Articles written in Pramana – Journal of Physics

• Analysis of shape isomer yields of ${}^{237}$Pu in the framework of dynamical–statistical model

Data on shape isomer yield for $\alpha +^{235}$U reaction at $E^{\text{lab}}_$\alpha = 20–29$MeV are analysed in the framework of a combined dynamical–statistical model. From this analysis, information on the double humped ﬁssion barrier parameters for some Pu isotopes has been obtained and it is shown that the depth of the second potential well should be less than the results of statistical model calculations. • Fission dynamics of the compound nucleus 213Fr formed in heavy-ion-induced reactions A stochastic approach based on one-dimensional Langevin equations was used to calculate the average pre-fission multiplicities of neutrons, light charged particles and the fission probabilities for the compound nucleus 213Fr and the results are compared with the experimental data. In these calculations, a modified wall and window dissipation with a reduction coefficient,$k_{s}$, has been used in the Langevin equations. It was shown that the results of the calculations are in good agreement with the experimental data by using values of$k_{s}$in the range$0.3 \leq k_{s} \leq 0.5.$• Fission characteristics of$^{216}$Ra formed in heavy-ion induced reactions A Kramers-modified statistical model is used to calculate the cross-section of the evaporation residue, fission cross-section, average pre-fission multiplicities of protons and$\alpha$-particles for$^{216}$Ra formed in$^{19}{\text{F}} + ^{197}{\text{Au}}$reactions and results are compared with the experimental data. To calculate these quantities, the effects of temperature and spin$K$about the symmetry axis have been considered in the calculations of the potential energy surfaces and the fission widths. It is shown that the results of the calculations using values of the temperature coefficient of the effective potential$k = 0.008 \pm 0.003$MeV$^{−2}$and scaling factor of the fission-barrier height$r_{s} = 1.004 \pm 0.002\$ are in good agreement with the experimental data.

• Fission anisotropy of 197Tl produced in fusion reactions in the framework of the modified statistical model

The anisotropy of fission fragment angular distribution, evaporation residue crosssection and the fission cross-section were calculated for 197Tl formed in 16O+181Ta reactions in the framework of the modified statistical model and the results were compared with the experimental data. The effects of temperature and projection of spin about the symmetry axis 𝐾 have been considered for calculating potential energy surfaces and fission widths. It was shown that in the framework of the modified statistical model, by choosing appropriate values for the temperature coefficient of the effective potential, 𝛼, and scaling factor of the fission-barrier height, 𝑟s, one can satisfactorily reproduce the above-mentioned experimental data. It was also shown that the appropriate values of these parameters for 197Tl are 𝛼 = 0.0185 ± 0.0050 MeV-2 and 𝑟s = 1.0006 ± 0.0020.

• # Pramana – Journal of Physics

Current Issue
Volume 93 | Issue 5
November 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019