THz radiation generation from plasma wakefield driven by skew-cosh-Gaussian laser beam under an undulator magnetic field

Abstract

The paper examines theoretically the generation of terahertz (THz) radiation as a result of wakefields generated by skew-cosh-Gaussian (skew-chG) laser beam propagating in collisional plasma under an undulator magnetic field. Analytical and non-linear equations have been derived to describe the generation of THz radiation by skew-chG laser beam. Using equations of motion, continuity equations, and perturbation technique, the transverse and longitudinal wakefield has also been derived in the presence of an undulator magnetic field. It is shown that the collisional plasma carries a higher longitudinal wakefield amplitude while the undulator amplitudes are lower. In addition, it is found that smaller collision frequencies make larger wakefield amplitudes that generate terahertz radiation. However, when the collision frequency becomes equal to the plasma frequency, the wakefield amplitude is greatly reduced. Moreover, it is observed that the THz field decreases with the increase of the beam waist of the skew-chG laser beam. It is also shown that the THz field exhibits an increasing behavior with increasing s parameter and undulator amplitudes despite the presence of significant collisions.