New Type of Experiment for Average Resonance Parameter Estimation in Unresolved Neutron Resonance Region

1992 ◽  
pp. 447-448
Author(s):  
W. K. Basenko ◽  
S. N. Ezhov ◽  
G. A. Prokopets
Keyword(s):  
Parameter Estimation ◽  
Resonance Parameter ◽  
Resonance Region ◽  
Neutron Resonance ◽  
New Type ◽  
Average Resonance

Is there incomplete mixing of states with differentKquantum numbers in the neutron resonance region?

1992 ◽  
Vol 45 (4) ◽  
pp. R1417-R1419 ◽  
Author(s):  
B. R. Barrett ◽  
R. F. Casten ◽  
J. N. Ginocchio ◽  
T. Seligman ◽  
H. A. Weidenmüller
Keyword(s):  
Resonance Region ◽  
Neutron Resonance ◽  
Incomplete Mixing

Neutron Activation Resonance Integral of 74Ge and 76Ge and Evaluation of the 74Ge keV Neutron Radiative Capture Cross Section and Resonance Integral

1972 ◽  
Vol 50 (17) ◽  
pp. 1978-1986
Author(s):  
M. D. Ricabarra ◽  
R. Turjanski ◽  
G. H. Ricabarra
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Capture Cross Section ◽  
Radiative Capture ◽  
Resonance Integral ◽  
Neutron Resonance ◽  
Capture Cross ◽  
Resonance Parameters ◽  
Radiative Capture Cross Section ◽  
Average Resonance

Values of the reduced activation resonance integral relative to the thermal cross section I′/σ0 of 74Ge and 76Ge were determined relative to gold by measuring cadmium ratios in a reactor spectrum.A lithium-drifted germanium γ-ray spectrometer was used to resolve the activities of the samples.The results for 74Ge are I′/σ0 = 1.514 ± 0.031 and I′ = 0.681 ± 0.123 b with an assumed σ0 = 0.45 ± 0.08 b; for 76GeI′/σ0 = 12.00 ± 0.16 and I′ = 1.992 ± 0.359 with an assumed σ0 = 0.166 ± 0.030 b.The values obtained for I′ are in serious disagreement with the values calculated with neutron resonance parameters and confirm previous results obtained in similar keV average resonance spacing isotopes.Due to this fact a careful evaluation of the keV neutron radiative capture cross section and resonance integral for 74Ge was undertaken.The evaluation and comparison with the experimental value of the resonance integral shows first that for nuclides with an average resonance spacing of keV the unresolved resonance integral has been seriously underestimated in many evaluations, and second that between 10 and 100 keV, resonance integrals calculated with smooth low resolution activation cross sections give a better calculation of neutron captures than that obtained with neutron resonance parameters.

scholarly journals Resonance parameter covariance representation: file32 versus file33

2018 ◽  
Vol 4 ◽  
pp. 17
Author(s):  
Luiz Leal
Keyword(s):  
Experimental Data ◽  
Resonance Parameter ◽  
Resonance Region ◽  
Nuclear Data ◽  
Computer Code ◽  
Covariance Matrices ◽  
Data Uncertainty ◽  
Resonance Parameters ◽  
Data Libraries ◽  
Group Structures

Sensitivity and uncertainty analysis in error propagation studies are carried out based on nuclear data uncertainty information available in the basic nuclear data libraries such as ENDF, JEFF, JENDL and others. The uncertainty files (covariance matrices) are generally obtained from analysis of experimental data. In the resonance region, the computer code SAMMY is used for analyses of experimental data and generation of resonance parameters. In addition to resonance parameters evaluation, SAMMY also generates resonance parameter covariance matrices (RPCM). The intent of this paper is to discuss the use of the RPCM in contrast to the use of a cross section covariance matrix (CSCM) representation. For so, the resonance evaluation for 48Ti in the resonance range from 10−5 eV to 400 keV is used. The RPCM is translated into two distinct CSCM by using a coarser and a finer group structures. The results are presented and discussions of the feasibility of using these covariance representations are depicted.

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