First beta-decay studies of the neutron-rich isotopes Sc53-55 and V56-59
Author
Sorlin, O.
Borrel, V.
Grevy, S.
Guillemaud-Mueller, D.
Mueller, A.C.
Pougheon, F.
Bohmer, W.
Kratz, K.L.
Mehren, T.
Moller, P.
Pfeiffer, B.
Rauscher, T.
Saint-Laurent, M.G.
Anne, R.
Lewitowicz, M.
Ostrowski, A.
Dorfler, T.
Schmidt-Ott, W.D.
Attention
2299/11032
Abstract
The neutron-rich isotopes Sc53-55 and V56-59 have been produced at GANIL in interactions of a 64.5 MeV/u Cu-65 beam with a Be-9 target. They were separated by the doubly achromatic spectrometer LISE3. Beta-decay half-lives and subsequent low-energy gamma-rays were observed for the first time. The present results are compared to QRPA model predictions. The quick drop of the half-life observed at N = 33 for Ca-53(20)33 is water V-56(23)33 and absent for Sc-54(21)33, indicating a vanishing of the N = 32 subshell north to Ca-52(32). In an astrophysical context, these neutron-rich isotopes represent r-process progenitors which, after beta-decay, would produce the correlated isotopic over-abundances of Cr-54, Fe-58, Ni-64 in certain refractory inclusions of meteorites. (C) 1998 Elsevier Science B.V.