TITLE

Diffusion coefficients from resonant interactions with electrostatic electron cyclotron harmonic waves

AUTHOR(S)
Tripathi, A. K.; Singhal, R. P.
PUB. DATE
November 2009
SOURCE
Physics of Plasmas;Nov2009, Vol. 16 Issue 11, p112107
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Pitch-angle diffusion coefficients have been calculated for resonant interaction with electrostatic electron cyclotron harmonic (ECH) waves using quasilinear diffusion theory. Unlike previous calculations, the parallel group velocity has been included in this study. Further, ECH wave intensity is expressed as a function of wave frequency and wave normal angle with respect to ambient magnetic field. It is found that observed wave electric field amplitudes in Earth’s magnetosphere are sufficient to set electrons on strong diffusion in the energy ranges of a few hundred eV. However, the required amplitudes are larger than the observed values for keV electrons and higher by about a factor of 3 compared to past calculations. Required electric field amplitudes are smaller at larger radial distances. It is concluded that ECH waves are responsible for diffuse auroral precipitation of electrons with energies less than about 500 eV.
ACCESSION #
45515202

 

Related Articles

  • Effect of poloidal electric field on electron cyclotron current drive in a tokamak geometry. Lee, Sanghyuk; Chang, C. S. // Physics of Plasmas;Dec2000, Vol. 7 Issue 12 

    Effect of a poloidal electric field on the electron cyclotron current drive is studied in a tokamak geometry. A general discussion of its influence on the electron phase-space dynamics and current drive efficiency is presented. It is shown that the modification to the current drive efficiency...

  • The effect of the radial diffusion on the effectiveness of ECCD for neoclassical tearing mode stabilization in ITER. Bertelli, N.; Westerhof, E. // AIP Conference Proceedings;11/26/2009, Vol. 1187 Issue 1, p527 

    The article discusses the impact of radial diffusion on the role of electron cyclotron current drive (ECCD) in mode stabilization of neoclassical tearing. It is stated that ECCD can be effective in neoclassical tearing mode (NTM) stabilization as only a small part of the total plasma current is...

  • Three-dimensional modulation of electron-cyclotron waves. Shukla, P. K.; Stenflo, L. // Physics of Fluids (00319171);Aug86, Vol. 29 Issue 8, p2479 

    A set of nonlinear mode coupling equations, describing the interaction of large amplitude electron-cyclotron waves with low-frequency electrostatic as well as electromagnetic fluctuations, is presented. Accounting for the contributions of the ponderomotive force and relativistic electron mass...

  • Self-consistent simulation of electron cyclotron resonance plasma discharge. Liu, Minghai; Hu, Xiwei; Wu, Qinchong; Yu, Guoyang; Pan, Yuan // Physics of Plasmas;Jul2000, Vol. 7 Issue 7 

    Microwave fields in an extended electron cyclotron resonance (ECR) plasma reactor were analyzed in the resonant cavity from Maxwell's equations, and a formalism of microwave absorption was investigated at the resonance zone with plasma kinetic theory and simulated using a two-dimension computer...

  • Parametric excitation of surface electron cyclotron X- and O- modes by alternating electric fields. Girka, V. O.; Girka, A. V.; Yarko, V. V. // EPJ Web of Conferences;2012, Issue 32, p01009-p.1 

    The article offers a theory of parametric instability of slow surface electron cyclotron X-modes (SECXM) and surface electron cyclotron O-modes (SECXM) at electron cyclotron frequency for the model of semi-bounded plasma. An infinite set of equations for tangential component of SECOM and SECXM...

  • Low frequency electromagnetic oscillations in dense degenerate electron-positron pair plasma, with and without ions. Khan, S. A.; Ayub, M. K.; Ahmad, Ali // Physics of Plasmas;Oct2012, Vol. 19 Issue 10, p102104 

    Quantum plasma oscillations are studied in a strongly magnetized, ultra-dense plasma with degenerate electrons and positrons. The dispersive role of electron and positron quantum effects on low frequency (in comparison to electron cyclotron frequency) shear electromagnetic wave is investigated...

  • Measurement of a potential barrier created by electron cyclotron resonance heating. Chang, C. P.; Lieberman, M. A.; Meuth, H.; Lichtenberg, A. J. // Physics of Fluids (00319171);Jan88, Vol. 31 Issue 1, p123 

    An electrostatic potential well and mirror-trapped hot electrons are created by high power (250 kW), short pulse (3 μsec) electron cyclotron resonance heating (ECRH) of a plasma in one magnetic mirror cell of a multiple mirror experiment. The creation and subsequent decay of the potential...

  • Optimization of a two-stages electrostatic reflex ion source. Farchi, A.; Wartski, L.; Boukari, F.; Roy, V.; Coste, Ph.; Aubert, J. // Review of Scientific Instruments;Apr94, Vol. 65 Issue 4, p1101 

    In our argon, oxygen, or nitrogen broad beam ion source, 80 mm in diameter, which is either an electrostatic reflex ion source, or a magnetic and electrostatic reflex ion source, the hot filament has been replaced by a carefully optimized microwave plasma (MP) cathode under the electron...

  • Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source. Castro, G.; Mascali, D.; Romano, F. P.; Celona, L.; Gammino, S.; Lanaia, D.; Di Giugno, R.; Miracoli, R.; Serafino, T.; Di Bartolo, F.; Gambino, N.; Ciavola, G. // Review of Scientific Instruments;Feb2012, Vol. 83 Issue 2, p02B501 

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics