Youjun Hu 1
In Sec. 1 of this note, resonant wave particle interactions are demonstrated by a simple test particle simulation. Section 2 reproduces Stix's derivation of Landau damping from the view of test particles[4]. In Sec. 3, linearized Vlasov-Poison equations are solved numerically to demonstrate the ``phase mix'' in velocity space and the resulting Landau damping.