Coulomb excitation of 68,70Cu: first use of postaccelerated isomeric beams.
We report on the first low-energy Coulomb excitation measurements with radioactive Ipi=6- beams of odd-odd nuclei 68,70Cu. The beams were produced at ISOLDE, CERN and were post-accelerated by REX-ISOLDE to 2.83 MeV/nucleon. Gamma rays were detected with the MINIBALL spectrometer. The 6- beam was used to study the multiplet of states (3-, 4-, 5-, 6-) arising from the pi2p3/2 nu 1g9/2 configuration. The 4- state of the multiplet was populated via Coulomb excitation and the B(E2;6--->4-) value was determined in both nuclei. The results obtained illustrate the fragile stability of the Z=28 shell and N=40 subshell closures. A comparison with large-scale shell-model calculations using the 56Ni core shows the importance of the proton excitations across the Z=28 shell gap to the understanding of the nuclear structure in the neutron-rich nuclei with N approximately 40.
Stefanescu
I
I
Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
Georgiev
G
G
Ames
F
F
Aystö
J
J
Balabanski
D L
DL
Bollen
G
G
Butler
P A
PA
Cederkäll
J
J
Champault
N
N
Davinson
T
T
De Maesschalck
A
A
Delahaye
P
P
Eberth
J
J
Fedorov
D
D
Fedosseev
V N
VN
Fraile
L M
LM
Franchoo
S
S
Gladnishki
K
K
Habs
D
D
Heyde
K
K
Huyse
M
M
Ivanov
O
O
Iwanicki
J
J
Jolie
J
J
Jonson
B
B
Kröll
Th
T
Krücken
R
R
Kester
O
O
Köster
U
U
Lagoyannis
A
A
Liljeby
L
L
Lo Bianco
G
G
Marsh
B A
BA
Niedermaier
O
O
Nilsson
T
T
Oinonen
M
M
Pascovici
G
G
Reiter
P
P
Saltarelli
A
A
Scheit
H
H
Schwalm
D
D
Sieber
T
T
Smirnova
N
N
Van De Walle
J
J
Van Duppen
P
P
Zemlyanoi
S
S
Warr
N
N
Weisshaar
D
D
Wenander
F
F