Journal of Nuclear Physics, Material Sciences, Radiation and Applications
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Theoretical Study of Interplay Between Superconductivity and Itinerant Ferromagnetism
Get PDFFollowing Green’s function technique and equation of motion method, the coexistence of superconductivity (SC) and itinerant ferromagnetism (FM) is investigated in a single band homogenous system. Self consistent equations for SC and FM order parameters, Δ and m or I respectively are derived. It is shown that there generally exists a coexistent (Δ ≠ 0, and m or I ≠ 0) solutions to the coupled equations of the order parameter in the,temperature range 0 < T < min(TC, TFM), where TC and TFM are respectively the superconducting and ferromagnetic transition temperatures. Expressions for specific heat, density of states, free energy and critical field are derived. The specific heat has linear temperature dependence as opposed to the exponential decrease in the bCS theory. The density of states for a finite m increases as opposed to that of a ferromagnetic metal. Free energy study reveals that FM-SC state has lowest energy than the normal FM state and therefore realized at low enough temperature .Effect of small external field is also studied. The theory is applied to explain the observations in uranium based intermetallics systems UCoGe and UIr. The agreement between theory and experiments is quite encouraging
Fission in Rapidly Rotating Nuclei
Get PDFWe study the effect of rotation in fission of the atomic nucleus256Fm using an independent-particle shell modelwith the mean field represented by a deformed Woods-Saxon potential and the shapes defined through the Cassinian oval parametrization. The variations of barrier height with increasing angular momentum, appearance of double hump in fission path are analysed. Our calculations explain the appearance of double hump in fission path of 256Fm nucleus. The second minimum vanishes with increase in angular momentum which hints that the fission barrier disappears at large spin
Elemental Analysis of Soil Samples Using Thick Target-Particle Induced X-Ray Emission (TT-PIXE) Technique
Get PDFIn this work thick target-proton induced x-ray emission (TT-PIXE) technique has been employed for the elemental analysis of soil samples collected from Budha nullah region of Ludhiana city, Punjab. TT-PIXE analysis of samples has been carried out using 3 MeV proton beam from 3 UD pelletron (9SDH2 from NEC, USA) facility at the Institute of Physics (IOP), Bhubaneswar, Orissa. The emitted x-rays were detected using Si(Li) detector (CANBERRA US, FWHM = 180 eV at 5.9 keV) positioned at 90° to the beam line and using suitable electronics. The trace elements 15P, 16S, 19K, 20Ca, 22Ti, 24Cr, 25Mn, 26Fe, 29Cu, 30Zn, 33As, 37Rb, 38Sr, and 82Pb were quantified in the soil samples. The quantitative estimation of PIXE spectrum of the soil samples was performed using GUPIX computer code. The presence of 24Cr, 33As, and 82Pb toxic elements in soils is likely to be due to the pollution caused by seepage of the water at the breached locations of nullah. The present study brings to focus the need to improve the effluent treatment of the industrial wastes and repair of the breached Budha nullah. In comparison to other analytical techniques for elemental analysis, PIXE is sensitive and its multi-elemental character brings advantage to investigators for the determination of minor and trace elements in a variety of soil samples
The Meijer’s G-functions Convenient for Describing β & γ-decays
Get PDFThe purpose of this paper is to show that the Meijer’s G-functions, as a very general complex functions which include all elementary, and most of the special functions, can describe some phenomena in nuclear physics. In fact, some interesting properties of Meijer’s G-functions triggered us to apply these functions in the processes βand γ-decay. The role of these functions is as “wave function” for parent and daughter nucle
On the Fusion of Neutron/ Proton-Rich Colliding Nuclei Using Isospin-Dependent Potentials
Get PDFBy using different isospin dependent proximity-type potentials, we performed a detailed study of neutron/proton-rich colliding nuclei with N/Z ratio between 0.5 and 2.0. Isotopes of three different series namely, Ne-Ne, Ca-Ca, and Zr-Zr are taken into account. A monotonous increase (decrease) in the fusion barrier positions (heights) using a unified second order nonlinear parametrization in the normalized fusion barrier positions and heights with (N/Z−1) is presented. These predictions are in good agreement with the available theoretical as well as experimental results. The fusion probabilities, however shows linear dependence. Further, the neutron/proton content plays dominant role at near barrier energies only. Our results are also independent of the model used as well as reaction partner and isospin content. More experiments are needed to verify our predictions
Extensions of Natural Radioactivity to 4th-Type and of the Periodic Table to Super-heavy Nuclei: Contribution of Raj K Gupta to Cold Nuclear Phenomena
Get PDFWe have studied here the contribution of Indian Scientists associated with Prof. Raj K. Gupta to cold nuclear phenomena during the last almost four decades, which led to the discovery of fourth kind of natural radioactivity (also known as Cluster Radioactivity, CR) and to the extension of periodic table to super heavy nuclei. It is exclusively pointed out how the Quantum Mechanical Fragmentation Theory (QMFT) advanced by Prof. Raj K. Gupta and Collaborators led to the discovery of unique phenomenon of CR along with the predictions leading to the synthesis of super heavy elements. We have also mentioned the development of dynamical theories based on QMFT, the Preformed Cluster Model(PCM) and the dynamical cluster-decay model (DCM), to study the ground and excited state decays of nuclei, respectively, by Gupta and Collaborators. It is matter of great honor and pride for us to bring out this study to enthuse the young researchers to come up with novel ideas and have inspiration from the scientific contributions of Prof. Raj K. Gupta who is coincidentally celebrating his platinum jubilee birthday anniversary this year
Level Statistics of SU(3)↔ SU(3) Transitional Region
Get PDFLevel statistics oftransitional region of SU(3)↔ SU(3) bar interacting boson model is described with emphasis on the nearest neighbor spacing distributions. The energy levels of transitional Hamiltonian are calculated via the SO(6) representation of eigenstates. By employing the MLE technique, the parameter of Abul-Magd distribution is estimated which suggests less regular dynamics for transitional region as compared to dynamical symmetry limits. Also, the O(6) dynamical symmetry which is known as the critical point of this transitional region, describes a deviation to more regular dynamics
Formation of Medium-Heavy Elements in Rapid Neutron Capture Process
Get PDFWe predict the neutron drip-line and simulate the r—process path for Cu — Sn, based on the calculation of binding energy in the frame-work of relativistic and non-relativistic mean field formalisms. We also compare the quadrupole deformation parameterβ2, and one neutron separation energy Sn of these isotopic series with the results of finite range droplet model (FRDM) prediction. the results produced by RMF and ShF are comparable to each other and also agreeable with the FRDM model
Quantum Effects on the Linear Dispersion Characteristics in Electron-Positron Plasma
Get PDFIn electron-positron plasmas some of the plasma modes are decoupled due to the equal charge to mass ratio of both species. The dispersion properties of the propagation of linear waves in degenerate electron–positron magnetoplasma are investigated. By using the quantum hydrodynamic equations with magnetic fields of the Wigner–Maxwell system, we have obtained a set of new dispersion relations in which ions’ motions are not considered. The general dielectric tensor is derived using the electron and positron densities and its momentum response to the quantum effects due to Bohm potential and the statistical effect of Femi temperature. It has been demonstrated the importance of magnetic field and its role with the quantum effects in these plasmas which support the propagation of electromagnetic linear waves. Besides, the dispersion relations in case of parallel and perpendicular modes are investigated for different positron-electron density ratios
Cluster Radioactivity in 127I
Get PDFUsing the preformation cluster model of Gupta and collaborators we have studied all the possible cluster decay modes of 127 I. The calculated half-lives are compared with recently measured lower limits of cluster decay half-lives (for the clusters like 24Ne, 28Mg, 30Mg, 32Si, 34Si, 48Ca and 49Sc) of 127I. Our calculated half-life values lies well above the experimentally measured lower limits and the trend of the values also matches with experimental ones