Browsing by Author "Rudra N. Sahoo"

Now showing 1 - 2 of 2

Quasielastic scattering measurements in the Si 28 + Nd 142,150 systems
(American Physical Society, 2020) Saumyajit Biswas; A. Chakraborty; A. Jhingan; D. Arora; B.R. Behera; Rohan Biswas; Nabendu Kumar Deb; S.S. Ghugre; Pankaj K. Giri; K.S. Golda; G. Kaur; A. Kumar; M. Kumar; B. Mukherjee; B.K. Nayak; A. Parihari; N.K. Rai; S. Rai; R. Raut; Rudra N. Sahoo; A.K. Sinha
Barrier distributions for the Si28+Nd142,150 systems were extracted from large-angle quasielastic scattering measurements. The measurements were carried out over a wide range of incident beam energies around the Coulomb barriers. The experimental results were compared with the predictions from coupled-channels calculations carried out using different coupling schemes. Reasonable agreement between the experimental and theoretical results was obtained. The role of coupling effects of the various excitation modes of the projectile and target on the observed barrier distributions is discussed. The sensitivity of the quasielastic scattering process on the mode of projectile excitation is clearly been seen from the use of two different types of targets, Nd142 and Nd150, having spherical and deformed shapes at the ground state, respectively. © 2020 American Physical Society.
Role of neutron transfer in the sub-barrier fusion cross section in O 18 + Sn 116
(American Physical Society, 2020) Nabendu Kumar Deb; Kushal Kalita; Harun Al Rashid; S. Nath; J. Gehlot; N. Madhavan; Rohan Biswas; Rudra N. Sahoo; Pankaj K. Giri; Amar Das; Tapan Rajbongshi; Anamika Parihari; Niraj K. Rai; Saumyajit Biswas; Khushboo; Amritraj Mahato; B.J. Roy; A. Vinayak; Anjali Rani
Background: In heavy-ion-induced fusion reactions, cross sections in the sub-barrier region are enhanced compared to predictions of the one-dimensional barrier penetration model. This enhancement is often understood by invoking deformation and coupling of the relative motion with low-lying inelastic states of the reaction partners. However, effects of nucleon transfer on fusion below the barrier, especially for the systems having positive Q value neutron transfer (PQNT) channels, are yet to be disentangled completely. Purpose: We intend to study the role of the PQNT effect on the sub-barrier fusion of the O18 + Sn116 system having positive Q value for the two-neutron stripping channel. Also we reflect on the interplay of couplings involved in the system around the Coulomb barrier. Method: The fusion excitation function was measured at energies from 11% below to 46% above the Coulomb barrier for O18 + Sn116 using a recoil mass spectrometer, viz., the Heavy-Ion Reaction Analyser (HIRA). Fusion barrier distributions were extracted from the data. Results from the experiment were analyzed within the framework of the coupled-channels model. Results: Fusion cross sections at energies below the Coulomb barrier showed strong enhancement compared to predictions of the one-dimensional barrier penetration model. The fusion process is influenced by couplings to the collective excitations with coupling to single- A nd two-phonon vibrational states of the target and the projectile respectively. Inclusion of the two-neutron transfer channel in the calculation along with these couplings could reproduce the data satisfactorily. Conclusions: The significant role of PQNT in enhancing the sub-barrier fusion cross section for the chosen system is not observed. It simply reduced the sub-barrier fusion cross section. Therefore, a consistent link between PQNT and sub-barrier fusion enhancement could not be established vividly while comparing the fusion excitation function from this work with the same from other O16,18-induced reactions. This clearly points to the need for more experimental as well as theoretical investigation in this field. © 2020 American Physical Society.