Q Beta Measurements Of Neutron-Rich Rare Earth Nuclei Produced With Proton Induced Fission Of U-238

The beta-decay energy (Q(beta)) of neutron-rich rare earth nuclei Pm-158,Pm-159, Sm-159,Sm-161 and Tb-166, produced with the 16 MeV proton induced fission of U-238, were measured using a total absorption detector installed in an on-line mass separator. By means of the measurement having time information, their half-lives were also measured, simultaneously, from the decay curves. We propose a measuring method of atomic masses of rare nuclei, and indicate that the predicted half-lives by some models are longer than the experimental ones if the models adopt the present Q(beta)s in this region.