Nuclear spin relaxation of 13.9 msec sup(88m)Y in liquid rubidium

The nuclear spin relaxation time of the 13.9 msec isomer of sup(88m)Y in liquid rubidium has been measured as a function of temperature and applied field by the technique of time-differential perturbed angular correlations following nuclear reactions (DPAD). The 8+ isomeric level was produced and aligned by bombardment of a liquid rubidium target with 40 MeV alpha particles from the Heavy Ion Accelerator. The relaxation time for solid rubidium was less than 1 msec. For the liquid, the nuclear spin relaxation time decreased as the temperature increased. From the Knight shift in rubidium and the Korringa relation, the relaxation time is expected to be 2.5 msec, just above the melting point. The explanation for the discrepancy must lie in the hyperfine interactions of the Y-Rb system. (Auth.)