Analysis of x-ray polarization to determine the three-dimensionally anisotropic velocity distributions of hot electrons in plasma produced by ultrahigh intensity lasers

Y. Inubushi, T. Kai, T. Nakamura, S. Fujioka, H. Nishimura, and K. Mima

Phys. Rev. E 75, 026401 – Published 1 February 2007

Abstract

A new polarization spectroscopy model has been developed to analyze energetic electrons distributed in a three-dimensional phase space. This model calculates the polarization degrees for a given line of sight. Time-dependent polarization degrees of $He α$ line emitted from heliumlike chlorine ions was obtained for two different lines of sight by using three-dimensional electron velocity distributions provided with two-dimensional particle-in-cell simulations. These results demonstrate that the polarization degrees are sensitively dependent on the profile of the electron velocity distributions which are affected by the polarization of the laser pulse.