Exploring dissipative processes at high angular momentum in ⁵⁸Ni+⁶⁰Ni reactions

Date

2016

Authors

Williams, E.
Hinde, David
Dasgupta, Mahananda
Carter, I.P.
Cook, K.J.
Jeung, D.Y.
Luong, D.H.
McNeil, S.D.
Palshetkar, C.S.
Rafferty, D.C.

Journal Title

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Volume Title

Publisher

EDP Sciences

Abstract

Current coupled channels (CC) models treat fusion as a coherent quantum-mechanical process, in which coupling between the collective states of the colliding nuclei influences the probability of fusion in near-barrier reactions. While CC models have been used to successfully describe many experimental fusion barrier distribution (BD) measurements, the CC approach has failed in the notable case of ¹⁶O+²⁰⁸Pb. The reason for this is poorly understood; however, it has been postulated that dissipative processes may play a role. Traditional BD experiments can only probe the physics of fusion for collisions at the top of the Coulomb barrier (L = 0ħ). In this work, we will present results using a novel method of probing dissipative processes inside the Coulomb barrier. The method exploits the predicted sharp onset of fission at L ~ 60ħ for reactions forming compound nuclei with A < 160. Using the ANU’s 14UD tandem accelerator and CUBE spectrometer, reaction outcomes have been measured for the ⁵⁸Ni+⁶⁰Ni reaction at a range of energies, in order to explore dissipative processes at high angular momentum. In this reaction, deep inelastic processes have been found to set in before the onset fission at high angular momentum following fusion. The results will be discussed in relation to the need for a dynamical model of fusion.

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Citation

Source

EPJ Web of Conferences

Type

Conference paper

Book Title

12th International Conference on Nucleus-Nucleus Collisions 2015

Entity type

Access Statement

Open Access

License Rights

DOI

10.1051/epjconf/201611708021

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