Large enhancement of radiative strength for soft transitions in the quasicontinuum.
Radiative strength functions (RSFs) for the (56,57)Fe nuclei below the separation energy are obtained from the 57Fe(3He,alphagamma)56Fe and 57Fe(3He,3He'gamma)57Fe reactions, respectively. An enhancement of more than a factor of 10 over common theoretical models of the soft (E(gamma) less than or approximately equal 2 MeV) RSF for transitions in the quasicontinuum (several MeV above the yrast line) is observed. Two-step cascade intensities with soft primary transitions from the 56Fe(n,2gamma)57Fe reaction confirm the enhancement.
Voinov
A
A
Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, 141980 Dubna, Moscow region, Russia. voinov@ohiou.edu
Algin
E
E
Agvaanluvsan
U
U
Belgya
T
T
Chankova
R
R
Guttormsen
M
M
Mitchell
G E
GE
Rekstad
J
J
Schiller
A
A
Siem
S
S