Nonlinear plasma wakefield excitation by an ultra-relativistic square Gaussian beam is simulated using FBPIC code. The beam interaction with the background plasma electrons revealed blowout cavity formation. As the beam propagates further into the plasma, blowout cavity elongation along the beam propagation direction was observed. The corresponding electromagnetic field components excited within the plasma wake generated at different iteration stages showed impressive field magnitude. The magnitude of the longitudinal electric field gradients at two different iteration stages is observed in excess of *500GV/m* and several *TV/m* scale levels respectively. Also, the azimuthal magnetic field components is observed to be in excess of *60MT* and *47MT* levels. The radial electric field and net focusing field components were also assessed as well.

Nonlinear plasma wakefield excitation by an ultra-relativistic square Gaussian beam is simulated using FBPIC code. The beam interaction with the background plasma electrons revealed blowout cavity formation. As the beam propagates further into the plasma, blowout cavity elongation along the beam propagation direction was observed. The corresponding electromagnetic field components excited within the plasma wake generated at different iteration stages showed impressive field magnitude. The magnitude of the longitudinal electric field gradients at two different iteration stages is observed in excess of *500GV/m* and several *TV/m* scale levels respectively. Also, the azimuthal magnetic field components is observed to be in excess of *60MT* and *47MT* levels. The radial electric field and net focusing field components were also assessed as well.