Nuclear structure studies at Saha Institute of Nuclear Physics using gammadetector arrays

In-beam gamma-ray spectroscopy, carried out at the Saba Institute of Nuclea r Physics in the recent past, using heavy-ion projectiles from the pelletro n accelerator centres in the country and multi-detector arrays have yielded significant data on the structure of a large number of nuclei spanning dif ferent mass regions. The experiments included the study of two-fold gamma g amma -coincidence events for establishing decay schemes, directional correl ation of oriented nuclei (DCO) for help in spin assignments and Doppler shi ft attenuation for lifetime information. The studies have led to the observ ation of rotational sequences of states in nuclei near closed shell in the mass A = 110 region, vibrational spectra in nuclei with A similar to 60, in terplay between single-particle and collective modes of excitation in the d oubly-odd bromine isotopes, decoupled bands with large quadrupole deformati on in Br-77, shape transition with rotational frequency within a band in Pm -138 and octupole collectivity in Eu-153. Particle-rotor-model and cranked- shell-model calculations have been carried out to provide an understanding of the underlying nuclear structure.