Eur. Phys. J. A (2007) 34: 29-39
https://doi.org/10.1140/epja/i2007-10487-1

Regular Article - Experimental Physics

Observation of complete- and incomplete-fusion components in ¹⁵⁹Tb , ¹⁶⁹Tm ( ¹⁶O , x) reactions: Measurement and analysis of forward recoil ranges at E/A ≈ 5-6 MeV

¹ Accelerator Laboratory, Department of Physics, A. M. University, (UP)-202 002, Aligarh, India
² NP Group, Inter-University Accelerator Center, P. O. Box No. 10502, 110 067, New Delhi, India

Received: 18 April 2007
Accepted: 1 October 2007
Published online: 30 October 2007

Abstract

With a view to study complete- and incomplete-fusion components in ¹⁵⁹Tb , ¹⁶⁹Tm ( ¹⁶O , x reactions, experiments have been carried out at the Inter-University Accelerator Center, New Delhi, India using the 15UD Pelletron accelerator facilities. The forward mean recoil ranges for some radio-nuclides; ^168m Lu , ¹⁶⁷Lu , ¹⁶⁷Yb , ¹⁶⁶Tm produced in the

¹⁶O$ + $¹⁵⁹Tb

system at ≈ 90 MeV, and ¹⁷⁹Re , ¹⁷⁷Re , ¹⁷⁷W , ¹⁷⁸Ta and ¹⁷⁷Hf produced in the

¹⁶O$ + $¹⁶⁹Tm

system at ≈ 87 MeV have been measured. The recoil-catcher activation technique followed by off-line γ -spectrometry has been employed in the present work. The analysis of forward mean ranges for different radio-nuclides has been done in the framework of the degree of linear momentum transfer from projectile to target nucleus by adopting break-up fusion model considerations. Different complete- and incomplete-fusion components, which may be attributed to the fusion of ¹⁶O and/or ¹²C and ⁸Be transfer from the ¹⁶O projectile to the target nucleus have been observed. An attempt has also been made to separate out the relative percentage contributions of complete- and incomplete-fusion components using experimentally measured forward recoil ranges. The complete-fusion contributions deduced from recoil range distribution are found to be consistent with the prediction of the theoretical model code PACE. The analysis of data indicates the complete- and incomplete-fusion competition for both the systems at the given energies.