Measuring drift velocity and electric field in mirror machine by fast photography

Abstract. This study compares the measurements of electron density and temperature and the integral airglow intensity at 630 nm in the SAR arc region and slightly south of this (obtained by the Isis 2 spacecraft during the 18 December 1971 magnetic storm), with the model results obtained using the time dependent one-dimensional mathematical model of the Earth\\'s ionosphere and plasmasphere. The explicit expression in the third Enskog approximation for the electron thermal conductivity coefficient in the multicomponent mixture of ionized gases and a simplified calculation method for this coefficient presents an opportunity to calculate more exactly the electron temperature and density and 630 nm emission within SAR arc region are used in the model. Collisions between N2 and hot thermal electrons in the SAR arc region produce vibrationally excited nitrogen molecules. It appears that the loss rate of O+(4S) due to reactions with the vibrationally excited nitrogen is enough to explain electron density depression by a factor of two at F-region heights and the topside ionosphere density variations within the SAR arc if the erosion of plasma within geomagnetic field tubes, during the main phase of the geomagnetic storm and subsequent filling of geomagnetic tubes during the recovery phase, are considered. To explain the disagreement by a factor 1.5 between the observed and modeled SAR arc electron densities an additional plasma drift velocity ~–30 m s–1 in the ion continuity equations is needed during the recovery phase. This additional plasma drift velocity is likely caused by the transition from convecting to corotating flux tubes on the equatorward wall of the trough. The electron densities and temperatures and 630 nm integral intensity at the SAR arc and slightly south of this region as measured for the 18 December 1971 magnetic storm were correctly described by the model without perpendicular electric fields. Within this model framework the effect of the perpendicular electric field ~100 mv m–1 with a duration ~1 h on the SAR arc electron density profiles was found to be large. However, this effect is small if ~1–2 h have passed after the electric field was set equal to zero.

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Drift Velocity, Longitudinal and Transverse Diffusion in Hydrocarbons derived from Distributions of Single Electrons

Australian Journal of Physics ◽

10.1071/ph920351 ◽

1992 ◽

Vol 45 (3) ◽

pp. 351 ◽

Cited By ~ 23

Author(s):

Bernhard Schmidt ◽

Michael Roncossek

Keyword(s):

Field Strength ◽

Electric Field ◽

Electric Field Strength ◽

Drift Velocity ◽

Simultaneous Measurement ◽

Diffusion Coefficients ◽

Number Density ◽

Transverse Diffusion ◽

Single Electrons ◽

Time Of Flight Method

A time of flight method is described which allows the simultaneous measurement of drift velocity w and the ratios of the longitudinal and transverse diffusion coefficients to mobility (DL/JL, DT/JL) of electrons in gases. The accuracy achieved in this omnipurpose experiment is comparable with that of specialised techniques and is estimated to be �1 % for w and �5% for the D / JL measurements .. Results for methane, ethane, ethene, propane, propene and cyclopropane for values of E/N (the electric field strength divided by the number density) ranging from 0�02 to 15 Td are presented and discussed (1 Td = 10-21 Vm2 ).

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Drift velocity of ions and electrons in non-polar dielectric liquids at high electric field strengths

2011 IEEE International Conference on Dielectric Liquids ◽

10.1109/icdl.2011.6015493 ◽

2011 ◽

Cited By ~ 3

Author(s):

Werner F. Schmidt ◽

George Bakale ◽

Alexey Khrapak ◽

Katsumi Yoshino

Keyword(s):

Electric Field ◽

Drift Velocity ◽

High Electric Field ◽

Polar Dielectric ◽

Dielectric Liquids ◽

Field Strengths

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Free-swarm method: a new approach for measuring electron drift velocity in a gas in an electric field

Il Nuovo Cimento D ◽

10.1007/bf02484366 ◽

1995 ◽

Vol 17 (6) ◽

pp. 645-648

Author(s):

F. Giusiano ◽

M. Giusiano ◽

G. Mambriani

Keyword(s):

Electric Field ◽

Drift Velocity ◽

Electron Drift Velocity ◽

Electron Drift ◽

New Approach

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Electron Mobility in Liquid Argon

Australian Journal of Physics ◽

10.1071/ph590105 ◽

1959 ◽

Vol 12 (1) ◽

pp. 105 ◽

Cited By ~ 12

Author(s):

FD Stacey

Keyword(s):

Kinetic Theory ◽

Electric Field ◽

Electron Energy ◽

Cross Section ◽

Drift Velocity ◽

Electron Mobility ◽

Alternative Explanation ◽

Liquid Argon ◽

Scattering Cross Section ◽

Scattering Cross

Experiments of Williams (1957) showed that the drift velocity of electrons in liquid argon to which an electric field F is applied is essentially independent of F. If the electrons remain free then their motion can be described by kinetic theory, from which it appears that electron mobility is proportional to F-I and drift velocity to Fli. This is the dependence reported by Malkin and Schultz (1951), but it is evident that the recent, more exhaustive work of Williams (1957) is correct on this point and therefore that kinetic theory is not applicable to the problem. This theory could in principle be extended to explain a fieldindependent velocity, by supposing a special dependence upon electron energy of the scattering cross section for the collision of electrons with argon atoms, but this is very artificial and unnecessary in view of the alternative explanation suggested here; in any case it leaves further serious objections, which will also be discussed briefly.

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Morphological Patterns During Quasi-Two-Dimensional Electrodeposition

MRS Proceedings ◽

10.1557/proc-451-141 ◽

1996 ◽

Vol 451 ◽

Author(s):

Jacob Jorne ◽

Sen-Wei Wu

Keyword(s):

Natural Convection ◽

Electric Field ◽

Space Charge ◽

Drift Velocity ◽

Space Charge Region ◽

Two Dimensional ◽

Degree Of Anisotropy ◽

Morphological Patterns

ABSTRACTThe quasi-two-dimensional electrodeposition of several metals (zinc, copper, silver and lithium) of varying levels of anisotropy has been investigated. The morphologies are very diverse for the different metals and the morphology selection depends on the degree of anisotropy. The fast propagation of the quasi-two-dimensional deposit is due to the lack of convection in the confined electrolyte. The velocity of the deposit is determined by the drift velocity of the anions, as the system is attempting to maintain electroneutrality and reduce the electric field in the space charge region. The effects of impurities and natural convection on the morphology are investigated as well.

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