Scholz, P., Endres, A., Hennig, A., Netterdon, L., Becker, H. W., Endres, J., Mayer, J., Giesen, U., Rogalla, D., Schlueter, F., Pickstone, S. G., Zell, K. O. and Zilges, A. (2014). Measurement of the Re-187(alpha, n)Ir-190 reaction cross section at sub-Coulomb energies using the Cologne Clover Counting Setup. Phys. Rev. C, 90 (6). COLLEGE PK: AMER PHYSICAL SOC. ISSN 1089-490X
Full text not available from this repository.Abstract
Background: Uncertainties in adopted models of particle + nucleus optical-model potentials directly influence the accuracy in the theoretical predictions of reaction rates as they are needed for reaction-network calculations in, for instance, gamma-process nucleosynthesis. The improvement of the alpha + nucleus optical-model potential is hampered by the lack of experimental data at astrophysically relevant energies especially for heavier nuclei. Purpose: Measuring the Re-187(alpha,n)Ir-190 reaction cross section at sub-Coulomb energies extends the scarce experimental data available in this mass region and helps understanding the energy dependence of the imaginary part of the alpha + nucleus optical-model potential at low energies. Method: Applying the activation method, after the irradiation of natural rhenium targets with alpha-particle energies of 12.4 to 14.1 MeV, the reaction yield and thus the reaction cross section were determined via gamma-ray spectroscopy by using the Cologne Clover Counting Setup and the method of gamma gamma coincidences. Results: Cross-section values at five energies close to the astrophysically relevant energy region were measured. Statistical model calculations revealed discrepancies between the experimental values and predictions based on widely used alpha+nucleus optical-model potentials. However, an excellent reproduction of the measured cros-ssection values could be achieved from calculations based on the so-called Sauerwein-Rauscher alpha + nucleus optical-model potential. Conclusion: The results obtained indicate that the energy dependence of the imaginary part of the alpha + nucleus optical-model potential can be described by an exponential decrease. Successful reproductions of measured cross sections at low energies for alpha-induced reactions in the mass range 141 <= A <= 187 confirm the global character of the Sauerwein-Rauscher potential.
| Item Type: | Journal Article | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| URN: | urn:nbn:de:hbz:38-420021 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DOI: | 10.1103/PhysRevC.90.065807 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Journal or Publication Title: | Phys. Rev. C | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Volume: | 90 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Number: | 6 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Date: | 2014 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Publisher: | AMER PHYSICAL SOC | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Place of Publication: | COLLEGE PK | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ISSN: | 1089-490X | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Language: | English | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Faculty: | Unspecified | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Divisions: | Unspecified | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Subjects: | no entry | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| URI: | http://kups.ub.uni-koeln.de/id/eprint/42002 |
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