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Partial cross sections of the 92Mo(p,γ) reaction and the γ strength in 93Tc.
- Source :
-
Physical Review C . Apr2016, Vol. 93 Issue 4, p1-1. 1p. - Publication Year :
- 2016
-
Abstract
- Background: 92Mo is the most abundant nucleus of the p nuclei, with an isotopic abundance of more than 14%. The γ-process nucleosynthesis is believed to produce 92Mo but fails to explain its large abundance, especially with respect to the other p nuclei produced in the same stellar environment. Further studies require precise nuclear models for the calculation of reaction cross sections. Purpose: A measurement of the total and partial cross sections of the 92Mo(p,γ)93Tc reaction allows for a stringent test of statistical-model predictions. Not only different proton+nucleus optical model potentials, but also the γ-ray strength function of 93Tc can be investigated. In addition, high-resolution in-beam γ-ray spectroscopy enables the determination of new precise nuclear structure data for 93Tc. Method: Total and partial cross-section values were measured by using the in-beam method. Prompt γ rays emitted during the irradiation of 92Mo with protons at seven different energies between 3.7 and 5.3 MeV were detected by using the high-purity germanium (HPGe) detector array HORUS at the Institute for Nuclear Physics, University of Cologne. The γγ-coincidence method was applied to correlate γ-ray cascades in 93Tc with their origin in the 92Mo+p compound state. Results: The measured cross sections are compared to Hauser-Feshbach calculations by using the statistical-model code talys on the basis of different nuclear physics input models. Using default settings based on standard phenomenological models, the experimental values cannot be reproduced. A shell-model calculation was carried out to predict the low-energy M1 strength in 93Tc. Together with Gogny-Hartree-Fock-Bogoliubov (Gogny-HFB) or Skyrme-HFB plus quasi-particle random-phase approximation (QRPA) models for the γ-ray strength function, the agreement between experimental data and theoretical predictions could be significantly improved. In addition, deviations from the adopted level scheme were found. Conclusions: By using Gogny- or Skyrme-HFB+QRPA E1 and shell-model M1 strength functions, statistical-model predictions can be significantly improved. Partial cross sections provide a valuable testing ground for γ-ray strength functions for nuclear astrophysics applications. In addition, they can be used to investigate nuclear-structure properties of the compound nucleus. [ABSTRACT FROM AUTHOR]
- Subjects :
- *NEUTRON cross sections
*ISOTOPIC abundance
*NUCLEOSYNTHESIS
Subjects
Details
- Language :
- English
- ISSN :
- 24699985
- Volume :
- 93
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Physical Review C
- Publication Type :
- Academic Journal
- Accession number :
- 132694280
- Full Text :
- https://doi.org/10.1103/PhysRevC.93.045809