Physics Commons^™

Laser-Induced Breakdown Spectroscopy For Analysis Of High Density Methane-Oxygen Mixtures, Matthew Dackman

Masters Theses

The applicability of laser-induced breakdown spectroscopy (LIBS) toward greater than atmospheric density combustion diagnostics is examined. Specifically, this involves ascertaining the feasibility of measuring chemical equivalence ratios directly from atomic emission spectra at high density. The need for such measurement arises from the desire to quantify real time, localized combustion performance in weakly mixed flows. Insufficiently mixed flows generally result in unwanted byproducts, possess the propensity for overall combustion instability, and are increasingly likely to experience localized flame extinction.

We simulate methane/oxygen combustion in ambient pressures ranging 1 to 4 atmospheres, demonstrating these results to be analogous to what would …

Optical Spectroscopy Of Xenon-Related Defects In Diamond, Yury Dziashko

Dissertations, Theses, and Capstone Projects

The work presents the results of optical studies of Xe-related defect in diamond. This defect is one of a few having narrow zero-phonon line in the near-infrared part of the photo-luminescence spectra. It appears in diamond after Xe+ ion implantation followed by thermal annealing. Given unique physical properties of diamond (hardness, optical transparency in wide spectral range, chemical inertness, high thermal conductivity, low thermal expansion coefficient) and stability of Xe-related center it can be viewed as an potential candidate for the source of single-photons, or as optically manipulated qubit, not unlike nitrogen-vacancy center. However, compared to the latter Xe-related center …

Optimization Of Plasmon Decay Through Scattering And Hot Electron Transfer, Drew Dejarnette

Graduate Theses and Dissertations

Light incident on metal nanoparticles induce localized surface oscillations of conductive electrons, called plasmons, which is a means to control and manipulate light. Excited plasmons decay as either thermal energy as absorbed phonons or electromagnetic energy as scattered photons. An additional decay pathway for plasmons can exist for gold nanoparticles situated on graphene. Excited plasmons can decay directly to the graphene as through hot electron transfer. This dissertation begins by computational analysis of plasmon resonance energy and bandwidth as a function of particle size, shape, and dielectric environment in addition to diffractive coupled in lattices creating a Fano resonance. With …

Analysis Of Atmospheric Aerosols Collected In An Urban Area In Upstate Ny Using Proton Induced X-Ray Emission (Pixe) Spectroscopy, Jeremy Smith

Honors Theses

We have performed a PIXE analysis of atmospheric aerosol samples collected in Schenectady, NY, to study airborne pollution in an urban environment. The samples were collected using a PIXE International, 9-stage, cascade impactor that separates the airborne particles according to aerodynamic diameter and deposits them on thin Kapton foils. The impacted foils were bombarded with 2.2-MeV proton beams from the Union College 1.1-MV Pelletron accelerator and the emitted X-rays were detected with an Amptek silicon drift detector. The X-ray energy spectra were analyzed using GUPIX software to determine the elemental concentrations in the samples. A broad range of elements from …

A Comparative Study Of Gupix And Geopixe Software In The Analysis Of Pixe Spectra Of Aerosol Samples, Sean Collison

Honors Theses

Proton-induced X-ray emission (PIXE) spectroscopy is a powerful tool used in the Union College Ion-Beam Analysis Laboratory for the elemental analysis of environmental pollution. Samples are bombarded with proton beams from the 1.1‐MV Pelletron accelerator and characteristic X-rays emitted from the samples are detected, resulting in X-ray energy spectra. These spectra are analyzed using software packages that fit the data and calculate the concentrations of elements in the samples. I have performed a comparative study of two of the most popular software packages, GUPIX and GeoPIXE, in the analysis of atmospheric aerosol samples to assess the strengths and weaknesses of …