Browsing by Author "I. Bala"

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Evolution of collectivity and shape transition in Zn 66
(American Physical Society, 2020) S. Rai; U.S. Ghosh; B. Mukherjee; A. Biswas; A.K. Mondal; K. Mandal; A. Chakraborty; S. Chakraborty; G. Mukherjee; A. Sharma; I. Bala; S. Muralithar; R.P. Singh
Excited states in Zn66 were investigated through the in-beam ?-ray spectroscopic techniques using the Cr52(O18, 2p2n) fusion-evaporation reaction at a beam energy of 72.5 MeV. The ?-rays emitted by the de-exciting nuclei were recorded in coincidence mode using the 14 Compton suppressed Ge clover detectors of the Indian National Gamma Array. With 14 new transitions being identified, the level scheme of Zn66 has been extended up to the excitation energy ˜12.3MeV and spin ˜17?. A rotational band, associated with the two quasineutrons from the 1g9/2 orbital, has been found to exhibit a band crossing with the ground-state band at a spin of 6?. The evolution of the collectivity and shape transition in this nucleus have been discussed in the framework of the total Routhian surface calculations and in comparison with the neighboring Ge68,70 nuclei. © 2020 American Physical Society.
High spin states in 63Cu
(Springer New York LLC, 2018) S. Rai; B. Mukherjee; U.S. Ghosh; A. Biswas; A. Chakraborty; A.K. Mondal; S. Chakraborty; G. Mukherjee; I. Bala; S. Muralithar; R.P. Singh
High-spin states in 63Cu were investigated through in-beam γ-ray spectroscopic techniques using the 52Cr(18O,αp2n) fusion-evaporation reaction at a beam energy of 72.5 MeV. The γ-rays emitted by the excited nucleus were recorded in the coincidence mode using fourteen Compton suppressed Ge clover detectors of the Indian National Gamma-ray Array (INGA). Based on the γ-γ coincidence data, twenty-one new γ-ray transitions have been observed and placed --thereby extending the level scheme of 63Cu up to spin 25 / 2 ℏ and excitation energy ∼ 8. 36 MeV. Shell model calculations are performed in the f5 / 2pg9 / 2 model space with a 56Ni core using two effective interactions, viz. JUN45 and jj44b to interpret the observed excited states of this nucleus. A reasonable agreement is found between the experimental finding and the shell-model calculations --which implies that the excitations within the f5 / 2p3 / 2p1 / 2 orbitals are more dominant in defining the observed level structure than the excitation across the magic shell gap N= Z= 28. © 2018, SIF, Springer-Verlag GmbH Germany, part of Springer Nature.
In-beam spectroscopic study of Zn 63
(American Physical Society, 2019) U.S. Ghosh; S. Rai; B. Mukherjee; A. Biswas; A.K. Mondal; K. Mandal; A. Chakraborty; S. Chakraborty; G. Mukherjee; A. Sharma; I. Bala; S. Muralithar; R.P. Singh
Investigation on the excited states of Zn63 was done through in-beam γ-ray spectroscopic techniques using the Cr52(O18,α3n) fusion-evaporation reaction at a beam energy of 72.5 MeV. Detection of the emitted γ rays from the excited nuclei was performed in the coincidence mode using 14 Compton suppressed Ge clover detectors of the Indian National Gamma Array. Based on the γ-γ coincidence data, 13 new transitions have been placed in the level scheme following their coincidence relationship and intensity balance. Spin and parity assignments of the excited levels have been carried out by extracting the directional correlation from oriented states ratio and polarization asymmetry values of the emitted γ rays. Shell model calculations have been performed in the f5/2pg9/2 model space with a Ni56 core using the jj44bpn interaction, to interpret the observed excited states of the nucleus. A reasonable agreement is found between the experimental findings and the shell-model calculations. In order to understand the evolution of a collective shape built on the 9/2+ (1704 keV) state, we have performed total Routhian surface calculations with a 1g9/2 quasineutron and found reasonable agreement. © 2019 American Physical Society.
Spectroscopic investigation of complex nuclear excitations in Ga 66
(American Physical Society, 2020) U.S. Ghosh; S. Rai; B. Mukherjee; A. Biswas; A.K. Mondal; K. Mandal; A. Chakraborty; S. Chakraborty; G. Mukherjee; A. Sharma; I. Bala; S. Muralithar; R.P. Singh
In-beam spectroscopic technique using the fusion evaporation reaction Cr52(O18,1p3n), at a beam energy of 72.5 MeV, was employed to explore the structural phenomena in Ga66, mainly at intermediate and high spins. The experimental setup involved an array of 14 Compton suppressed Ge clover detectors, placed around the target position to detect emitted γ rays from excited states. A new level scheme has been proposed, which is enriched with more than 20 new transitions and is extended up to an excitation energy ≈12 MeV. A few observed intermediate spin states of Ga66 are discussed in the framework of coupling of single-particle configurations with the vibrational core of Zn64. Shell model calculations have also been performed with two different interactions, viz., jj44bpn and jun45pn, for the interpretation of the observed level structure in Ga66. © 2020 American Physical Society.