A comprehensive activation analysis of fusion-fission cross-sections for 14N +175Lu system

The experiments for measuring the cross sections of 35 fission-like residues (with mass numbers 74  ≤  A  ≤  111) and 10 fusion-like residues have been carried out at energies  ≈  72.7 MeV, 80.3 MeV and 88.0 MeV. In this measurement, the recoil catcher technique followed by an off-beam activation γ-ray spectroscopy is used. The analysis of fusion cross-section data with code PACE4 reveals the contribution of complete and incomplete fusion processes in ¹⁴N +¹⁷⁵Lu reactions. Fission fragments produced as a result of fusion of ¹⁴N projectile with ¹⁷⁵Lu target have also been confirmed by comparing the values of post-fission observables viz., mass (σ_A) and charge (σ_Z) dispersions (deduced from the isotopic mass and isobaric yield distributions) with literature data. In addition to this, the statistical scission-point model based theoretical calculations performed (as per the prescription of Gubbi et. al., [31]) for determining the charge dispersion (σ_Z) of Br and Kr isotopes validate the experimental values of σ_Z obtained from the isobaric yield distribution. Thus, the consistency between theoretical and experimental values of charge dispersion (σ_Z) indicates the production of fission fragments from a equilibrated compound nucleus ¹⁸⁹Pt* in ¹⁴N +¹⁷⁵Lu reactions. In the present work, an alternative method is used for converting isotopic mass distribution into isobaric yield distribution. Furthermore, the experimental finding of mass variance (${\sigma }_M^2$) of fission fragments also complements the investigations of mass (σ_A) and charge (σ_Z) dispersions, as width of mass distribution (i.e., mass variance, ${\sigma }_M^2$) of fission fragments is found to be exponentially function of excitation energy, hence, temperature of equilibrated compound nucleus.