Langmuir soliton ( Zakharov 1972 ) and Langmuir turbulence in two dimensional periodic geometries are studied by numerical simulation Particle-in-Cell (PIC) simulation method is employed to generate Langmuir solitons First a general solution for electric field and ion density from Zakharov equation and nonlinear Schr?dinger equation are obtained and inverse Gauss’s law is employed to obtain electron density as initial profile Second external pumping electric field in Lorentz force is employed Langmuir waves and Ion-acoustic waves are nonlinearly coupled satisfying frequency matching condition Through resonance by pumping energy into system nonperiodic pulse like structures are generated that are solitons are generated in two dimensional geometry In two dimensional or three dimensional systems solitons can burn out because the nonlinearity becomes dominant over dispersion effects The dynamics in k-spectrum of electric field energy is revealed Furthermore background magnetic field is superimposed onto the two dimensional system to observe particles’ influence by gyromotion and E×B drift The background magnetic effect disturbs the process of burn out and elongate the lifetime of solitons
Nonlinear Langmuir soliton dynamics in magnetized plasma employing two dimensional kinetic simulation
致皞, 蘇. (Author). 2016 12月 29
學生論文: Master's Thesis