Browsing by Author "Dr. Muhammad Jamil"

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Alfven Instability in Charge Fluctuating Quantum Plasma
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) IQRA NAEEM; CIIT/fa17-RPH-062/LHR; Dr. Muhammad Jamil; LHR TP 5736
The interest of plasma researchers has been shifted towards quantum plasma due to its abundant occurrence in space. The physical processes of the common ion-electron plasma changes to a large scale due to highly charged dust particles. This field is fascinating for researchers due to wide range of waves and instabilities. Dusty magneto plasma with number of species like ions, electrons and dust particles which are highly charged is considered. The low frequency, long wavelength electromagnetic waves, viz., Shear Alfven waves in quantum dusty magneto plasmas, has been examined using quantum magneto hydrodynamic model. The time dependent charging effects on dust particles around its equilibrium charge are taken into account. A modiﬁed dispersion relation of the shear Alfven waves by the magnetized electrons and ions and unmagnetized dust is derived. The dispersion relation is then explained by graphical representation. The external magnetic ﬁeld and size of the dust particles have new physical effects over the propagation of such waves.
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 5802
Collective 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.
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 9429
This 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 dynamics
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 5737
In 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.
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 7259
Kelvin-Helmholtz Instability in Quantum Plasmas
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 7700
Electrostatic 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.
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 8791
In 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 representation
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 5726
The 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.
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 7686
In 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.
Study of Collective Interactions in Low Beta Dense Plasmas
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2022) Ayesha Rehman; CIIT/SP15-PPH-004/LHR; Dr. Muhammad Jamil; LHR TP 8173
The low-beta plasmas reflect the strong magnetic pressure in the comparison of thermal statistical pressure which affects the plasma characteristics and the wave propagation. The collective interactions in low beta plasmas, for the reason of its micro and nano scale applications in the latest technological era, is studied in this research thesis. The electrostatic and electromagnetic modes, their instabilities and growth rates to study new horizon of frequency spectrum is focused in this dissertation. Whenever two charged particles mutually interact, it is done through Coulomb interaction. Though the separation distance among two particles becomes greater than the mean separation distance of particles and as a result the particles immediately interact with many other charged particles in its surroundings and causes collective interactions in plasma. In dense plasmas the charged particles act as a Fermi gas, so the quantum mechanical effects due to significant associated de Broglie length become important while studying the dynamics of charge carriers. The quantum hydrodynamic (QHD) model is helpful for the study of collective interactions in dense plasmas that works well for low beta. The QHD is comparatively simple and captures many of the essential properties of plasma dynamics. This thesis contains three papers. The first paper discussion reveals novel aspects of dusty plasmas as the dust particles can coagulate and grow in size ranging from tens of nanometers to about hundreds of microns size. A semi classical Quantum Hydrodynamic Model (QHD) is employed which includes the quantum effects for plasma electrons in the terms of statistical degenerate pressure, Landau quantization, exchange-correlation potential, and tunneling potential. The low beta plasma characteristics provides the opportunity for the usage of two potential theory in order to derive a complex equation of dispersion of the shear Alfvén wave in quantum dusty magneto plasmas. Analytical simplification of dispersion equation provides the damping rate of the shear Alfvén wave which is verified graphically for a typical set of parameters. It is noticed that the damping rate depends upon the quantum properties of Landau quantization, exchange-correlation, and tunneling potential in addition to the dust radius which modifies the floating potential of the dust particles. Secondly, a system of single wall carbon nano-tubes is considered to study dispersive properties of plasma waves in the presence of uniform axial magnetic field. The impact of quantum characteristics of plasma electrons on the growth rate in the carbon nano- tubes are studied. It is noticed that wave-guide configuration of the plasma system plays a significant role in the growth rate. The graphical analysis depicts the significant role of axial magnetic field in the Landau quantization. Thirdly, an electrostatic wave in a bounded geometry is studied for e-p-i quantum plasmas. The quantum hydrodynamic model is employed to find the dispersion relation xi of waveguide mode. The complex frequency leads to the growth rate and the phase speed in the cylindrical geometry.
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 5230
In 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.
Study of Landau quantization effect over Jeans- Alfven Instability in Dense Plasmas
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) ZAHRA SHAHID; CIIT/SP17-RPH-004/LHR; Dr. Muhammad Jamil; LHR TP 5708
Quantum plasmas have gained significance due to its applications in magnetized/un- magnetized semiconductor and astrophysical plasmas. Quantum effects are usually incorporated through exchange and correlation potential, Bohm potential, Fermi degenerate pressure in the presence or absence of external magnetic field. The electromagnetic waves of low frequency are commonly known as Alfven waves. The modification in the electronic properties of materials as a function of the applied magnetic field are Landau quantization. Henceforth in this thesis studied the Landau Quantization effect over Jeans Instability in Dense Plasma. The self-gravitational or Jeans instability come to play due to the gravitational characteristics of massive species in plasmas. This thesis deals with two scales competing with each other. First, the gravitational time scale associated with massive particles called ion. Second, acoustic time scale. The source of acoustic scale is the lighter particles like electron fluid that exert acoustic pressure outward. If the two scales are comparable then the system will be at equilibrium. On other case, if the acoustic time scale is larger, then the gravitational collapse will take case and if the gravitational time scale is larger than the explosion will take place. In this work the comparative analysis of Jeans and quantum plasmas have analyzed under different conditions. In other words, the macroscopic effects evolved
Study of Nonlinear Interactions in Dense Plasmas
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2021) Zahid Mir; CIIT/FA14-PPHY-004/LHR; Dr. Muhammad Jamil; LHR TP 7539
It is intended here in this thesis to study the nonlinear interactions evolved from the interaction of linear modes in dense plasmas like astrophysical objects, laser produced plasmas and semiconductor plasmas, etc. The dense plasma systems in focus contain electrons, ions and negatively charged dust grains. The constituent modes are electrostatic and electromagnetic in nature. In addition to the coupling mechanism, an electron beam is also considered as an energy source. A multi-fluid model consisting upon momentum balancing equation, equation of continuity, Poisson’s equation and set of Maxwell equations for quantum plasmas is used to diagnose the plasmas analytically. The thesis is composed of two-fold studies of nonlinear interactions based upon the published papers. Firstly, excitation of a beat wave generated by the parametric coupling of two modes of slightly different wavelengths is discussed. The linear analysis of the dispersive nature of the incident (pump) and scattered (sideband) is carried out. A derivation of the nonlinear dispersion expression is carried out due to the linear coupling of the pump and sideband in the assembly of a homogeneous dense dusty magneto-plasmas. This leads to the growth rate of the parametric instability of three waves. Secondly, the nonlinear growth of the parametric instability of electrostatic electron Langmuir wave, produced by the coupling of two waves with slightly different frequencies in semiconductor plasma is discussed. The linearity behaviour of an electrostatic pump (upper-hybrid wave) and electromagnetic sideband (O-mode) in semiconductor quantum plasma is studied. The second order convective term couples the fields of pair modes to derive the nonlinear beat frequency of the resultant perturbation leading to three waves parametric instability in semiconductor quantum plasma system. In both the cases the quantum mechanical effects arising due to degenerate pressure of Fermi gas, quantum tunneling effect, and exchange-correlation potential have been incorporated for the fermions. The instability is analyzed graphically for both cases on varying different parameters.
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 5240
In 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 plasmas
Temperature Contributions on Large Amplitude High Frequency Oscillations in Quantum Plasmas
(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2019) MUBEEN ALI; CIIT/FA17-RPH-027/LHR; Dr. Muhammad Jamil; LHR TP 5721
The development of plasma physics theory is closely related to the investigations of various nonlinear phenomena. Most of this theory concerns rather small disturbances which can be treated by means of perturbation techniques, such as quasi-linear theory, wave-wave interactions, etc. Although much effort has been devoted to the search for exact solutions, there are, however, comparatively few results in this field. Therefore, at least for pedagogical purposes, it is still vitally important to look for new exact large amplitude solutions. Most of the previous studies concern cold plasmas. However, the present work will demonstrate that somewhat analogous non-trivial exact solutions also can be found in classical as well as in quantum system where temperature effects are taken into account. Firstly, we find solution of amplitude of oscillating wave in classical plasma and after that at certain condition when classical plasma unable to find amplitude of electron plasma oscillation than we switch towards quantum plasma.