Physics Commons^™

Tunable Refractive Index Through Spatially Modified Nanoparticle Films For Long-Range Spr Biosensing Applications, Stephen Joshua Binderup

Graduate Research Theses & Dissertations

Despite optics and refraction being among the oldest scientific principles, material limitations have prevented scientists from taking full advantage of the potential this technology holds. Indeed, films with designer optical properties have potential for use in exotic cloaking architectures, advanced waveguides, and precise optical biosensors. This thesis focuses on the fabrication methodology for making thin films with refractive index tuned to a desired value through self-assembly of amorphous nanoparticle films made of organosilicate materials. The inclusion of a slowly evaporating polymer phase along with the organosilicate nanoparticles results in nanopores formed within the film, which effectively reduce the film’s refractive …

On Systematics And Their Mitigation In Magis-100 Atomic Interferometer Experiment To Explore The Dark Sector And Early Universe, Jeremiah Thomas Mitchell

Graduate Research Theses & Dissertations

Understanding the dark sector and early universe are of great importance to those in cosmology as well as physics in general. To probe these areas many large detector platforms and international experiments have come online to work in unison to test proposed models of dark matter and to provide direct detection of gravitational waves to explore what cannot be seen. Along these lines the Matter-wave Atomic Gradiometer and Interferometric Sensor (MAGIS-100) has set out to explore these fields of study using atom interferometry which provides a unique and scalable method for making sensitive measurements as well as being a test …

Development Of An Electron-Beam Halo Diagnostics, Christopher James Marshall

Graduate Research Theses & Dissertations

Electron beam halos defined as the peripheral fraction of the beam that does not contribute to the front end application. Particles located in the halo can cause damage to the particle accelerator and lower the power and quality of the beam. Being able to measure the beam halo could provide insight on the halo-formation mechanism and ultimately will improve the overall performance and quality of the beam. A halo diagnostic was designed, and a prototype built and commissioned. The diagnostics relies on detecting optical radiation by the electron beam and masking its core to enhance the detection of the halo. …

Shape Tuning Of Silicon Nano-Tip Arrays Through Reactive Ion Etching For Cold Field Emission, Giridhar Tulasi Ram Sankabathula

Graduate Research Theses & Dissertations

Large area silicon nano-tip arrays have been predominantly used as cold cathode electron sources in the wide range of field emission applications. Various fabrication methodologies have been developed over the decades to obtain sharp-pointed field emitters. In this thesis, we mainly emphasized on reproducing high aspect ratio field emitters and to study their surface topographical changes encountered through reactive ion etching. A discrete set of high-density field emitters have been fabricated over the large area surfaces through a three-step nanofabrication process. The surface curvatures of the obtained emitter tips are finely tuned with multiple oxidation cycles to achieve a tip’s …

Search For Higgs Pair Production In The Bbτ Τ Final State With The Atlas Detector At The Large Hadron Collider, Puja Saha

Graduate Research Theses & Dissertations

Abstract: This is a search for a Beyond Standard Model (BSM) heavy scalar in the ATLAS detector at 13 TeV center of mass energy using Run 2 data set recorded in 2018 with an integrated luminosity 58.5 fb^{-1}. The heavy scalar (X) decays to two Standard Model (SM) like light Higgs (H) bosons that decay into the bbtautau final state. Particularly, the semi-leptonic final state of two tau's is considered in this search where one tau decays in leptonic final state and other to a hadronic final state. No evidence of a new scalar found, so upper limits are set …

A Search For Resonant And Non-Resonant Di-Higgs Production In The Γγbb Channel Using The Atlas Detector, Tyler James Burch

Graduate Research Theses & Dissertations

This dissertation presents a search for resonant and non-resonant di-Higgs production in the γγb ̄b final state using data from the ATLAS detector at the Large Hadron Collider (LHC). The search is performed on 36.1 fb−1 of data from proton-proton collisions at a center-of-mass energy of √s= 13 TeV collected in 2015 and 2016.

No significant excesses are observed in this search. The non-resonant analysis sets limits on the HH→γγb ̄b cross-section times branching ratio, with an upper observed (expected) limit of 0.73 (0.93) pb. The observed (expected) limits on the Higgs boson trilinear coupling at 95% Confidence Level (CL) …

The Synthesis Of Pb2sr2sm1-Xcaxcu3o8 And Characterization Of Its Structural And Superconducting Properties., Deblina Das

Graduate Research Theses & Dissertations

Superconducting lead-based cuprate materials of the 2213 structural type, Pb2Sr2MCu3O8 (M=Sm1-xCax, Y1-xCax, Er1-xCax and Yb1-xCax), were synthesized and characterized using x-ray powder diffraction and the Rietveld structural refinements method. Pb2Sr2Sm1-xCaxCu3O8 single crystals were grown by an optimized flux method using various combinations of PbO/PbF2 solvents. Samples with different Sm/Ca ratios were investigated for their superconducting properties. Magnetic measurements reveal the presence of a transition at 120K. Preliminary x-ray diffuse scattering experiment at the Advanced Photon Source of Argonne National Laboratory demonstrates the high quality of one of our crystals and the presence of rod-like diffuse scattering connecting the Bragg peaks …

Nonlinear Integrable Optics Beam Dynamics Experimentand Diagnostics, Sebastian Szustkowski

Graduate Research Theses & Dissertations

All present circular particle accelerators are built around linear focusing optics. Unavoidable nonlinear elements appear in accelerators, such as magnetic aberrations and space-charge effects, which are typically corrected using nonlinear magnets. However, these added nonlinearities degrade particle beam stability, and in most cases, the system becomes non-integrable. The Integrable Optics Test Accelerator (IOTA), at Fermi National Accelerator Laboratory (Fermilab), is a test bed to study beam dynamics in integrable lattices for both electron and proton beams, independently.This work presents experimental results of the nonlinear electron beam dynamics behavior in IOTA using an elliptical nonlinear magnet. The elliptical nonlinear magnet allows …

On The Self-Force Problem Of Point-Like Charged Particles In Classical Electrodynamics, Kevin J. Hamilton

Graduate Research Theses & Dissertations

The problem of a point-like charged particle’s self-interaction force has been along-standing problem in the field of classical electrodynamics. For over a century,physicists have unsuccessfully developed a satisfactory solution until recently. Weexpand on the work done by Gralla et. al. [1] in order to establish a smooth andrelativistically correct formulation of point-like charged particles in motion and shedlight on related problems and applications, particularly the motion of elementary par-ticles with magnetic dipoles through non-uniform static magnetic fields. We conductnumerical simulations in order to quantify the magnitude of the perturbations fromthis self-force due to the new equations of motion relative to …