ON THE COLLECTIVE DESCRIPTION OF CLASSICAL PLASMAS.
Technical note no. 1,
PARIS UNIV (FRANCE)
Pagination or Media Count:
Collective coordinates are considered as a linear transformation of deviations from the unperturbed orbit. In general they are admixtures of particle coordinates and of particle momenta. On this basis a reformulation and generalization of the Bohm-Pines theory and a classical equivalent of Brouts method is introduced. The correspondence of the two treatments is demonstrated. The method developed is employed to establish a collective description of magnetostatic interaction. A Hamiltonian describing magnetic interaction in terms of particle variables is derived. This serves as a starting point. The Fourier transform of the momentum density appears as a collective coordinate. Subsequent canonical transformations lead to a collective fluid-like description, to an extended Hamiltonian with coupling and to dressed uncoupled collective variables. A new collective mode with two transverse polarizations emerges it exhibits an unstable behaviour and prevails in the case of unisotropic velocity distribution only. In general it is coupled to the plasma oscillation mode. Finally the dielectric description of a system with unisotropic temperature-tensor is presented. Author