NEXAFS spectroscopy and spectromicroscopy with laser-produced plasma sources of soft x-ray radiation

Abstract

In this work, a near edge X-ray fine structure spectroscopy (NEXAFS) based on a laser-plasma compact soft X-ray (SXR) source is presented. The NEXAFS spectrum was acquired simultaneously for all energies near the absorption edge, using a broadband emission from krypton plasma, in contrary to the existing, synchrotron-based spectroscopic systems. In such SXR source, a plasma is produced by an interaction of a laser beam with a double stream gas puff target. The plasma efficiently emits SXR radiation from 2-5 nm wavelength (250-620 eV photon energy). Such broadband emission allows acquiring simultaneously a sample and a reference spectra, to obtain optical density spectrum of the sample near C-Kα absorption edge, due to a special construction of the SXR spectrometer. The NEXAFS spectra were obtained using PET polymer test sample, from both, the large area and spatially localized to ~30×30 μm2 area. The spatially localized spectra were used to construct 2-D spectromicroscopic maps of sample constituents. Single-shot spectra were also acquired with laser pulse energies of ~10 times larger than in the case of multiple exposures. A short overview of those NEXAFS experiments will be presented.