Physics Commons^™

Analysis, Prototyping, And Design Of An Ionization Profile Monitor For The Spallation Neutron Source Accumulator Ring, Dirk A. Bartkoski

Doctoral Dissertations

The Spallation Neutron Source (SNS) located in the Oak Ridge National Laboratory is comprised of a 1 GeV linear H^- [H^-] accelerator followed by an accumulator ring that delivers high intensity 1 μs [microsecond] long pulses of 1.5x10¹⁴ [1.5x10^14] protons to a liquid mercury target for neutron production by spallation reaction. With its strict 0.01% total beam loss condition, planned power upgrade, and proposed second target station, SNS ring beam-profile diagnostics capable of monitoring evolving beam conditions during high-power conditions are crucial for efficient operation and improvement. By subjecting ionized electrons created during beam interactions with the residual …

Measurement Of The Prompt Double J/Psi Production Cross Section In Pp Collisions At Sqrt(S) = 7 Tev, Andrew David York

Doctoral Dissertations

The simultaneous production of two J/psi mesons has been significantly observed in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector. The two J/psi mesons are fully reconstructed in their decay to muons. The signal yield is extracted with an extended maximum likelihood fit based on four event variables. A method was developed to correct for detector acceptances and efficiencies based on the measured momenta of the J/psi and their decay muons to maintain the least model dependence possible.

The measurement is performed in an acceptance region defined by the individual J/psi transverse momentum and rapidity. …

Identifying Productive Resources In Secondary School Students' Discourse About Energy, Benedikt Walter Harrer

Electronic Theses and Dissertations

A growing program of research in science education acknowledges the beginnings of disciplinary reasoning in students’ ideas and seeks to inform instruction that responds productively to these disciplinary progenitors in the moment to foster their development into sophisticated scientific practice. This dissertation examines secondary school students’ ideas about energy for progenitors of disciplinary knowledge and practice. Previously, researchers argued that students’ ideas about energy were constrained by stable and coherent conceptual structures that conflicted with an assumed unified scientific conception and therefore needed to be replaced. These researchers did not attend to the productive elements in students’ ideas about energy. …

Michael's Awesome Italian Adventure (With A Bit Of Science, Too), Michael W. Haskin

Physics

This senior project will provide the reader with a brief background about neutrinos, neutrinoless double beta decay, and the CUORE experiment being constructed in the Gran Sasso National Laboratory in Assergi, Italy. The remainder of the paper will follow my experience working as an undergraduate researcher at the laboratory during the summer of 2012. It will discuss the process of performing a cool down with the CUORE-0 cryostat as well as quality assurance testing of Teflon spacers to be used in the CUORE towers.

Investigating The Potential Applications Of A Raman Tweezer System, John Wray

Theses and Dissertations

This thesis describes the construction of an Optical Tweezer apparatus to be used in conjunction with a confocal Raman spectrometer. The tweezer utilizes an infrared (λ=1064 nm) laser directed into an inverted microscope with NA=1.4 oil immersion 100x objective lens that strongly focuses the laser light into a sample to function as a single-beam gradient force trap. The long term goal of this research program is to develop a single molecule Raman tweezers apparatus that allows one to control the position of a Raman nanoplasmonic amplifier. This thesis describes the construction of the Raman tweezer apparatus along with several Raman …

Superfluidity In Neutron Stars, Samuel J. Witte

Undergraduate Theses—Unrestricted

Nucleon pairing is studied with specific considerations directed toward the possible influence on neutron star cooling. We present an in-depth analysis of BCS theory using realistic nuclear potentials and consider the impact short-range correlations can have on the gap. Gap calculations are incorporated into neutron star cooling simulations and the significance of the 3P2 −3F2 channel in various hadronic cooling models is closely examined. An analysis of the 1S0 gap in neutron matter suggests short-range correlations can drastically alter the magnitude, density range, and temperature dependence of the gap. While the newly constructed 1S0 gap does not significantly alter the …

Quantum Programming In Python: Quantum 1d Simple Harmonic Oscillator And Quantum Mapping Gate, Matthew Hoff

Physics

A common problem when learning Quantum Mechanics is the complexity in the mathematical and physical concepts, which leads to difficulty in solving and understanding problems. Using programming languages like Python have become more and more prevalent in solving challenging physical systems. An open-source computer algebra system, SymPy, has been developed using Python to help solve these difficult systems. I have added code to the SymPy library for two different systems, a One-Dimensional Quantum Harmonic Oscillator and a Quantum Mapping Gate used in Quantum Computing.

An Effective Field Theory Calculation Of N(P, D)Γ Cross-Section For Big Bang Nucleo-Synthesis, Rasha Adnan Kamand

Theses and Dissertations

Studying the nuclear reaction n(p,d)γ and calculating its cross-section is not only a matter of interest from theoretical particle physics point of view but also from the viewpoint of cosmology. We now know that the universe is made up of only 5% baryonic matter. So, computing the density of baryons is of particular importance to physicists in general and cosmologists in particular. Deuterium production during Big Bang Nucleo-synthesis (BBN) is very sensitive to the density of baryons, thus baryon density can be inferred from the abundance of deuterium. In order to calculate deuterium abundance one needs to use the cross-section …

A Potential Framework For Emergent Space-Time And Geometry From Order, Newshaw Bahreyni

Legacy Theses & Dissertations (2009 - 2024)

This research is about seeking laws of physics and geometry from order. Anything that is measured is the result of something influencing something else. An act of influencing and the response to such influence form a pair of events. A collection of such events along with their binary ordering relation of influence which forms a