Interpretation of the spectra of a laser-irradiated Au plasma in the 3.0–4.0-Arange

The spectrum of a laser-produced gold plasma (3. 0--4. 0 A) was interpreted by Kiyokawa et al. Phys. Rev. Lett. 54, 1999 (1985) as due to multiple inner-shell vacancy states of Au^26+--Au^32+. New extended observations (3. 5--6. 1 A) obtained from a similar Au plasma with a better resolution lead to unambiguous identification of several emission lines of Au^51+, and an alternative theoretical interpretation of all spectral features from 3. 0--3. 8 A is proposed in terms of unresolved transition arrays (3d-5f and 3d-6f types) of Au^52+--Au^48+.