Plasma biasing by non-resonant ponderomotive forces of radio-frequency waves

1995 ◽  
Vol 54 (2) ◽  
pp. 245-258 ◽  
Author(s):  
R. van Nieuwenhove ◽  
V. Petržíka ◽  
J. A. Tataronis
Keyword(s):  
Electric Field ◽  
Radio Frequency ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Numerical Data ◽  
Bias Field ◽  
Wave Frequency ◽  
Numerical Code ◽  
Ponderomotive Forces ◽  
Radio Frequency Waves

A numerical code that computes stationary radial electric fields E0r induced by ponderomotive forces of radio-frequency waves is developed. The computed value of E0r is typically several hundred volts per centimetre when the wave frequency is 1 % lower or higher than the ion-cyclotron frequency. This value of E0r suggests that the ponderomotively induced electric field would be an effective bias in tokamaks. Numerical data are presented to illustrate the properties of this bias field.

Suppression of runaway of electrons in a Lorentz plasma. II. crossed electric and magnetic fields

1970 ◽  
Vol 4 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Barbara Abraham-Shrauner
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Collision Frequency ◽  
Uniform Electric Field ◽  
Drift Motion ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

Suppression of runaway of electrons in a weak, uniform electric field in a fully ionized Lorentz plasma by crossed magnetic and electric fields is analysed. A uniform, constant magnetic field parallel to a constant or harmonically time varying electric field does not alter runaway from that in the absence of the magnetic field. For crossed, constant fields the passage to runaway or to free motion as described by constant drift motion and spiral motion about the magnetic field is lengthened in time for strong magnetic fields. The new ‘runaway’ time scale is roughly the ratio of the cyclotron frequency to the collision frequency squared for cyclotron frequencies much greater than the collision frequency. All ‘runaway’ time scales may be given approximately by t2E Teff where tE is the characteristic time of the electric field and Teff is the ffective collision time as estimated from the appropriate component of the electrical conductivity.

scholarly journals Resistive MHD reconstruction of two-dimensional coherent structures in space

2010 ◽  
Vol 28 (11) ◽  
pp. 2113-2125 ◽  
Author(s):  
W.-L. Teh ◽  
B. U. Ö. Sonnerup ◽  
J. Birn ◽  
R. E. Denton
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Synthetic Data ◽  
Two Dimensions ◽  
Mhd Equations ◽  
Numerical Code ◽  
Reconstruction Technique ◽  
Two Dimensional ◽  
Geomagnetic Tail ◽  
Spacecraft Spin

Abstract. We present a reconstruction technique to solve the steady resistive MHD equations in two dimensions with initial inputs of field and plasma data from a single spacecraft as it passes through a coherent structure in space. At least two components of directly measured electric fields (the spacecraft spin-plane components) are required for the reconstruction, to produce two-dimensional (2-D) field and plasma maps of the cross section of the structure. For convenience, the resistivity tensor η is assumed diagonal in the reconstruction coordinates, which allows its values to be estimated from Ohm's law, E+v×B=η·j. In the present paper, all three components of the electric field are used. We benchmark our numerical code by use of an exact, axi-symmetric solution of the resistive MHD equations and then apply it to synthetic data from a 3-D, resistive, MHD numerical simulation of reconnection in the geomagnetic tail, in a phase of the event where time dependence and deviations from 2-D are both weak. The resistivity used in the simulation is time-independent and localized around the reconnection site in an ellipsoidal region. For the magnetic field, plasma density, and pressure, we find very good agreement between the reconstruction results and the simulation, but the electric field and plasma velocity are not predicted with the same high accuracy.

Interchange stabilization of a mirror plasma using radio-frequency waves below the ion cyclotron frequency

1988 ◽  
Vol 31 (4) ◽  
pp. 714 ◽  
Author(s):  
J. J. Browning ◽  
R. Majeski ◽  
T. Intrator ◽  
N. Hershkowitz ◽  
S. Meassick
Keyword(s):  
Radio Frequency ◽  
Cyclotron Frequency ◽  
Ion Cyclotron ◽  
Radio Frequency Waves

Modelling of Heat and Mass Transfer Processes and Emulsion Stratification Under the Influence of Electric Fields

2009 ◽  
Vol 4 (4) ◽  
pp. 15-22
Author(s):  
Galiya Zakirjanova ◽  
Liana Kovaleva ◽  
Nur Nasyrov
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Radio Frequency ◽  
Heat And Mass Transfer ◽  
Electric Fields ◽  
Transfer Processes ◽  
Mass Transfer Processes ◽  
Ponderomotive Forces ◽  
Calculation Results ◽  
Em Field

The influence of the radio-frequency (RF) and law-frequency (LF) electric fields and their joint impact on processes of heat and mass transfer and emulsion stratification on oil and water are theoretically investigated. At modeling the effect of ponderomotive forces on the medium from electromagnetic (EM) field and also heat and mass transfer cross effects arising at nonisothermal current of liquid are considered. Comparison of calculation results with known experimental data is carried out.

scholarly journals Laser-induced diamond-like carbon film under different electric field directions

2016 ◽  
Vol 34 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Wu Shenjiang ◽  
Li Dangjuan ◽  
Su Junhong
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Intensity ◽  
Electric Field Intensity ◽  
Laser Energy ◽  
Carbon Film ◽  
Bias Field ◽  
Diamond Like Carbon ◽  
Dlc Film ◽  
Laser Induced Damage

AbstractTi electrodes were directly deposited at different positions on diamond-like carbon (DLC) films to form horizontal and longitudinal electric fields on their surfaces. The ID/IG ratio increased with the sp3 content in the membrane when the DLC film was laser-irradiated and the electric field intensity was 0 V/cm. The bias electric field intensity increased from 0 to 1000 V/cm, and the corresponding laser-induced damage threshold (LIDT) increased. The three-dimensional damage morphology of the DLC film with two different electrode structures was observed when the electric field intensity was 220 V/cm. Two types of electrode structures were observed in the Raman spectra under an electric field intensity of 110 V/cm and laser energy densities of 0 and 1.56 J/cm2. Results showed that the horizontal bias field had a more obvious influence than the longitudinal electric field on the decrease of the sp3–sp2 hybridization, preventing the formation of sp2 clusters, thereby slowing down the graphitization process of DLC. Applying the bias field to the DLC film could slow down the DLC film graphitization process and improve the LIDT of the DLC film.

Inactivation of Saccharomyces cerevisiae with Radio Frequency Electric Fields†

2003 ◽  
Vol 66 (9) ◽  
pp. 1712-1715 ◽  
Author(s):  
DAVID J. GEVEKE ◽  
CHRISTOPHER BRUNKHORST
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Field Strength ◽  
Electric Field ◽  
Radio Frequency ◽  
Electric Fields ◽  
Flow Rate ◽  
Low Temperatures ◽  
Thermal Inactivation ◽  
Rf System ◽  
Radio Frequency Electric Fields

The application of radio frequency (RF) electric fields as a nonthermal alternative to thermal inactivation of microorganisms in liquids was investigated. A novel RF system producing frequencies in the range of 20 to 60 kHz was developed. Electric field strengths of 20 and 30 kV/cm were applied to suspensions of Saccharomyces cerevisiae in water over a temperature range of 35 to 55°C. The flow rate was 1.2 liters/min. The S. cerevisiae population was reduced by 2.1 ± 0.1 log units following exposure to a 30-kV/cm field at 40°C. The results of the present study provide the first evidence that strong RF electric fields inactivate microorganisms at moderately low temperatures. Increasing the field strength, the number of treatments, and the temperature enhanced inactivation. Frequency had no effect on inactivation over the range of frequencies studied.

scholarly journals MOVEMENT OF CHARGED PARTICLES IN MAGNETIC AND NONUNIFORM STOCHASTIC ELECTRIC FIELDS

2021 ◽  
pp. 112-117
Author(s):  
N.A. Azarenkov ◽  
A.D. Chibisov ◽  
D.V. Chibisov
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Charged Particles ◽  
Planck Equation ◽  
Homogeneous Magnetic Field ◽  
Equation Of Motion ◽  
Stochastic Field ◽  
Characteristic Oscillation ◽  
Diffusion Motion

The equation of motion of charged plasma particles in a homogeneous magnetic field and in an inhomogeneous stochastic electric field with a characteristic oscillation frequency much lower than the electron cyclotron frequency and much higher than the ion cyclotron frequency is solved. The diffusion motion, as well as the drift of ions and guiding center of electrons, due to the inhomogeneity of the stochastic electric field, is considered. The obtained values of the diffusion coefficient and drift velocity are used in the Fokker-Planck equation to determine the stationary distribution of the plasma density due to the effect of an inhomogeneous stochastic field.

Comparison of random field strengths in (1-x)SrTiO3-xBiFeO3 and (1-x)SrTiO3-xBaTiO3 relaxor ferroelectrics by means of acoustic emission

2020 ◽  
Vol 92 (2) ◽  
pp. 20401
Author(s):  
Evgeniy Dul'kin ◽  
Michael Roth
Keyword(s):  
Acoustic Emission ◽  
Random Field ◽  
Electric Fields ◽  
Bias Field ◽  
Relaxor Ferroelectrics ◽  
External Bias ◽  
Field Strengths

In relaxor (1-x)SrTiO3-xBiFeO3 ferroelectrics ceramics (x = 0.2, 0.3 and 0.4) both intermediate temperatures and Burns temperatures were successfully detected and their behavior were investigated in dependence on an external bias field using an acoustic emission. All these temperatures exhibit a non-trivial behavior, i.e. attain the minima at some threshold fields as a bias field enhances. It is established that the threshold fields decrease as x increases in (1-x)SrTiO3-xBiFeO3, as it previously observed in (1-x)SrTiO3-xBaTiO3 (E. Dul'kin, J. Zhai, M. Roth, Phys. Status Solidi B 252, 2079 (2015)). Based on the data of the threshold fields the mechanisms of arising of random electric fields are discussed and their strengths are compared in both these relaxor ferroelectrics.

Maxwell’s Equations versus Newton’s Third Law

2018 ◽  
Author(s):  
Glyn Kennell ◽  
Richard Evitts
Keyword(s):  
Electric Fields ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Simulated Data ◽  
Numerical Data ◽  
Transport Equations ◽  
Concentration Gradients ◽  
Third Law

The presented simulated data compares concentration gradients and electric fields with experimental and numerical data of others. This data is simulated for cases involving liquid junctions and electrolytic transport. The objective of presenting this data is to support a model and theory. This theory demonstrates the incompatibility between conventional electrostatics inherent in Maxwell's equations with conventional transport equations. <br>

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