Compound nucleus formation probability P_CN defined within the dynamical cluster-decay model

Department of Physics, Panjab University, Chandigarh - 160014, India

^a e-mail: chopra.sahila@gmail.com
^b e-mail: arshdeep.pu@gmail.com
^c e-mail: rajkgupta.chd@gmail.com

Published online: 29 January 2015

Abstract

With in the dynamical cluster-decay model (DCM), the compound nucleus fusion/ formation probability P_CN is defined for the first time, and its variation with CN excitation energy E* and fissility parameter χ is studied. In DCM, the (total) fusion cross section σ_fusion is sum of the compound nucleus (CN) and noncompound nucleus (nCN) decay processes, each calculated as the dynamical fragmentation process. The CN cross section σ_CN is constituted of the evaporation residues (ER) and fusion-fission (ff), including the intermediate mass fragments (IMFs), each calculated for all contributing decay fragments (A₁, A₂) in terms of their formation and barrier penetration probabilities P₀ and P. The nCN cross section σ_nCN is determined as the quasi-fission (qf) process where P₀=1 and P is calculated for the entrance channel nuclei. The calculations are presented for six different target-projectile combinations of CN mass A~100 to superheavy, at various different center-of-mass energies with effects of deformations and orientations of nuclei included in it. Interesting results are that the P_CN=1 for complete fusion, but P_CN <1 or ≪1 due to the nCN conribution, depending strongly on both E* and χ.