Indian National Gamma Research Articles

Indication of the onset of collectivity inP30

$^{30}\mathrm{P}$ has been studied by in-beam \ensuremath{\gamma}-spectroscopy following the fusion-evaporation reaction $^{16}\mathrm{O}$($^{16}\mathrm{O}$,$\mathit{pn}$) at ${E}_{\mathrm{lab}}=40$ MeV, using the Indian National Gamma (Clover) Array (INGA) up to moderate spins ($I=5$). Polarization measurements of seven gamma rays have been performed for the first time. To understand the underlying structure of the levels and transition mechanisms, experimental data have been compared with the results from large basis cross-shell shell model calculations. The results for the negative parity states are especially important in this respect. Positive parity states indicate an onset of collectivity, whereas the negative parity states are members of \ensuremath{\nu}-\ensuremath{\pi} multiplets.

High spin structure of 35Cl and the sd– fp shell gap

The high spin states of 35Cl have been studied by in-beam γ-spectroscopy following the fusion–evaporation reaction 12C( 28 Si , α p ) 35Cl at E lab = 70 and 88 MeV, using the Indian National Gamma (Clover) Array (INGA). Lifetimes of six new excited states have been estimated for the first time. To understand the underlying structure of the levels and transition mechanisms, experimental results have been compared with those from the large basis cross-shell shell model calculations. Involvement of orbitals from fp shell and squeezing of the sd– fp shell gap seem to be essential for reliable reproduction of high spin states.