Nuclear Structure Study Using Low-Temperature Nuclear Orientation

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Following experiments for Au nuclear region have done at CERN using ISOLDE and NICOL facilities. For ^<184>Au, the two isomers are found and these half-life are 53 s and 12 s. The spin of the two isomers are proposed to be either 2, 5 or 3, 6. The intention to study Time Resolved Nuclear Orientation of ^<181>Au was rendered impossibly by the highly fragmented decay of this isotope and the overwhelming intensity of radiations from the ^<181>Hg primary implant which has comparable half-life. Accordingly this measurement needs to await the availability of separated gold beams at ISOLDE. To replace the ^<181>Au TR-OLNO study, the systematic measurement of ground state properties of proton rich nuclei below Z=82 implanted at the NICOL facility was extended to the lightest accessible Ir isotopes, ^<183-176>Ir. Measurements were made on the temperature depedence of orientation of the isotope ^<183>Ir, ^<182>Ir, ^<180>Ir, ^<179>Ir (by alpha decay of ^<183>Hg), ^<178>Ir (by alpha decay of ^<182>Hg) and ^<176>Ir (by alpha decay of ^<180>Hg). Large effects were observed and these experiments are now being analyzed.In Niigata Univ. NMR-ON measurements have been performed for ^<124>INi at low temperature of 8 mK. The magnetic hyperfine splitting frequency was determined to be 165.8 (1) MHz. With the known magnetic moment of ^<124>I, the hyperfine field could be determined as B_<HF>(^<124>INi)=30.08 (8) T. The effective relaxation time was determined to be 3.7 (7) s at 8 mK and with the external magnetic field of 0.2 T.