F Ostovarpour - Department of Physics and Institute for Plasma Research, Kharazmi University, ۴۹ Dr. Mofatteh Avenue, Tehran ۱۵۷۱۹-۱۴۹۱۱, Iran
K Hajisharifi - Department of Physics and Institute for Plasma Research, Kharazmi University, ۴۹ Dr. Mofatteh Avenue, Tehran ۱۵۷۱۹-۱۴۹۱۱, Iran
H Mehdian - Department of Physics and Institute for Plasma Research, Kharazmi University, ۴۹ Dr. Mofatteh Avenue, Tehran ۱۵۷۱۹-۱۴۹۱۱, Iran

In this paper, PIC simulation method has been employed to study the thermal effects on the spatio-temporal evolution of nonlinear electrostatic plasma waves (EPWs) in the wave-breaking regime. The coherent oscillation evolved into disordered motion. After wave breaking, a multistream flow and fast electron generation developed. Also, the occurance of electron holes is illustrated. We found that the initial thermal velocity of particles not only has an important role on the reduction of wave-breaking amplitude, in agreement with previous theoretical finding, but also decreases the BGK modes amplitude in the system after approaching the steady state. Finally, we conclude that in the warm plasma system the absorption rate is more than the cold ones.

Particle-in-cell simulation, wave-breaking, nonlinear electrostatic plasma waves, BGK waves, thermal velocity, nonlinear phenomena