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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. Ion energy distribution and basic characteristics of plasma flows of nonself-sustained arc discharge

    International Nuclear Information System (INIS)

    Experimental results on study of the nonself-sustained arc discharge basic characteristics at currents up to 35 A are presented. The ion energy distributions and dynamics of the directed motion average energy of plasma flow ions are studied. Floating potentials in the plasma flows are measured. Ionization coefficients of the generated plasma flows and their dependence on the discharge current are studied. It is shown that at the discharge currents equal 20...30 A the vacuum arc discharge in anode material vapors can effectively create dropless and highly ionized plasma flows of different metals and provides films deposition rates, which are comparable to possibilities of the cathode vacuum arc discharge

  5. Study on a negative hydrogen ion source with hot cathode arc discharge

    International Nuclear Information System (INIS)

    A negative hydrogen (H−) ion source with hot cathode arc discharge was designed and fabricated as a primary injector for a 10 MeV PET cyclotron at IMP. 1 mA dc H− beam with ε N,RMS = 0.08 π mm mrad was extracted at 25 kV. Halbach hexapole was adopted to confine the plasma. The state of arc discharge, the parameters including filament current, arc current, gas pressure, plasma electrode bias, and the ratio of Ie−/IH− were experimentally studied. The discussion on the result, and opinions to improve the source were given

  6. 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.

  7. Production mechanism of high proton ratio plasma in a hydrogen arc discharge ion source

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Takatoshi; Inoue, Takashi; Iga, Takashi; Watanabe, Kazuhiro; Kashiwagi, Mieko; Taniguchi, Masaki; Hanada, Masaya; Imai, Tsuyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Shimizu, Takashi [Doshisha Univ., Kyoto (Japan)

    2003-03-01

    Generally a large volume plasma generator with strong plasma confinement is suitable for production of a high proton yield of >90%. Recently a small ion source whose discharge volume is only 1.4 liter produced a high proton ratio of {approx}90% by applying transverse magnetic field. Mechanism of a high proton ration plasma production in such a small ion source has not been studied. The proton production mechanisms in a hydrogen arc discharge were numerically studied by solving rate equations to obtain H{sup +}, H{sub 2}{sup +}, H{sub 3}{sup +}, and H{sup 0} densities in various scales of ion sources. It was revealed that a main process of proton production depends strongly on a following process of H{sub 2}{sup +} + e {yields} H{sup +} + H + e in the small volume discharge. By applying the transverse magnetic field in the plasma volume, flow of primary electrons through the magnetic field is restrained, resulting in suppression of H{sub 2}{sup +} production near the plasma grid. In addition, H{sup +} is produced near the plasma grid from dissociation of H{sub 2}{sup +} due to the large cross section with low temperature electrons. Thus the proton yield is enhanced even in the small volume discharge by applying the magnetic field. Using the same numerical method, the plasma production mechanism was calculated for a large ion source. The high proton ratio and the high atomic hydrogen density can be easily obtained under the low-pressure discharge, where the contribution of proton production reaction H + e {yields} H{sup +} + 2e is comparable or higher than that of H{sub 2}{sup +} e {yields} H{sup +} + H + e. From the negative ion production point of view, experimentally obtained negative ion beam current was evaluated quantitatively from the numerical analysis. As a result, it was shown that the high atom flux to the plasma grid surface generates large amount of negative ion flux rather than that by the positive ions in Cs-seeded large ion sources. (author)

  8. Modification of a metallic surface in a vacuum arc discharge plasma using thermally stimulated ion diffusion

    Science.gov (United States)

    Muboyadzhyan, S. A.

    2008-12-01

    A new process for modifying a metallic surface in a vacuum arc discharge plasma using thermally stimulated ion diffusion is considered. The effect of the bias voltage (negative substrate potential) on the processes that occur on the surface of a treated part is studied when the substrate material interacts with an accelerated metallic-ion flow. The phase and elemental compositions of the modified layer are studied for substrates made of nickel-based superalloys, austenitic and martensitic steels, and titanium-based alloys. The heat resistance, the salt corrosion resistance, and the corrosion cracking resistance of steels and titanium-based alloys are investigated after their modification in vacuum arc plasmas of pure metals (Ti, Zr, Al, Cr, Y) and related alloys. The surface modification caused by the thermally stimulated ion saturation of the surfaces of parts made from structural materials is shown to change the structural-phase states of their surfaces and, correspondingly, the properties of these materials in relation to the state of the surface.

  9. 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.

  10. Three-dimensional Ion Distribution in a Filtered Vacuum Arc Discharge

    International Nuclear Information System (INIS)

    Three-dimensional measurements of the ion flux along the filter of a magnetically filtered d-c vacuum arc are presented. The device includes a metallic plasma-generating chamber with cooper electrodes coupled to a substrate chamber through a quarter-torus magnetic filter. The filtering magnetic field was high enough to magnetize the electrons but not the ions. The ion current distribution was studied using a multi-element Cu probes, placed at three different positions along the filter. The ion saturation current of each probe was measured by biasing the probe at -70V with respect the grounded anode. Preliminary results of the three dimensional ion flux distribution and the floating potential of the plasma as functions of the bias filter voltage and magnetic field intensity are reported

  11. 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)

  12. 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...

  13. 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

  14. 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

  15. Microwave Discharge Ion Sources

    CERN Document Server

    Celona, L

    2013-01-01

    This chapter describes the basic principles, design features and characteristics of microwave discharge ion sources. A suitable source for the production of intense beams for high-power accelerators must satisfy the requirements of high brightness, stability and reliability. The 2.45 GHz off-resonance microwave discharge sources are ideal devices to generate the required beams, as they produce multimilliampere beams of protons, deuterons and singly charged ions. A description of different technical designs will be given, analysing their performance, with particular attention being paid to the quality of the beam, especially in terms of its emittance.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

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

    International Nuclear Information System (INIS)

    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 (105 - 106 rad sec-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

  2. Properties of surface arc discharge in a supersonic airflow

    International Nuclear Information System (INIS)

    An experimental study of a direct-current, surface arc discharge in a Mach 2 cold supersonic airflow is presented. The surface arc discharge is generated with cylindrical tungsten electrodes flush-mounted on a boron-nitride ceramic plate embedded in the lower wall of the supersonic test section. In the presence of airflow, gas breakdown voltage increases from 1.5 kV in stationary air to 2 kV due to particle number density augmentation in the flow. The surface arc discharge transforms from a continuous mode in stationary air to a pulsed-repetitive mode in the flow. The mean time interval between discharge pulses is about 4.3 ms. For a single pulse, arc discharge occupies only about 60 μs. The discharge photos taken by a high-speed CCD camera (framing rate 1125 Hz) validate this pulsed-repetitive process and indicate that the plasma channel of the surface arc discharge is blown downstream by the supersonic flow. As the length of the plasma channel increases, the discharge voltage also increases. When the channel length reaches a critical value (∼25 mm), the dc power supply (3 kV-4 kW) cannot sustain the discharge voltage (∼3 kV) and the Joule heating energy cannot balance the dissipation of constrained convection, and hence the discharge quenches immediately. Current and voltage measurements demonstrate that the discharge process in a single pulse can be separated into three distinct phases: strong-pulsed breakdown process, steady discharge process and discharge attenuation process. Finally, the underlying mechanism of the dynamic process of surface arc discharge in supersonic flow is discussed. This paper provides more insights into the mechanism of supersonic flow control (in particular, shock waves) by a surface arc discharge.

  3. Automatic arc discharge technology for inscribing long period fiber gratings.

    Science.gov (United States)

    Yin, Guolu; Tang, Jian; Liao, Changrui; Wang, Yiping

    2016-05-10

    We experimentally demonstrate an automatic arc discharge technology for inscribing high-quality long period fiber gratings (LPFGs) with greatly improved inscription efficiency for single mode fiber (SMF) and photonic crystal fiber (PCF). The proposed technology was developed by implementing an embedded program in a commercial fusion splicer. In addition, the improved technology employs an ultraprecision motorized translation stage, and the tensioning mass required by conventional technology was eliminated. While hundreds of arc discharges are generally required by conventional technology, only 30 and 60 arc discharges were required to inscribe LPFGs with dip attenuations of 30 and 20 dB for SMF and PCF, respectively. PMID:27168306

  4. 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.

  5. 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.

  6. Degradation of Verapamil hydrochloride in water by gliding arc discharge

    Czech Academy of Sciences Publication Activity Database

    Krishna, S.; Mašláni, Alan; Izdebski, T.; Horáková, M.; Klementová, Š.; Špatenka, P.

    2016-01-01

    Roč. 152, June (2016), s. 47-54. ISSN 0045-6535 Institutional support: RVO:61389021 Keywords : Gliding arc discharge * Emission spectroscopy * Pharmaceuticals * Half-life * Degradation mechanism Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.340, year: 2014 http://www.sciencedirect.com/science/article/pii/S0045653516302442

  7. 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.

  8. 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.

  9. Suprathermal electrons in a stationary magnetic arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Waldmann, Ole [Lawrence Berkeley National Lab, 1 Cyclotron Road Mail Stop 5-121, Berkeley, CA 94720 (United States); Langowski, Martin [Universitaet Bremen, Institut fuer Umweltphysik (IUP), Otto-Hahn-Allee 1, 28359 Bremen (Germany); Fussmann, Gerd, E-mail: OWaldmann@lbl.go [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Newtonstr. 15, 12489 Berlin (Germany)

    2010-08-15

    Stochastic short voltage spikes occur in the stationary arc discharge of the linear plasma generator PSI-2. Similar spikes are also found when detecting the infrared bremsstrahlung emission at various plasma positions. They are related to suprathermal electrons which have energies up to 150 eV, i.e. 1.5 times the average discharge voltage and 15 times k{sub B}T{sub e}, the thermal energy of the bulk electrons. These electrons are examined by different diagnostic methods, in particular a newly constructed segmented neutralizer plate was used as a diagnostic tool. The suprathermal particles are found to exist in a thin circular ring of the plasma column which is the region of field lines connected directly to the cathode. For low neutral gas pressure the suprathermal electrons can be treated as collisionless, but when increasing the neutral gas background, scattering with the molecules must be taken into account. In some cases the peak in the potential of the collecting neutralizer plate exceeds the peak of the accelerating voltage. This is explained as a transient event occurring when a bunch of electrons is approaching the collecting surface. The maximum current associated with these electrons is found to compensate the ion saturation current. Their peak density is thus estimated to be in the range of 10{sup -3} of the thermal electrons; on temporal average the ratio (n{sub st})/n{sub e} is of order 10{sup -8}. To the best of our knowledge this is the first extensive study on suprathermal electrons in magnetized arcs. They provide an interesting physical phenomenon but are unlikely to affect the interpretation of electrical probes or optical diagnostic measurements.

  10. 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.

  11. 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.

  12. 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

  13. Role of substrate temperature at graphene synthesis in arc discharge

    CERN Document Server

    Fang, Xiuqi; Keidar, Michael

    2015-01-01

    Substrate temperature required for synthesis of graphene in arc discharge plasma was studied. It was shown that increase of the copper substrate temperature up to melting point leads to increase in the amount of graphene production and quality of graphene sheets. Favorable range of substrate temperatures for arc-based graphene synthesis was determined in relatively narrow range of about 1340-1360K which is near the melting point of copper.

  14. 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

  15. 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.

  16. Vacuum Arc Ion Sources: Recent Developments and Applications

    International Nuclear Information System (INIS)

    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

  17. Iron nanoparticles grown in a carbon arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.; du Marchie van Voorthuysen, E.; Szymanski, K.; Boom, G.; Verwerft, M.; Jonkman, H.; Niesen, L. [Kijksuniversitet Groningen (Netherlands). Materials Science Centre

    1996-02-01

    Iron particles, encapsulated by graphite layers, were produced by means of the Kratschmer arc discharge method in an iron pentacarbonyl atmosphere. The Moessbauer effect is dominated by the vibration of the particles as a whole. Superparamagnetism is dominant for iron oxide particles. No endohedral iron fullerenes were observed, contrary to a previous report.

  18. Iron nanoparticles grown in a carbon arc discharge

    International Nuclear Information System (INIS)

    Iron particles, encapsulated by graphite layers, were produced by means of the Kratschmer arc discharge method in an iron pentacarbonyl atmosphere. The Moessbauer effect is dominated by the vibration of the particles as a whole. Superparamagnetism is dominant for iron oxide particles. No endohedral iron fullerenes were observed, contrary to a previous report

  19. 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.

  20. Baking of tandem accelerator tube by low voltage arc discharge

    International Nuclear Information System (INIS)

    In designing the accelerating tube for a static tandem accelerator in Kyushu University, the basic policy was as described below: individual unit composing the accelerating tube should fully withstand the electric field of 2 MV/m, and electric discharge must not be propagated from one unit to the adjacent unit when these are assembled to the accelerating tube. The accelerating tube units are each 25 cm in length, and both high and low energy sides are composed of 20 units, respectively. Although about 10-9 Torr vacuum was obtained at the both ends of the accelerating tube by baking the tube at 300 to 350 deg C with electric heaters wound outside the tube in the conventional method, vast outgas was generated, which decreased vacuum by two or three figures if breakdown occurred through the intermediary of outgas. As a method of positively outgassing and cleaning the electrodes inside the accelerating tube, it was attempted to directly bake all the electrodes in the accelerating tube by causing strong arc discharge flowing H2 gas in the tube. As a result of considering the conditions for this method, the low voltage arc discharge was employed using oxide cathodes. Thus, after implementing 10A arc discharge for several hours, the voltage was able to be raised to 10 MV almost immediately after the vacuum recovery, and further, after another conditioning for several hours, it was successful to raise voltage up to 11 MV. (Wakatsuki, Y.)

  1. 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.

  2. 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.

  3. Production of hyperthermal hydrogen atoms by an arc discharge

    International Nuclear Information System (INIS)

    A magnetically confined thermal electric arc gas heater has been designed and built as a suitable source of heat for dissociating hydrogen molecules with energy in the range of a few eV. Specifically, the average beam kinetic energy is determined to be 1.5 eV, the dissociation rate is 0.5 atoms per molecule and the atom beam intensity in the forward direction is 1018 atoms/sr-sec. The working pressure in the arc discharge region is from 15 to 25 torr. This novel atom source has been successfully ignited and operated with pure hydrogen during several hours of continuous performance, maintaining its characteristics. The hyperthermal hydrogen atom beam, which is obtained from this source is analyzed and characterized in a high vacuum system, the characterization of the atom beam is accomplished by two different methods: calorimetry and surface ionization. Calorimetic sensor were used for detecting the atom beam by measuring the delivered power of the impinging atoms on the sensor surface. In the second approach an H-surface production backscattering experiment from a low work function surface was conducted. The validity of these two methods is discussed, and the results are compared. The different collision mechanisms to dissociate and ionize hydrogen molecules in the arch discharge are reviewed, as well as the physics of electric arcs. Finally, a Monte Carlo simulation program is used to calculate the ionization probability of low energy atoms perpendicularly reflected from a surface converter, as a model for atom surface ionization

  4. Magnetic circuit design of magnetically driving gliding arc discharge device

    International Nuclear Information System (INIS)

    A gliding arc discharge driven by magnetic field at atmospheric pressure can generate non-equilibrium plasma with good confinement property, and has extensive application in the areas of microelectronic fabrication, environmental engineering, etc. The magnetic circuit of the generator is designed with the permeance method, and analytic expression is obtained on the magnetic induction, the permeant magnetic material thickness and length of air gap. The results have been compared with those of the finite element method, the difference is 3.1%. But the permeance method is more concise and convenient and more universal and economical. So the permeance method is a more credible and useful engineering arithmetic

  5. 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...

  6. 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.

  7. 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.

  8. 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%.

  9. 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%

  10. The Main Plasma Chemical Process of Nitric Oxide Production by Arc Discharge

    International Nuclear Information System (INIS)

    By adopting the optical multi-channel analyzer combined with fourier transform infrared (FTIR) spectrometer, the dominant free radicals and products generated by arc discharge were measured and studied, and the main plasma chemical reaction process in the nitric oxide production by arc discharge was identified. Plasma chemical kinetic curves of O, O2, N2, N and NO were simulated by using CHEMKIN and MATLAB. The results show that the main plasma chemical reaction process of nitric oxide production by arc discharge is a replacement reaction between O and N2, where NO can be generated instantaneously when discharging reaches stable. (15th asian conference on electrical discharge)

  11. 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.

  12. 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

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

    International Nuclear Information System (INIS)

    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

  14. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ehiasarian, A P [Materials Research Institute, Sheffield Hallam University, Howard St., Sheffield, S1 1WB (United Kingdom); Hovsepian, P Eh [Materials Research Institute, Sheffield Hallam University, Howard St., Sheffield, S1 1WB (United Kingdom); New, R [Materials Research Institute, Sheffield Hallam University, Howard St., Sheffield, S1 1WB (United Kingdom); Valter, J [HVM Plasma Ltd, Na Hutmance 2, Prague 5, 158 00 (Czech Republic)

    2004-08-07

    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{sup -2} depending on the magnetic field shape. The magnetic field strongly influenced the relative optical emission from Cr{sup 0}, Cr{sup 1+} and Cr{sup 2+} 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.

  16. The Main Plasma Chemical Process of Nitric Oxide Production by Arc Discharge

    Science.gov (United States)

    Yang, Qi; Hu, Hui; Chen, Weipeng; Xu, Jie; Zhang, Jinli; Wu, Shuang

    2011-12-01

    By adopting the optical multi-channel analyzer combined with fourier transform infrared (FTIR) spectrometer, the dominant free radicals and products generated by arc discharge were measured and studied, and the main plasma chemical reaction process in the nitric oxide production by arc discharge was identified. Plasma chemical kinetic curves of O, O2, N2, N and NO were simulated by using CHEMKIN and MATLAB. The results show that the main plasma chemical reaction process of nitric oxide production by arc discharge is a replacement reaction between O and N2, where NO can be generated instantaneously when discharging reaches stable.

  17. 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......, synchronized with simultaneously recorded current and voltage waveforms. Dynamic details of the novel non-equilibrium discharge are revealed, which is characterized by a sinusoidal current waveform with amplitude stabilized at around 200 mA intermediate between thermal arc and glow discharge, shedding light to...

  18. Technological plasma source equipped with combined system of vacuum-arc discharge initiation

    International Nuclear Information System (INIS)

    The construction and the operation principle of erosion plasma source with a three-stage system of vacuum-arc discharge excitation is described. As first two step was used the modified contactless start system with plasma injector, which was widely used in standard plasma sources of the ''Bulat'' systems. The operation principle of the third stage was based on the transition of glow discharge to arc discharge. Coordinated operation of three stages during various stages of coating deposition provided significant increasing of service life and reliability of the system of vacuum-arc discharge initiation and extended the functionality of the plasma source

  19. 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

  20. Enhancement of emission currents in plasma electron sources based on a low-pressure arc discharge

    Science.gov (United States)

    Koval, T. V.; Devyatkov, V. N.; Hung, Nguyen Bao

    2015-11-01

    The paper reports on a theoretical and experimental study of the discharge plasma generation with an enhanced electron emission current in a plasma electron source based on a low-pressure arc discharge with a grid-stabilized plasma emission boundary. The source operates at a pressure in the working chamber of p = 0.02-0.05 Pa (Ar), accelerating voltage of up to Ua = 10 kV, and longitudinal magnetic field for electron beam transport of up to Bz = 0.1 T. The experiments show that in the mode of electron emission from the plasma, the voltage Ud between the cathode and grid electrode changes its sign. The numerical simulation demonstrates that the plasma potential and voltage Ud depend on the electric field penetrating from the acceleration gap into the discharge region through the grid meshes, and on the discharge current, gas pressure, geometric transparency of the grid, and gas kind. It is shown that the main mechanisms responsible for the increase in the discharge current and electron emission current from the plasma are associated with secondary ion-electron emission from the emission electrode and with positive feedback between the region of cathode plasma generation and the channel of electron beam transport.

  1. 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.

  2. Preparation of gold ethanol colloid by the arc discharge method

    International Nuclear Information System (INIS)

    A new method using the arc discharge method (ADM) to synthesize gold nanoparticles in an anhydrous ethanol was studied. Fabricated gold nanoparticles were characterized by different techniques. Unlike conventional methods for metal nanoparticles synthesis, the ADM method does not require application of chemical surfactants and stabilizers. The microstructure of ADM-produced gold nanoparticles was examined by transmission electron microscope (TEM) and scanning electron microscope (SEM). The particle size was found in the range of 2-40 nm. The chemical composition of gold nanoparticles has been confirmed by the energy dispersive X-ray analysis (EDX). The crystal structure of the nanoscale gold particles was studied using the X-ray diffraction (XRD) method. Images of the gold nanoparticles, Zeta potential, size distribution, and ultraviolet-visible (UV-vis) absorbance were investigated. This innovative approach for gold nanoparticles preparation has been successfully established. The experimental results showed that the ADM technique is easy, cheap and clean method which can be used to manufacture gold nanoparticles suspended in ethanol solution without any surfactant

  3. 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.

  4. Bernas ion source discharge simulation

    International Nuclear Information System (INIS)

    As the technology and applications continue to grow up, the development of plasma and ion sources with clearly specified characteristic is required. Therefore comprehensive numerical studies at the project stage are the key point for ion implantation source manufacturing (especially for low energy implantation). Recently the most commonly encountered numerical approach is the Monte Carlo particle-in-cell (MCPIC) method also known as particle-in-cell method with Monte Carlo collisions. In ITEP the 2D3V numerical code PICSIS-2D realizing MCPIC method was developed in the framework of the joint research program. We present first results of the simulation for several materials interested in semiconductors. These results are compared with experimental data obtained at the ITEP ion source test bench

  5. Dynamic behaviour of an electric arc gas discharge

    International Nuclear Information System (INIS)

    The time-dependent energy and circuit equations are solved numerically to obtain temperature profiles, current-voltage characteristics and electric field strength vs axial temperature diagrams in the asymptotic region of a wall-stabilized electric arc operated in nitrogen. Dynamic current-voltage characteristics and transient phenomena of steady state formation during the spark ignition phase are studied. The arc time-constant for free decay is computed and compared with approximate analytical results. It is found that for fixed initial conditions, the arc response to the variable applied voltage is several times longer than the arc time-constant for free decay. (author) 4 figs., 11 refs

  6. Effects of filament geometry on the arc efficiency of a high-intensity He+ ion source.

    Science.gov (United States)

    Kobuchi, T; Kisaki, M; Shinto, K; Okamoto, A; Kitajima, S; Sasao, M; Tsumori, K; Kaneko, O; Sakakita, H; Kiyama, S; Hirano, Y; Wada, M

    2008-10-01

    A strongly focusing high-intensity He(+) ion source equipped with three concave electrodes has been designed and constructed as the beam source for a high-energy He(0) neutral beam probe system to diagnose fusion-produced alpha particles in thermonuclear fusion plasmas. The reduction of heat load onto the concave extraction electrodes is particularly important for a long pulse operation, as the heat load deforms the electrodes and thus the beam focal length. The effects on the arc efficiency (beam current/arc power) of the ion source due to the discharge filament structure (straight-type and L-shape-type filaments), size (filament diameters of 2 and 1.5 mm), number, and the locations have been studied. Choice of the appropriate filament structure improved the arc efficiency by 17%. PMID:19044629

  7. 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.

  8. Comparison of laser induced plasma and arc discharge emission spectra of Al, Fe, Cu and C

    International Nuclear Information System (INIS)

    Emission spectra of laser induced plasma and arc discharge were measured and compared for Al, Fe, Cu and C. Such a comparison shows a higher presence of ionized transitions, but also a higher background in the emission spectra of laser induced plasma than in arc discharge. It can be concluded that in general it is not possible to predict laser induced plasma for material analysis purposes, calibration by reference laser induced plasma spectra of pure elements in vacuum will be necessary. (Authors)

  9. Optical absorption spectroscopy on a metal-halide high intensity discharge arc lamp using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bonvallet, G A; Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2003-07-07

    A sensitive, spatially resolved optical absorption spectroscopy experiment using synchrotron radiation on metal-halide high intensity discharge (MH-HID) lamps was performed. This experiment was used to measure the absolute column densities of ground and excited level Sc atoms, ground level Sc{sup +} ions, and ground level Na atoms in a 250 W MH-HID lamp during operation. The column densities were Abel inverted and used to determine the arc temperature as a function of radius and the absolute electron density as a function of radius. Although most of these measurements were made using a one-dimensional spectrally-multiplexed experiment, a two-dimensional spatially and spectrally multiplexed experiment has also been demonstrated. The absolute density and temperature maps from this experiment were used to determine the absolute near-infrared output power from the MH-HID lamp as described in the companion paper (Smith et al 2003)

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Arc plasma generator of atomic driver for steady-state negative ion source.

    Science.gov (United States)

    Ivanov, A A; Belchenko, Yu I; Davydenko, V I; Ivanov, I A; Kolmogorov, V V; Listopad, A A; Mishagin, V V; Putvinsky, S V; Shulzhenko, G I; Smirnov, A

    2014-02-01

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode. PMID:24593569

  16. Electrostatic discharges on solar arrays: common characteristics with vacuum arcs

    International Nuclear Information System (INIS)

    Satellite solar arrays are likely to be charged by the space environment up to a discharging threshold level, resulting in electrostatic discharges. Electrostatic discharges are phenomena known to cause temporary anomalies, mainly electromagnetic disturbances. Such discharges are studied experimentally in this paper on laboratory samples made of zinc or silver, and on real solar cell samples. Spectroscopic data show for all these samples the presence of eroded metal vapours, and microscopic photographs confirm the local melting of the electrode, even for low values of the capacitors (10 nF and 330 pF) used in the electrical circuit. (author)

  17. Contribution of neutral production to ion flux from a vacuum arc source

    Science.gov (United States)

    Humphries, Stanley, Jr.; Lockner, Thomas R.

    1996-02-01

    This article describes studies of the effect of electrode spacing on the performance of vacuum arc plasma sources for ion accelerators and other applications. We measured the time-resolved emission of neutrals from a compact arc source with a titanium cathode and 100 A drive current and found that the source emitted roughly 100 atoms for each extracted ion. The inferred neutral pressure in the arc gap was about 500 mTorr. The result suggested the possibility of achieving significant ionization in the plasma expansion region by increasing the anode-cathode gap length, thereby forcing the drive current to flow through the gas column. With a new two-stage trigger, we were able to ignite arcs with gaps as long as 20 cm. Extended gaps doubled the ion flux, gave better output directionality, and helped to stabilize the location of emission spots on the cathode. These improvements, coupled with direct observations of discharge luminosity, support the hypothesis of ionization of the expanding vapor.

  18. 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.

  19. Thermal motion of carbon clusters and production of carbon nanotubes by gravity-free arc discharge

    International Nuclear Information System (INIS)

    Thermal and diffusion properties of hot gas around a dc arc discharge under a gravity-free condition are investigated using a jet plane in order to improve the arc production of carbon clusters. Spherically symmetric temperature distribution of He gas around the arc plasma and monotonic slow expansion of the high-temperature region are observed. By means of the passive-type Mie scattering method, random slow diffusion of carbon clusters around the arc plasma is clearly observed under the gravity-free condition. This indicates that carbon clusters including single-walled carbon nanotubes are synthesized around the arc plasma where the He temperature is higher than 1000 K. It is confirmed that large bundles of fatter single-walled carbon nanotubes are produced under the gravity-free condition

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

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas; Li, Zhongshan; Aldén, Marcus; Salewski, Mirko; Leipold, Frank; Kusano, Yukihiro

    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...

  1. 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.

  2. 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.

  3. 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

  4. Ion velocities in a micro-cathode arc thruster

    International Nuclear Information System (INIS)

    Ion velocities in the plasma jet generated by the micro-cathode arc thruster are studied by means of time-of-flight method using enhanced ion detection system (EIDS). The EIDS triggers perturbations (spikes) on arc current waveform, and the larger current in the spike generates denser plasma bunches propagating along with the mainstream plasma. The EIDS utilizes double electrostatic probes rather than single probes. The average Ti ion velocity is measured to be around 2×104 m/s without a magnetic field. It was found that the application of a magnetic field does not change ion velocities in the interelectrode region while leads to ion acceleration in the free expanding plasma plume by a factor of about 2. Ion velocities of about 3.5×104 m/s were detected for the magnetic field of about 300 mT at distance of about 100–200 mm from the cathode. It is proposed that plasma is accelerated due to Lorentz force. The average thrust is calculated using the ion velocity measurements and the cathode mass consumption rate, and its increase with the magnetic field is demonstrated.

  5. 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

  6. 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

  7. 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.

  8. Formation of Self-Organized Anode Patterns in Arc Discharge Simulations

    CERN Document Server

    Trelles, Juan Pablo

    2013-01-01

    Pattern formation and self-organization are phenomena commonly observed experimentally in diverse types of plasma systems, including atmospheric-pressure electric arc discharges. However, numerical simulations reproducing anode pattern formation in arc discharges have proven exceedingly elusive. Time-dependent three-dimensional thermodynamic nonequilibrium simulations reveal the spontaneous formation of self-organized patterns of anode attachment spots in the free-burning arc, a canonical thermal plasma flow established by a constant DC current between an axi-symmetric electrodes configuration in the absence of external forcing. The number of spots, their size, and distribution within the pattern depend on the applied total current and on the resolution of the spatial discretization, whereas the main properties of the plasma flow, such as maximum temperatures, velocity, and voltage drop, depend only on the former. The sensibility of the solution to the spatial discretization stresses the computational require...

  9. 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.

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

    International Nuclear Information System (INIS)

    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

  11. 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.

  12. 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.

  13. Arc-based smoothing of ion beam intensity on targets

    International Nuclear Information System (INIS)

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  14. Arc-based smoothing of ion beam intensity on targets

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Alex [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States) and The Virtual National Laboratory for Heavy Ion Fusion Science (United States)

    2012-06-15

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ('heavy-ion fusion'). Here, we consider an approach to such smoothing that is based on rapidly 'wobbling' each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  15. Arc-based smoothing of ion beam intensity on targets

    Science.gov (United States)

    Friedman, Alex

    2012-06-01

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy ("heavy-ion fusion"). Here, we consider an approach to such smoothing that is based on rapidly "wobbling" each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  16. 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

  17. 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.

  18. 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.

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

    International Nuclear Information System (INIS)

    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 40 mm.The test results could provide reference to design the high voltage vacuum interrupter adopting the single coil type AMF electrode

  20. 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

  1. Experimental study on the magnetized discharge sources (PIG type) for the multicharged ions production

    International Nuclear Information System (INIS)

    The physical phenomena controlling the performance of a source of ions, applying magnetized discharges, is studied. The ions source is formed by three electrodes placed in a homogeneous magnetic field. The electron beam injection is effectuated by means of an indirectly heated cathode. The anti-cathode is placed in front of the cathode, at a potential (value) equal to that of the electron's source. The determination of the mass and charge of the extracted ions is performed by the magnetic analysis, at 180 degrees, of the ions current. The influence of the different macroscopic parameters, such as heating, arc potential, arc current, pressure, gas flow in the source, is described. The inner lowest residual pressure is estimated to be about 10-5 torr. The improvement in high charge yields is obtained by using gas mixtures (Kr with Ne or Ar). The characteristics of the discharges are given. Parameters such as the metal sublimation energy, the influence of the ion mass in the metal target sputtering, the atoms time delay in the plasma, and the charge exchange process are considered. It is shown that the discharge equilibrium can be analyzed in the same way as that for a binary mixture

  2. Infrared losses from a Na/Sc metal-halide high intensity discharge arc lamp

    International Nuclear Information System (INIS)

    A study of the near-infrared (IR) emission from the arc of a metal-halide high intensity discharge (MH-HID) lamp with a sodium/scandium chemistry is reported. Radiometrically calibrated spectra from 0.7 to 2.5 μm were recorded as a function of position on the arc tube of a 250 W lamp. These spectra were analysed to determine the relative densities of Na and Sc atoms and the arc temperature as a function of radius. Information from these spectra, combined with absorption measurements in the companion paper (Bonvallet and Lawler 2003), were used to determine the absolute output power in the near-IR from the MH-HID lamp

  3. Infrared losses from a Na/Sc metal-halide high intensity discharge arc lamp

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D J; Bonvallet, G A; Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2003-07-07

    A study of the near-infrared (IR) emission from the arc of a metal-halide high intensity discharge (MH-HID) lamp with a sodium/scandium chemistry is reported. Radiometrically calibrated spectra from 0.7 to 2.5 {mu}m were recorded as a function of position on the arc tube of a 250 W lamp. These spectra were analysed to determine the relative densities of Na and Sc atoms and the arc temperature as a function of radius. Information from these spectra, combined with absorption measurements in the companion paper (Bonvallet and Lawler 2003), were used to determine the absolute output power in the near-IR from the MH-HID lamp.

  4. 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...... adhesion with a vinylester adhesive. The treatment improved wettability and increased the polar component of the surface energy and the density of oxygen-containing polar functional groups at the surfaces. Double cantilever beam specimens were prepared for fracture mechanics characterisation (fracture...... resistance as a function of nominal mode mixity) of the laminate adhesive interface. It was found that gliding arc treatment significantly increases the interfacial fracture energy and fracture resistance in comparison with a standard peel ply treatment, although the mixed mode fracture energy of the gliding...

  5. Properties of Arc Discharge with Hybrid Stabilization for Different Radiation Models

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Bartlová, M.; Aubrecht, V.

    Praha: CZECH TECHNICAL UNIVERSITY, PRAGUE, INSTITUTE OF PLASMA PHYSICS ACADEMY OF SCIENCES, PRAGUE, 2008 - (Khun, J.; Kříha, V.; Píchal, J.; Píchal, M.). s. 62-63 ISBN 978-80-01-04030-0. [Symposium on Plasma Physics and Technology /23rd./. 16.06.2008-19.06.2008, Praha] R&D Projects: GA ČR GA202/08/1084 Institutional research plan: CEZ:AV0Z20430508 Keywords : arc discharge * divergence of radiation flux * partial characteristics * radiation model * reabsorption Subject RIV: BL - Plasma and Gas Discharge Physics

  6. 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...

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

    OpenAIRE

    Zielinski, J. J.; Van Der Meiden, H. J.; Morgan, T W; Schram, D.C.; 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 its stationary value (200 A) up to 14.5 kA in 650 mu s. The discharge power is thus raised from 18kW to 6.5 MW, corresponding to a power density of up to 1.7x10(12)W m(-3)-10(2) times higher than in...

  8. 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...

  9. 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...

  10. Nanosecond neutron pulse generation in diode acceleration tubes with vacuum arc discharge and laser deuteron sources

    International Nuclear Information System (INIS)

    Nonsteady process of deuteron pulse formation and acceleration to neutron produced target at vacuum acceleration tubes is investigated. Deuterons are emitted from vacuum arc discharge or laser deuteron sources. This generation mechanism has been studied by numerical simulations using a relativistic electromagnetic PIC code. The results obtained shows essential dependence of deuteron plasma emission, forming and accelerating processes in diode from the final deuteron current. Neutron flow calculation can be done based on short pulse dynamic investigation.

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

    International Nuclear Information System (INIS)

    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

  12. Mechanism of Synthesis of Ultra-Long Single Wall Carbon Nanotubes in Arc Discharge Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Keidar, Michael [George Washington University

    2013-06-23

    In this project fundamental issues related to synthesis of single wall carbon nanotubes (SWNTs), which is relationship between plasma parameters and SWNT characteristics were investigated. Given that among plasma-based techniques arc discharge stands out as very advantageous in several ways (fewer defects, high flexibility, longer lifetime) this techniques warrants attention from the plasma physics and plasma technology standpoint. Both experimental and theoretical investigations of the plasma and SWNTs synthesis were conducted. Experimental efforts focused on plasma diagnostics, measurements of nanostructures parameters, and nanoparticle characterization. Theoretical efforts focused to focus on multi-dimensional modeling of the arc discharge and single wall nanotube synthesis in arc plasmas. It was demonstrated in experiment and theoretically that controlling plasma parameters can affect nanostucture synthesis altering SWNT properties (length and diameter) and leading to synthesis of new structures such as a few-layer graphene. Among clearly identified parameters affecting synthesis are magnetic and electric fields. Knowledge of the plasma parameters and discharge characteristics is crucial for ability to control synthesis process by virtue of both magnetic and electric fields. New graduate course on plasma engineering was introduced into curriculum. 3 undergraduate students were attracted to the project and 3 graduate students (two are female) were involved in the project. Undergraduate student from Historically Black University was attracted and participated in the project during Summer 2010.

  13. Measurement of anode surface temperature in carbon nanomaterial production by arc discharge method

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Feng; Tanaka, Manabu; Choi, Sooseok [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, Yokohama 226-8502 (Japan); Watanabe, Takayuki, E-mail: watanabe@chem-eng.kyushu-u.ac.jp [Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, Yokohama 226-8502 (Japan); Department of Chemical Engineering, Kyushu University, Fukuoka 819-0395 (Japan)

    2014-12-15

    Highlights: • We measured the temperature of anode surface by two-color pyrometry combined with a high speed camera successfully. • Growth temperature of pyrolytic graphite, MWNTs, and nano-graphite particles were in ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. • High temperature contributes to form thermodynamically unstable material. - Abstract: Nano-graphite particles, multi-wall carbon nanotube (MWNT), and pyrolytic graphite were prepared at different positions of the anode surface in an arc discharge. Graphite electrodes were employed for the arc discharge under helium environment at atmospheric pressure. Nano-sized carbon products were characterized by scanning electron microscopy and transmission electron microscopy. During the arc discharge, two-color pyrometry combined with a high-speed camera was conducted to measure the temperature distribution of the anode surface. The growth temperature of pyrolytic graphite, MWNT, and nano-graphite particles were in the ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. The local temperature of anode surface is a critical parameter to determine the products with different morphologies. The formation mechanism of these carbon nanomaterials is suggested based on the local temperature of anode surface and their thermodynamic stability.

  14. Measurement of anode surface temperature in carbon nanomaterial production by arc discharge method

    International Nuclear Information System (INIS)

    Highlights: • We measured the temperature of anode surface by two-color pyrometry combined with a high speed camera successfully. • Growth temperature of pyrolytic graphite, MWNTs, and nano-graphite particles were in ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. • High temperature contributes to form thermodynamically unstable material. - Abstract: Nano-graphite particles, multi-wall carbon nanotube (MWNT), and pyrolytic graphite were prepared at different positions of the anode surface in an arc discharge. Graphite electrodes were employed for the arc discharge under helium environment at atmospheric pressure. Nano-sized carbon products were characterized by scanning electron microscopy and transmission electron microscopy. During the arc discharge, two-color pyrometry combined with a high-speed camera was conducted to measure the temperature distribution of the anode surface. The growth temperature of pyrolytic graphite, MWNT, and nano-graphite particles were in the ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. The local temperature of anode surface is a critical parameter to determine the products with different morphologies. The formation mechanism of these carbon nanomaterials is suggested based on the local temperature of anode surface and their thermodynamic stability

  15. 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.

  16. 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

  17. Experimental analysis on the effects of DC arc discharges at various flow regimes

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, G. [University of L’Aquila, L’Aquila 67100 (Italy); Saracoglu, B. H., E-mail: saracog@vki.ac.be; Regert, T. [von Karman Institute for Fluid Dynamics, Rhode Saint Genèse B-1640 (Belgium); Paniagua, G. [Purdue University, West-Lafayette, Indiana 47907 (United States)

    2015-03-15

    This paper addresses the control of the boundary layer on a compression ramp by means of DC electrical arc discharges. The development and realization of the control system are first described and then assessed in the wind tunnel. The objective of the research was to control the supersonic flow using the minimum amount of energy. The array of electrodes was located at the base of a ramp, where a low momentum flow develops. The electrical discharge was generated by a custom designed electronic facility based on high-voltage ignition coils. The slanted tungsten electrodes were insulated by mounting them in a ceramic support. The discharge evolution was studied through high-speed flow visualizations, while electrical measurements at the high-voltage section of the circuitry allowed to estimate the energy release. The development of a high-speed short exposure Schlieren imaging technique, based on a very short duration laser pulse illumination and a double shot CCD camera, allowed to observe the macroscopic effects associated with the arc establishment between the electrodes (glow, sound wave and heat release). Due to the long residence time, the thermal perturbation spread along the streamwise direction. Cross correlation of Schlieren images with short time separation revealed that in supersonic conditions, the discharges led to an overall acceleration of the flow field underneath the oblique shock wave.

  18. Surface properties of plasma-functionalized graphite-encapsulated gold nanoparticles prepared by a direct current arc discharge method

    Science.gov (United States)

    Yang, Enbo; Chou, Han; Tsumura, Shun; Nagatsu, Masaaki

    2016-05-01

    The graphite-encapsulated gold nanoparticles (Au@C NPs) fabricated by a direct current arc discharge method were surface-functionalized by an inductively-coupled radio frequency ammonia plasma with a particle explosion technique for enhancing surface modification efficiency. To investigate the structural and surface properties of Au@C NPs, characterizations using x-ray diffraction, high resolution transmission electron microscopy and x-ray photoelectron spectroscopy have been conducted on the untreated and plasma treated Au@C NPs. Based on the experimental results, we give insight into the possible formation of Au ions in the interface between the graphite layers and gold core particles of the Au@C NPs. Finally, the role of the plasma treatment on the surface functionalization of Au@C NPs with amino groups is discussed.

  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 × 1016 cm-3 is generated in the plasma channel.

  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 × 10(16) cm(-3) is generated in the plasma channel. PMID:27587119

  2. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap.

    Science.gov (United States)

    Nikolaev, A G; Savkin, K P; Oks, E M; Vizir, A V; Yushkov, G Yu; Vodopyanov, A V; Izotov, I V; Mansfeld, D A

    2012-02-01

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent "minimum-B" structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap--axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 μs) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams. PMID:22380156

  3. Analysis of products of arc discharge plasma synthesis with a graphite cathode and a composite anode

    Science.gov (United States)

    Podgornyi, V. I.; Belashev, B. Z.; Kolodei, V. A.; Osaulenko, R. N.

    2015-01-01

    The composition, structure, and morphology of compounds formed in an argon arc discharge with a graphite cathode and a composite anode are studied by the methods of Raman scattering, X-ray diffraction analysis, X-ray microanalysis, and electron microscopy. Among the synthesis produces, graphite-like substances and metal carbides dominate; metal microcrystallites, fullerenes, and carbon nanotubes are present in some cases. It is found that carbides are not formed when anodes with a nickel admixture are used. The Raman spectra indicate the synthesis of single-wall carbon nanotubes in arcs with the C-Fe and C-Ni-V anodes. In the case of C-Ni and C-V anodes, electron microscopy data indicate the existence of micrometer-size carbon fiber structures in the synthesis products.

  4. Single-step synthesis of nanocomposite of copper and carbon nanoparticles using arc discharge in liquid nitrogen

    International Nuclear Information System (INIS)

    A new strategy for single-step synthesis of copper and carbon nanoparticle composite by arc discharge in liquid nitrogen was proposed. The synthesized products consist of carbon nanoparticles (CNPs) which include multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanohorns (SWCNHs) and multi-shelled carbon nanocapsules (MSCNCs) containing Cu clusters inside. Evidence of transmission electron microscopic analyses reveal that under with arc current of 180 A arc discharge between copper and graphite electrodes in liquid nitrogen could provide MSCNCs with narrow size distribution in a range of 70-150 nm. Meanwhile, MWCNTs with diameter of 20-40 nm and length of 150-350 nm became selectively synthesized under the condition of discharge in liquid nitrogen with arc current of 100 A. Spectroscopic analyses confirm that copper nanoparticles are cuprite while BET analyses also reveal that the synthesized nanocomposite possess acceptably high specific surface area.

  5. 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.

  6. 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

  7. 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

  8. Research on the use of UHV arc discharges for deposition of superconducting layers

    International Nuclear Information System (INIS)

    High-field superconducting cavities, as used in charged particle accelerators, are at present based mostly on the Nb-bulk technology, but Nb-coated Cu-cavities might offer several advantages. In order to study possibilities of the vacuum arc technique to form high-quality superconducting thin films for the coating RF copper cavities, special efforts have been undertaken within a framework of the scientific collaboration between the 'Tor Vergata' University of Rome and the Andrzej Soltan Institute for Nuclear Studies at Swierk. During recent years several experimental arc-based devices have been designed and constructed in the both research centers. In particular, cathodic-arc sources with planar- and cylindrical-cathodes made of pure Nb have been constructed and investigated. Arc discharges with magnetic filters (for the elimination of micro-droplets) have also been investigated. All these systems have been exploited under ultra-high vacuum (UHV) conditions. The paper describes the status of research on the deposition of superconducting Nb-films, and particularly the recent progress in these investigations. It has been shown that high-quality Nb-films can be deposited with the described UHV arc technique. The critical temperature of film samples, which were coated in planar geometry, is very close to the Nb-bulk value. The very narrow transitions as well as X-ray diffraction patterns indicate that the obtained films are less stressed and more homogeneous than standard ones produced by means of the sputtering technique. The deposited Nb-films have higher RRR (up to 80) and larger grain sizes in a comparison with sputtered ones, which were deposited at the same temperature. The RF measurements have also demonstrated good RF properties of the produced Nb-films. (author)

  9. Electric fields, ions, and chemistry in RF discharges

    International Nuclear Information System (INIS)

    This paper deals primarily with recent diagnostic advances in the study of rf discharge chemistry. Time-dependent, local electric fields are measured by detection of laser-induced fluorescence from parity mixed levels of the BCI molecule, formed in discharges through BCl/sub 3/. Positive ion densities are measured by laser-induced fluorescence while negative ions are probed using photodetachment spectroscopy. Excitation, ionization, and energy relaxation rates are determined from the intensity of plasma-induced emission

  10. 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)

  11. The biological effect of arc discharge plasma combined with gradual magnetic field on tomato seeds

    International Nuclear Information System (INIS)

    Using arc discharge plasma combined with gradual magnetic field to treat seeds is a new plasma biological technology. The biological effect and drought resistance of tomato seeds treated with different plasma parameters were compared. The increasing of proline content indicates that the drought resistance of tomato seedlings could be increased due to reduction of penetration potential of plant cell. Increased SOD, POD activity, root activity and ATP content show that water stress could be alleviated by eliminating the free radicle and increasing metabolism. (authors)

  12. 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)

  13. Carbon nanostructures obtained by underwater arc discharge of graphite electrodes: Synthesis and characterization

    International Nuclear Information System (INIS)

    In the present work, the application of the method of underwater arc discharge of graphite electrodes for obtaining several carbon nano structures is described. The analysis of the obtained products by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Raman spectroscopy, Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD) showed that the samples collected from the material floating on the water surface were composed mainly by polyhedral onion-like particles, while those taken from the precipitate were a mixture multi walled nano-tubes, onion-like particles and other graphitic structures. The main features of the obtained nano structures are discussed. (Author)

  14. Synthesis of Cubic Chromium Nitride Nanocrystals Powders by Arc Discharge Plasma Method

    OpenAIRE

    SHEN Long-Hai,CUI Qi-Liang

    2010-01-01

    Cubic CrN nanoparticles with the size less than 10 nm were synthesized through direct reaction of metal Cr with N2 by arc discharge plasma method. The products synthesized under different nitrogen gas pressure were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared spectra (FT-IR). The effect of N2 pressure and accession of NH3 on the formation of cubic phase CrN were studied. The results indicate that it is beneficial for the conve...

  15. Thermal plasma of electric arc discharge in air between composite Cu-C electrodes

    International Nuclear Information System (INIS)

    The complex technique of plasma property studies is suggested. As the first step the radial profiles of temperature and electron density in plasma of free burning electric arc discharge in air between Cu-C composite and brass electrodes, as well as copper electrodes in air flow, were measured by optical emission spectroscopy techniques. As the next step the radial profiles of electric conductivity of plasma mixture were calculated by solution of energy balance equation. The electron density is obtained from electric conductivity by calculation in assumption of local thermodynamical equilibrium in plasma.

  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. Sensing and identification of carbon monoxide using carbon films fabricated by methane arc discharge decomposition technique.

    Science.gov (United States)

    Akbari, Elnaz; Buntat, Zolkafle; Enzevaee, Aria; Yazdi, Mahsa Khoshkhooy; Bahadoran, Mahdi; Nikoukar, Ali

    2014-01-01

    Carbonaceous materials have recently received attention in electronic applications and measurement systems. In this work, we demonstrate the electrical behavior of carbon films fabricated by methane arc discharge decomposition technique. The current-voltage (I-V) characteristics of carbon films are investigated in the presence and absence of gas. The experiment reveals that the current passing through the carbon films increases when the concentration of CO2 gas is increased from 200 to 800 ppm. This phenomenon which is a result of conductance changes can be employed in sensing applications such as gas sensors. PMID:25177219

  18. 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.

  19. Pore Structures and Electrochemical Properties of Graphene Prepared by Arc Discharge Method

    Directory of Open Access Journals (Sweden)

    LV Yan, WANG Zhi-Yong, ZHANG Hao, FANG Jin, CAO Gao-Ping, SHI Zu-Jin, WANG Bi-Yan

    Full Text Available A graphene material was prepared by arc discharge method, and its pore structures and electrochemical capacitive properties were studied. The graphene presents developed and open mesopore structure, and its specific surface area and mesopore ratio are 77.8 m2/g and 74.7%, respectively. The electrochemical capacitor using graphene as electrode materials, has a capacitance of 12.9 F/g. Its cyclic voltammograms show rectangular shape even under a high scan rate of 200 mV/s, and the specific frequency f0 on the electrochemical impedance spectroscopy is as high as 18.5 Hz, exhibiting excellent rate capability.

  20. Synthesis of multiwalled carbon nanotube from different grades of carbon black using arc discharge method

    Science.gov (United States)

    Arora, Neha; Sharma, N. N.

    2016-04-01

    This paper describes the synthesis of nanotube from different grades (Tread * A(non-ASTM), N134,N121,N660 and N330)of carbon black using DC arc discharge method at 40A current for 60sec. Carbon black samples of different grades were procured from industry (Aditya Birla Science and Technology Limited, India). Scanning Electron Micrographs (SEM) of the deposited carbon nanostructures suggests that MWCNTs are formed at 40A and for a minimal exposure time of 60sec.The result formed indicates the N330 grade of carbon black gets converted to MWCNTs (Multiwall Carbon nanotube) as compared to other grades.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

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

    International Nuclear Information System (INIS)

    Microparticles with sizes up to 130 μm 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.

  6. 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)

  7. Production of High Energy Ions Near an Ion Thruster Discharge Hollow Cathode

    Science.gov (United States)

    Katz, Ira; Mikellides, I. G.; Goebel, D. M.; Jameson, K. K.; Wirz, R.; Polk, James E.

    2006-01-01

    Several researchers have measured ions leaving ion thruster discharge chambers with energies far greater than measured discharge chamber potentials. Presented in this paper is a new mechanism for the generation of high energy ions and a comparison with measured ion spectra. The source of high energy ions has been a puzzle because they not only have energies in excess of measured steady state potentials, but as reported by Goebel et. al. [1], their flux is independent of the amplitude of time dependent plasma fluctuations. The mechanism relies on the charge exchange neutralization of xenon ions accelerated radially into the potential trough in front of the discharge cathode. Previous researchers [2] have identified the importance of charge exchange in this region as a mechanism for protecting discharge cathode surfaces from ion bombardment. This paper is the first to identify how charge exchange in this region can lead to ion energy enhancement.

  8. Study of W/WC films produced by plasma assisted vacuum arc discharge

    International Nuclear Information System (INIS)

    W/WC films were grown by the PAPVD repetitive pulsed vacuum arc technique on 304 stainless steel substrates. To produce the coatings, a target of W with purity of 99.9999% was used. The system is composed by a reaction chamber with two opposite electrodes placed inside it. The target is located on the cathode and the samples on the anode. A pulsed power supply is used to generate the discharge. For the production of the W layer, the chamber was filled with Ar gas at a pressure of 3 mbar, and the voltage of the discharge was 270 V with 3 pulses. WC films were grown in an atmosphere of methane at 3 mbar and a voltage discharge of 275 V with 4 pulses. The active and passive times of the discharge were 1 s and 0.5 s, respectively. XRD technique was employed to study the coatings, to study the present phases and the crystallographic orientation of the films, the XRD analyses were carried out varying the temperature of the system-coating-substrate between room temperature and 600 C, when the WC coatings are degradated, leaving just the tungsten. XPS analyses present the apparition of WC, WO and WO2 compounds. AFM analyses allowed to measure the morphological properties and the thickness around 3 μm. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Study of W/WC films produced by plasma assisted vacuum arc discharge

    Science.gov (United States)

    Ospina, R.; Arango, P.; Arango, Y. C.; Restrepo, E.; Devia, A.

    2005-08-01

    W/WC films were grown by the PAPVD repetitive pulsed vacuum arc technique on 304 stainless steel substrates. To produce the coatings, a target of W with purity of 99.9999% was used. The system is composed by a reaction chamber with two opposite electrodes placed inside it. The target is located on the cathode and the samples on the anode. A pulsed power supply is used to generate the discharge. For the production of the W layer, the chamber was filled with Ar gas at a pressure of 3 mbar, and the voltage of the discharge was 270 V with 3 pulses. WC films were grown in an atmosphere of methane at 3 mbar and a voltage discharge of 275 V with 4 pulses. The active and passive times of the discharge were 1 s and 0.5 s, respectively.XRD technique was employed to study the coatings, to study the present phases and the crystallographic orientation of the films, the XRD analyses were carried out varying the temperature of the system-coating-substrate between room temperature and 600 °C, when the WC coatings are degradated, leaving just the tugsten. XPS analyses present the apparition of WC, WO and WO2 compounds. AFM analyses allowed to measure the morphological properties and the thickness around 3 μm.

  10. Study of W/WC films produced by plasma assisted vacuum arc discharge

    Energy Technology Data Exchange (ETDEWEB)

    Ospina, R.; Arango, P.; Arango, Y.C.; Restrepo, E.; Devia, A. [Universidad Nacional de Colombia Sede Manizales, Km. 9 via al aeropuerto Campus La Nubia, Manizales (Colombia)

    2005-08-01

    W/WC films were grown by the PAPVD repetitive pulsed vacuum arc technique on 304 stainless steel substrates. To produce the coatings, a target of W with purity of 99.9999% was used. The system is composed by a reaction chamber with two opposite electrodes placed inside it. The target is located on the cathode and the samples on the anode. A pulsed power supply is used to generate the discharge. For the production of the W layer, the chamber was filled with Ar gas at a pressure of 3 mbar, and the voltage of the discharge was 270 V with 3 pulses. WC films were grown in an atmosphere of methane at 3 mbar and a voltage discharge of 275 V with 4 pulses. The active and passive times of the discharge were 1 s and 0.5 s, respectively. XRD technique was employed to study the coatings, to study the present phases and the crystallographic orientation of the films, the XRD analyses were carried out varying the temperature of the system-coating-substrate between room temperature and 600 C, when the WC coatings are degradated, leaving just the tungsten. XPS analyses present the apparition of WC, WO and WO{sub 2} compounds. AFM analyses allowed to measure the morphological properties and the thickness around 3 {mu}m. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. 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.

  12. 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

  13. 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

  14. Investigation and application of hollow anode glow discharge ion source

    Energy Technology Data Exchange (ETDEWEB)

    Abdelsalam, F.W.; Helal, A.G. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. Box 13759 Inchas, Cairo (Egypt); Saddeek, Y.B. [Physics Dep., Faculty of Science, AL-Azhar University in Assuitt, Assuitt (Egypt); Abdelrahman, M.M., E-mail: moustafa82003@yahoo.co [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. Box 13759 Inchas, Cairo (Egypt); Soliman, B.A. [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.O. Box 13759 Inchas, Cairo (Egypt)

    2010-11-15

    In the present work, a new shape of a glow discharge ion source has been designed, fabricated and constructed at Accelerators and Ion Sources Department, Nuclear Research Center, Egyptian Atomic Energy Authority, Egypt. The discharge and output beam characteristics of the ion source at different operating gas pressures have been measured at the optimum distance between the anode and the cathode (3.5 mm) using hydrogen and nitrogen gases. Furthermore, mixture of different gases was studied, e.g., addition of H{sub 2} gas to N{sub 2} gas with different ratios has been investigated. Finally, as an application of this new ion source, ion beam modification of insulators (glass) which depends on glass structure has been achieved. It has been found that, the transmission of light is decreased by coating the glass surface with Ar ion beam more than coating with plasma of Ar gas at the same pressure and the same exposure time. So we could use this ion source as a coating tool for borate glass surface. The parameters affected the glow discharge ion source efficiency have been examined carefully using a mixture of gases. Using helium gas, the glow discharge is in a turbulent state due to instabilities. An investigated H{sub 2}-N{sub 2} mixture has been used in order to obtain an optimum percentage of the mixture of the two gases to increase the electric field necessary for ionization balance.

  15. 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

  16. 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

  17. Effect of metal vapour vacuum arc ion implantation of aluminium on sliding wear characteristics of Ti-6Al-4V

    International Nuclear Information System (INIS)

    The metal vapour vacuum arc ion source is introduced and its more important features and system characteristics are described. Specific reference is made to applications in the field of metallurgical surface treatment by metal ion implantation and some recent developments are reviewed. The effects of aluminium ion implantation (doses up to 1.3 x 1017 ions/cm2) on the sliding wear properties of Ti-6Al-4V forms the emphasis of the ensuing investigation. Damage induced in sliding wear tests was reduced by about 50% after aluminium implantation, owing to a higher surface hardness. Several techniques of surface analysis including glancing angle X-ray diffraction and glow discharge optical emission spectroscopy indicated that subsurface precipitates were primarily responsible for the observed wear mechanism. The strengthening of subsurface material delayed the onset of superficial plastic deformation and resulted in enhanced tribological properties. (Author)

  18. X-ray elastic constants of chromium nitride films deposited by arc-ion plating

    International Nuclear Information System (INIS)

    Thin films have been successfully utilized to improve the property of mechanical components. However, it is generally known that mechanical properties, such as elastic constants and tensile strength of thin films, are different from those of bulk material, and they are not known in the present state. In many times, x-ray stress measurement revealed a very high compressive residual stress state in the film when bulk elastic constants were used in the stress calculation. The purpose of this research is to investigate the elastic constants of chromium nitride (CrN) films. The film was deposited on austenitic stainless steel (JIS: SUS304) substrates by the arc-ion-plating (AIP) method under the following conditions: the pressure of nitrogen atmosphere was maintained at 2.63 Pa, the substrate temperature of about 573 K, the arc discharge current of 100 A, the bias voltage between -300 and -100 V, and the substrate rotating rate at 3 rpm. The lattice strain of CrN films was measured by x-ray method at various loading stages and the x-ray elastic constants of CrN films were evaluated

  19. 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.

  20. Ion charge state distributions of pulsed vacuum arc plasmas in strong magnetic fields

    International Nuclear Information System (INIS)

    Vacuum arc plasmas with discharge currents of 300 A and duration 250 μs have been produced in strong magnetic fields up to 4 T. Ion charge state distributions have been measured for C, Al, Ag, Ta, Pt, Ho, and Er with a time-of-flight charge-mass spectrometer. Our previous measurements have been confirmed which show that ion charge states can be considerably enhanced when increasing the magnetic field up to about 1 T. The new measurements address the question of whether or not the additional increase continues at even higher magnetic field strength. It has been found that the increase becomes insignificant for field strengths greater than 1 T. Ion charge state distributions are almost constant for magnetic field strengths between 2 and 4 T. The results are explained by comparing the free expansion length with the freezing length. The most significant changes of charge state distributions are observed when these lengths are similar. copyright 1998 American Institute of Physics

  1. Ion charge state distributions of pulsed vacuum arc plasmas in strong magnetic fields

    International Nuclear Information System (INIS)

    Vacuum arc plasmas with discharge currents of 300 A and duration 250 μs have been produced in strong magnetic fields up to 4 T. Ion charge state distributions have been measured for C, Al, Ag, Ta, Pt, Ho, and Er with a time-of-flight charge-mass-spectrometer. Our previous measurements have been confirmed which show that ion charge states can be considerably enhanced when increasing the magnetic field up to about 1 T. The new measurements address the question of whether or not the additional increase continues at even higher magnetic field strength. It has been found that the increase becomes insignificant for field strengths greater than 1 T. Ion charge state distributions are almost constant for magnetic field strengths between 2 and 4 T. The results are explained by comparing the free expansion length with the freezing length. The most significant changes of charge state distributions are observed when these lengths are similar. copyright 1998 American Institute of Physics

  2. 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

  3. 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

    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......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...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Substrate temperature influence on W/WCNx bilayers grown by pulsed vacuum arc discharge

    International Nuclear Information System (INIS)

    W/WCNx 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 °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 α-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-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/WCNx bilayers, caused by the competition between carbon and nitrogen.

  10. Substrate temperature influence on W/WCNx bilayers grown by pulsed vacuum arc discharge

    Science.gov (United States)

    Ospina, R.; Escobar, D.; Restrepo-Parra, E.; Arango, P. J.; Jurado, J. F.

    2012-04-01

    W/WCNx 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 °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 α-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-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/WCNx bilayers, caused by the competition between carbon and nitrogen.

  11. Carbon-coated YC2 nanocapsules synthesized by arc-discharge in methane

    International Nuclear Information System (INIS)

    Carbon-coated YC2 nanocapsules were prepared by arc-discharging bulk yttrium in methane. The core/shell structure was obtained, where a polyhedral crystalline YC2 core was coated by defective graphite shell with size of 1-3 nm. The hydrolyzing of the zero-dimensional superconductors YC2 was controlled by the shell. The magnetic properties of the carbon-coated YC2 nanocapsules show that the dimensional effect has a very small influence on its superconducting transition temperature. The Raman spectrum of the carbon-coated YC2 nanocapsules shows that the shell is defective graphite and also suggests that the aberrance structure of the carbon shell is related to the zone-edge vibration of the YC2 core.

  12. 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.

  13. 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.

  14. 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.

  15. 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)

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

    International Nuclear Information System (INIS)

    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 °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 °C, TiO2 phase begun to appear and it was well observed at 500 °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.

  17. 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.

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

    International Nuclear Information System (INIS)

    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.

  19. 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.

  20. 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.

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

    International Nuclear Information System (INIS)

    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

  2. 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...

  3. The electron cyclotron resonance ion source with arc-shaped coils concept (invited).

    Science.gov (United States)

    Koivisto, H; Suominen, P; Tarvainen, O; Spädtke, P

    2012-02-01

    The main limitation to further improve the performance of ECR ion sources is set by the magnet technology related to the multipole magnet field used for the closed minimum-B structure. The JYFL ion source group has sought different approaches to improve the strength of the minimum-B structure required for the production of highly charged ion beams. It was found out that such a configuration can be realized with arc shaped coils. The first prototype, electron cyclotron resonance ion source with arc-shaped coils (ARC-ECRIS), was constructed and tested at JYFL in 2006. It was confirmed that such an ion source can be used for the production of highly charged ion beams. Regardless of several cost-driven compromises such as extraction mirror ratio of 1.05-1.2, microwave frequency of 6.4 GHz, and beam line with limited capacity, Ar(4+) beam intensity of up to 2 μA was measured. Subsequent design study has shown that the ARC-ECRIS operating at the microwave frequency above 40 GHz could be constructed. This specific design would be based on NbTi-wires and it fulfills the experimental magnetic field scaling laws. In this article, the ARC-ECRIS concept and its potential applications will be described. PMID:22380159

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  14. 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

  15. 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.

  16. Studies on the mechanisms of the reactions between ethanol and D2O by arc-discharge

    International Nuclear Information System (INIS)

    An arc-discharge was carried out to a mixture of ethanol and heavy water under a nitrogen atmosphere. GC-MS analysis showed that DCH2CH2OH and DOCH2CH2OH were produced. This result implies the decomposition of water molecules, which possibly serves as an initial step for the reaction in aqueous solution. In addition, CH3COOD and HOCH2CH2ND2 were also identified in the products, and it was considered that the ''nitrogen deposition'' effect was caused by capture of D from D2O with N+ to form ·ND2 radicals. Based on these results, we infer that arc-discharge-induced reactions are mainly initiated by decomposition of water molecules; both H· and ·OH radicals play an important role in the reaction process

  17. The electron cyclotron resonance ion source with arc-shaped coils concept

    OpenAIRE

    Koivisto, Hannu; Suominen, Pekka; Tarvainen, Olli; Spädtke, P.

    2012-01-01

    The main limitation to further improve the performance of ECR ion sources is set by the magnet technology related to the multipole magnet field used for the closed minimum-B structure. The JYFL ion source group has sought different approaches to improve the strength of the minimum-B structure required for the production of highly charged ion beams. It was found out that such a configuration can be realized with arc shaped coils. The first prototype, electron cyclotron resonance io...

  18. Quasi-Laminar Flow Characteristics in Hybrid-Stabilized Argon–Water Arc Discharge for Subsonic-Supersonic Regimes

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Takana, H.; Nishiyama, H.; Křenek, Petr; Bartlová, M.; Aubrecht, V.

    2014-01-01

    Roč. 42, č. 10 (2014), s. 2632-2633. ISSN 0093-3813 R&D Projects: GA ČR GAP205/11/2070 Institutional support: RVO:61389021 Keywords : Hybrid-stabilized electric arc * large-eddy simulation * partial characteristics * the Smagorinsky subgrid scale model Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.101, year: 2014 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6876210

  19. DBD as a post-discharge bipolar ions source and selective ion-induced nucleation versus ions polarity

    Science.gov (United States)

    Bourgeois, E.; Jidenko, N.; Alonso, M.; Borra, J. P.

    2009-10-01

    Ions densities and mobilities in post-dielectric barrier discharge (post-DBD) are presented here. To extract ions from DBD and perform post-discharge measurements the best functioning conditions are low overpressure, high frequency (>=25 kHz, to avoid electrocollection) and low flow rate (1 lpm, to reduce dilution). Besides, ions densities in post-discharge increase with electrode temperature and, at low flow rates, with the number of discharge filaments by time and surface unit (controlled by voltage at fixed frequency). In both cases, the reinforcement of dielectric material surface polarization reduces the local electrocollection of ions inside DBD or increases the production of ions by subcritical avalanches outside filaments. Concerning mobility measurements, it is shown that for low saturation, vapours emitted from post-DBD polymer tubes only affect positive ions mobility due to selective ion-induced nucleation on positive ions. When metal post-DBD tubes are used, positive ions keep the same range of electric mobility at any temperature while there is a drop in negative ions mobility around 100 °C, probably related to a chemical transition between O3 and NOx.

  20. DBD as a post-discharge bipolar ions source and selective ion-induced nucleation versus ions polarity

    International Nuclear Information System (INIS)

    Ions densities and mobilities in post-dielectric barrier discharge (post-DBD) are presented here. To extract ions from DBD and perform post-discharge measurements the best functioning conditions are low overpressure, high frequency (≥25 kHz, to avoid electrocollection) and low flow rate (1 lpm, to reduce dilution). Besides, ions densities in post-discharge increase with electrode temperature and, at low flow rates, with the number of discharge filaments by time and surface unit (controlled by voltage at fixed frequency). In both cases, the reinforcement of dielectric material surface polarization reduces the local electrocollection of ions inside DBD or increases the production of ions by subcritical avalanches outside filaments. Concerning mobility measurements, it is shown that for low saturation, vapours emitted from post-DBD polymer tubes only affect positive ions mobility due to selective ion-induced nucleation on positive ions. When metal post-DBD tubes are used, positive ions keep the same range of electric mobility at any temperature while there is a drop in negative ions mobility around 100 0C, probably related to a chemical transition between O3 and NOx.

  1. 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

  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. Experimental investigation of the relation between H− negative ion density and Lyman-α emission intensity in a microwave discharge

    International Nuclear Information System (INIS)

    A new mechanism for producing negative ions in low density and low power hydrogen plasmas was proposed recently. It refers to anion formation due to collisions between hydrogen atoms being in the first excited state. The proposed mechanism was indirectly supported by the quadratic relation observed between the extracted negative ion current and Lyman-α radiation of a filament-driven arc discharge, when borrowed data from the literature were combined. The present work provides experimental data comparing directly the absolute negative ion density and Lyman-α radiation in an ECR-driven hydrogen plasma source. The previously mentioned quadratic relation is not observed in the specific source studied, underlying the difficulty of distinguishing between the proposed mechanism and other negative ion production paths. (paper)

  4. Plasma source ion implantation of metal ions: Synchronization of cathodic-arc plasma production and target bias pulses

    International Nuclear Information System (INIS)

    An erbium cathodic-arc has been installed on a Plasma Source Ion Implantation (PSII) experiment to allow the implantation of erbium metal and the growth of adherent erbia (erbium oxide) films on a variety of substrates. Operation of the PSII pulser and the cathodic-arc are synchronized to achieve pure implantation, rather than the hybrid implantation/deposition being investigated in other laboratories. The relative phase of the 20 μs PSII and cathodic-arc pulses can to adjusted to tailor the energy distribution of implanted ions and suppress the initial high-current drain on the pulse modulator. The authors present experimental data on this effect and make a comparison to results from particle-in-cell simulations

  5. Improved ion implant fluence uniformity in hydrogen enhanced glow discharge plasma immersion ion implantation into silicon

    Science.gov (United States)

    Luo, J.; Li, L. H.; Liu, H. T.; Yu, K. M.; Xu, Y.; Zuo, X. J.; Zhu, P. Z.; Ma, Y. F.; Fu, Ricky K. Y.; Chu, Paul K.

    2014-06-01

    Enhanced glow discharge plasma immersion ion implantation does not require an external plasma source but ion focusing affects the lateral ion fluence uniformity, thereby hampering its use in high-fluence hydrogen ion implantation for thin film transfer and fabrication of silicon-on-insulator. Insertion of a metal ring between the sample stage and glass chamber improves the ion uniformity and reduces the ion fluence non-uniformity as the cathode voltage is raised. Two-dimensional multiple-grid particle-in-cell simulation confirms that the variation of electric field inside the chamber leads to mitigation of the ion focusing phenomenon and the results are corroborated experimentally by hydrogen forward scattering.

  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. Measurements of actinometry and ions energy in a microwave discharge

    International Nuclear Information System (INIS)

    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 N2-H2 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)

  8. Effect of surface temperature on the concentration of C60/C70 molecules in dc arc discharge fullerene generator

    International Nuclear Information System (INIS)

    Synthesis of C60, C70 and higher fullerenes was carried out at Pakistan Institute of Nuclear Science and Technology (PINSTECH) using dc arc discharge technique. High-performance liquid chromatography (HPLC) and UV-vis spectroscopy are employed to characterize the fullerenes. The toluene extracted fullerene solutions of the raw soot collected from four different regions (A-D) of dc arc discharge fullerene generator were compared with pure C60 toluene solution. Due to poor solubility of C60 in HPLC grade methanol, different fractions of methanol as a mobile phase with toluene were tried. The mobile phase composition of 80:20 methanol:toluene was found an optimal ratio to achieve the best separation factor of 1.246 between C60 and C70 fullerenes. Quantitative concentration is calculated from the HPLC and UV-vis spectra. The molarity of C60 carbon molecules for all the regions is calculated from the HPLC spectra by comparing the spectra of known molar solution of C60. The maximum concentration of C70 is found to be 21% in the region B that is nearer the arc zone and at a higher temperature than other regions. Both the techniques confirm the presence of C60, C70 and higher fullerenes in all the four regions with variation in concentration of C60 and C70. UV-vis spectra of the region C show the additional absorption bands at 285 and 305 nm

  9. 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.

  10. Preparation of carbon-encapsulated iron nanoparticles in high yield by DC arc discharge and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Cui, Lan; Lin, Kui [Center of Analysis, Tianjin University, Tianjin 300072 (China); Jin, Feng-min; Wang, Bin [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Shi, Shu-xiu [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China); Yang, De-an [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Wang, Hui [Center of Analysis, Tianjin University, Tianjin 300072 (China); He, Fei [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Chen, Xiao-ping [Center of Analysis, Tianjin University, Tianjin 300072 (China); Cui, Shen, E-mail: cuishen@tju.edu.cn [Department of Chemistry, School of Science, Tianjin University, Tianjin 300072 (China)

    2013-03-15

    Highlights: ► CEINPs with core–shell structure and high Fe content were prepared in high yield by DC arc discharge. ► The anode II with a mass ratio of total iron to carbon 8:1 was used in DC arc discharge. ► The possible process of formation of CEINPs is briefly discussed. ► The uniformity of composition of anode is very important for the formation of CEINPs. ► The MEF and MMF of iron element may also play an important role in the formation of CEINPs. -- Abstract: Carbon-encapsulated iron nanoparticles (CEINPs) were prepared by DC arc discharge under nitrogen atmosphere of high temperature. The products were characterized by transmission electron microscope (TEM), high-resolution transmission electron microscope (HRTEM), X-ray diffractometer (XRD), energy dispersive X-ray (EDX) spectroscope, and X-ray photoelectron spectroscope (XPS), and their magnetic properties were measured by physical property measurement system (PPMS). The product B{sub I}, obtained from the anode I, contains the nanoparticles of iron and iron carbide, and carbon coating with imperfect and disordered layer structure. The product B{sub II}, obtained from the anode II, mainly consists of CEINPs, whose cores mainly consist of iron and iron carbide and shells contain about 3–7 graphitic layers. The iron contents in the products B{sub I} and B{sub II} are 44.8 and 82.6 wt.%, respectively. The products B{sub I} and B{sub II} have similar phase composition which includes carbon, iron, iron carbide, ferrous and ferric oxide, iron nitride, and carbon nitride. The saturation magnetization (Ms) of the products B{sub I} and B{sub II} are 29.35 and 88.66 emu/g and their coercivity (Hc) are 220 and 240 Oe, respectively. The total yields of all the products formed in the arc discharge chamber from anodes I and II, except for the cylinder-shaped deposits formed on the top of the cathode, are 25.8 and 22.3 wt.%, respectively. The possible process of formation of CEINPs is briefly discussed on

  11. 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.

  12. Comparative Study on Extinction Process of Gas-Blasted Air and CO2 Arc Discharge Using Two-Dimensional Electron Density Imaging Sensor

    Science.gov (United States)

    Inada, Yuki; Kamiya, Tomoki; Matsuoka, Shigeyasu; Kumada, Akiko; Ikeda, Hisatoshi; Hidaka, Kunihiko; Nakano, Tomoyuki; Murai, Kosuke; Tanaka, Yasunori; Shinkai, Takeshi

    2015-09-01

    Systematic comparison of the electron density images for various kinds of arc-quenching gas media inside high-voltage circuit breakers is a promising method for the effective search and development of SF6-alternative gases. However, electron density imaging over the decaying arcs around the nozzle throat of the circuit breakers is extremely difficult by using the conventional arc generation setup and localized type sensing systems, due to the nozzle opaqueness and spatiotemporal instability of long-gap arc discharges around current zero. Here, we achieved two-dimensional electron density imaging over the decaying arcs around the nozzle throat first in the world, by a combination of the development of a unique gas flow nozzle integrating a cubic quartz cell and the single-shot recordings using Shack-Hartmann sensors. Shack-Hartmann sensors were applied to gas-blasted air and CO2 arc discharges under current-zero phases after sudden switch-off of stationary arc currents. These experimental results showed that the electron densities and arc diameters took the minimums in the upper stream nozzle regions with the maximum blasting gas speeds. In addition, CO2 had a shorter electron density decaying time constant than air, which is consistent with the previous theoretical studies on higher interruption performance of CO2 compared with air.

  13. Generation of super-size macroparticles in a direct current vacuum arc discharge from a Mo-Cu cathode

    Science.gov (United States)

    Zhirkov, Igor; Petruhins, Andrejs; Polcik, Peter; Kolozsvári, Szilard; Rosen, Johanna

    2016-02-01

    An inherent property of cathodic arc is the generation of macroparticles, of a typical size ranging from submicrometer up to a few tens of μm. In this work, we have studied macroparticle generation from a Mo0.78Cu0.22 cathode used in a dc vacuum arc discharge, and we present evidence for super-size macroparticles of up to 0.7 mm in diameter. All analyzed particles are found to be rich in Mo (≥98 at. %). The particle generation is studied by visual observation of the cathode surface during arcing, by analysis of composition and geometrical features of the used cathode surface, and by examination of the generated macroparticles with respect to shape and composition. A mechanism for super-size macroparticle generation is suggested based on observed segregated layers of Mo and Cu identified in the topmost part of the cathode surface, likely due to the discrepancy in melting and evaporation temperatures of Mo and Cu. The results are of importance for increasing the fundamental understanding of macroparticle generation, which in turn may lead to increased process control and potentially provide paths for tuning, or even mitigating, macroparticle generation.

  14. 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

  15. 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.

  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. 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 with...

  18. 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

  19. Performance and preparation of tungsten coatings deposited onto graphite substrate by multi-arc ion plating

    International Nuclear Information System (INIS)

    Due to its high melting point, low sputtering rate and low tritium retention properties, tungsten is considered as a promising candidate material for plasma facing materials in fusion devices. Tungsten coating was deposited onto high-purity graphite substrate by multi-arc ion plating. The tungsten coating was characterized by X-ray diffraction (XRD), optical microscope (OM), scanning electron microscopy (SEM) and 3D laser scanning microscope. The results indicate that: The thickness of tungsten coating is in the range of 3μm-10μm. The results of XRD show that the oriented crystal growth of the coatings occurred along (110) crystal plane. The multi-arc ion plating method yield excellent coverage of the graphite surface, even in the open pores of the substrate. The coating is dense and homogeneous. The bond between graphite and the coating was relatively dense. The average surface roughness of the coatings is about 1.2μm. (authors)

  20. Ion flux onto conducting and isolated surfaces in the beam-plasma discharge: Computer simulation

    Science.gov (United States)

    Klykov, I. L.; Shustin, E. G.; Tarakanov, V. P.

    2010-12-01

    A physical model which allows the use of the program code KARAT for simulating the quasisteady state of the beam-plasma discharge with plasma regeneration from a neutral gas is developed. The results of simulation of the modes of discharge at different potentials at the discharge collector are reported. The results obtained for isolated and grounded ion collectors are compared.

  1. 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)

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

    OpenAIRE

    Coy, Stephen L.; Krylov, Evgeny V.; 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 prot...

  3. 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

    discharge, where the cross section for electron attachment increases. The formation of negative ions from sputtering of metals and metal oxides is compared with that for positive ions. It is shown that the negative ion signals of F(-) and TaO(2)F(-) are enhanced relative to positive ion signals and can be......A new method is presented for elemental and molecular analysis of halogen-containing samples by glow discharge time-of-flight mass spectrometry, consisting of detection of negative ions from a pulsed RF glow discharge in argon. Analyte signals are mainly extracted from the afterglow regime of the...... the formation of negative ions in glow discharge time-of-flight mass spectrometry are briefly discussed....

  4. 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.

  5. Ion spectra of vacuum arc plasma with compound and alloy cathodes

    International Nuclear Information System (INIS)

    We have carried out an experimental investigation of the charge state distribution of ions produced in the vacuum arc plasma for the case when the cathode is a compound or alloy. The plasma was generated in a metal vapor vacuum arc ion source, and the charge state spectra were measured using a time-of-flight method. We have compared these spectra to the spectra obtained from cathodes of the constituent elements. The cathode materials used and reported on here were the following groups: SiC/Si/C [i.e., we have compared the spectra obtained using a cathode of silicon carbide with the spectra obtained using (a) a silicon cathode and (b) a carbon cathode], TiC/TiN/TiO2/Ti/C, WC/W/C, (UC-ZrC)/UN/U/Zr/C, brass/Cu/Zn, and stainless steel/Fe/Cr/Ni. The arc current employed throughout was approximately 100 A. We find that the charge state distributions change depending on the elemental composition of the alloy or compound of which the cathode is fabricated

  6. 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.

  7. Multiple solutions in the theory of dc glow discharges and cathodic part of arc discharges. Application of these solutions to the modeling of cathode spots and patterns: a review

    Science.gov (United States)

    Benilov, M. S.

    2014-10-01

    A new class of stationary solutions in the theory of glow discharges and plasma-cathode interaction in ambient-gas arc discharges has been found over the past 15 years. These solutions exist simultaneously with the solution given in textbooks, which describes a discharge mode with a uniform or smooth distribution of current over the cathode surface, and describes modes with various configurations of cathode spots: normal spots on glow cathodes, patterns of multiple spots recently observed on cathodes of glow microdischarges and spots on arc cathodes. In particular, these solutions show that cathode spots represent a manifestation of self-organization caused by basic mechanisms of the near-cathode space-charge sheath; another illustration of the richness of the gas discharge science. As far as arc cathodes are concerned, the new solutions have proved relevant for industrial applications. This work is dedicated to reviewing the multiple solutions obtained to date, their systematization, and analysis of their properties and physical meaning. The treatment is performed in the context of general trends of self-organization in bistable nonlinear dissipative systems, which allows one to consider glow discharges or arc-cathode interaction within a single physically transparent framework without going into mathematical details and offers a possibility of systematic computation of the multiple solutions. Relevant computational aspects and experimental data are discussed.

  8. 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

  9. Ion Exchange Resin and Clay Vitrification by Plasma Discharges

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Single-walled nanohorns and other nanocarbons generated by submerged arc discharge between carbon electrodes in liquid argon and other media

    International Nuclear Information System (INIS)

    Arc discharge between two graphite electrodes submerged in different liquid media yields various dimensional nanocarbon structures such as 1D carbon nanotubes and 2D graphene. Single-walled carbon nanohorns (SWNHs) prepared by submerged arc discharge in liquid nitrogen medium are found to have nitrogen impurities. Here, we report the structure and properties of pure and nitrogen-doped SWNHs obtained by submerged arc discharge in a liquid argon medium. The absence of an XPS N 1s signal, which is present in nanohorns obtained in liquid nitrogen, indicate that the nanohorns are free from nitrogen impurities. Raman spectra show a strong defect-induced D band and current–voltage characteristics show a slight nonlinear behavior. N2 adsorption of pure SWNHs shows type-IV isotherms with a surface area of 300 m2 g−1. Adsorption of CO2 and H2 in pure SWNHs has also been measured. Arc discharge in other liquid media such as water, ethanol, dimethylformamide (DMF), n-methyl pyrrolidone (NMP), formamide, benzene, heptane and acetone yields different nanocarbon structures including multi-walled carbon nanotubes (MWNTs), few-layer graphene, carbon onions and carbon nanoparticles. (papers)

  19. 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

  20. 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.

  1. Effect of pressure on the deposition of hydrogen-free amorphous carbon and carbon nitride films by the pulsed cathodic arc discharge method

    International Nuclear Information System (INIS)

    Hydrogen-free amorphous carbon (a-C) and carbon nitride (a-C:N) films were deposited using the pulsed cathodic arc discharge at different argon and nitrogen pressures. The surface and mechanical properties of these films were found to strongly depend on the gas pressure. The tetrahedral amorphous carbon and hard a-C:N films with smooth surfaces (rms roughness: 0.15 nm) were prepared at lower gas pressures (-2 Pa). Incorporation of an increasing amount of nitrogen in a-C:N films caused a decrease in film hardness. All the films were covered with the thin (0.3-2 nm) graphite-like surface layers. The film hardness was correlated to the soft surface layer thickness, and the films with thinner surface layers exhibit higher hardness. The mean energies of pulsed plasma beams were measured as the functions of argon and nitrogen pressures. The mean energies of plasma beams decrease in an exponential fashion with increasing gas pressure due to the carbon ion collisions with the neutral gas species. The effects of mean energies of deposited species on the film deposition were explained in terms of the thermal spike migration of surface atoms. The formation of graphite-like surface layers is associated with the low-energy deposition process. The low-energy (10 eV) species may produce the strong thermal spike at film surface, and contribute to the formation of sp3 bonded structure at a sp3 bonded matrix

  2. 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

  3. CuO/Ta2O5 core/shell nanoparticles synthesized in immersed arc-discharge: production conditions and dielectric response

    International Nuclear Information System (INIS)

    We reported recently on a novel nanostructured material produced by the arc-discharge in water method, and extended studies were realized to identify the nature of this material, i.e., CuO/Ta2O5 core/shell crystalline nanoparticles (NPs). As a continuation of this investigation on the possibility of complex NP synthesis using immersed arc-discharge, the production conditions of the CuO/Ta2O5 NPs are herein presented in detail and the electrical properties of the nanopowder are examined comprehensively. The discharge is thus probed in situ by electrical measurements, optical emission spectroscopy and high speed imaging, and the electrical behavior of the NPs is considered by means of broadband dielectric spectroscopy. This combined study provides an integrated characterization of this new material, unveils its potential applications, and makes available suggestions on the process control.

  4. 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, ...

  5. 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...

  6. Construction and testing of arc dipoles and quadrupoles for the relativistic heavy ion collider (RHIC) at BNL

    International Nuclear Information System (INIS)

    The production run of superconducting magnets for the Relativistic Heavy Ion Collider (RHIC) project at Brookhaven National Laboratory (BNL) is well underway. Of the 288 arc dipoles needed for the collider, more than 120 have been delivered. More than 150 arc quadrupoles have been delivered. All of these magnets have been accepted for RHIC. This paper reports the construction and performance of these magnets. Novel features of design and test, introduced to enhance technical performance and control costs, are also discussed. Other papers submitted to this Conference summarize work on the sextupoles and tuning quads, arc correctors, and combined corrector-quadrupole-sextupole assemblies (CQS)

  7. 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.

  8. 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.

  9. Ion diffusion into metals by double glow discharge. A new plasma surface alloying technique

    International Nuclear Information System (INIS)

    The diffusion of ions into a metal by double glow discharge--a new plasma surface alloying technique--is presented. An enhanced discharge caused by double glow cross-interaction is introduced as a special discharge. The conditions and physics of double glow cross-interaction are discussed. The effects of this cross-interaction on plasma surface alloying are also discussed. Experimental results and industrial applications as well as future industrialization and problems of application and promotion are mentioned

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

    International Nuclear Information System (INIS)

    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 (H2), the ion beam contained three species: H+, H2+, and H3+. For all experimental conditions, the fraction of H2+ 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+ and H3+ 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+ fraction in ion beam. The maximum fraction of H+ 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 H3+ fraction in the beam. At optimum parameters, the fraction of H3+ ions reached 60% of the total ion beam current

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. Routing Application for Parallel computatIon of Discharge

    Science.gov (United States)

    David, C. H.; Maidment, D. R.; Yang, Z.

    2008-12-01

    Today, meteorological models can predict storm events and climate patterns, but there are few models that connect atmospheric models to the hydraulics of rivers. Such a model is necessary to advance the prediction of events such as floods or droughts. Furthermore, the increasingly available Geographic Information System-based hydrographic datasets offer ways to use actual mapped river for routing. Such GIS-based datasets include NHDPlus at the continental-scale [USEPA and USGS, 2007]and HydroSHEDS at the global- scale [Lehner, et al., 2006]. The objective of ongoing work is to develop RAPID (Routing Application for Parallel computatIon of Discharge), a large-scale river routing model that: - has physical representation of river flow - allows for coupling with both land surface models and groundwater models. In particular enabling bi-directional exchanges between rivers and aquifers through a computation of water volume and flow on a reach-to-reach basis - has some specific treatment for man-made infrastructures and anthropogenic actions (dams, pumping) - benefits from the latest scientific computing developments (supercomputing facilities and high performance parallel computing libraries) - will benefit from the increasingly available Geographic Information System hydrographic databases. RAPID has already been tested over France through a ten-year coupling with SIM-France [Habets, et al., 2008, using a river network made of 24,264 river reaches. RAPID has been adapted to run on the Lonestar supercomputer (http://www.tacc.utexas.edu/resources/hpcsystems/) and to allow the use of the NHDPlus dataset. RAPID is now being tested with the 74,615 river reaches of the entire Texas Gulf. This type of innovative model has strong implications for the future of hydrology. Such a tool can help improve the understanding of the effect of climate change on water resources as well as provide information on how many gages are needed and where are they needed the most. More broadly

  17. 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

  18. 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

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

    OpenAIRE

    Kozlov, A. A.

    2015-01-01

    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 lay...

  20. Synthesis of branched, nano channeled, ultrafine and nano carbon tubes from PET wastes using the arc discharge method

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Berkmans, A.; Jagannatham, M. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu (India); Priyanka, S. [Department of Electrical and Electronics Engineering, MS Ramaiah Institute of Technology, Bangalore 560054, Karnataka (India); Haridoss, Prathap, E-mail: prathap@iitm.ac.in [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu (India)

    2014-11-15

    Highlights: • Polymer wastes are converted into ultrafine and nano carbon tubes and spheres. • Simple process with a minimal processing time. • It is a catalyst free and solvent free approach. • This process forms branched ultrafine carbon tubules with nano channels. - Abstract: Upcycling polymer wastes into useful, and valuable carbon based materials, is a challenging process. We report a novel catalyst-free and solvent-free technique for the formation of nano channeled ultrafine carbon tubes (NCUFCTs) and multiwalled carbon nanotubes (MWCNTs) from polyethylene terephthalate (PET) wastes, using rotating cathode arc discharge technique. The soot obtain from the anode contains ultrafine and nano-sized solid carbon spheres (SCS) with a mean diameter of 221 nm and 100 nm, respectively, formed at the lower temperature region of the anode where the temperature is approximately 1700 °C. The carbon spheres are converted into long “Y” type branched and non-branched NCUFCTs and MWCNTs at higher temperature regions where the temperature is approximately 2600 °C, with mean diameters of 364 nm and 95 nm, respectively. Soot deposited on the cathode is composed of MWCNTs with a mean diameter of 20 nm and other nanoparticles. The tubular structures present in the anode are longer, bent and often coiled with lesser graphitization compared to the nanotubes in the soot on the cathode.

  1. 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

  2. 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.

  3. Rocketborne observations of ion convection and electric fields in dayside and nightside visual auroral arcs

    International Nuclear Information System (INIS)

    We present ionospheric ion convection measurements in a series of four rocket payloads in and near dayside and nightside auroral arcs: one at Cape Parry (75.40N invariant latitude) near 1300 MLT and three at Churchill (70.00N invariant latitude) between 1900 and 2200 MLT. Direct measurements were made of the ionospheric ion velocity distribution function, and the observed ion convection velocities and equivalent convective electric fields were correlated with the energetic particle precipitation, the optical morphology of the aurora, and the topology of the geomagnetic field. Both in the postnoon and premidnight sectors it was observed that (1) equatorward of the region(s) of precipitation the ion flow was predominantly westward, with velocity of about 1 km/s; (2) poleward of the region(s) the flow was predominantly westward, with velocity of about 1 km/s; (2) poleward of the region(s) the flow was predominantly eastward: (3) the change in the flow direction, where observed, occurred near though not exactly at the edges of the precipitation region; (4) the flow inside the precipitation region was lower; (5) the reversal of the ion flow, where observed, occurred on closed magnetic field lines; and (6) the convective electric field typically dropped from 40 to 80 mV/m outside the precipitation region to 10 to 30 mV/m within. In the dayside Cape Perry flight, where quantitative photometric measurements were available, detailed anticorrelation between the ion convection speed and the green line emission intensity was also observed

  4. 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...

  5. Influence of the oxygen concentration on the formation of crystalline phases of ZrO2 nanoparticles during the low-pressure arc-discharge plasma synthesis

    Science.gov (United States)

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

    2015-11-01

    The synthesis of nanoparticles of zirconium dioxide with different contents of the monoclinic and tetragonal phases has been investigated. The synthesis has been performed by controlling the oxygen content in the gas mixture in the plasma-chemical evaporation-condensation process in low-pressure arc-discharge plasma. The crystal structure of synthesized ZrO2 nanoparticles has been studied using X-ray diffraction. The morphology of the particles has been analyzed using transmission electron microscopy. The nanoparticle growth in arc-discharge plasma has been examined using optical emission spectroscopy. The X-ray powder diffraction analysis has revealed that the content of the monoclinic phase of ZrO2 increases with a decrease in the oxygen content in the oxygen-argon gas mixture.

  6. 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

  7. 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

  8. 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

  9. 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...

  10. Investigation of inhomogeneous mixing of plasma species in a hybrid-stabilized argon-water arc discharge: The very first simulations

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří; Takana, H.; Uehara, S.; Nishiyama, H.; Hrabovský, Milan; Murphy, A.B.; Bartlová, M.; Aubrecht, V.

    Sendai: Tohoku University, 2015, s. 56-57. ISSN 1344-2236. [International Symposium on Advanced Fluid Information (AFI 2015)/15./. Sendai (JP), 27.10.2015-29.10.2015] R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : hybrid-stabilized electric arc * inhomogeneous mixing * species * combined diffusion coefficients Subject RIV: BL - Plasma and Gas Discharge Physics http://www.researchgate.net/profile/Hidemasa_Takana/publications

  11. Real energy spread of ions produced in vacuum spark-discharge plasma

    International Nuclear Information System (INIS)

    The initial energy spread of ions formed in vacuum spark-discharge plasma is studied, and is found to be approx. 100 eV (at 50% of maximum intensity). Of three possible mechanisms for ion acceleration, the hydrodynamic mechanism and the action of the self-consistent electric field have been shown to be the basic mechanisms. The mechanism of ion acceleration in the inter-electrode field does not play an important role. The energy spread of ions can increase considerably during the formation of an ion beam, and this is usually the case in double-focusing mass spectrometers. (orig.)

  12. 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 ...

  13. 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

  14. 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.

  15. 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.

  16. Argon–oxygen dc magnetron discharge plasma probed with ion acoustic waves

    International Nuclear Information System (INIS)

    The precise determination of the relative concentration of negative ions is very important for the optimization of magnetron sputtering processes, especially for those undertaken in a multicomponent background produced by adding electronegative gases, such as oxygen, to the discharge. The temporal behavior of an ion acoustic wave excited from a stainless steel grid inside the plasma chamber is used to determine the relative negative ion concentration in the magnetron discharge plasma. The phase velocity of the ion acoustic wave in the presence of negative ions is found to be faster than in a pure argon plasma, and the phase velocity increases with the oxygen partial pressure. Optical emission spectroscopy further confirms the increase in the oxygen negative ion density, along with a decrease in the argon positive ion density under the same discharge conditions. The relative negative ion concentration values measured by ion acoustic waves are compared with those measured by a single Langmuir probe, and a similarity in the results obtained by both techniques is observed

  17. 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

  18. Characterization of the arc ion-plated CrN coatings oxidized at elevated temperatures

    International Nuclear Information System (INIS)

    Microstructure and chemistry of the arc ion-plated CrN coatings oxidized in air at temperatures ranging from 300 to 800 deg. C for 60 min were analyzed by x-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and Auger electron spectroscopy (AES). The CrN coatings were prepared by cathodic arc ion plating deposition on a type 304 stainless steel with a Cr interlayer. The XRD result shows that oxidation of the CrN-coated steel above 500 deg. C produces two new phases, Cr2O3 and β-Cr2N, and the amount of both phases increases with the oxidation temperature. Cross-section TEM shows three distinct regions including the steel substrate, the Cr interlayer, and the CrN coating in the as-deposited specimen, in which the CrN layer exhibits a columnar structure and preferred orientation. Oxidation of the CrN-coated steel at high temperatures produces an oxide layer, Cr2O3, on the coating surface, and the underlayer is a mixture of CrN and β-Cr2N phases. Unlike the as-deposited specimen, the dual phase layer in the oxidized specimens has an equiaxed grain structure and the average grain size of the layer increases with the oxidation temperature. In addition, pronounced grain growth in the dual phase layer near the coating surface is observed in the specimen heat-treated at 800 deg. C. Elemental analyses of the CrN coating near the free surface by EELS and AES reveal that the O/N ratio of the coating and the thickness of the oxide layer increase with the oxidation temperature

  19. 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

  20. 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

  1. Effects of D/sup +/-, H/sub e//sup +/-, and self-ions pre-irradiation to first wall materials on arcing erosion

    International Nuclear Information System (INIS)

    Arc erosion measurements of the materials for limiters and first walls in fusion devices are of importance in the fusion technology so as to help in estimation of plasma contamination. In this brief report, erosion rates due to arcing were measured for 316 stainless steel, titanium, titanium nitride coated on graphite, and titanium carbides coated on 440C stainless steel and graphite. The characteristic features of the experiment for a simulation study of arc erosion in fusion devices were on the points that test materials were irradiated before arcing with deuterium ions, helium ions and heavy (''self'')-ions, and that the irradiated materials were arced in hydrogen plasma produced beforehand. The erosion was observed by a SEM and a surface roughness gage. The mass loss of materials was measured by a microbalance. As the effects of pre-irradiation, the results show that arcs were inductive at the irradiated region, and that the erosion rates were enhanced by irradiation

  2. Arc and filament heater current control system for 5 MW ion source of neutral beam injector for SST1

    International Nuclear Information System (INIS)

    This paper presents control system used in managing power system deployed on 1.7 MW neutral beam injector at 80 kV. Power system consists of 24 arc discharge current power supplies (120 V, 80 A, DC), 8 filament heater power supplies (200V, 10 A, 400 Hz, AC) and one highly regulated high voltage power supply (80 kV, 60ADC)

  3. 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...

  4. Ion energy distribution measurements in rf and pulsed dc plasma discharges

    International Nuclear Information System (INIS)

    A commercial retarding field analyzer is used to measure the time-averaged ion energy distributions of impacting ions at the powered electrode in a 13.56 MHz driven, capacitively coupled, parallel plate discharge operated at low pressure. The study is carried out in argon discharges at 10 mTorr where the sheaths are assumed to be collisionless. The analyzer is mounted flush with the powered electrode surface where the impacting ion and electron energy distributions are measured for a range of discharge powers. A circuit model of the discharge, in combination with analytical solutions for the ion energy distribution in radio-frequency sheaths, is used to calculate other important plasma parameters from the measured energy distributions. Radio-frequency compensated Langmuir probe measurements provide a comparison with the retarding field analyzer data. The time-resolved capability of the retarding field analyzer is also demonstrated in a separate pulsed dc magnetron reactor. The analyzer is mounted on the floating substrate holder and ion energy distributions of the impinging ions on a growing film, with 100 ns time resolution, are measured through a pulse period of applied magnetron power, which are crucial for the control of the microstructure and properties of the deposited films. (paper)

  5. 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

  6. Corrosion behavior of Zr modified CrN coatings using metal vapor vacuum arc ion implantation

    International Nuclear Information System (INIS)

    In recent years, attention has focused on the use of alternative metal nitride coatings as replacements for TiN for not only improved wear resistance and surface hardness but also for increased corrosion resistance in selected environments. While these coatings display excellent wear resistance and surface hardness, like many nitride coatings, their corrosion behavior is determined to a large extent by the presence of defects such as pinholes within the coating. Improved corrosion resistance is expected through minimizing the porosity/number of pinholes within the coating, through postdeposition surface modification. The aim of this study was to modify the surface of CrN coatings using metal vapor vacuum arc ion implantation. CrN coatings were deposited on AISI 316 stainless steel and AISI 1020 mild steel substrates using physical vapor deposition technology, followed by implantation of Zr ions into the coating at doses varying from 6x1016 to 2x1017 ions/cm2. The corrosion behavior was assessed in saline environments using linear polarization techniques and the corroded surface of the coatings was characterized using x-ray photoelectron spectroscopy and scanning electron microscopy. The results of the study showed that implantation of Zr ions into CrN resulted in a lowering of the corrosion current density, suggesting improved corrosion resistance. This was though to be associated with two factors. Firstly, partial closure of the pinholes as a result of the implantation process and secondly, the formation of ZrN, CrZrN, and various oxynitrides/oxides at the surface

  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. 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...

  10. Study of a lithium-ion battery charge-discharge test unit characteristics*

    Science.gov (United States)

    Kopylov, E. A.; Mizrah, E. A.; Fedchenko, A. S.; Lobanov, D. K.

    2016-04-01

    The article describes the structure of a charge-discharge unit which allows to perform electrical, resource and thermal testing of several lithium-ion batteries simultaneously. The principle of operation of a one battery research channel (BRC) is shown. This study evaluated the stabilization error and rate of change of charge/discharge currents, the switching time from the charge mode to the discharge mode and vice versa for a single BRC and parallel BRCs. The possibility of increasing the maximum battery testing current due to the parallel connection of multiple BRCs without using a current alignment device between channels was discussed.

  11. Influence of argon and oxygen on charge-state-resolved ion energy distributions of filtered aluminum arcs

    OpenAIRE

    Rosen, Johanna; Anders, Andre; Mraz, Stanislav; Atiser, Adil; Schneider, Jochen M.

    2006-01-01

    The charge-state-resolved ion energy distributions (IEDs) in filtered aluminum vacuum arc plasmas were measured and analyzed at different oxygen and argon pressures in the range 0.5 8.0 mTorr. A significant reduction of the ion energy was detected as the pressure was increased, most pronounced in an argon environment and for the higher charge states. The corresponding average charge state decreased from 1.87 to 1.0 with increasing pressure. The IEDs of all metal ions in oxygen were fitte...

  12. 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.)

  13. Plasma diagnostics of discharge channels for neutralized ion beam transport

    OpenAIRE

    Niemann, Christoph

    2002-01-01

    Most of the future accelerators will be high intensity machines delivering mega-watt beams for applications such as spallation neutron production, muon colliders, neutrino factories, nuclear-waste transmutation or inertial confinement fusion energy (IFE). Especially in the field of heavy ion driven inertial confinement fusion, where space charge dominated multi kilo-ampere beams have to be transported over several meters through a reactor chamber to a mm-size target, some kind of beam neutral...

  14. 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

  15. 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.

  16. CXRS measurements of ion temperature in NBI discharges on Globus-M spherical tokamak

    Science.gov (United States)

    Avdeeva, G. F.; Miroshnikov, I. V.; Bakharev, N. N.; Kurskiev, G. S.; Patrov, M. I.; Sergeev, V. Yu; Schegolev, P. B.

    2016-01-01

    The thesis describes the Charge-eXchange Recombination Spectroscopy (CXRS) diagnostics setup and its application to the ion temperature determination in the NBI-heated discharges in the Globus-M spherical tokamak. Measurements of the spectral line shape of the radiation emitted by the hydrogen-like carbon ion CVI (5290.5 Å) are presented. Comparison of CXRS and Neutral Particle Analyser (NPA) data demonstrates good agreement.

  17. 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...

  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. 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

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Tribological property enhancement of CrN films by metal vapor vacuum arc implantation of Vanadium and Carbon ions

    International Nuclear Information System (INIS)

    CrN films have been extensively used in precision forming and molding applications because of their excellent tribological properties and oxidation-resisting characteristics. Vanadium and carbon ions are introduced into the near surface layer of deposited CrN films via metal vapor vacuum arc implantation to improve the wear performance of CrN films. Dense and smooth CrN film was deposited using a filtered arc deposition system, which provides fully ionized Cr plasma on the substrate surface. Subsequently, surface bombardment of the deposited CrN film with vanadium and carbon ions densifies the film and forms an alloy near the surface. These CrN-based films were characterized by X-ray photoelectron electron and Auger electron spectroscopies. Examinations of the tribological and mechanical film properties, including wear resistance, corrosion resistance and fracture toughness were performed and correlated with respect to the implantation parameters

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. Design and operation of a stable intense high-temperature arc-discharge source of hydrogen atoms and metastable trihydrogen molecules

    OpenAIRE

    Garvey, James F.; Kuppermann, Aron

    1986-01-01

    We report a design for a stable intense beam source of hyperthermal hydrogen atoms. The basis for the design is an arc heater used first by Knuth for the generation of high‐translational energy He–Ar beams. In the case of hydrogen atom generation this source is very unstable due to the corresponding higher temperatures which are generated by the plasma discharge. We have substantially eliminated these difficulties by the insertion of discharge‐localizing insulators and the use of a tungsten n...

  12. 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.

  13. External Mass Injection to Reduce Energetic Ion Production in the Discharge Plume of High Current Hollow Cathodes

    OpenAIRE

    Chu, Emily

    2012-01-01

    Hollow cathode discharge studies have shown the existence of energetic ions at high discharge currents that are likely responsible for the high erosion rates and erosion patterns observed on the keeper electrode of the hollow cathode. This thesis uses experimental methods to study the effects of neutral gas injection in the xenon hollow cathode discharge plume on the production of energetic ions to determine the injection conditions that yield optimum hollow cathode operation and life. Para...

  14. Electrostatic analyzer for electron and ion energy in glow discharge tube

    International Nuclear Information System (INIS)

    The project, the construction and use of an electrostatic energy analyser (Faraday Cup) are described explaining physically its working mechanism. The analyser was used in a glow discharge tube with air and an air-argon mixture. A chapter with the theory of the glow discharge is included. The ion and electron temperatures, the plasma potential and the distribution function for ions and electrons were measured. The electron temperature and plasma potential were also measured using a Langmuir probe and the results show reasonable agreement with the results of the analyser. Good fits of the experimental electron and ion distribution functions were obtained with Maxwellian distributions centered values near the plasma potential. Finally, we discuss the performance of the analyser compared to Langmuir probes. (author)

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

    International Nuclear Information System (INIS)

    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

  16. On the effect of ion irradiation on the structure and mechanical properties of vacuum-arc TiN coatings

    International Nuclear Information System (INIS)

    The structure and mechanical properties of vacuum-arc TiN coatings irradiated with argon, helium and hydrogen ions are studied. Phase composition and structural state were investigated by X-ray diffraction. Determination of residual macrostresses with a cubic crystal lattice were carried out by X-ray tensiometry. Hardness measurement was performed using a Berkovich pyramid mikroindentor 'Micron-Gamma with a load of around 50 G.

  17. In Vivo Osseointegration Performance of Titanium Dioxide Coating Modified Polyetheretherketone Using Arc Ion Plating for Spinal Implant Application

    OpenAIRE

    Hsi-Kai Tsou; Meng-Hui Chi; Yi-Wen Hung; Chi-Jen Chung; Ju-Liang He

    2015-01-01

    Polyetheretherketone (PEEK), which has biomechanical performance similar to that of human cancellous bone, is used widely as a spinal implant material. However, its bioinertness and hydrophobic surface properties result in poor osseointegration. This study applies a novel modification method, arc ion plating (AIP), that produces a highly osteoblast compatible titanium dioxide (TiO2) coatings on a PEEK substrate. This PEEK with TiO2 coating (TiO2/PEEK) was implanted into the femurs of New Zeal...

  18. 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

  19. Modelling of parametric kinetic ion-acoustic instability in helicon discharge

    International Nuclear Information System (INIS)

    A computer simulation of the development of the parametric kinetic ion-acoustic instability is carried out for the helicon discharge conditions by the ''particle in cell'' method. Linear and nonlinear stages of the ion-acoustic instability and turbulence are investigated for the typical parameters of the helicon plasma. It is shown that the high efficiency of the helicon plasma sources can relate to development of both short and long wavelength kinetic ion-acoustic parametric instabilities and the turbulent heating of electrons and ions caused by the ion-acoustic turbulence can be one of the dominant mechanisms of the pumping wave energy absorption in the helicon plasma

  20. 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

  1. Design and operation of a stable intense high-temperature arc-discharge source of hydrogen atoms and metastable trihydrogen molecules

    International Nuclear Information System (INIS)

    We report a design for a stable intense beam source of hyperthermal hydrogen atoms. The basis for the design is an arc heater used first by Knuth for the generation of high-translational energy He--Ar beams. In the case of hydrogen atom generation this source is very unstable due to the corresponding higher temperatures which are generated by the plasma discharge. We have substantially eliminated these difficulties by the insertion of discharge-localizing insulators and the use of a tungsten nozzle mounted in the center of a 1-kG electromagnet. This source generates exceptionally high hydrogen atom beam intensities of approx.1022 atoms s-1 sr-1 with translational energy distribution functions which extend to 18 eV and whose peak occurs at energies as high as 13 eV. In addition metastable H3 molecules having an intensity between 1020 and 1021 molecules s-1 sr-1 are formed

  2. Investigation of multipactoring discharge in an H-type resonator of an ion linac

    International Nuclear Information System (INIS)

    The study on the variation of parameters of an auto generator power supply of an ion linear accelerator which is under construction on the base of the H-type resonator with drift tube comb mounts has been made. The main attention was paid to investigating multipactor discharges. It is concluded, that presence of secondary autonomous self-oscillation circuit providing the field rise with the frequency close to operation frequency leads to the decrease of multipactor discharge intensity level, which is enough for the elimination of their harmful effect on accelerator steady-state performance. 8 refs., 3 figs

  3. 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

  4. 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...

  5. Theoretical analysis of the discharge performance of lithium ion and lithium/sulfur cells

    Science.gov (United States)

    Kumaresan, Karthikeyan

    In real world applications, the lithium based cells are subjected to highly random operating conditions such as varying charge/discharge rates, end of charge voltage, end of discharge voltage, temperature, etc. Studying the effect of such uncertainties in the operating conditions on the discharge/charge and cycle life performance of lithium based cells through experiments alone will be inefficient in terms of both time and cost. Furthermore, experimental analysis provides only a limited insight into the physical reasons behind the operating conditions - performance relationship. Mathematical models based on the first principles, when used along with experimental data will provide better understanding about how the operating conditions affect various physical phenomena happening inside the cell. Such theoretical analysis of experimental data will reduce the number of further experiments needed and there by decrease the overall cost and time required to design and analyze the cell for a given application. In this dissertation, theoretical analysis aimed at better under understanding of the discharge performance of two different cell chemistries namely, lithium-ion (MCMB/LiCoO2) cell and lithium/sulfur cell is presented. For the lithium ion cell, a set of parameters along with their concentration and temperature dependencies have been estimated by comparing the experimental discharge data with that predicted by a rigorous non-isothermal model. Using the parameters obtained, the model is used to understand the effect of the thermal dependence of various transport parameters on the discharge performance of the lithium-ion cell which, in turn, reveals the reason for decreasing discharge capacity with decreasing operating temperature. For the lithium/sulfur cell, a mathematical model based on the first principles is developed. The model describes various electrochemical and chemical (precipitation) reactions, multi-component transport phenomena in the electrolyte and the

  6. 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)

  7. 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

  8. Thermal Behavior of Small Lithium-Ion Secondary Battery during Rapid Charge and Discharge Cycles

    Science.gov (United States)

    Ohshima, Takamasa; Nakayama, Masato; Fukuda, Kenichi; Araki, Takuto; Onda, Kazuo

    The secondary batteries for the electric vehicle (EV) generate much heat during rapid charge and discharge cycles than the rated condition, when EV starts quickly consuming the battery power and stops suddenly recovering the inertia energy. During rapid charge and discharge cycles, the cell temperature rises significantly and may increase more than the allowable temperature. So we calculated the temperature rise of a small lithium-ion secondary battery during rapid charge and discharge cycles using our battery thermal behavior model, which we have developed being confirmed its validity during discharge cycle at the smaller current than the discharge rate of 1C. The heat source factors were measured by the methods described in our previous study, because the present batteries have been improved in their performance and have low overpotential resistance. The battery heat capacity was measured by a twin-type heat conduction calorimeter, and determined to be a linear function of temperature. Further, the heat transfer coefficient was measured again precisely by the method described in our previous study, and was arranged as a function of cell and ambient temperatures. The calculated temperature by our battery thermal behavior model using these measured data agrees well with the cell temperature measured by thermocouple. Therefore we can confirm the validity of this model again during rapid charge and discharge cycles.

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

    Science.gov (United States)

    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 of the time course effect of the process on bacterial morphology suggests that glidarc induces major alterations of the bacterial membrane. We showed that glidarc causes the release of bacterial genomic DNA. By contrast, an apparent decrease in the level of extractible lipopolysaccharide was observed; however, no changes in the electrophoretic pattern and cytotoxic activity of the macromolecule were noted. Analysis of extractible proteins from the outer membrane of the bacteria revealed that glidarc discharge induces the release of these proteins from the lipid environment, but may also be responsible for protein dimerization and/or aggregation. This effect was not observed in secreted enzymatic proteins, such as pectate lyase. Analysis of the data supports the hypothesis that the plasma generated by glidarc discharge is acting essentially through oxidative mechanisms. Furthermore, these results indicate that, in addition to effectively destroying bacteria, glidarc discharge should be used to improve the extraction of bacterial molecules. PMID:17644644

  10. 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.

  11. Influence of iodine concentration on microstructure and oxidation resistance of SiB6–MoSi2 coating deposited by pulse arc discharge deposition

    International Nuclear Information System (INIS)

    Highlights: • A SiB6–MoSi2 coating was prepared by pulse arc discharge deposition (PADD). • The coating can protect C/C composites from oxidation at 1773 K for 168 h. • Influence of iodine concentration on oxidation resistance was investigated. • The failure of the oxidation resistant coating was investigated. - Abstract: To improve the oxidation resistance of carbon/carbon (C/C) composites, a SiB6–MoSi2 coating was prepared by a novel pulse arc discharge deposition (PADD). The influence of iodine concentration on thickness, compactness and oxidation resistance of the multilayer coatings were investigated. Results show that the oxidation resistance of the multilayer coatings was improved with the increase of iodine concentration from 2.0 to 3.0 g L−1. The SiB6–MoSi2 coating prepared at iodine concentration of 3.0 g L−1 can protect C/C composites from oxidation at 1773 K in air for 168 h with a weight loss of 1.98%. The failure of the multilayer coatings is due to the volatilization of the multilayer coatings and the escape of CO and CO2

  12. 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.

  13. 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.

  14. 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

  15. A study of radial cataphoresis and ion densities in high power density Hg-Ar discharges

    Energy Technology Data Exchange (ETDEWEB)

    Aiura, Y; Lawler, J E [Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, WI 53706 (United States)

    2004-11-21

    A synchrotron radiation absorption experiment was used to measure the absolute density of ground level Hg atoms and Hg{sup +} ions in Hg-Ar discharge plasmas at high power densities. Ion densities from this experiment were tested using microwave interferometry and compared with Langmuir probe measurements of the electron density. Radial cataphoresis was observed in this experiment and compared with model predictions. The agreement was satisfactory between the experiment and model. The role of cataphoresis in the power balance of Hg-Ar plasmas was further explored in the research described in the companion paper (Lister et al. 2004 J. Phys. D: Appl. Phys. 37: 3099-3106)

  16. Sequential Monte Carlo Methods for Discharge Time Prognosis in Lithium-ion Batteries

    OpenAIRE

    Silva, Jorge F.; Marcos E. Orchard; Benjamín Olivares; Matías Cerda

    2012-01-01

    This paper presents the implementation of a particle-filtering-based prognostic framework that allows estimating the state-of-charge (SOC) and predicting the discharge time of energy storage devices (more specifically lithium-ion batteries). The proposed approach uses an empirical state-space model inspired in the battery phenomenology and particle-filtering to study the evolution of the SOC in time; adapting the value of unknown model parameters during the filtering stage and enabling fast c...

  17. Control of power characteristics of ion flow in plasma-etching reactor based on beam-plasma discharge

    International Nuclear Information System (INIS)

    It is shown that on the basis of the earlier revealed effect of generating the ion flow in the beam-plasma discharge from the discharge axis, a plasma processing reactor can be created for low-energy etching of semiconductor structures. The possibility of easily controlling the density and energy of ion flow by means of varying the potential of the discharge collector is demonstrated. The charge compensation of the ion flow incident on the nonconducting surface is implemented using the modulation of the potential of the substrate holder as well as the plasma-potential modulation.

  18. Regularities in the effect of model ion irradiation on the structure and properties of vacuum-arc nitride coatings

    International Nuclear Information System (INIS)

    The effect of irradiation with ions Ar+ (energy of 1 and 1.8 MeV) and He+ (energy of 0.6 MeV) on the structure, microhardness and elastic modulus of the vacuum-arc nitride coatings. It is shown that the level of exposure to radiation vacuum-arc nitride coatings can be divided into 3 classes: 1) the most structure persistent- significant changes occur only on the substructure level (as an example - multi-element system Ti-Zr-V-Hf-Nb-Ta-N); 2) ''the medium resistance- significant changes occur in the macro stress-strained state (as an example - the system Ti-N); 3) structural variable- significant changes in the macro-level and phase composition (as an example - the system Mo-N)

  19. 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)

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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)

  7. Search for alpha-driven TAE modes at lowered ion temperature in TFTR DT discharges

    International Nuclear Information System (INIS)

    An experiment was performed in TFTR DT plasmas to attempt to destabilize the alpha particle driven Toroidicity-induced Alfven Eigenmode (TAE) by transiently cooling the ions, which should have lowered the ion Landau damping of the TAE modes. Transient cooling perturbations were made during the NBI heating phase of high powered DT supershots using He gas puffs or deuterium (D) or lithium (Li) pellet injection. The ion temperature was successfully lowered from Ti(O) ∼ 20 keV to Ti(O) ∼ 10 keV in about 0.2 sec; however, no signs of alpha-driven TAE modes were observed. Theoretical analyses of these discharges suggested that the alpha pressure required for TAE instability was about a factor of 2--3 greater than actually obtained in this experiment, consistent with the absence of alpha-driven TAE modes

  8. Electromagnetic gyrokinetic simulation of turbulent transport in high ion temperature discharge of Large Helical Device

    Science.gov (United States)

    Ishizawa, Akihiro; Watanabe, Tomo-Hiko; Sugama, Hideo; Maeyama, Shinya; Nunami, Masanori; Nakajima, Noriyoshi

    2014-10-01

    Turbulent transport in a high ion temperature discharge of Large Helical Device (LHD) is investigated by means of electromagnetic gyrokinetic simulations including kinetic electrons. A new electromagnetic gyrokinetic simulation code GKV+enables us to examine electron heat and particle fluxes as well as ion heat flux in finite beta heliotron/stellarator plasmas. This problem has not been previously explored because of numerical difficulties associated with complex three-dimensional magnetic structures as well as multiple spatio-temporal scales related to electromagnetic ion and electron dynamics. The turbulent fluxes, which are evaluated through a nonlinear simulation carried out in the K-super computer system, will be reported. This research uses computational resources of K at RIKEN Advanced Institute for Computational Science through the HPCI System Research project (Project ID: hp140044).

  9. Vacuum arc with a distributed cathode spot as a plasma source for plasma separation of spent nuclear fuel and radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Amirov, R. Kh., E-mail: ravus46@yandex.ru; Vorona, N. A.; Gavrikov, A. V.; Lizyakin, G. D.; Polishchuk, V. P.; Samoilov, I. S.; Smirnov, V. P.; Usmanov, R. A.; Yartsev, I. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    Results from experimental studies of a vacuum arc with a distributed cathode spot on the heated cathode are presented. Such an arc can be used as a plasma source for plasma separation of spent nuclear fuel and radioactive waste. The experiments were performed with a gadolinium cathode, the properties of which are similar to those of an uranium arc cathode. The heat flux from the plasma to the cathode (and its volt equivalent) at discharge voltages of 4-15 V and discharge currents of 44-81 A, the radial distribution of the emission intensity of gadolinium atoms and singly charged ions in the arc channel at a voltage of 4.3 V, and the plasma electron temperature behind the anode were measured. The average charge of plasma ions at arc voltages of 3.5-8 V and a discharge current of 52 A and the average rate of gadolinium evaporation in the discharge were also determined.

  10. 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.

  11. 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.)

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

    Science.gov (United States)

    Ben Hamida, Mohamed Bechir; Charrada, Kamel

    2015-10-01

    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.

  13. 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.

  14. Electron energy distributions, vibrational population distributions, and negative-ion concentrations in hydrogen discharges

    International Nuclear Information System (INIS)

    We consider the negative ion concentrations in hydrogen discharges caused by electron excitation and dissociative attachment processes. The principal formation and destruction processes are discussed for electron densities in the range 108 to 1013 electrons cm-3. Expressions are developed for calculating the high energy portion of the electron energy distribution in the discharge; using these energy distributions the electron excitation rates are evaluated. At low densities, the vibrational distribution arises from singlet electronic excitations and triplet excitations through the 3π/sub u/ state, in equilibrium with wall de-excitation processes. At high densities singlet excitations predominate in equilibrium with atom-molecule de-excitation processes. Possibilities for negative ion generation in a two-chamber tandem system are discussed in which the vibrational excitation occurs in a high power, high electron temperature discharge, kT/sub e/ = 5 eV, and dissociative attachment occurs in a low temperature kT/sub e/ = 1 eV, plasma chamber

  15. 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)

  16. 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

  17. 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.

  18. Thermal behavior of small lithium-ion battery during rapid charge and discharge cycles

    Science.gov (United States)

    Onda, Kazuo; Ohshima, Takamasa; Nakayama, Masato; Fukuda, Kenichi; Araki, Takuto

    The secondary batteries for electric vehicles (EV) generate much heat during rapid charge and discharge cycles at current levels exceeding the batteries' rating, such as when the EV quickly starts consuming battery power or when recovering inertia energy during sudden stops. During these rapid charge and discharge cycles, the cell temperature may increase above allowable limits. We calculated the temperature rise of a small lithium-ion secondary battery during rapid charge and discharge cycles. The heat-source factors were measured again by the methods described in our previous study, because the performance of the battery reported here has been improved, showing lower overpotential resistance. Battery heat capacity was measured by a twin-type heat conduction calorimeter, and determined to be a linear function of temperature. Further, the heat transfer coefficient, measured again precisely by the method described in our previous study, was arranged as a function of cell and ambient temperatures. The temperature calculated by our battery thermal behavior model using these measured data agrees well with the cell temperature measured by thermocouple during rapid charge and discharge cycles. Also, battery radial temperature distributions were calculated to be small, and confirmed experimentally.

  19. Proton observations supporting the ion cyclotron wave heating theory of SAR arc formation

    International Nuclear Information System (INIS)

    Low altitude satellite observations of precipitated and locally mirroring protons during periods of ground-based SAR arc observations are presented. The SAR arcs are found to be located in a region with significantly enhanced proton pitch angle scattering and enhanced electron temperature, but inside the plasmapause where the proton pitch angle distribution is anisotropic. The increase in the pitch angle scattering takes place in a localised region having a width of a few tenths of an L-value. The observations can favourably be accounted for by the Cornwall et al. (1971) theory for the SAR arc formation. Using observed proton fluxes and typical energy spectra, the expected Hβ intensity in the SAR arc region is estimated to be a few Rayleighs, and the energy flux from precipitated protons above a few keV to be 10-2 - 10-1 ergs/cm2sec. These estimates are in reasonable agreement with previously published theoretical and experimental values. Simultaneous ground-based observations of Hα emissions were found in the region of intense, isotropic proton precipitation located outside the plasmapause. (Auth.)

  20. A convective transport theory for high rate discharge in lithium ion cells

    International Nuclear Information System (INIS)

    A solution phase transport theory considering solvent effects is developed for lithium ion cells. The solvent convection velocity is derived from a volume conservation argument, leading to a diffusive correction, a transference number gradient correction and a pore-wall flux correction to the material balance equation. The diffusive correction exactly cancels the solvent-related (1−dlnc0/dlnc) factor in the original diffusion term. The transference number gradient and pore-wall flux corrections lead to a larger effective value of the lithium ion transference number. Comparative discharge simulations are carried out for a graphite–LiMn2O4 cell with 1 M or 2 M LiPF6 solution. The convective transport theory demonstrates little cell voltage difference at low rates (1 C and 3 C) compared with the original approach that neglects convection. Nevertheless, at a 6 C rate, a maximum of 51.32 mV excess cell voltage is predicted by the convective theory for the 1 M cell. For the 2 M cell the convective theory predicts a slightly slower voltage drop at the beginning of discharge, but a faster drop at the end of the 6 C discharge. At all rates the convective theory also gives a lower salt concentration profile within the negative electrode, but higher within the positive electrode. This implies that the concentration gradient is diminished by convection. Detailed analysis shows that the transference number gradient correction is always positive during discharge and is highly rate sensitive; the pore-wall flux correction is not only rate sensitive but also proportional to the salt concentration and is thus more prominent in the 2 M cell.

  1. 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

  2. Multi-stress factor model for cycle lifetime prediction of lithium ion batteries with shallow-depth discharge

    Science.gov (United States)

    Cui, Yingzhi; Du, Chunyu; Yin, Geping; Gao, Yunzhi; Zhang, Lingling; Guan, Ting; Yang, Lijie; Wang, Fuping

    2015-04-01

    Accurate prediction of service life is a major challenge for the reliable application of lithium ion batteries in satellite and electric vehicle fields. This paper carries out systematic orthogonal experiments to extract key stress factor of capacity loss for commercial LiCoO2/MCMB (mesocarbon microbeads) lithium ion batteries cycled in shallow-depth discharge. Further, single stress factor and multi-stress factor models consisting of temperature, discharge rate, taper voltage and depth of discharge for cycle life prediction of lithium ion batteries are developed. The physicochemical significance of the life prediction model is interpreted by electrochemical analysis. The practical applicability of the models is validated by experimental data. Our multi-stress factor model is helpful to predicting the lifetime of LIBs with shallow-depth discharge, and to optimizing the operation regime of LIBs for electric vehicle or satellite use.

  3. Magnetocaloric properties of TbN, DyN and HoN nanopowders prepared by the plasma arc discharge method.

    Science.gov (United States)

    Shinde, K P; Jang, S H; Kim, J W; Kim, D S; Ranot, M; Chung, K C

    2015-12-21

    We report for the first time the synthesis of nanopowders of TbN, DyN and HoN crystallized in a cubic structure by the plasma arc discharge (PAD) method and investigate their magnetocaloric properties for magnetic refrigeration applications. The nitridization of terbium, dysprosium and holmium was obtained using a mixture of nitrogen and argon gas inside a discharge chamber with 4 kPa pressure. The structural and microstructural properties of these rare earth nitrides were investigated by using X-ray diffraction and transmission electron microscopy. The studied nitrides undergo a second-order ferromagnetic to paramagnetic phase transition at Curie temperatures of 35.7, 19.9 and 14.2 K for TbN, DyN and HoN, respectively. The magnetocaloric effects were estimated by calculating the magnetic entropy changes from the magnetization data sets measured at the different applied magnetic fields and temperatures. The changes in entropy -ΔSM were found to be 12.0, 13.6 and 24.5 J kg(-1) K(-1) at an applied magnetic field of 5 T. PMID:26492221

  4. 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.

  5. Collector floating potentials in a discharge plasma with two species of positive ions

    International Nuclear Information System (INIS)

    In this contribution we present the study on potential formation near a floating collector in discharge plasma with two ion populations and with a bi-Maxwellian electron distribution. It is performed analytically and complemented by computer simulations. In the analytical study we use a fully kinetic plasma sheath model, originally developed by Schwager and Birdsall (L.A. Schwager, C.K. Birdsall, Phys. Fluids B, 2 (1990) 1057] and later extended in order to include additional particles species like hot electrons [M. Cercek, T. Gyergyek, J. Phys. D: Appl. Phys. 34, (2001) 330] and/or negative ions. The collisionless one-dimensional pre-sheath/sheath plasma region is bounded by a planar plasma source on one side and by a floating collector on the other side. Two positive ion populations are injected from the Maxwellian plasma source into the system with an accelerated half-Maxwellian distribution, and the electron population is modeled with a truncated bi-Maxwellian distribution. The collector floating potential and the pre-sheath potential are calculated as functions of positive ion density fraction. For the simulations we use XPDP1 particle-in-cell simulation code for a bounded plasma system developed at Berkeley University. The potential and particle density profiles are examined and resulting particle velocity distribution functions along the system are calculated and displayed. Good agreement with analytical results is obtained. (author)

  6. 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

  7. Ion kinetics and self pulsing in DC microplasma discharges at atmospheric and higher pressure

    Science.gov (United States)

    Mahamud, Rajib; Farouk, Tanvir I.

    2016-04-01

    Atmospheric pressure microplasma devices have been the subject of considerable interest and research during the last decade. Most of the operation regime of the plasma discharges studied fall in the ‘abnormal’, ‘normal’ and ‘corona’ modes—increasing and a ‘flat’ voltage current characteristics. However, the negative differential resistance regime at atmospheric and high pressures has been less studied and possesses unique characteristics that can be employed for novel applications. In this work, the role of ion kinetics especially associated with trace impurities; on the self pulsing behavior has been investigated. Detailed numerical simulations have been conducted with a validated model for a helium-nitrogen feed gas mixture. Different oscillatory modes were observed where the discharge was found to undergo complete or partial relaxation. Trace amount of nitrogen was found to significantly alter the pulsing characteristics. External parameters influencing these self oscillations are also studied and aspects of the ion kinetics on the oscillatory behavior are discussed.

  8. 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

  9. 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.

  10. 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

  11. Deposition and current conduction of mixed hexagonal and cubic phases of AlN/p-Si films prepared by vacuum arc discharge: Effect of deposition temperature

    International Nuclear Information System (INIS)

    Cubic and hexagonal AlN films have been prepared by vacuum arc discharge technique at different deposition temperatures 100, 200 and 300 °C. The depositions were carried out from pure aluminum targets under nitrogen gas on p-type Si substrates, with Al forming the gate in a metal–insulator–semiconductor configuration. Preferential orientations (111) and (002) of the cubic and hexagonal phases have been affirmed by X-ray diffraction analysis. The Fourier transform infrared spectra revealed the manifestation of the two phases as well. The effect of deposition temperature on the crystalline quality and texture of the films has been also investigated and the grain size of which, has been evaluated as a function of temperature. The best crystalline quality i.e., largest grain size was found to be at 200 °C. The composition and stoichiometry of the films have been determined by the time-of-flight elastic recoil detection analysis (TOF-ERDA) and Rutherford backscattering techniques. The Al/N ratio was found to be around 1, while the O content was less than 1.8%. Scanning electron microscopy and TOF-ERDA measurements demonstrated films thickness of 260 nm. Current density versus electric field and capacitance–voltage (C–V) measurements were also investigated to reveal the field emission and conduction mechanism of the Al/AlN/p-Si devices. Schottky, Pool–Frenkel and Fowler–Nordheim conduction have been found to contribute to the electron transport, and the best emission properties were manifested at 200 °C with a highest current density 525 μA/cm2 at a field 71 V/μm. From C–V curves, the density of traps has been estimated to be 18 × 109 cm−2 eV−1 indicating a good quality of the deposited films. - Highlights: • AlN films containing its cubic phase were deposited by vacuum arc discharge. • MIS capacitors of these films of (111) preferential orientation were fabricated. • The best crystalline quality was found to be at 200 °C deposition

  12. 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

  13. 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.

  14. Microstructural control of Cr-Si-N films by a hybrid arc ion plating and magnetron sputtering process

    International Nuclear Information System (INIS)

    The microstructural evolution of Cr-Si-N films deposited by a hybrid arc ion plating and magnetron sputtering process was investigated by varying the sputtering power of Si target and substrate bias voltage. Detailed nanocomposite microstructures of the films were studied by high-resolution transmission electron microscopy. The results indicated that the incorporation of Si into the growing CrN films at 0 V led to the formation of a nanocomposite containing CrN nanocolumns embedded in amorphous SiNx matrix or near-amorphous microstructure. For the films having a Si content of ∼10 at.% and ∼15 at.%, a negative bias voltage of -50 V resulted in the aggregation of nanocolumns in the amorphous matrix. Further increase of negative bias voltage to -250 V led to the formation of a three-dimensional CrN/a-SiNx nanocomposite microstructure. The mechanism of microstructure evolution is discussed by considering the thermodynamic and kinetic factors.

  15. An ion thruster internal discharge chamber electrostatic probe diagnostic technique using a high-speed probe positioning system.

    Science.gov (United States)

    Herman, Daniel A; Gallimore, Alec D

    2008-01-01

    Extensive resources have been allocated to diagnose and minimize lifetime-limiting factors in gridded ion thrusters. While most of this effort has focused on grid erosion, results from wear tests indicate that discharge cathode erosion may also play an important role in limiting the lifetime of ring-cusp ion thrusters proposed for future large flagship missions. The detailed characterization of the near-cathode discharge plasma is essential for mitigating discharge cathode erosion. However, severe difficulty is encountered when attempting to measure internal discharge plasma parameters during thruster operation with conventional probing techniques. These difficulties stem from the high-voltage, high-density discharge cathode plume, which is a hostile environment for probes. A method for interrogating the discharge chamber plasma of a working ion thruster over a two-dimensional grid is demonstrated. The high-speed axial reciprocating probe positioning system is used to minimize thruster perturbation during probe insertion and to reduce heating of the probe. Electrostatic probe measurements from a symmetric double Langmuir probe are presented over a two-dimensional spatial array in the near-discharge cathode assembly region of a 30-cm-diameter ring-cusp ion thruster. Electron temperatures, 2-5 eV, and number density contours, with a maximum of 8 x 10(12) cm(-3) on centerline, are measured. These data provide detailed electron temperature and number density contours which, when combined with plasma potential measurements, may shed light on discharge cathode erosion processes and the effect of thruster operating conditions on erosion rates. PMID:18248026

  16. An ion thruster internal discharge chamber electrostatic probe diagnostic technique using a high-speed probe positioning system

    International Nuclear Information System (INIS)

    Extensive resources have been allocated to diagnose and minimize lifetime-limiting factors in gridded ion thrusters. While most of this effort has focused on grid erosion, results from wear tests indicate that discharge cathode erosion may also play an important role in limiting the lifetime of ring-cusp ion thrusters proposed for future large flagship missions. The detailed characterization of the near-cathode discharge plasma is essential for mitigating discharge cathode erosion. However, severe difficulty is encountered when attempting to measure internal discharge plasma parameters during thruster operation with conventional probing techniques. These difficulties stem from the high-voltage, high-density discharge cathode plume, which is a hostile environment for probes. A method for interrogating the discharge chamber plasma of a working ion thruster over a two-dimensional grid is demonstrated. The high-speed axial reciprocating probe positioning system is used to minimize thruster perturbation during probe insertion and to reduce heating of the probe. Electrostatic probe measurements from a symmetric double Langmuir probe are presented over a two-dimensional spatial array in the near-discharge cathode assembly region of a 30-cm-diameter ring-cusp ion thruster. Electron temperatures, 2-5 eV, and number density contours, with a maximum of 8x1012 cm-3 on centerline, are measured. These data provide detailed electron temperature and number density contours which, when combined with plasma potential measurements, may shed light on discharge cathode erosion processes and the effect of thruster operating conditions on erosion rates

  17. Element- and charge-state-resolved ion energies in the cathodic arc plasma from composite AlCr cathodes in argon, nitrogen and oxygen atmospheres

    OpenAIRE

    Franz, Robert; Polcik, Peter; 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 consist...

  18. Determination of ion temperature distributions from Doppler broadenings of impurity lines in the vacuum UV region for tokamak discharges

    International Nuclear Information System (INIS)

    Doppler broadenings of impurity (O, N and C) lines in hydrogen discharges were observed with the JFT-2 and DIVA tokamak devices for the purpose of determining the spatial distribution of the ion temperature. A 1-meter Czerny-Turner type vacuum monochromator was used in higher orders for sufficient resolution. Impurity emissions are localized in shell-like regions in the minor cross-section. The radial distribution of the ion temperature was determined from the Doppler broadening of various impurity lines and from the localization of line intensities. The Doppler temperatures of the 0+6 ion were found to be 256 eV for a 100 kA, 14 kG discharge with JFT-2 and 220 eV for a 28 KA, 20 kG discharge with DIVA. (author)

  19. 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.

  20. Caesium and tungsten behaviour in the filamented arc driven Kamaboko-III negative ion source

    International Nuclear Information System (INIS)

    The ITER neutral beam injection is based on the acceleration and neutralization of negative deuterium ions. The target performance for the ITER beam source is to accelerate to 1 MeV a 40 A D- beam, with a current density of 200 A m-2, with pulse lengths of ≥1000 s. It was found that in long pulse operation the negative ion yield from the filamented Kamaboko III ion source (a model of ITER ion source) degrades in comparison with short pulse operation, <5 s. This could be linked to the behaviour of caesium (Cs), which is added to the source to increase its negative ion yield and tungsten (W) evaporated from filaments. Cs and W are co-adsorbed on the source walls and the plasma grid and the composition of this coating can vary during long pulse operation. The possible consequences of this changing surface on the negative ion production will be discussed. Tungsten filaments have a limited lifetime in the ion source and changing filaments and refilling of the Cs oven are the only scheduled maintenance events for the ITER injectors. These are complicated operations as the ITER injectors will be highly activated and all maintenance has to be carried out remotely. Therefore, increasing the filament lifetime and decreasing the Cs consumption are highly desirable. This paper presents results of relative measurements (including spectroscopic and chemical) of the W content of the Kamaboko-III source and reports relevant calculations on Cs consumption and W evaporation

  1. 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.

  2. 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.

  3. 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%).

  4. The effect of nitrogen pressure during vacuum-arc tin coatings deposition on the erosion resistance in plasma of magnetron type discharges

    International Nuclear Information System (INIS)

    The erosion process was investigated of TiN coatings which were made with the vacuum-arc sputtering of Ti at the different nitrogen pressures (10-4...5X10-3 Torr). The erosion rates were measured by the weighting on analytical balance before and after treatment by plasmas of magnetron type, axial symmetrical discharges in nitrogen atmosphere, at the temperatures of 500...1100 C. It was shown that an erosion rate of TiN coatings deposited at low pressures (approx 1X10-4 Torr) is essentially (up to 1.5 times) lower than that for coatings produced at the more high pressures (5X10-3 Torr). For samples produced in the regime with high voltage pulses supply on substrate the erosion is lower than for coatings deposited in the regime without pulses supply. Taking into account the results of X-ray diffraction measurements, the physical mechanisms are suggested to explain such character of erosion behavior.

  5. 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

  6. 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

  7. Macroparticles in Ti-Si-N-coatings deposited from vacuum-arc plasma with ion implantation

    International Nuclear Information System (INIS)

    The results of experiments on research of macroparticles hitting TiSiN-coatings during vacuum-arc deposition from direct plasma stream with PBII and D method are presented. Sintered titanium-silicon powder composite was applied as a cathode material. The effect associated with the depression of macroparticles capture by growing TiSiN-coating as a result of increase of negative bias pulse on substrate simultaneous with periodic high-voltage negative potential pulses was found out. The depression of macroparticles capture at the increase of bias pulse with PBII and D technique takes a place under two factors. The main factor is electrostatic reflection of a large share of the negatively charged macroparticles stream. The second factor is the dispersion of macroparticles, surmounting electrostatic repulsion and 'stuck' to the coating surface.

  8. Secondary ion mass spectrometry measurements of deuterium penetration into silicon by low pressure rf glow discharges

    International Nuclear Information System (INIS)

    Using secondary ion mass spectrometry (SIMS) the penetration of deuterium into Si(100) substrates as a result of exposure to deuterium low pressure rf discharges has been determined as a function of exposure time, thermal contact of the Si wafers to the substrate electrode, substrate doping, and discharge pressure. For undoped (100) single crystal Si exposed without intentional heating to a 25 m torr D2 plasma for 1 min, the deuterium concentration in the near-surface region (0-30 nm) approaches 1021 at.cm-3. It drops off with depth, but is still greater than 1017 at.cm-3 at a silicon depth of 200 nm. The large penetration depth, the observation that lowering the substrate temperature decreases the rate of deuterium uptake, and the dependence of deuterium penetration on the substrate doping type indicate that hydrogen diffusion is of primary importance. The presence of a 50 nm thick oxide layer on the Si substrate during plasma exposure lowers the deuterium near-surface concentration in the Si substrate by about three orders of magnitude, while the presence of 10 nm of thermal oxide reduces the deuterium uptake only insignificantly. Heavily B and As doped polycrystalline Si show less deuterium penetration, while undoped polycrystalline Si shows more deuterium uptake than undoped single crystal Si for the same plasma treatment. (author)

  9. 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

  10. 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

  11. Lithium-fluoride flashover ion source cleaned with a glow discharge and irradiated with vacuum-ultraviolet radiation

    International Nuclear Information System (INIS)

    We have studied methods of varying the ion species generated by a lithium-fluoride overcoated anode in a 0.5-MV magnetically insulated ion diode. We found that cleaning the anode surface with a 13.6-MHz rf glow discharge or illuminating the anode with a pulsed soft x-ray, vacuum-ultraviolet (XUV) radiation source just before the accelerator pulse significantly altered the ion species of the ion beam produced by the diode. The glow-discharge plasma removed adsorbates (carbon, hydrogen, and oxygen) from the surface of the LiF flashover source. The ions seen were lithium and hydrogen. Unfortunately, the diode impedance with a lithium-fluoride anode was high and the ion efficiency was low; however, XUV irradiation of the surface dramatically lowered the impedance by desorbing neutrals from the ion source via photon-stimulated desorption. Current densities of ten times the Child--Langmuir space-charge limit were achieved under XUV irradiation. In particular, ion currents increased by over a factor of 3 when 12 mJ/cm2 of XUV radiation was used. However, with XUV irradiation the largest fraction of ions were fluorine, oxygen, carbon, and hydrogen, not lithium

  12. 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 ...

  13. 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

  14. 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.

  15. 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)

  16. 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.

  17. Electron heating and control of ion properties in capacitive discharges driven by customized voltage waveforms

    International Nuclear Information System (INIS)

    We investigate the electron heating dynamics in capacitively coupled radio frequency plasmas driven by customized voltage waveforms and study the effects of modifying this waveform and the secondary electron emission coefficient of the electrodes on the spatio-temporal ionization dynamics by particle-in-cell simulations. We demonstrate that changes in the electron heating dynamics induced by voltage waveform tailoring strongly affect the dc self-bias, the ion flux, Γi, and the mean ion energy, 〈Ei〉, at the electrodes. The driving voltage waveform is customized by adding N consecutive harmonics (N ⩽ 4) of 13.56 MHz with specific harmonics' amplitudes and phases. The total voltage amplitude is kept constant, while modifying the number of harmonics and their phases. In an argon plasma, we find a dc self-bias, η, to be generated via the electrical asymmetry effect for N ⩾ 2. η can be controlled by adjusting the harmonics' phases and is enhanced by adding more consecutive harmonics. At a low pressure of 3 Pa, the discharge is operated in the α-mode and 〈Ei〉 can be controlled by adjusting the phases at constant Γi. The ion flux can be increased by adding more harmonics due to the enhanced electron-sheath heating. 〈Ei〉 does not remain constant as a function of N at both electrodes due to a change in η. These findings verify previous results of Lafleur et al. At a high pressure of 100 Pa and using a high secondary electron emission coefficient of γ = 0.4, the discharge is operated in the γ-mode and mode transitions are induced by changing the driving voltage waveform. Due to these mode transitions and the specific ionization dynamics in the γ-mode, Γi is no longer constant as a function of the harmonics' phases and decreases with increasing N. (paper)

  18. Corrosion-related characteristics of plasma ion implanted samples exposed in a steady-state penning discharge

    International Nuclear Information System (INIS)

    It has been well established that the implantation of nitrogen ions having energies above 20 keV can have a beneficial effect on the hardness and wear resistance of metals of engineering interest. This paper is a report on the corrosion related characteristics of 304L stainless steel samples which have ben implanted with nitrogen ions having energies above 20 keV, using plasma ion implantation techniques in a steady-state Penning discharge. Plasma ion implantation offers may potential advantages over the wide-used ion beam implantation, including short exposure times (on the order of minutes), isotropic incidence of the ions, and the ability to uniformly implant complex surfaces such as screw threads, gear teeth, and turbine blades

  19. Experimental study on the impedance of linear discharge R.F. ion sources - modifications on the 'MOAK' type source

    International Nuclear Information System (INIS)

    A method of measuring the ion R.F. source impedance is described, and the influence of the working parameters on that impedance is studied. The origin of some working anomalies is deduced with a new coupling method. The gas flow is decreased by modifying the geometry of the discharge vessel. (author)

  20. 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)

  1. 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.

  2. 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,

  3. 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...... negative ion to electron exceeded 300 in dc mode while it was below 100 in the ICP mode. The possibility to apply a large positive bias to an electrode without affecting the plasma potential and the transition from a negative sheath to anodic glow are also investigated. The etching rates by positive and...... negative ions are evaluated on silicon substrate for different Ar/SF6 gas ratios. The etching rate by negative ions was with less than 5% smaller than that by positive ions....

  4. Lithium position and occupancy fluctuations in a cathode during charge/discharge cycling of lithium-ion battery

    International Nuclear Information System (INIS)

    Lithium-ion batteries are undergoing rapid development to meet the energy demands of the transportation and renewable energy-generation sectors. The capacity of a lithium-ion battery is dependent on the amount of lithium that can be reversibly incorporated into the cathode. Neutron diffraction provides greater sensitivity towards lithium relative to other diffraction techniques. In conjunction with the penetration depth afforded by neutron diffraction, the information concerning lithium gained in a neutron diffraction study allows commercial lithium-ion batteries to be explored with respect to the lithium content in the whole cathode. Furthermore, neutron diffraction instruments featuring area detectors that allow relatively fast acquisitions enable perturbations of lithium location and occupancy in the cathode during charge/discharge cycling to be determined in real time. Here, we present the time, current, and temperature dependent lithium transfer occurring within a cathode functioning under conventional charge-discharge cycling. The lithium location and content, oxygen positional parameter, and lattice parameter of the Li1+yMn204 cathode are measured and linked to the battery's charge/discharge characteristics (performance). We determine that the lithium-transfer mechanism involves two crystallographic sites, and that the mechanism differs between discharge and charge, explaining the relative ease of discharging (compared with charging) this material. Furthermore, we find that the rate of change of the lattice is faster on charging than discharging, and is dependent on the lithium insertion/ extraction processes (e.g. dependent on how the site occupancies evolve). Using in situ neutron diffraction data the atomic-scale understanding of cathode functionality is revealed, representing detailed information that can be used to direct improvements in battery performance at both the practical and fundamental level.

  5. Oxygen-Plasma-Treated Indium-Tin-Oxide Films on Nonalkali Glass Deposited by Super Density Arc Plasma Ion Plating

    Science.gov (United States)

    Kim, Soo Young; Hong, Kihyon; Son, Jun Ho; Jung, Gwan Ho; Lee, Jong-Lam; Choi, Kyu Han; Song, Kyu Ho; Ahn, Kyung Chul

    2008-02-01

    The effects of O2 plasma treatment on both the chemical composition and work function of an indium-tin-oxide (ITO) film were investigated. ITO films were deposited on non-alkali glass substrate by super density arc plasma ion plating for application in active-matrix organic light-emitting diodes (OLEDs). The water contact angle decreased from 38 to 11° as the ITO films were treated with O2 plasma for 60 s at a plasma power of 150 W, indicating an increase in the hydrophilicity of the surface. It was found that there were no distinct changes in the microstructure or electrical properties of the ITO films with O2 plasma treatment. Synchrotron radiation photoemission spectroscopy data revealed that O2 plasma treatment decreased the amount of carbon contamination and increased the number of unscreened states of In3+ and (O2)2- peroxo species. This played the role of increasing the work function of the ITO films by 1.7 eV. As a result, the turn-on voltage of the OLED decreased markedly from 24 to 8 V and the maximum luminance value of the OLED increased to 2500 cd/m2.

  6. High-temperature oxidation resistant (Cr, Al)N films synthesized using pulsed bias arc ion plating

    Science.gov (United States)

    Zhang, Min; Lin, Guoqiang; Lu, Guoying; Dong, Chuang; Kim, Kwang Ho

    2008-09-01

    (Cr, Al)N films were deposited by pulsed bias arc ion plating on HSS and 316L stainless steel substrates. With pulsed substrate bias ranging from -100 V to -500 V, the effect of pulsed bias on film composition, phase structure, deposition rate and mechanical properties was investigated by EDX, XRD, SEM, nanoindentation and scratch measurements. The high-temperature (up to 900 °C) oxidation resistance of the films was also evaluated. The results show that Al contents and deposition rates decrease with increasing pulsed bias and the ratio of (Cr + Al)/N is almost constant at 0.95. The as-deposited (Cr, Al)N films crystallize in the pseudo-binary (Cr, Al)N and Al phases. The film hardness increases with increasing bias and reaches the maximum 21.5 GPa at -500 V. The films deposited at -500 V exhibit a high adhesion force, about 70 N, and more interestingly good oxidation resistance when annealed in air at 900 °C for 10 h.

  7. 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...

  8. Liquid-metal-ion source development for space propulsion at ARC

    International Nuclear Information System (INIS)

    The Austrian Research Centers have a long history of developing indium Liquid-Metal-Ion Source (LMIS) for space applications including spacecraft charging compensators, SIMS and propulsion. Specifically the application as a thruster requires long-term operation as well as high-current operation which is very challenging. Recently, we demonstrated the operation of a cluster of single LMIS at an average current of 100 μA each for more than 4800 h and developed models for tip erosion and droplet deposition suggesting that such a LMIS can operate up to 20,000 h or more. In order to drastically increase the current, a porous multi-tip source that allows operation up to several mA was developed. Our paper will highlight the problem areas and challenges from our LMIS development focusing on space propulsion applications.

  9. 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

  10. 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

  11. 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...

  12. The source of X-rays and high-charged ions based on moderate power vacuum discharge with laser triggering

    Directory of Open Access Journals (Sweden)

    Alkhimova Mariya A.

    2015-06-01

    Full Text Available The source of X-ray radiation with the energy of quanta that may vary in the range hν = 1÷12 keV was developed for studies in X-ray interaction with matter and modification of solid surfaces. It was based on a vacuum spark discharge with the laser triggering. It was shown in our experiments that there is a possibility to adjust X-ray radiation spectrum by changing the configuration of the electrode system when the energy stored in the capacitor is varied within the range of 1÷17 J. A comprehensive study of X-ray imaging and quanta energy was carried out. These experiments were carried out for the case of both direct and reverse polarity of the voltage on the electrodes. Additionally, ion composition of plasma created in a laser-triggered vacuum discharge was analyzed. Highly charged ions Zn(+21, Cu(+20 and Fe(+18 were observed.

  13. 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...

  14. 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...

  15. The model of collective acceleration of ions in vacuum discharge based on the deep potential well concept

    International Nuclear Information System (INIS)

    The model of ions collective acceleration at the spark stage of a vacuum discharge is proposed on the basis of connection mechanism of a cathode spot functioning and deep nonstationary well concept. The principal possibility of the deep potential well formation by availability of an external electrical field is shown and the conditions of its formation in an explosion-emission diode are clarified. The mode proposed explains the basic processes, leading to the ions collective acceleration and it is in good agreement with the experimental results

  16. 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.

  17. One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Yongpeng; Shi, Zongqian; Jia, Shenli; Wang, Lijun [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2015-02-15

    The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay in the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma.

  18. One-dimensional particle-in-cell simulation on the influence of electron and ion temperature on the sheath expansion process in the post-arc stage of vacuum circuit breaker

    International Nuclear Information System (INIS)

    The inter-contact region of vacuum circuit breakers is filled with residual plasma at the moment when the current is zero after the burning of metal vapor arc. The residual plasma forms an ion sheath in front of the post-arc cathode. The sheath then expands towards the post-arc anode under the influence of a transient recovery voltage. In this study, a one-dimensional particle-in-cell model is developed to investigate the post-arc sheath expansion. The influence of ion and electron temperatures on the decrease in local plasma density at the post-arc cathode side and post-arc anode side is discussed. When the decay in the local plasma density develops from the cathode and anode sides into the high-density region and merges, the overall plasma density in the inter-contact region begins to decrease. Meanwhile, the ion sheath begins to expand faster. Furthermore, the theory of ion rarefaction wave only explains quantitatively the decrease in the overall plasma density at relatively low ion temperatures. With the increase of ion temperature to certain extent, another possible reason for the decrease in the overall plasma density is proposed and results from the more active thermal diffusion of plasma

  19. 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.

  20. Turbulent and Nonlinear Ion-Sound Resonance Induced by Ionization Instability in a Low-Pressure Discharge Plasmas

    International Nuclear Information System (INIS)

    In DC discharges with hot filament cathodes and in the presence of control grids, used as low-pressure plasma sources, at low current discharges regime and in a critical range of current depending by the base inert gas used, turbulent and nonlinear LF oscillations, associated with a frequency jumping phenomenon, can be observed. These oscillations are interpreted as nonlinear ion acoustic waves (IAW) induced by ionization instability when the potential grid-anode reaches a value near the first ionization potential and the ion current drifting velocity is of the order of the ion-sound velocity. This process observed for inert gas plasmas (Ar, Kr, Xe), when the electron temperature is very low with respect to the first ionization potential (1/Te = 7-8), is associated with the presence of a DL in the grid-anode interval and to a fast growth of the direct ionization with respect to the stepwise. A linearized theoretical model, suitable for low-pressure gas discharges, seems, in a first approximation, able to explain this phenomenon. (author)

  1. 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.

  2. Continuous Supersonic Expansion Discharge Source for High-Precision Mid-Infrared Spectroscopy of Cold Molecular Ions

    Science.gov (United States)

    Talicska, Courtney; Porambo, Michael; McCall, Benjamin J.

    2015-06-01

    The low temperatures and pressures of the interstellar medium provide an ideal environment for gas phase ion-neutral reactions that play an essential role in the chemistry of the universe. High-precision laboratory spectra of molecular ions are necessary to facilitate new astronomical discoveries and provide a deeper understanding of interstellar chemistry, but forming ions in measurable quantities in the laboratory has proved challenging. Even when cryogenically cooled, the high temperatures and pressures of typical discharge cells lead to diluted and congested spectra from which extracting chemical information is difficult. Here we overcome this challenge by coupling an electric discharge to a continuous supersonic expansion source to form ions cooled to low temperatures. The ion production abilities of the source have been demonstrated previously as ion densities on the order of 1010-1012 cm-3 have been observed for H3+.a With a smaller rotational constant and the expectation that it will be formed with comparable densities, HN2+ is used as a reliable measure of the cooling abilities of the source. Ions are probed through the use of a widely tunable mid-infrared (3-5 μm) spectrometer based on light formed by difference frequency generation and noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS).b To improve the sensitivity of the instrument the discharge is electrically modulated and the signal is fed into a lock-in amplifier before being recorded by a custom data acquisition program. Rovibrational transitions of H3+ and HN2+ have been recorded, giving rotational temperatures of 80-120 K and 35-40 K, respectively. With verification that the source is producing rotationally cold ions, we move toward the study of primary ions of more astronomical significance, including H2CO+. aK. N. Crabtree, C. A. Kaufman, and B. J. McCall, Rev. Sci. Instrum. 81, 086103 (2010). bM. W. Porambo, B. M. Siller, J. M. Pearson, and B. J. McCall, Opt

  3. 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.

  4. 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.

  5. 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.

  6. Stroke - discharge

    Science.gov (United States)

    ... stroke - discharge; Brain bleeding - discharge; Brain hemorrhage - discharge; Stroke - hemorrhagic - discharge; Hemorrhagic cerebrovascular disease - discharge; Cerebrovascular accident - discharge

  7. Vacuum arc anode phenomena

    International Nuclear Information System (INIS)

    A brief review of anode phenomena in vacuum arcs is presented. Discussed in succession are: the transition of the arc into the anode spot mode; the temperature of the anode before, during and after the anode spot forms; and anode ions. Characteristically the anode spot has a temperature of the order of the atmospheric boiling point of the anode material and is a copious source of vapor and energetic ions. The dominant mechanism controlling the transition of the vacuum arc into the anode spot mode appears to depend upon the electrode geometry, the electrode material, and the current waveform of the particular vacuum arc being considered. Either magnetic constriction in the gap plasma or gross anode melting can trigger the transition; indeed, a combination of the two is a common cause of anode spot formation

  8. 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

  9. 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. PMID:26079671

  10. 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.

  11. 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.

  12. 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

  13. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank;

    2014-01-01

    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...

  14. 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.

  15. 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

  16. Hg+ ion density in low-pressure Ar-Hg discharge plasma used for liquid crystal display back-lighting

    International Nuclear Information System (INIS)

    The positive column of a low-pressure Ar-Hg discharge has been applied as a fluorescent light source for illumination. Many studies on the diagnostics and fundamental mechanisms have been carried out on both the classical fluorescent lamp (d=36 mm) and the compact fluorescent lamp (d=12 mm). On the other hand, a lamp of extremely narrow diameter (usually below 6 mm) has been recently developed for liquid crystal display (LCD) back-lighting and its importance is undoubtedly increasing. Some characteristics or mechanisms of the narrow-diameter lamp may be similar to those of the 36 mm one; however the similarity rule does not hold between them due to the contributions from a stepwise ionization process. Therefore, in order to clarify the excitation mechanism in the narrow-diameter lamp quantitatively, various parameters must be measured directly and some analysis must be done. The Hg+ ion density and electron density are important parameters for the purpose of clarifying the excitation mechanism quantitatively. In this work, we have measured the Hg+ ion density using the modified absorption method, and the electron density using the probe method in the Ar-Hg discharge of the 4 mm bore tube on bath temperature. Moreover, with combining the modified absorption method and the probe method, the Hg2+ molecular ion density has been determined

  17. Investigation of ion and electron heat transport of high-T e ECH heated discharges in the large helical device

    Science.gov (United States)

    Pablant, N. A.; Satake, S.; Yokoyama, M.; Gates, D. A.; Bitter, M.; Bertelli, N.; Delgado-Aparicio, L.; Dinklage, A.; Goto, M.; Hill, K. W.; Igamai, S.; Kubo, S.; Lazerson, S.; Matsuoka, S.; Mikkelsen, D. R.; Morita, S.; Oishi, T.; Seki, R.; Shimozuma, T.; Suzuki, C.; Suzuki, Y.; Takahashi, H.; Yamada, H.; Yoshimura, Y.; the LHD Experiment Group

    2016-04-01

    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× {{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.

  18. 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

  19. Observation of closed current loops in high power arcs

    International Nuclear Information System (INIS)

    Ball lightning, in the form of free-floating, luminous spheres, has been frequently observed in nature. It appears to be an extremely hot, energetic ball of ionized gas that is self-contained by magnetic or other forces. As such it is of intense interest to plasma physicists and controlled thermonuclear fusion engineers. Other self confined plasmas have been routinely created. However the routine production of ball lightning has been impossible. In this abstract, they report on spark discharges that have many of the characteristics of ball lightning--closed current loops and existence at high pressure. This observation of these closed current loops occurs only in multi-megavolt electrostatic generators, and the discovery of these discharges is serendipitous. Photographed by two permanently placed cameras at the Holifield Heavy Ion Research Facility, the authors have over 100 photographs of these arcs, but these discharges only occur at the higher operating voltages and pressures. At lower operating voltages normal arcs are seen to occur. This suggests a definite power requirement to produce the arcs. These closed current loop discharges have been observed in several other accelerators

  20. 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...

  1. 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.

  2. 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.

  3. Linear and non-linear ion acoustic phenomena in magnetic multi-dipole discharges

    International Nuclear Information System (INIS)

    An experimental study of ion acoustic phenomena in a multi-magnetic-dipole plasma device is presented. The plasma is uniform and free from external field, permitting good observation of space and laboratory plasma phenomena. The major interest was in the observtion of the propagation characterics of solitions and ion acoustic waves in a double plasma configuration. In this experiment plane waves were studied in a plasma composed by a mixture of negative and positive ions. The most important result was the first observation of solitary waves with negative potential, that means rarefaction ion acoustic solitions. The formation of non neutral regions inside the plasma and its relations with the inhibition of electron thermal flux were studied. A bootstrap action enhances the ion acoustic instability which generates an anomalous resistivity self consistently with a potential step. It was observed that this is the mechanism of cold electron thermalization during diffusion through a warn collisionless plasma. The importance of the bootstrap action in ion acoustic double layer formation was experimentally verified by ion acoustic instability inhibition, obtained via induced Landau damping of the ion acoustic spectrum of the instability. (author)

  4. The optimization of molybdenum back contact films for Cu(In,Ga)Se2 solar cells by the cathodic arc ion plating method

    International Nuclear Information System (INIS)

    Molybdenum back contact films for Cu(In,Ga)Se2 (CIGS) solar cells have been deposited using DC magnetron sputtering methods. The electronic pathway properties of the molybdenum film have been highly dependent on the working gas pressure in magnetron sputtering, which should be carefully controlled to obtain high conductivity and adhesion. A coating method, cathodic arc ion plating, was used for molybdenum back contact electrode fabrication. The aim of this work was to find a metallization method for CIGS solar cells, which has less sensitivity on the working pressure. The resistivity, grain size, growth structures, stress, and efficiency of the films in CIGS solar cells were investigated. The results reveal that the growth structures of the molybdenum films mainly affect the conductivity. The lowest electrical resistivity of the ion-plated molybdenum films was 6.9 μΩ-cm at a pressure of 0.7 Pa. The electrical resistivity variation showed a gently increasing slope with linearity under a working gas pressure of 13.3 Pa. However, a high value of the residual stress of over 1.3 GPa was measured. In order to reduce stress, titanium film was selected as the buffer layer material, and the back contact films were optimized by double-layer coating of two kinds of hetero-materials with arc ion plating. CIGS solar cells prepared molybdenum films to measure the efficiency and to examine the effects of the back contact electrode. The resistivity, grain size, and surface morphology of molybdenum films were measured by four-point probe, X-ray diffraction, and a scanning electron microscope. The residual stress of the films was calculated from differences in bending curvatures measured using a laser beam. - Highlights: • Molybdenum back contact films for Cu(In,Ga)Se2 solar cells were prepared by the cathodic arc ion plating. • The lowest electrical resistivity of molybdenum film was 6.9 μΩ-cm. • Titanium buffer layer reduced the compressive residual stress of ion

  5. Electron cyclotron resonance discharge as a source for hydrogen and deuterium ions production

    CERN Document Server

    Velasco, A J C; Velasco, Angel Jose Chacon; Dougar-Jabon, Valeri

    2004-01-01

    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 thermoelectrons 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 thermoemission from heated tungsten filaments. Experiments seem to indicate that the negative ion generation occurs predominantly in the limited volume fille...

  6. Discharge mechanism of MoS2 for sodium ion battery: Electrochemical measurements and characterization

    International Nuclear Information System (INIS)

    New emerging large scale battery market has demanded low cost and high power or energy density materials. Sodium (Na) is a promising candidate for an anode material because of its low cost and natural abundance. Also molybdenum disulfide (MoS2) is an attractive cathode material with layered structure. In this study a Na/MoS2 cell was assembled so as to evaluate its electrochemical properties as a rechargeable battery. In the first discharge Na/MoS2 cell showed two characteristic plateaus at 0.93 V and 0.8 V. Galvanostatic charge/discharge cycle was carried out in different voltage ranges according to the discharge depths (0.85 V and 0.4 V). The electrochemical behaviors of Na/MoS2 cells at each discharge depth were analyzed through characterization of the crystallographic changes by employing ex situ X-ray diffractometry (XRD) and transmission electron microscopy (TEM). Finally, Na/MoS2 reaction mechanism was suggested

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. Computation of charge and ion drag force on multiple static spherical dust grains immersed in rf discharges

    International Nuclear Information System (INIS)

    Charging of multiple spherical dust grains located in presheath and sheath regions of an rf discharge has been studied using a three-dimensional particle-particle-particle-mesh (P3M) code. First, dust charge, potential, and ion drag force on two dust particles for various interparticle separations are computed. It is found that for dust separations larger than the shielding length the dust parameters for the two dust particles match with the single particle values. As the dust separation is equal to or less than the shielding length, the transverse component of ion force increases which is due to dynamic shielding effect caused by neighboring dust particle. However, dust charge, potential, and ion drag are found not to be affected considerably. Further, dust charge and potential on an arrangement of nine dust particles are computed. The dust charge and potential do not differ much from the single particle values for the presheath. However the dust charges of multiple dust particles in the sheath are much less negative compared to the single dust case which is shown to be due to ion focusing.

  12. 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

  13. Electron cyclotron resonance discharge as a source for hydrogen and deuterium ions production

    International Nuclear Information System (INIS)

    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- and D- ion production involves the process of high Rydberg state excitation. (authors)

  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. PMID:27161852

  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. Electron cyclotron resonance discharge as a source for hydrogen and deuterium ions production

    OpenAIRE

    Chacon Velasco, Angel Jose; Dougar-Jabon, Valeri

    2004-01-01

    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 thermoelectrons 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...

  17. Experimental investigations of electron heating dynamics and ion energy distributions in capacitive discharges driven by customized voltage waveforms

    International Nuclear Information System (INIS)

    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

  18. Ion energy and angular distributions onto polymer surfaces delivered by dielectric barrier discharge filaments in air: I. Flat surfaces

    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

    In atmospheric pressure discharges, ion energies are typically thought to be thermal with values dominantly <1 eV. In the heads of filaments in dielectric barrier discharges (DBDs), electric fields can exceed 200 kV cm{sup -1} when the filament is far from a surface. As the filament approaches and intersects a dielectric surface, much of the applied potential is compressed into the voltage drop across the head of the filament due to the high conductivity of the trailing plasma channel. When the filament strikes the surface, this voltage is transferred to the resulting sheath and into the material of the surface. The degree of electric field compression depends on the dielectric constant {epsilon}/{epsilon}{sub 0} of the surface. Upon intersection of the filament with the surface, the electric fields in the resulting sheath can exceed 400-800 kV cm{sup -1}, with larger values corresponding to larger {epsilon}/{epsilon}{sub 0}. When accelerated in these fields, ions can gain energies across their mean free path (0.5-1 {mu}m) up to 20 eV for dielectrics with low {epsilon}/{epsilon}{sub 0} and up to 150 eV for dielectrics with high {epsilon}/{epsilon}{sub 0}, albeit only for the duration of the intersection of the streamer with the surface of a few ns. In this paper we report on results from a computational investigation of the ion energy and angular distributions (IEADs) incident on dielectric flat surfaces resulting from the intersection of DBD filaments sustained in atmospheric pressure air. We describe the transient and spatially dependent IEADs as the filament spreads across the polymer.

  19. 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.

  20. Effect of negative bias voltage on CrN films deposited by arc ion plating. II. Film composition, structure, and properties

    International Nuclear Information System (INIS)

    Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating at various negative bias voltages and several groups of N2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the arc ion plating (AIP) CrN films. In this article, the authors investigated the influence of negative bias voltage on the chemical composition, structure, and mechanical properties of the CrN films. The results showed that the chemical composition and phase structure of the AIP CrN films were greatly altered by application of negative bias voltage. Due to the selective resputtering effect, substoichiometric CrN films were obtained. With increase in bias voltages, the main phases in the films transformed from Cr+CrN to Cr2N at low N2/Ar flow ratios, whereas the films at high N2/Ar flow ratios retained the CrN phase structure. The CrN films experienced texture transformation from CrN (200) to CrN (220), and Cr2N (300) to Cr2N(300)+Cr2N(110). Increase in negative bias voltage also resulted in microstructure evolution of coarse columnar grains→fine columnar grains→quasiamorphous microstructure→recrystallized structures. From the experimental results, the authors proposed a new structure zone model based on enhanced bombardment of incident ions by application of negative bias voltage. The influence of negative bias voltage on the microhardness and residual stresses of the films and the inherent mechanisms were also explored

  1. 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...

  2. Measurement of ion density in an atmospheric pressure argon with pin-to-plate dielectric barrier discharge by resonance of plasma radiation

    International Nuclear Information System (INIS)

    The measurements of the ion densities in the atmospheric AC barrier corona argon discharge are carried out by receiving and analyzing the frequencies of the electromagnetic radiation emitted from the plasma. An auxiliary excitation source composed of a pin-to-pin discharge system is introduced to excite the oscillations of the main discharge. To analyze the resonance mechanism, a complemented model based on a one-dimensional description of forced vibrations is given. Calculations indicate that Ar2+ is the dominant ion (∼89% in number density). By analyzing resonance frequencies, the ion densities of Ar2+ are in the order of 1019∼1020m−3 and increase slowly as the applied voltage increases

  3. 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

  4. 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...

  5. 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...

  6. 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.

  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. 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

  9. 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)

  10. 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

  11. 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.

  12. Effect of negative bias voltage on CrN films deposited by arc ion plating. I. Macroparticles filtration and film-growth characteristics

    International Nuclear Information System (INIS)

    Chromium nitride (CrN) films were deposited on Si wafers by arc ion plating (AIP) at various negative bias voltages and several groups of N2/Ar gas flux ratios and chamber gas pressures. The authors systematically investigated the influence of negative bias voltage on the synthesis, composition, microstructure, and properties of the AIP CrN films. In this part (Part I), the investigations were mainly focused on the macroparticle distributions and film-growth characteristics. The results showed that macroparticle densities on the film surfaces decreased greatly by applying negative bias voltage, which can be affected by partial pressure of N2 and Ar gases. From the statistical analysis of the experimental results, they proposed a new hybrid mechanism of ion bombardment and electrical repulsion. Also, the growth of the AIP CrN films was greatly altered by applying negative bias voltage. By increasing the bias voltage, the film surfaces became much smoother and the films evolved from apparent columnar microstructures to an equiaxed microstructure. The impinging high-energy Cr ions accelerated by negative bias voltages were deemed the inherent reason for the evolution of growth characteristics

  13. Arcing phenomena in fusion devices workshop

    International Nuclear Information System (INIS)

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included

  14. Arcing phenomena in fusion devices workshop

    Energy Technology Data Exchange (ETDEWEB)

    Clausing, R.E.

    1979-01-01

    The workshop on arcing phenomena in fusion devices was organized (1) to review the pesent status of our understanding of arcing as it relates to confinement devices, (2) to determine what informaion is needed to suppress arcing and (3) to define both laboratory and in-situ experiments which can ultimately lead to reduction of impurities in the plasma caused by arcing. The workshop was attended by experts in the area of vacuum arc electrode phenomena and ion source technology, materials scientists, and both theoreticians and experimentalists engaged in assessing the importance of unipolar arcing in today's tokamaks. Abstracts for papers presented at the workshop are included.

  15. 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.

  16. 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.

  17. Synthesis and properties of CrNx/amorphous-WC nanocomposites prepared using hybrid arc ion plating and direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Hybrid deposition method was used to prepare CrNx/amorphous-WC (CrNx/a-WC) films. The effect of the arc ion plating and direct current magnetron sputtering on the changes in microstructure and properties such as hardness and thermal stability were studied. The amorphous WC phase of the CrNx/a-WC films was confirmed by X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. A bi-phase nanocomposite kinetic model and the Koehler's theory were used to explain the growth mechanism of CrNx/a-WC films. A superhard superlattice Cr2N/a-WC film with hardness up to ∼ 48 GPa was abtained. The CrN/a-WC films displayed better resistance to oxidation than pure CrN and CrN-based films. As such, CrNx/a-WC nanocomposite films are very promising for high-speed drying machines and other high-temperature applications.

  18. 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.

  19. Local thermodynamic equilibrium study of H- abundance in negative-ion source discharges

    International Nuclear Information System (INIS)

    A local thermal equilibrium study of a hydrogen gas has been carried out for temperatures and densities relevant to the expected conditions in the Penning SAS source, which is a negative-ion source presently under investigation by AT-2 at Los Alamos National Laboratory. For the pure hydrogen mixture, it was found that the relative abundance of H- ions peaks at about 10,000 K but is extremely low. The inclusion of cesium does improve the H- abundance significantly only at low temperatures (≤5000 K), raising it to about several parts per million, which should be considered low in view of estimates from the sheath physics which is not based on the local thermodynamic equilibrium assumption. Incorporation of the enhancement of dissociative attachment from contributions by higher rotational-vibrational states associated with a nonthermal hot electron component has not been attempted, being an intrinsically nonthermal effect. The higher rotational-vibrational states themselves are, however, fully included

  20. 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.

  1. Study on Expansion Process of EDM Arc Plasma

    Science.gov (United States)

    Natsu, Wataru; Shimoyamada, Mayumi; Kunieda, Masanori

    In order to understand the phenomena of electrical discharge machining (EDM), the characteristics of transition arc plasma in EDM were investigated. The arc plasma was directly observed with a high speed video camera. In addition, to learn more about arc plasma expansion, plasma temperature was measured by spectroscopy. The arc plasma temperature was obtained by measuring the radiant fluxes of two different wavelengths from the arc plasma and applying the line pair method. Furthermore, a new expansion model for EDM arc plasma was proposed based on the observations, and validated by comparing experimental and computed results of the discharge crater.

  2. 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.

  3. 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 ...

  4. 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

  5. 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.

  6. 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

  7. Measurement and modeling of a diamond deposition reactor: Hydrogen atom and electron number densities in an Ar/H2 arc jet discharge

    International Nuclear Information System (INIS)

    A combination of experiment [optical emission and cavity ring-down spectroscopy (CRDS) of electronically excited H atoms] and two-dimensional (2D) modeling has enabled a uniquely detailed characterization of the key properties of the Ar/H2 plasma within a ≤10-kW, twin-nozzle dc arc jet reactor. The modeling provides a detailed description of the initial conditions in the primary torch head and of the subsequent expansion of the plasma into the lower pressure reactor chamber, where it forms a cylindrical plume of activated gas comprising mainly of Ar, Ar+, H, ArH+, and free electrons. Subsequent reactions lead to the formation of H2 and electronically excited atoms, including H(n=2) and H(n=3) that radiate photons, giving the plume its characteristic intense emission. The modeling successfully reproduces the measured spatial distributions of H(n>1) atoms, and their variation with H2 flow rate, FH20. Computed H(n=2) number densities show near-quantitative agreement with CRDS measurements of H(n=2) absorption via the Balmer-β transition, successfully capturing the observed decrease in H(n=2) density with increased FH20. Stark broadening of the Balmer-β transition depends upon the local electron density in close proximity to the H(n=2) atoms. The modeling reveals that, at low FH20, the maxima in the electron and H(n=2) atom distributions occur in different spatial regions of the plume; direct analysis of the Stark broadening of the Balmer-β line would thus lead to an underestimate of the peak electron density. The present study highlights the necessity of careful intercomparisons between quantitative experimental data and model predictions in the development of a numerical treatment of the arc jet plasma. The kinetic scheme used here succeeds in describing many disparate observations--e.g., electron and H(n=2) number densities, spatial distributions of optical emission from the plume, the variation of these quantities with added flow of H2 and, when CH4 is added

  8. 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

  9. Improved hydrogen ionization rate in enhanced glow discharge plasma immersion ion implantation by enlarging the interaction path using an insulating tube

    International Nuclear Information System (INIS)

    A small pointed hollow anode and large tabular cathode are used in enhanced glow discharge plasma immersion ion implantation (EGD-PIII). Electrons are repelled from the substrate by the electric field formed by the negative voltage pulses and concentrate in the vicinity of the anode to enhance the self-glow discharge process. To extend the application of EGD-PIII to plasma gases with low ionization rates, an insulating tube is used to increase the interaction path for electrons and neutrals in order to enhance the discharge near the anode. Results obtained from numerical simulation based on the particle-in-cell code, finite element method, and experiments show that this configuration enhances the ionization rate and subsequent ion implant fluence. The process is especially suitable for gases that have low ionization rates such as hydrogen and helium.

  10. 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.

  11. 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

  12. High-current vacuum-arc ion and plasma source 'Raduga-5' application to intermetallic phase formation

    International Nuclear Information System (INIS)

    Phase composition, structural state, and mechanical properties of the ion-doped surface layers of Ni, Ti, and Fe targets with Al and Ti ions implanted into using the metal ion beam and plasma source Raduga 5 have been investigated. The high-intensity mode of implantation allowed us to obtain the ion-doped layers with the thickness exceeding the ion projected range by several orders of magnitude. By the transmission electron microscopy, it has been found that the fine-dispersed equilibrium intermetallic phases (Me3Al, MeAl) and the solid solution of aluminum were formed in the doped Ni, Ti, and Fe surface layers at the depth of up to 2600 nm. The maximum dopant concentration reached 75%. It has been shown that the average size of the formed phases was of 70 nm. The microhardness of the different target surface layers increased by 1.5-3 times. The wear resistance of the samples did not change within the temperature range of 300-700 K

  13. 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...

  14. 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. ...

  15. Study of the external parameters influence on the channel discharge radius in Hg lamps

    International Nuclear Information System (INIS)

    In this paper, the plasma electric conductivity and the channel radius for high-pressure mercury arc discharge are calculated. The examined model emphasizes some correlations between various external parameters (current intensity, silicon tube diameter and working pressure) and the channel discharge radius. After model validation, the temperature distribution in the discharge zone is obtained and then the electrons and ions distribution, the electric carriers mobility and the electric conductivity for different lamp characteristics are calculated. The applied numerical simulation shows a linear increase of the channel radius with the tube radius Rw increasing, and a very week pressure dependence (in the range 0.5 - 5 atm.)

  16. 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.

  17. Preparation and investigation of diamond-like carbon stripper foils by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    Thin diamond-like carbon (DLC) stripper foils ∼5μg/cm2 in thickness were produced and evaluated as heavy-ion strippers for the Beijing HI-13 Tandem Accelerator. The DLC layers ∼4μg/cm2 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/cm2 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 197Au− (∼9MeV, ∼1μA) and 63Cu− (∼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 sp3 bonds of the DLC foils exceed 70%. The integral intensity ratio of the D peak to the G peak (ID/IG) measured by the Raman spectroscopy is 0.78

  18. 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)

  19. 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.

  20. Production and characterization of multilayer coatings of Ti/TiN on AISI 316L stainless steel by the PVD technique of cathodic arc ion plating

    International Nuclear Information System (INIS)

    Multilayer coatings were produced from bi-layers (compound layers) of Ti/TiN in a PVD reactor of cathodic arc ion plating. The process was carried out at an Argon gas pressure of 5x10-3 Torr for the interlayer of Ti and a nitrogen + argon pressure of 2x10-2 Torr for the deposit of TiN and a Bias voltage of -500V for the Ti layer and -100V for the TiN layer. The arc current held constant at 80 amp. The samples were kept at high temperatures ≥ 300oC, mounted on a rotating system that held the test piece 15-25 cm from the Ti electrode. Certified composition AISI 316L and AISI 410 stainless steel were used for the substrate. Coatings with one or two compound layers with similar thicknesses were made. The coatings were characterized mechanically by adherence, thickness and microhardness by Vickers indentation with 25g loads. The texture was studied by X-ray diffraction and present phases and residual tensions were determined. The results of the X-ray diffraction show the presence of the mostly TiN phase, with fcc structure in the mono-layer and the bi-layer. Residual tensions are compressive and elevated due to the expansion of the TiN network during the deposition process. Measurements of the bi-layers at different angles showed a relaxing of the tensions close to the surface, which could be due to the effect of the second interlayer of Ti. Preferential orientations associated with the growth process of the layers and the developed microstructure were detected in the TiN (CW)