Extreme ultraviolet spectra of highly charged hafnium, tantalum, and gold were produced with an electron beam ion trap (EBIT) at the National Institute of Standards and Technology (NIST) and recorded with a flat-field grazing-incidence spectrometer in the wavelength range 4 nm-20 nm. The beam energy was varied between 1.84 keV and 5.15 keV to selectively enhance spectra from specific ionization stages. Identifications of strong n=4-n=4 transitions from Rb-like hafnium (35+) to Co-like gold (52+) were determined with the aid of collisional-radiative modeling of the EBIT plasma. Good quantitative agreement between simulated and measured spectra was achieved. Over 150 spectral lines were identified, 115 of which are new.
Citation: Journal of Physics B-Atomic Molecular and Optical Physics
Pub Type: Journals
hafnium, tantalum, gold, EUV spectra, EBIT, collisional-radiative modeling, line identification, highly-charged ions