Excitation of KdV Alfven solitons by a pulsed CO2 laser in plasma in the presence of an external magnetic field

The interaction of laser with plasmas leads to many interesting phenomena which includes laser energy absorption, mode conversion, energetic particle generation etc. In this work, the excitation of Korteweg - de Vries (KdV) Alfven solitons in plasma is demonstrated with the help of 2-D Particle - In - Cell (PIC) simulations. For this purpose, the propagation of a pulsed $CO_2$ (with a wavelength of $10 \mu m$) laser normally incident on an overdense plasma target is considered in the presence of an external magnetic field. The magnitude of the external magnetic field is chosen so as to have the electrons magnetized and ions unmagnetized at the laser frequency. These solitons propagate stably and are observed to be responsible for energetic electron generation as the background undisturbed electrons of the medium get reflected from its front. It is also shown that subsequently, transverse modulations appear in the structure which grow with time. With recent technological advancements in the development of short pulse $CO_2$ lasers and also on the generation of magnetic fields of the order of tens of kilo - Tesla in the laboratory, these studies have practical relevance and have a possibility of getting replicated in laboratory in near future.