S. Santra

Fusion ofLi6withTb159at near-barrier energies

Complete and incomplete fusion cross sections for {sup 6}Li + {sup 159}Tb have been measured at energies around the Coulomb barrier by the {gamma}-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by {approx}34% compared to coupled-channel calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data for {sup 11,10}B + {sup 159}Tb and {sup 7}Li + {sup 159}Tb shows that the extent of suppression is correlated with the {alpha} separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction {sup 6}Li + {sup 159}Tb at below-barrier energies are primarily due to the d transfer to unbound states of {sup 159}Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.

The heavy-ion nuclear potential: determination of a systematic behavior at the region of surface interaction distances

Abstract Precise elastic scattering differential cross sections have been measured for the 16 O + 120 Sn , 138 Ba , 208 Pb systems at sub-barrier energies. The corresponding “experimental” nuclear potentials have been determined at interaction distances larger than the Coulomb barrier radii. These experimental potentials have been compared with our earlier results for other systems, and with theoretical calculations based on the double-folding and liquid-drop models. We have shown that the nuclear potentials have a systematic behavior at the surface region. The present results for the 16 O + 208 Pb system are used to extend earlier studies of the dispersion relation to sub-barrier energies.

Backscattering spectrometry studies on metal ion distribution in polymer inclusion membranes

Abstract Polymer inclusion membranes based on cellulose triacetate polymer, containing 2-nitrophenyloctyl ether as plasticizer and dinonyl napthalene sulfonic acid as cation exchanger were loaded with Cs+ and Ag+ and were studied by backscattering spectrometry technique to measure the distribution of the metal ions across the membrane using a proton beam. The study showed that the distribution of the metal ions across the membrane is uniform, thereby suggesting the uniform distribution of the cation exchanger. This indicates that the hydrophilic nature of the sulfonic acid group in the cation exchanger does not significantly influence its distribution in the predominantly hydrophobic matrix of cellulose triacetate. However, the microstructure of the membrane, obtained by atomic force microscopy, shows the formation of blobs on the surface of the PIM indicating the inhomogeneity at the sub-micron scale.

Fusion of 19F with 188, 192Os

Fission fragment angular distributions and evaporation residue excitation functions have been measured in the bombarding energy range from 80 to 105 MeV for the 19F+188, 192Os systems. The measured fission and evaporation residue excitation functions are compared with the predictions of the statistical model code PACE. The fission and the evaporation residue excitation functions alone are not sufficient to constrain the statistical model parameters. Hence, the pre-fission neutron multiplicity, multi-chance behaviour of fission and the fission fragment angular distribution, which are very sensitive to statistical model parameters, have also been considered in carrying out a comprehensive statistical model analysis. Fission fragment anisotropies calculated in the statistical saddle point model (SSPM) framework using rotating finite range model (RFRM) effective moment of inertia values were found to over-predict the experimental data. Using scaled up values of RFRM effective moment of inertia, a good agreement between the fission anisotropy data and the SSPM calculations has been obtained over the entire energy range except at the highest energy.

Exploring the breakup and transfer coupling effects in 9 Be elastic scattering

Two cluster structures of 9Be namely, 5He+4He and 8Be+n have been considered for its breakup to describe the available data on elastic scattering for 9Be projectile with 28Si, 64Zn and 144Sm targets. The results of these calculations suggest that the breakup coupling effects are significant for 5He+4He cluster model at above the barrier energies, while they are dominant at relatively lower energies for 8Be+n model. The addition of one neutron stripping channel in the 8Be+n model gives an overall good description of the elastic data for all the systems considered. The couplings generated by breakup in 8Be+n model have different behaviour than the coupling effects obtained within the 5He+4He model, the former being more prominent at lower energies and for the heavier target systems. The behaviour of extracted dynamic polarisation potentials (DPP) generated due to breakup and one neutron transfer couplings have been investigated.

Importance of the1n-stripping process in the6Li + 159Tb reaction

The inclusive cross sections of the

Inclusive α-production cross section for the 6 Li+ 90 Zr system at energies near the fusion barrier

\alpha

Determination of the {sup 233}Pa(n,f) reaction cross section from 11.5 to 16.5 MeV neutron energy by the hybrid surrogate ratio approach

-particles produced in the reaction

Beam energy calibration for the folded tandem ion accelerator

^{6}

A search for possible long range spin dependent interactions of the neutron from exotic vector boson exchange

Li+