Hindrance of {sup 16}O+{sup 208}Pb fusion at extreme sub-barrier energies

Journal Article · Thu Nov 15 04:00:00 EST 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.054609· OSTI ID:21067912

Esbensen, Henning; Misicu, Serban ^[1]

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1. Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

We analyze the fusion data for {sup 16}O+{sup 208}Pb using coupled-channels calculations. We include couplings to the low-lying surface excitations of the projectile and target and study the effect of the ({sup 16}O,{sup 17}O) one-neutron pickup. The hindrance of the fusion data that is observed at energies far below the Coulomb barrier cannot be explained by a conventional ion-ion potential and defining the fusion in terms of ingoing-wave boundary conditions (IWBC). We show that the hindrance can be explained fairly well by applying the M3Y double-folding potential which has been corrected with a calibrated, repulsive term that simulates the effect of nuclear incompressibility. We show that the coupling to one-neutron transfer channels plays a crucial role in improving the fit to the data. The best fit is achieved by increasing the transfer strength by 25% relative to the strength that is required to reproduce the one-neutron transfer data. The larger strength is not unrealistic because the calculated inelastic plus transfer cross section is in good agreement with the measured quasielastic cross section. We finally discuss the problem of reproducing the fusion data at energies far above the Coulomb barrier. Here we do not account for the data when we apply the IWBC but the discrepancy is essentially eliminated by applying the M3Y+repulsion potential and a weak, short-ranged imaginary potential.

• OSTI ID: 21067912
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 5 Vol. 76; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BOUNDARY CONDITIONS
COULOMB FIELD
COUPLED CHANNEL THEORY
COUPLING
CROSS SECTIONS
EXCITATION
HEAVY ION FUSION REACTIONS
LEAD 208
LEAD 208 TARGET
NEUTRON TRANSFER
NEUTRONS
NUCLEAR POTENTIAL
NUCLEON-NUCLEON INTERACTIONS
OXYGEN 16
OXYGEN 16 REACTIONS
OXYGEN 17
TRANSFER REACTIONS