M.Phil / MS
Permanent URI for this collectionhttps://repository.cuilahore.edu.pk/handle/123456789/60
This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.
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Item Study of Streaming Dust Acoustic Instability in Quantum Plasma(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2018) Asif Zahoor; FA16-RPH-031; Dr. Muhammad Jamil; LHR TP 5240In this thesis a study related to Streaming Dust Acoustic Instability in Quantum Plasma is done. In this investigation starting from equation of motion containing Fermi Pressure, Bohm Potential and Exchange Correlation term we use quantum hydrodynamic (QHD) model to derive a general expression for dielectric constant which led to the final dispersion relation. A graphical discussion is also made by considering real part which shows the phase speed of DAWs whereas the imaginary part give the growth rate. The graphical results are obtained by varying the mass of dust particles, number density of electrons and by taking different streaming speed. This research is expecting a great scope in astrophysical quantum plasmasItem Study of Dust Acoustic Waves with Dust Charge Fluctuation in Quantum Plasm(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2018) Rubina; FA16-RPH-016; Dr. Muhammad Jamil; LHR TP 5230In this dissertation, the time-dependent charge fluctuation of dust particles have been studied in quantum dusty plasmas. The dust acoustic wave has been taken as the perturbation of the plasma system. The quantum fluid model consisting upon momentum balance equation, continuity equation and gravitational Poisson’s equation has been employed to solve for the dispersion relation. The instability of the wave in the form of damping is observed. It is noticed that the dust acoustic wave went to damp for the whole spectrum of k on varying ion-thermal temperature, electron number density and dust radii.Item Electromagnetic Polarization in Ionized Quantum Plasmas(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2024) Muhammad Bilal Rafiq; CIIT/FA22-RPH-011/LHR; Dr. Muhammad Jamil; LHR TP 9429This study investigates the influence of ionization dynamics on polarized electromag netic modes in quantum plasmas, an area crucial for various applications from astro physics to nanotechnology. By employing a Quantum Hydrodynamic Model (QHD) and numerical simulations with Mathematica, we aim to understand how ionization affects the polarization characteristics of electromagnetic waves. Despite its signifi cance, there’s a lack of comprehensive research on this topic. The QHD model, inte grating quantum effects like Bohm potential and Fermi pressure, provides a mathemat ical framework to analyze the behavior of these modes at the quantum scale. Through analytical and numerical approaches, we aim to interpret the interplaybetween plasma ionization and polarization, shedding light on fundamental aspects of quantum plasma dynamicsItem Magneto Acoustic Analysis in Ion-Implanted Quantum Semiconductor Plasmas(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2023) Syad Ali Raza; CIIT/SP22-RPH-034/LHR; Dr. Muhammad Jamil; LHR TP 8791In semiconductor quantum plasmas, the instability behavior of magneto-acoustic waves is investigated. We derive the dispersion relation for magneto-acoustic wave behavior ion implantation quantum plasmas semiconductors using Maxwell’s equations and the quantum hydrodynamic model. In an external magnetic field, spin-based exchange correlation effects, Bohm tunneling potential, Fermi statistical pressure, and Landau Quantization. The process of ion-implantation modifies the structure and characteris tics of quantum semiconductors, which are advantageous for the creation of integrated circuits (ICs), metallic nanoparticles, nanoclusters (NCs), digital and storage chips, and their possible uses in a range of technological domains. The semiconductor medium is developed in this work as a plasma system. Numerous factors have a major impact on the growth rate and damping. Due to its many applications, the quantum aspects of plasma physics opened up a new field of study. For example, collision frequency, implantation density, tunneling effect, and external magnetic field. The effects of these parameters have been depicted in graphical representationItem Lower Hybrid Instability with Radiation Pressure Effects in Semiconductor Plasma(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Waseem Abbas; CIIT/SP20-RPH-054/LHR; Dr. Muhammad Jamil; LHR TP 7700Electrostatic modes can widely be categorized as acoustic and hybrid waves. We have studied the excitation of electrostatic, comparatively low frequency volume waves, lower-hybrid waves (LHWs) in semiconductor plasma by using a hydrodynamic model. The Hydrodynamic Model consisting upon fluid equations namely momentum balance equation, equation of continuity and the Poisson’s equation have used to study the physical properties and characteristics of semiconductor plasmas consisting upon electron and holes. Radiation pressure is considered as an exciting source in semiconductor plasma systems. For analytical examination of the linear dispersion relation, we elucidated the fluid equations for semiconductor plasmas. In this thesis, for semiconductor plasmas, we have analyzed the LHWs in the presence of radiation pressure, the thermal effects upon plasma species, in addition to the external magnetic field. For numerical analysis, we have used the assistance of Mathematica or MATLAB.Item Kelvin Helmholtz Instability in Quantum Plasmas(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Muhammad Asif Nazir; FA19-RPH-001; Dr. Muhammad Jamil; LHR TP 7259Kelvin-Helmholtz Instability in Quantum PlasmasItem Oxygen Cyclotron Harmonic Waves in the Inner Magnetosphere(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) Abdul Waheed; CIIT/FA17-RPH-037/LHR; Dr. Muhammad Jamil; LHR TP 5726The Banded emission of Oxygen cyclotron harmonic waves has been observed by Van Allen probes in the Earth inner magnetosphere. The general dispersion relation for electrostatic Oxygen cyclotron harmonic waves is derived by using Lerche-Newberger sum rule for Maxwellian and Kappa distributions. Oxygen ion kappa spectral index (𝜅𝑖𝑂) has a significant impact on the Oxygen cyclotron harmonic waves. The quasi Maxwellian behavior is being observed as 𝜅𝑖𝑂 ≥ 5. The curves shift toward the higher value of wavenumber, as the value of 𝜅𝑖𝑂 reduce. There is an increase in super-thermal particles as we reduce the value of 𝜅𝑖𝑂. By decreasing the value of 𝜅𝑖𝑂, the super-thermal particles reduce the frequency , 𝜔𝑝𝑒𝑎𝑘, where the group velocity vanish and the associated 𝑘𝑝𝑒𝑎𝑘 get increase. These cyclotron harmonic waves may be useful for the diagnostic for the velocity distribution characteristics. Oxygen cyclotron harmonic waves can be helpful for the diagnostic of Van Allen Radiation Belts.Item Radiation impact on acoustic waves in Semiconductor Plasmas(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Aashar Sajjad; SP20-RPH-016; Dr. Muhammad Jamil; LHR TP 7686In this thesis, we are discussing the radiation impact on acoustic wave that propagates along z-direction. The acoustic waves due to radiation impact are investigated using the classical multi-fluid approach in classical semiconductor plasma. The quantum effects are not considered in this work. Our model is applied to GaAs semiconductor plasmas. Dispersion relation of acoustic waves is calculated where the effects of the radiation modifies it. Numerically it is observed under different physical conditions, for example, on varying the thermal temperature values and plasma number density etc. For this study we are using multi fluid model. A set of fluid equations are applied to drive the dispersion relation. The said work is done qualitatively and quantitatively using MATHEMATICA.Item Electromagnetic Wave Instability with Dynamic Charge Fluctuation in Semiconductor(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) UZMA MAQSOOD; CIIT/FA17-RPH-063/LHR; Dr. Muhammad Jamil; LHR TP 5737In nature, the gravitational tragedy has been observed. Electromagnetic perturbations are the only reason of these gravitational tragedies. In quantum plasmas, these types of perturbations (electromagnetic) are propagated by cause of magnetic densities along with the manifestation of magnetic field. This study will cover the analytical and numerical features of electromagnetic waves in semiconductor quantum plasmas in the presence of external magnetic field including the quantum effects. The discussion will be based on the quantum effects like Fermi statistical pressure, Bohm tunneling potential and spin-based exchange correlation effects. The dust charging will be dynamical with respect to the time. The plasmas are omnipresent in space, inter- stellar and the dense astrophysical environment as well as in the metals and the semiconductors. The presence of charge species in plasmas ensures the plasma system to host variety of waves and the instability features. This work evolves around the semiconductor medium as a plasma system. In the semiconductor systems, the dust is produced in fabrication. The dust is charged either positive or negative. The dust charging is source of new features evolved at micro and nano scales. This study will cover the analysis of electromagnetic waves in semiconductor electron-hole plasmas in the presence of charge variation. The quantum effects will be included on taking different terms used in plasma which explain the quantum effect in equation of motion like Bohm criterion, exchange correlation and fermi pressure. The quantum features of plasma physics explored up a new area of research due to its wide range of application.Item Collective Interactions In Dense Plasma's(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2018) Areeb Fatima; CIIT/FA13-PPHY-001/LHR; Dr. Muhammad Jamil; LHR TP 5802Collective interactions in dense plasmas arise from strong coupling between charged particles, where long-range electromagnetic forces dominate individual particle behavior. These interactions lead to collective phenomena such as plasma oscillations, screening effects, wave propagation, instabilities, and transport processes that differ significantly from those in weakly coupled plasmas. In dense plasma environments—such as inertial confinement fusion, astrophysical objects, and solid-density laser–matter interactions—quantum effects and correlation among particles further influence collective dynamics. Understanding these interactions is essential for accurately describing plasma behavior under extreme conditions and for advancing applications in fusion energy, high-energy-density physics, and astrophysics.