Measurement and analysis of excitation functions and observation of mass-asymmetry effect on incomplete fusion dynamics

¹ Nuclear Physics Division, Inter-University Accelerator Centre, New Delhi - 110067, India
² Department of Physics, Aligarh Muslim University, Aligarh - 202002, India
³ Variable EnergyVariable Energy Cyclotron Centre, 1/AF, Bidhan Nagar, Kolkata - 700064, India

^a e-mail: dsinghiuac@gmail.com

Abstract

Excitation functions for sixteen evaporation residues produced in the interaction of ²⁰Ne with ¹⁶⁵Ho have been measured in the projectile energy range ≈88-164 MeV, using catcher foil activation technique followed by gamma-ray spectrometry. It has been found in general that the excitation functions of evaporation residues produced via xn/pxn channels satisfactorily reproduced with the statistical model code PACE-2 after subtraction of precursor decay contribution. The significant enhancement in the measured excitation functions for the residues produced in alpha emission channels over the PACE-2 predictions has been observed. These alpha emission channels are attributed to incomplete fusion reaction process. The results indicate the occurrence of incomplete fusion involving break-up of projectile ²⁰Ne into ⁴He + ¹⁶O and /or ⁸Be + ¹²C followed by fusion of one of the fragments with target nucleus ¹⁶⁵Ho. The analysis of the present data suggest that probability of incomplete fusion increases with projectile energy. The ICF fraction F^ICF also increases with increasing mass-asymmetry of the entrance channel.