The nonextensive effects on the supersoliton structure in critical plasma state

The production of iron using hydrogen as a reducing agent is an alternative to conventional iron- and steel-making processes, with an associated decrease in CO2 emissions. Hydrogen plasma smelting reduction (HPSR) of iron ore is the process of using hydrogen in a plasma state to reduce iron oxides. A hydrogen plasma arc is generated between a hollow graphite electrode and liquid iron oxide. In the present study, the thermodynamics of hydrogen thermal plasma and the reduction of iron oxide using hydrogen at plasma temperatures were studied. Thermodynamics calculations show that hydrogen at high temperatures is atomized, ionized, or excited. The Gibbs free energy changes of iron oxide reductions indicate that activated hydrogen particles are stronger reducing agents than molecular hydrogen. Temperature is the main influencing parameter on the atomization and ionization degree of hydrogen particles. Therefore, to increase the hydrogen ionization degree and, consequently, increase of the reduction rate of iron ore particles, the reduction reactions should take place in the plasma arc zone due to the high temperature of the plasma arc in HPSR. Moreover, the solubility of hydrogen in slag and molten metal are studied and the sequence of hematite reduction reactions is presented.

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Nonlinear Mirror and Weibel modes: peculiarities of quasi-linear dynamics

Annales Geophysicae ◽

10.5194/angeo-28-2161-2010 ◽

2010 ◽

Vol 28 (12) ◽

pp. 2161-2167 ◽

Cited By ~ 13

Author(s):

O. A. Pokhotelov ◽

R. Z. Sagdeev ◽

M. A. Balikhin ◽

V. N. Fedun ◽

G. I. Dudnikova

Keyword(s):

Distribution Function ◽

Mode Coupling ◽

Nonlinear Evolution ◽

Particle Interaction ◽

Velocity Distribution Function ◽

Larmor Radius ◽

Initial Stage ◽

Plasma State ◽

Bgk Modes ◽

Mirror Mode

Abstract. A theory for nonlinear evolution of the mirror modes near the instability threshold is developed. It is shown that during initial stage the major instability saturation is provided by the flattening of the velocity distribution function in the vicinity of small parallel ion velocities. The relaxation scenario in this case is accompanied by rapid attenuation of resonant particle interaction which is replaced by a weaker adiabatic interaction with mirror modes. The saturated plasma state can be considered as a magnetic counterpart to electrostatic BGK modes. After quasi-linear saturation a further nonlinear scenario is controlled by the mode coupling effects and nonlinear variation of the ion Larmor radius. Our analytical model is verified by relevant numerical simulations. Test particle and PIC simulations indeed show that it is a modification of distribution function at small parallel velocities that results in fading away of free energy driving the mirror mode. The similarity with resonant Weibel instability is discussed.

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Geometric scalings for the electrostatically driven helical plasma state

Physics of Plasmas ◽

10.1063/1.5011774 ◽

2017 ◽

Vol 24 (12) ◽

pp. 124507 ◽

Cited By ~ 1

Author(s):

Cihan Akçay ◽

John M. Finn ◽

Richard A. Nebel ◽

Daniel C. Barnes

Keyword(s):

Plasma State

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Plasma Enhanced Chemical Vapor Deposition synthesis of graphene-like structures from plasma state of CO2 gas

Carbon ◽

10.1016/j.carbon.2020.05.057 ◽

2020 ◽

Vol 167 ◽

pp. 132-139

Author(s):

M.Ye. Svavil’nyi ◽

V.Ye. Panarin ◽

A.A. Shkola ◽

A.S. Nikolenko ◽

V.V. Strelchuk

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Vapor ◽

Co2 Gas ◽

Plasma State

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Dynamical Spectra in Two-Dimensional Dusty Plasmas

10.4018/978-1-7998-8398-2.ch002 ◽

2022 ◽

pp. 34-48

Author(s):

Aamir Shahzad ◽

Zakia Rafiq ◽

Alina Manzoor ◽

Muhammad Kashif

Keyword(s):

Plasma Density ◽

Coupling Parameter ◽

Transient Behavior ◽

Dynamical Structure ◽

Two Dimensional ◽

Debye Screening ◽

Coulomb Coupling ◽

Plasma State ◽

Dynamical Spectra ◽

Number Of Particles

Equilibrium molecular dynamics (EMD) simulation has been employed to explore the dynamical structure factors (DSFs) of two-dimensional (2D) dusty plasma systems for a wide domain of plasma parameters of Coulomb coupling (Γ) and Debye screening strength (κ). The influence of varying wave vectors (k) on plasma DSFs S (k, ω) have been reported with different combinations of plasma state points (Γ, κ). New simulations have been tested for the influence of different wave vectors on plasma density S (k, ω) in addition to different combinations of plasma state points. New results of plasma density S (k, ω) show that amplitude of oscillation and frequency will vary with increasing value of Coulomb coupling parameter (Γ) and Debye screening strength (κ). These simulation techniques show that transient behavior has been reported for frequency (ω) with various values of Debye screening strength (κ) and number of particles (N). Moreover, EMD simulation has been checked in order to investigate the behavior of plasma DSFs with increasing number of particles (N). The outcomes of EMD simulations are matched to earlier known numerical and experimental data. It has been shown that fluctuation of dynamical density increases at intermediate to higher values of coupling parameter. However, it shows less fluctuation at higher values of Debye screening strength (κ).

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Spectroscopic Study and Amorphous Film Deposition in RF and Pulsed Plasma Processings

MRS Proceedings ◽

10.1557/proc-117-67 ◽

1988 ◽

Vol 117 ◽

Cited By ~ 1

Author(s):

Kenji Ebihara ◽

Seiji Kanazawa ◽

Sadao Maeda

Keyword(s):

Processing System ◽

Optical Emission ◽

Quantitative Relationship ◽

Amorphous Film ◽

Film Deposition ◽

Rf Discharge ◽

Pulsed Plasma ◽

Plasma Parameters ◽

Optical Emission Spectrum ◽

Plasma State

AbstractProcessing plasmas generated by three types of discharges are diagnosed spectroscopically in order to estimate the quantitative relationship between plasma parameters and electrical and optical properties of deposited materials. An rf discharge is capacitively produced by a 13.56 MHz rf oscillator. A microwave generator operating at 2.45 GHz is used to supply power to a discharge cavity. Further a pulsed plasma which is inductively generated by pulsed current ( 70 kA peak ) is applied to study dissociation process in the transient plasma and possibility of a novel processing system. The gases used are methane for amorphous carbon formation and silane for amorphous silicon deposition. Measurements of optical emission spectrum are performed to estimate the processing plasma state by the relative spectral intensity method and the Doppler-broadening method.

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FUSION OF STRINGS VS. PERCOLATION AND THE TRANSITION TO THE QUARK–GLUON PLASMA

International Journal of Modern Physics A ◽

10.1142/s0217751x99001354 ◽

1999 ◽

Vol 14 (17) ◽

pp. 2689-2704 ◽

Cited By ~ 31

Author(s):

M. A. BRAUN ◽

C. PAJARES ◽

J. RANFT

Keyword(s):

Phase Transition ◽

Quark Gluon Plasma ◽

Critical Density ◽

Gluon Plasma ◽

Second Order ◽

Plasma State ◽

Hadronic Collisions

In most of the models of hadronic collisions, the number of exchanged color strings grows with energy and atomic numbers of the projectile and target. At high string densities interaction between them becomes important, which should melt them into the quark–gluon plasma state in the end. It is shown that under certain reasonable assumptions about the string interaction, a phase transition to the quark–gluon plasma indeed takes place in the system of many color strings. It may be of the first or second order, depending on the particular mechanism of the interaction. The critical string density is about unity in both cases. In the latter case the percolation of strings occurs above the critical density. The critical density may have already been reached in central Pb–Pb collisions at 158A GeV.

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