Controlling polarization of THz radiation in pair plasma

Abstract

Polarization-tunable terahertz (THz) radiation in pair plasma has been generated under the combined configuration of a helical wiggler and solenoidal magnetic fields. The control over the electromagnetic vector of the emitted field (i.e. polarization) furnishes the knob of another degree of freedom which is very useful in numerous applications. With the optimization of wiggler period and frequency, the total angular spread of the field has been reduced which provides a narrow-band THz spectrum. Additionally, the solenoidal field not only prevents the escape of particles during laser-matter interaction but also enhances the magnitude of emitted field. Along with the external magnetic field, collisions among the particles and ripples in plasma density have also been considered to fine-tune the radiation.

Investigating pair-production by Breit–Wheeler process in a collisional plasma

“…Intense laser beams while propagating in plasma create an ion channel with the transverse focusing field that increases the emittance of the radiated beam [21,22]. During laserplasma interaction, the quiver electrons get accelerated up to relativistic energies over a short distance either by wakefield or by the direct ultra-intense electromagnetic field [23][24][25][26][27]. Numerous studies, theoretical [28][29][30] and numerical, have verified the feasibility of positron beam generation under such a QED regime [31,32].…”

A Three-Coil Setup for Controlled Divergence in Magnetic Nozzle

“…In most of the systems, there is a need to alter the orientation, convergence, and magnitude of the generated magnetic field at the desired locations to get the required output. For example, nonlinear media respond efficiently in the presence of magnetic field [11]- [13] during its interaction with electromagnetic radiation/lasers, and orientation of magnetic field can play another role in tuning of electromagnetic radiation [14]. Well-known for their almost completely axial component of the magnetic field, solenoids are widely employed in various systems as small as actuators [15] to big spacecraft [16].…”