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Sample records for arc discharge ion

  1. Arc-Discharge Ion Sources for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    A miniature multiple beamlet approach to an injector system was recently proposed in order to reduce the size, cost, and power requirements of the injector. The beamlets of very high current density are needed to meet the brightness requirement. Besides vacuum arc ion sources, cold-cathode gas ion sources are candidates for this application. Vacuum-arc metal ion sources and vacuum-arc-like gas ion sources are discussed. Experiments are presented that focus on the short-pulse plasma composition and ion charge state distribution. Mg and Sr have been identified as the most promising metals leading to mono-species beams when 20 μs arc pulses are used. It is shown that the efficient production of gas ions requires the presence of a magnetic field

  2. Measurement of total ion flux in vacuum Arc discharges

    OpenAIRE

    Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu.; Brown, Ian G.

    2004-01-01

    A vacuum arc ion source was modified allowing us to collect ions from arc plasma streaming through an anode mesh. The mesh had a geometric transmittance of 60 percent, which was taken into account as a correction factor. The ion current from twenty-two cathode materials was measured at an arc current of 100 A. The ion current normalized by the arc current was found to depend on the cathode material, with valuesin the range from 5 percent to 11 percent. The normalized ion current is gener...

  3. Measurement of total ion flux in vacuum Arc discharges

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu.; Brown, Ian G.

    2004-04-12

    A vacuum arc ion source was modified allowing us to collections from arc plasma streaming through an anode mesh. The mesh had ageometric transmittance of 60 percent, which was taken into account as acorrection factor. The ion current from twenty-two cathode materials wasmeasured at an arc current of 100 A. The ion current normalized by thearc current was found to depend on the cathode material, with valuesinthe range from 5 percent to 11 percent. The normalized ion current isgenerally greater for light elements than for heavy elements. The ionerosion rates were determined fromvalues of ion currentand ion chargestates, which were previously measured in the same experimental system.The ion erosion rates range from 12-94 mu g/C.

  4. Arc Discharge Ion Source Development at CERN ISOLDE

    CERN Document Server

    Penescu, Liviu; Stora, Thierry; Catherall, Richard; Cata-Danil, Gheorghe

    2010-01-01

    Within a Marie Curie Early Stage Training project at CERN, a detailed study (experimental, analytical and numerical) of the standard ISOLDE FEBIAD ion sources has been done. A new theoretical model global source behavior could be inferred, based on the acquired experimental data. The source model already served to the development of two FEBIAD prototypes which improved the I+ ionization efficiencies for the noble gases by 5 to 20 times (depending on element) This development can now serve to future ion source optimizations, for specific user or facility requirements around the world, especially for the production of high intensity radioactive beams.

  5. Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE

    International Nuclear Information System (INIS)

    We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5-20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of 229Rn, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS - Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.

  6. Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE.

    Science.gov (United States)

    Penescu, L; Catherall, R; Lettry, J; Stora, T

    2010-02-01

    We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5-20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of (229)Rn, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS--Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.

  7. Using Adaptive Discrete-Time Gas Supply Control for Long Pulse Arc Discharge of Ion Source on NBI

    Institute of Scientific and Technical Information of China (English)

    SHENG Peng; HU Chundong; SONG Shihua; LIU Sheng; LIU Zhimin

    2008-01-01

    A control model of gas supply system is introduced for ion source and an adaptive discrete-time control algorithm to regulate the hydrogen injection.A real-time feedback control system (RFCS) is designed to control the gas supply for ion source based on the control model and the discrete-time control algorithm.The experimental results have proved that RFCS could regulate the gas supply smoothly,suppress the arc's abrupt over-current at the end of the ion source discharging,prolong the discharge pulse and stabilize the ion concentration.With RFCS,the ion source for neutral beam injection has reached its longest pulse with a length of 4.5 seconds in a stable status.

  8. Use of a Low-Pressure Non-Self-Sustained Arc Discharge for Plasma Ion Treatment of Materials

    International Nuclear Information System (INIS)

    An efficient method for producing low-temperature gas plasmas in large vacuum volumes is based on the initiation and operation of a low-pressure non-self-sustained arc discharge with a combined cathode including a hot cathode and a hollow cathode. For this type of a discharge, the inner walls of the working vacuum chamber play the role of a hollow anode. In the range from 10-1 to 1 Pa, this method makes it possible to produce plasmas of both inert and reactive gases of density 109 - 1010 cm-3 uniform within 20% with respect to the average value in volumes of about 1 m3. This paper describes major applications of this type of plasma in technological processes, such as: finish surface cleaning of materials and articles in vacuum; plasma ion nitriding of steels and alloys; plasma-assisted deposition of functional coatings on materials and articles. (author)

  9. Vacuum Arc Ion Sources

    OpenAIRE

    Brown, I.

    2014-01-01

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the sourc...

  10. Formation of Sn-M (M=Fe, Al, Ni) alloy nanoparticles by DC arc-discharge and their electrochemical properties as anodes for Li-ion batteries

    Science.gov (United States)

    Gao, Song; Huang, Hao; Wu, Aimin; Yu, Jieyi; Gao, Jian; Dong, Xinglong; Liu, Chunjing; Cao, Guozhong

    2016-10-01

    A direct current arc-discharge method was applied to prepare the Sn-M (M=Fe, Al, Ni) bi-alloy nanoparticles. Thermodynamic is introduced to analyze the energy circumstances for the formation of the nanoparticles during the physical condensation process. The electrochemical properties of as-prepared Sn-M alloy nanoparticles are systematically investigated as anodes of Li-ion batteries. Among them, Sn-Fe nanoparticles electrode exhibits high Coulomb efficiency (about 71.2%) in the initial charge/discharge (257.9 mA h g-1/366.6 mA h g-1) and optimal cycle stability (a specific reversible capacity of 240 mA h g-1 maintained after 20 cycles) compared with others. Large differences in the electrochemical behaviors indicate that the chemical composition and microstructure of the nanoparticles determine the lithium-ion storage properties and the long-term cyclic stability during the charge/discharge process.

  11. Stretched arc discharge in produced water.

    Science.gov (United States)

    Cho, Y I; Wright, K C; Kim, H S; Cho, D J; Rabinovich, A; Fridman, A

    2015-01-01

    The objective of the present study was to investigate the feasibility of stretching an arc discharge in produced water to increase the volume of produced water treated by plasma. Produced water is the wastewater generated by hydraulic fracturing of shale during the production phase in shale-oil or shale-gas exploration. The electric conductivity of produced water is in the range of 50-200 mS/cm, which provides both a challenge and opportunity for the application of plasmas. Stretching of an arc discharge in produced water was accomplished using a ground electrode and two high-voltage electrodes: one positioned close to the ground electrode and the other positioned farther away from the ground. The benefit of stretching the arc is that the contact between the arc and water is significantly increased, resulting in more efficient plasma treatment in both performance and energy cost. PMID:25638080

  12. Ion nitriding of steel in plasma of non-selfsustained low-pressure arc discharge: phase transitions, faulted substructure and mechanical characteristics

    International Nuclear Information System (INIS)

    The purpose of the work is to find regularities of formation of phase composition, faulted substructure and mechanical characteristics of steels of martensite, ferrite-pearlite and austenite types exposed to low-temperature nitriding in plasma of non-self sustained low-pressure arc discharge with combined heated and hollow cathodes. The nitriding was made in pure nitrogen plasma with density ∼ 5 x 109 cm-3 by two temperature-time regimes. In the first case the temperature was 200oC and time was 2, 4, 6 and 8 hours. The temperature in this case was hold by following parameters of discharge: discharge current Idis = 10 A, discharge voltage Udis = 40 V and bias voltage Ubias = -200 V. In the second case the temperature was 530oC, time was 1, 2 and 5 hours and discharge parameters were discharge current Idis = 50 A, discharge voltage Udis = 40 V and bias voltage Ubias = -600 V. As the experimental materials the samples made from industrial steels 40H (0.4% C; 1.0% Cr), 12H2N4A (0.12% C, 2%Cr, 4%Ni), 12H18N10T (0.12%C, 18%Cr, 10%Ni, 1%Ti) after quenching and in initial state were used. Study of substructure and phase composition of nitrided surface of steel was made with light microscopy, scanning and transmission electron microscopy. Variation of mechanical characteristics was analyzed by micro- and nano-hardness, wear resistance and friction coefficient. The opportunity of low-temperature (∼ 200oC) nitriding of preliminary quenched and/or normalized steel is demonstrated. It is shown, that the volume of diffusion saturation of steel has multilayered structure and it consists of sub-layers differing by phase structure and a state of a faulted substructure. Formation on a nitriding surface a sublayer with nanocrystalline (∼ 10-30 nanometers) structure, containing crystallites of α-Fe, Fe2O3, nitride and carbon-nitride phases was found. It is found, that at nitriding steel with ferrite-pearlite structure (as against quenched) processes of a dynamic

  13. Hooded arc ion-source

    CERN Multimedia

    1972-01-01

    The positioning system for the hooded arc ion-source, shown prior to mounting, consists of four excentric shafts to locate the ion-source and central electrodes. It will be placed on the axis of the SC and introduced into the vacuum tank via the air locks visible in the foreground.

  14. Atmospheric pressure arc discharge with ablating graphite anode

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, V. A. [Keiser University, Fort Lauderdale Campus, FL, 33309, USA; Raitses, Y. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2015-05-18

    The anodic carbon arc discharge is used to produce carbon nanoparticles. Recent experiments with the carbon arc at atmospheric pressure helium demonstrated the enhanced ablation rate for narrow graphite anodes resulting in high deposition rates of carbonaceous products on the copper cathode (Fetterman et al 2008 Carbon 46 1322–6). The proposed model explains these results with interconnected steady-state models of the cathode and the anode processes. When considering cathode functioning, the model predicts circulation of the particles in the near-cathode region: evaporation of the cathode material, ionization of evaporated atoms and molecules in the near-cathode plasma, return of the resulting ions to the cathode, surface recombination of ions and electrons followed again by cathode evaporation etc. In the case of the low anode ablation rate, the ion acceleration in the cathode sheath provides the major cathode heating mechanism. In the case of an intensive anode ablation, an additional cathode heating is due to latent fusion heat of the atomic species evaporated from the anode and depositing at the cathode. Using the experimental arc voltage as the only input discharge parameter, the model allows us to calculate the anode ablation rate. A comparison of the results of calculations with the available experimental data shows reasonable agreement.

  15. Measurements of the total ion flux from vacuum arc cathodespots

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre; Oks, Efim M.; Yushkov, Georgy Yu; Savkin,Konstantin P.; Brown, Ian G.; Nikolaev, Alexey G.

    2005-05-25

    The ion flux from vacuum arc cathode spots was measured in two vacuum arc systems. The first was a vacuum arc ion source which was modified allowing us to collect ions from arc plasma streaming through an anode mesh. The second discharge system essentially consisted of a cathode placed near the center of a spherically shaped mesh anode. In both systems, the ion current streaming through the mesh was measured by a biased collector. The mesh anodes had geometric transmittances of 60 percent and 72 percent, respectively, which were taken into account as correction factors. The ion current from different cathode materials was measured for 50-500 A of arc current. The ion current normalized by the arc current was found to depend on the cathode material, with values in the range from 5 percent to 19 percent. The normalized ion current is generally greater for elements of low cohesive energy. The ion erosion rates were determined from values of ion current and ion charge states, which were previously measured in the same ion source. The absolute ion erosion rates range from 16-173 mu g/C.

  16. Operational characteristics of a metal vapor vacuum arc ion source

    International Nuclear Information System (INIS)

    The MEVVA ion source can produce high current pulsed beams of metallic ions using a metal vapor vacuum arc discharge as the plasma medium from which the ions are extracted. In this study, the operational characteristics of the MEVVA IV ion source are summarized. Results are presented of measurements of the ion beam current as a function of arc current over a range of extraction voltage. Ti, Ta and Pb were examined as the cathode materials. The arc current ranged from 50A to 250A and the extraction voltage from 10kV to 80kV. The ion beam current was measured at two different distances from the ion source using Faraday cups, so as to investigate the beam divergence. Additionally, the cathode erosion rates were measured. Optimum operating conditions of the MEVVA ion source were determined. 10 refs., 6 figs

  17. Discharge Characteristics of DC Arc Water Plasma for Environmental Applications

    Institute of Scientific and Technical Information of China (English)

    LI Tianming; Sooseok CHOI; Takayuki WATANABE

    2012-01-01

    A water plasma was generated by DC arc discharge with a hafnium embedded rodtype cathode and a nozzle-type anode. The discharge characteristics were examined by changing the operation parameter of the arc current. The dynamic behavior of the arc discharge led to significant fluctuations in the arc voltage and its frequency. Analyses of the high speed image and the arc voltage waveform showed that the arc discharge was in the restrike mode and its frequency varied within several tens of kilohertz according to the operating conditions. The larger thermal plasma volume was generated by the higher flow from the forming steam with a higher restrike frequency in the higher arc current conditions. In addition, the characteristics of the water plasma jet were investigated by means of optical emission spectroscopy to identify the abundant radicals required in an efficient waste treatment process.

  18. Study of Metal and Ceramic Thermionic Vacuum arc Discharges

    Institute of Scientific and Technical Information of China (English)

    Tamer AKAN; Serdar DEMIRKOL; Naci EKEM; Suat PAT; Geavit MUSA

    2007-01-01

    The thermionic vacuum arc (TVA) is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions between a heated cathode (electron gun) and an anode (tungsten crucible) containing the material. The accelerated electron beam, incident on the anode, heats the crucible, together with its contents, to a high temperature. After establishing a steady-state density of the evaporating anode material atoms, and when the voltage applied is high enough, a bright discharge is ignited between the electrodes. We generated silver and AI2O3 TVA discharges in order to compare the metal and ceramic TVA discharges. The electrical and optical characteristics of silver and AI2O3 TVA discharges were analysed. The TVA is also a new technique for the deposition of thin films. The film condenses on the sample from the plasma state of the vapour phase of the anode material, generated by a TVA. We deposited silver and AI2O3 thin films onto an aluminium substrate layer-by-layer using their TVA discharges, and produced micro and/or nano-layer Ag-Ab2O3 composite samples. The composite samples using scanning electron microscopy was also analysed.

  19. Arcing in LEO: Does the whole array discharge?

    OpenAIRE

    Ferguson, Dale C.; Vayner, Boris V.; Galofaro, Joel T.; Hillard, G. Barry

    2005-01-01

    The conventional wisdom about solar array arcing in LEO is that only the parts of the solar array that are swept over by the arc-generated plasma front are discharged in the initial arc. This limits the amount of energy that can be discharged. Recent work done at the NASA Glenn Research Center has shown that this idea is mistaken. In fact the capacitance of the entire solar array may be discharged, which for large arrays leads to very large and possibly debilitating arcs, even if no sustained...

  20. Particle tracking velocimetry of a gliding arc discharge

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas;

    2014-01-01

    A 35 kHz AC gliding arc discharge at atmospheric pressure is generated between two diverging electrodes and extended by an air flow. The gas flow velocity is measured by particle tracking velocimetry (PTV) while the moving velocity of the plasma column of the gliding arc discharge is measured...... by analyzing the movie taken by a high-speed camera. The two-dimensional velocity vector of the gas flow and of the gliding arc in the imaging plane was determined....

  1. Improvement on Diamond Nucleation Treated by Pulsed Arc Discharge Plasma

    Institute of Scientific and Technical Information of China (English)

    马志斌; 万军; 汪建华; 张文文

    2004-01-01

    A technique of improvement on diamond nucleation based on pulsed arc discharge plasma at atmospheric pressure was developed. The pulsed arc discharge was induced respectively by nitrogen, argon and methanol gas. After the arc plasma pretreatment, a nucleation density higher than 1010 cm-2 may be obtained subsequently in chemical vapor deposition (CVD) on a mirror-polished silicon substrate without any other mechanical treatment. The effects of the arc discharge plasma on the diamond nucleation were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR) and Raman spectroscopy. The enhancement of nucleation is postulated to be a result of the formation of carbonlike phase materials or nitrogenation on the substrate surface without surface defect produced by arc discharge.

  2. INFLUENCE OF VACUUM ARC PLASMA EVAPORATOR CATHODE GEOMETRY OF ON VALUE OF ADMISSIBLE ARC DISCHARGE CURRENT

    Directory of Open Access Journals (Sweden)

    I. A. Ivanou

    2015-01-01

    Full Text Available An analysis of main design parameters that determine a level of droplet formation intensity at the generating stage of plasma flow has been given in the paper. The paper considers the most widely used designs of water cooled consumable cathodes. Ti or Ti–Si and Fe–Cr alloys have been taken as a material for cathodes. The following calculated data: average ionic charge Zi for titanium plasma +1.6; for «titanium–silicon plasma» +1.2, an electronic discharge 1.6022 ⋅ 10–19 C, an ion velocity vi = 2 ⋅ 104 m/s, an effective volt energy equivalent of heat flow diverted in the cathode Uк = 12 V, temperature of erosion cathode surface Тп = 550 К; temperature of the cooled cathode surface То = 350 К have been accepted in order to determine dependence of a maximum admissible arc discharge current on cathode height. The calculations have been carried out for various values of the cathode heights hк (from 0.02 to 0.05 m. Diameter of a target cathode is equal to 0.08 m for a majority of technological plasma devices, therefore, the area of the erosion surface is S = 0.005 m2.A thickness selection for a consumable target cathode part in the vacuum arc plasma source has been justified in the paper. The thickness ensures formation of minimum drop phase in the plasma flow during arc cathode material evaporation. It has been shown that a maximum admissible current of an arc discharge is practically equal to the minimum current of stable arcing when thickness of the consumable cathode part is equal to 0.05 m. The admissible discharge current can be rather significant and ensure high productivity during coating process with formation of relatively low amount of droplet phase in the coating at small values of hк.

  3. Comparative study on pulsed arc discharge and pulsed corona like discharge in water

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y.; Yan, H.; Zhang, Z.; Li, S.; Yan, K. [Zhejiang Univ., Hangzhou (China). Industrial Ecology and Environment Research Inst.

    2010-07-01

    Electric discharge in water generates intense UV radiation, shockwaves, and active radicals. The technology of pulsed discharge in water has broad applications in marine services, medical treatment and environmental pollution control. This study compared pulsed arc discharge and pulsed corona like discharge using a homemade all solid-state pulsed power system. Voltage and current waveforms, light emission and shockwave strength were detected simultaneously to calculate energy partition of both kinds of pulsed discharge. The differences in current, light emission and shockwave strength were presented. The study showed that energy injection into plasma of pulsed arc discharge varies with the breakdown time, while pulsed corona like discharge has a stable energy injection. A time lag between the application of voltage and breakdown was observed in both pulsed arc discharge and pulsed corona like discharge. The peak current and the light emission of the pulsed arc discharge was much bigger than the pulsed corona discharge, but the difference of shockwave strength was not as obvious. It was concluded that the pulsed arc discharge is more suitable for treating waste water and disinfecting drinking water because of its stronger UV light emission. In marine service, pulsed corona like discharge is more suitable because of its comparative shockwave strength and its stable discharge process. 11 refs., 1 tab., 7 figs.

  4. Reinvestigation of the charge density distribution in arc discharge fusion system

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lin Horng; Yee, Lee Kim; Nan, Phua Yeong; Thung, Yong Yun; Khok, Yong Thian; Rahman, Faidz Abd [Centre of Photonics and Advance Material, Universiti Tunku Abdul Rahman Kuala Lumpur (Malaysia)

    2015-04-24

    A continual arc discharge system has been setup and the light intensity of arc discharge has been profiled. The mathematical model of local energy density distribution in arc discharge fusion has been simulated which is in good qualitative agreement with light intensity profile of arc discharge in the experiments. Eventually, the local energy density distribution of arc discharge system is able to be precisely manipulated to act as heat source in the fabrication of fused fiber devices.

  5. A review of vacuum ARC ion source research at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Evans, P.J.; Noorman, J.T.; Watt, G.C. [ANSTO, Menai (Australia)

    1996-08-01

    The authors talk briefly describes the history and current status of vacuum arc ion source research at the Australian Nuclear Science and Technology Organization (ANSTO). In addition, the author makes some mention of the important role of previous Vacuum Arc Ion Source Workshops in fostering the development of this research field internationally. During the period 1986 - 89, a type of plasma centrifuge known as a vacuum arc centrifuge was developed at ANSTO as part of a research project on stable isotope separation. In this device, a high current vacuum arc discharge was used to produce a metal plasma which was subsequently rotated in an axial magnetic field. The high rotational speeds (10{sup 5} - 10{sup 6} rad sec{sup {minus}1}) achievable with this method produce centrifugal separation of ions with different mass:charge ratios such as isotopic species. The first portent of things to come occurred in 1985 when Dr. Ian Brown visited ANSTO`s Lucas Heights Research Laboratories and presented a talk on the metal vapour vacuum arc (MEVVA) ion source which had only recently been invented by Brown and co-workers, J. Galvin and R. MacGill, at Lawrence Berkeley Laboratory. For those of us involved in vacuum arc centrifuge research, this was an exciting development primarily because the metal vapour vacuum arc plasma source was common to both devices. Thus, a type of arc, which had since the 1930`s been extensively investigated as a means of switching high current loads, had found wider application as a useful plasma source.

  6. Shunting arc plasma source for pure carbon ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y. [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan)

    2012-02-15

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm{sup 2} at the peak of the pulse.

  7. Shunting arc plasma source for pure carbon ion beama)

    Science.gov (United States)

    Koguchi, H.; Sakakita, H.; Kiyama, S.; Shimada, T.; Sato, Y.; Hirano, Y.

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA/mm2 at the peak of the pulse.

  8. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse.

  9. Shunting arc plasma source for pure carbon ion beam.

    Science.gov (United States)

    Koguchi, H; Sakakita, H; Kiyama, S; Shimada, T; Sato, Y; Hirano, Y

    2012-02-01

    A plasma source is developed using a coaxial shunting arc plasma gun to extract a pure carbon ion beam. The pure carbon ion beam is a new type of deposition system for diamond and other carbon materials. Our plasma device generates pure carbon plasma from solid-state carbon material without using a hydrocarbon gas such as methane gas, and the plasma does not contain any hydrogen. The ion saturation current of the discharge measured by a double probe is about 0.2 mA∕mm(2) at the peak of the pulse. PMID:22380206

  10. Is this an arc or a glow discharge?

    International Nuclear Information System (INIS)

    A well known criterion for distinguishing an arc discharge from a glow discharge is a low voltage drop (10--30 V) and a high current density that varies from a few tens to 106 A/cm2 depending on arc type. The high current density is an attribute of arcs with cathode spots. The authors report here a study of the mechanism of emission in cathode spot arc where they realized a spotless discharge with a low voltage drop (30--50 V) and a high mean current density (104--106 A/cm2). The discharge was initiated between a broad cathode and point anode. The cathode was a smooth tungsten sphere electrode of about 100 μm in diameter. The point anode was made of various materials (Mo, Cu, Cd) with initial radius 1 μm. Before the experiment the cathode was cleaned by heating at 2,000 K at high vacuum (10-8 Torr). The discharge was initiated by self-breakdown when electrodes under the voltage 200--500 V were brought to close proximity with each other. The cathode-anode spacing d at the moment of breakdown was estimated to be < 1 μm. The discharge current was varied within 1--3 A by changing the applied voltage and impedance of coaxial cable generator. The discharge burned during 100--1,000 ns. After the single discharge the cathode and anode were examined with a scanning electron microscope. The cathode surface exposed to the discharge was smooth, i.e. no erosion pits similar to arc craters were found on the cathode surface. The anode was shortened after discharge by 5--50 μm depending on current, material and cone angle. A high current density and low voltage drop implies that this is an arc discharge, while the cold cathode and the absence f cathode spot trace are pertinent to a dense glow discharge. The mechanism of emission involving secondary electron emission is to be discussed

  11. Carbon Coating Of Copper By Arc-Discharge Pyrolysis

    Science.gov (United States)

    Ebihara, Ben T.; Jopek, Stanley

    1988-01-01

    Adherent, abrasion-resistant coat deposited with existing equipment. Carbon formed and deposited as coating on copper substrate by pyrolysis of hydrocarbon oil in electrical-arc discharges. Technique for producing carbon deposits on copper accomplished with electrical-discharge-machining equipment used for cutting metals. Applications for new coating technique include the following: solar-energy-collecting devices, coating of metals other than copper with carbon, and carburization of metal surfaces.

  12. Vacuum Arc Ion Sources: Recent Developments and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Ian; Oks, Efim

    2005-05-01

    The vacuum arc ion source has evolved over the past twenty years into a standard laboratory tool for the production of high current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. The primary application of this kind of source has evolved to be ion implantation for material surface modification. Another important use is for injection of high current beams of heavy metal ions into the front ends of particle accelerators, and much excellent work has been carried out in recent years in optimizing the source for reliable accelerator application. The source also provides a valuable tool for the investigation of the fundamental plasma physics of vacuum arc plasma discharges. As the use of the source has grown and diversified, at the same time the ion source performance and operational characteristics have been improved in a variety of different ways also. Here we review the growth and status of vacuum arc ion sources around the world, and summarize some of the applications for which the sources have been used.

  13. Destruction of PCDD/Fs by gliding arc discharges

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    PCDD/Fs have been become a serious issue because of their lexicological effects and associated adverse health implications. In this study, the gliding arc plasma was tested for treatment of polychlorinated dibenzo-p-dioxins (PCDDs) and pol ychlorinated dibenzofurans (PCDFs), which was synthesized from pentachlorophenol in atmospheric condition at 350℃ with or without the catalysis of CuCh-From the experiment, we found that the destruction efficiency of PCDD/F homologues after gliding was discharge ranged from 25% to 79%. This result demonstrates that gliding arc plasma is an effective technology to decompose PCDDs/Fs in flue gas. A plausible degradation mechanism for PCDD/Fs by gliding arc was discussed. Finally, a multistage reactor structure of gliding arc was proposed to upgrade removal efficiency for PCDD/Fs.

  14. Arc discharge-mediated disassembly of viral particles in water.

    Science.gov (United States)

    Lee, Eun-Jung; Lee, Wooseong; Kim, Minwoo; Choi, Eun Ha; Kim, Yun-Ji

    2016-10-01

    In this study, we investigated the inactivation effects on murine norovirus (MNV-1) with/without purification in water using a submerged plasma reactor of arc discharge (underwater arc), which produced a shockwave, UV light, reactive oxygen species and reactive nitrogen species. Underwater arc treatments of 3 and 6 Hz at 12 kV resulted in 2.6- and 4.2-log reductions in the virus titer of non-purified MNV-1 after 1 min of treatment, respectively. The reduction of purified MNV-1 was higher than that of non-purified MNV-1 after underwater arc treatment for all applied conditions (12 or 15 kV and 3 or 6 Hz). One of the viral capsid proteins (VP1) was not detectable after underwater arc treatment, when its integrity was assessed by western blot analysis. Transmission electron microscopy analysis also revealed that MNV-1 particles were completely dissembled by the treatment. This study demonstrates that underwater arc treatment, which was capable of disintegrating the MNV-1 virion structure and the viral capsid protein, can be an effective disinfection process for the inactivation of water-borne noroviruses. PMID:27379726

  15. Carbon Nanotubes Synthesis via Arc Discharge with a Yttria Catalyst

    OpenAIRE

    M. I. Mohammad; Ahmed A. Moosa; J.H. Potgieter; Mustafa K. Ismael

    2013-01-01

    A facile method is proposed to use a computer controlled Arc discharge gap between graphite electrodes together with an yttria-nickel catalyst to synthesize carbon nanotubes under an Ar-H2 gases mixture atmosphere by applying different DC currents and pressure. This produces carbon nanotubes with decreased diameters and increased length. XRD evidence indicated a shift toward higher crystallinity nanotubes. Yields of the CNTs after purification were also enhanced.

  16. Transition characteristics from radio-frequency discharge to arc in hollow cathode configuration

    Institute of Scientific and Technical Information of China (English)

    许建平; 巩春志; 吴明忠; 田修波

    2014-01-01

    The technique ofglow discharges in radio frequency configuration was applied to ignite hollow cathode vacuum arc discharge.The effect of discharge parameters on the building up of hollow cathode arc discharge was investigated.The emission spectrum during the vacuum arc ignition process was measured to disclose the discharge dynamics.There exists a threshold radio frequency power (300 W),beyond which hollow cathode is in γmode discharge status while radio frequency discharge changes into the arc discharge.With the increase of the radio frequency power,the plasma temperature and electronic density increase,and the discharge mode transits more rapidly.The ignition time ofhollow cathode vacuum arc discharge is less than 4 s with a radio frequency power of700 W.

  17. Ti Coating on Magnesium Alloy by Arc-Added Glow Discharge Plasma Penetrating Technique

    Institute of Scientific and Technical Information of China (English)

    CUICai-e; MIAOQiang; PANJun-de; ZHANGPing-ze; ZHANGGao-hui

    2004-01-01

    Arc-added glow discharge plasma penetrating technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio. As the ion bombard and diffusion working on, the surface of the parts form deposited layer, penetrated layer and hybrid layer. Under lab condition, a commercial magnesium alloy Az91 had been coated with Ti film layer with the aim of improving its' anti-corrosion performance. This paper mainly summarized our studies on the testing and analyzing of the coating layer. The composition and microstructure of the coating layer had been analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the surface appearance had been surveyed by scanning electronic microscope (SEM). The adhesion strength between film and matrix had been evaluated by experiments of sticking-tearing. The results indicated that the coated layer on magnesium alloy were homogeneous, dense and robustly adhered.

  18. Ti Coating on Magnesium Alloy by Arc-Added Glow Discharge Plasma Penetrating Technique

    Institute of Scientific and Technical Information of China (English)

    CUI Cai-e; MIAO Qiang; PAN Jun-de; ZHANG Ping-ze; ZHANG Gao-hui

    2004-01-01

    Arc-added glow discharge plasma penetrating technique is a new surface coating method. With the help of vacuum arc discharge, a cold cathode arc source continually emits ion beams of coating elements with high currency density and high ionizing ratio. As the ion bombard and diffusion working on, the surface of the parts form deposited layer,penetrated layer and hybrid layer. Under lab condition, a commercial magnesium alloy Az91 had been coated with Ti film layer with the aim of improving its' anti-corrosion performance. This paper mainly summarized our studies on the testing and analyzing of the coating layer. The composition and microstructure of the coating layer had been analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the surface appearance had been surveyed by scanning electronic microscope (SEM). The adhesion strength between film and matrix had been evaluated by experiments of sticking-tearing. The results indicated that the coated layer on magnesium alloy were homogeneous, dense and robustly adhered.

  19. Multiwalled Carbon Nanotube Synthesis Using Arc Discharge with Hydrocarbon as Feedstock

    OpenAIRE

    Chaudhary, K. T.; Z. H. Rizvi; Bhatti, K. A.; Ali, J; P. P. Yupapin

    2013-01-01

    Synthesis of multiwalled carbon nanotube (MWCNT) by arc discharge process is investigated with methane (CH4) as background and feedstock gas. The arc discharge is carried out between two graphite electrodes for ambient pressures 100, 300, and 500 torr and arc currents 50, 70, and 90 A. Plasma kinetics such as the density and temperature for arc discharge carbon plasma is determined to find out the contribution of physical parameters as arc current and ambient pressure on the plasma dynamics a...

  20. Experimental study on high-voltage solar array sustained arc discharge induced by high charging

    Institute of Scientific and Technical Information of China (English)

    LI Kai; XIE ErQing; WANG Li; LIU YanXia; YANG Yang; SUN YanZheng; CUI XinYu; MAI ShengLi

    2007-01-01

    It has been reported that sustained arc discharge induced by electrostatic discharge (ESD) could cause permanent damage to high-power and high-voltage solar array of spacecrafts. The paper focuses on ESD simulating experiments on Si and GaAs samples, and induces sustained arc discharge. The physical mechanism of sustained arc discharge is discussed by comparing the charging/discharging phenomena between Si and GaAs samples. The experiments show that sustained arc discharge can produce a permanent short-circuit channel between solar cell strings through which the solar array's photovoltaic power may flow out sustainedly. The analyses show that sustained arc discharge strongly depends on solar array structure, solar array operating voltage, ESD characteristics and cell materials.

  1. Experimental study on high-voltage solar array sustained arc discharge induced by high charging

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    It has been reported that sustained arc discharge induced by electrostatic discharge (ESD) could cause permanent damage to high-power and high-voltage solar array of spacecrafts. The paper focuses on ESD simulating experiments on Si and GaAs samples, and induces sustained arc discharge. The physical mechanism of sustained arc discharge is discussed by comparing the charging/discharging phenomena between Si and GaAs samples. The experiments show that sustained arc discharge can produce a permanent short-circuit channel between solar cell strings through which the solar array’s photovoltaic power may flow out sustainedly. The analyses show that sustained arc discharge strongly depends on solar array structure, solar array operating voltage, ESD characteristics and cell materials.

  2. Boron ion beam generation utilizing lanthanum hexaboride cathodes: Comparison of vacuum arc and planar magnetron glow

    International Nuclear Information System (INIS)

    Boron ion beams are widely used for semiconductor ion implantation and for surface modification for improving the operating parameters and increasing the lifetime of machine parts and tools. For the latter application, the purity requirements of boron ion beams are not as stringent as for semiconductor technology, and a composite cathode of lanthanum hexaboride may be suitable for the production of boron ions. We have explored the use of two different approaches to boron plasma production: vacuum arc and planar high power impulse magnetron in self-sputtering mode. For the arc discharge, the boron plasma is generated at cathode spots, whereas for the magnetron discharge, the main process is sputtering of cathode material. We present here the results of comparative test experiments for both kinds of discharge, aimed at determining the optimal discharge parameters for maximum yield of boron ions. For both discharges, the extracted ion beam current reaches hundreds of milliamps and the fraction of boron ions in the total extracted ion beam is as high as 80%

  3. Boron ion beam generation utilizing lanthanum hexaboride cathodes: Comparison of vacuum arc and planar magnetron glow

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, A. G.; Vizir, A. V.; Yushkov, G. Yu., E-mail: gyushkov@mail.ru; Frolova, V. P. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Oks, E. M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation)

    2016-02-15

    Boron ion beams are widely used for semiconductor ion implantation and for surface modification for improving the operating parameters and increasing the lifetime of machine parts and tools. For the latter application, the purity requirements of boron ion beams are not as stringent as for semiconductor technology, and a composite cathode of lanthanum hexaboride may be suitable for the production of boron ions. We have explored the use of two different approaches to boron plasma production: vacuum arc and planar high power impulse magnetron in self-sputtering mode. For the arc discharge, the boron plasma is generated at cathode spots, whereas for the magnetron discharge, the main process is sputtering of cathode material. We present here the results of comparative test experiments for both kinds of discharge, aimed at determining the optimal discharge parameters for maximum yield of boron ions. For both discharges, the extracted ion beam current reaches hundreds of milliamps and the fraction of boron ions in the total extracted ion beam is as high as 80%.

  4. Spectra of Ions Produced by Corona Discharges

    International Nuclear Information System (INIS)

    A mass spectrometric study of ions extracted from both positive and negative DC corona discharges, initiated in point-to plane electrode system, has been carried out in ambient air at low air pressure (5 - 30) kPa. The average relative humidity of air was typically 40-50 %. Ions were extracted through a small orifice in the plane electrode into an intermediate gap where the low pressure prevented further ion-molecule reactions. Mass analysis of negative ions formed in the negative corona discharge using ambient air has shown that the yield of individual ions is strongly affected by trace concentrations of ozone, nitrogen oxides, carbon dioxide and water vapour. In dry air the CO3- ion was found to be dominant. In presence of water this is converted very efficiently to cluster ions CO3-·(H2O)n containing one and more water molecules. The yield of O3-·(H2O)n clusters or core ions was found to be considerably lower than in some other studies at atmospheric pressure. The mass spectrum of ions extracted from drift region of a positive corona discharge was simpler being dominantly cluster ions H3O+·(H2O)n most probably formed from O2+ ions, a two step process being active if water molecules are present in the discharge gap even at relatively low concentration

  5. Unstable behavior of anodic arc discharge for synthesis of nanomaterials

    Science.gov (United States)

    Gershman, Sophia; Raitses, Yevgeny

    2016-09-01

    A short carbon arc operating with a high ablation rate of the graphite anode exhibits a combined motion of the arc and the arc attachment to the anode. A characteristic time scale of this motion is in a 10‑3 s range. The arc exhibits a negative differential resistance before the arc motion occurs. Thermal processes in the arc plasma region interacting with the ablating anode are considered as possible causes of this unstable arc behavior. It is also hypothesized that the arc motion could potentially cause mixing of the various nanoparticles synthesized in the arc in the high ablation regime.

  6. A study of vacuum arc ion velocities using a linear set of probes

    Energy Technology Data Exchange (ETDEWEB)

    Hohenbild, Stefan; Grubel, Christoph; Yushkov, Georgy Yu.; Oks, Efim M.; Anders, Andre

    2008-07-15

    The most likely velocity of ions moving away from vacuum arc cathode spots was measured using a set of probes along the path of plasma expansion. The goal was to determine how much, if any, change of the ion drift velocity occurs in the expanded plasma. The arc discharge current was perturbed to create plasma density markers whose travel is picked up by the set of probes. It was found that the perturbation with current oscillations did not result in consistent data because ion current maxima and minima are not only determined by the plasma production but by the transients of the arc pulse and by the asymmetry of the ion velocity distribution function. Perturbation with a short current spike was more conclusive. The ion velocity was measured to be slightly reduced with increasing distance from the cathode, which can be explained by collisions of ions with the background of neutrals. The ion velocity was increased when the arc current was increased, which correlated with enhanced arc voltage and power dissipation. The ion velocity could be enhanced when the plasma was produced in a non-uniform magnetic field.

  7. Ion sources on basis contracted discharges

    International Nuclear Information System (INIS)

    The summary of the works about the contracted discharge with thermocathode and with cold whole cathode research was held with the purpose of their application in plasma generation on the ion beams sources

  8. Initiation of extended arc discharge in ICF reactor dense atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Kislev, H.

    1986-01-01

    Reduced density plasma channels are essential for LIB transport from external diodes to an ICF pellet centered in the 2-4 MPa superheated steamfilled cavity of the Heavy Water ICF Reactor. Forming such channels by ohmic heating requires the initiation of straight arc discharges along each beamline. The goal of this thesis is to evaluate the threshold beamline preionization and applied electric field for arc initiation. The capability of several preionizers to produce a straight preionized trail is evaluated through a ten-group Boltzmann equation solver. Electron densities around 10/sup 17/ m/sup -3/ could be maintained in the trail by monojoule output external preionizers. Trail preionization through the co-application of UV and CO/sub 2/ lasers appears to be the most promising technique. UV laser preionization of NO(a/sup 4/..pi..) formed in the fireball shows also good prospective. The large divergence of soft x-ray sources reduces their attractivity. The E/N dependent electron transport properties are used to construct the first streamer model capable of evaluating the steady state streamer wave shape. The streamers-induced highly ionized filament transition into a multi-kA carrying plasma channel is simulated by a modified radiation-MHD one-dimensional code.

  9. Photoelectron Emission from Metal Surfaces Induced by VUV-emission of Filament Driven Hydrogen Arc Discharge Plasma

    CERN Document Server

    Laulainen, J; Koivisto, H; Komppula, J; Tarvainen, O

    2015-01-01

    Photoelectron emission measurements have been performed using a filament-driven multi-cusp arc discharge volume production H^- ion source (LIISA). It has been found that photoelectron currents obtained with Al, Cu, Mo, Ta and stainless steel (SAE 304) are on the same order of magnitude. The photoelectron currents depend linearly on the discharge power. It is shown experimentally that photoelectron emission is significant only in the short wavelength range of hydrogen spectrum due to the energy dependence of the quantum efficiency. It is estimated from the measured data that the maximum photoelectron flux from plasma chamber walls is on the order of 1 A per kW of discharge power.

  10. Sustained diffusive alternating current gliding arc discharge in atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Li, Zhongshan;

    2014-01-01

    Rapid transition from glow discharge to thermal arc has been a common problem in generating stable high-power non-thermal plasmas especially at ambient conditions. A sustained diffusive gliding arc discharge was generated in a large volume in atmospheric pressure air, driven by an alternating...

  11. Influence of steering magnetic field on the time-resolved plasma chemistry in cathodic arc discharges

    Science.gov (United States)

    Ehiasarian, A. P.; Hovsepian, P. Eh; New, R.; Valter, J.

    2004-08-01

    External magnetic fields are used extensively to steer the cathode spot of arc discharges in order to improve target utilization and minimize droplet generation. Optical emission spectroscopy (OES) and electrostatic probe measurements in a Cr arc discharge were used to characterize the effect of the external magnetic field on the ion flux to the substrates and on the composition and time evolution of the plasma. A combination of a permanent magnet array and an electromagnetic coil was used to vary the shape and strength of the magnetic field on the cathode surface. Finite element modelling of the magnetic field distribution identified two types of geometry—through-field, with lines normal to the cathode surface, and arched-field, with lines forming a magnetic 'tunnel'. The magnetic flux densities measured with a Hall probe were in the range from -15 to +15 mT. The particular shape and strength of the magnetic field determined the specific confinement regions and diffusion pathways for the plasma. The total ion saturation current density at the substrate position was in the range between 2 and 11.5 mA cm-2 depending on the magnetic field shape. The magnetic field strongly influenced the relative optical emission from Cr0, Cr1+ and Cr2+ metal species, and the resulting charge state distribution. Time-resolved OES and probe measurements of a particular position on the arc cathode revealed that an Ar plasma is trapped near the cathode and is sustained even when the cathode spot is a significant distance from the observation volume. The importance of this 'residual' Ar plasma for the charge state distribution of metal ions is discussed.

  12. The Effect of Flow Distribution on the Concentration of NO Produced by Pulsed Arc Discharge

    Institute of Scientific and Technical Information of China (English)

    HU Hui; BAO Bin; WANG He-li; LIANG Hai-yan; HE Jun-jia; HE Zheng-hao; LI Jin

    2007-01-01

    As a new method to cure acute respiratory distress syndrome (ARDS),high blood pressure and some illnesses related to the lung,NO has recently received more attention.Thermal plasmas produced by arc discharge can create medical NO,but the concentration of NO2 produced by arc discharge must be controlled simultaneously.This paper investigates the characteristics and regulations of NO production at different flow distribution by pulsed arc discharge in dry air with a special pulsed power.The experimental results show that the flow distribution has a considerable effect on the NO concentration,the stabilization of NO.The production of NO2 could be controlled and the ratio of NO2/NO was decreased to about 10% in the arc discharge.Therefore,the arc discharge could produce stable inhaled NO for medical treatment by changing the flow distribution.

  13. High ion charge states in a high-current, short-pulse, vacuum ARC ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Anders, A.; Brown, I.; MacGill, R.; Dickinson, M. [Lawrence Berkeley National Lab., CA (United States)

    1996-08-01

    Ions of the cathode material are formed at vacuum arc cathode spots and extracted by a grid system. The ion charge states (typically 1-4) depend on the cathode material and only little on the discharge current as long as the current is low. Here the authors report on experiments with short pulses (several {mu}s) and high currents (several kA); this regime of operation is thus approaching a more vacuum spark-like regime. Mean ion charge states of up to 6.2 for tungsten and 3.7 for titanium have been measured, with the corresponding maximum charge states of up to 8+ and 6+, respectively. The results are discussed in terms of Saha calculations and freezing of the charge state distribution.

  14. Decomposition of toluene in a gliding arc discharge plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Du Changming [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Yan Jianhua [Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027 (China); Cheron, Bruno [UMR 6614 (CORIA), University of Rouen, 76821 Mont Saint Aignan (France)

    2007-11-15

    The decomposition of toluene in a gliding arc discharge (glidarc) was performed and studied. Experimental results indicate that the glidarc technology can effectively decompose toluene molecules and has bright prospects of being applied as an alternative tool to decompose volatile organic compounds. It is found that a change in the electrode material had an insignificant effect on the toluene removal efficiency. The toluene removal efficiency increases with increasing inlet gas temperature. The water vapor present in the gas mixture has a favorable effect on the toluene decomposition in the plasma. The energy efficiency is 29.46 g (kWh{sup -1}) at a relative humidity of 50% and a specific energy input of 0.26 kWh m{sup -3}, which is higher than other types of non-thermal plasmas. Too much or too little oxygen content does not favor toluene decomposition. The major gas phase products detected by FT-IR from the decomposition of toluene with air participation were CO, CO{sub 2}, H{sub 2}O and NO{sub 2}. Some brown depositions were found on the surface of the electrodes, which were polar oxygenous and nitrogenous compounds determined by the GC-MS analysis, such as benzaldehyde, benzoic acid, quinine and nitrophenol from the reaction of toluene with radicals. A possible mechanism for toluene destruction via glidarc technology is proposed and summarized.

  15. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; LIN Guo-qiang; WANG Fu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti, M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.Key Words: Arc Ion plating, hard coating, composition gradient coatings

  16. Influence of the vacuum-arc source configuration and arc discharge parameters on the evolution and location of arc spots on the cathode surface

    Directory of Open Access Journals (Sweden)

    J. Walkowicz

    2009-12-01

    Full Text Available Purpose: The paper presents investigations of the evolution, structure and location of arc spots on the cathode frontal surfaces of two types of industrial arc sources.Design/methodology/approach: The temporal behaviour of cathode spots was recorded with the use of a fast CCD camera. The experiments were performed at four values of arc current, nine compositions of the process atmosphere N2+C2H2 and three pressure ranges of the process atmosphere.Findings: The analysis of the recorded pictures revealed the fine structure of the arc discharge for the investigated range of process conditions. Both temporal and spatial behaviour of cathode spots were different for both investigated arc sources. The correspondence between radial distributions of the cathode spots on the cathode surface and radial distribution of plasma flow elements analysed in the volume of the vacuum chamber was revealed.Research limitations/implications: The paper show experimental methodology that can be used for the research of the specificity of cathode spots movement on the cathodes made from different materials.Originality/value: The originality of the research presented in the paper consists in assigning overall correlation between vacuum-arc source configuration and parameters of vacuum-arc discharge – on the one hand, and space-time behaviour of the arc spots during their movement on the circular cathode surface and radial distribution of excited and ionized atoms of the cathode material in the deposition chamber – on the other.

  17. Lifetime of hydrogenated composite cathodes in a vacuum arc ion source

    Energy Technology Data Exchange (ETDEWEB)

    Savkin, K. P., E-mail: savkin@opee.hcei.tsc.ru; Frolova, V. P.; Nikolaev, A. G.; Yushkov, G. Yu. [Institute of High Current Electronics SB RAS, Tomsk 634055 (Russian Federation); Oks, E. M. [Institute of High Current Electronics SB RAS, Tomsk 634055 (Russian Federation); Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Barengolts, S. A. [Prokhorov General Physics Institute RAS, Moscow 119991 (Russian Federation)

    2016-02-15

    The paper reports on a study of the mass-charge state of the plasma produced in a vacuum arc discharge with composite cathodes which were copper-disk coated with a hydrogenated Zr film of thicknesses 9, 22, and 35 μm. The cathodes allow the generation of multicomponent gas and metal ion beams with a hydrogen ion content from several to several tens of percent. Also investigated is the dependence of the H ion fraction in a beam on the Zr film thickness during erosion to the point of disappearance of Zr peaks in mass-charge spectra. The ability of the vacuum arc system to produce H ions is analyzed by analyzing the cathode lifetime as a function of the film thickness and pulse repetition frequency.

  18. Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom;

    2013-01-01

    A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve adhes...

  19. Multi-Seconds Diagnostic Neutral Beam Injector Based on Arc-Discharge with LaB6 Hollow Cathode

    International Nuclear Information System (INIS)

    The diagnostic neutral beam injector based on arc-discharge plasma source with LaB6 hollow cathode is described.The ion source of the diagnostic injector provides a proton beam with a current up to 2.5A, the particle energy up to 50 keV, the beam divergence is ∼0.5 deg. The beam species at the 2 A ion current are: H+-83%, H2+-5%, H3+-12%. The injector was tested at pulse duration up to 2 seconds

  20. Ecton mechanism of ion flow generation in vacuum arc

    CERN Document Server

    Mesyats, G A

    2001-01-01

    The basic characteristics of cathode plasma generation in vacuum arc (ion erosion, ion average charge) were studied from the point of an ecton model of a cathode spot in vacuum arc. The estimates of ion parameters obtained for a single cell of a cathode spot show qualitative conformity with the experimental data. One introduces the following mechanism of cathode plasma generation in vacuum arc. In case of explosion-like destruction of a cathode segment under the effect of the Joule heating the cathode matter changes sequentially its state: condensed one, nonideal and ideal plasma ones. During this change one observes formation of plasma charge composition and ion acceleration under the effect of plasma pressure gradient

  1. Multiple Ionization Of Metal Ions By ECR Heating Of Electrons In Vacuum Arc Plasmas

    Science.gov (United States)

    Vodopyanov, A. V.; Golubev, S. V.; Mansfeld, D. A.; Nikolaev, A. G.; Oks, E. M.; Razin, S. V.; Savkin, K. P.

    2005-03-01

    A joint research and development effort has been initiated, whose ultimate goal is the enhancement the mean ion charge states in vacuum arc metal plasmas by a combination of a vacuum arc discharge and an electron cyclotron resonance (ECR) heating. Metal plasma was generated by a special vacuum arc mini-gun and injected into mirror magnetic trap. Plasma was pumped by high frequency gyrotron-generated microwave radiation (frequency 37.5 GHz, max power 100 kW, pulse duration 1.5 ms). Using of powerful microwaves makes it possible to sustain sufficient temperature of electrons needed for multiple ionizations at high plasma density (more then 1013 cm-3). Parameter of multiple ionization efficiency Neτi, where Ne is plasma density, τi, is ion lifetime, in such a case could reach rather high value ˜109 cm-3-s. In our situation τi = Ltrap/Vi, where Ltrap is trap length, Vi is plasma gun flow velocity. The results have demonstrated substantial multiple ionization of metal ions (including metals with high melting temperature). For a metal (lead, platinum) plasma, ECR heating shifted the average ion charge up to 5+. Further increase of the ion charge states will be attained by increasing the vacuum arc plasma density and optimizing the ECR heating conditions.

  2. Dual arc penning ion source gas flow experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.D.; Lord, R.S.; Mallory, M.L.; Antaya, T.A.

    1984-01-01

    Support gas, when added directly to an arc or admitted to an auxiliary chamber of a two-arc chamber ion source, increases the beam intensity for multicharged ions such as /sup 16/O/sup 5 +/. To clarify the mechanism of this intensity increase, gas flow rates from the auxiliary chamber to the main chamber have been measured by using the ORIC cyclotron as a mass spectrometer. The results show that only about three percent of the gas admitted to the auxiliary chamber reaches the main chamber. One can then infer that the improved operation probably results from the stabilizing effect of heating the common cathodes with the auxiliary arc and/or the more favorable distribution of the support gas to the part of the main arc close to the cathodes.

  3. Multiwalled Carbon Nanotube Synthesis Using Arc Discharge with Hydrocarbon as Feedstock

    Directory of Open Access Journals (Sweden)

    K. T. Chaudhary

    2013-01-01

    Full Text Available Synthesis of multiwalled carbon nanotube (MWCNT by arc discharge process is investigated with methane (CH4 as background and feedstock gas. The arc discharge is carried out between two graphite electrodes for ambient pressures 100, 300, and 500 torr and arc currents 50, 70, and 90 A. Plasma kinetics such as the density and temperature for arc discharge carbon plasma is determined to find out the contribution of physical parameters as arc current and ambient pressure on the plasma dynamics and growth of MWCNT. With increase in applied arc current and ambient pressure, an increase in plasma temperature and density is observed. The synthesized samples of MWCNT at different experimental conditions are characterized by transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. A decrease in the diameter and improvement in structure quality and growth of MWCNT are observed with increase in CH4 ambient pressure and arc current. For CH4 ambient pressure 500 torr and arc current 90 A, the well-aligned and straight MWCNT along with graphene stakes are detected.

  4. General intense electron beams by means of a contracted arc discharge

    International Nuclear Information System (INIS)

    Two types of contracted arc discharge are investigated with a view to generating intense electron beams over a wide pressure range (1-10-3 Pa). For an arc discharge with a hollow cathode and anode, an electron beam corresponding to a current of up to 300 A and a pulse length of 25 μsec is obtained at a pressure of 1-10-1 Pa in the accelerating gap with an accelerating voltage of up to 15 kV. At pressures of 10-2-10-3 Pa, emitting plasma is created by a low-pressure arc discharge on the basis of a Penning cell. Three discharge systems operating in parallel are used to increase the working life of the cathode and improve the current density distribution of the beam. An electron beam of diameter 200 mm with a current of up to 125 A and a pulse length of 50 μsec is obtained

  5. Removal of hexavalent chromium in carbonic acid solution by oxidizing slag discharged from steelmaking process in electric arc furnace

    Science.gov (United States)

    Yokoyama, Seiji; Okazaki, Kohei; Sasano, Junji; Izaki, Masanobu

    2014-02-01

    Hexavalent chromium (Cr(VI)) is well-known to be a strong oxidizer, and is recognized as a carcinogen. Therefore, it is regulated for drinking water, soil, groundwater and sea by the environmental quality standards all over the world. In this study, it was attempted to remove Cr(VI) ion in a carbonic acid solution by the oxidizing slag that was discharged from the normal steelmaking process in an electric arc furnace. After the addition of the slag into the aqueous solution contained Cr(VI) ion, concentrations of Cr(VI) ion and total chromium (Cr(VI) + trivalent chromium (Cr(III)) ions decreased to lower detection limit of them. Therefore, the used slag could reduce Cr(VI) and fix Cr(III) ion on the slag. While Cr(VI) ion existed in the solution, iron did not dissolve from the slag. From the relation between predicted dissolution amount of iron(II) ion and amount of decrease in Cr(VI) ion, the Cr(VI) ion did not react with iron(II) ion dissolved from the slag. Therefore, Cr(VI) ion was removed by the reductive reaction between Cr(VI) ion and the iron(II) oxide (FeO) in the slag. This reaction progressed on the newly appeared surface of iron(II) oxide due to the dissolution of phase composed of calcium etc., which existed around iron(II) oxide grain in the slag.

  6. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma

    Science.gov (United States)

    Kang, Min Ho; Pengkit, Anchalee; Choi, Kihong; Jeon, Seong Sil; Choi, Hyo Won; Shin, Dong Bum; Choi, Eun Ha; Uhm, Han Sup; Park, Gyungsoon

    2015-01-01

    Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds). Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease) spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection. PMID:26406468

  7. Differential Inactivation of Fungal Spores in Water and on Seeds by Ozone and Arc Discharge Plasma.

    Directory of Open Access Journals (Sweden)

    Min Ho Kang

    Full Text Available Seed sterilization is essential for preventing seed borne fungal diseases. Sterilization tools based on physical technologies have recently received much attention. However, available information is very limited in terms of efficiency, safety, and mode of action. In this study, we have examined antifungal activity of ozone and arc discharge plasma, potential tools for seed sterilization. In our results, ozone and arc discharge plasma have shown differential antifungal effects, depending on the environment associated with fungal spores (freely submerged in water or infected seeds. Ozone inactivates Fusarium fujikuroi (fungus causing rice bakanae disease spores submerged in water more efficiently than arc discharge plasma. However, fungal spores associated with or infecting rice seeds are more effectively deactivated by arc discharge plasma. ROS generated in water by ozone may function as a powerful fungicidal factor. On the other hand, shockwave generated from arc discharge plasma may have greatly contributed to antifungal effects on fungus associated with rice seeds. In support of this notion, addition of ultrasonic wave in ozone generating water has greatly increased the efficiency of seed disinfection.

  8. Controlling synthesis of carbon nanostructures by plasma means in arc discharge

    Science.gov (United States)

    Volotskova, Olga; Shashurin, Alexey; Torrey, Jon; Raitses, Yevgeny; Keidar, Michael

    2009-11-01

    Thermal stability of SWNTs at conditions of atmospheric arc is crucial for determination of region of their synthesis in arc and in general for clarification of the thermal regime of SWNT in arc plasmas. We investigated electrical resistance dependence on temperature of mats of SWNTs under variable pressures in helium atmosphere, in the air and in vacuum in high temperature ranges (300-1200K) which closely mimic conditions during the synthesis in arc discharge. Dependence of SWNT resistance on temperature exhibits similar ``V-shape'' behavior for all applied conditions which characterized by two temperatures: Tmin (temperature of the minimum of resistance) and Tcr (temperature of destruction of SWNT bundles). It is found that Tmin and Tcr increased with helium pressure, so that at 500 Torr Tcr was 1100K, while Tmin -900K. This is the temperature that corresponds to buffer region between the arc plasma and helium background in arc discharge. Based on that it can be suggested that region of formation of SWNTs in arc should be close to arc periphery. Our study also demonstrates a strong effect of electric and magnetic fields on properties and growth conditions of SWNTs and other carbon nanostructures such as graphene. These effects are quantified by variety of diagnostics tools: SEM, TEM, AFM - microcopies, TGA, RAMAN and UV-vis-NIR.

  9. Vacuum ARC ion sources - activities & developments at LBL

    Energy Technology Data Exchange (ETDEWEB)

    Brown, I. [Lawrence Berkeley Laboratory, CA (United States)

    1996-08-01

    The author describes work at LBL on the development and application of vacuum arc ion sources. Work has been done on vacuum spark sources - to produce very high charge states, studies of high charge states in magnetic field, hybrid ion source operation on metal/gas plasma, multipole operation, work on MEVVA V for implantation applications, development of broad beam sources, and removal of particles from the output of the source.

  10. Vacuum arc ion source development at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Spaedtke, P.; Emig, H.; Wolf, B.H. [GSI Darmstadt (Germany)

    1996-08-01

    Ion beams produced by the Mevva ion source are well suited for the injection into a synchrotron accelerator due to the low repetition rate (0.2 ... 5 Hz, the higher repetition rate is for the optimization of the linear accelerator only) and the short pulse length (up to 0.5ms). From the beginning of the authors experience with the Mevva ion source at GSI they tried to improve the reliability of pulse-to-pulse reproducibility and to minimize the noise on the extracted ion beam. For accelerator application this is highly necessary, otherwise the accelerator tuning and optimization becomes very difficult or even impossible. Already the beam transport becomes difficult for a noisy beam, because space charge compensation can be destroyed (at least partially). Furthermore a noisy dc-beam results in some rf-buckets which might be even empty.

  11. Translational, rotational and vibrational temperatures of a gliding arc discharge at atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas;

    2014-01-01

    Gliding arc discharges have generally been used to generate non-equilibrium plasma at atmospheric pressure. Temperature distributions of a gliding arc are of great interest both for fundamental plasma research and for practical applications. In the presented studies, translational, rotational...... and vibrational temperatures of a gliding arc generated at atmospheric pressure air are investigated. Translational temperatures (about 1100 K) were measured by laser-induced Rayleigh scattering, and two-dimensional temperature imaging was performed. Rotational and vibrational temperatures (about 3600 K and 6700...

  12. Temperature and Nitric Oxide Generation in a Pulsed Arc Discharge Plasma

    Institute of Scientific and Technical Information of China (English)

    T.NAMIHIRA; S.SAKAI; M.MATSUDA; D.WANG; T.KIYAN; H.AKIYAMA; K.OKAMOTO; K.TODA

    2007-01-01

    Nitric oxide (NO) is increasingly being used in medical treatments of high blood pressure,acute respiratory distress syndrome and other illnesses related to the lungs.Currently a NO inhalation system consists of a gas cylinder of N2 mixed with a high concentration of NO.This arrangement is potentially risky due to the possibility of an accidental leak of NO from the cylinder.The presence of NO in the air leads to the formation of nitric dioxide (NO2),which is toxic to the lungs.Therefore,an on-site generator of NO would be highly desirable for medical doctors to use with patients with lung disease.To develop the NO inhalation system without a gas cylinder,which would include a high concentration of NO,NAMIHIRA et al have recently reported on the production of NO from room air using a pulsed arc discharge.In the present work,the temperature of the pulsed arc discharge plasma used to generate NO was measured to optimize the discharge condition.The results of the temperature measurements showed the temperature of the pulsed arc discharge plasma reached about 10,000 K immediately after discharge initiation and gradually decreased over tens of microseconds.In addition,it was found that NO was formed in a discharge plasma having temperatures higher than 9,000 K and a smaller input energy into the discharge plasma generates NO more efficiently than a larger one.

  13. An ion source based on the cathodic arc

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, D.M.; Falabella, S.

    1992-12-31

    This invention is comprised of a cylindrically symmetric arc source to produce a ring of ions which leave the surface of the arc target radially and are reflected by electrostatic fields present in the source to a point of use, such as a part to be coated. An array of electrically isolated rings positioned in the source serves the duel purpose of minimizing bouncing of macroparticles and providing electrical insulation to maximize the electric field gradients within the source. The source also includes a series of baffles which function as a filtering or trapping mechanism for any macroparticles.

  14. Composition Gradient Hard Coatings by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    CHENJun; LINGuo-qiang; WANGFu-gang

    2004-01-01

    Arc Ion Plating can be used to synthesize multi-component composition gradient hard coatings by adjusting arc currents of metal targets. The present work aims at a comprehensive description of such a technique. The examples of TiAl multi-layer alloy coatings and (Ti,M) N composition-gradient films were taken (M representing Zr, Nb etc.) for the purpose of explaining the working process and evaluating practical effects. The results show that this technique has the advantages of easy manipulation, rapid deposition, and wide composition range.

  15. Arc plasma simulation of the KAERI large ion sourcea)

    Science.gov (United States)

    In, S. R.; Jeong, S. H.; Kim, T. S.

    2008-02-01

    The KAERI large ion source, developed for the KSTAR NBI system, recently produced ion beams of 100keV, 50A levels in the first half campaign of 2007. These results seem to be the best performance of the present ion source at a maximum available input power of 145kW. A slight improvement in the ion source is certainly necessary to attain the final goal of an 8MW ion beam. Firstly, the experimental results were analyzed to differentiate the cause and effect for the insufficient beam currents. Secondly, a zero dimensional simulation was carried out on the ion source plasma to identify which factors control the arc plasma and to find out what improvements can be expected.

  16. Iron nanoparticles grown in a carbon arc discharge

    NARCIS (Netherlands)

    Zhang, G.L.; du Marchie van Voorthuysen, E.H.; Szymanski, K.; Boom, G; Verwerft, M.G M; Jonkman, H.T.; Niesen, L

    1996-01-01

    Iron particles, encapsulated by graphite layers, were produced by means of the Kratschmer are discharge method in an iron pentacarbonyl atmosphere. The Mossbauer effect is dominated by the vibration of the particles as a whole. Superparamagnetism is dominant for iron oxide particles. No endohedral i

  17. Temporal evolution of ion energy distribution functions and ion charge states of Cr and Cr-Al pulsed arc plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Koichi, E-mail: tanak@mmc.co.jp [Central Research Institute, Mitsubishi Materials Corporation, 1002-14 Mukohyama, Naka-shi, Ibaraki 311-0102 (Japan); Anders, André [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 53, Berkeley, California 94720 (United States)

    2015-11-15

    To study the temporal evolution of ion energy distribution functions, charge-state-resolved ion energy distribution functions of pulsed arc plasmas from Cr and Cr-Al cathodes were recorded with high time resolution by using direct data acquisition from a combined energy and mass analyzer. The authors find increases in intensities of singly charged ions, which is evidence that charge exchange reactions took place in both Cr and Cr-Al systems. In Cr-Al plasmas, the distributions of high-charge-state ions exhibit high energy tails 50 μs after discharge ignition, but no such tails were observed at 500 μs. The energy ratios of ions of different charge states at the beginning of the pulse, when less neutral atoms were in the space in front of the cathode, suggest that ions are accelerated by an electric field. The situation is not so clear after 50 μs due to particle collisions. The initial mean ion charge state of Cr was about the same in Cr and in Cr-Al plasmas, but it decreased more rapidly in Cr-Al plasmas compared to the decay in Cr plasma. The faster decay of the mean ion charge state and ion energy caused by the addition of Al into a pure Cr cathode suggests that the mean ion charge state is determined not only by ionization processes at the cathode spot but also by inelastic collision between different elements.

  18. "Super-acceleration" of ions in a stationary plasma discharge

    Science.gov (United States)

    Bardakov, Vladimir; Ivanov, Sergey; Kazantsev, Alexander; Strokin, Nikolay; Stupin, Aleksey

    2016-10-01

    We report on the detection of the acceleration effect of the bulk of ions in a stationary plasma E × B discharge to energies exceeding considerably the value equivalent to the discharge voltage. We determined the conditions necessary for the generation of high-energy ions, and ascertained the influence exerted on the value of the ion energies by pressure (flow rate) and the kind of plasma-producing gas, and by the value of discharge current. The possible acceleration mechanism is suggested.

  19. Gliding arc discharge — Application for adhesion improvement of fibre reinforced polyester composites

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Teodoru, Steluta; Leipold, Frank;

    2008-01-01

    production, and surface treatment. However, the application for adhesion improvement of structural materials has been rarely reported. In the present work, glass fibre reinforced polyester plates were treated using atmospheric pressure gliding arcs with high speed air flow for adhesion improvement...... and the discharge....

  20. Size-controlled synthesis and gas sensing application of tungsten oxide nanostructures produced by arc discharge.

    Science.gov (United States)

    Fang, F; Kennedy, J; Futter, J; Hopf, T; Markwitz, A; Manikandan, E; Henshaw, G

    2011-08-19

    Several different synthetic methods have been developed to fabricate tungsten oxide (WO(3)) nanostructures, but most of them require exotic reagents or are unsuitable for mass production. In this paper, we present a systematic investigation demonstrating that arc discharge is a fast and inexpensive synthesis method which can be used to produce high quality tungsten oxide nanostructures for NO(2) gas sensing measurements. The as-synthesized WO(3) nanostructures are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), finger-print Raman spectroscopy and proton induced x-ray emission (PIXE). The analysis shows that spheroidal-shaped monoclinic WO(3) crystal nanostructures were produced with an average diameter of 30 nm (range 10-100 nm) at an arc discharge current of 110 A and 300 Torr oxygen partial pressure. It is found that the morphology is controlled by the arc discharge parameters of current and oxygen partial pressure, e.g. a high arc discharge current combined with a low oxygen partial pressure results in small WO(3) nanostructures with improved conductivity. Sensors produced from the WO(3) nanostructures show a strong response to NO(2) gas at 325 °C. The ability to tune the morphology of the WO(3) nanostructures makes this method ideal for the fabrication of gas sensing materials. PMID:21778569

  1. Size-controlled synthesis and gas sensing application of tungsten oxide nanostructures produced by arc discharge

    International Nuclear Information System (INIS)

    Several different synthetic methods have been developed to fabricate tungsten oxide (WO3) nanostructures, but most of them require exotic reagents or are unsuitable for mass production. In this paper, we present a systematic investigation demonstrating that arc discharge is a fast and inexpensive synthesis method which can be used to produce high quality tungsten oxide nanostructures for NO2 gas sensing measurements. The as-synthesized WO3 nanostructures are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), finger-print Raman spectroscopy and proton induced x-ray emission (PIXE). The analysis shows that spheroidal-shaped monoclinic WO3 crystal nanostructures were produced with an average diameter of 30 nm (range 10-100 nm) at an arc discharge current of 110 A and 300 Torr oxygen partial pressure. It is found that the morphology is controlled by the arc discharge parameters of current and oxygen partial pressure, e.g. a high arc discharge current combined with a low oxygen partial pressure results in small WO3 nanostructures with improved conductivity. Sensors produced from the WO3 nanostructures show a strong response to NO2 gas at 325 0C. The ability to tune the morphology of the WO3 nanostructures makes this method ideal for the fabrication of gas sensing materials.

  2. Measurements of 3D slip velocities and plasma column lengths of a gliding arc discharge

    NARCIS (Netherlands)

    Zhu, J.; Gao, J.; Ehn, A.; Alden, M.; Li, Z.; Moseev, D.; Kusano, Y.; Salewski, M.; Alpers, A.; Gritzmann, P.; Schwenk, M.

    2015-01-01

    A non-thermal gliding arc discharge was generated at atmospheric pressure in an air flow. The dynamics of the plasma column and tracer particles were recorded using two synchronized highspeed cameras. Whereas the data analysis for such systems has previously been performed in 2D (analyzing the singl

  3. Characterization of a high-power/current pulsed magnetized arc discharge

    NARCIS (Netherlands)

    Zielinski, J. J.; van der Meiden, H. J.; Morgan, T. W.; D.C. Schram,; De Temmerman, G.

    2012-01-01

    A high-power pulsed magnetized arc discharge has been developed to allow the superimposition of a dc plasma and a high-power plasma impulse with a single plasma source. A capacitor bank (8400 mu F) is parallel-coupled to the current regulated power supply. The current is transiently increased from i

  4. Growth of small diameter multi-walled carbon nanotubes by arc discharge process

    Science.gov (United States)

    T. Chaudhary, K.; J., Ali; P. Yupapin, P.

    2014-03-01

    Multi-walled carbon nanotubes (MWCNTs) are grown by arc discharge method in a controlled methane environment. The arc discharge is produced between two graphite electrodes at the ambient pressures of 100 torr, 300 torr, and 500 torr. Arc plasma parameters such as temperature and density are estimated to investigate the influences of the ambient pressure and the contributions of the ambient pressure to the growth and the structure of the nanotubes. The plasma temperature and density are observed to increase with the increase in the methane ambient pressure. The samples of MWCNT synthesized at different ambient pressures are analyzed using transmission electron microscopy, scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. An increase in the growth of MWCNT and a decrease in the inner tube diameter are observed with the increase in the methane ambient pressure.

  5. Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution

    International Nuclear Information System (INIS)

    The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment was carried out putting the EAF dust from 1 g to 200 g in weight into 1 L of water that was introduced by CO2. Generally, the pH in the aqueous solution increased with an increase in weight of the additive EAF dust. Maximums of the eluted concentrations of zinc and chloride ion increased with an increase in the weight of the additive EAF dust whereas the extraction ratios of both of them decreased with an increase in the weight of the additive EAF dust. Iron in the EAF dust remained in the dust without elution. The limit of extraction of zinc from the EAF dust to water was given by the solubilities of ZnFe2O4 and ZnO expressed by eq. (6) and eq. (9) respectively.

  6. Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution

    Science.gov (United States)

    Yokoyama, S.; Sasaki, T.; Sasano, J.; Izaki, M.

    2012-03-01

    The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment was carried out putting the EAF dust from 1 g to 200 g in weight into 1 L of water that was introduced by CO2. Generally, the pH in the aqueous solution increased with an increase in weight of the additive EAF dust. Maximums of the eluted concentrations of zinc and chloride ion increased with an increase in the weight of the additive EAF dust whereas the extraction ratios of both of them decreased with an increase in the weight of the additive EAF dust. Iron in the EAF dust remained in the dust without elution. The limit of extraction of zinc from the EAF dust to water was given by the solubilities of ZnFe2O4 and ZnO expressed by eq. (6) and eq. (9) respectively.

  7. Mechanism of Arc Discharge in Vacuum Interrupter Based on PIC-MCC Method

    Institute of Scientific and Technical Information of China (English)

    CAO Yun-dong; LI Jing; LIU Xiao-ming; HOU Chun-guang; WANG Er-zhi

    2011-01-01

    With the raise of voltage level in electric power grid, the phenomena of high voltage gas insulation has re- ceived extensive attention from all over the world. The research on the breakdown mechanism of vacuum which is the main insulation gas in high voltage level is one of the most important issues. It is also important to the study of vacu- um arc in vacuum switch. But for the limitations of available method used in analyzing the breakdown mechanism of vacuum, the main research on vacuum breakdown is macroscopic experiment. The experiments are greatly influenced by environmental factors and high vacuum degree is difficult to be ensured. So the data from the experiments are dis- persive and the complex physical change in vacuum breakdown can not be revealed. The purpose of this work is to an- alyze the mechanism of vacuum breakdown quantitatively by microscopic numerical simulation. The particle in cell and Monte Carlo methods are used here to solve microscopic dynamic equation of gas. Based on the field emission theory in vacuum, electrons produced by the cathode and ions produced by the collision between electron and metal vapor molecule are the objects of this study. The motions of microscopic particles which are at the functions of the applied and self-consistent electric filed are traced in time and two space dimensions. Mont Carlo method is used here to cope with the collisions between electrons and metal vapor molecules. The cross sections of the collision which is related with the energy are all from the experiments. The secondary electron emission, exciting, elastic and ionizing collisions between electrons and metal vapor molecules have been considered in this paper. By the simulation, the number densi- ties of electron and ion are acquired and the microscopic dynamic electric field produced by space charge is also calcu- lated. The effect of vacuum degree on discharge voltage is also discussed here. According to the simulation data, we draw the

  8. Measurement of cathode surface temperature using the method of CCD imaging in arc discharge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A two-wavelength pyrometry device using ordinary array CCD (charge coupled device) to collect the radiation data in the horizontal and vertical directions has been developed for measuring the cathode surface temperature during the arc discharge. Analyses of experimental results show that the device can make the measurement of the cathode surface temperature feasible. The cathode surface temperatures measured are lower than the melting point of tungsten (3653 K), and the arc current, cathode diameter, and the cathode length are the main influencing factors of the cathode surface temperature.

  9. The Discharge Development and Arc Modes in Vacuum at A Long Gap Distance in Vacuum Interrupters

    Institute of Scientific and Technical Information of China (English)

    CHENG Shaoyong; XIU Shixin; WANG Jimei; SHEN Zhengchao

    2007-01-01

    The influence of an arc current on the discharge development and the arc modes of a single coil type axial magnetic field (AMF) electrode were investigated by a high-speed charge couple device (CCD) video camera in a long gap distance of 40 mm. The distribution of the axial magnetic field of the single coil type AMF electrode was computed. By computational results, the single coil type AMF electrode could generate higher axial magnetic flux density than the slot type AMF electrode. It was found that the single coil type AMF electrode could perform better than the slot type AMF electrode with the same designing parameters. And the development of the arc modes experienced diffuse mode, constricted but unstable mode, and constricted and stable mode with the amplitude of the arc current increasing. The correlation between the vacuum arc and the noise components of arc voltage was investigated too. The interruption capability could be known in a practical commercial vacuum interrupter by the test results in a demountable vacuum interrupter (DVC) with a electrode diameter of 50 mm and a gap distance of 40mm.The test results could provide reference to design the high voltage vacuum interrupter adopting the single coil type AMF electrode.

  10. Low pressure arc discharges with hollow cathodes and their using in plasma generators and charged particle sources

    CERN Document Server

    Vintizenko, L G; Koval, N N; Tolkachev, V S; Lopatin, I V; Shchanin, P M

    2001-01-01

    Paper presents the results of investigation into arc discharges with a hollow cathode generating 10 sup 1 sup 0 -10 sup 1 sup 2 concentration gas-discharge plasma in essential (approx 1 m sup 3) volumes at low (10 sup - sup 2 -1 Pa) pressures and up to 200 A discharge currents. One studied design of discharge systems with heated and cold cathodes their peculiar features, presented the parameters of plasma generators and of charged particle sources based on arc discharges and discussed, as well, the problems of more rational application of those systems in the processes for surface modification of solids

  11. Recent advances in high current vacuum arc ion sources for heavy ion fusion

    CERN Document Server

    Qi Nian Sheng; Prasad, R R; Krishnan, M S; Anders, A; Kwan, J; Brown, I

    2001-01-01

    For a heavy ion fusion induction linac driver, a source of heavy ions with charge states 1+-3+, approx 0.5 A current beams, approx 20 mu s pulse widths and approx 10 Hz repetition rates is required. Thermionic sources have been the workhorse for the Heavy Ion Fusion (HIF) program to date, but suffer from heating problems for large areas and contamination. They are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states in short and long pulse bursts and high beam current density. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications was investigated. We have modifie...

  12. Carbon Nanostructures Production by AC Arc Discharge Plasma Process at Atmospheric Pressure

    OpenAIRE

    Shenqiang Zhao; Ruoyu Hong; Zhi Luo; Haifeng Lu; Biao Yan

    2011-01-01

    Carbon nanostructures have received much attention for a wide range of applications. In this paper, we produced carbon nanostructures by decomposition of benzene using AC arc discharge plasma process at atmospheric pressure. Discharge was carried out at a voltage of 380 V, with a current of 6 A–20 A. The products were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), and Raman spectra. The results sho...

  13. Arc Discharge Synthesis and Photoluminescence of 3D Feather-like AlN Nanostructures

    OpenAIRE

    Zou ZY; Yang SL; Gao RS; Niu PL; Yu RH

    2011-01-01

    Abstract A complex three-dimensional (3D) feather-like AlN nanostructure was synthesized by a direct reaction of high-purity Al granules with nitrogen using an arc discharge method. By adjusting the discharge time, a coral-like nanostructure, which evolved from the feather-like nanostructure, has also been observed. The novel 3D feather-like AlN nanostructure has a hierarchical dendritic structure, which means that the angle between the trunk stem and its branch is always about 30° in an...

  14. Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source.

    Science.gov (United States)

    Usmanov, D T; Chen, L C; Yu, Z; Yamabe, S; Sakaki, S; Hiraoka, K

    2015-04-01

    The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 µm inner diameter and 12 mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41 ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1 mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 µl methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx (-) (x = 2,3), O3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO + HNO3 ](-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26149109

  15. Boosting persistence time of laser-induced plasma by electric arc discharge for optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Eschlböck-Fuchs, S., E-mail: simon.eschlboeck-fuchs@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Kolmhofer, P.J.; Bodea, M.A.; Hechenberger, J.G.; Huber, N. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Rössler, R. [voestalpine Stahl GmbH, A-4031 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2015-07-01

    Plasma induced by nanosecond laser ablation is re-excited by a pulsed electric discharge and the parameters and optical emission of the plasma are measured. The discharge is a low-voltage and high-current electric arc that is triggered by the laser-induced plasma and slowly decaying with time. The optical emission of such combined plasma lasts up to several milliseconds which is much longer than without re-excitation (μs range). The emission spectra of re-excited plasma measured on different sample materials show higher line intensities than spectra measured by conventional laser-induced breakdown spectroscopy (LIBS). Moreover, emission lines of fluorine (spectral range 683–691 nm) and sulfur (range 520–550 nm) not detected by conventional LIBS become easily detectable with the combined plasma. The concentration of major components in metallurgical slags, as determined by calibration-free LIBS, agrees very well to the reference data evaluating the spectra taken from re-excited plasma. - Highlights: • Persistence time of laser-induced plasma in air is increased from ~ 10 μs to ~ 1 ms. • Laser-induced plasma triggers an electric arc discharge that boosts the plasma. • The combined laser-arc plasma is in LTE state over very long time (ms range). • CF-LIBS method delivers accurate results evaluating spectra of combined plasma. • Emission from S and F, not detected by LIBS, is detected with combined plasma.

  16. Surface modification of compressor steels using thermally assisted ionic diffusion in the titanium plasma of a vacuum arc discharge

    Science.gov (United States)

    Muboyadzhyan, S. A.; Azarovskii, E. N.

    2015-11-01

    The thermally stimulated ionic diffusion (ionic modification) of titanium ions at the surfaces of EP866 and EI961 compressor steels is considered in the plasma of the high-current vacuum-arc discharge (VAD) in an ion-plasma MAP-3 plant. The dependences of the sample temperature in the sputtering chamber of the ion-plasma MAP-3 plant and the rate of specific change of the sample mass on the bias voltage at a VAD current of 300 A are obtained. The elemental composition of the surface layers of the samples subjected to ion treatment is studied. It is shown that, at a VAD current of 300 A and a bias voltage up to 400 V, the compressor steel sample temperature does not exceed 440°C and the inversion voltage, which determines the transition from coating condensation to ion etching of a substrate, is ~360 V for EP866 steel and ~390 V for EI961 steel. The corrosion resistance of the compressor steels modified at a VAD current of 300 A is investigated.

  17. Investigation of the Solution Electrical Conductivity Effect upon the Synthesis of Carbon Nanotubes by Arc Discharge Method

    Directory of Open Access Journals (Sweden)

    Asieh Dehghani Kiadehi

    2013-01-01

    Full Text Available Some techniques have been developed to produce carbon nanotubes (CNTs in sizeable quantities, including arc discharge, laser ablation and chemical vapor deposition (CVD. Arc discharge in liquid environment is a new, simple and cheap method of synthesizing CNTs. CNTs in this study were fabricated by arc discharge in liquid. The present work was undertaken to study the effect of electrical conductivity of liquid on CNTs production and was fabricated using arc discharge between two graphite electrodes submerged in different aqueous solutions of NaCl, KCl and LiCl. For comparative study, CNTs were synthesized under different electrical conductivity conditions and the results were analyzed, compared and discussed. The scanning electron microscopy (SEM, transmission electron microscopy (TEM and Raman spectroscopy were employed to study the morphology of these carbon nanostructures. Based on LiCl 0.25 N, high-crystalline and a longed multi MWCNTs, SWCNTs were synthesized by using this technique.

  18. Ecton mechanism for the generation of ion flows in a vacuum arc

    CERN Document Server

    Mesyats, G A

    2001-01-01

    Physical substantiation of the parameters of the ion flow, generated by the vacuum arc cathode spots is given for the first time in this work. The main characteristics of the vacuum arc cathode plasma generation process (the ion erosion, the ions average charge) are considered within the frames, of the ecton model of the vacuum arc cathode spot. According to this model the vacuum arc cathode spot consists of separate cells, emitting ectons. The ions parameter evaluations, obtained within the frames of the ecton model, qualitatively and quantitatively agree with the experimental data

  19. Plasma arc pyrolysis of radioactive ion exchange resin

    International Nuclear Information System (INIS)

    This paper reports on two ion exchange resins (IRN 77 and IRN 78) which were pyrolysed in a plasma-arc furnace. Both continuous and batch tests were performed. Volume reduction ratios of 10 to 1 and 10 to 3.5 were achieved for IRN 78 and IRN 77 respectively. The product of the resin pyrolysis was a char which contained the radioactive elements such as cobalt. The off-gases consisted of mainly hydrogen and carbon monoxide. There was a relatively small amount of dust in the off-gases. At the present time radioactive ion exchange resign is being kept in storage. The volume of this waste is increasing and it is important that the volume be reduce. The volume reduction ratio should be of the order of ten-to-one. Also, it is required that the radioactive elements can be collected or fixed in a form which could easily be disposed of. Plasma arc treatment offers considerable potential for the processing of the waste

  20. Development of a cascade arc discharge source for an atmosphere-vacuum interface device.

    Science.gov (United States)

    Namba, S; Endo, T; Fujino, S; Suzuki, C; Tamura, N

    2016-08-01

    To realize a novel vacuum-atmosphere interface that does not require a large differential pumping system, a robust cascade arc discharge source called a plasma window is constructed and tested for long-term operation. By modifying a test plasma with a direct current discharge, a vacuum interface with a high gas pressure ratio of 1/407 between the discharge and expansion sections is demonstrated for currents as high as 20 A. No significant damage to the electrodes is observed during the operation. Analysis of the visible emission spectra reveals that a stationary, stable argon plasma having a temperature of 1 eV and a density of 1.5 × 10(16) cm(-3) is generated in the plasma channel. PMID:27587119

  1. Development of a cascade arc discharge source for an atmosphere-vacuum interface device

    Science.gov (United States)

    Namba, S.; Endo, T.; Fujino, S.; Suzuki, C.; Tamura, N.

    2016-08-01

    To realize a novel vacuum-atmosphere interface that does not require a large differential pumping system, a robust cascade arc discharge source called a plasma window is constructed and tested for long-term operation. By modifying a test plasma with a direct current discharge, a vacuum interface with a high gas pressure ratio of 1/407 between the discharge and expansion sections is demonstrated for currents as high as 20 A. No significant damage to the electrodes is observed during the operation. Analysis of the visible emission spectra reveals that a stationary, stable argon plasma having a temperature of 1 eV and a density of 1.5 × 1016 cm-3 is generated in the plasma channel.

  2. Comments on the sampling of ions from negative corona discharge

    International Nuclear Information System (INIS)

    Mass spectra were evaluated in a negative corona discharge between point-to-plane electrodes in dry air at a constant discharge current and at various air pressures. For the correct interpretation of mass-spectroscopic data the actual abundances of ions in the total extracted ion current must be calculated. A simple correction formula was derived for the case of Maxwell-Boltzmann distribution of ions. Reduced and non-reduced abundances of ions extracted from air at two different pressures were compared. The maximum difference between the reduced and the non-reduced data did not exceed 20 per cent. (J.U.). 3 figs., 2 refs

  3. Ion temperature in SOC and IOC discharges in ASDEX

    International Nuclear Information System (INIS)

    Active and passive charge exchange measurements were made to investigate the behaviour of the central ion temperature and the temperature profile for SOC and IOC discharges in ASDEX. Both methods show an increase in the central ion temperature during transition from SOC to IOC. Both methods also show a wider temperature profile for ions than for electrons. Peaking of the ion temperature profile during IOC cannot be definitely concluded from the measurements. (author) 7 refs., 4 figs

  4. Ignition method of corona discharge with modulation of the field in ion source of ion mobility spectrometer

    International Nuclear Information System (INIS)

    The new method for the ignition of the corona discharge has been developed, which improves the stability of the ion mobility spectrometer and the resolution of the instrument. The system of forming a corona discharge without additional electrodes, which are used in a number of known structures for the pre-ionization, has been developed. This simplifies the design of the proposed source and an electronic control circuit. IMS technology is widely used in different civil and military fields for vapor-phase detection of explosive, narcotics, chemical warfare agents, biology molecules and so on. There are set of methods whose are used for the ionization of molecules under analysis. They are the following: radioactive ionization, ultraviolet photoionization, laser ionization, electric field ionization, corona spray ionization, electro spray ionization, roentgen ionization, and surface ionization. All these methods has their own advantages and disadvantages. A comparing of ion mobility spectra of non-polar hydrocarbons for photoionization, corona discharge ionization and 63Ni ionization, had carried in. In our work we have investigated four types of IMS spectrometers whose use different sources for molecules under analysis ionization. They use radioactive ionization, ultraviolet photoionization, laser ionization, and roentgen ionization. The traditional explosives had investigated in experiments. In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the potential gradient (the strength of the electric field) exceeds a certain value, but conditions are insufficient to cause complete electrical breakdown or arcing.

  5. Design and test of the ion mobility spectrometer with corona discharge ion source

    International Nuclear Information System (INIS)

    In the present paper we describe in detail the design and construction of a home built ion mobility spectrometer with corona discharge as an ionization source. The ion mobility spectra have been recorded using the corona discharge in two different modes: i) chemical ionization and ii) direct ionization in the corona discharge. The chemical ionization of the organic compounds resulted in less fragmented ion mobility spectra in comparison to the direct ionization of the compounds in the corona discharge. The measured positive ion mobility spectra of several organic compounds including acetone, methanol, ethanol and benzene are presented. (Authors)

  6. Arc discharge deposition of stainless steel coatings at different nitrogen pressures

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, J. [VTT Manufacturing Technology (Finland); Torri, P. [Helsinki Univ. (Finland). Dept. of Physics; Hirvonen, J.P. [VTT Manufacturing Technology (Finland); Mahiout, A. [VTT Manufacturing Technology (Finland); Stanishevsky, A. [Plasmoteg Engineering Centre, Minsk (Belarus)

    1996-03-01

    A filtered arc discharge process was employed to deposit stainless steel films using an AISI316 cathode. In this procedure, macroparticles and droplets, which are the most serious drawback of arc deposition processes especially in corrosion applications, are mostly filtered out. Films were deposited in vacuum or in the presence of a nitrogen plasma at different partial pressures. Low carbon steel and silicon single crystals were employed as substrates. Rutherford backscattering spectrometry (RBS), nuclear reaction analysis (NRA) and X-ray diffraction (XRD) were used to characterize the films. The corrosion properties were examined using electrochemical polarization measurements. The corrosion current density was clearly lower than that of bulk steel, but higher than that of bulk AISI316. Increasing the film thickness and nitrogen content lowered the corrosion current density. (orig.)

  7. One-step preparation of transparent superhydrophobic coatings using atmospheric arc discharge

    Science.gov (United States)

    Li, Jian; Huang, Zhengyong; Wang, Feipeng; Yan, Xinzhu; Wei, Yuan

    2015-08-01

    In this letter, we report a fast, simple, and single step approach to the preparation of transparent super-hydrophobic coatings on a copper conductor via atmosphere pressure arc discharges. The preparation procedures, hydrophobic characteristics, anti-pollution capability, and transparency of the super-hydrophobic coating are presented. A dual micro- and nano-scale hierarchical structure is observed on the super-hydrophobic coating with a water contact angle greater than 150°. The coating is, thus, capable of removing a significant amount of contaminants with a small quantity of water droplets. Attenuated total reflection Fourier transform infrared spectroscopy indicates that hydrophobic methyl groups exist on the surface of the coating. The surface roughness measurement results prove that the super-hydrophobic surface obeys the Cassie-Baxter model and its light scattering is very weak. Results demonstrate the conceptual feasibility of production of optically transparent super-hydrophobic coating by arc spraying of polymers under the atmospheric pressure.

  8. Arc-Discharge Synthesis of Iron Encapsulated in Carbon Nanoparticles for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    S. Chaitoglou

    2014-01-01

    Full Text Available The objective of the present work is to improve the protection against the oxidation that usually appears in core@shell nanoparticles. Spherical iron nanoparticles coated with a carbon shell were obtained by a modified arc-discharge reactor, which permits controlling the diameter of the iron core and the carbon shell of the particles. Oxidized iron nanoparticles involve a loss of the magnetic characteristics and also changes in the chemical properties. Our nanoparticles show superparamagnetic behavior and high magnetic saturation owing to the high purity α-Fe of core and to the high core sealing, provided by the carbon shell. A liquid iron precursor was injected in the plasma spot dragged by an inert gas flow. A fixed arc-discharge current of 40 A was used to secure a stable discharge, and several samples were produced at different conditions. Transmission electron microscopy indicated an iron core diameter between 5 and 9 nm. Selected area electron diffraction provided evidences of a highly crystalline and dense iron core. The magnetic properties were studied up to 5 K temperature using a superconducting quantum interference device. The results reveal a superparamagnetic behaviour, a narrow size distribution (σg=1.22, and an average diameter of 6 nm for nanoparticles having a blocking temperature near 40 K.

  9. Orbital motion of dust particles in an rf magnetron discharge. Ion drag force or neutral atom wind force

    Energy Technology Data Exchange (ETDEWEB)

    Pal, A. F.; Ryabinkin, A. N.; Serov, A. O. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Dyatko, N. A.; Starostin, A. N.; Filippov, A. V., E-mail: fav@triniti.ru [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

    2012-03-15

    Microparticles with sizes up to 130 {mu}m have been confined and the velocity and diameter of particles in a plasma trap of an rf magnetron discharge with an arc magnetic field have been simultaneously measured. The motion of the gas induced by electron and ion cyclotron currents has been numerically simulated using the Navier-Stokes equation. The experimental and numerical results confirm the mechanism of the orbital motion of dust particles in the magnetron discharge plasma that is associated with the orbital motion of the neutral gas accelerated by electron and ion drift flows in crossed electric and magnetic fields.

  10. a Continuous Supersonic Expansion Discharge Nozzle for Rotationally Cold Ions

    Science.gov (United States)

    Kauffman, Carrie A.; Crabtree, Kyle N.; McCall, Benjamin J.

    2009-06-01

    Molecular ions play an important role in chemistry and astronomy. In particular, molecular ions are key reaction intermediates, and in the interstellar medium, where temperatures and densities are low, they dominate the chemistry. Studying these ions spectroscopically in the laboratory poses a difficult challenge due to their reactivity. In our effort to study molecular ions, our research group is building SCRIBES (Sensitive Cooled Resolved Ion BEam Spectroscopy), which combines a cold ion source, mass spectrometry, and cavity ring-down spectroscopy. With this apparatus, we will be able to record rotationally-resolved gas-phase spectra, enabling interstellar searches for these species. The SCRIBES instrument requires a source of rotationally cold ions, and this has been accomplished by coupling a supersonic expansion with an electric discharge. Other groups (e.g. Thaddeus and McCarthy at Harvard, Salama et. al at NASA-Ames) have produced cold ions in a similar fashion, but always with a pulsed discharge source. Due to our need for a continuous ion source for SCRIBES, we have designed a continuous supersonic expansion discharge nozzle. We will discuss the various design factors considered during the construction of our continuous self-aligning cold ion source.

  11. Ion clusters, REB, and current sheath characteristics in focused discharges

    International Nuclear Information System (INIS)

    Small fluctuations in the current sheath characteristics (peak current density, FWHM of leading sheath, control parameters of sheath internal structure) are linked to wide fluctuations of ion and ion cluster emission from the pinch. Magnetic probe data are used for correlating variations of current sheath parameters with particle emission intensity, Z/M composition, particle energy spectrum. The emission of ion and ion clusters at 90 degrees from the axis of a plasma focus discharge is monitored simultaneously with the 0 degrees emission. The particle energy spectrum is analyzed with a Thomson (parabola) spectrometer (time resolution ∼ 1 nanosec). The cross-sectional structure of the REB at 180 degrees along the discharge axis is monitored via the deposition of collective-field accelerated ions on a target in the REB direction. Etched tracks of ion and ion clusters are in all cases recorded on CR-39 plates. Sharp peaks of the D+-ion spectrum at 90 degrees are found for E > 200 keV/unit charge in all focused discharges. These peaks are due to ion crossing of the azimuthal magnetic field of the pinch region, in a predominant ion cluster structure

  12. Synthesis of Crystalline Carbon Nitride Thin Films by Pulsed Arc Discharge at Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    SHI Changyong; MA Zhibin

    2007-01-01

    The preparation of crystalline C3N4 films was investigated using pulsed arc discharge from mixed methanol and ammonia water at atmospheric pressure.The X-ray diffraction(XRD)patterns of the films prepared at a substrate temperature of 450℃ suggested that the film was composed of α-C3N4 and β-C3N4 crystallites.Raman spectra exhibited distinct peaks which are in good agreement with those predicted theoretically for C3N4 crystallites.

  13. Growth of metal micro and/or nanoparticles utilizing arc-discharge immersed in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Rebollo P, B.; Gallardo G, G.; Ortega M, N.; Daniel P, G. [Instituto Tecnologico Superior de Irapuato, Km 12.5 Carretera Irapuato-Silao, 36821 Irapuato, Guanajuato (Mexico); Sampedro, M. P.; Zenteno M, B. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria, Ciudad Universitaria, 72590 Puebla, Puebla (Mexico); Bravo B, C. F. [Comision Federal de Electricidad, Laboratorio de Pruebas de Equipos y Materiales, Irapuato, Guanajuato (Mexico); Hernandez C, D. [Universidad Autonoma de Chiapas, Facultad de Ingenieria, 29050 Tuxtla Gutierrez, Chiapas (Mexico); Jimenez S, S., E-mail: mpstraviata@hotmail.com [Instituto Politecnico Nacional, Centro de Investigacion y de Estudios Avanzados, Laboratorio de Investigacion en Materiales, 76230 Santiago de Queretaro, Queretaro (Mexico)

    2014-07-01

    In this paper, we present results on the metal microcrystals and nanoparticles of Al, Cu and Al-Cu composite growth by arc-discharge with the system immersed in distilled water, under different conditions and varying the current from 50 to 150 A with constant voltage (27 V). These structures are characterized using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV-Vis spectroscopy. Our results demonstrate that metal micro and nano structures can be prepared at low cost with high quality. (Author)

  14. Growth of metal micro and/or nanoparticles utilizing arc-discharge immersed in liquid

    International Nuclear Information System (INIS)

    In this paper, we present results on the metal microcrystals and nanoparticles of Al, Cu and Al-Cu composite growth by arc-discharge with the system immersed in distilled water, under different conditions and varying the current from 50 to 150 A with constant voltage (27 V). These structures are characterized using X-ray diffraction, scanning electron microscopy, Raman spectroscopy and UV-Vis spectroscopy. Our results demonstrate that metal micro and nano structures can be prepared at low cost with high quality. (Author)

  15. Arc-Discharge Synthesis and Microstructure Characterization of AlN Nanowires

    Institute of Scientific and Technical Information of China (English)

    Zhijie LI; Zhiqi SHEN; Fu WANG; Lianlong HE

    2006-01-01

    AIN nanowires with a hexagonal structure were synthesized using an improved arc-discharge method and their microstructures were characterized using a high-resolution transmission electron microscope. The synthesized AIN nanowires were of various shapes. Their diameters ranged from 20 to 110 nm and the lengths were up to 20μm. Most of the AIN nanowires were coated by an amorphous layer of aluminum oxide. Fabrication yield was about several grams. The growth mechanism was considered to be a vapor-liquid-solid process and an Al droplet formed on the top of as-grown AIN nanowire played a role of catalyst.

  16. Synthesis of Large Quantity Single-Walled Carbon Nanotubes by Arc Discharge

    Institute of Scientific and Technical Information of China (English)

    李振华; 王淼; 王新庆; 朱海滨; 卢焕明; 安藤义则

    2002-01-01

    We report on a new method to prepare large quantity single-walled carbon nanotubes (SWCNTs) with high purity.Using a Y-Ni powder composite graphite rod as an anode, at a given angle with the high-purity graphite cathode rod, a cloth-like deposit can be obtained by dc arc discharge in helium at high temperature, which contains about 60% SWCNTs. In this way, we can obtain a deposit of more than one gram in ten minutes. Transmission electron microscopy and Raman scattering have been used to observe the structure and morphology of the SWCNTs.

  17. Study on the hydrogen negative ion in low pressure discharges

    International Nuclear Information System (INIS)

    A new use of negative hydrogen ions is the production of intense fast neutral atom beams useful in plasma heating in thermonuclear heating. That is one of the reasons that started this study. The density of negative hydrogen ions in diffusion, and multipole-type low pressure (10-3 - 10-2 Torr) discharges is deduced from the various formation and destruction processes of the species present in these discharges. The H- ions are essentially produced by dissociative attachment to vibrationally excited molecules and destroyed by processes the relative importance of which is discussed as a function of the discharge parameters. The experimental study of the density of the H- ions, measured by photodetachment, as a function of these parameters, coroborates the theoretical model

  18. Steam Reforming of Dimethyl Ether by Gliding Arc Gas Discharge Plasma for Hydrogen Production

    Institute of Scientific and Technical Information of China (English)

    王保伟; 孙启梅; 吕一军; 杨美琳; 闫文娟

    2014-01-01

    Gliding arc gas discharge plasma was used for the generation of hydrogen from steam reforming of di-methyl ether (DME). A systemic procedure was employed to determine the suitable experimental conditions. It was found that DME conversion first increased up to the maximum and then decreased slightly with the increase of added water and air. The increase of total feed gas flow rate resulted in the decrease of DME conversion and hy-drogen yield, but hydrogen energy consumption dropped down to the lowest as total feed gas flow rate increased to 76 ml·min-1. Larger electrode gap and higher discharge voltage were advantageous. Electrode shape had an impor-tant effect on the conversion of DME and production of H2. Among the five electrodes, electrode 2# with valid length of 55 mm and the radian of 34 degrees of the top electrode section was the best option, which enhanced ob-viously the conversion of DME.

  19. Investigation of hydrocarbon oil transformation by gliding arc discharge: comparison of batch and recirculated configurations

    Science.gov (United States)

    Whitehead, J. Christopher; Prantsidou, Maria

    2016-04-01

    The degradation of liquid dodecane was studied in a gliding arc discharge (GAD) of humid argon or nitrogen. A batch or recirculating configuration was used. The products in the gaseous and liquid phase were analysed by infrared and chromatography and optical emission spectroscopy was used to identify the excited species in the discharge. The best degradation performance comes from the use of humid N2 but a GAD of humid argon produces fewer gas-phase products but more liquid-phase end-products. A wide range of products such as heavier saturated or unsaturated hydrocarbons both aliphatic and aromatic, and oxidation products mainly alcohols, but also aldehydes, ketones and esters are produced in the liquid-phase. The recirculating treatment mode is more effective than the batch mode increasing the reactivity and changing the product selectivities. Overall, the study shows promising results for the organic liquid waste treatment, especially in the recirculating mode.

  20. Discharge coefficient correlations for circular-arc venturi flowmeters at critical /sonic/ flow

    Science.gov (United States)

    Arnberg, B. T.; Britton, C. L.; Seidl, W. F.

    1973-01-01

    Experimental data are analyzed to support theoretical predictions for discharge coefficients in circular-arc venturi flow meters operating in the critical sonic flow regime at throat Reynolds numbers above 150 thousand. The data tend to verify the predicted 0.25% decrease in the discharge coefficient during transition from a laminar to turbulent boundary layer. Four different test gases and three flow measurement facilities were used in the experiments with 17 venturis with throat sizes from 0.15 to 1.37 in. and Beta ratios ranging from 0.014 to 0.25. Recommendations are given as to how the effectiveness of future studies in the field could be improved.

  1. Particle-in-cell and Monte Carlo collision simulations of the cathode sheath in an atmospheric direct-current arc discharge

    Science.gov (United States)

    Zhou, Wen; Guo, Heng; Jiang, Wei; Li, He-Ping; Li, Zeng-Yao; Lapenta, Giovanni

    2016-10-01

    A sheath is the transition region from plasma to a solid surface, which also plays a critical role in determining the behaviors of many lab and industrial plasmas. However, the cathode sheath properties in arc discharges are not well understood yet due to its multi-scale and kinetic features. In this letter, we have adopted an implicit particle-in-cell Monte Carlo collision (PIC-MCC) method to study the cathode sheath in an atmospheric arc discharge plasma. The cathode sheath thickness, number densities and averaged energies of electrons and ions, the electric field distribution, as well as the spatially averaged electron energy probability function (EEPF), are predicted self-consistently by using this newly developed kinetic model. It is also shown that the thermionic emission at the hot cathode surface is the dominant electron emission process to sustain the arc discharges, while the effects from secondary and field electron emissions are negligible. The present results verify the previous conjectures and experimental observations.

  2. Preparation of Metallic Aluminum Compound Particles by Submerged Arc Discharge Method in Aqueous Media

    Science.gov (United States)

    Liao, Chih-Yu; Tseng, Kuo-Hsiung; Lin, Hong-Shiou

    2013-02-01

    Fine metal particles are produced by chemical methods, which add surfactants to control particle size and concentration. This study used the submerged arc discharge method (SADM) to prepare metal fluid containing nanoparticles and submicron particles in pure dielectric fluid (deionized water or alcohol). The process is fast and simple, and it does not require the addition of chemical agents. The SADM uses electrical discharge machining (EDM) equipment, and the key parameters of the production process include discharge voltage, current, and pulse discharge on-off duration. This study added a capacitive component between the electrodes and the electrode Z-axis regulation in the control parameters to render the aluminum fluid process smooth, which is the main difference of this article from the literature. The experimental results showed that SADM can produce aluminum particles from nanometer to submicron grade, and it can obtain different compounds from different dielectric fluids. The dielectric fluids used in this study were deionized water and ethanol, and aluminum hydroxide Al(OH)3 particles with suspending power and precipitated aluminum particles were obtained, respectively. The preparations of metal colloid and particles by the SADM process have the characteristics of low cost, high efficiency, high speed, and mass production. Thus, the process has high research value and developmental opportunities.

  3. Copper induced hollow carbon nanospheres by arc discharge method: controlled synthesis and formation mechanism.

    Science.gov (United States)

    Hu, Rui; Ciolan, Mihai Alexandru; Wang, Xiangke; Nagatsu, Masaaki

    2016-08-19

    Hollow carbon nanospheres with controlled morphologies were synthesized via the copper-carbon direct current arc discharge method by alternating the concentrations of methane in the reactant gas mixture. A self-healing process to keep the structural integrity of encapsulated graphitic shells was evolved gradually by adding methane gas from 0% to 20%. The outer part of the coated layers expanded and hollow nanospheres grew to be large fluffy ones with high methane concentrations from 30% to 50%. A self-repairing function by the reattachment of broken graphitic layers initiated from near-electrode space to distance was also distinctly exhibited. By comparing several comparable metals (e.g. copper, silver, gold, zinc, iron and nickel)-carbon arc discharge products, a catalytic carbon-encapsulation mechanism combined with a core-escaping process has been proposed. Specifically, on the basis of the experimental results, copper could be applied as a unique model for both the catalysis of graphitic encapsulation and as an adequate template for the formation of hollow nanostructures. PMID:27377038

  4. Copper induced hollow carbon nanospheres by arc discharge method: controlled synthesis and formation mechanism

    Science.gov (United States)

    Hu, Rui; Alexandru Ciolan, Mihai; Wang, Xiangke; Nagatsu, Masaaki

    2016-08-01

    Hollow carbon nanospheres with controlled morphologies were synthesized via the copper-carbon direct current arc discharge method by alternating the concentrations of methane in the reactant gas mixture. A self-healing process to keep the structural integrity of encapsulated graphitic shells was evolved gradually by adding methane gas from 0% to 20%. The outer part of the coated layers expanded and hollow nanospheres grew to be large fluffy ones with high methane concentrations from 30% to 50%. A self-repairing function by the reattachment of broken graphitic layers initiated from near-electrode space to distance was also distinctly exhibited. By comparing several comparable metals (e.g. copper, silver, gold, zinc, iron and nickel)-carbon arc discharge products, a catalytic carbon-encapsulation mechanism combined with a core-escaping process has been proposed. Specifically, on the basis of the experimental results, copper could be applied as a unique model for both the catalysis of graphitic encapsulation and as an adequate template for the formation of hollow nanostructures.

  5. Synthesis and structural, magnetic and magnetotransport properties of permalloy powders containing nanoparticles prepared by arc discharge

    International Nuclear Information System (INIS)

    Highlights: • New method of arc discharge used to synthesise permalloy containing nanoparticles. • The highest quality powders were made using a 78% Ni permalloy rod in N2. • The Saturation moment was slightly less and the coercive field was low (3 mT). • MR contributions from the spin-dependent tunneling between the particles. - Abstract: We report the synthesis of permalloy powders that were made using an arc-discharge method and with 78% or 45% Ni concentrations in N2 or Ar. Our research was motivated by the fact that magnetic nanoparticles displaying large magnetoresistances are useful for magnetic field sensors applications. The permalloy powders contained some nanoparticles and the particle sizes ranged from 10 nm to ∼20 μm. The highest quality powders were made using a 78% Ni permalloy rod in N2 where the coercivity was low (0.3 mT) and the saturation moment per formula unit was slightly less than that expected for the bulk compound. Magnetoresistance was observed in a cold pressed pellet where it is likely to be dominated by the ordinary magnetoresistance and spin-dependent tunneling between the particles

  6. XPS and RBS investigation of TiNxOy films prepared by vacuum arc discharge

    International Nuclear Information System (INIS)

    Highlights: ► We prepare three TiNxOy films by vacuum arc discharge technique with different temperatures. ► Increasing the temperature will improve titanium nitride components. ► Temperature plays a major role in the thickness of films. ► Crystalline and texture developments of the films depend on the temperature. - Abstract: Three titanium oxynitride films have been prepared by vacuum arc discharge technique at different chamber temperatures (50 °C, 150 °C and 300 °C). X-ray photoelectron spectroscopy was used to reveal the elemental and chemical compositions by analyzing high resolution spectra of Ti 2p3/2, N 1s and O 1s. Higher temperatures were found to promote the nitride components and to produce nitrogen-rich films. Homogeneity and thickness of the films have been estimated by means of Rutherford Back Scattering technique, which showed that the film thickness increased with the increasing of temperature. A significant improvement in the crystalline quality and texture when increasing the temperature was found by X-ray diffraction technique. Electrical resistivity of the films was measured at room temperature and was found to decrease from 46.6 μΩ cm down to 26.3 μΩ cm for the samples prepared at 50 °C and 300 °C, respectively.

  7. High-discharge-rate lithium ion battery

    Science.gov (United States)

    Liu, Gao; Battaglia, Vincent S; Zheng, Honghe

    2014-04-22

    The present invention provides for a lithium ion battery and process for creating such, comprising higher binder to carbon conductor ratios than presently used in the industry. The battery is characterized by much lower interfacial resistances at the anode and cathode as a result of initially mixing a carbon conductor with a binder, then with the active material. Further improvements in cycleability can also be realized by first mixing the carbon conductor with the active material first and then adding the binder.

  8. The transition from spark to arc discharge and its implications with respect to nanoparticle production

    Energy Technology Data Exchange (ETDEWEB)

    Hontanon, Esther, E-mail: esther.hontanon@uni-due.de [University of Duisburg-Essen, Institute for Technology of Nanostructures (NST) and Center for Nanointegration (CENIDE) (Germany); Palomares, Jose Maria [Eindhoven University of Technology, Faculty of Applied Physics (Netherlands); Stein, Matthias [University of Duisburg-Essen, Institute for Technology of Nanostructures (NST) and Center for Nanointegration (CENIDE) (Germany); Guo, Xiaoai [Karlsruhe Institute of Technology (KIT), Institute for Mechanical Process Engineering and Mechanics (MVM) (Germany); Engeln, Richard [Eindhoven University of Technology, Faculty of Applied Physics (Netherlands); Nirschl, Hermann [Karlsruhe Institute of Technology (KIT), Institute for Mechanical Process Engineering and Mechanics (MVM) (Germany); Kruis, Frank Einar [University of Duisburg-Essen, Institute for Technology of Nanostructures (NST) and Center for Nanointegration (CENIDE) (Germany)

    2013-09-15

    The synthesis of nanoparticles by means of electrical discharges between two electrodes in an inert gas at atmospheric pressure, as driven by a constant current ranging from a few milliamps to tens of amps, is investigated in this work. An extensive series of experiments are conducted with copper as a consumable electrode and pure nitrogen as the inert gas. Three different DC power supplies are used to drive electrical discharges for the entire operating current range. Then, three electrical discharge regimes (spark, glow, and arc) with distinct voltage-current characteristics and plasma emission spectra are recognized. For the first time, nanoparticles are synthesized by evaporation of an electrode by atmospheric pressure inert gas DC glow discharge of a few millimeters in size. The discharge regimes are characterized in terms of the mass output rate and the particle size distribution of the copper aerosols by means of online (tapered element oscillating microbalance, TEOM; and scanning mobility particle sizer, SPMS) and offline (gravimetric analysis; small and wide angle X-ray scattering, SWAXS; and transmission electron microscopy, TEM) techniques. The electrical power delivered to the electrode gap and the gas flow rate are two major parameters determining the aerosol mass output rate and the aerosol particle size distribution. The mass output rate of copper aerosols raises from 2 mg h{sup -1} to 2 g h{sup -1} when increasing the electrical power from 9 to 900 W. The particle mean size (SMPS d{sub g}) varies between 20 and 100 nm depending upon the electrical power and the gas flow rate, whereas the particle size dispersion (SMPS {sigma}{sub g}) ranges from 1.4 to 1.7 and is only weakly dependent on the gas flow rate.

  9. Charge state distribution studies of the metal vapor vacuum arc ion source

    International Nuclear Information System (INIS)

    We have studied the charge state distribution of the ion beam produced by the MEVVA (metal vapor vacuum arc) high current metal ion source. Beams produced from a wide range of cathode materials have been examined and the charge state distributions have been measured as a function of many operational parameters. In this paper we review the charge state data we have accumulated, with particular emphasis on the time history of the distribution throughout the arc current pulse duration. We find that in general the spectra remain quite constant throughout most of the beam pulse, so long as the arc current is constant. There is an interesting early-time transient behavior when the arc is first initiated and the arc current is still rising, during which time the ion charge states produced are observed to be significantly higher than during the steady current region that follows. 12 refs., 5 figs

  10. Generation of metallic arc spectrum of pumping discharge of XeCl laser; XeCl ekishima laser reiki hoden ni okeru arc iko to kinzoku supekutoru no hassei

    Energy Technology Data Exchange (ETDEWEB)

    Koike, H.; Yukimura, K. [Doshisha University, Kyoto (Japan)

    1997-12-20

    An arc generation of a long-pulse spiker-sustainer excimer laser with about 250ns of pulse width , is discussed by using time-varying spectroscopic method. First arcing occurs during a main discharge for laser excitation and shows XeII spectrum, while a glow-like discharge represents only XeI spectrum, the metallic spectrum such as Nil caused by vaporization of electrode material begins to appear just after the termination of the main discharge. Second arcing occurs after about 2{mu}s, which brings strong intensity of Nil spectrum. It means that the reignition arc might be produced in a metallic vapor that appears during the main discharge. Accordingly, it is concluded that the reignition arc is inherently metallic, which is different from the main arc with rare gas plasma. 9 refs., 9 figs.

  11. Electron and ion kinetics in a micro hollow cathode discharge

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G J; Iza, F; Lee, J K [Electronics and Electrical Engineering Department, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2006-10-21

    Electron and ion kinetics in a micro hollow cathode discharge are investigated by means of two-dimensional axisymmetric particle-in-cell Monte Carlo collision simulations. Argon discharges at 10 and 300 Torr are studied for various driving currents. Electron and ion energy probability functions (IEPF) are shown at various times and locations to study the spatio-temporal behaviour of the discharge. The electron energy probability function (EEPF) evolves from the Druyvesteyn type in the early stages of the discharge into a two (or three) temperature distribution when steady state is reached. In steady state, secondary electrons accelerated across the cathode fall populate the high energy tail of the EEPF while the low energy region is populated by trapped electrons. The IEPF evolves from a Maxwellian in the negative glow (bulk) to a two temperature distribution on the cathode surface. The overpopulation of low energy ions near the cathode surface is attributed to a larger collision cross section for low energy ions and ionization within the cathode fall.

  12. Simultaneous removal of ethyl acetate, benzene and toluene with gliding arc gas discharge

    Institute of Scientific and Technical Information of China (English)

    Zheng BO; Jian-hua YAN; Xiao-dong LI; Yong CHI; Ke-fa CEN

    2008-01-01

    The simultaneous removal of ethyl acetate, benzene and toluene with relatively low or high initial concentration is studied using a laboratory scale gliding arc gas discharge (GA) reactor. Good decomposition efficiencies are obtained which proves that the GA is effective for the treatment of volatile organic compounds (VOCs) with either low or high concentration. A theoretical decomposition mechanism is proposed based on detection of the species in the plasma region and analysis of the decomposition by-products. This preliminary investigation reveals that the GA has potential to be applied to the treatment of exhaust air during color printing and coating works, by either direct removal or combination with activated carbon adsorption/desorption process.

  13. The mechanism of liquid metal jet formation in the cathode spot of vacuum arc discharge

    Science.gov (United States)

    Gashkov, M. A.; Zubarev, N. M.; Mesyats, G. A.; Uimanov, I. V.

    2016-08-01

    We have theoretically studied the dynamics of molten metal during crater formation in the cathode spot of vacuum arc discharge. At the initial stage, a liquid-metal ridge is formed around the crater. This process has been numerically simulated in the framework of the two-dimensional axisymmetric heat and mass transfer problem in the approximation of viscous incompressible liquid. At a more developed stage, the motion of liquid metal loses axial symmetry, which corresponds to a tendency toward jet formation. The development of azimuthal instabilities of the ridge is analyzed in terms of dispersion relations for surface waves. It is shown that maximum increments correspond to instability of the Rayleigh-Plateau type. Estimations of the time of formation of liquid metal jets and their probable number are obtained.

  14. Electroless nickel plating of arc discharge synthesized carbon nanotubes for metal matrix composites

    Science.gov (United States)

    Jagannatham, M.; Sankaran, S.; Prathap, Haridoss

    2015-01-01

    Electroless nickel (EN) plating was performed on arc discharge synthesized multiwalled carbon nanotubes for various deposition times. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Raman spectroscopy characterization techniques are used to identify the presence of nickel deposition on the carbon nanotubes (CNTs) and the degree of graphitization. The results indicate that impurities are less in the purified CNTs as compared to raw carbon soot. Increasing deposition time up to 60 min increases uniform deposition of nickel throughout the length of the CNTs. However, for deposition time longer than 60 min, nickel particles are seen separated from the surface of the CNTs. Uniformly coated nickel CNTs throughout their length are potential candidates for reinforcements in composite materials. Magnetic properties of the nickel coated CNTs, with deposition time of 30 and 60 min were also evaluated. The magnetic saturation of nickel coated CNTs with deposition time of 30 min is less compared to nickel coated CNTs with deposition time of 60 min.

  15. Measurements of 3D slip velocities and plasma column lengths of a gliding arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas; Aldén, Marcus; Li, Zhongshan, E-mail: zhongshan.li@forbrf.lth.se, E-mail: alpers@ma.tum.de [Division of Combustion Physics, Lund University, P.O. Box 118, S-221 00 Lund (Sweden); Moseev, Dmitry [Max-Planck-Institut für Plasmaphysik, D-85748 Garching bei München (Germany); FOM Institute DIFFER, 3430 BE Nieuwegein (Netherlands); Kusano, Yukihiro [Department of Wind Energy, Section for Composites and Materials Mechanics, Technical University of Denmark, Risø Campus, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Salewski, Mirko [Department of Physics, Section for Plasma Physics and Fusion Energy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Alpers, Andreas, E-mail: zhongshan.li@forbrf.lth.se, E-mail: alpers@ma.tum.de; Gritzmann, Peter; Schwenk, Martin [Zentrum Mathematik, Technische Universität München, D-85747 Garching bei München (Germany)

    2015-01-26

    A non-thermal gliding arc discharge was generated at atmospheric pressure in an air flow. The dynamics of the plasma column and tracer particles were recorded using two synchronized high-speed cameras. Whereas the data analysis for such systems has previously been performed in 2D (analyzing the single camera image), we provide here a 3D data analysis that includes 3D reconstructions of the plasma column and 3D particle tracking velocimetry based on discrete tomography methods. The 3D analysis, in particular, the determination of the 3D slip velocity between the plasma column and the gas flow, gives more realistic insight into the convection cooling process. Additionally, with the determination of the 3D slip velocity and the 3D length of the plasma column, we give more accurate estimates for the drag force, the electric field strength, the power per unit length, and the radius of the conducting zone of the plasma column.

  16. Measurements of 3D slip velocities and plasma column lengths of a gliding arc discharge

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas;

    2015-01-01

    the single camera image), we provide here a 3D data analysis that includes 3D reconstructions of the plasma column and 3D particle tracking velocimetry based on discrete tomography methods. The 3D analysis, in particular, the determination of the 3D slip velocity between the plasma column and the gas flow......, gives more realistic insight into the convection cooling process. Additionally, with the determination of the 3D slip velocity and the 3D length of the plasma column, we give more accurate estimates for the drag force, the electric field strength, the power per unit length, and the radius......A non-thermal gliding arc discharge was generated at atmospheric pressure in an air flow. The dynamics of the plasma column and tracer particles were recorded using two synchronized high-speed cameras. Whereas the data analysis for such systems has previously been performed in 2D (analyzing...

  17. Study of Ag and Au Nanoparticles Synthesized by Arc Discharge in Deionized Water

    Directory of Open Access Journals (Sweden)

    Der-Chi Tien

    2010-01-01

    Full Text Available The paper presents a study of Ag and Au nanofluids synthesized by the arc discharge method (ADM in deionized water. The metallic Ag nanoparticle (Ag0 and ionic Ag (Ag+ have played an important role in the battle against germs which are becoming more drug-resistant every year. Our study indicates that Ag nanoparticle suspension (SNPS fabricated by using ADM without added surfactants exclusively contains the metallic Ag nanoparticle and ionic Ag. Besides that, the ADM in deionized water has also been employed for the fabrication process of Au nanoparticles. The experimental results indicate that the prepared Ag nanoparticles can react with the dissolved H2CO3 in deionized water, leading to the formation of Ag2CO3. Significantly different to Ag, the prepared Au nanoparticles with their surfaces bonded by oxygen are suspended in deionized water by the formation of hydrogen bonded with the neighboring water molecules.

  18. Nanoscratch technique for aligning multiwalled carbon nanotubes synthesized by the arc discharge method in open air

    Indian Academy of Sciences (India)

    A Joseph Berkmans; M Jagannatham; Prathap Haridoss

    2015-08-01

    Horizontally aligned and densely packed multiwalled carbon nanotubes (MWCNTs) were synthesized in an open air, without the need for a controlled atmosphere, using a rotating cathode arc discharge method with the help of a metal scraper. The physical force exerted by the scraper results in in-situ alignment of MWCNTs along the direction of scrape marks. This strategy, which enables the alignment of nanotubes in a controlled fashion to any length and direction of interest, was examined to determine the force required to align a nanotube. A model is developed to understand the alignment process. Using the nanoscratch technique to mimic this strategy, and incorporating the data obtained from the nanoscratch technique into the model developed, the minimum force required to align a MWCNT, as well as the energy required to align a gram of nanotubes, has been estimated. The method demonstrated represents an economical approach for large-scale synthesis of aligned MWCNTs at low costs.

  19. On-chip purification via liquid immersion of arc-discharge synthesized multiwalled carbon nanotubes

    Science.gov (United States)

    Hokkanen, Matti J.; Lautala, Saara; Shao, Dongkai; Turpeinen, Tuomas; Koivistoinen, Juha; Ahlskog, Markus

    2016-07-01

    Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT) have been proven to be of high quality, but their use is very limited due to difficulties in obtaining them in a clean and undamaged form. Here, we present a simple method that purifies raw AD-MWNT material in laboratory scale without damage, and that in principle can be scaled up. The method consists of depositing raw AD-MWNT material on a flat substrate and immersing the substrate slowly in water, whereby the surface tension force of the liquid-substrate contact line selectively sweeps away the larger amorphous carbon debris and leaves relatively clean MWNTs on the substrate. We demonstrate the utility of the method by preparing clean individual MWNTs for measurement of their Raman spectra. The spectra exhibit the characteristics of high-quality tubes free from contaminants. We also show how one concomitantly with the purification process can obtain large numbers of clean suspended MWNTs.

  20. Account of near-cathode sheath in numerical models of high-pressure arc discharges

    Science.gov (United States)

    Benilov, M. S.; Almeida, N. A.; Baeva, M.; Cunha, M. D.; Benilova, L. G.; Uhrlandt, D.

    2016-06-01

    Three approaches to describing the separation of charges in near-cathode regions of high-pressure arc discharges are compared. The first approach employs a single set of equations, including the Poisson equation, in the whole interelectrode gap. The second approach employs a fully non-equilibrium description of the quasi-neutral bulk plasma, complemented with a newly developed description of the space-charge sheaths. The third, and the simplest, approach exploits the fact that significant power is deposited by the arc power supply into the near-cathode plasma layer, which allows one to simulate the plasma-cathode interaction to the first approximation independently of processes in the bulk plasma. It is found that results given by the different models are generally in good agreement, and in some cases the agreement is even surprisingly good. It follows that the predicted integral characteristics of the plasma-cathode interaction are not strongly affected by details of the model provided that the basic physics is right.

  1. Numerical study of the anode boundary layer in atmospheric pressure arc discharges

    Science.gov (United States)

    Semenov, I. L.; Krivtsun, I. V.; Reisgen, U.

    2016-03-01

    The anode boundary layer in atmospheric pressure arc discharges is studied numerically on the basis of the hydrodynamic (diffusion) equations for plasma components. The governing equations are formulated in a unified manner without the assumptions of thermal equilibrium, ionization equilibrium or quasi-neutrality. For comparison, a quasi-neutral model of the anode layer is also considered. The numerical computations are performed for an argon arc at typical values of the current density in anode layers (500-2000 A cm-2). The results of numerical modelling show that the common collisionless model of the sheath fails to describe the sheath region for the problem under consideration. For this reason, a detailed analysis of the anode sheath is performed using the results of unified modelling. In addition, the distributions of plasma parameters in the anode layer are analysed and the basic characteristics of the layer (anode voltage drop, sheath voltage drop, anode layer thickness, sheath thickness, heat flux to the anode) are calculated. Our results are found to be in good agreement with the existing theoretical predictions and experimental data. The dependence of the anode layer characteristics on the current density is also discussed.

  2. Formation of Multicharged Metal Ions in Vacuum Arc Plasma Heated by Gyrotron Radiation%Formation of Multicharged Metal Ions in Vacuum Arc Plasma Heated by Gyrotron Radiation

    Institute of Scientific and Technical Information of China (English)

    G. Yu. YUSHKOV; K. P. SAVKIN; A. G. NIKOLAEV; E. M. OKS; A.V. VODOPYANOV; I. V. IZOTOV; D. A. MANSFELD

    2011-01-01

    A new method for the generation of high charged state metal ion beams is developed. This method is based on microwave heating of vacuum arc plasma in a magnetic trap under electron cyclotron resonance (ECR) conditions. Two gyrotrons for plasma heating were used, which were with the following parameters. The first is with a wave frequency of 37.5 GHz, a pulse duration of 1 ms and power of 100 kW, another is with 75 GHz, 0.15 ms and 400 kW. Two different magnetic traps were considered for vacuum arc plasma confinement. The first one is a simple mirror trap. Such system was already investigated and could provide high charge state ions. The second trap was with a cusp magnetic field configuration with native "minimum-B" field structure. Two different ways of metal plasma injection into the magnetic trap were used. The first one is an axial injection from an arc source located out of the trap, and the second is a radial injection from four arc sources mounted at the center of the trap. Both traps provide up to 200 eMA of ion beam current for platinum ions with highest charge state 10+. Ion beams were successfully extracted from the plasma and accelerated by a voltage of up to 20 kV.

  3. Highly sensitive Shack–Hartmann sensor for two-dimensional electron density imaging over extinguishing arc discharges

    International Nuclear Information System (INIS)

    Highly sensitive Shack–Hartmann-type laser wavefront sensors incorporating meniscus microlens arrays with a long focal length of 238 or 467 mm were developed for imaging two-dimensional electron density distributions over extinguishing atmospheric arc discharges. The use of the novel microlens arrays also had the advantage of realizing the spatial synchronization of the measuring system. The highly sensitive Shack–Hartmann sensors were successfully used for the single-shot imaging of two-dimensional electron density distributions over the extinguishing arc discharges with currents of several amperes and were proven to have improved the measurement sensitivity by two orders of magnitude from 1023 to 1021 m−3. Spatiotemporal evolution of the electron density images showed that just before arc extinction the electron densities at outer radial positions with respect to the interelectrode gap were higher than those on the geometrical axis defined by the electrodes. (paper)

  4. Electric field induced needle-pulsed arc discharge carbon nanotube production apparatus: Circuitry and mechanical design

    Science.gov (United States)

    Kia, Kaveh Kazemi; Bonabi, Fahimeh

    2012-12-01

    A simple and low cost apparatus is reported to produce multiwall carbon nanotubes and carbon nano-onions by a low power short pulsed arc discharge reactor. The electric circuitry and the mechanical design details and a micro-filtering assembly are described. The pulsed-plasma is generated and applied between two graphite electrodes. The pulse width is 0.3 μs. A strong dc electric field is established along side the electrodes. The repetitive discharges occur in less than 1 mm distance between a sharp tip graphite rod as anode, and a tubular graphite as cathode. A hydrocarbon vapor, as carbon source, is introduced through the graphite nozzle in the cathode assembly. The pressure of the chamber is controlled by a vacuum pump. A magnetic field, perpendicular to the plasma path, is provided. The results show that the synergetic use of a pulsed-current and a dc power supply enables us to synthesize carbon nanoparticles with short pulsed plasma. The simplicity and inexpensiveness of this plan is noticeable. Pulsed nature of plasma provides some extra degrees of freedom that make the production more controllable. Effects of some design parameters such as electric field, pulse frequency, and cathode shape are discussed. The products are examined using scanning probe microscopy techniques.

  5. Effect of annealing process on TiN/TiC bilayers grown by pulsed arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Rivera, L., E-mail: lramosr@unal.edu.co [Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Aeropuerto Campus La Nubia (Colombia); Escobar, D.; Benavides-Palacios, V.; Arango, P.J.; Restrepo-Parra, E. [Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Aeropuerto Campus La Nubia (Colombia)

    2012-08-15

    In this work, a study of annealing process effect on TiN/TiC bilayer is presented. The annealing temperature was varied between room temperature and 500 Degree-Sign C. Materials were produced by the plasma-assisted pulsed vacuum arc discharge technique. In order to grow the films, a target of Ti with 99.9999% purity and stainless-steel 304 substrate were used. For the production of TiN layer, the reaction chamber was filled up with nitrogen gas until reaching 25 Pa and the discharge was performed at 310 V. The TiC layer was grown in a methane atmosphere at 30 Pa and 270 V. X-ray diffraction and X photoelectron spectroscopy were employed for studying the structure and chemical composition evolution during the annealing process. At 400 Degree-Sign C, TiO{sub 2} phase begun to appear and it was well observed at 500 Degree-Sign C. Crystallite size and microstrain was obtained as a function of the annealing temperature. XPS technique was employed for analyzing the bilayers before and after the annealing process. Narrow spectra of Ti2p, N1s and O1s were obtained, presenting TiO phases.

  6. Interpretation of duoplasmatron-type ion sources from a model of the discharge

    International Nuclear Information System (INIS)

    The performance logical improvement of these sources needs a precise knowledge of the emitting ionized medium, on which the whole of the properties is depending. Ion production mechanisms have been studied in the discharge together with their transport towards the extraction hole. The source properties are described, in a new manner, as a function of the discharge modes. The discharge is characterized by the existence of a mode change, related to anode column neutral atom lowering in anode column (arc starvation). The complementarity of probe measurements and the energy spectra analysis of the charges emitted by the anode hole allowed to get the potential axial profile, to discover an electric energetic electron beam extracted from cathodic plasma by the striction shealth potential difference and to determine the electron density radial profile in the anode column. Result analysis allows to get a simple scheme of plasmas and laws controlling them in each of the important modes. The density and potential axial theoretical repartition has been calculated as a function of independent parameters-anode pressure and arc intensity and of three secondary parameters characterizing the energy exchange (electron temperature) and magnetic field topography. The agreement between model predictions and experimental variations for source properties -more specifically gas nature and geometry- allow to give the duoplasmatrons sources similitude rules. The discharge model has allowed to interpret the luminous emission spectra from the anode column. It has been shown theoretically that the peculiar conditions of ionization and excitation allow to use the column as an amplifier medium in the optically field. This plasma has been used successfully as an active medium for an ionic laser in a continuous mode

  7. Determination of alcohol compounds using corona discharge ion mobility spectrometry

    Institute of Scientific and Technical Information of China (English)

    HAN Hai-yan; HUANG Guo-dong; JIN Shun-ping; ZHENG Pei-chao; XU Guo-hua; LI Jian-quan; WANG Hong-mei; CHU Yan-nan

    2007-01-01

    Ion mobility spectrometry (IMS) is a very fast, highly sensitive, and inexpensive technique, it permits efficient monitoring of volatile organic compounds like alcohols. In this article, positive ion mobility spectra for six alcohol organic compounds have been systematically studied for the first time using a high-resolution IMS apparatus equipped with a discharge ionization source. Utilizing protonated water cluster ions (H2O)nH+ as the reactant ions and clean air as the drift gas, alcohol organic compounds, ethanol, 1-propanol, 2-propanol, 1-butanol, 1-pentanol and 2-octanol, all exhibit product ion characteristic peaks in their respective ion mobility spectrometry, that is a result of proton transfer reactions between the alcohols and reaction ions (H2O)nH+. The mixture of these alcohols, including two isomers, has been detected, and the result shows that they can also be distinguished effectively in the ion mobility spectrum. The reduced mobility values have been determined, which are in very well agreement with the traditional 63Ni-IMS experimental values. The exponential dilution method was used to calibrate the alcohol concentrations, and a detection limit available for the alcohols is in order of magnitude of a few ng/L.

  8. Modification of anti-bacterial surface properties of textile polymers by vacuum arc ion source implantation

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaev, A.G., E-mail: nik@opee.hcei.tsc.ru [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Yushkov, G.Yu.; Oks, E.M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Sciences, Tomsk 634055 (Russian Federation); Oztarhan, A. [Izmir University, Izmir 35140 (Turkey); Akpek, A.; Hames-Kocabas, E.; Urkac, E.S. [Bioengineering Department, Ege University, Bornova 35100, Izmir (Turkey); Brown, I.G. [Lawrence Berkeley National Laboratory, Berkeley, CA 94708 (United States)

    2014-08-15

    Highlights: • Ion implantation. • Anti-bacterial properties. • Textile polymer. • Vacuum arc ion source. - Abstract: Ion implantation provides an important technology for the modification of material surface properties. The vacuum arc ion source is a unique instrument for the generation of intense beams of metal ions as well as gaseous ions, including mixed metal–gas beams with controllable metal:gas ion ratio. Here we describe our exploratory work on the application of vacuum arc ion source-generated ion beams for ion implantation into polymer textile materials for modification of their biological cell compatibility surface properties. We have investigated two specific aspects of cell compatibility: (i) enhancement of the antibacterial characteristics (we chose to use Staphylococcus aureus bacteria) of ion implanted polymer textile fabric, and (ii) the “inverse” concern of enhancement of neural cell growth rate (we chose Rat B-35 neuroblastoma cells) on ion implanted polymer textile. The results of both investigations were positive, with implantation-generated antibacterial efficiency factor up to about 90%, fully comparable to alternative conventional (non-implantation) approaches and with some potentially important advantages over the conventional approach; and with enhancement of neural cell growth rate of up to a factor of 3.5 when grown on suitably implanted polymer textile material.

  9. The Study of Complex (Ti, Zr, Cs) Nanopowder Influencing the Effective Ionization Potential of Arc Discharge When Mma Welding

    Science.gov (United States)

    Sapozhkov, S. B.; Burakova, E. M.

    2016-08-01

    Strength is one of the most important characteristics of a weld joint. Mechanical properties of a weld metal can be improved in a variety of ways. One of the possibilities is to add a nanopowder to the weld metal. Authors of the paper suggest changing the production process of MMA welding electrodes via adding nanopowder Ti, Zr, Cs to electrode components through liquid glass. Theoretical research into the nanopowder influence on the effective ionization potential (Ueff) of welding arc discharge is also necessitated. These measures support arcing stability, improve strength of a weld joint, as the consequence, ensure quality enhancing of a weld joint and the structure on the whole.

  10. Influence of the vacuum-arc source configuration and arc discharge parameters on the evolution and location of arc spots on the cathode surface

    OpenAIRE

    J. Walkowicz; J. Smolik; Z. Słomka; B. Kułakowska-Pawlak; W. Żyrnicki

    2009-01-01

    Purpose: The paper presents investigations of the evolution, structure and location of arc spots on the cathode frontal surfaces of two types of industrial arc sources.Design/methodology/approach: The temporal behaviour of cathode spots was recorded with the use of a fast CCD camera. The experiments were performed at four values of arc current, nine compositions of the process atmosphere N2+C2H2 and three pressure ranges of the process atmosphere.Findings: The analysis of the recorded picture...

  11. Analysing bifurcations encountered in numerical modelling of current transfer to cathodes of dc glow and arc discharges

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, P G C; Benilov, M S; Cunha, M D; Faria, M J [Departamento de Fisica, Universidade da Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2009-10-07

    Bifurcations and/or their consequences are frequently encountered in numerical modelling of current transfer to cathodes of gas discharges, also in apparently simple situations, and a failure to recognize and properly analyse a bifurcation may create difficulties in the modelling and hinder the understanding of numerical results and the underlying physics. This work is concerned with analysis of bifurcations that have been encountered in the modelling of steady-state current transfer to cathodes of glow and arc discharges. All basic types of steady-state bifurcations (fold, transcritical, pitchfork) have been identified and analysed. The analysis provides explanations to many results obtained in numerical modelling. In particular, it is shown that dramatic changes in patterns of current transfer to cathodes of both glow and arc discharges, described by numerical modelling, occur through perturbed transcritical bifurcations of first- and second-order contact. The analysis elucidates the reason why the mode of glow discharge associated with the falling section of the current-voltage characteristic in the solution of von Engel and Steenbeck seems not to appear in 2D numerical modelling and the subnormal and normal modes appear instead. A similar effect has been identified in numerical modelling of arc cathodes and explained.

  12. Analysis of biogenic amines using corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Hashemian, Z; Mardihallaj, A; Khayamian, T

    2010-05-15

    A new method based on corona discharge ion mobility spectrometry (CD-IMS) was developed for the analysis of biogenic amines including spermidine, spermine, putrescine, and cadaverine. The ion mobility spectra of the compounds were obtained with and without n-Nonylamine used as the reagent gas. The high proton affinity of n-Nonylamine prevented ion formation from compounds with a proton affinity lower than that of n-Nonylamine and, therefore, enhanced its selectivity. It was also realized that the ion mobility spectrum of n-Nonylamine varied with its concentration. A sample injection port of a gas chromatograph was modified and used as the sample introduction system into the CD-IMS. The detection limits, dynamic ranges, and analytical parameters of the compounds with and without using the reagent gas were obtained. The detection limits and dynamic ranges of the compounds were about 2ng and 2 orders of magnitude, respectively. The wide dynamic range of CD-IMS originates from the high current of the corona discharge. The results revealed the high capability of the CD-IMS for the analysis of biogenic amines. PMID:20298897

  13. The evolution of ion charge states in cathodic vacuum arc plasmas: a review

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2011-12-18

    Cathodic vacuum arc plasmas are known to contain multiply charged ions. 20 years after “Pressure Ionization: its role in metal vapour vacuum arc plasmas and ion sources” appeared in vol. 1 of Plasma Sources Science and Technology, it is a great opportunity to re-visit the issue of pressure ionization, a non-ideal plasma effect, and put it in perspective to the many other factors that influence observable charge state distributions, such as the role of the cathode material, the path in the density-temperature phase diagram, the “noise” in vacuum arc plasma as described by a fractal model approach, the effects of external magnetic fields and charge exchange collisions with neutrals. A much more complex image of the vacuum arc plasma emerges putting decades of experimentation and modeling in perspective.

  14. Scaled Tests and Simulation of Triboelectric Charging and Arc Discharge in an Expanding Dust Plume

    Science.gov (United States)

    Sears, J.; Kuhl, A.; Grote, D.; Converse, M.; Kueny, C.; Larson, D.; Poole, B.; Schmidt, A.; Rose, D. V.; Kirkendall, B.

    2015-12-01

    The arc breakdown commonly generated in volcanic eruptions is reproduced in field experiments of rapidly expanding dust clouds driven by explosive charges. The controlled format also conveniently allows us to vary particulate content and velocities and to precisely instrument the event with radiofrequency, optical and spectral sensors. We observe electrical discharges during the turbulent phase of the cloud expansion, which we use as benchmarks to validate a multiphase 3D simulation. The simulation computes electrostatic potentials by considering the hydrodynamics, chemical kinetics and charge transport for a distribution of particle sizes entrained in the expanding gas cloud. A separate hybrid fluid/kinetic plasma code is employed to simulate the avalanche breakdown between charge pockets. Finally the propagation of radiated fields through regions of strongly dispersive partially ionized gas are computed in an electromagnetic finite element solver. Insight from the model validation may help us better understand the connection between plume dynamics and volcanic lightning. Prepared by LLNL under Contract DE-AC52-07NA27344.

  15. Structures and properties of Fe-C fine particles prepared by AC arc discharge

    Science.gov (United States)

    Li, Jian; Liu, Cunye; Zhao, Baogang; Lin, Yaoqiang; Deng, Zhaojing

    1999-05-01

    Fe-C fine particles are produced by an alternating arc discharge between iron and carbon electrodes in an Ar gas atmosphere at pressures of 8, 14 and 18 kPa. The crystal structure, morphology and surface composition have been studied, respectively, by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and X-ray photoelectron spectroscopy. Magnetic properties and Curie temperatures have also been determined by a vibrating sample magnetometer. Results show that the particles are of two different crystal structures, one is hexagonal FeC and the other is cubic iron. The iron particles have a multi-layered structure composed of an α-Fe core wrapped by Fe 3O 4, FeO and FeO(OH) shells. It is found that the compositions and the specific saturation magnetization of the Fe-C particles prepared in different pressures of Ar gas are not the same, but their Curie temperatures are all 580±5°C.

  16. Nitrogen dioxide formation in the gliding arc discharge-assisted decomposition of volatile organic compounds

    International Nuclear Information System (INIS)

    To apply gliding arc discharge (GAD) plasma processing to volatile organic compounds (VOCs) emission control, the formation of NO2 as an undesired byproduct needs to be addressed. Comparative results of effluent temperature and product concentrations between experiment and thermodynamic equilibrium calculation show that the NO2 formation in dry air GAD is totally out of thermodynamic equilibrium. Meanwhile, obvious NO (A2Σ+) and N2+ (B2Σu+) are detected as the major reactive species in the dry air GAD plasma region. These results suggest that the thermal (or Zeldovich) NOx formation mechanism is not significant in GAD system, while the energy level and the density of electrons in the plasma region will severely influence the NO2 formation. The presence of 500 ppm VOCs in the feed gases shows a limiting influence on the NO2 formation, which is in the order of aromatic hydrocarbon (C6H6 and C7H8) > straight-chain hydrocarbon (C4H10 and C6H14) > halogenated hydrocarbon (CCl4). The influences of VOCs chemical structure, supply voltage, feed gas humidity, and reactor geometry on NO2 formation are investigated, and the results correspond to above mechanism analysis. Based on the above, the possible pathways of the inhibition of NO2 formation in GAD-assisted VOCs decomposition process are discussed.

  17. Electroless nickel plating of arc discharge synthesized carbon nanotubes for metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Jagannatham, M.; Sankaran, S.; Prathap, Haridoss, E-mail: prathap@iitm.ac.in

    2015-01-01

    Highlights: • Electroless Ni coatings have been performed on CNTs for various deposition times. • The deposition of nickel increased with increase in deposition time. • A deposition time of 60 min has been optimum for uniform coating of Ni on CNTs. • The CNTs with uniform coating of Ni are potential for reinforcements in composites. • Electroless nickel coatings are determined to be super paramagnetic behavior. - Abstract: Electroless nickel (EN) plating was performed on arc discharge synthesized multiwalled carbon nanotubes for various deposition times. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Raman spectroscopy characterization techniques are used to identify the presence of nickel deposition on the carbon nanotubes (CNTs) and the degree of graphitization. The results indicate that impurities are less in the purified CNTs as compared to raw carbon soot. Increasing deposition time up to 60 min increases uniform deposition of nickel throughout the length of the CNTs. However, for deposition time longer than 60 min, nickel particles are seen separated from the surface of the CNTs. Uniformly coated nickel CNTs throughout their length are potential candidates for reinforcements in composite materials. Magnetic properties of the nickel coated CNTs, with deposition time of 30 and 60 min were also evaluated. The magnetic saturation of nickel coated CNTs with deposition time of 30 min is less compared to nickel coated CNTs with deposition time of 60 min.

  18. Quantitative evaluation of fiber fuse initiation with exposure to arc discharge provided by a fusion splicer

    Science.gov (United States)

    Todoroki, Shin-Ichi

    2016-05-01

    The optical communication industry and power-over-fiber applications face a dilemma as a result of the expanding demand of light power delivery and the potential risks of high-power light manipulation including the fiber fuse phenomenon, a continuous destruction of the fiber core pumped by the propagating light and triggered by a heat-induced strong absorption of silica glass. However, we have limited knowledge on its initiation process in the viewpoint of energy flow in the reactive area. Therefore, the conditions required for a fiber fuse initiation in standard single-mode fibers were determined quantitatively, namely the power of a 1480 nm fiber laser and the arc discharge intensity provided by a fusion splicer for one second as an outer heat source. Systematic investigation on the energy flow balance between these energy sources revealed that the initiation process consists of two steps; the generation of a precursor at the heated spot and the transition to a stable fiber fuse. The latter step needs a certain degree of heat accumulation at the core where waveguide deformation is ongoing competitively. This method is useful for comparing the tolerance to fiber fuse initiation among various fibers with a fixed energy amount that was not noticed before.

  19. Sintering of high alumina translucent ARC-discharge tubes for HPSV-lamps

    International Nuclear Information System (INIS)

    One of the most representative success in the field of sintering in the already passed 20 century was the achievement of translucent high-alumina (99.9 % Al2O3) which is really a synthetic sapphire. The difficulties to obtain by sintering such very refractory, hard and non-plastic material were doubled by the necessity to work it in the form of relative long but very thin (0.7...0.8 mm) tubes as necessary for the electric-arc discharge tubes of the high pressure sodium vapor lamps for public lighting. The paper is dealing with some complex influences of the main technological parameters, as quality of initials powders, peculiar consolidation procedures, high temperature sintering. Aspects concerning sealing materials and methods for assembling the tubes with other components of the HPSV-lamps are also referred. It is mentioned the high consolidation degree (99.9 %) obtained starting from colloidal powders, also the remarkable maintenance of form in reaching the final predicted dimensions, in spite of the high contraction during technology. (author)

  20. Quantitative evaluation of fiber fuse initiation with exposure to arc discharge provided by a fusion splicer.

    Science.gov (United States)

    Todoroki, Shin-Ichi

    2016-01-01

    The optical communication industry and power-over-fiber applications face a dilemma as a result of the expanding demand of light power delivery and the potential risks of high-power light manipulation including the fiber fuse phenomenon, a continuous destruction of the fiber core pumped by the propagating light and triggered by a heat-induced strong absorption of silica glass. However, we have limited knowledge on its initiation process in the viewpoint of energy flow in the reactive area. Therefore, the conditions required for a fiber fuse initiation in standard single-mode fibers were determined quantitatively, namely the power of a 1480 nm fiber laser and the arc discharge intensity provided by a fusion splicer for one second as an outer heat source. Systematic investigation on the energy flow balance between these energy sources revealed that the initiation process consists of two steps; the generation of a precursor at the heated spot and the transition to a stable fiber fuse. The latter step needs a certain degree of heat accumulation at the core where waveguide deformation is ongoing competitively. This method is useful for comparing the tolerance to fiber fuse initiation among various fibers with a fixed energy amount that was not noticed before. PMID:27140935

  1. Substrate temperature influence on W/WCN{sub x} bilayers grown by pulsed vacuum arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Ospina, R.; Escobar, D. [Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia); Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia); Arango, P.J.; Jurado, J.F. [Universidad Nacional de Colombia Sede Manizales, Km. 9 via al Magdalena, Manizales (Colombia)

    2012-04-01

    W/WCN{sub x} coatings were produced by using a repetitive pulsed vacuum arc discharge on stainless-steel 304 substrates, varying the substrate temperature from room temperature to 200 Degree-Sign C. Energy dispersive spectroscopy (EDS) was used for determining W, C and N concentrations dependence on the substrate temperature. A competition between C and N can be observed. Atomic force microscopy was employed for obtaining the thickness and grain size that present similar tendencies as a function of the temperature. X-ray diffraction characterization showed phases of W and {alpha}-WCN (hexagonal). Raman spectra for all substrate temperatures were obtained, presenting two peaks corresponding to D (disorder) and G (graphite) bands in the region of 1100-1700 cm{sup -1} due to the amorphous carbon. As an important conclusion, it was stated that substrate temperature has strong influence on the structure, chemical composition and morphology of W/WCN{sub x} bilayers, caused by the competition between carbon and nitrogen.

  2. Vortex focusing of ions produced in corona discharge.

    Science.gov (United States)

    Kolomiets, Yuri N; Pervukhin, Viktor V

    2013-06-15

    Completeness of the ion transportation into an analytical path defines the efficiency of ionization analysis techniques. This is of particular importance for atmospheric pressure ionization sources like corona discharge, electrospray, ionization with radioactive ((3)H, (63)Ni) isotopes that produce nonuniform spatial distribution of sample ions. The available methods of sample ion focusing are either efficient at reduced pressure (~1Torr) or feature high sample losses. This paper deals with experimental research into atmospheric pressure focusing of unipolar (positive) ions using a highly swirled air stream with a well-defined vortex core. Effects of electrical fields from corona needle and inlet capillary of mass spectrometer on collection efficiency is considered. We used a corona discharge to produce an ionized unipolar sample. It is shown experimentally that with an electrical field barrier efficient transportation and focusing of an ionized sample are possible only when a metal plate restricting the stream and provided with an opening covered with a grid is used. This gives a five-fold increase of the transportation efficiency. It is shown that the electric field barrier in the vortex sampling region reduces the efficiency of remote ionized sample transportation two times. The difference in the efficiency of light ion focusing observed may be explained by a high mobility and a significant effect of the electric field barrier upon them. It is possible to conclude based on the experimental data that the presence of the field barrier narrows considerably (more than by one and half) the region of the vortex sample ion focusing. PMID:23618173

  3. THE RAMAN SCATTERING OF CARBON NANOTUBES PRODUCED IN DIFFERENT INERT GASES AND THEIR PRESSURES BY ARC DISCHARGE

    Institute of Scientific and Technical Information of China (English)

    ZHANG HAI-YAN; CHEN JIAN; LIU SONG-HAO; CHEN DI-HU; WU CHUN-YAN; HE YAN-YANG; LIANG LI-ZHENG; PENG SHAO-QI

    2000-01-01

    First- and second-order Raman spectra of carbon nanotubes produced in helium and argon atmospheres at a pressure ranging from 11 to 92 kPa by arc discharge have been measured and compared with each other. The position and bandwidth of the spectral lines depend on the kind of inert gases and their pressure. The Raman spectra of the nanotubes produced in argon gas atmosphere are much more similar to that of polycrystalline graphite than those of the nanotubes produced in helium gas atmosphere. The position and bandwidth of nanotube Raman peaks change with gas pressure in arc discharge because different diameter distribution of nanotubes is produced at different inert gas pressure. The Raman spectra of nanotubes produced at high pressure is much more like that of graphite than those produced in lower pressure

  4. Influence of the temperature of electrode material on its disintegration under the action of an arc discharge in hydrogen

    Science.gov (United States)

    Bolotov, A. V.; Yukhimchuk, S. A.

    1985-01-01

    An analysis is made of the electrophysical processes occurring at the end surface of rod electrodes during constant and alternating arc discharge in hydrogen. Experiments are reported on the effect of surface temperature of tungsten electrodes on their erosion. The influence of activating additions of thorium oxide, the structure of the tungsten, and the gas surrounding the electrode on the specific thermal loading and the erosion of the electrodes is discussed.

  5. Formation of the high-intensity microsecond flow of electrons in the channel of high pressure arc discharge

    CERN Document Server

    Volkolupov, Yu Ya; Kolyada, Y E; Fedun, V I; Onishchenko, I N

    2000-01-01

    The possibility of microsecond duration powerful electron flows formation in the channel of high current arc discharge at atmosphere pressure has been experimentally demonstrated. The flow of electrons is formed at applying the high voltage pulse to the plasma source after plasma ejection and the pressure decreasing. Because the acceleration by the electric field prevails over the friction force due to collisions the conditions for arising of running electrons are fulfilled.

  6. Production of GW electron and ion beams by focused discharges

    International Nuclear Information System (INIS)

    This chapter attempts to determine how magnetized plasma structure and current distribution must vary with time in the pinch region to have a consistent picture. A method is presented to evaluate the total charge of a beam from a single discharge. Discusses the experimental system; an optimized mode of operation; ion beams; electron beams; the beam source; and plasmoid imaging by nuclear tracks in solids. The data support the existence of a fibrous structure for all stages of evolution of the current sheath (CS), from propagation in the interelectrodegap to axial-pinch collapse and at a later time when CS is fragmented

  7. Nonthermal Biological Treatments Using Discharge Plasma Produced by Pulsed Power 5. Inactivation of Cryptosporidium Oocysts by UV Emission Generated from Pulsed Arc Discharge in Water

    Science.gov (United States)

    Kunitomo, Shinta

    Cryptosporidium contaminates most surface waters around the world. It is difficult to remove through conventional treatment processes, and is extremely resistant to the method of chemical disinfection typically used to inactivate these microorganisms. We have developed a new technology for inactivating Cryptosporidium oocysts by using a pulsed arc discharge in water, which creates shock waves, UV emissions, and radicals. The pulsed arc is generated between two cylindrical stainless steel rod electrodes, 6 mm in diameter, and 2 mm apart. We applied this method to the inactivation of oocysts in backwash water from a sand-filter unit of a drinking water plant. The results indicate that the major factor influencing inactivation is UV emissions, and that more than 99% of the oocysts in the high turbidity backwash water (80 NTU) are inactivated with an energy of 0.24 kWh/m3.

  8. Effect of oxygen impurities on atmospheric-pressure surface streamer discharge in argon for large gap arc breakdown

    Science.gov (United States)

    Sharma, Ashish; Levko, Dmitry; Raja, Laxminarayan L.

    2016-10-01

    We report the results of a computational study that investigates the effect of impurities (molecular oxygen) on the development of argon surface streamers at atmospheric-pressure conditions. A continuous surface streamer has been proposed as a low-voltage mechanism to generate a conductive bridge for arc breakdown of a large interelectrode gap at high pressures. The streamer discharge model is based on the self-consistent, multispecies, continuum description of the plasma. Below a threshold voltage, no streamer discharge is observed and charge is localized only in the vicinity of the anode in the form of a localized corona. Above this voltage threshold in pure argon, a continuous conductive streamer successfully bridges the gap between two electrodes indicating high probability of transition to the arc. For small oxygen impurities (less than 5%), the threshold voltage is found to decrease by a few hundred volts compared to the threshold voltage in pure argon while the streamer induction time increases. No noticeable changes in the streamer conductivity is obtained for low impurities of oxygen in the above range. An increase of the oxygen density above the 5% impurity level causes a significant decrease in the continuous streamer conductivity and leads to a decrease in the probability of transition to arc.

  9. Effect of Background Ions on the Selection of the Discharge Path

    Institute of Scientific and Technical Information of China (English)

    HE Zheng-Hao; LI Jin

    2001-01-01

    The effects of the background ions on the selection of the discharge path in an air gap have been studied with two different methods. The lightning impulse air discharge experiment is conducted using an independent ion generator, while the air discharge experiment uses a lightning impulse superimposed on a dc high voltage used to produce background ions. The influence of different background ions on the leader development, and thus on the discharge path, is observed. Consistent results have been obtained with the two methods. The probability for the discharge path passing through the negative ion space is much higher than that for the passing through the positive ion space. The mechanism of the effects of background ions is analysed based on the eleetron avalanche and the electric field.

  10. Approach to modeling of the fast energy discharge in cryogenic systems in the form of an electric arc

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Superconducting magnets are supplied with a few kA of electric current and can store a large amount of energy. Therefore, cryogenic systems which are comprised of such magnets are subject to the risk of fast energy discharge from the magnets themselves in the form of an electric arc. The arcing can be a result of failure in the insulation of an electric circuit or in the connection between the magnet and its current lead. During the discharge, energy can be partially dissipated into the cryogen and partially into the cryogenic system metallic structure. The part of the energy that is transferred to the metallic structure will strongly heat up the metal surface, which can lead to material burning. In this case, the cryogen will flow through the perforation to the insulation vacuum space, which can trigger a rapid increase in pressure in the vacuum enclosure. However, the discharged energy that has been stored in the cryogen also causes a rapid increase in cryogenic pressure. Hence, the proper estimation of the...

  11. Chemistry of sprite discharges through ion-neutral reactions

    Science.gov (United States)

    Hiraki, Y.; Kasai, Y.; Fukunishi, H.

    2008-07-01

    We estimate the concentration changes, caused by streamer discharge in sprites, of ozone and related minor species as odd nitrogen (NOx) and hydrogen (HOx) families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head, where a large number of chemically-radical ions and atoms are produced through electron impact on neutral molecules. After its propagation, densities of minor species can be perturbed through ion-neutral chemical reactions initiated by the relaxation of these radical products. We evaluate the production rates of ions and atoms using an electron kinetics model and by assuming that the electric field and electron density are in the head region. We calculate the density variations mainly for NOx, Ox, and HOx species using a one-dimensional model of the neutral and ion composition of the middle atmosphere, including the effect of the sprite streamer. Results at the nighttime condition show that the densities of NO, O3, H, and OH increase suddenly through reactions triggered by the first atomic nitrogen and oxygen product, and electrons just after streamer initiation. It is shown that NO and NO2 still remain for 1 h by a certain order of increase with their source-sink balance, predominantly around 60 km; for other species, increases in O3, OH, HO2, and H2O2 still remain in the range of 40 70 km. From this affirmative result of long-time behavior previously not presented, we emphasize that sprites would have the power to impact local chemistry at night. We also discuss the consistency with previous theoretical and observational studies, along with future suggestions.

  12. Chemistry of sprite discharges through ion-neutral reactions

    Directory of Open Access Journals (Sweden)

    Y. Hiraki

    2008-07-01

    Full Text Available We estimate the concentration changes, caused by streamer discharge in sprites, of ozone and related minor species as odd nitrogen (NOx and hydrogen (HOx families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head, where a large number of chemically-radical ions and atoms are produced through electron impact on neutral molecules. After its propagation, densities of minor species can be perturbed through ion-neutral chemical reactions initiated by the relaxation of these radical products. We evaluate the production rates of ions and atoms using an electron kinetics model and by assuming that the electric field and electron density are in the head region. We calculate the density variations mainly for NOx, Ox, and HOx species using a one-dimensional model of the neutral and ion composition of the middle atmosphere, including the effect of the sprite streamer. Results at the nighttime condition show that the densities of NO, O3, H, and OH increase suddenly through reactions triggered by the first atomic nitrogen and oxygen product, and electrons just after streamer initiation. It is shown that NO and NO2 still remain for 1 h by a certain order of increase with their source-sink balance, predominantly around 60 km; for other species, increases in O3, OH, HO2, and H2O2 still remain in the range of 40–70 km. From this affirmative result of long-time behavior previously not presented, we emphasize that sprites would have the power to impact local chemistry at night. We also discuss the consistency with previous theoretical and observational studies, along with future suggestions.

  13. Fusion of heavy ions in advanced focused discharges

    International Nuclear Information System (INIS)

    Field distortion elements (FDEs) in the interelectrode gap of focused discharge machines with a peak current of ≥0.6 MA have been successfully used for increasing the current density in the pinch at the stage of maximum compression. A suitable FDE increases the neutron emission per shot, Yn, by a factor of ≥5 as compared with the value of Yn from DD fusion reactions in the same machine operating under identical conditions but without an FDE. The variations of the current distribution with and without an FDE (peak current density and current sheath width in the interelectrode gap) are monitored from magnetic probe signals and are of the order of 20%. With a doping by pressure of 2-8% of the filling gas of the discharge chamber with CD4 or N2 the reactions 12C(d,n)13N(β+) or 14N(d,n)15O(β+), of the order of ∼ 1% of the DD reactions in the same shot, are detected. The location and linear dimensions (n = AW02, A approx.= 1.3x108 neutrons/(kJ)2 (where W0 is the energy in kJ of the capacitor bank which feeds the discharge) for 5 kJ 0 n) are virtually eliminated. All reaction yields and ion energy spectrum data are consistent with the view that the bulk of the reactions occur in a multiplicity of localized regions with a density of >1020cm-3. (author). 14 refs, 2 figs

  14. Plasma-catalytic hybrid system using spouted bed with a gliding arc discharge: CH4 reforming as a model reaction

    Science.gov (United States)

    Lee, H.; Sekiguchi, H.

    2011-07-01

    A combination of a gliding arc discharge and a spouted catalytic bed was used to investigate a plasma-catalytic hybrid system using CH4 reforming as a model reaction. Alumina-supported catalysts that contained 0.5 wt% of Pt, Pd, Rh, and Ru (denoted as Pt/Al2O3, Pd/Al2O3, Rh/Al2O3 and Ru/Al2O3, respectively) were used. For comparison, active Al2O3 particles were also examined. The conversion of CH4 and the selectivity of the product were investigated by changing the feed flow rate and reaction time. The production of C2H2, H2 and soot was observed in the gliding arc discharge without a catalyst. Using Pt/Al2O3 and Pd/Al2O3with the gliding arc discharge, C2H4, C2H6 and C2H2 were produced. It is considered that C2H4 and C2H6 were formed by the hydrogenation of C2H2 on the active site of Pt/Al2O3 and Pd/Al2O3. A stronger resistance to deactivation was shown in the presence of Pd/Al2O3 than in the presence of Pt/Al2O3, whereas the selectivity of hydrocarbon using Rh/Al2O3 and Ru/Al2O3 showed a tendency similar to that in active Al2O3 and non-catalytic experiments. The proposed reactor has a potential to improve the selectivity of the plasma process.

  15. Influence of Jet Angle and Ion Density of Cathode Side on Low Current Vacuum Arc Characteristics

    Institute of Scientific and Technical Information of China (English)

    WANG Lijun; JIA Shenli; SHI Zongqian

    2008-01-01

    In this study, the influence of the initial jet angles (IJAs) and ion number densities (INDs) at the cathode side on the low current vacuum arc (LCVA) characteristics is simulated and analysed. The results show that the ion temperature, electron temperature, ion number density, axial current density and plasma pressure all decrease with the increase of the cathode IJAs. It is also shown that LCVA can cause a current constriction for lower cathode IND, and the anode sheath potential is more nonuniform, which is mainly related to the nonuniform distribution of the axial current density at the anode side.

  16. Measurement of the tungsten ion concentration after forced extinction of a vacuum arc

    International Nuclear Information System (INIS)

    The concentrations of singly ionized and neutral tungsten atoms were measured by laser-induced fluorescence after the forced extinction of vacuum arcs between tungsten-copper butt contacts, 28-mm in diam and 10-mm apart. The 50-Hz current was forced to zero at its maximum of 200 A in 1.3 μs by application of a reverse voltage. Near current zero, the ion concentration of 4 x 1017 m- 3 is of the same order of magnitude as the atomic tungsten concentration, which is 6 x 1017 m- 3. While the concentration of the neutrals remains virtually constant during 20 μs after current zero, the ion concentration decays by three orders of magnitude in the same time. The decay-time constant varies from 1.9 μs close to the post-arc cathode to 3.6 μs near the post-arc anode. It is concluded that the dielectric recovery of vacuum gaps after diffuse arcs is mainly controlled by residual charge carriers

  17. Axial ion charge state distribution in the vacuum arc plasma jet

    International Nuclear Information System (INIS)

    We report on our experimental studies of the ion charge state distribution (CSD) of vacuum arc plasmas using a time-of-flight diagnostic method. The dependence of the CSD on the axial distance from the plasma source region was measured for a titanium vacuum arc. It was found that the axial CSD profile is nonuniform. Generally, the mean charge state increases approximately linearly with axial distance from about 1.7 at 12 cm up to 1.9 at 25 cm from the plasma source. A model for ion transport in the free boundary plasma jet is proposed which is based on the existence of an electric field in the quasineutral plasma. This model qualitatively explains the experimental results. (c) 2000 American Institute of Physics

  18. Ion velocities in direct current arc plasma generated from compound cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhirkov, I.; Rosen, J. [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Eriksson, A. O. [Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden); Oerlikon Balzers Coating AG, Iramali 18, 9496 Balzers (Liechtenstein)

    2013-12-07

    Arc plasma from Ti-C, Ti-Al, and Ti-Si cathodes was characterized with respect to charge-state-resolved ion energy. The evaluated peak velocities of different ion species in plasma generated from a compound cathode were found to be equal and independent on ion mass. Therefore, measured difference in kinetic energies can be inferred from the difference in ion mass, with no dependence on ion charge state. The latter is consistent with previous work. These findings can be explained by plasma quasineutrality, ion acceleration by pressure gradients, and electron-ion coupling. Increasing the C concentration in Ti-C cathodes resulted in increasing average and peak ion energies for all ion species. This effect can be explained by the “cohesive energy rule,” where material and phases of higher cohesive energy generally result in increasing energies (velocities). This is also consistent with the here obtained peak velocities around 1.37, 1.42, and 1.55 (10{sup 4} m/s) for ions from Ti{sub 0.84}Al{sub 0.16}, Ti{sub 0.90}Si{sub 0.10}, and Ti{sub 0.90}C{sub 0.10} cathodes, respectively.

  19. Towards metals analysis using corona discharge ionization ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2016-02-25

    For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 μg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 μg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation. PMID:26851088

  20. Ion Exchange Resin and Clay Vitrification by Plasma Discharges

    Science.gov (United States)

    Díaz A., Laura V.; Pacheco S., Joel O.; Pacheco P., Marquidia; Monroy G., Fabiola; Emeterio H., Miguel; Ramos F., Fidel

    2006-12-01

    The lack of treatment of a low and intermediate level radioactive waste (LILRW) lead us to propose a vitrification process based on a plasma discharge; this technique incorporates LILRW into a matrix glass composed of ceramic clays material. The Mexican Institute of Nuclear Research (ININ), uses an ion exchange resin IRN 150 (styrene-divinilbence copolymer) in the TRIGA MARK III nuclear reactor. The principal objective of this resin is to absorb particles containing heavy metals and low-level radioactive particles. Once the IRN 150 resin filter capacity has been exceeded, it should be replaced and treated as LILRW. In this work, a transferred plasma system was realized to vitrify this resin taking advantage of its high power density, enthalpy and chemical reactivity as well as its rapid quenching and high operation temperatures. In order to characterize the morphological structure of these clay samples, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Thermogravimetric analysis (TGA) techniques were applied before and after the plasma treatment.

  1. Towards metals analysis using corona discharge ionization ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2016-02-25

    For the first time, the capability of corona discharge ionization ion mobility spectrometry (CD-IMS) in the determination of metal complex was evaluated. The extreme simplicity of dispersive liquid-liquid microextraction (DLLME) coupled to the high sensitivity of CD-IMS measurement could make this combination really useful for simple, rapid, and sensitive determination of metals in different samples. In this regard, mercury, as a model metal, was complexed with diethyldithiocarbamate (DEDTC), and then extracted into the carbon tetrachloride using DLLME. Some parameters affecting the extraction efficiency, including the type and volume of the extraction solvent, the type and volume of the disperser solvent, the concentration of the chelating agent, salt addition and, pH were exhaustively investigated. Under the optimized condition, the enrichment factor was obtained to be 142. The linear range of 0.035-10.0 μg mL(-1) with r(2) = 0.997 and the detection limit of 0.010 μg mL(-1) were obtained. The relative standard deviation values were calculated to be lower than 4% and 8% for intra-day and inter-day, respectively. Finally, the developed method was successfully applied for the extraction and determination of mercury in various real samples. The satisfactory results revealed the capability of the proposed method in trace analysis without tedious derivatization or hydride generation.

  2. Double plasma arc in a graphite tube - application of discharge atmospheres

    International Nuclear Information System (INIS)

    With a view to safety and economic efficiency element-specific limits are required for permissible impurities in reactor graphite. This leads to the necessity of developing suitable methods of analysis. Emission spectroscopy has proved to be a method of analysis featuring a high detection capability and offering the possibility of determining several elements simultaneously. A prolongation of the particle residence time in the plasma (and, thus, an increase in radiation intensity) was the objective when developing a novel spectrochemical source of excitation. The method uses two d.c. arcs burning in a horizontally arranged graphite tube. The double plasma arc in a graphite tube has proved to be an excellent source of excitation for the analysis of powder and solutions. (orig./IHOE)

  3. Alkali ion migration between stacked glass plates by corona discharge treatment

    Science.gov (United States)

    Kawaguchi, Keiga; Suzuki, Toshio; Ikeda, Hiroshi; Sakai, Daisuke; Funatsu, Shiro; Uraji, Keiichiro; Yamamoto, Kiyoshi; Harada, Kenji; Nishii, Junji

    2015-05-01

    Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

  4. QUALITY ASSESSMENT OF SF6 INSULATION AT WARU 150 KV GIS COMPARTMENT USING PARTIAL DISCHARGE ION MOBILITY SPECTROMETER

    Directory of Open Access Journals (Sweden)

    Yulistya Negara

    2009-05-01

    Full Text Available Almost all of modern gas insulated switchgears (GIS use sulphur hexafluoride (SF6 as insulation material. Therefore, GIS quality much or less depends on quality of its SF6. Failure however can arise within operation of SF6 GIS due to quality decline of SF6. Quality decline of SF6 in GIS can be recognized by existence of decomposition product of SF6, which may appear due to partial discharge, arc during switching, etc. Therefore quality control of SF6 insulation in GIS is necessary in order to prevent failure occurred due to SF6 quality decline. In this study, quality assessment of SF6 at Waru 150 kV SF6 GIS is done using equipment namely partial discharge ion mobility spectrometer.  This equipment assesses quality of SF6 based on ions mobility. Concentration of decomposition product is then obtained from ion mobility of gas analyzed. For all compartment tested of Waru 150 kV SF6 GIS, it was found that the largest concentration of decomposition product is between 1000-2000 ppmv. Generally, SF6 condition at Waru 150 kV SF6 GIS is normal based on CIGRE standard.

  5. Investigation on the Tribology of Co Implanted Stainless Steel Using Metal Vapor Vacuum Arc Ion Source

    Institute of Scientific and Technical Information of China (English)

    Junxia GUO; Xun CAI; Qiulong CHEN

    2004-01-01

    AISI 304 stainless steel was ion implanted with Co, and the tribological property on the surface of the stainless steel was investigated. The Co ion implantation was carried out using a metal vapor vacuum arc (Mevva) broad-beam ion source with an extraction voltage of 40 kV, implantation doses of 3×1017/cm2 and 5×1017/cm2, and ion current densities of 13, 22 and 32 μA/cm2. The results showed that the near-surface hardness of Co-implanted stainless steel sample was increased by 50% or more, and it increased with increasing ion current density at first and then declined. The friction coefficient decreased from 0.74 to 0.20 after Co implantation. The wear rate after Co implantation reduced by 25% or more as compared to the unimplanted sample. The wear rate initially decreased with increasing ion current density and then an increase was observed. Within the range of experimental parameters, there exists a critical ion current density for the Co-implanted stainless steel, at which the wear rate decreased with increasing retained dose, going through a minimum and then increased. The critical ion current density in this paper is about 22 μA/cm2.

  6. Characterization of ion emission of an extreme ultraviolet generating discharge produced Sn plasma

    NARCIS (Netherlands)

    Gielissen, K.; Sidelnikov, Y.; Glushkov, D.; Soer, W.A.; Banine V.Y.; Van der Mullen, J.

    2010-01-01

    The ion emission of a Sn-based discharge produced extreme ultraviolet producing plasma is characterized with the combined use of different time-of-flight techniques. An electrostatic ion spectrometer isemployed to measure the average charge distribution of the emitted Sn ions. A dedicated Faraday

  7. Structural and magnetic properties of Fe3O4 nanoparticles prepared by arc-discharge in water

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    By using a simple and low-cost arc-discharge method in deionized water, high purity Fe3O4 nanoparticles have been synthesized on large scale. The structure of these nanoparticles has been studied by means of transmission electron microscope and X-ray diffraction. The synthesized Fe3O4 nanoparticles show well-defined spherical shape, with diameters ranging from 10 to 30 nm and the average diameter about 20 nm. By investigating the effects of the different processing conditions, optimum parameters were obtained. Moreover, the size of the as-grown nanoparticles can also be controlled through adjusting the processing parameters. These Fe3O4 nanoparticles were magnetic materials, showing saturation magnetization of 64.97 emu/g at room temperature.

  8. Calculation of net emission coefficient of electrical discharge machining arc plasmas in mixtures of nitrogen with graphite, copper and tungsten

    Science.gov (United States)

    Adineh, V. R.; Coufal, O.; Bartlova, M.

    2015-10-01

    This work reports theoretical calculations of electrical discharge machining (EDM) radiative properties for mixture systems of N2-C, N2-Cu and N2-W arc plasmas, in the temperature range of 3000-10 000 K, and at 1 and 10 bar pressures. Radiative properties are computed for various plasma sizes as well as vapour proportions. Calculations consider line overlapping with spectrum coverage from 30 to 10 000 nm. Doppler, Natural, Van-der-Waals, Resonance and Stark broadening are taken into account as the line broadening mechanisms. Besides, continuum calculations consider bound-free and free-free emissions along with molecular bands radiation for selected molecular systems. Results show that contamination vapours of EDM electrode have strong influence on the amount of EDM plasma radiation to the surrounding environment. However, comparison of impurities from workpiece with electrode one indicates that Fe vapour has stronger impact on modifying the EDM arc plasma radiative properties, compared to the C, Cu and W species studied in this research.

  9. Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gu-Ling; YANG Si-Ze; WANG Jiu-Li; WU Xing-Fang; FENG Wen-Ran; CHEN Guang-Liang; GU Wei-Chao; NIU Er-Wu; FAN Song-Hua; LIU Chi-Zi

    2006-01-01

    @@ A new method named the magnetic glow-arc plasma source ion implantation (MCA-PSⅡ) is proposed for inner surface modification of tubes. In MGA-PSⅡ, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90mm and length 600mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.

  10. Inner Surface Modification of a Tube by Magnetic Glow-Arc Plasma Source Ion Implantation

    Science.gov (United States)

    Zhang, Gu-Ling; Wang, Jiu-Li; Wu, Xing-Fang; Feng, Wen-Ran; Chen, Guang-Liang; Gu, Wei-Chao; Niu, Er-Wu; Fan, Song-Hua; Liu, Chi-Zi; Yang, Si-Ze

    2006-05-01

    A new method named the magnetic glow-arc plasma source ion implantation (MGA-PSII) is proposed for inner surface modification of tubes. In MGA-PSII, under the control of an axial magnetic field, which is generated by an electric coil around the tube sample, glow arc plasma moves spirally into the tube from its two ends. A negative voltage applied on the tube realized its inner surface implantation. Titanium nitride (TiN) films are prepared on the inner surface of a stainless steel tube in diameter 90 mm and length 600 mm. Hardness tests show that the hardness at the tube centre is up to 20 GPa. XRD, XPS and AES analyses demonstrate that good quality of TiN films can be achieved.

  11. Synthesis of (B-C-N) Nanomaterials by Arc Discharge Using Heterogeneous Anodes

    Institute of Scientific and Technical Information of China (English)

    Djamel Eddine GOURARI; Manitra RAZAFINIMANANA; Marc MONTHIOUX; Raul ARENAL; Flavien VALENSI; Sébastien JOULIE; Virginie SERIN

    2016-01-01

    In spite of the current prevalence of the CVD-based processes,the electric arc remains an interesting process for the synthesis of carbon nanoforms,thanks to its versatility,robustness and easiness.It also allows performing in-situ substitution of carbon atoms by hetero-elements in the graphene lattice.Our work aims to establish a correlation between the plasma properties,type and chemical composition (and the substitution rate) of the obtained single-wall carbon nanotubes.The plasma was characterized by optical emission spectroscopy and the products were analyzed by high resolution transmission electron microscopy and core level Electron Energy-Loss Spectroscopy (EELS).Results show that a high boron content leads to a plasma temperature decrease and hinders the formation of nanotubes.This effect can be compensated by increasing the arc current and/or yttrium content.The optimal conditions for the synthesis of boron-and/or nitrogen-substituted nanotubes correspond to a high axial plasma temperature associated to a strong radial gradient.EELS analysis confirmed that the boron incorporates into the graphenic lattice.

  12. Synthesis of (B-C-N) Nanomaterials by Arc Discharge Using Heterogeneous Anodes

    Science.gov (United States)

    Djamel Eddine, Gourari; Manitra, Razafinimanana; Marc, Monthioux; Raul, Arenal; Flavien, Valensi; Sébastien, Joulie; Virginie, Serin

    2016-05-01

    In spite of the current prevalence of the CVD-based processes, the electric arc remains an interesting process for the synthesis of carbon nanoforms, thanks to its versatility, robustness and easiness. It also allows performing in-situ substitution of carbon atoms by hetero-elements in the graphene lattice. Our work aims to establish a correlation between the plasma properties, type and chemical composition (and the substitution rate) of the obtained single-wall carbon nanotubes. The plasma was characterized by optical emission spectroscopy and the products were analyzed by high resolution transmission electron microscopy and core level Electron Energy-Loss Spectroscopy (EELS). Results show that a high boron content leads to a plasma temperature decrease and hinders the formation of nanotubes. This effect can be compensated by increasing the arc current and/or yttrium content. The optimal conditions for the synthesis of boron- and/or nitrogen-substituted nanotubes correspond to a high axial plasma temperature associated to a strong radial gradient. EELS analysis confirmed that the boron incorporates into the graphenic lattice.

  13. Ion distribution effects of turbulence on a kinetic auroral arc model

    Science.gov (United States)

    Cornwall, J. M.; Chiu, Y. T.

    1982-03-01

    An inverted-V auroral arc structure plasma-kinetic model is extended to phenomenologically include the effects of electrostatic turbulence, with k-parallel/k-perpendicular being much less than unity. It is shown that, unless plasma sheet ions are very much more energetic than the electrons, anomalous resistivity is not a large contributor to parallel electrostatic potential drops, since the support of the observed potential drop requires a greater dissipation of energy than can be provided by the plasma sheet. Wave turbulence can, however, be present, with the ion cyclotron turbulence levels suggested by the ion resonance broadening saturation mechanism of Dum and Dupree (1970) being comparable to those observed on auroral field lines. The diffusion coefficient and net growth rate are much smaller than estimates based solely on local plasma properties.

  14. Ion distribution effects of turbulence on a kinetic auroral arc model

    Science.gov (United States)

    Cornwall, J. M.; Chiu, Y. T.

    1982-01-01

    An inverted-V auroral arc structure plasma-kinetic model is extended to phenomenologically include the effects of electrostatic turbulence, with k-parallel/k-perpendicular being much less than unity. It is shown that, unless plasma sheet ions are very much more energetic than the electrons, anomalous resistivity is not a large contributor to parallel electrostatic potential drops, since the support of the observed potential drop requires a greater dissipation of energy than can be provided by the plasma sheet. Wave turbulence can, however, be present, with the ion cyclotron turbulence levels suggested by the ion resonance broadening saturation mechanism of Dum and Dupree (1970) being comparable to those observed on auroral field lines. The diffusion coefficient and net growth rate are much smaller than estimates based solely on local plasma properties.

  15. Initial operation of the CW 8X H- ion source discharge

    International Nuclear Information System (INIS)

    A pulsed 8Χ source was built and the H- beam current, emittance, and power efficiency were measured. These results were promising, so a cooled, dc version designed for operation at arc power levels up to 30 kW was built. Testing of the CW 8Χ source discharge is underway. The design dc power loading on the cathode surface is 900 W/cm2, considerably higher than achieved in any pervious Penning surface-plasma source (SPS). Thus, the electrode surfaces are cooled with pressurized, hot water. We describe the source and present the initial operating experience and arc test results

  16. 基于通道型光电倍增管的电弧放电检测%Arc Discharge Detection Based on Channel Photomultipliers

    Institute of Scientific and Technical Information of China (English)

    何宁; 梁坡; 于胜云

    2011-01-01

    According to the influence of arc discharge on safe operation of electrical equipment caused by quality defects or poor contact, the mechanism and detection methods of arc were analyzed. According to the characteristics of UV intensity radiation, an arc detecting system based on channel photomultipliers was designed. The captured arc discharge intensity was monitored, as a judgment basis of arc discharge degree, to realize the protection and control of electrical equipments effectively. The results show that the system can detect weak UV light with high sensitivity and linearity, and achieve the on-line monitoring of weak UV light detection.%针对电气设备接触不良或质量缺陷引起的电弧放电现象对用电设备安全运行的影响,本文分析了电弧的产生机理及检测方法.依据紫外光强辐射特点,设计了基于通道型光电倍增管的检测系统.通过实验,对放电弧光进行捕获,作为判断电弧放电程度依据,实现对电气设备的有效保护和控制.实验表明,该系统灵敏度高,线性度好,能实现微弱紫外光探测在线监测.

  17. A gapless micro-dielectric-barrier-discharge ion source for analytical applications

    CERN Document Server

    Coy, Stephen L; Eiceman, Gary A; Kanik, Isik

    2016-01-01

    Use of dielectric barrier discharge (DBD) as an ion source for sensitive chemical analysis is uncommon because barrier discharges generate excess noise due to spatial and temporal instability. This design uses contacted, crossed glass-coated micro-wires to focus the field into a gradually vanishing gap, suppressing spatial and temporal variability, reducing pressure, temperature, and humidity effects, stabilizing discharge initiation and limiting chemical fragmentation. Positive-ion-mode proton transfer, chemical fragmentation from a micro-discharge, and NO+ adducts combine to allow broad chemical sensitivity. We analyze noise properties of the ion source and report chemical responsivity for a wide range of volatile organic compounds. Source noise spectral density is compared for three systems: the contacted coated wires source, a gapped dielectric barrier discharge source, and a 5 mCi Ni-63 radioactive source. The crossed-wires source shows noise properties approaching those of the white-noise Ni-63 source, ...

  18. Direct determination of trace amounts of acetic acid using a novel ambient glow discharge ion source

    Institute of Scientific and Technical Information of China (English)

    Xiao Hao Wang; Kun Liu; Fei Tang; Jiu Ming He; Xue Ye Wei; Zeper Abliz

    2010-01-01

    A novel ambient glow discharge ion source with improved line-cylinder electrodes is put forward and designed in this paper.The diameters of inner and outer electrodes are 0.16 and 4 mm respectively.With a special assembly method,a perfect coaxiality of the two electrodes is obtained.From the gas discharge experiment,it can be seen that the discharge can stably work in normal glow discharge mode.The operating currents of the ion source are in an order of milliamperes and can generate a much larger number and wider variety of reagent ions.The MS experiment shows that the ion source has higher detection sensitivity.

  19. Operating modes of a hydrogen ion source based on a hollow-cathode pulsed Penning discharge

    Energy Technology Data Exchange (ETDEWEB)

    Oks, E. M. [Institute of High Current Electronics, Siberian Branch of Russian Academy of Science, Tomsk (Russian Federation); Tomsk State University of Control System and Radioelectronics, Tomsk (Russian Federation); Shandrikov, M. V., E-mail: shandrikov@opee.hcei.tsc.ru; Vizir, A. V. [Institute of High Current Electronics, Siberian Branch of Russian Academy of Science, Tomsk (Russian Federation)

    2016-02-15

    An ion source based on a hollow-cathode Penning discharge was switched to a high-current pulsed mode (tens of amperes and tens of microseconds) to produce an intense hydrogen ion beam. With molecular hydrogen (H{sub 2}), the ion beam contained three species: H{sup +}, H{sub 2}{sup +}, and H{sub 3}{sup +}. For all experimental conditions, the fraction of H{sub 2}{sup +} ions in the beam was about 10 ÷ 15% of the total ion beam current and varied little with ion source parameters. At the same time, the ratio of H{sup +} and H{sub 3}{sup +} depended strongly on the discharge current, particularly on its distribution in the gap between the hollow and planar cathodes. Increasing the discharge current increased the H{sup +} fraction in ion beam. The maximum fraction of H{sup +} reached 80% of the total ion beam current. Forced redistribution of the discharge current in the cathode gap for increasing the hollow cathode current could greatly increase the H{sub 3}{sup +} fraction in the beam. At optimum parameters, the fraction of H{sub 3}{sup +} ions reached 60% of the total ion beam current.

  20. Mechanisms for negative reactant ion formation in an atmospheric pressure corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Waltman, Melanie J.

    2009-06-02

    In an effort to better understand the formation of negative reactant ions in air produced by an atmospheric pressure corona discharge source, the neutral vapors generated by the corona were introduced in varying amounts into the ionization region of an ion mobility spectrometer/mass spectrometer containing a 63Ni ionization source. With no discharge gas the predominant ions were O2- , however, upon the introduction of low levels of discharge gas the NO2- ion quickly became the dominant species. As the amount of discharge gas increased the appearance of CO3- was observed followed by the appearance of NO3-. At very high levels, NO3- species became effectively the only ion present and appeared as two peaks in the IMS spectrum, NO3- and the NO3-•HNO3 adduct, with separate mobilities. Since explosive compounds typically ionize in the presence of negative reactant ions, the ionization of an explosive, RDX, was examined in order to investigate the ionization properties with these three primary ions. It was found that RDX forms a strong adduct with both NO2- and NO3- with reduced mobility values of 1.49 and 1.44 cm2V-1s-1, respectively. No adduct was observed for RDX with CO3- although this adduct has been observed with a corona discharge mass spectrometer. It is believed that this adduct, although formed, does not have a sufficiently long lifetime (greater than 10 ms) to be observed in an ion mobility spectrometer.

  1. Cavitation-erosion resistance of arc ion-plated (Ti, Cr) N coatings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The cavitation-erosion behavior of (Ti,Cr)N multi-component coatings produced by arcion-plating on grey cast iron was studied by using an ultrasonic cavitation -erosion testing appara-tus and scanning electron microscopy. The test results indicated that surface roughness of thesubstrate, surface morphology of the coating, substrate bias voltage and the thickness of the coat-ing had certain influence on the erosion rate. Arc ion-plated (Ti,Cr)N multi-component coatingsshowed better cavitation -erosion resistance than single component coatings because of highermicrohardness and good adhesion.

  2. Characterization of surface enhancement of carbon ion-implanted TiN coatings by metal vapor vacuum arc ion implantation

    CERN Document Server

    Chang, C L

    2002-01-01

    The modification of the surfaces of energetic carbon-implanted TiN films using metal vapor vacuum arc (MEVVA) ion implantation was investigated, by varying ion energy and dose. The microhardness, microstructure and chemical states of carbon, implanted on the surface layer of TiN films, were examined, as functions of ion energy and dose, by nanoindenter, transmission electron microscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Results revealed that the microhardness increased from 16.8 up to 25.3 GPa and the friction coefficient decreased to approximately 0.2, depending on the implanted ion energy and dose. The result is attributed to the new microcrystalline phases of TiCN and TiC formed, and carbon concentration saturation of the implanted matrix can enhance the partial mechanical property of TiN films after MEVVA treatment. The concentration distribution, implantation depth and chemical states of carbon-implanted TiN coatings depended strongly on the ion dose and...

  3. Influence of electrode material on measured ion kinetic-energy distributions in radio-frequency discharges

    International Nuclear Information System (INIS)

    The measurement of ion kinetic energies is important for understanding processes that occur in discharges, e.g., the influence of ions on the etching of semiconductor materials in plasma reactors. Direct measurements of ion kinetic energies striking surfaces exposed to the discharge requires sampling through an orifice in a surface. Difficulties with ion sampling through a small aperture, manifested by errors or distortions in measured ion kinetic-energy distributions (IEDs) have been encountered in previous investigations of both dc and radio-frequency (rf) discharges. The errors are usually most significant at relatively low ion energies. Previous measurements in our laboratory of IEDs for ions sampled through a 0.1-mm hole in a grounded, aluminum electrode for rf discharges in argon showed evidence of reduced detection efficiency (discrimination) for low energy ions (<10 eV), and apparent shifts in the measured ion energies for plasmas generated in other gases. It has been suggested that surface charging at or near the sampling orifice can cause both discrimination and energy shifts. The existence of an insulating, or partially insulating, layer of aluminum oxide on the surface of an electrode allows the possibility of surface-charge accumulation. In the present work, IEDs were measured at both aluminum and 304 stainless-steel grounded electrodes with 0.1 mm sampling orifices in rf plasmas generated in argon and oxygen

  4. Joule heat generation in thermionic cathodes of high-pressure arc discharges

    Energy Technology Data Exchange (ETDEWEB)

    Benilov, M. S.; Cunha, M. D. [Departamento de Fisica, CCCEE, Universidade da Madeira, Largo do Municipio, 9000 Funchal (Portugal)

    2013-02-14

    The nonlinear surface heating model of plasma-cathode interaction in high-pressure arcs is extended to take into account the Joule effect inside the cathode body. Calculation results are given for different modes of current transfer to tungsten cathodes of different configurations in argon plasmas of atmospheric or higher pressures. Special attention is paid to analysis of energy balances of the cathode and the near-cathode plasma layer. In all the cases, the variation of potential inside the cathode is much smaller than the near-cathode voltage drop. However, this variation can be comparable to the volt equivalent of the energy flux from the plasma to the cathode and then the Joule effect is essential. Such is the case of the diffuse and mixed modes on rod cathodes at high currents, where the Joule heating causes a dramatic change of thermal and electrical regimes of the cathode. The Joule heating has virtually no effect over characteristics of spots on rod and infinite planar cathodes.

  5. Stability of very-high pressure arc discharges against perturbations of the electron temperature

    Energy Technology Data Exchange (ETDEWEB)

    Benilov, M. S. [Departamento de Fisica, Ciencias Exactas e Engenharia, Universidade da Madeira, Largo do Municipio, Funchal 9000 (Portugal); Hechtfischer, U. [Philips Lighting, BU Automotive Lamps, Technology, Philipsstrasse 8, Aachen 52068 (Germany)

    2012-04-01

    We study the stability of the energy balance of the electron gas in very high-pressure plasmas against longitudinal perturbations, using a local dispersion analysis. After deriving a dispersion equation, we apply the model to a very high-pressure (100 bar) xenon plasma and find instability for electron temperatures, T{sub e}, in a window between 2400 K and 5500-7000 K x 10{sup 3} K, depending on the current density (10{sup 6}-10{sup 8} A/m{sup 2}). The instability can be traced back to the Joule heating of the electron gas being a growing function of T{sub e}, which is due to a rising dependence of the electron-atom collision frequency on T{sub e}. We then analyze the T{sub e} range occurring in very high-pressure xenon lamps and conclude that only the near-anode region exhibits T{sub e} sufficiently low for this instability to occur. Indeed, previous experiments have revealed that such lamps develop, under certain conditions, voltage oscillations accompanied by electromagnetic interference, and this instability has been pinned down to the plasma-anode interaction. A relation between the mechanisms of the considered instability and multiple anodic attachments of high-pressure arcs is discussed.

  6. discoloration of an azo dye Red Methyl by gas-liquid gliding arc discharge plasma of humid air

    International Nuclear Information System (INIS)

    This paper reports on using non-thermal plasma provided by an electric gliding discharge in humid air to the treatment of Red Methyl. The main advantage of this system is that reactive species like OH produced by the Glidarc can be used for the treatment of wastewater. Additive amount of ferrous ions and titanium oxide increase the discoloration rate. The degradation efficiency is around 97,8 pour cent. This implies that the majority molecules of Red Methyl are destroyed. The hydroxylation reaction of Red Methyl can then be treated as a kinetic pseudo-first order.

  7. Electrochemical Corrosion Characteristics of Arc-Ion-Plated AlTiN Coating for Marine Application.

    Science.gov (United States)

    Lee, Jung-Hyung; Kim, MyoungJun; Kim, Seong-Jong

    2016-02-01

    In this study, aluminum titanium nitride (AlTiN) coating was deposited by arc ion plating onto mirror finish STS 304 plate. The surface and cross-section of the coating was characterized by SEM and EDX analysis. Several electrochemical corrosion experiments were performed including rest potential measurement, potentiodynamic polarization experiment and Tafel analysis. The result of the experiments indicated that the AlTiN coating presented lower corrosion current density than the substrate material (STS 304) under uniform corrosion environment. It was also observed that AlTiN coating may have a risk of being attacked by localized corrosion attack such as pitting when pores or micro/nano particles in the coating are exposed to chloride ion containing corrosion environment, especially marine environment. PMID:27433658

  8. Plasma Ion Sources

    International Nuclear Information System (INIS)

    A wide variety of ion source types has been developed. Ion sources can provide beams of hundreds of amperes for fusion applications, nano-amperes for microprobe trace analysis and broad beams for ion implantation, space thrusters, industrial polymerisation and food sterilisation. Also it can be used in medical, military and accelerators applications. In this paper, three different types of plasma ion sources with different means for producing the discharge current and the ions extracting current from the plasma are studied. The various plasma described include, d.c glow discharge plasma, arc discharge plasma and radio frequency discharge plasma

  9. Ion charge state distributions of vacuum arc plasmas: The origin of species

    International Nuclear Information System (INIS)

    Vacuum arc plasmas are produced at micrometer-size, nonstationary cathode spots. Ion charge state distributions (CSD close-quote s) are experimentally known for 50 elements, but the theoretical understanding is unsatisfactory. In this paper, CSD close-quote s of vacuum arc plasmas are calculated under the assumption that the spot plasma experiences an instantaneous transition from equilibrium to nonequilibrium while expanding. Observable charge state distributions are the result of a freezing process at this transition. open-quotes Frozenclose quotes CSD close-quote s have been calculated using Saha equations in the Debye-Hueckel approximation of the nonideal plasma for all metals of the Periodic Table and for boron, carbon, silicon, and germanium. The results are presented in a open-quotes periodic table of CSD.close quotes The table contains also the mean ion charge state, the neutral vapor fraction, and the effective plasma temperature and density at the freezing point for each element. The validity of the concepts of open-quotes instantaneous freezingclose quotes and open-quotes effective temperature and densityclose quotes is discussed for low and high currents and for the presence of a magnetic field. Temperature fluctuations have been identified to cause broadening of CSD close-quote s. copyright 1997 The American Physical Society

  10. Alkali ion migration between stacked glass plates by corona discharge treatment

    International Nuclear Information System (INIS)

    Highlights: • Two stacked glass plates with a 1 mm gap were treated by corona discharge. • Spatial migration of alkali ion over the gap was demonstrated. • Hydrogen gas was necessary for uniform migration. • Surface modification was done with this process without high temperature or vacuum. - Abstract: Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates

  11. Alkali ion migration between stacked glass plates by corona discharge treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Keiga [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan); Suzuki, Toshio [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Ikeda, Hiroshi [Art, Science and Technology Center for Cooperative Research, Kyushu University, 6-1 Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Sakai, Daisuke [Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Funatsu, Shiro; Uraji, Keiichiro [Production Technology Center, Asahi Glass Co., Ltd., 1-1 Suehiro-cyo, Tsurumiku, Yokohama, Kanagawa 230-0045 (Japan); Yamamoto, Kiyoshi [Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku, Yokohama, Kanagawa 221-8755 (Japan); Harada, Kenji [Department of Computer Science, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507 (Japan); Nishii, Junji, E-mail: nishii@es.hokudai.ac.jp [Research Institute for Electronic Science, Hokkaido University, N20 W10, Kita-ku, Sapporo, Hokkaido 001-0020 (Japan)

    2015-05-30

    Highlights: • Two stacked glass plates with a 1 mm gap were treated by corona discharge. • Spatial migration of alkali ion over the gap was demonstrated. • Hydrogen gas was necessary for uniform migration. • Surface modification was done with this process without high temperature or vacuum. - Abstract: Corona discharge reflects the spatial migration of alkali ions over a gap between two glass plates. This study examined stacked glass plates containing different alkali ions treated with the corona discharge plasma generated by applied voltage of 4.5 kV at 200 °C. Protons generated at the anode electrode penetrate into the potassium-ion-containing upper glass plate, which is located 5 mm below the anode electrode. Potassium ions intruded into the lower glass plate containing sodium ions placed on the cathode electrode, even over a 1 mm gap separating the plates. Finally, the sodium ion discharged on the cathode electrode. The hydrogen atmosphere was effective at inhibiting the potassium ion reaction with ambient gases during the spatial migration between the two glass plates.

  12. Microprocessor-controlled electron impact ion source operated at constant discharge current and voltage

    International Nuclear Information System (INIS)

    An electron impact ion source using a solid charge was interfaced with A/D and D/A units which are connected to a microprocessor control unit. A PID (proportional, integral, and derivative) control algorithm was implemented to control the ion source. The power fed to the ion source filament and furnace filament are controlled so as to keep both the discharge voltage and current constant. With this controlled ion source, the result shows a steady ion current. For example, with Pb+ ions, an initial ion current of 13 μA stayed within +- 1.5 μA for 60 min; with no control, the ion current fell steadily and had to be manually reset three times every 20 min over a 60-min run. Similar results have been obtained with Mg+, Al+, Zn+, and Sn+ ions

  13. Ion-ion neutralization of iodine in radio-frequency inductive discharges of Xe and I2 mixtures

    International Nuclear Information System (INIS)

    Xe/I2 low-pressure electric discharges are being developed as efficient, long-lived ultraviolet lighting sources. In this work the kinetics of low pressure, 0.5 endash 5 Torr, radio-frequency inductively excited discharges sustained in Xe and I2 were investigated to determine the source of radiating states. The diagnostics applied in this study include optical absorption and emission spectroscopy, microwave interferometry, and microwave absorption. We found that in time modulated discharges, the emissions from excited states of atomic iodine decays with time constants of hundreds of microseconds. These observations are consistent with those states being populated by ion-ion neutralization. Electron-ion recombination leading to excited states appears not to be an important source of emission

  14. Positive corona discharge ion source with IMS/MS to detect impurities in high purity Nitrogen

    OpenAIRE

    Sabo, M.; Klas, M.; Wang, H.; Huang, C.; Chu, Y; Matejčík, Š.

    2011-01-01

    Abstract We have applied the Ion Mobility Spectrometry/Mass Spectrometry (IMS/MS) and the Atmospheric Pressure Chemical Ionisation/Mass Spectrometry (APCI/MS) techniques to study the formation of the ions in the positive corona discharge (CD) in highly purified nitrogen with impurities at 100 ppt level. The main products observed were H3O+(H2O)n ions (reduced ion mobility of 2.15 cm2?V-1?s-1). Additionally, we have observed ions with reduced mobilities 2.42 ...

  15. Microwave Discharge Ion Engines onboard Hayabusa Asteroid Explorer

    International Nuclear Information System (INIS)

    The Hayabusa spacecraft rendezvoused with the asteroid Itokawa in 2005 after the powered flight in the deep space by the μl0 cathode-less electron cyclotron resonance ion engines. Though the spacecraft was seriously damaged after the successful soft-landing and lift-off, the xenon cold gas jets from the ion engines rescued it. New attitude stabilization method using a single reaction wheel, the ion beam jets, and the photon pressure was established and enabled the homeward journey from April 2007 aiming the Earth return on 2010. The total accumulated operational time of the ion engines reaches 31,400 hours at the end of 2007. One of four thrusters achieved 13,400-hour space operation

  16. USE OF BATTERY CARBON AS ELECTRODES IN ARC DISCHARGE METHOD FOR FABRICATION OF CARBON-MODIFIED TIO2

    Directory of Open Access Journals (Sweden)

    Isya Fitria Andhika

    2016-09-01

    Full Text Available Fabrication with carbon-modified TiO2 by arc discharge method in liquid medium has been studied. This research was performed in two steps including fabrication and characterization. This fabrication was done by arcdischarge method with graphite electrodes from dry cell batteries and liquid medium suspension of TiO2 in ethanol 30, 50 and 70 %. A strong current was applied to electrode as 10 -50 A (20-40 V. Nanocomposites formed on the liquid medium surface were collected and characterized using X-ray diffraction (XRD,scanning electron microscope (SEM dan energy dispersive spectroscopy (EDS to determine crystallinity, surface morphology and the constituent elements, respectively. XRD data shows that the most effective fabrication TiO2/Karbon by liquid medium in ethanol 50 % indicated from the formation of a new peak with high intensity of TiC on 2Ɵ= 36.02 °. SEM data shows that the morphology of each aggregated TiO2/Karbon compared to the morphology of TiO2. In addition, EDS data shows the presence of the element carbon, titanium and oxygen in the same area indicating that the successful formation of composite material between TiO2 dan carbon.

  17. Kinetic-Energy Distributions of Positive and Negative Ions in DC Townsend Discharges of Carbon Dioxide

    Science.gov (United States)

    Rao, M. V. V. S.; van Brunt, R. J.; Olthoff, J. K.

    1997-10-01

    Ion kinetic-energy distributions (IEDs), mean energies, and relative abundances are measured for CO_2^+, CO^+, O_2^+, O^+, C^+, and O^- ions produced in dc Townsend discharges in pure carbon dioxide. The discharges are generated at electric field-to-gas density ratios (E/N) ranging from 3.5 x 10-18 Vm^2 to 20 x 10-18 Vm^2 (3.5 to 20 kTd). Ions sampled from the discharge through a small orifice in the center of the grounded electrode were energy and mass analyzed by an electrostatic energy analyzer attached to a quadrupole mass spectrometer.(M. V. V. S. Rao, R. J. Van Brunt, and J. K. Olthoff, Phys. Rev. E 54), 5641 (1996) In the present experiments, CO_2^+ was determined to be the dominant positive ion (greater than 85%) at all E/N. The IEDs of CO_2^+, O_2^+, and O^+ are Maxwellian at all E/N, with CO^+ exhibiting non-Maxwellian behavior above 10 kTd, and C^+ exhibiting non-Maxwellian behavior at all E/N. Negative ion fluxes were substantially lower than positive ion fluxes, with O^- being the only detectable negative ion. The IEDs for O^- are Maxwellian at 6 kTd and below. The fact that O^- is the only negative ion indicates that no asymmetric charge transfer exists for O^- in CO_2.

  18. Development of a short pulsed corona discharge ionization source for ion mobility spectrometry

    International Nuclear Information System (INIS)

    The development of a pulsed corona discharge ionization source and its use in ion mobility spectrometry (IMS) is presented. In a point-plane electrode geometry, an electrical pulse up to 12 kV, 150 ns rise time and 500 ns pulse width was used to generate a corona discharge in air. A single positive high voltage pulse was able to generate about 1.6x1010 ions at energy consumption of 22 μJ. Since the temporal distribution of ions is in a pulsed form, the possibility of removal the ion gate has been investigated. By purposely arranging the interface between discharge field and drift field, nearly 107 positive ions were drawn into the drift region with absence of the ion gate after every single discharge. The positive spectrum of acetone dimer (working at room temperature) was obtained with a resolving power of 20 by using this configuration. The advantages of this new scheme are the low power consumption compared with the dc method as well as the simplicity of the IMS cell structure

  19. Some novel design features of the LBL metal vapor vacuum arc ion sources

    International Nuclear Information System (INIS)

    The family of MEVVA (metal vapor vacuum arc) high current metal ion sources developed at LBL over the past several years has grown to include a number of different source versions with a wide range of some of the design and operational parameters. The MicroMEVVA source is a particularly compact version, about 2 cm diameter and 10 cm long, while the MEVVA IV weighs some 30 kG. MEVVAs IV and V incorporate multiple cathode assemblies (16 and 18 separate cathodes, respectively), and the operating cathode can be switched rapidly and without down-time. The new MEVVA V embodiment is quite compact considering its broad beam (10 cm), high voltage (100 kV) and multiple cathode features. The large-area extractor grids used in the MEVVA V were fabricated using a particularly simple technique, and they are clamped into position and so can be changed simply and quickly. The electrical system used to drive the arc is particularly simple and incorporates several attractive features. In this paper we review and describe a number of the mechanical and electrical design features that have been developed for these sources. 9 refs., 5 figs

  20. 激光-电弧复合焊接中激光脉冲对电弧正-负半波作用%Effect of Laser Pulse on Positive/negative Waveform of Arc Discharge during Laser-arc Welding

    Institute of Scientific and Technical Information of China (English)

    赵建智; 陈明华; 赵作福; 辛立军

    2016-01-01

    Coupling effect between laser and arc plasma was studied when laser acting at the positive and negative wave-form of the arc discharge during laser-arc hybrid welding of magnesium alloy. By the methods of direct observation, high speed imaging and spectral analysis, the surface status of weld seams after welding, the welding penetration depths, the plasma behav-iors and the spectral characteristics of welding plasma were investigated gradually. Results show that compared with the situa-tion of laser pulse acting at the negative waveform the arc plasma discharge, better weld seam formation can be achieved when laser pulse acts at the positive waveform of the arc discharge. At the same time, the radiation intensity of Mg atoms in arc plasma greatly increases, and however, the welding penetration depth is much weaker. After analysis, it is found that when laser pulse acting at the negative waveform the arc plasma discharge, the position of arc plasma discharge on workpiece can be restrained by the laser acting point, which improves the energy density of the welding arc.%本论文研究了激光-电弧复合热源焊接镁合金过程中激光脉冲作用于交流电弧放电的正、负半波时激光与电弧的耦合作用。本文采用直接观察焊缝表面状态、高速摄像和光谱分析相结合的方式,研究了激光脉冲分别作用于电弧正、负半波时焊缝的成型特点、熔化深度、等离子体行为以及光辐射特性。结果表明,激光脉冲作用于电弧放电正、负半波时,均能实现连续焊接,电弧体积均发生膨胀。相比于激光脉冲作用于电弧放电负半波,激光脉冲作用于正半波时的焊缝成型较好,电弧等离子体中镁原子辐射强度的增加程度较大,但焊接熔深较小。通过分析,发现激光脉冲作用于电弧放电负半波可以固定电弧在板材的放电位置,提高电弧的能量密度。

  1. Antibacterial TiO2Coating Incorporating Silver Nanoparticles by Micro arc Oxidation and Ion Implantation

    International Nuclear Information System (INIS)

    Infection associated with titanium implants remains the most common serious complication in hard tissue replacement surgery. Since such postoperative infections are usually difficult to cure, it is critical to find optimal strategies for preventing infections. In this study, TiO2 coating incorporating silver (Ag) nanoparticles were fabricated on pure titanium by micro arc oxidation and ion implantation. The antibacterial activity was evaluated by exposing the specimens to Staphylococcus aureus and comparing the reaction of the pathogens to Ti-MAO-Ag with Ti-MAO controls. Ti-MAO-Ag clearly inhibited bacterial colonization more than the control specimen. The coating’s antibacterial ability was enhanced by increasing the dose of silver ion implantation, and Ti-MAO-Ag 20.0 had the best antibacterial ability. In addition, cytocompatibility was assessed by culturing cell colonies on the specimens. The cells grew well on both specimens. These findings indicate that surface modification by means of this process combining MAO and silver ion implantation is useful in providing antibacterial activity and exhibits cytocompatibility with titanium implants

  2. Multi-layer Ti-based Coating Obtained by Arc PVD Method

    OpenAIRE

    Pavlov, Konstantin; Gorchakov, Konstantin; Gorchakova, Svetlana; Salojoki, Kari; Barchenko, Vladimir; Sokolov, Aleksandr

    2013-01-01

    We report the obtaining and primary studies of ~ 250microns thick multi-layer Ti-based protective coating deposited at high cooling rate from substance generated by cathode arc discharge in vacuum. High adhesion to steel substrate was attained through prior Arc plasma generator cleaning and successive Ion Bombardment method. All three arc-generated fractions including mainly droplet, vapour and ions have been utilised to form the coating. Obtained coating features pore-free, least defects and...

  3. Gliding Arc Discharge in the Potato Pathogen Erwinia carotovora subsp. atroseptica: Mechanism of Lethal Action and Effect on Membrane-Associated Molecules▿

    OpenAIRE

    Moreau, M; Feuilloley, M. G. J.; Veron, W.; Meylheuc, T.; Chevalier, S.; Brisset, J.-L.; Orange, N.

    2007-01-01

    Gliding arc (glidarc) discharge is a physicochemical technique for decontamination at atmospheric pressure and ambient temperature. It leads to the destruction of bacterial phytopathogens responsible for important losses in industrial agriculture, namely, Erwinia spp., without the formation of resistant forms. We investigated the effect of a novel optimized prototype allowing bacterial killing without lag time. This prototype also decreases the required duration of treatment by 50%. The study...

  4. Wear-resistance and anti-scuffing of multi-arc ion plating molybdenum films

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-dou; XU Bin-shi; LIU Jia-jun; ZHUANG Da-ming

    2004-01-01

    The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.

  5. Composition Control of Alloy Coatings and Composition Designof Cathode Targets in Multi-Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The composition from alloy cathode target to alloy coating generally changes to some extentin multi-arc ion plating. This demixing effect leads to the difficulties in the control of alloycomposition of coating and in the design of composition of alloy cathode target. A new simple formula,is proposed in present work to deal with the problem. According to this formula, the composition of alloy coating can be calculated bymeans of the degrees of ionization of alloy elements. The results of calculation agree with theexperimental ones within very limited error range. Modifying the formula into another form,the design for alloy composition of cathode target can be conveniently carried out, and the ideal composition of alloy coating can be obtained.

  6. Effects of virtual anode formation on the beam optics of grid-controlled vacuum arc ion source

    International Nuclear Information System (INIS)

    New concepts are proposed for intense long pulse ion injectors of several A (ampere) level. In order to control space charge effects on the emitting surface, a vacuum arc ion source which has double grid structure is tested. For ion injection of higher current level, a plasma gun type injector is also developed. It utilizes an electromagnetic injection of the source plasma and post-acceleration of it by a plasma filled diode gap. With this configuration, we can expect to get stable, high flux ion beams without forming a virtual anode in the extraction gap. copyright 1996 American Institute of Physics

  7. The influence of negative ions in helium-oxygen barrier discharges: I. Laser photodetachment experiment

    Science.gov (United States)

    Tschiersch, R.; Nemschokmichal, S.; Meichsner, J.

    2016-04-01

    This work is the experimental part of a comprehensive study that aims to understand the influence of negative ions on the development of atmospheric pressure barrier discharges in electronegative systems. The investigations will be complemented by a 1D numerical fluid simulation. Laser photodetachment experiments were performed in a glow-like barrier discharge operated in helium with admixtures of oxygen up to 1 vol.% at a gas pressure of 500 mbar. The discharge gap between the glass-coated electrodes was 3 mm. The discharge properties were characterized by electrical measurements and optical emission spectroscopy. Laser photodetachment of {{\\text{O}}-} , {\\text{O}}2- , and {\\text{O}}3- was studied using the fundamental and second harmonic wavelength of a Nd-YAG laser. The laser photodetachment of negative ions influences the breakdown characteristics when the laser is fired during the prephase of the discharge only. The breakdown voltage is reduced, which indicates an enhanced pre-ionization initiated by the detached electrons. Systematic variations in the laser pulse in time, the axial laser beam position, the laser pulse energy, and the laser wavelength provided detailed knowledge on this process. The investigation underlines the importance of the discharge prephase in general and aims to differentiate between the negative ion species {{\\text{O}}-} , {\\text{O}}2- , and {\\text{O}}3- .

  8. Effect of Ne Glow Discharge on Ion Density Control in LHD

    Institute of Scientific and Technical Information of China (English)

    S.Morita; M. Goto; S. Masuzaki; H. Suzuki; K. Tanaka; H. Nozato; Y. Takeiri; J. Miyazawa; LHD esperimental group

    2004-01-01

    Neon glow discharge cleaning was firstly attempted in Large Helical Device (LHD) instead of He glow discharge to remove hydrogen neutrals and to control the ion density, ni. The Ne glow discharge continued for 8 hours overnight after a three-day experiment. At the second night Halpha emission became weaker than the emission usually observed in the He glow discharge. A clear reduction of the hydrogen influx was also observed in neutral beam injection (NBI) discharges with Ne puff, whereas the neon recycling was strongly enhanced with appearance of a flat density profile. As a result, the lowest density limit was further reduced down to 0.2 times10 13 ,cm-3. The use of Ar puff formed a peaked density profile with a high Ti of 7 keV.

  9. Single discharge of the matrix source of negative hydrogen ions: Influence of the neutral particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Paunska, Ts.; Todorov, D., E-mail: dimitar-tdrv@phys.uni-sofia.bg; Shivarova, A. [Faculty of Physics, Sofia University, BG-1164 Sofia (Bulgaria); Tarnev, Kh. [Department of Applied Physics, Technical University–Sofia, BG-1000 Sofia (Bulgaria)

    2015-04-08

    The study presents two-dimensional (2D) fluid-plasma-model description of a planar-coil inductively-driven discharge, considered as a single element of a matrix source of volume-produced negative hydrogen ions. Whereas the models developed up to now have been directed towards description of the charged particle behavior in the discharge, including that of the negative ions, this model stresses on the role of the neutral particle dynamics and of the surface processes in the formation of the discharge structure. The latter is discussed based on comparison of results obtained for discharges in a flowing gas and at a constant gas pressure as well as for different values of the coefficient of atom recombination on the walls. The conclusions are that the main plasma parameters – electron density and temperature and plasma potential – determining the gas discharge regime stay stable, regardless of changes in the redistribution of the densities of the neutral particles and of the positive ions. With regards to the volume production of the ions, which requires high density of (vibrationally excited) molecules, the impact on the degree of dissociation of the coefficient of atom recombination on the wall is discussed.

  10. Inactivation of bacteria using dc corona discharge: role of ions and humidity

    OpenAIRE

    Dobrynin, Danil; Friedman, Gary; Fridman, Alexander; Starikovskiy, Andrey

    2011-01-01

    Here we present the results of an experimental study of the effect of ions produced in a dc corona discharge on inactivation of bacteria on the surface of agarose gel. Both positive and negative corona discharges in various gases at different humidities were studied. The measurements in air, O2, N2, Ar and He mixtures show that there is no inactivation in pure N2, pure O2 and an N2–H2O mixture. The best results were achieved in the case of direct treatment, when discharge was ignited in oxyge...

  11. Effect of high energy electrons on H− production and destruction in a high current DC negative ion source for cyclotron

    International Nuclear Information System (INIS)

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H− production. The modelling results reasonably explains the dependence of the H− extraction current on the arc-discharge power in the experiments

  12. Direct Liquid Sampling for Corona Discharge Ion Mobility Spectrometry.

    Science.gov (United States)

    Sabo, Martin; Malásková, Michaela; Harmathová, Olga; Hradski, Jasna; Masár, Marián; Radjenovic, Branislav; Matejčík, Štefan

    2015-07-21

    We present a new technique suitable for direct liquid sampling and analysis by ion mobility spectrometry (IMS). The technique is based on introduction of a droplet stream to the IMS reaction region. The technique was successfully used to detect explosives dissolved in methanol and oil as well as to analyze amino acids and dipeptides. One of the main advantages of this technique is its ability to analyze liquid samples without the requirement of any special solution. PMID:26154532

  13. Chemistry of sprite discharges through ion-neutral reactions

    Directory of Open Access Journals (Sweden)

    Y. Hiraki

    2008-02-01

    Full Text Available We estimate the concentration changes, caused by a single streamer in sprites, of ozone and related minor species as odd nitrogen (NOx and hydrogen (HOx families in the upper stratosphere and mesosphere. The streamer has an intense electric field and high electron density at its head where a large number of chemically-radical ions and atoms are produced through electron impact on neutral molecules. After propagation of the streamer, the densities of minor species can be perturbed through ion-neutral chemical reactions initiated by the relaxation of these radical products. We evaluate the production rates of ions and atoms using electron kinetics model and assuming the electric field and electron density in the streamer head. We calculate the density variations mainly for NOx, Ox, and HOx species using a one-dimensional model of the neutral and ion composition of the middle atmosphere, including the effect of the sprite streamer. Results at the nighttime condition show that the densities of NO, O3, H, and OH increase suddenly through reactions triggered by firstly produced atomic nitrogen and oxygen, and electrons just after streamer initiation. It is shown that NO and NO2 still remain for 1 h by a certain order of increase with their source-sink balance predominantly around 60 km; for other species, increases in O3, OH, HO2, and H2O2 still remain in the range of 40–70 km. From this affirmative result of long time behavior previously not presented, we emphasize that sprites would have a power to impact on local chemistry at night. We also discuss comparison with previous studies and suggestion for satellite observations.

  14. Adding high time resolution to charge-state-specific ion energy measurements for pulsed copper vacuum arc plasmas

    CERN Document Server

    Tanaka, Koichi; Zhou, Xue; Anders, André

    2015-01-01

    Charge-state-resolved ion energy-time-distributions of pulsed Cu arc plasma were obtained by using direct (time dependent) acquisition of the ion detection signal from a commercial ion mass-per-charge and energy-per-charge analyzer. We find a shift of energies of Cu2+, Cu3+ and Cu4+ ions to lower values during the first few hundred microseconds after arc ignition, which is evidence for particle collisions in the plasma. The generation of Cu1+ ions in the later part of the pulse, measured by the increase of Cu1+ signal intensity and an associated slight reduction of the mean charge state point to charge exchange reactions between ions and neutrals. At the very beginning of the pulse, when the plasma expands into vacuum and the plasma potential strongly fluctuates, ions with much higher energy (over 200 eV) were observed. Early in the pulse, the ion energies observed are approximately proportional to the ion charge state, and we conclude that the acceleration mechanism is primarily based on acceleration in an e...

  15. Analysis of the ion energy transport in ohmic discharges in the ASDEX tokamak

    International Nuclear Information System (INIS)

    An analysis of the local ion energy transport is performed for more than one hundred well documented ohmic ASDEX discharges. These are characterized by three different confinement regimes: the linear ohmic confinement (LOC), the saturated ohmic confinement (SOC) and the improved ohmic confinement (IOC). All three are covered by this study. To identify the most important local transport mechanism of the ion heat, the ion power balance equation is analyzed. Two methods are used: straightforward calculation with experimental data only, and a comparison of measured and calculated profiles of the ion temperature and the ion heat conductivity, respectively. A discussion of the power balance shows that conductive losses dominate the ion energy transport in all ohmic discharges of ASDEX. Only inside the q=1-surface losses due to sawtooth activity play a role, while at the edge convective fluxes and CX-losses influence the ion energy transport. Both methods lead to the result that both the ion temperature and the ion heat conductivity are consistent with predictions of the neoclassical theory. Enhanced heat losses as suggested by theories eg. on the basis of ηi modes can be excluded. (orig.)

  16. Spacecraft design and flight status of HAYABUSA asteroid explorer propelled by microwave discharge ion engines

    OpenAIRE

    Kuninaka, Hitoshi; Nishiyama, Kazutaka; Funaki, Ikko; Shimizu, Yukio; Yamada, Tetsuya; 國中 均; 西山 和孝; 船木 一幸; 清水 幸夫; 山田 哲哉

    2005-01-01

    The microwave discharge ion engines 'micro10s' are devoted to the main propulsion on 'HAYABUSA' asteroid explorer. In the development program various kinds of tests and assessments were applied to the ion engines and the spacecraft; the endurance test, the EMI susceptibility test, the interference test between plasma and communication microwave, the beam exhaust test on the spacecraft, the assessment on plasma interference with solar array, so on. The spacecraft was input in the deep space by...

  17. A Monte Carlo Simulation for the Ion Transport in Glow Discharges with Dusts

    Institute of Scientific and Technical Information of China (English)

    SUN Ai-Ping; PU Wei; QIU Xiao-Ming

    2001-01-01

    We use the Monte Carlo method to simulate theion transport in the rf parallel plate glow discharge with a negative-voltage pulse connected to the electrode. It is found that self-consistent field, dust charge, dust concentration,and dust size influence the energy distribution and the density of the ions arriving at the target, and in particular, the latter two make significant influence. As dust concentration or dust size increases, the number of ions arriving at the target reduces greatly.

  18. Combined corona discharge and UV photoionization source for ion mobility spectrometry.

    Science.gov (United States)

    Bahrami, Hamed; Tabrizchi, Mahmoud

    2012-08-15

    An ion mobility spectrometer is described which is equipped with two non-radioactive ion sources, namely an atmospheric pressure photoionization and a corona discharge ionization source. The two sources cannot only run individually but are additionally capable of operating simultaneously. For photoionization, a UV lamp was mounted parallel to the axis of the ion mobility cell. The corona discharge electrode was mounted perpendicular to the UV radiation. The total ion current from the photoionization source was verified as a function of lamp current, sample flow rate, and drift field. Simultaneous operation of the two ionization sources was investigated by recording ion mobility spectra of selected samples. The design allows one to observe peaks from either the corona discharge or photoionization individually or simultaneously. This makes it possible to accurately compare peaks in the ion mobility spectra from each individual source. Finally, the instrument's capability for discriminating two peaks appearing in approximately identical drift times using each individual ionization source is demonstrated. PMID:22841099

  19. Simulated Beam Extraction Performance Characterization of a 50-cm Ion Thruster Discharge

    Science.gov (United States)

    Foster, John E.; Hubble, Aimee; Nowak-Gucker, Sarah; Davis, Chris; Peterson, Peter; Viges, Eric; Chen, Dave

    2013-01-01

    A 50 cm ion thruster is being developed to operate at >65 percent total efficiency at 11 kW, 2700 s Isp and over 25 kW, 4500 s Isp at a total efficiency of >75 percent. The engine is being developed to address the need for a multimode system that can provide a range of thrust-to- power to service national and commercial near-earth onboard propulsion needs such as station-keeping and orbit transfer. Operating characteristics of the 50 cm ion thruster were measured under simulated beam extraction. The discharge current distribution at the various magnet rings was measured over a range of operating conditions. The relationship between the anode current distribution and the resulting plasma uniformity and ion flux measured at the thruster exit plane is discussed. The thermal envelope will also be investigated through the monitoring of magnet temperatures over the range of discharge powers investigated. Discharge losses as a function of propellant utilization was also characterized at multiple simulated beam currents. Bulk plasma conditions such as electron temperature and electron density near engine centerline was measured over a range of operating conditions using an internal Langmuir probe. Sensitivity of discharge performance to chamber length is also discussed. This data acquired from this discharge study will be used in the refinement of a throttle table in anticipation for eventual beam extraction testing.

  20. The effects of high-voltage pulse electric discharges on ion adsorption on activated carbons

    Science.gov (United States)

    Gafurov, M. M.; Sveshnikova, D. A.; Larin, S. V.; Rabadanov, K. Sh.; Shabanova, Z. E.; Yusupova, A. A.; Ramazanov, A. Sh.

    2008-07-01

    The effects of high-voltage pulse electric discharges (HPED) on sorption of boron and sulfate ions on activated carbons of different kinds (KM-2, BAU, DAK) were investigated. The effect of HPED activation on the sorption characteristics of the systems was found to be similar to the temperature effect.

  1. Determination of thiocyanate (biomarkers of ETS) and other inorganic ions in human nasal discharge samples using ion chromatography.

    Science.gov (United States)

    Narkowicz, Sylwia; Polkowska, Żaneta; Marć, Mariusz; Simeonov, Vasil; Namieśnik, Jacek

    2013-10-01

    Environmental tobacco smoke (ETS) is a mixture of air and tobacco smoke containing more than 4000 chemical substances. In view of the health risks of many of these substances, studies are needed to determine biomarkers of exposure to ETS constituents in people who actively or passively are exposed to the toxic compounds. The methodologies for determining most biomarkers from saliva, urine and blood samples are known, but methods for analyzing these compounds in nasal discharges are not available. The objective of this work was to develop an analytical procedure for the determination of thiocyanate and other biomarker compounds in samples of nasal discharge using ion chromatography.

  2. NITROGEN POTENTIAL DURING ION NITRIDING PROCESS IN GLOW-DISCHARGE PLASMA

    Directory of Open Access Journals (Sweden)

    A. A. Kozlov

    2015-01-01

    Full Text Available The paper considers problems on regulation of phase composition of a nitrided layer during gas and ion nitriding process in a glow-discharge. It has been established that  available models for control of nitrided layer structure with the help of nitriding index (nitrogen potential can not be applied for nitriding process in the glow-discharge. Principal difference of the ion nitriding from the gas one is in the fact that chemically active nitrogen is formed in the discharge zone (cathode layer and its mass-transfer is carried out in the form of an active particle flow (ions, atoms, molecules which directed to the metal surface.Interrelation of chemical discharge activity with such characteristics of nitriding steel as nitrogen solubility in  α-solid solution and  coefficient diffusion during ion nitriding in low-discharge plasma. It has been shown that regulation of the nitride layer structure during ion nitriding is reached due to changes in nitrogen flow density in plasma. While supporting the flow at the level of nitrogen solubility in  one phase or another (α, γ′  it is possible to obtain the nitrided layer consisting only of α-solid solution or γ′-nitride layer and diffusion sub-layer. Moreover a specific range of nitrogen flow density values exists for every steel grade where it is possible to ensure a limiting nitrogen concentration in α-solid solution and the γ′-layer characterized by low diffusion  mobility is not formed on the surface.

  3. Negative Corona Discharge Ion Source Under Ambient Conditions with Mini Line-cylinder Electrodes

    Institute of Scientific and Technical Information of China (English)

    Kun Liu; Fei Tang; Xiao-hao Wang; Liang Zhang; Xue-ye Wei

    2009-01-01

    A novel ambient negative corona discharge ion source with mini line-cylinder electrodes is designed. The diameters of inner and outer electrode are 0.16 and 4 mm respectively. With a special assembly method, a perfect coaxiality of the two electrodes is obtained. An injection system utilizing a temperature control technique, achieves a constant and stable concentra-tion of the sample, which is critical to the experiment. The formulas of the corona onset voltage of line-cylinder electrodes are also introduced. The experiment results show that negative substances such as formic acid and acetic acid can be ionized under ambient con-ditions. When combined with micro electrical mechanical system fabrication process, the volume of the ion source can be reduced dramatically, but there is an undesirable surface discharge. To solve the surface discharge problem, an improved structure was designed and tested. The simplicity of the interface of the ion source makes it suitable for mass spec-trometer, micro mass spectrometer, ion mobility spectrometer, and high-field asymmetric waveform ion mobility spectrometer applications.

  4. Optimization of the Adhesion Strength of Arc Ion Plating TiAlN Films by the Taguchi Method

    Directory of Open Access Journals (Sweden)

    Tong-Yul Cho

    2009-06-01

    Full Text Available A three-level six-factor (arc power, substrate temperature, pre-treatment bias voltage, working pressure, deposition bias voltage and pretreatment time orthogonal experimental array (L18 to optimize the adhesion strength of arc ion plating (AIP TiAlN films was designed using the Taguchi method. An optimized film process, namely substrate temperature 220 °C, arc power 60 A, negative bias voltage -800 V, nitrogen pressure 10-2 Torr, pretreated voltage -450 V and pretreated time 15 minutes was obtained by the Taguchi program for the purpose of obtaining a larger critical load. The critical load of the optimized TiAlN film (53 N was increased by 43% compared to the film with the highest critical load before optimization. The improvement in the adhesion strength of the films was attributed to the enhancement of hardness and the competitive growth of the (111, (200 and (220 orientations in the film.

  5. Discharge characteristics of a penning ion source for compact neutron generator

    Science.gov (United States)

    Liu, Weibo; Li, Mingjuan; Gao, Kun; Gu, Deshan

    2014-12-01

    We investigate the discharge characteristics of a penning ion source for a compact sealed neutron generator in DC mode. A measuring system consisting of console, vacuum gauges, and teslameter is established. By using the measuring system, the discharge current as a function of ion source voltage, gas pressure, and magnetic field is studied. The results show that the neutron generator can operate in a safe and steady state when the experimental parameters are as follows: ion source voltage of 1.2-2 kV, gas pressure of 4×10-2-8×10-2 Pa, and magnetic field of 0.3-0.5 T. Within these ranges, the neutron yield of the generator can reach 2×108 n/s.

  6. Discharge characteristics of a penning ion source for compact neutron generator

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weibo, E-mail: liuwb_1108@163.com [Department of Opto-Electronic Engineering, Binzhou University, Binzhou 256603 (China); Li, Mingjuan [Flying College, Binzhou University, Binzhou 256603 (China); Gao, Kun [Department of Opto-Electronic Engineering, Binzhou University, Binzhou 256603 (China); Gu, Deshan [School of Physics, Northeast Normal University, Changchun 130024 (China)

    2014-12-21

    We investigate the discharge characteristics of a penning ion source for a compact sealed neutron generator in DC mode. A measuring system consisting of console, vacuum gauges, and teslameter is established. By using the measuring system, the discharge current as a function of ion source voltage, gas pressure, and magnetic field is studied. The results show that the neutron generator can operate in a safe and steady state when the experimental parameters are as follows: ion source voltage of 1.2–2 kV, gas pressure of 4×10{sup −2}–8×10{sup −2} Pa, and magnetic field of 0.3–0.5 T. Within these ranges, the neutron yield of the generator can reach 2×10{sup 8} n/s.

  7. Specific interaction between negative atmospheric ions and organic compounds in atmospheric pressure corona discharge ionization mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Sakai, Mami; Takayama, Mitsuo

    2012-06-01

    The interaction between negative atmospheric ions and various types of organic compounds were investigated using atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. Atmospheric negative ions such as O(2)(-), HCO(3)(-), COO(-)(COOH), NO(2)(-), NO(3)(-), and NO(3)(-)(HNO(3)) having different proton affinities served as the reactant ions for analyte ionization in APCDI in negative-ion mode. The individual atmospheric ions specifically ionized aliphatic and aromatic compounds with various functional groups as atmospheric ion adducts and deprotonated analytes. The formation of the atmospheric ion adducts under certain discharge conditions is most likely attributable to the affinity between the analyte and atmospheric ion and the concentration of the atmospheric ion produced under these conditions. The deprotonated analytes, in contrast, were generated from the adducts of the atmospheric ions with higher proton affinity attributable to efficient proton abstraction from the analyte by the atmospheric ion. PMID:22528201

  8. Specific interaction between negative atmospheric ions and organic compounds in atmospheric pressure corona discharge ionization mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Sakai, Mami; Takayama, Mitsuo

    2012-06-01

    The interaction between negative atmospheric ions and various types of organic compounds were investigated using atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. Atmospheric negative ions such as O(2)(-), HCO(3)(-), COO(-)(COOH), NO(2)(-), NO(3)(-), and NO(3)(-)(HNO(3)) having different proton affinities served as the reactant ions for analyte ionization in APCDI in negative-ion mode. The individual atmospheric ions specifically ionized aliphatic and aromatic compounds with various functional groups as atmospheric ion adducts and deprotonated analytes. The formation of the atmospheric ion adducts under certain discharge conditions is most likely attributable to the affinity between the analyte and atmospheric ion and the concentration of the atmospheric ion produced under these conditions. The deprotonated analytes, in contrast, were generated from the adducts of the atmospheric ions with higher proton affinity attributable to efficient proton abstraction from the analyte by the atmospheric ion.

  9. Carbon Nanotube Emissions from Arc Discharge Production: Classification of Particle Types with Electron Microscopy and Comparison with Direct Reading Techniques

    Science.gov (United States)

    Ludvigsson, Linus; Isaxon, Christina; Nilsson, Patrik T.; Tinnerberg, Hakan; Messing, Maria E.; Rissler, Jenny; Skaug, Vidar; Gudmundsson, Anders; Bohgard, Mats; Hedmer, Maria; Pagels, Joakim

    2016-01-01

    Introduction: An increased production and use of carbon nanotubes (CNTs) is occurring worldwide. In parallel, a growing concern is emerging on the adverse effects the unintentional inhalation of CNTs can have on humans. There is currently a debate regarding which exposure metrics and measurement strategies are the most relevant to investigate workplace exposures to CNTs. This study investigated workplace CNT emissions using a combination of time-integrated filter sampling for scanning electron microscopy (SEM) and direct reading aerosol instruments (DRIs). Material and Methods: Field measurements were performed during small-scale manufacturing of multiwalled carbon nanotubes using the arc discharge technique. Measurements with highly time- and size-resolved DRI techniques were carried out both in the emission and background (far-field) zones. Novel classifications and counting criteria were set up for the SEM method. Three classes of CNT-containing particles were defined: type 1: particles with aspect ratio length:width >3:1 (fibrous particles); type 2: particles without fibre characteristics but with high CNT content; and type 3: particles with visible embedded CNTs. Results: Offline sampling using SEM showed emissions of CNT-containing particles in 5 out of 11 work tasks. The particles were classified into the three classes, of which type 1, fibrous CNT particles contributed 37%. The concentration of all CNT-containing particles and the occurrence of the particle classes varied strongly between work tasks. Based on the emission measurements, it was assessed that more than 85% of the exposure originated from open handling of CNT powder during the Sieving, mechanical work-up, and packaging work task. The DRI measurements provided complementary information, which combined with SEM provided information on: (i) the background adjusted emission concentration from each work task in different particle size ranges, (ii) identification of the key procedures in each work

  10. Pressure-dependent synthesis of high-quality few-layer graphene by plasma-enhanced arc discharge and their thermal stability

    International Nuclear Information System (INIS)

    In this article, a simple and cost-effective method to produce high-quality few-layer graphene (FLG) sheets (∼4 layers) have been achieved by the direct current arc discharge under argon atmosphere, using pure graphite rods as the electrodes. Ar was used as a buffer gas with pure graphite rods as anode and cathode electrodes. We explored the suitable conditions for producing FLG by changing the Ar gas pressure inside the arcing chamber. This method has several advantages over the previous methods to produce graphene for research applications. No toxic and hazardous intercalant was used for producing FLG in this process. The optimum Ar pressure was 500 Torr, for producing minimum number of FLG and this also shows the good thermal stability. The FLG product so obtained has been characterized by X-ray diffraction, scanning and electron microscopy, Raman and Fourier transform infrared spectroscopy. Thermal stabilities of FLG were determined by thermal gravimetric analysis

  11. PARAMETRIC STUDY FOR THE PREPARATION OF ALIGNED SINGLE-WALLED CARBON NANOTUBES BY ANODE-ARC DISCHARGE METHOD

    Institute of Scientific and Technical Information of China (English)

    J.F. Dai; Q. Wang; W.X. Li; Z.Q. Wei; G.J. Xu

    2005-01-01

    Well aligned quasi-straight single-walled carbon nanotubes (SWCNTs) and straight SWCNTs bundle have been prepared in large scale by anode-arc vaporization of graphite with metallic catalysts. Various parameters such as the catalyst preparation, the kinds and pressure of the buffer gases, the quantity of anode-arc current intensity, and the method of purification have been examined. The influence of these parameters on the deposited carbon yield is reported, together with observations of the produced material. Improvement in synthetic techniques has resulted in the optimal conditions for the production of large quantities of high quality SWCNTs in our semi-continuous synthesis method. The formation of carbon nanotubes (CNTs) was studied briefly in this paper. Owing to the magnetic pinching effect of arc current, the CNTs arrange in parallel lines along the arc current direction.

  12. Generation of ion-acoustic and magnetoacoustic waves in an RF helicon discharge

    International Nuclear Information System (INIS)

    One investigates into generation of ion and magnetic sound in a plasma-wave discharge within a longitudinal magnetic field. The sound excitation is explained by decomposition of a hybrid mode HF into LH sonic waves and new HF-waves meeting the dispersion ratios for a waveguide and decomposition terms. The resonance nature of sound excitation results from the necessity of simultaneous meeting of a number of conditions of generation of waves in a waveguide and the relevant conforming nonlinear wave processes there. To determine plasma parameters one introduces a diagnostic procedure enabling to determine thermal velocity of electrons making use of decomposition and dispersion ratios for waves in a discharge channel

  13. Synthesis and characterization of CrCN-DLC composite coatings by cathodic arc ion-plating

    Science.gov (United States)

    Wang, R. Y.; Wang, L. L.; Liu, H. D.; Yan, S. J.; Chen, Y. M.; Fu, D. J.; Yang, B.

    2013-07-01

    CrCN-DLC composite coatings were deposited onto silicon (1 0 0) and cemented carbides substrates using pure Cr targets under C2H2 ambient by cathodic arc ion plating system. The influence of C2H2 flow rate on the structure and mechanical properties of the coatings was investigated systemically. The coatings structure and bonding state were characterized by XRD, Raman and X-ray photoelectron spectroscopy. The chemical composition was measured by EDS. The mechanical performance and tribological behaviour of the coatings were studied by a hardness tester and ball-on-disc wear tester. The results showed that with increasing C2H2 flow rate from 50 to 100 sccm, the corresponding hardness of coatings increased firstly and then decreased with further addition of C2H2 flow rate. The coatings deposited at lower C2H2 flow rate (less than 200 sccm) exhibited a relatively higher hardness value (more than HV0.0252000) and then the hardness decrease with increasing C2H2 flow rate. The friction coefficient also exhibited similar variation trend, when the C2H2 flow rate was higher than 100 sccm, the friction coefficient decreased and then maintained in a relatively lower value from 0.18 to 0.24, which may be attribute to the increasing carbon content and the coating exhibited more diamond-like structure.

  14. Synthesis and characterization of CrCN–DLC composite coatings by cathodic arc ion-plating

    International Nuclear Information System (INIS)

    CrCN–DLC composite coatings were deposited onto silicon (1 0 0) and cemented carbides substrates using pure Cr targets under C2H2 ambient by cathodic arc ion plating system. The influence of C2H2 flow rate on the structure and mechanical properties of the coatings was investigated systemically. The coatings structure and bonding state were characterized by XRD, Raman and X-ray photoelectron spectroscopy. The chemical composition was measured by EDS. The mechanical performance and tribological behaviour of the coatings were studied by a hardness tester and ball-on-disc wear tester. The results showed that with increasing C2H2 flow rate from 50 to 100 sccm, the corresponding hardness of coatings increased firstly and then decreased with further addition of C2H2 flow rate. The coatings deposited at lower C2H2 flow rate (less than 200 sccm) exhibited a relatively higher hardness value (more than HV0.0252000) and then the hardness decrease with increasing C2H2 flow rate. The friction coefficient also exhibited similar variation trend, when the C2H2 flow rate was higher than 100 sccm, the friction coefficient decreased and then maintained in a relatively lower value from 0.18 to 0.24, which may be attribute to the increasing carbon content and the coating exhibited more diamond-like structure

  15. Oxidation and corrosion behavior of titanium aluminum nitride coatings by arc ion plating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-sheng; FENG Chang-jie; ZHANG Zhi-feng; WANG Fu-hui

    2006-01-01

    Composite metastable TiN and Ti1-xAlxN coatings with different Al content were deposited on 1Cr11Ni2W2MoV stainless steel for aero-engine compressor blades by arc ion plating. The results show that all coatings have a B1NaCl structure and the preferred orientation changes from (111) to (220) with increasing Al content; the lattice parameter of Ti1-xAlxN decreases with the increase of Al content. The oxidation-resistance of (Ti,Al)N coatings is significantly improved owing to the formation of Al-riched oxide on the surface of the coatings. The nitride coatings can significantly improve the corrosion-resistance of 1Cr11Ni2W2MoV stainless steel under the synergistic of water vapor and NaCl, and the corrosion-resistance becomes better when the Al content increases, because not only the quick formation of thin alumina layer prevents the further corrosion but also the formation of alumina seals the pinholes or defects in the coatings, which prevents the occurrence of localized nodules-like corrosion.

  16. The production of large concentrations of molecular ions in the lengthened negative glow region of a discharge

    OpenAIRE

    De Lucia, Frank C.; Herbst, Eric; Plummer, Grant M.; Blake, Geoffrey A.

    1983-01-01

    A technique for enhancement of positive molecular ion concentrations in a glow discharge is presented. The technique consists of modifying an anomalous glow discharge by the addition of a longitudinal magnetic field of up to 300 G. Enhancements in the ion signal strength, as measured by millimeter and submillimeter wave spectroscopy, are approximately two orders of magnitude. Evidence is presented that the magnetic field increases the length of the ion rich negative glow by restricting inside...

  17. Inactivation of bacteria using dc corona discharge: role of ions and humidity

    International Nuclear Information System (INIS)

    Here we present the results of an experimental study of the effect of ions produced in a dc corona discharge on inactivation of bacteria on the surface of agarose gel. Both positive and negative corona discharges in various gases at different humidities were studied. The measurements in air, O2, N2, Ar and He mixtures show that there is no inactivation in pure N2, pure O2 and an N2-H2O mixture. The best results were achieved in the case of direct treatment, when discharge was ignited in oxygen and water-containing mixtures. We show that neither UV radiation, ozone or H2O2 nor other neutral active species alone produced by corona have an effect on bacteria viability. It is shown that the main role of charged particles may be related to the faster transport of active peroxide species - cluster ions OH-(H2O)n and H3O+(H2O)n. The efficiency of these radicals is much higher than that of the oxygen radicals and ions (including O-2, O+4 and O3) and that of nitrogen and argon ions. (paper)

  18. Inactivation of bacteria using dc corona discharge: role of ions and humidity.

    Science.gov (United States)

    Dobrynin, Danil; Friedman, Gary; Fridman, Alexander; Starikovskiy, Andrey

    2011-10-01

    Here we present the results of an experimental study of the effect of ions produced in a dc corona discharge on inactivation of bacteria on the surface of agarose gel. Both positive and negative corona discharges in various gases at different humidities were studied. The measurements in air, O(2), N(2), Ar and He mixtures show that there is no inactivation in pure N(2), pure O(2) and an N(2)-H(2)O mixture. The best results were achieved in the case of direct treatment, when discharge was ignited in oxygen and water-containing mixtures. We show that neither UV radiation, ozone or H(2)O(2) nor other neutral active species alone produced by corona have an effect on bacteria viability. It is shown that the main role of charged particles may be related to the faster transport of active peroxide species-cluster ions OH(-)(H(2)O)(n) and H(3)O(+)(H(2)O)(n). The efficiency of these radicals is much higher than that of the oxygen radicals and ions (including [Formula: see text] and O(3)) and that of nitrogen and argon ions. PMID:22403515

  19. Characterization of Downstream Ion Energy Distributions From a High Current Hollow Cathode in a Ring Cusp Discharge Chamber

    Science.gov (United States)

    Foster, John E.; Patterson, Michael J.

    2003-01-01

    The presence of energetic ions produced by a hollow cathodes operating at high emission currents (greater than 10 Angstroms) has been documented in the literature. As part of an ongoing effort to uncover the underlying physics of the formation of these ions, ion efflux from a high current hollow cathode operating in an ion thruster discharge chamber was investigated. Using a spherical sector electrostatic energy analyzer located downstream of the discharge cathode, the ion energy distribution over a 0 to 60 eV energy range was measured. The sensitivity of the ion energy distribution function to zenith angle was also assessed at 3 different positions: 0, 15, and 25 degrees. The measurements suggest that the majority of the ion current at the measuring point falls into the analyzer with an energy approximately equal to the discharge voltage. The ion distribution, however, was found to be quite broad. The high energy tail of the distribution function tended to grow with increasing discharge current. Sensitivity of the profiles to flow rate at fixed discharge current was also investigated. A simple model is presented that provides a potential mechanism for the production of ions with energies above the discharge voltage.

  20. SiC Nanowires Synthesized by Rapidly Heating a Mixture of SiO and Arc-Discharge Plasma Pretreated Carbon Black

    Directory of Open Access Journals (Sweden)

    Wang Feng-Lei

    2008-01-01

    Full Text Available Abstract SiC nanowires have been synthesized at 1,600 °C by using a simple and low-cost method in a high-frequency induction furnace. The commercial SiO powder and the arc-discharge plasma pretreated carbon black were mixed and used as the source materials. The heating-up and reaction time is less than half an hour. It was found that most of the nanowires have core-shell SiC/SiO2nanostructures. The nucleation, precipitation, and growth processes were discussed in terms of the oxide-assisted cluster-solid mechanism.

  1. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    International Nuclear Information System (INIS)

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N2 and 30% H2 gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples

  2. Investigation of micro-structure and micro-hardness properties of 304L stainless steel treated in a hot cathode arc discharge plasma

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Hitendra K., E-mail: hkmalik@physics.iitd.ac.in [Department of Physics, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Singh, Omveer [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Dahiya, Raj P. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi – 110016 (India); Deenbandhu Chhotu Ram University of Science and Technology, Murthal–131039 (India)

    2015-08-28

    We have established a hot cathode arc discharge plasma system, where different stainless steel samples can be treated by monitoring the plasma parameters and nitriding parameters independently. In the present work, a mixture of 70% N{sub 2} and 30% H{sub 2} gases was fed into the plasma chamber and the treatment time and substrate temperature were optimized for treating 304L Stainless Steel samples. Various physical techniques such as x-ray diffraction, energy dispersive x-ray spectroscopy and micro-vickers hardness tester were employed to determine the structural, surface composition and surface hardness of the treated samples.

  3. Gas-discharge sources with charged particle emission from the plasma of glow discharge with a hollow cathode

    CERN Document Server

    Semenov, A P

    2001-01-01

    One studied properties of a magnetron discharge with a cold hollow and uncooled rod cathodes. One demonstrated the dominant effect of thermoelectron emission of a rod cathode heated in a discharge on characteristics of discharge and on emission properties of a gas-discharge plasma and the possibility pf a smooth transition of glow discharge to diffusion mode of arc discharge combustion. Paper describes sources of ions and electrons with improved physical and generalized design and engineering parameters. One shows the promise of the electrode structure of a hollow cathode magnetron discharge to be used as a source, in particular, of the atomic hydrogen and of atom flow of a working rod cathode

  4. New ion-assisted filtered cathodic arc deposition (IFCAD) technology for producing advanced thin films on temperature-sensitive substrates

    Science.gov (United States)

    Fulton, Michael L.

    1999-10-01

    An innovative Ion-Assisted Filtered Cathodic Arc Deposition (IFCAD) system has been developed for low temperature production of thin-film coatings. The IFCAD system employs electro-magnetic and mechanical filtering techniques to remove unwanted macroparticles and neutral atoms from the plasma stream. Therefore, only ions within a defined energy range arrive at the substrate surface, depositing thin-films with excellent mechanical and optical properties. Ion- Assisted-Deposition is coupled with Filtered Cathodic Arc technology to enhance and modify the arc deposited thin- films. Using an advanced computer controlled plasma beam scanning system, high quality, large area, uniform IFCAD multi-layer film structures are attained. Amorphous Diamond- Like-Carbon films (up to 85% sp3 bonded carbon; and micro- hardness greater than 50 GPa) have been deposited in multi- layer thin-film combinations with other IFCAD source materials (such as: Al2O3) for optical and tribological applications. Rutile TiO2 (refractive index of 2.8 at 500 nm) has been deposited with this technology for advanced optical filter applications. The new IFCAD technology has been included in development programs, such as: plastic and glass lens coatings for optical systems; wear resistant coatings on various metal substrates, ultra smooth, durable, surface hydrophobic coatings for aircraft windows; EUV coatings for space instrumentation; transparent conductive coatings; and UV protective coatings for solar cell concentrator plastic Fresnel lens elements for space power.

  5. Hardness and stress of amorphous carbon film deposited by glow discharge and ion beam assisting deposition

    CERN Document Server

    Marques, F C

    2000-01-01

    The hardness and stress of amorphous carbon films prepared by glow discharge and by ion beam assisting deposition are investigated. Relatively hard and almost stress free amorphous carbon films were deposited by the glow discharge technique. On the other hand, by using the ion beam assisting deposition, hard films were also obtained with a stress of the same order of those found in tetrahedral amorphous carbon films. A structural analysis indicates that all films are composed of a sp sup 2 -rich network. These results contradict the currently accepted concept that both stress and hardness are only related to the concentration of sp sup 3 sites. Furthermore, the same results also indicate that the sp sup 2 sites may also contribute to the hardness of the films.

  6. Ion energy distribution functions behind the sheaths of magnetized and non-magnetized radio frequency discharges

    International Nuclear Information System (INIS)

    The effect of a magnetic field on the characteristics of capacitively coupled radio frequency discharges is investigated and found to be substantial. A one-dimensional particle-in-cell simulation shows that geometrically symmetric discharges can be asymmetrized by applying a spatially inhomogeneous magnetic field. This effect is similar to the recently discovered electrical asymmetry effect. Both effects act independently, they can work in the same direction or compensate each other. Also the ion energy distribution functions at the electrodes are strongly affected by the magnetic field, although only indirectly. The field influences not the dynamics of the sheath itself but rather its operating conditions, i.e. the ion flux through it and voltage drop across it. To support this interpretation, the particle-in-cell results are compared with the outcome of the recently proposed ensemble-in-spacetime algorithm. Although that scheme resolves only the sheath and neglects magnetization, it is able to reproduce the ion energy distribution functions with very good accuracy, regardless of whether the discharge is magnetized or not. (paper)

  7. Synthesis and characterization of CrCN–DLC composite coatings by cathodic arc ion-plating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.Y. [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Wang, L.L. [Key Laboratory of Artificial Nanomaterials and Nanostructure of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Liu, H.D. [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Yan, S.J. [Key Laboratory of Artificial Nanomaterials and Nanostructure of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Chen, Y.M. [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Fu, D.J. [Key Laboratory of Artificial Nanomaterials and Nanostructure of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yang, B., E-mail: toyangbing@163.com [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China)

    2013-07-15

    CrCN–DLC composite coatings were deposited onto silicon (1 0 0) and cemented carbides substrates using pure Cr targets under C{sub 2}H{sub 2} ambient by cathodic arc ion plating system. The influence of C{sub 2}H{sub 2} flow rate on the structure and mechanical properties of the coatings was investigated systemically. The coatings structure and bonding state were characterized by XRD, Raman and X-ray photoelectron spectroscopy. The chemical composition was measured by EDS. The mechanical performance and tribological behaviour of the coatings were studied by a hardness tester and ball-on-disc wear tester. The results showed that with increasing C{sub 2}H{sub 2} flow rate from 50 to 100 sccm, the corresponding hardness of coatings increased firstly and then decreased with further addition of C{sub 2}H{sub 2} flow rate. The coatings deposited at lower C{sub 2}H{sub 2} flow rate (less than 200 sccm) exhibited a relatively higher hardness value (more than HV{sub 0.025}2000) and then the hardness decrease with increasing C{sub 2}H{sub 2} flow rate. The friction coefficient also exhibited similar variation trend, when the C{sub 2}H{sub 2} flow rate was higher than 100 sccm, the friction coefficient decreased and then maintained in a relatively lower value from 0.18 to 0.24, which may be attribute to the increasing carbon content and the coating exhibited more diamond-like structure.

  8. Properties of TiAlCrN coatings prepared by vacuum cathodic arc ion plating

    Institute of Scientific and Technical Information of China (English)

    RU Qiang; HU Shejun; HUANG Nacan; ZHAO Lingzhi; QIU Xiuli; HU Xianqi

    2008-01-01

    TiAlCrN coatings were deposited by means of vacuum cathodic arc ion plating technique on TC11 (Ti-6.5 Al-3.5 Mo-1.5 Zr-0.3Si) titanium alloy substrates. The composition, phase structure, mechanical performance, and oxidation-resistance of the nitride coatings were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), auger electron spectroscopy (AES), and X-ray photoelectron microscopy (XPS). A new process for preparing protective coatings of the titanium alloy is successfully acquired. The experimental results indicate that the added element chromium in the TiAlN coatings make a contribution to form the (220) preferred direction. The phases of the coatings are composed of (Ti, Al)N and (Ti, Cr)N. After 700℃ and 800℃ oxidation, AES analysis shows that the diffusion distribution of the TiAlCrN coatings emerges a step shape. From the outside to the inner, the concentrations of O, Al, and Cr reduce, but those of Ti and N increase. The Al-rich oxide is formed on the surface of the coatings, and the mixed structure of Ti-rich and Cr-rich oxides is formed in the internal layer. The oxidation resistance of the TiAlCrN coatings is excellent at the range of 700 to 800℃. Adhesion wear is the dominant mechanical characteristic for the titanium alloy at room temperature, and the protective coatings with high hardness can improve the mechanical properties of the titanium alloy. The wear resistance of the TC11 alloy is considerably improved by the TiAlCrN coatings.

  9. Specific O₂⁻ generation in corona discharge for ion mobility spectrometry.

    Science.gov (United States)

    Sabo, Martin; Matúška, Ján; Matejčík, Stefan

    2011-07-15

    This study deals with O(2)(-) generation in corona discharge (CD) in point to plane geometry for single flow ion mobility spectrometry (IMS) with gas outlet located behind the ionization source. We have designed CD of special geometry in order to achieve the high O(2)(-) yield. Using this ion source we have achieved in zero air conditions that up to 74% all negative ions were O(2)(-) or O(2)(-)(H(2)O). It has been demonstrated that the non-electronegative nitrogen positively influences the efficiency of O(2)(-) generation in O(2)/N(2) mixtures. The reduced ion mobility of 2.27 cm(2)V(-1)s(-1) has been measured for O(2)(-)/O(2)(-)(H(2)O) ions in zero air. Additional ions detected in zero air (less than 200 ppb CO(2)) using the mass spectrometric and IMS technique were, NO(2)(-), N(2)O(2)(-) (2.37 cm(2)V(-1)s(-1)), NO(3)(-), N(2)O(3)(-) and N(2)O(3)(-)(H(2)O). The CO(3)(-) and CO(4)(-) ions have been detected after the introduction of 5 ppm CO(2) into zero air. PMID:21645716

  10. Development of ion sources for implantation technology

    International Nuclear Information System (INIS)

    Ion implantation for modification of surface properties of large areas requires ion sources of a particular type. The sources must be capable of producing rather high currents within somewhat poor vacuum conditions. Two types of source are typically used, the glow discharge and the vacuum arc. This paper describes both types. The glow discharge source has a low discharge voltage to minimize beam contamination from metal ions sputtered from the source chamber. To maintain the discharge, electrons are injected from outside the source chamber. The glow discharge source will generate up to 20 mA beam currents. The vacuum arc sources have the advantage of producing high currents of metal ions using a penning discharge. Metal ion currents up to 70 mA are mentioned

  11. Laser-induced fluorescence from N2(+) ions generated by a corona discharge in ambient air.

    Science.gov (United States)

    Konthasinghe, Kumarasiri; Fitzmorris, Kristin; Peiris, Manoj; Hopkins, Adam J; Petrak, Benjamin; Killinger, Dennis K; Muller, Andreas

    2015-09-01

    In this work, we present the measurement of laser-induced fluorescence from N2(+) ions via the B(2)Σu(+)-X(2)Σg(+) band system in the near-ultraviolet. The ions were generated continuously by a plasma glow discharge in low pressure N2 and by a corona discharge in ambient air. The fluorescence decay time was found to rapidly decrease with increasing pressure leading to an extrapolated decay rate of ≍10(10) s(-1) at atmospheric pressure. In spite of this quenching, we were able to observe laser induced fluorescence in ambient air by means of a time-gated spectral measurement. In the process of comparing the emission signal with that of N2 spontaneous Raman scattering, ion concentrations in ambient air of order 10(8-)10(10) cm(-3) were determined. With moderate increases in laser power and collection efficiency, ion concentrations of less than 10(6) cm(-3) may be measurable, potentially enabling applications in atmospheric standoff detection of ionizing radiation from hazardous radioactive sources. PMID:26414524

  12. Charging and discharging in ion implanted dielectric films used for capacitive radio frequency microelectromechanical systems switch

    International Nuclear Information System (INIS)

    In this work, metal-insulator-semiconductor (MIS) capacitor structure was used to investigate the dielectric charging and discharging in the capacitive radio frequency microelectromechanical switches. The insulator in MIS structure is silicon nitride films (SiN), which were deposited by either low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD) processes. Phosphorus or boron ions were implanted into dielectric layer in order to introduce impurity energy levels into the band gap of SiN. The relaxation processes of the injected charges in SiN were changed due to the ion implantation, which led to the change in relaxation time of the trapped charges. In our experiments, the space charges were introduced by stressing the sample electrically with dc biasing. The effects of implantation process on charge accumulation and dissipation in the dielectric are studied by capacitance-voltage (C-V) measurement qualitatively and quantitatively. The experimental results show that the charging and discharging behavior of the ion implanted silicon nitride films deposited by LPCVD is quite different from the one deposited by PECVD. The charge accumulation in the dielectric film can be reduced by ion implantation with proper dielectric deposition method.

  13. Fast ion generation in the cathode plasma jet of a multipicosecond laser-triggered vacuum discharge

    International Nuclear Information System (INIS)

    Ion generation in the cathode plasma jet of a moderate-current (∼2.3 kA), low-energy (≤20 J) vacuum spark discharge triggered by ∼27 ps, 10 mJ laser pulses is studied using time of flight technique. Fastest ion velocity and velocity corresponding to the peak of the time of flight signals for Al cathode were measured to be ∼5.25x108 cm/s (energy of ∼143 keV/u) and ∼8.1x107 cm/s (energy of ∼3.4 keV/u), respectively. Corresponding velocities in the case of ions generated from laser-produced Al plasma (energy of ∼550 mJ, intensity of ∼1014 W/cm2) were found to be much smaller, viz., ∼1.05x108 cm/s (energy of ∼5.75 keV/u) and ∼2.63x107 cm/s (energy of ∼0.36 keV/u), respectively. Study shows efficient acceleration of ions in a current-carrying cathode plasma jet of a small-energy multipicosecond laser-triggered spark discharge as compared with that in a high-energy multipicosecond laser-produced plasma plume.

  14. The behaviour of negative oxygen ions in the afterglow of a reactive HiPIMS discharge

    International Nuclear Information System (INIS)

    Using a single Langmuir probe, the temporal evolution of the oxygen negative ion, n−, and electron, ne, densities in the afterglow of a reactive HiPIMS discharge operating in argon–oxygen gas mixtures have been determined. The magnetron was equipped with a titanium target and operated in ‘poisoned’ mode at a frequency of 100 Hz with a pulse width of 100 µs for a range of oxygen partial pressures, pO2/ptotal=0.0-0.5. In the initial afterglow, the density of the principle negative ion in the discharge (O−) was of the order of 1016 m−3 for all conditions. The O− concentration was found to decay slowly with characteristic decay times between 585 µs and 1.2 ms over the oxygen partial pressure range. Electron densities were observed to fall more rapidly, resulting in long-lived highly electronegative afterglow plasmas where the ratio, α = n−/ne, was found to reach values up to 672 (±100) for the highest O2 partial pressure. By comparing results to a simple plasma-chemical model, we speculate that with increased pO2/ptotal ratio, more O− ions are formed in the afterglow via dissociative electron attachment to highly excited metastable oxygen molecules, with the latter being formed during the active phase of the discharge. After approximately 2.5 ms into the off-time, the afterglow degenerates into an ion–ion plasma and negative ions are free to impinge upon the chamber walls and grounded substrates with flux densities of the order of 1018 m−2 s−1, which is around 10% of the positive ion flux measured during the on-time. This illustrates the potential importance of the long afterglow in reactive HiPIMS, which can act as a steady source of low energy O− ions to a growing thin film at the substrate during periods of reduced positive ion bombardment. (paper)

  15. Temperature Effect on the Formation of Amorphous Carbon Nanotubes by An Arc Discharge%温度对电弧放电法制备形成无定型碳纳米管的影响

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ting-kai; LIU Yong-ning; SONG Xiao-long Song; ZHANG Zhao-hui; ZHU Jie-wu; YU Guang

    2005-01-01

    Large amounts of amorphous earhon noatubes (ACNTs) were prepared by a modified arc - discharging furnace, which can control temperature from room temperature to 900℃ during the electric arcing process. There are siφ10×100mm2 graphite rode anode with aφ6×80mm2 hole drilled in them which was filled with a mixture powders of Co-Ni(1. lwt%) alloy.

  16. Characteristics of corona discharge and ion flow field in cryogenic gaseous helium

    International Nuclear Information System (INIS)

    DC corona discharge in gaseous helium under non-uniform electric fields down to 4.2 K at atmospheric pressure has been investigated. Although helium is a non-electro negative gas, a negative pulse corona is observed only near the normal boiling point and then negative breakdown voltage increases remarkably. Positive ion space charge modifies the electric field distribution in the gap space considerably. Criteria for corona inception and positive breakdown preceded by corona are proposed, and their availability is confirmed experimentally. The electric field strength, corona current density and space charge density are measured successfully and are analyzed theoretically using a bias probe method and a numerical field calculation technique. Apparent mobilities of charge carriers generated by positive and negative corona discharge are obtained with these discharge parameters. As a result, it is suggested that major ion species in positive corona is He+, and that an electronic bubble plays an important role in the negative pulse corona development near the normal boiling point. (author)

  17. Design for gas chromatography-corona discharge-ion mobility spectrometry.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Sherafatmand, Hossein

    2012-11-20

    A corona discharge ionization-ion mobility spectrometry (CD-IMS) with a novel sample inlet system was designed and constructed as a detector for capillary gas chromatography. In this design, a hollow needle was used instead of a solid needle which is commonly used for corona discharge creation, helping us to have direct axial interfacing for GC-IMS. The capillary column was passed through the needle, resulting in a reaction of effluents with reactant ions on the upstream side of the corona discharge ionization source. Using this sample introduction design, higher ionization efficiency was achieved relative to the entrance direction through the side of the drift tube. In addition, the volume of the ionization region was reduced to minimize the resistance time of compounds in the ionization source, increasing chromatographic resolution of the instrument. The effects of various parameters such as drift gas flow, makeup gas flow, and column tip position inside the needle were investigated. The designed instrument was exhaustively validated in terms of sensitivity, resolution, and reproducibility by analyzing the standard solutions of methyl isobutyl ketone, heptanone, nonanone, and acetophenone as the test compounds. The results obtained by CD-IMS detector were compared with those of the flame ionization detector, which revealed the capability of the proposed GC-IMS for two-dimensional separation (based on the retention time and drift time information) and identification of an analyte in complex matrixes. PMID:23083064

  18. Structure and properties of Mo-containing diamond-like carbon films produced by ion source assisted cathodic arc ion-plating

    International Nuclear Information System (INIS)

    Ion source assisted cathodic arc ion-plating was used to synthesize molybdenum containing diamond-like carbon films. The element of molybdenum is uniformly distributed in our sample as analyzed by Rutherford backscattering spectroscopy. The surface morphology of the films was analyzed by scanning electron microscope and atomic force microscope. The structure and bond state of the molybdenum containing diamond-like carbon films were characterized by X-ray diffraction, high resolution transmission electron microscopy, Raman spectra, and X-ray photoelectron spectroscopy. The Mo content in the films was controlled by varying of the acetylene gas flow rates. The root-mean square roughness of the as-deposited sample was found in the range of 1.5 nm. The hardness of 35 GPa has been achieved at the optimum conditions of synthesis. This can be attributed to formation multilayer structure during deposition process and the formation of hard molybdenum carbide phase with C=Mo bonding. The results show that ion source assisted cathodic arc ion-plating is an effective technique to fabricate metal-containing carbon films with controlled metal contents.

  19. Thermal Behavior of Prismatic Lithium-Ion Battery during Rapid Charge and Discharge Cycles

    Science.gov (United States)

    Araki, Takuto; Wakahara, Kenji; Fukuda, Kenichi; Ohmori, Yositake; Nakayama, Masato; Onda, Kazuo

    The temperature of secondary batteries may increase above allowable limits and deteriorate its performance, during rapid charge and discharge cycles. Therefore, assessing thermal behavior of battery is essential. On the other hand, rectangular parallelepiped shape batteries are supposedly going to be used more commonly for cars and electrical devices because of their better space efficiency. Then, we constructed a two dimensional Cartesian coordinates battery thermal behavior model for a prismatic lithium-ion secondary battery during rapid charge and discharge cycles. It was extended from one dimensional cylindrical coordinates model, which had been developed and experimentally verified. As parameters of the numerical model, battery heat source factors such as overpotential resistance, entropy change, heat transfer coefficient and heat capacity have been measured. The radiation thermometer was used for obtaining battery surface temperature variance and distributions. Battery temperature generally increases as charge and discharge cycle proceeds, nevertheless temperature drops were observed at begging of low rate charge cycle and vicinity of SOC=0.8 in discharge cycle. Our modified model could predict these phenomena and agreed well with experimental results. Then the reliability of our numerical model and measuring techniques of heat source factors are confirmed each other.

  20. Plasma-catalytic hybrid system using spouted bed with a gliding arc discharge: CH{sub 4} reforming as a model reaction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H; Sekiguchi, H, E-mail: lee.h.ac@m.titech.ac.jp [Department of Chemical Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2011-07-13

    A combination of a gliding arc discharge and a spouted catalytic bed was used to investigate a plasma-catalytic hybrid system using CH{sub 4} reforming as a model reaction. Alumina-supported catalysts that contained 0.5 wt% of Pt, Pd, Rh, and Ru (denoted as Pt/Al{sub 2}O{sub 3}, Pd/Al{sub 2}O{sub 3}, Rh/Al{sub 2}O{sub 3} and Ru/Al{sub 2}O{sub 3}, respectively) were used. For comparison, active Al{sub 2}O{sub 3} particles were also examined. The conversion of CH{sub 4} and the selectivity of the product were investigated by changing the feed flow rate and reaction time. The production of C{sub 2}H{sub 2}, H{sub 2} and soot was observed in the gliding arc discharge without a catalyst. Using Pt/Al{sub 2}O{sub 3} and Pd/Al{sub 2}O{sub 3}with the gliding arc discharge, C{sub 2}H{sub 4}, C{sub 2}H{sub 6} and C{sub 2}H{sub 2} were produced. It is considered that C{sub 2}H{sub 4} and C{sub 2}H{sub 6} were formed by the hydrogenation of C{sub 2}H{sub 2} on the active site of Pt/Al{sub 2}O{sub 3} and Pd/Al{sub 2}O{sub 3}. A stronger resistance to deactivation was shown in the presence of Pd/Al{sub 2}O{sub 3} than in the presence of Pt/Al{sub 2}O{sub 3}, whereas the selectivity of hydrocarbon using Rh/Al{sub 2}O{sub 3} and Ru/Al{sub 2}O{sub 3} showed a tendency similar to that in active Al{sub 2}O{sub 3} and non-catalytic experiments. The proposed reactor has a potential to improve the selectivity of the plasma process.

  1. Research of the Effects of Electron Focused Electric Field upon an Enhanced Glow Discharge Plasma Ion Implantation

    Institute of Scientific and Technical Information of China (English)

    LI Liu-he; WU Yong-qin; ZHANG Yan-hua; CAI Xun; CHU Paul K

    2004-01-01

    A new Enhanced Glow Discharge Plasma Ion Implantation methods are introduced, in which the plasma are produced by the self glow discharge excitated by high negative voltage bias. The electric field is designed to a electron focusing mode by using a small area hollow anode and a large area sample holder cathode. The pattern of equipotentials of the electric field are calculated through finite-element method. By using the special electron-focusing field, the self glow discharge are enhanced and provide denser ions to implanted into the substrate.

  2. Analysis of explosives using corona discharge ionization combined with ion mobility spectrometry-mass spectrometry.

    Science.gov (United States)

    Lee, Jihyeon; Park, Sehwan; Cho, Soo Gyeong; Goh, Eun Mee; Lee, Sungman; Koh, Sung-Suk; Kim, Jeongkwon

    2014-03-01

    Corona discharge ionization combined with ion mobility spectrometry-mass spectrometry (IMS-MS) was utilized to investigate five common explosives: cyclonite (RDX), trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclotetramethylenetetranitramine (HMX), and 2,4-dinitrotoluene (DNT). The MS scan and the selected ion IMS analyses confirmed the identities of the existing ion species and their drift times. The ions observed were RDX·NO3(-), TNT(-), PETN·NO3(-), HMX·NO3(-), and DNT(-), with average drift times of 6.93 ms, 10.20 ms, 9.15 ms, 12.24 ms, 11.30 ms, and 8.89 ms, respectively. The reduced ion mobility values, determined from a standard curve calculated by linear regression of (normalized drift times)(-1) versus literature K0 values, were 2.09, 1.38, 1.55, 1.15, 1.25, and 1.60 cm(2) V(-1) s(-1), respectively. The detection limits were found to be 0.1 ng for RDX, 10 ng for TNT, 0.5 ng for PETN, 5.0 ng for HMX, and 10 ng for DNT. Simplified chromatograms were observed when nitrogen, as opposed to air, was used as the drift gas, but the detection limits were approximately 10 times worse (i.e., less sensitivity of detection). PMID:24468343

  3. Experimental Verification of the Physical Model for Droplet-Particles Cleaning in Pulsed Bias Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    Yanhui ZHAO; Guoqiang LIN; Chuang DONG; Lishi WEN

    2005-01-01

    It has been reported that application of pulsed biases in arc ion plating could effectively eliminate droplet particles.The present paper aims at experimental verification of a physical model proposed previously by us which is based on particle charging and repulsion in the pulsed plasma sheath. An orthogonal experiment was designed for this purpose,using the electrical parameters of the pulsed bias for the deposition of TiN films on stainless steel substrates. The effect of these parameters on the amount and the size distribution of the particles were analyzed, and the results provided sufficient evidence for the physical model.

  4. Adaptive mass alteration to model ion-ion recombination in a Particle-in-Cell simulation of silane radio-frequency discharges

    NARCIS (Netherlands)

    Snytnikov, A. V.; Vshivkov, V. A.; W. J. Goedheer,

    2010-01-01

    In discharges in electronegative gases, negative ions are generated by (dissociative) attachment and lost by recombination with positive ions. Straightforward modeling of the recombination in a Particle-in-Cell simulation by removing a positive and negative super-particle gives rise to large numeric

  5. Influence of the oxygen concentration on the formation of crystalline phases of TiO2 during the low-pressure arc-discharge plasma synthesis

    Science.gov (United States)

    Ushakov, A. V.; Karpov, I. V.; Lepeshev, A. A.

    2016-02-01

    The synthesis of titanium dioxide (TiO2) nanoparticles with different percentage of anatase and rutile phases is investigated. The synthesis is performed by controlling the oxygen percentage in the gas mixture in the plasmachemical evaporation-condensation process employing a low-pressure arc discharge. In all our experiments, the pressure in the plasmachemical reactor and the average size of particles remain constant and are 60 Pa and 6 nm, respectively. The crystal structure of synthesized TiO2 is studied using X-ray diffraction; the morphology of the particles is analyzed employing transmission electron microscopy. Using X-ray phase analysis, it is established that the concentration of the TiO2 anatase phase decreases upon a decrease in the oxygen concentration in the gas mixture. It is shown that the TiO2 anatase phase is more efficient for photocatalytic decomposition of methylene blue than the rutile phase.

  6. Comparative study of the interface composition of TiN and TiCN hard coatings on high speed steel substrates obtained by arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Roman, E. (Lab. de Fisica de Superficies, Inst. de Ciencia de Materiales, CSIC, Madrid (Spain)); Segovia, J.L. de (Lab. de Fisica de Superficies, Inst. de Ciencia de Materiales, CSIC, Madrid (Spain)); Alberdi, A. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain)); Calvo, J. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain)); Laucirica, J. (TEKNIKER, Asociacion de Investigacion Tecnologica, Eibar (Spain))

    1993-05-15

    In this paper the composition of the interface of TiN and TiCN hard coatings deposited onto high speed steel substrates obtained by the arc discharge technique is studied using Auger electron spectroscopy at two different substrate temperatures, 520 K and 720 K. The low temperature (520 K) TiN coating developed an oxygen phase at the interface, producing a weak adherence of 40 N, while the high temperature coatings (720 K) had a less intense oxygen phase, giving a greater adherence to the substrate of 60 N. TiCN coatings at 520 K are characterized by a low oxygen intensity at the interface. However, their adherence of 50 N is lower than the value of 60 N for the high temperature TiN coatings and is independent of the substrate temperature. (orig.)

  7. Three dimensional numerical study of different parameters effect on the external magnetic field applied to center the arc of the horizontal mercury discharge lamp

    Directory of Open Access Journals (Sweden)

    Mohamed Bechir Ben Hamida

    2015-10-01

    Full Text Available The aim of this paper is to evaluate the magnitude of the external magnetic field to be applied to a horizontal mercury discharge lamp such that the Lorentz forces counterbalance buoyancy forces and the hot region of the arc remains centered inside the lamp with the variation of six parameters of the lamp such as the external temperature of the lamp, envelope thickness, convective loss, Interelectrodeslength, pressure and current supply pointing to the influence of the parameters to the compensating magnetic field value. To achieve this objective, a commercial numerical software “Comsol Multiphysics” is used to implement the model that solves the equations of mass, energy and momentum for laminar compressible flow combined with the Laplace equation for the plasma in a three dimensional.

  8. Using corona discharge-ion mobility spectrometry for detection of 2,4,6-Trichloroanisole.

    Science.gov (United States)

    Lichvanová, Zuzana; Ilbeigi, Vahideh; Sabo, Martin; Tabrizchi, Mahmoud; Matejčík, Stefan

    2014-09-01

    In this work possible application of the corona discharge-ion mobility spectrometer (CD-IMS) for detection of 2,4,6-Trichloroanisole (TCA) has been investigated. We applied CD-IMS interfaced with orthogonal acceleration time of flight mass spectrometer (CD-IMS-oaTOF) to study the ion processes within the CD-IMS technique. The CD-IMS instrument was operated in two modes, (i) standard and (ii) reverse flow modes resulting in different chemical ionisation schemes by NO3(-)(HNO3)n (n=0,1,2) and O2(-)(H2O)n (n=0,1,2), respectively. The O2(-)(H2O)n ionisation was associated with formation of Cl(-) and (TCA-CH3)(-) ions from TCA. The NO3(-)(HNO3)n ionisation, resulted in formation of NO3(-)(HNO3)(TCA-Cl) adduct ions. Limit of detection (LOD) for TCA was determined in gas (100 ppb) and solid phases (150 ng). PMID:24913882

  9. Surface Coating Constraint Induced Self-Discharging of Silicon Nanoparticles as Anodes for Lithium Ion Batteries.

    Science.gov (United States)

    Luo, Langli; Zhao, Peng; Yang, Hui; Liu, Borui; Zhang, Ji-Guang; Cui, Yi; Yu, Guihua; Zhang, Sulin; Wang, Chong-Min

    2015-10-14

    One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemi-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemi-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to "self-delithiation" or "self-discharging" at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ∼150 nm for bare SiNPs to ∼380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries. PMID:26414120

  10. Synthesis of few-walled carbon nanotube-Rh nanoparticles by arc discharge: Effect of selective oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yanfeng, E-mail: zyfshu@gmail.com

    2012-06-15

    Highly crystalline rhodium (Rh) nanoparticles supported on carbon nanotubes were prepared by selective oxidation method. Carbon nanotubes and FeRh nanoparticles were simultaneously generated in hydrogen arc plasma. The as-grown nanomaterials can be purified by heat treatment in open air and by soaking in HCl. X-ray diffraction and selected area electron diffraction results reveal that as-grown FeRh nanoparticles have a typical chemical CsCl-type structure which can be transformed into a face-centered cubic structure by thermal annealing in the purification process. The purification process is selective toward the removal of the amorphous carbon coating the nanoparticles, and transforms Fe to Fe{sub 2}O{sub 3}. Fe{sub 2}O{sub 3} can be easily dissolved in hydrochloric acid, leaving carbon nanotubes-Rh nanoparticles. Rh nanoparticles with diameters of 2-60 nm are deposited uniformly on the surface of the carbon nanotube bundles. This simple and selective chemistry offers a new process for synthesizing and controlling Fe content in carbon nanotube-FeRh nanoparticles. Highlights: Black-Right-Pointing-Pointer High-crystallinity CNTs and FeRh nanoparticles were simultaneously generated in arc plasma. Black-Right-Pointing-Pointer The diameter distribution of CNTs depends on different gases. Black-Right-Pointing-Pointer Heat treatment in open air and soaking in HCl can convert CNTs-FeRh to CNTs-Rh. Black-Right-Pointing-Pointer The selective oxidation mechanisms of metal nanoparticles and carbon materials differ.

  11. The study of micro-arc discharges during cathodic plasma electrolysis of refractory metals using the spectral line shape of Na I lines

    Science.gov (United States)

    Jovović, Jovica; Stojadinović, Stevan; Tadić, Nenad; Vasilić, Rastko; Šišović, Nikola M.

    2016-03-01

    The micro-arc discharges during cathodic plasma electrolysis of refractory metals (Zr, Ti, Ta) are studied by means of optical emission spectroscopy. The fitting procedure based on three mutually shifted profiles is developed to analyze the complex line shape of Na I 568.64 nm and 615.86 nm doublets. Each profile includes effects of instrumental, Doppler, Stark, van der Waals and resonance broadening. The results show the existence of three discharge zones with electron number density values Ne1=7× 1014 \\text{cm}-3 , Ne2=(0.5\\text{--}1)× 1016 \\text{cm}-3 and Ne3= (1.5\\text{--}2.8)× 1016 \\text{cm}-3 while those of sodium ground-state atoms are Ng1=1.4×1017 \\text{cm}-3 , Ng2=3.6×1017 \\text{cm}-3 and Ng3=(1.7\\text{--}3.7)×1018 \\text{cm}-3 .

  12. Diagnostics of a negative hydrogen ion source based on a planar-coil inductively-driven discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lishev, Stiliyan St.; Shivarova, Antonia P.; Iordanov, Dimitar I.; Todorov, Dimitar T.; Demerdzhiev, Angel P. [Faculty of Physics, Sofia University, 5 J. Bourchier Blvd., BG-1164 Sofia (Bulgaria)

    2013-02-08

    Recent activity on a volume-production negative-hydrogen-ion source with the design of a matrix of small-radius discharges inductively driven by a planar coil is reported. A single discharge of the matrix has been studied by employing probe-and laser-photodetachment diagnostics. The measurements have been carried out in the first - small-size - chamber of a two-chamber discharge vessel, with rf power introduced by a planar coil positioned on its front wall. The measured profiles of the negative ion density show strong axial dependence, with two maxima located at the positions corresponding to the maxima of the dc potential, where the maxima of the electron density are also located. The first maximum is in the vicinity of the rf power input and the second one is close to the interface between the two chambers of the discharge vessel.

  13. Theoretical analysis of ion kinetic energies and DLC film deposition by CH4+Ar (He) dielectric barrier discharge plasmas

    Institute of Scientific and Technical Information of China (English)

    Liu Yan-Hong; Zhang Jia-Liang; Ma Teng-Cai; Li Jian; Liu Dong-Ping

    2007-01-01

    The kinetic energy of ions in dielectric barrier discharge plasmas are analysed theoretically using the model of binary collisions between ions and gas molecules. Langevin equation for ions in other gases, Blanc law for ions in mixed gases, and the two-temperature model for ions at higher reduced field are used to determine the ion mobility. The kinetic energies of ions in CH4 + Ar(He) dielectric barrier discharge plasma at a fixed total gas pressure and various Ar (He)concentrations are calculated. It is found that with increasing Ar (He) concentration in CH4 + Ar (He) from 20% to 83%,the CH4+ kinetic energy increases from 69.6 (43.9) to 92.1 (128.5)eV, while the Ar+ (He+) kinetic energy decreases from 97 (145.2) to 78.8 (75.5)eV. The increase of CH4+ kinetic energy is responsible for the increase of hardness of diamond-like carbon films deposited by CH4 + Ar (He) dielectric barrier discharge without bias voltage over substrates.

  14. Laser desorption with corona discharge ion mobility spectrometry for direct surface detection of explosives.

    Science.gov (United States)

    Sabo, M; Malásková, M; Matejčík, S

    2014-10-21

    We present a new highly sensitive technique for the detection of explosives directly from the surface using laser desorption-corona discharge-ion mobility spectrometry (LD-CD-IMS). We have developed LD based on laser diode modules (LDM) and the technique was tested using three different LDM (445, 532 and 665 nm). The explosives were detected directly from the surface without any further preparation. We discuss the mechanism of the LD and the limitations of this technique such as desorption time, transport time and desorption area. After the evaluation of experimental data, we estimated the potential limits of detection of this method to be 0.6 pg for TNT, 2.8 pg for RDX and 8.4 pg for PETN. PMID:25118619

  15. Direct determination of ammoniacal nitrogen in water samples using corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Jafari, M T; Khayamian, T

    2008-09-15

    In this study, direct determination of ammoniacal nitrogen residues in water samples using corona discharge ion mobility spectrometry (CD-IMS) was investigated. Pyridine was used as an alternate reagent gas to enhance selectivity and sensitivity of the method. The results indicate that the limit of detection (LOD) was about 9.2x10(-3)mugmL(-1) and the linear dynamic range was obtained from 0.03 to 2.00mugmL(-1). The relative standard deviation was about 11%. Furthermore, this method was successfully applied to the direct determination of ammoniacal nitrogen in river and tap water samples and the results were compared with the Nessler method. The comparison of the results validates the potential of the proposed method as an alternative technique for the analysis of the ammoniacal nitrogen in water samples. PMID:18761176

  16. Comparison of reactant and analyte ions for ⁶³Nickel, corona discharge, and secondary electrospray ionization sources with ion mobility-mass spectrometry.

    Science.gov (United States)

    Crawford, C L; Hill, H H

    2013-03-30

    (63)Nickel radioactive ionization ((63)Ni) is the most common and widely used ion source for ion mobility spectrometry (IMS). Regulatory, financial, and operational concerns with this source have promoted recent development of non-radioactive sources, such as corona discharge ionization (CD), for stand-alone IMS systems. However, there has been no comparison of the negative ion species produced by all three sources in the literature. This study compares the negative reactant and analyte ions produced by three sources on an ion mobility-mass spectrometer: conventional (63)Ni, CD, and secondary electrospray ionization (SESI). Results showed that (63)Ni and SESI produced the same reactant ion species while CD produced only the nitrate monomer and dimer ions. The analyte ions produced by each ion source were the same except for the CD source which produced a different ion species for the explosive RDX than either the (63)Ni or SESI source. Accurate and reproducible reduced mobility (K0) values, including several values reported here for the first time, were found for each explosive with each ion source. Overall, the SESI source most closely reproduced the reactant ion species and analyte ion species profiles for (63)Ni. This source may serve as a non-radioactive, robust, and flexible alternative for (63)Ni. PMID:23598216

  17. Direct coupling of packed column supercritical fluid chromatography to continuous corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Rahmanian, A; Ghaziaskar, H S; Khayamian, T

    2013-01-11

    In this study, packed column supercritical fluid chromatography (SFC) was directly coupled to a continuous corona discharge (CD) ion mobility spectrometer (IMS) with several modifications. The main advantage of the developed detector is its capability to introduce full column effluent up to 2000 mL min(-1) CO(2) gas directly into the IMS cell relative to 40 mL min(-1) CO(2) gas as a maximum tolerance, reported for the previous IMS detectors. This achievement was made possible because of using corona discharge instead of (63)Ni as an ionization source and locating the inlet and outlet of the CO(2) gas in the counter electrode of the CD in opposite direction. In addition, a heated interface was placed between back pressure regulator (BPR) and the IMS cell to heat the output of the BPR for introducing sample as the gas phase into the IMS cell. Furthermore, a make-up methanol flow was introduced between the column outlet and BPR to provide a more uniform flow through the BPR and also to prevent freezing and deposition of the analytes in the BPR. The performance of the SFC-CD-IMS was evaluated by analysis of testosterone, medroxyprogesterone, caffeine, and theophylline as test compounds and figures of merit for these compounds have been calculated. PMID:23261285

  18. An innovative high-power constant-current pulsed-arc power-supply for a high-density pulsed-arc-plasma ion-source using a LaB6-filament

    International Nuclear Information System (INIS)

    An innovative high-power constant-current (CC) pulsed-arc (PA) power-supply (PS) indispensable for a high-density PA plasma ion-source using a lanthanum hexaboride (LaB6) filament was devised by combining a constant-voltage (CV) PA-PS, which is composed of an insulated gate bipolar transistor (IGBT) switch, a CV direct-current (dc) PS and a 270 mF capacitor with a CC-PA-PS, which is composed of an IGBT-switch, a CC-dc-PS and a 400 μH inductor, through the inductor. The hybrid-CC-PA-PS succeeded in producing a flat arc-pulse with a peak power of 56 kW (400 Ax140 V) and a duty factor of more than 1.5%(600 μsx25 Hz) for Japan Proton Accelerator Research Complex (J-PARC) H- ion-source stably. It also succeeded in shortening the 99% rising-time of the arc-pulse-current to about 20 μs and tilting up or down the arc-pulse-current arbitrarily and almost linearly by changing the setting voltage of its CV-dc-PS.

  19. An innovative high-power constant-current pulsed-arc power-supply for a high-density pulsed-arc-plasma ion-source using a LaB6-filament.

    Science.gov (United States)

    Ueno, A; Oguri, H; Ikegami, K; Namekawa, Y; Ohkoshi, K; Tokuchi, A

    2010-02-01

    An innovative high-power constant-current (CC) pulsed-arc (PA) power-supply (PS) indispensable for a high-density PA plasma ion-source using a lanthanum hexaboride (LaB(6)) filament was devised by combining a constant-voltage (CV) PA-PS, which is composed of an insulated gate bipolar transistor (IGBT) switch, a CV direct-current (dc) PS and a 270 mF capacitor with a CC-PA-PS, which is composed of an IGBT-switch, a CC-dc-PS and a 400 microH inductor, through the inductor. The hybrid-CC-PA-PS succeeded in producing a flat arc-pulse with a peak power of 56 kW (400 A x 140 V) and a duty factor of more than 1.5% (600 micros x 25 Hz) for Japan Proton Accelerator Research Complex (J-PARC) H(-) ion-source stably. It also succeeded in shortening the 99% rising-time of the arc-pulse-current to about 20 micros and tilting up or down the arc-pulse-current arbitrarily and almost linearly by changing the setting voltage of its CV-dc-PS. PMID:20192388

  20. Purification of Cu by hydrogen plasma-arc zone melting and characterization of trace impurities by secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Purification of 4N (99.99%) and 6N (99.9999%) purity Cu rods by hydrogen plasma-arc zone melting was carried out. Weight loss in the 4N and 6N Cu rods as a function of number of zone refined passes revealed a higher rate of impurity removal by vaporization in 4N Cu when compared to 6N Cu. Purification effect was studied by analyzing major impurities like Mg, Si, Ca, Ti, Cr, Ni and Fe by O2+ ions and C, O, As, Cl, P and S by Cs+ ion sources using secondary ion mass spectrometry. A remarkable decrease of Si, Ti and Fe impurity concentrations in Cu at x/L = 0.03 after 10 zone passes was observed, but no similar purification effect along the remaining length of the zone refined copper rod was observed. Mg, Se and Ca in the Cu rods were reduced faster by a high evaporation effect due to Pi/PCu > 102. On the other hand, removal of O, C, S and Se was expectedly dominated by vaporization in the form of H2O, CH4, H2S, and H2Se through thermodynamically favored reactions. The overall segregation rate of the individual impurity elements was decreased with an increase in the purity from 4N to 6N of Cu rods. SIMS analysis of trace impurities was successfully carried out on HPZM Cu for quantitative estimation

  1. Effect of Sample Configuration on Droplet-Particles of TiN Films Deposited by Pulse Biased Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    Yanhui Zhao; Guoqiang Lin; Jinquan Xiao; Chuang Dong; Lishi Wen

    2009-01-01

    Orthogonal experiments are used to design the pulsed bias related parameters, including bias magnitude, duty cycle and pulse frequency, during arc ion deposition of TiN films on stainless steel substrates in the case of samples placing normal to the plasma flux. The effect of these parameters on the amount and the size distribution of droplet-particles are investigated, and the results have provided sufficient evidence for the physical model, in which particles reduction is due to the case that the particles are negatively charged and repulsed from negative pulse electric field. The effect of sample configuration on amount and size distribution of the particles are analyzed. The results of the amount and size distribution of the particles are compared to those in the case of samples placing parallel to the plasma flux.

  2. Mechanical properties and phase structure of (TiAlZr)N films deposited by multi arc ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jun, E-mail: zhjun88@126.co [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China) and State Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Dalian 116024 (China); Guo Wenying [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China); Zhang Yu [Department of Physics, Applied Science School, University of Science and Technology Beijing, Beijing, 100083 (China); Guo Qiang; Wang Chuang; Zhang Lipeng [Department of Materials Science and Engineering, Shenyang University, Shenyang 110044 (China)

    2009-07-01

    A series of Ti-Al-Zr alloy targets with the atomic ratio of (Al + Zr)/(Ti + Al + Zr) from 0.29 to 0.40 were used directly to prepare (Ti,Al,Zr)N multi component hard reactive films on high speed steel substrates by multi arc ion plating (MAIP) technology. The surface morphology, the cross-fracture microstructure, the surface compositions and the phase structure of the (Ti,Al,Zr)N films were investigated by scanning electronic microscope (SEM) and X-ray diffraction (XRD). The dense columnar microstructure was obtained in all of the (Ti,Al,Zr)N films, though micro-droplets evidently existed on the surface of the films. The XRD analysis revealed f.c.c. structure only existing in all of the (Ti,Al,Zr)N films. The lattice parameter was changed with varying the Al and Zr contents in alloy targets. The micro-hardness of film surface and the adhesive property of film/substrate were measured. All the (Ti,Al,Zr)N films displayed excellent mechanical properties. The adhesive strength, in terms of critical load, was larger than 100N and the hardness was bigger than 3000Kg(f)/mm{sup 2}. The (Ti,Al,Zr)N film displayed the highest micro-hardness as the atomic ratio of (Al + Zr)/(Ti + Al + Zr) in Ti-Al-Zr alloy target reached 0.40. The present results suggest the expectant substitution of (Ti,Al,Zr)N films for TiN, (Ti,Al)N and (Ti,Zr)N hard films in industrial application and the technical advantage of Ti-Al-Zr alloy targets in preparing (Ti,Al,Zr)N hard films by multi arc ion plating.

  3. Trapped ions and the shielding of dust particles in low-density non-equilibrium plasma of glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Sukhinin, Gennady; Fedoseev, Alexander [Institute of Thermophysics SB RAS, Ave. Lavrentyev, 1, Novosibirsk 630090 (Russian Federation); Antipov, Sergei; Petrov, Oleg; Fortov, Vladimir [Joint Institute for High Temperatures RAS, Izhorskaya 13/19, Moscow 127412 (Russian Federation)], E-mail: sukhinin@itp.nsc.ru

    2009-05-29

    A new model for the formation of trapped ions around a negatively charged dust particle immersed in low-density non-equilibrium plasma of gas discharge is presented. It is shown that the ionic coat leads to a shielding of the proper charge of the dust particle. In experiments it is only possible to detect the effective charge of a dust particle that is equal to the difference between the proper charge of the particle and the charge of trapped ion000.

  4. QUALITY ASSESSMENT OF SF6 INSULATION AT WARU 150 KV GIS COMPARTMENT USING PARTIAL DISCHARGE ION MOBILITY SPECTROMETER

    OpenAIRE

    Yulistya Negara; Syariffuddin Mahmudsyah; Ade Kurniawan

    2009-01-01

    Almost all of modern gas insulated switchgears (GIS) use sulphur hexafluoride (SF6) as insulation material. Therefore, GIS quality much or less depends on quality of its SF6. Failure however can arise within operation of SF6 GIS due to quality decline of SF6. Quality decline of SF6 in GIS can be recognized by existence of decomposition product of SF6, which may appear due to partial discharge, arc during switching, etc. Therefore quality control of SF6 insulation in GIS is necessary in order ...

  5. Pulsed ion beam-assisted carburizing of titanium in methane discharge

    International Nuclear Information System (INIS)

    The carburizing of titanium (Ti) is accomplished by utilizing energetic ion pulses of a 1.5 kJ Mather type dense plasma focus (DPF) device operated in methane discharge. X-ray diffraction (XRD) analysis confirms the deposition of polycrystalline titanium carbide (TiC). The samples carburized at lower axial and angular positions show an improved texture for a typical (200)TiC plane. The Williamson–Hall method is employed to estimate average crystallite size and microstrains in the carburized Ti surface. Crystallite size is found to vary from ∼ 50 to 100 nm, depending on the deposition parameters. Microstrains vary with the sample position and hence ion flux, and are converted from tensile to compressive by increasing the flux. The carburizing of Ti is confirmed by two major doublets extending from 300 to 390 cm−1 and from 560 to 620 cm−1 corresponding to acoustic and optical active modes in Raman spectra, respectively. Analyses by scanning electron microscopy/energy dispersive x-ray spectroscopy (SEM/EDS) have provided qualitative and quantitative profiles of the carburized surface. The Vickers microhardness of Ti is significantly improved after carburizing. (nuclear physics)

  6. Surface Coating Constraint Induced Self-Discharging of Silicon Nanoparticles as Anodes for Lithium Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Langli; Zhao, Peng; Yang, Hui; Liu, Borui; Zhang, Jiguang; Cui, Yi; Yu, Guihua; Zhang, Sulin; Wang, Chong M.

    2015-10-01

    One of the key challenges of Si-based anodes for lithium ion batteries is the large volume change upon lithiation and delithiation, which commonly leads to electrochemo-mechanical degradation and subsequent fast capacity fading. Recent studies have shown that applying nanometer-thick coating layers on Si nanoparticle (SiNPs) enhances cyclability and capacity retention. However, it is far from clear how the coating layer function from the point of view of both surface chemistry and electrochemo-mechanical effect. Herein, we use in situ transmission electron microscopy to investigate the lithiation/delithiation kinetics of SiNPs coated with a conductive polymer, polypyrrole (PPy). We discovered that this coating layer can lead to “self-delithiation” or “self-discharging” at different stages of lithiation. We rationalized that the self-discharging is driven by the internal compressive stress generated inside the lithiated SiNPs due to the constraint effect of the coating layer. We also noticed that the critical size of lithiation-induced fracture of SiNPs is increased from ~ 150 nm for bare SiNPs to ~ 380 nm for the PPy-coated SiNPs, showing a mechanically protective role of the coating layer. These observations demonstrate both beneficial and detrimental roles of the surface coatings, shedding light on rational design of surface coatings for silicon to retain high-power and high capacity as anode for lithium ion batteries.

  7. 水或液氮中电弧放电制备炭纳米材料%The production of carbon nano-materials by arc discharge under water or liquid nitrogen

    Institute of Scientific and Technical Information of China (English)

    邢刚; 贾申利; 史宗谦

    2007-01-01

    The growth mechanism of carbon nano-materials by arc discharge in water or liquid nitrogen was investigated using a special arc discharge apparatus. High-resolution transmission electron microscopy was used to observe and analyze the products. Results indicated that multi-walled carbon nanotubes (MWCNTs) and carbon onions can be produced by arc discharge in water and liquid nitrogen respectively. Single-walled carbon nanohorns can be produced by arc discharge in liquid nitrogen, and cobalt encapsulated carbon nano-particles can be produced by cobalt catalyzed carbon arc discharge in water. The liquids acted as quenching walls for the nucleation and growth of carbon nano-materials, resulting in the formation of different forms of carbon nano-materials. A cross alternating magnetic field with a frequency 5 Hz can affect the nucleation of nano-materials to form MWCNTs or carbon onions because nucleation time is longer than the periodicity of the magnetic field. Based on the experimental phenomena, a primary physical model was proposed to interpret the growth of nano-materials by arc discharge in liquids.%利用特制的电弧放电装置,研究了水或液氮中碳电弧放电形成炭纳米材料的机理.借助高分辨率透射电子显微镜对电弧放电生成的产物进行了观察和分析.结果表明:在水或液氮中碳电弧放电可以生成多壁碳纳米管和碳纳米洋葱结构,液氮中碳电弧放电可以生成单壁碳纳米角,水中钴催化碳电弧放电可以生成碳包裹的纳米钴颗粒.横向低频交变磁场会影响碳纳米材料的形核过程,并且可以推测磁场交变的频率5 Hz与纳米管、纳米洋葱等结构的生长周期存在某种拟合.根据实验现象,提出了一种解释液体中碳电弧放电过程纳米材料生成的理论模型.

  8. Ion energy distributions for the identification of active species and processes in low pressure hollow cathode discharges

    Energy Technology Data Exchange (ETDEWEB)

    Tanarro, I; Herrero, V J [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)], E-mail: itanarro@iem.cfmac.csic.es

    2009-08-15

    Energy distributions of ions generated in hollow cathode low pressures dc discharges of different gases and gas mixtures containing Ar, H{sub 2}, N{sub 2}, O{sub 2} or CH{sub 4} are studied by quadrupole mass spectrometry. The ions are sampled through a small diaphragm in the grounded cathode. The measured distributions are mostly determined by the acceleration of ions in the sheath region between the negative glow and the cathode, displaying in general a narrow peak centred at energies close to the anode potential, but with specific features for the distinct ions. It is shown that information about ion production and sheath collision processes can be derived from the shapes of the different energy distributions. In some cases these distributions are used for the estimation of the relative abundance of ions with the same mass/charge ratio but different compositions in complex gas mixtures.

  9. ZnO nanoparticles decorated on graphene sheets through liquid arc discharge approach with enhanced photocatalytic performance under visible-light

    Science.gov (United States)

    Ashkarran, Ali Akbar; Mohammadi, Bahareh

    2015-07-01

    We present an innovative approach for synthesis of zinc oxide-graphene (ZnO-G) hybrid nanostructures through combination of improved hummer and arc discharge methods in liquid. A detailed study of the considerable visible-light photocatalytic activities of these nanostructures for the degradation of Phenol red (PR) and Methyl orange (MO) as standard organic compounds under the irradiation of 90 W halogen light for 2 h has been performed. The ZnO-G nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer Emmett Teller (BET) and ultra violet-visible absorption spectroscopy (UV-vis). The results revealed that the ZnO-G nanostructures extended the light absorption spectrum toward the visible region and remarkably enhanced the photodegradation of standard dyes under visible-light irradiation. It has been confirmed that the ZnO-G nanostructures could be excited by visible-light (E ∼ 2.6 eV). The major enhancement in the photocatalytic activity of ZnO-G nanostructures under visible-light irradiation can be attributed to the effect of electron transport among ZnO nanoparticles (NPs) and graphene sheets. A mechanism for photocatalytic degradation of organic pollutants over ZnO-G photocatalyst was proposed based on our observations.

  10. Influence of N2 partial pressure on structural and microhardness properties of TiN/ZrN multilayers deposited by Ar/N2 vacuum arc discharge

    Science.gov (United States)

    Naddaf, M.; Abdallah, B.; Ahmad, M.; A-Kharroub, M.

    2016-08-01

    The influence of N2 partial pressure on structural, mechanical and wetting properties of multilayered TiN/ZrN thin films deposited on silicon substrates by vacuum arc discharge of (N2 + Ar) gas mixtures is investigated. X-ray diffraction (XRD) results show that the average texturing coefficient of (1 1 1) orientation and the grain size of both TiN and ZrN individual layers increase with increasing the N2 partial pressure. The Rutherford back scattering (RBS) measurements and analysis reveal that incorporation of the nitrogen in the film increases with increasing the N2 partial pressure and both TiN and ZrN individual layers have a nitrogen over-stoichiometry for N2 partial pressure ⩾50%. The change in the film micro-hardness is correlated to the changes in crystallographic texture, grain size, stoichiometry and the residual stress in the film as a function of the N2 partial pressure. In particular, stoichiometry of ZrN and TiN individual is found to play the vital role in determining the multilayer hardness. The multilayer film deposited at N2 partial pressure of 25% has the best stoichiometric ratio of both TiN and ZrN layers and the highest micro-hardness of about 32 GPa. In addition, water contact angle (WCA) measurements and analysis show a decrease in the work of adhesion on increasing the N2 partial pressure.

  11. On the influence of a TiN interlayer on DLC coatings produced by pulsed vacuum arc discharge: Compositional and morphological study

    Energy Technology Data Exchange (ETDEWEB)

    Segura-Giraldo, B. [Departamento de Fisica y Quimica, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia); Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [Departamento de Fisica y Quimica, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia); Grupo de Desarrollo de Nuevos Materiales, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia); Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia); Arango-Arango, P.J. [Departamento de Fisica y Quimica, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia); Laboratorio de Fisica del Plasma, Universidad Nacional de Colombia Sede Manizales, Campus La Nubia, Km. via al aeropuerto, Manizales (Colombia)

    2009-10-15

    The influence of a TiN interlayer on DLC coatings grown on silicon (1 0 0), 316 stainless steel and KCl by using the PAPVD pulsed arc discharge technique is presented in this paper. The structure of the coatings was determined by means of FTIR through observation of the absorption band modes of CH{sub 2} between 3100 and 2800 cm{sup -1} and representation of the sp{sup 3} and sp{sup 2} carbon bonds, respectively. The sp{sup 3}/sp{sup 2} bonds ratio was calculated by using the base line method and producing a value greater than 1 which was a good prediction of high hardness. XPS analysis of the films was made; the wide spectrum showed the elemental composition of the films (Ti, N, C). A narrow spectrum of C1s at binding energy of 284.48 eV was obtained, and its deconvolution showed peaks of sp{sup 3}, sp{sup 2} and Ti-C. Ti-C bonds were formed due to diffusion of carbon atoms into a TiN matrix. The concentration for the XPS spectra was calculated by using the area under the curve of sp{sup 3} and sp{sup 2} peaks. The morphology of the bilayer, including roughness, grain size and thickness was studied through SPM techniques.

  12. Deposition of silicon-carbon coatings from the plasma of a non-self-sustained arc discharge with a heated cathode

    Science.gov (United States)

    Grenadyorov, A. S.; Oskomov, K. V.; Solov'ev, A. A.; Rabotkin, S. V.

    2016-05-01

    Amorphous hydrogenated carbon doped with silicon oxide ( a-C:H:Si:O), which is referred to as silicon-carbon coatings in this work, consists of thin amorphous films, which are used as commercial solid lubricants due to their higher stability under extreme environmental conditions as compared to amorphous hydrogenated carbon. The deposition of silicon-carbon coatings from the plasma of a non-self-sustained arc discharge with a heated cathode is considered. Silicon-carbon coatings are deposited using polyphenul methylsiloxane as a precursor at a flow rate of 0.05 mL/min in an argon atmosphere at a pressure of 0.1 Pa. A high-frequency power supply is used to apply a high-frequency bias voltage to a substrate during deposition. After deposition, the mechanical properties of the coatings are studied. The maximum hardness of the coating is 20 GPa at a minimum friction coefficient of 0.16 and a wear rate of 1.3 × 10-5 mm3 N-1 m-1. Energy dispersive analysis shows that the coatings contain a significant content of carbon and oxygen (about 80 and 15%, respectively) and a low content of silicon (about 5%).

  13. Properties and etching rates of negative ions in inductively coupled plasmas and dc discharges produced in Ar/SF6

    DEFF Research Database (Denmark)

    Draghici, Mihai; Stamate, Eugen

    2010-01-01

    Negative ion production is investigated in a chamber with transversal magnetic filter operated in dc or inductively coupled plasma (ICP) modes in Ar/SF6 gas mixtures. Plasma parameters are evaluated by mass spectrometry and Langmuir probe for different discharge conditions. The density ratio of n...

  14. Local Ion Nitriding of 38KhMYuA Steel with Glow Discharge in a Hollow Cathode

    Directory of Open Access Journals (Sweden)

    V.V. Budilov

    2015-09-01

    Full Text Available The effect of local ion nitriding in glow discharge with the hollow cathode effect (HCE on microstructure, phase composition and microhardness of steel 38KhMYuA was studied. Optical microscopy of the nitrided layer was carried out. The kinetic of diffusion layer growth was investigated.

  15. Three Filtered Vacuum Arc Plasma Sources Deposition & Implantation System

    Institute of Scientific and Technical Information of China (English)

    WU Xian-ying; ZHANG Hui-xing; LI Qiang

    2004-01-01

    A deposition & implantation system, which includes three filtered vacuum arc plasma sources, has been built. Vacuum arc discharge is used to produce high-density metal plasma; Curved magnetic filtering technique is used to transfer the plasma into out-of-sight vacuum chamber and reduce macro-particles from the vacuum arc plasma in order to drastically reduce the macro-particles contamination of the films. The up to 30 kV negative bias applied to the target can be used for ion implantation in order to improve the film adhesion; or for ion sputtering to clear the substrate surface. The 0 to 300 V negative bias can be used to adjust the ion energy which forming films. The system is designed for various thin films synthesizing, such as single-layer, compound layer, multi-layer films. It's principle, components and applications are described in the literature.

  16. 滑动弧等离子体分解二甲醚制氢%Hydrogen Generation from DME Using Gliding Arc Gas Discharge

    Institute of Scientific and Technical Information of China (English)

    王保伟; 葛文杰; 吕一军; 孙启梅; 胡爽慧

    2013-01-01

      对常温常压下滑动弧等离子体放电分解二甲醚(DME)制氢进行了研究,探讨了进气流量、电极间距、放电电压、电极形状和水/DME摩尔比以及添加的空气量对滑动弧等离子体DME转化制氢的影响。结果表明,当进气流量由43 mLmin1增加到76 mLmin1时,DME转化率从58.9%下降至50.6%,H2收率从26.9%下降至19.7%。随着电极间距由2 mm增加到4 mm、放电电压由11.2 kV增加到17.1kV时,DME转化率和H2收率增加,制氢能耗降低。电极最宽处有5mm平滑的竖直部分、上端电极长度50 mm,弧度23o的2#电极对DME放电反应最有利;添加水蒸汽和适量的空气对 DME 分解制氢反应有利,当水/DME 摩尔比为2.3,添加空气的体积分数为25.8%时,DME 转化率最大为74.1%,氢气的收率最大为43.4%。%Gliding arc gas discharge was used for the generation of hydrogen from dimethyl ether (DME). Effects of reaction conditions, such as total feed gas flow rate, the electrode gap, discharge voltage, the electrode shape, H2O/DME ratio and addition amount of air, on the DME conversion and hydrogen yield were studied. The results show that, as the total feed gas flow rate increases from 43 mLmin1 to 76 mLmin1, DME conversion decreases from 58.9% to 50.6% and hydrogen yield decreases from 26.9% to 19.7%. As the electrode gap increases from 2 mm to 4 mm and discharge voltage increases from 11.2 kV to 17.1 kV, the DME conversion and hydrogen yield increase, while hydrogen energy consumption (SEC) decreases. It was found that the 2electrode is most in favor to DME conversion, which has a smooth vertical part of 5 mm in the widest place of the electrode, an upper part electrode length of 50 mm and an electrode upper arc part of 23. Addition of steam and addition of air are favorable for DME conversion. When H2O/DME mole ratio is 2.3 and air volume concentration is 25.8%, the maximum DME conversion and hydrogen

  17. Multi-Component Ion Modifiers and Arcing Suppressants to Enhance Differential Mobility Spectrometry for Separation of Peptides and Drug Molecules

    Science.gov (United States)

    Blagojevic, Voislav; Koyanagi, Gregory K.; Bohme, Diethard K.

    2014-03-01

    The optimization of ion/molecule chemistry in a differential mobility spectrometer (DMS) is shown to result in improved peak capacity, separation, and sensitivity. We have experimented with a modifier composed of multiple components, where each component accomplishes a specific task on mixtures of peptides and small drug molecules. Use of a higher proton affinity modifier (hexanol) provides increased peak capacity and separation. Analyte ion/modifier proton transfer is suppressed by adding a large excess of low proton affinity modifier (water or methanol), significantly increasing signal intensity and sensitivity for low proton affinity analytes. Finally, addition of an electrical arcing suppressant (chloroform) allows the device to operate reliably at higher separation fields, improving peak capacity and separation. We demonstrate a 20 % increase in the device peak capacity without any loss of sensitivity and estimate that further optimization of the modifier composition can increase this to 50 %. Use of 3-, 4-, or even 5-component modifiers offers the opportunity for the user to fine-tune the modifier performance to maximize the device performance, something not possible with a single component modifier.

  18. ION GUN

    Science.gov (United States)

    Dandl, R.A.

    1961-10-24

    An ion gun is described for the production of an electrically neutral ionized plasma. The ion gun comprises an anode and a cathode mounted in concentric relationship with a narrow annulus between. The facing surfaces of the rear portions of the anode and cathode are recessed to form an annular manifold. Positioned within this manifold is an annular intermediate electrode aligned with the an nulus between the anode and cathode. Gas is fed to the manifold and an arc discharge is established between the anode and cathode. The gas is then withdrawn from the manifold through the annulus between the anode and cathode by a pressure differential. The gas is then ionized by the arc discharge across the annulus. The ionized gas is withdrawn from the annulus by the combined effects of the pressure differential and a collimating magnetic field. In a 3000 gauss magnetic field, an arc voltage of 1800 volts, and an arc current of 0.2 amp, a plasma of about 3 x 10/sup 11/ particles/cc is obtained. (AEC)

  19. Welding arc plasma physics

    Science.gov (United States)

    Cain, Bruce L.

    1990-01-01

    The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

  20. Simultaneous determination of 2-furfural and 5-methyl-2-furfural using corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Jafari, M T; Khayamian, T

    2009-06-01

    A novel technique, corona discharge ion mobility spectrometry (CD-IMS), was developed for the qualitative and quantitative determination of 2-furfural (F) and 5-methyl-2-furfural (MF) in aqueous solutions. The limits of detection (LODs) were 5.3 x 10(-3) microg/mL for F and 6.7 x 10(-3) microg/mL for MF. The linear dynamic ranges of 1.16 x 10(-2) to 1.04 microg/mL and 2.20 x 10(-2) to 1.10 microg/mL were obtained for F and MF, respectively. The relative standard deviation was below 12% for both compounds. In addition to analysis of the individual compound, simultaneous determination of F and MF was also investigated. It was realized that F imposes a matrix effect on the MF signal and vice versa. The standard addition method was used to deal with the matrix effect. The recovery of the compounds in the synthetic samples validates the capability of the method. PMID:19531891

  1. Direct analysis of human breath ammonia using corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Jazan, Elham; Mirzaei, Hadi

    2014-01-01

    In this study, ammonia in human breath was directly determined using corona discharge ionization ion mobility spectrometry (CD-IMS) technique with several important advantages including high sensitivity, low cost, high speed, and ease of maintenance. The temperature effect on the ammonia signal was evaluated too. The results indicated that the best temperature for the investigation of breath ammonia was 150°C. The analytical results showed that the linear dynamic range was between 12 and 810ppb and the detection limit was 6.6ppb. The relative standard deviation (RSD) was obtained to be 5, 3, and 3 for 290, 348, and 522ppb, respectively. The amounts of ammonia in breath of eight healthy volunteers were measured. The values were between 236 and 1218ppb. Also, the inequality in breath ammonia levels was scrutinized over a 6h working day for three healthy volunteers. The results showed a drop in breath ammonia from the morning amount to the mid-day measurement and then, a progressive increase while the day continued. In addition, the amounts of ammonia were determined to be 1494-1553ppb in exhaled breath of two renal failure patients. The results obtained in this work revealed that the method was conveniently established without any considerable sample pretreatment for direct analysis of ammonia in human breath. PMID:24120979

  2. Three-dimensional particle-in-cell simulation of a miniature plasma source for a microwave discharge ion thruster

    OpenAIRE

    Takao, Yoshinori; Koizumi, Hiroyuki; Komurasaki, Kimiya; Eriguchi, Koji; Ono, Kouichi

    2014-01-01

    We have developed a three-dimensional particle model for a miniature microwave discharge ion thruster to elucidate the mechanism of ECR discharges confined in a small space. The model consists of a particle-in-cell simulation with a Monte Carlo collision algorithm (PIC-MCC) for the kinetics of charged particles, a finite-difference time-domain method for the electromagnetic fields of 4.2 GHz microwaves, and a finite element analysis for the magnetostatic fields of permanent magnets. The PIC-M...

  3. Time-evolution of the ion velocity distribution function in the discharge of a Hall effect thruster

    CERN Document Server

    Mazouffre, S; Sadeghi, N

    2009-01-01

    The temporal characteristics of the Xe$^+$ ion axial Velocity Distribution Function (VDF) were recorded in the course of low-frequency discharge current oscillations ($\\sim$~14 kHz) of the 5 kW-class PPS$\\circledR$X000 Hall thruster. The evolution in time of the ion axial velocity component is monitored by means of a laser induced fluorescence diagnostic tool with a time resolution of 100 ns. As the number of fluorescence photons is very low during such a short time period, a hom-made pulse-counting lock-in system was used to perform real-time discrimination between background photons and fluorescence photons. The evolution in time of the ion VDF was observed at three locations along the thruster channel axis after a fast shut down of the thruster power. The anode discharge current is switched off at 2 kHz during 5 $\\mu$s without any synchronization with the current oscillation cycle. This approach allows to examine the temporal behavior of the ion VDF during decay and ignition of the discharge as well as dur...

  4. ZnO nanoparticles decorated on graphene sheets through liquid arc discharge approach with enhanced photocatalytic performance under visible-light

    Energy Technology Data Exchange (ETDEWEB)

    Ashkarran, Ali Akbar, E-mail: ashkarran@umz.ac.ir; Mohammadi, Bahareh

    2015-07-01

    Graphical abstract: TEM image of ZnO–graphene composite. - Highlights: • Innovative approach for synthesis of zinc oxide–graphene (ZnO–G) hybrid nanostructures. • Combination of bottom-up and top-down methods. • Decoration of ZnO nanoparticles on the surface of graphene. • Visible-light photocatalytic performance. - Abstract: We present an innovative approach for synthesis of zinc oxide–graphene (ZnO–G) hybrid nanostructures through combination of improved hummer and arc discharge methods in liquid. A detailed study of the considerable visible-light photocatalytic activities of these nanostructures for the degradation of Phenol red (PR) and Methyl orange (MO) as standard organic compounds under the irradiation of 90 W halogen light for 2 h has been performed. The ZnO–G nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer Emmett Teller (BET) and ultra violet–visible absorption spectroscopy (UV–vis). The results revealed that the ZnO–G nanostructures extended the light absorption spectrum toward the visible region and remarkably enhanced the photodegradation of standard dyes under visible-light irradiation. It has been confirmed that the ZnO–G nanostructures could be excited by visible-light (E ∼ 2.6 eV). The major enhancement in the photocatalytic activity of ZnO–G nanostructures under visible-light irradiation can be attributed to the effect of electron transport among ZnO nanoparticles (NPs) and graphene sheets. A mechanism for photocatalytic degradation of organic pollutants over ZnO–G photocatalyst was proposed based on our observations.

  5. Arc Power Limit and Distribution on the Large Negative Ion Source Based on JT-60 NNBI

    Institute of Scientific and Technical Information of China (English)

    LEIGuangjiu; N.Umeda; M.Kawai; T.Yamamoto; M.Kuriyama; T.Ohga; N.Ebisawa; T.Yamazaki; M.Kusaka; K.Kikuchi; S.Hikida; K.Usui; M.Kazawa; S.Numazawa; K.Mogaki; A.Honda; F.Satoh; S.Norio; K.Ooshima

    2001-01-01

    The target of the large negative ion source based on neutral beam injection (N-NBI) is to produce neutral beam current of 22 A and beam power of 10 MW at 500 keV with duration time of 10 s. Since it was successfully operated in 1996, the 5.3 MW neutral beam power at 380 keV with duration time of 3 s has been achieved. In recent years improving and enhancing the beam power are going on. Several reasons such as plasma non-uniformity, higher beam density at the upper region in the beam profile,

  6. A new type of MHD activity in JET ICRF-only discharges with high fast-ion energy contents

    Energy Technology Data Exchange (ETDEWEB)

    Mantsinen, M.J. [JET Joint Undertaking, Abingdon, Oxfordshire (United Kingdom); Helsinki University of Technology, Association Euratom-Tekes (Finland); Sharapov, S.; Alper, B.; Gondhalekar, A.; McDonald, D.C. [JET Joint Undertaking, Abingdon, Oxfordshire (United Kingdom)

    2000-12-01

    The question of sawtooth stabilization at very high fast-ion energy contents has been addressed in discharges carried out in the JET tokamak with ion cyclotron resonance frequency (ICRF) heating and varying plasma density, controlled by deuterium gas puffs. In these experiments dramatic differences in the sawtooth behaviour have been observed. When the plasma density n{sub e} decreases below a certain threshold, the sawtooth frequency and the crash duration time increase by a factor of five. Since the fast-ion energy content increases with decreasing n{sub e} due to the inverse proportionality of the fast-ion slowing-down time on n{sub e}, the threshold in n{sub e} corresponds to a threshold in the fast-ion energy content. In the present experiments, this threshold is reached when the fast-ion energy contribution to the total plasma diamagnetic energy content becomes larger than 45%. The sawtooth activity with short sawtooth free period is accompanied by MHD activity, with a toroidal mode number n = 1 at frequencies between 55 and 65 kHz. This activity is interpreted as an energetic particle fishbone mode that is resonant with the ICRF-driven fast ions. The experimental results appear to be consistent with the stability diagram for sawtooth and fishbone modes (White 1989 Theory of Tokamak Plasmas (Amsterdam: North-Holland)), exploring the part of the diagram with a very large fast-ion population. (author)

  7. A new type of MHD activity in JET ICRF-only discharges with high fast-ion energy contents

    Energy Technology Data Exchange (ETDEWEB)

    Mantsinen, M.; Sharapov, S.; Alper, B. [and others

    2000-12-01

    The question of sawtooth stabilisation at very high fast ion energy contents has been addressed in discharges carried out in the JET tokamak with ion cyclotron resonance frequency (ICRF) heating and varying plasma density, controlled by deuterium gas puffs. In these experiments dramatic differences in the sawtooth behaviour have been observed. When the plasma density n{sub e} decreases below a certain threshold, the sawtooth frequency and the crash duration time increase by a factor of five. Since the fast-ion energy content increases with decreasing n{sub e} due to the inverse proportionality of the fast-ion slowing-down time on n{sub e}, the threshold in n{sub e} corresponds to a threshold in the fast ion energy content. In the present experiments, this threshold is reached when the fast ion energy contribution to the total plasma diamagnetic energy content becomes larger than 45%. The sawtooth activity with short sawtooth free period is accompanied by MHD activity, with a toroidal mode number n = 1 at frequencies between 55-65 kHz. This activity is interpreted as an energetic particle fishbone mode that is resonant with the ICRF-driven fast ions. The experimental results appear to be consistent with the stability diagram for sawtooth and fishbone modes [White, Theory of Tokamak Plasmas (North-Holland, Amsterdam, 1989)], exploring the part of the diagram with a very large fast ion population. (author)

  8. A new type of MHD activity in JET ICRF-only discharges with high fast-ion energy contents

    Science.gov (United States)

    Mantsinen, M. J.; Sharapov, S.; Alper, B.; Gondhalekar, A.; McDonald, D. C.

    2000-12-01

    The question of sawtooth stabilization at very high fast-ion energy contents has been addressed in discharges carried out in the JET tokamak with ion cyclotron resonance frequency (ICRF) heating and varying plasma density, controlled by deuterium gas puffs. In these experiments dramatic differences in the sawtooth behaviour have been observed. When the plasma density ne decreases below a certain threshold, the sawtooth frequency and the crash duration time increase by a factor of five. Since the fast-ion energy content increases with decreasing ne due to the inverse proportionality of the fast-ion slowing-down time on ne, the threshold in ne corresponds to a threshold in the fast-ion energy content. In the present experiments, this threshold is reached when the fast-ion energy contribution to the total plasma diamagnetic energy content becomes larger than 45%. The sawtooth activity with short sawtooth free period is accompanied by MHD activity, with a toroidal mode number n = 1 at frequencies between 55 and 65 kHz. This activity is interpreted as an energetic particle fishbone mode that is resonant with the ICRF-driven fast ions. The experimental results appear to be consistent with the stability diagram for sawtooth and fishbone modes (White 1989 Theory of Tokamak Plasmas (Amsterdam: North-Holland)), exploring the part of the diagram with a very large fast-ion population.

  9. STRUCTURE, MECHANICAL PROPERTIES AND THERMAL STABILITY OF DIAMOND-LIKE CARBON FILMS PREPARED BY ARC ION PLATING

    Institute of Scientific and Technical Information of China (English)

    Y.S. Zou; J.D. Zheng; J. Gong; C. Sun; R.F. Huang; L.S. Wen

    2005-01-01

    Diamond-like Carbon (DLC) films have been prepared on Si(100) substrates by arc ion plating in conjunction with pulse bias voltage under H2 atmosphere. The deposited films have been characterized by scanning electron microscopy and atomic force microscopy. The results show that the surface of the film is smooth and dense without any cracks, and the surface roughness is low. The bonding characteristic of the films has been studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. It shows the sp3 bond content of the film deposited at -200V is 26.7%. The hardness and elastic modulus of the film determined by nanoindentation technique are 30.8 and 250.1GPa, respectively. The tribological characteristic of the films reveals that they have low friction coefficient and good wear-resistance. After deposition, the films have been annealed in the range of 350-700℃ for 1h in vacuum to investigate the thermal stability. Raman spectra indicate that the ID/IG ratio and G peak position have few detectable changes below 500℃. Further increasing the annealing temperature, the hydrogen can be released, the structure rearranges, and the phase transition of sp3 configured carbon to sp2 configured carbon appears.

  10. Time-evolution of the ion velocity distribution function in the discharge of a Hall effect thruster

    OpenAIRE

    Mazouffre, S.; Gawron, D.; N. Sadeghi

    2009-01-01

    The temporal characteristics of the Xe$^+$ ion axial Velocity Distribution Function (VDF) were recorded in the course of low-frequency discharge current oscillations ($\\sim$~14 kHz) of the 5 kW-class PPS$\\circledR$X000 Hall thruster. The evolution in time of the ion axial velocity component is monitored by means of a laser induced fluorescence diagnostic tool with a time resolution of 100 ns. As the number of fluorescence photons is very low during such a short time period, a hom-made pulse-c...

  11. Factors Influencing the Electron Yield of Needle-Ring Pulsed Corona Discharge Electron Source for Negative Ion Mobility Spectrometer

    Science.gov (United States)

    Liu, Xin; Li, Shengli; Li, Mingshu

    2013-12-01

    A simple negative ion mobility spectrometer (IMS) is designed and used to investigate the factors that influence the number and efficiency of electrons generated by the needle-ring pulsed corona discharge electron source. Simulation with Ansoft Maxwell 12 is carried out to analyze the electric field distribution within the IMS, and to offer the basis and foundation for analyzing the measurement results. The measurement results of the quantities of electrons show that when the drift electric field strength and the ring inner diameter rise, both the number of effective electrons and the effective electron rate are increased. When the discharge voltage becomes stronger, the number of effective electrons goes up while the effective electron rate goes down. In light of the simulation results, mechanisms underlying the effects of drift electric field strength, ring inner diameter, and discharge voltage on the effective electron number and effective electron rate are discussed. These will make great sense for designing negative ion mode IMS using the needle-ring pulsed corona discharge as the electron source.

  12. Pollutant removal from industrial discharge water using individual and combined effects of adsorption and ion-exchange processes: Chemical abatement

    Directory of Open Access Journals (Sweden)

    Jérémie Charles

    2016-03-01

    Full Text Available In this study, adsorption-oriented processes for pollutant removal from metal polycontaminated surface-finishing discharge water were applied individually as well as in combination with ion-exchange treatment to remove the remaining metal ions and organic load. Several materials were compared using batch experiments, namely an activated carbon, three ion-exchange resins (IRA 402Cl, IR 120H and TP 207, and two non-conventional cross-linked polysaccharide-based biosorbents (starch and cyclodextrin. This article presents the abatements obtained in chemical pollution as monitored by complete chemical analysis. For the same experimental conditions (similar discharge water, pollutant concentrations, stirring rate, contact time, and initial pH, the highest levels of pollutant removal were attained with the combined use of two materials, an activated carbon and a mixture of two ion-exchange resins. This physicochemical treatment effectively lowered the main pollutants present in the discharge water such as Cu, Ni and COD, by more than 96%, 79% and 74% respectively (average values for three samples, while the treatment with carbon alone lowered them by 58%, 9% and 70%, and resins alone by 85%, 61% and 16%. Similar interesting results were obtained with the cyclodextrin-based adsorbent and its use alone was sufficient to obtain decreases in Cu, Ni and COD of more than 94%, 77% and 67% respectively. The adsorption-oriented process using cyclodextrin polymer could be an advantageous approach for removing organic and metallic pollutants from metal surface-finishing discharge water due to the non-toxic character of CD to humans and the environment.

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

    Science.gov (United States)

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

    2016-07-01

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

  14. Charge-state and element-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    CERN Document Server

    Franz, Robert; Anders, André

    2014-01-01

    The energy distribution functions of ions in the cathodic arc plasma using composite AlCr cathodes were measured as a function of the background gas pressure in the range 0.5 to 3.5 Pa for different cathode compositions and gas atmospheres. The most abundant aluminium ions were Al$^{+}$ regardless of the background gas species, whereas Cr$^{2+}$ ions were dominating in Ar and N$_2$ and Cr$^{+}$ in O$_2$ atmospheres. The energy distributions of the aluminium and chromium ions typically consisted of a high energy fraction due to acceleration in the expanding plasma plume from the cathode spot and thermalised ions that were subjected to collisions in the plasma cloud. The fraction of the latter increased with increasing background gas pressure. Atomic nitrogen and oxygen ions showed similar energy distributions as the aluminium and chromium ions, whereas the argon and molecular nitrogen and oxygen ions were mainly thermalised. In addition to the positively charged metal and gas ions, negatively charged oxygen an...

  15. Frequency Stabilization of a 369 nm Diode Laser by Nonlinear Spectroscopy of Ytterbium Ions in a Discharge

    CERN Document Server

    Lee, Michael W; Marciniak, Christian; Biercuk, Michael J

    2014-01-01

    We demonstrate stabilisation of an ultraviolet diode laser via Doppler free spectroscopy of Ytterbium ions in a discharge. Our technique employs polarization spectroscopy, which produces a natural dispersive lineshape whose zero-crossing is largely immune to environmental drifts, making this signal an ideal absolute frequency reference for Yb$^+$ ion trapping experiments. We stabilise an external-cavity diode laser near 369 nm for cooling Yb$^+$ ions, using amplitude-modulated polarisation spectroscopy and a commercial PID feedback system. We achieve stable, low-drift locking with a standard deviation of measured laser frequency ~400 kHz over 10 minutes, limited by the instantaneous linewidth of the diode laser. These results and the simplicity of our optical setup makes our approach attractive for stabilization of laser sources in atomic-physics applications.

  16. The effect of lithium loadings on anode to the voltage drop during charge and discharge of Li-ion capacitors

    Science.gov (United States)

    Cao, W. J.; Greenleaf, M.; Li, Y. X.; Adams, D.; Hagen, M.; Doung, T.; Zheng, J. P.

    2015-04-01

    The IR voltage drop from the anode and cathode of Li-ion capacitors during charge and discharge was studied. Li-ion capacitors were made with activated carbon cathode and hard carbon anode with different loadings of stabilized lithium metal powder (SLMP). It was found that the LICs with high SLMP loadings showed smaller voltage drop than LICs with low SLMP loadings. It was also found that at low SLMP loadings, the IR voltage drops at high cell voltages were smaller than that at low cell voltages; while at high SLMP loadings, small IR voltage drops were obtained for both low and high cell voltages. The electrochemical impedance spectroscopy confirmed that voltage drops are directly related to the internal resistances of Li-ion capacitors.

  17. Collision-induced dissociation analysis of negative atmospheric ion adducts in atmospheric pressure corona discharge ionization mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2013-05-01

    Collision-induced dissociation (CID) experiments were performed on atmospheric ion adducts [M + R](-) formed between various types of organic compounds M and atmospheric negative ions R(-) [such as O2(-), HCO3(-), COO(-)(COOH), NO2(-), NO3(-), and NO3(-)(HNO3)] in negative-ion mode atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. All of the [M + R](-) adducts were fragmented to form deprotonated analytes [M - H](-) and/or atmospheric ions R(-), whose intensities in the CID spectra were dependent on the proton affinities of the [M - H](-) and R(-) fragments. Precursor ions [M + R](-) for which R(-) have higher proton affinities than [M - H](-) formed [M - H](-) as the dominant product. Furthermore, the CID of the adducts with HCO3(-) and NO3(-)(HNO3) led to other product ions such as [M + HO](-) and NO3(-), respectively. The fragmentation behavior of [M + R](-) for each R(-) observed was independent of analyte type (e.g., whether the analyte was aliphatic or aromatic, or possessed certain functional groups). PMID:23479312

  18. Collision-induced dissociation analysis of negative atmospheric ion adducts in atmospheric pressure corona discharge ionization mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2013-05-01

    Collision-induced dissociation (CID) experiments were performed on atmospheric ion adducts [M + R](-) formed between various types of organic compounds M and atmospheric negative ions R(-) [such as O2(-), HCO3(-), COO(-)(COOH), NO2(-), NO3(-), and NO3(-)(HNO3)] in negative-ion mode atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. All of the [M + R](-) adducts were fragmented to form deprotonated analytes [M - H](-) and/or atmospheric ions R(-), whose intensities in the CID spectra were dependent on the proton affinities of the [M - H](-) and R(-) fragments. Precursor ions [M + R](-) for which R(-) have higher proton affinities than [M - H](-) formed [M - H](-) as the dominant product. Furthermore, the CID of the adducts with HCO3(-) and NO3(-)(HNO3) led to other product ions such as [M + HO](-) and NO3(-), respectively. The fragmentation behavior of [M + R](-) for each R(-) observed was independent of analyte type (e.g., whether the analyte was aliphatic or aromatic, or possessed certain functional groups).

  19. Towards Stable Lithium-Sulfur Batteries with a Low Self-Discharge Rate: Ion Diffusion Modulation and Anode Protection.

    Science.gov (United States)

    Xu, Wen-Tao; Peng, Hong-Jie; Huang, Jia-Qi; Zhao, Chen-Zi; Cheng, Xin-Bing; Zhang, Qiang

    2015-09-01

    The self-discharge of a lithium-sulfur cell decreases the shelf-life of the battery and is one of the bottlenecks that hinders its practical applications. New insights into both the internal chemical reactions in a lithium-sulfur system and effective routes to retard self-discharge for highly stable batteries are crucial for the design of lithium-sulfur cells. Herein, a lithium-sulfur cell with a carbon nanotube/sulfur cathode and lithium-metal anode in lithium bis(trifluoromethanesulfonyl)imide/1,3-dioxolane/dimethyl ether electrolyte was selected as the model system to investigate the self-discharge behavior. Both lithium anode passivation and polysulfide anion diffusion suppression strategies are applied to reduce self-discharge of the lithium-sulfur cell. When the lithium-metal anode is protected by a high density passivation layer induced by LiNO3 , a very low shuttle constant of 0.017 h(-1) is achieved. The diffusion of the polysulfides is retarded by an ion-selective separator, and the shuttle constants decreased. The cell with LiNO3 additive maintained a discharge capacity of 97 % (961 mAh g(-1) ) of the initial capacity after 120 days at open circuit, which was around three times higher than the routine cell (32 % of initial capacity, corresponding to 320 mAh g(-1) ). It is expected that lithium-sulfur batteries with ultralow self-discharge rates may be fabricated through a combination of anode passivation and polysulfide shuttle control, as well as optimization of the lithium-sulfur cell configuration.

  20. Effect of vehicle speed on pantograph arc discharge for high speed EMU%高速动车组车速对弓网离线电弧放电的影响

    Institute of Scientific and Technical Information of China (English)

    马云双; 刘志刚; 闻映红; 马岚; 张金宝

    2013-01-01

    高速动车组列车运行时的车体振动使得受电弓和接触线之间产生电孤放电,从而产生电磁骚扰,研究由弓网离线电弧放电形成电磁骚扰的特征,为评估电磁骚扰对动车组安全的影响提供依据.本文针对动车组极高的运行速度与高速接触网系统振动方程导出弓网的离线概率、弓网接触力和接触线动态抬升量与速度的关系;建立了弓网电弧放电模型,对弓网电弧离线放电的电磁骚扰进行仿真;最后,分析了不同车速条件下,弓网离线电弧放电电磁骚扰发生的频率、大小的变化趋势.%Due to extremely high vehicle speed of high speed EMU, arc discharge is generated by vibrations between pantograph and contact line. Consequently, electromagnetic harassment comes out. The electromagnetic harassment must be studied in order to propose a basis which further evaluate the affects of such harassment on safety of high speed EMU. In this paper, firstly, relationship among vehicle speed versus pantograph off-line probability, pantograph contact force and contact line dynamic uplift is built up via pantograph system vibration equation. Then pantograph arc discharge model is established, and simulations are carried out. Finally, analysis under different speed conditions are presented, in view of trends frequency and magnitude of electromagnetic harassment caused by pantograph arc discharge.

  1. A mass spectrometric study of ions extracted from a point-to-plane dc corona discharge in N{sub 2}O at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Skalny, J D; Orszagh, J [Department of Plasma Physics, Comenius University, Mlynska dolina F-2, 84248 Bratislava (Slovakia); Mason, N J [Department of Physics and Astronomy, Centre of Molecular and Optical Sciences, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Rees, J A; Aranda-Gonzalvo, Y; Whitmore, T D [Plasma and Surface Analysis Division, Hiden Analytical Ltd, 420 Europa Boulevard, Warrington WA5 7UN (United Kingdom)], E-mail: Skalny@fmph.uniba.sk

    2008-04-21

    In this paper we report the first study of ions formed in both positive and negative point-to-plane corona discharges fed by N{sub 2}O containing less than 0.1% of H{sub 2}O at atmospheric pressure. Considerable differences were observed in the mass spectra of the ions produced from corona discharges of different polarities. In all the discharges the product ions were observed mainly in the form of clusters. However, in positive corona discharges only four major groups of cluster ions were monitored whereas in all corona discharges operated with negative polarity a much more varied and complex variety of negative ions was observed. The spectrum of positive ions is highly sensitive to the content of water vapour in nitrous oxide with H{sub 3} O{sup +} {center_dot} (H{sub 2}O){sub n} clusters (especially H{sub 3}O{sup +} {center_dot} (H{sub 2}O){sub 3}) and NO{sup +} {center_dot} (H{sub 2}O){sub n} clusters being the dominant products. The yield of NO{sup +} {center_dot} (H{sub 2}O){sub n} was found to increase strongly with increasing discharge current while the yield of H{sub 3}O{sup +} {center_dot} (H{sub 2}O){sub n} clusters was reduced. Spectra of ions detected in negative corona discharges contain clusters of NO{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -} ions and also HNO{sub 3}{sup -} clustered with N{sub 2}O, NO, NO{sub 2}, H{sub 2}O and HNO{sub 3}. This paper reports how the yield of such ions is influenced by the plasma characteristics and discusses how these results may be explained by physical and chemical processes in the plasma.

  2. A mass spectrometric study of ions extracted from a point-to-plane dc corona discharge in N2O at atmospheric pressure

    International Nuclear Information System (INIS)

    In this paper we report the first study of ions formed in both positive and negative point-to-plane corona discharges fed by N2O containing less than 0.1% of H2O at atmospheric pressure. Considerable differences were observed in the mass spectra of the ions produced from corona discharges of different polarities. In all the discharges the product ions were observed mainly in the form of clusters. However, in positive corona discharges only four major groups of cluster ions were monitored whereas in all corona discharges operated with negative polarity a much more varied and complex variety of negative ions was observed. The spectrum of positive ions is highly sensitive to the content of water vapour in nitrous oxide with H3 O+ · (H2O)n clusters (especially H3O+ · (H2O)3) and NO+ · (H2O)n clusters being the dominant products. The yield of NO+ · (H2O)n was found to increase strongly with increasing discharge current while the yield of H3O+ · (H2O)n clusters was reduced. Spectra of ions detected in negative corona discharges contain clusters of NO-, NO2-, NO3- ions and also HNO3- clustered with N2O, NO, NO2, H2O and HNO3. This paper reports how the yield of such ions is influenced by the plasma characteristics and discusses how these results may be explained by physical and chemical processes in the plasma

  3. MHD-induced Energetic Ion Loss during H-mode Discharges in the National Spherical Torus Experiment (NSTX)

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley; N.N. Gorelenkov; R. Andre; R.E. Bell; D.S. Darrow; E.D. Fredrickson; S.M. Kaye; B.P. LeBlanc; A.L. Roquemore; and the NSTX Team

    2004-03-15

    MHD-induced energetic ion loss in neutral-beam-heated H-mode [high-confinement mode] discharges in NSTX [National Spherical Torus Experiment] is discussed. A rich variety of energetic ion behavior resulting from magnetohydrodynamic (MHD) activity is observed in the NSTX using a horizontally scanning Neutral Particle Analyzer (NPA) whose sightline views across the three co-injected neutral beams. For example, onset of an n = 2 mode leads to relatively slow decay of the energetic ion population (E {approx} 10-100 keV) and consequently the neutron yield. The effect of reconnection events, sawteeth, and bounce fishbones differs from that observed for low-n, low-frequency, tearing-type MHD modes. In this case, prompt loss of the energetic ion population occurs on a time scale of less than or equal to 1 ms and a precipitous drop in the neutron yield occurs. This paper focuses on MHD-induced ion loss during H-mode operation in NSTX. After H-mode onset, the NPA charge-exchange spectrum usually exhibits a significant loss of energetic ions only for E > E(sub)b/2 where E(sub)b is the beam injection energy. The magnitude of the energetic ion loss was observed to decrease with increasing tangency radius, R(sub)tan, of the NPA sightline, increasing toroidal field, B(sub)T, and increasing neutral-beam injection energy, E(sub)b. TRANSP modeling suggests that MHD-induced ion loss is enhanced during H-mode operation due to an evolution of the q and beam deposition profiles that feeds both passing and trapped ions into the region of low-n MHD activity. ORBIT code analysis of particle interaction with a model magnetic perturbation supported the energy selectivity of the MHD-induced loss observed in the NPA measurements. Transport analysis with the TRANSP code using a fast-ion diffusion tool to emulate the observed MHD-induced energetic ion loss showed significant modifications of the neutral- beam heating as well as the power balance, thermal diffusivities, energy confinement times

  4. Power balance in ELMO Bumpy Torus: bulk electrons and ions in a 37 kW discharge

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, D.H.

    1985-10-01

    The power balance of the bulk electrons and ions in discharges with 37 kW of applied microwave power in the ELMO Bumpy Torus (EBT) is examined in a zero-dimensional model using data on the intensity and linewidth of the molecular and atomic hydrogen emission. At least 60% of the applied power is ultimately dissipated by processes involving the neutral particles, including dissociation of molecules, ionization of and radiation from atoms, and heating of cold electrons produced during atomic ionization. The molecular influx rate and the density of atoms are used independently to determine the bulk electron particle confinement time, and an upper bound estimate is made of the diffusional power loss from the bulk plasma electrons. Parameters derived from the basic spectroscopic data presented in this paper include the neutral atom density 2 - 5x10/sup 10/ cm/sup -3/, incident molecular flux 3 - 5x10/sup 15/ cm/sup -2/s/sup -1/, bulk ion temperature approx. =3 eV, and particle confinement time <1.1 ms. The bulk electron energy confinement time is 0.7 ms or less in the standard operating regime. Published data on the nonthermal electron and ion populations in the plasma are used to evaluate approximately the overall energy flow in the discharge. 54 refs.

  5. Power balance in ELMO Bumpy Torus: bulk electrons and ions in a 37 kW discharge

    International Nuclear Information System (INIS)

    The power balance of the bulk electrons and ions in discharges with 37 kW of applied microwave power in the ELMO Bumpy Torus (EBT) is examined in a zero-dimensional model using data on the intensity and linewidth of the molecular and atomic hydrogen emission. At least 60% of the applied power is ultimately dissipated by processes involving the neutral particles, including dissociation of molecules, ionization of and radiation from atoms, and heating of cold electrons produced during atomic ionization. The molecular influx rate and the density of atoms are used independently to determine the bulk electron particle confinement time, and an upper bound estimate is made of the diffusional power loss from the bulk plasma electrons. Parameters derived from the basic spectroscopic data presented in this paper include the neutral atom density 2 - 5x1010 cm-3, incident molecular flux 3 - 5x1015 cm-2s-1, bulk ion temperature approx. =3 eV, and particle confinement time <1.1 ms. The bulk electron energy confinement time is 0.7 ms or less in the standard operating regime. Published data on the nonthermal electron and ion populations in the plasma are used to evaluate approximately the overall energy flow in the discharge. 54 refs

  6. Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source

    Energy Technology Data Exchange (ETDEWEB)

    Castro, G.; Di Giugno, R.; Miracoli, R. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); Mascali, D. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Romano, F. P. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR-IBAM Via Biblioteca 4, 95124 Catania (Italy); Celona, L.; Gammino, S.; Lanaia, D.; Ciavola, G. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Serafino, T. [CSFNSM, Viale A. Doria 6, 95125 Catania (Italy); Di Bartolo, F. [Universita di Messina, Ctr. da Papardo-Sperone, 98100 Messina (Italy); Gambino, N. [INFN- Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli Studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); IET-Institute of Energy Technology, LEC-Laboratory for Energy Conversion, ETH Zurich, Sonneggstrasse 3, CH-8092 Zurich (Switzerland)

    2012-02-15

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating.

  7. Dynamic Electrochemical Impedance Spectroscopy of a Three-Electrode Lithium-Ion Battery during Pulse Charge and Discharge

    International Nuclear Information System (INIS)

    Highlights: • Dynamic EIS is performed on a three-electrode pouch cell; • Charge transfer resistance during insertion is generally larger than that during deinsertion due to the surface concentration change; • An inductive behavior is revealed at low frequencies due to the violation of stationary condition in DEIS measurement; • Electrochemical models of a single active particle in both time and frequency domain are developed. • The model predicts a positive correlation between the lower frequency limit and the DC current. - Abstract: The dynamic electrochemical impedance spectroscopy (DEIS) of a three-electrode pouch type lithium-ion battery is measured using a series of sine wave perturbations super-imposed on pulse charge and discharge. The DEIS reveals noticeable differences between charge and discharge at frequencies corresponding to the charge transfer reaction. The charge transfer resistance during intercalation is generally found to be larger than that during deintercalation for the battery chemistry in this study. This result is mainly attributed to the decreased Li ion concentration in the electrolyte during intercalation. At low frequencies, an abnormal inductive behavior is also observed. Such abnormality is found to result from the violation of stationary condition, i.e. the state of the battery under pulse charge or discharge deviates significantly from its initial condition for the perturbation of low frequencies. To analytically define the stationary condition, we develop electrochemical models of a single active particle in both time and frequency domain, which describes the transport of lithium ions in both active particle and electrolyte phase and the interfacial charge transfer reactions at their interface. The lower frequency limit is a key parameter to ensure a quasistationary state during the DEIS measurement. An explicit formulation of the stationary condition predicts a positive correlation between the lower frequency limit and

  8. Effect of high energy electrons on H{sup −} production and destruction in a high current DC negative ion source for cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Onai, M., E-mail: onai@ppl.appi.keio.ac.jp; Fujita, S.; Hatayama, A. [Faculty of Science and Technology, Keio University, Yokohama 223-8522 (Japan); Etoh, H.; Aoki, Y. [Sumitomo Heavy Industries, Ltd., Tokyo 141-6025 (Japan); Shibata, T. [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan); Mattei, S.; Lettry, J. [CERN Rte de Meyrin, 1200 Geneva (Switzerland)

    2016-02-15

    Recently, a filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In this study, numerical modeling of the filament arc-discharge source plasma has been done with kinetic modeling of electrons in the ion source plasmas by the multi-cusp arc-discharge code and zero dimensional rate equations for hydrogen molecules and negative ions. In this paper, main focus is placed on the effects of the arc-discharge power on the electron energy distribution function and the resultant H{sup −} production. The modelling results reasonably explains the dependence of the H{sup −} extraction current on the arc-discharge power in the experiments.

  9. Ion energy and angular distributions onto polymer surfaces delivered by dielectric barrier discharge filaments in air: II. Particles

    Energy Technology Data Exchange (ETDEWEB)

    Babaeva, Natalia Yu; Kushner, Mark J, E-mail: nbabaeva@umich.edu, E-mail: mjkush@umich.edu [University of Michigan, Department of Electrical Engineering and Computer Science 1301 Beal Ave, Ann Arbor, MI 48109 (United States)

    2011-06-15

    Atmospheric pressure streamers intersecting particles are of interest in the context of plasma aided combustion, where the particle may be a fuel aerosol droplet, or in sterilization of air, where the particle may be a bacterium. The ion energy and angular distributions (IEADs) incident on the particles, small curved dielectric surfaces, then in part determine the propensity for activating chemical reactions or, in the case of bacteria, the plasma's sterilization capability. In this paper, we discuss results from a computational investigation of IEADs on small particles (45 {mu}m radius) produced by atmospheric pressure discharge. Streamers intersecting a particle momentarily generate a large sheath potential as the streamer passes by as the particle charges towards the plasma floating potential. During that time, ions of energies up to 3-10 eV can strike the particle. The permittivity of the particle and the streamer polarity in part determine the character of the IEAD.

  10. Ion energy and angular distributions onto polymer surfaces delivered by dielectric barrier discharge filaments in air: II. Particles

    Science.gov (United States)

    Babaeva, Natalia Yu; Kushner, Mark J.

    2011-06-01

    Atmospheric pressure streamers intersecting particles are of interest in the context of plasma aided combustion, where the particle may be a fuel aerosol droplet, or in sterilization of air, where the particle may be a bacterium. The ion energy and angular distributions (IEADs) incident on the particles, small curved dielectric surfaces, then in part determine the propensity for activating chemical reactions or, in the case of bacteria, the plasma's sterilization capability. In this paper, we discuss results from a computational investigation of IEADs on small particles (45 µm radius) produced by atmospheric pressure discharge. Streamers intersecting a particle momentarily generate a large sheath potential as the streamer passes by as the particle charges towards the plasma floating potential. During that time, ions of energies up to 3-10 eV can strike the particle. The permittivity of the particle and the streamer polarity in part determine the character of the IEAD.

  11. Potential profile near singularity point in kinetic Tonks-Langmuir discharges as a function of the ion sources temperature

    Science.gov (United States)

    Kos, L.; Tskhakaya, D. D.; Jelić, N.

    2011-05-01

    A plasma-sheath transition analysis requires a reliable mathematical expression for the plasma potential profile Φ(x) near the sheath edge xs in the limit ɛ ≡λD/ℓ =0 (where λD is the Debye length and ℓ is a proper characteristic length of the discharge). Such expressions have been explicitly calculated for the fluid model and the singular (cold ion source) kinetic model, where exact analytic solutions for plasma equation (ɛ =0) are known, but not for the regular (warm ion source) kinetic model, where no analytic solution of the plasma equation has ever been obtained. For the latter case, Riemann [J. Phys. D: Appl. Phys. 24, 493 (1991)] only predicted a general formula assuming relatively high ion-source temperatures, i.e., much higher than the plasma-sheath potential drop. Riemann's formula, however, according to him, never was confirmed in explicit solutions of particular models (e.g., that of Bissell and Johnson [Phys. Fluids 30, 779 (1987)] and Scheuer and Emmert [Phys. Fluids 31, 3645 (1988)]) since "the accuracy of the classical solutions is not sufficient to analyze the sheath vicinity" [Riemann, in Proceedings of the 62nd Annual Gaseous Electronic Conference, APS Meeting Abstracts, Vol. 54 (APS, 2009)]. Therefore, for many years, there has been a need for explicit calculation that might confirm the Riemann's general formula regarding the potential profile at the sheath edge in the cases of regular very warm ion sources. Fortunately, now we are able to achieve a very high accuracy of results [see, e.g., Kos et al., Phys. Plasmas 16, 093503 (2009)]. We perform this task by using both the analytic and the numerical method with explicit Maxwellian and "water-bag" ion source velocity distributions. We find the potential profile near the plasma-sheath edge in the whole range of ion source temperatures of general interest to plasma physics, from zero to "practical infinity." While within limits of "very low" and "relatively high" ion source temperatures

  12. Potential profile near singularity point in kinetic Tonks-Langmuir discharges as a function of the ion sources temperature

    International Nuclear Information System (INIS)

    A plasma-sheath transition analysis requires a reliable mathematical expression for the plasma potential profile Φ(x) near the sheath edge xs in the limit ε≡λD/l=0 (where λD is the Debye length and l is a proper characteristic length of the discharge). Such expressions have been explicitly calculated for the fluid model and the singular (cold ion source) kinetic model, where exact analytic solutions for plasma equation (ε=0) are known, but not for the regular (warm ion source) kinetic model, where no analytic solution of the plasma equation has ever been obtained. For the latter case, Riemann [J. Phys. D: Appl. Phys. 24, 493 (1991)] only predicted a general formula assuming relatively high ion-source temperatures, i.e., much higher than the plasma-sheath potential drop. Riemann's formula, however, according to him, never was confirmed in explicit solutions of particular models (e.g., that of Bissell and Johnson [Phys. Fluids 30, 779 (1987)] and Scheuer and Emmert [Phys. Fluids 31, 3645 (1988)]) since ''the accuracy of the classical solutions is not sufficient to analyze the sheath vicinity''[Riemann, in Proceedings of the 62nd Annual Gaseous Electronic Conference, APS Meeting Abstracts, Vol. 54 (APS, 2009)]. Therefore, for many years, there has been a need for explicit calculation that might confirm the Riemann's general formula regarding the potential profile at the sheath edge in the cases of regular very warm ion sources. Fortunately, now we are able to achieve a very high accuracy of results [see, e.g., Kos et al., Phys. Plasmas 16, 093503 (2009)]. We perform this task by using both the analytic and the numerical method with explicit Maxwellian and ''water-bag'' ion source velocity distributions. We find the potential profile near the plasma-sheath edge in the whole range of ion source temperatures of general interest to plasma physics, from zero to ''practical infinity.'' While within limits of ''very low'' and ''relatively high'' ion source

  13. Detection of negative ions in glow discharge mass spectrometry for analysis of solid specimens

    DEFF Research Database (Denmark)

    Canulescu, Stela; Molchan, Igor S.; Tauziede, C.;

    2010-01-01

    be used to study the distribution of a tantalum fluoride layer within the anodized tantala layer. Further, comparison is made with data obtained using glow-discharge optical emission spectroscopy, where elemental fluorine can only be detected using a neon plasma. The ionization mechanisms responsible...

  14. Electrochemical Ion-Exchange Regeneration and Fluidized Bed Crystallization for Zero-Liquid-Discharge Water Softening.

    Science.gov (United States)

    Chen, Yingying; Davis, Jake R; Nguyen, Chi H; Baygents, James C; Farrell, James

    2016-06-01

    This research investigated the use of an electrochemical system for regenerating ion-exchange media and for promoting the crystallization of hardness minerals in a fluidized bed crystallization reactor (FBCR). The closed-loop process eliminates the creation of waste brine solutions that are normally produced when regenerating ion-exchange media. A bipolar membrane electrodialysis stack was used to generate acids and bases from 100 mM salt solutions. The acid was used to regenerate weak acid cation (WAC) ion-exchange media used for water softening. The base solutions were used to absorb CO2 gas and to provide a source of alkalinity for removing noncarbonate hardness by WAC media operated in H(+) form. The base solutions were also used to promote the crystallization of CaCO3 and Mg(OH)2 in a FBCR. The overall process removes hardness ions from the water being softened and replaces them with H(+) ions, slightly decreasing the pH value of the softened water. The current utilization efficiency for acid and base production was ∼75% over the operational range of interest, and the energy costs for producing acids and bases were an order of magnitude lower than the costs for purchasing acid and base in bulk quantities. Ion balances indicate that the closed-loop system will accumulate SO4(2-), Cl(-), and alkali metal ions. Acid and base balances indicate that for a typical water, small amounts of base will be accumulated.

  15. Electron cyclotron resonance discharge as a source for hydrogen and deuterium ions production

    Energy Technology Data Exchange (ETDEWEB)

    Chacon Velasco, A.J. [Universidad de Pamplona, Pamplona (Colombia); Dougar-Jabon, V.D. [Universidad Industrial de Santander, Bucaramanga (Colombia)

    2004-07-01

    In this report, we describe characteristics of a ring-structure hydrogen plasma heated in electron cyclotron resonance conditions and confined in a mirror magnetic trap and discuss the relative efficiency of secondary electrons and thermo-electrons in negative hydrogen and deuterium ion production. The obtained data and calculations of the balance equations for possible reactions demonstrate that the negative ion production is realized in two stages. First, the hydrogen and deuterium molecules are excited in collisions with the plasma electrons to high-laying Rydberg or vibrational levels in the plasma volume. The second stage leads to the negative ion production through the process of dissociative attachment of low energy electrons. The low energy electrons are originated due to a bombardment of the plasma electrode by ions of one of the driven rings and thermo-emission from heated tungsten filaments. Experiments seem to indicate that the negative ion generation occurs predominantly in the limited volume filled with thermo-electrons. Estimation of the negative ion generation rate shows that the main channel of H{sup -} and D{sup -} ion production involves the process of high Rydberg state excitation. (authors)

  16. Neutron imaging of a commercial Li-ion battery during discharge: Application of monochromatic imaging and polychromatic dynamic tomography

    International Nuclear Information System (INIS)

    A commercial lithium-ion polymer battery of prismatic construction was imaged in 2D by monochromatic neutron radiography at wavelengths around a LiC6 spectral feature. Over the range of 3-4 A, the neutron attenuation spectra for charged and discharged batteries are distinctly different. In a real-time experiment, a battery was observed during discharge at wavelengths spanning the LiC6 spectral feature and its disappearance monitored. No evidence of 'staging' was detected in this preliminary experiment. A similar battery was imaged in 3D with a new tomographic data acquisition scheme based on the Greek golden ratio; the scheme allows convenient post-processing to establish 'time windows' for 3D image reconstruction. The 3D images at 5% state of charge intervals are compromised by beam hardening, but still show some asymmetric battery volume change with discharge. Finally comments on the future of neutron imaging for battery experiments, whether at continuous sources at nuclear reactors or at pulsed spallation sources, are discussed.

  17. Corona discharge ion mobility spectrometry with orthogonal acceleration time of flight mass spectrometry for monitoring of volatile organic compounds.

    Science.gov (United States)

    Sabo, Martin; Matejčík, Štefan

    2012-06-19

    We demonstrate the application of corona discharge ion mobility spectrometry with orthogonal acceleration time of flight mass spectrometry (CD IMS-oaTOF) for volatile organic compounds (VOCs) monitoring. Two-dimensional (2D) IMS-oaTOF spectra of VOCs were recorded in nearly real time. The corona discharge atmospheric pressure chemical ionization (APCI) source was operated in positive mode in nitrogen and air. The CD ion source generates in air H(3)O(+)(H(2)O)(n) and NO(+). The NO(+) offers additional possibility for selective ionization and for an increase of the sensitivity of monoaromatic compounds. In addition to H(3)O(+)(H(2)O)(n) and NO(+), we have carried out ionization of VOCs using acetone as dopant gas ((CH(3))(2)COH(+)). Sixteen model VOCs (tetrahydrofuran, butanol, n-propanol, iso-propano, acetone, methanol, ethanol, toluene, benzene, amomnia, dioxan, triethylamine, acetonitrile, formaldehyde, m-xylene, 2,2,2-trifluoroethylamine) were tested using these ionization techniques. PMID:22594852

  18. Kinetic-Energy Distributions of Positive and Negative Ions in DC Townsend Discharges of CHF3 at High E/N

    Science.gov (United States)

    Rao, M. V. V. S.; van Brunt, R. J.; Olthoff, J. K.

    1997-10-01

    In this paper we present ion kinetic-energy distributions (IEDs), mean energies, and relative abundances of CF_3^+, CF_2^+, CF^+, CHF_2^+, CHF^+, CH^+, C^+, H^+, and F- ions produced in dc Townsend discharges in pure CHF_3. The discharges are generated at electric field-to-gas density ratios (E/N) ranging from 5 x 10-18 Vm^2 to 25 x 10-18 Vm^2 (5 to 25 kTd). Ions sampled from the discharge through a small orifice in the center of the grounded electrode were energy and mass analyzed by an electrostatic energy analyzer attached to a quadrupole mass spectrometer.(M. V. V. S. Rao, R. J. Van Brunt, and J. K. Olthoff, Phys. Rev. E 54), 5641 (1996) In the present experiments, CHF_2^+ was determined to be the dominant positive ion at all E/N, followed by CF^+. The negative ion fluxes were substantially lower than the positive ion fluxes, with F^- being the only negative ion with significant intensity. At 5 kTd, the IEDs of all positive ions exhibit Maxwellian behavior. However, at higher E/N the role of collisional dissociation processes increases and the IEDs of the positive ions deviate from those predicted by simple collisional charge-transfer models. The IEDs for F^- are non-maxwellian at all E/N.

  19. The Improvement of Discharge Capacity of Zr-doped Lithium Titanate for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Chen Yongjian

    2016-01-01

    Full Text Available Li4Ti5−xZrxO12 (0 ≪ x ≪ 0.05 materials are synthesized via one-step liquid method in this work. The morphology, elemental distribution and lithium storage performance of Zr-doped lithium titanate are systematic analyzed by field emitting scanning electron microscopy (FE-SEM, Hitachi S-4800, energy dispersive X-ray (EDS and Land battery test system (LAND CT2001A together with the pristine lithium titanate for comparison. The FE-SEM images show the uniform morphology and narrow particle size distribution of Zr-doped samples. The cycle performance measurements demonstrate that the Li4Ti4.97Zr0.03O12 electrode displays the best discharge capacities among the composites. It delivers the initial discharge capacities of 165.4 mAh/g and 152.9 mAh/g at 5C and 10C, and remains the values of 142.9 mAh/g and 127.4 mAh/g after 200 cycles. Furthermore, the charge and discharge curves exhibit that the Zr-doped composite presents smaller polarization than the pristine lithium titanate.

  20. Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Birk [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Institute for Theoretical Electrical Engineering, Ruhr University Bochum, D-44780 Bochum (Germany); Brandt, Steven; Franek, James; Schüngel, Edmund; Koepke, Mark; Schulze, Julian [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Mussenbrock, Thomas [Institute for Theoretical Electrical Engineering, Ruhr University Bochum, D-44780 Bochum (Germany)

    2015-12-14

    Capacitively coupled radio frequency plasmas driven by customized voltage waveforms provide enhanced opportunities to control process-relevant energy distributions of different particle species. Here, we present an experimental investigation of the spatio-temporal electron heating dynamics probed by Phase-Resolved Optical Emission Spectroscopy (PROES) in an argon discharge driven by up to three consecutive harmonics of 13.56 MHz with individually adjustable harmonics' amplitudes and phases. PROES and voltage measurements are performed at fixed total voltage amplitudes as a function of the number of driving harmonics, their relative phases, and pressure to study the effects of changing the applied voltage waveform on the heating dynamics in collisionless and collisional regimes. Additionally, the ion energy distribution function (IEDF) is measured at low pressure. In this collisionless regime, the discharge is operated in the α-mode. The velocity of energetic electron beams generated by the expanding sheaths is found to be affected by the number of driving harmonics and their relative phases. This is understood based on the sheath dynamics obtained from a model that determines sheath voltage waveforms. The formation of the measured IEDFs is understood and found to be directly affected by the observed changes in the electron heating dynamics. It is demonstrated that the mean ion energy can be controlled by adjusting the harmonics' phases. In the collisional regime at higher pressures changing the number of harmonics and their phases at fixed voltage is found to induce heating mode transitions from the α- to the γ-mode. Finally, a method to use PROES as a non-invasive diagnostic to monitor and detect changes of the ion flux to the electrodes is developed.

  1. Effect of deposition parameters on mechanical properties of TiN films coated on 2A12 aluminum alloys by arc ion plating (AIP)

    Institute of Scientific and Technical Information of China (English)

    AWAD Samir Hamid; QIAN Han-cheng

    2005-01-01

    TiN films were deposited on 2A12 aluminum alloy by arc ion plating (AIP). The Vickers hardness of the films deposited at different bias voltages and different nitrogen gas pressures, and that of the substrate were measured. The surface roughness of the TiN films diposited at -30 V and -80 V respectively and at different nitrogen gas pressure was measured also. The mass loss of TiN films deposited at 0 V, -30 V and -80 V respectively were analyzed in dry sand rubber wheel abrasive wear tests and wet ones in comparison with uncoated Al alloy and austenitic stainless steel (AISI 316L). It is revealed that the highest hardness of the TiN film is obtained at a bias voltage of -30 V and a N2 gas pressure of 0.5 Pa. The surface roughness of the film is larger at -80 V than that at -30 V and reduces as the increase of the N2 gas pressure. The mass loss of TiN-film coated 2A12 aluminum alloy is remarkably less than that of uncoated Al alloy and also that of AISI 316L, which indicates that the abrasive wear rate is greatly reduced by the application of TiN coating. TiN coating deposited by arc ion plating (AIP) technique on aluminum alloy can be a potential coating for machine parts requiring preciseness and lightness.

  2. Improved L-mode discharges using ion cyclotron resonance frequency heating on Tore Supra

    International Nuclear Information System (INIS)

    Recent results of ion cyclotron minority heating have been obtained with an improved L-mode confinement, close to ELMy H-mode prediction, at relatively high density. The confinement exceeds the standard L-mode by a factor up to 1.7. The improvement of the confinement is observed in both electron and ion channels with reduction of heat diffusivities. This improved confinement regime presents some features similar to the results previously observed in many tokamaks: ALCATOR C-MOD [1] with ICRH, and radiation improved confinement (RI) mode with neutral beam injection in TEXTOR [2], TFTR [3], DIII-D [4

  3. Ion mobility spectrometric analysis of vaporous chemical warfare agents by the instrument with corona discharge ionization ammonia dopant ambient temperature operation.

    Science.gov (United States)

    Satoh, Takafumi; Kishi, Shintaro; Nagashima, Hisayuki; Tachikawa, Masumi; Kanamori-Kataoka, Mieko; Nakagawa, Takao; Kitagawa, Nobuyoshi; Tokita, Kenichi; Yamamoto, Soichiro; Seto, Yasuo

    2015-03-20

    The ion mobility behavior of nineteen chemical warfare agents (7 nerve gases, 5 blister agents, 2 lachrymators, 2 blood agents, 3 choking agents) and related compounds including simulants (8 agents) and organic solvents (39) was comparably investigated by the ion mobility spectrometry instrument utilizing weak electric field linear drift tube with corona discharge ionization, ammonia doping, purified inner air drift flow circulation operated at ambient temperature and pressure. Three alkyl methylphosphonofluoridates, tabun, and four organophosphorus simulants gave the intense characteristic positive monomer-derived ion peaks and small dimer-derived ion peaks, and the later ion peaks were increased with the vapor concentrations. VX, RVX and tabun gave both characteristic positive monomer-derived ions and degradation product ions. Nitrogen mustards gave the intense characteristic positive ion peaks, and in addition distinctive negative ion peak appeared from HN3. Mustard gas, lewisite 1, o-chlorobenzylidenemalononitrile and 2-mercaptoethanol gave the characteristic negative ion peaks. Methylphosphonyl difluoride, 2-chloroacetophenone and 1,4-thioxane gave the characteristic ion peaks both in the positive and negative ion mode. 2-Chloroethylethylsulfide and allylisothiocyanate gave weak ion peaks. The marker ion peaks derived from two blood agents and three choking agents were very close to the reactant ion peak in negative ion mode and the respective reduced ion mobility was fluctuated. The reduced ion mobility of the CWA monomer-derived peaks were positively correlated with molecular masses among structurally similar agents such as G-type nerve gases and organophosphorus simulants; V-type nerve gases and nitrogen mustards. The slope values of the calibration plots of the peak heights of the characteristic marker ions versus the vapor concentrations are related to the detection sensitivity, and within chemical warfare agents examined the slope values for sarin, soman

  4. The influence of negative ions in helium-oxygen barrier discharges: II. 1D fluid simulation and adaption to the experiment

    Science.gov (United States)

    Nemschokmichal, Sebastian; Tschiersch, Robert; Meichsner, Jürgen

    2016-10-01

    A 1D fluid simulation was developed to investigate the influence of negative ions in a helium-oxygen barrier discharge between two glass plates at a distance of 3~\\text{mm} . The paper describes setting up the simulation for a pressure of 500~\\text{mbar} and an admixture of 400~\\text{ppm} oxygen to helium. In order to enable the comparison with laser photodetachment experiments, the simulation is adapted to the experimentally observed discharge current and gap voltage by varying gas temperature, flux of thermally desorpted electrons and secondary electron emission coefficients. The discharge is characterized by evaluation of the most important elementary collision processes as well as the kinetics of the charged species. Besides, the influence of long-living species on the discharge behavior is taken into account by long-time simulations. The negative ions are characterized by their spatio-temporal distribution in the gap and their production and loss processes. The comparison between simulations without and with consideration of negative ions reveals the importance of negative ions on the discharge development.

  5. Synthesis and charge-discharge properties of LiF-NiO composite as a cathode material for Li-ion batteries

    Science.gov (United States)

    Tomita, Yasumasa; Nasu, Hiromasa; Izumi, Yusuke; Arai, Juichi; Otsuka, Satoshi; Yamane, Yohei; Yamada, Koji; Kohno, Yoshiumi; Kobayashi, Kenkichiro

    2016-10-01

    LiF-NiO composites in a molar ratio of 1:1 are synthesized by the mechanical milling of equal amounts of LiF and NiO for 12-144 h. The synthesized composites are investigated by XRD, charge-discharge measurements, and XPS. The XRD peaks of NiO broaden with an increase in the milling time, while those of LiF disappear. Rietveld analysis shows that the LiF-NiO composites prepared by milling for more than 72 h form a solid solution and that the arrangement of Li+ and Ni2+ ions in them is disordered. The LiF and NiO samples milled individually do not exhibit a noticeable discharge capacity, while the composites show a large one. Further, the discharge capacity of the LiF-NiO composites increases with the milling time, with the composite prepared by milling for 144 h exhibiting a discharge capacity of 216 mA h g-1 and an average voltage of 3.53 V at 0.05 C for voltages of 2.0-5.0 V. The XPS data suggest that the Ni ions are probably oxidized and reduced repeatedly during the charge-discharge process and that the Ni2+ ions are partially oxidized to Ni3+ ions during charging to 5.0 V.

  6. Analysis of testosterone in human urine using molecularly imprinted solid-phase extraction and corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Mirmahdieh, Shiva; Mardihallaj, Azam; Hashemian, Zahra; Razavizadeh, Jalal; Ghaziaskar, Hassan; Khayamian, Taghi

    2011-01-01

    Analysis of testosterone was accomplished using corona discharge ion mobility spectrometry. Molecular imprinted polymer was used for the extraction and pre-concentration of testosterone. Analytical parameters including precision, dynamic range and detection limit were obtained. The linear dynamic range was from 10 to 250 ng/mL and the limit of detection was 0.9 ng/mL. The proposed method was used for analysis of testosterone in urine samples. A urine sample from a 3-year-old girl was used as the blank. The RSD was below 10%. The obtained results from the method were also compared with the standard method for analysis of testosterone using SPE-HPLC analysis. The results demonstrate the accuracy of the method. PMID:21171183

  7. Novel plasma immersion ion implantation and deposition hardware and technique based on high power pulsed magnetron discharge

    International Nuclear Information System (INIS)

    A novel plasma immersion ion implantation technique based on high power pulsed magnetron sputtering (HPPMS) discharge that can produce a high density metal plasma is described. The metal plasma is clean and does not suffer from contamination from macroparticles, and the process can be readily scaled up for industrial production. The hardware, working principle, and operation modes are described. A matching circuit is developed to modulate the high-voltage and HPPMS pulses to enable operation under different modes such as simultaneous implantation and deposition, pure implantation, and selective implantation. To demonstrate the efficacy of the system and technique, CrN films with a smooth and dense surface without macroparticles were produced. An excellent adhesion with a critical load of 59.9 N is achieved for the pure implantation mode.

  8. Measurements of actinometry and ions energy in a microwave discharge; Mediciones de actinometria y energia de iones en una descarga de microondas

    Energy Technology Data Exchange (ETDEWEB)

    Becerril, F.; Camps, E. [Instituto Nacional de Investigaciones Nucleares, Departamento de Fisica, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Villagran, M. [CI-UNAM, Mexico D.F. (Mexico); Muhl, S. [IIM-UNAM, Mexico D.F. (Mexico)

    1998-07-01

    In the present work it is showed the implementation of the plasma diagnostic technique through actinometry which allows to determine the absolute density of excited species. It is showed the range of the technique application, for the case of N{sub 2}-H{sub 2} mixtures plasmas used for the metals nitridation. The effects of magnetic field and the work pressure over ions energy were determined, using a Faraday cup type energy analyser. The results showed that in our device it is possible to vary such energy in a range between 10-45 eV, which amplify the range of applications perceptibly in comparison with another type of discharges. (Author)

  9. Neutron spectrometry of JET discharges with ICRH-acceleration of helium beam ions

    International Nuclear Information System (INIS)

    Recent experiments at JET aimed at producing 4He ions in the MeV range through third harmonic ion cyclotron resonance heating (ICRH) acceleration of 4He beams in a 4He dominated plasma. MeV range D was also present through parasitic ICRH absorption on residual D. In this contribution, we analyze TOFOR neutron spectrometer data from these experiments. A consistent description of the data is obtained with d(d,n)3He and 9Be(α,n)12C neutron components calculated using Stix distributions for the fast D and 4He, taking finite Larmor radius effects into account and with a ICRH power partition of PDRF=0.01xP4HeRF, in agreement with TOMCAT simulations.

  10. Application of Glow Discharge Aes for Investigation of Metal Ions and Water in Biology and Medicine

    CERN Document Server

    Bregadze, Vasil G; Tsakadze, Ketevan J

    2007-01-01

    AES VHF inductively coupled plasmatron may be applied to wide range of studies. It enables rapid microanalysis of various solutions including biological objects and peripheral blood serum. In addition, it may be used for investigation of water desorption from solid bodies and for determination of energetic metal-macromolecule complexes. Study of hydration energy and hydration number by kinetic curves of water glow discharge atomic spectral analysis of hydrogen (GD EAS analysis of hydrogen) desorption from Na-DNA humidified fibers allowed to reveal that structural and conformational changes in activation energy of hydrated water molecules increases by 0.65kcal/Mole of water. The developed method of analysis of elements in solutions containing high concentrations of organic materials allows systematic study of practically healthy persons and reveals risk factors for several diseases. Microelemental content of blood serum fractions showed that amount of not bounded with ceruloplasmin copper was three times more ...

  11. A Comparison of the Effects of RF Plasma Discharge and Ion Beam Supply on the Growth of Cubic Boron Nitride Films Formed by Laser Physical Vapor Deposition

    Science.gov (United States)

    Kaneda, Kayo; Shibata, Kimihiro

    1994-01-01

    This paper presents a comparison of the effects of RF plasma discharge and ion beam supply on the growth of cubic boron nitride films formed by excimer laser physical vapor deposition (laser PVD). The film structure was analyzed by fourier transformation infrared region (FT-IR) spectroscopy and thin-film X-ray diffraction analysis. The structure of the film deposited with an RF plasma discharge provided between the substrate and target was hexagonal BN. On the other hand, that of the film deposited by irradiating the substrate directly with an ion beam was hexagonal BN (hBN) and cubic BN (cBN). It is thought that direct irradiation of the vapor generated from the target by accelerated ions increased the activation energy of the vapor, with the result that the film structure was changed. Besides irradiating the substrate directly with the ion beam resulted primarily in the etching of hBN while cBN remained.

  12. A Hot Cavity Laser Ion Source at IGISOL

    OpenAIRE

    Reponen, M.; Kessler, T.; Moore, I D; Rothe, S.; Äystö, J.

    2008-01-01

    A development program is underway at the IGISOL (Ion Guide Isotope Separator On-Line) facility, University of Jyvaskyla, to efficiently and selectively produce low-energy radioactive ion beams of silver isotopes and isomers, with a particular interest in N=Z 94Ag. A hot cavity ion source has been installed, based on the FEBIAD (Forced Electron Beam Induced Arc Discharge) technique, combined with a titanium:sapphire laser system for selective laser ionization. The silver recoils produced via t...

  13. Feasibility of corona discharge ion mobility spectrometry for direct analysis of samples extracted by dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Jafari, Mohammad T; Riahi, Farhad

    2014-05-23

    The capability of corona discharge ionization ion mobility spectrometry (CD-IMS) for direct analysis of the samples extracted by dispersive liquid-liquid microextraction (DLLME) was investigated and evaluated, for the first time. To that end, an appropriate new injection port was designed and constructed, resulting in possibility of direct injection of the known sample volume, without tedious sample preparation steps (e.g. derivatization, solvent evaporation, and re-solving in another solvent…). Malathion as a test compound was extracted from different matrices by a rapid and convenient DLLME method. The positive ion mobility spectra of the extracted malathion were obtained after direct injection of carbon tetrachloride or methanol solutions. The analyte responses were compared and the statistical results revealed the feasibility of direct analysis of the extracted samples in carbon tetrachloride, resulting in a convenient methodology. The coupled method of DLLME-CD-IMS was exhaustively validated in terms of sensitivity, dynamic range, recovery, and enrichment factor. Finally, various real samples of apple, river and underground water were analyzed, all verifying the feasibility and success of the proposed method for the easy extraction of the analyte using DLLME separation before the direct analysis by CD-IMS. PMID:24742534

  14. Janus Solid-Liquid Interface Enabling Ultrahigh Charging and Discharging Rate for Advanced Lithium-Ion Batteries.

    Science.gov (United States)

    Zheng, Jiaxin; Hou, Yuyang; Duan, Yandong; Song, Xiaohe; Wei, Yi; Liu, Tongchao; Hu, Jiangtao; Guo, Hua; Zhuo, Zengqing; Liu, Lili; Chang, Zheng; Wang, Xiaowei; Zherebetskyy, Danylo; Fang, Yanyan; Lin, Yuan; Xu, Kang; Wang, Lin-Wang; Wu, Yuping; Pan, Feng

    2015-09-01

    LiFePO4 has long been held as one of the most promising battery cathode for its high energy storage capacity. Meanwhile, although extensive studies have been conducted on the interfacial chemistries in Li-ion batteries,1-3 little is known on the atomic level about the solid-liquid interface of LiFePO4/electrolyte. Here, we report battery cathode consisted with nanosized LiFePO4 particles in aqueous electrolyte with an high charging and discharging rate of 600 C (3600/600 = 6 s charge time, 1 C = 170 mAh g(-1)) reaching 72 mAh g(-1) energy storage (42% of the theoretical capacity). By contrast, the accessible capacity sharply decreases to 20 mAh g(-1) at 200 C in organic electrolyte. After a comprehensive electrochemistry tests and ab initio calculations of the LiFePO4-H2O and LiFePO4-EC (ethylene carbonate) systems, we identified the transient formation of a Janus hydrated interface in the LiFePO4-H2O system, where the truncated symmetry of solid LiFePO4 surface is compensated by the chemisorbed H2O molecules, forming a half-solid (LiFePO4) and half-liquid (H2O) amphiphilic coordination environment that eases the Li desolvation process near the surface, which makes a fast Li-ion transport across the solid/liquid interfaces possible. PMID:26305572

  15. Effect of ion bombarding energies on photocatalytic TiO2 films growing in a pulsed dual magnetron discharge

    International Nuclear Information System (INIS)

    Photocatalytic crystalline TiO2 films were deposited by a pulsed dc dual magnetron system. The depositions were performed using two unbalanced magnetrons with planar titanium targets of 50 mm diameter in Ar+O2 gas mixtures at a total pressure of 0.9 Pa with oxygen partial pressures ranging from 0.2 to 0.9 Pa. The maximum substrate surface temperature was 160 deg. C Both magnetrons operated in the same asymmetric bipolar mode at the repetition frequencies of 100 and 350 kHz with a fixed 50% duty cycle and the average target power densities of 52-74 W cm-2 in the negative voltage phase of the pulses, but the magnetron operations were shifted by a half of the period. Time-averaged energy-resolved mass spectroscopy was performed at a substrate position located 100 mm from the targets. The measured structure of the ion energy distributions was correlated with the distinct pulse phases of the magnetron discharges. A decrease in the energy delivered by fast ions (E≥10 eV) to the unit volume of the growing films, together with possible effects of plasma-chemical processes, during the depositions at the oxygen partial pressures of 0.5-0.75 Pa and the repetition frequency of 350 kHz resulted in a strong predominance of the highly photoactive crystalline anatase phase in the TiO2 films.

  16. Modeling Vacuum Arcs On Spacecraft Solar Panel Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft charging and subsequent vacuum arcing poses a significant threat to satellites in LEO and GEO plasma conditions. Localized arc discharges can cause a...

  17. The use of accelerating rate calorimetry (ARC) for the study of the thermal reactions of Li-ion battery electrolyte solutions

    Science.gov (United States)

    Gnanaraj, J. S.; Zinigrad, E.; Asraf, L.; Gottlieb, H. E.; Sprecher, M.; Aurbach, D.; Schmidt, M.

    The thermal stability of 1M LiPF 6, LiClO 4, LiN(SO 2CF 2CF 3) 2 (LiBETI) and LiPF 3(CF 2CF 3) 3 (LiFAP) solutions in mixtures of ethylene carbonate, diethyl carbonate and dimethyl carbonate in the temperature range 40-350 °C was studied by ARC and DSC. NMR was used to analyze the reaction products at different reaction stages. The least thermally stable are LiClO 4 solutions. LiPF 3(CF 2CF 3) 3 solutions showed higher thermal stability than LiPF 6 solutions. The highest thermal stability was found for LiN(SO 2CF 2CF 3) 2 solutions. Studies by DSC and pressure measurements during ARC experiments with LiPF 6 and LiFAP solutions detected an endothermic reaction, which occurs before a number of exothermic reactions as the temperature increases. Fluoride ions are formed and react with the alkyl carbonate molecules both as bases and as nucleophiles.

  18. Investigations into electrical discharges in gases

    CERN Document Server

    Klyarfel'D, B N

    2013-01-01

    Investigations into Electrical Discharges in Gases is a compilation of scientific articles that covers the advances in the investigation of the fundamental processes occurring in electrical discharges in gases and vapors. The book details the different aspects of the whole life cycle of an arc, which include the initiation of a discharge, its transition into an arc, the lateral spread of the arc column, and the recovery of electric strength after extinction of an arc. The text also discusses the methods for the dynamic measurement of vapor density in the vicinity of electrical discharges, alon

  19. Effect of pulsed bias on TiO2 thin films prepared on silicon by arc ion plating and simulation of pulsed plasma sheath dynamics

    International Nuclear Information System (INIS)

    Dielectric TiO2 thin films were fabricated on p-(100) Si substrates by arc ion plating. A pulsed substrate bias ranging from 0 V to − 900 V was applied to investigate the effect of pulsed bias on phase structure and growth of the films. Phase, microstructure, and growth morphology of TiO2 films prepared at different bias voltages were evaluated with grazing incident x-ray diffraction and atomic force microscopy (AFM). The results show that pulsed bias exerts an evident influence on phase structure and growth morphology. High substrate bias facilitates the formation of rutile phase, a (220) preferred orientation is observed in TiO2 films obtained at − 900 V. AFM images show that pulsed substrate bias exerts a strong influence on the growth of TiO2 films. With increasing bias voltage, the film is initially composed of tiny surface islands separated by shallow boundaries, then of large and spiky surface islands isolated by deep boundaries. Correspondingly, surface roughness increases from 1.1 nm at 0 V to 3.8 nm at − 900 V. To explain the phenomena observed in this study, pulsed plasma sheath model was used to simulate the ion sheath dynamics. By analyzing experimental and simulated results, it can be concluded that film growth and property relate close to ion density and energy in the sheath, which is dominantly governed by negative substrate bias.

  20. Effect of enamel top coating on oxidation behavior of multi-arc ion plating NiCrAlY coating in oxygen containing water vapor

    Institute of Scientific and Technical Information of China (English)

    XIE Dong-bai; ZHU Sheng-long; WANG Fu-hui

    2004-01-01

    The oxidation behavior of Ni-Cr-Al-Y coating produced by multi-arc ion plating with and without an enamel coating was investigated in flow oxygen and oxygen containing water vapor at 900 ℃. The results show that Ni-Cr-Al-Y coating exhibits low oxidation rate at 900 ℃ in pure oxygen and the oxidation kinetics follow the parabolic rate law. The presence of water vapor accelerates the oxidation rate of Ni-Cr-Al-Y coating and K38G alloy.The enamel top coating is very effective in protecting the Ni-Cr-Al-Y coating from water vapor corrosion attack, but the corrosion attack beneath the enamel coating is not observed.

  1. Effect of Rare Earth Element Cerium on Mechanical Properties and Morphology of TiN Coating Prepared by Arc Ion Plating

    Institute of Scientific and Technical Information of China (English)

    黄拿灿; 胡社军; 谢光荣; 曾鹏; 汝强

    2003-01-01

    TiN coatings were deposited on polished substrates of W18Cr4V high speed steel by means of vacuum arc ion plating. The effect of cerium on adhesion between TiN coating and substrate was studied. The microstructures and composition of TiN coatings were also investigated by means of scanning electron microscope (SEM), Auger electron spectroscopy (AES), and X-ray diffraction (XRD) technique. It was found that cerium is an effective modifying agent and the addition of suitable amount of cerium to TiN coatings can produce relatively excellent properties such as micro-hardness, wear resistance, oxidation resistance and porosity. The experimental results show that the added cerium in TiN coatings makes a contribution to form the preferred direction along with a (111) or (222) close packed face, which may be one of the reasons that improves some properties mentioned above.

  2. Structure and Performance of TiC-containing Diamond-like Carbon Nanocomposite Coatings Deposited by Rectangular Cathodic Arc Ion-plating

    Institute of Scientific and Technical Information of China (English)

    XIE Guosheng; YIN Zhimin; DING Hui; LI Xiaohong; YANG Bing

    2009-01-01

    TiC-containing diamond-like carbon(TiC-DLC)nanocomposite coatings were deposited by a rectangular cathodic arc ion-plating system using C_2H_2 as reacting gas.Raman spectroscopy and transmission electron microscopy analysis show that with increasing flow rate of C_2H_2,the structure of nanocomposite coatings changes from TiC nanograin-containing to graphite nanograin-containing DLC.The hardness measurements show that the hardness decreases from 28 GPa to 18 GPa with increasing C_2H_2 flow rate.The scratch test show that a high critical load(>40 N)was obtained and exhibited a good adhesion between the coating and the substrate.Wear experiment shows that the friction coefficient of TiC-DLC nanocomposite coatings decreases with increasing C_2H_2.A low friction coefficient of 0.07 was obtained at 480 sccm C_2H_2.

  3. Influence of processes of structure formation in mixed solvent and anion nature on cadmium ions discharge kinetics from water-dimethylformamide electrolyte

    International Nuclear Information System (INIS)

    Electrochemical reaction of cadmium ion discharge in water-dimethylformamide (DMF) solutions is studied. The influence of DMF concentration in the presence of different anions (ClO4-, F-, I-) on both reaction kinetics and mechanism is discussed on the basis of structural transformations in the mixed solvent and near the surface electrode processes

  4. Determination of discharge parameters via OES at the Linac4 H- ion source

    Science.gov (United States)

    Briefi, S.; Fink, D.; Mattei, S.; Lettry, J.; Fantz, U.

    2016-02-01

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (Te ≈ 1.2 eV, ne ≈ 1 × 1019 m-3, and nH/nH2 ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal "hockey-stick" rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  5. Determination of discharge parameters via OES at the Linac4 H⁻ ion source.

    Science.gov (United States)

    Briefi, S; Fink, D; Mattei, S; Lettry, J; Fantz, U

    2016-02-01

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (T(e) ≈ 1.2 eV, n(e) ≈ 1 × 10(19) m(-3), and n(H/)n(H2) ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal "hockey-stick" rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients. PMID:26931986

  6. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    A gliding arc is a quenched plasma that can be operated as a non-thermal plasma at atmospheric pressure and that is thus suitable for large-scale plasma surface treatment. For its practical industrial use the discharge should be extended stably in ambient air. A simple analytical calculation based...... on Ohm’s law indicates that the critical length of alternating current (AC) gliding arc discharge columns can be larger than that of a corresponding direct current (DC) gliding arc. This finding is supported by previously published images of AC and DC gliding arcs. Furthermore, the analysis shows...

  7. Mass spectrometric analysis of small negative ions (e/m < 100) produced by Trichel pulse negative corona discharge fed by ozonised air

    OpenAIRE

    Skalny, J. D.; Horvath, G.; Mason, N

    2007-01-01

    Mass spectrometric analysis of small negative ions (e/m < 100) produced by DC negative corona discharge in ozonised wet air both in flow and flow-stopped regimes was conducted at pressure of 30 kPa. The point-to-plain electrode system has been used. The yield of individual ions is strongly affected by trace concentrations of ozone in both regimes. Ozone concentration greater than 25 ppm is sufficient to completely suppress the appearance of O2- and a NO2- ion as well as theirs clusters in the...

  8. Experimental studies of the formation of cluster ions formed by corona discharge in an atmosphere containing SO2, NH3, and H2O

    DEFF Research Database (Denmark)

    Hvelplund, Preben; Pedersen, Jens Olaf Pepke; Støchkel, Kristian;

    2013-01-01

    Abstract We report on studies of ion-induced nucleation in a corona discharge taking place in an atmosphere containing SO2, NH3, and H2O at standard temperature and pressure. Positive ions such as H3O+(H2O)n, NH4+(H2O)n, and H+(H2SO4)(H2O)n and negative ions such as HSO5-(H2O)n, SO4-(H2O)n, HSO4-(H...

  9. Determination of discharge parameters via OES at the Linac4 H{sup −} ion source

    Energy Technology Data Exchange (ETDEWEB)

    Briefi, S., E-mail: stefan.briefi@physik.uni-augsburg.de [AG Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg (Germany); Fink, D.; Mattei, S.; Lettry, J. [Linac4 Ion Source Team, CERN-ABP, 1211 Geneva 23 (Switzerland); Fantz, U. [AG Experimentelle Plasmaphysik, Institut für Physik, Universität Augsburg, 86135 Augsburg (Germany); Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany)

    2016-02-15

    Optical emission spectroscopy (OES) measurements of the atomic Balmer series and the molecular Fulcher transition have been carried out at the Linac4 ion source in order to determine plasma parameters. As the spectroscopic system was only relatively calibrated, the data evaluation only yielded rough estimates of the plasma parameters (T{sub e} ≈ 1.2 eV, n{sub e} ≈ 1 × 10{sup 19} m{sup −3}, and n{sub H}/n{sub H{sub 2}} ≈ 0.5 at standard operational parameters). The analysis of the Fulcher transition revealed a non-thermal “hockey-stick” rotational population of the hydrogen molecules. At varying RF power, the measurements at the on-axis line of sight (LOS) showed a peak in the rotational temperatures between 25 and 40 kW of RF power, whereas a steady decrease with power was observed at a tilted LOS, indicating the presence of strong plasma parameter gradients.

  10. Characterisation of charge and discharge behaviour of lithium ion batteries with olivine based cathode active material

    Energy Technology Data Exchange (ETDEWEB)

    Roscher, Michael A.; Sauer, Dirk Uwe [RWTH Aachen University, Electrochemical Energy Conversion and Storage Systems Group, Institute for Power Electronics and Electrical Drives (ISEA), 52066 Aachen (Germany); Vetter, Jens [BMW Group, 80788 Muenchen (Germany)

    2009-06-15

    This paper gives insight to the physical processes taking part during the two-phase transition in lithium intercalation compounds. The behaviour of olivine based electrodes is in the special focus of this work. These electrodes exhibit phase juxtaposition within the electrode particles over a wide state of charge (SOC) range. Measurements were made to explore effects related to the formation of distinct phase sequences within the particles. Asymmetric charge characteristics, a load history dependency of the internal resistance and a voltage effect related to the disappearance of certain phase regions (the later on called vanishing phase effect) were identified. Moreover, these measurements give evidence to the existence of stable phase regions inside the electrode active material. An intuitive model is given to visualize the phase regions within spherical olivine particles. Therefore an analytical approach is developed in order to take the geometry of the particles, the ion permeability as well as the size distribution of the particles in consideration. According to the developed approach and the obtained measurement results, an enhanced cell equivalent electrical circuit is evaluated, considering phase shell development effects. (author)

  11. Optical emission spectroscopy of point-plane corona and back-corona discharges in air

    Science.gov (United States)

    Czech, T.; Sobczyk, A. T.; Jaworek, A.

    2011-12-01

    Results of spectroscopic investigations and current-voltage characteristics of corona discharge and back discharge on fly-ash layer, generated in point-plane electrode geometry in air at atmospheric pressure are presented in the paper. The characteristics of both discharges are similar but differ in the current and voltage ranges of all the discharge forms distinguished during the experiments. Three forms of back discharge, for positive and negative polarity, were investigated: glow, streamer and low-current back-arc. In order to characterize ionisation and excitation processes in back discharge, the emission spectra were measured and compared with those obtained for normal corona discharge generated in the same electrode configuration but with fly ash layer removed. The emission spectra were measured in two discharge zones: near the tip of needle electrode and near the plate. Visual forms of the discharge were recorded with digital camera and referred to current-voltage characteristics and emission spectra. The measurements have shown that spectral lines emitted by back discharge depend on the form of discharge and the discharge current. From the comparison of the spectral lines of back and normal discharges an effect of fly ash layer on the discharge morphology can be determined. The recorded emission spectra formed by ionised gas and plasma near the needle electrode and fly ash layer are different. It should be noted that in back arc emission, spectral lines of fly ash layer components can be distinguished. On the other hand, in needle zone, the emission of high intensity N2 second positive system and NO γ lines can be noticed. Regardless of these gaseous lines, also atomic lines of dust layer were present in the spectrum. The differences in spectra of back discharge for positive and negative polarities of the needle electrode have been explained by considering the kind of ions generated in the crater in fly ash layer. The aim of these studies is to better

  12. ADHESION STRENGTH OF TiN COATINGS AT VARIOUS ION ETCHING DEPOSITED ON TOOL STEELS USING CATHODIC ARC PVD TECHNIQUE

    OpenAIRE

    MUBARAK ALI; ESAH HAMZAH; NOUMAN ALI

    2009-01-01

    Titanium nitride (TiN) widely used as hard coating material was coated on tool steels, namely on high-speed steel (HSS) and D2 tool steel by physical vapor deposition method. The goal of this study was to examine the effect of ion etching with and without titanium (Ti) and chromium (Cr) on the adhesion strength of TiN coatings deposited on tool steels. From the scratch tester, it was observed that by increasing Ti ion etching showed an increase in adhesion strength of the deposited coatings. ...

  13. Regression Models Using Fully Discharged Voltage and Internal Resistance for State of Health Estimation of Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Kuo-Hsin Tseng

    2015-04-01

    Full Text Available Accurate estimation of lithium-ion battery life is essential to assure the reliable operation of the energy supply system. This study develops regression models for battery prognostics using statistical methods. The resultant regression models can not only monitor a battery’s degradation trend but also accurately predict its remaining useful life (RUL at an early stage. Three sets of test data are employed in the training stage for regression models. Another set of data is then applied to the regression models for validation. The fully discharged voltage (Vdis and internal resistance (R are adopted as aging parameters in two different mathematical models, with polynomial and exponential functions. A particle swarm optimization (PSO process is applied to search for optimal coefficients of the regression models. Simulations indicate that the regression models using Vdis and R as aging parameters can build a real state of health profile more accurately than those using cycle number, N. The Monte Carlo method is further employed to make the models adaptive. The subsequent results, however, show that this results in an insignificant improvement of the battery life prediction. A reasonable speculation is that the PSO process already yields the major model coefficients.

  14. Fluorine and boron co-doped diamond-like carbon films deposited by pulsed glow discharge plasma immersion ion processing

    CERN Document Server

    He, X M; Peters, A M; Taylor, B; Nastasi, M

    2002-01-01

    Fluorine (F) and boron (B) co-doped diamond-like carbon (FB-DLC) films were prepared on different substrates by the plasma immersion ion processing (PIIP) technique. A pulse glow discharge plasma was used for the PIIP deposition and was produced at a pressure of 1.33 Pa from acetylene (C sub 2 H sub 2), diborane (B sub 2 H sub 6), and hexafluoroethane (C sub 2 F sub 6) gas. Films of FB-DLC were deposited with different chemical compositions by varying the flow ratios of the C sub 2 H sub 2 , B sub 2 H sub 6 , and C sub 2 F sub 6 source gases. The incorporation of B sub 2 H sub 6 and C sub 2 F sub 6 into PIIP deposited DLC resulted in the formation of F-C and B-C hybridized bonding structures. The levels of the F and B concentrations effected the chemical bonding and the physical properties as was evident from the changes observed in density, hardness, stress, friction coefficient, and contact angle of water on films. Compared to B-doped or F-doped DLC films, the F and B co-doping of DLC during PIIP deposition...

  15. Complementary low energy ion scattering and X-ray photoelectron spectroscopy characterization of polystyrene submitted to N{sub 2}/H{sub 2} glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Bonatto, F., E-mail: bonatto02@yahoo.com.br [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Rovani, S. [Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Kaufmann, I.R.; Soares, G.V. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Baumvol, I.J.R. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Krug, C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil)

    2012-02-15

    Low energy ion scattering (LEIS) and X-ray photoelectron spectroscopy (XPS) were used to access the elemental composition and chemical bonding characteristics of polystyrene (PS) surfaces sequentially treated by corona and glow discharge (plasma) processing in N{sub 2}/H{sub 2} ambient. The latter has shown activity as suppressor of pathogenic Staphylococcus epidermidis biofilms. LEIS indicated that oxygen from the corona discharge process is progressively replaced by nitrogen at the PS surface. XPS shows C=N and N-C=O chemical groups as significant inhibitors of bacterial adhesion, suggesting application in medical devices.

  16. Studies of corona and back discharges in carbon dioxide

    Science.gov (United States)

    Czech, Tadeusz; Sobczyk, Arkadiusz Tomasz; Jaworek, Anatol; Krupa, Andrzej; Rajch, Eryk

    2013-01-01

    Results of spectroscopic investigations and current-voltage characteristics of corona and back discharges generated in point-plane electrode geometry in CO2 at atmospheric pressure for positive and negative polarity of the discharge electrode are presented in the paper. Three forms of back discharge, for both polarities, were investigated: glow, streamer and low-current back-arc. To generate the back-discharges for the conditions similar to electrostatic precipitator, the plate electrode was covered with fly ash layer. In order to characterize back discharge processes, the emission spectra were measured and compared with those obtained for normal discharge, generated in the same electrode configuration but without the fly ash layer on the plate electrode. The measurements have shown that optical emission spectral lines of atoms and molecules, excited or ionised in back discharge, depend on the forms of the discharge, the discharge current, and are different in the zones close to needle electrode and fly ash layer. From the comparison of spectral lines of back and normal discharges, an effect of fly ash layer on discharge characteristics and morphology has been determined. In normal corona, the emission spectra are mainly predetermined by the working gas components, but in the case of back discharge, the atomic and molecular lines, resulting from chemical composition of fly ash, are also identified. Differences in the spectra of back discharge for positive and negative polarities of the needle electrode have been explained by considering the kind of ions generated in the crater in fly ash layer. For back arc, the emission of spectral lines of atoms and molecules from fly ash layer can be recorded in the crater zone, but in the needle zone, only the emission lines of CO2 and its decomposition products (CO and C2) can be noticed. The studies of back discharge in CO2, as one of the main components of flue gases, were undertaken because this type of discharge, after

  17. Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Qiwen, E-mail: fanqiwen0926@163.com [Department of Nuclear Physics, China Institute of Atomic Energy, P.O. Box 275(62), Beijing 102413 (China); Du, Yinghui; Zhang, Rong; Xu, Guoji [Department of Nuclear Physics, China Institute of Atomic Energy, P.O. Box 275(62), Beijing 102413 (China)

    2013-04-21

    Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm{sup 2} in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm{sup 2} in thickness were produced by the filtered cathodic vacuum arc technology onto glass slides coated with betaine–saccharose as releasing agent, which were previously covered with evaporated carbon layers ∼1μg/cm{sup 2} in thickness by the controlled ac arc-discharge method. Irradiation lifetimes of the DLC stripper foils were tested using the heavy-ion beams at the terminal of the Beijing HI-13 Tandem Accelerator, and compared with those of the standard carbon stripper foils made by the combined dc and ac arc-discharge method. The measurements indicate that the DLC stripper foils outlast the standard combined dc and ac arc-discharge carbon stripper foils by a factor of at least 13 and 4 for the {sup 197}Au{sup −} (∼9MeV, ∼1μA) and {sup 63}Cu{sup −} (∼9MeV, ∼1μA) ion beams, respectively. The structure and properties of the DLC foils deposited onto silicon substrates by the filtered cathodic vacuum arc technology were also evaluated and analyzed by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The scanning electron microscopy images show that the DLC foils contain hardly droplets through the double 90° filters. The X-ray photoelectron spectrum indicates that sp{sup 3} bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (I{sub D}/I{sub G}) measured by the Raman spectroscopy is 0.78.

  18. Characterization of Micro-arc Oxidized Titanium

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro-arc oxidized titanium was evaluated by human body derived osteoblasts and slightly better than those of blasted surface.

  19. Charging and discharging tests for obtaining an accurate dynamic electro-thermal model of high power lithium-ion pack system for hybrid and EV applications

    DEFF Research Database (Denmark)

    Mihet-Popa, Lucian; Camacho, Oscar Mauricio Forero; Nørgård, Per Bromand

    2013-01-01

    This paper presents a battery test platform including two Li-ion battery designed for hybrid and EV applications, and charging/discharging tests under different operating conditions carried out for developing an accurate dynamic electro-thermal model of a high power Li-ion battery pack system....... The aim of the tests has been to study the impact of the battery degradation and to find out the dynamic characteristics of the cells including nonlinear open circuit voltage, series resistance and parallel transient circuit at different charge/discharge currents and cell temperature. An equivalent...... circuit model, based on the runtime battery model and the Thevenin circuit model, with parameters obtained from the tests and depending on SOC, current and temperature has been implemented in MATLAB/Simulink and Power Factory. A good alignment between simulations and measurements has been found....

  20. The relationship between visible light emission and species fraction of the hydrogen ion beams extracted from 2.45 GHz microwave discharge

    CERN Document Server

    Cortázar, O D; Tarvainen, O; Kalvas, T; Koivisto, H

    2015-01-01

    The relationship between Balmer-α and Fulcher-band emissions with extracted H +, H+2 , and H+3 ions is demonstrated for a 2.45 GHz microwave discharge. Ion mass spectra and optical measurements of Balmer-α and Fulcher-band emissions have been obtained with a Wien Filter having an optical view-port on the plasma chamber axis. The beam of approximately 1 mA is analyzed for different plasma conditions simultaneously with the measurement of light emissions both with temporal resolution. The use of visible light emissions as a valuable diagnostic tool for monitoring the species fraction of the extracted beams is proposed.

  1. 直流电弧自催化合成β-SiC纳米线%Self-catalytic Synthesis of β-SiC Nanowires by Direct Current Arc Discharge

    Institute of Scientific and Technical Information of China (English)

    王峰; 王秋实; 崔启良; 张剑; 邹广田

    2009-01-01

    采用C,Si和SiO2为反应原料,利用直流电弧法制备出长直的β-SiC纳米线.纳米线的直径为100~200 nm,长度为10~20 μm,并且沿着方向生长.通过X射线衍射(XRD)、扫描电子显微术(SEM)、透射电子显微术(TEM)、拉曼光谱等手段,对β-SiC纳米线进行表征.探讨了β-SiC纳米线自催化气-液-固(VLS)生长机制.%Straight and long β-SiC nanowires were synthesized in direct current arc discharge using a mixture of graphite, silicon, and silicon dioxide as the precursor. The diameter of the nanowires is 100~200 nm, and the length is about 10~20 μm. The axis of the nanowire is preferentially along the direction. The morphology and structure of the nanowires were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and Raman spectroscopy. The β-SiC nanowires are suggested to be formed via a self-catalyzed vapor-liquid-solid growth mechanism.

  2. A highly accurate predictive-adaptive method for lithium-ion battery remaining discharge energy prediction in electric vehicle applications

    International Nuclear Information System (INIS)

    Highlights: • An energy prediction (EP) method is introduced for battery ERDE determination. • EP determines ERDE through coupled prediction of future states, parameters, and output. • The PAEP combines parameter adaptation and prediction to update model parameters. • The PAEP provides improved ERDE accuracy compared with DC and other EP methods. - Abstract: In order to estimate the remaining driving range (RDR) in electric vehicles, the remaining discharge energy (ERDE) of the applied battery system needs to be precisely predicted. Strongly affected by the load profiles, the available ERDE varies largely in real-world applications and requires specific determination. However, the commonly-used direct calculation (DC) method might result in certain energy prediction errors by relating the ERDE directly to the current state of charge (SOC). To enhance the ERDE accuracy, this paper presents a battery energy prediction (EP) method based on the predictive control theory, in which a coupled prediction of future battery state variation, battery model parameter change, and voltage response, is implemented on the ERDE prediction horizon, and the ERDE is subsequently accumulated and real-timely optimized. Three EP approaches with different model parameter updating routes are introduced, and the predictive-adaptive energy prediction (PAEP) method combining the real-time parameter identification and the future parameter prediction offers the best potential. Based on a large-format lithium-ion battery, the performance of different ERDE calculation methods is compared under various dynamic profiles. Results imply that the EP methods provide much better accuracy than the traditional DC method, and the PAEP could reduce the ERDE error by more than 90% and guarantee the relative energy prediction error under 2%, proving as a proper choice in online ERDE prediction. The correlation of SOC estimation and ERDE calculation is then discussed to illustrate the importance of an

  3. Energy- and time-resolved measurements of fast ions emitted from plasma-focus discharges by means of a Thomson spectrometer

    Science.gov (United States)

    Kwiatkowski, R.; Czaus, K.; Paduch, M.; Sadowski, M. J.; Skladnik-Sadowska, E.; Zaloga, D. R.; Zielinska, E.; Żebrowski, J.

    2015-09-01

    The paper presents results of time-resolved measurements of fast deuterons emitted from high-current discharges of the Plasma-Focus (PF) type. The measurements were performed in a modified PF-1000U facility which is operated at the IFPiLM in Warsaw, Poland. The device was equipped with a fast-acting gas valve placed inside the inner electrode and oriented along the z-axis. The valve could inject a small volume of a chosen gas in front of this electrode. The PF discharges were initiated at the initial deuterium pressure equal to 1.6 or 2 hPa, with or without the use of the gas-puffing. Such discharges emitted intense beams of accelerated primary ions and X-ray pulses as well as products of nuclear fusion reactions. The reported measurements of the fast ion beams were performed by means of a Thomson-type spectrometer located at a chosen distance at the z-axis and equipped with miniature scintillation detectors. These detectors were placed in different points upon the deuteron parabola which corresponded to determined energy values. The detectors configuration allowed us to determine instants of the ion emission (using a TOF technique) and to compare them with instants of the X-ray emission. The collected data provided important information about emission characteristics of the modified PF-1000U facility.

  4. Analytical modeling and simulation of electrochemical charge/discharge behavior of Si thin film negative electrodes in Li-ion cells

    Science.gov (United States)

    Jagannathan, M.; Chandran, K. S. Ravi

    2014-02-01

    Physically-based analytical models that provide insights into the diffusion and/or interface charge transfer effects in bulk (lithiating/delithiating) electrodes are needed to truly assess the performance/limitations of electrode materials for Li-ion batteries. In this context, an analytical modeling framework is constructed here to predict the electrochemical charge-discharge characteristics during lithiation and delithiation of solid amorphous Si (a-Si) thin film electrodes. The framework includes analytical expressions that satisfy Fick's second law for Li transport and the requisite flux boundary conditions of lithiation and delithiation steps. The expressions are derived here by the method of separation of variables. They enable the determination of transient Li concentration profiles in the thin film electrode as a function of state of charge/discharge. The time-dependent electrode surface concentrations (at the electrode-electrolyte interface) obtained from these profiles were used to determine the activation overpotentials and thus, the non-equilibrium cell potentials, as a function of state of charge/discharge using Butler-Volmer kinetics. The simulated charge/discharge characteristics agreed well with the experimental data of a-Si thin film electrodes obtained at different C-rates. The model offers insights into how the charge-discharge behavior is controlled by diffusion limitation within electrode and/or the activation overpotentials at the interface. The analytical framework is also shown to predict successfully the hysteretic behavior of lithiation/delithiation voltage curves.

  5. Diffuse and spot mode of cathode arc attachments in an atmospheric magnetically rotating argon arc

    International Nuclear Information System (INIS)

    A model including the cathode, near-cathode region, and arc column was constructed. Specifically, a thermal perturbation layer at the arc fringe was calculated in order to couple sheath/presheath modelling with typical arc column modelling. Comparative investigation of two modes of attachment of a dc (100, 150, 200 A) atmospheric-pressure arc in argon to a thermionic cathode made of pure tungsten was conducted. Computational data revealed that there exists two modes of arc discharge: the spot mode, which has an obvious cathode surface temperature peak in the arc attachment centre; and the diffuse mode, which has a flat cathode surface temperature distribution and a larger arc attachment area. The modelling results of the arc attachment agree with previous experimental observations for the diffuse mode. A further 3D simulation is obviously needed to investigate the non-axisymmetrical features, especially for the spot mode. (paper)

  6. Experimental studies of the formation of cluster ions formed by corona discharge in an atmosphere containing SO2, NH3, and H2O

    Science.gov (United States)

    Pedersen, J. O.; Hvelplund, P.; Støchkel, K.; Enghoff, M. B.; Kurten, T.

    2013-12-01

    We report on studies of ion induced nucleation in a corona discharge taking place in an atmosphere containing SO2, NH3, and H2O at standard temperature and pressure. Positive ions such as H3O+(H2O)n, NH4+(H2O)n, and H+(H2SO4)(H2O)n and negative ions such as HSO5-(H2O)n, SO4-(H2O)n, HSO4-(H2O)n and NO3-(H2O)n have been recorded. Large values of n (> 100) were observed and the experiment indicates the existence of even larger water clusters. In contrast, only clusters with a maximum of 2 sulfuric acid molecules were observed. Fragmentation studies also revealed that the negative ion HSO5-, which has been observed in many studies, in our experiments is contaminated by O2-(HNO3)(H2O) ions, and this may also have been the case in other experiments. Finally an ion with m/z = 232 (where m is the cluster mass in amu and z the charge state), capable of attaching H2O-molecules was observed and studied by fragmentation. Positive ion m/z (mass/charge) spectrum

  7. High thrust-to-power ratio micro-cathode arc thruster

    Directory of Open Access Journals (Sweden)

    Joseph Lukas

    2016-02-01

    Full Text Available The Micro-Cathode Arc Thruster (μCAT is an electric propulsion device that ablates solid cathode material, through an electrical vacuum arc discharge, to create plasma and ultimately produce thrust in the μN to mN range. About 90% of the arc discharge current is conducted by electrons, which go toward heating the anode and contribute very little to thrust, with only the remaining 10% going toward thrust in the form of ion current. A preliminary set of experiments were conducted to show that, at the same power level, thrust may increase by utilizing an ablative anode. It was shown that ablative anode particles were found on a collection plate, compared to no particles from a non-ablative anode, while another experiment showed an increase in ion-to-arc current by approximately 40% at low frequencies compared to the non-ablative anode. Utilizing anode ablation leads to an increase in thrust-to-power ratio in the case of the μCAT.

  8. A comparison study between atomic and ionic nitrogen doped carbon films prepared by ion beam assisted cathode arc deposition at various pulse frequencies

    International Nuclear Information System (INIS)

    A comparison study of microstructure and bonds composition of carbon nitride (CNx) films fabricated at atomic and ionic nitrogen source by pulse cathode arc method was presented. The relative fractions of CN/CC bonds, N-sp3C/N-sp2C and graphite-like/pyridine-like N bonding configurations in the CN films were evaluated by combining C1s and N1s X-ray photoelectron spectroscopy with the hardness and optical band gap measurement. The dependence of microstructure (quantity, size and disordering degree of Csp2 clusters) of CNx films on the nitrogen source and pulse frequency was determined by Raman spectroscopy. Films with high atomic ratio of nitrogen/carbon (0.17) and high hardness were produced at ionic nitrogen source and low pulse frequency. The results showed that ionic nitrogen source facilitated the formation of CN bonds and N-sp2C bonding configurations (mainly in graphite-like N form). Moreover presenting an optimum pulse frequency (∼10 Hz) leaded to the most nitrogen coordinated with sp3-C and the highest ratio of CN/CC bonds in the CNx films. An equilibrium action mechanism might exist between the quantity and energy of carbon and nitrogen ions/atoms, giving more nitrogen-incorporated carbon materials. These allow us to obtain the high content of N-Csp3 bonding and expected bonding structure by optimizing pulse frequency and nitrogen source.

  9. Incidence Angle Effect of Energetic Carbon Ions on Deposition Rate, Topography, and Structure of Ultrathin Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc

    KAUST Repository

    Wang, N.

    2012-07-01

    The effect of the incidence angle of energetic carbon ions on the thickness, topography, and structure of ultrathin amorphous carbon (a-C) films synthesized by filtered cathodic vacuum arc (FCVA) was examined in the context of numerical and experimental results. The thickness of a-C films deposited at different incidence angles was investigated in the light of Monte Carlo simulations, and the calculated depth profiles were compared with those obtained from high-resolution transmission electron microscopy (TEM). The topography and structure of the a-C films were studied by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. The film thickness decreased with the increase of the incidence angle, while the surface roughness increased and the content of tetrahedral carbon hybridization (sp 3) decreased significantly with the increase of the incidence angle above 45° , measured from the surface normal. TEM, AFM, and XPS results indicate that the smoothest and thinnest a-C films with the highest content of sp 3 carbon bonding were produced for an incidence angle of 45°. The findings of this study have direct implications in ultrahigh-density magnetic recording, where ultrathin and smooth a-C films with high sp 3 contents are of critical importance. © 2012 IEEE.

  10. EXPERIMENTAL STUDY ON SUPERFICIAL COAT OF GEARS OF NITRIDED 32Cr2MoV COATED WITH TiN FILM BY MULTI-ARC ION PLATING

    Institute of Scientific and Technical Information of China (English)

    LI Hui; LI Runfang; XU Hongbin; ZHANG Jin

    2007-01-01

    After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare their difference concerning properties and microstructure. Experiment results indicate that tooth surface of the coated-TiN gears does not suffer surface abnormalities in meshed zone. Instead, the gears with nitrided case exhibit an abrasion mark on the meshed zone of tooth surface, which results in more weight loss of nitrided gears. The morphology of the surface suggests TiN film with more than 2000 HV is so dense and smooth that coated-TiN gears have higher wear resistance compared with the uncoated gears. The microstructure of coated-TiN gears is finer, hardness is higher and its distribution of coated-TiN gears is more reliable than uncoated ones, which makes nitride layer combined with TiN film tightly. Consequently, the wear-resistance of gears has been dramatically promoted.

  11. Arc Statistics

    CERN Document Server

    Meneghetti, M; Dahle, H; Limousin, M

    2013-01-01

    The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is compatible with observations, several studies were carried out which helped to significantly improve our knowledge of strong lensing clusters, unveiling their extremely complex internal structure. In particular, the abundance and the frequency of strong lensing events like gravitational arcs turned out to be a potentially very powerful tool to trace the structure formation. However, given the limited size of observational and theoretical data-sets, the power of arc statistics as a cosmological tool has been only minimally exploited so far. On the other hand, the last years were characterized by significant advancements in the field, and several cluster surveys that are ongoing or planned for the near future seem to have the potential to make arc statistics a competitive cosmo...

  12. Microspheric Na2Ti3O7 consisting of tiny nanotubes: an anode material for sodium-ion batteries with ultrafast charge-discharge rates

    Science.gov (United States)

    Wang, Wei; Yu, Chengjun; Lin, Zheshuai; Hou, Jungang; Zhu, Hongmin; Jiao, Shuqiang

    2012-12-01

    Conventionally, rechargeable batteries with a fast charge-discharge rate, while being able to be implemented in large-scale applications with low prices, are critical for new energy storage systems. In this work, first-principles simulations were employed to theoretically investigate the insertion of sodium into the Na2Ti3O7 structure. The result discovered that the theoretical capacity of Na2Ti3O7 was 311 mA h g-1. Furthermore, a microspheric Na2Ti3O7 material consisting of tiny nanotubes of ca. 8 nm in outside diameter and a few hundred nanometers in length has been synthesized. The galvanostatic charge-discharge measurements, using the as-prepared Na2Ti3O7 nanotubes as a working electrode with a voltage range of 0.01-2.5 V vs. Na+/Na, disclosed that a high capacity was maintained even under an ultrafast charge-discharge rate. At a current density of 354 mA g-1, the discharge capacity was maintained at 108 mA h g-1 over 100 cycles. Even at a very large current density of 3540 mA g-1, the discharge capacity was still 85 mA h g-1. HRTEM analysis and electrochemical tests proved that sodium ions could not only intercalate into the Na2Ti3O7 crystal, but could also be stored in the intracavity of the nanotubes. All of the results disclose that the as-prepared Na2Ti3O7 nanotubes are able to be used as anode materials in large-scale applications for rechargeable sodium-ion batteries at low cost while maintaining excellent performance.

  13. Influence of Triply-Charged Ions and Ionization Cross-Sections in a Hybrid-PIC Model of a Hall Thruster Discharge

    Science.gov (United States)

    Smith, Brandon D.; Boyd, Iain D.; Kamhawi, Hani

    2014-01-01

    The sensitivity of xenon ionization rates to collision cross-sections is studied within the framework of a hybrid-PIC model of a Hall thruster discharge. A revised curve fit based on the Drawin form is proposed and is shown to better reproduce the measured crosssections at high electron energies, with differences in the integrated rate coefficients being on the order of 10% for electron temperatures between 20 eV and 30 eV. The revised fit is implemented into HPHall and the updated model is used to simulate NASA's HiVHAc EDU2 Hall thruster at discharge voltages of 300, 400, and 500 V. For all three operating points, the revised cross-sections result in an increase in the predicted thrust and anode efficiency, reducing the error relative to experimental performance measurements. Electron temperature and ionization reaction rates are shown to follow the trends expected based on the integrated rate coefficients. The effects of triply-charged xenon are also assessed. The predicted thruster performance is found to have little or no dependence on the presence of triply-charged ions. The fraction of ion current carried by triply-charged ions is found to be on the order of 1% and increases slightly with increasing discharge voltage. The reaction rates for the 0?III, I?III, and II?III ionization reactions are found to be of similar order of magnitude and are about one order of magnitude smaller than the rate of 0?II ionization in the discharge channel.

  14. Modeling Arcs

    CERN Document Server

    Insepov, Zeke; Veitzer, Seth; Mahalingam, Sudhakar

    2011-01-01

    Although vacuum arcs were first identified over 110 years ago, they are not yet well understood. We have since developed a model of breakdown and gradient limits that tries to explain, in a self-consistent way: arc triggering, plasma initiation, plasma evolution, surface damage and gra- dient limits. We use simple PIC codes for modeling plasmas, molecular dynamics for modeling surface breakdown, and surface damage, and mesoscale surface thermodynamics and finite element electrostatic codes for to evaluate surface properties. Since any given experiment seems to have more variables than data points, we have tried to consider a wide variety of arcing (rf structures, e beam welding, laser ablation, etc.) to help constrain the problem, and concentrate on common mechanisms. While the mechanisms can be comparatively simple, modeling can be challenging.

  15. A vacuum spark ion source: High charge state metal ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Yushkov, G. Yu., E-mail: gyushkov@mail.ru; Nikolaev, A. G.; Frolova, V. P. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Oks, E. M. [High Current Electronics Institute, Siberian Branch of the Russian Academy of Science, Tomsk 634055 (Russian Federation); Tomsk State University of Control System and Radioelectronics, Tomsk 634050 (Russian Federation)

    2016-02-15

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.

  16. A vacuum spark ion source: High charge state metal ion beams

    Science.gov (United States)

    Yushkov, G. Yu.; Nikolaev, A. G.; Oks, E. M.; Frolova, V. P.

    2016-02-01

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described.

  17. A vacuum spark ion source: High charge state metal ion beams

    International Nuclear Information System (INIS)

    High ion charge state is often important in ion beam physics, among other reasons for the very practical purpose that it leads to proportionately higher ion beam energy for fixed accelerating voltage. The ion charge state of metal ion beams can be increased by replacing a vacuum arc ion source by a vacuum spark ion source. Since the voltage between anode and cathode remains high in a spark discharge compared to the vacuum arc, higher metal ion charge states are generated which can then be extracted as an ion beam. The use of a spark of pulse duration less than 10 μs and with current up to 10 kA allows the production of ion beams with current of several amperes at a pulse repetition rate of up to 5 pps. We have demonstrated the formation of high charge state heavy ions (bismuth) of up to 15 + and a mean ion charge state of more than 10 +. The physics and techniques of our vacuum spark ion source are described

  18. Effect of discharge current and deposition temperature on roughness and density of NbC films fabricated by ion beam sputtering technique

    Energy Technology Data Exchange (ETDEWEB)

    Dhawan, Rajnish, E-mail: rajnish@rrcat.gov.in; Rai, Sanjay, E-mail: rajnish@rrcat.gov.in; Lodha, G. S., E-mail: rajnish@rrcat.gov.in [X-ray optics Section, Indus Synchrotron Utilization Division, Raja Ramanna Center for Advanced Technology, Indore-452013 (India)

    2014-04-24

    NbC films were prepared using Ion beam sputtering system at various discharges current from 0.4 amps to 1.2 amps at room temperature. Effect of temperature on NbC films were also studied by depositing NbC films at various temperatures from room temperature to 200,300,400 and 600°C. X-ray reflectivity (XRR) study shows that surface roughness of the film decreases with decrease in discharge current. The optimum lowest roughness 3.2Å having density 92% of bulk was achieved at discharge current 0.6 amps at 3.0 cm{sup 3}/min Ar gas flow. X-ray study also shows that film roughness decreases with increase in temperature of the film and after a certain temperature it increases with increase in temperature. The lowest surface roughness 2.1Å was achieved at 300°C with density 83% of bulk NbC at constant discharge current 0.6 amps.

  19. Ion and neutral energy flux distributions to the cathode in glow discharges in Ar/Ne and Xe/Ne mixtures

    Science.gov (United States)

    Capdeville, H.; Pédoussat, C.; Pitchford, L. C.

    2002-02-01

    The work presented in the article is a study of the heavy particle (ion and neutral) energy flux distributions to the cathode in conditions typical of discharges used for luminous signs for advertising ("neon" signs). The purpose of this work is to evaluate the effect of the gas mixture on the sputtering of the cathode. We have combined two models for this study: a hybrid model of the electrical properties of the cathode region of a glow discharge and a Monte Carlo simulation of the heavy particle trajectories. Using known sputtering yields for Ne, Ar, and Xe on iron cathodes, we estimate the sputtered atom flux for mixtures of Ar/Ne and Xe/Ne as a function of the percent neon in the mixture.

  20. Comparative study of the structure and corrosion behavior of Zr-20%Cr and Zr-20%Ti alloy films deposited by multi-arc ion plating technique

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Farhat, E-mail: ilatahraf@yahoo.com [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Mehmood, Mazhar, E-mail: mazhar@pieas.edu.pk [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Qasim, Abdul Mateen; Ahmad, Jamil; Naeem-ur-Rehman [National Centre for Nanotechnology, Department of Metallurgy and Materials Engineering (DMME), Pakistan Institute of Engineering and Applied Sciences (PIEAS), PO Nilore, Islamabad 45650 (Pakistan); Iqbal, Muhammad [Physics Division, Pakistan Institute of Science and Technology (PINSTECH), Islamabad 45650 (Pakistan); Qureshi, Ammad H. [Materials Division, Pakistan Institute of Science and Technology (PINSTECH), Islamabad 45650 (Pakistan)

    2014-08-01

    The primary focus of the present work was to perform comparative study of the structure as well as corrosion behavior of two Zr-rich alloy films, i.e. Zr-20%Cr and Zr-20%Ti, as well as metallic Ti, Cr and Zr films, formed by multi-arc ion plating technique. The required alloy film composition was obtained by co-deposition with proper choice of current for the targets of the constituent metals. The deposited alloy film composition was determined by energy dispersion X-ray spectroscopy, X-ray fluorescence and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) techniques, which were in close agreement with each other. The film thickness lied in the range of 550-620 nm. The crystal structure was studied by X-ray diffraction, which revealed the formation of nanocrystalline and semi-amorphous structures. The corrosion rates of the films were determined through weight loss measurement in 1 M, 6 M and 12 M hydrochloric acid (HCl) by ICP-AES analysis of the solution after immersion for 200-350 h. Anodic (potentiodynamic) polarization was also performed. Zr-20%Cr alloy film exhibited the best corrosion resistance, and its dissolution rate was less than 0.5 μm/year in 6 M HCl and about 4 μm/year in 12 M HCl. - Highlights: • Fine control over the stoichiometry of each alloy film • Development of either nano-crystalline or semi-amorphous alloy films • Development of highly corrosion resistant films.

  1. Influence of modulation period and modulation ratio on structure and mechanical properties of TiBN/CrN coatings deposited by multi-arc ion plating

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, S.Y.; Yan, S.J.; Han, B. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Yang, B. [School of Power and Mechanical Engineering, Wuhan University, 430072 Wuhan (China); Lin, B.Z.; Zhang, Z.D.; Ai, Z.W. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Pelenovich, V.O. [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China); Institute of Ion-Plasma and Laser Technologies, Academy of Sciences of Uzbekistan, 700135 Tashkent (Uzbekistan); Fu, D.J., E-mail: djfu@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education and School of Physics and Technology, Wuhan University, 430072 Wuhan (China)

    2015-10-01

    Highlights: • TiBN/CrN multilayers were synthesized with varied modulation period and ratio. • The maximum hardness of 38.6 GPa is observed at Λ = 11.7 nm and R = 5:1. • The lowest multilayer COF of 0.32 is lower than that of CrN (0.56). • The wear rate of the coatings is improved and related to H/E and H{sup 3}/E{sup *2} ratios. - Abstract: TiBN/CrN multilayered superlattice coatings with modulation periods Λ (bilayer thickness) ranging from 22.5 to 4.2 nm and modulation ratio R (the thickness ratio of CrN and TiBN layers) ranging from 6:1 to 3:1 were synthesized using an industrial-scale cathodic arc ion plating system in an Ar–N{sub 2} gas mixture. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindention were employed to investigate the influence of modulation period and ratio on microstructure and mechanical properties of the multilayers. The sharp interfaces and nanoscale multilayered modulation were confirmed by TEM. TiBN/CrN multilayer coatings were crystallized with orientations at the (1 1 1), (2 0 0) and (2 2 0) crystallographic planes and the microstructure was strengthened at (2 0 0) preferred orientation. The maximum hardness of 38.6 GPa and elastic modulus of 477 GPa were obtained at Λ = 11.7 nm and R = 5:1. The lowest value of the friction coefficient at 0.32 sliding against a WC-Co ball was obtained at a bilayer period of 11.7 nm, compared to those of the coatings with other modulation periods and monolithic coatings. The wear rate of the multilayered coatings was also lower than those of the monolithic CrN and TiBN coatings.

  2. Influence of modulation period and modulation ratio on structure and mechanical properties of TiBN/CrN coatings deposited by multi-arc ion plating

    International Nuclear Information System (INIS)

    Highlights: • TiBN/CrN multilayers were synthesized with varied modulation period and ratio. • The maximum hardness of 38.6 GPa is observed at Λ = 11.7 nm and R = 5:1. • The lowest multilayer COF of 0.32 is lower than that of CrN (0.56). • The wear rate of the coatings is improved and related to H/E and H3/E*2 ratios. - Abstract: TiBN/CrN multilayered superlattice coatings with modulation periods Λ (bilayer thickness) ranging from 22.5 to 4.2 nm and modulation ratio R (the thickness ratio of CrN and TiBN layers) ranging from 6:1 to 3:1 were synthesized using an industrial-scale cathodic arc ion plating system in an Ar–N2 gas mixture. X-ray diffraction (XRD), transmission electron microscopy (TEM) and nanoindention were employed to investigate the influence of modulation period and ratio on microstructure and mechanical properties of the multilayers. The sharp interfaces and nanoscale multilayered modulation were confirmed by TEM. TiBN/CrN multilayer coatings were crystallized with orientations at the (1 1 1), (2 0 0) and (2 2 0) crystallographic planes and the microstructure was strengthened at (2 0 0) preferred orientation. The maximum hardness of 38.6 GPa and elastic modulus of 477 GPa were obtained at Λ = 11.7 nm and R = 5:1. The lowest value of the friction coefficient at 0.32 sliding against a WC-Co ball was obtained at a bilayer period of 11.7 nm, compared to those of the coatings with other modulation periods and monolithic coatings. The wear rate of the multilayered coatings was also lower than those of the monolithic CrN and TiBN coatings

  3. Investigation of ion and electron heat transport of high- T e ECH heated discharges in the large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Pablant, N. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Satake, S. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Yokoyama, M. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Gates, D. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bitter, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bertelli, N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Delgado-Aparicio, L. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Dinklage, A. [Max-Planck-Institut für Plasmaphysik, 17491 Greifswald, Germany; Goto, M. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Hill, K. W. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Igamai, S. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Kubo, S. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Lazerson, S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Matsuoka, S. [Research Organization for Information Science and Technology, Kobe, Hyogo 650-0047, Japan; Mikkelsen, D. R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Morita, S. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Oishi, T. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Seki, R. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Shimozuma, T. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Suzuki, C. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Suzuki, Y. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Takahashi, H. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; Yamada, H. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan; SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292 Japan; Yoshimura, Y. [National Institute for Fusion Science, Toki, Gifu 509-5292, Japan

    2016-01-28

    An analysis of the radial electric field and heat transport, both for ions and electrons, is presented for a high-${{T}_{\\text{e}}}$ electron cyclotron heated (ECH) discharge on the large helical device (LHD). Transport analysis is done using the task3d transport suite utilizing experimentally measured profiles for both ions and electrons. Ion temperature and perpendicular flow profiles are measured using the recently installed x-ray imaging crystal spectrometer diagnostic (XICS), while electron temperature and density profiles are measured using Thomson scattering. The analysis also includes calculated ECH power deposition profiles as determined through the travis ray-tracing code. This is the first time on LHD that this type of integrated transport analysis with measured ion temperature profiles has been performed without NBI, allowing the heat transport properties of plasmas with only ECH heating to be more clearly examined. For this study, a plasma discharge is chosen which develops a high central electron temperature (${{T}_{\\text{eo}}}=9$ keV) at moderately low densities (${{n}_{\\text{eo}}}=1.5\\times {{10}^{19}}$ m-3). The experimentally determined transport properties from task3d are compared to neoclassical predictions as calculated by the gsrake and fortec-3d codes. The predicted electron fluxes are seen to be an order of magnitude less than the measured fluxes, indicating that electron transport is largely anomalous, while the neoclassical and measured ion heat fluxes are of the same magnitude. Neoclassical predictions of a strong positive ambipolar electric field (${{E}_{\\text{r}}}$ ) in the plasma core are validated through comparisons to perpendicular flow measurements from the XICS diagnostic. This provides confidence that the predictions are producing physically meaningful results for the particle fluxes and radial electric field, which are a key component in correctly predicting plasma confinement.

  4. Nitrogen incorporation in saturated aliphatic C6-C8 hydrocarbons and ethanol in low-pressure nitrogen plasma generated by a hollow cathode discharge ion source.

    Science.gov (United States)

    Usmanov, Dilshadbek T; Chen, Lee Chuin; Hiraoka, Kenzo; Wada, Hiroshi; Nonami, Hiroshi; Yamabe, Shinichi

    2016-06-01

    Ion/molecule reactions of saturated hydrocarbons (n-hexane, cyclohexane, n-heptane, n-octane and isooctane) in 28-Torr N2 plasma generated by a hollow cathode discharge ion source were investigated using an Orbitrap mass spectrometer. It was found that the ions with [M+14](+) were observed as the major ions (M: sample molecule). The exact mass analysis revealed that the ions are nitrogenated molecules, [M+N](+) formed by the reactions of N3 (+) with M. The reaction, N3 (+) + M → [M+N](+) + N2 , were examined by the density functional theory calculations. It was found that N3 (+) abstracts the H atom from hydrocarbon molecules leading to the formation of protonated imines in the forms of R'R″CNH2 (+) (i.e. C-H bond nitrogenation). This result is in accord with the fact that elimination of NH3 is the major channel for MS/MS of [M+N](+) . That is, nitrogen is incorporated in the C-H bonds of saturated hydrocarbons. No nitrogenation was observed for benzene and acetone, which was ascribed to the formation of stable charge-transfer complexes benzene⋅⋅⋅⋅N3 (+) and acetone⋅⋅⋅⋅N3 (+) revealed by density functional theory calculations. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27270868

  5. Measurements of ion temperature and plasma hydrogenic composition by collective Thomson scattering in neutral beam heated discharges at TEXTOR

    DEFF Research Database (Denmark)

    Stejner Pedersen, Morten; Salewski, Mirko; Korsholm, Søren Bang;

    2013-01-01

    A method is developed to perform plasma composition and ion temperature measurements across the plasma minor radius in TEXTOR based on ion cyclotron structures in collective Thomson scattering spectra. By gradually moving the scattering volume, we obtain measurements across the outer midplane of ...

  6. Intense Pulsed Heavy Ion Beam Technology

    Science.gov (United States)

    Masugata, Katsumi; Ito, Hiroaki

    Development of intense pulsed heavy ion beam accelerator technology is described for the application of materials processing. Gas puff plasma gun and vacuum arc discharge plasma gun were developed as an active ion source for magnetically insulated pulsed ion diode. Source plasma of nitrogen and aluminum were successfully produced with the gas puff plasma gun and the vacuum arc plasma gun, respectively. The ion diode was successfully operated with gas puff plasma gun at diode voltage 190 kV, diode current 2.2 kA and nitrogen ion beam of ion current density 27 A/cm2 was obtained. The ion composition was evaluated by a Thomson parabola spectrometer and the purity of the nitrogen ion beam was estimated to be 86%. The diode also operated with aluminum ion source of vacuum arc plasma gun. The ion diode was operated at 200 kV, 12 kA, and aluminum ion beam of current density 230 A/cm2 was obtained. The beam consists of aluminum ions (Al(1-3)+) of energy 60-400 keV, and protons (90-130 keV), and the purity was estimated to be 89 %. The development of the bipolar pulse accelerator (BPA) was reported. A double coaxial type bipolar pulse generator was developed as the power supply of the BPA. The generator was tested with dummy load of 7.5 ohm, bipolar pulses of -138 kV, 72 ns (1st pulse) and +130 kV, 70 ns (2nd pulse) were succesively generated. By applying the bipolar pulse to the drift tube of the BPA, nitrogen ion beam of 2 A/cm2 was observed in the cathode, which suggests the bipolar pulse acceleration.

  7. Ion velocity distribution functions in argon and helium discharges: detailed comparison of numerical simulation results and experimental data

    CERN Document Server

    Wang, Huihui; Kaganovich, Igor D; Mustafaev, Alexander S

    2016-01-01

    Using Monte Carlo Collisions (MCC) method, we have performed simulations of ion velocity distribution functions (IVDF) taking into account both elastic collisions and charge exchange collisions of ions with atoms in uniform electric fields for argon and helium background gases. The simulation results are verified by comparison with the experiment data of the ion drift velocities and the ion transverse diffusion coefficients in argon and helium. The recently published experimental data for the first seven coefficients of the Legendre polynomial expansion of the ion energy and angular distribution functions are used to validate simulation results for IVDF. Good agreements between measured and simulated IVDFs show that the developed simulation model can be used for accurate calculations of IVDFs.

  8. Negative corona discharge-ion mobility spectrometry as a detection system for low density extraction solvent-based dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Ebrahimi, Amir; Jafari, Mohammad T

    2015-03-01

    This paper deals with a method based on negative corona discharge ionization ion mobility spectrometry (NCD-IMS) for the analysis of ethion (as an organophosphorus pesticide). The negative ions such as O2(-) and NO(x)(-) were eliminated from the background spectrum to increase the instrument sensitivity. The method was used to specify the sample extracted via dispersive liquid-liquid microextraction (DLLME) based on low density extraction solvent. The ion mobility spectrum of ethion in the negative mode and the reduced mobility value for its ion peak are firstly reported and compared with those of the positive mode. In order to combine the low density solvent DLLME directly with NCD-IMS, cyclohexane was selected as the extraction solvent, helping us to have a direct injection up to 20 µL solution, without any signal interference. The method was exhaustively validated in terms of sensitivity, enrichment factor, relative recovery, and repeatability. The linear dynamic range of 0.2-100.0 µg L(-1), detection limit of 0.075 µg L(-1), and the relative standard deviation (RSD) of about 5% were obtained for the analysis of ethion through this method. The average recoveries were calculated about 68% and 92% for the grape juice and underground water, respectively. Finally, some real samples were analyzed and the feasibility of the proposed method was successfully verified by the efficient extraction of the analyte using DLLME before the analysis by NCD-IMS. PMID:25618728

  9. Explicit formulae for the internal stress in spherical particles of active material within lithium ion battery cathodes during charging and discharging

    International Nuclear Information System (INIS)

    Highlights: • Closed form expression proposed for Li ion concentration in a spherical particle. • This solution for fast (dis)charging depends explicitly on time and radius. • Explicit internal stress solution derived further is useful in design calculations. - Abstract: The fundamental process underlying the operation of lithium ion batteries is the diffusion of charge-carrying ions through the electrolyte that separates the anode from the cathode, and the reversible insertion of lithium ions into the host material’s crystal structure (intercalation and de-intercalation). Alongside the principal electrochemical consequences of this process, mechanical phenomena that accompany (de)intercalation are of fundamental significance for deformation and fragmentation of the active materials, since it is these phenomena that ultimately determine the battery structural integrity and durability. This article presents a sequentially coupled analytical treatment of the transient diffusion and stress analysis (eigenstrain) problem related to the lithiation and de-lithiation processes at the level of an individual spherical secondary particle of active material. Explicit closed form approximate solutions are derived for the stresses that arise within the particles during fast charging. They provide a firm basis for the assessment of the charging conditions influence on the internal stress states and the effects on battery damage, mechanical integrity and durability

  10. Ion energy distributions in a pulsed dual frequency inductively coupled discharge of Ar/CF{sub 4} and effect of duty ratio

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Anurag; Seo, Jin Seok; Kim, Tae Hyung [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Yeom, Geun Young, E-mail: gyyeom@skku.edu [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology(SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2015-08-15

    Controlling time averaged ion energy distribution (IED) is becoming increasingly important in many plasma material processing applications for plasma etching and deposition. The present study reports the evolution of ion energy distributions with radio frequency (RF) powers in a pulsed dual frequency inductively discharge and also investigates the effect of duty ratio. The discharge has been sustained using two radio frequency, low (P{sub 2 MHz} = 2 MHz) and high (P{sub 13.56 MHz} = 13.56 MHz) at a pressure of 10 mTorr in argon (90%) and CF{sub 4} (10%) environment. The low frequency RF powers have been varied from 100 to 600 W, whereas the high frequency powers from 200 to 1200 W. Typically, IEDs show bimodal structure and energy width (energy separation between the high and low energy peaks) increases with increasing P{sub 13.56 MHz}; however, it shows opposite trends with P{sub 2 MHz}. It has been observed that IEDs bimodal structure tends to mono-modal structure and energy peaks shift towards low energy side as duty ratio increases, keeping pulse power owing to mode transition (capacitive to inductive) constant.

  11. Experimental study of the low power arc discharge assisted methane combustion%低功率电弧放电辅助甲烷燃烧的实验研究

    Institute of Scientific and Technical Information of China (English)

    张军; 方世东; 舒兴胜; 汪闯; 左潇; 孟月东; 王守国

    2015-01-01

    利用低功率电弧放电辅助甲烷燃烧,研究了在不同甲烷/空气比例的情况下,等离子体对甲烷燃烧的影响。采用发射光谱仪进行光谱诊断,比较有/无等离子体辅助甲烷燃烧火焰发射光谱的异同,讨论了等离子体辅助燃烧可能发生的过程和机理。比较有/无等离子体辅助甲烷燃烧火焰温度的变化。利用气相色谱和烟气分析仪对甲烷燃烧产物中的CH4、CO和O2进行分析。实验结果表明,加等离子体后,火焰的温度升高,尾气中的可燃性成分减少,氧气含量降低,在很大程度上提高了甲烷的燃烧效率;甲烷/空气的比例越低,燃烧效率的提高越明显;甲烷的富燃燃烧极限从16%调高到21%。%Different ratios of methane/air in the low power arc discharges assisted methane combustion were studied at atmospheric pressure. Plasma emission spectroscopy was recorded by an optical emission spectrometer. The possible physical and chemical reaction process and mechanisms were discussed. With a plasma in the on or off state, the physical appearances of the methane combustion flame were observed and compared, the temperature of the flame in the main combustion zone was investigated. The gas compositions of CH4, CO and O2 were analyzed by the gas chromatography and flue gas analyzer. The results showed that when plasma was in the on state, the temperature of flame increased and the combustion efficiency enhanced in stable combustion due to decrease of CH4, CO and O2; the combustion enhancement was more obvious at low ratio of methane/air; the rich combustion limits in terms of the ratio of methane/air was extended from 16% to 21%.

  12. Phenomenology of surface arcs on spacecraft dielectric materials

    Science.gov (United States)

    Balmain, K. G.; Gossland, M.; Reeves, R. D.; Kuller, W. G.

    1982-01-01

    For electron beam incidence on large specimens of Kapton thermal blanket material, surface arc discharges are shown to cause damage consisting of punchthrough holes which act as focal points for other types of damage, including subsurface tunnels, blowout holes and surface breakup. Under electron bombardment, dielectric sheet specimens separated by a gap are shown to discharge simultaneously. Teflon specimens which have been brushed or rubbed are shown to exhibit directional guidance of discharge arcs, and this phenomenon has been used to generate straight arcs whose velocities have been measured optically.

  13. Performance optimization of 20 cm xenon ion thruster discharge chamber%20cm氙离子推力器放电室性能优化

    Institute of Scientific and Technical Information of China (English)

    陈娟娟; 张天平; 贾艳辉; 李小平

    2012-01-01

    This paper describes the performance of the LIPSr200 ion thruster discharge chamber which was developed by Lanzhou Institute of Physics. Based on the discharge chamber geometric configuration and magnetic field, the completely self-consistent analytical model is utilized to discuss performance optimization of the discharge chamber of the LIPS-200. The thrust is enhanced from 40 mN up to 60 mN at rated impulse and efficiency. The results show that the 188. 515 W/A beam ion production cost at a propellant flow rate of 2. 167 × 1017 m-3 requires that the thruster runs at a discharge current of 6. 9 A to produce 1. 2 A ion beam current. Also, during the process of LIPS-200 ion thruster discharge chamber performance optimization, the sheath potential is always within 3.80~6.65 eV.%束流离子生产成本和推进剂利用率是表征离子推力器放电室性能的重要参数.在考虑不改变放电室几何结构、磁场分布并保持离子推力器比冲和效率的前提下,利用一维经验分析模型对兰州空间技术物理研究所研制的LIPS-200离子推力器放电室性能进行了优化分析,以实现推力器的推力从40 mN提高到60mN的目标要求.分析结果表明,提高放电室推进剂流率至2.06 mg/s,放电室内放电电流维持在6.9A,放电室内平均氙离子密度达到2.167×1017m-3时,可以保证引出1.2A的束流,推力器达到60 mN的推力.与之对应的推进剂利用率为92%,束流离子生产成本约为188.515 W/A,相比推力40 mN时,推进剂利用率为88%、束流离子生产成本为188.29 W/A的情况,放电室性能有所提高.另外,放电室性能优化过程中其鞘层电位始终保持在3.80~6.65 eV范围内.

  14. Development of a web application for estimate the total charge in an electric discharge

    Science.gov (United States)

    Vera-Rivera, F. H.; Dugar-Zhabon, V. D.; Dulce-Moreno, H. J.; V-Niño, E. D.

    2016-02-01

    This research seeks to implement a web application to estimate the total charge in an electric discharge from the experimental parameters established in reactors such as the JUPITER-MOSMET [1-5], used to perform surface modifications of metallic and nonmetallic species in solids substrates by hybrid discharges pulsed of high voltage and electric arc at low pressures [6-13]. Estimate the total charge generated in an electric discharge will allow to know the approximate value of the dose of ions implanted in the material surface [14-15], which are of great importance in each one of the experiments performed in the plasma laboratory of the Universidad Industrial de Santander (UIS), where the reactor is installed. Currently there are no applications developed to ease the process optimization and estimate the total charge generated in a pulsed electric discharge.

  15. MS/MS studies for the selective detection of isomeric biogenic VOCs using a Townsend Discharge Triple Quadrupole Tandem MS and a PTR-Linear Ion Trap MS

    Directory of Open Access Journals (Sweden)

    M. Müller

    2009-08-01

    Full Text Available We performed MS/MS investigations of biogenic volatile organic compounds (BVOC using a triple quadrupole tandem mass spectrometer (QqQ-MS equipped with a Townsend Discharge ion source and a Proton Transfer Reaction Linear Ion Trap (PTR-LIT mass spectrometer. Both instruments use H2O chemical ionization to produce protonated molecular ions. Here we report a study of the application of these instruments to determine methyl vinyl ketone (MVK and methacrolein (MACR and a series of monoterpenes (α-pinene, β-pinene, 3-carene, limonene, myrcene, ocimene and sesquiterpenes (humulene and farnesene. Both instruments achieved sub-ppb detection limits in the single MS mode and in the MS/MS mode for differentiating MVK and MACR. Collision induced dissociation (CID of protonated monoterpenes and sesquiterpenes was studied under the high-energy, single-to-few collision conditions of the QqQ-MS instrument and under the low-energy, multiple collision conditions of the PTR-LIT. Differences and similarities in the breakdown curves obtained are discussed. In addition, we performed MS4 of protonated limonene to illustrate the analytical power of the PTR-LIT. In spite of the progress we have made, the selective on-line mass-spectrometric detection of individual monoterpenes or sesquiterpenes in complex mixtures currently does not yet seem to be possible.

  16. Charge/discharge characteristics of the coal-tar pitch carbon as negative electrode in Li-ion batteries

    Science.gov (United States)

    Kim, Jung-Sik

    The charge/discharge characteristics were studied for the coal-tar pitch-based carbon (CTPC), which was pyrolyzed under the condition to form anisotropic mesophase pitch and then heat treated at temperatures ranging from 500 to 1300°C in N 2 atmosphere. As the heat treatment temperature increased, the reversible capacity for the CTPC increased progressively up to 1000°C, while the irreversible capacity decreased continuously. Carbons synthesized through the extraction of anisotropic mesophases showed higher reversible and lower irreversible capacities than the directly pyrolyzed ones.

  17. Arc saw development report

    International Nuclear Information System (INIS)

    The arc saw is one of the key components of the Contaminated Equipment Volume Reduction (CEVR) Program. This report describes the progress of the arc saw from its inception to its current developmental status. History of the arc saw and early contributors are discussed. Particular features of the arc saw and their advantages for CEVR are detailed. Development of the arc saw including theory of operation, pertinent experimental results, plans for the large arc saw and advanced control systems are covered. Associated topics such as potential applications for the arc saw and other arc saw installations in the world is also touched upon

  18. Non-uniform temperature distribution in Li-ion batteries during discharge - A combined thermal imaging, X-ray micro-tomography and electrochemical impedance approach

    Science.gov (United States)

    Robinson, James B.; Darr, Jawwad A.; Eastwood, David S.; Hinds, Gareth; Lee, Peter D.; Shearing, Paul R.; Taiwo, Oluwadamilola O.; Brett, Dan J. L.

    2014-04-01

    Thermal runaway is a major cause of failure in Li-ion batteries (LIBs), and of particular concern for high energy density transport applications, where safety concerns have hampered commercialisation. A clear understanding of electro-thermal properties and how these relate to structure and operation is vital to improving thermal management of LIBs. Here a combined thermal imaging, X-ray tomography and electrochemical impedance spectroscopy (EIS) approach was applied to commercially available 18650 cells to study their thermal characteristics. Thermal imaging was used to characterise heterogeneous temperature distributions during discharge above 0.75C; the complementary information provided by 3D X-ray tomography was utilised to evaluate the internal structure of the battery and identify the regions causing heating, specifically the components of the battery cap.

  19. A centre-triggered magnesium fuelled cathodic arc thruster uses sublimation to deliver a record high specific impulse

    Science.gov (United States)

    Neumann, Patrick R. C.; Bilek, Marcela; McKenzie, David R.

    2016-08-01

    The cathodic arc is a high current, low voltage discharge that operates in vacuum and provides a stream of highly ionised plasma from a solid conducting cathode. The high ion velocities, together with the high ionisation fraction and the quasineutrality of the exhaust stream, make the cathodic arc an attractive plasma source for spacecraft propulsion applications. The specific impulse of the cathodic arc thruster is substantially increased when the emission of neutral species is reduced. Here, we demonstrate a reduction of neutral emission by exploiting sublimation in cathode spots and enhanced ionisation of the plasma in short, high-current pulses. This, combined with the enhanced directionality due to the efficient erosion profiles created by centre-triggering, substantially increases the specific impulse. We present experimentally measured specific impulses and jet power efficiencies for titanium and magnesium fuels. Our Mg fuelled source provides the highest reported specific impulse for a gridless ion thruster and is competitive with all flight rated ion thrusters. We present a model based on cathode sublimation and melting at the cathodic arc spot explaining the outstanding performance of the Mg fuelled source. A further significant advantage of an Mg-fuelled thruster is the abundance of Mg in asteroidal material and in space junk, providing an opportunity for utilising these resources in space.

  20. Optical arc sensor using energy harvesting power source

    Science.gov (United States)

    Choi, Kyoo Nam; Rho, Hee Hyuk

    2016-06-01

    Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.

  1. Lung surgery - discharge

    Science.gov (United States)

    Thoracotomy - discharge; Lung tissue removal - discharge; Pneumonectomy - discharge; Lobectomy - discharge; Lung biopsy - discharge; Thoracoscopy - discharge; Video-assisted thoracoscopic surgery - discharge; VATS - ...

  2. Radical prostatectomy - discharge

    Science.gov (United States)

    ... prostatectomy - discharge; Laparoscopic radical prostatectomy - discharge; LRP - discharge; Robotic-assisted laparoscopic prostatectomy - discharge ; RALP - discharge; Pelvic lymphadenectomy - ...

  3. Improving the Mach number capabilities of arc driven shock tubes

    Science.gov (United States)

    Johnson, J. A., III; Santiago, J.; I, L.

    1980-01-01

    New systematic trends in one of the performance parameters of pressure loaded arc driven shock tubes have been determined. For a given configuration, the Mach number increases with the cube root of capacitor energy; however, the initial driver gas pressure is relatively unimportant. A qualitative model based on the assumption of Joule-preheating by the arc discharge is discussed.

  4. Characteristics of Single Cathode Cascaded Bias Voltage Arc Plasma

    Science.gov (United States)

    Ou, Wei; Deng, Baiquan; Zeng, Xianjun; Gou, Fujun; Xue, Xiaoyan; Zhang, Weiwei; Cao, Xiaogang; Yang, Dangxiao; Cao, Zhi

    2016-06-01

    A single cathode with a cascaded bias voltage arc plasma source has been developed with a new quartz cathode chamber, instead of the previous copper chambers, to provide better diagnostic observation and access to the plasma optical emission. The cathode chamber cooling scheme is also modified to be naturally cooled only by light emission without cooling water to improve the optical thin performance in the optical path. A single-parameter physical model has been developed to describe the power dissipated in the cascaded bias voltage arc discharge argon plasmas, which have been investigated by utilizing optical emission spectroscopy (OES) and Langmuir probe. In the experiments, discharge currents from 50 A to 100 A, argon flow rates from 800 sccm to 2000 sccm and magnetic fields of 0.1 T and 0.2 T were chosen. The results show: (a) the relationship between the averaged resistivity and the averaged current density exhibits an empirical scaling law as \\barη \\propto \\bar {j}-0.63369 and the power dissipated in the arc has a strong relation with the filling factor; (b) through the quartz, the argon ions optical emission lines have been easily observed and are dominating with wavelengths between 340 nm and 520 nm, which are the emissions of Ar+‑434.81 nm and Ar+‑442.60 nm line, and the intensities are increasing with the arc current and decreasing with the inlet argon flow rate; and (c) the electron density and temperature can reach 2.0 × 1019 m‑3 and 0.48 eV, respectively, under the conditions of an arc current of 90 A and a magnetic field of 0.2 T. The half-width of the ne radial profile is approximatively equal to a few Larmor radii of electrons and can be regarded as the diameter of the plasma jet in the experiments. supported by the International Thermonuclear Experimental Reactor (ITER) Program Special of Ministry of Science and Technology (No. 2013GB114003), and National Natural Science Foundation of China (Nos. 11275135, 11475122)

  5. Characteristics of Single Cathode Cascaded Bias Voltage Arc Plasma

    Science.gov (United States)

    Ou, Wei; Deng, Baiquan; Zeng, Xianjun; Gou, Fujun; Xue, Xiaoyan; Zhang, Weiwei; Cao, Xiaogang; Yang, Dangxiao; Cao, Zhi

    2016-06-01

    A single cathode with a cascaded bias voltage arc plasma source has been developed with a new quartz cathode chamber, instead of the previous copper chambers, to provide better diagnostic observation and access to the plasma optical emission. The cathode chamber cooling scheme is also modified to be naturally cooled only by light emission without cooling water to improve the optical thin performance in the optical path. A single-parameter physical model has been developed to describe the power dissipated in the cascaded bias voltage arc discharge argon plasmas, which have been investigated by utilizing optical emission spectroscopy (OES) and Langmuir probe. In the experiments, discharge currents from 50 A to 100 A, argon flow rates from 800 sccm to 2000 sccm and magnetic fields of 0.1 T and 0.2 T were chosen. The results show: (a) the relationship between the averaged resistivity and the averaged current density exhibits an empirical scaling law as \\barη \\propto \\bar {j}-0.63369 and the power dissipated in the arc has a strong relation with the filling factor; (b) through the quartz, the argon ions optical emission lines have been easily observed and are dominating with wavelengths between 340 nm and 520 nm, which are the emissions of Ar+-434.81 nm and Ar+-442.60 nm line, and the intensities are increasing with the arc current and decreasing with the inlet argon flow rate; and (c) the electron density and temperature can reach 2.0 × 1019 m-3 and 0.48 eV, respectively, under the conditions of an arc current of 90 A and a magnetic field of 0.2 T. The half-width of the ne radial profile is approximatively equal to a few Larmor radii of electrons and can be regarded as the diameter of the plasma jet in the experiments. supported by the International Thermonuclear Experimental Reactor (ITER) Program Special of Ministry of Science and Technology (No. 2013GB114003), and National Natural Science Foundation of China (Nos. 11275135, 11475122)

  6. Mechanism of surface modification in the plasma surface interaction in electrical arcs

    CERN Document Server

    Timko, Helga; Djurabekova, Flyura; Nordlund, Kai; Matyash, Konstantin; Schneider, Ralf; Toerklep, Anders; Arnau-Izquierdo, Gonzalo; Descoeudres, Antoine; Calatroni, Sergio; Taborelli, Mauro; Wuensch, Walter

    2010-01-01

    Electrical sparks and arcs are plasma discharges that carry large currents and can strongly modify surfaces. This damage usually comes in the form of micrometer-sized craters and frozen-in liquid on the surface. Using a combination of experiments, plasma and atomistic simulation tools, we now show that the observed formation of deep craters and liquidlike features during sparking in vacuum is explained by the impacts of energetic ions, accelerated under the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so high that in combination with kiloelectron volt energies it produces multiple overlapping heat spikes, which can lead to cratering even in materials such as Cu, where a single heat spike normally does not.

  7. Mechanism of surface modification in the plasma-surface interaction in electrical arcs

    CERN Document Server

    Timko, H; Nordlund, K; Costelle, L; Matyash, K; Schneider, R; Toerklep, A; Arnau-Izquierdo, G; Descoeudres, A; Calatroni, S; Taborelli, M; Wuensch, W

    2010-01-01

    Electrical sparks and arcs are plasma discharges that carry large currents and can strongly modify surfaces. This damage usually comes in the form of micrometer-sized craters and frozen-in liquid on the surface. Using a combination of experiments, plasma and atomistic simulation tools, we now show that the observed formation of deep craters and liquidlike features during sparking in vacuum is explained by the impacts of energetic ions, accelerated under the given conditions in the plasma sheath to kiloelectron volt energies, on surfaces. The flux in arcs is so high that in combination with kiloelectron volt energies it produces multiple overlapping heat spikes, which can lead to cratering even in materials such as Cu, where a single heat spike normally does not.

  8. A novel isotope analysis of oxygen in uranium oxides: comparison of secondary ion mass spectrometry, glow discharge mass spectrometry and thermal ionization mass spectrometry

    Science.gov (United States)

    Pajo, L.; Tamborini, G.; Rasmussen, G.; Mayer, K.; Koch, L.

    2001-05-01

    The natural variation of the oxygen isotopic composition is used among geologists to determine paleotemperatures and the origin of minerals. In recent studies, oxygen isotopic composition has been recognized as a possible tool for identification of the origin of seized uranium oxides in nuclear forensic science. In the last 10 years, great effort has been made to develop new direct and accurate n( 18O)/ n( 16O) measurements methods. Traditionally, n( 18O)/ n( 16O) analyses are performed by gas mass spectrometry. In this work, a novel oxygen isotope analysis by thermal ionization mass spectrometry (TIMS), using metal oxide ion species (UO +), is compared to the direct methods: glow discharge mass spectrometry (GDMS) and secondary ion mass spectrometry (SIMS). Because of the possible application of the n( 18O)/ n( 16O) ratio in nuclear forensics science, the samples were solid, pure UO 2 or U 3O 8 particles. The precision achieved using TIMS analysis was 0.04%, which is similar or even better than the one obtained using the SIMS technique (0.05%), and clearly better if compared to that of GDMS (0.5%). The samples used by TIMS are micrograms in size. The suitability of TIMS as a n( 18O)/ n( 16O) measurement method is verified by SIMS measurements. In addition, TIMS results have been confirmed by characterizing the n( 18O)/ n( 16O) ratio of UO 2 sample also by the traditional method of static vacuum mass spectrometry at the University of Chicago.

  9. Note: Triggering behavior of a vacuum arc plasma source

    Science.gov (United States)

    Lan, C. H.; Long, J. D.; Zheng, L.; Dong, P.; Yang, Z.; Li, J.; Wang, T.; He, J. L.

    2016-08-01

    Axial symmetry of discharge is very important for application of vacuum arc plasma. It is discovered that the triggering method is a significant factor that would influence the symmetry of arc discharge at the final stable stage. Using high-speed multiframe photography, the transition processes from cathode-trigger discharge to cathode-anode discharge were observed. It is shown that the performances of the two triggering methods investigated are quite different. Arc discharge triggered by independent electric source can be stabilized at the center of anode grid, but it is difficult to achieve such good symmetry through resistance triggering. It is also found that the triggering process is highly correlated to the behavior of emitted electrons.

  10. Chaos in gas discharges

    International Nuclear Information System (INIS)

    Many gas discharges exhibit natural oscillations which undergo a transition from regular to chaotic behavior by changing an experimental parameter or by applying external modulation. Besides several isolated investigations, two classes of discharge phenomena have been studied in more detail: ionization waves in medium pressure discharges and potential relaxation oscillations in filament cathode discharges at very low pressure. The latter phenomenon will be discussed by comparing experimental results from different discharge arrangements with particle-in-cell simulations and with a model based on the van-der-Pol equation. The filament cathode discharge has two stable modes of operation: the low current anode-glow-mode and the high current temperature-limited-mode, which form the hysteresis curve in the I(U) characteristics. Close to the hysteresis point of the AGM periodic relaxation oscillations occur. The authors demonstrate that the AGM can be understood by ion production in the anode layer, stopping of ions by charge exchange, and trapping in the virtual cathode around the filament. The relaxation oscillations consist of a slow filling phase and a rapid phase that invokes formation of an unstable double-layer, current-spiking, and ion depletion from the cathodic plasma. The relaxation oscillations can be mode-locked by external modulation. Inside a mode-locked state, a period doubling cascade is observed at high modulation degree

  11. Gas arc constriction for plasma arc welding

    Science.gov (United States)

    McGee, William F. (Inventor); Rybicki, Daniel J. (Inventor)

    1994-01-01

    A welding torch for plasma arc welding apparatus has an inert gas applied circumferentially about the arc column externally of the constricting nozzle so as to apply a constricting force on the arc after it has exited the nozzle orifice and downstream of the auxiliary shielding gas. The constricting inert gas is supplied to a plenum chamber about the body of the torch and exits through a series of circumferentially disposed orifices in an annular wall forming a closure at the forward end of the constricting gas plenum chamber. The constricting force of the circumferential gas flow about the arc concentrates and focuses the arc column into a more narrow and dense column of energy after exiting the nozzle orifice so that the arc better retains its energy density prior to contacting the workpiece.

  12. 车载锂离子电池放电性能影响因素研究%Influence factors of discharge performance of lithium-ion battery for electric vehicle

    Institute of Scientific and Technical Information of China (English)

    郭伟春; 付艳恕; 王丹; 张庭芳; 李中立

    2013-01-01

    Series working environment of lithium-ion battery were simulated by temperature-controlled test-box and discharge current controller. The discharge performance of single LiFePO4 battery was tested, and its operating voltage, discharge time and capacity were analyzed. The results show that the discharge performance changes with discharge current, temperature and humidity; the discharge current has the greatest influence on curves of discharge time and capacity; the influence of the environment humidity is not very seriously. It can be concluded that the effective control of the working environment of the lithium-ion battery can improve its discharge performance, and ameliorate the electric vehicle dynamic property and driving range.%通过可控温湿度实验箱和放电电流控制器模拟锂离子电池在实际应用中可能遇到的不同工作环境,对单体LiFePO4锂离子电池进行了放电实验,对电池工作电压、放电时间和放电量等工作特性进行了分析,得出电池放电性能随放电电流、温度和湿度变化的规律.其中放电电流对电池放电性能影响最大,环境湿度影响不大.综合分析可知,有效地控制锂离子电池的工作环境,可提高电池的放电性能,改善电动汽车的动力性和续驶里程.

  13. Capacitor discharge engineering

    CERN Document Server

    Früngel, Frank B A

    1976-01-01

    High Speed Pulse Technology, Volume III: Capacitor Discharge Engineering covers the production and practical application of capacitor dischargers for the generation and utilization of high speed pulsed of energy in different forms. This nine-chapter volume discusses the principles of electric current, voltage, X-rays, gamma rays, heat, beams of electrons, neutrons and ions, magnetic fields, sound, and shock waves in gases and liquids. Considerable chapters consider the applications of capacitor discharges, such as impulse hardening of steel, ultrapulse welding of precision parts, X-ray flash t

  14. Innovation approaches to controlling the electric regimes of electric arc furnaces

    Science.gov (United States)

    Bikeev, R. A.; Serikov, V. A.; Ognev, A. M.; Rechkalov, A. V.; Cherednichenko, V. S.

    2015-12-01

    The processes of current passage in an ac electric arc furnace (EAF) are subjected to industrial experiments and mathematical simulation. It is shown that, when a charge is melted, arcs between charge fragments exist in series with main arc discharges, and these arcs influence the stability of the main arc discharges. The measurement of instantaneous currents and voltages allowed us to perform a real-time calculation of the electrical characteristics of a three-phase circuit and to determine the θ parameter, which characterizes the nonlinearity of the circuit segment between electrodes. Based on these studies, we created an advanced system for controlling the electric regime of EAF.

  15. Observations of different core water cluster ions Y-(H2O)n (Y = O2, HOx, NOx, COx) and magic number in atmospheric pressure negative corona discharge mass spectrometry.

    Science.gov (United States)

    Sekimoto, Kanako; Takayama, Mitsuo

    2011-01-01

    Reliable mass spectrometry data from large water clusters Y(-)(H(2)O)(n) with various negative core ions Y(-) such as O(2)(-), HO(-), HO(2)(-), NO(2)(-), NO(3)(-), NO(3)(-)(HNO(3))(2), CO(3)(-) and HCO(4)(-) have been obtained using atmospheric pressure negative corona discharge mass spectrometry. All the core Y(-) ions observed were ionic species that play a central role in tropospheric ion chemistry. These mass spectra exhibited discontinuities in ion peak intensity at certain size clusters Y(-)(H(2)O)(m) indicating specific thermochemical stability. Thus, Y(-)(H(2)O)(m) may correspond to the magic number or first hydrated shell in the cluster series Y(-)(H(2)O)(n). The high intensity discontinuity at HO(-)(H(2)O)(3) observed was the first mass spectrometric evidence for the specific stability of HO(-)(H(2)O)(3) as the first hydrated shell which Eigen postulated in 1964. The negative ion water clusters Y(-)(H(2)O)(n) observed in the mass spectra are most likely to be formed via core ion formation in the ambient discharge area (760 torr) and the growth of water clusters by adiabatic expansion in the vacuum region of the mass spectrometers (≈1 torr). The detailed mechanism of the formation of the different core water cluster ions Y(-)(H(2)O)(n) is described. PMID:21184434

  16. Acoustic characteristics of electric arc furnaces

    Science.gov (United States)

    Cherednichenko, V. S.; Bikeev, R. A.; Cherednichenko, A. V.; Ognev, A. M.

    2016-06-01

    A mathematical model is constructed to describe the appearance and development of the noise characteristics of superpower electric arc furnaces. The noise formation is shown to be related to the pulsation of the axial plasma flows in arc discharges because of the electrodynamic pressure oscillations caused by the interaction of the self-magnetic field with the current passing in an arc. The pressure in the arc axis changes at a frequency of 100 Hz at the maximum operating pressure of 66 kPa for an arc current of 80 kA. The main ac arc sound frequencies are multiples of 100 Hz, which is supported in the practice of operation of electric arc furnaces. The sound intensity in the furnace laboratory reaches 160 dB and is decreased to 115-120 dB in the working furnace area due to shielding by the furnace jacket, the molten metal, and the molten slag. The appropriateness of increasing the hermetic sealing of electric furnaces and creating furnaces operating at low currents and high transformer voltages is corroborated.

  17. Bone marrow transplant - discharge

    Science.gov (United States)

    Transplant - bone marrow - discharge; Stem cell transplant - discharge; Hematopoietic stem cell transplant - discharge; Reduced intensity; Non-myeloablative transplant - discharge; Mini transplant - discharge; Allogenic bone marrow transplant - discharge; ...

  18. Comparative study on interactions between laser and arc plasma during laser-GTA welding and laser-GMA welding

    Science.gov (United States)

    Chen, Minghua; Xu, Jiannan; Xin, Lijun; Zhao, Zuofu; Wu, Fufa

    2016-10-01

    This paper describes an investigation on differences in interactions between laser and arc plasma during laser-gas tungsten arc (LT) welding and laser-gas metal arc (LM) welding. The characteristics of LT heat source and LM heat source, such as plasma behavior, heat penetration ability and spectral information were comparably studied. Based on the plasma discharge theory, the interactions during plasma discharge were modeled and analyzed. Results show that in both LT and LM welding, coupling discharge between the laser keyhole plasma and arc happens, which strongly enhance the arc. But, the enhancing effect in LT welding is much more sensitive than that in LM welding when parameters are adjusted.

  19. A simple alkali-metal and noble gas ion source for SIMS equipments with mass separation of the primary ions

    International Nuclear Information System (INIS)

    An alkali-metal ion source working without a store of alkali-metals is described. The alkali-metal ions are produced by evaporation of alkali salts and ionization in a low-voltage arc discharge stabilized with a noble gas plasma or in the case of small alkali-metal ion currents on the base of the well known thermic ionization at a hot tungsten wire. The source is very simple in construction and produces a stable ion current of 0.3 μA for more than 100 h. It is possible to change the ion species in a short time. This source is applicable to all SIMS equipments using mass separation for primary ions. (author)

  20. Investigations of DC corona and back discharge characteristics in various gases

    Energy Technology Data Exchange (ETDEWEB)

    Jaworek, A; Sobczyk, A T [Institute of Fluid Flow Machinery, Polish Academy of Sciences, 80-952 Gdansk (Poland); Rajch, E [Institute of Physics, Pomeranian Academy, 76-200 Slupsk (Poland)], E-mail: jaworek@imp.gda.pl

    2008-12-01

    The paper presents investigations of forward and back discharges occurring in air, carbon dioxide, and nitrogen, with plate electrode covered with fly ash. For the glow discharge, the back corona current is lower than for normal corona discharge, but for back-arc discharge, both currents are nearly the same. A dielectric layer covering the plate electrode causes that the arc discharge can start at higher voltages. In the arc discharge, the elements present in fly ash can volatilise due to electron bombardment of the layer.

  1. Investigations of DC corona and back discharge characteristics in various gases

    International Nuclear Information System (INIS)

    The paper presents investigations of forward and back discharges occurring in air, carbon dioxide, and nitrogen, with plate electrode covered with fly ash. For the glow discharge, the back corona current is lower than for normal corona discharge, but for back-arc discharge, both currents are nearly the same. A dielectric layer covering the plate electrode causes that the arc discharge can start at higher voltages. In the arc discharge, the elements present in fly ash can volatilise due to electron bombardment of the layer.

  2. The double sheath on cathodes of discharges burning in cathode vapour

    Energy Technology Data Exchange (ETDEWEB)

    Benilov, M S; Benilova, L G [Departamento de Fisica, Universidade da Madeira, Largo do MunicIpio, 9000 Funchal (Portugal)

    2010-09-01

    The model of a collisionless near-cathode space-charge sheath with ionization of atoms emitted by the cathode surface is considered. Numerical calculations showed that the mathematical problem is solvable and its solution is unique. In the framework of this model, the sheath represents a double layer with a potential maximum, with the ions which are produced before the maximum returning to the cathode surface and those produced after the maximum escaping into the plasma. Numerical results are given in a form to be readily applicable in analysis of discharges burning in cathode vapour, such as vacuum arcs. In particular, the results indicate that the ion backflow coefficient in such discharges exceeds 0.5, in agreement with values extracted from the experiment.

  3. A mechanism that triggers double arcing during plasma arc cutting

    Energy Technology Data Exchange (ETDEWEB)

    Nemchinsky, Valerian, E-mail: nemchinsky@bellsouth.ne [Keiser University, Fort Lauderdale, FL 33309 (United States)

    2009-10-21

    Double arcing (DA) is a phenomenon when a transferred arc, flowing inside an electrically insulated nozzle, breaks into two separate arcs: one that connects the cathode and the nozzle and another that connects the nozzle and a work-piece. It is a commonly accepted opinion that the reason for DA is high voltage drop in the plasma inside the nozzle. However, the specific mechanism that triggers the DA development is not clear. In this paper, we propose such a mechanism. Dielectric films deposited inside the nozzle's orifice play the key role in this mechanism. These films are charged by ion current from plasma. A strong electric field is created inside the film and at the boundary of the film and clean metal of the nozzle. This gives rise to a thermo-field electron emission from the clean metal that borders the film. Emitted electrons are accelerated at the voltage drop between the nozzle and plasma. These electrons produce extra ions, which in turn move back to the film and additionally charge it. This sequence of events leads to explosive instability if the voltage drop inside the nozzle is high enough. Experiments to check the proposed mechanism are suggested.

  4. An electric arc in the magnetic field of a solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Ungurs, I.A.; Shilova, Ye.I.

    1982-01-01

    A qualitative experiment is described, enabling investigation of the structure of the arc discharge between rod and ring electrodes, and evaluation of the speed of the axial flux created by electromagnetic forces. It is shown that placement of the plasma stream during discharge in the magnetic field of the solenoid provides the possibility of controlling this stream.

  5. Bronchiolitis - discharge

    Science.gov (United States)

    RSV bronchiolitis - discharge; Respiratory syncytial virus bronchiolitis - discharge ... Your child has bronchiolitis , which causes swelling and mucus to build up in the smallest air passages of the lungs. In the hospital, ...

  6. Detection of Amines and Ammonia with an Ambient Pressure Mass Spectrometer using a Corona Discharge Ion Source, in an Urban Atmosphere and in a Teflon Film Chamber

    Science.gov (United States)

    Alves, M.; Hanson, D. R.; Grieves, C.; Ortega, J. V.

    2015-12-01

    Amines and ammonia are an important group of molecules that can greatly affect atmospheric particle formation that can go on to impact cloud formation and their scattering of thermal and solar radiation, and as a result human health and ecosystems. In this study, an Ambient Pressure Mass Spectrometer (AmPMS) that is selective and sensitive to molecules with a high proton affinity, such as amines, was coupled with a newly built corona discharge ion source. AmPMS was used to monitor many different nitrogenous compound that are found in an urban atmosphere (July 2015, Minneapolis), down to the single digit pmol/mol level. Simultaneous to this, a proton transfer mass spectrometer also sampled the atmosphere through an inlet within 20 m of the AmPMS inlet. In another set of studies, a similar AmPMS was attached to a large Teflon film chamber at the Atmospheric Chemistry Division at NCAR (August 2015, Boulder). Exploratory studies are planned on the sticking of amines to the chamber walls as well as oxidizing the amine and monitoring products. Depending on the success of these studies, results will be presented on the reversability of amine partitioning and mass balance for these species in the chamber.

  7. Comparison of two methods for selegiline determination: A flow-injection chemiluminescence method using cadmium sulfide quantum dots and corona discharge ion mobility spectrometry

    Science.gov (United States)

    Khataee, Alireza; Lotfi, Roya; Hasanzadeh, Aliyeh; Iranifam, Mortaza; Zarei, Mahmoud; Joo, Sang Woo

    2016-01-01

    Two analytical approaches including chemiluminescence (CL) and corona discharge ionization ion mobility spectrometry (CD-IMS) were developed for sensitive determination of selegiline (SG). We found that the CL intensity of the KMnO4-Na2S2O3 CL system was significantly enhanced in the presence of L-cysteine capped CdS quantum dots (QDs). A possible CL mechanism for this CL reaction is proposed. In the presence of SG, the enhanced CL system was inhibited. Based on this inhibition, a simple and sensitive flow-injection CL method was proposed for the determination of SG. Under optimum experimental conditions, the decreased CL intensity was proportional to SG concentration in the range of 0.01 to 30.0 mg L- 1. The detection limit (3σ) was 0.004 mg L- 1. Also, SG was determined using CD-IMS, and under optimum conditions of CD-IMS, calibration curves were linear in the range of 0.15 to 42.0 mg L- 1, with a detection limit (3σ) of 0.03 mg L- 1. The precision of the two methods was calculated by analyzing samples containing 5.0 mg L- 1 of SG (n = 11). The relative standard deviations (RSDs%) of the flow-injection CL and CD-IMS methods are 2.17% and 3.83%, respectively. The proposed CL system exhibits a higher sensitivity and precision than the CD-IMS method for the determination of SG.

  8. Analysis of amantadine in biological fluids using hollow fiber-based liquid-liquid-liquid microextraction followed by corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Saraji, Mohammad; Khayamian, Taghi; Mirmahdieh, Shiva; Bidgoli, Ali Akbar Hajialiakbari

    2011-10-15

    A method based on liquid-liquid-liquid microextraction combined with corona discharge ion mobility spectrometry was developed for the analysis of amantadine in human urine and plasma samples. Amantadine was extracted from alkaline aqueous sample as donor phase through a thin phase of organic solvent (n-dodecane) filling the pores of the hollow fiber wall and then back extracted into the organic acceptor phase (methanol) located in the lumen of the hollow fiber. All variables affecting the extraction of analyte including acceptor organic solvent type, concentration of NaOH in donor phase, ionic strength of the sample and extraction time were studied. The linear range was 20-1000 and 5-250 ng/mL for plasma and urine, respectively (r(2)≥0.990). The limits of detection were calculated to be 7.2 and 1.6 ng/mL for plasma and urine, respectively. The relative standard deviation was lower than 8.2% for both urine and plasma samples. The enrichment factors were between 45 and 54. The method was successfully applied for the analysis of amantadine in urine and plasma samples. PMID:21956021

  9. Carbon nanotubes@silicon dioxide nanohybrids coating for solid-phase microextraction of organophosphorus pesticides followed by gas chromatography-corona discharge ion mobility spectrometric detection.

    Science.gov (United States)

    Saraji, Mohammad; Jafari, Mohammad Taghi; Mossaddegh, Mehdi

    2016-01-15

    A high efficiency solid-phase microextraction (SPME) fiber coated with porous carbon nanotubes-silicon dioxide (CNTs-SiO2) nanohybrids was synthesized and applied for the determination of some organophosphorus pesticides (OPPs) in vegetables, fruits and water samples. Gas chromatography-corona discharge ion mobility spectrometry was used as the detection system. Glucose, as a biocompatible compound, was used for connecting CNT and SiO2 during a hydrothermal process. The electrospinning technique was also applied for the fiber preparation. The parameters affecting the efficiency of extraction, including stirring rate, salt effect, extraction temperature, extraction time, desorption temperature and desorption time, were investigated and optimized. The developed CNTs@SiO2 fiber presented better extraction efficiency than the commercial SPME fibers (PA, PDMS, and PDMS-DVB). The intra- and inter-day relative standard deviations were found to be lower than 6.2 and 9.0%, respectively. For water samples, the limits of detection were in the range of 0.005-0.020 μg L(-1) and the limits of quantification were between 0.010 and 0.050 μg L(-1). The results showed a good linearity in the range of 0.01-3.0 μg L(-1) for the analytes. The spiking recoveries ranged from 79 (± 9) to 99 (± 8). The method was successfully applied for the determination of OPPs in real samples. PMID:26709024

  10. The use of electrical discharge for ignition and control of combustion of solid propellants

    Science.gov (United States)

    Tachibana, Takeshi; Kobayashi, Tsuruo; Matsuda, Takashi; Kimura, Itsuro

    1987-01-01

    As the first step of the study of the combustion control of solid propellants by electrical discharges, the effects of an arc discharge, which flows along the burning surface, on the burning rate and on the increase of enthalpy of the combustion product were investigated. For specially devised composite propellants, which are composed of Al and Teflon powders, it was shown that the combination can be controlled by an arc discharge; the combustion continues when the arc discharge is applied and is interrupted when the arc discharge breaks. In the present investigation, it was also shown that an arc discharge coupled with a high-frequency electrical discharge has potential as an effective ignition method for solid propellants. For the application of this type of combustion control to an ignitor for a solid propellant rocket motor or to a control rocket motor, this method lacks flexibility in the configuration scale and needs relatively high electric power at the present stage.

  11. Rotating arc spark plug

    Science.gov (United States)

    Whealton, John H.; Tsai, Chin-Chi

    2003-05-27

    A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

  12. A hot cavity laser ion source at IGISOL

    Science.gov (United States)

    Reponen, M.; Kessler, T.; Moore, I. D.; Rothe, S.; Äystö, J.

    2009-12-01

    A development program is underway at the IGISOL (Ion Guide Isotope Separator On-Line) facility, University of Jyväskylä, to efficiently and selectively produce low-energy radioactive ion beams of silver isotopes and isomers, with a particular interest in N = Z 94Ag . A hot cavity ion source has been installed, based on the FEBIAD (Forced Electron Beam Induced Arc Discharge) technique, combined with a titanium:sapphire laser system for selective laser ionization. The silver recoils produced via the heavy-ion fusion-evaporation reaction, 40Ca(58Ni, p3n)94Ag , are stopped in a graphite catcher, diffused, extracted and subsequently ionized using a three-step laser ionization scheme. The performance of the different components of the hot cavity laser ion source is discussed and initial results using stable 107, 109Ag are presented.

  13. A hot cavity laser ion source at IGISOL

    Energy Technology Data Exchange (ETDEWEB)

    Reponen, M.; Kessler, T.; Moore, I.D.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, PO Box 35 (YFL), Jyvaeskylae (Finland); Rothe, S. [Johannes Gutenberg Universitaet, AG Larissa/Quantum, Institut fuer Physik, Mainz (Germany)

    2009-12-15

    A development program is underway at the IGISOL (Ion Guide Isotope Separator On-Line) facility, University of Jyvaeskylae, to efficiently and selectively produce low-energy radioactive ion beams of silver isotopes and isomers, with a particular interest in N=Z {sup 94}Ag. A hot cavity ion source has been installed, based on the FEBIAD (Forced Electron Beam Induced Arc Discharge) technique, combined with a titanium:sapphire laser system for selective laser ionization. The silver recoils produced via the heavy-ion fusion-evaporation reaction, {sup 40}Ca({sup 58}Ni, p3n){sup 94}Ag, are stopped in a graphite catcher, diffused, extracted and subsequently ionized using a three-step laser ionization scheme. The performance of the different components of the hot cavity laser ion source is discussed and initial results using stable {sup 107,} {sup 109}Ag are presented. (orig.)

  14. A Hot Cavity Laser Ion Source at IGISOL

    CERN Document Server

    Reponen, M; Moore, I D; Rothe, S; Äystö, J

    2008-01-01

    A development program is underway at the IGISOL (Ion Guide Isotope Separator On-Line) facility, University of Jyvaskyla, to efficiently and selectively produce low-energy radioactive ion beams of silver isotopes and isomers, with a particular interest in N=Z 94Ag. A hot cavity ion source has been installed, based on the FEBIAD (Forced Electron Beam Induced Arc Discharge) technique, combined with a titanium:sapphire laser system for selective laser ionization. The silver recoils produced via the heavy-ion fusion-evaporation reaction, 40Ca(58Ni, p3n)94Ag, are stopped in a graphite catcher, diffused, extracted and subsequently ionized using a three-step laser ionization scheme. The performance of the different components of the hot cavity laser ion source is discussed and initial results using stable 107,109Ag are presented.

  15. The Effects of Annealing and Discharging on the Characteristics of MgO Thin Films Prepared by Ion Beam-Assisted Deposition as a Protective Layer of AC-PDP

    Institute of Scientific and Technical Information of China (English)

    YU Zhinong; SUN Jian; XUE Wei; ZHENG Dexiu

    2007-01-01

    This study investigated the effects of annealing and discharging on the characteristics of MgO thin films prepared by ion beam-assisted deposition as a protective layer of AC-PDP. By an annealing process at a temperature of 450 °C for more than three hours, the crystallinity of the deposited MgO films was improved, but the surface of the (200)-oriented MgO thin films in the vicinity of the discharge electrodes, especially on the inner sides of the electrodes, was subjected to crack formation. The failure mechanism of the (200)-oriented MgO films was due to the compressive stress of MgO films plus the additional compressive stress induced by the differences in the coefficient of thermal expansion between the electrode and the dielectric layer. In the discharging process, all MgO films were eroded unevenly, and the serious erosion occurred near the edges of the discharge electrodes. ATM(atomic force microscopy) images show that the eroded surface of the (200)-oriented MgO thin film is smoother than that of the (lll)-oriented film. Also, the (200)-oriented MgO thin film shows an improved ability to resist ion erosion compared to the (lll)-oriented film.

  16. Intense metal ion beam source for heavy ion fusion

    International Nuclear Information System (INIS)

    We have developed an ion source which can produce high current beams of metal ions. The source uses a metal vapor vacuum arc discharge as the plasma medium from which the ions are extracted, so we have called this source the MEVVA ion source. The metal plasma is created simply and efficiently and no carrier gas is required. Beams have been produced from metallic elements spanning the periodic table from lithium through uranium, at extraction voltages from 10 to 60 kV and with beam currents as high as 1.1 Amperes (electrical current in all charge states). A brief description of the source is given and its possible application as an ion source for heavy ion fusion is considered. Beams such as C+ (greater than or equal to99% of the beam in this species and charge state), Cr2+ (80%), and Ta/sup 3+,4+,5+/ (mixed charge states) have been produced. Beam emittance measurements and ways of increasing the source brightness are discussed

  17. Hip fracture - discharge

    Science.gov (United States)

    Inter-trochanteric fracture repair - discharge; Subtrochanteric fracture repair - discharge; Femoral neck fracture repair - discharge; Trochanteric fracture repair - discharge; Hip pinning surgery - discharge

  18. Characteristics of Atmospheric Pressure Rotating Gliding Arc Plasmas

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hao; ZHU Fengsen; TU Xin; BO Zheng; CEN Kefa; LI Xiaodong

    2016-01-01

    In this work,a novel direct current (DC) atmospheric pressure rotating gliding arc (RGA) plasma reactor has been developed for plasma-assisted chemical reactions.The influence of the gas composition and the gas flow rate on the arc dynamic behaviour and the formation of reactive species in the N2 and air gliding arc plasmas has been investigated by means of electrical signals,high speed photography,and optical emission spectroscopic diagnostics.Compared to conventional gliding arc reactors with knife-shaped electrodes which generally require a high flow rate (e.g.,10-20 L/min) to maintain a long arc length and reasonable plasma discharge zone,in this RGA system,a lower gas flow rate (e.g.,2 L/min) can also generate a larger effective plasma reaction zone with a longer arc length for chemical reactions.Two different motion patterns can be clearly observed in the N2 and air RGA plasmas.The time-resolved arc voltage signals show that three different arc dynamic modes,the arc restrike mode,takeover mode,and combined modes,can be clearly identified in the RGA plasmas.The occurrence of different motion and arc dynamic modes is strongly dependent on the composition of the working gas and gas flow rate.

  19. Characteristics of Atmospheric Pressure Rotating Gliding Arc Plasmas

    Science.gov (United States)

    Zhang, Hao; Zhu, Fengsen; Tu, Xin; Bo, Zheng; Cen, Kefa; Li, Xiaodong

    2016-05-01

    In this work, a novel direct current (DC) atmospheric pressure rotating gliding arc (RGA) plasma reactor has been developed for plasma-assisted chemical reactions. The influence of the gas composition and the gas flow rate on the arc dynamic behaviour and the formation of reactive species in the N2 and air gliding arc plasmas has been investigated by means of electrical signals, high speed photography, and optical emission spectroscopic diagnostics. Compared to conventional gliding arc reactors with knife-shaped electrodes which generally require a high flow rate (e.g., 10-20 L/min) to maintain a long arc length and reasonable plasma discharge zone, in this RGA system, a lower gas flow rate (e.g., 2 L/min) can also generate a larger effective plasma reaction zone with a longer arc length for chemical reactions. Two different motion patterns can be clearly observed in the N2 and air RGA plasmas. The time-resolved arc voltage signals show that three different arc dynamic modes, the arc restrike mode, takeover mode, and combined modes, can be clearly identified in the RGA plasmas. The occurrence of different motion and arc dynamic modes is strongly dependent on the composition of the working gas and gas flow rate. supported by National Natural Science Foundation of China (No. 51576174), the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20120101110099) and the Fundamental Research Funds for the Central Universities (No. 2015FZA4011)

  20. Halloysite nanotubes-titanium dioxide as a solid-phase microextraction coating combined with negative corona discharge-ion mobility spectrometry for the determination of parathion.

    Science.gov (United States)

    Saraji, Mohammad; Jafari, Mohammad Taghi; Mossaddegh, Mehdi

    2016-07-01

    Halloysite nanotubes-titanium dioxide (HNTs-TiO2) as a biocompatible environmentally friendly solid-phase microextraction (SPME) fiber coating was prepared. HNTs-TiO2 was chemically coated on the surface of a fused-silica fiber using a sol-gel process. Parathion as an organophosphorus pesticide was selected as a model compound to investigate the extraction efficiency of the fiber. The extracted analyte was detected by negative corona discharge-ion mobility spectrometer (NCD-IMS). The effective parameters on the extraction efficiency, such as salt effect, extraction temperature and extraction time were investigated and optimized. The extraction efficiency of HNTs-TiO2 fiber was compared with bare-silica (sol-gel based coating without HNTs-TiO2), HNTs, carbon nanotubes and commercial SPME fibers (PA, PDMS, and PDMS-DVB). The HNTs-TiO2 fiber showed highest extraction efficiency among the studied fibers. The intra- and inter-day relative standard deviations were found to be 4.3 and 6.3%, respectively. The limit of detection and limit of quantification values were 0.03 and 0.1 μg L(-1), respectively. The dynamic range of the method was in the range of 0.1-25 μg L(-1). The spiking recoveries were between 85 (±9) and 97 (±6). The SPME-HNTs-TiO2 combined with NCD-IMS was successfully applied for the determination of parathion in apple, strawberry, celery and water samples. PMID:27216393

  1. Numerical investigation of the double-arcing phenomenon in a cutting arc torch

    Energy Technology Data Exchange (ETDEWEB)

    Mancinelli, B. R., E-mail: bmancinelli@frvt.utn.edu.ar [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651 (2600) Venado Tuerto, Santa Fe (Argentina); Minotti, F. O.; Kelly, H. [Grupo de Descargas Eléctricas, Departamento Ingeniería Electromecánica, Facultad Regional Venado Tuerto (UTN), Laprida 651 (2600) Venado Tuerto, Santa Fe (Argentina); Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina); Prevosto, L. [Instituto de Física del Plasma (CONICET), Departamento de Física, Facultad de Ciencias Exactas y Naturales (UBA) Ciudad Universitaria Pab. I, 1428 Buenos Aires (Argentina)

    2014-07-14

    A numerical investigation of the double-arcing phenomenon in a cutting arc torch is reported. The dynamics of the double-arcing were simulated by using a two-dimensional model of the gas breakdown development in the space-charge layer contiguous to the nozzle of a cutting arc torch operated with oxygen. The kinetic scheme includes ionization of heavy particles by electron impact, electron attachment, electron detachment, electron–ion recombination, and ion–ion recombination. Complementary measurements during double-arcing phenomena were also conducted. A marked rise of the nozzle voltage was found. The numerical results showed that the dynamics of a cathode spot at the exit of the nozzle inner surface play a key role in the raising of the nozzle voltage, which in turn allows more electrons to return to the wall at the nozzle inlet. The return flow of electrons thus closes the current loop of the double-arcing. The increase in the (floating) nozzle voltage is due to the fact that the increased electron emission at the spot is mainly compensated by the displacement current (the ions do not play a relevant role due to its low-mobility) until that the stationary state is achieved and the electron return flow fully-compensates the electron emission at the spot. A fairly good agreement was found between the model and the experiment for a spot emission current growth rate of the order of 7 × 10{sup 4} A/s.

  2. 锂盐浓度对高功率锂离子电池性能的影响%Effect of lithium salt concentration on performance of high-rate discharge Li-ion battery

    Institute of Scientific and Technical Information of China (English)

    袁卉军; 陈真; 刘建生; 王姣丽

    2012-01-01

    考察了电解液中锂盐浓度对高功率锂离子电池倍率放电及高低温性能的影响.锂盐浓度为0.9~1.5 mol/L时,浓度越高越有利于大电流放电,但高于1.4 mol/L后,倍率放电中值电压的提升趋向平缓;在-20℃下以170 mA(1 C)放电,1.2 mol/L时的性能最好.%Effects of lithium salt concentration on rate discharge, high-low temperature performance of high-rate discharge Li-ion battery were investigated. When the lithium salt concentration was 0.9 ~ 1.5 mol/L, the higher concentration was benefit to heavy load discharge, but when higher than 1.4 mol/L, the increasing of rate discharge middle voltage trended gentle. When discharged with 1 C (170 mA) at - 20℃, the performance was the best with 1.2 mol/L.

  3. Discharge Process of Insertion Electrodes Controlled by Lithium Ion Diffusion in Solid Materials%锂离子固相扩散控制下的材料放电过程

    Institute of Scientific and Technical Information of China (English)

    唐致远; 薛建军; 李建刚; 王占良

    2001-01-01

    从理论上分析了在锂离子固相扩散控制条件下 ,电极材料的恒流放电过程 .数值计算的结果表明 ,Q值(放电时率和扩散时间常数之比)对材料的放电容量有非常重要的影响 .模拟了 LiMn2O4正极材料和石墨负极材料的恒流放电曲线 ,分析了颗粒粒径对这两种材料放电容量的影响 .%We have analyzed the galvanostatic discharge process of insertion electrodes controlled by lithium ion diffusion in solid materials. It is demonstrated by mathematic calculation that the discharge capacity of insertion electrode depends on the value of Q(defined as the ratio of discharge hour rate and diffusion time constant). The galvanostatic discharge curve of spinel LiMn2O4 cathode and graphite anode have been simulated. The effect of particle size on the discharge capacity of spinel LiMn2O4 cathode and graphite anode is evaluated.

  4. Wear Resistance of TiN Coating Prepared by Multi-arc Ion Plating on Aluminum Alloy Surface%铝合金表面多弧离子镀TiN涂层的耐磨性能

    Institute of Scientific and Technical Information of China (English)

    谭银元; 潘应君

    2009-01-01

    Wear resistance of TiN coating prepared by multi-arc ion plating on ZL109 aluminum alloy surface has been examined. The results show that wear resist-ance of the ZL109 aluminum alloy with multi-arc ion plating TiN coating can be significantly improved. With applying 1N and wearing for 90min, the abrasive width of the samples without TiN coating makes ap-proximately 2 times of that with TiN coating, and av-erage frictional coefficient of the samples with TiN coating makes approximately 50% of that without coating. With applying 2N, the morphology and abra-sive width are varied as time increases. The wear mor-phology of the ZL109 alloy samples with TiN coating is characterized by adhesive abrasion in early stage and by abrasive abrasion in last stage.%采用多弧离子镀在ZL109铝合金表面进行了TiN涂层处理,并对涂层的载荷耐磨性进行了分析和讨论.结果表明,ZL109铝合金表面多弧离子镀TiN涂层后,其耐磨性得到明显提高.在1 N的载荷下,连续磨损90 min时,未镀膜试样的磨痕宽度几乎是TiN试样的2倍,镀有TiN膜试样的平均摩擦因数几乎是未镀样的50%.在2 N的载荷下,由磨痕的形貌和宽度随时间的变化可见,镀有TiN涂层的试样在磨损前期,主要以粘着磨损为主,在磨损后期以磨粒磨损为主.

  5. High power nano-LiMn2O4 cathode materials with high-rate pulse discharge capability for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    Chen Ying-Chao; Xie Kai; Pan Yi; Zheng Chun-Man; Wang Hua-Lin

    2011-01-01

    Nano-LiMn2O4 cathode materials with nano-sized particles are synthesized via a citric acid assisted sol-gel route. The structure, the morphology and the electrochemical properties of the nano-LiMn2O4 are investigated. Compared with the micro-sized LiMn2O4, the nano-LiMn2O4 possesses a high initial capacity (120 mAh/g) at a discharge rate of 0.2 C (29.6 mA/g). The nano-LiMn2O4 also has a good high-rate discharge capability, retaining 91% of its capacity at a discharge rate of 10 C and 73% at a discharge rate of 40 C. In particular, the nano-LiMn2O4 shows an excellent high-rate pulse discharge capability. The cut-off voltage at the end of 50-ms pulse discharge with a discharge rate of 80 C is above 3.40 V, and the voltage returns to over 4.10 V after the pulse discharge. These results show that the prepared nano-LiMn2O4 could be a potential cathode material for the power sources with the capability to deliver very high-rate pulse currents.

  6. Peek Arc Consistency

    CERN Document Server

    Bodirsky, Manuel

    2008-01-01

    This paper studies peek arc consistency, a reasoning technique that extends the well-known arc consistency technique for constraint satisfaction. In contrast to other more costly extensions of arc consistency that have been studied in the literature, peek arc consistency requires only linear space and quadratic time and can be parallelized in a straightforward way such that it runs in linear time with a linear number of processors. We demonstrate that for various constraint languages, peek arc consistency gives a polynomial-time decision procedure for the constraint satisfaction problem. We also present an algebraic characterization of those constraint languages that can be solved by peek arc consistency, and study the robustness of the algorithm.

  7. Modeling electronegative plasma discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenberg, A.J.; Lieberman, M.A. [Univ. of California, Berkley, CA (United States)

    1995-12-31

    Macroscopic analytic models for a three-component electronegative gas discharge are developed. Assuming the negative ions to be in Boltzmann equilibrium, a positive ion ambipolar diffusion equation is derived. The discharge consists of an electronegative core and electropositive edges. The electron density in the core is nearly uniform, allowing a parabolic approximation to the plasma profile to be employed. The resulting equilibrium equations are solved analytically and matched to a constant mobility transport model of an electropositive edge plasma. The solutions are compared to a simulation of a parallel-plane r.f. driven oxygen plasma for p = 50 mTorr and n{sub eo}= 2.4 x 10{sup 15} m{sup -3}. The ratio {alpha}{sub o} of central negative ion density to electron density, and the electron temperature T{sub e}, found in the simulation, are in reasonable agreement with the values calculated from the model. The model is extended to: (1) low pressures, where a variable mobility model is used in the electropositive edge region; and (2) high {alpha}{sub o} in which the edge region disappears. The inclusion of a second positive ion species, which can be very important in describing electronegative discharges used for materials processing, is a possible extension of the model.

  8. Discharging patients.

    Science.gov (United States)

    Causey, Amy

    2016-06-22

    What was the nature of the CPD activity and/or practice-related feedback and/or event or experience in your practice? The CPD article discussed the importance of effective planning when discharging patients from acute care hospitals. It emphasised the benefit of early assessment and planning, and outlined the essential principles that should be followed when discharging a patient. PMID:27332612

  9. NIPPLE DISCHARGE

    Directory of Open Access Journals (Sweden)

    T. N. Bukharova

    2008-01-01

    Full Text Available According to the data available in the literature, as high as 50% of women have benign breast tumors frequently accompanied by nip- ple discharge. Nipple discharge may be serous, bloody, purulent, and colostric. The most common causes are breast abscess, injury, drugs, prolactinoma, intraductal pappiloma, ductal ectasia, intraductal cancer (not more than 10%.

  10. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  11. Lifetime of charge stripping foils and transmission of heavy ions in 12UD-pelletron tandem accelerator

    International Nuclear Information System (INIS)

    The lifetime of charge stripping foils produced by means of new arc-discharge method developed by Sugai was measured for the bombardment of 10 MeV Au ions. Transmission of Au ions through 12UD-pelletron tandem accelerator was also measured. The lifetime of tested charge stripping foils for 10-15 μg/cm2 thick and 3.8-5.0 μg/cm2 thick, respectively, demonstrated to be longer than that of usual arc-discharge method by more than 30 times and 20 times, meanwhile, the transmission of 3.8-5.0 μg/cm2 thick foils was about 4 times higher than that of 10-15 μg/cm2 thick foils. (orig.)

  12. Experimental and theoretical determination of the efficiency of a sub-atmospheric flowing high power cascaded arc hydrogen plasma source

    NARCIS (Netherlands)

    Vijvers, W. A. J.; D.C. Schram,; Shumack, A. E.; Cardozo, N. J. L.; Rapp, J.; van Rooij, G. J.

    2010-01-01

    Cascaded arc plasma sources with channel diameters between 4 and 8mm were experimentally investigated at discharge currents up to 900A and hydrogen (H-2) flow rates up to 10 slm. Pressure measurements at the arc exit showed that the heavy particle temperature in the discharge channel was about 0.8 e

  13. Electric arc in three-phase metallurgical furnaces

    Science.gov (United States)

    Vorob'ev, V. P.

    2013-12-01

    The theoretical and practical assumptions relative to the studies of electric arcs in steel-melting furnaces presented in journal Electrometallurgiya in 2011-2012 are subjected to a critical analysis. Based on classical concepts and the author experiments, the concept is presented regarding to the phases of the state and parameters of arc discharge in the ac electromagnetic field of a three-phase system. Industrial methods of eliminating the injurious effect of flash arc on furnace lining and the furnace efficiency are considered.

  14. Development of circuit model for arcing on solar panels

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Bhoomi K; Deshpande, S P; Mukherjee, S; Gupta, S B; Ranjan, M; Rane, R; Vaghela, N; Acharya, V [FCIPT, Institute for Plasma Research, Bhat, Gandhinagar 382428 (India); Sudhakar, M; Sankaran, M; Suresh, E P, E-mail: bhoomi@ipr.res.i [ISRO Satellite Centre (ISAC), Bangalore 560017 (India)

    2010-02-01

    The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 {mu}s duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between

  15. Development of circuit model for arcing on solar panels

    International Nuclear Information System (INIS)

    The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 μs duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between insulator

  16. Vaginal Discharge

    Science.gov (United States)

    ... vulva Intense itching Painful sexual intercourse Signs of bacterial vaginosis A white, gray or yellowish vaginal discharge A fishy odor that is strongest after sex or after washing with soap Itching or burning Slight redness and swelling of ...

  17. Angina - discharge

    Science.gov (United States)

    ... Avoid salty and fatty foods. Stay away from fast-food restaurants. Your doctor can refer you to a ... Controlling your high blood pressure Dietary fats explained Fast food tips Heart attack - discharge Heart attack - what to ...

  18. Deposition and Damping Property of Arc Ion Plated NiCrAlY Coatings%基底偏压对电弧离子镀NiCrAlY涂层阻尼性能的影响

    Institute of Scientific and Technical Information of China (English)

    杜广煜; 谭祯; 孙伟; 柴昊; 巴德纯; 韩清凯

    2012-01-01

    The NiCrAlY coatings were deposited by arc ion plating on stainless steel substrates. The effects of the deposition conditions, such as the pressure, substrate bias, and arc current, on damping property of the NiCrAlY coatings were evaluated. The rnicrostructures and damping property were characterized with X-ray diffraction, scanning electron microscopy and dynamic mechanical analyzer. The results show that the substrate bias significantly improves the damping properties of the NiCrAlY coating. For example, the damping factor of the NiCrAlY coated stainless steel substrate increased with an increase of the bias voltage. The fairly smooth, compact NiCrAlY coatings mainly consisted of γ-Ni, α-NiAl,γ-Ni3Al,and α- Cr phases.%采用电弧离子镀方法在不锈钢基片上制备了NiCrAlY涂层,在制备过程中改变基底偏压分别取50,100,200,300V.对涂层样品分别进行物相分析,表面形貌观察,测定微区化学成分,并利用动态机械分析仪(DMA)对涂层样品的阻尼性能进行测试.结果表明,利用电弧离子镀的方法可以在不锈钢基底上获得均匀的NiCrAlY涂层.涂层为晶态结构,主要由γ-Ni相,β-NiAl相,γ'-Ni3Al相和α-Cr组成.制备过程中的偏压变化对涂层的表面形貌有明显影响,对涂层的化学成分影响不大.DMA结果表明NiCrAlY涂层能明显地提高基底材料的阻尼性能,同时随着偏压增大,涂层样品的阻尼因子有所提高.

  19. Intelligent Controller of Digital High Intensity Discharge Lamp

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    High-intensity discharge (HID) lamps include these types of electrical lamps: mercury vapor, metal halide (also HQI), high-pressure sodium, low-pressure sodium and less commonly, xenon short-arc lamps. The light-producing element of these lamp types is a well-stabilized arc discharge contained within a refractory envelope (arc tube) with wall loading in excess of 3 W/cm (19.4 W/in.). Compared to fluorescent and incandescent lamps, HID lamps produce a much larger quantity of light in a relatively small package. With tests made by the National Quality Supervision and

  20. Development of a new corona discharge based ion source for high resolution time-of-flight chemical ionization mass spectrometer to measure gaseous H2SO4 and aerosol sulfate

    Science.gov (United States)

    Zheng, Jun; Yang, Dongsen; Ma, Yan; Chen, Mindong; Cheng, Jin; Li, Shizheng; Wang, Ming

    2015-10-01

    A new corona discharge (CD) based ion source was developed for a commercial high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) (Aerodyne Research Inc.) to measure both gaseous sulfuric acid (H2SO4) and aerosol sulfate after thermal desorption. Nitrate core ions (NO3-) were used as reagent ions and were generated by a negative discharge in zero air followed by addition of excess nitrogen dioxide (NO2) to convert primary ions and hydroxyl radicals (OH) into NO3- ions and nitric acid (HNO3). The CD-HRToF-CIMS showed no detectable interference from hundreds parts per billion by volume (ppbv) of sulfur dioxide (SO2). Unlike the atmospheric pressure ionization (API) ToF-CIMS, the CD ion source was integrated onto the ion-molecule reaction (IMR) chamber and which made it possible to measure aerosol sulfate by coupling to a filter inlet for gases and aerosols (FIGAERO). Moreover, compared with a quadrupole-based mass spectrometer, the desired HSO4- signal was detected by its exact mass of m/z 96.960, which was well resolved from the potential interferences of HCO3-ṡ(H2O)2 (m/z 97.014) and O-ṡH2OṡHNO3 (m/z 97.002). In this work, using laboratory-generated standards the CD-HRToF-CIMS was demonstrated to be able to detect as low as 3.1 × 105 molecules cm-3 gaseous H2SO4 and 0.5 μg m-3 ammonium sulfate based on 10-s integration time and two times of the baseline noise. The CD ion source had the advantages of low cost and a simple but robust structure. Since the system was non-radioactive and did not require corrosive HNO3 gas, it can be readily field deployed. The CD-HRToF-CIMS can be a powerful tool for both field and laboratory studies of aerosol formation mechanism and the chemical processes that were critical to understand the evolution of aerosols in the atmosphere.