Generation of Cold Magnetized Relativistic Plasmas at the Rear of Thin Foils Irradiated by Ultra-High-Intensity Laser Pulses

Artem V Korzhimanov

doi:10.3390/app112411966

Abstract

A scheme to generate magnetized relativistic plasmas in a laboratory setting is proposed. It is based on the interaction of ultra-high-intensity sub-picosecond laser pulses with few-micron-thick foils or films. By means of Particle-In-Cell simulations, it is shown that energetic electrons produced by the laser and evacuated at the rear of the target trigger an expansion of the target, building up a strong azimuthal magnetic field. It is shown that in the expanding plasma sheath, a ratio of the magnetic pressure and the electron rest-mass energy density exceeds unity, whereas the plasma pressure is lower than the magnetic pressure and the electron gyroradius is lower than the plasma dimension. This scheme can be utilized to study astrophysical extreme phenomena such as relativistic magnetic reconnection in laboratory.

Highlights

There has been an increased interest in the possibility of investigating processes characteristic of extreme astrophysical objects in laboratories using powerful laser systems [1,2]
We studied in more detail the properties of the resulting plasma and found that conditions for a cold magnetized relativistic plasma are realized in it, allowing using this mechanism for observing relativistic magnetic reconnection under laboratory conditions
At a later moment in time (Figure 1g–i), an increase in the azimuthal magnetic field is observed in the formed plasma sheath

Summary

Introduction

There has been an increased interest in the possibility of investigating processes characteristic of extreme astrophysical objects in laboratories using powerful laser systems [1,2]. Much attention is paid to the study of the magnetic reconnection process, which is widely encountered in space Typical experiments in this area use two nanosecond laser pulses with energies ranging from a few Joules to several kilojoules to irradiate a metal surface. As a result of the interaction, ablation of a heated substance takes place, in which azimuthal magnetic fields are self-generated due to the Biermann battery effect. Such magnetized expanding plumes may be arranged to collide with each other, initiating a reconnection of oppositely directed magnetic lines in an interaction region [3,4,5,6,7]. The case of the magnetized relativistic plasma corresponds to σ > 1, and until recently such values were unattainable in the laboratory

Methods

Results

Conclusion