On the Fusion of Neutron/ Proton-Rich Colliding Nuclei Using Isospin-Dependent Potentials

By 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. 

Keywords: Heavy-ion fusion reaction, proximity potential, fusion barriers and cross sections. 
Authors:- Ishwar Dutt

School of Applied Sciences, Chitkara University, Himachal Pradesh-174 103, India.
Department of Physics, Panjab University, Chandigarh-160014, India.
Email:- ishwar.dutt1@chitkarauniversity.edu.in

Maninder Kaur
Department of Physics, Panjab University, Chandigarh-160014, India.

Probable Projectile-Target Combinations for the Synthesis of Super Heavy Nucleus 286112

The fusion cross sections for the reactions of all the projectile-target combinations found in the cold valleys of 286112 have been studied using scattering potential as the sum of Coulomb and proximity potential, so as to predict the most probable projectile-target combinations in heavy ion fusion reactions for the synthesis of super heavy nucleus 286112. While considering the nature of potential pockets and half lives of the colliding nuclei, the systems ⁸²Ge + ²⁰⁴Hg, ⁸⁰Ge + ²⁰⁶Hg and⁷⁸Zn + ²⁰⁸Pb found in the deep cold valley region and the systems ⁴⁸Ca+²³⁸U, ³⁸S+²⁴⁸Cm and ⁴⁴Ar+²⁴²Pu in the cold valleys are predicted to be the better optimal projectile-target combinations for the synthesis of super heavy nucleus ²⁸⁶112. 

Keywords:-Heavy-ion reactions; Coulomb and proximity potential 

Authors:- K. P. Santhosh and V. Bobby Jose

School of Pure and Applied Physics, Kannur University, Swami Anandatheertha Campus,Payyanur, 670327, India.
Email :- drkpsanthosh@gmail.com

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

We 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. 

Keywords:- Cluster model, low energy, super heavy elements, alpha decay 

Authors:- BirBikram Singh

Department of Physics, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, INDIA
Email:-birbikram.singh@gmail.com

Manoj K. Sharma
School of Physics and Materials Science, Thapar University, Patiala-147004, INDIA

S. K. Patra 
Institute of Physics, Sachivalaya Marg, Bhubaneswar-751005, INDIA

Partial as Well as Total Photon Interaction Effective Atomic Numbers for Some Concretes

Photon interaction effective atomic number (Z ) for partial as eff well as total photon interaction processes has been used computed using logarithmic interpolation method for seven different concretes viz. (i) Ordinary, (ii) Hematite - Serpentine, (iii) Ilmenite - Limonite, (iv) Basalt - magnetite, (v) Ilmenite, (vi) Steel - scrap and (vii) Steel - magnetite concrete in the wide energy range from 10.0 keV to 100 GeV. It has been concluded that this method has an advantage over the atomic to electronic cross-section ratio method especially for mixtures in the intermediate energy level. However, due to lack of experimental data in the higher energy region, it is dificult to discuss, its validity in these energy regions. 

Keywords:- Photon interactions, mass attenuation coeficient, effective atomic number, concrete
.Authors:- Tejbir Singh 

Department of Physics, Sri Guru Granth Sahib World University, Fatehgarh Sahib - 140406.
Parjit S. Singh 

Department of Physics, Punjabi University, Patiala-147002, Punjab, India.

Alignment Studies for Tungsten Near L3 Sub-Shell Threshold Via Theoretical, Experimental and Empirical Methods

Alignment studies are made for tungsten near L3 sub-shell hreshold using theoretical, experimental and empirical approaches. Experimentally to measure alignment parameter, the angular distribution of L x-rays of tungsten (W-74) is measured in the angular range 0 to 120, where maximum anisotropy is expected. The experimental measurements are performed in XRF laboratories of Raja Ramanna Center for Advanced Technology (RRCAT), Indore, India using a three-dimensional double relection set-up. The weighted average of alignment values with 10% error comes 0.155 0.009. Theoretically, the value of alignment parameter A is calculated using non-relativistic dipole approximation in a point 20 Coulomb potential and is found 0.151 at L3 threshold energy (10.676 keV). For empirical A evaluations, IGELCS interpolated experimental 20 LXRF cross-section *Lg (g = , ) values of Mann et al with 8% reported errors are used along with the radiative decay rates. The comparison among heoretical, experimental and empirical values are similar and values being >0.1 at L3 threshold energy are certainly higher than the 5 to 8 percent uncertainties quoted in earlier experimental results. 

Keywords:- Alignment, cross-section, anisotropy, angular distribution and x-ray luorescence 
Authors:- Ajay Sharma 
Physics Department, Chitkara University, Himachal Pradesh-174103-INDIA 
Raj Mittal 

Nuclear science Laboratories, Physics department, Punjabi University Patiala-147002-INDIA