Abstract:
Spectroscopic methods were used to detect Y, Zr, Nb, Mo, Ta, and W ions of charge ~30–50 in a laser plasma interacting with a laser beam of 5×1014 W/cm2 density. Spectra of neonlike ions Y3929+, Zr4030+, Nb4131+, and Mo4232+ were identified. The presence of Ta and W lines in the 0.55–0.60 nm range yielded the ionization potential of ~4.2–5.2 keV, which corresponded to an ionic charge from 48 to 54. The intensities of the spectral lines were used to estimate the total number of ions created by one laser pulse and this number was at least 1011.