Search

The high spin states in A = 75, Kr and Br isotopes have been populated via fusion-evaporation reaction at an incident beam energy of 90 MeV. The de-exciting γ- rays were detected utilizing the Indian National Gamma Array (INGA). Lifetime of these excited high spin states were determined by Doppler-shift attenuation method. Experimental results obtained from lifetime measurement are interpreted in the frame work of projected shell-model to get better insight into the evolution of collectivity. Comparison of the calculations of the model with transitional quadrupole moments Qt of the positive and negative parity bands firmly established their configurations. [ABSTRACT FROM AUTHOR]

The level structures in 98,99Rh, and 99Pd nuclei have been investigated through in beam γ-ray spectroscopic techniques following the 75As(28Si, xpyn) fusion-evaporation reaction at Elab =120 MeV. These investigations were carried out using Indian-National-Gamma-Array (INGA) consisting of Compton-suppressed clover detectors at the Inter-University Accelerator Centre, New Delhi. The level structures observed in 99Pd, and 98,99Rh have been established up to ~11 MeV, 10 MeV and 16 MeV excitation energy and spin ~ 23ħ,23ħ, and 28ħ respectively. In the doubly-odd 98Rh nucleus, new bandstructures and isomeric states have been identified at lower spins and new states below the previously identified 2+ ground state (T1/2 = 8.5 m) are identified. In the present work 99Rh structure have been observed similar to 101Rh which is based on p1/2 and g9/2 orbitals. Various positive and negative parity states in these nuclei are observed to be energetically more favored with respect to the neighboring ones, and are likely to be the maximally aligned states obtained by angular momentum coupling of the valence particles (holes). The level structures observed in Pd have been interpreted in the framework of a microscopic theorybased on the deformed Hartree-Fock (HF) and angular momentum projection techniques. Bandstructures at low excitation energy are based on the low-Ω vg7/2 and vd5/2 orbitals, have been observed in 99Pd. Band structure at higher spins are reproduced with the v(g7/2)² ⊗ v(g7/2)-1 ⊗ v(h11/2)² ⊗ n(g9/2)6 configurations. Observation of new E1 transitions linking the opposite parity vh11/2 and vd5/2 bands provide fingerprints of possible octupole correlations in 99Pd. The extracted values of the B(E1)/B(E2) ratios for the lower levels in the vh11/2 band are ~ 10-7 [fm]-2. [ABSTRACT FROM AUTHOR]

Band structure and electromagnetic properties of bands of 160,162,164Gd are studied theoretically upto high spin values using self-consisstent mean field theory. Predictions for the band structures are made. A K = 6-- isomer at fairly low energy is predicted. Four quasi-particle bands involving i3/2 neutron and h11/2 protons are also studied. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]