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An exclusive systematic study of the giant dipole resonance (GDR) parameters has been performed in very light mass nucleus P 31 in the temperature range of ∼ 0.8 – 2.1 MeV and average angular momentum of ∼ 11 – 16 ħ . The high-energy γ rays from the decay of the GDR, evaporated neutrons and γ-ray multiplicities have been measured. The angular distribution of high-energy γ rays has also been measured at E beam = 42 MeV . The GDR parameters, nuclear level density parameter and nuclear temperature were precisely determined by simultaneous statistical model analysis of high-energy γ ray and evaporated neutron spectra. It is observed that the measured width remains roughly constant up to a temperature of ∼ 1.6 MeV . Moreover, the thermal pairing plays no role in describing the GDR width in this open-shell light nucleus at the above-mentioned temperatures and angular momenta. The present measurements provide an excellent platform to extend the applicability of the existing theoretical models down to the very light mass nuclei.

The High-spin states in 195Tl, populated through the 185,187Re(13C, xn) fusion evaporation reaction at the beam energy of 75 MeV, were studied using the Indian National Gamma Array (INGA). More than 50 new γ transitions have been placed in the proposed level scheme which is extended up to the excitation energy of ≈ 5.6 MeV and spin=22.5ħ. Two pairs of degenerate bands based on two different quasi-particle configurations have been identified in this nucleus indicating the first observation of such bands in an odd-A nucleus in A∼190 region and signify the first evidence of multiple chiral bands in a nucleus in this region. The total Routhian surface calculations predict triaxial shapes for both the configurations and thereby, support the experimental observation. The importance of multiple neutron holes in the i13/2 orbital and the stability of shapes for these two configurations have been discussed. Keywords: Nuclear Structure, γ-ray spectroscopy, Doubly degenerate bands, TRS calculation

The development of a digitizer based pulse processing and data acquisition system for γ -ray spectroscopy with large detector arrays is presented. The system is based on 250 MHz 12-bit digitizers, and is triggered by a user chosen multiplicity of Compton suppressed detectors. The logic for trigger generation is similar to the one practised for analog (NIM/CAMAC) pulse processing electronics, while retaining the fast processing merits of the digitizer system. Codes for reduction of data acquired from the system have also been developed. The system has been tested with offline studies using radioactive sources as well as in the in-beam experiments with an array of Compton suppressed Clover detectors. The results obtained therefrom validate its use in spectroscopic efforts for nuclear structure investigations.

The present work reports the performance of 1.5 ′ ′ x 1.5 ′ ′ CeBr 3 cylindrical fast scintillator detectors, coupled to the Photomultiplier Tube (PMT) Hamamatsu R13089-100. The detectors are characterized with respect to the energy linearity response, energy resolution, absolute photopeak efficiency and time resolution, using standard radioactive sources. The energy spectra recorded for different radioactive sources and the absolute photopeak efficiency at different source-to-detector distances are compared with the GEANT4 Monte Carlo simulation. The best time resolution of 141 ( 1 ) ps, measured for the 1173–1332 keV prompt γ -ray cascade for a single 1.5 ′ ′ x 1.5 ′ ′ CeBr 3 detector, is reported from the present work. The results are compared with the values reported for similar detectors of different sizes.

Two opposite parity dipole sequences (DB I and DB II) in 142Eu have been investigated using the Indian National Gamma Array (INGA), and heavy-ion induced fusion-evaporation reaction, 116Cd(31P, 5n) at ELab = 148 MeV. The Configurations of these bands are assigned on the basis of tilted axis cranking covariant density functional theory (TAC-CDFT) calculations. The measured B(M1) and B(E2) rates of the DB I and DB II, have been well reproduced within the shears mechanism with the principal axis cranking model (SPAC) calculations leading to the conclusion that these bands have been based on the shears mechanism. The large B(E1) transition rates between DB I and DB II indicate the existence of octupole correlation in 142Eu that has also been corroborated through microscopic multidimensionally-constrained covariant density functional theory (MDC-CDFT) calculations. Thus, the present investigation leads to the novel observation of the presence of octupole correlation between two shears band. Keywords: Lifetime measurement, Tilted axis rotation, Principal axis rotation, Octupole correlation, 142Eu

The synthesis is described of a globotetraose trimer in 74% yield by the reaction of tris(2-aminoethyl)amine with the hydrophobic squaric decyl ester glycoside of globotetraose. The synthesis was readily monitored and purified using reversed phase HPLC. Unreacted squaric decyl ester globotetraoside was recovered rendering the method highly economical.