Attempting to Close the Loop on the Oslo
Technique at 198 Au: Constraining
the Nuclear Spin Distribution
Paul Koehler , John Ullmann , Aaron Couture , and Shea Mosby
1 Introduction
Average s-wave neutron resonance spacings D 0 and total radiation widths γ 0
are routinely used to calibrate nuclear level densities (NLDs) and photon strength
functions (PSFs) obtained with the Oslo technique [1]. However, there is more
information beyond D 0 and γ 0 , so it is possible to use additional pieces
of the neutron resonance data to test other calibrations as well as assumptions
inherent in the extraction of NLDs and PSFs from the Oslo data. For example
[2], the distribution of total radiation widths can be calculated, in the framework
of the nuclear statistical model (NSM), using the same NLD and PSF which were
calibrated using D 0 and γ 0 from the same neutron resonance data set. Recently
published NLDs [3] and PSFs [4] for 198 Au, together with new γ data from our
new R-matrix analysis of new neutron total cross section data and previous neutron
total [5] and capture [6] data make possible such a test for 198 Au as described herein.
2 New 197 Au + n Total Cross Section Data and R-Matrix
Analysis
At the Los Alamos Neutron Science Center (LANSCE), we have been developing
[7] the Device for Indirect Neutron Capture Experiments on Radionuclides (DICER)
to tightly constrain (n, γ ) cross sections on short-lived radionuclides by measurement and analysis of resonance neutron total cross sections on the same nuclides.
P. Koehler () · J. Ullmann · A. Couture · S. Mosby
Group P-27, Los Alamos National Laboratory, Los Alamos, NM, USA
e-mail: koehler@lanl.gov
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_22
187
Technique at 198 Au: Constraining
the Nuclear Spin Distribution
Paul Koehler , John Ullmann , Aaron Couture , and Shea Mosby
1 Introduction
Average s-wave neutron resonance spacings D 0 and total radiation widths γ 0
are routinely used to calibrate nuclear level densities (NLDs) and photon strength
functions (PSFs) obtained with the Oslo technique [1]. However, there is more
information beyond D 0 and γ 0 , so it is possible to use additional pieces
of the neutron resonance data to test other calibrations as well as assumptions
inherent in the extraction of NLDs and PSFs from the Oslo data. For example
[2], the distribution of total radiation widths can be calculated, in the framework
of the nuclear statistical model (NSM), using the same NLD and PSF which were
calibrated using D 0 and γ 0 from the same neutron resonance data set. Recently
published NLDs [3] and PSFs [4] for 198 Au, together with new γ data from our
new R-matrix analysis of new neutron total cross section data and previous neutron
total [5] and capture [6] data make possible such a test for 198 Au as described herein.
2 New 197 Au + n Total Cross Section Data and R-Matrix
Analysis
At the Los Alamos Neutron Science Center (LANSCE), we have been developing
[7] the Device for Indirect Neutron Capture Experiments on Radionuclides (DICER)
to tightly constrain (n, γ ) cross sections on short-lived radionuclides by measurement and analysis of resonance neutron total cross sections on the same nuclides.
P. Koehler () · J. Ullmann · A. Couture · S. Mosby
Group P-27, Los Alamos National Laboratory, Los Alamos, NM, USA
e-mail: koehler@lanl.gov
© This is a U.S. government work and not under copyright protection
in the U.S.; foreign copyright protection may apply 2021
J. Escher et al. (eds.), Compound-Nuclear Reactions, Springer Proceedings in
Physics 254, https://doi.org/10.1007/978-3-030-58082-7_22
187