Electromagnetic transitions and alpha decay of the Pa-223 nucleus - art. no. 057301

Actinides with N similar to 132 present the best explored region of pear sh ape nuclei. Still almost no spectroscopic information is available for the heaviest elements, Z=91-98, which are predicted to be octupole instable. Th e lack of data for the latter nuclei results from the high fission probabil ity encountered in the heavy-ion reactions used to populate them. In order to overcome this handicap, an alpha-decay tagging technique was used to ide ntify gamma rays in Pa-223 produced through the Pb-208(F-19,4n) reaction. A new value of 4.9(4) ms for the half-life of Pa-223 was obtained as a by-pr oduct. [S0556-2813(99)00711-6].