Variation of ICF strength function with projectile energy for ¹²C + ¹⁶⁵Ho system at E_lab ≤ 7MeV/A

During the last few decades, research in heavy-ion induced nuclear reactions has opened numerous fields, in its theoretical and experimental domains. At energies, from near the Coulomb barrier to well above it, the complete fusion (CF) and incomplete fusion (ICF) reactions compete with each other. The relative contribution of these processes depends on various entrance channel parameters. In order to study the dependence of CF and ICF reaction dynamics on various entrance channel parameters, comparative studies with different statistical model codes have been done for various reaction systems. In this paper, an attempt has been made to study the dependence of incomplete fusion strength function on incident energy for ¹²C + ¹⁶⁵Ho system at energies ≤ 7 MeV/A. The analysis of data has been done within the frame work of statistical model code PACE4, which do not take ICF into account; and thus predicts cross-section values only due to complete fusion process. For the present reaction system, the excitation functions (EFs) for xn/pxn channels, predicted by PACE4 code, well reproduces the experimentally measured values, indicating their production via CF only. However, for α and 2α-emitting channels, calculated EFs through PACE4 code under predict the experimentally measured cross-sections by ≈25-30%, in general. The enhancement of experimental cross-sections for α and 2α-emitting channels as compared to the PACE4 predictions, indicates that the major contribution of their production comes from the ICF of ¹²C, if it breaks up into ⁸Be and α fragments, and one of the fragments fuses with the target nucleus. The incomplete fusion strength function (F_ICF), which gives relative importance of ICF processes over CF process has also been deduced. Comparative results of CF, ICF components and the ICF strength function will be presented. (author)