Nonlinear harmonics coupled by parallel wave propagations in a time-dependent plasma flow. (1st May 2022)

• Record Type: Journal Article
• Authors: Uk Lee, Min; Yun, Gunsu S; Ji, Jeong-Young
• Is Part Of: Plasma physics and controlled fusion. Volume 64:Number 5(2022)
• Publication Date: 2022-05-01
• Subjects: plasma flow -- fluid wave harmonics -- wave-wave coupling; Plasma (Ionized gases) -- Periodicals; Controlled fusion -- Periodicals; 530.44
• DOI: 10.1088/1361-6587/ac57cd
• Languages: English
• ISSNs: 0741-3335

Abstract

Abstract: In a time-dependent flow, nonlinear harmonics can be excited by coupling between linear waves and flow-induced harmonic waves. Examining the dispersion relations and selection rules for the coupling, we investigate nonlinearly coupled harmonics for waves propagating along the magnetic field line in a magnetized plasma, as well as waves in an unmagnetized plasma. The coupled harmonics in a plasma flow are described by analytic dispersion relations and selection rules. This nonlinear coupling is corroborated by the particle-in-cell simulation. The coupled-harmonics model describes a mechanism for the excitation of nonlinear harmonics from linear waves in a time-dependent flow. The spectral analysis of the dispersion relation provides a useful way to evaluate the spatiotemporal behavior of a plasma flow.