Observation of Asymmetric Stark Profiles from Plasmas Created by a Picosecond KrF Laser

High-resolution extreme-ultraviolet spectra from solid targets irradiated by a picosecond KrF laser focused to ${10}^{16}$ W/${\mathrm{cm}}^2$ have been recorded. The line profiles of transitions in Li-like fluorine and oxygen are asymmetric and up to 2 Å in width. Calculations indicate the presence of transitions of the type $2p-3p$ and other forbidden Stark components.