291 results on '"Plasma jet"'
Search Results
2. Discharge Initiation in Globus-M2 and KTM Tokamaks Using a Coaxial Plasma Jet Accelerator
- Author
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A. V. Voronin, V. B. Minaev, E.G. Zhilin, B. Zh. Chektybaev, A.D. Sadykov, A. T. Kusainov, V. Yu. Goryainov, A. N. Novokhatskii, Yu. V. Petrov, N. V. Sakharov, E. A. Sarsembaev, and V. K. Gusev
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Materials science ,Tokamak ,Physics and Astronomy (miscellaneous) ,Plasma jet ,Plasma ,Condensed Matter Physics ,law.invention ,Magnetic field ,law ,Breakdown voltage ,Duct (flow) ,Atomic physics ,Coaxial ,Voltage - Abstract
Studies were performed on the possibility of using the coaxial plasma jet accelerator to facilitate breakdown and the plasma current start-up in the Globus-M2 and KTM tokamaks. The results of experiments on the jet injection into the Globus-M2 tokamak with a magnetic field of 0.7 T showed that the discharge current rise began 1–2 ms earlier than it did in experiments using gas puffing and inductive breakdown of the working gas. In this case, the breakdown voltage decreased approximately 2 times. The results of experiments on plasma jet injection through the equatorial diagnostic duct into the KTM tokamak with a magnetic field of 0.9 T showed that the gas breakdown occurred up to 6 ms earlier than the breakdown initiated using the inductive method. In this case, the loop voltage decreases approximately 1.5 times. In almost all shots using the accelerator, the gas breakdown occurred, while in its absence, sometimes the gas breakdown could not be obtained.
- Published
- 2021
3. Measurements of nitrogen atom density in a microwave‐excited plasma jet produced under moderate pressures
- Author
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Shingo Hirose, Tetsuji Shimizu, Masaru Hori, Hisato Ogiso, Jae-Ho Kim, Xue-Lun Wang, Hirotomo Itagaki, Hajime Sakakita, Keigo Takeda, Naoto Kumagai, Hiroki Kondo, and Takayoshi Tsutsumi
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Materials science ,Nitrogen atom ,Nitrogen plasma ,Excited state ,Plasma jet ,Electrical and Electronic Engineering ,Atomic physics ,Microwave - Published
- 2020
4. Experimental and Theoretical Investigation of Microdischarge Plasma in the Vortex Gas Flow
- Author
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O. Prysiazhna, O. Fentisova, D. Nikulin, Valeriy Chernyak, B. Portnyak, O. Kolomiiets, O. Tsimbalyuk, and V.V. Iukhymenko
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Materials science ,Physics and Astronomy (miscellaneous) ,Flow (psychology) ,Kinetics ,Plasma jet ,Atmospheric-pressure plasma ,Plasma ,Electron ,Atomic physics ,Condensed Matter Physics ,Ion source ,Vortex - Abstract
Experimental studies of the electrical parameters of the microdischarge and the plasma of the microdischarge in the vortex flow of CO2 as the plasma-forming gas was carried out. The kinetics of the formation of some components of microwave plasma was considered using ZDPlasKin computer code and Bolsig+ at experimentally measured electric field strengths, pressure and gas temperature. The key reactions of microdischarge were determined. The Bolsig+ code was used to determine the mean energy of electrons.
- Published
- 2020
5. Electric Field Mechanism of Thin Plasma Jet Formation in an Open Atmospheric Discharge
- Author
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Aleksandr Kokovin, Vasily Yu. Kozhevnikov, A. G. Sitnikov, Victor A. Panarin, Natalia S. Semeniuk, and A. V. Kozyrev
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010302 applied physics ,Materials science ,010308 nuclear & particles physics ,Electric field ,0103 physical sciences ,Plasma jet ,General Physics and Astronomy ,Head (vessel) ,Plasma ,Atomic physics ,Conductivity ,01 natural sciences - Abstract
Experimental and theoretical investigations of a new form of pulsed periodic discharge burning in the form of a thin plasma jet – apokamp – have been carried out. It is shown that for sustainable apokamp formation, the presence of a weak external electric field is required which is enhanced near the head of a growing streamer at the expense of good conductivity of the plasma trace. It is experimentally demonstrated that the apokamp formation is initiated by external electric field strength of ~1 kV/cm.
- Published
- 2020
6. Bunches of accelerated electrons with a quasi-monoenegetic distribution in a laser-plasma injector using a highly inhomogeneous plasma jet
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V.S. Popov
- Subjects
Bunches ,Materials science ,Distribution (number theory) ,law ,Plasma jet ,Injector ,Electron ,Plasma ,Atomic physics ,Laser ,law.invention - Published
- 2020
7. Static elimination in vacuum using plasma jet
- Author
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Takashi Ikehata
- Subjects
Materials science ,Plasma jet ,Atomic physics ,Condensed Matter Physics ,Instrumentation ,Surfaces, Coatings and Films - Published
- 2019
8. Thin plasma jet formation in open atmospheric discharge by electro-field mechanism
- Author
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A. V. Kozyrev, Victor A. Panarin, Aleksandr Kokovin, Vasily Yu. Kozhevnikov, A.G. Sitnikov, and N.S. Semeniuk
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Materials science ,Field (physics) ,Plasma jet ,Atomic physics ,Geotechnical Engineering and Engineering Geology ,Mechanism (sociology) - Published
- 2019
9. Effect of gas flow rate on plasma temperature and electron density of atmospheric argon plasma jet
- Author
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Kadhim A. Aadim
- Subjects
Electron density ,Argon ,Materials science ,Plasma jet ,chemistry.chemical_element ,Plasma ,Volumetric flow rate ,symbols.namesake ,chemistry ,Boltzmann constant ,symbols ,Electron temperature ,Optical emission spectroscopy ,Atomic physics - Abstract
In this study, method for experimentally determining the electron density (ne) and the electron temperature (Te) in the atmospheric Argon plasma jet is used; it is based on optical emission spectroscopy (OES). Boltzmann plot method used to calculate these parameters measured for different values of gas flow rate. The results show that the electron temperature decreasing with the increase of gas flow rate also indicates an increasing in the electron density of plasma jet with increasing of gas flow rate.
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- 2018
10. Periodic forced flow in a nanosecond pulsed cold atmospheric pressure argon plasma jet
- Author
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Michel Fleury, Stéphane Pasquiers, Joao Santos Sousa, Thibault Darny, G. Bauville, Laboratoire de physique des gaz et des plasmas (LPGP), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010302 applied physics ,Materials science ,Argon ,Atmospheric pressure ,Flow (psychology) ,[SPI.PLASMA]Engineering Sciences [physics]/Plasmas ,Plasma jet ,chemistry.chemical_element ,Nanosecond ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,chemistry ,0103 physical sciences ,Atomic physics - Abstract
International audience; This paper is devoted to the study of the argon flow modification in a cold atmospheric pressure plasma jet driven by nanosecond high voltage (HV) pulses, from single to multiple HV shots applications. A schlieren optical bench has been designed in order to visualize the argon flow downstream expansion in quiescent air, for moderate flow rates below 1 standard liter per minute. A coupled approach is used between charge coupled device (CCD) schlieren imaging and intensified CCD (ICCD) plasma plume imaging, both time-resolved. It is shown that the application of only one HV pulse (i.e. single HV shot) is enough to disturb the flow. The disturbed flow exhibits ripple propagation, on a timescale similar to the flow velocity. When operating in double HV shots, the second ionization wave can be used as a probe, to instantly visualize the flow structure any time after the first HV pulse application. For some flow rates, the ripple can increase in amplitude up to the point when it strongly deforms, or even stops, the plasma plume expansion, after which it is entrained by the flow and the plasma plume retrieves its full usual expansion. When a series of HV pulses are applied, the maximal disturbance of the flow is achieved for a certain pulse repetition frequency (PRF), specific of each flow rate. It is associated with ripples alternation in the plasma plume, in a 3D helicallike arrangement. For greater PRF, the ripples progressively vanish, and the flow is clearly less disturbed. Once the ripples have vanished, increasing further the PRF does not change the plasma plume and flow structures. We suggest that the repetitive plasma ignition mechanically forces the flow inside the capillary with consequences on the global flow structure, similarly to a forced backward-facing step flow with actuator.
- Published
- 2021
11. Theoretical investigation of a miniature microwave driven plasma jet
- Author
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Michael Klute, Ilija Stefanovic, Wolfgang Heinrich, Horia-Eugen Porteanu, Ralf Peter Brinkmann, and Peter Awakowicz
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microwave ,Capacitive sensing ,inductively ,FOS: Physical sciences ,MMWICP ,01 natural sciences ,010305 fluids & plasmas ,Resonator ,Physics::Plasma Physics ,0103 physical sciences ,010302 applied physics ,Capacitive coupling ,Physics ,Jet (fluid) ,plasma jet ,ICP ,Plasma ,Condensed Matter Physics ,miniature ,LC-resonators ,Physics - Plasma Physics ,Plasma Physics (physics.plasm-ph) ,Excited state ,RF ,miniature microwave driven plasma jet ,Radio frequency ,Atomic physics ,miniature micro wave ICP ,Microwave - Abstract
Radio frequency driven plasma jets are compact plasma sources which are used in many advanced fields such as surface engineering or biomedicine. The MMWICP (miniature micro wave ICP) is a particular variant of that device class. Unlike other plasma jets which employ capacitive coupling, the MMWICP uses the induction principle. The jet is integrated into a miniature cavity structure which realizes an LC-resonator with a high quality factor. When excited at its resonance frequency, the resonator develops a high internal current which—transferred to the plasma via induction—provides an efficient source of RF power. This work presents a theoretical model of the MMWICP. The possible operation points of the device are analyzed. Two different regimes can be identified, the capacitive E-mode with a plasma density of n e ≈ 5 × 1017 m−3, and the inductive H-mode with densities of n e ⩾ 1019 m−3. The E to H transition shows a pronounced hysteresis behavior.
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- 2020
12. Influence of the expansion velocity of laser plasma bunches on the intensity of a plasma jet and quasistationary waves generated in a magnetic tube
- Author
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I. F. Shaikhislamov, A. G. Berezutsky, L. R. Dmitrieva, V. N. Tishchenko, and I. B. Miroshnichenko
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Physics ,Plasma jet ,Plasma ,Laser ,Magnetic tube ,Intensity (physics) ,law.invention ,Wavelength ,symbols.namesake ,Bunches ,Mach number ,Physics::Plasma Physics ,law ,Physics::Space Physics ,symbols ,Physics::Accelerator Physics ,Atomic physics - Abstract
The influence of the Alfven Mach number (MA) on the intensity and length of quasistationary Alfven (AQW) and slow magnetosonic (MQW) waves and plasma jets generated by periodic laser plasma bunches in a of magnetized plasma was studied. It was shown that the intensity and wavelength at low velocities of the plasma expansion are maximum, which correspond to MA ∼ 0.2 − 0.5. Waves and energy of pumping bunches contain more than 60% of energy of bunches.
- Published
- 2020
13. Disalignment rate coefficient of argon $\mathrm{2p_8}$ due to nitrogen collision
- Author
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Leonard W. Isberner, Slobodan Mitic, Roman Bergert, and Markus H. Thoma
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Physics ,Argon ,Plasma jet ,chemistry.chemical_element ,FOS: Physical sciences ,Dielectric barrier discharge ,Condensed Matter Physics ,Collision ,Nitrogen ,Physics - Plasma Physics ,Atomic and Molecular Physics, and Optics ,Plasma Physics (physics.plasm-ph) ,chemistry ,Atomic physics ,Laser-induced fluorescence - Abstract
Tunable diode laser induced fluorescence (TDLIF) measurements are discussed and quantitatively evaluated for nitrogen admixtures in argon plasma under the influence of a strong magnetic field. TDLIF measurements were used to evaluate light-transport properties in a strongly magnetized optically thick argon/nitrogen plasma under different pressure conditions. Therefore, a coupled system of rate balance equations was constructed to describe laser pumping of individual magnetic sub-levels of $\mathrm{2p_8}$ state through frequency-separated sub-transitions originating from $\mathrm{1s_4}$ magnetic sub-levels. The density distribution (alignment) of $\mathrm{2p_8}$ multiplet was described by balancing laser pumping with losses including radiative decay, transfer of excitation between the neighboring sub-levels in the $\mathrm{2p_8}$ multiplet driven by neutral collisions (argon and nitrogen) and quenching due to electron and neutral collisions. Resulting $\mathrm{2p_8}$ magnetic sub-level densities were then used to model polarization dependent fluorescence, considering self-absorption, which could be directly compared with polarization-resolved TDLIF measurements. This enables to estimate the disalignment rate constant for the $\mathrm{2p_8}$ state due to collisions by molecular nitrogen. A comparison to molecular theory description is given providing satisfactory agreement. The presented measurement method and model can help to describe optical emission of argon and argon-nitrogen admixtures in magnetized conditions and provides a basis for further description of optical emission spectra in magnetized plasmas., Comment: 15 pages , 8 figures
- Published
- 2020
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14. Spot Plasma and Plasma Jet
- Author
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Isak I. Beilis
- Subjects
General Relativity and Quantum Cosmology ,Materials science ,Physics::Plasma Physics ,Speed of sound ,Ionization ,Physics::Space Physics ,Plasma jet ,Physics::Accelerator Physics ,Cathode spots ,Plasma ,Vacuum arc ,Atomic physics - Abstract
Metallic plasma formed in the cathode spots of a vacuum arc expands into vacuum as highly ionized and considerably accelerated plasma jets.
- Published
- 2020
15. Numerical and Experimental Studies on the Interactions Between the Radio-Frequency Glow Discharge Plasma Jet and the Shielding Gas at Atmosphere
- Author
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Xiao-Fei Zhang, He-Ping Li, Jing Li, and Heng Guo
- Subjects
010302 applied physics ,Nuclear and High Energy Physics ,Jet (fluid) ,Materials science ,Astrophysics::High Energy Astrophysical Phenomena ,Shielding gas ,Plasma jet ,Atmospheric-pressure plasma ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Atmosphere ,Physics::Plasma Physics ,Radio frequency glow discharge ,Physics::Space Physics ,0103 physical sciences ,Electromagnetic shielding ,Atomic physics - Abstract
It is a useful method to lengthen the cold atmospheric plasma jet with the aid of gas shielding. In this paper, the interactions between the shielding gas and the radio-frequency atmospheric-pressure glow discharge plasma jet are studied numerically and experimentally. The modeling results show that both the chemical compositions and flowrates of the shielding gas strongly influence the characteristics of the plasma jets. A long helium-shielding plasma jet with a length of 34-35 mm is obtained. The predicted lengths of the plasma shielding jets under specified operating conditions are qualitatively consistent with the experimental measurements.
- Published
- 2018
16. Optical Property of The Atmospheric Pressure Argon Plasma Jet Generated by Three Types of Electrodes
- Author
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唐蕾 Tang Lei, 尹增谦 Yin Zeng-qian, 袁春琪 Yuan Chun-qi, and 王永杰 Wang Yong-jie
- Subjects
Radiation ,Argon ,Materials science ,chemistry ,Atmospheric pressure ,Electrode ,Optical property ,Plasma jet ,chemistry.chemical_element ,Atomic physics ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2018
17. Planar Helium Plasma Jet: Plasma 'Bullets' Formation, 2D 'Bullets' Concept and Imaging
- Author
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Alexander Fridman and Danil Dobrynin
- Subjects
Jet (fluid) ,Planar ,Materials science ,Biomedical Engineering ,Plasma jet ,General Physics and Astronomy ,Plasma ,Atomic physics ,Helium plasma - Published
- 2018
18. (Invited) Stabilizing Effect of Impinging Plasma Jet on the Water Surface
- Author
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Joo-Young Park, Wonho Choe, Jinwoo Kim, Sanghoo Park, Se Youn Moon, Uroš Cvelbar, and Hyungyu Lee
- Subjects
Surface (mathematics) ,Materials science ,Plasma jet ,Atomic physics - Published
- 2021
19. An optical emission of plasma jet excited by barrier discharge in argon-air and he-air mixtures
- Subjects
Materials science ,Argon ,chemistry ,Excited state ,Plasma jet ,chemistry.chemical_element ,Optical emission spectroscopy ,Atomic physics - Published
- 2017
20. Electron-excitation Temperature with the Relative OpticalspectrumIntensity in an Atmospheric-pressure Ar-plasma Jet
- Author
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Guangsup Cho and Gook-Hee Han
- Subjects
010302 applied physics ,Atmospheric pressure discharge ,Materials science ,Atmospheric pressure ,Materials Science (miscellaneous) ,Plasma jet ,General Medicine ,Plasma ,Condensed Matter Physics ,01 natural sciences ,010305 fluids & plasmas ,Electron excitation ,0103 physical sciences ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry ,Atomic physics ,Spectroscopy - Published
- 2017
21. Characteristics of Ar Plasma Jet Generated by 50 Hz Alternating Current
- Author
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K Honglertkongsakul, K Nilgumhang, P. Tangjitsomboon, R. Mongkolnavin, S Acharry, and D. Ngamrungroj
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History ,Materials science ,law ,Plasma jet ,Atomic physics ,Alternating current ,Computer Science Applications ,Education ,law.invention - Abstract
Plasma jet generated by dielectric barrier discharge system has gain importance in surface modification processes. Characteristics of plasma of the plasma jet depend on type of gas, flow rate of gas, design of electrodes, power and frequency of the power source. In this research, the argon gas is flowed through a hollow tube is investigated. Alternating high voltage power supply connected to electrodes is operated with frequency of 50 Hz. It was found that the lengths of the plasma jet generated by this system ranges from 0.5 cm and 1 cm. The minimum and the maximum electron temperature of the plasma was 0.44 eV and 0.86 eV respectively. The electron temperature increased as the applied voltage was increased. However, the electron temperature decreased when the operating voltage was increased above 6.5 kV to 7.5 kV. It can be explained by the effect of arcing between the electrodes which causes the lost in energy. Also, increasing of the flow rate over a critical limit produces turbulence that also causes reduction in electron temperature of the plasma jet.
- Published
- 2021
22. Observation of the ionization wave and the shock wave ahead of the plasma jet generated in the plasma focus discharge
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A. M. Kharrasov, P. V. Silin, V. Ya. Nikulin, A. A. Eriskin, E. N. Peregudova, S. N. Polukhin, and A. E. Gurei
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010302 applied physics ,Shock wave ,Physics ,Dense plasma focus ,Waves in plasmas ,Astrophysics::High Energy Astrophysical Phenomena ,Plasma jet ,Electron ,complex mixtures ,01 natural sciences ,010305 fluids & plasmas ,Electronic, Optical and Magnetic Materials ,Two-stream instability ,Physics::Plasma Physics ,Ionization ,Physics::Space Physics ,0103 physical sciences ,Electromagnetic electron wave ,Atomic physics ,human activities - Abstract
An ionization wave travelling ahead of the shock wave of the plasma jet, propagating in residual gas (nitrogen) of the plasma focus discharge, is detected by the laser-interferometry method at the plasma focus. Radial and axial distributions of electron densities of the shock wave and plasma jet are measured.
- Published
- 2017
23. Ministarters and mini blue jets in air and nitrogen at a pulse-periodic discharge in a laboratory experiment
- Author
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V. S. Skakun, Victor A. Panarin, E. A. Sosnin, Victor F. Tarasenko, and E. Kh. Baksht
- Subjects
010504 meteorology & atmospheric sciences ,Physics and Astronomy (miscellaneous) ,синие струи ,Astrophysics::High Energy Astrophysical Phenomena ,chemistry.chemical_element ,01 natural sciences ,010305 fluids & plasmas ,Pressure range ,Atmosphere ,Optics ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,0105 earth and related environmental sciences ,Physics ,апокампы ,business.industry ,плазменные струи ,Plasma jet ,Nitrogen ,Pulse (physics) ,chemistry ,атмосфера Земли ,Torr ,High Energy Physics::Experiment ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Laboratory experiment ,business - Abstract
Miniature analogs of starters and blue jets that are observed in the upper atmosphere of the Earth and have dimensions of tens of kilometers are formed and studied in air and nitrogen at pressures of tens and hundreds of Torr. Ministarters and mini blue jets have been obtained in laboratory experiments owing to the application of a pulse-periodic discharge with a plasma jet referred to as apokamp. The velocities of propagation of apokamps have been measured at various pressures. It has been found that the average values of these velocities are about the velocities of propagation of starters and blue jets in the atmosphere of the Earth. It has been shown that jets (apokamps) with the maximum length are observed in the pressure range corresponding to the altitudes of appearance and propagation of starters and blue jets.
- Published
- 2017
24. A New Plasma Jet Array Source: Discharge Characteristics and Mechanism
- Author
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Mingzhe Rong, Zeyu Chen, Dong Li, Dingxin Liu, and Michael G. Kong
- Subjects
Nuclear and High Energy Physics ,Materials science ,business.product_category ,Astrophysics::High Energy Astrophysical Phenomena ,complex mixtures ,01 natural sciences ,010305 fluids & plasmas ,Physics::Plasma Physics ,0103 physical sciences ,Homogeneity (physics) ,Bottle ,Surface charge ,010302 applied physics ,Plasma jet ,Plasma ,respiratory system ,equipment and supplies ,Condensed Matter Physics ,Temporal Regions ,Physics::Space Physics ,Electrode ,High Energy Physics::Experiment ,Atomic physics ,business ,human activities ,circulatory and respiratory physiology ,Voltage - Abstract
A new plasma jet array source is reported, which has two plasma regions: a cylindrical bottle in which plasmas are generated to deposit charged species on the inner wall, and the outside atmosphere in which plasma jets are generated between the small holes in the underside of the bottle and the grounded sample underneath the bottle. Four temporal regions of discharge are found to exist during a voltage cycle, in which the first one has maximal amount of charge transfer but minimal discharge energy. The surface charges supply the seed charge to initiate and sustain the plasma jets, while restricting the intensity of each plasma jet because their amount is limited. Only the surface charges near the underside hole of the cylindrical bottle are possible to participate in the discharge. Therefore, the plasma jets have a good jet-to-jet homogeneity relatively independent of the number of jets and their relative positions, indicating that the plasma jets can be arbitrarily arranged to a large extent. This is an application advantage but with a limitation, i.e., two plasma jets cannot be closer than 2.5 mm, because the surface charge between them will be shunted, and therefore, the plasma jets will be weakened.
- Published
- 2016
25. The study of the effect of anode outer surface material and geometry of plasma jet injector on the spatial distribution of electric field in reflex discharge background plasma
- Author
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N.N. Antonov and G.D. Liziakin
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Surface (mathematics) ,Materials science ,law ,Electric field ,Reflex ,Plasma jet ,Injector ,Plasma ,Atomic physics ,Spatial distribution ,law.invention ,Anode - Published
- 2018
26. Ignition of A Plasma Discharge Inside An Electrodeless Chamber: Methods and Characteristics
- Author
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Mounir Laroussi and Old Dominion University
- Subjects
Materials science ,02 engineering and technology ,01 natural sciences ,diffuse plasma ,010305 fluids & plasmas ,law.invention ,symbols.namesake ,law ,Physics::Plasma Physics ,Ionization ,Electric field ,0103 physical sciences ,Langmuir probe ,Emission spectrum ,ionization wave ,Number density ,plasma jet ,[SPI.PLASMA]Engineering Sciences [physics]/Plasmas ,Plasma ,021001 nanoscience & nanotechnology ,electric field ,Ignition system ,plasma bullet ,Torr ,Physics::Space Physics ,symbols ,Atomic physics ,0210 nano-technology - Abstract
International audience; In this paper the generation and diagnostics of a reduced pressure (300 mTorr to 3 Torr) plasma generated inside an electrodeless containment vessel/chamber are presented. The plasma is ignited by a guided ionization wave emitted by a low temperature pulsed plasma jet. The diagnostics techniques include Intensified Charge Coupled Device (ICCD) imaging, emission spectroscopy, and Langmuir probe. The reduced-pressure discharge parameters measured are the magnitude of the electric field, the plasma electron number density and temperature, and discharge expansion speed.
- Published
- 2019
27. Study of the influence of discharge loop parameters on anode side on generation characteristics of metal plasma jet in a pulsed vacuum discharge
- Author
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Wenzheng Liu, Pengxiang Liu, Jia Tian, Xitao Jiang, Wenjun Zhang, and Gao Yongjie
- Subjects
Loop (topology) ,Metal ,Materials science ,visual_art ,visual_art.visual_art_medium ,Plasma jet ,Atomic physics ,Condensed Matter Physics ,Anode - Abstract
In a pulsed vacuum discharge, the ejection performance of a metal plasma jet can be effectively improved by preventing charged particles from moving to the anode. In this paper, the effects of resistance and capacitance on the anode side on the discharge characteristics and the generation characteristics of plasma jet are investigated. Results show that the existence of a resistor on the anode side can increase the anode potential, thereby preventing charged particles from entering the anode and promoting the ejection of charged particles along the axis of the insulating sleeve nozzle. The application of a capacitor on the anode side can not only absorb electrons at the initial stage of discharge, increasing the peak value of the cathode hump potential, but also prevent charged particles from moving to the anode, thereby improving the ejection performance of the plasma jet. In addition, the use of a larger resistance and a smaller capacitance can improve the blocking effect on charged particles and further improve the ejection performance of the plasma jet. Results of this study will provide a reference for the improvement of the ejection performance of plasma jets and their applications.
- Published
- 2021
28. The twisted behavior of a rotating electrode atmospheric-pressure argon plasma jet
- Author
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J Liu, Lanlan Nie, Yubin Xian, and Xinpei Lu
- Subjects
Argon ,Materials science ,Acoustics and Ultrasonics ,Atmospheric pressure ,Plasma jet ,chemistry.chemical_element ,Atmospheric-pressure plasma ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Physics::Plasma Physics ,Metastability ,Electrode ,Atomic physics - Abstract
The twisted behavior of a rotating electrode atmospheric-pressure argon plasma jet is reported and its mechanism is investigated. It is found that the plasma channel turns into a smooth pathway when about 5% of O2 or 3% of N2 are added to the main working gas, argon. Further investigation shows that the rotational frequency of the electrode, which can enhance the turbulence of the gas flow, does not affect the appearance of the plasma channel for both pure argon and argon mixed with different amounts of O2/N2. The optical emission spectra show that the emission intensities of the transitions from seven excited argon levels to two metastable states decrease dramatically when O2/N2 is added. Detailed analyses suggest that when O2/N2 is added, both the concentrations of argon in the two metastable states and their lifetimes decrease significantly, which results in a transition of the discharge channel from a turbulent pathway to a smooth pathway. In short, the metastable state of argon rather than the seed electrons plays the key role in the appearance of the plasma channel.
- Published
- 2021
29. Study on the characteristics of helium plasma jet by pulsed micro-hollow cathode discharge
- Author
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Feng He, Ruoyu Han, Jiting Ouyang, Zhengchao Duan, and Peizhen Li
- Subjects
Jet (fluid) ,Materials science ,Physics::Plasma Physics ,law ,Plasma jet ,Atomic physics ,Condensed Matter Physics ,Helium plasma ,Cathode ,law.invention - Abstract
In this paper, the helium plasma jet generated by micro-hollow cathode discharge (MHCD) was studied. The MHCD was driven by a square-wave pulsed power source, and the characteristics of discharge and plasma jet were measured experimentally. The influences of the gas flow rate on the MHCD and the plasma jet were investigated. And the propagation mechanisms of the plasma jet were analyzed. The results show that within 100–1000 sccm of the gas flow rate, the breakdown delay time of the MHCD increases with the helium flow increasing. It is considered that the gas flow affects the density of seed electrons and thus the breakdown delay time. With the helium flow rate increasing, the whole plasma jet length increases firstly and then decreases. A detailed investigation shows that during one discharge pulse, two distinguishable propagation processes of the plasma jet are observed. It is found that the jet of the first stage is formed during the rising edge of the current pulse, while the other is generated after the discharge current becomes stable. The propagation velocity of jet in the first stage is on the order of several km s−1, which is similar to that of the discharge evolution obtained by simulation. And the propagation speed of the jet in the second stage is on the order of several hundred m s−1, which is close to the velocity of gas flow. The spatial–temporal distributions of light emission show that high-energy electrons can only be observed during the jet propagation in the first stage, and low-energy electrons can be detected in both the first and second stages. The results show that the electric field plays an important role on the jet propagation in the first stage, and the jet propagation during the second stage is mainly promoted by the thermal gas expansion.
- Published
- 2021
30. Three-dimensional hybrid simulation of single cathode spot vacuum arc plasma jet under axial magnetic field
- Subjects
Materials science ,Physics::Plasma Physics ,law ,Plasma jet ,General Physics and Astronomy ,Vacuum arc ,Atomic physics ,Cathode ,law.invention ,Magnetic field - Abstract
Vacuum arc is a special metal vapor discharge phenomenon, because its discharge medium totally comes from the evaporation and ionization of electrode materials. In the case of low current, the vacuum arc is completely composed of plasma jets emitted from discrete cathode spots on the cathode surface and the current carried by each spot depends on the cathode material. When the arc current exceeds a certain value, a certain number of cathode spot plasma jets will appear. Vacuum arcs play a very important role in some industrial applications such as vacuum circuit breakers, vacuum coatings and electric thrusters. As an important plasma control method, the external axial magnetic field (AMF) has an important influence on the macroscopic morphology and microscopic parameter distribution of the vacuum arc. Various studies of vacuum arc under AMF have been carried out and some progress has been made. However, the existing literature about the simulation research of vacuum arc is mostly concentrated in the case of large current, and less attention is paid to the case of small current. The reason is that the traditional methods, magneto-hydrodynamics or particle-in-cell, are limited by either accuracy or efficiency, and cannot be effectively applied to the low current vacuum arc plasma jet simulations. In this paper, we develop a fully three-dimensional hybrid plasma simulation algorithm to study the single cathode spot vacuum arc plasma jet under AMF. In this model, ions are modelled as particles while electrons are treated as massless fluid, and the self-generated magnetic field is also considered. To simplify the condition, the cathode spot in our model only exists as a plasma jet source, thus the detailed mechanism of producing plasmas is neglected. And the movement of the cathode spot is not considered either. The results show that the single cathode spot plasma jet diffuses into the interelectrode in a cone shape after leaving the cathode spot, and the ion density drops rapidly from cathode to anode. Under the simulation conditions in this paper (I ≤ 150 A), the self-generated magnetic field will not have a significant influence on the plasma jet itself in the case of low current. The external AMF has a compressive effect on the diffusion of the vacuum arc plasma jet. Under the AMF, the radial movement of the ions is suppressed, and the decrease of the ion radial velocity leads to a smaller diffusion radius of the jet. This compression effect of the AMF on the plasma jet is related to both the intensity of the external AMF and the magnitude of the arc current. In the case of a constant arc current magnitude, the compression effect gradually increases as the value of the AMF intensity gradually increases; in the case of a constant value of the external AMF, the compression effect gradually decreases as the current gradually becomes larger.
- Published
- 2021
31. Measurements of energy absorbed in metal foils during their exposure to plasma jet at the Plasma Focus facility
- Author
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V N Kokololtsev, P. V. Silin, E. N. Peregudova, S. A. Maslyaev, I. V. Borovitskaya, and V. Ya. Nikulin
- Subjects
Metal ,History ,Materials science ,Dense plasma focus ,visual_art ,Plasma jet ,visual_art.visual_art_medium ,Atomic physics ,Energy (signal processing) ,Computer Science Applications ,Education - Abstract
The work presents the results of estimating the energy absorbed in metal foils (copper, aluminium, and vanadium) during their exposure to the high-speed (>107 cm/s) plasma jets generated in a plasma focus facility. The absorbed energy was calculated under assumption that the plasma jet power is not too high, which allowed us to neglect the loss of material due to evaporation. In this case, when the foils were exposed to the single plasma jet, the amount of absorbed energy was determined using data on the mass of the molten metal layer and the ablated melt mass. The energy absorbed in the Al, Cu and V foils calculated in this way turned out to be ~6.5, 5 and 2.1 J, respectively, which is considerably less than the plasma jet energy, which is of the of the order ~100 J.
- Published
- 2020
32. Interaction of microwave radiation with an erosion plasma jet
- Author
-
Vadim Brovkin, A. S. Pashchina, and N. M. Ryazanskiy
- Subjects
010302 applied physics ,Physics ,Physics and Astronomy (miscellaneous) ,Turbulence ,Capillary action ,Attenuation ,Plasma jet ,Perturbation (astronomy) ,respiratory system ,equipment and supplies ,complex mixtures ,01 natural sciences ,010305 fluids & plasmas ,Physics::Plasma Physics ,0103 physical sciences ,Atomic physics ,human activities ,Microwave ,circulatory and respiratory physiology - Abstract
The interaction of high-power pulsed microwave radiation with a plasma jet formed by a discharge in an ablative capillary is studied. A significant influence of microwave radiation on the plasma jet flow is found. Depending on the intensity of the initial perturbation of the jet, different scenarios of its evolution downstream are possible: attenuation or amplification accompanied with the development of turbulence up to the disruption of the flow if a certain threshold of the energy action is exceeded. A significant influence of the plasma jet and its state on the spatial position of the microwave energy release zone is found.
- Published
- 2016
33. Modelling of new generation plasma optical devices
- Author
-
Irina V. Litovko, Alexy A. Goncharov, Lily V. Naiko, Irina V. Naiko, and Andrew N. Dobrovolskiy
- Subjects
Nuclear and High Energy Physics ,ComputerSystemsOrganization_COMPUTERSYSTEMIMPLEMENTATION ,plasma jet ,Science ,Plasma jet ,Plasma ,plasma lens ,Condensed Matter Physics ,01 natural sciences ,Space charge ,010305 fluids & plasmas ,Nuclear Energy and Engineering ,Physics::Plasma Physics ,anode layer ,0103 physical sciences ,Physics::Space Physics ,plasma accelerator ,space charge ,Atomic physics ,Safety, Risk, Reliability and Quality ,Waste Management and Disposal ,Instrumentation - Abstract
The paper presents new generation plasma optical devices based on the electrostatic plasma lens configuration that opens a novel attractive possibility for effective high-tech practical applications. Original approaches to use of plasma accelerators with closed electron drift and open walls for the creation of a cost-effective low-maintenance plasma lens with positive space charge and possible application for low-cost, low-energy rocket engine are described. The preliminary experimental, theoretical and simulation results are presented. It is noted that the presented plasma devices are attractive for many different applications in the state-of-the-art vacuum-plasma processing.
- Published
- 2016
34. Time-resolved electric field measurements during and after the initialization of a kHz plasma jet : from streamers to guided streamers
- Author
-
Oyn Olivier Guaitella, Elmar Slikboer, A Ana Sobota, Atmospheric pressure non-thermal plasmas and their interaction with substrates, Elementary Processes in Gas Discharges, Laboratoire de Physique des Plasmas (LPP), Université Paris-Sud - Paris 11 (UP11)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010302 applied physics ,initialization ,Chemistry ,plasma jet ,Analytical chemistry ,Initialization ,Atmospheric-pressure plasma ,guided streamers ,Plasma ,Dielectric ,time resolved ,Condensed Matter Physics ,01 natural sciences ,Pockels effect ,010305 fluids & plasmas ,electric field ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Physics::Plasma Physics ,pockels effect ,Ionization ,Electric field ,0103 physical sciences ,ionization waves ,Atomic physics ,Voltage - Abstract
International audience; This work presents the investigation of a 30 kHz operated atmospheric pressure plasma jet impinging a dielectric BSO-crystal, allowing time-resolved electric field measurements based on the Pockels effect. Observations indicate that from the time the voltage is applied, the plasma first develops through unstable branching before a stable periodic behavior is established. This initialization of the plasma jet suggests the importance of the build-up of leftover ionization, which creates a preferred pathway for the streamer-like discharges. After initialization the time and spatially resolved electric field of guided ionization waves induced in the crystal is obtained, showing a highly periodic charging and discharging at the surface of the crystal. When the ionization wave arrives at the crystal charge is deposited and constant electric fields are generated for approximately 14 μs. Then a (back) discharge will remove the deposited charge at the surface, related to the moment when the applied voltage changes polarity and it agrees with imaging reported on in other literature.
- Published
- 2016
35. Diagnostics of Plasma Jet Generated in Water/Argon DC Arc Torch
- Author
-
O. Hurba, M. Hrabovský, and M. Hlina
- Subjects
Torch ,Argon ,Materials science ,Physics and Astronomy (miscellaneous) ,Plasma jet ,chemistry.chemical_element ,Condensed Matter Physics ,law.invention ,Physics::Fluid Dynamics ,chemistry ,Physics::Plasma Physics ,law ,Physics::Space Physics ,Atomic physics - Abstract
Thermal plasma jet generated by the torch with water/argon stabilized arc was investigated. Plasma torches of this type have been used for plasma spraying, waste treatment and gasification of organic materials. Electric probes, enthalpy probe, and schlieren photography were used for diagnostics of the jet in the region downstream of the torch exit. Information about structure and shape of plasma jet was evaluated from the measured data. Large extent of radial plasma spread and high level of turbulence were found from both the schlieren and the probe diagnostics. Plasma temperature corresponding to measured ion saturation currents was determined using calculated composition of plasma assuming ex-istence of local thermodynamic equilibrium.
- Published
- 2016
36. Formation of a cathode plasma jet in a laser-induced vacuum discharge
- Author
-
A. S. Shikanov, V. A. Podvyaznikov, V. L. Paperny, V. K. Chevokin, A. A. Rupasov, I. V. Romanov, and Yu. V. Korobkin
- Subjects
010302 applied physics ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Plasma jet ,Plasma ,Laser ,01 natural sciences ,Cathode ,010305 fluids & plasmas ,law.invention ,Pulse (physics) ,Optics ,law ,HOT Region ,0103 physical sciences ,Atomic physics ,business ,Pulse energy - Abstract
The process of formation of micropinch structures in the plasma of a vacuum discharge initiated by a laser pulse on the cathode is studied. It is demonstrated that the micropinch formation takes place mainly in the substance evaporated by the laser pulse upon the discharge initiation. The size of the hot region of the plasma jet and the distance from the cathode to the micropinch increase with increasing laser pulse energy.
- Published
- 2016
37. A Microsecond-Pulsed Cold Plasma Jet for Medical Application
- Author
-
Chao Zheng, Zhen Liu, Yifan Huang, Hongqiang Jiang, Keping Yan, Anna Zhu, and Kou Yanqin
- Subjects
Microsecond ,Materials science ,Plasma torch ,Biomedical Engineering ,Plasma jet ,General Physics and Astronomy ,Atomic physics ,Plasma medicine ,Pulsed power ,Nonthermal plasma - Published
- 2016
38. Emission Properties of an Atmospheric Pressure Argon Plasma Jet Excited by Barrier Discharge
- Author
-
O.M. Korbut, M.S. Klenivskyi, Yu.V. Zhmenyak, and V. A. Kel’man
- Subjects
Argon ,Materials science ,chemistry ,Atmospheric pressure ,Plasma cleaning ,Excited state ,Plasma jet ,General Physics and Astronomy ,chemistry.chemical_element ,Atomic physics - Published
- 2015
39. Heat Transfer Between a Plasma Jet and a Metal Surface in a Cut Cavity
- Author
-
A. N. Veremeichik, V. M. Khvisevich, D. L. Tsyganov, and M. I. Sazonov
- Subjects
Surface (mathematics) ,Electric arc ,Work (thermodynamics) ,Materials science ,Plasma torch ,Heat transfer ,General Engineering ,Plasma jet ,Plasma ,Mechanics ,Atomic physics ,Condensed Matter Physics ,Plasmatron - Abstract
Investigations are presented of the formation of a plasma jet and of the current-density and heat-flux distributions in the process of metal cutting along the cut cavity with direct and reverse polarities of the plasmatron connection. The study of the specific features of heat transfer of the arc with the surface of the cut cavity was carried out on the basis of the developed plasma unit which makes it possible to model the technological process of separating metal cutting. A sectional cut model is proposed which can be used to work out and optimize the methods of determination of cutting parameters.
- Published
- 2015
40. Tuning of operational parameters for effective production of nitric oxide using an ambient air rotating glow discharge jet
- Author
-
Naoyuki Iwata, Masafumi Ito, Mineo Hiramatsu, and Vladislav Gamaleev
- Subjects
Glow discharge ,chemistry.chemical_compound ,Jet (fluid) ,Physics and Astronomy (miscellaneous) ,chemistry ,General Engineering ,Plasma jet ,General Physics and Astronomy ,Plasma medicine ,Atomic physics ,Nitric oxide ,Ambient air - Published
- 2020
41. The effect of a second grounded electrode on the atmospheric pressure argon plasma jet
- Author
-
Jamal Q. M. Almarashi, Mazen Mohamed Aljuhani, Ali A. Alhazime, and Abdel-Aleam H. Mohamed
- Subjects
Nuclear and High Energy Physics ,Argon ,Materials science ,Nuclear Energy and Engineering ,chemistry ,Atmospheric pressure ,Electrode ,Plasma jet ,chemistry.chemical_element ,Atomic physics ,Condensed Matter Physics - Published
- 2020
42. Study on plasma ejection near the anode in a pulsed low-current vacuum discharge
- Author
-
Jia Tian, Yongjie Gao, Wenjun Zhang, Wenzheng Liu, and Luxiang Zhao
- Subjects
Materials science ,Plasma jet ,General Physics and Astronomy ,Plasma ,Microporous material ,01 natural sciences ,010305 fluids & plasmas ,Anode ,Theory analysis ,0103 physical sciences ,Electrode ,Atomic physics ,Current (fluid) ,010306 general physics ,Layer (electronics) - Abstract
An electrode structure with two anodes, one of which is covered by an insulating material layer with a micropore, is proposed in this letter, and adopting this electrode structure enables a special vacuum discharge phenomenon, by which a visible ejected plasma jet is formed near the anode in a pulsed low-current (∼200 A) vacuum discharge to be firstly observed. According to experimental study and theory analysis, the formation mechanism of the discharge phenomenon observed above is analysed. Study on this special discharge phenomenon is of vital importance for revealing the basic physical processes in a vacuum discharge.
- Published
- 2020
43. Extending the volume of atmospheric pressure plasma jets through the use of additional helium gas streams
- Author
-
Michael J. Johnson, Tzvetelina Petrova, David R. Boris, and Scott G. Walton
- Subjects
Materials science ,Helium gas ,Volume (thermodynamics) ,Plasma jet ,Atmospheric-pressure plasma ,Optical emission spectroscopy ,Plasma ,STREAMS ,Atomic physics ,Condensed Matter Physics - Published
- 2020
44. The effect of mixed electric field on characteristic of Ar–N2 plasma jets for TiN surface treatment
- Author
-
Ahmad Khademi, Ali Reza Farhadizadeh, Saeed Ghasemi, Pourya Seyfi, and Hamidreza Ghomi
- Subjects
Surface (mathematics) ,Materials science ,Acoustics and Ultrasonics ,chemistry ,Electric field ,Plasma jet ,chemistry.chemical_element ,Plasma ,Atomic physics ,Condensed Matter Physics ,Tin ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2020
45. Measurement of time-varying electron density of air spark shock wave plasma jet by the method of microwave Rayleigh scattering
- Author
-
Chen Zhao-quan, Zhou Yu-Ming, Zhang Huang, Wu Jin-Fang, Feng De-ren, Zhang Ming, and Zhang San-Yang
- Subjects
Shock wave ,symbols.namesake ,Electron density ,Materials science ,Physics::Plasma Physics ,Spark (mathematics) ,symbols ,Plasma jet ,General Physics and Astronomy ,Atomic physics ,Rayleigh scattering ,Microwave - Abstract
It is difficult in measuring the electron density of an atmospheric air spark shock wave plasma jet, due to its variation on the time scale of sub-microseconds. In this paper, the time-varying electron density of air spark shock wave plasma jet is measured, based on the principle of microwave Rayleigh scattering. The system constant A is determined by using calibration of materials with known properties; the results show that the system constant is obtained as A = 1.04 × 105 V·Ω·m–2. According to the principle of microwave Rayleigh scattering, the electron density of the plasma jet is related to its radius and length of the plasma jet plume. Combined with the discharge image captured by ICCD camera, it is observed that the plasma jet plumes are with irregular patterns. In order to facilitate the calculation, the plasma jet plumes are replaced by cylinders with the same volume as the original shapes. Thus, the equivalent radius and length of the plasma jet plume are obtained. According to the known data, the electron density is determined to be in the order of 1020 m–3; its value increases rapidly to the peak value, and after then exponential attenuates along with time. In addition, the effect of different equivalent dimensions of the plasma jet plume on the measurement results is also discussed. It is shown that the calculation result with the time-varying equivalent radius and the time-varying equivalent length is the most effective one. In addition, the first fast peak is caused by the ionization wave of the photo ionization. The actual ionization process is that the air discharge in the cathode cavity releases a large number of high energy photons, which pass through the cathode nozzle and project into the region outside the nozzle; and then the O2 molecule in the ambient air are ionized by those high energy photons to form the plasma jet plume at the time of 1 μs.
- Published
- 2020
46. Modeling of plasma jet of vacuum arc with copper-chromium cathode under action of strong axial magnetic field
- Author
-
Igor V. Uimanov, D. L. Shmelev, and V. P. Frolova
- Subjects
History ,PLASMA JETS ,CALCULATION RESULTS ,COPPER CHROMIUM ,Materials science ,ELECTRIC DISCHARGES ,COPPER ,chemistry.chemical_element ,COMPOSITE CATHODE ,Education ,law.invention ,Chromium ,CHROMIUM ,Physics::Plasma Physics ,law ,VACUUM ARCS ,CATHODES ,PLASMA THEORY ,AXIAL MAGNETIC FIELD ,VACUUM TECHNOLOGY ,Plasma jet ,MAGNETIC FIELDS ,Vacuum arc ,Copper ,HYBRID MODEL ,Cathode ,Action (physics) ,Computer Science Applications ,Magnetic field ,VACUUM APPLICATIONS ,chemistry ,MACRO-PARTICLES ,Atomic physics ,MAGNETOPLASMA ,AVERAGE CHARGE STATE - Abstract
This paper deals with the computer simulation of a vacuum arc with composite cathode under action of external axial magnetic using hybrid model. The described hybrid model treats the electrons as a massless fluid and ions as macroparticles. It is shown that the average charge state of ions in a jet of a vacuum arc increases with increasing magnetic field. The calculation results are consistent with experimental data. © 2019 IOP Publishing Ltd. All rights reserved. Russian Science Foundation, RSF: 18-19-00069 This work was supported by Russian Science Foundation (project No. 18-19-00069).
- Published
- 2019
47. Pulsed plasma jet interaction with a metal targets
- Author
-
A. I. Klimov, B. N. Tolkunov, V. Kh Timirbulatov, A. S. Pashchina, and N. K. Belov
- Subjects
History ,Materials science ,Plasma jet ,Atomic physics ,Computer Science Applications ,Education - Abstract
The results of experimental studies of the interaction of plasma jets, created by a pulsed capillary discharge with an evaporating wall, with metal targets are presented. It is shown that the main mechanism of targets destruction is the material melting and the subsequent removal of the melt under the dynamic pressure of the plasma jet. The main sources of energy transmitted to the target are: the high-speed flow of high-enthalpy plasma created inside the capillary, and the fluxes of charged particles accelerated in the near-electrode layers. The energy transport provided by charged particles does not exceed ∼0.1–0.2 of the total energy input onto the target. The enthalpy transport is capable to provide heat flux densities of ∼5-6 kW/mm2, an order of magnitude exceeding the values achievable in welding arcs.
- Published
- 2019
48. Investigation of plasma jet sources with high kinetic energy
- Author
-
V. Yu Goryainov, A. N. Novokhatsky, A. V. Voronin, S. A. Ponyaev, and V. K. Gusev
- Subjects
History ,Materials science ,Physics::Instrumentation and Detectors ,Physics::Plasma Physics ,Plasma jet ,Physics::Accelerator Physics ,Atomic physics ,High kinetic energy ,Computer Science Applications ,Education - Abstract
Results of coaxial and rail electromagnetic accelerators investigation with pulsed gas puffing and different shapes and lengths of electrodes are presented. The influence of an additional magnetic field on accelerator parameters was studied. The method for plasma jet parameters controlling was developed with the use of a piezo-sensor and infrared camera. The plasma jet pressure dependences on the accelerator length and polarity of the electrode voltage, as well as on the distance from accelerator were derived in experiments on the plasma gun test bench. Coaxial plasma gun with the electrode length 220 mm, negative polarity of the central electrode voltage and focusing insert placed into the initial part of the accelerator proved to be most effective. At the output of the accelerator deuterium plasma jet was obtained with flow velocity up to 160 km/s and pressure up to 2 MPa.
- Published
- 2019
49. Ar(1s(5)) absolute radial densities in a ns-pulsed argon plasma jet impinging on dielectric targets at floating potential - plasma action on organic molecules
- Author
-
Kristaq Gazeli, Blandine Bournonville, N. Blin-Simiand, G. Bauville, Pascal Jeanney, Thomas Vazquez, Stéphane Pasquiers, Sara Al-Homsi, Michel Fleury, O. Neveu, Joao Santos Sousa, Laboratoire de physique des gaz et des plasmas (LPGP), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
- Subjects
010302 applied physics ,argon plasma jet ,Argon ,Materials science ,Polymers and Plastics ,dielectric targets ,Floating potential ,physical and chemical desorption ,Plasma jet ,chemistry.chemical_element ,organic substances ,Dielectric ,Plasma ,Condensed Matter Physics ,01 natural sciences ,Action (physics) ,010305 fluids & plasmas ,Organic molecules ,chemistry ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,volatile organic compounds ,0103 physical sciences ,argon metastables ,laser absorption spectroscopy ,Atomic physics - Abstract
International audience; The present work is devoted to the precise spatiotemporal mapping of the absolute density of Ar(1s(5)) in a ns-pulsed argon plasma jet. The plasma impinges on glass and alumina targets at floating potential placed 5mm away from the reactor's nozzle. Under these conditions, diffuse discharges are established in the small gas gap. As so, the line-of-sight absolute density of Ar(1s(5)) is effectively evaluated via laser absorption spectroscopy. The application of the Abel-inversion is also demonstrated for different operating conditions leading to the precise radial mapping of the Ar(1s(5)) absolute density. The influence of each target is studied for two gas flow rates, 0.3 and 0.4lmin(-1). The temporal density profiles over a voltage pulse period reveal two maxima related with the Ar(1s(5)) production in the streamer head and in the residual diffuse plasma channel. Furthermore, the maximum Ar(1s(5)) axial/radial density (approximate to 10(13)-3.5x10(14)cm(-3)) depends on the target material and gas flow rate. Finally, the plasma is proved to be very effective for the fast desorption of organic molecules (bibenzyl) deposited on both targets. The results obtained suggest that the desorption of bibenzyl is due to the production of high Ar(1s(5)) densities at the close vicinity of the targets. [GRAPHICS] .
- Published
- 2018
50. Searching for order in atmospheric pressure plasma jets
- Author
-
Jan Schäfer, Florian Sigeneger, Rüdiger Foest, Cornelia Rodenburg, and Jiří Šperka
- Subjects
010302 applied physics ,Physics ,Atmospheric pressure ,Convective heat transfer ,plasma jet ,Flow (psychology) ,Order (ring theory) ,Atmospheric-pressure plasma ,Plasma ,Condensed Matter Physics ,Rotation ,Atmospheric sciences ,01 natural sciences ,self-organization ,010305 fluids & plasmas ,hydrodynamic simulation ,Azimuth ,Nuclear Energy and Engineering ,Physics::Plasma Physics ,0103 physical sciences ,Atomic physics ,Konferenzschrift - Abstract
The self-organized discharge behaviour occurring in a non-thermal radio-frequency plasma jet in rare gases at atmospheric pressure was investigated. The frequency of the azimuthal rotation of filaments in the active plasma volume and their inclination were measured along with the gas temperature under varying discharge conditions. The gas flow and heating were described theoretically by a three-dimensional hydrodynamic model. The rotation frequencies obtained by both methods qualitatively agree. The results demonstrate that the plasma filaments forming an inclination angle α with the axial gas velocity u z are forced to a transversal movement with the velocity ${u}_{\phi }=\tan (\alpha )\cdot {u}_{z}$, which is oriented in the inclination direction. Variations of ${u}_{\phi }$ in the model reveal that the observed dynamics minimizes the energy loss due to convective heat transfer by the gas flow. The control of the self-organization regime motivates the application of the plasma jet for precise and reproducible material processing.\ud \ud
- Published
- 2017
- Full Text
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