Physics Commons^™

Optically Detected Magnetic Resonance Of Silicon Vacancies In Sic: Predicting Resonance Of Cylindrical Cavities, Kyle Miller, John Colton

Journal of Undergraduate Research

Optically Detected Magnetic Resonance is one method of performing Electron Spin Resonance (ESR) on a material. ESR is used to determine the electron spin lifetime of a material, an important parameter for use in quantum computing. Resonant cavities are conducting containers that are frequently used in ESR to create a strong magnetic field near the sample. As such it is valuable to design a resonant cavity and predict its resonant frequency. Cylindrical cavities modified with dielectric resonators (DRs) are viable for such experiments.

Exploring The Weak Mach Reflection Regime, Kevin Leete, Dr. Kent Gee

Journal of Undergraduate Research

When a shock wave reflects off a rigid surface with certain combinations of incident shock strength and angle, a Mach reflection can occur. This is when portions of the incident and reflected waves merge to create a stronger shock called a Mach stem that travels parallel to the reflecting surface. This phenomenon has been studied extensively for two extreme cases: large outdoor explosions and small, laboratory experiments of weak shocks. The purpose of this project was to design and execute an outdoor experiment where this phenomenon could be observed by microphones as well as high speed video imaging to detect …

High Resolution Shock Capturing On Gpus, Forrest Glines, David Neilsen

Journal of Undergraduate Research

This research project concerns the development simulation code to confirm neutron star mergers as the progenitors of Short Hard Gamma Ray Bursts. Short Hard Gamma Ray Bursts (SHGBs) are short (less than 2 second) high energy bursts that we observe with satellites. Their exact cause has not yet been confirmed, but they are believed to be created by the merging of either two neutron stars or a neutron star falling into a black hole. Neutron stars are ultra dense, highly magnetic, and compact stars at the end of their evolution. In a binary system the stars lose angular momentum to …

Determining The Size Of A Light Source Using The Hanbury Brown And Twiss Effect, Adam Kingsley, Dallin Durfee

Journal of Undergraduate Research

In 1956, Hanbury Brown and Twiss (HBT) published a paper¹ on a method of determining the angular size of a star by comparing the intensities gathered from two detectors. They used this effect by using two photomultiplier tubes and by increasing the distance between them, saw a drop in the correlation between the currents. Because the correlations are made by the interference at the detectors but only the intensity is measured, the effect is sometimes referred to as intensity interferometry.

The idea arose to use the HBT effect to teach undergraduates various principles of light in a lab setting. …

Phase Matching In Laser Generated Harmonics, David Squires, Justin Peatross

Journal of Undergraduate Research

In this mentored research project, we investigated how intense laser light is scattered by samples of gas. In particular, we measured light scattered in non-phase-matched directions perpendicular to the laser beam.

According to classical phase matching, the intensity of light scattered from a sample depends on whether the sample is best approximated as a continuous medium or a collection of discrete emitters (Figure 1). In the former case, as the angle between the phase-matching direction and the radiated harmonic approaches π/2 radians, the intensity of that radiated harmonic light approaches 0. In the latter case, the light intensity reaches …

Porous Cantilevers As Chemical Sensors, Steven Noyce, Robert Davis

Journal of Undergraduate Research

Many chemical sensing methods rely on the binding mechanism of the analyte to create a measurable response, making it difficult to create new sensors quickly, but resonant sensors require only that an analyte be bound and rely on the resulting change in mass to obtain a measurement. Solid resonant microcantilevers, or small vibrating fixed-free beams, are a type of resonant sensor that have shown extremely high sensitivities in vacuum environments. The sensitivity of these cantilevers, however, decreases greatly in fluid environments such as air or water due to fluid damping. We propose that porous microcantilever sensors offers both a ten …

Measuring Frequency Noise For Use In Preventing Mode Hops In Extended Cavity Diode Lasers, Mckinley Pugh, Dallin Durfee

Journal of Undergraduate Research

Diode lasers are useful in physics because they are relatively cheap and robust, they are available in a number of wavelengths, and they are tunable. However, because diode lasers have large bandwidths compared to atomic resonances, a reflection grating is added outside the laser. This creates the extended cavity in extended cavity diode lasers (ECDLs) and forces the lasers to operate at a narrower line width, one acceptable for use in atomic physics. Unfortunately, because the ECDL has many factors trying to control the wavelength of the laser (e.g. temperature, current, grating angel and position) small changes in the lasers …

Systematic Analysis Of Nonlinearities In Complex Models, Alexander Shumway, Mark Transtrum

Journal of Undergraduate Research

Mathematical models are ubiquitous in science. Many models are nonlinear in the parameters and may have dozens to thousands of parameters and make hundreds to thousands of predictions. Analysis and application of these models is thus theoretically complicated and computationally expensive.

The standard method of model analysis is a model-by-model approach that relies on the intuition of expert researchers. Recent research, however, has shown that many models—known as sloppy models—are statistically similar, despite coming from widely varied fields⁴. This suggests the possibility of developing a theory of modeling in place of relying on expert intuition. Our research …

Dual Species Calcium And Ytterbium Magneto Optical Trap, Alexander Erickson, Scott Bergeson

Journal of Undergraduate Research

One area of particular interest in modern physics research is creating a viable fusion system for sustainable energy. Fusion occurs when a high energy plasma is manipulated in such a way that small atoms collide together, combining to create larger atoms and releasing tremendous amounts of harvestable energy. However, there are many theoretical, mathematical, and practical roadblocks to creating a stable fusion experiment. One practical limitation and one mathematical limitation are as follows: practically, much of the energy used to create a fusion-grade plasma ends up in the kinetic energy of the electrons and is lost to the experiment; mathematically, …

Reflectometry Of Aluminum Thin Films In The Vacuum Ultraviolet, Benjamin Smith, R. Steven Turley

Journal of Undergraduate Research

Vacuum Ultraviolet (VUV) is a range of light on the electromagnetic spectrum corresponding to wavelengths from 40 – 280 nm. VUV photons have too much energy to see visibly and are blocked completely by atmosphere. This wavelength range, however, shows promise for applications in space-based exoplanet research telescopes. Specifically, the chemical fingerprints that this light contains can tell us about the composition and formation of exoplanet atmospheres.