Application of implicit symplectic difference scheme in calculating propagation trajectory of wave in non-magnetized plasma

Abstract

Ray tracing method is an important tool of studying wave propagation in plasma. The ray tracing equations are Hamiltonian and usually calculated by traditional Runge-Kutta-Fehlberg method. Symplectic geometric structure of Hamiltonian system is not considered in Runge-Kutta-Fehlberg method. In order to preserve the symplectic geometric structure of Hamiltonian system, symplectic geometric algorithm is used to solve ray tracing equations. In a calculation example, the propagation trajectories of waves in non-magnetized plasmas are calculated by using the symplectic geometric algorithm, and the results are compared with those obtained by Runge-Kutta-Fehlberg algorithm. The results show that the symplectic geometric algorithm has a unique advantage in maintaining the propagation trajectory and dispersion function value.