Systematic study of the nuclear potential through high precision back-angle quasi-elastic scattering measurements of {sup 16}O and {sup 32}S on various targets
- Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT0200 (Australia)
Elastic and inelastic scattering have proven an excellent method to probe the nuclear potential in the surface region [1]. A surface diffuseness parameter of around 0.63 fm is accepted as describing elastic and inelastic scattering data. A new method to determine the diffuseness was proposed [2] using high precision quasi-elastic excitation functions at sub-barrier energies, and at backward angles. In response to this proposal, we have made measurements for {sup 32}S+{sup 170}Er, {sup 186}W, {sup 197}Au, {sup 208}Pb[3], and more recently for the reactions {sup 16}O+{sup 144,154}Sm, {sup 186}W, {sup 197}Au, {sup 208}Pb[4].Both single channel and coupled-channels calculations have been performed to extract the diffuseness parameter of the nuclear potential, assuming a Woods-Saxon shape. For the reactions involving near-spherical targets, both theoretical analyses give the same diffuseness parameter, as had been hoped, showing that the effect of couplings to intrinsic excited states in the target and projectile is negligible. On the other hand, for deformed systems, coupling effects are surprisingly important even at deep sub-barrier energies, reducing the flux at backward angles.Energy spectra recorded with the back-angle Si detector show a large number of distinct peaks as well as a broad structure at even higher excitation energies. A comparison of the back-scattered energy spectra with coupled-channels calculations demonstrates that including couplings only to low lying collective states in coupled-channels calculations is inadequate in describing the reaction mechanism even at energies close to the barrier.
- OSTI ID:
- 21289445
- Journal Information:
- AIP Conference Proceedings, Vol. 1098, Issue 1; Conference: FUSION08: International conference on new aspects of heavy ion collisions near the Coulomb barrier, Chicago, IL (United States), 22-26 Sep 2008; Other Information: DOI: 10.1063/1.3108756; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Systematic study of the surface properties of the nuclear potential with high precision large-angle quasi-elastic scatterings
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Related Subjects
BACKSCATTERING
COUPLED CHANNEL THEORY
COUPLING
ELASTIC SCATTERING
ERBIUM 170 TARGET
EXCITATION FUNCTIONS
EXCITED STATES
GOLD 197 TARGET
HEAVY ION FUSION REACTIONS
INELASTIC SCATTERING
LEAD 208 TARGET
NUCLEAR STRUCTURE
OXYGEN 16 REACTIONS
QUASI-ELASTIC SCATTERING
SAMARIUM 144 TARGET
SAMARIUM 154 TARGET
SULFUR 32 REACTIONS
TUNGSTEN 186 TARGET
WOODS-SAXON POTENTIAL