A discovery of the neutron's permanent electric dipole moment larger than the standard model prediction of dn ≈ 10-31 e·cm would signal a new source of CP-violation and help explain the matter-antimatter asymmetry in the universe. Tightening the limits on dn constrain extensions to the standard model in a complementary fashion to the atomic and electron EDM searches. The recent upgrade of the Los Alamos ultracold neutron source makes it possible for a new room temperature search with the statistical reach to improve upon current limits by a factor of 10 or more. During the 2018 LANSCE cycle a prototype apparatus was used to demonstrate the capability to transport and manipulate polarized neutrons and perform Ramsey and Rabi sequence measurements. I will report on the measurements made over the last year, efforts underway to upgrade the prototype chamber, and possible future upgrades of the ultracold neutron source.

Thesis advisor: Krzysztof Kempa / Though nature provides a plethora of materials to work with, their properties are very much restricted, forcing severe limitations on the devices that are built from them. A huge portion of current technology stands to be significantly advanced and even revolutionized by the emergence of a new class of “configurable” materials. This class, generally referred to as metamaterials, has become more feasible than ever due to advancements in nanotechnology and fabrication techniques. Notable among nature’s limitations is an ever-positive index of refraction. This barrier has only recently been broken, and the known paths to negative refraction are few and limited. This paper introduces two distinct three-dimensional crystals capable of all-angle negative refraction. One uses the familiar photonic band, while the other is the first of its kind to rely on polaritonic waves. Their mode structures are examined and a set of parameters are chosen at which a negative effective index of refraction can be harnessed for unrestricted sub-wavelength lensing, demonstrated via numerical simulation. This work is expected to enable experimental observation of polaritonic negative refraction and sub-wavelength lensing at microwave frequencies. / Thesis (BS) — Boston College, 2009. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Physics.

The following results were obtained in the presented thesis: 1. Based on a previous work on the MoM method, a software modulus was created and tested in MATLAB, which solves a small-size scanning metal array with arbitrary element position and arbitrary lumped loading. 2. The solver was applied to optimize a broadband planar array of dipoles using the concept of negative lumped loading, which was introduced by R.C. Hansen in 2003. The problem statement was formulated by E. Kratzenberg of MIT Haystack Observatory. 3. The optimization implies full testing of varied array configurations with different element numbers, dipole thicknesses, generator impedances, and lumped loading values. 4. The results obtained indicate that that both 4x4 and 6x6 arrays of dipoles may be optimized over the frequency band from 50 to 300 MHz. The optimization means that the Scan Element Pattern of the array at zenith nearly follows the theoretical limit (area gain per element).

<p>Starting from Maxwell’s equations, we derive a sensor model for three-axis magnetometerssuitable for localization and tracking applications. The model dependson the relative position between the sensor and the target, orientation of the targetand its magnetic signature. Both point targets and extended target modelsare provided. The models are validated on data taken from various road vehicles.The suitability of magnetometers for tracking is analyzed in terms of local observabilityand Cramér Rao lower bound as a function of the sensor positions in atwo sensor scenario. Also the signal to noise ratio is computed to determine theeffective range of the magnetometer. Results from field test data indicate excellenttracking of position and velocity of the target, as well as identification of themagnetic target model suitable for target classification.</p><p> </p>

C. I. Beard, B. P. Dailey. / "June 3, 1949." / Bibliography: p. 11. / Office of Naval Research Contract N5ori-76 Joint Service Contract W-36-039sc-32037

This thesis provides a summary of the laser system constructed in the Quantum Degenerate Gases Laboratory for laser cooling and trapping of 85/87Rband 6Li as well as of experiments that have been pursued in our lab to date. The first chapter provides an overview of the experimental focus of the QDG lab. The second and third chapters provide the fundamental theory behind laser cooling and trapping. The fourth chapter provides details of the laser system. The fifth chapter describes an experiment performed on the subject of dual-injection, performed in collaboration with Dr. James Booth of the British Columbia Institute of Technology (BCIT) involving the dual-injection of a single slave amplifier. The last chapter describes the progress made on the experimental setup needed for the study of Feshbach resonances between 85/87Rb and 6Li and the photoassociative formation of molecules.

Nitrogen-containing molecules are ubiquitous in both natural products and pharmaceutical drugs, thus an efficient method for the formation of these motifs is of great importance. Hydroamination, that is the addition of an N-H bond across an unsaturated carbon-carbon bond of an alkene or alkyne, stands out as a potential approach to obtain such molecules. To date, most research in this area relies on transition-metal catalysis to enable such reactivity. In efforts directed towards metal-free alternatives, we have developed a simple, metal-free hydroamination of alkenes using hydrazides. Further investigation into the corresponding reactivity of alkynes with hydrazides has provided access to novel azomethine imine products. In Chapter 2, expansion of the substrate scope with respect to the intramolecular hydroamination of alkenes using hydrazides, as well as studies directed towards elucidation of the mechanism of this reaction will be presented. The intramolecular hydroamination of alkynes using hydrazides and methods to access and isolate the azomethine imine products formed will be discussed in Chapter 3.

<p>We have performed a measurement of the photodisintegration of the lithium isotopes, 6Li and 7Li, using a monochromatic, polarised photon beam and a segmented neutron detector array which covers approximately 1/4 of 4Î srad. Using time-of-flight and scintillator light-output spectra we separate the data into individual reaction channels. This work is motivated by the need to compare with recent theoretical predictions and to provide data for future theoretical work. <p>For the photodisintegration of 6Li we took data at 12 photon energies between 8 and 35 MeV. We describe the data using a model consisting of two-body reaction channels and obtain angular distributions and absolute cross sections for many of these reaction channels. We compare our results with a recent Lorentz integral transform calculation (Bacca et al. Phys. Rev. C 69, 057001 (2004)). Our results are in reasonable agreement with the calculation, in contradiction with previous experimental results. <p>For the photodisintegration of 7Li, we took data at 9 photon energies between 10 and 35 MeV. We obtain cross sections for the reaction channel 7Li + Á ¨ n + 6Li(g.s.) at all photon energies with angular distributions at all but the highest energy. We obtain angular distributions and total cross sections for reaction channels involving excited states of the daughter nucleus, 6Li, at select energies. We hope that these measurements will provide incentive for new theoretical calculations. <p>We observe neutrons that can only be described by the reaction channel 7Li+Á ¨ n+6Li(10.0) which necessitates an excited state of 6Li with excitation energy Ex = 10.0 } 0.5 MeV that is not in the standard tables of excited states.

Nitrogen-containing molecules are ubiquitous in both natural products and pharmaceutical drugs, thus an efficient method for the formation of these motifs is of great importance. Hydroamination, that is the addition of an N-H bond across an unsaturated carbon-carbon bond of an alkene or alkyne, stands out as a potential approach to obtain such molecules. To date, most research in this area relies on transition-metal catalysis to enable such reactivity. In efforts directed towards metal-free alternatives, we have developed a simple, metal-free hydroamination of alkenes using hydrazides. Further investigation into the corresponding reactivity of alkynes with hydrazides has provided access to novel azomethine imine products. In Chapter 2, expansion of the substrate scope with respect to the intramolecular hydroamination of alkenes using hydrazides, as well as studies directed towards elucidation of the mechanism of this reaction will be presented. The intramolecular hydroamination of alkynes using hydrazides and methods to access and isolate the azomethine imine products formed will be discussed in Chapter 3.

This thesis reports the first observation of the resonant electric dipole-dipole interaction between cold Rydberg atoms using microwave spectroscopy, the observation of the magnetic field suppression of resonant interactions, and the development of a unique technique for precise magnetic field measurements. <br /><br /> A Rydberg state 46<em>d</em>_5/2 of laser cooled ⁸⁵Rb atoms has been optically excited. A fraction of these atoms has been transferred to another Rydberg state 47<em>p</em>_3/2 or 45<em>f</em>_5/2,7/2 to introduce resonant electric dipole-dipole interactions. The line broadening of the two-photon 46<em>d</em>_5/2-47<em>d</em>_5/2 microwave transition due to the interaction of 46<em>d</em>_5/2 with 47<em>p</em>_3/2 or 45<em>f</em>_5/2,7/2 atoms has been used as a probe of the interatomic interactions. This experiment has been repeated with a DC magnetic field applied. The application of a weak magnetic field (&le;0. 6G) has reduced the line broadening due to the resonant electric dipole-dipole interaction, indicating that the interactions are suppressed by the field. Theoretical models have been developed that predict the energy shifts due to the resonant electric dipole-dipole interaction, and the suppression of interactions by magnetic fields. A novel technique for sensitive measurement of magnetic fields using the 34<em>s</em>_1/2-34<em>p</em>_1/2 one-photon microwave transition has also been presented. Using this technique, it has been possible to calibrate magnetic fields in the magneto-optical trap (MOT) apparatus to less than 10mG, and put an upper bound of 17mG on any remaining field inhomogeneity.