@article{oai:nagoya.repo.nii.ac.jp:00012272, author = {Nariyuki, Y. and Umeda, T.}, issue = {5}, journal = {PHYSICS OF PLASMAS}, month = {May}, note = {In the present study, we analyze the data sets produced by a one-dimensional Vlasov.Poisson simulation of the weak electron beam-plasma instability to clarify the nonlinearity of the Langmuir turbulence excited by the weak-beam interaction. The growth of wave number modes is analyzed by using the momentum equation of the whole electrons. The analysis shows that the primary Langmuir wave mode is almost linear, while the nonlinear terms play important roles in the growth of the lower harmonic mode and the secondary higher harmonic mode. After the linear growth saturates, while the wave power of the primary mode is much larger than the other modes, linear and nonlinear interactions occurring in both lower harmonic and secondary higher harmonic modes are more active than those in the primary mode. Nonlinearity in the system comes from the advection rather than the ponderomotive forces.}, pages = {054506--054506}, title = {On the nonlinearity of the Langmuir turbulence excited by a weak electron beam-plasma interaction}, volume = {17}, year = {2010} }