Initial Frequency Shift of Large Amplitude Plasma Wave : Langmuir Wave

概要

論文の詳細を見る
A distribution function which is an exact solution to the collisionless Boltzmann equation is obtained in an expansion form in terms of the potential φ (x, t). A complex nonlinear frequency shift ω_N (t) is obtained by use of the Poisson equation and the expansion. The theory is valid for arbitrary φ_0 and v_p as long as ω_p>>γ_L, and in the initial phase defined by 0<t<t_c where φ_0,v_p, ω_p, γ_L and t_c are the initial value of φ, the phase velocity, the Langmuir frequency, the linear Landau damping coefficient and the time for the first minimum of the amplitude oscillation. The ω_N (0) dose not vanish and Reω_N (0)/γ_L>1 holds even for eφ_0/T<<1 when kλ_D<<1,λ_D being the Debye length. It is shown that ω_N (t) is dominant over the Morales and O'Neil's one^1 in the initial phase for v_p>v_T. The theory reproduces main features of experimental results and that of simulations.
核融合科学研究所の論文