arXiv subjects

S. R. Mohanty

Publications and source records attributed to S. R. Mohanty.

4 recordsLinked to original sources

arXiv2024

Unstable Anisotropic Neutron Stars: Probing the Limits of Gravitational Collapse

Neutron stars (NSs) are incredibly versatile for studying various important aspects of high-energy and compact-object physics. These celestial objects contain extreme matter at incredibly high densities in their interiors, leading to the risk of instabilities that may cause them to collapse into a black hole (BH). This paper focuses on exploring the stability and gravitational collapse of NSs. For a more realistic approach we have considered the pressure to be locally anisotropic. We utilize the BL-Model to describe the anisotropy inside the NS. The presence of quarks in the core of an NS can heavily affect its stability. Hence, along with pure hadronic EOSs, we have also considered Hadron-Quark phase transition (HQPT) EOSs for this paper's analysis. We subject the anisotropic NSs to radial perturbations to study their stability against radial oscillations. NSs exhibiting imaginary eigen-frequencies are identified as unstable, and their inevitable destiny is gravitational collapse, resulting in the formation of a BH. We consider the interior of these unstable anisotropic NSs to be a non-ideal fluid in a non-adiabatic background in order to study its dynamical evolution during the collapse. We examine the temporal evolution of key properties of NSs, such as mass, density, heat flux, and anisotropy during the process of gravitational collapse. We present an innovative and viable approach to detect such high-energy gravitational collapse events, providing valuable insights into the properties of the static NS before its collapse.

nucl-th↗

arXiv2021

Effect of Positive Polarity in an Inertial Electrostatic Confinement Fusion Device: Electron Confinement, X-ray Production, and Radiography

The conventional inertial electrostatic confinement fusion (IECF) operation is based on the application of high negative voltage to the central grid which results in the production of neutrons due to the fusion of lighter ions. The neutron has enormous applications in diversified fields. Apart from the neutrons, it can also be used as an application based x-ray source by altering the polarity of the central grid. In this work, the electron dynamics during the positive polarity of the central grid have been studied using an object-oriented particle-in-cell code (XOOPIC). The trapped electron density inside the anode is found to be of the order of 1016 m-3 during 10 kV simulation. The re-circulatory characteristics of the electrons are also studied from the velocity distribution function. The x-ray production, imaging and radiography have been investigated at different voltages and using different structure of the anode. The x-ray emitting zone have been studied via pinhole imaging technique. Lastly, the radiography of metallic as well as biological samples have been studied in the later part of this paper. This study shows the versatile nature of the IECF device in terms of its applications, both in the field of neutron and x-ray.

physics.plasm-ph↗

arXiv2020

Kinetic characteristics of ions in an inertial electrostatic confinement device

The kinetic analyses are quite important when it comes to understand the particle behavior in any device as they start to deviate from continuum nature. In the present study, kinetic simulations are performed using Particle-in-Cell (PIC) method to analyze the behavior of ions inside a cylindrical Inertial Electrostatic Confinement Fusion (IECF) device which is being developed as a tabletop neutron source. Here, the lighter ions, like deuterium are accelerated by applying an electrostatic field between the chamber wall (anode) and the cathode (cylindrical gridded wire), placed at the center of the device. The plasma potential profiles obtained from the simulated results indicate the formation of multiple potential well structures inside the cathode grid depending upon the applied cathode potential (from $-1$ to $-5~kV$). The ion density at the core region of the device is found to be of the order of $10^{16}~m^{-3}$, which closely resembles the experimental observations. Spatial variation of Ion Energy Distribution Function (IEDF) has been measured in order to observe the characteristics of ions at different cathode voltages. Finally, the simulated results are compared and found to be in good agreement with the experimental profiles. The present analysis can serve as a reference guide to optimize the technological parameters of the discharge process in IECF devices.

physics.plasm-ph↗

arXiv2016

A Novel Fault Classification Scheme Based on Least Square SVM

This paper presents a novel approach for fault classification and section identification in a series compensated transmission line based on least square support vector machine. The current signal corresponding to one-fourth of the post fault cycle is used as input to proposed modular LS-SVM classifier. The proposed scheme uses four binary classifier; three for selection of three phases and fourth for ground detection. The proposed classification scheme is found to be accurate and reliable in presence of noise as well. The simulation results validate the efficacy of proposed scheme for accurate classification of fault in a series compensated transmission line.

eess.SY↗