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Title: Oscillations above the barrier in the fusion of 28 Si + 28 Si

Abstract

Fusion cross sections of Si-28 + Si-28 have been measured in a range above the barrier with a very small energy step (Delta E-lab = 0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y + repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
Croatian Science Foundation; USDOE Office of Science - Office of Nuclear Physics; European Commission - Community Research and Development Information Service (CORDIS) - Seventh Framework Programme (FP7)
OSTI Identifier:
1392415
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Physics Letters B
Additional Journal Information:
Journal Volume: 746; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Country of Publication:
United States
Language:
English

Citation Formats

Montagnoli, G., Stefanini, A. M., Esbensen, H., Corradi, L., Courtin, S., Fioretto, E., Grebosz, J., Haas, F., Jia, H. M., Jiang, C. L., Mazzocco, M., Michelagnoli, C., Mijatović, T., Montanari, D., Parascandolo, C., Scarlassara, F., Strano, E., Szilner, S., and Torresi, D. Oscillations above the barrier in the fusion of 28 Si + 28 Si. United States: N. p., 2015. Web. doi:10.1016/j.physletb.2015.05.021.
Montagnoli, G., Stefanini, A. M., Esbensen, H., Corradi, L., Courtin, S., Fioretto, E., Grebosz, J., Haas, F., Jia, H. M., Jiang, C. L., Mazzocco, M., Michelagnoli, C., Mijatović, T., Montanari, D., Parascandolo, C., Scarlassara, F., Strano, E., Szilner, S., & Torresi, D. Oscillations above the barrier in the fusion of 28 Si + 28 Si. United States. https://doi.org/10.1016/j.physletb.2015.05.021
Montagnoli, G., Stefanini, A. M., Esbensen, H., Corradi, L., Courtin, S., Fioretto, E., Grebosz, J., Haas, F., Jia, H. M., Jiang, C. L., Mazzocco, M., Michelagnoli, C., Mijatović, T., Montanari, D., Parascandolo, C., Scarlassara, F., Strano, E., Szilner, S., and Torresi, D. 2015. "Oscillations above the barrier in the fusion of 28 Si + 28 Si". United States. https://doi.org/10.1016/j.physletb.2015.05.021.
@article{osti_1392415,
title = {Oscillations above the barrier in the fusion of 28 Si + 28 Si},
author = {Montagnoli, G. and Stefanini, A. M. and Esbensen, H. and Corradi, L. and Courtin, S. and Fioretto, E. and Grebosz, J. and Haas, F. and Jia, H. M. and Jiang, C. L. and Mazzocco, M. and Michelagnoli, C. and Mijatović, T. and Montanari, D. and Parascandolo, C. and Scarlassara, F. and Strano, E. and Szilner, S. and Torresi, D.},
abstractNote = {Fusion cross sections of Si-28 + Si-28 have been measured in a range above the barrier with a very small energy step (Delta E-lab = 0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y + repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.},
doi = {10.1016/j.physletb.2015.05.021},
url = {https://www.osti.gov/biblio/1392415}, journal = {Physics Letters B},
issn = {0370-2693},
number = C,
volume = 746,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 2015},
month = {Mon Jun 01 00:00:00 EDT 2015}
}

Works referenced in this record:

Fusion Cross Sections of Light Heavy-Ion Systems: Resonances and Shell Effects
journal, August 1976


Oscillations in the Excitation Function for Complete Fusion of O 16 + C 12
journal, February 1976


Systematics of carbon- and oxygen-induced fusion on nuclei with 12 A 19
journal, October 1979


Total fusion cross section for the O 16 + O 16 system
journal, October 1978


Fusion oscillations for symmetric light heavy-ion systems
journal, December 1983


Structures in high-energy fusion data
journal, June 2012


Search for structure in the fusion of Si 28 + 28 , 30 Si and Si 30 + 30 Si
journal, June 1986


Unexpected Behavior of Heavy-Ion Fusion Cross Sections at Extreme Sub-Barrier Energies
journal, July 2002


Systematics of heavy-ion fusion hindrance at extreme sub-barrier energies
journal, January 2006


Beyond the Coherent Coupled Channels Description of Nuclear Fusion
journal, November 2007


Fusion hindrance for Ni 58 + Fe 54
journal, July 2010


Analysis of heavy-ion fusion reactions at extreme sub-barrier energies
journal, January 2004


Recent developments in heavy-ion fusion reactions
journal, March 2014


Fusion of 40 Ca + 40 Ca and other Ca + Ca systems near and below the barrier
journal, February 2012


Fusion of 40Ca + 96Zr revisited: Transfer couplings and hindrance far below the barrier
journal, January 2014


Hindrance of Heavy-Ion Fusion due to Nuclear Incompressibility
journal, March 2006


Signature of shallow potentials in deep sub-barrier fusion reactions
journal, March 2007


Signature of Smooth Transition from Sudden to Adiabatic States in Heavy-Ion Fusion Reactions at Deep Sub-Barrier Energies
journal, November 2009


Damping of quantum vibrations revealed in deep sub-barrier fusion
journal, July 2013


Fusion of Si 28 + Si 28 , 30 : Different trends at sub-barrier energies
journal, October 2014


Fusion of 28 Si + 28 Si: oscillations above the barrier and the behavior down to 1 μ b
journal, January 2014


Influence of Complex Surface Vibrations on the Fusion of Ni 58 + Ni 60
journal, February 1995


Nuclear Constitution and the Interpretation of Fission Phenomena
journal, March 1953


On the “distribution of barriers” interpretation of heavy-ion fusion
journal, January 1991


Works referencing / citing this record: