Anomalous transport due to long-lived fluctuations in plasma Part 2. Hydrodynamic contributions to transport in two-dimensional, strongly magnetized systems

1976 ◽  
Vol 16 (2) ◽  
pp. 229-260 ◽  
Author(s):  
John A. Krommes ◽  
Carl Oberman
Keyword(s):  
Test Particle ◽  
Thermal Equilibrium ◽  
Transport Coefficients ◽  
Low Frequency ◽  
Anomalous Transport ◽  
Magnetized Plasma ◽  
Local Thermal Equilibrium ◽  
Generalized Langevin Equation ◽  
Particle Diffusion ◽  
Image Position

The general formalism for treating two-time fluctuations in magnetized plasma, developed in part 1 of this series, is applied to the case of anomalous cross-field transport in 2-D, strongly magnetized, thermal equilibrium systems. For (where εP is the plasma parameter), classical predictions for the ion shear viscosity and test particle diffusion coefficients are dominated by the anomalous contributions of low frequency, long wavelength hydrodynamic fluctuations (convective cells). The anomalous transport is discussed from the points of view of (a) kinetic theory; (b) the assumption of long-time local thermal equilibrium (Landau-Placzek method); and (c) a renormalized mode-coupling version of the generalized Langevin equation. The results of all these approaches are in agreement, and they predict that the transport coefficients scale with magnetic field B as 1/B for, and as independent of B forin good agreement with the computer simulations of Okuda & Dawson. The transport is weakly non-Markovian, the Green-Kubo integrands decay non-classically for long times as [t ln (t)]−½, and the test particle ‘;diffusion’ coefficient does not asymptotically approach a constant for t → ∞.

Anomalous transport due to long-lived fluctuations in plasma Part 1. A general formalism for two-time fluctuations

1976 ◽  
Vol 16 (2) ◽  
pp. 193-227 ◽  
Author(s):  
John A. Krommes ◽  
Carl Oberman
Keyword(s):  
Classical Theory ◽  
Test Particle ◽  
Initial Conditions ◽  
Superposition Principle ◽  
Transport Coefficients ◽  
Collision Operator ◽  
Magnetized Plasma ◽  
Constructive Proof ◽  
Fluid Viscosity ◽  
Image Position

A general formalism for describing two-time fluctuations in magnetized plasma is presented. Two-time expectations of one-body operators (phase functions) are written in terms of the phase space density autocorrelation functionwhere δN is the fluctuation in the singular Klimontovich microdensity. It is shown that is the first member of a set of two-time quantitieswhich collectively obeys the linearized BBGKY cumulant hierarchy in the (Xi, t) variables, with initial conditions successively smaller in the plasma parameter . We study in detail the case of fluctuations in thermal equilibrium, although the general formalism holds also for the non-equilibrium case. To lowest order in εP, Γ obeys the linearized Vlasov equation. From this are recovered all of Rostoker's results for fluctuations excited by Cherenkov emission and absorbed by Landau damping, as well as a constructive proof of the test particle superposition principle. To first order, Γ obeys (in the Markovian approximation) the linearized Balescu-Guernsey-Lenard equation. For frequencies and wavenumbers in the hydrodynamic regime, the velocity moments of Γ obey linearized fluid equations with classical transport coefficients (i.e. essentially those computed by Braginskii in the 3-D case). It has been found that the classical theory is in disagreement with certain computer and laboratory experiments performed in strong magnetic fields. This defect is attributed to the absence in the classical theory of contributions to the collision operator, hence transport coefficients, of fluctuations long-lived on the Vlasov scale. Analogous difficulties arise in the theory of hydrodynamics in neutral fluids. To improve the plasma theory, a renormalization of the two-time hierarchy is proposed which sums selected terms from all orders in εP and thus treats the hydrodynamic fluctuations self-consistently. The resulting theory retains appropriate fluid conservation laws, thereby avoiding erroneous results encountered in certain diffusing orbit theories, when the fluid viscosity is indiscriminantly replaced by the test particle diffusion coefficient. In order to explain the results of the computer simulations, the theory is applied in part 2 to the problem of anomalous hydrodynamic contributions to the transport coefficients.

Anomalous transport coefficients in a magnetized turbulent plasma

1982 ◽  
Vol 28 (2) ◽  
pp. 193-214 ◽  
Author(s):  
Qiu Xiaoming ◽  
R. Balescu
Keyword(s):  
Transport Coefficients ◽  
Collision Operator ◽  
Turbulent Plasma ◽  
Anomalous Transport ◽  
Weak Turbulence ◽  
Dissipative Effects ◽  
Dependent Transport ◽  
Two Fluid ◽  
Two Fluid Plasma

In this paper we generalize the formalism developed by Balescu and Paiva-Veretennicoff, valid for any kind of weak turbulence, for the determination of all the transport coefficients of an unmagnetized turbulent plasma, to the case of a magnetized one, and suggest a technique to avoid finding the inverse of the turbulent collision operator. The implicit plasmadynamical equations of a two-fluid plasma are presented by means of plasmadynamical variables. The anomalous transport coefficients appear in their natural places in these equations. It is shown that the necessary number of transport coefficients for describing macroscopically the magnetized turbulent plasma does not exceed the number for the unmagnetized one. The typical turbulent and gyromotion terms, representing dissipative effects peculiar to the magnetized system, which contribute to the frequency-dependent transport coefficients are clearly exhibited.

scholarly journals Electron acoustic solitons in the Earth's magnetotail

2004 ◽  
Vol 11 (2) ◽  
pp. 215-218 ◽  
Author(s):  
S. G. Tagare ◽  
S. V. Singh ◽  
R. V. Reddy ◽  
G. S. Lakhina
Keyword(s):  
Electron Beam ◽  
Small Amplitude ◽  
Low Frequency ◽  
Frequency Component ◽  
Magnetized Plasma ◽  
Cold Electron ◽  
Ion Plasma ◽  
Electron Acoustic ◽  
Two Temperature ◽  
Perpendicular Polarization

Abstract. Small amplitude electron - acoustic solitons are studied in a magnetized plasma consisting of two types of electrons, namely cold electron beam and background plasma electrons and two temperature ion plasma. The analysis predicts rarefactive solitons. The model may provide a possible explanation for the perpendicular polarization of the low-frequency component of the broadband electrostatic noise observed in the Earth's magnetotail.

scholarly journals Behavior of three colicine factors and an R (drug-resistance) factor in Hfr crosses inSalmonella typhimurium

1967 ◽  
Vol 9 (3) ◽  
pp. 283-297 ◽  
Author(s):  
Eugenie Dubnau ◽  
B. A. D. Stocker
Keyword(s):  
Drug Resistance ◽  
Low Frequency ◽  
Resistance Factor ◽  
Chromosomal Locus ◽  
Very Low Frequency ◽  
R Factor ◽  
Phage P22 ◽  
Donor Chromosome ◽  
Image Position ◽  
Line Analysis

An LT2 Hfr strain,his metC gal, was crossed to a multiply marked LT2 F−line. Analysis of recombinant yields, segregation of unselected markers and interrupted matings indicated injection of the Hfr chromosome in the sequenceThe introduction into the Hfr of the colicine factorscolI, colE1andcolE2and the R factorR2had little or no effect on its fertility. All four factors were transmitted at low frequency to the F−population, and to recombinants at higher frequencies (colI5–30%,colE130–80%,colE25–30%,R20–9%). Transfer ofcolE1occurred before 20 min., that ofcolE2andcolIlater than 100 min. Segregation data did not reveal close linkage of any factor to any chromosomal locus, but recombinants with a long stretch of donor chromosome were more likely than others to have acquiredcolE2andcolI. Nearly all recombinants andF−cells which acquiredcolIorcolE2acquired both, andcolE1also. Most cells which acquiredR2acquired one or more colicine factors. These plasmid associations can be formally represented by transfer of plasmids, independently of the chromosome, in the sequencecolE1—(colI, colE2)—R2. Phage P22 grown on the Hfr carrying the four plasmids transduced thetet-rtrait ofR2at very low frequency, and thesul-r str-rcharacters, together, at low frequency. Some of each sort of drug-resistance transductant, but no transductants in respect of chromosomal characters, acquiredcolEl or colE2by co-transduction.

scholarly journals Resonant scattering of energetic electrons in the plasmasphere by monotonic whistler-mode waves artificially generated by ionospheric modification

2014 ◽  
Vol 32 (5) ◽  
pp. 507-518 ◽  
Author(s):  
S. S. Chang ◽  
B. B. Ni ◽  
J. Bortnik ◽  
C. Zhou ◽  
Z. Y. Zhao ◽  
...  
Keyword(s):  
Test Particle ◽  
Pitch Angle ◽  
Low Frequency ◽  
Resonant Scattering ◽  
High Energy ◽  
Whistler Waves ◽  
Energetic Electrons ◽  
High Energy Electrons ◽  
Angle Scattering ◽  
Vlf Waves

Abstract. Modulated high-frequency (HF) heating of the ionosphere provides a feasible means of artificially generating extremely low-frequency (ELF)/very low-frequency (VLF) whistler waves, which can leak into the inner magnetosphere and contribute to resonant interactions with high-energy electrons in the plasmasphere. By ray tracing the magnetospheric propagation of ELF/VLF emissions artificially generated at low-invariant latitudes, we evaluate the relativistic electron resonant energies along the ray paths and show that propagating artificial ELF/VLF waves can resonate with electrons from ~ 100 keV to ~ 10 MeV. We further implement test particle simulations to investigate the effects of resonant scattering of energetic electrons due to triggered monotonic/single-frequency ELF/VLF waves. The results indicate that within the period of a resonance timescale, changes in electron pitch angle and kinetic energy are stochastic, and the overall effect is cumulative, that is, the changes averaged over all test electrons increase monotonically with time. The localized rates of wave-induced pitch-angle scattering and momentum diffusion in the plasmasphere are analyzed in detail for artificially generated ELF/VLF whistlers with an observable in situ amplitude of ~ 10 pT. While the local momentum diffusion of relativistic electrons is small, with a rate of < 10−7 s−1, the local pitch-angle scattering can be intense near the loss cone with a rate of ~ 10−4 s−1. Our investigation further supports the feasibility of artificial triggering of ELF/VLF whistler waves for removal of high-energy electrons at lower L shells within the plasmasphere. Moreover, our test particle simulation results show quantitatively good agreement with quasi-linear diffusion coefficients, confirming the applicability of both methods to evaluate the resonant diffusion effect of artificial generated ELF/VLF whistlers.

scholarly journals Precise Measurements of CH Maser Emission and Its Abundance in Translucent Clouds

2021 ◽  
Vol 257 (2) ◽  
pp. 47
Author(s):  
Ningyu Tang ◽  
Di Li ◽  
Gan Luo ◽  
Carl Heiles ◽  
Sheng-Li Qin ◽  
...  
Keyword(s):  
Thermal Equilibrium ◽  
Column Density ◽  
High Sensitivity ◽  
Local Thermal Equilibrium ◽  
Molecular Gas ◽  
Excitation Temperature ◽  
Hyperfine Transitions ◽  
Visible Wavelengths ◽  
Log Normal ◽  
Log Normal Distribution

Abstract We present high-sensitivity CH 9 cm ON/OFF observations toward 18 extragalactic continuum sources that have been detected with OH 18 cm absorption in the Millennium survey with the Arecibo telescope. CH emission was detected toward 6 of the 18 sources. The excitation temperature of CH has been derived directly through analyzing all detected ON and OFF velocity components. The excitation temperature of CH 3335 MHz transition ranges from −54.5 to −0.4 K and roughly follows a log-normal distribution peaking within [−5, 0] K, which implies overestimation by 20% to more than 10 times during calculating CH column density by assuming the conventional value of −60 or −10 K. Furthermore, the column density of CH would be underestimated by a factor of 1.32 ± 0.03 when adopting local thermal equilibrium assumption instead of using the CH three hyperfine transitions. We found a correlation between the column density of CH and OH following log N(CH) = (1.80 ± 0.49) and log N(OH −11.59 ± 6.87. The linear correlation between the column density of CH and H2 is consistent with that derived from visible wavelengths studies, confirming that CH is one of the best tracers of H2 components in diffuse molecular gas.

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