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Sample records for inductive plasma generation

  1. Inductively generated streaming plasma ion source

    DOEpatents

    Glidden, Steven C.; Sanders, Howard D.; Greenly, John B.

    2006-07-25

    A novel pulsed, neutralized ion beam source is provided. The source uses pulsed inductive breakdown of neutral gas, and magnetic acceleration and control of the resulting plasma, to form a beam. The beam supplies ions for applications requiring excellent control of ion species, low remittance, high current density, and spatial uniformity.

  2. Plasma Characteristics Using Superimposed Dual Frequency Inductively Coupled Plasma Source for Next Generation Device Processing.

    PubMed

    Lee, Seung Min; Lee, Chul Hee; Kim, Tae Hyung; Yeom, Geun Young; Kim, Kyong Nam

    2015-11-01

    U-shaped inductively coupled plasma (ICP) source was investigated as a linear plasma source for the next generation roll-to-toll flexible display processing. For the radio frequency power to the source, the dual frequency composed of 13.56 MHz and 2 MHz was used and the effect of dual frequency to the U-shaped ICP source on the plasma density, electron temperature, and plasma uniformity was investigated. As the operating condition, 200 mTorr Ar was used without operating turbo pumps. The use of superimposed dual frequency composed of 13.56 MHz + 2 MHz instead the single frequency of 13.56 MHz increased the plasma density slightly at the same total power. In addition, the addition of 2 MHz rf power to 0.4 kW while maintaining 1 kW 13.56 MHz rf power not only decreased electron temperature but also improved both the plasma uniformity and the process uniformity measured by photoresist etching. Therefore, by using the dual frequency to the U-shaped ICP source, not only the plasma density but also plasma uniformity could be improved in addition to the decrease of possible damage to the substrate. PMID:26726573

  3. Nitrogen Gas Plasma Generated by a Static Induction Thyristor as a Pulsed Power Supply Inactivates Adenovirus

    PubMed Central

    Sakudo, Akikazu; Toyokawa, Yoichi; Imanishi, Yuichiro

    2016-01-01

    Adenovirus is one of the most important causative agents of iatrogenic infections derived from contaminated medical devices or finger contact. In this study, we investigated whether nitrogen gas plasma, generated by applying a short high-voltage pulse to nitrogen using a static induction thyristor power supply (1.5 kilo pulse per second), exhibited a virucidal effect against adenoviruses. Viral titer was reduced by one log within 0.94 min. Results from detection of viral capsid proteins, hexon and penton, by Western blotting and immunochromatography were unaffected by the plasma treatment. In contrast, analysis using the polymerase chain reaction suggested that plasma treatment damages the viral genomic DNA. Reactive chemical products (hydrogen peroxide, nitrate, and nitrite), ultraviolet light (UV-A) and slight temperature elevations were observed during the operation of the gas plasma device. Viral titer versus intensity of each potential virucidal factor were used to identify the primary mechanism of disinfection of adenovirus. Although exposure to equivalent levels of UV-A or heat treatment did not inactivate adenovirus, treatment with a relatively low concentration of hydrogen peroxide efficiently inactivated the virus. Our results suggest the nitrogen gas plasma generates reactive chemical products that inactivate adenovirus by damaging the viral genomic DNA. PMID:27322066

  4. Nitrogen Gas Plasma Generated by a Static Induction Thyristor as a Pulsed Power Supply Inactivates Adenovirus.

    PubMed

    Sakudo, Akikazu; Toyokawa, Yoichi; Imanishi, Yuichiro

    2016-01-01

    Adenovirus is one of the most important causative agents of iatrogenic infections derived from contaminated medical devices or finger contact. In this study, we investigated whether nitrogen gas plasma, generated by applying a short high-voltage pulse to nitrogen using a static induction thyristor power supply (1.5 kilo pulse per second), exhibited a virucidal effect against adenoviruses. Viral titer was reduced by one log within 0.94 min. Results from detection of viral capsid proteins, hexon and penton, by Western blotting and immunochromatography were unaffected by the plasma treatment. In contrast, analysis using the polymerase chain reaction suggested that plasma treatment damages the viral genomic DNA. Reactive chemical products (hydrogen peroxide, nitrate, and nitrite), ultraviolet light (UV-A) and slight temperature elevations were observed during the operation of the gas plasma device. Viral titer versus intensity of each potential virucidal factor were used to identify the primary mechanism of disinfection of adenovirus. Although exposure to equivalent levels of UV-A or heat treatment did not inactivate adenovirus, treatment with a relatively low concentration of hydrogen peroxide efficiently inactivated the virus. Our results suggest the nitrogen gas plasma generates reactive chemical products that inactivate adenovirus by damaging the viral genomic DNA. PMID:27322066

  5. Closed inductively coupled plasma cell

    DOEpatents

    Manning, T.J.; Palmer, B.A.; Hof, D.E.

    1990-11-06

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies is disclosed. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy. 1 fig.

  6. Closed inductively coupled plasma cell

    DOEpatents

    Manning, Thomas J.; Palmer, Byron A.; Hof, Douglas E.

    1990-01-01

    A closed inductively coupled plasma cell generates a relatively high power, low noise plasma for use in spectroscopic studies. A variety of gases can be selected to form the plasma to minimize spectroscopic interference and to provide a electron density and temperature range for the sample to be analyzed. Grounded conductors are placed at the tube ends and axially displaced from the inductive coil, whereby the resulting electromagnetic field acts to elongate the plasma in the tube. Sample materials can be injected in the plasma to be excited for spectroscopy.

  7. Photochemical vapor generation of lead for inductively coupled plasma mass spectrometric detection

    NASA Astrophysics Data System (ADS)

    Duan, Hualing; Zhang, Ningning; Gong, Zhenbin; Li, Weifeng; Hang, Wei

    2016-06-01

    Photochemical vapor generation (PCVG) of lead was successfully achieved with a simplified and convenient system, in which only low molecular weight organic acid and a high-efficiency photochemical reactor were needed. The reactor was used to generate lead volatile species when a solution of lead containing a small amount of low molecular weight organic acid was pumped through. Several factors, including the concentration of acetic acid, the concentration of hydrochloride acid, and the irradiation time of UV light were optimized. Under the optimal conditions, including the addition of 0.90% (v/v) acetic acid and 0.03% (v/v) hydrochloride acid, and irradiation time of 28 s, intense and repeatable signal of lead volatile species was successfully obtained and identified with inductively coupled plasma mass spectrometry (ICPMS). In addition, the effects from inorganic anions and transition metal ions, including Cl-, NO3-, SO42 -, Cu2 +, Fe3 +, Co2 + and Ni2 +, were investigated, which suggests that their suppression to the PCVG of lead was in the order of Cl- < SO42 - < NO3- for anions and Ni2 +, Co2 + < Fe3 + < Cu2 + for transition metal ions. Under optimized conditions, relative standard derivation (RSD) of 4.4% was achieved from replicate measurements (n = 5) of a standard solution of 0.1 μg L- 1 lead. And, the limit of quantitation (LOQ, 10σ) of 0.012 μg L- 1 lead was obtained using this method and the method blank could be easily controlled down to 0.023 μg L- 1. To validate applicability of this method, it was also employed for the determination of lead in tap water, rain water and lake water.

  8. PLASMA GENERATOR

    DOEpatents

    Foster, J.S. Jr.

    1958-03-11

    This patent describes apparatus for producing an electricity neutral ionized gas discharge, termed a plasma, substantially free from contamination with neutral gas particles. The plasma generator of the present invention comprises a plasma chamber wherein gas introduced into the chamber is ionized by a radiofrequency source. A magnetic field is used to focus the plasma in line with an exit. This magnetic field cooperates with a differential pressure created across the exit to draw a uniform and uncontaminated plasma from the plasma chamber.

  9. Initial Operation of the Miniaturized Inductively Heated Plasma Generator IPG6

    NASA Astrophysics Data System (ADS)

    Dropmann, Michael; Herdrich, Georg; Laufer, Rene; Koch, Helmut; Gomringer, Chris; Cook, Mike; Schmoke, Jimmy; Matthews, Lorin; Hyde, Truell

    2012-10-01

    In close collaboration between the Center for Astrophysics, Space Physics and Engineering Research (CASPER) at Baylor University, Texas, and the Institute of Space Systems (IRS) at the University of Stuttgart, Germany, two plasma wind tunnel facilities of similar type have been established using the inductively heated plasma source IPG6 which is based on proven IRS designs. The facility at Baylor University (IPG6-B) works at a frequency of 13.56 MHz and a maximum power of 15 kW. A vacuum pump of 160m^3/h in combination with a butterfly valve allows pressure control in a wide range. First experiments have been conducted with Air, O2 and N2 as working gases and volumetric flow rates of up to 14 L/min at pressures of a few 100 Pa, although pressures below 1 Pa are achievable at lower flow rates. The maximum tested electric power so far was 8 kW. Plasma powers and total pressures in the plasma jet have been obtained. In the near future the set up of additional diagnostics, the use of other gases (i.e. H2, He), and the integration of a dust particle accelerator are planned. The intended fields of research are basic investigation in thermo-chemistry and plasma radiation, space plasma environments and high heat fluxes e.g. in fusion devices or during atmospheric entry of spacecraft.

  10. Induction plasma tube

    SciTech Connect

    Hull, D.E.

    1984-02-14

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  11. Induction plasma tube

    DOEpatents

    Hull, D.E.

    1982-07-02

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  12. Induction plasma tube

    DOEpatents

    Hull, Donald E.

    1984-01-01

    An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

  13. Analysis of non-equilibrium phenomena in inductively coupled plasma generators

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Lani, A.; Panesi, M.

    2016-07-01

    This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

  14. Pulsed, Inductively Generated, Streaming Plasma Ion Source for Heavy Ion Fusion Linacs

    SciTech Connect

    Steven C. Glidden; Howard D Sanders; John B. Greenly; Daniel L. Dongwoo

    2006-04-28

    This report describes a compact, high current density, pulsed ion source, based on electrodeless, inductively driven gas breakdown, developed to meet the requirements on normalized emittance, current density, uniformity and pulse duration for an ion injector in a heavy-ion fusion driver. The plasma source produces >10 μs pulse of Argon plasma with ion current densities >100 mA/cm2 at 30 cm from the source and with strongly axially directed ion energy of about 80 eV, and sub-eV transverse temperature. The source has good reproducibility and spatial uniformity. Control of the current density during the pulse has been demonstrated with a novel modulator coil method which allows attenuation of the ion current density without significantly affecting the beam quality. This project was carried out in two phases. Phase 1 used source configurations adapted from light ion sources to demonstrate the feasibility of the concept. In Phase 2 the performance of the source was enhanced and quantified in greater detail, a modulator for controlling the pulse shape was developed, and experiments were conducted with the ions accelerated to >40 kV.

  15. Development of a direct hydride generation nebulizer for the determination of selenium by inductively coupled plasma optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    Carrión, Nereida; Murillo, Miguel; Montiel, Edie; Díaz, Dorfe

    2003-08-01

    A study was conducted to evaluate the performance of a new direct hydride generation nebulizer system for determination of hydride forming elements by inductively coupled plasma optical emission spectroscopy. This system was designed and optimized to obtain the highest sensitivity. Several experimental designs were used for these purposes. To optimize the individual parameters of the system, and to study the interaction between these parameters for both direct hydride generation nebulizers, a central composite orthogonal design with eight factors was set up. Significant behavioral differences were observed in the two direct hydride generation nebulizers studied. Finally, a 70 μm gas orifice nebulizer exhibits a better detection limit than the 120 μm nebulizer. Generally, for determination of selenium, this new direct hydride generation nebulizer system exhibits a linear dynamic range and detection limit (3 σb) of 3 orders of magnitude and 0.2 μg l -1 for selenium, respectively. This new hydride generator is much simpler system that conventional hydride generation systems, which does not need to be changed to work in normal mode with the inductively coupled plasma, since this system may be used for hydride forming elements and those that do not form them. It produces a rapid response with low memory effect. It reduces the interference level of Ni, Co and Cu to 600, 500 and 5 mg l -1, respectively. The accuracy of the system was verified by the determination of selenium in several standard reference materials of ambient, food and clinical sample matrices. No statistically significant differences (95 confidence level) were obtained between our method and the reference values.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Generation Of High Non-inductive Plasma Current Fraction H-mode Discharges By High-harmonic Last Wave Heating In The National Spherical Torus Experiment

    SciTech Connect

    Taylor, G; Kessel, C E; LeBlanc, B P; Mueller, D; Phillips, D K; Valeo, E J; Wilson, J R; Ryan, P M; Bonoli, P T; Wright, J C

    2012-02-13

    1.4 MW of 30 MHz high-harmonic fast wave (HHFW) heating, with current drive antenna phasing, has generated a Ip = 300kA, BT (0) = 0.55T deuterium H-mode plasma in the National Spherical Torus Experiment that has a non-inductive plasma current fraction, fNI = 0.7-1. Seventy-five percent of the non-inductive current was generated inside an internal transport barrier that formed at a normalized minor radius, r/a {approx} 0.4 . Three quarters of the non-inductive current was bootstrap current and the remaining non-inductive current was generated directly by HHFW power inside r/a {approx} 0.2.

  18. Inductively coupled helium plasma torch

    SciTech Connect

    Montaser, Akbar; Chan, Shi-Kit; Van Hoven, Raymond L.

    1989-01-01

    An inductively coupled plasma torch including a base member, a plasma tube and a threaded insert member within the plasma tube for directing the plasma gas in a tangential flow pattern. The design of the torch eliminates the need for a separate coolant gas tube. The torch can be readily assembled and disassembled with a high degree of alignment accuracy.

  19. Investigation of a rf inductively coupled plasma ion source capable of highly uniform and collimated ion-beam generation

    SciTech Connect

    Kanarov, V.; Hayes, A.; Yevtukhov, R.; Kameyama, I.; Siegfried, D.; Waahlin, E.

    2006-03-15

    In accordance with advanced data storage device fabrication requirements, we have evaluated a new broad-beam rf ion source for ion beam etching and deposition application. This source utilizes a novel reentrant shaped plasma inductively coupled plasma generator for improved radial plasma density uniformity and a dynamic magnetic field for improved static etch uniformity. It has the capability of reproducibly generating extremely uniform ion beams from 500 to 1500 eV with divergence angle <3 deg. and high directionality [Kanarov et al. (patent pending)]. For a 150 mm diameter wafer, an etch uniformity of <1% {sigma}/mean in static condition or <0.5% with wafer rotation is obtained over an ion incident angle range of 0 deg. - 65 deg. Recently, we have investigated extending the operation of this source to the critical low energy range, 100-500 eV, required for fabricating thin film magnetic head sensors. It was found that, under optimum operating conditions, excellent static etch uniformity (1%-1.5% {sigma}/mean) could be obtained at high ion beam current densities, up to 0.5 mA/cm{sup 2}, over the entire low-energy range while still achieving low divergence angles (<5 deg.) and high beam directionality. The ion beam performance was consistent with results obtained by simulation and by experiment using a 19-hole array ion optic test stand with scanning ion probe [E. Waahlin (unpublished)]. In this article we will describe the design of the ion source and then present the experimental performance data including plasma density distribution measured by an array of flat Langmuir probes, beam divergence distribution obtained by a 'pepper-pot' etch measurement technique, and etching rate distributions.

  20. Multivariate optimization of mercury determination by flow injection-cold vapor generation-inductively coupled plasma optical emission spectrometry.

    PubMed

    dos Santos, Vanessa Cristina Gonçalves; Grassi, Marco Tadeu; de Campos, Mônica Soares; Peralta-Zamora, Patricio Guillermo; Abate, Gilberto

    2012-10-01

    In this work a procedure for mercury determination by Flow Injection-Cold Vapor Generation-Inductively Coupled Plasma Optical Emission Spectrometry (FI-CVG-ICP OES) has been developed. The system uses a small homemade glass separator constructed to drive the Hg vapor to the plasma. An evolutionary operation factorial design was used to evaluate the optimal experimental conditions for mercury vapor generation, aiming at the low consumption of reagents, the improvement of the analytical signal and consequently greater sensitivity. The procedure allowed the determination of mercury and showed excellent linearity for the concentration range from 0.50 μg L(-1) to 100.0 μg L(-1), with Limits of Detection (LOD) and Quantification (LOQ) of 0.11 μg L(-1) and 0.36 μg L(-1), respectively, and a sampling rate of 36 analyses per hour. The optimized procedure showed good accuracy and precision, and the method was validated by the analysis of two certified reference materials: Buffalo River Sediment (NIST 2704) and human hair (IAEA 085). A good agreement with the certified values was achieved, with recovery values of 99% and 98% and relative standard deviation close to 2%. PMID:22870503

  1. PLASMA GENERATOR

    DOEpatents

    Wilcox, J.M.; Baker, W.R.

    1963-09-17

    This invention is a magnetohydrodynamic device for generating a highly ionized ion-electron plasma at a region remote from electrodes and structural members, thus avoiding contamination of the plasma. The apparatus utilizes a closed, gas-filled, cylindrical housing in which an axially directed magnetic field is provided. At one end of the housing, a short cylindrical electrode is disposed coaxially around a short axial inner electrode. A radial electrical discharge is caused to occur between the inner and outer electrodes, creating a rotating hydromagnetic ionization wave that propagates aiong the magnetic field lines toward the opposite end of the housing. A shorting switch connected between the electrodes prevents the wave from striking the opposite end of the housing. (AEC)

  2. Ferromagnetic enhanced inductive plasma sources

    NASA Astrophysics Data System (ADS)

    Godyak, Valery

    2013-07-01

    The subject of this paper is the review of inductively coupled plasma (ICP) sources enhanced with ferromagnetic cores, FMICP, found in various applications, including plasma fusion, space propulsion, light sources, plasma chemistry and plasma processing of materials. The history of FMICP, early attempts for their realization, some recent developments and examples of successful FMICP devices are given here. A comparative study of FMICPs with conventional ICPs demonstrates their certain advantages in power transfer efficiency, power factor and their ability to operate without rf plasma potentials at low plasma densities and with small gaps, while effectively controlling plasma density profile.

  3. Tin Content Determination in Canned Fruits and Vegetables by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

    PubMed Central

    Rončević, Sanda; Benutić, Anica; Nemet, Ivan; Gabelica, Buga

    2012-01-01

    Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES), and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS). Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1) and limit of quantification (6.4 μg kg−1). Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate. PMID:22550488

  4. Determination of Hg and Pb in fuels by inductively coupled plasma mass spectrometry using flow injection chemical vapor generation.

    PubMed

    Chen, Feng-yi; Jiang, Shiuh-Jen

    2009-12-01

    An isotope dilution inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Hg and Pb in fuels using flow injection vapor generation (VG) as the sample introduction system. A simple and inexpensive in-situ nebulizer/vapor generator was employed in this study. An emulsion containing 10% v/v fuel, 2% m/v Triton X-100 and 1.0% m/v tartaric acid was injected into VG-ICP-MS system for the determination of Hg and Pb. Sodium borohydride was used for vapor generation. Since the sensitivities of Hg and Pb in emulsion and those in aqueous solution are quite different, isotope dilution and standard addition methods were used for the determination of Hg and Pb in selected fuel samples. The influences of vapor generation conditions and emulsion preparation on the ion signals are reported. This method has been applied for the determination of Hg and Pb in various fuel samples such as diesel, gasoline and engine oil obtained locally. The analytical results obtained by isotope dilution and standard addition methods were in good agreement with each other and also with those of digested samples analyzed by pneumatic nebulization ICP-MS. Under the optimum operating conditions, the detection limits obtained were 0.02 and 0.03 ng mL(-1) for Hg and Pb, respectively, in prepared emulsified solutions, corresponding to 0.2 and 0.3 ng mL(-1) of Hg and Pb, respectively, in the original fuel samples. PMID:20009337

  5. Starter for inductively coupled plasma tube

    DOEpatents

    Hull, D.E.; Bieniewski, T.M.

    1988-08-23

    A starter assembly is provided for use with an inductively coupled plasma (ICP) tube to reliably initiate a plasma at internal pressures above about 30 microns. A conductive probe is inserted within the inductor coil about the tube and insulated from the tube shield assembly. A capacitive circuit is arranged for momentarily connecting a high voltage radio-frequency generator to the probe while simultaneously energizing the coil. When the plasma is initiated the probe is disconnected from the generator and electrically connected to the shield assembly for operation. 1 fig.

  6. Starter for inductively coupled plasma tube

    DOEpatents

    Hull, Donald E.; Bieniewski, Thomas M.

    1988-01-01

    A starter assembly is provided for use with an inductively coupled plasma (ICP) tube to reliably initate a plasma at internal pressures above about 30 microns. A conductive probe is inserted within the inductor coil about the tube and insulated from the tube shield assembly. A capacitive circuit is arranged for momentarily connecting a high voltage radio-frequency generator to the probe while simultaneously energizing the coil. When the plasma is initiated the probe is disconnected from the generator and electrically connected to the shield assembly for operation.

  7. Determination of mercury in fish otoliths by cold vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS)†

    PubMed Central

    Kenduzler, Erdal; Ates, Mehmet; Arslan, Zikri; McHenry, Melanie; Tchounwou, Paul B.

    2012-01-01

    A method based on cold vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS) has been developed for determination of inorganic mercury, Hg(II), and total mercury in fish otoliths. Sodium borohydride (NaBH4) was used as the only reducing agent and its concentration was optimized across an acidity gradient to selectively reduce Hg(II) without affecting methylmercury, CH3Hg(I). Inorganic Hg was quantitatively reduced to elemental mercury (Hg0) with 1×10−4% (m/v) NaBH4. CH3Hg(I) required a minimum of 0.5% (m/v) NaBH4 for complete reduction. Increasing the HCl concentration of solution to 5% (v/v) improved the selectivity toward Hg(II) as it decreased the signals from CH3Hg(I) to baseline levels. Potassium ferricyanide solution was the most effective in eliminating the memory effects of Hg compared with a number of chelating and oxidizing agents, including EDTA, gold chloride, thiourea, cerium ammonium nitrate and 2-mercaptoethylamine chloride. The relative standard deviation (RSD) was less than 5% for 1.0 μg L−1 Hg(II) solution. The detection limits were 4.2 and 6.4 ng L−1 (ppt) for Hg(II) and total Hg, respectively. Sample dissolution conditions and recoveries were examined with ultra-pure CaCO3 (99.99%) spiked with Hg(II) and CH3HgCl. Methylmercury was stable when dissolution was performed with up to 20% (v/v) HCl at 100 oC. Recoveries from spiked solutions were higher than 95% for both Hg(II) and CH3Hg(I). The method was applied to the determination of Hg(II) and total Hg concentrations in the otoliths of red emperor (CRM 22) and Pacific halibut. Total Hg concentration in the otoliths was 0.038 ± 0.004 μg g−1 for the red emperor and 0.021 ± 0.003 μg g−1 for the Pacific halibut. Inorganic Hg accounted for about 25% of total Hg indicating that Hg in the otoliths was predominantly organic mercury (e.g., methylmercury). However, as opposed to the bioaccumulation in tissues, methylmercury levels in otoliths was very low suggesting a

  8. Determination of mercury in fish otoliths by cold vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS).

    PubMed

    Kenduzler, Erdal; Ates, Mehmet; Arslan, Zikri; McHenry, Melanie; Tchounwou, Paul B

    2012-05-15

    A method based on cold vapor generation inductively coupled plasma mass spectrometry (CVG-ICP-MS) has been developed for determination of inorganic mercury, Hg(II), and total mercury in fish otoliths. Sodium borohydride (NaBH(4)) was used as the only reducing agent and its concentration was optimized across an acidity gradient to selectively reduce Hg(II) without affecting methylmercury, CH(3)Hg(I). Inorganic Hg was quantitatively reduced to elemental mercury (Hg(0)) with 1 × 10(-4)% (m/v) NaBH(4). CH(3)Hg(I) required a minimum of 0.5% (m/v) NaBH(4) for complete reduction. Increasing the HCl concentration of solution to 5% (v/v) improved the selectivity toward Hg(II) as it decreased the signals from CH(3)Hg(I) to baseline levels. Potassium ferricyanide solution was the most effective in eliminating the memory effects of Hg compared with a number of chelating and oxidizing agents, including EDTA, gold chloride, thiourea, cerium ammonium nitrate and 2-mercaptoethylamine chloride. The relative standard deviation (RSD) was less than 5% for 1.0 μg L(-1) Hg(II) solution. The detection limits were 4.2 and 6.4 ng L(-1) (ppt) for Hg(II) and total Hg, respectively. Sample dissolution conditions and recoveries were examined with ultra-pure CaCO(3) (99.99%) spiked with Hg(II) and CH(3)HgCl. Methylmercury was stable when dissolution was performed with up to 20% (v/v) HCl at 100°C. Recoveries from spiked solutions were higher than 95% for both Hg(II) and CH(3)Hg(I). The method was applied to the determination of Hg(II) and total Hg concentrations in the otoliths of red emperor (CRM 22) and Pacific halibut. Total Hg concentration in the otoliths was 0.038 ± 0.004 μg g(-1) for the red emperor and 0.021 ± 0.003 μg g(-1) for the Pacific halibut. Inorganic Hg accounted for about 25% of total Hg indicating that Hg in the otoliths was predominantly organic mercury (e.g., methylmercury). However, as opposed to the bioaccumulation in tissues, methylmercury levels in otoliths was

  9. Mobile inductively coupled plasma system

    DOEpatents

    D`Silva, A.P.; Jaselskis, E.J.

    1999-03-30

    A system is described for sampling and analyzing a material located at a hazardous site. A laser located remotely from the hazardous site is connected to an optical fiber, which directs laser radiation proximate the material at the hazardous site. The laser radiation abates a sample of the material. An inductively coupled plasma is located remotely from the material. An aerosol transport system carries the ablated particles to a plasma, where they are dissociated, atomized and excited to provide characteristic optical reduction of the elemental constituents of the sample. An optical spectrometer is located remotely from the site. A second optical fiber is connected to the optical spectrometer at one end and the plasma source at the other end to carry the optical radiation from the plasma source to the spectrometer. 10 figs.

  10. Induction plasma spraying of ceramics

    NASA Astrophysics Data System (ADS)

    Fan, Xiao-Bao; Gougeon, Patrick; Gitzhofer, Francois; Boulos, Maher

    A study is carried out on the influence of in-flight particle parameters on their splatting properties during the induction plasma deposition of ceramics. Results are presented for alumina powders with mean particle diameters of 21 microns and 82 microns under soft vacuum conditions. The chamber pressure was varied between 46.6 and 66.6 kPa. Measurements are carried out on the particle surface temperature and velocity prior to impact on stainless steel substrates. The form of the splat obtained is evaluated using SEM. The results are used for the parametric optimization of the induction plasma spraying process. Thick alumina coatings with total porosities as low as 2 percent were obtained.

  11. Global model analysis of negative ion generation in low-pressure inductively coupled hydrogen plasmas with bi-Maxwellian electron energy distributions

    SciTech Connect

    Huh, Sung-Ryul; Kim, Nam-Kyun; Jung, Bong-Ki; Chung, Kyoung-Jae; Hwang, Yong-Seok; Kim, Gon-Ho

    2015-03-15

    A global model was developed to investigate the densities of negative ions and the other species in a low-pressure inductively coupled hydrogen plasma with a bi-Maxwellian electron energy distribution. Compared to a Maxwellian plasma, bi-Maxwellian plasmas have higher populations of low-energy electrons and highly vibrationally excited hydrogen molecules that are generated efficiently by high-energy electrons. This leads to a higher reaction rate of the dissociative electron attachment responsible for negative ion production. The model indicated that the bi-Maxwellian electron energy distribution at low pressures is favorable for the creation of negative ions. In addition, the electron temperature, electron density, and negative ion density calculated using the model were compared with the experimental data. In the low-pressure regime, the model results of the bi-Maxwellian electron energy distributions agreed well quantitatively with the experimental measurements, unlike those of the assumed Maxwellian electron energy distributions that had discrepancies.

  12. Enhanced current flow through a plasma cloud by induction of plasma turbulence. [electrodynamic tethers for generating power for spacecraft in low earth orbit

    NASA Technical Reports Server (NTRS)

    Hastings, D. E.; Gioulekas, A.

    1987-01-01

    Electrodynamic tethers have been proposed as a means of generating power in low earth orbit. One of the limitations on the power generated is the relatively low electron current that can be collected. It is proposed that the electron current can be significantly enhanced by means of current induced plasma turbulence in a plasma cloud around the collecting anode. This is examined for the specific case of lower hybrid turbulence. An important conclusion is that the use of plasma clouds in the ionosphere will entail a high impedance (no instability) and a low impedance (lower hybrid instability) mode of operation depending on the current density.

  13. SYSTEM OPTIMIZATION FOR THE AUTOMATIC SIMULTANEOUS DETERMINATION OF ARSENIC, SELENIUM, AND ANTIMONY, USING HYDRIDE GENERATION INTRODUCTION TO AN INDUCTIVELY COUPLED PLASMA.

    USGS Publications Warehouse

    Pyen, Grace S.; Browner, Richard F.; Long, Stephen

    1986-01-01

    A fixed-size simplex has been used to determine the optimum conditions for the simultaneous determination of arsenic, selenium, and antimony by hydride generation and inductively coupled plasma emission spectrometry. The variables selected for the simplex were carrier gas flow rate, rf power, viewing height, and reagent conditions. The detection limit for selenium was comparable to the preoptimized case, but there were twofold and fourfold improvements in the detection limits for arsenic and antimony, respectively. Precision of the technique was assessed with the use of artificially prepared water samples.

  14. Ultra-trace determination of iodine in sediments and biological material using UV photochemical generation-inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Grinberg, Patricia; Sturgeon, Ralph E.

    2009-03-01

    Several sample preparation techniques have been evaluated for the determination of iodine using UV-photochemical generation-quadrupole inductively coupled plasma mass spectrometry. Thermal decomposition of samples at 1000 °C followed by capture of the liberated iodine in dilute acetic acid permitted subsequent UV-photochemical generation of a volatile iodine species that serves to enhance sensitivity 25-fold over conventional solution nebulization, delivering reagent blank detection limits of 8.75 pg g -1 127I and 0.075 pg g -1 129I for solid samples (400 mg test mass). The methodology was validated through determination of total iodine in several Standard Reference Materials, including NIST 1572 Citrus leaves, NIST 1549 Non-fat milk powder, NIST 1566a Oyster tissue and NIST 2709 San Joaquin Soil. Liberation of iodine from samples and its collection as well as photochemical generation were quantitative, permitting calibration to be achieved using standards prepared in dilute acetic acid.

  15. Characterization of a Second-generation Focal-plane Camera Coupled to an Inductively Coupled Plasma Mattauch-Herzog Geometry Mass Spectrograph

    SciTech Connect

    Schilling, G D.; Andrade, Francisco J.; Barnes, James H.; Sperline, Roger P.; Denton, M BONNER.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

    2006-07-01

    A second-generation Faraday-strip array detector has been coupled to an inductively coupled plasma Mattauch- Herzog geometry mass spectrograph, thereby offering simultaneous acquisition of a range of mass-to-charge ratios. The second-generation device incorporates narrower, more closely spaced collectors than the earlier system. Furthermore, the new camera can acquire signal on all collectors at a frequency greater than 2 kHz and has the ability to independently adjust the gain level of each collector. Each collector can also be reset independently. With these improvements, limits of detection in the hundreds of picograms per liter for metals in solution have been obtained. Some additional features, such as a broader linear dynamic range (over 7 orders of magnitude), greater resolving power (up to 600), and improved isotope ratio accuracy were attained. In addition, isotope ratio precision as low as 0.018% RSD was achieved.

  16. Characteristics of the inductive nitrogen laser generation

    NASA Astrophysics Data System (ADS)

    Razhev, A. M.; Churkin, D. S.; Kargapoltsev, E. S.

    2016-05-01

    The results of the experimental study of energy, temporal, spectral and spatial characteristics of UV inductive laser generation are presented. The study has identified a number of characteristics which demonstrate the differences between electron parameters of inductively coupled plasma and the plasma of longitudinal and transverse electrical discharges. The mechanism of simultaneous occurrence of Lewis-Rayleigh afterglow representing transitions between higher vibrational substates of B3Πg and A3∑u+ states; laser generation at C3Πu→B3Πg transition as well as the absence of IR radiation at 1st positive system typical for electrical discharge nitrogen lasers has been thoroughly researched. The major characteristic is ring shaped laser beam which size and width depend on excitation conditions. Inductive UV nitrogen laser is found to operate in ASE regime, but has a low divergence of 0.4±0.1 mrad and high pulse-to-pulse stability (laser pulse deviation amplitude did not exceed 1%).

  17. Energy saving concepts relating to induction generators

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1980-01-01

    Energy saving concepts relating to induction generators are presented. The first describes a regenerative scheme using an induction generator as a variable load for prime movers under test is described. A method for reducing losses in induction machines used specifically as wind driven generators is also described.

  18. Solid expellant plasma generator

    NASA Technical Reports Server (NTRS)

    Stone, Nobie H. (Inventor); Poe, Garrett D. (Inventor); Rood, Robert (Inventor)

    2010-01-01

    An improved solid expellant plasma generator has been developed. The plasma generator includes a support housing, an electrode rod located in the central portion of the housing, and a mass of solid expellant material that surrounds the electrode rod within the support housing. The electrode rod and the solid expellant material are made of separate materials that are selected so that the electrode and the solid expellant material decompose at the same rate when the plasma generator is ignited. This maintains a point of discharge of the plasma at the interface between the electrode and the solid expellant material.

  19. Development of novel and sensitive methods for the determination of sulfide in aqueous samples by hydrogen sulfide generation-inductively coupled plasma-atomic emission spectroscopy.

    PubMed

    Colon, M; Todolí, J L; Hidalgo, M; Iglesias, M

    2008-02-25

    Two new, simple and accurate methods for the determination of sulfide (S(2-)) at low levels (microgL(-1)) in aqueous samples were developed. The generation of hydrogen sulfide (H(2)S) took place in a coil where sulfide reacted with hydrochloric acid. The resulting H(2)S was then introduced as a vapor into an inductively coupled plasma-atomic emission spectrometer (ICP-AES) and sulfur emission intensity was measured at 180.669nm. In comparison to when aqueous sulfide was introduced, the introduction of sulfur as H(2)S enhanced the sulfur signal emission. By setting a gas separator at the end of the reaction coil, reduced sulfur species in the form of H(2)S were removed from the water matrix, thus, interferences could be avoided. Alternatively, the gas separator was replaced by a nebulizer/spray chamber combination to introduce the sample matrix and reagents into the plasma. This methodology allowed the determination of both sulfide and sulfate in aqueous samples. For both methods the linear response was found to range from 5microgL(-1) to 25mgL(-1) of sulfide. Detection limits of 5microgL(-1) and 6microgL(-1) were obtained with and without the gas separator, respectively. These new methods were evaluated by comparison to the standard potentiometric method and were successfully applied to the analysis of reduced sulfur species in environmental waters. PMID:18261510

  20. SPECIATION OF SELENIUM AND ARSENIC COMPOUNDS BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW AND ON-LINE REDUCTION OF SELENIUM(VI) TO SELENIUM(IV) WITH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRIC DETECTION

    EPA Science Inventory

    Capillary electrophoresis (CE) with hydride generation inductively coupled plasma mass spectrometry was used to determine four arsenicals and two selenium species. Selenate (SeVI) was reduced on-line to selenite (SeIV') by mixing the CE effluent with concentrated HCl. A microporo...

  1. Laser ablation inductively coupled plasma mass spectrometry

    SciTech Connect

    Durrant, S.F.

    1996-07-01

    Laser ablation for solid sample introduction to inductively coupled plasma mass spectrometry for bulk and spatially-resolved elemental analysis is briefly reviewed. {copyright} {ital 1996 American Institute of Physics.}

  2. Determination of Se in biological samples by axial view inductively coupled plasma optical emission spectrometry after digestion with aqua regia and on-line chemical vapor generation

    NASA Astrophysics Data System (ADS)

    dos Santos, Éder José; Herrmann, Amanda Beatriz; de Caires, Suzete Kulik; Frescura, Vera Lúcia Azzolin; Curtius, Adilson José

    2009-06-01

    A simple and fast method for the determination of Se in biological samples, including food, by axial view inductively coupled plasma optical emission spectrometry using on-line chemical vapor generation (CVG-ICP OES) is proposed. The concentrations of HCl and NaBH 4, used in the chemical vapor generation were optimized by factorial analysis. Six certified materials (non-fat milk powder, lobster hepatopancreas, human hair, whole egg powder, oyster tissue, and lyophilised pig kidney) were treated with 10 mL of aqua regia in a microwave system under reflux for 15 min followed by additional 15 min in an ultrasonic bath. The solutions were transferred to a 100 mL volumetric flask and the final volume was made up with water. The Se was determined directly in these solutions by CVG-ICP OES, using the analytical line at 196.026 nm. Calibration against aqueous standards in 10% v/v aqua regia in the concentration range of 0.5-10.0 µg L - 1 Se(IV) was used for the analysis. The quantification limit, considering a 0.5 g sample weight in a final volume of 100 mL - 1 was 0.10 µg g - 1. The obtained concentration values were in agreement with the total certified concentrations, according to the t-test for a 95% confidence level.

  3. Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor generation-inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Chiou, Chwei-Sheng; Jiang, Shiuh-Jen; Kumar Danadurai, K. Suresh

    2001-07-01

    A method employing a vapor generation system and LC combined with inductively coupled plasma mass spectrometry (LC-ICP-MS) is presented for the determination of mercury in biological tissues. An open vessel microwave digestion system was used to extract the mercury compounds from the sample matrix. The efficiency of the mobile phase, a mixture of L-cysteine and 2-mercaptoethanol, was evaluated for LC separation of inorganic mercury [Hg(II)], methylmercury (methyl-Hg) and ethylmercury (ethyl-Hg). The sensitivity, detection limits and repeatability of the liquid chromatography (LC) ICP-MS system with a vapor generator were comparable to, or better than, that of an LC-ICP-MS system with conventional pneumatic nebulization, or other sample introduction techniques. The experimental detection limits for various mercury species were in the range of 0.05-0.09 ng ml -1 Hg, based on peak height. The proposed method was successfully applied to the determination of mercury compounds in a swordfish sample purchased from the local market. The accuracy of the method was evaluated by analyzing a marine biological certified reference material (DORM-2, NRCC).

  4. Determination of free and total sulfur dioxide in wine samples by vapour-generation inductively coupled plasma-optical-emission spectrometry.

    PubMed

    Cmelík, Jirí; Machát, Jirí; Niedobová, Eva; Otruba, Vítezslav; Kanický, Viktor

    2005-10-01

    Sulfur dioxide (SO(2)) is used as a preservative and stabilizer in wine production to prevent undesired biochemical processes in the must and the final product. The concentration of SO(2) is restricted by national regulations. There are two main forms of SO(2) in wine-free (inorganic forms) and bound (fixed to organic compounds, e.g. aldehydes). Iodometric titration is commonly employed for determination of SO(2) concentration (either by direct titration or after pre-separation by distillation); other techniques are also used. In this work inductively coupled plasma-optical-emission spectrometry with vapour generation was used for determination of free and total SO(2) in wine. Gaseous SO(2) is released from the sample by addition of acid and swept into the ICP by an argon stream. The intensity of the sulfur atomic emission lines is measured in the vacuum UV region. Determination of total SO(2) is performed after hydrolysis of bound forms with sodium hydroxide (NaOH). Concentrations of acid for vapour generation and NaOH for hydrolysis were optimised. The method was used for determination of free and total SO(2) in red and white wine samples and results were compared with those from iodometric titration. PMID:16052345

  5. Intelligent autonomous inductively coupled plasma instrumental operation

    NASA Astrophysics Data System (ADS)

    Webb, Douglas P.

    The development of a framework for the automated analysis of inductively couple plasma atomic emission spectroscopy is present. Some of the research that lead to current state of this framework is presented. A small expert system that uses information about the current sample to generate a line search strategy which minimizes the number of emission lines which need to be measured, and avoids spectral overlaps when possible. A program is presented that evaluates the minimum number of spectral windows required to perform elemental analysis by ICP- AES, given a certain spectral window width. A method with the potential for rapidly ascertaining the physical properties of the sample matrix is presented. This system has the potential to help reduce sample introduction related system failures. Finally, three optimization algorithms are compared in their ability to optimize ICP- AES performance, from this an optimization module was developed for inclusion in the automated analysis framework.

  6. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of As, Cd, and Hg in cereals.

    PubMed

    Chen, Feng-Yi; Jiang, Shiuh-Jen

    2009-08-12

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of As, Cd, and Hg in cereals using flow injection chemical vapor generation (VG) as the sample introduction system. A slurry containing 6% m/v flour, 0.7% m/v thiourea, 0.4 microg mL(-1) Co(II), and 2.5% v/v HCl was injected into a VG-ICP-MS system for the determination of As, Cd, and Hg without dissolution and mineralization. Because the sensitivities of the elements studied in the slurry and that of aqueous solution were quite different, a standard addition method and an isotope dilution method were used for the determination of As, Cd, and Hg in selected cereal samples. The influences of vapor generation conditions and slurry preparation on the ion signals were reported. The effectiveness of the vapor generation sample introduction technique in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied for the determination of As, Cd, and Hg in NIST SRM 1567a Wheat Flour reference material, NIST SRM 1568a Rice Flour reference material, and cereal samples obtained from local market. The As, Cd, and Hg analysis results of the reference materials agreed with the certified values. The method detection limits estimated from standard addition curves were about 0.10, 0.16, and 0.07 ng g(-1) for As, Cd, and Hg, respectively, in the original cereal samples. PMID:19606866

  7. Determination of As, Hg and Pb in herbs using slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry.

    PubMed

    Tai, Chia-Yi; Jiang, Shiuh-Jen; Sahayam, A C

    2016-02-01

    Analysis of herbs for As, Hg and Pb has been carried out using slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) with flow injection vapor generation. Slurry containing 0.5% m/v herbal powder, 0.1% m/v citric acid and 2% v/v HCl was injected into the VG-ICP-MS system for the determination of As, Hg and Pb that obviate dissolution and mineralization. Standard addition and isotope dilution methods were used for quantifications in selected herbal powders. This method has been validated by the determination of As, Hg and Pb in NIST standard reference materials SRM 1547 Peach Leaves and SRM 1573a Tomato Leaves. The As, Hg and Pb analysis results of the reference materials agreed with the certified values. The precision obtained by the reported procedure was better than 7% for all determinations. The detection limit estimated from standard addition curve was 0.008, 0.003, and 0.007 ng mL(-1) for As, Hg and Pb, respectively. PMID:26304347

  8. On-line determination of Sb(III) and total Sb using baker's yeast immobilized on polyurethane foam and hydride generation inductively coupled plasma optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    Menegário, Amauri A.; Silva, Ariovaldo José; Pozzi, Eloísa; Durrant, Steven F.; Abreu, Cassio H.

    2006-09-01

    The yeast Saccharomyces cerevisiae was immobilized in cubes of polyurethane foam and the ability of this immobilized material to separate Sb(III) and Sb(V) was investigated. A method based on sequential determination of total Sb (after on-line reduction of Sb(V) to Sb(III) with thiourea) and Sb(III) (after on-line solid-liquid phase extraction) by hydride generation inductively coupled plasma optical emission spectrometry is proposed. A flow system assembled with solenoid valves was used to manage all stages of the process. The effects of pH, sample loading and elution flow rates on solid-liquid phase extraction of Sb(III) were evaluated. Also, the parameters related to on-line pre-reduction (reaction coil and flow rates) were optimized. Detection limits of 0.8 and 0.15 μg L - 1 were obtained for total Sb and Sb(III), respectively. The proposed method was applied to the analysis of river water and effluent samples. The results obtained for the determination of total Sb were in agreement with expected values, including the river water Standard Reference Material 1640 certified by the National Institute of Standards and Technology (NIST). Recoveries of Sb(III) and Sb(V) in spiked samples were between 81 ± 19 and 111 ±15% when 120 s of sample loading were used.

  9. Optimization of a single-drop microextraction method for multielemental determination by electrothermal vaporization inductively coupled plasma mass spectrometry following in situ vapor generation

    NASA Astrophysics Data System (ADS)

    Gil, Sandra; de Loos-Vollebregt, Margaretha T. C.; Bendicho, Carlos

    2009-03-01

    A headspace single-drop microextraction (HS-SDME) method has been developed in combination with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the simultaneous determination of As, Sb, Bi, Pb, Sn and Hg in aqueous solutions. Vapor generation is carried out in a 40 mL volume closed-vial containing a solution with the target analytes in hydrochloric acid and potassium ferricyanide medium. Hydrides (As, Sb, Bi, Pb, Sn) and Hg vapor are trapped onto an aqueous single drop (3 µL volume) containing Pd(II), followed by the subsequent injection in the ETV. Experimental variables such as medium composition, sodium tetrahydroborate (III) volume and concentration, stirring rate, extraction time, sample volume, ascorbic acid concentration and palladium amount in the drop were fully optimized. The limits of detection (LOD) (3 σ criterion) of the proposed method for As, Sb, Bi, Pb, Sn and Hg were 0.2, 0.04, 0.01, 0.07, 0.09 and 0.8 µg/L, respectively. Enrichment factors of 9, 85, 138, 130, 37 and 72 for As, Sb, Bi, Pb, Sn and Hg, respectively, were achieved in 210 s. The relative standard deviations ( N = 5) ranged from 4 to 8%. The proposed HS-SDME-ETV-ICP-MS method has been applied for the determination of As, Sb, Bi, Pb, Sn and Hg in NWRI TM-28.3 certified reference material.

  10. Inductive coupled radio frequency plasma bridge neutralizer.

    PubMed

    Scholze, F; Tartz, M; Neumann, H

    2008-02-01

    A 13.56 MHz radio frequency plasma bridge neutralizer (rf-PBN) for ion thruster applications as well as ion beam surface processing of insulating materials is presented. The energy for the plasma excitation is inductively coupled into the plasma chamber. Because no components are located inside the plasma, the lifetime of the rf-PBN is expected to be very long. A compact tuning system adapts the input power to the plasma impedance. The electron current may be controlled over a wide range by the rf input power. An electron current of up to 1.6 A has been extracted. PMID:18315215

  11. Slurry sampling flow injection chemical vapor generation inductively coupled plasma mass spectrometry for the determination of trace Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions.

    PubMed

    Chen, Wei-Ni; Jiang, Shiuh-Jen; Chen, Yen-Ling; Sahayam, A C

    2015-02-20

    A slurry sampling inductively coupled plasma mass spectrometry (ICP-MS) method has been developed for the determination of Ge, As, Cd, Sb, Hg and Bi in cosmetic lotions using flow injection (FI) vapor generation (VG) as the sample introduction system. A slurry containing 2% m/v lotion, 2% m/v thiourea, 0.05% m/v L-cysteine, 0.5 μg mL(-1) Co(II), 0.1% m/v Triton X-100 and 1.2% v/v HCl was injected into a VG-ICP-MS system for the determination of Ge, As, Cd, Sb, Hg and Bi without dissolution and mineralization. Because the sensitivities of the analytes in the slurry and that of aqueous solution were quite different, an isotope dilution method and a standard addition method were used for the determination. This method has been validated by the determination of Ge, As, Cd, Sb, Hg and Bi in GBW09305 Cosmetic (Cream) reference material. The method was also applied for the determination of Ge, As, Cd, Sb, Hg and Bi in three cosmetic lotion samples obtained locally. The analysis results of the reference material agreed with the certified value and/or ETV-ICP-MS results. The detection limit estimated from the standard addition curve was 0.025, 0.1, 0.2, 0.1, 0.15, and 0.03 ng g(-1) for Ge, As, Cd, Sb, Hg and Bi, respectively, in original cosmetic lotion sample. PMID:25682241

  12. Determination of methylmercury and inorganic mercury by coupling short-column ion chromatographic separation, on-line photocatalyst-assisted vapor generation, and inductively coupled plasma mass spectrometry.

    PubMed

    Chen, Kuan-ju; Hsu, I-hsiang; Sun, Yuh-chang

    2009-12-18

    We have combined short-column ion chromatographic separation and on-line photocatalyst-assisted vapor generation (VG) techniques with inductively coupled plasma mass spectrometry to develop a simple and sensitive hyphenated method for the determination of aqueous Hg(2+) and MeHg(+) species. The separation of Hg(2+) and MeHg(+) was accomplished on a cation-exchange guard column using a glutathione (GSH)-containing eluent. To achieve optimal chromatographic separation and signal intensities, we investigated the influence of several of the operating parameters of the chromatographic and photocatalyst-assisted VG systems. Under the optimized conditions of VG process, the shortcomings of conventional SnCl(2)-based VG techniques for the vaporization of MeHg(+) was overcome; comparing to the concentric nebulizer-ICP-MS system, the analytical sensitivity of ICP-MS toward the detection of Hg(2+) and MeHg(+) were also improved to 25- and 7-fold, respectively. With the use of our established HPLC-UV/nano-TiO(2)-ICP-MS system, the precision for each analyte, based on three replicate injections of 2 ng/mL samples of each species, was better than 15% RSD. This hyphenated method also provided excellent detection limits--0.1 and 0.03 ng/mL for Hg(2+) and MeHg(+), respectively. A series of validation experiments--analysis of the NIST 2672a Standard Urine Reference Material and other urine samples--confirmed further that our proposed method could be applied satisfactorily to the determination of inorganic Hg(2+) and MeHg(+) species in real samples. PMID:19913233

  13. Ultrasound- and microwave-assisted extractions followed by hydride generation inductively coupled plasma optical emission spectrometry for lead determination in geological samples.

    PubMed

    Welna, Maja; Borkowska-Burnecka, Jolanta; Popko, Malgorzata

    2015-11-01

    Followed the current idea of simplified sample pretratmet before analysis we evaluated the procedure for the determination of Pb in calcium-rich materials such as dolomites after ultrasound- or microwave- assisted extraction with diluted acids using hydride generation inductively coupled plasma optical emission spectrometry (HG-ICP-OES). Corresponding Pb hydride was generated in the reaction of an acidified sample solution with NaBH4 after pre-oxidation of Pb(II) to Pb(IV) by K3[Fe(CN)6]. Several chemical (acidic media: HCl, HNO3 or CH3COOH, concentration of the reductant as well as type and concentration of oxidazing agents) and physical (reagents flow rates, reaction coil length) parameters affecting the efficiency of plumbane formation were optimized in order to improve the detectability of Pb using HG-ICP-OES. Limitation of the method derived from the matrix effects was pointed out. Employing Pb separation by HG technique allows the significant reduction of interferences caused by sample matrix constituents (mainly Ca and Mg), nevertheless they could not be overcame at all, hence calibration based on the standard addition method was recommended for Pb quantification in dolomites. Under the selected conditions, i.e. 0.3 mol L(-1) HCl, HNO3 or CH3COOH, 1.5% NaBH4 and 3.0% K3[Fe(CN)6] the limits of detection (LODs) between 2.3-5.6 μg L(-1) (3.4-6.8 μg L(-1) considering matrix effects) and the precision below 5% were achieved. The accuracy of the procedure was verified by analysis of certified reference materials (NCS DC70308 (Carbonate Rock) and NIST 14000 (Bone Ash)) and recovery test with satisfactory results of Pb recoveries ranging between 94-108% (CRMs analysis) and 92-114% (standard addition method). The applicability of the proposed method was demonstrated by the determination of Pb in dolomites used by different fertiliser factories. PMID:26452913

  14. Pulsed Inductive Plasma Acceleration: Performance Optimization Criteria

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.

    2014-01-01

    Optimization criteria for pulsed inductive plasma acceleration are developed using an acceleration model consisting of a set of coupled circuit equations describing the time-varying current in the thruster and a one-dimensional momentum equation. The model is nondimensionalized, resulting in the identification of several scaling parameters that are varied to optimize the performance of the thruster. The analysis reveals the benefits of underdamped current waveforms and leads to a performance optimization criterion that requires the matching of the natural period of the discharge and the acceleration timescale imposed by the inertia of the working gas. In addition, the performance increases when a greater fraction of the propellant is initially located nearer to the inductive acceleration coil. While the dimensionless model uses a constant temperature formulation in calculating performance, the scaling parameters that yield the optimum performance are shown to be relatively invariant if a self-consistent description of energy in the plasma is instead used.

  15. Impact of Gas Heating in Inductively Coupled Plasmas

    NASA Technical Reports Server (NTRS)

    Hash, D. B.; Bose, D.; Rao, M. V. V. S.; Cruden, B. A.; Meyyappan, M.; Sharma, S. P.; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Recently it has been recognized that the neutral gas in inductively coupled plasma reactors heats up significantly during processing. The resulting gas density variations across the reactor affect reaction rates, radical densities, plasma characteristics, and uniformity within the reactor. A self-consistent model that couples the plasma generation and transport to the gas flow and heating has been developed and used to study CF4 discharges. A Langmuir probe has been used to measure radial profiles of electron density and temperature. The model predictions agree well with the experimental results. As a result of these comparisons along with the poorer performance of the model without the gas-plasma coupling, the importance of gas heating in plasma processing has been verified.

  16. Inductive and Electrostatic Acceleration in Relativistic Jet-Plasma Interactions

    SciTech Connect

    Ng, Johnny S.T.; Noble, Robert J.; /SLAC

    2005-07-13

    We report on the observation of rapid particle acceleration in numerical simulations of relativistic jet-plasma interactions and discuss the underlying mechanisms. The dynamics of a charge-neutral, narrow, electron-positron jet propagating through an unmagnetized electron-ion plasma was investigated using a three-dimensional, electromagnetic, particle-in-cell computer code. The interaction excited magnetic filamentation as well as electrostatic (longitudinal) plasma instabilities. In some cases, the longitudinal electric fields generated inductively and electrostatically reached the cold plasma wave-breaking limit, and the longitudinal momentum of about half the positrons increased by 50% with a maximum gain exceeding a factor of two. The results are relevant to understanding the micro-physics at the interface region of an astrophysical jet with the interstellar plasma, for example, the edge of a wide jet or the jet-termination point.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Plasma Interaction and Induction Signatures at Callisto: Preparations for JUICE

    NASA Astrophysics Data System (ADS)

    Liuzzo, Lucas; Feyerabend, Moritz; Simon, Sven; Motschmann, Uwe

    2016-04-01

    The interaction of the Jovian magnetospheric environment with an atmosphere and induced dipole at Callisto is investigated by applying a hybrid (kinetic ions, fluid electrons) simulation code. Callisto is unique among the Galilean satellites in its interaction with the ambient magnetospheric plasma as the gyroradii of the impinging plasma and pickup ions are large compared to the size of the moon. A kinetic representation of the ions is therefore mandatory to adequately describe the resulting asymmetries in the electromagnetic fields and the deflection of the plasma flow near Callisto. When Callisto is embedded in the magnetodisk lobes of Jupiter, a dipolar magnetic field is generated via induction in a subsurface ocean. This field creates an obstacle to the impinging magnetospheric plasma flow at the moon. However, when Callisto is located near the center of the Jovian current sheet, local magnetic perturbations due to the magnetosphere-ionosphere interaction are more than twice the strength of the background field and may therefore obscure any magnetic signal generated via induction in a subsurface ocean. Our simulations demonstrate that the deflection of the magnetospheric plasma into Callisto's wake cannot alone explain the plasma density enhancement of two orders of magnitude measured in the wake of the interaction region during Galileo flybys of the moon. However, through inclusion of an ionosphere around Callisto, modeled densities in the wake are consistent with in situ measurements.

  19. Entropy generation analysis of magnetohydrodynamic induction devices

    NASA Astrophysics Data System (ADS)

    Salas, Hugo; Cuevas, Sergio; López de Haro, Mariano

    1999-10-01

    Magnetohydrodynamic (MHD) induction devices such as electromagnetic pumps or electric generators are analysed within the approach of entropy generation. The flow of an electrically-conducting incompressible fluid in an MHD induction machine is described through the well known Hartmann model. Irreversibilities in the system due to ohmic dissipation, flow friction and heat flow are included in the entropy-generation rate. This quantity is used to define an overall efficiency for the induction machine that considers the total loss caused by process irreversibility. For an MHD generator working at maximum power output with walls at constant temperature, an optimum magnetic field strength (i.e. Hartmann number) is found based on the maximum overall efficiency.

  20. Resonant planar antenna as an inductive plasma source

    SciTech Connect

    Guittienne, Ph.; Lecoultre, S.; Howling, A. A.; Hollenstein, Ch.; Fayet, P.; Larrieu, J.

    2012-04-15

    A resonant planar antenna as an inductive plasma source operating at 13.56 MHz inside a low pressure vacuum vessel is presented for potential plasma processing applications. Its principle consists in interconnecting elementary resonant meshes composed of inductive and capacitive elements. Due to its structure, the antenna shows a set of resonant modes associated with peaks of the real input impedance. Each of these modes is defined by its own current and voltage distribution oscillating at the frequency of the mode. A rectangular antenna of 0.55mx0.20m has been built, and first results obtained with argon plasmas are presented. Plasma generation is shown to be efficient as densities up to 4{center_dot}10{sup 17}m{sup -3} at 2000 W have been measured by microwave interferometry at a distance of 4 cm from the source plane. It is also demonstrated that the plasma couples inductively with the resonating currents flowing in the antenna above a threshold power of about 60 W. A non-uniformity of less than {+-}5% is obtained at 1000 W at a few centimeters above the antenna over 75% of its surface.

  1. Plasma motor generator system

    NASA Technical Reports Server (NTRS)

    Hite, Gerald E.

    1987-01-01

    The significant potential advantages of a plasma motor generator system over conventional systems for the generation of electrical power and propulsion for spacecraft in low Earth orbits warrants its further investigation. The two main components of such a system are a long insulated wire and the plasma generating hollow cathodes needed to maintain electrical contact with the ionosphere. Results of preliminary theoretical and experimental investigations of this system are presented. The theoretical work involved the equilibrium configurations of the wire and the nature of small oscillation about these equilibrium positions. A particularly interesting result was that two different configurations are allowed when the current is above a critical value. Experimental investigations were made of the optimal starting and running conditions for the proposed, low current hollow cathodes. Although optimal ranges of temperature, argon pressure and discharge voltage were identified, start up became progressively more difficult. This supposed depletion or contamination of the emissive surface could be countered by the addition of new emissive material.

  2. Induction generator-induction motor wind-powered pumping system

    SciTech Connect

    Miranda, M.S.; Lyra, R.O.C.; Silva, S.R.

    1997-12-31

    The energy storage matter plays an important role in wind-electric conversion systems for isolated applications. Having that in mind, two different approaches can be basically considered: either the immediate conversion of the generated electric energy, as in a water pumping system or electric energy storage for later use, as in a battery charging system. Due to some features such as no need of an external reactive power source and, sometimes, a gearbox, permanent-magnet synchronous generators have been broadly used in low rated power isolated systems. Despite that, system performance can be affected when the generator is feeding an inductive load (e.g., an induction motor) under variable-speed-variable-frequency operational conditions. Since there is no effective flux control, motor overload may occur at high wind speeds. Thus, good system performance can be obtained through additional control devices which may increase system cost. Although being rugged and cheap, induction machines always work as a reactive power drain; therefore, they demand an external reactive power source. Considering that, reactive static compensators appear as an attractive alternative to the cost x performance problem. In addition to that, different control strategies can be used so that system performance can be improved.

  3. Inductive Measurement of Plasma Jet Electrical Conductivity

    NASA Technical Reports Server (NTRS)

    Turner, Matthew W.; Hawk, Clark W.; Litchford, Ron J.

    2005-01-01

    An inductive probing scheme, originally developed for shock tube studies, has been adapted to measure explosive plasma jet conductivities. In this method, the perturbation of an applied magnetic field by a plasma jet induces a voltage in a search coil, which, in turn, can be used to infer electrical conductivity through the inversion of a Fredholm integral equation of the first kind. A 1-inch diameter probe was designed and constructed, and calibration was accomplished by firing an aluminum slug through the probe using a light-gas gun. Exploratory laboratory experiments were carried out using plasma jets expelled from 15-gram high explosive shaped charges. Measured conductivities were in the range of 3 kS/m for unseeded octol charges and 20 kS/m for seeded octol charges containing 2% potassium carbonate by mass.

  4. Thin film coating process using an inductively coupled plasma

    DOEpatents

    Kniseley, Richard N.; Schmidt, Frederick A.; Merkle, Brian D.

    1990-01-30

    Thin coatings of normally solid materials are applied to target substrates using an inductively coupled plasma. Particles of the coating material are vaporized by plasma heating, and pass through an orifice to a first vacuum zone in which the particles are accelerated to a velocity greater than Mach 1. The shock wave generated in the first vacuum zone is intercepted by the tip of a skimmer cone that provides a second orifice. The particles pass through the second orifice into a second zone maintained at a higher vacuum and impinge on the target to form the coating. Ultrapure coatings can be formed.

  5. Electrical Coupling Efficiency of Inductive Plasma Accelerators

    NASA Technical Reports Server (NTRS)

    Martin, Adam K.; Eskridge, Richard H.

    2005-01-01

    A single-stage pulsed inductive plasma accelerator is modeled as an inductive mass-driver. The plasma is treated as a rigid slug, which acts as the armature. The system is a transformer, with the drive coil serving as the primary and the slug as the secondary. We derive a set of coupled dynamic-circuit equations, which depend on five dimensionless coefficients, and on the functional form of the mutual inductance profile, M (z). For a given coil geometry, M (z) was determined experimentally and compared to the results of calculations carried out with QuickField. The equations are solved with various coefficient values, in order to determine the conditions that yield high efficiencies. It was found that the coupling efficiency can be quite high and likely scales with power, although this does not preclude operation at lower power with acceptable efficiency. The effect of an imbedded magnetic bias flux, as for the case of a plasmoid thruster, was also included in the calculations.

  6. Plasma instabilities in electronegative inductive discharges

    NASA Astrophysics Data System (ADS)

    Marakhtanov, Alexei Mikhail

    Plasma instabilities have been observed in low-pressure inductive discharges, in the transition between low density capacitive mode and high density inductive mode of the discharge when attaching gases such as SF6 and Ar/SF 6 mixtures are used. Oscillations of charged particles, plasma potential and light emitted from the plasma with the frequencies from a few hertz to tens of kilohertz are seen for gas pressures between 1 and 100 mTorr and the discharge power in the range of 75--1200 W. The region of instability increases as the plasma becomes more electronegative and the frequency of plasma oscillations increases as the power, pressure, and gas flow rate increase. The instability frequencies may also depend on the settings of a matching network. A volume-averaged (global) model of the instability has been developed, for a discharge containing time varying densities of electrons, positive ions, and negative ions, and time invariant excited states and neutral densities. The particle and energy balance equations are integrated to produce the dynamical behavior. As pressure or power is varied to cross a threshold, the instability goes through a series of oscillatory states to large scale relaxation oscillations between higher and lower density states. The model qualitatively agrees with experimental observations, and also shows a significant influence of the matching network. A stability analysis of an electronegative discharge has been performed, using a Hurwitz criterion, for a system of linearized particle and power balance differential equations. Capacitive coupling plays a crucial role in the instability process. A variable electrostatic (Faraday) shield has been used to control the capacitive coupling from the excitation coil to the plasma. The plasma instability disappears when the shielded area exceeds 65% of the total area of the coil. The global model of instability gives a slightly higher value of 85% for instability suppression with the same discharge

  7. High frequency plasma generator for ion thrusters

    NASA Technical Reports Server (NTRS)

    Goede, H.; Divergilio, W. F.; Fosnight, V. V.; Komatsu, G.

    1984-01-01

    The results of a program to experimentally develop two new types of plasma generators for 30 cm electrostatic argon ion thrusters are presented. The two plasma generating methods selected for this study were by radio frequency induction (RFI), operating at an input power frequency of 1 MHz, and by electron cyclotron heating (ECH) at an operating frequency of 5.0 GHz. Both of these generators utilize multiline cusp permanent magnet configurations for plasma confinement and beam profile optimization. The program goals were to develop a plasma generator possessing the characteristics of high electrical efficiency (low eV/ion) and simplicity of operation while maintaining the reliability and durability of the conventional hollow cathode plasma sources. The RFI plasma generator has achieved minimum discharge losses of 120 eV/ion while the ECH generator has obtained 145 eV/ion, assuming a 90% ion optical transparency of the electrostatic acceleration system. Details of experimental tests with a variety of magnet configurations are presented.

  8. Titanium oxidation by rf inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    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.

  9. Method of processing materials using an inductively coupled plasma

    DOEpatents

    Hull, Donald E.; Bieniewski, Thomas M.

    1990-01-01

    A method for making fine power using an inductively coupled plasma. The method provides a gas-free environment, since the plasma is formed without using a gas. The starting material used in the method is in solid form.

  10. Line-type inductively coupled plasma source with ferromagnetic module

    NASA Astrophysics Data System (ADS)

    Hyeuk Lim, Jong; Kim, Kyong Nam; Gweon, Gwang Ho; Yeom, Geun Young

    2009-01-01

    The characteristics of a line-type, internal antenna for an inductively coupled plasma (ICP) source installed with a ferromagnetic module were investigated for possible application to roll-to-roll processing of next-generation display devices. The use of 2 MHz instead of 13.56 MHz for the 2300 mm long ICP source improved the plasma uniformity to less than 11% along the antenna line. In addition, the use of Ni-Zn ferromagnetic material in the line-type antenna improved the plasma density to about 3.1 × 1011 cm-3 at 3500 W of 2 MHz radio frequency power by confining the induced, time-varying magnetic field between the antenna line and the substrate. When the photoresist-covered glass substrate was etched at 4000 W using 40 mTorr and Ar/O2 (7 : 3), an etch uniformity of about 5-6% was obtained along the antenna line.

  11. Thrust Stand Measurements of a Conical Pulsed Inductive Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.; Emsellem, Gregory D.

    2012-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters can su er from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA)[4], shown in Fig. 1 is a pulsed inductive plasma thruster that is able to operate at lower pulse energies by partially ionizing propellant with an electron cyclotron resonance (ECR) discharge inside a conical inductive coil whose geometry serves to potentially increase propellant and plasma plume containment relative to at coil geometries. The ECR plasma is created with the use of permanent mag- nets arranged to produce a thin resonance region along the inner surface of the coil, restricting plasma formation and, in turn, current sheet formation to areas of high magnetic coupling to the driving coil.

  12. Automated Induction Thermography of Generator Components

    NASA Astrophysics Data System (ADS)

    Goldammer, M.; Mooshofer, H.; Rothenfusser, M.; Bass, J.; Vrana, J.

    2010-02-01

    Using Active Thermography defects such as cracks can be detected fast and reliably. Choosing from a wide range of excitation techniques the method can be adapted to a number of tasks in non-destructive evaluation. Induction thermography is ideally suited for testing metallic components for cracks at or close to the surface. In power generation a number of components are subjected to high loads and stresses—therefore defect detection is crucial for a safe operation of the engines. Apart from combustion turbines this also applies to generators: At regular inspection intervals even small cracks have to be detected to avoid crack growth and consequently failure of the component. As an imaging technique thermography allows for a fast 100% testing of the complete surface of all relevant parts. An automated setup increases the cost effectiveness of induction thermography significantly. Time needed to test a single part is reduced, the number of tested parts per shift is increased, and cost for testing is reduced significantly. In addition, automation guarantees a reliable testing procedure which detects all critical defects. We present how non-destructive testing can be automated using as an example an industrial application at the Siemens sector Energy, and a new induction thermography setup for generator components.

  13. Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    PubMed Central

    Hutchinson, Robert W.; McLachlin, Katherine M.; Riquelme, Paloma; Haarer, Jan; Broichhausen, Christiane; Ritter, Uwe; Geissler, Edward K.; Hutchinson, James A.

    2015-01-01

    ABSTRACT New analytical techniques for multiparametric characterisation of individual cells are likely to reveal important information about the heterogeneity of immunological responses at the single-cell level. In this proof-of-principle study, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied to the problem of concurrently detecting 24 lineage and activation markers expressed by human leucocytes. This approach was sufficiently sensitive and specific to identify subpopulations of isolated T, B, and natural killer cells. Leucocyte subsets were also accurately detected within unfractionated peripheral blood mononuclear cells preparations. Accordingly, we judge LA-ICP-MS to be a suitable method for assessing expression of multiple tissue antigens in solid-phase biological specimens, such as tissue sections, cytospins, or cells grown on slides. These results augur well for future development of LA-ICP-MS–based bioimaging instruments for general users. PMID:27500232

  14. Ion deposition by inductively coupled plasma mass spectrometry

    SciTech Connect

    Hu, K.; Houk, R.S.

    1996-03-01

    An atmospheric pressure inductively coupled plasma (ICP) is used with a quadrupole mass spectrometer (MS) for ion deposition. The deposited element is introduced as a nebulized aqueous solution. Modifications to the ICP-MS device allow generation and deposition of a mass-resolved beam of {sup 165}Ho{sup +} at 5{times}10{sup 12} ions s{sup {minus}1}. The ICP is a universal, multielement ion source that can potentially be used for applications such as deposition of mixtures of widely varying stoichiometry or of alternating layers of different elements. {copyright} {ital 1996 American Vacuum Society}

  15. Method for generating surface plasma

    DOEpatents

    Miller, Paul A.; Aragon, Ben P.

    2003-05-27

    A method for generating a discharge plasma which covers a surface of a body in a gas at pressures from 0.01 Torr to atmospheric pressure, by applying a radio frequency power with frequencies between approximately 1 MHz and 10 GHz across a plurality of paired insulated conductors on the surface. At these frequencies, an arc-less, non-filamentary plasma can be generated to affect the drag characteristics of vehicles moving through the gas. The plasma can also be used as a source in plasma reactors for chemical reaction operations.

  16. Design of a Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2010-01-01

    A new plasma accelerator concept that employs electrodeless plasma preionization and pulsed inductive acceleration is presented. Preionization is achieved through an electron cyclotron resonance discharge that produces a weakly-ionized plasma at the face of a conical theta pinch-shaped inductive coil. The presence of the preionized plasma allows for current sheet formation at lower discharge voltages than those found in other pulsed inductive accelerators. The location of an electron cyclotron resonance discharge can be controlled through the design of the applied magnetic field in the thruster. A finite-element model of the magnetic field was used as a design tool, allowing for the implementation of an arrangement of permanent magnets that yields a small volume of preionized propellant at the coil face. This allows for current sheet formation at the face of the inductive coil, minimizing the initial inductance of the pulse circuit and maximizing the potential efficiency of the new accelerator.

  17. High Frequency Plasma Generators for Ion Thrusters

    NASA Technical Reports Server (NTRS)

    Divergilio, W. F.; Goede, H.; Fosnight, V. V.

    1981-01-01

    The results of a one year program to experimentally adapt two new types of high frequency plasma generators to Argon ion thrusters and to analytically study a third high frequency source concept are presented. Conventional 30 cm two grid ion extraction was utilized or proposed for all three sources. The two plasma generating methods selected for experimental study were a radio frequency induction (RFI) source, operating at about 1 MHz, and an electron cyclotron heated (ECH) plasma source operating at about 5 GHz. Both sources utilize multi-linecusp permanent magnet configurations for plasma confinement. The plasma characteristics, plasma loading of the rf antenna, and the rf frequency dependence of source efficiency and antenna circuit efficiency are described for the RFI Multi-cusp source. In a series of tests of this source at Lewis Research Center, minimum discharge losses of 220+/-10 eV/ion were obtained with propellant utilization of .45 at a beam current of 3 amperes. Possible improvement modifications are discussed.

  18. Plasma Generated Spherules

    NASA Astrophysics Data System (ADS)

    Ransom, C. J.

    2005-04-01

    Z-pinch plasma simulations have been performed that indicate the production of spherules under certain experimental parameters. (A. L. Peratt, private communication) While performing experiments dealing with the impact of plasma discharges on various materials, we observed that spherules were created at the surface of some of the materials. For specific materials and conditions, spherules were always produced. Both individual spherules and joined spherules were created. The size and shapes were nearly identical to items found by the Mars rover, Opportunity, and called ``blueberries.'' Sky & Telescope, June 2004, p. 20, among other sources indicated the blueberries were gray spherules composed of hematite. The experiments produced hematite spherules identical in appearance to those found on Mars. These experiments suggest how the newly discovered blueberries were formed on Mars while providing an explanation that does not depend on the presence of water.

  19. Vacuum arc plasma thrusters with inductive energy storage driver

    NASA Technical Reports Server (NTRS)

    Krishnan, Mahadevan (Inventor)

    2009-01-01

    A plasma thruster with a cylindrical inner and cylindrical outer electrode generates plasma particles from the application of energy stored in an inductor to a surface suitable for the formation of a plasma and expansion of plasma particles. The plasma production results in the generation of charged particles suitable for generating a reaction force, and the charged particles are guided by a magnetic field produced by the same inductor used to store the energy used to form the plasma.

  20. Thrust Stand Measurements of a Conical Inductive Pulsed Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2013-01-01

    Inductive Pulsed Plasma Thrusters (iPPT) spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current Propellant is accelerated and expelled at a high exhaust velocity (O(10 -- 100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, inductive pulsed plasma thrusters can suffer from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, inductive pulsed plasma thrusters can suffer from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. A conical coil geometry may offer higher propellant utilization efficiency over that of a at inductive coil, however an increase in propellant utilization may be met with a decrease in axial electromagnetic acceleration, and in turn, a decrease in the total axially-directed kinetic energy imparted to the propellant.

  1. Characterization of the Inductively Heated Plasma Source IPG6-B

    NASA Astrophysics Data System (ADS)

    Dropmann, Michael; Laufer, Rene; Herdrich, Georg; Matthews, Lorin; Hyde, Truell

    2014-10-01

    In close collaboration between the Center for Astrophysics, Space Physics and Engineering Research (CASPER) at Baylor University, Texas, and the Institute of Space Systems (IRS) at the University of Stuttgart, Germany, two plasma facilities have been established using the Inductively heated Plasma Generator 6 (IPG6). The facility at Baylor University (IPG6-B) works at a frequency of 13.56 MHz and a maximum power of 15 kW. A vacuum pump of 160 m3/h in combination with a butterfly valve allows pressure control over a wide range. Intended fields of research include basic investigation into thermo-chemistry and plasma radiation, space plasma environments and high heat fluxes e.g. those found in fusion devices or during atmospheric re-entry of spacecraft. After moving the IPG6-B facility to the Baylor Research and Innovation Collaborative (BRIC) it was placed back into operation during the summer of 2014. Initial characterization in the new lab, using a heat flux probe, Pitot probe and cavity calorimeter, has been conducted for Air, Argon and Helium. The results of this characterization are presented.

  2. EVALUATION OF AN INDUCTIVELY COUPLED PLASMA, MULTICHANNEL SPECTROMETRIC ANALYSIS SYSTEM

    EPA Science Inventory

    An inductively coupled plasma, multielement atomic emission spectrometric analysis system has been evaluated with respect to the Environmental Protection Agency's need for a rapid method for determination of trace elemental concentrations in water. Data are presented on detection...

  3. Deposition Of Materials Using A Simple Planar Coil Radio Frequency Inductively Coupled Plasma System

    SciTech Connect

    Ng, K. H.; Wong, C. S.; Yap, S. L.; Gan, S. N.

    2009-07-07

    A planar coil RF inductively coupled plasma (PC-RFICP) systems is set up for the purpose of thin film deposition. The system is powered by a 13.56 MHz, 550 W, 50 OMEGA RF generator. The RF power is transferred to the plasma via a planar induction coil. The impedance matching unit consists of an air core step-down transformer and a tunable vacuum capacitor. This system is used for the plasma enhanced chemical vapor deposition (PECVD) of diamond-like carbon (DLC) film on silicon substrate, and hydrogenated amorphous carbon (a-C:H) film.

  4. Efficient Generation of Non-Inductive, Off-axis, Ohkawa Current, Driven by Electron Bernstein Waves in High Beta, Spherical Torus Plasmas

    SciTech Connect

    G. Taylor; P.C. Efthimion; C.E. Kessel; R.W. Harvey; A.P. Smirnov; N.M. Ershov; M.D. Carter; C.B. Forest

    2004-04-26

    Off-axis rf-driven current can play a critical role in sustaining high Beta spherical torus (ST) plasmas without a central solenoid. Numerical modeling of electron Bernstein wave current drive (EBWCD) for a {Beta} {approx} 40% ST plasma predicts efficient, off-axis, Ohkawa EBWCD. Current can be efficiently driven at r/a greater than 0.5 where the large trapped electron fraction precludes conventional Fisch-Boozer current drive and provides near-ideal conditions for Ohkawa EBWCD. Also, Ohkawa EBWCD efficiency increases with r/a. Enhancement over Fisch-Boozer current drive is a factor of two at r/a {approx} 0.2 rising to over an order of magnitude at r/a {approx} 0.5.

  5. Matrix effects in inductively coupled plasma mass spectrometry

    SciTech Connect

    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.

  6. Method of processing materials using an inductively coupled plasma

    DOEpatents

    Hull, Donald E.; Bieniewski, Thomas M.

    1989-01-01

    A method for coating surfaces or implanting ions in an object using an inductively coupled plasma. The method provides a gas-free environment, since the plasma is formed without using a gas. The coating material or implantation material is intitially in solid form.

  7. A COMPARISON OF URINARY ARSENIC SPECIATION VIA DIRECT NEBULIZATION AND ON-LINE PHOTOOXIDATION-HYDRIDE GENERATION WITH DETECTION BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

    EPA Science Inventory

    Arsenic speciation continues to be important in assessing human and environmental exposure risk. Urinary arsenic analysis provides information on recent arsenic exposure. In this study, two sample introduction pathways: direct nebulization (DN) and hydride generation (HG) were ut...

  8. SPECIATION OF ARSENIC COMPOUNDS IN DRINKING WATER BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW DETECTED THROUGH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS..

    EPA Science Inventory

    Capillary electrophoresis (CE) was used to speciate four environmentally significant, toxic forms of arsenic: arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid. Hydride generation (HG) was used to convert the species into their respective hydrides. The hydride ...

  9. SPECIATION OF ARSENIC COMPOUNDS IN DRINKING WATER BY CAPILLARY ELECTROPHORESIS WITH HYDRODYNAMICALLY MODIFIED ELECTROOSMOTIC FLOW DETECTED THROUGH HYDRIDE GENERATION INDUCTIVELY COUPLED PLASMA MASS...

    EPA Science Inventory

    Capillary electrophoresis (CE) was used to speciate four environmentally significant, toxic forms of arsenic: arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid. Hydride generation (HG) was used to convert the species into their respective hydrides. The hydride s...

  10. Ion-wave stabilization of an inductively coupled plasma

    SciTech Connect

    Camparo, J.C.; Mackay, R.

    2006-04-24

    Stabilization of the rf power driving an inductively coupled plasma (ICP) has implications for fields ranging from atomic clocks to analytical chemistry to illumination technology. Here, we demonstrate a technique in which the plasma itself acts as a probe of radio wave power, and provides a correction signal for active rf-power control. Our technique takes advantage of the resonant nature of forced ion waves in the plasma, and their observation in the ICP's optical emission.

  11. Inductively coupled plasma etching of GaN

    SciTech Connect

    Shul, R.J.; McClellan, G.B.; Casalnuovo, S.A.; Rieger, D.J.; Pearton, S.J.; Constantine, C.; Barratt, C.; Karlicek, R.F. Jr.; Tran, C.; Schurman, M.

    1996-08-01

    Inductively coupled plasma (ICP) etch rates for GaN are reported as a function of plasma pressure, plasma chemistry, rf power, and ICP power. Using a Cl{sub 2}/H{sub 2}/Ar plasma chemistry, GaN etch rates as high as 6875 A/min are reported. The GaN surface morphology remains smooth over a wide range of plasma conditions as quantified using atomic force microscopy. Several etch conditions yield highly anisotropic profiles with smooth sidewalls. These results have direct application to the fabrication of group-III nitride etched laser facets. {copyright} {ital 1996 American Institute of Physics.}

  12. Thrust Stand Measurements of a Conical Inductive Pulsed Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2012-01-01

    Inductive Pulsed Plasma Thrusters (iPPT) are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10 .. 100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, inductive pulsed plasma thrusters can suffer from both high pulse energy requirements imposed by the voltage demands of inductive propellant ionization, and low propellant utilization efficiencies. A conical coil geometry may o er higher propellant utilization efficiency over that of a at inductive coil, however an increase in propellant utilization may be met with a decrease in axial electromagnetic acceleration, and in turn, a decrease in the total axially-directed kinetic energy imparted to the propellant.

  13. Performance Evaluation of a Permanent-Magnet Induction Generator

    NASA Astrophysics Data System (ADS)

    Fukami, Tadashi; Yokoi, Masahiro; Kanamaru, Yasunori; Miyamoto, Toshio

    A permanent-magnet induction generator (PMIG) is a special induction machine self-excited from the inside of the squirrel-cage rotor by a permanent-magnet rotor (PM rotor). In order to evaluate the practical value of the PMIG, its steady-state performance is analyzed theoretically and experimentally. As a result, it was found that the PMIG exhibits good power factor and efficiency compared to a general-purpose induction generator (GPIG) of the same size.

  14. Determination of soluble toxic arsenic species in alga samples by microwave-assisted extraction and high performance liquid chromatography-hydride generation-inductively coupled plasma-atomic emission spectrometry.

    PubMed

    García Salgado, S; Quijano Nieto, M A; Bonilla Simón, M M

    2006-09-29

    A microwave-based procedure for arsenic species extraction in alga samples (Sargassum fulvellum, Chlorella vulgaris, Hizikia fusiformis and Laminaria digitata) is described. Extraction time and temperature were tested in order to evaluate the extraction efficiency of the process. Arsenic compounds were extracted in 8 ml of deionised water at 90 degrees C for 5 min. The process was repeated three times. Soluble arsenic compounds extracted accounted for about 78-98% of total arsenic. The results were compared with those obtained in a previous work, where the extraction process was carried out by ultrasonic focussed probe for 30 s. Speciation studies were carried out by high performance liquid chromatography-hydride generation-inductively coupled plasma-atomic emission spectrometry (HPLC-HG-ICP-AES). The chromatographic method allowed us to separate As(III), As(V), monomethylarsonic acid and dimethylarsinic acid in less than 13 min. The chromatographic analysis of the samples allowed us to identify and quantify As(V) in Hizikia sample and Sargasso material, while the four arsenic species studied were found in Chlorella sample. In the case of Laminaria sample, none of these species was identified by HPLC-HG-ICP-AES. However, in the chromatographic analysis of this alga by HPLC-ICP-AES, an unknown arsenic species was detected. PMID:16876177

  15. Channel-wall limitations in the magnetohydrodynamic induction generator

    NASA Technical Reports Server (NTRS)

    Jackson, W. D.; Pierson, E. S.

    1969-01-01

    Discussion of magnetohydrodynamic induction generator examines the machine in detail and materials problems influencing its design. The higher upper-temperature limit of the MHD system promises to be more efficient than present turbine systems for generating electricity.

  16. INDUCTIVELY COUPLED ARGON PLASMA AS AN ION SOURCE FOR MASS SPECTROMETRIC DETERMINATION OF TRACE ELEMENTS

    EPA Science Inventory

    Solution aerosols are injected into an inductively coupled argon plasma (ICP) to generate a relatively high number density of positive ions derived from elemental constituents. A small fraction of these ions is extracted through a sampling orifice into a differentially pumped vac...

  17. Atlas of atomic spectral lines of plutonium emitted by an inductively coupled plasma

    SciTech Connect

    Edelson, M.C.; DeKalb, E.L.; Winge, R.K.; Fassel, V.A.

    1986-09-01

    Optical emission spectra from high-purity Pu-242 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 2280 to 7008 Angstrom wavelength range are presented along with general commentary on ICP-Pu spectroscopy.

  18. Synthesis of carbon onionlike nanostructures from methane in plasma flow of induction plasmatron

    NASA Astrophysics Data System (ADS)

    Anchukov, K. E.; Zalogin, G. N.; Krasil'nikov, A. V.; Popov, M. Yu.; Kul'nitskii, B. A.

    2015-11-01

    The results of synthesis of carbon onionlike nanostructures from methane in plasma flow of inert gas (argon) generated in induction high-frequency plasmatron are considered and discussed. Carbon vapor obtained via dissociation of methane in plasma flow was condensed on copper substrates placed in a working chamber of the setup. The content of the synthesized soot was analyzed using scanning and transmission electron microscopy. As a result of the performed experiments, carbon onionlike structures with 20- to 100-nm sizes were obtained.

  19. Feedback control of plasma electron density and ion energy in an inductively coupled plasma etcher

    SciTech Connect

    Lin Chaung; Leou, K.-C.; Huang, H.-M.; Hsieh, C.-H.

    2009-01-15

    Here the authors report the development of a fuzzy logic based feedback control of the plasma electron density and ion energy for high density plasma etch process. The plasma electron density was measured using their recently developed transmission line microstrip microwave interferometer mounted on the chamber wall, and the rf voltage was measured by a commercial impedance meter connected to the wafer stage. The actuators were two 13.56 MHz rf power generators which provided the inductively coupled plasma power and bias power, respectively. The control system adopted the fuzzy logic control algorithm to reduce frequent actuator action resulting from measurement noise. The experimental results show that the first wafer effect can be eliminated using closed-loop control for both poly-Si and HfO{sub 2} etching. In particular, for the HfO2 etch, the controlled variables in this work were much more effective than the previous one where ion current was controlled, instead of the electron density. However, the pressure disturbance effect cannot be reduced using plasma electron density feedback.

  20. Pulsed metallic-plasma generators.

    NASA Technical Reports Server (NTRS)

    Gilmour, A. S., Jr.; Lockwood, D. L.

    1972-01-01

    A pulsed metallic-plasma generator is described which utilizes a vacuum arc as the plasma source. The arc is initiated on the surface of a consumable cathode which can be any electrically conductive material. Ignition is accomplished by using a current pulse to vaporize a portion of a conductive film on the surface of an insulator separating the cathode from the ignition electrode. The film is regenerated during the ensuing arc. Over 100 million ignition cycles have been accomplished by using four 0.125-in. diameter zinc cathodes operating in parallel and high-density aluminum-oxide insulators. Among the applications being investigated for the generator are metal deposition, vacuum pumping, electric propulsion, and high-power dc arc interruption.

  1. Dissolution and nanoparticle generation behavior of Be-associated materials in synthetic lung fluid using inductively coupled plasma mass spectroscopy and flow field-flow fractionation.

    PubMed

    Huang, Wenjie; Fernandez, Diego; Rudd, Abigail; Johnson, William P; Deubner, David; Sabey, Philip; Storrs, Jason; Larsen, Rod

    2011-07-01

    Various Be-containing micro-particle suspensions were equilibrated with simulated lung fluid (SLF) to examine their dissolution behavior as well as the potential generation of nanoparticles. The motivation for this study was to explore the relationship between dissolution/particle generation behaviors of Be-containing materials relevant to Be-ore processing, and their epidemiologically indicated inhalation toxicities. Limited data suggest that BeO is associated with higher rates of beryllium sensitization (BS) and chronic beryllium disease (CBD) relative to the other five relevant materials studied: bertrandite-containing ore, beryl-containing ore, frit (a processing intermediate), Be(OH)₂ (a processing intermediate), and silica (control). These materials were equilibrated with SLF at two pH values (4.5 and 7.2) to reflect inter- and intra-cellular environments in lung tissue. Concentrations of Be, Al, and Si in SLF increased linearly during the first 20 days of equilibration, and then rose slowly, or in some cases reached a maximum, and subsequently decreased. Relative to the other materials, BeO produced relatively low Be concentration in solution at pH 7.2; and relatively high Be concentration in solution at pH 4.5 during the first 20 days of equilibration. For both pH values, however, the Be concentration in SLF normalized to Be content of the material was lowest for BeO, demonstrating that BeO was distinct among the four other Be-containing materials in terms of its persistence as a source of Be to the SLF solution. Following 149 days of equilibration, the SLF solutions were fractionated using flow-field flow fractionation (FlFFF) with detection via ICP-MS. For all materials, nanoparticles (which were formed during equilibration) were dominantly distributed in the 10-100 nm size range. Notably, BeO produced the least nanoparticle-associated Be mass (other than silica) at both pH values. Furthermore, BeO produced the highest Be concentrations in the size

  2. New Energy-Saving Technologies Use Induction Generators

    NASA Technical Reports Server (NTRS)

    Nola, F.

    1982-01-01

    Two energy-saving technologies tested recently at Marshall Space Flight Center use an induction motor operated in reverse (as an induction generator). In the first, energy ordinarily dissipated during load testing of machinery is recovered and returned to powerline. In the second, efficiency of wind-driven induction generator is improved, and useful range of windspeed is broadened. Both technologies take advantage of ac voltage developed across terminals of an induction motor when rotated at higher than-synchronous speed in the direction it normally turns when power is appled.

  3. Comparison of two lab-made spray chambers based on MSIS™ for simultaneous metal determination using vapor generation-inductively coupled plasma optical emission spectroscopy.

    PubMed

    Fuentes-Cid, A; Villanueva-Alonso, J; Peña-Vázquez, E; Bermejo-Barrera, P

    2012-10-24

    The objective of this study is to evaluate the performance of two lab-made systems based on the Multimode Introduction System (MSIS™) and the modified MSIS™, to generate and introduce vapors of Ag, Cu, Cd, Cu, Ni, Sn, Zn, and also Au in the ICP torch. An univariate procedure was used to select the optimized working conditions (Ar flow, sample, reductant and waste flows, and reagent concentrations). Optimum conditions for working with modified MSIS were: nitric acid concentration 0.35 M, 8-hydroxyquinoline concentration: 40 mg L(-1), sodium borohydride concentration: 1.75% (w/v)+0.4% (w/v) NaOH, argon purge flow to sweep the vapors to the torch: 1.2 L min(-1), sample flow and sodium borohydride flows: 2.3 L min(-1); waste flow: 7.7 mL min(-1). For the optimum working conditions for lab-made MSIS in dual mode the concentration of 8-hydroxyquinoline was 225 mg L(-1), the Ar purge flow was 0.75 L min(-1), and the conventional nebulization flow was 2.3 L min(-1). The sensitivity obtained was higher using the lab-made MSIS than using the lab-made modified MSIS or a forced outlet gas-liquid separator. The limits of detection were better for Au, Cd, Sn than those obtained using conventional nebulization; the measurements were precise (RSDs≤5% in dual mode) and a good accuracy was obtained in the determination of Cd, Cu, Ni and Zn in a wastewater reference material using aqueous calibration and the lab-made MSIS in dual mode. PMID:23036464

  4. Design of a Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2010-01-01

    The design and construction of a thruster that employs electrodeless plasma preionization and pulsed inductive acceleration is described. Preionization is achieved through an electron cyclotron resonance discharge that produces a weakly-ionized plasma at the face of a conical theta pinch-shaped inductive coil. The presence of the preionized plasma allows for current sheet formation at lower discharge voltages than those employed in other pulsed inductive accelerators that do not employ preionization. The location of the electron cyclotron resonance discharge is controlled through the design of the applied magnetic field in the thruster. Finite element analysis shows that there is an arrangement of permanent magnets that yields a small volume of resonant magnetic field at the coil face. Preionization in the resonant zone leads to current sheet formation at the coil face, which minimizes the initial inductance of the pulse circuit and maximizes the potential electrical efficiency of the accelerator. A magnet assembly was constructed around an inductive coil to provide structural support to the selected arrangement of neodymium magnets. Measured values of the resulting magnetic field compare favorably with the finite element model.

  5. Aerosol detection efficiency in inductively coupled plasma mass spectrometry

    DOE PAGESBeta

    Hubbard, Joshua A.; Zigmond, Joseph A.

    2016-03-02

    We used an electrostatic size classification technique to segregate particles of known composition prior to being injected into an inductively coupled plasma mass spectrometer (ICP-MS). Moreover, we counted size-segregated particles 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 bymore » 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

  6. Aerosol detection efficiency in inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    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

  7. Advances in induction-heated plasma torch technology

    NASA Technical Reports Server (NTRS)

    Poole, J. W.; Vogel, C. E.

    1972-01-01

    Continuing research has resulted in significant advances in induction-heated plasma torch technology which extend and enhance its potential for broad range of uses in chemical processing, materials development and testing, and development of large illumination sources. Summaries of these advances are briefly described.

  8. On-line speciation of inorganic and methyl mercury in waters and fish tissues using polyaniline micro-column and flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS).

    PubMed

    Krishna, M V Balarama; Chandrasekaran, K; Karunasagar, D

    2010-04-15

    A simple and efficient method for the determination of ultra-trace amounts of inorganic mercury (iHg) and methylmercury (MeHg) in waters and fish tissues was developed using a micro-column filled with polyaniline (PANI) coupled online to flow injection-chemical vapour generation-inductively coupled plasma mass spectrometry (FI-CVG-ICPMS) system. Preliminary studies indicated that inorganic and methyl mercury species could be separated on PANI column in two different speciation approaches. At pH <3, only iHg could be sorbed and almost no adsorption of MeHg was found (speciation procedure 1). If the sample solution pH is approximately 7, both MeHg and iHg species could be sorbed on the PANI column. Subsequently both the Hg species were selectively eluted with 2% HCl and a mixture of 2% HCl and 0.02% thiourea respectively (speciation procedure 2). The adsorption percentage of iHg on the PANI column was unchanged even with acidity of the sample solution increased to 6 mol L(-1). Therefore, an acidic solution (5 mol L(-1) HCl), used for ultra-sound assisted extraction of the mercury species from biological samples, was used directly to separate MeHg from iHg in the fish tissues (tuna fish ERM-CE 463, ERM-CE 464 and IAEA-350) by PANI column using speciation procedure 1. The determined values were in good agreement with certified values. Under optimal conditions, the limits of detection (LODs) were 2.52 pg and 3.24 pg for iHg and MeHg (as Hg) respectively. The developed method was applied successfully to the direct determination of iHg and MeHg in various waters (tap water, lake water, ground water and sea-water) and the recoveries for the spiked samples were in the range of 96-102% for both the Hg species. PMID:20188947

  9. Method of processing materials using an inductively coupled plasma

    DOEpatents

    Hull, D.E.; Bieniewski, T.M.

    1987-04-13

    A method of processing materials. The invention enables ultrafine, ultrapure powders to be formed from solid ingots in a gas free environment. A plasma is formed directly from an ingot which insures purity. The vaporized material is expanded through a nozzle and the resultant powder settles on a cold surface. An inductively coupled plasma may also be used to process waste chemicals. Noxious chemicals are directed through a series of plasma tubes, breaking molecular bonds and resulting in relatively harmless atomic constituents. 3 figs.

  10. Inductively coupled plasma torch with laminar flow cooling

    DOEpatents

    Rayson, Gary D.; Shen, Yang

    1991-04-30

    An improved inductively coupled gas plasma torch. The torch includes inner and outer quartz sleeves and tubular insert snugly fitted between the sleeves. The insert includes outwardly opening longitudinal channels. Gas flowing through the channels of the insert emerges in a laminar flow along the inside surface of the outer sleeve, in the zone of plasma heating. The laminar flow cools the outer sleeve and enables the torch to operate at lower electrical power and gas consumption levels additionally, the laminar flow reduces noise levels in spectroscopic measurements of the gaseous plasma.

  11. Development of very small-diameter, inductively coupled magnetized plasma device.

    PubMed

    Kuwahara, D; Mishio, A; Nakagawa, T; Shinohara, S

    2013-10-01

    In order to miniaturize a high-density, inductively coupled magnetized plasma or helicon plasma to be applied to, e.g., an industrial application and an electric propulsion field, small helicon device has been developed. The specifications of this device along with the experimental results are described. We have succeeded in generating high-density (~10(19) m(-3)) plasmas using quartz tubes with very small diameters of 10 and 20 mm, with a radio frequency power ~1200 and 700 W, respectively, in the presence of the magnetic field less than 1 kG. PMID:24182105

  12. Vacuum arc plasma thrusters with inductive energy storage driver

    NASA Technical Reports Server (NTRS)

    Schein, Jochen (Inventor); Gerhan, Andrew N. (Inventor); Woo, Robyn L. (Inventor); Au, Michael Y. (Inventor); Krishnan, Mahadevan (Inventor)

    2004-01-01

    An apparatus for producing a vacuum arc plasma source device using a low mass, compact inductive energy storage circuit powered by a low voltage DC supply acts as a vacuum arc plasma thruster. An inductor is charged through a switch, subsequently the switch is opened and a voltage spike of Ldi/dt is produced initiating plasma across a resistive path separating anode and cathode. The plasma is subsequently maintained by energy stored in the inductor. Plasma is produced from cathode material, which allows for any electrically conductive material to be used. A planar structure, a tubular structure, and a coaxial structure allow for consumption of cathode material feed and thereby long lifetime of the thruster for long durations of time.

  13. 3-Dimensional Modeling of Capacitively and Inductively Coupled Plasma Etching Systems

    NASA Astrophysics Data System (ADS)

    Rauf, Shahid

    2008-10-01

    Low temperature plasmas are widely used for thin film etching during micro and nano-electronic device fabrication. Fluid and hybrid plasma models were developed 15-20 years ago to understand the fundamentals of these plasmas and plasma etching. These models have significantly evolved since then, and are now a major tool used for new plasma hardware design and problem resolution. Plasma etching is a complex physical phenomenon, where inter-coupled plasma, electromagnetic, fluid dynamics, and thermal effects all have a major influence. The next frontier in the evolution of fluid-based plasma models is where these models are able to self-consistently treat the inter-coupling of plasma physics with fluid dynamics, electromagnetics, heat transfer and magnetostatics. We describe one such model in this paper and illustrate its use in solving engineering problems of interest for next generation plasma etcher design. Our 3-dimensional plasma model includes the full set of Maxwell equations, transport equations for all charged and neutral species in the plasma, the Navier-Stokes equation for fluid flow, and Kirchhoff's equations for the lumped external circuit. This model also includes Monte Carlo based kinetic models for secondary electrons and stochastic heating, and can take account of plasma chemistry. This modeling formalism allows us to self-consistently treat the dynamics in commercial inductively and capacitively coupled plasma etching reactors with realistic plasma chemistries, magnetic fields, and reactor geometries. We are also able to investigate the influence of the distributed electromagnetic circuit at very high frequencies (VHF) on the plasma dynamics. The model is used to assess the impact of azimuthal asymmetries in plasma reactor design (e.g., off-center pump, 3D magnetic field, slit valve, flow restrictor) on plasma characteristics at frequencies from 2 -- 180 MHz. With Jason Kenney, Ankur Agarwal, Ajit Balakrishna, Kallol Bera, and Ken Collins.

  14. Electron energy distributions in a magnetized inductively coupled plasma

    SciTech Connect

    Song, Sang-Heon E-mail: Sang-Heon.Song@us.tel.com; Yang, Yang; Kushner, Mark J.

    2014-09-15

    Optimizing and controlling electron energy distributions (EEDs) is a continuing goal in plasma materials processing as EEDs determine the rate coefficients for electron impact processes. There are many strategies to customize EEDs in low pressure inductively coupled plasmas (ICPs), for example, pulsing and choice of frequency, to produce the desired plasma properties. Recent experiments have shown that EEDs in low pressure ICPs can be manipulated through the use of static magnetic fields of sufficient magnitudes to magnetize the electrons and confine them to the electromagnetic skin depth. The EED is then a function of the local magnetic field as opposed to having non-local properties in the absence of the magnetic field. In this paper, EEDs in a magnetized inductively coupled plasma (mICP) sustained in Ar are discussed with results from a two-dimensional plasma hydrodynamics model. Results are compared with experimental measurements. We found that the character of the EED transitions from non-local to local with application of the static magnetic field. The reduction in cross-field mobility increases local electron heating in the skin depth and decreases the transport of these hot electrons to larger radii. The tail of the EED is therefore enhanced in the skin depth and depressed at large radii. Plasmas densities are non-monotonic with increasing pressure with the external magnetic field due to transitions between local and non-local kinetics.

  15. Effect of antenna capacitance on the plasma characteristics of an internal linear inductively coupled plasma system

    NASA Astrophysics Data System (ADS)

    Lim, Jong Hyeuk; Kim, Kyong Nam; Park, Jung Kyun; Yeom, Geun Young

    2008-08-01

    This study examined the effect of the antenna capacitance of an inductively coupled plasma (ICP) source, which was varied using an internal linear antenna, on the electrical and plasma characteristics of the ICP source. The inductive coupling at a given rf current increased with decreasing antenna capacitance. This was caused by a decrease in the inner copper diameter of the antenna made from coaxial copper/quartz tubing, which resulted in a higher plasma density and lower plasma potential. By decreasing the diameter of the copper tube from 25to10mm, the plasma density of a plasma source size of 2750×2350mm2 was increased from approximately 8×1010/cm3to1.5×1011/cm3 at 15mTorr Ar and 9kW of rf power.

  16. Self-energized plasma compressor. [for compressing plasma discharged from coaxial plasma generator

    NASA Technical Reports Server (NTRS)

    Shriver, E. L.; Igenbergs, E. B. (Inventor)

    1974-01-01

    The self-energized plasma compressor is described which compresses plasma discharged from a coaxial plasma generator. The device includes a helically shaped coil which is coaxially aligned with the center axis of the coaxial plasma generator. The plasma generator creates a current through the helical coil which, in turn, generates a time varying magnetic field that creates a force which acts radially upon the plasma. The coaxial plasma generator and helical coil move the plasma under high pressure and temperature to the narrow end of the coil. Positioned adjacent to the narrow end of the coil are beads which are engaged by the plasma to be accelerated to hypervelocities for simulating meteoroids.

  17. Improvement of uniformity in a weakly magnetized inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Lee, W. H.; Cheong, H. W.; Kim, J. W.; Whang, K. W.

    2015-12-01

    Magnetic fields are applied to inductively coupled plasma (ICP) to achieve high plasma densities using electromagnets. If the magnetic fields are set up such that the magnitude of magnetic flux density on the substrate decreases with both radial and axial distances from the substrate’s center (here after referred to as M-ICP-A), the plasma density increases by 237% compared with that for ICP although the non-uniformity of the plasma density for M-ICP-A (11.1%) is higher than that for ICP (10.9%). As the rate of decrease in the magnitude of magnetic flux density on the substrate increases both radially and axially, the non-uniformity in the plasma density increases further. The increase in the non-uniformity for M-ICP-A was confirmed to arise from the flute instability. To suppress the flute instability, we arranged the magnitude of magnetic flux density on the substrate to increase with increasing distance from the substrate center both radially and axially (here after referred to as M-ICP-V). In this configuration, plasma fluctuations were not observed, hence the plasma density non-uniformity was lowered to 8.1%, although the measured plasma density was higher than that for M-ICP-A. The oxide etch-rate non-uniformity in M-ICP-V (2.5%) was also lower than that for ICP (5.2%) or that for M-ICP-A (21.4%).

  18. AETHER: A simulation platform for inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    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.

  19. Relatively high plasma density in low pressure inductive discharges

    SciTech Connect

    Kang, Hyun-Ju; Kim, Yu-Sin; Chung, Chin-Wook

    2015-09-15

    Electron energy probability functions (EEPFs) were measured in a low pressure argon inductive discharge. As radio frequency (RF) power increases, discharge mode is changed from E-mode (capacitively coupled) to H-mode (inductively coupled) and the EEPFs evolve from a bi-Maxwellian distribution to a Maxwellian distribution. It is found that the plasma densities at low RF powers (<30 W) are much higher than the density predicted from the slope of the densities at high powers. Because high portion of high energy electrons of the bi-Maxwellian distribution lowers the collisional energy loss and low electron temperature of low energy electrons reduces particle loss rate at low powers. Therefore, the energy loss of plasma decreases and electron densities become higher at low powers.

  20. Complex image method for RF antenna-plasma inductive coupling calculation in planar geometry. Part II: measurements on a resonant network

    NASA Astrophysics Data System (ADS)

    Guittienne, Ph; Jacquier, R.; Howling, A. A.; Furno, I.

    2015-12-01

    Measurements and analysis of a radio-frequency planar antenna are presented for applications in inductively-coupled plasma processing. The network of inductive and capacitive elements exhibits high currents under resonance which are efficient for plasma generation. Mode frequencies and impedances are accurately calculated by accounting for the mutual partial inductances using the impedance matrix. The effect of plasma inductive coupling on mode frequency shift and mode impedance is estimated using the complex image method, giving good agreement with experiment. It is proposed that the complex image method combined with the partial inductance concept (see the accompanying paper, Part I (Howling et al 2015 Plasma Sources Sci. Technol. 24 065014)) offers a general way to calculate the impedance characteristics of inductively-coupled plasma sources in planar geometry.

  1. Effects of capacitor termination to an antenna coil on the plasma parameters in a radio frequency inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Han, Duksun; Lee, Hyo-Chang; Kim, H. J.; Sin Kim, Yu; Chung, Chin-Wook; Chae, Heesun

    2013-10-01

    The effects of capacitor termination to a solenoidal antenna coil on the plasma parameters, such as the plasma density, the electron temperature, the electron energy distribution function and the plasma potential, are studied in an Ar or O2/N2 gas mixture inductively coupled plasma (ICP). As the capacitance is varied from tens to hundreds of pF, the plasma parameters change significantly. When the reactance of the capacitor is half that of the antenna, there is a resonance condition where the electrostatic coupling between the antenna coil and the chamber wall is effectively suppressed. The plasma density is maximal, while the electron temperature and the plasma potential are minimal under this resonance condition. This result shows that the ICP generated by the antenna coil with capacitor termination can be applied to a plasma process that requires high plasma density and low ion damage. The ashing process of a photoresistor by the ICP source with capacitor termination is also performed in this study and it is found that the ashing rate is enhanced under the resonance condition compared with the non-resonance condition.

  2. Technoeconomic analysis for the destruction of toxic liquid wastes using induction plasma technology

    SciTech Connect

    Soucy, G.; Bergeron, E.; Boulos, M.I.

    1995-12-31

    During the past decade, thermal plasma technology has been pointed out as one of the most promising innovative technologies for the thermal destruction of hazardous wastes and for this role, it has been supported by the EPA. In this field, many process alternatives have been developed but insufficient attention have been given to the details of their economic viability. The objective of this paper is to carry out an economic analysis of a particular thermal induction plasma technology for toxic liquid waste destruction. This work is presented in three parts. The first part presents a description of the conceptual design for a process using high frequency (HF) induction plasma. The second part, based on an order-of-magnitude factored estimate, provides an analysis of the capital investment cost of this process. The third part presents an estimation of the operating costs and a discounted cash flow analysis of this conceptual project using a HF plasma generator. The analysis of the economic viability is discussed with reference to the net present worth and the internal rate of return. The discussion examines those variables that significantly affect the viability of such technology by exploring its advantages towards minimizing impacts on the global environment and economic situation. Finally, a comparison is drawn up between the induction plasma technology and other alternative competitive processes.

  3. Optical plasma torch electron bunch generation in plasma wakefield accelerators

    NASA Astrophysics Data System (ADS)

    Wittig, G.; Karger, O.; Knetsch, A.; Xi, Y.; Deng, A.; Rosenzweig, J. B.; Bruhwiler, D. L.; Smith, J.; Manahan, G. G.; Sheng, Z.-M.; Jaroszynski, D. A.; Hidding, B.

    2015-08-01

    A novel, flexible method of witness electron bunch generation in plasma wakefield accelerators is described. A quasistationary plasma region is ignited by a focused laser pulse prior to the arrival of the plasma wave. This localized, shapeable optical plasma torch causes a strong distortion of the plasma blowout during passage of the electron driver bunch, leading to collective alteration of plasma electron trajectories and to controlled injection. This optically steered injection is more flexible and faster when compared to hydrodynamically controlled gas density transition injection methods.

  4. Effect of Inductive Coil Geometry on the Operating Characteristics of a Pulsed Inductive Plasma Accelerator

    NASA Astrophysics Data System (ADS)

    Hallock, Ashley Kristin

    The effect of inductive coil geometry on the operating characteristics of a pulsed inductive plasma thruster is investigated analytically and experimentally. Coil inductance is measured as a function of the position of a simulated current sheet and modeled using finite element analysis to develop a two-dimensional semi-empirical inductance relation that is used to expand a circuit-based acceleration model from one to two dimensions. The model includes electromagnetic and gas-dynamic forces but excludes any process to translate radial plasma motion into axial motion. Furthermore a magnetically-impermeable current sheet encompassing all the propellant for a pulse is assumed to form immediately at the start of the pulse and at the surface of the inductive coil. The two-dimensional acceleration model is nondimensionalized, yielding a set of dimensionless performance scaling parameters. Model results indicate that the introduction of radial current sheet motion caused by a conical inductive coil geometry (versus a flat circular plate) increases the axial dynamic impedance parameter at which thrust efficiency is maximized and generally decreases the overall achievable thrust efficiency. Operational characteristics of two thrusters with inductive coils of different cone angles are explored through thrust stand measurements and time-integrated, unfiltered photography. Trends in impulse bit measurements indicate that, in the present configuration, the thruster with the inductive coil possessing a smaller cone angle produced larger values of thrust, in apparent contradiction to results of the model. Areas of increased light intensity in photographs of thruster operation are assumed to qualitatively represent locations of increased current density. Light intensity is generally greater in images of the thruster with the smaller cone angle when compared to those of the thruster with the larger half cone angle for the same operating conditions, and generally decreases in both

  5. Simulation of Plasma Characteristics for Inductively Coupled Argon Plasma Using Dual-Frequency Antennas

    NASA Astrophysics Data System (ADS)

    Li, Xue-Chun; Sun, Xiao-Yan; Wang, You-Nian

    2014-10-01

    A large-area wafer size is necessary for plasma processing in the micro-electronics industry. However, it is one of the most important issues to obtain uniform plasma over a large-area substrate in addition to high-density plasmas for the plasma processing. Recently, the experimental study on the dual-frequency inductively coupled plasma (ICP) has been reported as a mean of improving the plasma uniformity over the large-area substrate. In this work, we develop a self-consistent method combined with the electromagnetic theory and fluid model to simulate the plasma characteristics for dual-frequency inductively coupled argon plasma. In the model, the ICP source consists of two planar-spiral coils. We investigate the plasma uniformity problem by adjusting the parameters of the two coils, such as the RF current, the position of the coils and the RF frequency ratio. It was found that the uniformity of the ion density over the wafer is improved with dual-frequency antennas comparing with a single-frequency antenna. The plasma uniformity increases when the coils are located farther from the centre of the ICP source. It is consistent with the experimental study. This work was supported by the National Natural Science Foundation of China (No. 11175034, No. 11075029).

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

    NASA Astrophysics Data System (ADS)

    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)

  7. Optical spectra of FLASH generated plasmas

    NASA Astrophysics Data System (ADS)

    Stránský, M.; Rohlena, Karel

    2014-05-01

    Time integrated measurements of optical spectra of the plasma generated by pulses of the free electron laser facility FLASH on a solid target at DESY Hamburg are interpreted in terms of plasma hydrodynamics. It is shown that the main contribution to the optical range comes from the expanding stage of the plasma evolution on a ns scale, whereas the UV part is partially obscured by the optically dense outstreaming plasma near the ablated hole.

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

    SciTech Connect

    Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong; Kim, Hyuk; Park, Wanjae

    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.

  9. Electron density measurement of inductively coupled plasmas by terahertz time-domain spectroscopy (THz-TDS)

    SciTech Connect

    Ando, Ayumi; Kurose, Tomoko; Kitano, Katsuhisa; Hamaguchi, Satoshi; Reymond, Vivien; Kitahara, Hideaki; Takano, Keisuke; Hangyo, Masanori; Tani, Masahiko

    2011-10-01

    The electron densities of argon inductively coupled plasmas were measured by terahertz time-domain spectroscopy (THz-TDS). At a low pressure, the electron densities were also measured with a Langmuir-type double probe and the validity of THz-TDS electron-density measurement in a plasma has been corroborated. As the input radio-frequency (RF) power increases, the plasma density and gas temperature increase, which makes the probe measurement less reliable or even impossible, due to the large heat load to the probe surface. On the contrary, the THz-TDS measurement is unaffected by the gas temperature and becomes more reliable due to the higher electron density at higher input power for plasma generation.

  10. Negative ion density in inductively coupled chlorine plasmas

    SciTech Connect

    Hebner, G.A.

    1995-12-31

    The negative ion density in radio-frequency (rf) inductively-coupled chlorine discharges has been inferred using laser photodetachment spectroscopy. A Gaseous Electronics Conference (GEC) rf Reference Cell with an inductively coupled plasma source was used to produce the plasma. For this experiment, the chlorine pressure was between 20 and 50 mTorr and the rf power into the plasma was 150 to 250 Watts at 13.56 MHz. Light from a frequency quadrupled Nd:YAG laser (266 nm) was used to photodetach electrons from Cl{sup {minus}}. The time dependent excess electron density was then detected by a microwave interferometer operating at 80 GHz. Based upon the cross section for photodetachment and the measurement geometry, negative ion densities can be calculated. The inferred negative ion densities are at least an order of magnitude higher than the steady state electron density over the parameter space investigated. The dependence of the negative ion density on rf power, gas pressure, flow rate and rf phase will be discussed.

  11. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, Carl J.; Warner, David K.

    1988-12-27

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an r.f. induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the r.f. heating coil is disposed around the outer tube above and adjacent to the water inlet.

  12. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, C.J.; Warner, D.K.

    1984-02-16

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an rf induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the rf heating coil is disposed around the outer tube above and adjacent to the water inlet.

  13. Plasma plume MHD power generator and method

    DOEpatents

    Hammer, James H.

    1993-01-01

    Highly-conducting plasma plumes are ejected across the interplanetary magnetic field from a situs that is moving relative to the solar wind, such as a spacecraft or an astral body, such as the moon, having no magnetosphere that excludes the solar wind. Discrete plasma plumes are generated by plasma guns at the situs extending in opposite directions to one another and at an angle, preferably orthogonal, to the magnetic field direction of the solar wind plasma. The opposed plumes are separately electrically connected to their source by a low impedance connection. The relative movement between the plasma plumes and the solar wind plasma creates a voltage drop across the plumes which is tapped by placing the desired electrical load between the electrical connections of the plumes to their sources. A portion of the energy produced may be used in generating the plasma plumes for sustained operation.

  14. Characteristics of Plasma Using a Ferromagnetic Enhanced Inductively Coupled Plasma Source

    NASA Astrophysics Data System (ADS)

    Kim, Kyong Nam; Hyeuk Lim, Jong; Park, Jung Kyun; Lim, Jong Tae; Yeom, Geun Young

    2008-09-01

    Plasma characteristics and electrical parameters of an internal linear inductively coupled plasma (ICP) source with a U-type antenna with/without a Ni-Zn ferromagnetic material installed near the antenna were investigated. The application of the ferromagnetic material to the antenna increased the plasma density, improved the plasma uniformity, lowered the antenna voltage, and increased the stability of the plasma during the operation. For the U-type ferromagnetic enhanced internal linear ICP source, a high density plasma on the order of 4.5×1011 cm-3 which is about three higher than that obtained for the source without the ferromagnetic material could be obtained at the pressure of 10 mTorr Ar and at the RF power of 600 W at 13.56 MHz.

  15. Effect of bias application to plasma density in weakly magnetized inductively coupled plasma

    SciTech Connect

    Kim, Hyuk; Lee, Woohyun; Park, Wanjae; Whang, Ki-Woong

    2013-07-15

    Independent control of the ion flux and energy can be achieved in a dual frequency inductively coupled plasma (ICP) system. Typically, the plasma density is controlled by the high-frequency antenna radio-frequency (RF) power and the ion energy is controlled by the low-frequency bias RF power. Increasing the bias power has been known to cause a decrease in the plasma density in capacitively coupled discharge systems as well as in ICP systems. However, an applied axial magnetic field was found to sustain or increase the plasma density as bias power is increased. Measurements show higher electron temperatures but lower plasma densities are obtained in ordinary ICP systems than in magnetized ICP systems under the same neutral gas pressure and RF power levels. Explanations for the difference in the behavior of plasma density with increasing bias power are given in terms of the difference in the heating mechanism in ordinary unmagnetized and magnetized ICP systems.

  16. Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry

    SciTech Connect

    Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

    2009-11-01

    Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. Unfortunately, the accuracy of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

  17. Induction plasma calcining of pigment particles for thermal control coatings

    NASA Technical Reports Server (NTRS)

    Farley, E. P.

    1971-01-01

    Induction plasma heating techniques were studied for calcining zinc orthotitanate particles for use in thermal control coatings. Previous studies indicated that the optimum calcining temperature is between 1400 and 1750 C. An intermediate temperature (1670 C) was chosen as a reference point for running a temperature series at the reference point and 220 C on both sides. The effect of varying chamber temperature on the reflectance spectra, before and after vacuum UV irradiation, is presented. The correlation between Zn2Ti04 paramagnetic resonance activity and its susceptibility to vacuum UV damage is discussed.

  18. A controlled stand-alone single-phase induction generator

    SciTech Connect

    Ojo, O.; Gonoh, B.

    1995-12-31

    This paper sets forth the steady-state and dynamic performance characteristics of a novel stand-alone, single-phase induction generator scheme in which the load voltage and frequency are regulated using a full-bridge pulse-width modulation (PWM) DC/AC inverter. A battery feeding the PWM inverter supplies (receives) power to (from) the generator when load demand is greater (lesser) than the power supplied from the prime mover which could be diesel engine, wind or hydro.

  19. Hollow-Cathode Source Generates Plasma

    NASA Technical Reports Server (NTRS)

    Deininger, W. D.; Aston, G.; Pless, L. C.

    1989-01-01

    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  20. A study of increasing radical density and etch rate using remote plasma generator system

    NASA Astrophysics Data System (ADS)

    Lee, Jaewon; Kim, Kyunghyun; Cho, Sung-Won; Chung, Chin-Wook

    2013-09-01

    To improve radical density without changing electron temperature, remote plasma generator (RPG) is applied. Multistep dissociation of the polyatomic molecule was performed using RPG system. RPG is installed to inductively coupled type processing reactor; electrons, positive ions, radicals and polyatomic molecule generated in RPG and they diffused to processing reactor. The processing reactor dissociates the polyatomic molecules with inductively coupled power. The polyatomic molecules are dissociated by the processing reactor that is operated by inductively coupled power. Therefore, the multistep dissociation system generates more radicals than single-step system. The RPG was composed with two cylinder type inductively coupled plasma (ICP) using 400 kHz RF power and nitrogen gas. The processing reactor composed with two turn antenna with 13.56 MHz RF power. Plasma density, electron temperature and radical density were measured with electrical probe and optical methods.

  1. Hydrogen ionic plasma generated using Al plasma grid

    NASA Astrophysics Data System (ADS)

    Oohara, W.; Anegawa, N.; Egawa, M.; Kawata, K.; Kamikawa, T.

    2016-08-01

    Negative hydrogen ions are produced in the apertures of a plasma grid made of aluminum under the irradiation of positive ions, generating an ionic plasma consisting of positive and negative ions. The saturation current ratio obtained using a Langmuir probe reflects the existence ratio of electrons and is found to increase in connection with the diffusion of the ionic plasma. The local increment of the current ratio suggests the collapse of negative ions and the replacement of detached electrons.

  2. Characterization of silicon isotropic etch by inductively coupled plasma etcher for microneedle array fabrication

    NASA Astrophysics Data System (ADS)

    Ji, Jing; Tay, Francis E. H.; Miao, Jianmin; Sun, Jianbo

    2006-04-01

    This work investigates the isotropic etching properties in inductively coupled plasma (ICP) etcher for microneedle arrays fabrication. The effects of process variables including powers, gas and pressure on needle structure generation are characterized by factorial design of experiment (DOE). The experimental responses of vertical etching depth, lateral etching length, ratio of vertical etching depth to lateral etching length and photoresist etching rate are reported. The relevance of the etching variables is also presented. The obtained etching behaviours for microneedle structure generation will be applied to develop recipes to fabricate microneedles in designed dimensions.

  3. Langmuir Probe Measurements in an Inductively Coupled Ar/CF4 Plasmas

    NASA Technical Reports Server (NTRS)

    Rao, M. V. V. S.; Meyyappan, M.; Sharma, S. P.; Arnold, James O. (Technical Monitor)

    2000-01-01

    Technological advancement in the microelectronics industry requires an understanding of the physical and chemical processes occurring in plasmas of fluorocarbon gases, such as carbon tetrafluoride (CF4) which is commonly used as an etchant, and their mixtures to optimize various operating parameters. In this paper we report data on electron number density (ne), electron temperature'(Te), electron energy distribution function (EEDF), mean electron energy, ion number density (ni), and plasma potential (Vp) measured by using Langmuir probe in an inductively coupled 13.56 MHz radio frequency plasmas generated in 50%Ar:50%CF4 mixture in the GEC cell. The probe data were recorded at various radial positions providing radial profiles of these plasma parameters at 10-50 mTorr pressures and 200 W and 300 W of RF power. Present measurements indicate that the electron and ion number densities increase with increase in pressure and power. Whereas the plasma potential and electron temperature decrease with increase in pressure, and they weakly depend on RF power. The radial profiles exhibit that the electron and ion number densities and the plasma potential peak at the center of the plasma with an exponential fall away from it, while the electron temperature has a minimum at the center and it increases steadily towards the electrode edge. The EEDFs have a characteristic drop near the low energy end at all pressures and pressures and their shapes represent non-Maxwellian plasma and exhibit more like Druyvesteyn energy distribution.v

  4. Effect of Inductive Coil Geometry on the Thrust Efficiency of a Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley; Polzin, Kurt; Emsellem, Gregory

    2012-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA) [4, 5] is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and permanent magnets that are arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the inductive coil is high. The use of a conical theta-pinch coil is under investigation. The conical geometry serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT) [2, 3], however a conical coil imparts a direct radial acceleration of the current sheet that serves to rapidly decouple the propellant from the coil, limiting the direct axial electromagnetic acceleration in favor of an indirect acceleration mechanism that requires significant heating of the propellant within the volume bounded by the current sheet. In this paper, we describe thrust stand measurements performed to characterize the performance

  5. Inductive Pulsed Plasma Thruster Model with Time-Evolution of Energy and State Properties

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Sankaran, Kamesh

    2012-01-01

    A model for pulsed inductive plasma acceleration is presented that consists of a set of circuit equations coupled to both a one-dimensional equation of motion and an equation governing the partitioning of energy. The latter two equations are obtained for the plasma current sheet by treating it as a single element of finite volume and integrating the governing equations over that volume. The integrated terms are replaced where necessary by physically-equivalent quantities that are calculated through the solution of other parts of the governing equation set. The model improves upon previous one-dimensional performance models by permitting the time-evolution of the energy and state properties of the plasma, the latter allowing for the tailoring of the model to different gases that may be chosen as propellants. The time evolution of the various energy modes in the system and the associated plasma properties, calculated for argon propellant, are presented to demonstrate the efficacy of the model. The model produces a result where efficiency is maximized at a given value of the electrodynamic scaling term known as the dynamic impedance parameter. Qualitatively and quantitatively, the model compares favorably with performance measured for two separate inductive pulsed plasma thrusters, with disagreements attributable to simplifying assumptions employed in the generation of the model solution.

  6. Mode transition in CF4 + Ar inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Gao, Fei; Zhao, Shu-Xia; Li, Xue-Chun; Wang, You-Nian

    2013-12-01

    The E to H mode transitions are studied by a hairpin probe and optical emission spectroscopy in inductively coupled CF4 + Ar plasmas. Electron density, optical emission intensity of Ar, and the voltage and current are measured during the E to H mode transitions. It is found that the electron density and plasma emission intensity increase continuously at low pressure during the E to H mode transition, while they jump up discontinuously at high pressure. Meanwhile, the transition threshold power and △P (the power interval between E and H mode) increase by increasing the pressure. When the ratio of CF4 increases, the E to H mode transition happens at higher applied power, and meanwhile, the △P also significantly increases. Besides, the effects of CF4 gas ratio on the plasma properties and the circuit electrical properties in both pure E and H modes were also investigated. The electron density and plasma emission intensity both decrease upon increasing the ratio of CF4 at the two modes, due to the stronger electrons loss scheme. The applied voltages at E and H modes both increase as increasing the CF4 gas ratio, however the applied current at two modes behave just oppositely with the gas ratio.

  7. A study on plasma parameters in various mixed Ar/SF6 inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Oh, Seung-Ju; Lee, Hyo-Chang; Chung, Chin-Wook

    2011-10-01

    SF6 gas or Ar/SF6 mixing gas is widely used in plasma processes. However, there are a little experimental study with various external parameters such as gas pressures and mixing ratios. In this work, a study of the plasma parameters was done in Ar/SF6 inductively coupled plasma (ICP) from a careful measurement of the electron energy distribution function (EEDF). The measured plasma parameters are compared to the theoretical results with simplified global model. At a low gas pressure, as mixing ratio of SF6 gas increased at a fixed ICP power, electron density decreased and electron temperature increased, but they were not changed largely. However, a remarkable increase in the electron temperature was observed with decrease in the electron density at higher gas pressures. These changes in the plasma parameters could be explained by large electron losses due to the electron attachment and the experimental results were in agreement with the theoretical results.

  8. Plasma generating apparatus for large area plasma processing

    DOEpatents

    Tsai, C.C.; Gorbatkin, S.M.; Berry, L.A.

    1991-07-16

    A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm[sup 2]. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity. 3 figures.

  9. Plasma generating apparatus for large area plasma processing

    DOEpatents

    Tsai, Chin-Chi; Gorbatkin, Steven M.; Berry, Lee A.

    1991-01-01

    A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm.sup.2. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity.

  10. Pulse generator with intermediate inductive storage as a lightning simulator.

    PubMed

    Kovalchuk, B M; Kharlov, A V; Zherlytsyn, A A; Kumpyak, E V; Tsoy, N V

    2016-06-01

    Compact transportable generators are required for simulating a lightning current pulse for electrical apparatus testing. A bi-exponential current pulse has to be formed by such a generator (with a current rise time of about two orders of magnitude faster than the damping time). The objective of this study was to develop and investigate a compact pulse generator with intermediate inductive storage and a fuse opening switch as a simulator of lightning discharge. A Marx generator (six stages) with a capacitance of 1 μF and an output voltage of 240 kV was employed as primary storage. In each of the stages, two IK-50/3 (50 kV, 3 μF) capacitors are connected in parallel. The generator inductance is 2 μH. A test bed for the investigations was assembled with this generator. The generator operates without SF6 and without oil in atmospheric air, which is very important in practice. Straight copper wires with adjustable lengths and diameters were used for the electro-explosive opening switch. Tests were made with active-inductive loads (up to 0.1 Ω and up to 6.3 μH). The current rise time is lower than 1200 ns, and the damping time can be varied from 35 to 125 μs, following the definition of standard lightning current pulse in the IEC standard. Moreover, 1D MHD calculations of the fuse explosion were carried out self-consistently with the electric circuit equations, in order to calculate more accurately the load pulse parameters. The calculations agree fairly well with the tests. On the basis of the obtained results, the design of a transportable generator was developed for a lightning simulator with current of 50 kA and a pulse shape corresponding to the IEEE standard. PMID:27370452

  11. Pulse generator with intermediate inductive storage as a lightning simulator

    NASA Astrophysics Data System (ADS)

    Kovalchuk, B. M.; Kharlov, A. V.; Zherlytsyn, A. A.; Kumpyak, E. V.; Tsoy, N. V.

    2016-06-01

    Compact transportable generators are required for simulating a lightning current pulse for electrical apparatus testing. A bi-exponential current pulse has to be formed by such a generator (with a current rise time of about two orders of magnitude faster than the damping time). The objective of this study was to develop and investigate a compact pulse generator with intermediate inductive storage and a fuse opening switch as a simulator of lightning discharge. A Marx generator (six stages) with a capacitance of 1 μF and an output voltage of 240 kV was employed as primary storage. In each of the stages, two IK-50/3 (50 kV, 3 μF) capacitors are connected in parallel. The generator inductance is 2 μH. A test bed for the investigations was assembled with this generator. The generator operates without SF6 and without oil in atmospheric air, which is very important in practice. Straight copper wires with adjustable lengths and diameters were used for the electro-explosive opening switch. Tests were made with active-inductive loads (up to 0.1 Ω and up to 6.3 μH). The current rise time is lower than 1200 ns, and the damping time can be varied from 35 to 125 μs, following the definition of standard lightning current pulse in the IEC standard. Moreover, 1D MHD calculations of the fuse explosion were carried out self-consistently with the electric circuit equations, in order to calculate more accurately the load pulse parameters. The calculations agree fairly well with the tests. On the basis of the obtained results, the design of a transportable generator was developed for a lightning simulator with current of 50 kA and a pulse shape corresponding to the IEEE standard.

  12. Physics issues associated with low-beta plasma generators

    NASA Technical Reports Server (NTRS)

    Borovsky, Joseph E.

    1992-01-01

    Kinetic aspects of MHD generators are explored by examining the propagation of dense, low-beta streams of plasma. Three situations are considered: the basic principles of plasma-stream propagation, the propagation of plasma streams into vacuum, and the propagation of plasma streams into ambient plasmas. These three situations are analogous to plasma generators, plasma generators with vacuum loads, and plasma generators with plasma loads. Kinetic (microphysics) aspects include oscillations of the generator plasma, the effects of diocotron instabilities, the acceleration of particles, the starvation of current systems, and plasma-wave production.

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

    SciTech Connect

    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.

  14. Control of plasma density distribution via wireless power transfer in an inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Jin; Lee, Hyo-Chang; Kim, Young-Cheol; Chung, Chin-Wook

    2013-06-01

    With an enlargement of the wafer size, development of large-area plasma sources and control of plasma density distribution are required. To control the spatial distribution of the plasma density, wireless power transfer is applied to an inductively coupled plasma for the first time. An inner powered antenna and an outer resonant coil connected to a variable capacitor are placed on the top of the chamber. As the self-resonance frequency ωr of the resonant coil is adjusted, the power transfer rate from the inner powered coil to the outer resonant coil is changed and the dramatic evolution of the plasma density profile is measured. As ωr of the outer resonant coil changes from the non-resonant condition (where ωr is not the driving angular frequency ωrf) to the resonant condition (where ωr = ωrf), the plasma density profile evolves from a convex shape with maximal plasma density at the radial center into a concave shape with maximal plasma density in the vicinity of the resonant antenna coil. This result shows that the plasma density distribution can be successfully controlled via wireless resonance power transfer.

  15. Comparison between experiment and simulation for argon inductively coupled plasma

    SciTech Connect

    Gao Fei; Zhao Shuxia; Li Xiaosong; Wang Younian

    2009-11-15

    In order to include the nonlocal characteristics of electrons and investigate the inductively coupled plasma (ICP) resources more completely, we have developed a hybrid Monte Carlo (MC)/fluid hybrid model and calculated the axial and radial distributions of electron density, electron temperature, plasma potential, and electron energy distribution functions (EEDFs) of Ar discharge in a planar ICP. Furthermore, to make the model more practical, we still incorporate the effects of metastable atoms, whose sets of rate coefficients and density are, respectively, calculated through the electron MC part and fluid module. Besides, the corresponding Langmuir probe measurements are used to compare these data to validate the simulated results. Under all the selected discharge powers and pressures, the theoretically simulated and experimentally measured quantity profiles agree reasonably with each other, embodied in the generally identical magnitude ranges and spatial distributions. Furthermore, the interpretations about their detailed differences are given, which are based on the designs of both experimental schematic and model configuration. The analysis implements that the inclusions of electron-electron collision and a neutral density distribution into the hybrid model are likely to improve the comparison between the model predictions and experiment diagnostics. Furthermore, the evolution of plasma parameters and EEDFs with discharge conditions is discussed.

  16. An inductance on the Marx generator tail branch

    SciTech Connect

    Carrus, A.

    1989-01-01

    A new technique is presented for generation of short tailed lightning impulses (STLI) with an acceptable degree of efficiency. The method consists in connecting an in-air inductance in series with the tail resistance in one of the standard configurations of the Marx circuit. The validity of the solution has been ascertained experimentally and a criterion is provided for the analytical determination of the most suitable value of this parameter.

  17. Transient Current Analysis of Induction Generators for Wind Power Generating System

    NASA Astrophysics Data System (ADS)

    Senjyu, Tomonobu; Sueyoshi, Norihide; Uezato, Katsumi; Fujita, Hideki

    In recent year, non-conventional energy generation is coming up for effective use of natural energy, such as wind energy. Induction generators consisting squirrel-cage rotors are widly used as wind generators because of their salient features like robust rotor design, simple in the construction, maintenance free operation, etc. However these induction generators will draw large transient inrush current, several times as large as the machine rated current, the instant when they are connected to utility grid or restored after the fault clearance. Under such situations, there will be a severe voltage fluctuations in the power system. In this paper, we present transient analysis of induction generators before and after a three-phase fault conditions. Theoretical discission is developed to determine the initial phase angle and the time at which maximum transient currents flow in the system.

  18. Resonant RF network antennas for large-area and large-volume inductively coupled plasma sources

    NASA Astrophysics Data System (ADS)

    Hollenstein, Ch; Guittienne, Ph; Howling, A. A.

    2013-10-01

    Large-area and large-volume radio frequency (RF) plasmas are produced by different arrangements of an elementary electrical mesh consisting of two conductors interconnected by a capacitor at each end. The obtained cylindrical and planar RF networks are resonant and generate very high RF currents. The input impedance of such RF networks shows the behaviour of an RLC parallel resonance equivalent circuit. The real impedance at the resonance frequency is of great advantage for power matching compared with conventional inductive devices. Changes in the RLC equivalent circuit during the observed E-H transition will allow future interpretation of the plasma-antenna coupling. Furthermore, high power transfer efficiencies are found during inductively coupled plasma (ICP) operation. For the planar RF antenna network it is shown that the E-H transition occurs simultaneously over the entire antenna. The underlying physics of these discharges induced by the resonant RF network antenna is found to be identical to that of the conventional ICP devices described in the literature. The resonant RF network antenna is a new versatile plasma source, which can be adapted to applications in industry and research.

  19. Combination induction plasma tube and current concentrator for introducing a sample into a plasma

    DOEpatents

    Hull, Donald E.; Bieniewski, Thomas M.

    1988-01-01

    An induction plasma tube in combination with a current concentrator. The rent concentrator has a substantially cylindrical body having an open end and a partially closed end which defines an aperture. A first slot extends the longitudinal length of the cylindrical body and a second slot extends radially outward from the aperture. Together the first and second slots form a single L-shaped slot. The current concentrator is disposed within a volume bounded by an induction coil substantially along the axis thereof, and when power is applied to the induction coil a concentrated current is induced within the current concentrator aperture. The concentrator is moveable relative to the coil along the longitudinal axis of the coil to control the amount of current which is concentrated at the aperture.

  20. Inductively Coupled Plasma Mass Spectrometry Uranium Error Propagation

    SciTech Connect

    Hickman, D P; Maclean, S; Shepley, D; Shaw, R K

    2001-07-01

    The Hazards Control Department at Lawrence Livermore National Laboratory (LLNL) uses Inductively Coupled Plasma Mass Spectrometer (ICP/MS) technology to analyze uranium in urine. The ICP/MS used by the Hazards Control Department is a Perkin-Elmer Elan 6000 ICP/MS. The Department of Energy Laboratory Accreditation Program requires that the total error be assessed for bioassay measurements. A previous evaluation of the errors associated with the ICP/MS measurement of uranium demonstrated a {+-} 9.6% error in the range of 0.01 to 0.02 {micro}g/l. However, the propagation of total error for concentrations above and below this level have heretofore been undetermined. This document is an evaluation of the errors associated with the current LLNL ICP/MS method for a more expanded range of uranium concentrations.

  1. Transition of electron kinetics in weakly magnetized inductively coupled plasmas

    SciTech Connect

    Kim, Jin-Yong; Lee, Hyo-Chang; Kim, Young-Do; Chung, Chin-Wook; Kim, Young-Cheol

    2013-10-15

    Transition of the electron kinetics from nonlocal to local regime was studied in weakly magnetized solenoidal inductively coupled plasma from the measurement of the electron energy probability function (EEPF). Without DC magnetic field, the discharge property was governed by nonlocal electron kinetics at low gas pressure. The electron temperatures were almost same in radial position, and the EEPFs in total electron energy scale were radially coincided. However, when the DC magnetic field was applied, radial non-coincidence of the EEPFs in total electron energy scale was observed. The electrons were cooled at the discharge center where the electron heating is absent, while the electron temperature was rarely changed at the discharge boundary with the magnetic field. These changes show the transition from nonlocal to local electron kinetics and the transition is occurred when the electron gyration diameter was smaller than the skin depth. The nonlocal to local transition point almost coincided with the calculation results by using nonlocal parameter and collision parameter.

  2. Induction suspension plasma sprayed biological-like hydroxyapatite coatings.

    PubMed

    Loszach, Max; Gitzhofer, François

    2015-04-01

    Substituted hydroxyapatite coatings with different ions (Mg, Na, K, Cl, F) have been developed by the induction suspension plasma spray process. Suspensions were prepared with sol-gel. The main objective of this study was to demonstrate that induction suspension plasma spray technology possesses high material composition flexibility that allows as-sprayed coatings to closely mimic natural bone composition. Long-term in vitro behaviour of as-sprayed substituted coatings was evaluated with simulated body fluid. Data on the suspensions showed the formation of a pure hydroxyapatite phase. Transmission electron microscopy characterized various preparation stages of the suspensions. As-sprayed samples were distinguished by X-ray diffraction and scanning electron microscopy. Substituted elements were quantified by neutron activation. A well-crystallized hydroxyapatite phase was produced with concentration in various substitutions very close to natural bone composition. Ca/P and (Ca + Mg + Na + K)/P ratios provided evidence of the introduction of different cations into apatite structures. The immersion of samples into simulated body fluid led to the nucleation and growth of a flake-like octacalcium phosphate crystal layer at the surface of as-sprayed coatings after one week. Proof of octacalcium phosphate transformation and its partial dissolution and direct re-precipitation into apatite was disclosed by local energy dispersive spectroscopy and microstructure observation. Formation of a Ca/P ratio gradient from the precipitated layer surface to the as-sprayed coatings interface was observed after four weeks once the octacalcium phosphate crystals reached a critical size, resulting in the formation of a rich apatite layer at the interface after six weeks. A set of mechanisms has been proposed to explain these findings. PMID:25586411

  3. High-harmonic generation in cavitated plasmas

    SciTech Connect

    Schroeder, C. B.; Esarey, E.; Comier-Michel, E.; Leemans, W. P.

    2008-05-15

    A method is proposed for producing coherent x-rays via high-harmonic generation using ultraintense lasers interacting with highly stripped ions in cavitated plasmas. This method relies on plasma cavitation by the wake of an intense drive beam (laser or electron beam) to produce an ion cavity. An ultrashort pulse laser propagating in the plasma-electron-free ion cavity generates laser harmonics. The longitudinal electron motion, which inhibits high-harmonic generation at high laser intensities, can be suppressed by the space-charge field in the ion cavity or by using a counterpropagating laser pulse. Periodic suppression of the longitudinal electron motion may also be used to quasi-phase-match. This method enables harmonic generation to be extended to the sub-A regime.

  4. 30-cm electron cyclotron plasma generator

    NASA Technical Reports Server (NTRS)

    Goede, Hank

    1987-01-01

    Experimental results on the development of a 30-cm-diam electron cyclotron resonance plasma generator are presented. This plasma source utilizes samarium-cobalt magnets and microwave power at a frequency of 4.9 GHz to produce a uniform plasma with densities of up to 3 x 10 to the 11th/cu cm in a continuous fashion. The plasma generator contains no internal structures, and is thus inherently simple in construction and operation and inherently durable. The generator was operated with two different magnetic geometries. One used the rare-earth magnets arranged in an axial line cusp configuration, which directly showed plasma production taking place near the walls of the generator where the electron temperature was highest but with the plasma density peaking in the central low B-field regions. The second configuration had magnets arranged to form azimuthal line cusps with approximately closed electron drift surfaces; this configuration showed an improved electrical efficiency of about 135 eV/ion.

  5. Sequential photocatalyst-assisted digestion and vapor generation device coupled with anion exchange chromatography and inductively coupled plasma mass spectrometry for speciation analysis of selenium species in biological samples.

    PubMed

    Tsai, Yun-ni; Lin, Cheng-hsing; Hsu, I-hsiang; Sun, Yuh-chang

    2014-01-01

    We have developed an on-line sequential photocatalyst-assisted digestion and vaporization device (SPADVD), which operates through the nano-TiO2-catalyzed photo-oxidation and reduction of selenium (Se) species, for coupling between anion exchange chromatography (LC) and inductively coupled plasma mass spectrometry (ICP-MS) systems to provide a simple and sensitive hyphenated method for the speciation analysis of Se species without the need for conventional chemical digestion and vaporization techniques. Because our proposed on-line SPADVD allows both organic and inorganic Se species in the column effluent to be converted on-line into volatile Se products, which are then measured directly through ICP-MS, the complexity of the procedure and the probability of contamination arising from the use of additional chemicals are both low. Under the optimized conditions for SPADVD - using 1g of nano-TiO2 per liter, at pH 3, and illuminating for 80 s - we found that Se(IV), Se(VI), and selenomethionine (SeMet) were all converted quantitatively into volatile Se products. In addition, because the digestion and vaporization efficiencies of all the tested selenicals were improved when using our proposed on-line LC/SPADVD/ICP-MS system, the detection limits for Se(IV), Se(VI), and SeMet were all in the nanogram-per-liter range (based on 3σ). A series of validation experiments - analysis of neat and spiked extracted samples - indicated that our proposed methods could be applied satisfactorily to the speciation analysis of organic and inorganic Se species in the extracts of Se-enriched supplements. PMID:24331052

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

    PubMed

    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. PMID:27250421

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Thrust Stand Measurements of the Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.; Emsellem, Gregory D.

    2011-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. This type of pulsed thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Dis- charge Inductive Plasma Accelerator (MAD-IPA), shown in Fig. 1, is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil before the main current pulse via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and a static magnetic field from a set of permanent magnets arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the theta-pinch coil is high. The use of a conical theta-pinch coil also serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT) [1, 2]. In this paper, we describe thrust stand measurements performed to characterize the performance (specific impulse, thrust efficiency) of the MAD-IPA thruster. Impulse data are obtained at various pulse energies, mass flow rates and inductive coil geometries. Dependencies on these experimental parameters are discussed in the context of the current sheet formation and electromagnetic plasma

  9. Magnetic Field Analysis of a Permanent-Magnet Induction Generator

    NASA Astrophysics Data System (ADS)

    Tsuda, Toshihiro; Fukami, Tadashi; Kanamaru, Yasunori; Miyamoto, Toshio

    The permanent-magnet induction generator (PMIG) is a new type of induction machine that has a permanent-magnet rotor inside a squirrel-cage rotor. In this paper, a new technique for the magnetic field analysis of the PMIG is proposed. The proposed technique is based on the PMIG's equivalent circuit and the two-dimensional finite-element analysis (2D-FEA). To execute the 2D-FEA, the phasors of primary and secondary currents are calculated from the equivalent circuit, and the input data for the 2D-FEA is found by converting these phasors into the space vectors. As a result, the internal magnetic fields of the PMIG can be easily analyzed without complicated calculations.

  10. Al wire array implosion experiments on the inductive storage generator GIT-4

    SciTech Connect

    Baksht, R.B.; Datsko, I.M.; Kim, A.A.; Loginov, S.V.; Labetsky, A.Yu.; Shishlov, A.V.

    1995-12-31

    In High Current Electronics Institute the first successful wire array implosion experiments on the inductive storage generator GIT-4 with a long conductive plasma opening switch were carried out in 1989. Those experiments were aimed at obtaining the radiation with quantum energy below 1 keV. Recently the authors carried out aluminum wire array implosion experiments on the GIT-4 generator varying the value of mr{sub 0}{sup 2} parameter from 2.2 {center_dot} 10{sup {minus}5} to 2.4 {center_dot} 10{sup {minus}4} g {center_dot} cm at different charge voltage and at different values of downstream inductance. The aims were two-fold: (1) to obtain the {eta}-dependence of the K-shell radiation yield and determine the liner parameters which provide a maximum K-shell radiation yield; and (2) to study whether the liner resistance, its inductance and change of its inductance during implosion influence on the POS performance. The results of these experiments are presented.

  11. Ion beams from laser-generated plasmas

    NASA Technical Reports Server (NTRS)

    Hughes, R. H.; Anderson, R. J.; Gray, L. G.; Rosenfeld, J. P.; Manka, C. K.; Carruth, M. R.

    1980-01-01

    The paper describes the space-charge-limited beams produced by the plasma blowoffs generated by 20-MW bursts of 1.06-micron radiation from an active Q-switched Nd:YAG laser. Laser power densities near 10 to the 11th/sq cm on solid targets generate thermalized plasma plumes which drift to a 15-kV gridded extraction gap where the ions are extracted, accelerated, and electrostatically focused; the spatially defined ion beams are then magnetically analyzed to determine the charge state content in the beams formed from carbon, aluminum, copper, and lead targets. This technique preserves time-of-flight (TOF) information in the plasma drift region, which permits plasma ion temperatures and mass flow velocities to be determined from the Maxwellian ion curve TOF shapes for the individual charge species.

  12. Effect of Inductive Coil Geometry and Current Sheet Trajectory of a Conical Theta Pinch Pulsed Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.; Bonds, Kevin W.; Emsellem, Gregory D.

    2011-01-01

    Results are presented demonstrating the e ect of inductive coil geometry and current sheet trajectory on the exhaust velocity of propellant in conical theta pinch pulsed induc- tive plasma accelerators. The electromagnetic coupling between the inductive coil of the accelerator and a plasma current sheet is simulated, substituting a conical copper frustum for the plasma. The variation of system inductance as a function of plasma position is obtained by displacing the simulated current sheet from the coil while measuring the total inductance of the coil. Four coils of differing geometries were employed, and the total inductance of each coil was measured as a function of the axial displacement of two sep- arate copper frusta both having the same cone angle and length as the coil but with one compressed to a smaller size relative to the coil. The measured relationship between total coil inductance and current sheet position closes a dynamical circuit model that is used to calculate the resulting current sheet velocity for various coil and current sheet con gura- tions. The results of this model, which neglects the pinching contribution to thrust, radial propellant con nement, and plume divergence, indicate that in a conical theta pinch ge- ometry current sheet pinching is detrimental to thruster performance, reducing the kinetic energy of the exhausting propellant by up to 50% (at the upper bound for the parameter range of the study). The decrease in exhaust velocity was larger for coils and simulated current sheets of smaller half cone angles. An upper bound for the pinching contribution to thrust is estimated for typical operating parameters. Measurements of coil inductance for three di erent current sheet pinching conditions are used to estimate the magnetic pressure as a function of current sheet radial compression. The gas-dynamic contribution to axial acceleration is also estimated and shown to not compensate for the decrease in axial electromagnetic acceleration

  13. Characterization of railgun-generated plasma armatures

    SciTech Connect

    Propp, A.D.

    1991-01-01

    Production and acceleration of plasmas using railguns is of interest because of the high temperatures and velocities which can be achieved. Railgun-generated plasmas can be used to model difficult-to-study phenomena such as the conditions present when a space vehicle re-enters the earth's atmosphere. There is also interest in the use of plasma railguns in material-processing applications such as deposition of heated particles onto a substrate. To understand and control these processes it is necessary to be able to determine parameters of the plasmas such as temperature, density, and composition. The methods by which these plasma characteristics can be systematically determined are the foci of this study. A rectangular-bore railgun and the vacuum chamber in which it was enclosed were constructed and successfully operated. Magnetic probes and phototransistors were used to determine the velocities of the plasma armatures produced by the railgun. Gated plasma-emission spectroscopy was used to determine the composition, electron density, and temperature at various positions within the plasma armatures.

  14. Surface plasma source with saddle antenna radio frequency plasma generator.

    PubMed

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing. PMID:22380221

  15. Surface plasma source with saddle antenna radio frequency plasma generator

    SciTech Connect

    Dudnikov, V.; Johnson, R. P.; Murray, S.; Pennisi, T.; Piller, C.; Santana, M.; Stockli, M.; Welton, R.

    2012-02-15

    A prototype RF H{sup -} surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA/kW. Control experiments with H{sup -} beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  16. Cold plasma brush generated at atmospheric pressure

    SciTech Connect

    Duan Yixiang; Huang, C.; Yu, Q. S.

    2007-01-15

    A cold plasma brush is generated at atmospheric pressure with low power consumption in the level of several watts (as low as 4 W) up to tens of watts (up to 45 W). The plasma can be ignited and sustained in both continuous and pulsed modes with different plasma gases such as argon or helium, but argon was selected as a primary gas for use in this work. The brush-shaped plasma is formed and extended outside of the discharge chamber with typical dimension of 10-15 mm in width and less than 1.0 mm in thickness, which are adjustable by changing the discharge chamber design and operating conditions. The brush-shaped plasma provides some unique features and distinct nonequilibrium plasma characteristics. Temperature measurements using a thermocouple thermometer showed that the gas phase temperatures of the plasma brush are close to room temperature (as low as 42 deg. C) when running with a relatively high gas flow rate of about 3500 ml/min. For an argon plasma brush, the operating voltage from less than 500 V to about 2500 V was tested, with an argon gas flow rate varied from less than 1000 to 3500 ml/min. The cold plasma brush can most efficiently use the discharge power as well as the plasma gas for material and surface treatment. The very low power consumption of such an atmospheric argon plasma brush provides many unique advantages in practical applications including battery-powered operation and use in large-scale applications. Several polymer film samples were tested for surface treatment with the newly developed device, and successful changes of the wettability property from hydrophobic to hydrophilic were achieved within a few seconds.

  17. Diagnostics of Argon Inductively Coupled Plasma and Dielectric Barrier Discharge Plasma by Optical Emission Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Jia-liang; Yu, Shi-ji; Ma, Teng-cai; Deng, Xin-lu

    2001-08-01

    An experimental setup was built up to carry out radio frequency (RF) inductively coupled plasma (ICP) and dielectric barrier discharge (DBD), and to depict the optical emission spectra (OES) of the discharges. OES from argon ICP and DBD plasmas in visible and near ultraviolet region were measured. For argon ICP, the higher RF power input (higher than 500 W for our machine), the higher degree of argon plasma ionization. But that doesn't mean a higher mean electron energy. With the increase in the power input, the mean electron energy increases slightly, whereas the density of electron increases apparently. Or, the contrary, argon DBD discharge behaves in the manner of a pulsed DC discharge on optical emission spectroscopy and V-I characteristics. DBD current is composed of a series of pulses equally spaced in temporal domain. The kinetics of DBD emission strength is mainly governed by the frequency of the current pulse.

  18. Development and characterization of induction heating electrothermal vaporization (IH-ETV) sample introduction for inductively coupled plasma spectrometry

    NASA Astrophysics Data System (ADS)

    Rybak, Michael E.; Salin, Eric D.

    2001-03-01

    A general study of performance attributes was conducted for a prototypical electrothermal vaporization (ETV) sample introduction system, in which induction heating (IH) was used to facilitate the drying, pyrolysis, and vaporization of samples from long, undercut graphite cup probes in a radio-frequency (RF) induction field. In the first part of this study, experiments were carried out to determine the heating characteristics and temperature control aspects of an IH-ETV arrangement. Using a remote-sensing infrared thermocouple, it was determined that a 3/8-inch (9.53-mm) outer diameter graphite cup sample probe could be heated to a maximum temperature of 1860°C in the induction field of the IH-ETV under full forward power (1.5 kW). The IH-ETV device was found to have a rapid heating response (1/ e time-constant of 2.0±0.2 s) that was independent of the initial/final temperatures chosen. Linear temperature control was possible by regulating either the DC voltage applied to the plate or the current flowing to the grid of the RF generator oscillator tube. The second part of this work consisted of studies to establish benchmarks, such as limits of detection (LOD) with inductively coupled plasma optical emission spectrometry (ICP-OES) and transport efficiency for analyte vaporization under several x-Ar mixed gas atmospheres [where x=15% N 2, 10% O 2, HCl (sparged), or 15% SF 6 (v/v)]. In general, reproducible transient signals with evolution times of 5-15 s were seen for the vaporization of most elements studied, with peak area intensity and reproducibility generally being the best with SF 6-Ar. A 10-fold increase in transport efficiency was seen for refractory carbide-forming analytes (Cr, V) when vaporization was conducted in a halogenous ( x=HCl, SF 6) versus non-halogenous ( x=N 2, O 2) environment, with a two-fold improvement being observed for most other non-refractory elements (Cd, Cu, Fe, Mn, Ni, Pb, Zn). The transport of arsenic proved to be a special case

  19. Induction linac driven free-electron lasers for microwave generation

    NASA Astrophysics Data System (ADS)

    Barletta, William A.

    1992-03-01

    The recent development of highly reliable components for linear induction accelerators (LIA) and free-electron lasers (FEL) enable one to use these devices as economical sources of microwave power to drive magnetic fusion reactors and high gradient, rf linear accelerators. Based on the specifications and costs of the recently designed and fabricated LIA components at the Lawrence Livermore National Laboratory, Science Research Laboratory, Inc., and Pulse Sciences, Inc., this paper reviews the present technology of linear induction accelerators and presents an algorithm for scaling the cost of LIA-driven microwave sources to the high average power regime of interest for the next generation of fusion research machines and linear electorn-positron colliders at TeV energies. The algorithm allows one to optimize the output power of the sources with respect to cost (or other figure of merit) by varying he characteristics (pulse length, driven current, repetition rate, etc.) of the linear induction accelerator. It also allows one to explore cost sensitivities as a guide to formulating research strategies for developing advanced accelerator technologies.

  20. Mechanism for Plasma Etching of Shallow Trench Isolation Features in an Inductively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Agarwal, Ankur; Rauf, Shahid; He, Jim; Choi, Jinhan; Collins, Ken

    2011-10-01

    Plasma etching for microelectronics fabrication is facing extreme challenges as processes are developed for advanced technological nodes. As device sizes shrink, control of shallow trench isolation (STI) features become more important in both logic and memory devices. Halogen-based inductively coupled plasmas in a pressure range of 20-60 mTorr are typically used to etch STI features. The need for improved performance and shorter development cycles are placing greater emphasis on understanding the underlying mechanisms to meet process specifications. In this work, a surface mechanism for STI etch process will be discussed that couples a fundamental plasma model to experimental etch process measurements. This model utilizes ion/neutral fluxes and energy distributions calculated using the Hybrid Plasma Equipment Model. Experiments are for blanket Si wafers in a Cl2/HBr/O2/N2 plasma over a range of pressures, bias powers, and flow rates of feedstock gases. We found that kinetic treatment of electron transport was critical to achieve good agreement with experiments. The calibrated plasma model is then coupled to a string-based feature scale model to quantify the effect of varying process parameters on the etch profile. We found that the operating parameters strongly influence critical dimensions but have only a subtle impact on the etch depths.

  1. Plasma treatment for next-generation nanobiointerfaces.

    PubMed

    Levchenko, Igor; Keidar, Michael; Mai-Prochnow, Anne; Modic, Martina; Cvelbar, Uros; Fang, Jinghua; Ostrikov, Kostya Ken

    2015-01-01

    Energy deficiency, global poverty, chronic hunger, chronic diseases, and environment conservation are among the major problems threatening the whole mankind. Nanostructure-based technologies could be a possible solution. Such techniques are now used for the production of many vitally important products including cultured and fermented food, antibiotics, various medicines, and biofuels. On the other hand, the nanostructure-based technologies still demonstrate low efficiency and controllability, and thus still are not capable to decisively address the global problems. Furthermore, future technologies should ensure lowest possible environmental impact by implementing green production principles. One of the most promising approaches to address these challenges are the sophisticatedly engineered biointerfaces. Here, the authors briefly evaluate the potential of the plasma-based techniques for the fabrication of complex biointerfaces. The authors consider mainly the atmospheric and inductively coupled plasma environments and show several examples of the artificial plasma-created biointerfaces, which can be used for the biotechnological and medical processes, as well as for the drug delivery devices, fluidised bed bioreactors, catalytic reactors, and others. A special attention is paid to the plasma-based treatment and processing of the biointerfaces formed by arrays of carbon nanotubes and graphene flakes. PMID:26104191

  2. Non-inductive Solenoid-less Plasma Current Start-up in NSTX Using Transient CHI

    SciTech Connect

    Raman, R; Jarboe, T R; Nelson, B A; Bell, M G; Ono, M; Bigelow, T; Kaita, R; LeBlanc, B; Lee, K C; Maqueda, R; Menard, J; Paul, S

    2007-05-23

    Coaxial Helicity Injection (CHI) has been successfully used in the National Spherical Torus Experiment (NSTX) for a demonstration of closed flux current generation without the use of the central solenoid. The favorable properties of the Spherical Torus (ST) arise from its very small aspect ratio. However, small aspect ratio devices have very restricted space for a substantial central solenoid. Thus methods for initiating the plasma current without relying on induction from a central solenoid are essential for the viability of the ST concept. CHI is a promising candidate for solenoid-free plasma startup in a ST. The method has now produced closed flux current up to 160 kA verifying the high current capability of this method in a large ST built with conventional tokamak components.

  3. Fabrication of resonator-quantum well infrared photodetector focal plane array by inductively coupled plasma etching

    NASA Astrophysics Data System (ADS)

    Sun, Jason; Choi, Kwong-Kit

    2016-02-01

    Inductively coupled plasma (ICP) etching has distinct advantages over reactive ion etching in that the etching rates are considerably higher, the uniformity is much better, and the sidewalls of the etched material are highly anisotropic due to the higher plasma density and lower operating pressure. Therefore, ICP etching is a promising process for pattern transfer required during microelectronic and optoelectronic fabrication. Resonator-quantum well infrared photodetectors (R-QWIPs) are the next generation of QWIP detectors that use resonances to increase the quantum efficiency (QE). To fabricate R-QWIP focal plane arrays (FPAs), two optimized ICP etching processes are developed. Using these etching techniques, we have fabricated R-QWIP FPAs of several different formats and pixel sizes with the required dimensions and completely removed the substrates of the FPAs. Their QE spectra were tested to be 30 to 40%. The operability and spectral nonuniformity of the FPA is ˜99.5 and 3%, respectively.

  4. Laser ablation inductively coupled plasma mass spectrometry measurement of isotope ratios in depleted uranium contaminated soils.

    PubMed

    Seltzer, Michael D

    2003-09-01

    Laser ablation of pressed soil pellets was examined as a means of direct sample introduction to enable inductively coupled plasma mass spectrometry (ICP-MS) screening of soils for residual depleted uranium (DU) contamination. Differentiation between depleted uranium, an anthropogenic contaminant, and naturally occurring uranium was accomplished on the basis of measured 235U/238U isotope ratios. The amount of sample preparation required for laser ablation is considerably less than that typically required for aqueous sample introduction. The amount of hazardous laboratory waste generated is diminished accordingly. During the present investigation, 235U/238U isotope ratios measured for field samples were in good agreement with those derived from gamma spectrometry measurements. However, substantial compensation was required to mitigate the effects of impaired pulse counting attributed to sample inhomogeneity and sporadic introduction of uranium analyte into the plasma. PMID:14611049

  5. Behavior of Excited Argon Atoms in Inductively Driven Plasmas

    SciTech Connect

    HEBNER,GREGORY A.; MILLER,PAUL A.

    1999-12-07

    Laser induced fluorescence has been used to measure the spatial distribution of the two lowest energy argon excited states, 1s{sub 5} and 1s{sub 4}, in inductively driven plasmas containing argon, chlorine and boron trichloride. The behavior of the two energy levels with plasma conditions was significantly different, probably because the 1s{sub 5} level is metastable and the 1s{sub 4} level is radiatively coupled to the ground state but is radiation trapped. The argon data is compared with a global model to identify the relative importance of processes such as electron collisional mixing and radiation trapping. The trends in the data suggest that both processes play a major role in determining the excited state density. At lower rfpower and pressure, excited state spatial distributions in pure argon were peaked in the center of the discharge, with an approximately Gaussian profile. However, for the highest rfpowers and pressures investigated, the spatial distributions tended to flatten in the center of the discharge while the density at the edge of the discharge was unaffected. The spatially resolved excited state density measurements were combined with previous line integrated measurements in the same discharge geometry to derive spatially resolved, absolute densities of the 1s{sub 5} and 1s{sub 4} argon excited states and gas temperature spatial distributions. Fluorescence lifetime was a strong fi.mction of the rf power, pressure, argon fraction and spatial location. Increasing the power or pressure resulted in a factor of two decrease in the fluorescence lifetime while adding Cl{sub 2} or BCl{sub 3} increased the fluorescence lifetime. Excited state quenching rates are derived from the data. When Cl{sub 2} or BCl{sub 3} was added to the plasma, the maximum argon metastable density depended on the gas and ratio. When chlorine was added to the argon plasma, the spatial density profiles were independent of chlorine fraction. While it is energetically possible for

  6. Characteristics of pulsed dual frequency inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Seo, Jin Seok; Kim, Kyoung Nam; Kim, Ki Seok; Kim, Tae Hyung; Yeom, Geun Young

    2015-01-01

    To control the plasma characteristics more efficiently, a dual antenna inductively coupled plasma (DF-ICP) source composed of a 12-turn inner antenna operated at 2 MHz and a 3-turn outer antenna at 13.56 MHz was pulsed. The effects of pulsing to each antenna on the change of plasma characteristics and SiO2 etch characteristics using Ar/C4F8 gas mixtures were investigated. When the duty percentage was decreased from continuous wave (CW) mode to 30% for the inner or outer ICP antenna, decrease of the average electron temperature was observed for the pulsing of each antenna. Increase of the CF2/F ratio was also observed with decreasing duty percentage of each antenna, indicating decreased dissociation of the C4F8 gas due to the decreased average electron temperature. When SiO2 etching was investigated as a function of pulse duty percentage, increase of the etch selectivity of SiO2 over amorphous carbon layer (ACL) was observed while decreasing the SiO2 etch rate. The increase of etch selectivity was related to the change of gas dissociation characteristics, as observed by the decrease of average electron temperature and consequent increase of the CF2/F ratio. The decrease of the SiO2 etch rate could be compensated for by using the rf power compensated mode, that is, by maintaining the same time-average rf power during pulsing, instead of using the conventional pulsing mode. Through use of the power compensated mode, increased etch selectivity of SiO2/ACL similar to the conventional pulsing mode could be observed without significant decrease of the SiO2 etch rate. Finally, by using the rf power compensated mode while pulsing rf powers to both antennas, the plasma uniformity over the 300 mm diameter substrate could be improved from 7% for the CW conditions to about around 3.3% with the duty percentage of 30%.

  7. Bulk plasma fragmentation in a C{sub 4}F{sub 8} inductively coupled plasma: A hybrid modeling study

    SciTech Connect

    Zhao, Shu-Xia; Zhang, Yu-Ru; Gao, Fei; Wang, You-Nian; Bogaerts, Annemie

    2015-06-28

    A hybrid model is used to investigate the fragmentation of C{sub 4}F{sub 8} inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. C{sub x}F{sub y} (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C{sub 4}F{sub 8} inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C{sub 4}F{sub 8} reaction set used in the model. The C{sub 4}F{sub 8} plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.

  8. Tin removal from extreme ultraviolet collector optics by inductively coupled plasma reactive ion etching

    SciTech Connect

    Shin, H.; Srivastava, S. N.; Ruzic, D. N.

    2008-05-15

    Tin (Sn) has the advantage of delivering higher conversion efficiency compared to other fuel materials (e.g., Xe or Li) in an extreme ultraviolet (EUV) source, a necessary component for the leading next generation lithography. However, the use of a condensable fuel in a lithography system leads to some additional challenges for maintaining a satisfactory lifetime of the collector optics. A critical issue leading to decreased mirror lifetime is the buildup of debris on the surface of the primary mirror that comes from the use of Sn in either gas discharge produced plasma (GDPP) or laser produced plasma (LPP). This leads to a decreased reflectivity from the added material thickness and increased surface roughness that contributes to scattering. Inductively coupled plasma reactive ion etching with halide ions is one potential solution to this problem. This article presents results for etch rate and selectivity of Sn over SiO{sub 2} and Ru. The Sn etch rate in a chlorine plasma is found to be much higher (of the order of hundreds of nm/min) than the etch rate of other materials. A thermally evaporated Sn on Ru sample was prepared and cleaned using an inductively coupled plasma etching method. Cleaning was confirmed using several material characterization techniques. Furthermore, a collector mock-up shell was then constructed and etching was performed on Sn samples prepared in a Sn EUV source using an optimized etching recipe. The sample surface before and after cleaning was analyzed by atomic force microscopy, x-ray photoelectron spectroscopy, and Auger electron spectroscopy. The results show the dependence of etch rate on the location of Sn samples placed on the collector mock-up shell.

  9. Complex image method for RF antenna-plasma inductive coupling calculation in planar geometry. Part I: basic concepts

    NASA Astrophysics Data System (ADS)

    Howling, A. A.; Guittienne, Ph; Jacquier, R.; Furno, I.

    2015-12-01

    The coupling between an inductive source and the plasma determines the power transfer efficiency and the reflected impedance in the primary circuit. Usually, the plasma coupling is analysed by means of a transformer equivalent circuit, where the plasma inductance and resistance are estimated using a global plasma model. This paper shows that, for planar RF antennas, the mutual inductance between the plasma and the primary circuit can be calculated using partial inductances and the complex image method, where the plasma coupling is determined in terms of the plasma skin depth and the distance to the plasma. To introduce the basic concepts, the mutual inductance is calculated here for a linear conductor parallel to the plasma surface. In the accompanying paper part II Guittienne et al (2015 Plasma Sources Sci. Technol. 24 065015), impedance measurements on a RF resonant planar plasma source are modeled using an impedance matrix where the plasma-antenna mutual impedances are calculated using the complex image method presented here.

  10. rf-generated ambient-afterglow plasma

    NASA Astrophysics Data System (ADS)

    Shakir, Shariff; Mynampati, Sandhya; Pashaie, Bijan; Dhali, Shirshak K.

    2006-04-01

    Atmospheric pressure plasmas have gained importance due to their potential application in polymer surface treatment, surface cleaning of metals, thin film deposition, and destruction of biological hazards. In this paper a radio-frequency driven atmospheric pressure afterglow plasma source in argon and helium is discussed. The light intensity measurement shows that the radio-frequency discharge is continuous in time unlike the intermittent nature of a low frequency dielectric-barrier discharge. The discharge, under ambient conditions, can be generated in argon, helium, and nitrogen. Spectroscopic measurements show that metastables are capable of producing oxygen atoms and other excited species. The argon afterglow, in particular, is capable of dissociating oxygen molecules in the ambient gas. An afterglow model has been developed to study the interaction of the plasma with the ambient gas. Results from applications of the plasma to surface treatment of metals and polymers, and bacterial decontamination are briefly discussed.

  11. Plasma generators, reactor systems and related methods

    DOEpatents

    Kong, Peter C.; Pink, Robert J.; Lee, James E.

    2007-06-19

    A plasma generator, reactor and associated systems and methods are provided in accordance with the present invention. A plasma reactor may include multiple sections or modules which are removably coupled together to form a chamber. Associated with each section is an electrode set including three electrodes with each electrode being coupled to a single phase of a three-phase alternating current (AC) power supply. The electrodes are disposed about a longitudinal centerline of the chamber and are arranged to provide and extended arc and generate an extended body of plasma. The electrodes are displaceable relative to the longitudinal centerline of the chamber. A control system may be utilized so as to automatically displace the electrodes and define an electrode gap responsive to measure voltage or current levels of the associated power supply.

  12. Inductively coupled plasma etching of BZN thin films in SF6/Ar plasmas

    NASA Astrophysics Data System (ADS)

    Wang, Gang; Li, Ping; Zhang, Guojun; Li, Wei; Dai, Liping; Jiang, Jing

    2013-03-01

    Etching mechanisms and characteristics of bismuth zinc niobate (BZN) thin films were investigated in inductively coupled SF6/Ar plasmas. The influences of various etching parameters including the gas flow ratio, process pressure, and ICP power on the etching results were analyzed. It is found that the chemical etching with F radicals was more effective than the physical sputtering etching with Ar ions for the inductively coupled plasma etching of BZN thin films. The mechanism of ion assisted chemical etching of BZN thin films in SF6/Ar plasmas was proposed. A maximum etch rate of approximately 43.15 nm/min for the BZN thin film was obtained at the optimum etching conditions: 3/2 for the SF6/Ar gas flow ratio, 10 mTorr for the process pressure, and 600 W for the ICP power. The surface morphology of the etched BZN thin film was observed, where was smooth and clean and no post-etch residues were remained.

  13. Plasma plume MHD power generator and method

    DOEpatents

    Hammer, J.H.

    1993-08-10

    A method is described of generating power at a situs exposed to the solar wind which comprises creating at separate sources at the situs discrete plasma plumes extending in opposed directions, providing electrical communication between the plumes at their source and interposing a desired electrical load in the said electrical communication between the plumes.

  14. Etch Process Sensitivity To An Inductively Coupled Plasma Etcher Treated With Fluorine-Based Plasma

    NASA Astrophysics Data System (ADS)

    Xu, Songlin; Sun, Zhiwen; Qian, Xueyu; Yin, Gerald

    1997-10-01

    Significant etch rate drop after the treatment of an etch chamber with Fluorine-based plasma has been found for some silicon etch processes on an inductively coupled plasma reactor, which might cause problems in IC production line once the etch chamber runs alternative processes with F-based and F-free chemistry, or needs frequent cleaning with F-plasma. In this work, a systematic study of the root cause of process sensitivity to the etch chamber treated with F-plasma has been conducted. The experimental results show that pressure is a key factor to affect the etch rate drop. Processes at high pressure are more sensitive than those at low pressure because the quenching of neutral reactive species becomes more severe after the F-treatment. O2 addition also increases the etch rate sensitivity, basically due to higher O2(subscript: )concentration after F-treatment which enhances the oxidation of silicon. The EDX and XPS elemental analysis of the chamber interior wall reveals a significant composition change after the interaction with F-plasma, the altered surface might accelerate the recombination of free radical species.

  15. Gold fingerprinting by laser ablation inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Watling, R. John; Herbert, Hugh K.; Delev, Dianne; Abell, Ian D.

    1994-02-01

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been applied to the characterization of the trace element composition "fingerprint" of selected gold samples from Western Australia and South Africa. By comparison of the elemental associations it is possible to relate gold to a specific mineralizing event, mine or bullion sample. This methodology facilitates identification of the provenance of stolen gold or gold used in salting activities. In this latter case, it is common for gold from a number of sources to be used in the salting process. Consequently, gold in the prospect being salted will not come from a single source and identification of multiple sources for this gold will establish that salting has occurred. Preliminary results also indicate that specific elemental associations could be used to identify the country of origin of gold. The technique has already been applied in 17 cases involving gold theft in Western Australia, where it is estimated that up to 2% of gold production is "relocated" each year as a result of criminal activities.

  16. Inductively Coupled Plasma Zoom-Time-of-Flight Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Dennis, Elise A.; Ray, Steven J.; Enke, Christie G.; Hieftje, Gary M.

    2016-03-01

    A zoom-time-of-flight mass spectrometer has been coupled to an inductively coupled plasma (ICP) ionization source. Zoom-time-of-flight mass spectrometry (zoom-TOFMS) combines two complementary types of velocity-based mass separation. Specifically, zoom-TOFMS alternates between conventional, constant-energy acceleration (CEA) TOFMS and energy-focused, constant-momentum acceleration (CMA) (zoom) TOFMS. The CMA mode provides a mass-resolution enhancement of 1.5-1.7× over CEA-TOFMS in the current, 35-cm ICP-zoom-TOFMS instrument geometry. The maximum resolving power (full-width at half-maximum) for the ICP-zoom-TOFMS instrument is 1200 for CEA-TOFMS and 1900 for CMA-TOFMS. The CMA mode yields detection limits of between 0.02 and 0.8 ppt, depending upon the repetition rate and integration time—compared with single ppt detection limits for CEA-TOFMS. Isotope-ratio precision is shot-noise limited at approximately 0.2% relative-standard deviation (RSD) for both CEA- and CMA-TOFMS at a 10 kHz repetition rate and an integration time of 3-5 min. When the repetition rate is increased to 43.5 kHz for CMA, the shot-noise limited, zoom-mode isotope-ratio precision is improved to 0.09% RSD for the same integration time.

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

    PubMed

    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. PMID:22944582

  18. Induced magnetic-field effects in inductively coupled plasmas

    SciTech Connect

    Cohen, R.H.; Rognlien, T.D.

    1995-11-04

    In inductive plasma sources, the rapid spatial decay of the electric field arising from the skin effect produces a large radio frequency (RF) magnetic field via Faraday`s law. We previously determined that this magnetic field leads to a reduction of the electron density in the skin region, as well as a reduction in the collisionless heating rate. The electron deficit leads to the formation of an electrostatic potential which pulls electrons in to restore quasineutrality. Here we calculate the electron density including both the induced and electrostatic fields. If the wave frequency is not too low, the ions respond only to the averaged fields, and hence the electrostatic field is oscillatory, predominantly at the second harmonic of the applied field. We calculate the potential required to establish a constant electron density, and compare with numerical orbit-code calculations. For times short compared to ion transit times, the quasineutral density is just the initial ion density. For timescales long enough that the ions can relax, the density profile can be found from the solution of fluid equations with an effective (ponderomotive-like) potential added. Although the time-varying electrostatic potential is an extra source of heating, the net effect of the induced magnetic and electrostatic fields through trapping, early turning, and direct heating is a significant reduction in collisionless heating for parameters of interest.

  19. Temporal Analysis of Electrostatic Chuck Characteristics in Inductively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Shim, Gyu Il; Sugai, Hideo

    Johnsen-Rahbek electrostatic chuck (ESC) for holding a silicon wafer in semiconductor processing is investigated in inductively coupled plasma (ICP). Bi-layer model of the ESC consisting of a thick bulk layer and a thin interface layer is proposed. The resistance of each layer is obtained by measuring the ESC voltage-current (V-I) characteristic with and without the wafer in ICP, along with the voltage effectively applied to the interface layer. Surface charges stored in the interface layer capacitance are found by the time-integration of current in a turn-on phase of a ramped voltage. On the other hand, the chuck holding force is in situ obtained in a turn-off phase of slowly ramped voltage, from the critical conditions of helium gas pressurization for wafer de-chuck. The electrostatic force predicted on a basis of equivalent circuit in the bi-layer model coincides with the mechanical force obtained in the wafer de-touch experiments.

  20. Design and Testing of a Small Inductive Pulsed Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Martin, Adam K.; Dominguez, Alexandra; Eskridge, Richard H.; Polzin, Kurt A.; Riley, Daniel P.; Perdue, Kevin A.

    2015-01-01

    The design and testing of a small inductive pulsed plasma thruster (IPPT) is described. The device was built as a test-bed for the pulsed gas-valves and solid-state switches required for a thruster of this kind, and was designed to be modular to facilitate modification. The thruster in its present configuration consists of a multi-turn, spiral-wound acceleration coil (270 millimeters outer diameter, 100 millimeters inner diameter) driven by a 10 microfarad capacitor and switched with a high-voltage thyristor, a propellant delivery system including a fast pulsed gas-valve, and a glow-discharge pre-ionizer circuit. The acceleration coil circuit may be operated at voltages up to 4 kilovolts (the thyristor limit is 4.5 kilovolts) and the thruster operated at cyclic-rates up to 30 Herz. Initial testing of the thruster, both bench-top and in-vacuum, has been performed. Cyclic operation of the complete device was demonstrated (at 2 Herz), and a number of valuable insights pertaining to the design of these devices have been gained.

  1. Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

    SciTech Connect

    Mortazavi, M.; Urzay, J. Mani, A.

    2015-06-15

    This study addresses the optical performance of a plasma adaptive lens for aero-optical applications by using both axisymmetric and three-dimensional numerical simulations. Plasma adaptive lenses are based on the effects of free electrons on the phase velocity of incident light, which, in theory, can be used as a phase-conjugation mechanism. A closed cylindrical chamber filled with Argon plasma is used as a model lens into which a beam of light is launched. The plasma is sustained by applying a radio-frequency electric current through a coil that envelops the chamber. Four different operating conditions, ranging from low to high powers and induction frequencies, are employed in the simulations. The numerical simulations reveal complex hydrodynamic phenomena related to buoyant and electromagnetic laminar transport, which generate, respectively, large recirculating cells and wall-normal compression stresses in the form of local stagnation-point flows. In the axisymmetric simulations, the plasma motion is coupled with near-wall axial striations in the electron-density field, some of which propagate in the form of low-frequency traveling disturbances adjacent to vortical quadrupoles that are reminiscent of Taylor-Görtler flow structures in centrifugally unstable flows. Although the refractive-index fields obtained from axisymmetric simulations lead to smooth beam wavefronts, they are found to be unstable to azimuthal disturbances in three of the four three-dimensional cases considered. The azimuthal striations are optically detrimental, since they produce high-order angular aberrations that account for most of the beam wavefront error. A fourth case is computed at high input power and high induction frequency, which displays the best optical properties among all the three-dimensional simulations considered. In particular, the increase in induction frequency prevents local thermalization and leads to an axisymmetric distribution of electrons even after introduction of

  2. Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

    NASA Astrophysics Data System (ADS)

    Mortazavi, M.; Urzay, J.; Mani, A.

    2015-06-01

    This study addresses the optical performance of a plasma adaptive lens for aero-optical applications by using both axisymmetric and three-dimensional numerical simulations. Plasma adaptive lenses are based on the effects of free electrons on the phase velocity of incident light, which, in theory, can be used as a phase-conjugation mechanism. A closed cylindrical chamber filled with Argon plasma is used as a model lens into which a beam of light is launched. The plasma is sustained by applying a radio-frequency electric current through a coil that envelops the chamber. Four different operating conditions, ranging from low to high powers and induction frequencies, are employed in the simulations. The numerical simulations reveal complex hydrodynamic phenomena related to buoyant and electromagnetic laminar transport, which generate, respectively, large recirculating cells and wall-normal compression stresses in the form of local stagnation-point flows. In the axisymmetric simulations, the plasma motion is coupled with near-wall axial striations in the electron-density field, some of which propagate in the form of low-frequency traveling disturbances adjacent to vortical quadrupoles that are reminiscent of Taylor-Görtler flow structures in centrifugally unstable flows. Although the refractive-index fields obtained from axisymmetric simulations lead to smooth beam wavefronts, they are found to be unstable to azimuthal disturbances in three of the four three-dimensional cases considered. The azimuthal striations are optically detrimental, since they produce high-order angular aberrations that account for most of the beam wavefront error. A fourth case is computed at high input power and high induction frequency, which displays the best optical properties among all the three-dimensional simulations considered. In particular, the increase in induction frequency prevents local thermalization and leads to an axisymmetric distribution of electrons even after introduction of

  3. Characteristics of plasma generated by hypervelocity impact

    SciTech Connect

    Song, Weidong; Li, Jianqiao; Ning, Jianguo

    2013-09-15

    The characteristics of plasma generated by hypervelocity impact were studied through both theoretical analysis and numerical simulation. Based on thermodynamics and statistical physics, a thermal ionization model was proposed to explore the relationships of ionization degree and plasma conductivity to temperature with consideration of the velocity distribution law in the thermodynamic equilibrium state. In order to derive the temperature, internal energy, and density of the plasma generated by the impact for the above relationships, a 3-D model for the impact of an aluminum spherical projectile on an aluminum target was established and five cases with different impact angles were numerically simulated. Then, the temperature calculated from the internal energy and the Thomas Fermi (TF) model, the internal energy and the density of the plasma were put into the function of the ionization degree to study the characteristics of plasma. Finally, based on the experimental data, a good agreement was obtained between the theoretical predictions and the experimental results, and the feasibility of this theoretical model was verified.

  4. Plasma driven neutron/gamma generator

    DOEpatents

    Leung, Ka-Ngo; Antolak, Arlyn

    2015-03-03

    An apparatus for the generation of neutron/gamma rays is described including a chamber which defines an ion source, said apparatus including an RF antenna positioned outside of or within the chamber. Positioned within the chamber is a target material. One or more sets of confining magnets are also provided to create a cross B magnetic field directly above the target. To generate neutrons/gamma rays, the appropriate source gas is first introduced into the chamber, the RF antenna energized and a plasma formed. A series of high voltage pulses are then applied to the target. A plasma sheath, which serves as an accelerating gap, is formed upon application of the high voltage pulse to the target. Depending upon the selected combination of source gas and target material, either neutrons or gamma rays are generated, which may be used for cargo inspection, and the like.

  5. Modeling and simulation of ion-filtered inductively coupled plasma using argon plasma

    NASA Astrophysics Data System (ADS)

    Wu, Chao; Wang, Jian; Zhang, Weiwang; Luo, Yi

    2015-03-01

    An ion-filtered inductively coupled plasma (IF-ICP) is proposed to reduce ion bombardment and provide high metastable species density for chemical vapor deposition. Argon plasma, which has simple reaction mechanism, is simulated to show the effects of ion filter. Compared to typical ICP, the maximum density of ions of IF-ICP is lower while that of metastable species is higher. The filter can absorb ions effectively and relatively small amount of metastable species, with the absorption coefficient proportional to its surface area. A proper gap between filter and substrate can achieve more metastable species and less ions on the substrate. The pressure and RF power need to be optimized based on the tradeoff between deposition rate and ion damage. The density of ions on the substrate can be reduced by two orders of magnitude while that of metastable species are maintained in the order of 1017 m-3 under the optimized conditions.

  6. Electric-arc steam plasma generator

    NASA Astrophysics Data System (ADS)

    Anshakov, A. S.; Urbakh, E. K.; Radko, S. I.; Urbakh, A. E.; Faleev, V. A.

    2015-01-01

    Investigation results on the arc plasmatorch for water-steam heating are presented. The construction arrangement of steam plasma generator with copper electrodes of the stepped geometry was firstly implemented. The energy characteristics of plasmatorch and erosion of electrodes reflect the features of their behavior at arc glow in the plasma-forming environment of steam. The results of numerical study of the thermal state of the composite copper-steel electrodes had a significant influence on optimization of anode water-cooling aimed at improvement of its operation life.

  7. An inductively coupled plasma source for the Gaseous Electronics Conference RF Reference Cell

    SciTech Connect

    Miller, P.A.; Hebner, G.A.; Greenberg, K.E.; Pochan, P.D.; Aragon, B.P.

    1995-07-01

    In order to extend the operating range of the GEC RF Reference Cell, the authors developed an inductively coupled plasma source that replaced the standard parallel-plate upper-electrode assembly. Voltage and current probes, Langmuir probes, and an 80 GHz interferometer provided information on plasmas formed in argon, chlorine, and nitrogen at pressures from 0.1 Pa to 3 Pa. For powers deposited in the plasma from 20 W to 300 W, the source produced peak electron densities between 10{sup 10}/cm{sup 3} and 10{sup 12}/cm{sup 3} and electron temperatures near 4 eV. The electron density peaked on axis with typical full-width at half maximum of 7 cm to 9 cm. Discharges in chlorine and nitrogen had bimodal operation that was clearly evident from optical emission intensity. A dim mode occurred at low power and a bright mode at high power. The transition between modes had hysteresis. After many hours of high-power operation, films formed on electrodes and walls of one Cell. These deposits affected the dim-to-bright mode transition, and also apparently caused generation of hot electrons and increased the plasma potential.

  8. Effect of Antenna Diameter on the Characteristics of Internal-Type Linear Inductively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Hyeuk Lim, Jong; Kim, Kyong Nam; Gweon, Gwang Ho; Hong, Seung Pyo; Yeom, Geun Young

    2009-09-01

    In this study, the antenna characteristics of an internal-type, linear, inductively coupled plasma (ICP) source were varied by changing the inner conductor diameter of the ICP antenna composed of an inner conductor enclosed by outer dielectric tubing. The effect of the varied antenna characteristics on the plasma characteristics and the electrical characteristics of the large area plasma source with a substrate area of 2300×2000 mm2 were investigated. The decrease of the antenna conductor diameter from 25 to 10 mm decreased the capacitance of the antenna between the conductor and the dielectric tubing, increased the plasma density, decreased the plasma potential at the same rf power, and improved the plasma uniformity. The increased plasma density and the decreased plasma potential obtained with the smaller antenna conductor diameter were attributed to the increased power transfer efficiency caused by the increased inductive coupling at the same rf power.

  9. Effect of Antenna Diameter on the Characteristics of Internal-Type Linear Inductively Coupled Plasma

    NASA Astrophysics Data System (ADS)

    Lim, Jong Hyeuk; Kim, Kyong Nam; Gweon, Gwang Ho; Hong, Seung Pyo; Yeom, Geun Young

    2009-09-01

    In this study, the antenna characteristics of an internal-type, linear, inductively coupled plasma (ICP) source were varied by changing the inner conductor diameter of the ICP antenna composed of an inner conductor enclosed by outer dielectric tubing. The effect of the varied antenna characteristics on the plasma characteristics and the electrical characteristics of the large area plasma source with a substrate area of 2300× 2000 mm2 were investigated. The decrease of the antenna conductor diameter from 25 to 10 mm decreased the capacitance of the antenna between the conductor and the dielectric tubing, increased the plasma density, decreased the plasma potential at the same rf power, and improved the plasma uniformity. The increased plasma density and the decreased plasma potential obtained with the smaller antenna conductor diameter were attributed to the increased power transfer efficiency caused by the increased inductive coupling at the same rf power.

  10. Effect of an Additional, Parallel Capacitor on Pulsed Inductive Plasma Accelerator Performance

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Sivak, Amy D.; Balla, Joseph V.

    2011-01-01

    A model of pulsed inductive plasma thrusters consisting of a set of coupled circuit equations and a one-dimensional momentum equation has been used to study the effects of adding a second, parallel capacitor into the system. The equations were nondimensionalized, permitting the recovery of several already-known scaling parameters and leading to the identification of a parameter that is unique to the particular topology studied. The current rise rate through the inductive acceleration coil was used as a proxy measurement of the effectiveness of inductive propellant ionization since higher rise rates produce stronger, potentially better ionizing electric fields at the coil face. Contour plots representing thruster performance (exhaust velocity and efficiency) and current rise rate in the coil were generated numerically as a function of the scaling parameters. The analysis reveals that when the value of the second capacitor is much less than the first capacitor, the performance of the two-capacitor system approaches that of the single-capacitor system. In addition, as the second capacitor is decreased in value the current rise rate can grow to be twice as great as the rise rate attained in the single capacitor case.

  11. Plasma surface kinetics studies of silicon dioxide etch process in inductively coupled fluorocarbon plasmas

    NASA Astrophysics Data System (ADS)

    Chang, Won-Seok; Yu, Dong-Hun; Cho, Deog-Gyun; Yook, Yeong-Geun; Chun, Poo-Reum; Lee, Se-Ah; Kwon, Deuk-Chul; Im, Yeon-Ho

    2013-09-01

    With continuous decrease of nanoscale design rule, plasma etching processes to form high aspect ratio contact hole still remains a challenge to overcome their inherent drawbacks such as bowing and twisted feature. Due to their complexities there still exist big gaps between current research status and predictable modeling of this process. To address this issue, we proposed a surface kinetic model of silicon nitride etch process under inductively coupled fluorocarbon plasmas. For this work, the cut-off probe and quadrapole mass spectroscopy were used for measuring electrical plasma properties, the ion and neutral radical species. Furthermore, the systematic surface analysis was performed to investigate the thickness and chemical bonding of polymer passivation layer during the etch process. The proposed semi-global surface kinetic model can consider deposition of polymer passivation layer and silicon nitride etching self-consistently. The predicted modeling results showed good agreement with experimental data. We believe that our research will provide valuable information to avoid the empirical development of plasma etching process.

  12. Evolution of plasma parameters in a He - N2/Ar magnetic pole enhanced inductive plasma source

    NASA Astrophysics Data System (ADS)

    Younus, Maria; Rehman, N. U.; Shafiq, M.; Zakaullah, M.; Abrar, M.

    2016-02-01

    A magnetic pole enhanced inductively coupled H e - N2/A r plasma is studied at low pressure, to monitor the effects of helium mixing on plasma parameters like electron number density (ne) , electron temperature (Te) , plasma potential (Vp ) , and electron energy probability functions (EEPFs). An RF compensated Langmuir probe is employed to measure these plasma parameters. It is noted that electron number density increases with increasing RF power and helium concentration in the mixture, while it decreases with increase in filling gas pressure. On the other hand, electron temperature shows an increasing trend with helium concentration in the mixture. At low RF powers and low helium concentration in the mixture, EEPFs show a "bi-Maxwellian" distribution with pressure. While at RF powers greater than 50 W and higher helium concentration in the mixture, EEPFs evolve into "Maxwellian" distribution. The variation of skin depth with RF power and helium concentration in the mixture, and its relation with EEPF are also studied. The effect of helium concentrations on the temperatures of two electron groups ( Tb u l k and Tt a i l ) in the "bi-Maxwellian" EEPFs is also observed. The temperature of low energy electron group ( Tb u l k) shows significant increase with helium addition, while the temperature of tail electrons ( Tt a i l) increases smoothly as compared to ( Tb u l k).

  13. RELIABLE ANALYSES OF WATER BY INDUCTIVELY COUPLED PLASMA EMISSION SPECTROSCOPY. ANALYTICAL CHEMISTRY BRANCH

    EPA Science Inventory

    Reduction of stray light in the inductively coupled plasma emission spectrometer (ICPES) has greatly increased its reliability as a technique for the multielemental analysis of water. Because of interferences introduced by matrix elements, reliable analysis of some less-sensitive...

  14. Inductively Coupled Plasma and Electron Cyclotron Resonance Plasma Etching of InGaAlP Compound Semiconductor System

    SciTech Connect

    Abernathy, C.R.; Hobson, W.S.; Hong, J.; Lambers, E.S.; Pearton, S.J.; Shul, R.J.

    1998-11-04

    Current and future generations of sophisticated compound semiconductor devices require the ability for submicron scale patterning. The situation is being complicated since some of the new devices are based on a wider diversity of materials to be etched. Conventional IUE (Reactive Ion Etching) has been prevalent across the industry so far, but has limitations for materials with high bond strengths or multiple elements. IrI this paper, we suggest high density plasmas such as ECR (Electron Cyclotron Resonance) and ICP (Inductively Coupled Plasma), for the etching of ternary compound semiconductors (InGaP, AIInP, AlGaP) which are employed for electronic devices like heterojunction bipolar transistors (HBTs) or high electron mobility transistors (HEMTs), and photonic devices such as light-emitting diodes (LEDs) and lasers. High density plasma sources, opeiating at lower pressure, are expected to meet target goals determined in terms of etch rate, surface morphology, surface stoichiometry, selectivity, etc. The etching mechanisms, which are described in this paper, can also be applied to other III-V (GaAs-based, InP-based) as well as III-Nitride since the InGaAIP system shares many of the same properties.

  15. Examination of aluminium and zinc plasmas from an inductive furnace by spectroscopy

    NASA Astrophysics Data System (ADS)

    Burm, K. T. A. L.; Burm

    2013-02-01

    The production of aluminium and zinc plasmas for the deposition of coatings upon steel strip is monitored by optical emission spectroscopy measurements. The plasma is created from an inductive source. The atom and the ion densities as well as the electron temperature are obtained such that the plasma can be characterized. It will be shown that the obtained plasmas are typically highly ionized and deviate from thermal equilibrium.

  16. A Vector Control for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation due to high efficiently for wind energy capture. An inverter system is required to control wind turbine speed and power factor in those generators. The inverter rating of the synchronous generator equals to generator rating. However, DFIG has the advantage that the inverter rating is about 25% to the generator rating. The paper describes a vector control of DFIG inter-connected to power line. The performance of proposed vector control is examined using power system simulation software PSCAD/EMTDC for the DFIG inter-connected to 6.6kv distribution line. The results show good dynamic responses and high accuracy to the stator active power control and the stator reactive power control.

  17. Design and Testing of a Small Inductive Pulsed Plasma Thruster

    NASA Technical Reports Server (NTRS)

    Martin, Adam K.; Eskridge, Richard H.; Dominguez, Alexandra; Polzin, Kurt A.; Riley, Daniel P.; Kimberlin, Adam C.

    2015-01-01

    The design and testing of a small inductive pulsed plasma thruster (IPPT), shown in Fig. 1 with all the major subsystems required for a thruster of this kind are described. Thrust measurements and imaging of the device operated in rep-rated mode are presented to quantify the performance envelope of the device. The small IPPT described in this paper was designed to serve as a test-bed for the pulsed gas-valves and solid-state switches required for a IPPTs. A modular design approach was used to permit future modifications and upgrades. The thruster consists of the following sub-systems: a) a multi-turn, spiral-wound acceleration coil (27 cm o.d., 10 cm i.d.) driven by a 10 microFarad capacitor and switched with a high-voltage thyristor, b) a fast pulsed gas-valve, and c.) a glow-discharge pre-ionizer (PI) circuit. The acceleration-coil circuit may be operated at voltages up to 4 kV (the thyristor limit is 4.5 kV). The device may be operated at rep-rates up to 30 Hz with the present gas-valve. Thrust measurements and imaging of the device operated in rep-rated mode will be presented. The pre-ionizer consists of a 0.3 microFarad capacitor charged to 4 kV and connected to two annular stainless-steel electrodes bounding the area of the coil-face. The 4 kV potential is held across them and when the gas is puffed in over the coil, the PI circuit is completed, and a plasma is formed. Even at the less than optimal base-pressure in the chamber (approximately 5 × 10(exp -4) torr), the PI held-off the applied voltage, and only discharged upon command. For a capacitor charge of 2 kV the peak coil current is 4.1 kA, and during this pulse a very bright discharge (much brighter than from the PI alone) was observed (see Fig. 2). Interestingly, for discharges at this charge voltage the PI was not required as the current rise rate, dI/dt, of the coil itself was sufficient to ionize the gas.

  18. A new continuous calibration method for inductively coupled plasma spectrometry.

    PubMed

    Paredes, E; Maestre, S E; Todolí, J L

    2006-01-01

    A new calibration method was developed and applied to inductively coupled plasma atomic emission spectrometry. External calibration was performed as follows. A container was filled with a given volume of deionized (V(p)) water. Then a concentrated standard was introduced at a controlled rate (Q(e)) into the tank by means of a peristaltic pump. The resulting solution was stirred throughout the experiment. Simultaneously, the solution inside the tank was pumped from the vessel to the plasma at a given rate (Q(s)). The signal was continuously recorded. The variation of the concentration of the solution leaving the tank with time was determined by applying a basic equation of stirred tanks. The representation of the emission intensity versus the time and the further conversion of the time scale into a concentration scale gave rise to the calibration line. The best results in terms of linearity were achieved for V(p)=15 cm3, Q(e)=0.6-0.75 ml min(-1) and Q(s)=1-1.2 ml min(-1). Graphs with more than 40 standards were obtained within about 10 min. The results found were not statistically different from those afforded by the conventional calibration method. In addition, the new method was faster and supplied better linearity and precision than the conventional one. Another advantage of the stirred tank was that procedures such as dynamic calibration and standard additions could be easily and quickly applied, thus shortening the analysis time. A complete analysis following these procedures based on the measurement of 30 standards took about 5 min. Several synthetic as well as certified samples (i.e., bovine liver, mussel tissue and powdered milk) were analyzed with the stirred tank by applying four different calibration methodologies (i.e., external calibration, internal calibration, standard additions and a combination of internal standardization and standard additions), with the combination of internal standardization and standard additions being the method that provided

  19. Pulsed Energy Systems for Generating Plasmas

    NASA Technical Reports Server (NTRS)

    Rose, M. Franklin; Shotts, Z.

    2005-01-01

    This paper will describe the techniques needed to electrically generate highly ionized dense plasmas for a variety of applications. The components needed in pulsed circuits are described in terms of general performance parameters currently available from commercial vendors. Examples of pulsed systems using these components are described and technical data from laboratory experiments presented. Experimental data are given for point designs, capable of multi-megawatt power levels.

  20. Enhanced current flow through a plasma cloud by induction of plasma turbulence

    NASA Technical Reports Server (NTRS)

    Hastings, D. E.

    1987-01-01

    Electrodynamic tethers have been proposed as a means of generating power in low earth orbit. One of the limitations on the power generated is the relatively low electron current that can be collected. It is proposed that the electron current can be significantly enhanced by means of current-induced plasma turbulence in a plasma cloud around the collecting anode. This is examined for the specific case of ion acoustic turbulence. An important conclusion is that the use of plasma clouds in the ionosphere will entail a high-impedance (no instability) and a low-impedance (ion acoustic instability) mode of operation. The low-impedance mode of operation will have two submodes, one steady state and one pulsed.

  1. Laboratory investigations of impact-generated plasma

    NASA Technical Reports Server (NTRS)

    Crawford, David A.; Schultz, Peter H.

    1991-01-01

    The characteristics of plasma that was produced in laboratory by hypervelocity impacts were investigated to demonstrate the feasibility of generation of magnetic fields by meteoritic impacts and to explain the presence of paleomagnetic fields on the lunar surface. The impact-generated magnetic fields were found to exhibit spatial and temporal complexity that depended on the impact angle, the velocity, and the projectile/target composition. The results suggest that crater-related paleomagnetism associated with this mechanism should exhibit similar complexity with spatial wavelengths on the order of a fraction of the crater radius.

  2. High Non-inductive Fraction H-mode Discharges Generated by High-harmonic Fast Wave Heating and Current Drive in the National Spherical Torus Experiment

    SciTech Connect

    Taylor, G.; Hosea, J.; Kessel, C. E.; LeBlanc, B; Mueller, D.; Phillips, C. K.; Valeo, E. J.; Wilson, J. R.; Ryan, Philip Michael; Bonoli, P.; Harvey, R. W.

    2012-01-01

    A deuterium H-mode discharge with a plasma current of 300 kA, an axial toroidal magnetic field of 0.55 T, and a calculated non-inductive plasma current fraction of 0.7 1 has been generated in the National Spherical Torus Experiment by 1.4MW of 30MHz high-harmonic fast wave (HHFW) heating and current drive. Seventy-five percent of the non-inductive current was generated inside an internal transport barrier that formed at a normalized minor radius 0.4. Three quarters of the non-inductive current was bootstrap current, and the remaining non-inductive current was generated directly by HHFW power inside a normalized minor radius 0.2. VC 2012 American Institute of Physics.

  3. Power Smoothing and MPPT for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

    Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation, and variable speed control and power factor control are executed for high efficiently for wind energy capture and high quality for power system voltage. In variable speed control, a wind speed or a generator speed is used for maximum power point tracking. However, performances of a wind generation power fluctuation due to wind speed variation have not yet investigated for those controls. The authors discuss power smoothing by those controls for the DFIG inter-connected to 6.6kV distribution line. The performances are verified using power system simulation software PSCAD/EMTDC for actual wind speed data and are examined from an approximate equation of wind generation power fluctuation for wind speed variation.

  4. Online tuning of impedance matching circuit for long pulse inductively coupled plasma source operation—An alternate approach

    SciTech Connect

    Sudhir, Dass; Bandyopadhyay, M. Chakraborty, A.; Kraus, W.; Gahlaut, A.; Bansal, G.

    2014-01-15

    Impedance matching circuit between radio frequency (RF) generator and the plasma load, placed between them, determines the RF power transfer from RF generator to the plasma load. The impedance of plasma load depends on the plasma parameters through skin depth and plasma conductivity or resistivity. Therefore, for long pulse operation of inductively coupled plasmas, particularly for high power (∼100 kW or more) where plasma load condition may vary due to different reasons (e.g., pressure, power, and thermal), online tuning of impedance matching circuit is necessary through feedback. In fusion grade ion source operation, such online methodology through feedback is not present but offline remote tuning by adjusting the matching circuit capacitors and tuning the driving frequency of the RF generator between the ion source operation pulses is envisaged. The present model is an approach for remote impedance tuning methodology for long pulse operation and corresponding online impedance matching algorithm based on RF coil antenna current measurement or coil antenna calorimetric measurement may be useful in this regard.

  5. Beat-wave generation of plasmons in semiconductor plasmas

    SciTech Connect

    Berezhiani, V.I.; Mahajan, S.M. |

    1995-08-01

    It is shown that in semiconductor plasmas, it is possible to generate large amplitude plasma waves by the beating of two laser beams with frequency difference close to the plasma frequency. For narrow gap seimconductors (for example n-type InSb), the system can simulate the physics underlying beat wave generation in relativistic gaseous plasmas.

  6. Effects of magnetic field on pulse wave forms in plasma immersion ion implantation in a radio-frequency, inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Tong, Honghui; Fu, Ricky K. Y.; Tang, Deli; Zeng, Xuchu; Chu, Paul K.

    2002-09-01

    The time-dependent current wave forms measured using a pulse biased planar electrode in hydrogen radio-frequency (rf), inductively coupled plasma, plasma immersion ion implantation experiments are observed to vary in the presence of an external magnetic field B. Results further indicate that the magnitude of the pulse current is related to the strength and direction of the magnetic field, rf power, and pressure, but the pulse current curves can be primarily correlated with B. The plasma discharges are enhanced in all cases due to magnetic confinement of the electrons, enlargement of the plasma generation volume, and increase in the rf power absorbing efficiency. The plasma density diagnosed by Langmuir probe diminishes in front of the sample chuck with B, whereas the plasma is confined nearby the sidewall of the vacuum chamber at high magnetic field. The high degree of plasma density nonuniformity at high B in front of the sample chuck is not desirable for the processing of planar samples such as silicon wafers and must be compensated. The reduction in the plasma density and plasma density gradient in the sheath can be accounted for by the changes in the pulse current wave forms.

  7. Control Capabilities of Low-Inductance-Antenna-Driven RF Plasmas for Low-Damage Processing of Polymers

    NASA Astrophysics Data System (ADS)

    Setsuhara, Yuichi; Takenaka, Kosuke; Cho, Ken; Ebe, Akinori; Shiratani, Masaharu; Sekine, Makoto; Hori, Masaru

    2008-10-01

    Low-damage processing of polymers is of key importance for fabrication of next-generation devices including electronics on polymers, which require development of plasma sources with reduced plasma potential in order to control interface between the polymer substrate and functional films without suffering degradations due to ion bombardment. Furthermore, applications to polymer-based displays and photovoltaic devices require ultra-large area processes at high throughput. To meet these requirements, we have developed plasma processing technologies with low-inductance antenna (LIA) modules to sustain inductively-coupled RF plasmas. Ion energy distributions showed considerably suppressed ion energy as low as 3.8 eV. The polymer surfaces after plasma exposure were analyzed via hard x-ray photoelectron spectroscopy (HXPES) at SPring8 (National SOR facility in Japan), which exhibited nano-surface modification of polymer surface without suffering degradation of molecular structures underneath. Furthermore, plasma-enhanced deposition of silicon films showed low-temperature (200 deg.C) formation of micro-crystalline silicon films due to sufficiently reduced damage during deposition.

  8. Neutralization efficiency estimation in a neutral beam source based on inductively coupled plasma

    NASA Astrophysics Data System (ADS)

    Vozniy, O. V.; Yeom, G. Y.

    2009-01-01

    This study examined the optimal conditions of neutral beam generation to maintain a high degree of neutralization and focusing during beam energy variation for a neutral beam source based on inductively coupled plasma with a three-grid ion beam acceleration system. The neutral beam energy distribution was estimated by measuring the energy profiles of ions that "survived" the neutralization after reflection. The energy measurements of the primary and reflected ions showed narrow distribution functions, each with only one peak. At higher beam energies, both the ratio of the ion energy loss to the primary energy and the degree of energy divergence decreased, confirming the precise alignment of the neutral beam. The neutralization efficiency of the neutral beam source with a three-grid acceleration system was found to be affected mainly by the beam angle divergence rather than by the particle translation energy.

  9. Osmium isotopic ratio measurements by inductively coupled plasma source mass spectrometry

    SciTech Connect

    Russ, G.P. III; Bazan, J.M.; Date, A.R.

    1987-04-01

    The isotopic composition of nanogram quantities of osmium was measured by using an inductively coupled plasma source mass spectrometer. Sensitivity was enhanced a factor of approx.100 by the use of an osmium tetraoxide vapor generator rather than nebulization of solution. For samples less than or equal to5 ng, the ratios /sup 190/Os//sup 192/Os, /sup 189/Os//sup 192/Os, and /sup 188/Os//sup 192/Os were determined to better than +/- 0.5% (1sigma/sub m/) precision. For the minor isotopes, the ratios /sup 187/Os//sup 192/Os and /sup 186/Os//sup 192/Os were determined to +/-1%, and /sup 184/Os//sup 192/Os (4 x 10/sup -4/) was determined to approx.10%. Isotope ratios for common osmium are reported.

  10. Neutralization efficiency estimation in a neutral beam source based on inductively coupled plasma

    SciTech Connect

    Vozniy, O. V.; Yeom, G. Y.

    2009-01-01

    This study examined the optimal conditions of neutral beam generation to maintain a high degree of neutralization and focusing during beam energy variation for a neutral beam source based on inductively coupled plasma with a three-grid ion beam acceleration system. The neutral beam energy distribution was estimated by measuring the energy profiles of ions that 'survived' the neutralization after reflection. The energy measurements of the primary and reflected ions showed narrow distribution functions, each with only one peak. At higher beam energies, both the ratio of the ion energy loss to the primary energy and the degree of energy divergence decreased, confirming the precise alignment of the neutral beam. The neutralization efficiency of the neutral beam source with a three-grid acceleration system was found to be affected mainly by the beam angle divergence rather than by the particle translation energy.

  11. Thin-layer chromatography combined with diode laser thermal vaporization inductively coupled plasma mass spectrometry.

    PubMed

    Bednařík, Antonín; Tomalová, Iva; Kanický, Viktor; Preisler, Jan

    2014-10-17

    Here we present a novel coupling of thin-layer chromatography (TLC) to diode laser thermal vaporization inductively coupled plasma mass spectrometry (DLTV ICP MS). DLTV is a new technique of aerosol generation which uses a diode laser to induce pyrolysis of a substrate. In this case the cellulose stationary phase on aluminum-backed TLC sheets overprinted with black ink to absorb laser light. The experimental arrangement relies on economic instrumentation: an 808-nm 1.2-W continuous-wave infrared diode laser attached to a syringe pump serving as the movable stage. Using a glass tubular cell, the entire length of a TLC separation channel is scanned. The 8-cm long lanes were scanned in ∼35 s. The TLC - DLTV ICP MS coupling is demonstrated on the separation of four cobalamins (hydroxo-; adenosyl-; cyano-; and methylcobalamin) with limits of detection ∼2 pg and repeatability ∼15% for each individual species. PMID:25193171

  12. Determination of arsenic in gold by flow injection inductively coupled plasma mass spectrometry with matrix removal by reductive precipitation

    NASA Astrophysics Data System (ADS)

    Becotte-Haigh, Paul; Tyson, Julian F.; Denoyer, Eric; Hinds, Michael W.

    1996-12-01

    Arsenic was determined in gold by flow injection hydride generation inductively coupled plasma-mass spectrometry following a batch mode reductive precipitation removal of the interfering gold matrix. A solution of potassium iodide, L-ascorbic acid, and hydrochloric acid was used as the reluctant. The recovery of gold by precipitation and filtration was 99 ± 3%. The detection limit for arsenic in gold was 55 ng g -1 in the solid. The concentration of arsenic that was determined in the Royal Canadian Mint gold sample FAU-10 was 29.7 μg g -1 in the solid; this value was indistinguishable, with 95% confidence, from values determined at the Royal Canadian Mint by graphite furnace atomic absorption spectrometry and by inductively coupled plasma-mass spectrometry. The standard deviation for four replicate determinations of the arsenic in FAU-10 was 0.972 μg g -1 in the solid.

  13. Thrust Stand Measurements Using Alternative Propellants in the Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2011-01-01

    Storable propellants (for example water, ammonia, and hydrazine) are attractive for deep space propulsion due to their naturally high density at ambient interplanetary conditions, which obviates the need for a cryogenic/venting system. Water in particular is attractive due to its ease of handling and availability both terrestrially and extra-terrestrially. While many storable propellants are reactive and corrosive, a propulsion scheme where the propellant is insulated from vulnerable (e.g. metallic) sections of the assembly would be well-suited to process these otherwise incompatible propellants. Pulsed inductive plasma thrusters meet this criterion because they can be operated without direct propellant-electrode interaction. During operation of these devices, electrical energy is capacitively stored and then discharged through an inductive coil creating a time-varying current in the coil that interacts with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, many pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA) is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil before the main current pulse via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and a static magnetic field from a set of permanent magnets arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the theta

  14. Investigation of Non-inductive Plasma Current Start-up by RF on QUEST

    NASA Astrophysics Data System (ADS)

    Ishiguro, Masaki; Hanada, Kazuaki; Liu, Hiqing; Ogata, Ryota; Isobe, Mitsutaka; Tashima, Saya; Zushi, Hideki; Sato, Khonosuke; Fujisawa, Akihide; Nakamura, Kazuo; Idei, Hiroshi; Sakamoto, Mizuki; Hasegawa, Makoto; Takase, Yuichi; Maekawa, Takashi; Kishimoto, Yasuaki; Mitarai, Osamu; Kawasaki, Shoji; Nakashima, Hisatoshi; Higashijima, Aki

    2014-05-01

    Formations of a closed flux surface (CFS) on QUEST are achieved by fully non-inductive current start-up driven by RF, which is 8.2GHz in frequency and more than 40kW in power. It found that appropriate magnetic configuration with positive n-index and reduction of particle recycling was crucial to achieve the non-inductive plasma current start-up (PCS) successfully. Especially the controllability of particle recycling should be improved by wall conditioning based on successive plasma production and wall cleaning with electron cyclotron resonance heating (ECR) plasmas induced by RF in frequency of 2.45GHz.

  15. Spatial measurements of electron energy distribution and plasma parameters in a weakly magnetized inductive discharge

    SciTech Connect

    Kim, Young-Do; Lee, Young-Kwang; Lee, Hyo-Chang; Chung, Chin-Wook

    2013-02-15

    Spatial characteristics of plasma parameters such as electron temperature, plasma density, plasma potential, and electron energy distribution (EED) were studied in inductively coupled plasma with an axial dc magnetic field. With dc magnetic field, the measured EEDs in the total electron energy scale are spatially coincided except cutting of the low electron energy part indicating the conserved non-local electron kinetics in an axial direction, even though the dc magnetic field is applied. Spatial distributions of the plasma densities at axial positions have almost same trends with various magnetic field strengths. We also discuss the reduction of the ambipolar potential along the axial direction as the applied magnetic field increased.

  16. Volumetric Near-Field Microwave Plasma Generation

    NASA Technical Reports Server (NTRS)

    Exton, R. J.; Balla, R. Jeffrey; Herring, G. C.; Popovic, S.; Vuskovic, L.

    2003-01-01

    A periodic series of microwave-induced plasmoids is generated using the outgoing wave from a microwave horn and the reflected wave from a nearby on-axis concave reflector. The plasmoids are spaced at half-wavelength separations according to a standing-wave pattern. The plasmoids are enhanced by an effective focusing in the near field of the horn (Fresnel region) as a result of a diffractive narrowing. Optical imaging, electron density, and rotational temperature measurements characterize the near field plasma region. Volumetric microwave discharges may have application to combustion ignition in scramjet engines.

  17. Glass Formulation for Next Generation Cold Crucible Induction Melter

    SciTech Connect

    Kim, Dong-Sang; Schweiger, Michael J.; Vienna, John D.; Johnson, Fabienne; Marra, James C.; Peeler, David K.; Smith, Gary L.

    2011-12-21

    Transformational melter technologies are being considered to support mission acceleration within the U.S. Department of Energy (DOE) complex. New glass formulations are required to take full advantage of the next generation melters, for example, the cold crucible induction melter (CCIM). The key advantage of CCIM technology over current reference technologies is its capability to provide higher processing temperatures, which can lead to an increased waste throughput rate by achieving higher waste loadings and by increasing the feed processing rate. Various waste compositions within the DOE complex were evaluated to determine their potential for successfully demonstrating the unique advantages of the CCIM technology. Glass formulations that satisfy a set of constraints for product quality and assumed CCIM processing conditions were developed for two Hanford waste streams, AZ-101 high-level waste (HLW) and AN-105 low-activity waste (LAW). Three glasses selected for AZ-101 HLW have waste loadings of 40, 42.5, and 45 wt%. The 45-wt% waste loading corresponds to a 22% increase from 37 wt%, which is the maximum expected waste loading based on the current reference formulation. One glass selected for AN-105 LAW has a waste loading of 31.3 wt% at 24 wt% Na2O in glass, which is a 14% increase from the current reference formulation maximum of 21 wt% Na2O. These four glasses are planned for scaled melter tests for initial demonstration of the CCIM technologies for Hanford wastes.

  18. Radiofrequency plasma antenna generated by femtosecond laser filaments in air

    SciTech Connect

    Brelet, Y.; Houard, A.; Point, G.; Prade, B.; Carbonnel, J.; Andre, Y.-B.; Mysyrowicz, A.; Arantchouk, L.; Pellet, M.

    2012-12-24

    We demonstrate tunable radiofrequency emission from a meter-long linear plasma column produced in air at atmospheric pressure. A short-lived plasma column is initially produced by femtosecond filamentation and subsequently converted into a long-lived discharge column by application of an external high voltage field. Radiofrequency excitation is fed to the plasma by induction and detected remotely as electromagnetic radiation by a classical antenna.

  19. Study of Low Voltage Ride Through Performance for Wind Power Generation with Doubly Fed Induction Generator

    NASA Astrophysics Data System (ADS)

    Hirawata, Ryoya; Kai, Takaaki

    Recently, the introduction of wind power generation is increasing rapidly. The ratio of wind power generation to the capacity of a total generation is getting higher and higher. When the phase-to-phase fault occurs in the power system, the frequency of power system is lower due to disconnecting of the wind power generation with doubly fed induction generator (DFIG). Therefore, the power system might become unstable. This paper describes the LVRT (low voltage ride through) performance improvement scheme of the wind power generation with DFIG. The wind power generation is disconnected from the grid in case of the power system fault. It is independently in operation from the grid by controlling of the inverter equipped in the generation. After clearance of the power system fault, the wind power generation is immediately re-connected to the grid. As a result, instability in the power system disappears. The performance of LVRT is confirmed by using simulation software PSCAD/EMTDC. The simulation result shows an excellent result to the three-phase short-circuit fault of the voltage dip 100%.

  20. The Behavior of Plasma Gases in Explosively-Driven Plasma Generator

    NASA Astrophysics Data System (ADS)

    Seo, Minsu; Choi, Jin Soo; Kim, Inho

    2011-06-01

    The plasma-hydrodynamic computer simulation has been performed in order to investigate the thermodynamic and electrical properties of plasma generated in an explosively-driven cylindrical plasma generator. An one-dimensional hydrodynamic code, One-D, was written for this study and a realistic plasma equation of state model was applied to the code. A couple of plasma generators were manufactured and filled by dry air or pressurized argon gas for plasma medium. The plasma thickness and flow velocity were measured by utilizing the optical and electrical pins. The simulation results of the plasma characteristics were in good agreement with the measured values.

  1. Comparative Study of Plasma Parameters in Magnetic Pole Enhanced Inductively Coupled Argon Plasmas

    NASA Astrophysics Data System (ADS)

    F., Jan; W. Khan, A.; Saeed, A.; Zakaullah, M.

    2013-04-01

    Langmuir probe measurements of radio frequency (RF) magnetic pole enhanced inductively coupled (MaPE-ICP) argon plasma were accomplished to obtain the electron number densities and electron temperatures. The measurements were carried out with a fixed RF frequency of 13.56 MHz in a pressure range of 7.5 mTorr to 75 mTorr at an applied RF power of 10 W and 100 W. These results are compared with a global (volume average) model. The results show good agreement between theoretical and experimental measurements. The electron number density shows an increasing trend with both RF power and pressure while the electron temperature shows decreasing trend as the pressure increases. The difference in the plasma potential and floating potential as a function of electron temperature measured from the electrical probe and that obtained theoretically shows a linear relation with a small difference in the coefficient of proportionality. The intensity of the emission line at 750.4 nm due to 2p1 → 1s2 (Paschen's notation) transition closely follows the variation of ne with RF power and filling gas pressure. Measured electron energy probability function (EEPF) shows that electron occupation changes mostly in the high-energy tail, which highlights close similarity of 750.4 nm argon line to ne.

  2. Energy deposition into heavy gas plasma via pulsed inductive theta-pinch

    NASA Astrophysics Data System (ADS)

    Pahl, Ryan Alan

    The objective of this research is to study the formation processes of a pulsed inductive plasma using heavy gases, specifically the coupling of stored capacitive energy into plasma via formation in a theta pinch coil. To aid in this research, the Missouri Plasmoid Experiment Mk. I (and later Mk. II) was created. In the first paper, the construction of differential magnetic field probes are discussed. The effects of calibration setup on B-dot probes is studied using a Helmholtz coil driven by a vector network analyzer and a pulsed-power system. Calibration in a pulsed-power environment yielded calibration factors at least 9.7% less than the vector network analyzer. In the second paper, energy deposition into various gases using a pulsed inductive test article is investigated. Experimental data are combined with a series RLC model to quantify the energy loss associated with plasma formation in Argon, Hydrogen, and Xenon at pressures from 10-100 mTorr. Plasma resistance is found to vary from 25.8-51.6 mΩ and plasma inductance varies from 41.3--47.0 nH. The greatest amount of initial capacitively stored energy that could be transferred to the plasma was 6.4 J (8.1%) of the initial 79.2 +/- 0.1 J. In the third paper, the effects of a DC preionization source on plasma formation energy is studied. The preionization source radial location is found to have negligible impact on plasma formation repeatability while voltage is found to be critical at low pressures. Without preionization, plasma formation was not possible. At 20 mTorr, 0.20 W of power was sufficient to stabilize plasma formation about the first zero-crossing of the discharge current. Increasing power to 1.49 W increased inductively coupled energy by 39%. At 200 mTorr, 4.3 mW was sufficient to produce repeatable plasma properties.

  3. Performance Effects of Adding a Parallel Capacitor to a Pulse Inductive Plasma Accelerator Powertrain

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Sivak, Amy D.; Balla, Joseph V.

    2011-01-01

    Pulsed inductive plasma accelerators are electrodeless space propulsion devices where a capacitor is charged to an initial voltage and then discharged through a coil as a high-current pulse that inductively couples energy into the propellant. The field produced by this pulse ionizes the propellant, producing a plasma near the face of the coil. Once a plasma is formed if can be accelerated and expelled at a high exhaust velocity by the Lorentz force arising from the interaction of an induced plasma current and the magnetic field. While there are many coil geometries that can be employed to inductively accelerate a plasma, in this paper the discussion is limit to planar geometries where the coil take the shape of a flat spiral. A recent review of the developmental history of planar-geometry pulsed inductive thrusters can be found in Ref. [1]. Two concepts that have employed this geometry are the Pulsed Inductive Thruster (PIT) and the Faraday Accelerator with Radio-frequency Assisted Discharge (FARAD).

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

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

    Brihoum, Melisa; Cunge, Gilles; Darnon, Maxime; Joubert, Olivier; Gahan, David; Braithwaite, Nicholas St. J.

    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. Flow dynamics and magnetic induction in the von-Kármán plasma experiment

    NASA Astrophysics Data System (ADS)

    Plihon, N.; Bousselin, G.; Palermo, F.; Morales, J.; Bos, W. J. T.; Godeferd, F.; Bourgoin, M.; Pinton, J.-F.; Moulin, M.; Aanesland, A.

    2015-01-01

    The von-Kármán plasma experiment is a novel versatile experimental device designed to explore the dynamics of basic magnetic induction processes and the dynamics of flows driven in weakly magnetized plasmas. A high-density plasma column (1016-1019 particles. m-3) is created by two radio-frequency plasma sources located at each end of a 1 m long linear device. Flows are driven through J × B azimuthal torques created from independently controlled emissive cathodes. The device has been designed such that magnetic induction processes and turbulent plasma dynamics can be studied from a variety of time-averaged axisymmetric flows in a cylinder. MHD simulations implementing volume-penalization support the experimental development to design the most efficient flow-driving schemes and understand the flow dynamics. Preliminary experimental results show that a rotating motion of up to nearly 1 km/s is controlled by the J × B azimuthal torque.

  7. ICPP: Low-frequency, inductively coupled plasma sources: operation and applications

    NASA Astrophysics Data System (ADS)

    Xu, Shuyan

    2000-10-01

    Low-frequency, inductively coupled plasmas (LFICP) have recently attracted great attention in connection with the plasma processing of materials. The low-frequency sources feature high plasma density (10^18 - 10^19 m-3), excellent uniformity over large areas, low electron temperature, moderate plasma potential, deeper RF filed penetration and high power transfer efficiency. This work presents a comprehensive experimental and theoretical investigation of the electric/electromagnetic properties, electron density and temperature, and the optical emission in 500 kHz ICP sources. A series of experiments conducted in Ar/N_2/H2 and CH4 discharges show that the high-density plasmas are generated in the two distinctive E- and H- operating regimes. Near the mode transitions the power reflection coefficient exhibits resonant minima. The optical emission spectra of neutral atoms and ions together with global power balance arguments reveal that the step-wise ionization via excited states can be responsible for delaying the backward transition between the H- and E- discharge states, and, hence, lead to hysteresis. The experimental and theoretical results on the discharge mode transitions and hysteresis are discussed as well. It is demonstrated that the low-frequency ICP source is extremely efficient for nitriding of solid materials, especially of stainless steel. A low-temperature ( 350^oC) steel nitriding experiments undertaken in plasmas of various Ar/N_2/H2 gas mixtures show that very high nitriding rates, ranging from 40 μm/hour (stainless steel AISI304) to 90 μm/hour (AISI410), can be achieved. The microstructure, phases and composition of the nitrided surface layers have been characterized by Scanning Electron Microscopy, x-ray photoelectron spectroscopy, x-ray diffraction spectroscopy and energy dispersive x-ray spectroscopy. It has been shown that the crystalline phases of the nitrided layer can efficiently be controlled by the processing conditions. The nitrogen

  8. Generator of steam plasma for gasification of solid fuels

    NASA Astrophysics Data System (ADS)

    An'shakov, A. S.; Urbakh, E. K.; Rad'ko, S. I.; Urbakh, A. E.; Faleev, V. A.

    2013-12-01

    A structural design of an electric-arc steam plasma torch (plasmatron) with copper tubular electrodes has been proposed and implemented. Operational parameters are determined for the stable generation of steam plasma. Experimental data are presented on the energy characteristics of the plasma generator with the capacity up to 100 kW.

  9. Surface modification of polypropylene separators in lithium-ion batteries using inductively coupled plasma treatment.

    PubMed

    Son, Jinyoung; Kim, Min-Sik; Lee, Hyun Woo; Yu, Jong-Sung; Kwon, Kwang-Ho

    2014-12-01

    We describe herein an improvement in the surface wettability of plasma-treated separators for use in lithium-ion batteries. We treated the separators with an O2/Ar inductively coupled plasma to increase their surface energy. The plasma treatment on the separator and plasma diagnostic experiments were performed in an inductively coupled plasma (ICP) reactor. The fraction of Ar in the O2/Ar plasma was changed from 0% to 100%. The plasma diagnostics were performed using optical emission spectroscopy and a double Langmuir probe. To confirm the morphological change of the separator membrane by the plasma treatment, we used the scanning electron microscopy. The surface energy measurements were performed using the drop method. We found that the plasma treatment transformed the separator from a hydrophobic membrane to a hydrophilic one, thereby achieving high separator wettability. After the treatment of the separators with O2/Ar plasma, the batteries exhibited better cycle performance and rate capacity than those employing the untreated ones. PMID:25971067

  10. Inductively coupled plasma mass spectrometry applied to isotopic analysis of iron in human fecal matter

    SciTech Connect

    Ting, B.T.G.; Janghorbani, M.

    1986-06-01

    Inductively coupled plasma mass spectrometry combined with stable isotope dilution is applied to accurate isotopic analysis of human fecal matter for /sup 54/Fe and /sup 58/Fe. Argon plasma generated interferences are of minor concern. The interference from /sup 54/Cr can be corrected instrumentally, whereas /sup 58/Ni must be removed chemically. The ratio of the stable isotopes of interest can be measured routinely with a relative standard deviation of about 1%. The overall accuracy of the method for quantitative isotopic analyses is evaluated in Standard Reference Material (SRM) 1577a (Bovine Liver), fecal homogenate subsamples, and synthetic solutions of iron. For SRM 1577a, the respective comparisons are (..mu..g/g) 192.2 +/- 2.2 (present method) vs. 194 +/- 20 (certified value). For the fecal matrix, the present method yields (..mu..g/mL) 15.14 +/- 0.36 vs. 15.82 +/- 0.48 based on atomic absorption spectrophotometry. For an iron solution (250 ppm), replicate analyses yield the value of 245.4 +/- 1.5 ppm.