Shape evolution in odd-A 137 Pm

The odd mass nucleus ¹³⁷Pm has been studied to high spins through the ¹⁰⁹Ag(³²S, 2p2n)¹³⁷Pm reaction at an incident beam energy of 150 MeV. The de-exciting ??-rays were detected using an array of 18 Compton suppressed clover detectors. The level scheme of ¹³⁷Pm has been extended up to $J^\pi = \tfrac{{43}} {2}^ -$ and excitation energy of E _x ? 6 MeV with the observation of 42 new gamma transitions. The linear polarization (IPDCO) measurements for the ??-ray transitions have been done for the first time. The spin and parity assignments for most of the reported levels have been made using these results and the coincidence angular anisotropy (R_DCO) measurements. The nuclear shape evolution is discussed in the light of Total Routhian Surface (TRS) and Cranked Shell Model (CSM) calculations.     

Measurements of elastic scattering for 7Be, 7Li + 9Be systems and fusion cross sections for 7Li + 9Be system

Elastic scattering angular distributions have been measured for ⁷Be + ⁹Be system at E_lab = 17, 19 and 21 MeV in the angular range θ_cm=26^○–58°, and for ⁷Li + ⁹Be system at E_lab= 15.75, 24 and 30 MeV. An optical model (OM) analysis of these data have been carried out. For the ⁷Li + ⁹Be system fusion cross sections were obtained at E_lab = 15.75, 24 and 30 MeV by measuring the α-evaporation spectra from the compound nucleus at backward angles. The measured α-evaporation spectra were reproduced by the statistical model calculations and fusion cross sections were extracted therefrom. The ratios of the experimental fusion cross sections to the total reaction cross sections (obtained form OM analysis) were found to be rather small. This result suggests that break-up process has a strong influence on fusion process leading to a reduction in fusion cross section.     

Field integral measurement of a six period undulator in a pulsed wire set up

A pulsed wire method is described for undulator field measurement. The results of the second field integral are compared with Hall probe results. The pulsed wire data are taken at different locations of the sensor along the length of the wire and with different gap of the undulator. A planar undulator with six periods is used in the pulsed wire set up. The total length of the undulator is 30 cm. The pulsed wire result shows good agreement with the Hall probe data.     

A recyclable/reusable hydrotalcite supported copper nano catalyst for 1,4-disubstituted-1,2,3-triazole synthesis via click chemistry approach

Using hydrotalcite as solid support, copper nano particles were synthesized and used in azide-alkyne cycloaddition reaction en route to the synthesis of 1,4-disubstituted-1,2,3-triazoles. The catalyst is heterogeneous and can be recycled and reused easily. Room temperature reaction condition and the use of ethylene glycol as solvent make it an environment friendly system.     

Approximate analysis of planar photonic bandgap waveguides: a simple semi-analytical method

A semi-analytical approximate method, Vopt, is applied to a planar photonic bandgap (PBG) waveguide and a coupler configuration. The variational process of the Vopt method presents simple effective index analysis of the complex two dimensional (2-D) structures. The Vopt method expresses the refractive index profile of the 2-D structure as two 1-D refractive index profiles and obtains the optimized indices for the two structures iteratively. The Vopt method separates the planar PBG waveguide into an effective multilayer waveguide confining optical field in the lateral direction and a 1-D Bragg reflector that gives characteristic reflection/transmission spectra. The results obtained by the Vopt method show good agreement with the numerical results of the finite difference time domain analysis. The present analysis is helpful in understanding the optical properties of such complex waveguides and can be used as starting approximation for optimizing the structures for various applications.