Investigation of laser interaction with tungsten target by means of time-resolved optical spectroscopy

The paper reports on space- and time-resolved spectroscopic measurements performed during the interaction of an intense laser pulse (0.7 J, 2 ns) with a tungsten target, which was located inside a vacuum chamber. The optical spectra were recorded with a Mechelle(R) 900 optical spectrometer and a CCD camera coupled with a computer equipped with the GRAMS32-v.6.0 software. Spectral lines emitted by excited tungsten atoms and single-charged tungsten ions were identified and analyzed. Using a two-step procedure for fitting the line profile, it was possible to estimate parameters of a tungsten plasma plume formed in the front of the investigated target. The appearance of the tungsten ions was also confirmed by measurements performed with an electrostatic ion-energy analyzer.