma (ICP) sustained by a radiofrequency current coil has a mode transition and hysteresis characteristics of the internal plasma parameter as a function of the external plasma parameter. We focus on the contributions of low- and high-energy electrons to the phase transition between the capacitive E-mode and the inductive H-mode in an ICP. Our analysis is based on the diagnostics for a time-resolved two-dimensional net excitation rate of short-lived excited atoms, mainly produced collisionally by low- and high-energy electrons by using an intensified charge coupled device optical image. Short-lived excited atoms Ar(2p1) and Ar(2p9) with different excitation processes have been employed as optical probes in an axisymmetric configuration of the ICP chamber, driven at 13.56 MHz by an external single-turn current coil at 300 mTorr in pure Ar. The E-to-H transition is characterized by two time constants of electrons: establishment of an axisymmetric distribution by electron diffusion and the accumulation of symmetric high-density electrons in order to sustain the inductive discharge under a weak electromagnetic field. On the other hand, the H-to-E transition is strongly influenced by the presence of a long-lived excited atom (i.e. metastables).

  3. A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Punjabi, Sangeeta B. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India); Joshi, N. K. [Faculty of Engineering and technology, MITS, lakshmangarh, (Sikar), Rajasthan 332311 (India); Mangalvedekar, H. A.; Lande, B. K. [Electrical Engineering Department, V. J.T.I, Matunga, Mumbai 400019 (India); Das, A. K. [Laser and Plasma Technology Division, BARC, Mumbai 400085 (India); Kothari, D. C. [Department of Physics, University of Mumbai, Kalina, Santacruz(E) 400098 (India)

    2012-01-15

    A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software fluent{sup (c)}. The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications.

  4. Effective Potential Theory: A Practical Way to Extend Plasma Transport Theory to Strong Coupling

    CERN Document Server

    Baalrud, Scott D; Daligault, Jerome

    2014-01-01

    The effective potential theory is a physically motivated method for extending traditional plasma transport theories to stronger coupling. It is practical in the sense that it is easily incorporated within the framework of the Chapman-Enskog or Grad methods that are commonly applied in plasma physics and it is computationally efficient to evaluate. The extension is to treat binary scatterers as interacting through the potential of mean force, rather than the bare Coulomb or Debye-screened Coulomb potential. This allows for aspects of many-body correlations to be included in the transport coefficients. Recent work has shown that this method accurately extends plasma theory to orders of magnitude stronger coupling when applied to the classical one-component plasma model. The present work shows that similar accuracy is realized for the Yukawa one-component plasma model and it provides a comparison with other approaches.

  5. Measuring the EOS of a Dense, Strongly Coupled Plasma; Description of the Technique

    Energy Technology Data Exchange (ETDEWEB)

    Benage, John F. Jr.; Kyraka, George; Workman, Jonathan; Tierney, Thomas

    1997-12-31

    This paper describes a new experimental design which we believe can produce reasonably accurate data for the equation of state (EOS) of a dense plasma. This design takes advantage of the standard shock technique used for determining the high pressure EOS of solids. It also utilizes recently developed experimental techniques for producing dense, strongly coupled plasmas as well as new diagnostic techniques for measuring the properties of these plasmas. The results should be able to distinguish among theoretical models for plasmas at just under solid density and temperatures of 10`s of eV.

  6. False capacitance of supercapacitors

    OpenAIRE

    Ragoisha, G. A.; Aniskevich, Y. M.

    2016-01-01

    Capacitance measurements from cyclic voltammetry, galvanostatic chronopotentiometry and calculation of capacitance from imaginary part of impedance are widely used in investigations of supercapacitors. The methods assume the supercapacitor is a capacitor, while real objects correspond to different equivalent electric circuits and show various contributions of non-capacitive currents to the current which is used for calculation of capacitance. Specific capacitances which are presented in F g-1...

  7. Modelling of the dual frequency capacitive sheath in the intermediate pressure range

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, P C [Plasma Research Laboratory, National Centre for Plasma Science and Technology and School of Physical Sciences, Dublin City University, Dublin 9 (Ireland); Robiche, J [Laboratoire de Physique et Technologie des Plasmas, Ecole Polytechnique, Palaiseau 91 128 Cedex (France); Turner, M M [Plasma Research Laboratory, National Centre for Plasma Science and Technology and School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

    2004-05-21

    The nonlinearity of the plasma sheath in dual frequency capacitively coupled reactors is investigated for frequencies well above the ion plasma frequency. This work focuses on the behaviour of the voltage and the sheath width with respect to the driving current source and the collisionality regime. For typical plasma processing applications, the gas pressure ranges from a few milliTorrs to hundreds of milliTorrs, and the ion dynamics span different collisional regimes. To describe these different ion dynamics, we have used a collisionless model and a variable mobility model. The sheath widths and the voltages obtained from these two models have then been compared.

  8. Coupling electron-hole and electron-ion plasmas: Realization of an npn plasma bipolar junction phototransistor

    Science.gov (United States)

    Wagner, C. J.; Tchertchian, P. A.; Eden, J. G.

    2010-09-01

    Coupling e--h+ and gas phase plasmas with a strong electric field across a potential barrier yields a transistor providing photosensitivity and voltage gain but also a light-emitting collector whose radiative output can be switched and modulated. This optoelectronic device relies on the correspondence between the properties of a low temperature, nonequilibrium plasma and those for the e--h+ plasma in an n-type semiconductor. Hysteresis observed in the collector current-base current characteristics is attributed primarily to charge stored in the base, and the photogeneration of e--h+ pairs at the base-collector junction. Extinguishing the collector plasma requires an emitter-base junction reverse bias of <1 V.

  9. Coupled two-dimensional edge plasma and neutral gas modeling of tokamak scrape-off-layers

    Energy Technology Data Exchange (ETDEWEB)

    Maingi, R. [North Carolina State Univ., Raleigh, NC (United States)

    1992-08-01

    The objective of this study is to devise a detailed description of the tokamak scrape-off-layer (SOL), which includes the best available models of both the plasma and neutral species and the strong coupling between the two in many SOL regimes. A good estimate of both particle flux and heat flux profiles at the limiter/divertor target plates is desired. Peak heat flux is one of the limiting factors in determining the survival probability of plasma-facing-components at high power levels. Plate particle flux affects the neutral flux to the pump, which determines the particle exhaust rate. A technique which couples a two-dimensional (2-D) plasma and a 2-D neutral transport code has been developed (coupled code technique), but this procedure requires large amounts of computer time. Relevant physics has been added to an existing two-neutral-species model which takes the SOL plasma/neutral coupling into account in a simple manner (molecular physics model), and this model is compared with the coupled code technique mentioned above. The molecular physics model is benchmarked against experimental data from a divertor tokamak (DIII-D), and a similar model (single-species model) is benchmarked against data from a pump-limiter tokamak (Tore Supra). The models are then used to examine two key issues: free-streaming-limits (ion energy conduction and momentum flux) and the effects of the non-orthogonal geometry of magnetic flux surfaces and target plates on edge plasma parameter profiles.

  10. Design of Capillary Electrophoresis Capacitively Coupled Contactless Conductivity Detector%毛细管电泳电容耦合非接触电导检测器

    Institute of Scientific and Technical Information of China (English)

    曾凡亚; 苏建坡; 赵书俊; 张书胜; 张斌; 卢艳艳

    2011-01-01

    A kind of capillary electrophoresis capacitively coupled contactless conductivity detector (CE-C4D) was designed, which had signal source,detection circuit and data acquisition unit. Wien bridge oscillator was used to get a signal source,and absolute value demodulation was used to process signals. And a data acquisition circuit with USB interface and software were designed to acquire and store the signal data and draw spectrum. The principle and circuit of CE-C D were also introduced, glucose (0. 04 mol/L) +fructose(0. 04 mol/L) +sucrose(0. 04 mol/L) were took as samples to test the repeatability and at the same time,six kinds of phenolic acids were separated and determined to evaluate the detection limit. The results show that the relative standard deviation ( RSD) of peak retention time and area are less than 1% and 7. 5% ,and the detection limit of six kinds of phenolic acids is 5 u,g/mL (signal noise ratio,S/N =3) ,the detector has good repeatability and high sensitivity.%设计了一种集激励、检测和数据采集功能于一体的毛细管电泳非接触电导检测器,采用文氏电桥振荡器产生激励信号,运用绝对值检波技术对检测信号进行处理,并设计USB数据采集电路和上位机软件,实现波形数据的采集、存储和图谱的绘制.介绍了其检测原理、电路结构及实现,使用葡萄糖(0.04 mol/L)+果糖(0.04 mol/L)+蔗糖(0.04 mol/L)样品进行了检测器重复性实验,并分离检测了6种酚酸,对检测器检测限作出评定.实验结果表明:峰保留时间和峰面积相对标准差分别小于1%和7.5%,对酚酸的最低检测限为5μg/mL(信噪比S/N =3),检测器灵敏度高、重复性好.

  11. Measurement of helicon wave coupling for current drive and anticipated role for high beta KSTAR plasmas

    Science.gov (United States)

    Wang, S. J.; Kim, H. J.; Joung, M.; Jeong, J. H.; Kim, J. H.; Bae, Y. S.; Kwak, J. G.; Wi, H. H.; Kim, H.-S.

    2015-11-01

    Helicon wave current drive has been suggested for efficient off-axis current drive in high electron beta tokamak plasmas. Fast wave drives centrally peaking current in the frequency range up to several ion cyclotron harmonics in the present tokamaks, such as KSTAR. Increasing fast wave frequency up to LH resonance frequency at the plasma edge, the spiral propagation of wave at the outer region of plasma lengthens the wave path to the plasma center. Also, optical thickness increases with frequency. It is expected that these effects produce efficient off-axis power deposition depending on the electron beta and magnetic field pitch. A low power TWA for helicon wave was installed and tested in KSTAR tokamak which is aiming for the steady-state high beta plasma requiring off-axis current drive. The power coupling properties of TWA at various plasma conditions will be presented. In addition to the coupling efficiency, issues such as load sensitivity and unwanted slow wave coupling will be addressed. Also, the simulation of plasma performance with the combination of helicon wave current drive and other conventional heating and current drive power in KSTAR will be discussed. This work was supported by the Korean Ministry of Science, ICT and Future Planning and by R&D Program through the National Fusion Research Institute of Korea (NFRI) funded by the Government funds.

  12. Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasma

    CERN Document Server

    Choudhary, Mangilal; Bandyopadhyay, P

    2016-01-01

    A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current (DC) glow discharge. These dust particles are found to get trapped in an electrostatic potential well which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self excited dust acoustic waves and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust par...

  13. Heat Transfer During Radio Frequency Inductively Coupled Plasma Deposition of Tungsten

    Institute of Scientific and Technical Information of China (English)

    JIANG Xianliang; M.I.BOULOS

    2007-01-01

    Particle melting and substrate temperature are important in controlling deposited density and residual stress in thermal plasma deposition of refractory materials.In this paper,both the heating and cooling behaviours of tungsten particles inside a radio frequency inductively coupled plasma(ICP)and the plasma heat flux to the substrate were investigated.The distribution of the plasma-generated heat on device,powder injection probe,deposition chamber,and substrate Was determined by measuring the water flow rate and the flow-in and flow-out water temperatures in the four parts.Substrate temperature Was measured by a two-colour pyrometer during the ICP deposition of tungsten.Experimental results show that the heat flux to the substrate accounts for about 20% of the total plasma energy,the substrate temperature can reach as high as 2100 K,and the heat loss by radiation is significant in the plasma deposition of tungsten.

  14. Dissecting graphene capacitance in electrochemical cell

    International Nuclear Information System (INIS)

    Quantum capacitance of graphene plays a significant role for graphene's applications in electrochemical devices and sensors, while the determination of these basic characters of Dirac point, Fermi energy, quantum capacitance, etc is still a subject of considerable debate in both experiments and simulations. Here, we report joint first-principles/continuum calculations (JFPCCs) on a monolayer graphene electrode immersed in an electrolyte coupled with a reference electrode under an applied potential. The JFPCCs gave the Fermi level, charge density on graphene, Dirac point energy, electrostatic potential, electric double layer etc as a function of the applied potential with respect to the reference electrode. These results revealed the strongly coupled relationship between Fermi level change and Dirac point shift in electrochemical cell. The total capacitance of the electrochemical cell was dissected into the quantum capacitance of the graphene electrode and the capacitance of the electric double layer. Furthermore, simple and analytic formulas were proposed for the three capacitances, which predicted, in sufficient accuracy, the behavior of capacitance versus potential. These findings deepen the understanding of quantum capacitance of graphene, which will stimulate novel experimental and theoretical studies and boost the applications of graphene in electrochemical and energy areas

  15. Nonlinear coupling of acoustic and shear mode in a strongly coupled dusty plasma with a density dependent viscosity

    Science.gov (United States)

    Garai, S.; Janaki, M. S.; Chakrabarti, N.

    2016-09-01

    The nonlinear propagation of low frequency waves, in a collisionless, strongly coupled dusty plasma (SCDP) with a density dependent viscosity, has been studied with a proper Galilean invariant generalized hydrodynamic (GH) model. The well known reductive perturbation technique (RPT) has been employed in obtaining the solutions of the longitudinal and transverse perturbations. It has been found that the nonlinear propagation of the acoustic perturbations govern with the modified Korteweg-de Vries (KdV) equation and are decoupled from the sheared fluctuations. In the regions, where transversal gradients of the flow exists, coupling between the longitudinal and transverse perturbations occurs due to convective nonlinearity which is true for the homogeneous case also. The results, obtained here, can have relative significance to astrophysical context as well as in laboratory plasmas.

  16. Plasma effect in silicon charge coupled devices (CCDs)

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, J., E-mail: estrada@fnal.gov [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Molina, J., E-mail: jmolina@ing.una.py [Facultad de Ingenieria, Universidad Nacional de Asuncion, Laboratorio de Mecanica y Energia, Campus de la UNA, San Lorenzo 2160 (Paraguay); Blostein, J.J., E-mail: jeronimo@cab.cnea.gov.ar [CONICET (Argentina); Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Bariloche (Argentina); Fernandez, G., E-mail: fmoroni.guillermo@gmail.com [Universidad Nacional del Sur, Bahia Blanca (Argentina)

    2011-02-11

    Plasma effect is observed in CCDs exposed to heavy ionizing {alpha}-particles with energies in the range 0.5-5.5 MeV. The results obtained for the size of the charge clusters reconstructed on the CCD pixels agree with previous measurements in the high energy region ({>=}3.5 MeV). The measurements were extended to lower energies using {alpha}-particles produced by (n,{alpha}) reactions of neutrons in a {sup 10}B target. The effective linear charge density for the plasma column is measured as a function of energy. The results demonstrate the potential for high position resolution in the reconstruction of {alpha} particles, which opens an interesting possibility for using these detectors in neutron imaging applications.

  17. Plasma effect in Silicon Charge Couple Devices (CCDs)

    CERN Document Server

    Estrada, Juan; Blostein, J

    2011-01-01

    Plasma effect is observed in CCDs exposed to heavy ionizing alpha-particles with energies in the range 0.5 - 5.5 MeV. The results obtained for the size of the charge clusters reconstructed on the CCD pixels agrees with previous measurements in the high energy region (>3.5 MeV). The measurements were extended to lower energies using alpha-particles produced by (n,alpha) reactions of neutrons in a Boron-10 target. The effective linear charge density for the plasma column is measured as a function of energy. The results demonstrate the potential for high position resolution in the reconstruction of alpha particles, which opens an interesting possibility for using these detectors in neutron imaging applications.

  18. Accumulative coupling between magnetized tenuous plasma and gravitational waves

    Science.gov (United States)

    Zhang, Fan

    2016-07-01

    We explicitly compute the plasma wave (PW) induced by a plane gravitational wave (GW) traveling through a region of strongly magnetized plasma, governed by force-free electrodynamics. The PW comoves with the GW and absorbs its energy to grow over time, creating an essentially force-free counterpart to the inverse-Gertsenshtein effect. The time-averaged Poynting flux of the induced PW is comparable to the vacuum case, but the associated current may offer a more sensitive alternative to photodetection when designing experiments for detecting/constraining high-frequency gravitational waves. Aside from the exact solutions, we also offer an analysis of the general properties of the GW to PW conversion process, which should find use when evaluating electromagnetic counterparts to astrophysical gravitational waves that are generated directly by the latter as a second-order phenomenon.

  19. Accumulative coupling between magnetized tenuous plasma and gravitational waves

    CERN Document Server

    Zhang, Fan

    2016-01-01

    We explicitly compute the plasma wave (PW) induced by a plane gravitational wave (GW) travelling through a region of strongly magnetized plasma, governed by force-free electrodynamics. The PW co-moves with the GW and absorbs its energy to grow over time, creating an essentially force-free counterpart to the inverse-Gertsenshtein effect. The time-averaged Poynting flux of the induced PW is comparable to the vacuum case, but the associated current may offer a more sensitive alternative to photodetection when designing experiments for detecting/constraining high frequency gravitational waves. Aside from the exact solutions, we also offer an analysis of the general properties of the GW to PW conversion process, which should find use when evaluating electromagnetic counterparts to astrophysical gravitational waves, that are generated directly by the latter as a second order phenomenon.

  20. Revisiting the Anomalous rf Field Penetration into a Warm Plasma

    International Nuclear Information System (INIS)

    Radio-frequency [rf] waves do not penetrate into a plasma and are damped within it. The electric field of the wave and plasma current are concentrated near the plasma boundary in a skin layer. Electrons can transport the plasma current away from the skin layer due to their thermal motion. As a result, the width of the skin layer increases when electron temperature effects are taken into account. This phenomenon is called anomalous skin effect. The anomalous penetration of the rf electric field occurs not only for transversely propagating to the plasma boundary wave (inductively coupled plasmas) but also for the wave propagating along the plasma boundary (capacitively coupled plasmas). Such anomalous penetration of the rf field modifies the structure of the capacitive sheath. Recent advances in the nonlinear, non-local theory of the capacitive sheath are reported. It is shown that separating the electric field profile into exponential and non-exponential parts yields an efficient qualitative and quantitative description of the anomalous skin effect in both inductively and capacitively coupled plasma

  1. Influence of coupling on thermal forces and dynamic friction in plasmas with multiple ion species

    CERN Document Server

    Kagan, Grigory; Daligault, Jerome

    2016-01-01

    The recently proposed effective potential theory [Phys. Rev. Lett. 110, 235001 (2013)] is used to investigate the influence of coupling on inter-ion-species diffusion and momentum exchange in multi-component plasmas. Thermo-diffusion and the thermal force are found to diminish rapidly as strong coupling onsets. For the same coupling parameters, the dynamic friction coefficient is found to tend to unity. These results provide an impetus for addressing the role of coupling on diffusive processes in inertial confinement fusion experiments.

  2. PLASMA POLYMERIZATION OF ACETYLENE/CO2/H2

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ji; FANG Yuee; SHI Tianyi; SHOHEI INOUE

    1989-01-01

    A study has been made on the plasma polymerization of acetylene/CO2/H2 in a capacitively coupled RF plasma. The monomer mixture yielded a crosslinked film with light brown color. A kinetic study is reported for the plasma polymerization of acetylene/CO2/H2. The effects of discharge power level and reactor geometry on the rate of polymer formation are reported. The structure of the plasma polymer is investigated by IR study.

  3. Spectra of heliumlike carbon, aluminium and argon under strongly coupled plasma

    International Nuclear Information System (INIS)

    Spectral line positions for the highly stripped helium like carbon, aluminium and argon embedded in intense plasma environments have been calculated theoretically to compare with the existing data available from laser plasma experiments. The changes in the ionization potentials for such ions have been determined and the excitation energies, oscillator strengths and transition probabilities for the transitions 1s2 1S → 1snp 1P (n 2-5) have been evaluated for the diagnostic determination of such plasmas. The ion sphere (IS) model was used for estimating the effect of strongly coupled plasma on the ions within the non-relativistic as well as the relativistic framework. Time dependent perturbation theory has been applied for obtaining the linear response properties of the ions in the non-relativistic approximation. The effects of the plasma environment on such properties of the ions under the Debye screening model with suitable cut off radii have also been considered for comparing the data with those obtained from the IS model of the plasma. These results show that the IS model seems to be a viable method for predicting the data obtained from experiments involving strongly coupled plasmas generated in laser produced Icf plasmas

  4. Spectra of heliumlike carbon, aluminium and argon under strongly coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sil, A. [Heidelberg Univ., Theoretische Chemie (Germany); Anton, J. [Ulm Univ., Institut fur Elektrochemie (Germany); Fritzsche, S. [Gesellschaft fur Schwerionenforschung Darmstadt, Darmstadt (Germany); Mukherjee, P.K. [Indian Association for the Cultivation of Science, Jadavpur, Kolkata (India); Ramakrishna Mission Vivekananda Univ., West Bengal (India); Fricke, B. [Kassel Univ., Institut fur Physik (Germany)

    2009-12-15

    Spectral line positions for the highly stripped helium like carbon, aluminium and argon embedded in intense plasma environments have been calculated theoretically to compare with the existing data available from laser plasma experiments. The changes in the ionization potentials for such ions have been determined and the excitation energies, oscillator strengths and transition probabilities for the transitions 1s{sup 2} 1S -> 1snp {sup 1}P (n 2-5) have been evaluated for the diagnostic determination of such plasmas. The ion sphere (IS) model was used for estimating the effect of strongly coupled plasma on the ions within the non-relativistic as well as the relativistic framework. Time dependent perturbation theory has been applied for obtaining the linear response properties of the ions in the non-relativistic approximation. The effects of the plasma environment on such properties of the ions under the Debye screening model with suitable cut off radii have also been considered for comparing the data with those obtained from the IS model of the plasma. These results show that the IS model seems to be a viable method for predicting the data obtained from experiments involving strongly coupled plasmas generated in laser produced Icf plasmas

  5. Plasma cell differentiation is coupled to division-dependent DNA hypomethylation and gene regulation.

    Science.gov (United States)

    Barwick, Benjamin G; Scharer, Christopher D; Bally, Alexander P R; Boss, Jeremy M

    2016-10-01

    The epigenetic processes that regulate antibody-secreting plasma cells are not well understood. Here, analysis of plasma cell differentiation revealed DNA hypomethylation of 10% of CpG loci that were overrepresented at enhancers. Inhibition of DNA methylation enhanced plasma cell commitment in a cell-division-dependent manner. Analysis of B cells differentiating in vivo stratified by cell division revealed a fivefold increase in mRNA transcription coupled to DNA hypomethylation. Demethylation occurred first at binding motifs for the transcription factors NF-κB and AP-1 and later at those for the transcription factors IRF and Oct-2 and was coincident with activation and differentiation gene-expression programs in a cell-division-dependent manner. These data provide mechanistic insight into cell-division-coupled transcriptional and epigenetic reprogramming and suggest that DNA hypomethylation reflects the cis-regulatory history of plasma cell differentiation.

  6. Strong Helioseismic Constraints on Weakly-Coupled Plasmas

    Science.gov (United States)

    Nayfonov, Alan

    The extraordinary accuracy of helioseismic data allows detailed theoretical studies of solar plasmas. The necessity to produce solar models matching the experimental results in accuracy imposes strong constrains on the equations of state of solar plasmas. Several discrepancies between the experimental data and models have been successfully identified as the signatures of various non-ideal phenomena. Of a particular interest are questions of the position of the energy levels and the continuum edge and of the effect of the excited states in the solar plasma. Calculations of energy level and continuum shifts, based on the Green function formalism, appeared recently in the literature. These results have been used to examine effects of the shifts on the thermodynamic quantities. A comparison with helioseismic data has shown that the calculations based on lower-level approximations, such as the static screening in the effective two-particle wave equation, agree very well with the experimental data. However, the case of full dynamic screening produces thermodynamic quantities inconsistent with observations. The study of the effect of different internal partition functions on a complete set of thermodynamic quantities has revealed the signature of the excited states in the MHD (Mihalas, Hummer, Dappen) equation of state. The presence of exited states causes a characteristic 'wiggle' in the thermodynamic quantities due to the density-dependent occupation probabilities. This effect is absent if the ACTEX (ACTivity EXpansion) equation of state is used. The wiggle has been found to be most prominent in the quantities sensitive to density. The size of this excited states effect is well within the observational power of helioseismology, and very recent inversion analyses of helioseismic data seem to indicate the presence of the wiggle in the sun. This has a potential importance for the helioseismic determination of the helium abundance of the sun.

  7. Alfvén wave coupled with flow-driven fluid instability in interpenetrating plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Vranjes, J. [Instituto de Astrofisica de Canarias, 38205 La Laguna, Tenerife, Spain and Departamento de Astrofisica, Universidad de La Laguna, 38205 La Laguna, Tenerife (Spain)

    2015-05-15

    The Alfvén wave is analyzed in case of one quasineutral plasma propagating with some constant speed v{sub 0} through another static quasineutral plasma. A dispersion equation is derived describing the Alfvén wave coupled with the flow driven mode ω=kv{sub 0} and solutions are discussed analytically and numerically. The usual solutions for two oppositely propagating Alfvén waves are substantially modified due to the flowing plasma. More profound is modification of the solution propagating in the negative direction with respect to the magnetic field and the plasma flow. For a large enough flow speed (exceeding the Alfvén speed in the static plasma), this negative solution may become non-propagating, with frequency equal to zero. In this case, it represents a spatial variation of the electromagnetic field. For greater flow speed it becomes a forward mode, and it may merge with the positive one. This merging of the two modes represents the starting point for a flow-driven instability, with two complex-conjugate solutions. The Alfvén wave in interpenetrating plasmas is thus modified and coupled with the flow-driven mode and this coupled mode is shown to be growing when the flow speed is large enough. The energy for the instability is macroscopic kinetic energy of the flowing plasma. The dynamics of plasma particles caused by such a coupled wave still remains similar to the ordinary Alfvén wave. This means that well-known stochastic heating by the Alfvén wave may work, and this should additionally support the potential role of the Alfvén wave in the coronal heating.

  8. Influence of External Magnetic Field on Anomalous Skin Effects in Inductively Coupled Plasmas

    Institute of Scientific and Technical Information of China (English)

    MAO Ming; WANG You-Nian

    2004-01-01

    @@ Using a one-dimensional slab model, we study the influence of the external static magnetic field on the anomalous skin effects in the inductively coupled plasma. The rf electromagnetic field in the plasma is determined by solving the linearized Boltzmann equation incorporating with the Maxwell equations. The numerical results show that,due to the existence of the external magnetic field, the anomalous skin effects are greatly enhanced and the number of regions with negative absorption is decreased.

  9. Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

    CERN Document Server

    Bandyopadhyay, P; Sen, A; Kaw, P K

    2016-01-01

    The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and $MnO_2$ dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of $\\partial\\omega/\\partial k < 0$ are identified as signatures of dust-dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects.

  10. Two-dimensional simulation of inductively coupled plasma based on COMSOL and comparison with experimental data

    Institute of Scientific and Technical Information of China (English)

    Cheng Jia; Ji Linhong; Wang Kesheng; Han Chuankun; Shi Yixiang

    2013-01-01

    A two-dimensional axisymmetric inductively coupled plasma (ICP) model,and its implementation in the COMSOL multiphysical software,is described.The simulations are compared with the experimental results of argon discharge from the gaseous electronics conference RF reference cell in the inductively coupled plasma mode.The general trends of the number density and temperature of electrons with radial scanning are approximately correct.Finally,we discuss the reasons why the comparisons are not in agreement,and then propose an improvement in the assumptions of the Maxwellian electron energy distribution function and reaction rate.

  11. Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, P. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)], E-mail: pintu@ipr.res.in; Prasad, G.; Sen, A.; Kaw, P.K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

    2007-09-03

    The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and MnO{sub 2} dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of {partial_derivative}{omega}/{partial_derivative}k<0 are identified as signatures of dust-dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects.

  12. Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

    International Nuclear Information System (INIS)

    The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and MnO2 dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of ∂ω/∂k<0 are identified as signatures of dust-dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects

  13. Stable explicit coupling of the Yee scheme with a linear current model in fluctuating magnetized plasmas

    International Nuclear Information System (INIS)

    This work analyzes the stability of the Yee scheme for non-stationary Maxwell's equations coupled with a linear current model with density fluctuations. We show that the usual procedure may yield unstable scheme for physical situations that correspond to strongly magnetized plasmas in X-mode (TE) polarization. We propose to use first order clustered discretization of the vectorial product that gives back a stable coupling. We validate the schemes on some test cases representative of direct numerical simulations of X-mode in a magnetic fusion plasma including turbulence

  14. Stable explicit coupling of the Yee scheme with a linear current model in fluctuating magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Filipe da, E-mail: tanatos@ipfn.ist.utl.pt [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal); Pinto, Martin Campos, E-mail: campos@ann.jussieu.fr [CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Després, Bruno, E-mail: despres@ann.jussieu.fr [Sorbonne Universités, UPMC Univ Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Heuraux, Stéphane, E-mail: stephane.heuraux@univ-lorraine.fr [Institut Jean Lamour, UMR 7198, CNRS – University Lorraine, Vandoeuvre (France)

    2015-08-15

    This work analyzes the stability of the Yee scheme for non-stationary Maxwell's equations coupled with a linear current model with density fluctuations. We show that the usual procedure may yield unstable scheme for physical situations that correspond to strongly magnetized plasmas in X-mode (TE) polarization. We propose to use first order clustered discretization of the vectorial product that gives back a stable coupling. We validate the schemes on some test cases representative of direct numerical simulations of X-mode in a magnetic fusion plasma including turbulence.

  15. New approach to the calculation of relative sensitivity factors in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The relative sensitivity factors (RSFs) of 68 elements including alkali, alkaline earth, rare earth, and transition elements, Cd, B, In, Te, I in the analysis by inductively coupled plasma mass spectrometry were determined. The ionization process in an inductively coupled plasma was found to be only approximately described by the Saha-Eggert equation. A relationship between the RSFs and the absolute electronegativities of atoms of the elements was found. This factor has the strongest effect on the accuracy of calculations of RSFs for chemically active elements. The average relative systematic error of calculations of RSFs with consideration for absolute electronegativity was reduced to 0.30

  16. Numerical and Experimental Investigation on the Attenuation of Electromagnetic Waves in Unmagnetized Plasmas Using Inductively Coupled Plasma Actuator

    Science.gov (United States)

    Lin, Min; Xu, Haojun; Wei, Xiaolong; Liang, Hua; Song, Huimin; Sun, Quan; Zhang, Yanhua

    2015-10-01

    The attenuation of electromagnetic (EM) waves in unmagnetized plasma generated by an inductively coupled plasma (ICP) actuator has been investigated both theoretically and experimentally. A numerical study is conducted to investigate the propagation of EM waves in multilayer plasma structures which cover a square flat plate. Experimentally, an ICP actuator with dimensions of 20 cm×20 cm×4 cm is designed to produce a steady plasma slab. The attenuation of EM waves in the plasma generated by the ICP actuator is measured by a reflectivity arch test method at incident waves of 2.3 GHz and 10.1 GHz, respectively. A contrastive analysis of calculated and measured results of these incident wave frequencies is presented, which suggests that the experiment accords well with our theory. As expected, the plasma slab generated by the ICP actuator can effectively attenuate the EM waves, which may have great potential application prospects in aircraft stealth. supported by National Natural Science Foundation of China (Nos. 51276197, 11472306 and 11402301)

  17. Investigation of large-area multicoil inductively coupled plasma sources using three-dimensional fluid model

    Science.gov (United States)

    Brcka, Jozef

    2016-07-01

    A multi inductively coupled plasma (ICP) system can be used to maintain the plasma uniformity and increase the area processed by a high-density plasma. This article presents a source in two different configurations. The distributed planar multi ICP (DM-ICP) source comprises individual ICP sources that are not overlapped and produce plasma independently. Mutual coupling of the ICPs may affect the distribution of the produced plasma. The integrated multicoil ICP (IMC-ICP) source consists of four low-inductance ICP antennas that are superimposed in an azimuthal manner. The identical geometry of the ICP coils was assumed in this work. Both configurations have highly asymmetric components. A three-dimensional (3D) plasma model of the multicoil ICP configurations with asymmetric features is used to investigate the plasma characteristics in a large chamber and the operation of the sources in inert and reactive gases. The feasibility of the computational calculation, the speed, and the computational resources of the coupled multiphysics solver are investigated in the framework of a large realistic geometry and complex reaction processes. It was determined that additional variables can be used to control large-area plasmas. Both configurations can form a plasma, that azimuthally moves in a controlled manner, the so-called “sweeping mode” (SM) or “polyphase mode” (PPM), and thus they have the potential for large-area and high-density plasma applications. The operation in the azimuthal mode has the potential to adjust the plasma distribution, the reaction chemistry, and increase or modulate the production of the radicals. The intrinsic asymmetry of the individual coils and their combined operation were investigated within a source assembly primarily in argon and CO gases. Limited investigations were also performed on operation in CH4 gas. The plasma parameters and the resulting chemistry are affected by the geometrical relation between individual antennas. The aim of

  18. Energy Conservation Tests of a Coupled Kinetic-kinetic Plasma-neutral Transport Code

    Energy Technology Data Exchange (ETDEWEB)

    Stotler, D. P.; Chang, C. S.; Ku, S. H.; Lang, J.; Park, G.

    2012-08-29

    A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.

  19. Solid Carbon Produced in an Inductively Coupled Plasma Torch with a Titan Like Atmosphere

    Directory of Open Access Journals (Sweden)

    D. Vacher

    2013-01-01

    Full Text Available Solid carbon is deposited on the surfaces of an inductively coupled plasma torch operating with a Titan like atmosphere plasma gas. The frame of the initial research is the study of the radiative properties of plasma encountered around a spacecraft during its hypersonic entry in upper layers of planetary atmosphere. Deposition of carbon is observed not only on the quartz tube outside the inductor but also on the ceramic protection of the torch injector. Carbon exhibits two types of morphology more or less dense and it is analyzed by various analytic devices as MEB, SEM, TEM, EDS and Raman spectroscopy. The gathered carbon powder shows the presence of nanostructured particles.

  20. Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

    International Nuclear Information System (INIS)

    An investigation was made into polystyrene (PS) grafted onto nanometre silicon carbide (SiC) particles. In our experiment, the grafting polymerization reaction was induced by a radio frequency (RF) inductively coupled plasma (ICP) treatment of the nanometre powder. FTIR (Fourier transform infrared spectrum) and XPS (X-ray photoelectron spectroscopy) results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.

  1. Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

    Science.gov (United States)

    Wei, Gang; Meng, Yuedong; Zhong, Shaofeng; Liu, Feng; Jiang, Zhongqing; Shu, Xingsheng; Ren, Zhaoxing; Wang, Xiangke

    2008-02-01

    An investigation was made into polystyrene (PS) grafted onto nanometre silicon carbide (SiC) particles. In our experiment, the grafting polymerization reaction was induced by a radio frequency (RF) inductively coupled plasma (ICP) treatment of the nanometre powder. FTIR (Fourier transform infrared spectrum) and XPS (X-ray photoelectron spectroscopy) results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.

  2. Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

    Institute of Scientific and Technical Information of China (English)

    WEI Gang; MENG Yuedong; ZHONG Shaofeng; LIU Feng; JIANG Zhongqing; SHU Xingsheng; REN Zhaoxing; WANG Xiangke

    2008-01-01

    An investigation was made into polystyrene (PS) grafted onto nanometre sili-con carbide (SIC) particles. In our experiment, the grafting polymerization reaction was in-duced by a radio frequency (RF) inductively coupled plasma (ICP) treatment of the nanome-tre powder. FTIR (Fourier transform infrared spectrum) and XPS (X-ray photoelectron spec-troscopy) results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.

  3. Methane Coupling Using Hydrogen Plasma and Pt/γ-Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this paper, methane coupling at ambient temperature, under atmospheric pressure and in the presence of hydrogen was firstly investigated by using pulse corona plasma and Pt/γ-Al2O3 catalyst. Experimental results showed that Pt/γ-Al2O3 catalyst has catalytic activity for methane coupling to C2H4. Over sixty percent of outcomes of C2 hydrocarbons were detected to be ethylene.

  4. Effects of Hydrogen on the Methane Coupling under Non-equilibrium Plasma

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, hydrogen is first utilized in the study on methane coupling under nonequilibrium plasma. Results indicate that the addition of hydrogen is beneficial to the methanecoupling so as to increase the conversion rate of methane and the yield of C2 hydrocarbon with agradual increase in the addition of hydrogen in a certain range of proportionality. This conclusionexplores a new route of hydrogenated methane coupling.PACS: 52.75

  5. On conductivity type conversion of p-type silicon exposed to a low-frequency inductively coupled plasma of Ar + H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, H P; Xu, L X; Xu, S; Huang, S Y; Wei, D Y; Xiao, S Q; Yan, W S [Plasma Sources and Application Center, NIE, Nanyang Technological University, Singapore 637616 (Singapore); Xu, M, E-mail: shuyan.xu@nie.edu.s [Laboratory for Low-dimensional Structure Physics, Institute of Solid State Physics and School of Physics and Electronic Engineering, Sichuan Normal University, 5 Jing' an Road, Chengdu 610068 (China)

    2010-12-22

    The treatment of an Ar + H{sub 2} plasma generated by a low-frequency inductively coupled plasma system at 500 {sup 0}C introduces an n-type region (of average electron concentration {approx}10{sup 15} cm{sup -3}) on a Czochralski p-type substrate, forming a deep p-n junction. Examination by an electron microscope shows that the plasma treatment produces uniform nanocones on the surface and some defects, such as dislocations and platelets, in the subsurface. All these observed results are hydrogen-related. The conductivity type conversion is due to the formation of hydrogen-enhanced oxygen-related thermal donors (OTDs) as well as hydrogen-incorporated shallow thermal donors. The OTD-related signals are directly observed in the infrared absorption spectra. Both donors are annihilated after annealing at 550 {sup 0}C for 10 min, resulting in conductivity recovery from n-type to original p-type. The electrical properties of the as-formed junction are investigated using current versus voltage (I-V), capacitance versus voltage (C-V) and Hall effect measurements. On this basis, the junction depth, carrier profile and hydrogen diffusion behaviour are studied. Moreover, a clear photovoltaic effect of the junction has been observed through the Suns-Voc and illuminated I-V tests.

  6. Elemental speciation by capillary electrophoresis with inductively coupled plasma spectrometry: A new approach by flow focusing® nebulization

    OpenAIRE

    Kovachev, Nikolay; Aguirre Pastor, Miguel Ángel; Hidalgo Núñez, Montserrat; Simitchiev, Kiril; Stefanova, Violeta M.; Kmetov, Veselin Y.; Canals Hernández, Antonio

    2014-01-01

    A novel system for Capillary Electrophoresis (CE) and Inductively Coupled Plasma (ICP) sample introduction that incorporates a dedicated Flow-Focusing® based nebulizer as aerosol generation unit is presented, aiming to provide high signal sensitivity and low detection limits for element speciation at short analysis times. To prove its viability, the system prototype constructed has been coupled to an inductively coupled plasma - optical emission spectrometer (ICP-OES) and an inductively coupl...

  7. On Drag Forces and Jet Quenching in Strongly Coupled Plasmas

    CERN Document Server

    Caceres, E; Caceres, Elena; Guijosa, Alberto

    2006-01-01

    We compute the drag force experienced by a heavy quark that moves through plasma in a gauge theory whose dual description involves arbitrary metric and dilaton fields. As a concrete application, we consider the cascading gauge theory at temperatures high above the deconfining scale, where we obtain a drag force with a non-trivial velocity dependence. We compare our results with the jet-quenching parameter for the same theory, and find qualitative agreement between the two approaches. Conversely, we calculate the jet-quenching parameter for N=4 super-Yang-Mills with an R-charge density (or equivalently, a chemical potential), and compare our result with the corresponding drag force.

  8. Capacitively coupled and direct-current resistivity surveys of selected reaches of Cozad, Thirty-Mile, Orchard-Alfalfa, Kearney, and Outlet Canals in Nebraska, 2012-13

    Science.gov (United States)

    Hobza, Christopher M.; Burton, Bethany L.; Lucius, Jeffrey E.; Tompkins, Ryan E.

    2014-01-01

    Understanding the spatial characteristics of leakage from canals is critical to effectively managing and utilizing water resources for irrigation and hydroelectric purposes. Canal leakage in some parts of Nebraska is the primary source of water for groundwater recharge and helps maintain the base flow of streams. Because surface-water supplies depend on the streamflow of the Platte River and the available water stored in upstream reservoirs, water managers seek to minimize conveyance losses, which can include canal leakage. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District and Nebraska Public Power District, used capacitively coupled (CC) and direct-current (DC) resistivity techniques for continuous resistivity profiling to map near-surface lithologies near and underlying the Cozad, Thirty-Mile, Orchard-Alfalfa, Kearney, and Outlet Canals. Approximately 84 kilometers (km) of CC-resistivity data were collected along the five canals. The CC-resistivity data were compared with results from continuous sediment cores and electrical conductivity logs. Generally, the highest resistivities were recorded at the upstream reaches of the Cozad, Thirty-Mile, and Orchard-Alfalfa canals where flood-plain deposits of silt and clay mantle coarser channel deposits of sand and gravel. The finer grained deposits gradually thicken with increasing distance away from the Platte River. Consequently, for many surveyed reaches the thickness of fine-grained deposits exceeded the 8-meter depth of investigation. A detailed geophysical investigation along a 5-km reach of the Outlet Canal southwest of North Platte, Nebraska, used CC and DC resistivity to examine the condition of a compacted-core bank structure and characterized other potential controls on areas of focused seepage. CC-resistivity data, collected along the 5-km study reach, were compared with continuous sediment cores and DC-resistivity data collected near a selected seep near Outlet

  9. Inductively coupled plasma-atomic emission spectroscopy: The determination of trace impurities in uranium hexafluoride

    Science.gov (United States)

    Floyd, M. A.; Morrow, R. W.; Farrar, R. B.

    An analytical method has been developed for the determination of trace impurities in high-purity uranium hexafluoride using liquid-liquid extraction of the uranium from the trace impurities followed by analysis with inductively coupled plasma-atomic emission spectroscopy. Detection limits, accuracy, and precision data are presented.

  10. Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

    Science.gov (United States)

    Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

    2016-01-01

    Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

  11. Longitudinal Waves in Strongly Coupled Magnetized Dusty Plasma with Dust Charging Relaxation

    Institute of Scientific and Technical Information of China (English)

    谢柏松

    2002-01-01

    Low-frequency longitudinal dust waves in strongly coupled magnetized dusty plasmas are investigated. The dustcharging relaxation is taken into account. It is found that the frequency and damping of dust waves are modifiedsignificantly due to the existence of the magnetic field as well as the effect of dust charging.

  12. Thorium determination in thorotrast patient organs using inductively coupled plasma mass spectrometry and imaging plate autoradiography

    International Nuclear Information System (INIS)

    In this study inductively coupled plasma mass spectrometry (ICP-MS) have been used for the determination of Th in liver and spleen collected from autopsy subjects in Thorotrast patients to obtain useful information for dosimetry. The applicability of an imaging plate autoradiography technique for the determination of thorium distributions in organs to obtain information related to microdosimetry has also been evaluated

  13. Simultaneous multielement analysis of rock samples by inductively coupled plasma mass spectrometry using discrete microsampling technique

    International Nuclear Information System (INIS)

    Simultaneous multielement analysis of geological standard rock samples (JG-1 and JB-2) has been successfully performed by inductively coupled plasma mass spectrometry using a discrete microsampling technique. In this technique only 100 μl sample solution was used for simultaneous determination of 5-10 elements in solution. (author)

  14. Ignition delay of a pulsed inductively coupled plasma (ICP) in tandem with an auxiliary ICP

    Science.gov (United States)

    Liu, Lei; Sridhar, Shyam; Donnelly, Vincent M.; Economou, Demetre J.

    2015-12-01

    Plasma ignition delays were observed in a ‘main’ inductively coupled plasma (ICP), in tandem with an ‘auxiliary’ ICP. The Faraday-shielded ICPs were separated by a grounded metal grid. Power (13.56 MHz) to the main ICP was pulsed with a frequency of 1 kHz, while the auxiliary ICP was operated in continuous wave (cw) mode. In chlorine plasmas, ignition delay was observed for duty cycles greater than 60% and, in contrast to expectation, the delay was longer with increasing duty cycle up to ~99.5%. The ignition delay could be varied by changing the auxiliary and/or main ICP power. Langmuir probe measurements provided the temporal evolution of electron temperature, and electron and positive ion densities. These measurements revealed that the plasma was ignited shortly after the decaying positive ion density (n +), in the afterglow of the main ICP, reached the density ({{n}+},\\text{aux} ) prevailing when only the auxiliary ICP was powered. At that time, production of electrons began to dominate their loss in the main ICP, due to hot electron injection from the auxiliary ICP. As a result, {{n}\\text{e}} increased from a value below {{n}\\text{e,\\text{aux}}} , improving inductive power coupling efficiency, further increasing plasma density leading to plasma ignition. Plasma ignition delay occurred when the afterglow of the pulsed plasma was not long enough for the ion density to reach {{n}+},\\text{aux} during the afterglow. Besides Cl2, plasma ignition delays were also observed in other electronegative gases (SF6, CF4/O2 and O2) but not in an electropositive gas (Ar).

  15. Resistive wall mode and neoclassical tearing mode coupling in rotating tokamak plasmas

    CERN Document Server

    McAdams, Rachel; Chapman, I T

    2013-01-01

    A model system of equations has been derived to describe a toroidally rotating tokamak plasma, unstable to Resistive Wall Modes (RWMs) and metastable to Neoclassical Tearing Modes (NTMs), using a linear RWM model and a nonlinear NTM model. If no wall is present, the NTM growth shows the typical threshold/saturation island widths, whereas a linearly unstable kink mode grows exponentially in this model plasma system. When a resistive wall is present, the growth of the linearly unstable RWM is accelerated by an unstable island: a form of coupled RWM-NTM mode. Crucially, this coupled system has no threshold island width, giving the impression of a triggerless NTM, observed in high beta tokamak discharges. In addition, increasing plasma rotation at the island location can mitigate its growth, but does not restore the threshold width.

  16. Experimental measurement of non-Markovian dynamics and self-diffusion in a strongly coupled plasma

    CERN Document Server

    Strickler, T S; McQuillen, P; Daligault, J; Killian, T C

    2015-01-01

    We present a study of the collisional relaxation of ion velocities in a strongly coupled, ultracold neutral plasma on short timescales compared to the inverse collision rate. Non-exponential decay towards equilibrium for the average velocity of a tagged population of ions heralds non-Markovian dynamics and a breakdown of assumptions underlying standard kinetic theory. We prove the equivalence of the average-velocity curve to the velocity autocorrelation function, a fundamental statistical quantity that provides access to equilibrium transport coefficients and aspects of individual particle trajectories in a regime where experimental measurements have been lacking. From our data, we calculate the ion self-diffusion constant. This demonstrates the utility of ultracold neutral plasmas for isolating the effects of strong coupling on collisional processes, which is of interest for dense laboratory and astrophysical plasmas.

  17. Lithium Iron Phosphate Powders and Coatings Obtained by Means of Inductively Coupled Thermal Plasma

    Science.gov (United States)

    Major, K.; Veilleux, J.; Brisard, G.

    2016-01-01

    Lithium-ion batteries have high energy efficiency and good cycling life and are considered as one of the best energy storage device for hybrid and/or electrical vehicle. Still, several problems must be solved prior to a broad adoption by the automotive industry: energy density, safety, and costs. To enhance both energy density and safety, the current study aims at depositing binder-free cathode materials using inductively coupled thermal plasma. In a first step, lithium iron phosphate (LiFePO4) powders are synthesized in an inductively coupled thermal plasma reactor and dispersed in a conventional polyvinylidene fluoride (PVDF) binder. Then, binder-free LiFePO4 coatings are directly deposited onto nickel current collectors by solution precursor plasma spraying (SPPS). The morphology, microstructure, and composition of the synthesized LiFePO4 powders and coatings are fully characterized by electronic microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy (XPS). Quantifying Li with XPS requires the substitution of iron with manganese in the SPPS precursors (LiMPO4, where M = Fe or Mn). The plasma-derived cathodes (with and without PVDF binder) are assembled in button cells and tested. Under optimized plasma conditions, cyclic voltammetry shows that the electrochemical reversibility of plasma-derived cathodes is improved over that of conventional sol-gel-derived LiFePO4 cathodes.

  18. Plasma-Chemical Synthesis of Oxide Powders Using Transformer-Coupled Discharge

    International Nuclear Information System (INIS)

    An experimental investigation of transformer-coupled discharge in an Ar-O2 mixture with the addition of SiCl4, TiCl4 and ZrCl4 has been carried out under the atmospheric pressure of plasma-forming gases. Discharge power and discharge heat losses have been determined, and the dispersion and phase composition of reaction products (oxide powders) has been analyzed with SEM and X-ray diffraction analysis. Investigations reveal the formation of ultrafine oxide powders in the case of vaporized chloride (SiCl4 and TiCl4) injecting into the transformer coupled discharge. In the case of fine powder (ZrCl4) injection, full oxidation was not observed and reaction products consisted of a mixture of ZrO2 and ZrOCl2. A conclusion has been made regarding the perspectives of using transformer-coupled discharge to produce ultrafine oxide powders. (plasma technology)

  19. Momentum transport in strongly coupled anisotropic plasmas in the presence of strong magnetic fields

    CERN Document Server

    Finazzo, Stefano Ivo; Rougemont, Romulo; Noronha, Jorge

    2016-01-01

    We present a holographic perspective on momentum transport in strongly coupled, anisotropic non-Abelian plasmas in the presence of strong magnetic fields. We compute the anisotropic heavy quark drag forces and Langevin diffusion coefficients and also the anisotropic shear viscosities for two different holographic models, namely, a top-down deformation of strongly coupled $\\mathcal{N} = 4$ Super-Yang-Mills (SYM) theory triggered by an external Abelian magnetic field, and a bottom-up Einstein-Maxwell-dilaton (EMD) model which is able to provide a quantitative description of lattice QCD thermodynamics with $(2+1)$-flavors at both zero and nonzero magnetic fields. We find that, in general, energy loss and momentum diffusion through strongly coupled anisotropic plasmas are enhanced by a magnetic field being larger in transverse directions than in the direction parallel to the magnetic field. Moreover, the anisotropic shear viscosity coefficient is smaller in the direction of the magnetic field than in the plane pe...

  20. Shear viscosity of two-dimensional strongly coupled complex (dusty) plasmas

    International Nuclear Information System (INIS)

    A molecular dynamics method has been employed of studying shear viscosity for two-dimensional plasma liquids. For the entire range of strongly coupled liquid states, shear autocorrelation functions indicate overall valid viscosity coefficients. A systematic dependence of shear viscosity value on screening strength (appa) is observed for an intermediate and higher Coulomb coupling strengths (gamma). The simulation data indicate that the position of the viscosity value shifts towards higher gamma as appa increases. It is observed that valid viscosity coefficient exists and it is dependent on plasma parameters (gamma, appa). A finite minimum viscosity exists nearly at the same value of T where the most extreme super-diffusion was earlier found and is reported for a wide range of coupling and screening parameters. (author)

  1. Shear viscosity of two-dimensional strongly coupled complex (dusty) plasmas

    International Nuclear Information System (INIS)

    A molecular dynamics method has been employed of studying shear viscosity for two-dimensional plasma liquids. For the entire range of strongly coupled liquid states, shear autocorrelation functions indicate overall valid viscosity coefficients. A systematic dependence of shear viscosity value on screening strength (κ) is observed for an intermediate and higher Coulomb coupling strengths (Γ). The simulation data indicate that the position of the viscosity value shifts towards higher Γ as κ increases. It is observed that valid viscosity coefficient exists and it is dependent on plasma parameters (Γ, κ). A finite minimum viscosity exists nearly at the same value of T where the most extreme super-diffusion was earlier found and is reported for a wide range of coupling and screening parameters

  2. 脉冲调制射频容性耦合SiH/C2H4/Ar放电的发射光谱诊断%Optical emission spectrometry diagnosis of pulse-modulated RF capacitive coupling discharge in SiH4/C2H4/Ar

    Institute of Scientific and Technical Information of China (English)

    张娇; 张鹏云

    2011-01-01

    Characteristics of pulse-modulated capacitive coupling plasmas in SiH4/C2H4/Ar gas mixture were diagnosed by optical emission spectroscopy.The electron excitation temperature of plasmas was calculated with the five Ar emission spectral lines by Boltzmann slope method.Then, the dependence of the excitation temperature and relative emission intensity on the discharge power, duty cycle, modulation frequency and gas pressure were presented.%本文采用发射光谱法诊断了低气压下氩气(Ar)、硅烷(SiH4)及乙烯(C2H4)混合气体(SiH4/C2H4/Ar)脉冲调制射频放电等离子体特性,利用了Ar发射光谱中的五条谱线通过Boltzmann斜率法计算了电子激发温度,研究了占空比、调制频率、功率及气压等对电子激发温度和谱线相对强度的影响.

  3. New Applications of Inductively Coupled Plasma-Mass Spectrometry in the Nuclear Industry

    Energy Technology Data Exchange (ETDEWEB)

    Rob Henry; Dagmar Koller; Phil Marriott

    1998-12-31

    Inductively coupled plasma mass spectrometry (ICP-MS) complements the traditional methods of quantitation of radioactive isotopes. Because of the favorable ionization potential of most actinides and their daughter products, the argon plasma provides a rich, stable source of ions, which are introduced through a plasma-mass spectrometer interface into the mass spectrometer for isotopic separation. Samples are normally introduced in solution, although direct solids analysis has also been achieved using laser ablation of the sample into the argon plasma. Since 1983, improvements in ICP-MS sensitivity have resulted in correspondingly lower mass detection capability. This development has in turn expanded the number of isotopes accessible to measurement at the levels required in the nuclear industry.

  4. Ab-initio calculations on two-electron ions in strongly coupled plasma environment

    CERN Document Server

    Bhattacharyya, S; Mukherjee, T K

    2015-01-01

    In this work, the controversy between the interpretations of recent measurements on dense aluminum plasma created with Linac coherent light sources (LCLS) X-ray free electron laser (FEL) and Orion laser has been addressed. In both kind of experiments, helium-like and hydrogen-like spectral lines are used for plasma diagnostics . However, there exist no precise theoretical calculations for He-like ions within dense plasma environment. The strong need for an accurate theoretical estimates for spectral properties of He-like ions in strongly coupled plasma environment leads us to perform ab initio calculations in the framework of Rayleigh-Ritz variation principle in Hylleraas coordinates where ion-sphere potential is used. An approach to resolve the long-drawn problem of numerical instability for evaluating two-electron integrals with extended basis inside a finite domain is presented here. The present values of electron densities corresponding to disappearance of different spectral lines obtained within the fram...

  5. Single laser pulse compression via strongly coupled stimulated Brillouin scattering in plasma

    Science.gov (United States)

    Peng, H.; Wu, Z. H.; Zuo, Y. L.; Zhang, Z. M.; Zhou, K. N.; Su, J. Q.

    2016-07-01

    Laser amplification in plasma, including stimulated Raman scattering amplification and strongly coupled stimulated Brillouin scattering (sc-SBS) amplification, is very promising to generate ultrahigh-power and ultrashort laser pulses. But both are quite complex in experiments: at least three different laser pulses must be prepared; temporal delay and spatial overlap of these three pulses are difficult. We propose a single pulse compression scheme based on sc-SBS in plasma. Only one moderately long laser is applied, the front part of which ionizes the gas to produced plasma, and gets reflected by a plasma mirror at the end of the gas channel. The reflected front quickly depletes the remaining part of the laser by sc-SBS in the self-similar regime. The output laser is much stronger and shorter. This scheme is at first considered theoretically, then validated by using 1D PIC simulations.

  6. Ion kinetic energies in inductively coupled plasma/mass spectrometry (ICP-MS)

    International Nuclear Information System (INIS)

    Ion kinetic energies in an inductively coupled plasma/mass spectrometer (ICP-MS) system have been measured with the use of a retarding potential on the analyzing quadrupole. The energies differ markedly from those previously reported in the literature. This is attributed to the elimination of any arcing of the ICP to the sampling orifice or skimmer of the ICP-MS system. In the absence of secondary discharge effects, the ion energies increase with the mass of the ion and are consistent with those expected from molecular beam sampling from a plasma with a temperature of --5000 K and a potential of --2 V. Ion energies are found to be virtually independent of aerosol gas flow, plasma power, and sample matrix composition, allowing independent optimization of plasma parameters and ion optics

  7. An argon–nitrogen–hydrogen mixed-gas plasma as a robust ionization source for inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Makonnen, Yoseif; Beauchemin, Diane, E-mail: diane.beauchemin@chem.queensu.ca

    2014-09-01

    Multivariate optimization of an argon–nitrogen–hydrogen mixed-gas plasma for minimum matrix effects, while maintaining analyte sensitivity as much as possible, was carried out in inductively coupled plasma mass spectrometry. In the presence of 0.1 M Na, the 33.9 ± 3.9% (n = 13 elements) analyte signal suppression on average observed in an all-argon plasma was alleviated with the optimized mixed-gas plasma, the average being − 4.0 ± 8.8%, with enhancement in several cases. An addition of 2.3% v/v N{sub 2} in the outer plasma gas, and 0.50% v/v H{sub 2} to the central channel, as a sheath around the nebulizer gas flow, was sufficient for this drastic increase in robustness. It also reduced the background from ArO{sup +} and Ar{sub 2}{sup +} as well as oxide levels by over an order of magnitude. On the other hand, the background from NO{sup +} and ArN{sup +} increased by up to an order of magnitude while the levels of doubly-charged ions increased to 7% (versus 2.7% in an argon plasma optimized for sensitivity). Furthermore, detection limits were generally degraded by 5 to 15 fold when using the mixed-gas plasma versus the argon plasma for matrix-free solution (although they were better for several elements in 0.1 M Na). Nonetheless, the drastically increased robustness allowed the direct quantitative multielement analysis of certified ore reference materials, as well as the determination of Mo and Cd in seawater, without using any matrix-matching or internal standardization. - Highlights: • Addition of N{sub 2} to the plasma gas and H{sub 2} as a sheath gas results in a very robust ICP. • ArO{sup +} and Ar{sub 2}{sup +} background and oxide levels are reduced by over an order of magnitude. • Multielement analysis of rock digests is possible with a simple external calibration. • No internal standardization or matrix-matching is required for accurate analysis. • Cd and Mo were accurately determined in undiluted seawater.

  8. An argon–nitrogen–hydrogen mixed-gas plasma as a robust ionization source for inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Multivariate optimization of an argon–nitrogen–hydrogen mixed-gas plasma for minimum matrix effects, while maintaining analyte sensitivity as much as possible, was carried out in inductively coupled plasma mass spectrometry. In the presence of 0.1 M Na, the 33.9 ± 3.9% (n = 13 elements) analyte signal suppression on average observed in an all-argon plasma was alleviated with the optimized mixed-gas plasma, the average being − 4.0 ± 8.8%, with enhancement in several cases. An addition of 2.3% v/v N2 in the outer plasma gas, and 0.50% v/v H2 to the central channel, as a sheath around the nebulizer gas flow, was sufficient for this drastic increase in robustness. It also reduced the background from ArO+ and Ar2+ as well as oxide levels by over an order of magnitude. On the other hand, the background from NO+ and ArN+ increased by up to an order of magnitude while the levels of doubly-charged ions increased to 7% (versus 2.7% in an argon plasma optimized for sensitivity). Furthermore, detection limits were generally degraded by 5 to 15 fold when using the mixed-gas plasma versus the argon plasma for matrix-free solution (although they were better for several elements in 0.1 M Na). Nonetheless, the drastically increased robustness allowed the direct quantitative multielement analysis of certified ore reference materials, as well as the determination of Mo and Cd in seawater, without using any matrix-matching or internal standardization. - Highlights: • Addition of N2 to the plasma gas and H2 as a sheath gas results in a very robust ICP. • ArO+ and Ar2+ background and oxide levels are reduced by over an order of magnitude. • Multielement analysis of rock digests is possible with a simple external calibration. • No internal standardization or matrix-matching is required for accurate analysis. • Cd and Mo were accurately determined in undiluted seawater

  9. On-line elemental analysis of fossil fuel process streams by inductively coupled plasma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, W.P.

    1995-06-01

    METC is continuing development of a real-time, multi-element plasma based spectrometer system for application to high temperature and high pressure fossil fuel process streams. Two versions are under consideration for development. One is an Inductively Coupled Plasma system that has been described previously, and the other is a high power microwave system. The ICP torch operates on a mixture of argon and helium with a conventional annular swirl flow plasma gas, no auxiliary gas, and a conventional sample stream injection through the base of the plasma plume. A new, demountable torch design comprising three ceramic sections allows bolts passing the length of the torch to compress a double O-ring seal. This improves the reliability of the torch. The microwave system will use the same data acquisition and reduction components as the ICP system; only the plasma source itself is different. It will operate with a 750-Watt, 2.45 gigahertz microwave generator. The plasma discharge will be contained within a narrow quartz tube one quarter wavelength from a shorted waveguide termination. The plasma source will be observed via fiber optics and a battery of computer controlled monochromators. To extract more information from the raw spectral data, a neural net computer program is being developed. This program will calculate analyte concentrations from data that includes analyte and interferant spectral emission intensity. Matrix effects and spectral overlaps can be treated more effectively by this method than by conventional spectral analysis.

  10. A novel double hohlraum target to create a moderately coupled plasma for ion stopping experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ortner, A., E-mail: a.ortner@gsi.de [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany); Helmholtz International Center for FAIR (HIC for FAIR), Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Faik, S. [Goethe-Universität Frankfurt am Main, Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); Schumacher, D. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Basko, M.M. [Keldysh Institute of Applied Mathematics (KIAM), Miusskaya sq. 4, 125047 Moscow (Russian Federation); Helmholtz International Center for FAIR (HIC for FAIR), Max-von-Laue-Str. 1, 60438 Frankfurt am Main (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Blazevic, A. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Busold, S. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany); GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Bedacht, S. [Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt (Germany); Cayzac, W. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); and others

    2015-01-15

    We present a new double hohlraum target for the creation of a moderately coupled (0.1<Γ<1) carbon plasma for energy loss and charge state measurements of projectile ions interacting with this plasma. A spherical cavity of 600μm in diameter is heated with a 150-J laser pulse (λ{sub L}=527nm) within 1.2ns to produce a quasi-Planckian X-ray source with a radiation temperature of T{sub r}≈100eV. These X-rays are then used to heat volumetrically two thin carbon foils in a secondary cylindrical hohlraum to a dense plasma state. An axi-symmetric plasma column with a free-electron density of up to 8×10{sup 21}cm{sup -3}, a temperature of T≈10 eV, and an average ionization degree of Z≈3 is generated. This plasma stays in a dense and an almost uniform state for about 5ns. Ultimately, such targets are supposed to be used in experiments where a heavy ion beam is launched through the sample plasma, and the ion energy losses as well as the charge distributions are to be measured. The present paper is in a certain sense a symbiotic one, where the theoretical analysis and the experimental results are combined to investigate the basic properties and the prospects of this type of plasma targets.

  11. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    International Nuclear Information System (INIS)

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described

  12. Josephson coupling, phase correlations, and Josephson plasma resonance in vortex liquid phase

    International Nuclear Information System (INIS)

    Josephson plasma resonance (JPR) has been introduced recently as a powerful tool to probe interlayer Josephson coupling in different regions of the vortex phase diagram in layered superconductors. In the liquid phase, the high-temperature expansion with respect to the Josephson coupling connects the Josephson plasma frequency with the phase correlation function. This function, in turn, is directly related to the pair distribution function of the liquid. We develop a recipe to extract the phase and density correlation functions from the dependencies of the plasma resonance frequency ωp(B) and the c-axis conductivity σc(B) on the ab component of the magnetic field at fixed c component. Using Langevin dynamic simulations of two-dimensional vortex arrays we calculate density and phase correlation functions at different temperatures. Calculated phase correlations describe very well the experimental angular dependence of the plasma resonance field. We also demonstrate that in the case of weak damping in the liquid phase, broadening of the JPR line is caused mainly by random Josephson coupling arising from the density fluctuations of pancake vortices. In this case the JPR line has a universal shape, which is determined only by parameters of the superconductors and temperature

  13. Direct solid soil analysis by laser ablation inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Determination of heavy metals in soils by inductively coupled plasma atomic emission spectrometry (ICP-AES) usually involves the time-consuming step of preparing a solution of the solid that is then nebulized into the plasma. According to regulations, digestion by aqua regia(hydrochloric acid + nitric acid, 3 + 1) should be carried out although it is known that this method is incomplete for silicate soils. The problem can be eliminated by introducing the solid directly into the plasma using the laser ablation technique for sampling. Results are described for a study of laser ablation using a Q-switched Nd: YAG laser coupled with a new échelle spectrometer which has a multichannel solid-state detector. The laser pulses were focused onto the solid surface of pressed soil samples to generate an aerosol which is entrained in a flowing Ar stream, transported through a tube and then introduced directly into the inductively coupled plasma. Some characteristics of the preparation technique, the selection of an internal standard and homogeneity tests of the elemental distribution are reported along with a comparison and evaluation of three methods of calibration. The criteria used to measure the performance of laser ablation ICP-AES are the relative standard deviations obtained of 4.9–12.7% and the accuracy, 0.3–12.4% for Fe, Mn, Cu, Pb, Cr, Zn and Ni

  14. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez, Raquel [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Todolí, José Luis, E-mail: jose.todoli@ua.es [Department of Analytical Chemistry, Nutrition and Food Sciences, P.O. Box 99, 03080, Alicante (Spain); Lienemann, Charles-Philippe [IFP Energies Nouvelles, Rond-point de l' échangeur de Solaize, BP 3, F-69360 Solaize (France); Mermet, Jean-Michel [Spectroscopy Forever, 01390 Tramoyes (France)

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described.

  15. Study on the O2 Plasma Treatment of Indium Tin Oxide for Organic Light Emitting Diodes Using Inductively Coupled Plasma

    Science.gov (United States)

    Jeong, Chang Hyun; Lee, June Hee; Lim, Jong Hyeuk; Lim, Jong Tae; Yeom, Geun Young

    2006-04-01

    In this study, the effect of O2 inductively coupled plasma (ICP) conditions for the indium tin oxide (ITO) surface treatment on the organic light emitting diode (OLED) device performances were investigated. By the O2 plasma treatment of ITO glass, better OLED device performances such as a lower turn-on voltage, a higher luminescence, and a higher power efficiency could be obtained and the use of lower oxygen pressure and higher ICP power improved the device properties further. DC-biasing of the ITO glass substrate degraded the device properties. The use of lower oxygen pressure and higher ICP power increased the densities of O2+ and O* in the plasma, and the plasma-treated ITO surface showed a lower carbon, a higher O/(Sn+In), and a higher Sn4+/In for the condition of lower oxygen pressure and higher ICP power. The improved OLED device properties with the ITO treated at the higher ICP power and the lower pressure appear to be from the increased hole injection to the OLED materials by decreasing the resistance of ITO and by increasing the work function of the ITO.

  16. Plasma sterilization of Geobacillus Stearothermophilus by O{mathsf2}:N{mathsf2} RF inductively coupled plasma

    Science.gov (United States)

    Kylián, O.; Sasaki, T.; Rossi, F.

    2006-05-01

    The aim of this work is to identify the main process responsible for sterilization of Geobacillus Stearothermophilus spores in O{2}:N{2} RF inductively coupled plasma. In order to meet this objective the sterilization efficiencies of discharges in mixtures differing in the initial O{2}/N{2} ratios are compared with plasma properties and with scanning electron microscopy images of treated spores. According to the obtained results it can be concluded that under our experimental conditions the time needed to reach complete sterilization is more related to O atom density than UV radiation intensity, i.e. complete sterilization is not related only to DNA damage as in UV sterilization but more likely to the etching of the spore.

  17. Non-Markovian Dynamics and Self-Diffusion in Strongly Coupled Plasmas

    Science.gov (United States)

    Strickler, Trevor; Langin, Thomas; McQuillen, Patrick; Daligault, Jerome; Maksimovich, Nikola; Killian, Thomas

    2015-11-01

    In weakly coupled plasmas, collisions are dominated by long range, small angle scattering, and each collision is an uncorrelated binary event. In contrast, collisions in strongly coupled plasmas (coupling parameter Γ > 1) are dominated by short range, large angle scattering in which the collisions may be correlated and non-independent in time, i.e., non-Markovian. In this work, we present experimental results indicative of non-Markovian processes in a strongly coupled ultracold neutral plasma (UCNP) created by photoionizing strontium atoms in a magneto-optical trap. We use optical pumping to create spin ``tagged'' subpopulations of ions having non-zero average velocity , and use laser induced fluorescence (LIF) imaging to measure the relaxation of back to equilibrium. We observe clear non-exponential decay in , which indicates non-Markovian dynamics. We further demonstrate there is a theoretical basis to consider as an approximation to the ion velocity autocorrelation function (VAF). We then calculate diffusion coefficients from our data, demonstrating experimental measurement of self-diffusion coefficients for 0 . 3 Air Force Office of Scientific Research (FA9550- 12-1-0267).

  18. Linear and nonlinear heavy ion-acoustic waves in a strongly coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ema, S. A., E-mail: ema.plasma@gmail.com; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh); Hossen, M. R. [Deparment of Natural Sciences, Daffodil International University, Sukrabad, Dhaka-1207 (Bangladesh)

    2015-09-15

    A theoretical study on the propagation of linear and nonlinear heavy ion-acoustic (HIA) waves in an unmagnetized, collisionless, strongly coupled plasma system has been carried out. The plasma system is assumed to contain adiabatic positively charged inertial heavy ion fluids, nonextensive distributed electrons, and Maxwellian light ions. The normal mode analysis is used to study the linear behaviour. On the other hand, the well-known reductive perturbation technique is used to derive the nonlinear dynamical equations, namely, Burgers equation and Korteweg-de Vries (K-dV) equation. They are also numerically analyzed in order to investigate the basic features of shock and solitary waves. The adiabatic effects on the HIA shock and solitary waves propagating in such a strongly coupled plasma are taken into account. It has been observed that the roles of the adiabatic positively charged heavy ions, nonextensivity of electrons, and other plasma parameters arised in this investigation have significantly modified the basic features (viz., polarity, amplitude, width, etc.) of the HIA solitary/shock waves. The findings of our results obtained from this theoretical investigation may be useful in understanding the linear as well as nonlinear phenomena associated with the HIA waves both in space and laboratory plasmas.

  19. Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

    2000-01-01

    measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...... than 2% in this range. The estimated limit of detection was 2 mu g/l and the experimentally verified quantification limit was 5 mu g/l, giving a relative standard deviation less than 2%. (C) 2000 Elsevier Science B.V. All rights reserved...

  20. Stability of an elliptical vortex in a strongly coupled dusty plasma

    Science.gov (United States)

    Jana, Sayanee; Banerjee, Debabrata; Chakrabarti, Nikhil

    2015-08-01

    The stability of a long scale equilibrium vortex structure to short scale perturbations is studied in a strongly coupled dusty plasma in the framework of a generalized hydrodynamic model. It is shown that the free energy associated with the velocity shear of the vortex can drive secondary instabilities consisting of transverse shear waves when the resonance condition between the vortex rotation frequency and the secondary wave frequency is met. Such a process can transfer energy from the long scale vortex to the short scale secondary wave and thereby provide a saturation mechanism for long scale vortices in plasmas in a manner analogous to that in neutral fluids.

  1. Line photon transport in a non-homogeneous plasma using radiative coupling coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P. [Las Palmas de Gran Canaria Univ., Dept. de Fisica (Spain); Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Minguez, E. [Madrid Univ. Politecnica, Instituto de Fusion Nuclear-DENIM (Spain)

    2006-06-15

    We present a steady-state collisional-radiative model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature, but the main difference between our model and those ones is that the details of geometry are exactly treated in the definition of coupling coefficients and a local profile is taken into account in each plasma cell. (authors)

  2. Instability and dynamics of two nonlinearly coupled laser beams in a plasma

    CERN Document Server

    Shukla, P K; Marklund, M; Stenflo, L; Kourakis, I; Parviainen, M; Dieckmann, M E

    2006-01-01

    We investigate the nonlinear interaction between two laser beams in a plasma in the weakly nonlinear and relativistic regime. The evolution of the laser beams is governed by two nonlinear Schroedinger equations that are coupled with the slow plasma density response. We study the growth rates of the Raman forward and backward scattering instabilities as well of the Brillouin and self-focusing/modulational instabilities. The nonlinear evolution of the instabilities is investigated by means of direct simulations of the time-dependent system of nonlinear equations.

  3. Kinetic theory of the shear viscosity of a strongly coupled classical one-component plasma

    International Nuclear Information System (INIS)

    We present an approximation to the linearized collision operator or memory function of the exact kinetic equation obeyed by the correlation function of the phase-space density of a classical one-component plasma. This approximate collision operator generalizes the well known Balescu-Guernsey-Lenard (BGL) operator to finite wavelengths, finite frequencies, and finite coupling constants. It, moreover, satisfies the necessary symmetry relations, leads to appropriate conservation laws, and fulfills its first sum rule exactly. Next we use this operator to compute the shear viscosity eta for a series of coupling constants spanning the whole fluid phase. For weak coupling we make contact with the BGL theory, while for strong coupling we confirm, at least qualitatively, the results of Vieillefosse and Hansen, who predicted a minimum in eta as a function of temperature. We also demonstrate the important role played by the sum rules in the quantitative evaluation of a transport coefficient such as eta

  4. Partons and Jets in a Strongly-Coupled Plasma from AdS/CFT

    Science.gov (United States)

    Iancu, E.

    2008-12-01

    We give a pedagogical review of recent progress towards understanding the response of a strongly coupled plasma at finite temperature to a hard probe. The plasma is that of the N=4 supersymmetric Yang-Mills theory and the hard probe is a virtual photon, or, more precisely, an R-current. Via the gauge/gravity duality, the problem of the current interacting with the plasma is mapped onto the gravitational interaction between a Maxwell field and a black hole embedded in the AdS5×S5 geometry. The physical interpretation of the AdS/CFT results can be then reconstructed with the help of the ultraviolet/infrared correspondence. We thus deduce that, for sufficiently high energy, the photon (or any other hard probe: a quark, a gluon, or a meson) disappears into the plasma via a universal mechanism, which is medium-induced quasi-democratic parton branching: the current develops a parton cascade such that, at any step in the branching process, the energy is almost equally divided among the daughter partons. The branching rate is controlled by the plasma which acts on the coloured partons with a constant force sim T2. When reinterpreted in the plasma infinite momentum frame, the same AdS/CFT results suggest a parton picture for the plasma structure functions, in which all the partons have fallen at very small values of Bjorken's x. For a time-like current in the vacuum, quasi-democratic branching implies that there should be no jets in electron-positron annihilation at strong coupling, but only a spatially isotropic distribution of hadronic matter.

  5. Radio-frequency inductively coupled plasma-chemical installation for preparation of nanodispersed powders

    International Nuclear Information System (INIS)

    Full text: The wide application of radio-frequency inductively coupled plasma (rf-ICP) is due to the following. Rf-ICPs are clean because these types of plasma do not use any electrode and, hence, are contamination free. Rf-ICPs are stable and can be used over a wide range of operating conditions. They have relatively large volumes and low plasma velocities, which result in complete melting of the solid materials in materials processing because of the longer residence time. The preciseness of the rf-ICPs is important in determining contamination effects (which inevitably occur because of electrode evaporation and nozzle ablation) on gas circuit breaker arcs as well as to predict plasma properties for all materials processing, and any gas or mixture of gases can be excited by the rf fields, so there is wide flexibility when choosing plasma gas(es) depending on the type of application [1].; The experimental plasma set-up used for the production of nanosized powders (carbides, carbon nano-structures (nanotubes, fullerenes), oxides, nitrides, catalysts, pigments, etc.) consists of a radio-frequency generator (maximum power 60 kW, frequency 1+30 MHz), a water-cooled quartz plasma-chemical reactor with inductor, raw powder and gas supply systems, a gas quenching device, heat exchangers and cloth filter for powder collection. Ar, N2, Ar+N2, air, air+O2, and Ar+H2 can be used as plasma-forming gases. The quenching gases are air, Ar, N2, and CO2. The raw powder is injected into the upper part of the plasma-chemical reactor. A chemical reaction is carried out in the reactor and after complete evaporation of the micron size powder, it enters the quenching device. After that, the nanosized product is captured by the heat exchangers and cloth filter

  6. Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (Te) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (ne) is in the range 108--1010-cm at the skimmer tip and drops abruptly to 106--108 cm-3 near the skimmer tip and drops abruptly to 106--108 cm-3 downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 104--105 downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z2 intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z2 fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument

  7. The concept of coupling impedance in the self-consistent plasma wake field excitation

    Science.gov (United States)

    Fedele, R.; Akhter, T.; De Nicola, S.; Migliorati, M.; Marocchino, A.; Massimo, F.; Palumbo, L.

    2016-09-01

    Within the framework of the Vlasov-Maxwell system of equations, we describe the self-consistent interaction of a relativistic charged-particle beam with the surroundings while propagating through a plasma-based acceleration device. This is done in terms of the concept of coupling (longitudinal) impedance in full analogy with the conventional accelerators. It is shown that also here the coupling impedance is a very useful tool for the Nyquist-type stability analysis. Examples of specific physical situations are finally illustrated.

  8. Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasmas

    Science.gov (United States)

    Choudhary, Mangilal; Mukherjee, S.; Bandyopadhyay, P.

    2016-05-01

    A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current glow discharge. These dust particles are found to get trapped in an electrostatic potential well, which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self-excited dust acoustic waves, and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust particle, and some of the preliminary experimental results are presented.

  9. Surface characterization of hydrophobic thin films deposited by inductively coupled and pulsed plasmas

    International Nuclear Information System (INIS)

    Different fluorocarbon thin films were deposited on Si substrates using a plasma-polymerization method. Fluorine-containing hydrophobic thin films were obtained by inductively coupled plasma (ICP) and pulsed plasma (PP) with a mixture of fluorocarbon precursors C2F6, C3F8, and c-C4F8 and the unsaturated hydrocarbons of C2H2. The influence on the fluorocarbon surfaces of the process parameters for plasma polymerization, including the gas ratio and the plasma power, were investigated under two plasma-polymerized techniques with different fluorocarbon gas precursors. The hydrophobic properties, surface morphologies, and chemical compositions were elucidated using water contact angle measurements, field emission-scanning electron microscope, x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). In this study, the ICP technique provides coarser grained films and more hydrophobic surfaces as well as a higher deposition rate compared to the PP technique. XPS, FT-IR, and TOF-SIMS analyses indicated that the ICP technique produced more fluorine-related functional groups, including CF2 and CF3, on the surface. From the curve-fitted XPS results, fluorocarbon films grown under ICP technique exhibited less degree of cross-linking and higher CF2 concentrations than those grown under PP technique.

  10. State-space modeling of the radio frequency inductively-coupled plasma generator

    International Nuclear Information System (INIS)

    Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

  11. State-space modeling of the radio frequency inductively-coupled plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Dewangan, Rakesh Kumar; Punjabi, Sangeeta B; Mangalvedekar, H A; Lande, B K [Electrical Engineering Department, V J T I, Mumbai-400019 (India); Joshi, N K; Barve, D N, E-mail: ham.vjti@gmail.co [Laser and Plasma Technology Division, BARC, Mumbai-400085 (India)

    2010-02-01

    Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

  12. Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

    Science.gov (United States)

    Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

  13. Equilibration Rates in a Strongly Coupled Nonconformal Quark-Gluon Plasma.

    Science.gov (United States)

    Buchel, Alex; Heller, Michal P; Myers, Robert C

    2015-06-26

    We initiate the study of equilibration rates of strongly coupled quark-gluon plasmas in the absence of conformal symmetry. We primarily consider a supersymmetric mass deformation within N=2^{*} gauge theory and use holography to compute quasinormal modes of a variety of scalar operators, as well as the energy-momentum tensor. In each case, the lowest quasinormal frequency, which provides an approximate upper bound on the thermalization time, is proportional to temperature, up to a prefactor with only a mild temperature dependence. We find similar behavior in other holographic plasmas, where the model contains an additional scale beyond the temperature. Hence, our study suggests that the thermalization time is generically set by the temperature, irrespective of any other scales, in strongly coupled gauge theories. PMID:26197117

  14. Model of a microwave beam coupling to CO 2 laser plasma

    Science.gov (United States)

    Caraway, E. L.; Sokol, M.; Grossman, B. G.

    2002-04-01

    We have designed a transmission line model of the microwave coupling mechanism for a microwave pumped CO 2 laser. The model is a total loss ridge waveguide transmission line having nonuniform impedance. The laser plasma is modeled as a frequency-dependent lossy dielectric and acts as a distributed resistance in the length of the microwave cavity. The coupling structure of the microwaves is designed not to be resonant at the microwave source frequency of 2.45 GHz at 1 kW and propagating the total microwave field energy to be absorbed without internal reflection. An exact solution to this general transmission line propagation constant for a shunt resistance along length of the guide is found. The measurements and predictions of the parameters of the plasma conductivity as a function of the attenuation constant agree closely.

  15. Considerations about the detection efficiency in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Experimental investigations of analyte atomization, ionization and diffusion processes in the inductively coupled plasma applying single droplet introduction and optical emission spectroscopy provide hints how to improve the detection efficiency of inductively coupled plasma mass spectrometry. It is discussed how the flow, amount and type of injector gas, the size of droplets injected, the analyte mass, and the sampler interface of the mass spectrometer determine the position of analyte atomization and ionization as well as the magnitude of radial analyte ion diffusion at the interface of the mass spectrometer applied. - Highlights: ► Parameters determining analyte atomization and ionization in ICP's are discussed. ► Dependence of analyte diffusion on experimental conditions is described. ► Actions for improving the detection efficiency of ICP-MS are highlighted.

  16. Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

    Energy Technology Data Exchange (ETDEWEB)

    Luong, E.

    1999-05-10

    This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 {+-} 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 {+-} 0.4 ng/g, while the certified value is 11.5 {+-} 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 {+-} 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and {beta}-cyclodextrin are chosen for the study, initial observation of spectral interference of {sup 13}C{sup +} with {sup 12}C{sup 1}H{sup +} comes from the incomplete dissociation of myoglobin and/or {beta}-cyclodextrin.

  17. Jet-Medium Interactions at NLO in a Weakly-Coupled Quark-Gluon Plasma

    OpenAIRE

    Ghiglieri, Jacopo; Moore, Guy; Teaney, Derek

    2015-01-01

    We present an extension to next-to-leading order in the strong coupling constant $g$ of the AMY effective kinetic approach to the energy loss of high momentum particles in the quark-gluon plasma. At leading order, the transport of jet-like particles is determined by elastic scattering with the thermal constituents, and by inelastic collinear splittings induced by the medium. We reorganize this description into collinear splittings, high-momentum-transfer scatterings, drag and diffusion, and p...

  18. Charge creation and nucleation of longitudinal plasma wave in coupled Josephson junctions

    OpenAIRE

    Shukrinov, Yu M.; Hamdipour, M.

    2009-01-01

    We study the phase dynamics in coupled Josephson junctions describing by system of nonlinear differential equations. Results of detailed numerical simulations of charge creation in the superconducting layers and the longitudinal plasma wave (LPW) nucleation are presented. We demonstrate the different time stages in the development of the LPW and present results of FFT analysis at different values of bias current. The correspondence between the breakpoint position on the outermost branch of cu...

  19. Copper Determination in Gunshot Residue by Cyclic Voltammetric and Inductive Coupled Plasma-Optical Emission Spectroscopy

    OpenAIRE

    Mohd Hashim Nurul’Afiqah Hashimah; Mohd Zain Zainiharyati; Jaafar Mohd Zuli

    2016-01-01

    Analysis of gunshot residue (GSR) is a crucial evidences for a forensic analyst in the fastest way. GSR analysis insists a suitable method provides a relatively simple, rapid and precise information on the spot at the crime scene. Therefore, the analysis of Cu(II) in GSR using cyclic voltammetry (CV) on screen printed carbon electrode (SPCE) is a better choice compared to previous alternative methods such as Inductive Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) those required a lon...

  20. Dust acoustic solitary and shock waves in strongly coupled dusty plasmas with nonthermal ions

    Indian Academy of Sciences (India)

    Hamid Reza Pakzad; Kurosh Javidan

    2009-11-01

    The Korteweg–de Vries–Burgers (KdV–Burgers) equation and modified Korteweg–de Vries–Burgers equation are derived in strongly coupled dusty plasmas containing nonthermal ions and Boltzmann distributed electrons. It is found that solitary waves and shock waves can be produced in this medium. The effects of important parameters such as ion nonthermal parameter, temperature, density and velocity on the properties of shock waves and solitary waves are discussed.

  1. Reduction of plyatomic ion interferences in indictively coupled plasma mass spectrometry with cryogenic desolvation

    Energy Technology Data Exchange (ETDEWEB)

    Alves, L.C.

    1993-09-01

    A desolvation scheme for introducing aqueous and organic samples into an argon inductively coupled plasma is described; the aerosol generated by nebulizer is heated (+140 C) and cooled ({minus}80 C) repeatedly, and the dried aerosol is then injected into the mass spectrometer. Polyatomic ions are greatly suppressed. This scheme was validated with analysis of seawater and urine reference samples. Finally, the removal of organic solvents by cryogenic desolvation was studied.

  2. Numerical methods for TVD transport and coupled relaxing processes in gases and plasmas

    Science.gov (United States)

    Cambier, Jean-Luc

    1990-01-01

    The construction of second-order upwind schemes for nonequilibrium plasmas, for both one- and two-fluid formulations is demonstrated. Coupled relaxation processes, including ionization kinetics and radiative processes and their algorithms for nonequilibrium, multiple temperature conditions are described as well. The paper applies the numerical techniques on some simple test cases, points out critical problems and their solutions, and makes qualitative comparisons with known results, whenever possible.

  3. Magnetosphere--Ionosphere Coupling: Effects of Plasma Alfven Wave Relative Motion

    Science.gov (United States)

    Christiansen, P. J.; Dum, C. T.

    1989-06-01

    The introduction of relative perpendicular motion between a flux-tube supporting shear Alfven wave activity and the background plasma is studied in the context of the coupling of a wave generating region with a distant ionosphere. The results of a representative simulation, using an extended version of the code developed by Lysak & Dum (J. geophys. Res. 88, 365 (1983)), are used as a basis for interpreting some aspects of recent satellite observations.

  4. Magnetosphere-ionosphere coupling: effects of plasma Alfvén wave relative motion.

    Science.gov (United States)

    Christiansen, P. J.; Dum, C. T.

    The introduction of relative perpendicular motion between a flux-tube supporting shear Alfvén wave activity and the background plasma is studied in the context of the coupling of a wave generating region with a distant ionosphere. The results of a representative simulation, using an extended version of the code developed by Lysak & Dum, are used as a basis for interpreting some aspects of recent satellite observations.

  5. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    OpenAIRE

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-01-01

    International audience We propose a method to measure the densities of vibrationally excited Cl 2 (v) molecules in levels up to v = 3 in pure chlorine inductively coupled plasmas. The absorption continuum of Cl 2 in the 250 – 450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab-initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mec...

  6. Simple thermodynamics of strongly coupled one-component-plasma in two and three dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Khrapak, Sergey A., E-mail: Sergey.Khrapak@dlr.de [Forschungsgruppe Komplexe Plasmen, Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen (Germany); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Khrapak, Alexey G. [Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-10-15

    Simple analytical approximations for the internal energy of the strongly coupled one-component-plasma in two and three dimensions are discussed. As a result, new practical expressions for the internal energy in the fluid phase are proposed. Their accuracy is checked by evaluating the location of the fluid-solid phase transition from the free energy consideration. Possible applications to other related systems are briefly discussed.

  7. Dust-Acoustic Waves in Strongly Coupled Dusty Plasmas Containing Variable-Charge Impurities

    Institute of Scientific and Technical Information of China (English)

    XIE Bai-Song; HE Kai-Fen; M. Y. Yu

    2000-01-01

    A relatively self-consistent theory of dust-acoustic waves in the strongly coupled dusty plasmas containing variable charge impurities is given. Relevant physical processes such as dust elastic relaxation and dust charge relaxation are taken into account. It is shown that the negative dispersion of dust-acoustic waves due to the strong correlation of dusts is enhanced in the presence of dust-neutral collisions.

  8. Suppression of Instability in Strongly Coupled Dusty Plasmas with Ion Flow

    Institute of Scientific and Technical Information of China (English)

    贺凯芬; 谢柏松; 刘克富

    2001-01-01

    The instability of low-frequency longitudinal modes in strongly coupled dusty plasmas with an ion flow is investigated. The dust charging relaxation is taken into account. It is found that when the ion flow is strong enough,the suppression, even disappearance. of instability can occur. Similar to that of the real frequency of waves, the imaginary part of waves also exhibits a transition, which arises from the sensitive dependences on the system parameters and their competition.

  9. Ion balance in waters through inductively coupled plasma optical emission spectrometry

    OpenAIRE

    Sánchez Rodríguez, Carlos; Maestre Pérez, Salvador; Prats Moya, Soledad; Todolí Torró, José Luis

    2014-01-01

    Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) has been employed to carry out the determination of both major anions and cations in water samples. The anion quantification has been performed by means of a new automatic accessory. In this device chloride has been determined by continuously adding a silver nitrate solution. As a result solid silver chloride particles are formed and retained on a nylon filter inserted in the line. The emission intensity is read at a silver ch...

  10. Integrated CFD Model for Nanoparticle Production in Inductively Coupled Plasma Reactor: Implementation and Application

    OpenAIRE

    Benros Santos Lopes, Silvania

    2016-01-01

    Nanoparticles represent a very exciting new area of research. Their small size, ranging from several nanometers to tens of nanometers, is responsible for many changes in the structural, thermal, electromagnetic, optical and mechanical properties in comparison with the bulk solid of the same materials. However, promoting the use of such material requires well-controlled synthesis techniques to be developed. Inductively coupled thermal plasma (ICTP) reactors have been shown to offer unique adva...

  11. Atomic Mineral Characteristics of Indonesian Osteoporosis by High-Resolution Inductively Coupled Plasma Mass Spectrometry

    OpenAIRE

    Zairin Noor; Sutiman Bambang Sumitro; Mohammad Hidayat; Agus Hadian Rahim; Akhmad Sabarudin; Tomonari Umemura

    2012-01-01

    Clinical research indicates that negative calcium balance is associated with low bone mass, rapid bone loss, and high fracture rates. However, some studies revealed that not only calcium is involved in bone strengthening as risk factor of fracture osteoporosis. Thus, in this report, the difference of metallic and nonmetallic elements in osteoporosis and normal bones was studied by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The influence of these elements on bone...

  12. Plutonium age dating (production date measurement) by inductively coupled plasma mass spectrometry

    OpenAIRE

    Varga, Zsolt; Nicholl, Adrian; Wallenius, Maria; Mayer, Klaus

    2015-01-01

    This paper describes rapid methods for the determination of the production date (age dating) of plutonium (Pu) materials by inductively coupled plasma mass spectrometry (ICP-MS) for nuclear forensic and safeguards purposes. One of the presented methods is a rapid, direct measurement without chemical separation using 235U/239Pu and 236U/240Pu chronometers. The other method comprises a straightforward extraction chromatographic separation, followed by ICP-MS measurement for the 234U/238Pu, 235U...

  13. Determination of Trace Elements in Ice Core Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    OpenAIRE

    Reinhardt, Heiko; Kriews, Michael; Schrems, Otto; Lüdke, C.; Hoffmann, E; Skole, J.

    2001-01-01

    The snow and iceshields of the polar regions serve as a climate archiveand deliver a useful insight back to about 250.000 years of earth climatehistory1,2. The aim of our investigation reported here was to establisha new method for the determination of trace elements in ice cores frompolar regions with Laserablation Inductively Coupled Plasma MassSpectrometry (LA-ICP-MS)3. Primarily, the construction of a cryogeniclaserablation chamber and the optimization of the analysis system forthe sample...

  14. 87Sr/86Sr measurements on marine sediments by inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    The application of inductively coupled plasma-mass spectrometry (ICP-MS) is documented for the study of the strontium isotopic composition (87Sr/86Sr) in geological samples, i.e. in the marine lithic fraction of core sediments. Methods for the determination of the isotopic composition, its accuracy and precision are reported. The results obtained simultaneously on 11 samples by both ICP-MS and thermal ionization mass spectrometry (TIMS) reveal a very good correlation (r2 = 0.955). (orig.)

  15. Development of analytical methods for multiplex bio-assay with inductively coupled plasma mass spectrometry

    OpenAIRE

    Ornatsky, Olga I.; Kinach, Robert; Bandura, Dmitry R.; Lou, Xudong; Tanner, Scott D; Baranov, Vladimir I.; Nitz, Mark; Mitchell A. Winnik

    2008-01-01

    Advances in the development of highly multiplexed bio-analytical assays with inductively coupled plasma mass spectrometry (ICP-MS) detection are discussed. Use of novel reagents specifically designed for immunological methods utilizing elemental analysis is presented. The major steps of method development, including selection of elements for tags, validation of tagged reagents, and examples of multiplexed assays, are considered in detail. The paper further describes experimental protocols for...

  16. Iron-Isotopic Fractionation Studies Using Multiple Collector Inductively Coupled Plasma Mass Spectrometry

    Science.gov (United States)

    Anbar, A. D.; Zhang, C.; Barling, J.; Roe, J. E.; Nealson, K. H.

    1999-01-01

    The importance of Fe biogeochemistry has stimulated interest in Fe isotope fractionation. Recent studies using thermal ionization mass spectrometry (TIMS) and a "double spike" demonstrate the existence of biogenic Fe isotope effects. Here, we assess the utility of multiple-collector inductively-coupled plasma mass spectrometry(MC-ICP-MS) with a desolvating sample introduction system for Fe isotope studies, and present data on Fe biominerals produced by a thermophilic bacterium. Additional information is contained in the original extended abstract.

  17. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    OpenAIRE

    Sánchez Romero, Raquel; Todolí Torró, José Luis; Lienemann, Charles Philippe; Mermet, Jean Michel

    2013-01-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decompositio...

  18. Determination of uranium and thorium isotope ratios by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Measurements conditions were selected and a procedure was proposed for determining the 234U/238U and 230Th/232Th isotope ratios using an ELEMENT single-channel double-focusing inductively coupled plasma mass spectrometer. The procedure was tested in analyzing bottom sediments from Lake Baikal with the extraction preconcentration of uranium and thorium. The accuracy of the procedure was verified using certified reference materials and a model solution by comparing the results obtained with the data of α spectrometry

  19. Applications of inductively coupled plasma mass spectrometry to the production control of aerospace and nuclear materials

    International Nuclear Information System (INIS)

    Inductively coupled plasma source mass spectrometry (ICP-MS) has proved to be a useful practical tool in a high-volume quality control laboratory. The application of this technique to materials produced for the aerospace and nuclear industries is discussed. Techniques employed for uranium isotope ratio determination and elemental determination of gadolinium, samarium and thorium in hafnium and zirconium alloys are described. Strategies employed for a semi-quantitative survey analysis for a wide range of elements are also presented. (author)

  20. Measurement of neutral gas temperature in a 13.56 MHz inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Jayapalan, Kanesh K.; Chin, Oi Hoong [Plasma Technology Research Centre, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-04-24

    Measuring the temperature of neutrals in inductively coupled plasmas (ICP) is important as heating of neutral particles will influence plasma characteristics such as the spatial distributions of plasma density and electron temperature. Neutral gas temperatures were deduced using a non-invasive technique that combines gas actinometry, optical emission spectroscopy and simulation which is described here. Argon gas temperature in a 13.56 MHz ICP were found to fall within the range of 500 − 800 K for input power of 140 − 200 W and pressure of 0.05 − 0.2 mbar. Comparing spectrometers with 0.2 nm and 0.5 nm resolution, improved fitting sensitivity was observed for the 0.2 nm resolution.

  1. Three-dimensional discharge simulation of inductively coupled plasma (ICP) etching reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    More and more importance has been attached to inductively coupled plasma (ICP) in semiconductor manufacture. For a deep understanding of the plasma discharge process in the etching reactor, this study made a three-dimensional simulation on the Ar plasma discharge process with the commercial software CFD-ACE, which is according to the real experiment conditions and data supplied by North Microelec-tronic Corporation. The error of the simulation results is in the range of ±20% with credibility. The numerical results show that the three-dimentional spatial distribu-tion of electron density is reduced from the chamber center to the wall. The distri-bution of electron density, electron temperature and power deposition is related to the shape and placement of the coil.

  2. Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

    DEFF Research Database (Denmark)

    Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.;

    2003-01-01

    Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

  3. Inductively Coupling Plasma (ICP) Treatment of Propylene (PP) Surface and Adhesion Improvement

    Science.gov (United States)

    Liu, Yenchun; Fu, Yenpei

    2009-12-01

    Study on increasing the roughness of the polymer substrate surface to enhance the adhesion with the copper layer in an inductively coupling plasma (ICP) process was carried out. The microstructure of the polymer substrate surfaces, which were exposed to different kinds of plasma treatment, was identified by scanning electron microscopy(SEM) analysis, peel strength of the copper coating and water surface contact angle. The adhesion of the substrate was largely enhanced by plasma treatment and the copper deposited coating reached a value of 7.68 kgf/m in verifying the adhesion of the copper coating with polymer material. The quality of the line/space 50/50 μm produced in the laboratory was examined by the pressure cooker test and proved to meet the requirement.

  4. A method for studies on interactions between a gold-based drug and plasma proteins based on capillary electrophoresis with inductively coupled plasma mass spectrometry detection

    DEFF Research Database (Denmark)

    Nguyen, Tam T T N; Østergaard, Jesper; Gammelgaard, Bente

    2015-01-01

    An analytical method based on capillary electrophoresis (CE) and inductively coupled plasma mass spectrometry (ICP-MS) detection was developed for studies on the interaction of gold-containing drugs and plasma proteins using auranofin as example. A detection limit of 18 ng/mL of auranofin...

  5. HEMOFILTRATION AND COUPLED PLASMA FILTRATION ADSORPTION IMPACT ON TACROLIMUS BLOOD CONCENTRATION IN RENAL TRANSPLANT RECIPIENTS

    Directory of Open Access Journals (Sweden)

    A.V. Vatazin

    2014-01-01

    Full Text Available Aim. To study the effect of hemofi ltration and coupled plasma fi ltration adsorption on tacrolimus blood concentration in renal transplant recipients.Methods and results. The study included 8 renal transplant recipients. In these patients immediately after the operation was performed the coupled plasma fi ltration adsorption with hemofiltration using a cartridge Mediasorb to reduce the severity of reperfusion injury. We have found that during this extracorporeal blood correction procedure there was statistically not signifi cant decrease of tacrolimus blood concentration. However, concentration of tacrolimus remained in the therapeutic range even after the procedure and it was not signifi cantly different from the control point С0.Conclusion. Coupled plasma fi ltration adsorption is safe in renal transplant recipients and has no signifi cant impact on tacrolimus blood concentration. However, the downward trend in the concentration of tacrolimus in the course of these procedures, especially in continuous or semicontinuous mode, as well as in patients with low hematocrit and hypoalbuminemia, requires individual monitoring.

  6. The Integrated Plasma Simulator: A Flexible Python Framework for Coupled Multiphysics Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Foley, Samantha S [ORNL; Elwasif, Wael R [ORNL; Bernholdt, David E [ORNL

    2011-11-01

    High-fidelity coupled multiphysics simulations are an increasingly important aspect of computational science. In many domains, however, there has been very limited experience with simulations of this sort, therefore research in coupled multiphysics often requires computational frameworks with significant flexibility to respond to the changing directions of the physics and mathematics. This paper presents the Integrated Plasma Simulator (IPS), a framework designed for loosely coupled simulations of fusion plasmas. The IPS provides users with a simple component architecture into which a wide range of existing plasma physics codes can be inserted as components. Simulations can take advantage of multiple levels of parallelism supported in the IPS, and can be controlled by a high-level ``driver'' component, or by other coordination mechanisms, such as an asynchronous event service. We describe the requirements and design of the framework, and how they were implemented in the Python language. We also illustrate the flexibility of the framework by providing examples of different types of simulations that utilize various features of the IPS.

  7. A simple, low-cost, versatile charge-coupled device spectrometer for plasma spectroscopy

    International Nuclear Information System (INIS)

    We have constructed a simple, low-cost charge-coupled device (CCD) spectrometer capable of both high resolution (Δλ≤0.015 nm) and large bandpass (110 nm with Δλ∼0.3 nm). These two modes of operation provide two broad areas of capability for plasma spectroscopy. The first major application is measurement of emission line broadening; the second is emission line surveys from the ultraviolet to the near infrared. Measurements have been made on a low-temperature plasma produced by a miniature electrostatic plasma source and the high-temperature plasma in the Madison Symmetric Torus reversed-field pinch. The spectrometer is a modified Jarrell endash Ash 0.5 m Ebert endash Fastie monochromator. Light is coupled into the entrance slit with a fused silica fiber optic bundle. The exposure time (2 ms minimum) is controlled by a fast electro-mechanical shutter. The exit plane detector is a compact and robust CCD detector developed for amateur astronomy by Santa Barbara Instrument Group. The CCD detector is controlled and read out by a Macintosh reg-sign computer. This spectrometer is sophisticated enough to serve well in a research laboratory, yet is simple and inexpensive enough to be affordable for instructional use. copyright 1997 American Institute of Physics

  8. Numerical Simulations of Low Pressure Inductively Coupled Plasmas in Geometrically Complex Reactors

    Science.gov (United States)

    Yu, Ben; Wu, Hanming; Krishnan, Anantha

    1996-10-01

    A two-dimensional fluid model has been developed for simulation of low pressure inductively coupled plasma (ICP) reactors. The model obtains solutions for the plasma density, electron temperature, and electric field for the given operating conditions. The physical phenomena and processes such as ambipolar diffusion, thermal diffusion, quasi-neutrality, ionization, inductive Joule heating, and excitations are considered in the model. A significant feature of the model is its capability of handling complex geometries that are often encountered in industrial reactors. Complex reactor geometries are modeled by a body-fitted-coordinate (BFC) formulation. A series of numerical experiments have been conducted using the model to study effects of various parameters such as chamber pressure, size of the wafer, position of the inductive coil, and the power input into the plasma. Different reactor geometries such as the GEC ICP reference cell and the belljar reactor have been simulated. The results of the parametric experiments are presented to show certain systematic trends in performance parameters such as uniformity and processing rates. The ICP model has been coupled to a computational fluid dynamics (CFD) code (capable of 3D simulations) that obtains the flow and pressure distribution inside the chamber. The ICP model will use pressure predictions (from the CFD model) to compute the local ionization rates. Chemical source/sink terms from the plasma dissociation model will be used by the CFD code to account for local reactant depletion effects.

  9. Initial design for an experimental investigation of strongly coupled plasma behavior in the ATLAS facility

    CERN Document Server

    Munson, C P; Taylor, A J; Trainor, R J; Wood, B P; Wysocki, F J

    1999-01-01

    Summary form only given. Atlas is a high current (~30 MA peak, with a current risetime ~4.5 mu sec), high energy (E/sub stored/=24 MJ, E /sub load/=3-6 MJ), pulsed power facility which is being constructed at Los Alamos National Laboratory with a scheduled completion date in the year 2000. When operational, this facility will provide a platform for experiments in high pressure shocks (>20 Mbar), adiabatic compression ( rho / rho /sub 0/>5, P>10 Mbar), high magnetic fields (~2000 T), high strain and strain rates ( epsilon >200, d epsilon /dt~10/sup 4/ to 10/sup 6/ s/sup -1/), hydrodynamic instabilities of materials in turbulent regimes, magnetized target fusion, equation of state, and strongly coupled plasmas. For the strongly coupled plasma experiments, an auxiliary capacitor bank will be used to generate a moderate density (<0.1 solid), relatively cold (~1 eV) plasma by ohmic heating of a conducting material of interest such as titanium. This target plasma will be compressed against a central column conta...

  10. Evaluation of the influence of the main plasma density parameters on antenna coupling and radio frequency potentials with TOPICA code

    International Nuclear Information System (INIS)

    The successful design of an ion cyclotron antenna mainly relies on the capability of accurately predicting its behavior both in terms of input parameters, and therefore power coupled to plasma, and radiated fields. All these features essentially depend on the antenna itself (its geometry, the matching and tuning systems) and, obviously, on the faced loading. In this paper a number of plasma profiles is analysed with the help of the TOPICA code, a predictive tool for the design and optimization of radio frequency (RF) launchers in front of a plasma, in order to understand which plasma parameters have the most significant influence on the coupling performances of a typical IC antenna. (paper)

  11. Eletroforese capilar acoplada à espectrometria com plasma: uma ferramenta eficiente para a especiação Capillary electrophoresis coupled to plasma spectrometry: an efficient tool for speciation

    Directory of Open Access Journals (Sweden)

    Ana Paula G. Gervasio

    2003-01-01

    Full Text Available The most important features of the CE-ICP hyphenation, as well as its advantages and drawbacks as a tool for speciation are discussed. The fundamental principles of capillary electrophoresis and inductively coupled plasma mass spectrometry are also presented. Some applications involving different designs proposed in the literature to couple CE and ICP system for elemental speciation are reviewed.

  12. Eletroforese capilar acoplada à espectrometria com plasma: uma ferramenta eficiente para a especiação Capillary electrophoresis coupled to plasma spectrometry: an efficient tool for speciation

    OpenAIRE

    Ana Paula G. Gervasio; André F. Lavorante; Maria Carolina B. Moraes; Maria Fernanda Giné; Carlos E. S. Miranda; Emanuel Carrilho

    2003-01-01

    The most important features of the CE-ICP hyphenation, as well as its advantages and drawbacks as a tool for speciation are discussed. The fundamental principles of capillary electrophoresis and inductively coupled plasma mass spectrometry are also presented. Some applications involving different designs proposed in the literature to couple CE and ICP system for elemental speciation are reviewed.

  13. Formation and evolution of vortices in a collisional strongly coupled dusty plasma

    Science.gov (United States)

    Jana, Sayanee; Banerjee, Debabrata; Chakrabarti, Nikhil

    2016-07-01

    Formation and evolution of vortices are studied in a collisional strongly coupled dusty plasma in the framework of a Generalized Hydrodynamic model (GH). Here we mainly present the nonlinear dynamical response of this strongly coupled system in presence of dust-neutral collisional drag. It is shown that the interplay between the nonlinear elastic stress and the dust-neutral collisional drag results in the generation of non-propagating monopole vortex for some duration before it starts to propagate like transverse shear wave. It is also found that the interaction between two unshielded monopole vortices having both same (co-rotating) and opposite (counter rotating) rotations result in the formation of two propagating dipole vortices of equal and unequal strength respectively. These results will provide some new understanding on the transport properties in such a strongly coupled system. The numerical simulation is carried out using a de-aliased doubly periodic pseudo-spectral code with Runge-Kutta-Gill time integrator.

  14. Dynamics of compressional Mach cones in a strongly coupled complex plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, P., E-mail: pintu@ipr.res.in; Dey, R.; Sen, Abhijit [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India); Kadyan, Sangeeta [Department of Physics, Maharshi Dayanand University, Rohtak 124001 (India)

    2014-10-15

    Using a Generalised-Hydrodynamic (GH) fluid model, we study the influence of strong coupling induced modification of the fluid compressibility on the dynamics of compressional Mach cones in a dusty plasma medium. A significant structural change of lateral wakes for a given Mach number and Epstein drag force is found in the strongly coupled regime. With the increase of fluid compressibility, the peak amplitude of the normalised perturbed dust density first increases and then decreases monotonically after reaching its maximum value. It is also noticed that the opening angle of the cone structure decreases with the increase of the compressibility of the medium and the arm of the Mach cone breaks up into small structures in the velocity vector profile when the coupling between the dust particles increases.

  15. Dynamics of compressional Mach cones in a strongly coupled complex plasma

    International Nuclear Information System (INIS)

    Using a Generalised-Hydrodynamic (GH) fluid model, we study the influence of strong coupling induced modification of the fluid compressibility on the dynamics of compressional Mach cones in a dusty plasma medium. A significant structural change of lateral wakes for a given Mach number and Epstein drag force is found in the strongly coupled regime. With the increase of fluid compressibility, the peak amplitude of the normalised perturbed dust density first increases and then decreases monotonically after reaching its maximum value. It is also noticed that the opening angle of the cone structure decreases with the increase of the compressibility of the medium and the arm of the Mach cone breaks up into small structures in the velocity vector profile when the coupling between the dust particles increases

  16. Dynamics of compressional Mach cones in a strongly coupled complex plasma

    CERN Document Server

    Bandyopadhyay, P; Kadyan, Sangeeta; Sen, Abhijit

    2016-01-01

    Using a Generalised-Hydrodynamic (GH) fluid model we study the influence of strong coupling induced modification of the fluid compressibility on the dynamics of compressional Mach cones in a dusty plasma medium. A significant structural change of lateral wakes for a given Mach number and Epstein drag force is found in the strongly coupled regime. With the increase of fluid compressibility, the peak amplitude of the normalised perturbed dust density first increases and then decreases monotonically after reaching its maximum value. It is also noticed that the opening angle of the cone structure decreases with the increase of the compressibility of the medium and the arm of the Mach cone breaks up into small structures in the velocity vector profile when the coupling between the dust particles increases.

  17. Variable Synthetic Capacitance

    Science.gov (United States)

    Kleinberg, L. L.

    1986-01-01

    Feedback amplifier circuit synthesizes electronically variable capacitance. Variable Synthetic Capacitor is amplifier circuit with follower/feedback configuration. Effective input capacitance depends on input set current. If synthetic capacitor is connected across resonant element of oscillator, oscillator frequency controlled via input set current. Circuit especially suitable for fine frequency adjustments of piezoelectric-crystal or inductor/capacitor resonant oscillators.

  18. Methods for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry

    Science.gov (United States)

    Chan, George C. Y.; Hieftje, Gary M.

    2010-08-03

    A method for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry (ICP-AES). ICP-AES analysis is performed across a plurality of selected locations in the plasma on an unknown sample, collecting the light intensity at one or more selected wavelengths of one or more sought-for analytes, creating a first dataset. The first dataset is then calibrated with a calibration dataset creating a calibrated first dataset curve. If the calibrated first dataset curve has a variability along the location within the plasma for a selected wavelength, errors are present. Plasma-related errors are then corrected by diluting the unknown sample and performing the same ICP-AES analysis on the diluted unknown sample creating a calibrated second dataset curve (accounting for the dilution) for the one or more sought-for analytes. The cross-over point of the calibrated dataset curves yields the corrected value (free from plasma related errors) for each sought-for analyte.

  19. Synthesis of ultrafine particles and processing of nano-structured films with inductively coupled plasma

    International Nuclear Information System (INIS)

    The inductively coupled plasma (ICP) at atmospheric pressure is particularly suited for melting and evaporation of materials. The electrodeless ICP can be generated without limitation of the kind of plasma forming gases. Therefore, using an argon-oxygen gas mixture as sheath gas of the ICP nanoparticles can be processed by combustion of metal-organic liquid precursors injected in the hot plasma core. By this way, nanoparticles of alumina, titania and of a perovskite type oxide are produced. The powder particles are collected by an electrostatic filter. They are characterized by a log-normal size distribution with a median diameter of about 10 nm depending on the plasma parameters used. Interesting metastable phases and exactly doped, very pure materials can be obtained. Nanophase coatings synthesized by the ICP are made from the same precursor materials. For depositions, the plasma jet has to be supersonic. Impinging onto the substrate placed near the nozzle thin and dense coatings are obtained. The composition and the grain size of as-deposited coatings are analyzed by XRD. (author)

  20. Conceptual study of moderately coupled plasmas and experimental comparison of laboratory x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Li, C. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

    1993-12-01

    In this thesis the fundamental concepts of moderately coupled plasmas, for which 2{approx_lt}ln{Lambda}{sub b}{approx_lt}10, are, for the first time, presented. This investigation is motivated because neither the conventional Fokker-Planck approximation [for weakly coupled plasmas (ln{Lambda}{sub b}{approx_lt}10)] nor the theory of dielectric response with correlations for strongly coupled plasmas (ln{Lambda}{sub b}{approx_lt}1) has satisfactorily addressed this regime. Specifically, herein the standard Fokker-Planck operator for Coulomb collisions has been modified to include hitherto neglected terms that are directly associated with large-angle scattering. In addition a reduced electron-ion collision operator has been calculated that, for the first time, manifests 1/ln{Lambda}{sub b} corrections. Precise calculations of some relaxation rates and crude calculations of electron transport coefficients have been made. As one of major applications of the modified Fokker-Planck equation, the stopping powers and {rho}R have been calculated for charged fusion products ({alpha}`s, {sup 3}H, {sup 3}He) and hot electrons interacting with plasmas relevant to inertial confinement fusion. In the second major topic of this thesis, advances made in the area of laboratory x-ray sources are presented. First, and most importantly, through the use a Cockcroft-Walton linear accelerator, a charged particle induced x-ray emission (PIXE) source has been developed. Intense line x radiation (including K-, L-, M-, and N-lines) with wavelengths from 0.5 {angstrom} to 111 {angstrom} have been successfully produced. Second, a new high intensity electron-beam x-ray generator has also been developed, and it has been used with advantage in the soft x-ray region ( < 3 keV). Finally, a direct comparisons of both sources (PIXE and electron-beam x-ray sources) to a commercially available radioactive {alpha} fluorescent x-ray source has been made.

  1. The charge-exchange induced coupling between plasma-gas counterflows in the heliosheath

    Directory of Open Access Journals (Sweden)

    H. J. Fahr

    Full Text Available Many hydrodynamic models have been presented which give similar views of the interaction of the solar wind plasma bubble with the counterstreaming partially ionized interstellar medium. In the more recent of these models it is taken into account that the solar and interstellar hydrodynamic flows of neutral atoms and protons are coupled by mass-, momentum-, and energy-exchange terms due to charge exchange processes. We shall reinvestigate the theoretical basis of this coupling here by use of a simplified description of the heliospheric interface and describe the main physics of the H-atom penetration through the more or less standing well-known plasma wall ahead of the heliopause. Thereby we can show that the type of charge exchange coupling terms used in up-to-now hydrodynamic treatments unavoidably leads to an O-type critical point at the sonic point of the H-atom flow, thus not allowing for a continuation of the integration of the hydrodynamic set of differential equations. The remedy for this problem is given by a more accurate formulation of the momentum exchange term for quasi-and sub-sonic H-atom flows. With a refined momentum exchange term derived from basic kinetic Boltzmann principles, we instead arrive at a characteristic equation with an X-type critical point, allowing for a continuous solution from supersonic to subsonic flow conditions. This necessitates that the often treated problem of the propagation of inter-stellar H-atoms through the heliosheath has to be solved using these newly derived, differently effective plasma – gas friction forces. Substantially different results are to be expected from this context for the filtration efficiency of the heliospheric interface.

    Key words. Interplanetary physics (heliopause and solar wind termination; interstellar gas – Ionosphere (plasma temperature and density

  2. Direct Determination of Total Arsenic and Arsenic Species by Ion Chromatography Coupled with Inductively Coupled Plasma Mass Spectrometry

    International Nuclear Information System (INIS)

    The simultaneous determination of As(III), As(V), and DMA has been performed by ion chromatography (IC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). The separation of the three arsenic species was achieved by an anionic separator column (AS 7) with an isocratic elution system. The separated species were directly detected by ICP-MS as an element-selective detection method. The IC-ICP-MS technique was applied for the determination of arsenic species in a NIST SRM 1643d water sample. An As(III) only was detected in the sample. The detection limits of As(III), As(V) and DMA were 0.31, 0.45, and 2.09 ng/mL, respectively. It was also applied for the determination of arsenic species in a human urine obtained by a volunteer, and three arsenic species were identified. The determination of total As in human urines that were obtained from 25 volunteers at the different age was also carried out by ICP-MS

  3. Frequency-dependent capacitance-voltage and conductance-voltage characteristics of low-dielectric-constant SiOC(-H) thin films deposited by using plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Young; Lee, Heang Seuk; Woo, Jong Kwan; Choi, Chi Kyu; Lee, Kwang Man; Hyun, Myung Taek [Jeju National University, Jeju (Korea, Republic of); Navamathavan, Rangaswamy [Chonbuk National University, Chonju (Korea, Republic of)

    2010-12-15

    We report on the electrical characteristics of the metal-insulator-semiconductor (MIS) structure of low-dielectric-constant SiOC(-H) films. SiOC(-H) thin films were deposited on p-Si(100) substrates by using a plasma-enhanced chemical vapor deposition (PECVD) system. The frequency dependence of the capacitance-voltage (C-V) and the conductance-voltage (G/{omega}-V) characteristics of the A1/SiOC(-H)/p-Si(100)/Al MIS structures was analyzed. C-V and G/{omega}-V measurements were carried out over a frequency range of 1 kHz to 5 MHz. Based on our analysis, the C-V and the G/{omega}-V characteristics confirmed that the surface states and the series resistance were important parameters that strongly influenced the electrical properties of the A1/SiOC(-H)/p-Si(100)/Al MIS structures.

  4. Elemental labelling combined with liquid chromatography inductively coupled plasma mass spectrometry for quantification of biomolecules: A review

    OpenAIRE

    Kretschy, Daniela; Koellensperger, Gunda; Hann, Stephan

    2012-01-01

    This article reviews novel quantification concepts where elemental labelling is combined with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) or liquid chromatography inductively coupled plasma mass spectrometry (LC–ICP-MS), and employed for quantification of biomolecules such as proteins, peptides and related molecules in challenging sample matrices. In the first sections an overview on general aspects of biomolecule quantification, as well as of labelling will be pre...

  5. Theoretical study of head-on collision of dust acoustic solitary waves in a strongly coupled complex plasma

    CERN Document Server

    Jaiswal, S; Sen, A

    2016-01-01

    We investigate the propagation characteristics of two counter propagating dust acoustic solitary waves (DASWs) undergoing a head-on collision, in the presence of strong coupling between micron sized charged dust particles in a complex plasma. A coupled set of nonlinear dynamical equations describing the evolution of the two DASWs using the extended Poincar?e{Lighthill{Kuo perturbation technique is derived. The nature and extent of post collision phase-shifts of these solitary waves are studied over a wide range of dusty plasma parameters in a strongly and a weakly coupled medium. We ?nd a signi?cant change in the nature and amount of phase delay in the strongly coupled regime as compared to a weakly coupled regime. The phase shift is seen to change its sign beyond a threshold value of compressibility of the medium for a given set of dusty plasma parameters.

  6. Critical behavior of non-hydrodynamic quasinormal modes in a strongly coupled plasma

    CERN Document Server

    Finazzo, Stefano I; Zaniboni, Maicon; Critelli, Renato; Noronha, Jorge

    2016-01-01

    We study the behavior of quasinormal modes in a top-down holographic dual corresponding to a strongly coupled $\\mathcal{N} = 4$ super Yang-Mills plasma charged under a $U(1)$ subgroup of the global $SU(4)$ R-symmetry. In particular, we analyze the spectra of quasinormal modes in the external scalar and vector diffusion channels near the critical point and obtain the behavior of the characteristic equilibration times of the plasma as the system evolves towards the critical point of its phase diagram. Except close to the critical point, we observe that by increasing the chemical potential one generally increases the damping rate of the quasinormal modes, which leads to a reduction of the characteristic equilibration times in the dual strongly coupled plasma. However, as one approaches the critical point the equilibration times associated with non-hydrodynamic modes at zero wavenumber are enhanced, acquiring an infinite slope at the critical point. We obtain that the derivatives of all the characteristic equilib...

  7. Sterilization of beehive material with a double inductively coupled low pressure plasma

    Science.gov (United States)

    Priehn, M.; Denis, B.; Aumeier, P.; Kirchner, W. H.; Awakowicz, P.; Leichert, L. I.

    2016-09-01

    American Foulbrood is a severe, notifiable disease of the honey bee. It is caused by infection of bee larvae with spores of the gram-positive bacterium Paenibacillus larvae. Spores of this organism are found in high numbers in an infected hive and are highly resistant to physical and chemical inactivation methods. The procedures to rehabilitate affected apiaries often result in the destruction of beehive material. In this study we assess the suitability of a double inductively coupled low pressure plasma as a non-destructive, yet effective alternative inactivation method for bacterial spores of the model organism Bacillus subtilis on beehive material. Plasma treatment was able to effectively remove spores from wax, which, under protocols currently established in veterinary practice, normally is destroyed by ignition or autoclaved for sterilization. Spores were removed from wooden surfaces with efficacies significantly higher than methods currently used in veterinary practice, such as scorching by flame treatment. In addition, we were able to non-destructively remove spores from the highly delicate honeycomb wax structures, potentially making treatment of beehive material with double inductively coupled low pressure plasma part of a fast and reliable method to rehabilitate infected bee colonies with the potential to re-use honeycombs.

  8. Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

    Science.gov (United States)

    Sánchez, Raquel; Todolí, José Luis; Lienemann, Charles-Philippe; Mermet, Jean-Michel

    2013-10-01

    The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques.

  9. A study on methane coupling to acetylene under the microwave plasma

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By optimizing the microwave chemistry reactor made of the rectangular waveguide resonator,the methane conversion(the maximum 93.7%),the C2 hydrocarbon yield(the maximum 91.0%) and the acetylene yield(the maximum 88.6%) were all greatly increased under the microwave plasma.Furthermore,for the optimal reactor,the change of the methane conversion and the C2 hydrocarbon yield is little within the range of the pressures in the experiments.The C2 hydrocarbon is mainly made up of acetylene,and the selectivity for acetylene is above 90%.Energy yield and space time yield of acetylene are also high.Optical emission spectroscopy(OES) was adopted for the diagnosis of methane coupling to acetylene under microwave plasma.The excited species(CH,C2,H2,Hα) were detected in the spectra range of 300-750 nm.Based on the products and the excited species,the reaction mechanism of methane coupling under microwave plasma was investigated,using the thermodynamics and kinetics of the chemical reaction.

  10. Properties and etching rates of negative ions in inductively coupled plasmas and dc discharges produced in Ar/SF6

    DEFF Research Database (Denmark)

    Draghici, Mihai; Stamate, Eugen

    2010-01-01

    Negative ion production is investigated in a chamber with transversal magnetic filter operated in dc or inductively coupled plasma (ICP) modes in Ar/SF6 gas mixtures. Plasma parameters are evaluated by mass spectrometry and Langmuir probe for different discharge conditions. The density ratio of n...

  11. Investigation of coupling between chemistry and discharge dynamics in radio frequency hydrogen plasmas in the Torr regime

    Energy Technology Data Exchange (ETDEWEB)

    Kalache, B [LPICM, UMR 7647 (CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France); Novikova, T [LPICM, UMR 7647 (CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France); Morral, A Fontcuberta i [LPICM, UMR 7647 (CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France); Cabarrocas, P Roca i [LPICM, UMR 7647 (CNRS), Ecole Polytechnique, 91128 Palaiseau Cedex (France); Morscheidt, W [LIMHP, UPR 1311 (CNRS), UPN, Av. J. B. Clement, 93430 Villetaneuse (France); Hassouni, K [LIMHP, UPR 1311 (CNRS), UPN, Av. J. B. Clement, 93430 Villetaneuse (France)

    2004-07-07

    We present the results of a study of a capacitively coupled hydrogen discharge by means of a one-dimensional numerical fluid model and experiments. The model includes a detailed description of the gas-phase chemistry taking into account the production of H{sup -} ions by dissociative attachment of H{sub 2} vibrational levels. The population of these levels is described by a Boltzmann vibrational distribution function characterized by a vibrational temperature T{sub V}. The effect of the dissociative-attachment reaction on the discharge dynamics was investigated by varying the vibrational temperature, which was used as a model input parameter. Increasing the vibrational temperature from 1000 to 6000 K affects both the chemistry and the dynamics of the electrical discharge. Because of dissociative attachment, the H{sup -} ion density increases by seven orders of magnitude and the H{sup -} ion density to electron density ratio varies from 10{sup -7} to 6, while the positive ion density increases slightly. As a consequence, the atomic hydrogen density increases by a factor of three, and the sheath voltage drops from 95 to 75 V. Therefore, clear evidence of a strong coupling between chemistry and electrical dynamics through the production of H{sup -} ions is demonstrated. Moreover, satisfactory agreement between computed and measured values of atomic hydrogen and H{sup -} ion densities gives further support to the requirement of a detailed description of the hydrogen vibrational kinetics for capacitively coupled radio frequency discharge models in the Torr regime.

  12. Thermochemical Nonequilibrium 2D Modeling of Nitrogen Inductively Coupled Plasma Flow

    Science.gov (United States)

    Yu, Minghao; Yusuke, Takahashi; Hisashi, Kihara; Ken-ichi, Abe; Kazuhiko, Yamada; Takashi, Abe; Satoshi, Miyatani

    2015-09-01

    Two-dimensional (2D) numerical simulations of thermochemical nonequilibrium inductively coupled plasma (ICP) flows inside a 10-kW inductively coupled plasma wind tunnel (ICPWT) were carried out with nitrogen as the working gas. Compressible axisymmetric Navier-Stokes (N-S) equations coupled with magnetic vector potential equations were solved. A four-temperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles. The third-order accuracy electron transport properties (3rd AETP) were applied to the simulations. A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process. The flow characteristics such as thermal nonequilibrium, inductive discharge, effects of Lorentz force were made clear through the present study. It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field. The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT. supported by Grant-in-Aid for Scientific Research (No. 23560954), sponsored by the Japan Society for the Promotion of Science

  13. Simultaneous electrothermal vaporization and nebulizer sample introduction system for inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The novel analytical application of the combination of an inline electrothermal vaporization (ETV) and nebulization source for inductively coupled plasma mass spectrometry (ICP-MS) has been studied. Wet plasma conditions are sustained during ETV introduction by 200 mL/min gas flow through the nebulizer, which is merged with the ETV transport line at the torch. The use of a wet plasma with ETV introduction avoided the need to change power settings and torch positions that normally accompany a change from wet to dry plasma operating conditions. This inline-ETV source is shown to have good detection limits for a variety of elements in both HNO3 and HCl matrices. Using the inline-ETV source, improved limits of detection (LOD) were obtained for elements typically suppressed by polyatomic interferences using a nebulizer. Specifically, improved LODs for 51V and 53Cr suffering from Cl interferences (51ClO+ and 53ClO+ respectively) in a 1% HCl matrix were obtained using the inline-ETV source. LODs were improved by factors of 65 and 22 for 51V and 53Cr, respectively, using the inline-ETV source compared to a conventional concentric glass nebulizer. For elements without polyatomic interferences, LODs from the inline-ETV were comparable to conventional dry plasma ETV-ICP time-of-flight mass spectrometry results. Lastly, the inline-ETV source offers a simple means of changing from nebulizer introduction to inline-ETV introduction without extinguishing the plasma. This permits, for example, the use of the time-resolved ETV-ICP-MS signals to distinguish between an analyte ion and polyatomic isobar.

  14. External control of electron energy distributions in a dual tandem inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Sridhar, Shyam; Zhu, Weiye; Donnelly, Vincent M., E-mail: vmdonnelly@uh.edu; Economou, Demetre J., E-mail: economou@uh.edu [Plasma Processing Laboratory, Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204-4004 (United States); Logue, Michael D.; Kushner, Mark J., E-mail: mjkush@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

    2015-08-28

    The control of electron energy probability functions (EEPFs) in low pressure partially ionized plasmas is typically accomplished through the format of the applied power. For example, through the use of pulse power, the EEPF can be modulated to produce shapes not possible under continuous wave excitation. This technique uses internal control. In this paper, we discuss a method for external control of EEPFs by transport of electrons between separately powered inductively coupled plasmas (ICPs). The reactor incorporates dual ICP sources (main and auxiliary) in a tandem geometry whose plasma volumes are separated by a grid. The auxiliary ICP is continuously powered while the main ICP is pulsed. Langmuir probe measurements of the EEPFs during the afterglow of the main ICP suggests that transport of hot electrons from the auxiliary plasma provided what is effectively an external source of energetic electrons. The tail of the EEPF and bulk electron temperature were then elevated in the afterglow of the main ICP by this external source of power. Results from a computer simulation for the evolution of the EEPFs concur with measured trends.

  15. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    Science.gov (United States)

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-06-01

    We propose a method to measure the densities of vibrationally excited Cl2(v) molecules in levels up to v  =  3 in pure chlorine inductively coupled plasmas (ICPs). The absorption continuum of Cl2 in the 250-450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mechanism of the Cl2 feedstock in the plasma. In these line-integrated absorption measurements, the absorption by the hot (and therefore rarefied) Cl2 gas in the reactor centre is masked by the cooler (and therefore denser) Cl2 near the walls. These radial gradients in temperature and density make it difficult to assess the degree of vibrational excitation in the centre of the reactor. The observed line-averaged vibrational distributions, when analyzed taking into account the radial temperature gradient, suggest that vibrational and translational degrees of freedom in the plasma are close to local equilibrium. This can be explained by efficient vibrational-translational (VT) relaxation between Cl2 and Cl atoms. Besides the Cl2(v) absorption band, a weak continuum absorption is observed at shorter wavelengths, and is attributed to photodetachment of Cl- negative ions. Thus, line-integrated densities of negative ions in chlorine plasmas can be directly measured using broad-band absorption spectroscopy.

  16. Partons and jets in a strongly-coupled plasma from AdS/CFT

    CERN Document Server

    Iancu, Edmond

    2008-01-01

    We give a pedagogical review of recent progress towards understanding the response of a strongly coupled plasma at finite temperature to a hard probe. The plasma is that of the N=4 supersymmetric Yang-Mills theory and the hard probe is a virtual photon, or, more precisely, an R-current. Via the gauge/gravity duality, the problem of the current interacting with the plasma is mapped onto the gravitational interaction between a Maxwell field and a black hole embedded in the AdS_5 x S^5 geometry. The physical interpretation of the AdS/CFT results can be then reconstructed with the help of the ultraviolet/infrared correspondence. We thus deduce that, for sufficiently high energy, the photon (or any other hard probe: a quark, a gluon, or a meson) disappears into the plasma via a universal mechanism, which is quasi-democratic parton branching: the current develops a parton cascade such that, at any step in the branching process, the energy is almost equally divided among the daughter partons. The branching rate is c...

  17. High Resolution Studies of the Origins of Polyatomic Ions in Inductively Coupled Plasma-Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jill Wisnewski Ferguson

    2006-08-09

    The inductively coupled plasma (ICP) is an atmospheric pressure ionization source. Traditionally, the plasma is sampled via a sampler cone. A supersonic jet develops behind the sampler, and this region is pumped down to a pressure of approximately one Torr. A skimmer cone is located inside this zone of silence to transmit ions into the mass spectrometer. The position of the sampler and skimmer cones relative to the initial radiation and normal analytical zones of the plasma is key to optimizing the useful analytical signal [1]. The ICP both atomizes and ionizes the sample. Polyatomic ions form through ion-molecule interactions either in the ICP or during ion extraction [l]. Common polyatomic ions that inhibit analysis include metal oxides (MO{sup +}), adducts with argon, the gas most commonly used to make up the plasma, and hydride species. While high resolution devices can separate many analytes from common interferences, this is done at great cost in ion transmission efficiency--a loss of 99% when using high versus low resolution on the same instrument [2]. Simple quadrupole devices, which make up the bulk of ICP-MS instruments in existence, do not present this option. Therefore, if the source of polyatomic interferences can be determined and then manipulated, this could potentially improve the figures of merit on all ICP-MS devices, not just the high resolution devices often utilized to study polyatomic interferences.

  18. Plasma-field Coupling at Small Length Scales in Solar Wind Near 1 AU

    Science.gov (United States)

    Livadiotis, G.; Desai, M. I.

    2016-10-01

    In collisionless plasmas such as the solar wind, the coupling between plasma constituents and the embedded magnetic field occurs on various temporal and spatial scales, and is primarily responsible for the transfer of energy between waves and particles. Recently, it was shown that the transfer of energy between solar wind plasma particles and waves is governed by a new and unique relationship: the ratio between the magnetosonic energy and the plasma frequency is constant, E ms/ω pl ˜ ℏ*. This paper examines the variability and substantial departure of this ratio from ℏ* observed at ˜1 au, which is caused by a dispersion of fast magnetosonic (FMS) waves. In contrast to the efficiently transferred energy in the fast solar wind, the lower efficiency of the slow solar wind can be caused by this dispersion, whose relation and characteristics are derived and studied. In summary, we show that (i) the ratio E ms/ω pl transitions continuously from the slow to the fast solar wind, tending toward the constant ℏ* (ii) the transition is more efficient for larger thermal, Alfvén, or FMS speeds; (iii) the fast solar wind is almost dispersionless, characterized by quasi-constant values of the FMS speed, while the slow wind is subject to dispersion that is less effective for larger wind or magnetosonic speeds; and (iv) the constant ℏ* is estimated with the best known precision, ℏ* ≈ (1.160 ± 0.083) × 10-22 Js.

  19. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  20. Expressing self-absorption in the analytical function of inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Kántor, Tibor; Bartha, András

    2015-11-01

    The self-absorption of spectral lines was studied with up to date multi-element inductively coupled plasma atomic emission spectrometry (ICP-AES) instrumentation using radial and axial viewing of the plasma, as well, performing line peak height and line peak area measurements. Two resonance atomic and ionic lines of Cd and Mg were studied, the concentration range was extended up to 2000 mg/L. At the varying analyte concentration, constant matrix concentration of 10,000 mg/L Ca was ensured in the pneumatically nebulized solutions. The physical and the phenomenological formulation of the emission analytical function is overviewed and as the continuity of the earlier results the following equation is offered:

  1. [Plasma temperature calculation and coupling mechanism analysis of laser-double wire hybrid welding].

    Science.gov (United States)

    Zheng, Kai; Li, Huan; Yang, Li-Jun; Gu, Xiao-Yan; Gao, Ying

    2013-04-01

    The plasma radiation of laser-double wire hybrid welding was collected by using fiber spectrometer, the coupling mechanism of arc with laser was studied through high-speed photography during welding process, and the temperature of hybrid plasma was calculated by using the method of Boltzmann plot. The results indicated that with laser hybrid, luminance was enhanced; radiation intensity became stronger; arc was attracted to the laser point; cross section contracted and arc was more stable. The laser power, welding current and arc-arc distance are important factors that have great influence on electron temperature. Increase in the laser power, amplification of welding current and reduction of arc-arc distance can all result in the rise of temperature. PMID:23841392

  2. Inductively coupled plasma induced deep levels in epitaxial n-GaAs

    International Nuclear Information System (INIS)

    The electronic properties of defects introduced by low energy inductively coupled Ar plasma etching of n-type (Si doped) GaAs were investigated by deep level transient spectroscopy (DLTS) and Laplace DLTS. Several prominent electron traps (Ec—0.046 eV, Ec—0.186 eV, Ec—0.314 eV. Ec—0.528 eV and Ec—0.605 eV) were detected. The metastable defect Ec—0.046 eV having a trap signature similar to E1 is observed for the first time. Ec—0.314 eV and Ec—0.605 eV are metastable and appear to be similar to the M3 and M4 defects present in dc H-plasma exposed GaAs.

  3. Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

    Energy Technology Data Exchange (ETDEWEB)

    Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

    2014-10-28

    We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

  4. Three-dimensional antenna coupling to core plasma in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.D.; Jaeger, E.F.; Stallings, D.C.; Galambos, J.D.; Batchelor, D.B.; Wang, C.Y.

    1995-09-01

    A complete understanding of the RF physics from the launcher to the plasma core is required to fully analyze RF experiments and to evaluate the performance of RF antenna designs in ITER. This understanding requires a consistent model for the RF power launching system, propagation and absorption through the edge region, and the response of the core plasma to the RF power. As a first step toward such a model, the three-dimensional (3D) antenna modeling code, RANT3D, has been coupled with the reduced order full wave code, PICES. Preliminary results from this model are presented in this paper for parameters similar to those found in the DIII-D experiment.

  5. Coupling and ionization effects on hydrogen spectral line shapes in dense plasmas

    Science.gov (United States)

    Calisti, A.; Bureyeva, L. A.; Lisitsa, V. S.; Shuvaev, D.; Talin, B.

    2007-06-01

    A study of hydrogen lines emitted in dense and low temperature plasmas is presented. Coupling and ionization effects in a transition from impact to quasi-static broadening for electrons are analyzed with the help of the Frequency Fluctuation Model (FFM). Electron broadening of Balmer series lines is studied for different densities and temperatures spanning a wide domain from impact to quasi-static limit. It is shown that electronic broadening makes a transition from impact to quasi-static limit depending on plasma conditions and principal quantum number. Even for the Balmer alpha line, at a density equals 1018 cm-3 and a temperature equals 1 eV, this transition occurs both in the wings and the core of the line.

  6. Improving the uniformity of RF-plasma density by a humped variable-gap spiral antenna

    Institute of Scientific and Technical Information of China (English)

    Xu Xu; Li Lin-Sen; Liu Feng; Zhou Qian-Hong; Liang Rong-Qing

    2008-01-01

    This paper develops a humped spiral antenna of top inductively coupled plasma with variable gap.Comparing with planar spiral antennas,it investigates the performance of humped spiral antennae in the calculated electromagnetic configurations and experimental results.It finds that the humped antenna has the improved uniformity of plasma density in the radial direction and the decreased electron temperature in the top inductively coupled plasma.By experimental and theoretical analyses,the plasma performance in the case of humped antennae is considered to be the combined results of the uniform electromagnetic configurations and the depressed capacitively coupling effect.

  7. Calculation and Analysis of Capacitive Sensor Plate Coupling Angular Displacement of Parallel Beam%平行梁式电容传感器极板耦合角位移计算和分析

    Institute of Scientific and Technical Information of China (English)

    李巨韬; 郭伟; 王建

    2013-01-01

    为了解决平行梁式电容称重传感器极板耦合角位移带来的输出电容值与输入载荷之间的非线性问题,运用力法对平行梁式弹性体超静定结构进行了计算分析,得出了与上下极板夹角关联的主要结构参数,通过内力对极板角度进行了解析,并在有限元软件中验证了计算的正确性.此结果为平行梁通过结构参数设计优化耦合角位移提供了理论方法,并根据非平行板电容计算公式,构建了更加精确的载荷与电容的数学模型,为传感器输出输入特性曲线的拟合提供了依据.%In order to solve nonlinear problems of the output capacitor value and the input load for which plate coupling angular displacement causes in parallel beam capacitive sensor,calculating and analyzing is made in this paper to the statically indeterminate structure of parallel beam elastomer in terms of the force method,and gets the main structural parameters correlating to the angle between the upper and lower plate.The coupling angle has been calculated by internal forces,and the conclusions have been confirmed in the finite element simulation.This conclusion can provide the theoretical approach for optimizing coupling angular displacement by means of designing the structure parameters of the parallel beam,meanwhile based on Non-parallel plate capacitor formula,a more accurate analytical model of load and capacitance has been constructed,which can provide the basis for fitting of the sensor input-output characteristic curve.

  8. Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

    International Nuclear Information System (INIS)

    Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system (ρ,ξ) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number α as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions

  9. Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S.Y.

    1991-07-01

    Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system ({rho},{xi}) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number {alpha} as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions.

  10. Oblique collision of dust acoustic solitons in a strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    The oblique collision between two equal amplitude dust acoustic solitons is observed in a strongly coupled dusty plasma. The solitons are subjected to oblique interaction at different colliding angles. We observe a resonance structure during oblique collision at a critical colliding angle which is described by the idea of three wave resonance interaction modeled by Kadomtsev-Petviashvili equation. After collision, the solitons preserve their identity. The amplitude of the resultant wave formed during interaction is measured for different collision angles as well as for different colliding soliton amplitudes. At resonance, the maximum amplitude of the new soliton formed is nearly 3.7 times the initial soliton amplitude

  11. Optimized condition for etching fused-silica phase gratings with inductively coupled plasma technology.

    Science.gov (United States)

    Wang, Shunquan; Zhou, Changhe; Ru, Huayi; Zhang, Yanyan

    2005-07-20

    Polymer deposition is a serious problem associated with the etching of fused silica by use of inductively coupled plasma (ICP) technology, and it usually prevents further etching. We report an optimized etching condition under which no polymer deposition will occur for etching fused silica with ICP technology. Under the optimized etching condition, surfaces of the fabricated fused silica gratings are smooth and clean. Etch rate of fused silica is relatively high, and it demonstrates a linear relation between etched depth and working time. Results of the diffraction of gratings fabricated under the optimized etching condition match theoretical results well.

  12. Inductively Coupled Plasma Optical-Emission Spectroscopy Determination of Major and Minor Elements in Vinegar

    Directory of Open Access Journals (Sweden)

    Arzu AKPINAR-BAYIZIT

    2010-12-01

    Full Text Available This study characterizes the mineral content of vinegar samples. The concentrations of Na, K, Ca, Mg and P (major elements as well as Fe, Mn, Sn, Cu, Ni, Zn, Pb and Cd (minor elements were determined in 35 commercial vinegar samples using inductively coupled plasma optical-emission spectrometry (ICP-OES. The elements with the highest concentrations were K, Na, Ca, Mg and P. The concentrations of heavy metals in the vinegar samples, including Cd, Ni, Sn and Pb, were not considered a health risk.

  13. Damping of hard excitations in strongly coupled $\\mathcal N\\,{=}\\,4$ plasma

    CERN Document Server

    Fuini, John F; Yaffe, Laurence G

    2016-01-01

    The damping of high momentum excitations in strongly coupled maximally supersymmetric Yang-Mills plasma is studied. Previous calculations of the asymptotic behavior of the quasinormal mode spectrum are extended and clarified. We confirm that subleading corrections to the lightlike dispersion relation $\\omega({\\bf q}) = |{\\bf q}|$ have a universal $|{\\bf q}|^{-1/3}$ form. Sufficiently narrow, weak planar shocks may be viewed as coherent superpositions of short wavelength quasinormal modes. The attenuation and evolution in profile of narrow planar shocks are examined as an application of our results.

  14. Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

    Institute of Scientific and Technical Information of China (English)

    FEI Yan-qun; LUO Gui-min; FENG Guo-dong; CHEN Huan-wen; FEI Qiang; HUAN Yan-fu; JIN Qin-han

    2008-01-01

    This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry (MPT-AES) coupled with online preconcentration vapor generation method.A new desolvation device,multistrand Nation dryer,was used as the substitute for condenser desolvation system.Some experimental conditions,such as preconcentration time,acidity of sample solution,rinsing solution acidity and dynamic linear range were investigated and optimized.The new desolvation system eliminates the problem of decreasing emission intensity of I(I) 206.238 nm line with the increase of working time on a conventional condenser desolvation system,thus greatly improving the reproducibility.

  15. Effect of neutral gas heating in argon radio frequency inductively coupled plasma

    International Nuclear Information System (INIS)

    Heating of neutral gas in inductively coupled plasma (ICP) is known to result in neutral gas depletion. In this work, this effect is considered in the simulation of the magnetic field distribution of a 13.56 MHz planar coil ICP. Measured electron temperatures and densities at argon pressures of 0.03, 0.07 and 0.2 mbar were used in the simulation whilst neutral gas temperatures were heuristically fitted. The simulated results showed reasonable agreement with the measured magnetic field profile. (author)

  16. Oblique collision of dust acoustic solitons in a strongly coupled dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Boruah, A.; Sharma, S. K., E-mail: sumita-sharma82@yahoo.com; Bailung, H.; Nakamura, Y. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati 781035 (India)

    2015-09-15

    The oblique collision between two equal amplitude dust acoustic solitons is observed in a strongly coupled dusty plasma. The solitons are subjected to oblique interaction at different colliding angles. We observe a resonance structure during oblique collision at a critical colliding angle which is described by the idea of three wave resonance interaction modeled by Kadomtsev-Petviashvili equation. After collision, the solitons preserve their identity. The amplitude of the resultant wave formed during interaction is measured for different collision angles as well as for different colliding soliton amplitudes. At resonance, the maximum amplitude of the new soliton formed is nearly 3.7 times the initial soliton amplitude.

  17. New type X—ray mask fabricated using inductvely coupled plasma deepetching

    Institute of Scientific and Technical Information of China (English)

    D.Chen; W.Lei; S.Wang; C.Li; X.Guo; H.Mao; D.Zhang; F.Yi

    2001-01-01

    The fabrication of X-ray masks is a critical and challenging process in LIGA technique.As inductively coupled plasma(ICP) deepetching appears to be the most suitable source for deep silicon etching,we fabricated a new type X-ray mask using this technique.In comparison with other types of X-ray masks,the mask we fabricated has the advantages of its low cost and its simple fabrication process.Besired microstructures have also been fabricated using this new type X-ray mask in LIGA technique.

  18. Concentrations of Th and U in human tissues determined by inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    In about 20 specimens of untreated human soft tissues, Th and U, were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). The concentration values obtained, particularly in the case of U, tended to be lower than reported ones. In order to investigate the source of the discrepancy, human tissue samples (treated for preservation), which had been analyzed for U in the previous study by fission tracks, were analyzed again by ICP-MS. This demonstrated the difference may be a reflection of the variance between treated and untreated samples. The problems involved in the analysis and the sample treatment are discussed. (author)

  19. Determination of thorium and uranium in total diet samples by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The Th and U contents in total diet samples were determined by inductively coupled plasma mass spectrometry (ICP-MS). The internal standardization method was adopted to compensate for non-spectral interferences arising from matrix elements in the sample solutions. Concentration levels of the order of pg ml-1 of Th and U in the total diet sample were determined easily and rapidly by using Bi as an internal standard. The mean concentrations and standard deviations of Th and U in the total diet samples were found to be 25 ± 12 and 44 ± 20 ng g-1 of ash, respectively (for n = 62). (author)

  20. Production date determination of uranium-oxide materials by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    The paper describes analytical methods developed for the production date determination of uranium-based nuclear materials by the measurement of 230Th/234U isotope ratio. An improved sample preparation method for the destructive analysis involving extraction chromatographic separation with TEVATM resin was applied prior to the measurement by isotope dilution inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The results obtained were compared with the direct, quasi-non-destructive measurement using laser ablation ICP-SFMS technique for age determination. The advantages and limitations of both methods are discussed

  1. Study of the linear and non-linear coupling of the LH wave to the tokamak plasmas

    International Nuclear Information System (INIS)

    In order to achieve long pulse operation with a tokamak, additional heating and current drive systems are necessary. High frequency antennas, which deliver several megawatts of power to the plasma, are currently used in several tokamaks. Moreover, a good control of the coupling of the wave launched by the antenna to the edge plasma is required to optimize the efficiency of heating and current drive LH systems. However, non-linear effects which depend on the level of injected power in the plasma strongly damage the coupling of the LH wave at particular edge parameters (density and temperature profiles). Results presented in the manuscript deal with the study of the linear and non-linear coupling of the LH wave to the plasma. In the framework of the commissioning of the Passive Active Multijunction antenna in 2009 on the Tore Supra tokamak aiming at validating the LH system suggested for ITER, the characterisation of its coupling properties was realized from low power experiments. The experimental results, which are compared with the linear coupling code ALOHA, have validated the theoretical predictions of good coupling at edge plasma density around the cut-off density. Besides, the ponderomotive effect is clearly identified as responsible for the deterioration in the coupling of the wave, which is measured under particular edge plasma conditions. A theoretical model combining the coupling of the LH wave with the ponderomotive force is suggested to explain the experimental observations. Thus, a new full wave code (named PICCOLO-2D) was developed and results from simulations validate the working hypothesis of the contribution of the ponderomotive effect in the non-linear observations of LHCD coupling on Tore Supra. (author)

  2. Determination of technetium-99 in soil samples by high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    A new powerful analytical technique viz. high performance liquid chromatography(HPLC) coupled to inductively coupled plasma mass spectrometry(HPLC/ICP-MS) has been applied to the determination of technetium-99(99Tc) in soils as a typical environmental sample. Technetium was enriched in a solution from incinerated soil samples by leaching in HNO3 and passed through 'TEVA resin' column. The solution was injected into HPLC/ICP-MS system to eliminate the interfering elements (i.e. Ru and Mo) and to determine the 99Tc concentration at the same time. The concentrations of 99Tc in the incinerated soils were found to be 0.49Bq/kg(0.77ng/kg)-1.4Bq/kg(2.2ng/kg) with the determination limit of 0.02Bq/kg(0.03ng/kg(0.03ppt)). The results indicate the following findings; 1) the determination of 99Tc by ICP-MS after strict elimination of the interfering elements by HPLC brings about the improvement in their reliability; 2) the detection limits identified are much lower compared with those by conventional ICP-MS methods because of the concentration of 99Tc to smaller volume, which is due to only 100μl of samples could be measured by HPLC/ICP-MS system; 3) sample preparation could be simplified because of strict elimination of the interfering elements by HPLC. This research showed that HPLC/ICP-MS system is very effective to determine 99Tc in environmental samples. (author)

  3. Charge creation and nucleation of the longitudinal plasma wave in coupled Josephson junctions

    Science.gov (United States)

    Shukrinov, Yu. M.; Hamdipour, M.

    2010-11-01

    We study the phase dynamics in coupled Josephson junctions described by a system of nonlinear differential equations. Results of detailed numerical simulations of charge creation in the superconducting layers and the longitudinal plasma wave (LPW) nucleation are presented. We demonstrate the different time stages in the development of the LPW and present the results of FFT analysis at different values of bias current. The correspondence between the breakpoint position on the outermost branch of current voltage characteristics (CVC) and the growing region in time dependence of the electric charge in the superconducting layer is established. The effects of noise in the bias current and the external microwave radiation on the charge dynamics of the coupled Josephson junctions are found. These effects introduce a way to regulate the process of LPW nucleation in the stack of IJJ.

  4. Fast, Deep-Record-Length, Fiber-Coupled Photodiode Imaging Array for Plasma Diagnostics

    Science.gov (United States)

    Brockington, Samuel; Case, Andrew; Witherspoon, F. Douglas

    2015-11-01

    HyperV Technologies has been developing an imaging diagnostic comprised of an array of fast, low-cost, long-record-length, fiber-optically-coupled photodiode channels to investigate plasma dynamics and other fast, bright events. By coupling an imaging fiber bundle to a bank of amplified photodiode channels, imagers and streak imagers can be constructed. By interfacing analog photodiode systems directly to commercial analog-to-digital converters and modern memory chips, a scalable solution for 100 to 1000 pixel systems with 14 bit resolution and record-lengths of 128k frames has been developed. HyperV is applying these techniques to construct a prototype 1000 Pixel framing camera with up to 100 Msamples/sec rate and 10 to 14 bit depth. Preliminary experimental results as well as future plans will be discussed. Work supported by USDOE Phase 2 SBIR Grant DE-SC0009492.

  5. Spin Polarized Photons from Axially Charged Plasma at Weak Coupling: Complete Leading Order

    CERN Document Server

    Mamo, Kiminad A

    2015-01-01

    In the presence of (approximately conserved) axial charge in the QCD plasma at finite temperature, the emitted photons are spin-aligned, which is a unique P- and CP-odd signature of axial charge in the photon emission observables. We compute this "P-odd photon emission rate" in weak coupling regime at high temperature limit to complete leading order in the QCD coupling constant: the leading log as well as the constant under the log. As in the P-even total emission rate in the literature, the computation of P-odd emission rate at leading order consists of three parts: 1) Compton and Pair Annihilation processes with hard momentum exchange, 2) soft t- and u-channel contributions with Hard Thermal Loop re-summation, 3) Landau-Pomeranchuk-Migdal (LPM) re-summation of collinear Bremstrahlung and Pair Annihilation. We present analytical and numerical evaluations of these contributions to our P-odd photon emission rate observable.

  6. Novel applications of high performance ion chromatography - inductively coupled plasma mass spectrometry (HPIC-ICP-MS)

    International Nuclear Information System (INIS)

    This work demonstrates the development of highly sensitive and selective analytical methods, which make use of the hyphenation of high performance ion chromatography (HPIC) to inductively coupled plasma sector field mass spectrometry (ICP-SFMS). On-line coupling a chromatographic separation method with an elemental detection method provides two advantages: (1) The components of a possibly interfering matrix can be separated allowing accurate and precise ultra trace analysis of the element of interest and (2) elemental species of an element can be separated and quantified. In this work, matrix separation methods for interference free determination of 232Th, 234U, 235U and 238U in geological matrices were developed and employed. Furthermore HPIC-ICP-SFMS was applied for ultra trace analysis of Pd in environmental and geological matrices. The usefulness of HPIC-ICP-SFMS for speciation studies was demonstrated by investigating the interaction of an anti-cancer drug (cisplatin) with guanosine monophosphates. (author)

  7. Deactivation of lipopolysaccharide by Ar and H2 inductively coupled low-pressure plasma

    Science.gov (United States)

    Bartis, E. A. J.; Barrett, C.; Chung, T.-Y.; Ning, N.; Chu, J.-W.; Graves, D. B.; Seog, J.; Oehrlein, G. S.

    2014-01-01

    Using an inductively coupled plasma system, we study the effects of direct plasma, plasma-generated high-energy photons in the ultraviolet and vacuum ultraviolet (UV/VUV), and radical treatments on lipopolysaccharide (LPS). LPS is a biomolecule found in the outer membrane of Gram-negative bacteria and a potent stimulator of the immune system composed of polysaccharide and lipid A, which contains six aliphatic chains. LPS film thickness spun on silicon was monitored by ellipsometry while the surface chemistry was characterized before and after treatments by x-ray photoelectron spectroscopy (XPS). Additionally, biological activity was measured using an enzyme-linked immunosorbent assay under (a) a sensitive regime (sub-µM concentrations of LPS) and (b) a bulk regime (above µM concentrations of LPS) after plasma treatments. Direct plasma treatment causes rapid etching and deactivation of LPS in both Ar and H2 feed gases. To examine the effect of UV/VUV photons, a long-pass filter with a cut-off wavelength of 112 nm was placed over the sample. H2 UV/VUV treatment causes material removal and deactivation due to atomic and molecular UV/VUV emission while Ar UV/VUV treatment shows minimal effects as Ar plasma does not emit UV/VUV photons in the transmitted wavelength range explored. Interestingly, radical treatments remove negligible material but cause deactivation. Based on the amphiphilic structure of LPS, we expect a lipid A rich surface layer to form at the air-water interface during sample preparation with polysaccharide layers underneath. XPS shows that H2 plasma treatment under direct and UV/VUV conditions causes oxygen depletion through removal of C-O and O-C = O bonds in the films, which does not occur in Ar treatments. Damage to these groups can remove aliphatic chains that contribute to the pyrogenicity of LPS. Radical treatments from both Ar and H2 plasmas remove aliphatic carbon from the near-surface, demonstrating the important role of neutral species.

  8. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  9. System for Measuring Capacitance

    Science.gov (United States)

    McNichol, Randal S. (Inventor)

    2001-01-01

    A system has been developed for detecting the level of a liquid in a tank wherein a capacitor positioned in the tank has spaced plates which are positioned such that the dielectric between the plates will be either air or the liquid, depending on the depth of the liquid in the tank. An oscillator supplies a sine wave current to the capacitor and a coaxial cable connects the capacitor to a measuring circuit outside the tank. If the cable is very long or the capacitance to be measured is low, the capacitance inherent in the coaxial cable will prevent an accurate reading. To avoid this problem, an inductor is connected across the cable to form with the capacitance of the cable a parallel resonant circuit. The impedance of the parallel resonant circuit is infinite, so that attenuation of the measurement signal by the stray cable capacitance is avoided.

  10. Capacitance pressure sensor

    Science.gov (United States)

    Eaton, William P.; Staple, Bevan D.; Smith, James H.

    2000-01-01

    A microelectromechanical (MEM) capacitance pressure sensor integrated with electronic circuitry on a common substrate and a method for forming such a device are disclosed. The MEM capacitance pressure sensor includes a capacitance pressure sensor formed at least partially in a cavity etched below the surface of a silicon substrate and adjacent circuitry (CMOS, BiCMOS, or bipolar circuitry) formed on the substrate. By forming the capacitance pressure sensor in the cavity, the substrate can be planarized (e.g. by chemical-mechanical polishing) so that a standard set of integrated circuit processing steps can be used to form the electronic circuitry (e.g. using an aluminum or aluminum-alloy interconnect metallization).

  11. Induced Charge Capacitive Deionization

    OpenAIRE

    Rubin, S.; Suss, M. E.; Biesheuvel, P. M.; Bercovici, M.

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, ...

  12. Nonlinear Quantum Capacitance

    OpenAIRE

    Wang, B; Zhao, X; Guo, H; Wang, J.

    1999-01-01

    We analyze the nonlinear voltage dependence of electrochemical capacitance for nanoscale conductors. This voltage dependence is due to the finite density of states of the conductors. Within Hartree theory we derive an exact expression for the electrochemical capacitance–voltage curve for a parallel plate system. The result suggests a quantum scanning capacitance microscopy at the nanoscale: by inverting the capacitance–voltage expression one is able to deduce the local spectral function of th...

  13. Coupling of methane under pulse corona plasma (Ⅰ)——In the absence of oxygen

    Institute of Scientific and Technical Information of China (English)

    朱爱民; 宫为民; 张秀玲; 张报安

    2000-01-01

    At normal temperature and pressure, pulse corona plasma was used as a new method for the dehydrogenative coupling of methane in the absence of oxygen. The effects of voltage polarity and input energy on the dehydrogenative coupling of methane were investigated. The parameter "energy efficiency" was introduced to examine the coupling of the input energy and the dehydrogenative coupling of methane. The experimental results show that positive corona gives higher energy efficiency than negative corona. When the positive corona was chosen, C2. yield per pass was 31.6% and acetylene yield per pass was 30.1% with 44.6% methane conversion at an input energy density of 1788kJ/mol and a pulse repetition frequency of 66Hz. The function of input energy density towards methane conversion may be expressed as a formula of -ln(1-X) = k (P/F). In the range of input energy employed, C2 yield is proportional to input energy density, but energy efficiency drops off with increasing input energy density.

  14. Transport of Sputtered Particles in Capacitive Sputter Sources

    CERN Document Server

    Trieschmann, Jan

    2015-01-01

    The transport of sputtered aluminum inside a multi frequency capacitively coupled plasma chamber is simulated by means of a kinetic test multi-particle approach. A novel consistent set of scattering parameters obtained for a modified variable hard sphere collision model is presented for both argon and aluminum. An angular dependent Thompson energy distribution is fitted to results from Monte-Carlo simulations and used for the kinetic simulation of the transport of sputtered aluminum. For the proposed configuration the transport of sputtered particles is characterized under typical process conditions at a gas pressure of p = 0.5 Pa. It is found that - due to the peculiar geometric conditions - the transport can be understood in a one dimensional picture, governed by the interaction of the imposed and backscattered particle fluxes. It is shown that the precise geometric features play an important role only in proximity to the electrode edges, where the effect of backscattering from the outside chamber volume be...

  15. Simulating Capacitances to Silicon Quantum Dots: Breakdown of the Parallel Plate Capacitor Model

    Science.gov (United States)

    Thorbeck, Ted; Fujiwara, Akira; Zimmerman, Neil M.

    2012-09-01

    Many electrical applications of quantum dots rely on capacitively coupled gates; therefore, to make reliable devices we need those gate capacitances to be predictable and reproducible. We demonstrate in silicon nanowire quantum dots that gate capacitances are reproducible to within 10% for nominally identical devices. We demonstrate the experimentally that gate capacitances scale with device dimensions. We also demonstrate that a capacitance simulator can be used to predict measured gate capacitances to within 20%. A simple parallel plate capacitor model can be used to predict how the capacitances change with device dimensions; however, the parallel plate capacitor model fails for the smallest devices because the capacitances are dominated by fringing fields. We show how the capacitances due to fringing fields can be quickly estimated.

  16. Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo, E-mail: bradywang@hit.edu.cn; Li, Guo; Ding, Fei; Jin, Huiliang

    2015-06-30

    Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP.

  17. Coupling ion-exchangers with inexpensive activated carbon fiber electrodes to enhance the performance of capacitive deionization cells for domestic wastewater desalination.

    Science.gov (United States)

    Liang, Peng; Yuan, Lulu; Yang, Xufei; Zhou, Shaoji; Huang, Xia

    2013-05-01

    A capacitive deionization (CDI) cell was built with electrodes made of an inexpensive commercial activated carbon fiber (ACF), and then modified by incorporating ion-exchangers into the cell compartment. Three modified CDI designs were tested: MCDI - a CDI with electrodes covered by ion-exchange membranes (IEMs) of the same polarity, FCDI - a CDI with electrodes covered by ion-exchange felts (IEFs), and R-MCDI - an MCDI with cell chamber packed with ion-exchange resin (IER) granules. The cell was operated in the batch reactor mode with an initial salt concentration of 1000 mg/L NaCl, a typical level of domestic wastewater. The desalination tests involved investigations of two consecutive operation stages of CDIs: electrical adsorption (at an applied voltage of 1.2 V) and desorption [including short circuit (SC) desorption and discharge (DC) desorption]. The R-MCDI showed the highest electric adsorption as measured in the present study by desalination rate [670 ± 20 mg/(L h)] and salt removal efficiency (90 ± 1%) at 60 min, followed by the MCDI [440 ± 15 mg/(L h) and 60 ± 2%, respectively]. The superior desalination performance of the R-MCDI over other designs was also affirmed by its highest charge efficiency (110 ± 7%) and fastest desorption rates at both the SC [1960 ± 15 mg/(L·h)] and DC [3000 ± 20 mg/(L·h)] modes. The desalination rate and salt removal efficiency of the R-MCDI increased from ∼270 mg/(L h) and 83% to ∼650 mg/(L h) and 98% respectively when the applied voltage increased from 0.6 V to 1.4 V, while decreased slightly when lowering the salt water flow rate that fed into the cell. The packing of IER granules in the R-MCDI provided additional surface area for ions transfer; meanwhile, according to the results of electrochemical impedance spectroscopy (EIS) analysis, it substantially lower down the R-MCDI's ohmic resistance, resulting in improved desalination performance. PMID:23497976

  18. Quantitation of motexafin lutetium in human plasma by liquid chromatography-tandem mass spectrometry and inductively coupled plasma-atomic emission spectroscopy

    OpenAIRE

    Miles, Dale; Mody, Tarak D.; Hatcher, Lori I.; Fiene, John; Stiles, Mark; Patrick P. Lin; Lee, J.W.

    2003-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) methods were developed and validated for the evaluation of motexafin lutetium (MLu, lutetium texaphyrin, PCI-0123) pharmacokinetics in human plasma. The LC-MS/MS method was specific for MLu, whereas the ICP-AES method measured total elemental lutetium. Both methods were fast, simple, precise, and accurate. For the LC-MS/MS method, a closely related analogue (PCI-0353...

  19. Quantum capacitance: a microscopic derivation

    OpenAIRE

    Mukherjee, Sreemoyee; MANNINEN, M; Deo, P. Singha

    2010-01-01

    We start from microscopic approach to many body physics and show the analytical steps and approximations required to arrive at the concept of quantum capacitance. These approximations are valid only in the semi-classical limit and the quantum capacitance in that case is determined by Lindhard function. The effective capacitance is the geometrical capacitance and the quantum capacitance in series, and this too is established starting from a microscopic theory.

  20. Excellent Silicon Surface Passivation Achieved by Industrial Inductively Coupled Plasma Deposited Hydrogenated Intrinsic Amorphous Silicon Suboxide

    Directory of Open Access Journals (Sweden)

    Jia Ge

    2014-01-01

    Full Text Available We present an alternative method of depositing a high-quality passivation film for heterojunction silicon wafer solar cells, in this paper. The deposition of hydrogenated intrinsic amorphous silicon suboxide is accomplished by decomposing hydrogen, silane, and carbon dioxide in an industrial remote inductively coupled plasma platform. Through the investigation on CO2 partial pressure and process temperature, excellent surface passivation quality and optical properties are achieved. It is found that the hydrogen content in the film is much higher than what is commonly reported in intrinsic amorphous silicon due to oxygen incorporation. The observed slow depletion of hydrogen with increasing temperature greatly enhances its process window as well. The effective lifetime of symmetrically passivated samples under the optimal condition exceeds 4.7 ms on planar n-type Czochralski silicon wafers with a resistivity of 1 Ωcm, which is equivalent to an effective surface recombination velocity of less than 1.7 cms−1 and an implied open-circuit voltage (Voc of 741 mV. A comparison with several high quality passivation schemes for solar cells reveals that the developed inductively coupled plasma deposited films show excellent passivation quality. The excellent optical property and resistance to degradation make it an excellent substitute for industrial heterojunction silicon solar cell production.

  1. Minimally-invasive Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis of model ancient copper alloys

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Senn, Marianne; Wichser, Adrian [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2014-09-01

    This work describes an evaluation of a strategy for multi-elemental analysis of typical ancient bronzes (copper, lead bronze and tin bronze) by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS).The samples originating from archeological experiments on ancient metal smelting processes using direct reduction in a ‘bloomery’ furnace as well as historical casting techniques were investigated with the use of the previously proposed analytical procedure, including metallurgical observation and preliminary visual estimation of the homogeneity of the samples. The results of LA-ICPMS analysis were compared to the results of bulk composition obtained by X-ray fluorescence spectrometry (XRF) and by inductively coupled plasma mass spectrometry (ICPMS) after acid digestion. These results were coherent for most of the elements confirming the usefulness of the proposed analytical procedure, however the reliability of the quantitative information about the content of the most heterogeneously distributed elements was also discussed in more detail. - Highlights: • The previously proposed procedure was evaluated by analysis of model copper alloys. • The LA-ICPMS results were comparable to the obtained by means of XRF and ICPMS. • LA-ICPMS results indicated the usefulness of the proposed analytical procedure.

  2. Inductively coupled plasma-mass spectrometry: an initial assessment of the VG isotopes Plasmaquad

    International Nuclear Information System (INIS)

    The Chemical Analysis Group has been approached by a British Scientific instrument maker regarding the possibility of the group participating in a Department of Trade and Industry sponsored scheme whereby we would have a 12 month period to assess the advantages and disadvantages of a new analytical technique, Inductively Coupled Plasma-Mass Spectrometry. This report details our initial assessment of the instrument, carried out in order to decide whether to participate in the scheme. We have attempted to discover whether the instrument meets the claims made of it in advertising literature, and have attempted to compare the technique with another, proven technique, Inductively Coupled Plasma - Optical Emission Spectroscopy. The Plasmaquad offers excellent sensitivity for almost all of the elements of the periodic table, giving a distinct improvement over the Chemical Analysis Group's present capabilities for many elements. The isotope ratio measuring ability is important, as the Group has no such capability at the moment and a demand for this type of measurement is foreseen. Our conclusions, while inevitably somewhat subjective, form the basis for recommending Harwell to participate in the scheme. (author)

  3. Solitary and shock structures in a strongly coupled cryogenic quantum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hossen, M. A., E-mail: armanplasma@gmail.com; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh)

    2015-07-15

    The quantum ion-acoustic (QIA) solitary and shock structures formed in a strongly coupled cryogenic quantum plasma (containing strongly coupled positively charged inertial cold ions and Fermi electrons as well as positrons) have been theoretically investigated. The generalized quantum hydrodynamic model and the reductive perturbation method have been employed to derive the Korteweg-de Vries (K-dV) and Burgers equations. The basic features of the QIA solitary and shock structures are identified by analyzing the stationary solitary and shock wave solutions of the K-dV and Burgers equations. It is found that the basic characteristics (e.g., phase speed, amplitude, and width) of the QIA solitary and shock structures are significantly modified by the effects of the Fermi pressures of electrons and positrons, the ratio of Fermi temperature of positrons to that of electrons, the ratio of effective ion temperature to electron Fermi temperature, etc. It is also observed that the effect of strong correlation among extremely cold ions acts as a source of dissipation, and is responsible for the formation of the QIA shock structures. The results of this theoretical investigation should be useful for understanding the nonlinear features of the localized electrostatic disturbances in laboratory electron-positron-ion plasmas (viz., super-intense laser-dense matter experiments)

  4. Minimally-invasive Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis of model ancient copper alloys

    International Nuclear Information System (INIS)

    This work describes an evaluation of a strategy for multi-elemental analysis of typical ancient bronzes (copper, lead bronze and tin bronze) by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS).The samples originating from archeological experiments on ancient metal smelting processes using direct reduction in a ‘bloomery’ furnace as well as historical casting techniques were investigated with the use of the previously proposed analytical procedure, including metallurgical observation and preliminary visual estimation of the homogeneity of the samples. The results of LA-ICPMS analysis were compared to the results of bulk composition obtained by X-ray fluorescence spectrometry (XRF) and by inductively coupled plasma mass spectrometry (ICPMS) after acid digestion. These results were coherent for most of the elements confirming the usefulness of the proposed analytical procedure, however the reliability of the quantitative information about the content of the most heterogeneously distributed elements was also discussed in more detail. - Highlights: • The previously proposed procedure was evaluated by analysis of model copper alloys. • The LA-ICPMS results were comparable to the obtained by means of XRF and ICPMS. • LA-ICPMS results indicated the usefulness of the proposed analytical procedure

  5. Determination of the rare-earth elements in geological materials by inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Lichte, F.E.; Meier, A.L.; Crock, J.G.

    1987-01-01

    A method of analysis of geological materials for the determination of the rare-earth elements using the Inductively coupled plasma mass spectrometric technique (ICP-MS) has been developed. Instrumental parameters and factors affecting analytical results have been first studied and then optimized. Samples are analyzed directly following an acid digestion, without the need for separation or preconcentration with limits of detection of 2-11 ng/g, precision of ?? 2.5% relative standard deviation, and accuracy comparable to inductively coupled plasma emission spectrometry and instrumental neutron activation analysis. A commercially available ICP-MS instrument is used with modifications to the sample introduction system, torch, and sampler orifice to reduce the effects of high salt content of sample solutions prepared from geologic materials. Corrections for isobaric interferences from oxide ions and other diatomic and triatomic ions are made mathematically. Special internal standard procedures are used to compensate for drift in metahmetal oxide ratios and sensitivity. Reference standard values are used to verify the accuracy and utility of the method.

  6. Applications of inductively coupled plasma-mass spectrometry to radionuclide determinations

    International Nuclear Information System (INIS)

    The symposium, Applications of Inductively Coupled-Mass Spectrometry to Radionuclide Determinations, was held in Gatlinburg, Tennessee on 13--14 October 1994. Despite the fact that the United States Department of Energy (DOE) is changing the mission of many facilities from defense-related nuclear materials production to site remediation and monitoring, the need to fully characterize wastes and environmental samples, combined with the need to monitor worker radiation exposure by means of internal dosimetry, continues to increase the demand for radioisotope determinations. Active nuclear facilities in the United States and elsewhere are strongly emphasizing these determinations, and they are concurrently demanding better and faster analysis techniques to assure the quality of the materials that they supply for nuclear energy production and other nuclear technologies. Many alternatives to radiometry are being studied, however, one of the most promising techniques for radionuclide determinations appears to be inductively coupled plasma - mass spectrometry (ICP-MS). The symposium was a continuation of work started by the Plasma Spectroscopy task group of ASTM Subcommittee C26.05 on Nuclear Fuel Cycle Test Methods, but the DOE Office of Transportation, Emergency Management, and Analytical Services (EM-76) was involved in the genesis of the symposium. Papers covered applications in nuclear material production, high-level waste characterization, environmental monitoring and waste management, and internal dosimetry and health protection. Eleven papers have been processed separately for inclusion on the data base

  7. Trace metal analysis of road dust by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Dust from roads in an air impingement zone close to anthropogenic sources of air pollutants can be a concern for people living in the immediate vicinity. The Ministry of the Environment (MOE) has conducted a case study to monitor the concentration of uranium, strontium, thorium and arsenic in road dust from one such area. A method for the analysis of road dust by inductively coupled plasma mass spectrometry (ICP-MS) has been developed with detection limits in the ng/1 range. A digestion technique has been developed by conducting experiments using single and combinations of acids in open-vessel wet digestions. Accuracy has been determined by the use of matrix representative certified reference materials (CRMs). Digestion precision was determined by elemental concentration measurements of the most representative CRM through replicates. Spike recovery data were from 95% to 110% for all elements, and inter-method comparison studies between hydride generation atomic absorption spectrometry (AAS) inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-MS for arsenic and strontium show good agreement. (author)

  8. Radio frequency energy coupling to high-pressure optically pumped nonequilibrium plasmas

    International Nuclear Information System (INIS)

    This article presents an experimental demonstration of a high-pressure unconditionally stable nonequilibrium molecular plasma sustained by a combination of a continuous wave CO laser and a sub-breakdown radio frequency (rf) electric field. The plasma is sustained in a CO/N2 mixture containing trace amounts of NO or O2 at pressures of P=0.4 - 1.2atm. The initial ionization of the gases is produced by an associative ionization mechanism in collisions of two CO molecules excited to high vibrational levels by resonance absorption of the CO laser radiation with subsequent vibration-vibration (V-V) pumping. Further vibrational excitation of both CO and N2 is produced by free electrons heated by the applied rf field, which in turn produces additional ionization of these species by the associative ionization mechanism. In the present experiments, the reduced electric field, E/N, is sufficiently low to preclude field-induced electron impact ionization. Unconditional stability of the resultant cold molecular plasma is enabled by the negative feedback between gas heating and the associative ionization rate. Trace amounts of nitric oxide or oxygen added to the baseline CO/N2 gas mixture considerably reduce the electron - ion dissociative recombination rate and thereby significantly increase the initial electron density. This allows triggering of the rf power coupling to the vibrational energy modes of the gas mixture. Vibrational level populations of CO and N2 are monitored by infrared emission spectroscopy and spontaneous Raman spectroscopy. The experiments demonstrate that the use of a sub-breakdown rf field in addition to the CO laser allows an increase of the plasma volume by about an order of magnitude. Also, CO infrared emission spectra show that with the rf voltage turned on the number of vibrationally excited CO molecules along the line of sight increase by a factor of 3 - 7. Finally, spontaneous Raman spectra of N2 show that with the rf voltage the vibrational

  9. Ion channels, phosphorylation and mammalian sperm capacitation.

    Science.gov (United States)

    Visconti, Pablo E; Krapf, Dario; de la Vega-Beltrán, José Luis; Acevedo, Juan José; Darszon, Alberto

    2011-05-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  10. Ion channels, phosphorylation and mammalian sperm capacitation

    Institute of Scientific and Technical Information of China (English)

    Pablo E Visconti; Dario Krapf; José Luis de la Vega-Beltrán; Juan José Acevedo; Alberto Darszon

    2011-01-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  11. Effect of low-damage inductively coupled plasma on shallow nitrogen-vacancy centers in diamond

    Energy Technology Data Exchange (ETDEWEB)

    Fávaro de Oliveira, Felipe; Momenzadeh, S. Ali; Wang, Ya; Denisenko, Andrej, E-mail: a.denisenko@physik.uni-stuttgart.de [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Konuma, Mitsuharu [Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany); Markham, Matthew; Edmonds, Andrew M. [Element Six Innovation, Harwell Oxford, Didcot, Oxfordshire OX11 0QR (United Kingdom); Wrachtrup, Jörg [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany)

    2015-08-17

    Near-surface nitrogen-vacancy (NV) centers in diamond have been successfully employed as atomic-sized magnetic field sensors for external spins over the last years. A key challenge is still to develop a method to bring NV centers at nanometer proximity to the diamond surface while preserving their optical and spin properties. To that aim we present a method of controlled diamond etching with nanometric precision using an oxygen inductively coupled plasma process. Importantly, no traces of plasma-induced damages to the etched surface could be detected by X-ray photoelectron spectroscopy and confocal photoluminescence microscopy techniques. In addition, by profiling the depth of NV centers created by 5.0 keV of nitrogen implantation energy, no plasma-induced quenching in their fluorescence could be observed. Moreover, the developed etching process allowed even the channeling tail in their depth distribution to be resolved. Furthermore, treating a {sup 12}C isotopically purified diamond revealed a threefold increase in T{sub 2} times for NV centers with <4 nm of depth (measured by nuclear magnetic resonance signal from protons at the diamond surface) in comparison to the initial oxygen-terminated surface.

  12. Damage in etching of (Ba, Sr)TiO3 thin films using inductively coupled plasma

    International Nuclear Information System (INIS)

    High dielectric (Ba, Sr)TiO3 thin films were etched in an inductively coupled plasma as a function of the Cl2/Ar gas mixing ratio. Under Cl2 (20)/Ar (80), the maximum etch rate of the BST film was 400 Aa/min and the selectivities of BST to Pt and PR obtained were 0.4 and 0.2, respectively. Etching by-products remained on the surface of BST and resulted in varying the stochiometry. Therefore, we investigated the surface of the etched BST using x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and x-ray diffraction (XRD). From the results of XPS analysis, we found that metal (Ba or Sr) chloride compounds remained on the surface of the etched BST for high boiling points. The morphology of the etched surface was evaluated with AFM. The surface roughness decreased as the Cl2 increased in the Cl2/Ar plasma. From the results of XRD analysis, the crystallinity of etched BST films under Ar only and under Cl2 (20)/Ar (80) was similar to that of as-deposited BST. However, the (100) diffraction peak abruptly decreased at the Cl2 only plasma. It was assumed that metal (Ba or Sr) chloride compounds remained on the etched BST surface and changed the stoichiometry, resulting in crystallinity of the BST film during the etch process

  13. Linewidth of c-axis plasma resonance in Josephson-coupled superconductors

    International Nuclear Information System (INIS)

    We derive equations which describe the interaction of the phase collective mode with vortex oscillations in multilayer superconductors with Josephson interlayer coupling. Using these dynamic equations for the phase difference between neighboring layers and pancake coordinates we calculate the linewidth of the c-axis plasma resonance in the vortex glass phase when a magnetic field is applied along the c axis. Three mechanisms contribute to the linewidth: interlayer tunneling of quasiparticles, inhomogeneous Josephson interaction in the presence of randomly positioned vortices (inhomogeneous broadening), and dissipation of the plasma mode into vortex oscillations. The phase collective mode is mixed with vortex oscillations in the linear approximation via the Josephson interaction when pancakes are positioned randomly along the c axis due to pinning and thermal fluctuations. Analyzing experimental data for the plasma resonance linewidth in a Bi-2:2:1:2 superconductor we conclude that in magnetic fields below 7 T the linewidth is determined mainly by inhomogeneous broadening. This leads to a nearly temperature-independent linewidth which is inversly proportional to the magnetic field. At higher fields or lower pinning the dissipation of the plasmon into vortex oscillations may become the dominant mechanism of line broadening. In this case the linewidth weakly depends on the magnetic field. copyright 1996 The American Physical Society

  14. Thin film passivation of organic light emitting diodes by inductively coupled plasma chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han-Ki [Department of Information and Nano Materials Engineering, Kumoh National Institute of Technology (KIT), 1 Yangho-dong, Gumi, Gyeongbuk, 730-701 (Korea, Republic of)]. E-mail: hkkim@kumoh.ac.kr; Kim, Sang-Woo [Department of Information and Nano Materials Engineering, Kumoh National Institute of Technology (KIT), 1 Yangho-dong, Gumi, Gyeongbuk, 730-701 (Korea, Republic of); Kim, Do-Geun [Surface Technology Research Center, Korea Institute of Machinery and Materials, 66 Sangnam-dong, Changwon-si, Gyeongnam, 641-831 (Korea, Republic of); Kang, Jae-Wook [Organic Light Emitting Diodes (OLED) Center, Seoul National University, Silim-dong, Seoul 151-741 (Korea, Republic of); Kim, Myung Soo [Core Technology Laboratory, Samsung SDI, Co., LTD., 575 Shin-dong, Youngtong-Gu, Suwon, Gyeonggi-Do, 442-391 (Korea, Republic of); Cho, Woon Jo [Nano Device Research Center, Korea Institute of Science and Technology, 39-1, Haweolgok-Dong, Seongbuk-Gu, Seoul, 136-791 (Korea, Republic of)

    2007-04-09

    The characteristics of an SiN {sub x} passivation layer grown by a specially designed inductively coupled plasma chemical vapor deposition (ICP-CVD) system with straight antennas for the top-emitting organic light emitting diodes (TOLEDs) are investigated. Using a high-density plasma on the order of {approx} 10{sup 11} electrons/cm{sup 3} formed by nine straight antennas connected in parallel, a high-density SiN {sub x} passivation layer was deposited on a transparent Mg-Ag cathode at a substrate temperature of 40 deg. C. Even at a low substrate temperature, single SiN {sub x} passivation layer prepared by ICP-CVD showed a low water vapor transmission rate of 5 x 10{sup -2} g/m{sup 2}/day and a transparency of {approx} 85% respectively. In addition, current-voltage-luminescence results of the TOLED passivated by the SiN {sub x} layer indicated that the electrical and optical properties of the TOLED were not affected by the high-density plasma during the SiN {sub x} deposition process.

  15. Influence of discharge and jet flow coupling on atmospheric pressure plasma homogeneity

    Science.gov (United States)

    Nizard, H.; Gaudy, T.; Toutant, A.; Iacono, J.; Descamps, P.; Leempoel, P.; Massines, F.

    2015-10-01

    The effect of flow dynamics on the discharge mode is studied in order to design a technical solution for thin film coating on large surfaces. The configuration consists in two atmospheric pressure helium plasma jets impacting a surface and confined in a tube. This system operates in open air. It has been studied by short exposure time pictures, current and voltage measurements, optical emission spectroscopy, schlieren flow visualization and computational fluid dynamics. Two discharge regimes directly connected to the gas flow dynamic have been pointed out. One is localized from the point electrodes to the surface; the other one entirely fills the confinement tube. A correlation between air intake inside the confinement tube and the discharge mode has been highlighted. Indeed, the discharge only develops in helium and the air intake confines the helium jets in volumes smaller than the confinement tube. The air intake is determined by the gas flow rate and the distance from the tube bottom to the substrate surface, parameters which have been linked to the change from laminar to turbulent flow. Finally, the understanding of flow dynamics and discharge plasma coupling allowed the design of a technical solution favoring plasma homogeneity for large surface treatment.

  16. Inductively coupled plasma--atomic emission spectrometry: trace elements in oil matrices

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, C. A.

    1977-12-01

    The simultaneous determination of up to 20 trace elements in various oil matrices by inductively coupled plasma-atomic emission spectrometry is reported. The oil matrices investigated were lubricating oils (for wear metals), fuel oil, centrifuged coal liquefaction product, crude soybean oil, and commercial edible oils. The samples were diluted with appropriate organic solvents and injected into the plasma as an aerosol generated by a pneumatic nebulization technique. Detection limits of the 28 elements studied ranged from 0.0006 to 9 ..mu..g/g with the majority falling in the 0.01 to 0.1 ..mu..g/g range. Analytical calibration curves were linear over at least two orders of magnitude and for some elements this linearity extended over 4.5 orders of magnitude. Relevant data on precision and accuracy are included. Because metals often occur as particles in lubricating oil and coal liquefaction products, the effect of particles on the analytical results was examined. Wear metal particles in used oil did not appear to affect the analytical results. However, incomplete recovery relative to organometallic reference solutions was obtained for iron particles with a nominal mean diameter of 3.0 ..mu..m suspended in oil. It was shown that the following factors contributed to incomplete recovery for the particles: settling of the suspended particles in the flask, a difference in nebulization efficiency between particle suspensions and organometallic solutions, and indications of incomplete vaporization of the larger particles in the plasma.

  17. Volatile organic compounds emission control in industrial pollution source using plasma technology coupled with F-TiO2/γ-Al2O3.

    Science.gov (United States)

    Zhu, Tao; Chen, Rui; Xia, Ni; Li, Xiaoyang; He, Xianxian; Zhao, Wenjuan; Carr, Tim

    2015-01-01

    Volatile organic compounds' (VOCs) effluents, which come from many industries, are triggering serious environmental problems. As an emerging technology, non-thermal plasma (NTP) technology is a potential technology for VOCs emission control. NTP coupled with F-TiO2/γ-Al2O3 is used for toluene removal from a gaseous influent at normal temperature and atmospheric pressure. NTP is generated by dielectric barrier discharge, and F-TiO2/γ-Al2O3 can be prepared by sol-gel method in the laboratory. In the experiment, the different packed materials were packed into the plasma reactor, including γ-Al2O3, TiO2/γ-Al2O3 and F-TiO2/γ-Al2O3. Through a series of characterization methods such as X-ray diffraction, scanning electronic microscopy and Brunner-Emmet-Teller measurements, the results show that the particle size distribution of F-TiO2 is relatively smaller than that of TiO2, and the pore distribution of F-TiO2 is more uniformly distributed than that of TiO2. The relationships among toluene removal efficiency, reactor input energy density, and the equivalent capacitances of air gap and dielectric barrier layer were investigated. The results show that the synergistic technology NTP with F-TiO2/γ-Al2O3 resulted in greater enhancement of toluene removal efficiency and energy efficiency. Especially, when packing with F-TiO2/γ-Al2O3 in NTP reactor, toluene removal efficiency reaches 99% and higher. Based on the data analysis of Fourier Transform Infrared Spectroscopy, the experimental results showed that NTP reactor packed with F-TiO2/γ-Al2O3 resulted in a better inhibition for by-products formation effectively in the gas exhaust.

  18. Volatile organic compounds emission control in industrial pollution source using plasma technology coupled with F-TiO2/γ-Al2O3.

    Science.gov (United States)

    Zhu, Tao; Chen, Rui; Xia, Ni; Li, Xiaoyang; He, Xianxian; Zhao, Wenjuan; Carr, Tim

    2015-01-01

    Volatile organic compounds' (VOCs) effluents, which come from many industries, are triggering serious environmental problems. As an emerging technology, non-thermal plasma (NTP) technology is a potential technology for VOCs emission control. NTP coupled with F-TiO2/γ-Al2O3 is used for toluene removal from a gaseous influent at normal temperature and atmospheric pressure. NTP is generated by dielectric barrier discharge, and F-TiO2/γ-Al2O3 can be prepared by sol-gel method in the laboratory. In the experiment, the different packed materials were packed into the plasma reactor, including γ-Al2O3, TiO2/γ-Al2O3 and F-TiO2/γ-Al2O3. Through a series of characterization methods such as X-ray diffraction, scanning electronic microscopy and Brunner-Emmet-Teller measurements, the results show that the particle size distribution of F-TiO2 is relatively smaller than that of TiO2, and the pore distribution of F-TiO2 is more uniformly distributed than that of TiO2. The relationships among toluene removal efficiency, reactor input energy density, and the equivalent capacitances of air gap and dielectric barrier layer were investigated. The results show that the synergistic technology NTP with F-TiO2/γ-Al2O3 resulted in greater enhancement of toluene removal efficiency and energy efficiency. Especially, when packing with F-TiO2/γ-Al2O3 in NTP reactor, toluene removal efficiency reaches 99% and higher. Based on the data analysis of Fourier Transform Infrared Spectroscopy, the experimental results showed that NTP reactor packed with F-TiO2/γ-Al2O3 resulted in a better inhibition for by-products formation effectively in the gas exhaust. PMID:25428439

  19. Wave excitation by nonlinear coupling among shear Alfvén waves in a mirror-confined plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ikezoe, R., E-mail: ikezoe@prc.tsukuba.ac.jp; Ichimura, M.; Okada, T.; Hirata, M.; Yokoyama, T.; Iwamoto, Y.; Sumida, S.; Jang, S.; Takeyama, K.; Yoshikawa, M.; Kohagura, J.; Shima, Y.; Wang, X. [Plasma Research Center, University of Tsukuba, Tsukuba 305-8577 (Japan)

    2015-09-15

    A shear Alfvén wave at slightly below the ion-cyclotron frequency overcomes the ion-cyclotron damping and grows because of the strong anisotropy of the ion temperature in the magnetic mirror configuration, and is called the Alfvén ion-cyclotron (AIC) wave. Density fluctuations caused by the AIC waves and the ion-cyclotron range of frequencies (ICRF) waves used for ion heating have been detected using a reflectometer in a wide radial region of the GAMMA 10 tandem mirror plasma. Various wave-wave couplings are clearly observed in the density fluctuations in the interior of the plasma, but these couplings are not so clear in the magnetic fluctuations at the plasma edge when measured using a pick-up coil. A radial dependence of the nonlinearity is found, particularly in waves with the difference frequencies of the AIC waves; bispectral analysis shows that such wave-wave coupling is significant near the core, but is not so evident at the periphery. In contrast, nonlinear coupling with the low-frequency background turbulence is quite distinct at the periphery. Nonlinear coupling associated with the AIC waves may play a significant role in the beta- and anisotropy-limits of a mirror-confined plasma through decay of the ICRF heating power and degradation of the plasma confinement by nonlinearly generated waves.

  20. Biomonitoring of hair samples by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

    Science.gov (United States)

    Sela, H.; Karpas, Z.; Zoriy, M.; Pickhardt, C.; Becker, J. S.

    2007-03-01

    An analytical method for determining essential elements (Zn, Fe and Cu) and toxic elements (Cr, Pb and U) on single hair strands by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-SFMS) using a double focusing sector field mass spectrometer was developed. Results obtained directly using LA-ICP-SFMS of hair were compared with those measured by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) of solutions of digested hair samples and the analytical methods were found to agree well. Different quantification strategies for trace element determination in hair samples such as external calibration, standard addition and isotope dilution were compared and demonstrated for uranium. For uranium determination in powdered hair by LA-ICP-MS solution-based calibration was applied by coupling the laser ablation chamber to an ultrasonic nebulizer. The significance of single hair analysis by LA-ICP-SFMS was demonstrated by a case study of a person who changed living environment. Differences in the uranium content observed along the single hair strand correlated with the changes in the level of uranium in drinking water. The uranium concentration in a single hair decreased from 212 to 18 ng g-1 with a change in the uranium concentration in drinking water from 2000 to 30 ng l-1. In addition, measurements of uranium isotope ratios showed a natural isotopic composition throughout the whole period in the drinking water, as well as in the hair samples. This paper demonstrates the potential use of laser ablation ICP-MS to provide measurements on a single hair strand and its potential to become a very powerful tool in hair analysis for biological monitoring.