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Title: On the validity of the guiding-center approximation in the presence of strong magnetic gradients

Authors:
ORCiD logo [1]
  1. Department of Physics, Saint Michael's College, Colchester, Vermont 05439, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1361830
Grant/Contract Number:
SC0014032
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 4; Related Information: CHORUS Timestamp: 2018-02-14 15:45:32; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Brizard, Alain J. On the validity of the guiding-center approximation in the presence of strong magnetic gradients. United States: N. p., 2017. Web. doi:10.1063/1.4981217.
Brizard, Alain J. On the validity of the guiding-center approximation in the presence of strong magnetic gradients. United States. doi:10.1063/1.4981217.
Brizard, Alain J. Sat . "On the validity of the guiding-center approximation in the presence of strong magnetic gradients". United States. doi:10.1063/1.4981217.
@article{osti_1361830,
title = {On the validity of the guiding-center approximation in the presence of strong magnetic gradients},
author = {Brizard, Alain J.},
abstractNote = {},
doi = {10.1063/1.4981217},
journal = {Physics of Plasmas},
number = 4,
volume = 24,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4981217

Citation Metrics:
Cited by: 3works
Citation information provided by
Web of Science

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  • The guiding center plasma description of an isotropic, collisionless plasma is used to study the linear stability of the diffuse screw pinch in the special case when the poloidal magnetic field component is small compared with the axial magnetic field component. A two-term approximation for growth rates is derived from the linearized guiding center plasma equations by straightforward asymptotic expansion in terms of a small parameter that is proportional to (B/sub theta//rB/sub z/)such thatub r/=0. The two-term approximate solution is compared with exact solutions and the range of validity of the approximations is examined. The result obtained from the guidingmore » center plasma model is compared and contrasted with that from ideal magnetohydrodynamics. It is shown that the isotropic guiding center plasma may be more unstable or less unstable than ideal magnetohydrodynamics for the same configuration, depending on the parameters.« less
  • The equations governing the guiding center motion of a charged particle in an electromagnetic field are obtained simultaneously and deductively, without considering individually the special geometric situations in which one effect or another occurs alone. The general expression is derived for the guiding center velocity at right angles to the magnetic field B. This expression contains five terms arising in the presence of an electric field. They are in addition to the usual "E x B" drift. Because these terms are unfamiliar objects in the literature on plasmas, they are illustrated by simple examples. Three of the five drifts occurmore » in rotating plasma machines of the lxion type. One of these three is also shown to be responsible for the Helmholtz instability of a plasma. A fourth one gives the now frequency) dielectric constant, while the fifth arises if the direction of B is time dependent. A detailed geometric picture of the fifth drift is given. The equation governing the guiding center motion parallel to B is also derived for the general time-dependent field. The conditions are dis paper, that the component of the current density parallel to B is the current due to the guiding center velocity parallel to B plus the parallel component of the curl of the magnetic moment per unit volume. A proper proof of the parallel component is quite lengthy. (auth)« less
  • The linearized three-dimensional guiding-center equations for a plasma of cold ions and thermal electrons are solved in a cylindrical geometry. Conditions under which solutions of the disperion relation with complex frequencies can exist are determined. The consequences on the possibility of developing a ’’plasma magnetron’’, where the electron fluid of a classical magnetron is substituted by a guiding-center plasma, are discussed.