Parametric instabilities of Langmuir waves in strong magnetic fields and phase transition of Langmuir turbulence

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871417· OSTI ID:165018

Akimoto, K ^[1]

---

1. Precursory Research for Embryonic Science and Technology Program (PRESTO), Research Development Corporation of Japan, Kawaguchi 332 (Japan)

Parametric instabilities of Langmuir waves in strong magnetic fields such that {Omega}{sub {ital e}}{gt}{omega}{sub {ital e}} were investigated, where {Omega}{sub {ital e}}({omega}{sub {ital e}}) denotes the electron cyclotron (plasma) frequency. It has been well established that as a plasma is more strongly magnetized, the parametric instabilities of Langmuir waves become more field aligned and thus one dimensional. Here, it is demonstrated that this trend continues only up to {Omega}{sub {ital e}}/{omega}{sub {ital e}}=1, and that above this value, most Langmuir waves decay to relatively short wavelength oblique-Langmuir and ion waves that are damped rapidly. These new parametric instabilities have growth rates greater than those of the conventional modulational and decay instabilities. Consequently, the scenario of strong Langmuir turbulence in which Langmuir solitons play a major role may not apply to the strong magnetic-field regime. In the weak Langmuir turbulence regime these decay instabilities make the turbulence more isotropic. Therefore, it is concluded that there occurs a type of phase transition in magnetized Langmuir turbulence at {Omega}{sub {ital e}}/{omega}{sub {ital e}}{similar_to}1. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

• OSTI ID: 165018
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 3 Vol. 2; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CYCLOTRON FREQUENCY
MAGNETIC FIELDS
PARAMETRIC INSTABILITIES
PHASE TRANSFORMATIONS
PLASMA WAVES
SOLITONS
TURBULENCE