No abstract available. / Thesis (Ph.D.)-University of Natal, 1995.

The launch of German geoscience satellite CHAMP inspired the increased interest in the study of ultra low frequency waves. In this work data from low Earth orbiting (LEO) German CHAMP satellite and South African ground-based magnetometer data were used to study geomagnetic pulsations, in particular continuous pulsations, Pc3, with periods in the range 10-45 seconds. Both Fast Fourier Transform (FFT) and Maximum Entropy Spectral Analysis (MESA) were used as analysis techniques to compute and compare spectra. We simulated a Pc3 oscillation using a sinusoidal function in order to test and establish appropriate parameters to use on the application of these analysis techniques. In this study the region chosen for a low latitude geomagnetic pulsations study excludes high current regions such as polar regions where field aligned currents occur. The structure of low-latitude pulsations was studied by comparing satellite and ground magnetic field measurements. The magnetic field measurements observed in the topside ionosphere by CHAMP were compared to Hermanus data for times when CHAMP crossed the ground station L-shell. The data were analysed for Pc3 pulsation activity using the MESA method to visualise field line resonance (FLR) in the vector magnetometer data. A number of discrete frequency oscillations for the fast mode wave were observed, one of which drives FLR at characteristic latitude as detected by both ground and satellite measurements. The toroidal mode frequency on CHAMP experiences a Doppler shift due to the rapid motion across the resonance region. Polarization hodograms in the resonance region show the expected 900 rotation of the field line resonant magnetic field components. We present first time ob- servations of toroidal standing Alfv´en mode oscillation with clearly L-dependent frequencies in the inner magnetosphere for L < 3. Our observations show FLR frequency continuously increasing as a function of decreasing latitude down to L = 1.6 and then decrease as a result of the larger plasma density of the upper ionosphere. The L-dependent frequency oscillations were observed in the presence of broadband compressional wave spectra. Our observation confirms the well-known magnetohydrodynamic (MHD) wave theoretical prediction of a compressional wave being the driver of the field line resonance, and that the Pc3 pulsations do not have a source with the same frequency structure. Keywords: ULF waves, Fast Fourier Transform, Maximum Entropy Spectral Analysis, CHAMP satellite, Geomagnetic pulsations, Pc3, Alfv´en wave, Field line resonance. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.

The behaviour of both small amplitude and arbitrary amplitude nonlinear electrostatic fluctuations are studied in electron-positron plasmas. The propagation characteristics of associated linear modes are also examined for selected plasma models. In the case of the four component, two-temperature, electron-positron plasma, three particular features are investigated. The first investigates existence conditions of the range of possible electrostatic linear waves that can propagate in a two-temperature electron-positron plasma, the study being particularly relevant to both astrophysical situations and laser induced fusion experiments. The second includes the development and investigation of the mKdV-ZK equation governing the three dimensional propagation of solitary waves in a magnetized plasma. The third application is the investigation of nonlinear electrostatic solitary waves structures, similar to those found in the broadband electrostatic noise observed in various regions of the earth’s magnetosphere. The study ends by considering relativistic effects on solitary waves in an electron-positron plasma. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2009.

An investigation of Ultra Low Frequency (ULF) pulsations was conducted using data

Thesis (MSc)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: The beam quality factor (M2) of a laser is important because it describes both the quality of a laser beam as well as its propagation. Particular applications require that the beam radii (from which the M2 factor is determined) be defined in a specific way. The International Standards Organisation (ISO) recently standardised the theoretically correct, but practically difficult second moment definition of the beam radius. This thesis aims to establish correlations between the second moment definition and other more practical definitions. Chapter 2 presents a systematic introduction of moment theory for general beams. Beam centre and radius definitions as well as beam classification are derived by means of second and mixed moments. In Chapter 3 simple laser beams are modelled by means of a resonator approach. The infinite number of solutions of this model is called Gaussian solutions, which are found to be different for rectangular and cylindrical symmetric resonators. The zero order solution for both symmetries is identified as the ideal solution to which all others can be compared to for quality determinations. Chapter 4 presents different beam scanning devices, beam radius definitions and correlations between these definitions. The theoretical basis for a new correlation theory is also given. Chapter 5 describes programs and computations used to verify existing correlation methods and to calculate correlation factors for a newly proposed theory. Chapter 6 presents the results of the computations for both circular and rectangular symmetric beams. The ISO’s correlation theories are tested first. Newly proposed correlation functions between the second moment and alternative definitions as well as theoretical error graphs are given for various beams. A novel method to correlate several important beam subclasses is also presented. Chapter 7 describes the experimental setup, automation software and post processing techniques that were used to characterise a modified CO2 TEA laser. It is further shown how the theory developed in previous chapters could be applied to the experimental data. Chapter 8 presents the experimental results of the beam characterisation measurements performed on two different beams that emanated from the CO2 TEA laser. Existing and newly developed correlation theories are applied to the experimental data and the corresponding results are compared. In Chapter 9, conclusions and suggestions with respect to the initial aims identified in the first chapter are made. Several suggestions for future work are also made. / AFRIKAANSE OPSOMMING: Die bundel kwalitietsfaktor (M2) is baie belangrik omdat dit beide die kwaliteit en voortplanting van ‘n laser bundel beskryf. Bundel radiusse (waarvan die M2 faktor bepaal word) word verskillend gedefinieer vir spesifike toepassings. Die teoreties korrekte, maar minder praktiese tweede moment definisie is onlangs deur die Internasionale Standaard Organisasie (ISO) gestandariseer. Hierdie tesis se hoofdoel is om die tweede moment definisie en ander meer praktiese definisies te korreleer. Hoofstuk 2 stel die moment teorie van bundels sistematies bekend. Dit word gewys hoe die senter en radius van ‘n bundel deur tweede en gemengde momente gedefinieer kan word. In Hoofstuk 3 word laser bundels gemodeleer deur middel van resonator aanslag. Die oneindige aantal oplossings wat verkry word heet Gaussiese oplossings en is verskillend vir reghoekige en silindriese simmetriese resonators. Dit word gewys dat die ideale bundel, waarmee alle ander bundels vergelyk word, die zero orde oplossing van beide simmetrieë is. Hoofstuk 4 stel verskillende bundel skanderings apparaat, bundel radius definisies en korrelasies tussen die definisies bekend. Die teoretiese basis vir ‘n nuwe korrelasie teorie word ook gegee. Hoofstuk 5 beskryf die rekenaarprogramme en berekeninge wat gebruik word om huidige korrelasie teorie mee te toets asook om nuwes mee te skep. Hooftuk 6 gee die resultate van die berekeninge van die rekenaarprogramme vir beide reghoekig en silindriese simmetrie. Die ISO se korrelasies word eerste getoets voordat nuwe teorieë bekend gestel word. In Hoofstuk 7 word die eksperimentele opstelling, outomisasie sagteware en postprosessering tegnieke gewys wat gebruik was om ‘n aangepaste CO2 TEA laser te karakteriseer. Verder word dit gewys hoe die teorie wat in voorafgaande hoofstukke ontwikkel is op eksperimentele data toegepas kan word. Hoofstuk 8 gee die eksperimentele resultate van die bundel karakterisering van twee verskillende bundels vanaf die CO2 TEA laser. Bestaande en nuwe korrelasie metodes word gebruik om die bundels te korreleer en die resultate van elke metode word dan met mekaar vergelyk. In Hoostuk 9 word afleidings gemaak. Daar word ook voorstelle gemaak vir potensiële toekomstige werk.

Dissertation (PhD)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The formation of Ni-, Co- and Fe-silicides through different diffusion barrier interlayers was investigated. The diffusion barrier layers examined were Ta, Ti and Cr. In some cases the thickness of the barrier layer and the influence of a capping layer was also investigated. The thin-film structures were prepared on single crystal Si-substrates by Electron Beam Vacuum Deposition. The samples were vacuum annealed for times ranging from 10 to 60 min at temperatures ranging from 340 - 800°C and sample characterization was carried out by conventional RBS, dynamic RBS, channeling RBS and X-ray diffraction (XRD). The use of a thin (20Å) Ta diffusion barrier in the Ni-Si system allowed no reaction even after annealing for 10 min at 400°C, but RBS measurements showed that after annealing for 15 min at 400°C uniform NiSi formed suddenly as first phase. XRD as well as dynamic RBS measurements confirmed this abrupt formation of NiSi instead of the normal first phase Ni2Si. According to the Effective Heat of Formation (EHF) model this shows that the diffusion barrier reduces the effective concentration of the Ni atoms to a value where the effective heat of formation of NiSi is more negative than that of Ni2Si and first phase formation of NiSi is thus thermodynamically favoured. The thickness uniformity of the first phase NiSi that formed through the thin Ta barrier improved at higher annealing temperatures. A thicker (100Å) Ta barrier also retarded the Ni diffusion and first phase, non-uniform NiSi only started to form at 500°C. The uniformity of this NiSi also improved with increased temperature but the use of the 20Å Ta barrier produced more uniform first phase NiSi in the 400 to 700°C temperature range. The use of a thin (30-50Å) Cr barrier also allowed the formation of mainly NiSi at 400°C, although XRD spectra indicated the presence of some Ni2Si. The uniformity of NiSi improved at higher temperature anneals. Similar results were obtained from samples with a thicker (100Å) Cr barrier layer at lower temperatures, i.e. the formation of NiSi as first phase at 400°C, but the first phase NiSi that formed at 500 to 700°C was non-uniform. In the case of Ti-barriers, the thicker (100Å) Ti barrier seems less effective than the thinner Ti barriers in delivering uniform first phase NiSi in the 500 to 700°C temperature range. The use of a thin (30-50Å) Ti barrier produced a mixture of Ni2Si and NiSi as first reaction at 400°C, but a 10 min anneal at 500°C formed uniform NiSi as confirmed by RBS and XRD measurements. The uniformity of the NiSi improved with an increase in annealing temperature up to 700°C. In the case of the thicker Ti interlayer no reaction occured at 400°C and non-uniform first phase NiSi formed at 500°C. All three thin barriers formed NiSi2 at temperatures of 750°C and above, but the thin Ti barrier formed the most uniform di-silicide. The NiSi2 that formed at 800°C through all three of the thicker barriers was non-uniform. The use of a thin (10-30Å) Ta diffusion barrier prevented Co-silicide formation up to 560°C. The effective Co concentration at the growth interface is lowered, thus skipping the usual first phase formation of Co2Si at 450°C. At 560°C a mixture of CoSi and CoSi2 formed, as was confirmed by XRD. The CoSi2 that formed at 640°C (a higher formation temperature than without barrier) was of quite uniform thickness, but XRD measurements indicated that some CoSi was present as well. The use of thicker (100Å) Ta barrier layers retarded the diffusion of Co atoms for temperatures of up to 600°C. Annealing at 700°C formed CoSi2 and some CoSi and at 800°C non-uniform CoSi2 formed. The addition of a Ta capping layer (of different thicknesses) in conjunction with a 30Å Ta diffusion barrier layer did not significantly improve Co-silicide formation. The use of thin (10-30Å) Ti barrier layers resulted in the skipping of the Co2Si precursor phase and the formation of quite uniform first phase CoSi at 520°C. Uniform CoSi2 started forming at 560°C and the CoSi2 remained uniform at higher temperatures. The presence of a thicker (100Å) Ti barrier lowered the effective concentration of Co at the growth interface to such an extent that CoSi2 started to form as first phase after annealing for 30 min at 600°C. At 700 and 800°C non-uniform CoSi2 formed. For Fe-silicide formation the use of 50Å and 100Å Cr barriers, as well as CrSi2 barriers, delivered very similar results. There was no change in the normal Fe-silicide phase formation sequence, as non-uniform FeSi was the first phase to form at 500°C and thereafter FeSi2 started to form at 600°C. At 700°C the use of Cr barriers resulted in the complete formation of FeSi2 of greater uniformity than was formed in the Si-Fe binary system without the presence of a diffusion barrier. In this study dynamic real-time RBS has been used for the first time to prove without any doubt that diffusion barrier layers can be used to bring about “phase skipping”. These results have been interpreted in terms of the Effective Heat of Formation (EHF) model and are good examples of concentration controlled phase selection (CCPS). In general it was found that the thicker the diffusion barrier layer, the higher the temperature of silicide formation. Furthermore, silicide formation was generally found to be more uniform at higher annealing temperatures and when thinner diffusion barrier layers were used. / AFRIKAANSE OPSOMMING: Die vorming van Ni-, Co- en Fe-silisiedes deur verskillende diffusie sper-tussenlagies is ondersoek. Die diffusie sperlagies onder beskouing was Ta, Ti en Cr. In sommige gevalle is die invloed van die dikte van die sperlagie en van ‘n deklagie ook ondersoek. Die dun-film strukture is voorberei op enkelkristal Si-substrate d.m.v. Elektronbundel Vakuum Deposisie. Die monsters is in vakuum uitgegloei vir tye wat wissel van 10 tot 60 minute by temperature wat wissel van 340 - 800°C en die karakterisering van die monsters is uitgevoer d.m.v. konvensionele RBS, dinamiese RBS, kanaliserings RBS en X-straal diffraksie (XRD). Die gebruik van a dun (20Å) Ta sperlagie in die Ni-Si sisteem het reaksie verhoed selfs na ‘n uitgloei van 10 min. by 400°C, maar RBS resultate het getoon dat uniforme NiSi skielik gevorm het as eerste fase na ‘n 15 min. uitgloei by 400°C. XRD sowel as dinamiese RBS metings het hierdie abrupte formasie van NiSi in plaas van die normale eerste fase Ni2Si bevestig. Volgens die Effektiewe Hitte van Formasie (EHF) model toon dit dat die diffusie sperlagie die effektiewe konsentrasie van die Ni-atome verlaag tot ‘n waarde waar die effektiewe hitte van formasie van NiSi meer negatief is as dié van Ni2Si en sodoende word die eerste fase formasie van NiSi termodinamies bevoordeel. Die dikte uniformiteit van die eerste fase NiSi wat deur die dun Ta sperlaag gevorm het, het verbeter met uitgloei by hoër temperature. ‘n Dikker (100Å) Ta sperlaag het ook Ni diffusie vertraag en nie-uniforme, eerste fase NiSi het eers by 500°C begin vorm. Die uniformiteit van hierde NiSi het ook verbeter met toename in temperatuur, maar die gebruik van die 20Å Ta sperlagie het meer uniforme eerste fase NiSi produseer in die 400 tot 700°C temperatuur gebied. Die gebruik van ‘n dun Cr (30-50Å) sperlagie het ook by 400°C die vorming van hoofsaaklik NiSi opgelewer, maar XRD spektra het Ni2Si ook aangedui. Die uniformiteit van NiSi het verbeter by hoër temparatuur uitgloeiings. Soortgelyke resultate is verkry van monsters met ‘n dikker (100Å) Cr sperlaag by laer temperature, d.w.s die vorming van NiSi as eerste fase by 400°C, maar die eerste fase NiSi wat by 500 tot 700°C gevorm het, was nie-uniform. In die geval van Ti-sperlagies was die dikker (100Å) Ti minder effektief as die dunner Ti sperlagies vir die verkryging van uniforme eerste fase NiSi in die 500 tot 700°C temperatuur gebied. Die gebruik van ‘n dun (30-50Å) Ti sperlagie het ‘n mengsel van Ni2Si en NiSi as eerste reaksie gevorm by 400°C, maar ‘n 10 min. uitgloei by 500°C het uniforme NiSi gevorm, soos bevestig is deur RBS en XRD metings. Die uniformiteit van die NiSi het verbeter met toename in uitgloei-temperatuur tot by 700°C. In die geval van die dikker Ti sperlagie het geen reaksie by 400°C plaasgevind nie en nie-uniforme eerste fase NiSi het by 500°C gevorm. Al drie dun sperlagies het NiSi2 gevorm by temperature van 750°C en hoër, maar die dun Ti sperlaag het die mees uniforme di-silisied gevorm. Die NiSi2 wat deur al drie die dikker sperlae by 800°C gevorm het, was nie-uniform. Die gebruik van ‘n dun (10-30Å) Ta diffusie sperlagie het Co-silisied formasie voorkom tot by 560°C. Die effektiewe Co-konsentrasie by die groei-intervlak is verlaag, derhalwe word die gewone eerste fase formasie van Co2Si by 450°C oorgeslaan. By 560°C het ‘n mengsel van CoSi en CoSi2 gevorm, soos bevestig deur XRD. Die CoSi2 wat by 640°C gevorm het (‘n hoër formasie temperatuur as sonder ‘n sperlagie) se dikte was redelik uniform, maar XRD metings het getoon dat daar ook CoSi teenwoordig was. Die gebruik van dikker (100Å) Ta sperlae het die diffusie van Co-atome vertraag tot by temperature so hoog as 600°C. Uitgloei by 700°C het CoSi2 sowel as CoSi gevorm en by 800°C het nie-uniforme CoSi2 gevorm. Die toevoeging van ‘n Ta deklagie (van verskillende diktes) in samehang met ‘n 30Å Ta diffusie sperlagie het nie Co-silisied formasie wesentlik beïnvloed nie. Die gebruik van dun (10-30Å) Ti sperlagies het gelei tot die oorslaan van die Co2Si voorloper fase en die vorming van redelik uniforme eerste fase CoSi by 520°C. Uniforme CoSi2 het by 560°C begin vorm en by hoër temperature was die CoSi2 steeds uniform. Die teenwoordigheid van ‘n dikker (100Å) Ti sperlagie het die effektiewe konsentrasie van Co by die groei-intervlak so verlaag dat CoSi2 as eerste fase begin vorm het na ‘n 30 min. uitgloei by 600°C. By 700 en 800°C het nie-uniforme CoSi2 gevorm. Vir Fe-silisied formasie het die gebruik van 50Å en 100Å Cr sperlae, sowel as CrSi2 sperlae, soortgelyke resultate opgelewer. Daar was geen verandering in die gewone Fe-silisied fase formasie volgorde nie, want nie-uniforme FeSi was die eerste fase wat by 500°C gevorm het en daarna het FeSi2 begin vorm by 600°C. Uitgloei by 700°C deur Cr sperlagies het gelei tot die volledige formasie van FeSi2 wat meer uniform was as dié wat in die Fe-Si binêre sisteem gevorm het sonder ‘n diffusie sperlagie. In hierdie studie is dinamiese intydse RBS vir die eerste keer gebruik om bo enige twyfel te bewys dat diffusie sperlae gebruik kan word om die “oorslaan” van fases te bewerkstellig. Hierdie resultate is interpreteer in terme van die Effektiewe Hitte van Formasie (EHF) model en is goeie voorbeelde van konsentrasie-gekontroleerde fase seleksie. In die algemeen is bevind dat hoe dikker die diffusie sperlagie, hoe hoër die temperatuur van silisied-formasie. Bowendien was silisied-formasie oor die algemeen meer uniform by hoër uitgloei-temperature en met die gebruik van dunner diffusie sperlagies.

Quantum Key Distribution (QKD) is a symmetric key sharing protocol. The theoretical process exploits the principles of quantum physics to underpin a physical security against any form of eavesdropping. QKD not only ensures an information theoretically secure key exchange but also provides an active real-time means of intrusion detection at a physical level. QKD is therefore considered the encryption technology for the next generation of nano-technology powered ICT solutions. The fundamental science at the basis of QKD has been researched and developed into workable solutions with the current focus on the engineering of quantum technology enabled products. The feasibility of integrating QKD systems into conventional communication solutions remains an active field of research. The implementation of QKD across a conventional communication network requires high levels of resources in terms of the network’s reliability, transparency, delay and bandwidth. This limits the maintainable Quality of Service of the network. Investigations towards overcoming these constraints will promote the uptake of QKD as a mainstream technology. There are two classes of technology that focus on the integration of QKD into conventional architecture. The first, and most immediate, development is the adaptation of conventional systems to handle the additional requirements of quantum technology enabled products. In the case of communication networks, all-optical solutions provide the ideal platform for this expansion. This ensures that the quantum data carriers remain in the quantum regime and are manipulated by only the authenticated end users or trusted nodes. The second, quantum technology enabled products, render techniques to manipulate quantum information in an untrusted environment within the network. This involves the development of quantum memories, repeaters and data collision control. The combination of both these classes as a hybrid solution will ensure an optimal Quality of Service for quantum communication networks. The long-term reasearch into quantum networking solutions is presented as the QuantumCity project. The project investigated the long-term stability of a quantum communication network within a live environment. The network is implemented through the adaptation of conventional switched networks. It has provided positive results with various future opportunities available to expand this initiative. The successful operation of the overall solution is of course dependent of the efficiency of the QKD systems themselves. While the European Telecommunication Standards Institute (ETSI) currently drives the standardisation (ETSI ISG-QKD) of QKD, there is a need for the development of supporting technologies. This thesis aims to understand the current gaps in QKD systems and touch on various technologies that will be essential towards the development of a hybrid QKD solution. This will allow the integration of various established QKD technologies in order to optimally utilise conventional communications networks. The technologies focused on include true random number generators, polarisation-encoded QKD in fibre systems and polarisation tracking in free space units. A study and implementation of each technology is presented in this thesis. / Thesis (Ph.D)-University of KwaZulu-Natal, Durban, 2012.

Optical trapping and tweezing has been around for the last 30 years and since found its place in the fields of physics and biology. Over the years this technique has advanced exceedingly and is a unique tool to carry out research in the micrometre and nanometre scale regime. The aim of this dissertation was to illustrate that an optical trapping and tweezing system is an effective tool for the manipulation of micron sized particles and that using such a system allows one the ability to accurately and precisely measure optical forces in the piconewton scale. A custom built single gradient optical trapping system was built to illustrate the manipulation of micron sized particles. Here we will highlight some of the key components of such a system and give an explanation of how these components affect the optical trap. To enhance this system, we exploit the ability to shape light and in particular laser light to generate novel laser beams. This was achieved using a diffractive optical element known as a spatial light modulator (SLM). A spatial light modulator is an electronically addressed optical element which when incorporated into an optical system effectively manipulates the phase of light in order to generate various novel laser beams. In particular these novel laser beams include Laguerre-Gaussian, Bessel and recently proposed Bessel-like beams. Each of these beams contains interesting properties which can be beneficially exploited. Laguerre-Gaussian beams are particularly known as ‘donut’ shaped beams since they have a central dark hole. Increasing the order of these Laguerre-Gaussian beams leads to an increase in the central dark region. These beams are of particular interest since they carry orbital angular momentum. This is not easily observed; however, when incorporated into the optical trapping system, leads to the rotation of trapped particles due to the transfer of photons carrying orbital angular momentum. Bessel and Bessel-like beams on the other hand are classes of beam that possess interesting non-diffracting and self-reconstructive properties upon encountering an obstacle. Here the generation and properties of these novel laser beams will be discussed in detail. Furthermore it is well known that these novel laser beams prove highly useful when incorporated into an optical trapping system hence we will illustrate the effects on a trapped particle when incorporating a Laguerre-Gaussian beam carrying a topological charge of one. It is expected that the trapped particle should rotate due to the transfer of orbital angular momentum. The knowledge gained from beam shaping and the means to trap micron sized particles optically allows one the ability to incorporate this technique in a number of fields, including the promising field of microfluidics. This is an emerging field that deals with investigating fluid properties at the nano and microlitre regime. Optical tweezers integrated into a microfluidic device are beneficial since they are an adequate tool for measuring fluid flow using Stokes’ Law. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2011.

Simulation of quantum dynamics for many-body systems is an open area of research. For interacting many-body quantum systems, the computer memory necessary to perform calculations has an astronomical value, so that approximated models are needed to reduce the required computational resources. A useful approximation that can often be made is that of quantum-classical dynamics, where the majority of the degrees are treated classically, while a few of them must be treated quantum mechanically. When energy is exchanged very quickly between the quantum subsystem and classical environment, the dynamics is nonadiabatic. Most theories for nonadiabatic dynamics are unsatisfactory, as they fail to properly describe the quantum backreaction of the subsystem on the environment. However, an approach based on the quantum-classical Liouville equation solves this problem. Even so, nonadiabatic dynamics is di cult to implement on a computer, and longer simulation times are often inaccessible due to statistical error. There is thus a need for improved algorithms for nonadiabatic dynamics. In this thesis, two algorithms that utilise the quantum-classical Liouville equation will be qualitatively and quantitatively compared. In addition, stochastic sampling schemes for nonadiabatic transitions will be studied, and a new sampling scheme is introduced [D. A. Uken et al., Phys. Rev. E. 88, 033301 (2013)] which proves to have a dramatic advantage over existing techniques, allowing far longer simulation times to be calculated reliably. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

The kinetic dispersion relation for a magnetized dusty plasma comprising of ions, electrons and massive, charged dust particles is solved for low frequency electrostatic instabilities in the dust plasma frequency regime. The free energy is provided by the drifting ion beam. The effect of varying parameters such as ion drift speed, particle densities, ion temperature and magnetic field strength on the real frequency and growth rate is examined. Initially light and heavy dust species of different charge are separately considered. This procedure is then repeated for a four-component plasma in an attempt to study the effect of the presence of both the dust species on low frequency electrostatic phenomena. Using a different plasma model, instabilities generated by an equal E x B drift of both the magnetized ions and electrons relative to the unmagnetized dust grains of both the heavy and light dust species is also investigated. The latter instabilities are applicable to the planetary ring plasmas of Saturn. Throughout our studies, numerical solutions of the full dispersion relation for the real frequency and growth rate are compared with approximate analytical solutions. / Thesis (M.Sc.)-University of Durban-Westville, 1999.