Abstract

A consistent set of statistical-model input parameters, validated by analysis of various independent data, makes possible the assessment of an alpha -particle optical model potential [Phys. Rev. C 90, 044612 (2014)] also for nucleon-induced alpha -emission within the A sim 60 mass-number range. The advantage of recent data for low-lying states feeding is taken as well. Consideration of additional reaction channels leading to increase of the alpha -emission beyond the statistical predictions has concerned the pickup direct interaction and Giant Quadrupole Resonance similar features.

Highlights

  • The α-particle interaction with nuclei as well as the corresponding optical model potential (OMP) were of special interest from nuclear-physics earliest days

  • The pre-equilibrium emission (PE)+HF results corresponding to use of the consistent parameter set mentioned above (Sect. 2) are compared in the following with measured cross sections of low-energy proton- and neutron-induced reactions leading to excited Fe, (a)

  • In order to describe 64N( p, α)61Co reaction, they normalized the formerly calculated semi-microscopic pickup contribution to account for the measured data at 15 MeV. This normalization depends notably on the preceding PE + HF calculated results. Since these are quite different as shown in Sect. 3.3.2, we have looked for absolute values by distorted-wave Born approximation (DWBA) analysis using spectroscopic factors corresponding to the outgoing α-particle angular distributions reported at 15 MeV by Jolivette and Browne [105], and at 30 MeV by Smits et al [102]

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Summary

Introduction

The α-particle interaction with nuclei as well as the corresponding optical model potential (OMP) were of special interest from nuclear-physics earliest days. The widely-used phenomenological OMP parameters have been derived from analysis of either elastic-scattering, which is ruled out below the Coulomb barrier B, or α-induced reaction data. They are used to describe the α–emission from excited nuclei, in terms of the statistical Hauser-Feshbach (HF) [1] and pre-equilibrium emission (PE) [2] models. There is a so-called α-potential mystery of the account at once of both absorption and emission of α-particles in nuclear reactions [4], of equal interest for nuclear astrophysics and fusion technology It was referred by Rauscher [4] to competition of the Coulomb excitation (CE). It was not an earlier version of the above-mentioned ones [14,16,17], while the issue of different OMPs for incident and emitted α particles [13,15,20,21] is still actual and forms the object of this work

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Statistical model parameters
Nuclear level densities
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Neutron optical model potentials
Proton optical model potentials
Pre-equilibrium emission modeling
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Fe isotopes de–excitation
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Cu isotopes de-excitation
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Zn isotopes de–excitation
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Conclusions
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Findings
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Full Text
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