P. K. Joshi

Study of the characteristics of a clover detector

Abstract The resolution, efficiency and summing characteristics of a clover detector obtained from Eurisys Mesures, France, have been studied in the singles and the add-back mode. The results of the measurements using 152 Eu and 60 Co sources are presented in this paper.

Characteristics of a Compton suppressed Clover detector up to 5 MeV

The Clover detectors in their addback mode are excellent tools for detecting high-energy gamma rays ðX2 MeVÞ: The characteristics ofthese detectors, at energies above 2 MeV ; are usually determined from simulation data or from extrapolation ofthe empirical data. This is the first time that the characteristics ofa Compton suppressed Clover germanium detector have been studied up to 5 MeV using a radioactive 66 Ga ðT1=2 ¼ 9:41 hÞ source. r 2002 Elsevier

Fusion cross sections for Li 6 , 7 + Mg 24 reactions at energies below and above the barrier

Measurement of fusion cross sections for the {sup 6,7}Li + {sup 24}Mg reactions by the characteristic {gamma}-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these {gamma}-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l{sub cr}) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions.

Band crossing in a shears band of Cd 108

The level lifetimes have been measured for a Shears band of 108 Cd which exhibits bandcrossing. The observed level energies and B(M1) rates have been successfully described by a semi-classical geometric model based on shear mechanism. In this geometric model, the bandcrossing in Shears

Characteristics of a two-fold segmented Clover detector

Abstract The characteristics of a Compton-suppressed, two-fold segmented, Clover detector have been studied in singles and add-back modes for using it in the study of heavy-ion fusion–evaporation reactions. The measurements have been performed with standard sources of 152 Eu , 60 Co and in-beam γ -rays from the fusion–evaporation reaction 28 Si on 27 Al at E lab =100 MeV . Reduction in γ -ray Doppler broadenings due to the two-fold segmentation is demonstrated through in-beam data.

Shape evolution of yrast-band in 78Kr

Abstract Lifetimes have been measured up to the I=22+ level in the yrast positive-parity band for 78Kr using the recoil distance and lineshape analysis methods. The B(E2) and Qt values obtained from these measurements show a significant drop with increasing spin. The band crossings and the observed variation in Qt are understood through cranked shell-model, TRS and configuration-dependent shell-correction calculations assuming an oblate deformation for 78Kr at low spins.

Structure of Dipole Bands in 112In: Through Lifetime Measurement

High-spin states of the 112In nucleus have been populated via 100Mo(16O, p3n) reaction at 80 MeV beam energy. Lifetimes of excited states of dipole bands have been measured using Doppler-shift attenuation method. The B(M1) transition rates deduced from the measured lifetimes show a rapid decrease with increasing angular momentum. The decrease in B(M1) values are well accounted by the prediction of tilted axis cranking calculations. These measurements confirm the presence of shears mechanism in this nuclei.

Evidence of antimagnetic rotation in odd-A {sup 105}Cd

The lifetimes of the levels above spin

Band crossing in a shears band ofCd108

23/{2}^{\ensuremath{-}}

Band crossing in Shears band of 108 Cd

in the negative-parity yrast band of