Journal article
Non-Linear Langmuir Wave Modulation in Collisionless Plasmas
A non-linear Schrodinger equation for Langmuir waves is presented. The equation is derived by using a fluid model for the electrons, while both a fluid and a Vlasov formulation are considered for the ion dynamics. The two formulations lead to significant differences in the final results, especially in the expressions concerning the modulation instability of a plane Langmuir wave.
When the Vlasov equation for the ions is applied, a Langmuir wave is modulationally unstable for arbitrary perturbations independent of the unperturbed wave amplitude, in contrast to what is found for fluid ions. A simple analogy with negative energy waves explaining the different features of the two cases is outlined.
Language: | English |
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Year: | 1977 |
Pages: | 931-943 |
ISSN: | 18792979 , 00321028 , 13616587 and 07413335 |
Types: | Journal article |
DOI: | 10.1088/0032-1028/19/10/004 |