An attempt to explore the production routes of Astatine radionuclides: Theoretical approach

In order to fulfil the recent thrust of Astatine radionuclides in the field of nuclear medicine various production routes have been explored in the present work. The possible production routes of $^{209-211}$At comprise both light and heavy ion induced reactions at the bombarding energy range starting from threshold to maximum 100 MeV energy. For this purpose, we have used the nuclear reaction model codes TALYS, ALICE91 and PACE-II. Excitation functions of those radionuclides, produced through various production routes, have been calculated using nuclear reaction model codes and compared with the available measured data. Contribution of various reaction mechanisms, like, direct, preequilibrium and equilibrium reactions, to the total reaction cross section has been studied using the codes. Result shows that equilibrium reaction mechanism dominates in all cases over other reaction mechanisms

Binary projectile fragmentation of 12C at an incident energy of 33.3 MeV/nucleon

Direct binary projectile fragmentation is being investigated for the case where a 400 MeV 12C projectile breaks up into an particle and a 8Be fragment in the interaction with a thin 93Nb and 197Au target. While the 8Be fragments were measured at 9 , the correlated particles were detected in an angular range between 16 and 30 on the opposite side of the beam. From the preliminary results presented here one may obtain information on the amount of quasi-elastic fragmentation (both fragments do not suffer any further interactions after they are produced). These experimental results indicate that the quasi-elastic break-up process is the dominant contribution to the measured correlation spectra. As was also observed in earlier work, the most forward quasi-elastically emitted particles have energies exceeding the beam velocity

Investigations on the stability of plasma modified silicone surfaces

In this work it was investigated the effect of the exposure to different plasmas on the wettability of silicone samples. We have observed that oxygen. argon, and hydrogen glow discharges are quite effective in reducing the water contact angle of such polymer. However, indifferently to efficiency of the treatment, practically all the modified surfaces recovered great part of their original hydrophobicity. We have investigated this hydrophobic recovery using surface energy measurements and theoretical simulations based on the exponential decay of the population of polar groups on the surface. According to our results such recovery can be attributed to the decrease of polar species at the interface water-polymer surface

Excitation functions of residues in the interaction of C-12 with Rh-103 up to an incident energy of 400 MeV

The excitation functions for production of 45 residues in the interaction of C-12 with Rh-103 at incident energies ranging from about 40 to 400 MeV are analysed in terms of many competing reaction mechanisms including complete and incomplete fusion reactions and the quite relevant contribution of the decay of the target nucleus excited in the inelastic scattering of the incident C-12 ions. The cross-sections of most of these mechanisms have been obtained by extrapolation from the values measured in the interaction of C-12 with the neighbouring nucleus Nb-93. The agreement between experimental data and model predictions is very good in most cases. (c) 2005 Elsevier B.V. All rights reserved

Excitation functions of evaporation residues in the interaction of

The excitation functions for production of 48 residues in the interaction of 16O with 103Rh have been measured at incident energies varying from about 40 to 400MeV. Their analysis shows that many competing reaction mechanism contribute to the formation of these residues including complete fusion, break-up-fusion reactions and 16O inelastic scattering. The cross-sections of most of these mechanisms are obtained by independent measurements of the spectra of intermediate-mass fragments observed in the interaction of 16O on 93Nb. The agreement between measured and calculated excitation functions is satisfactory in most of the cases