Frontiers in Gamma Ray Spectroscopy FIG18

Effect of single proton in driving the nucleus towards deformation

Not scheduled

AG66 (TIFR, Mumbai)

Poster

Speakers

Mr RANABIR BANIK (VARIABLE ENERGY CYCLOTRON CENTRE)Mr Soumik Bhattacharya (VARIABLE ENERGY CYCLOTRON CENTRE)

Description

In mass 200 region, nuclei close to 208Pb show variety of band structures representing different ways of coupling of the odd valance particles with the core. The ground and first few excited states are dominated by the pure single particle orbitals near Fermi level, while the excitation of valance particles or holes to the high-j intruder orbitals play an important role in bringing high angular momentum to the system. As a result, various core coupled structures are evolved while going from the deformed rare earth region to the spherical region near doubly magic shell closure. Odd-A mercury (Z=80) nuclei close to N=126 closed shell show decoupled band structures with a near spherical shape, built on the i13/2 isomeric state, while the proton particles are coupled to generate 0+ states. For the neighbouring Tl (Z=81) nuclei, the odd-proton occupies the intruder h9/2 orbital, which comes downwards for oblate deformation from the upper level of Z=82 shell gap. The shape driving effects of the h9/2 orbital drive the nucleus towards deformation leading to the strongly coupled rotational states in Thallium nuclei. The above effects have been investigated in 199Hg (Z=80,N=119) and 199Tl(Z=81,N=118) nuclei, which were produced by beam from K-130 Cyclotron at VECC, Kolkata using the reactions 198Pt(,3n)199Hg, 197Au(,3n)199Tl with 36 MeV and 30 MeV beam energies respectively. The excited states of these nuclei are studied by detecting the gamma-rays with VECC array for Nuclear Spectroscopy (VENUS), consisting of six Compton suppressed Clover HPGe detectors. The effect of high-j orbitals on the structure of 199Hg and 199Tl will be presented.