8 research outputs found
Nuclear structure of Ac-231
The low-energy structure of 231Ac has been investigated by means of gamma ray
spectroscopy following the beta-decay of 231Ra. Multipolarities of 28
transitions have been established by measuring conversion electrons with a
mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been
constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t)
method has been used to measure the half-lives of five levels. The moderately
fast B(E1) transition rates derived suggest that the octupole effects, albeit
weak, are still present in this exotic nucleus
Discovery of the actinium, thorium, protactinium, and uranium isotopes
Currently, 31 actinium, 31 thorium, 28 protactinium, and 23 uranium isotopes
have so far been observed; the discovery of these isotopes is discussed. For
each isotope a brief summary of the first refereed publication, including the
production and identification method, is presented.Comment: Accepted for publication in Atomic Data Nuclear Data Table