REACTION MECHANISMS IN 12C+93Nb SYSTEM: EXCITATION FUNCTIONS AND RECOIL RANGE DISTRIBUTIONS BELOW 7 MeV/u

The experiments were performed to study excitation functions (EFs) of evaporation residues (ERs), i.e. 103,102,101Ag, 101,100,99Pd, 101,100Rh, 97Ru, 96Tc, 95Tc, 94Tc, 93Mo m , 92Nb m populated in the reactions induced by 12C on 93Nb for exploring the reaction dynamics involved at energies ≈ 47–75 MeV. The activation technique followed by offline γ-ray spectrometry has been employed to measure EFs. These measurements were simulated with other reported values available in literature as well as with theoretical predictions based on computer code PACE-2. The effect of variation of level density parameter involved in this code has also been studied. An excellent agreement was found between theoretical and experimental values in some of the fusion evaporation channels. However, significant enhancement of cross-section as observed in α-emission channels may be due to incomplete fusion (ICF) process and/or direct reaction process. To confirm the aforesaid reaction mechanism, Recoil Range Distributions (RRDs) of various ERs have been measured at ≈ 80 MeV. Moreover, an attempt is made to separate the percentage relative contributions of complete and incomplete fusion components from the analysis of the measured RRDs data. Further, the relative percentage ICF fraction, also estimated from EFs data, was found to be sensitive with the projectile energy.

COMPLETE AND INCOMPLETE FUSION REACTIONS OF 16O WITH 75As AT INCIDENT ENERGIES BELOW 7 MeV/A

Excitation functions and differential recoil range distributions in the interaction of 16 O with 75 As have been measured to investigate complete and incomplete fusion reactions. The measured cross sections were compared with theoretical calculations using the computer code ALICE-91. The results indicated predominant incomplete fusion processes in the production of near target products. This was further confirmed by recoil range distribution studies of the products at 104 MeV of beam energy. The relative contributions of complete and incomplete fusion channels are estimated from recoil range distribution measurements.

MEASUREMENT AND ANALYSIS OF EXCITATION FUNCTIONS AND FORWARD RECOIL RANGE DISTRIBUTIONS IN 12C + 59Co SYSTEM

With the motivation of studying complete and incomplete fusion reactions in a 12 C +59 Co projectile target system, the excitation functions for ( C , p3n ), ( C , 2p2n ), ( C , αn ), ( C , α2n ), ( C , αp3n ) and ( C , 2α2n ) reactions have been measured up to 80 MeV. The well-known activation technique followed by offline high purity Ge γ-ray spectroscopy was used. The measured experimental values were compared with the statistical model calculations by using the ALICE-91 and CASCADE codes. For the calculations obtained by CASCADE, the variation of parameter Fθ, which is the ratio of actual moment of inertia to the rigid body value have also been studied. Considerable enhancement of the measured excitation functions compared to theoretical predictions for some channels clearly indicates the presence of incomplete fusion with complete fusion in the present projectile energy range. The measurements of forward recoil range distribution of evaporation residues at 80 MeV projectile energy confirm these observations.

Incomplete fusion mechanism in 16O + 93Nb reaction at 6 MeV/nucleon: Recoil range measurements

SummaryRecoil range distribution of evaporation residues formed in complete and incomplete fusion of 96 MeV