Chung-Sang Ng | Searcharxiv

arXiv2025

Asymptotic state of nonlinear Landau damping in one-dimensional plasma

In this work, the asymptotic state of nonlinear Landau damping in one-dimensional plasma has been examined using a quasi-linear model and a second-order symplectic integrator. The dispersion relation of the plateau distribution function for the steady-state solution of the quasi-linear mode is extended to the complex plane and compared with the nonlinear simulation. We determine that the asymptotic state of the collisionless plasma is a multi-wave BGK structure. This structure is characterized by multiple vortices in phase space, which correspond to distinct peaks in the frequency-wavenumber (ω, k) spectrum of the electric field

physics.plasm-ph↗

arXiv2011

WKB - Not So Bad After All

It was found recently that tunneling probabilities over a barrier is roughly twice as large as that given by standard WKB formula. Here we explained how this come from and showed that WKB method does give a good approximation over almost entire energy range provided that we use appropriate connection relations.

physics.plasm-ph↗