Evolution of the N=50 shell gap energy towards 78Ni.
Atomic masses of the neutron-rich isotopes (76-80)Zn, (78-83)Ga, (80-85)Ge, (81-87)As, and (84-89)Se have been measured with high precision using the Penning trap mass spectrometer JYFLTRAP at the IGISOL facility. The masses of (82,83)Ga, (83-85)Ge, (84-87)As, and 89Se were measured for the first time. These new data represent a major improvement in the knowledge of the masses in this neutron-rich region. Two-neutron separation energies provide evidence for the reduction of the N=50 shell gap energy towards germanium (Z=32) and a subsequent increase at gallium (Z=31). The data are compared with a number of theoretical models. An indication of the persistent rigidity of the shell gap towards nickel (Z=28) is obtained.
Hakala
J
J
Department of Physics,University of Jyväskylä, Finland.
Rahaman
S
S
Elomaa
V-V
VV
Eronen
T
T
Hager
U
U
Jokinen
A
A
Kankainen
A
A
Moore
I D
ID
Penttilä
H
H
Rinta-Antila
S
S
Rissanen
J
J
Saastamoinen
A
A
Sonoda
T
T
Weber
C
C
Aystö
J
J