The Experts below are selected from a list of 39795 Experts worldwide ranked by ideXlab platform
Yulia I Isakova - One of the best experts on this subject based on the ideXlab platform.
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a gigawatt power pulsed Ion beam generator for industrial applicatIons
Surface & Coatings Technology, 2013Co-Authors: A I Pushkarev, Yulia I IsakovaAbstract:Abstract The results of a comprehensive study of a gigawatt level power pulsed Ion beam used for material modificatIon are presented. The Ion beam is formed using a diode with self-magnetic insulatIon. The study was performed using the TEMP-4M accelerator in double pulse formatIon mode. The Ion Current Density is 30–300 A/cm 2 (for different designs of diodes), and the beam is composed of protons (15%) and carbon Ions (85%). It was shown that a diode with planar configuratIon generates an Ion beam with a fairly homogeneous energy Density over a cross sectIon of 80 cm 2 ; the energy Density is 0.3–0.4 J/cm 2 and the fluence is 2 × 10 13 cm − 2 per pulse. A diode with focusing geometry forms an Ion beam with an energy Density of 2–2.5 J/cm 2 at the focus and a pulse energy of 80–100 J.
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diagnostic equipment for the temp 4m generator of high Current pulsed Ion beams
Journal of the Korean Physical Society, 2011Co-Authors: Yulia I IsakovaAbstract:The results of calibratIon and optimizatIon of the diagnostic equipment for a gigawatt power pulsed Ion beam accelerator are presented. The study was performed using the TEMP-4M accelerator set in the mode of double pulse formatIon. The first pulse is negative (300 – 600 ns, 100 – 150 kV), followed by the second positive pulse (80 ns, 250 – 300 kV). The Ion Current Density is 30 – 300 A/cm(for different designs of diodes), the Ion energy is 250 – 300 keV, and the beam is composed of protons and carbon Ions. The calibratIon of the diagnostic equipment shows that it correctly reflects the accelerator operatIon in the short-circuit mode (U = 50 – 60 kV), when operating with a resistive load up to 10 Ω (200 – 300 kV) and when operating with a diode. A technique based on the time-of-flight (TOF) method for a quick determinatIon of the beam’s compositIon (Ion type and degree of IonizatIon) was tested. The method allowed for the determinatIon of the absolute values of the Ion Current Density and the energy spectrum for each Ion type with an accuracy of ±10%.
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diagnostic equipment for the temp 4m generator of high Current pulsed Ion beams
Journal of the Korean Physical Society, 2011Co-Authors: Yulia I IsakovaAbstract:The results of calibratIon and optimizatIon of the diagnostic equipment for a gigawatt power pulsed Ion beam accelerator are presented. The study was performed using the TEMP-4M accelerator set in the mode of double pulse formatIon. The first pulse is negative (300 – 600 ns, 100 – 150 kV), followed by the second positive pulse (80 ns, 250 – 300 kV). The Ion Current Density is 30 – 300 A/cm(for different designs of diodes), the Ion energy is 250 – 300 keV, and the beam is composed of protons and carbon Ions. The calibratIon of the diagnostic equipment shows that it correctly reflects the accelerator operatIon in the short-circuit mode (U = 50 – 60 kV), when operating with a resistive load up to 10 Ω (200 – 300 kV) and when operating with a diode. A technique based on the time-of-flight (TOF) method for a quick determinatIon of the beam’s compositIon (Ion type and degree of IonizatIon) was tested. The method allowed for the determinatIon of the absolute values of the Ion Current Density and the energy spectrum for each Ion type with an accuracy of ±10%.
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the effect of Ion Current Density amplificatIon in a diode with passive anode in magnetic self isolatIon mode
Physics of Plasmas, 2010Co-Authors: A I Pushkarev, Yulia I Isakova, Dmitry V VakhrushevAbstract:The results of a study on gigawatt power pulsed Ion beam parameters are presented here. The pulsed Ion beam is formed by a diode with an explosive-emissIon potential electrode, in magnetic self-isolatIon mode [A. I. Pushkarev, J. I. Isakova, M. S. Saltimakov et al., Phys. Plasmas 17, 013104 (2010)]. The Ion Current Density is 20–40 A/cm2, the energy of the Ions is 200–250 keV, and the beam compositIon is of protons and carbon Ions. Experiments have been performed on the TEMP-4M accelerator, set in double-pulse formatIon mode. To measure the beam parameters, we used a time-of-flight diagnosis. It is shown that the carbon Ion Current Density, formed in a planar diode with graphite potential electrode, is five to seven times higher than the values calculated from the Child–Langmuir ratio. A model of Ion Current Density amplificatIon in a diode with magnetic self-isolatIon is proposed. The motIon of electrons in the anode-cathode gap is simulated using the program CST PARTICLE STUDIO.
Chen Wang - One of the best experts on this subject based on the ideXlab platform.
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WSN-Based Measurement of Ion-Current Density Under High-Voltage Direct Current TransmissIon Lines
IEEE Access, 2019Co-Authors: Yong Cui, Xiao Song, Luxing Zhao, Haiwen Yuan, Chen WangAbstract:Ion-Current Density is a significant indicator of electromagnetic environment under high voltage direct Current lines. To improve measurement accuracy and convenience, this paper concluded factors that affect measurement results and a wireless measurement method was proposed. Wilson plate kind of sensor was designed according to the IEEE standard. The Ion Current was measured and digitalized by the measurement device, and the signal was transmitted to the computer via wireless sensor networks. The data were analyzed and recorded by automatic measurement software. Finally, the measurement system was calibrated and some field tests had been performed, the results show that the measurement system possesses the merits of good accuracy, simple structure, convenient operatIon, and high stability and reliability. The maximum Current measurement error is less than 3%.
Xiang Cui - One of the best experts on this subject based on the ideXlab platform.
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impact of fine particles on the direct Current electric field of the conductor due to corona discharge
Journal of Electrostatics, 2017Co-Authors: Zhilong Zou, Xiang Cui, Xingming BianAbstract:Abstract Corona-generated Ionized field is an essential electromagnetic parameter of high voltage direct Current transmissIon lines. In order to investigate the impact of atmospheric fine particles on the DC Ionized field, distributIons of the ground-level Ionized field and Ion Current Density were measured under various air contaminatIon extents in a wire-to-ground platform. The fine particles were generated from burning incense. Measurement results show that the magnitude of ground-level Ionized field may increase approximately by 20% when particles in the order of 10 2 μg m −3 exist in air. RestrictIon effect on the Ionized field by using grounded shielding lines was also examined.
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measurement method of charge densities at ground level under high voltage direct Current conductor
Iet Science Measurement & Technology, 2015Co-Authors: Zhilong Zou, Xiang CuiAbstract:Ions generated by corona discharge of high-voltage direct Current (HVDC) transmissIon lines exist in the space between conductors and the ground. Electric field strength, Ion Current Density, and space charge Density are significant electromagnetic environment parameters of HVDC transmissIon lines. To measure the charge densities at ground level under the HVDC power lines, an aspirator-type charge meter is designed and utilised. The charge meter is calibrated in the Ionised field generated by parallel metal mesh and plate. Charge densities on the ground under the unipolar HVDC conductor are measured by the calibrated devices in the laboratory. Experimental results show that reasonable agreement between measured data by the devices and the ones by field mills and Ion Current plates could be obtained, which establishes a foundatIon to research the charge characteristics of Ions near the ground.
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impact factors in measurements of Ion Current Density produced by high voltage dc wire s corona
IEEE Transactions on Power Delivery, 2013Co-Authors: Chao Fang, Xiang Cui, Xiangxian Zhou, Yongzan ZhenAbstract:The reduced-scale model of HVDC transmissIon lines in the laboratory is widely used to investigate the Ionized fields. This paper is aimed at analyzing impact factors of the Ion-Current Density measurement system based on Wilson plates in the laboratory. Both experimental and numerical simulatIon methods are used to obtain the characteristics of the measurement system. The results show that measurement data can be calibrated with different Wilson plates, and suitable parameters are proposed in this paper to meet the requirement of measurements. The measurement system described in this paper can be used in other similar applicatIons.
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Analysis of the Electric Field and Ion Current Density Under Ultra High-Voltage Direct-Current TransmissIon Lines Based on Finite Element Method
IEEE Transactions on Magnetics, 2007Co-Authors: Han Feng, Zhibin Zhao, Xiang CuiAbstract:The corona generated from high-voltage direct-Current transmissIon lines can induce the Ion around the lines, which will increase the electric field and the Ion Current Density and influence the environment nearby. Based on the finite-element method, an iterative algorithm to analyze the electric field and the Ion Current Density at the ground level generated from the bundled conductors of bipolar lines is proposed. After the validity of the method is testified, some examples are analyzed. The method has been used to design plusmn800 kV transmissIon lines system in China
S. Xu - One of the best experts on this subject based on the ideXlab platform.
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DistributIon of Ion-Current Density on Substrate Between Carbon Nanotubes Grown From Low-Temperature Plasma
IEEE Transactions on Plasma Science, 2008Co-Authors: Igor Levchenko, Kostya Ostrikov, S. XuAbstract:Using Monte Carlo simulatIon technique, we have calculated the distributIon of Ion Current extracted from low-temperature plasmas and deposited onto the substrate covered with a nanotube array. We have shown that a free-standing carbon nanotube is enclosed in a circular bead of the Ion Current, whereas in square and hexagonal nanotube patterns, the Ion Current is mainly concentrated along the lines connecting the nearest nanotubes. In a very dense array (with the distance between nanotubes/nanotube-height ratio less than 0.05), the Ions do not penetrate to the substrate surface and deposit on side surfaces of the nanotubes.
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microscopic Ion fluxes in plasma aided nanofabricatIon of ordered carbon nanotip structures
Journal of Applied Physics, 2005Co-Authors: Igor Levchenko, Kostya Ostrikov, Michael Keidar, S. XuAbstract:Three-dimensIonal topography of microscopic Ion fluxes in the reactive hydrocarbon-based plasma-aided nanofabricatIon of ordered arrays of vertically aligned single-crystalline carbon nanotip microemitter structures is simulated by using a Monte Carlo technique. The individual Ion trajectories are computed by integrating the Ion equatIons of motIon in the electrostatic field created by a biased nanostructured substrate. It is shown that the Ion flux focusing onto carbon nanotips is more efficient under the conditIons of low potential drop Us across the near-substrate plasma sheath. Under low-Us conditIons, the Ion Current Density onto the surface of individual nanotips is higher for higher-aspect-ratio nanotips and can exceed the mean Ion Current Density onto the entire nanopattern in up to approximately five times. This effect becomes less pronounced with increasing the substrate bias, with the mean relative enhancement of the Ion Current Density ξi not exceeding ∼1.7. The value of ξi is higher in denser...
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microscopic Ion fluxes in plasma aided nanofabricatIon of ordered carbon nanotip structures
Science & Engineering Faculty, 2005Co-Authors: Igor Levchenko, Kostya Ostrikov, Michael Keidar, S. XuAbstract:Three-dimensIonal topography of microscopic Ion fluxes in the reactive hydrocarbon-based plasma-aided nanofabricatIon of ordered arrays of vertically aligned single-crystalline carbon nanotip microemitter structures is simulated by using a Monte Carlo technique. The individual Ion trajectories are computed by integrating the Ion equatIons of motIon in the electrostatic field created by a biased nanostructured substrate. It is shown that the Ion flux focusing onto carbon nanotips is more efficient under the conditIons of low potential drop Us across the near-substrate plasma sheath. Under low- Us conditIons, the Ion Current Density onto the surface of individual nanotips is higher for higher-aspect-ratio nanotips and can exceed the mean Ion Current Density onto the entire nanopattern in up to approximately five times. This effect becomes less pronounced with increasing the substrate bias, with the mean relative enhancement of the Ion Current Density ξi not exceeding ∼1.7. The value of ξi is higher in denser plasmas and behaves differently with the electron temperature Te depending on the substrate bias. When the substrate bias is low, ξi decreases with Te, with the opposite tendency under higher- Us conditIons. The results are relevant to the plasma-enhanced chemical-vapor depositIon of ordered large-area nanopatterns of vertically aligned carbon nanotips, nanofibers, and nanopyramidal microemitter structures for flat-panel display applicatIons. © 2005 American Institute of Physics.
F Alvarez - One of the best experts on this subject based on the ideXlab platform.
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the influence of the Ion Current Density on plasma nitriding process
Surface & Coatings Technology, 2005Co-Authors: E A Ochoa, C A Figueroa, F AlvarezAbstract:Abstract In this paper, we report a comprehensive nitriding study carried out using low-alloy steel AISI 4140, combining nitrogen Ion-beam (IB) implantatIon and pulsed plasma (PP) nitriding. Quantitative relatIonships among hardness, nitrogen bulk profile concentratIon, and Current Ion densities are reported. The hardness profile showed a linear relatIonship with the nitrogen concentratIon. The samples were characterized by photoemissIon electron spectroscopy (XPS), X-rays diffractIon analysis (XRD), scanning electron microscopy (SEM) and in-depth nanohardness measurements. Samples treated by Ion-beam-implantatIon showed the presence of a compound layer formed principally by ɛ-Fe3N and γ′-Fe4N. On the other hand, samples treated by pulsed plasma nitriding showed only the existence of γ′-Fe4N. In the later set of samples, was possible to prove that hardness is proportIonal to the Ion Current Density.
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a comprehensive nitriding study by low energy Ion beam implantatIon on stainless steel
Surface & Coatings Technology, 2001Co-Authors: C A Figueroa, D Wisnivesky, Peter Hammer, R G Lacerda, R Droppa, F C Marques, F AlvarezAbstract:In this paper we report nitriding studies of stainless steel 316 using a broad Ion beam source. Experiments performed by changing the Ion energy (0.2-1.5 KeV), Ion Current Density (1.4-5.7 mAycm ) and implantatIon times ( 1a nd 8h ) at a 2 temperature around 3808C are reported. The microstructure and morphology are studied by glancing angle X-ray diffractIon and scanning electron microscopy. For constant Ion energy, higher nitrogen Ion flux increases the hardness. At higher Ion energies the sputtering process prevents the formatIon of a thick-nitrated layer, even for longer implantatIon times. The results are examined in the light of recent studies on physical models for Ion implantatIon. 2001 Elsevier Science B.V. All rights reserved. 2q
