L. Gaudefroy

Beta decay studies of neutron-rich 21Sc27Co nuclei at GANIL

The neutron-rich nuclei ~:‘5sS~, ;i-60Ti,!

First direct lifetime measurement of the 2(1)(+) state in Zn-72,Zn-74 : New evidence for a shape transition between N=40 and N=42 close to Z=28

-62V, ;z-66Cr, ;:-68Mn, ige7’Fe and ;F-71Co have been produced at Ganil via interactions of a 61.8 A.MeV 76Ge beam with a 58Ni target. Beta-decay studies have been achieved, bringing new half-lives and a better nuclear structure knowledge in this region. These results could help for understanding the overabundances of the neutron-rich stable 58Fe, 64Ni in certain inclusions of meteorites.

Lifetime measurements in

We report here the first direct lifetime measurement of the 2(1)(+) state in Zn-72,Zn-74. The neutron-rich beam was produced by in-flight fragmentation of Ge-76 at the Grand Accelerateur National dIons Lourds and separated with the LISE spectrometer. The 2(1)(+) state was excited by inelastic scattering and knock-out reaction on a CD2 target and its lifetime was measured by the recoil-distance Doppler-shift method with the Koln plunger device combined with the EXOGAM detectors. The lifetimes of the 2(1)(+) states in Zn-72,Zn-74 were determined to be 17.9(18) and 27.0(24) ps, which correspond to reduced transition probabilities B(E2; 2(1)(+)-> 0(+)) = 385(39) and 370(33) e(2) fm(4), respectively. These values support the idea of a systematic maximum of collectivity at N = 42 for Zn, Ge, and Se nuclei. In addition, the available systematics in the neighboring nuclei point toward a transition from a spherical oscillator at N = 40 to complete gamma-softness at N = 42.

^{63}

Lifetimes of the

Co and

9/2^-_1

^{65}

and

Co

3/2^-_1

The origin of the Ca-Ti-Cr-Fe-Ni isotopic anomalies in the inclusion EK-1-4-1 of the Allende meteorite

states in

Beta-decay of O-22

^{63}

Nuclear structure studies of F 24

Co and the