Physics Commons^™

Electron Transmission Through Micrometer Sized Funnelshaped Tapered Glass Capillaries And Electron Micro-Beam Production, Samanthi Jayamini Wickramarachchi

Dissertations

The prime motivation of this work is to understand the fundamental transmission process of an electron beam through a funnel-shaped capillary taking into account its shape together with the energy, angular and time dependence of the transmitted electrons produce a microsized electron beam. The utilized capillaries had inlet/outlet diameters of 800/16 μm, 800/100 μm and lengths of 35 mm. Considerable transmission of 800 and 1000 eV electrons for tilt angles up to 1.5^o and only small transmission for 500 eV electrons was observed for the capillary with the smaller outlet diameter of 16 μm. Incident electrons with energies of …

Compositional And Structural Analysis Of Nitrogen Incorporated And Ion Implanted Diamond Thin Films, Elias James Garratt

Dissertations

Significant progress in area of nano-structured thin film systems has taken place in recent decades. In particular, diamond thin film systems are being widely studied for their wear resistant, optical and electronic properties. Of the various methods researchers use to modify the structure of such films, three techniques in particular are of interest due to their versatility: modification of the growth atmosphere, growth on metalized substrates, providing an interfacial layer, and modification through post-growth ion implantation. The aim of this study is to investigate the effects each has to the structure and composition of elements. Different techniques are applied in …

Electron Transmission Characteristics And The Production Of Narrow Beams Using Glass Optics, Buddhika Senarath Dassanayake

Dissertations

Transmission of electrons through an insulating single cylindrically-shaped glass capillary of microscopic dimension has been investigated. Samples made with Borosilicate glass (PYREX 7740) were subjected to bombardment of 300-1000 eV electrons. Transmitted electrons were analyzed using a parallel-plate spectrometer coupled to a channel electron multiplier.

The transmitted electron intensity was found to decrease with increasing sample tilt angle relative to the direction of the primary beam. Two regions of transmission were found: direct where there is no interaction of the beam with the inner capillary wall, and indirect where the beam does interact with the wall. The rate of transmission …

Theoretical Study Of Localized Surface Plasmons Of Metal Nanoparticles, Clusters And Embedded Metal Nanoparticles In Matrices, Masoud Shabani Nezhad Navrood

Dissertations

Localized surface plasmons resonances (LSPRs) in metallic nanoparticles (NPs) arise from the interactions between incident light and conduction electrons and have attracted enormous research interest in recent years both for their fundamental nature as well as applications in interdisciplinary areas of sciences such as biological imaging, plasmonic photo-thermal therapy, photovoltaics, and plasmonic sensors. LSPRs are strongly localized and depend on the shape, size, the composition of the NPs, the polarization direction of the incident light, refractive index (RI) of the surrounding medium as well as on the chemical environment that surrounded NPs. Although significant research has progressed both theoretically and …