Determination of spin, magnetic moment and isotopic shift of neutron rich /sup 205/Hg by optical pumping

Neutron rich /sup 205/Hg (T/sub 1/2/=5.2 min) was produced and on-line mass separated at the ISOLDE facility at CERN. The polarization achieved by optical pumping via the atomic line (6s/sup 2/ /sup 1/S /sub 0/ from to 6s6p /sup 3/P/sub 1/, lambda =2537 AA) was monitored by the beta decay asymmetry. Hyperfine structure and isotopic shift of the /sup 205/Hg absorption line was determined by Zeeman scanning. In addition a magnetic resonance was performed on the polarized /sup 205 /Hg nuclei in the atomic ground state. The results are: I(/sup 205/Hg) =/sup 1///sub 2/(confirmed); mu /sub I/(/sup 205/Hg)=0.5915(1) mu /sub N/ (uncorrected for diamagnetism); isotopic shift delta nu /sup 204 /205/= nu (/sup 205/Hg)- nu (/sup 204/Hg)=-1.8(1) GHz. mu /sub I/ and IS are discussed briefly in the frame of current literature. (37 refs) .