Beta decay half-lives of neutron rich Ti-Co isotopes around N=40

The neutron-rich Ti57-59, V59-62, Cr61-64, Mn63-66, Fe65-68, Co67-70 have been produced at GANIL via interactions of a 60.4 MeV/u (KR34+)-K-86 With a Ni-58 target. They have been separated by the doubly achromatic spectrometer LISE3. Beta-decay half-lives have been determined for all produced nuclei, and subsequent gamma-rays have been observed for the most efficiently produced nuclei. The measured half-lives of vanadium and chromium isotopes are compared to QRPA calculations using ground states deformations from the FRDM or ETFSI models. In an astrophysical context, the short half-lives of Ti-58 and Cr-64 indicate that these nuclei are potential r-process progenitors, after beta-decay, of Fe-58 and Ni-64 in certain inclusions of meteorites. (C) 1999 Published by Elsevier Science B.V. All rights reserved.