X-ray line polarization spectroscopy to study hot electron transport in ultra-short laser produced plasma

摘要

Observation is reported of the polarization of the helium-like Cl-He alpha line (1s(2) S-1(0)- 1s2p P-1(1)), at 2.79 keV emitted from a triple-layer target irradiated with a 130 fs laser pulse. The polarization degree is determined as a function of overcoat thickness of the target. It is found that the emission from a layer closer to the target surface is polarized parallel to the surface direction whereas emission from a deeper region in perpendicular to the surface. The experimental result is analyzed using a two-dimensional (2D) Maxwellian distribution function for hot electrons. Beam-like distribution was found in the depth of plasma. (C) 2005 Elsevier Ltd. All rights reserved.