No abstract

No abstract

No abstract

No abstract

No abstract

The transient response of nonlinear coupling between relatively high frequency magnetosonic wave (HMSW) and low frequency magnetosonic wave (LMSW) in the overdense plasma has been presented in this paper. Along with this, the adiabatic response of HMSW also has been studied for low value of magnetic field in the underdense plasma. The ponderomotive force of relatively high frequency and high power pump magnetosonic wave is expected to excite the low frequency magnetosonic wave. The dynamical equation of LMSW in the presence of ponderomotive force of HMSW (pump wave) has been derived for this purpose. Using this coupled system of dynamical equations, the nonlinear behavior of the pump HMSW was studied, and the resulting turbulent spectrum has been presented. Numerical simulation has been carried out for dimensionless nonlinear coupled equations of HMSW and LMSW, and the results show quite complex localized structures that grow with time. The ensemble averaged power spectrum has also been studied which shows that the spectral index follows an approximate scaling of the order of ∼k−1.67 at larger scales and scaling of the order of ∼k−3.4 at smaller scales. The results indicate considerable randomness in the spatial structure of the magnetic field profile which gives sufficient indication of turbulence. In this context, filamentation of high frequency magnetosonic wave has been considered to be responsible for magnetic turbulence during the laser plasma interaction. The results of the present paper are found relevant with two different experimental observations. Such a nonlinear interaction is quite important in understanding turbulence in the astrophysical phenomenon.

This paper presents a theoretical model for the magnetic turbulence in laser plasma interaction due to the nonlinear coupling of magnetosonic wave with ion acoustic wave in overdense plasma. For this study, dynamical equations of magnetosonic waves and the ion acoustic waves have been developed in the presence of ponderomotive force due to the pump magnetosonic wave. Slowly converging and diverging behavior has been studied semi-analytically, this results in the formation of filaments of the magnetosonic wave. Numerical simulation has also been carried out to study nonlinear stage. From the results, it has been found that the localized structures become quite complex in nature. Further, power spectrum has been studied. Results show that the spectral index follows (∼k−2.0) scaling at smaller scale. Relevance of the present investigation has been shown with the experimental observation.

No abstract