On the nuclear spin and magnetic dipole moment of 180Ta

The hyperfine structure of an atomic transition in 180 Ta was investigated by laser-induced resonance fluorescence. As a result we obtained for the quantity μ I 180 (1+ 1 2 I 180 ) the value 5.04 (5) μ N . This experimental result is best reproduced assuming parallel coupling of a 9 2 − [514] proton and a 9 2 + [624] neutron. It is concluded that 180 Ta most likely has I π =9 − and a magnetic dipole moment μ I =4.77 (5) μ N .