LIBS for tungsten diagnostics in vacuum: Selection of analytes

A sample of pure bulk tungsten was studied by laser induced breakdown spectroscopy (LIBS) method with the aim to find out a set of W analytic lines allowing a reliable determination of main parameters of the laser-produced plasma. The background pressure as well as the recording direction of spectra were close with those occurring in fusion reactors. Varying the delay time between the laser pulse and the data acquisition time-gate, time-resolved LIBS spectra were recorded at two different laser wavelengths. On the basis of spectral lines with negligible overlapping and self-absorption, the laser-induced plasma temperature as a function of time has been found. (C) 2014 Elsevier B.V. All rights reserved.