Thesis (Ph. D.)--Syracuse University, 2003. / "Publication number AAT 3113223."

Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2006. / "Title from dissertation home page (viewed June 28, 2007)." Source: Dissertation Abstracts International, Volume: 67-06, Section: B, page: 3202. Adviser: Shyh-Yuan Lee.

<p> Oscillating single neutron stars are considered to be important quasi-continuous sources for gravitational wave emission and detection at the Laser Interferometer Gravitational-Wave Observatory (LIGO). In order to detect these oscillations above the noise level in the detector, LIGO data must be compared to theoretical templates of the signal, which means predicting the signal amplitude and frequency range. In this thesis, we compute the two most important eigenfrequencies of superfluid neutron stars where the signal might be peaked. To calculate this spectrum, we first construct the background structure of the neutron star using realistic microscopic models of dense and interacting nuclear matter. For this purpose, we use the CompOSE database which provides an array of such models with thermodynamically consistent interpolation. The fluid pertubation equations of the equilibrium configuration, including superfluidity in a two-fluid model, are solved numerically in the non-relativistic limit, yielding the eigenfrequencies upon imposing suitable boundary conditions. We find that the modes of the superfluid star support modes that are very close to the corresponding normal fluid star, but there also appear one or two purely superfluid modes, the lower one of which is intermediate between the two lowest order modes of the normal fluid. Thus, in the event that these oscillation modes can be observed, we can confirm the theoretical prediction of neutron superfluidity in neutron stars. A part of the results presented in this thesis have been published as a proceedings article in Jaikumar, Monroy and Klaehn, <i> Universe</i> 4, 58 (2018).</p><p>

<p> Patients receiving Intensity Modulated Radiation Therapy (IMRT) for late stage head and neck (HN) cancer often experience anatomical changes due to weight loss, tumor regression, and positional changes of normal anatomy (1). As a result, the actual dose delivered may vary from the original treatment plan. The purpose of this study was (a) to evaluate the dosimetric consequences of the parotid glands during the course of treatment, and (b) to determine if there would be an optimal timeframe for replanning. Nineteen locally advanced HN cancer patients underwent definitive IMRT. Each patient received an initial computerized tomography simulation (CT-SIM) scan and weekly cone beam computerized tomography (CBCT) scans. A Deformable Image Registration (DIR) was performed between the CT-SIM and CBCT of the parotid glands and Planning Target Volumes (PTVs) using the Eclipse treatment planning system (TPS) and the Velocity deformation software. A recalculation of the dose was performed on the weekly CBCTs using the original monitor units. The parameters for evaluation of our method were: the changes in volume of the PTVs and parotid glands, the dose coverage of the PTVs, the lateral displacement in the Center of Mass (COM), the mean dose, and Normal Tissue Complication Probability (NTCP) of the parotid glands. The studies showed a reduction of the volume in the PTVs and parotids, a medial displacement in COM, and alterations of the mean dose to the parotid glands as compared to the initial plans. Differences were observed for the dose volume coverage of the PTVs and NTCP of the parotid gland values between the initial plan and our proposed method utilizing deformable registration-based dose calculations.</p>

<p>This thesis discusses the process of extracting the longitudinal asymmetry, $A_L</p><p>{W\pm}$, describing $W\rightarrow\mu$ production in forward kinematic regimes. This asymmetry is used to constrain our understanding of the polarized parton distribution functions characterizing $\bar{u}$ and $\bar{d}$ sea quarks in the proton. This asymmetry will be used to constrain the overall contribution of the sea-quarks to the total proton spin. The asymmetry is evaluated over the pseudorapidity range of the PHENIX Muon Arms, $2.1 < |\eta|2.6$, for longitudinally polarized proton-proton collisions at 510 GeV $\sqrt{s}$. In particular, I will discuss the statistical methods used to characterize real muonic $W$ decays and the various background processes is presented, including a discussion of likelihood event selection and the Extended Unbinned Maximum Likelihood fit. These statistical methods serve estimate the yields of $W$ muonic decays, which are used to calculate the longitudinal asymmetry.

<p> The anti-matter counterpart to the electron, the positron, can be used for a myriad of different scientific research projects to include materials research, energy storage, and deep space flight propulsion. Currently there is a demand for large numbers of positrons to aid in these mentioned research projects. There are different methods of producing and harvesting positrons but all require radioactive sources or large facilities. Positron beams produced by relatively small accelerators are attractive because they are easily shut down, and small accelerators are readily available. </p><p> A 4MV Van de Graaff accelerator was used to induce the nuclear reaction ¹²C(d,n)¹³N in order to produce an intense beam of positrons. 13N is an isotope of nitrogen that decays with a 10 minute half life into ¹³C, a positron, and an electron neutrino. This radioactive gas is frozen onto a cryogenic freezer where it is then channeled to form an antimatter beam. The beam is then guided using axial magnetic fields into a superconducting magnet with a field strength up to 7 Tesla where it will be stored in a newly designed Micro-Penning-Malmberg trap. </p><p> Several source geometries have been experimented on and found that a maximum antimatter beam with a positron flux of greater than 0.55&times;10⁶ e+s^-1 was achieved. This beam was produced using a solid rare gas moderator composed of krypton. Due to geometric restrictions on this set up, only 0.1-1.0% of the antimatter was being frozen to the desired locations. Simulations and preliminary experiments suggest that a new geometry, currently under testing, will produce a beam of 107 e+s^-1 or more.</p>

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7399. Adviser: David W. Hertzog. Includes bibliographical references (leaves 131-133) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2007. / Title from PDF t.p. (viewed Nov. 20, 2008). Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1688. Adviser: David V. Baxter.

Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008. / Title from dissertation home page (viewed Sept. 30, 2008). Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1710. Adviser: Rex Tayloe.

Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008. / Title from PDF t.p. (viewed on Jul 27, 2009). Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6881. Adviser: Scott W. Wissink.