Goutam Dev Mukherjee

Energy levels in 141Nd from fusion evaporation study

The nucleus 141Nd has been investigated using two different heavy ion fusion evaporation reactions, namely 130Te(16O, 5n) at Elab = 80–85 MeV and 124Sn(24Mg,α3n) at Elab = 107 MeV, and the de-exciting gamma rays were detected using HPGe(GDA) and Clover detector (INGA) arrays, respectively. More than 30 new gamma transitions have been placed in the proposed level scheme, which has been extended up to 9 MeV excitation energy and spin parity values of 45/2−. Spin parity assignments have been made to most of the newly proposed levels. The structure up to approximately 6 MeV excitation energy and spin 31/2− can be explained using the shell model in a truncated basis. The levels with higher spin/energy cannot be described using even the full 50–82 shell, indicating the influence of neutron excitations across the shell gap in this mass region. One M1 band that has been observed is proposed to have a five quasiparticle configuration.

Lifetime measurements of triaxial strongly deformed bands in {sup 163}Tm

With the Doppler Shift Attenuation Method, quadrupole transition moments Q{sub t} were determined for the two recently proposed triaxial strongly deformed (TSD) bands in {sup 163}Tm. The measured Q{sub t} values indicate that the deformation of these bands is larger than that of the yrast signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the region.