Relativistic magnetic reconnection driven by a laser interacting with a micro-scale plasma slab

Distortion of a twisted beam passing through a plasma layer

In this paper, we explore what happens to the intensity profile, phase distribution, and centroid position of a vortex beam (VB) when it passes through a cold collision-less magnetized plasma layer. For this purpose, we utilize angular spectral expansion accompanied by a 4×4 matrix method to obtain the total transmission coefficient, intensity and phase profiles, and centroid shifts of VBs in the output plane. Based on numerical analyses, it is found that the evolution of transverse intensity as well as the distortion of the phase profile of transmitted VBs are greatly affected by variation of radial and angular mode numbers, external magnetic field, plasma number density, and incident angle. In addition, displacement of the VB centroid under variation of angular mode numbers is presented quantitatively. It is expected that the results of this study will give more insight into VB communication, radar probing, and plasma diagnostics.

Electromagnetic Burst Generation during Annihilation of Magnetic Field in Relativistic Laser-Plasma Interaction

We present the results of theoretical studies of formation and evolution of the current sheet in a colliosionless plasma during magnetic reconnection in relativistic limit. Relativistic magnetic reconnection is driven by parallel laser pulses interacting with underdense plasma target. Annihilation of laser created magnetic field of opposite polarity generates strong non-stationary electric field formed in between the region with opposite polarity magnetic field accelerating charged particles within the current sheet. This laser-plasma target configuration is discussed in regard with the laboratory modeling of charged particle acceleration and gamma flash generation in astrophysics. We present the results of 3-dimensional kinetic simulations and theoretical studies on the formation and evolution of the current sheet in a collisionless plasma during magnetic field annihilation in the ultra-relativistic limit. Annihilation of oppositively directed magnetic fields driven by two laser pulses interacting with underdense plasma target is accompanied by an electromagnetic burst generation. The induced strong non-stationary longitudinal electric field accelerates charged particles within the current sheet. Properties of the laser-plasma target configuration are discussed in the context of the laboratory modeling for charged particle acceleration and gamma flash generation in astrophysics.