Nuclear Structure Study Using Low-Temperature Nuclear Orientation

在CERN的ISOLDE和NICOL装置上进行了Au核区的下列实验。对于^<184>Au，发现两种异构体，这些半衰期分别为53 s和12 s。这两种异构体的自旋被认为是2，5或3，6。由于<181>该同位素的高度碎片化衰变以及半衰期相当的^ Hg初次植入物的辐射强度过大，因此不可能研究^ Au的时间分辨核取向<181>。因此，这种测量需要等待ISOLDE分离的金束的可用性。为了取代^<181>Au TR-OLNO研究，我们将NICOL装置注入Z=82以下的富质子核的基态性质的系统测量扩展到最轻的可获得的Ir同位素^<183-176>Ir.测量了同位素^<183>Ir，^<182>Ir，<180>^<179>Ir（^ Hg的α衰变<183>），^<178>Ir（^Hg的α衰变<182>）和^<176>Ir（^ Hg的α衰变<180>）的取向与温度的关系.在新泻大学，在8 mK的低温下对^ INI进行了NMR-ON测量<124>。磁超精细分裂频率为165.8（1）MHz。在已知磁矩^ I的情况下<124>，超精细场可确定为：B_<HF>（^<124>INi）=30.08（8）T。在8 mK和0.2T的外磁场下，测得有效弛豫时间为3.7（7）s。

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.