153 research outputs found
Extraction of level density and gamma strength function from primary gamma spectra
We present a new iterative procedure to extract the level density and the
gamma strength function from primary gamma spectra for energies close up to the
neutron binding energy. The procedure is tested on simulated spectra and on
data from the Yb-173(He-3,alpha)Yb-172 reaction.Comment: 23 pages including 1 table and 7 figure
Nuclear level densities and gamma-ray strength functions in 44,45Sc
The scandium isotopes 44,45Sc have been studied with the 45Sc(3He,alpha
gamma)44Sc and 45Sc(3He,3He' gamma)45Sc reactions, respectively. The nuclear
level densities and gamma-ray strength functions have been extracted using the
Oslo method. The experimental level densities are compared to calculated level
densities obtained from a microscopic model based on BCS quasiparticles within
the Nilsson level scheme. This model also gives information about the parity
distribution and the number of broken Cooper pairs as a function of excitation
energy. The experimental gamma-ray strength functions are compared to
theoretical models of the E1, M1, and E2 strength, and to data from (gamma,n)
and (gamma,p) experiments. The strength functions show an enhancement at low
gamma energies that cannot be explained by the present, standard models.Comment: 21 pages, 13 figures. Published versio
Determination of the electromagnetic character of soft dipole modes solely based on quasicontinuous gamma spectroscopy
We show that the combined analysis of the quasicontinuous gamma spectra from
the (He-3,alpha) and the (n-thermal,2gamma) reactions gives the possibility to
measure the electromagnetic character of soft dipole resonances. Two-step
gamma-cascade spectra have been calculated, using level densities and radiative
strength functions from the (He-3,alpha gamma) reaction. The calculations show
that the intensity of the two-step cascades depends on the electromagnetic
character of the soft dipole resonance under study. The difference reaches
40-100% which can be measured experimentally.Comment: 9 pages including 1 table and 2 figure
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