Browsing by Author "B.R. Behera"

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Evaporation residue cross-section measurements for 30Si+142Ce system
(Elsevier B.V., 2024) Amninderjeet Kaur; A. Kumar; Chetan Sharma; Neha Dhanda; Raghav; N. Madhavan; S. Nath; J. Gehlot; Gonika; Chandra Kumar; P. Sherpa; A. Parihari; Jyoti Pandey; A.K. Gupta; H.P. Sharma; B.R. Behera
Evaporation residue (ER) cross-sections were measured for 30Si+142Ce reaction at laboratory energies in the range of 105 - 132 MeV using the HYbrid Recoil mass Analyzer (HYRA) at IUAC, New Delhi. The transmission efficiency of the HYRA was estimated using the calibration reaction 28Si+142Ce. Sub-barrier fusion enhancement was observed when compared with the one-dimensional barrier penetration model predictions for the present system. To explore the phenomena responsible for sub-barrier fusion enhancement, coupled-channels calculations were performed using the CCFULL code. The effect of couplings and the role of positive Q-value neutron transfer (PQNT) channels on sub-barrier fusion cross-sections were investigated. Coupled-channels calculations were able to reproduce the data by including the coupling in both projectile and target nucleus along with two neutron-transfer channels having positive Q-value. The measured ER cross-sections were compared with the nearby systems to explore the role of deformation of the colliding nuclei. © 2023 Elsevier B.V.
Fission dynamics and entrance-channel study in the Po 210 compound nucleus via light-particle multiplicities
(American Physical Society, 2023) Chetan Sharma; B.R. Behera; Shruti; Amit; Bharti Rohila; Amninderjeet Kaur; Subodh; Neha Dhanda; Ashok Kumar; P. Sugathan; A. Jhingan; K.S. Golda; N. Saneesh; Mohit Kumar; H. Arora; Divya Arora; H.P. Sharma
Neutron multiplicities, folding angle distribution, mass distribution, and mass-energy distribution are measured for the compound nucleus Po210 populated through the C12+Pt198 reaction at an excitation energy of 61.6 MeV. The measured neutron multiplicities are compared with the statistical model code joanne2 to extract total fission time for the Po210 compound nucleus. The total fission time (τtot) obtained for this system is (10±5)×10-21 s at 49 MeV and increases to (23±5)×10-21 at 61.8 MeV excitation energy indicating that dissipation increases with excitation energy. A comparison with τtot of the O18+Os192 reaction populating the same compound nucleus indicates the influence of entrance channel mass asymmetry on the fission time. Dynamical model calculations have been performed to understand the fusion dynamics for these reactions and it is observed that the formation time of the compound nucleus increases as we go from the asymmetric to the symmetric entrance channels. Also, these calculations predict that 93% of the total angular momentum lead to the formation of a fully equilibrated compound nucleus for the C12+Pt198 reaction whereas this percentage decreases to 84%, for the O18+Os192 reaction indicating a higher percentage of noncompound nuclear processes in the latter case. © 2023 American Physical Society.
Fission time scale from pre-scission neutron and α multiplicities in the O 16 + Pt 194 reaction
(American Physical Society, 2017) K. Kapoor; S. Verma; P. Sharma; R. Mahajan; N. Kaur; G. Kaur; B.R. Behera; K.P. Singh; A. Kumar; H. Singh; R. Dubey; N. Saneesh; A. Jhingan; P. Sugathan; G. Mohanto; B.K. Nayak; A. Saxena; H.P. Sharma; S.K. Chamoli; I. Mukul; V. Singh
Pre- and post-scission α-particle multiplicities have been measured for the reaction O16+Pt194 at 98.4 MeV forming Rn210 compound nucleus. α particles were measured at various angles in coincidence with the fission fragments. Moving source technique was used to extract the pre- and post-scission contributions to the particle multiplicity. Study of the fission mechanism using the different probes are helpful in understanding the detailed reaction dynamics. The neutron multiplicities for this reaction have been reported earlier. The multiplicities of neutrons and α particles were reproduced using standard statistical model code joanne2 by varying the transient (τtr) and saddle to scission (τssc) times. This code includes deformation dependent-particle transmission coefficients, binding energies and level densities. Fission time scales of the order of 50-65 ×10-21 s are required to reproduce the neutron and α-particle multiplicities. © 2017 American Physical Society.
High spin structure in 130,131Ba
(Springer New York LLC, 2014) Navneet Kaur; A. Kumar; G. Mukherjee; Amandeep Singh; S. Kumar; Rajbir Kaur; Varinderjit Singh; B.R. Behera; K.P. Singh; G. Singh; H.P. Sharma; Suresh Kumar; M. Kumar Raju; P.V. Madhusudhan Rao; S. Muralithar; R.P. Singh; Rakesh Kumar; N. Madhvan; R.K. Bhowmik
High spin states of, 130,131Ba have been investigated via fusion evaporation reactions 122Sn (13C,4n)131Ba and 122Sn(13C, 5n)130Ba at Ebeam = 65MeV. The level schemes of 130,131Ba have been extended by placing several new γ transitions. A few interband transitions connecting two negative-parity bands, which are the experimental fingerprints of signature partners, have been established in 130Ba. Spin and parity of a side band have been assigned in 131Ba and this dipole band is proposed to have a three-quasiparticle configuration, vh11/2 ⊗ πh11/2⊗ πg7/2. The observed band structures and nuclear shape evolution as a function of the angular momentum have been discussed in the light of Total-Routhian-Surface calculations. © Società Italiana di Fisica/Springer-Verlag 2014.
Polarization measurements and high spin structure in 131Ba
(2013) Navneet Kaur; A. Kumar; G. Mukherjee; Amandeep Singh; Varinderjit Singh; Rohit Sandal; Rajbir Kaur; B.R. Behera; K.P. Singh; G. Singh; H.P. Sharma; Suresh Kumar; M.K. Raja; P.V. Madhusudhan Rao; S. Muralithar; R.P. Singh; Rakesh Kumar; N. Madhavan; C.R. Praharaj; Z. Naik
The high spin states of 131Ba have been populated in the fusion evaporation reaction 122Sn(13C,4n)131Ba at Ebeam=65MeV. The γ transitions belonging to various band structures were detected using an array of fifteen Clover Germanium detectors. Some of new transitions have been placed in high spin states. Spin and parity for a band has been calculated for first time in 131Ba. The said band is interpreted in term of multi-quasiparticle configurations, based on Total Rothian Surfaces (TRS) calculations. © 2013 AIP Publishing LLC.
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 viscosity in fusion-fission dynamics via simultaneously measured neutron and α -particle multiplicities
(American Physical Society, 2019) K. Kapoor; N. Bansal; Chetan Sharma; S. Verma; K. Rani; R. Mahajan; B.R. Behera; K.P. Singh; A. Kumar; H. Singh; R. Dubey; N. Saneesh; M. Kumar; A. Yadav; A. Jhingan; P. Sugathan; B.K. Nayak; A. Saxena; H.P. Sharma; S.K. Chamoli
The multiplicities of α particles and neutrons have been measured simultaneously for the reaction O16+Pt196 forming Rn212 compound nucleus at excitation energies of 56 MeV, 61 MeV, and 68 MeV. Neutrons and α particles were detected at various angles in coincidence with the fission fragments. To extract the contribution of pre- and postmultiplicities using the total α-particle and neutron spectra, moving source formalism was implemented. In the case of α particle, near scission contribution has also been extracted. Study of the fission mechanism using light particle emissions are helpful in understanding the detailed fusion-fission reaction dynamics. The statistical model code joanne2, which includes deformation-dependent particle transmission coefficients, binding energies and level densities, has been used to reproduce the measured multiplicities of neutrons and α particles by varying the transient (τtr) and saddle to scission (τssc) times. It is found that the fission time scales of the order of 50-70×10-21 sec are required to reproduce the neutron and α-particles multiplicities simultaneously. The fission time scales are the measure of the nuclear viscosity, which is responsible for the dynamic hindrance of the fission process. © 2019 American Physical Society.
Study of nuclear fusion-fission dynamics in 16O+194Pt reaction
(American Institute of Physics Inc., 2017) K. Kapoor; S. Verma; P. Sharma; R. Mahajan; N. Kaur; G. Kaur; B.R. Behera; K.P. Singh; H. Singh; R. Dubey; N. Saneesh; A. Jhingan; P. Sugathan; G. Mohanto; B.K. Nayak; A. Saxena; H.P. Sharma; S.K. Chamoli; I. Mukul; A. Kumar
Pre- and post-scission α-particle multiplicities have been measured for the reaction 16O + 194Pt at 98.4 MeV forming compound nucleus 210Rn. The α-particle's yield has been measured in coincidence with the fission fragments at various angles. The moving source analysis was performed to extract the alpha particle multiplicity which yielded the contribution of pre- and post- scission components. The pre-scission α-particle multiplicity has been compared with JOANNE2 statistical model code predictions to extract fission time scale and which is observed to be around 55zs (1zs=10-21s). © 2017 Author(s).