Large influence of incomplete fusion in12C+159Tb at

Abhishek Yadav

¹

,

Vijay R. Sharma

²

,

Pushpendra P. Singh

³

et al.

Abstract

Low energy incomplete fusion has been studied in 12 C+ 159 Tb system at energies ≈ 4-7 MeV/nucleon. The excitation functions of individual reaction channels have been measured using off-line γ spectroscopy, and analyzed in the framework of statistical model code PACE4 based on the concept of equilibrated compound nucleus decay. A significant fraction of incomplete fusion has been found in the production of residues involving α particle(s) in the exit channels. For better insights into the onset and strength of incomplete fusion, the incomplete fusion strength function has been deduced as a function of various entrance channel parameters. Large influence of incomplete fusion has been observed at slightly above barrier energies, and increases smoothly with incident projectile energy. Present results have been compared with the results obtained in the interactions of 12 C with nearby targets to probe the dependence of incomplete fusion on entrance channel mass asymmetry. It has been found that the percentage fraction of incomplete fusion increases linearly with mass asymmetry of interacting partners in the studied mass region.

Influence of a one-neutron-excess projectile on low-energy incomplete fusion

“…However, in the present case contradictory results in terms of binding energy have been observed. Similar observations have been made in the cases of 12 C, 13 C+ 159 Tb [44,53] and 12 C, 13 C+ 181 Ta [49] systems. In order to explore this issue, the ICF strength functions in 12 C, 13 C+ 169 Tm systems have been studied in terms of projectile α-Q value in which the projectiles may be assumed to break up into the following channels: 12 C ⇒ 8 Be + α, Q α = −7.37 MeV, 13 C ⇒ 9 Be + α, Q α = −10.64 MeV.…”

“…Thus, a comparison of experimental EFs with the statistical model code PACE4 may indicate the extent to which the formation of identified ERs may be explained by the equilibrated CN decay. Any deviation in the experimental EFs with respect to the PACE4 predictions may be attributed to ICF, which is not included in this code [44][45][46][47][48]. channels.…”

“…In order to study low-energy ICF, several inclusive experiments have been performed at the Inter-University Accelerator Center (IUAC), New Delhi [44][45][46][47][48]. This work is an extension of our earlier measurements to study the effect of a one-neutron (1n) excess projectile on the onset and strength of ICF.…”

“…Due to the unavailability of any reliable theoretical model to explain low-energy ICF data, the study of ICF is still an active area of investigations. Further, the observation of ICF at slightly above barrier energies where CF is supposed to be the sole contributor has triggered the study of low-energy ICF [3,44,45,53,54].…”

“…The aforementioned models have been used to fit the experimental data obtained at energies well above the Coulomb barrier (i.e., E lab 10.5 MeV/nucleon) but have shown certain failings in their ability to explain ICF data at relatively low bombarding energies (i.e., ≈ 3-7 MeV/nucleon) [44][45][46][47][48][49][50][51]. More recently, Diaz-Torres et al [52] proposed a three-dimensional classical model for low-energy breakup fusion reactions.…”