scholarly journals Plasma Parameters around a Chain-Like Structure of Dust Particles in an External Electric Field

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3846
Author(s):  
Mikhail Salnikov ◽  
Alexander Fedoseev ◽  
Gennadiy Sukhinin
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Electric Potential ◽  
Mean Free Path ◽  
The Self ◽  
Dust Particles ◽  
Charged Dust ◽  
Plasma Parameters ◽  
Self Consistent ◽  
A Chain

The formation of a 1D chain-like structure of dust particles in a low-temperature argon plasma was studied. A new numerical model for calculation of the self-consistent spatial distribution of plasma parameters around a chain of dust particles was presented. The model described the motion of positively charged ions in the electric potential of several negatively charged dust particles, taking into account the action of an external electric field. The main advantage of the model was that the charges of the dust particles and the interparticle distances were determined self-consistently. As a result of numerical simulations, the dependencies of the spatial distributions of the plasma parameters (the densities of electrons and ions and the self-consistent electric potential) near the dust particles chain on the strength of the external electric field, an external force acted on the last particle, and the mean free path of the ions was determined. The obtained results made it possible to describe the process of the formation of chain-like structures of dust particles in discharge plasma.

KINETIC CONFINEMENT AND ZERO–ELECTRIC–FIELD BINDING IN HgCdTe ACCUMULATION LAYERS

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3637-3640
Author(s):  
V. F. RADANTSEV ◽  
G. I. KULAEV ◽  
V. V. KRUZHAEV
Keyword(s):  
Experimental Data ◽  
Magnetic Fields ◽  
Electric Field ◽  
External Electric Field ◽  
Bound States ◽  
The Self ◽  
Screening Length ◽  
Self Consistent ◽  
Level Method ◽  
Capacitance Spectroscopy

The effects of kinetic confinement and forming of surface bound states at a zero external electric field (ZEF) are studied experimentally (by the magneto-capacitance spectroscopy of Landau level method) and theoretically (in 8×8 Kane model). The self-consistent calculations we performed predict the existence of occupied kinetically bound but not true bound states at a zero interface electric field that is in agreement with experimental data. The capacitance oscillations at in 2D plane magnetic fields orientation we observed are associated with oscillations of continuum electrons screening length.

scholarly journals Electrostatic Analyses for a System Constituted by an Insulating Disk Whose One Plane Surface is Charged and Which is Backed by a Concentric Earthed Metal Disk Smaller Than the Insulating Disk Itself and an Earthed Sphere Approaching the Charged Surface of the Insulating Disk, and Its Application to the Case of a Typical Oxygen Regulator

2019 ◽  
Author(s):  
Nirmalya Basu
Keyword(s):  
Electric Field ◽  
Plane Surface ◽  
Dust Particles ◽  
Charged Dust ◽  
Potential Candidate ◽  
Charged Surface ◽  
Electrostatic Discharges ◽  
Valve Stem ◽  
Metal Disk ◽  
Metal Diaphragm

There is a proposition that the possible occurrence of electrostatic discharges inside an oxygen regulator between charged insulating components, such as diaphragms, and earthed metal components, such as the valve stem, could be a potential candidate responsible for oxygen regulator fires. In this paper, the electric field which might be produced at the tip of the valve stem due to charge produced on the diaphragm of a typical oxygen regulator by deposition of charged dust particles or by their impact on the diaphragm or both has been evaluated. The diaphragm, in many cases, is backed partially by a concentric earthed metal disk. The diaphragm has been modelled as an insulating disk. The tip of the valve stem has been modelled as an earthed sphere which is very small compared to the insulating disk and the backing earthed metal disk. An analytical expression for the electric field produced at the point of the sphere nearest to the charged surface of the insulator has been derived. Our expression takes into account not only the effect of the charge on the insulating disk, but also that due to the presence of the backing earthed metal disk. Results for the magnitude of this electric field have been computed for the case of a sample oxygen regulator. An expression for the critical charge density on the surface of the insulating disk has been derived, and its value has been obtained for the case of our sample oxygen regulator. The electric field inside the non-metal diaphragm has also been evaluated. It appears from our analyses that there is a possibility that an electrostatic discharge might occur inside an oxygen regulator, and with an enriched-oxygen atmosphere being present there, such a discharge could also lead to a fire incident.

Electric Field Gradient Calculations of Various Borides

1996 ◽  
Vol 51 (5-6) ◽  
pp. 527-533 ◽  
Author(s):  
K. Schwarz ◽  
H. Ripplinger ◽  
P. Blaha
Keyword(s):  
Electric Field ◽  
First Principles ◽  
Density Functional ◽  
The Self ◽  
Full Potential ◽  
Electric Field Gradients ◽  
Charge Density Distribution ◽  
Functional Theory ◽  
Field Gradients ◽  
Self Consistent

Abstract A first-principles method for the computation of electric field gradients (EFG) is illustrated for various borides. It is based on energy band calculations using the full-potential linearized aug-mented plane wave (LAPW) method within density functional theory. From the self-consistent charge density distribution the EFG is obtained without further approximations by numerically solving Poisson's equation. The dependence of the EFG on structure, chemical composition or substitution is demonstrated for the diborides MB2 (with M = Ti, V, Cr, Zr, Nb, Mo, and Ta), the hexaborides (CaB6, SrB6 and BaB6) and boron carbide which is closely related to α-boron.

scholarly journals Evaluation of the Dreicer runaway generation rate in the presence of high- impurities using a neural network

2019 ◽  
Vol 85 (6) ◽  
Author(s):  
L. Hesslow ◽  
L. Unnerfelt ◽  
O. Vallhagen ◽  
O. Embreus ◽  
M. Hoppe ◽  
...  
Keyword(s):  
Neural Network ◽  
Runaway Electron ◽  
The Self ◽  
Generation Rate ◽  
Integrated Modelling ◽  
Plasma Parameters ◽  
The Neural Network ◽  
Wide Range ◽  
Self Consistent ◽  
Computationally Expensive

Integrated modelling of electron runaway requires computationally expensive kinetic models that are self-consistently coupled to the evolution of the background plasma parameters. The computational expense can be reduced by using parameterized runaway generation rates rather than solving the full kinetic problem. However, currently available generation rates neglect several important effects; in particular, they are not valid in the presence of partially ionized impurities. In this work, we construct a multilayer neural network for the Dreicer runaway generation rate which is trained on data obtained from kinetic simulations performed for a wide range of plasma parameters and impurities. The neural network accurately reproduces the Dreicer runaway generation rate obtained by the kinetic solver. By implementing it in a fluid runaway-electron modelling tool, we show that the improved generation rates lead to significant differences in the self-consistent runaway dynamics as compared to the results using the previously available formulas for the runaway generation rate.

scholarly journals Simulations of two-stream instability in opposite polarity dusty plasmas

2012 ◽  
Vol 78 (3) ◽  
pp. 211-224
Author(s):  
S. ERIC CLARK ◽  
M. ROSENBERG ◽  
K. QUEST
Keyword(s):  
Electric Field ◽  
Dusty Plasma ◽  
Electric Fields ◽  
Dusty Plasmas ◽  
Linear Instability ◽  
Dust Particles ◽  
Charged Dust ◽  
Collision Rate ◽  
Dust Trapping ◽  
Nonlinear Development

AbstractOne-dimensional Particle in Cell simulations of a dust–dust counterstreaming instability in a plasma containing dust grains of opposite charge polarity are presented. This dust–dust instability has potentially the lowest threshold drift for a dust wave instability in an unmagnetized dusty plasma. The linear and nonlinear development of this instability is investigated, including the effects of collisions with background neutrals, and a background electric field that acts as a driver to impart the drift velocities of the counter-streaming oppositely charged dust particles. The saturation of the linear instability appears to be due to dust heating related to dust trapping. Potential double layer formation from dust–dust instability turbulence is observed in cases with a high neutral collision rate. A comparative study is done with varying collision rates and background electric fields to explore the nonlinear development as a function of collision rate and background electric field. Applications to possible dusty plasma experimental parameters are discussed.

Fixed Wand Electronic Flame-Off for Ball Formation in the Wire Bonding Process

1994 ◽  
Vol 116 (3) ◽  
pp. 212-219 ◽  
Author(s):  
Wei Qin ◽  
Ira M. Cohen ◽  
P. S. Ayyaswamy
Keyword(s):  
Electric Field ◽  
Electrostatic Field ◽  
Wire Bonding ◽  
Bonding Process ◽  
The Self ◽  
Wire Length ◽  
Ball Bond ◽  
Self Consistent ◽  
The Wire ◽  
Wire Deflection

In the latest generation of wire bonders, the cycle is so short that the wand electrode is kept stationary and the electronic flame off (EFO) discharge is from the side of the wire. This is the discharge that heats and melts the wire causing roll up into a ball that is pressed down onto the chip to form a ball bond. The balls must be perfectly formed with defects in the few ppm range. In the first part of the paper, the fixed, conically shaped side wand and the improved ring wand design are studied by considering the electrostatic field before the breakdown. In the second part of the paper, discharge development starting from the initial electrostatic field between a wire and a ring wand up to the breakdown, and ionization growth in the gap between the electrodes are both examined by numerical simulations. In the computations, the conservation equations for ions and electrons and Poisson’s equation have been employed for the self-consistent electric field. Based on sensitivity to wire length and wire deflection, the results show that the ring wand is a better design than the conical side wand electrode for ball formation and wire bonding. Also, positive wire polarity is preferred over negative wire polarity.

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