Observation of non-symmetric side-scattering during high-intensity laser-plasma interactions

Ajay K Arunachalam,Malte C Kaluza,Matthew B Schwab,Alexander Sävert

doi:10.1088/1367-2630/aab039

Abstract

Non-symmetric side-scattering has been observed during the interaction between a high-intensity laser pulse and under-dense argon plasma. The angle between the laser’s forward direction and the scattered radiation is found to decrease for increasing electron densities ranging from 0.01 to 0.25nc, where nc is the critical density for the laser wavelength. We show that the observed features of the scattering cannot be described by Raman side-scattering but can be explained to be a consequence of the non-uniform density distribution of the plasma with the scattering angle being oriented along the direction of the resulting electron density gradient.

Highlights

We show that the observed features of the scattering cannot be described by Raman side-scattering but can be explained to be a consequence of and DOI
The non-uniform density distribution of the plasma with the scattering angle being oriented along the direction of the resulting electron density gradient
The interaction dynamics between an ultrashort laser pulse and nearcritical plasma (0.1nc < ne < nc) have been extensively investigated both in experiments and with the help of numerical simulations. These dynamics have been found to be uniquely characterized by phenomena, such as resonant laser absorption [5], relativistic self-focusing [6], direct laser acceleration (DLA) [7], hole boring [8], soliton formation [9], vortex formation [10], laser pulse collapse [11] and gamma ray generation [12]

Summary

29 March 2018

Observation of non-symmetric side-scattering during high-intensity laser-plasma interactions. In order to shed more light into the interaction dynamics and in an attempt to explore the DLA mechanism, an experiment was carried out at the JETI-40 laser system at the University of Jena, Germany, in which the phenomenon of side-scattering of electromagnetic radiation has been studied in detail. Such a scattering process has been previously reported [16], where it has been attributed to Raman scattering. This mechanism is based on the deflection of the laser light in a non-uniform plasma density distribution

Set-up

Measurements

Findings

Analysis