X-ray Spectrum Emitted by a Laser-Produced Cerium Plasma in the 7.5 to 12 Å Wavelength Range

A highly stripped cerium (Z = 58) plasma is produced by irradiating a solid cerium target with an intense short laser pulse. The X-ray spectrum emitted from the plasma is recorded in the 7.5-12 Å wavelength range using a flat RAP crystal spectrometer. Ab-initio calculations using the RELAC relativistic computer code, as well as isoelectronic trends deduced from previous works, together with spectra obtained under different laser beam focusing conditions, are all employed for the identification of the spectral lines and features emitted by various ions from Fe-like Ce³²⁺ to As-like Ce²⁵⁺. The technique of comparing spectra obtained using different laser intensities is also employed to confirm or to resolve some ambiguous identifications of spectral features in the spectrum of a laser-produced lanthanum plasma studied in a previous work.