• L Satpathy

Articles written in Pramana – Journal of Physics

• Fission decay properties of ultra neutron-rich uranium isotopes

The fission decay of highly neutron-rich uranium isotopes is investigated which shows interesting new features in the barrier properties and neutron emission characteristics in the fission process. 233U and 235U are the nuclei in the actinide region in the beta stability valley which are thermally fissile and have been mainly used in reactors for power generation. The possibility of occurrence of thermally fissile members in the chain of neutron-rich uranium isotopes is examined here. The neutron number $N = 162$ or 164 has been predicted to be magic in numerous theoretical studies carried out over the years. The series of uranium isotopes around it with $N = 154-172$ are identified to be thermally fissile on the basis of the fission barrier and neutron separation energy systematics; a manifestation of the close shell nature of $N = 162$ (or 164). We consider here the thermal neutron fission of a typical representative 249U nucleus in the highly neutron-rich region. Semiempirical study of fission barrier height and width shows that 250U nucleus is stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. On the basis of the calculation of the probability of fragment mass yields and the microscopic study in relativistic mean field theory, this nucleus is shown to undergo exotic decay mode of thermal neutron fission (multi-fragmentation fission) whereby a number of prompt scission neutrons are expected to be simultaneously released along with the two heavy fission fragments. Such properties will have important implications in stellar evolution involving 𝑟-process nucleosynthesis.

• Resonance states in 16O + 16O, 12C + 16O, $\alpha$ + 16O and 𝛼 + 12C with modified Morse potentials

The resonance states in 16O + 16O, 12C + 16O, 𝛼 + 16O and 𝛼 + 12C are described using modified Morse potential proposed earlier whose success has already been demon-strated in the case of 12C + 12C system. The general validity of such a potential with long range, shallow depth and repulsive soft core determined from the resonance data itself is being examined through the present study of the resonances in the above four systems. In each system, the experimental data of a large number of states have been successfully described with a modified Morse potential. The success points out a common mechanism of the origin of these states, and reaffirms authentically the diatomic-like rotational and vibrational picture of the nuclear molecular resonances proposed previously. The close resemblance between the physics of diatomic molecules and nuclear molecular resonances extending to the level of potential which is Morse type in both the cases - although belong to two different areas of physics - is further strengthened through the present study.

• # Pramana – Journal of Physics

Volume 96, 2022
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019