Nonlinear interactions of ion acoustic waves explored using fast imaging decompositions
Fast camera imaging is used to study ion acoustic waves propagating azimuthally in a magnetized plasma column. The high-speed image sequences are analyzed using proper orthogonal decomposition and 2D Fourier transform, allowing to evaluate the assets and differences of both decomposition techniques. The spatiotemporal features of the waves are extracted from the high-speed images, which highlight energy exchanges between modes. Growth rates of the modes are extracted from the reconstructed temporal evolution of the modes, revealing the influence of ion-neutral collisions as pressure increases. Finally, the nonlinear interactions between modes are extracted using bicoherence computations, and they show the importance of interactions between modes with azimuthal wave numbers m, m -1, and -1, with m as an integer.(c) 2023 Author(s).
main_article_iaw.pdf
postprint
openaccess
n/a
3.86 MB
Adobe PDF
4c98c58e6b0ca1352cdf9af7eeed62fc