For neutron-deficient 124,125,127-130La, QEC measurement has been performed by determining β+-ray maximum energies. The radioactive sources were prepared by on-line mass-separation following the fusion-evaporation reactions 92,natMo(36Ar, 3pxn). The β+-rays were measured with an HPGe detector in β - γ coincidence mode in which γ-rays were detected with another HPGe detector for specifying an excited state in daughter nucleus. By unfolding the β+-ray spectra using experimental response functions, the QEC-values of 124,125,127,130La were newly obtained, and those of 128,129La were improved in their accuracy. The QEC-values obtained and the resulting atomic masses are compared with theoretical predictions. The results of half-life calculation and two-neutron separation energies using the experimental QEC-values are also discussed.
ASJC Scopus subject areas
- Physics and Astronomy(all)