Dynamical decay of ³²S* and ³¹P* formed in ²⁰Ne+¹²C and ¹⁹F+¹²C reactions, respectively, at E*_CN = 60 MeV

¹ Department of Physics, Sri Guru Granth Sahib World University, Fatehgarh Sahib - 140406, India
² School of Physics and Materials Science, Thapar University, Patiala - 147004, India
³ Department of Physics, Panjab University, Chandigarh - 160014, India

^a e-mail: birbikram.singh@gmail.com

Published online: 29 January 2015

Abstract

The target-like C-yield in the decay of compound systems ³²S* and ³¹P* formed in ²⁰Ne+¹²C and ¹⁹F+¹²C reactions at E*_CN=60 MeV, is studied for the contribution of fusion-fission (ff) decay cross section σ_ff and the deep inelastic (DI) orbiting σ_orb from the compound nucleus (CN) and non-compound nucleus nCN processes, respectively. The calculations are performed using the collective clusterization of fragments within the dynamical cluster-decay model (DCM) of Gupta and collaborators. Besides studying the competition between ff and DI orbiting phenomenon in the C-yield of these systems, we exclusively investigate the preformation and barrier penetration probabilities P₀ and P as a function of angular momentum ℓ values which subsequently affects the contributions of σ_ff and σ_orb. For calculating the contribution of σ_ff in the C-yield, we have added the contributions from all the minimized intermediate mass fragments (IMFs) for Z=6 in the calculated fragmentation potentials for ³²S* (IMFs ^11,12,13C are minimized) and for ³¹P* (IMFs ^12,13C are minimized), while calculating subsequently, P₀ and the P for these IMFs. The distribution of preformed clusters/fragments as a function of fragment mass visibly explore the nuclear structure effects for the C-yield in decay of these compound systems, wherein, it is shown to be more favoured in the decay of ³¹P* in comparison to ³²S* decay. The contribution of σ_orb to the C-yield is calculated from P at different allowed ℓ-values (upto ℓ_max and also P≤1) of the outgoing fragments (same as that in the entrance channel, i.e., P₀=1). Though preliminary but useful results indicates the competition between the CN and nCN process in the C-yield for the compound system ³²S* only while the decay of ³¹P* is of pure CN origin, as observed in the experimental study. The calculations are in good comparison with the available experimental data.