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arXiv · 2402.07399

On beat-driven and spontaneous excitations of zonal flows by drift waves

Liu Chen·Zhiyong Qiu·Fulvio Zonca
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Abstract

Using the slab plasma as a paradigm model, we have derived analytically equations for the nonlinear generation of zero-frequency zonal flows by electron drift waves including, on the same footing, both the beat-driven and spontaneous excitations. It is found that the beat-driven zonal flow tends to reduce the frequency mismatch between the electron drift waves and, thereby, contributes to a significant O(1) enhancement of the modulational instability drive and lowering its threshold. Implications to tokamaks plasmas as well as drift-wave soliton formation are also discussed.

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Liu Chen, Zhiyong Qiu, Fulvio Zonca. 2024-02-12. On beat-driven and spontaneous excitations of zonal flows by drift waves. https://arxiv.org/abs/2402.07399

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