Fine-structure splittings of 2F states of singly ionized strontium

Abstract We have studied the 4 d − nf and 5 d − nf ( n = 4−8) transitions of singly ionized strontium using high-resolution optical spectroscopy. The 2 F fine structure is inverted in all the states observed and decreases from −1.06cm −1 in 4f to −0.26 cm −1 in 8f.