Program - Brookhaven National Laboratory

(AME2003) [1], and level schemes and gamma decays from the Reference Input Parameter Library (RIPL-
3) [2]. The data are stored in a hierarchical structure. An example of how POP stores nuclear masses
and energy levels will be presented here. ”This work was performed under the auspices of Department of
Energy contract No. DE-AC52-07NA27344 (Lawrence Livermore National Laboratory).”
[1] G. Audi et al., ”The Ame2003 atomic mass evaluation (II)”, Nuclear Physics A729, 337 (2006). [2] R.
Capote et al., ”Reference Input Parameter Library (RIP-3)”, Nuclear Data Sheets 110, 3107 (2009).
Session KC Evaluated Nuclear Data Libraries
Wednesday March 6, 2013
Room: Empire East at 1:30 PM
KC 1 1:30 PM
Current Status of Evaluated Nuclear Data of Mn-55
A. Trkov, Josef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia. R. Capote, International
Atomic Energy Agency, Wagramerstrasse 5, A-1400 Vienna, Austria. L. Leal, Oak Ridge National
Laboratory, Oak Ridge, TN 37831, U.S.A.. D.W. Muir, Consultant to the International Atomic Energy
Agency, Vienna, Austria. E. Sh. Sukhovitskii, Joint Institute for Energy and Nuclear Research, 220109,
Minsk-Sosny, Belarus.
Manganese is a common alloying material in steels and thus represents an important structural material.
The radiative capture cross section of manganese is also a dosimetry reaction, therefore good knowledge
of its nuclear data is desirable. The new resonance parameters from Oak Ridge that are included in
the ENDF/B-VII.1 evaluation of manganese remove the long-standing discrepancy between the thermal
cross section and resonance integral measurements by the activation technique. The overall trends in the
resonance data are supported very well by simulating the Grenoble lead-slowing-down experiment. The
remaining outstanding problems are the following:
• Resolved resonance parameters extend to 0.125 MeV and the unresolved resonance parameters are
defined up to 1 MeV. However, experimental data indicate that there is significant structure in
the cross sections up to about 4 MeV. At 1 MeV the calculated fully self-shielded capture cross
section differs from the one at infinite dilution by about 30%. The Oktavian benchmark experiment
measuring the leakage spectrum from a manganese sphere with a D-T source in the centre strongly
supports the need to consider self-shielding to higher energies, since the calculated spectrum shows
a distinct discontinuity at 1 MeV.
• Measurements of elastic scattering angular distributions with a fairly good energy resolution are
available near 1 MeV and they show significant structure. The average cosine of scattering derived
from the data also shows structure, but it is not directly correlated with the fluctuations of the elastic
cross sections.
In an attempt to remove some of the deficiencies in the current evaluated nuclear data of manganese, the
available experimental data in the EXFOR database were carefully selected and renormalized to more recent
standards, if necessary. Model calculations were performed with the EMPIRE code to obtain the reference
evaluation and the covariance matrix prior. The new feature in the calculations is the use of adjustment
factors, which compensate the deficiencies of the models in a reasonably consistent manner and allow for
the observed medium-range fluctuations in the cross sections. These can be used in combination with the
unresolved resonance parameters without double-counting the self-shielding effects. The new evaluation of
manganese is being tested on various benchmark experiments.
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