2017/10/01 by Prabal Singh Verma, Verma, Prabal Singh, Tapan Chandra Adhyapak +1
Engineering · Physics and Astronomy · #Dust and Plasma Wave Phenomena #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Particle accelerators and beam dynamics #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.1710.00334
openalex publication_date 2017/10/01 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
We study the spatio-temporal evolution of the nonlinear electrostatic\noscillations in a cold magnetized electron-positron (e-p) plasma using both\nanalytics and simulations. Using a perturbative method we demonstrate that the\nnonlinear solutions change significantly when a pure electrostatic mode is\nexcited at the linear level instead of a mixed upper-hybrid and zero-frequency\nmode that is considered in a recent study. The pure electrostatic oscillations\nundergo phase mixing nonlinearly. However, the presence of the magnetic field\nsignificantly delays the phase-mixing compared to that observed in the\ncorresponding unmagnetized plasma. Using 1D PIC simulations we then analyze the\ndamping of the primary modes of the pure oscillations in detail and infer the\ndependence of the phase-mixing time on the magnetic field and the amplitude of\nthe oscillations. The results are remarkably different from those found for the\nmixed upper-hybrid mode mentioned above. Exploiting the symmetry of the e-p\nplasma we then explain a generalized symmetry of our non-linear solutions. The\nsymmetry allows us to construct a unique nonlinear solution up to the second\norder which does not show any signature of phase mixing but results in a\nnonlinear wave traveling at upper-hybrid frequency. Our investigations have\nrelevance for laboratory/astrophysical e-p plasmas.\n