NEUTRON-DEFICIENT ISOTOPES OF LANTHANUM—La127, La128, La129, La130, and La131

Abstract
La127, La128, La129, and La131 were produced by the reaction of C12 ions with antimony. Half-lives of 3.5 ± 0.5, 4.6 ± 0.6, 8.6 ± l.8, and 56 ± 3 min respectively, were obtained from the observed growth of the respective barium daughters. The half-life for Ba128 was found to be 2.43 ± 0.05 days. La129 and La130 were produced and identified by the reactions Ba130(p,2n) and Ba130(p,n) respectively, carried out with targets enriched in Ba130. In the proton bombardments half-lives of l0.0 ± 0.5 min and 8.7 ± 0.1 min were found for La129 and La130 respectively.