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Title: Molecular interpretation of the oscillations of the fusion excitation function for the. cap alpha. +/sup 40/Ca system

Abstract

The oscillations observed in the experimental ..cap alpha..+ /sup 40/Ca fusion excitation function between E/sub ..cap alpha../ -- 10 and 27 MeV are described within the frame of the optical model. Use is made of an existing optical potential giving a precise description of the elastic scattering data for E/sub ..cap alpha../>24 MeV on a broad angular range, which is extrapolated to lower incident energies. A correct description of elastic scattering experimental excitation functions between E/sub ..cap alpha../ -- 12 and 18 MeV, as well as of the fusion excitation function, is achieved by using different imaginary geometries for both processes. The oscillations appearing in the calculated fusion excitation function are due to maxima in the even-l transmission coefficients, for l ranging from 6 to 12; these maxima correspond to shape resonances in the underlying potential, which are associated with states belonging to an excited positive parity band with N -- 14 in the ..cap alpha..+ /sup 40/Ca system. The same potential predicts an N -- 12 positive parity band of states whose energies are in good agreement with the /sup 44/Ti experimental ground state band. It is shown that the correct reproduction of the spacing between the fusion oscillationsmore » achieved here results from the use of a deep real potential, which automatically yields a decoupling between positive and negative parity bands.« less

Authors:
; ;
Publication Date:
Research Org.:
Faculte des Sciences, Universite de l'Etat, B-7000 Mons, Belgium
OSTI Identifier:
5143070
Resource Type:
Journal Article
Journal Name:
Phys. Rev. C; (United States)
Additional Journal Information:
Journal Volume: 34:4
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ALPHA REACTIONS; CAPTURE; ELASTIC SCATTERING; CALCIUM 40 TARGET; TITANIUM 44; ENERGY LEVELS; ANGULAR DISTRIBUTION; COULOMB FIELD; CROSS SECTIONS; EXCITATION FUNCTIONS; EXPERIMENTAL DATA; MEV RANGE 10-100; OPTICAL MODELS; PARITY; SPIN; ANGULAR MOMENTUM; BETA DECAY RADIOISOTOPES; CHARGED-PARTICLE REACTIONS; DATA; DISTRIBUTION; ELECTRIC FIELDS; ELECTRON CAPTURE RADIOISOTOPES; ENERGY RANGE; EVEN-EVEN NUCLEI; FUNCTIONS; INFORMATION; INTERMEDIATE MASS NUCLEI; ISOTOPES; MEV RANGE; NUCLEAR REACTIONS; NUCLEI; NUMERICAL DATA; PARTICLE PROPERTIES; RADIOISOTOPES; SCATTERING; TARGETS; TITANIUM ISOTOPES; YEARS LIVING RADIOISOTOPES; 651523* - Nuclear Properties & Reactions, A=39-58, Experimental- Energy Levels & Transitions- (-1987); 651525 - Nuclear Properties & Reactions, A=39-58, Experimental- Nuclear Reactions & Scattering- (-1987)

Citation Formats

Michel, F, Reidemeister, G, and Ohkubo, S. Molecular interpretation of the oscillations of the fusion excitation function for the. cap alpha. +/sup 40/Ca system. United States: N. p., 1986. Web. doi:10.1103/PhysRevC.34.1248.
Michel, F, Reidemeister, G, & Ohkubo, S. Molecular interpretation of the oscillations of the fusion excitation function for the. cap alpha. +/sup 40/Ca system. United States. doi:10.1103/PhysRevC.34.1248.
Michel, F, Reidemeister, G, and Ohkubo, S. Wed . "Molecular interpretation of the oscillations of the fusion excitation function for the. cap alpha. +/sup 40/Ca system". United States. doi:10.1103/PhysRevC.34.1248.
@article{osti_5143070,
title = {Molecular interpretation of the oscillations of the fusion excitation function for the. cap alpha. +/sup 40/Ca system},
author = {Michel, F and Reidemeister, G and Ohkubo, S},
abstractNote = {The oscillations observed in the experimental ..cap alpha..+ /sup 40/Ca fusion excitation function between E/sub ..cap alpha../ -- 10 and 27 MeV are described within the frame of the optical model. Use is made of an existing optical potential giving a precise description of the elastic scattering data for E/sub ..cap alpha../>24 MeV on a broad angular range, which is extrapolated to lower incident energies. A correct description of elastic scattering experimental excitation functions between E/sub ..cap alpha../ -- 12 and 18 MeV, as well as of the fusion excitation function, is achieved by using different imaginary geometries for both processes. The oscillations appearing in the calculated fusion excitation function are due to maxima in the even-l transmission coefficients, for l ranging from 6 to 12; these maxima correspond to shape resonances in the underlying potential, which are associated with states belonging to an excited positive parity band with N -- 14 in the ..cap alpha..+ /sup 40/Ca system. The same potential predicts an N -- 12 positive parity band of states whose energies are in good agreement with the /sup 44/Ti experimental ground state band. It is shown that the correct reproduction of the spacing between the fusion oscillations achieved here results from the use of a deep real potential, which automatically yields a decoupling between positive and negative parity bands.},
doi = {10.1103/PhysRevC.34.1248},
journal = {Phys. Rev. C; (United States)},
number = ,
volume = 34:4,
place = {United States},
year = {1986},
month = {10}
}