Physics Commons^™

Improvement Of Atomic Layer Deposition Techniques Of Tungsten Using Hydrogen As A Reducing Agent, Jason Kyle Anderson, Dr. David Allred

Journal of Undergraduate Research

Introduction: Traditional micro fabrication processes are confined to a small subset of possible materials due to limitations on etching. They are also confined to low aspect ratio fabrication due to limits in both etching process and stability of thicker film deposition processes. Carbon Nanotube Templated Microfabrication (CNT-M) technology has introduced a dramatically different approach to micro fabrication that fabricates without significant etching processes and achieves thick features with the equivalent of thin depositions. This is achieved by forming the desired structure in carbon nanotubes and then filling, or infiltrating, that structure with the material of choice. Optimal materials infiltration for …

Phase-Correlation And Propagation Analysis Of Near-Field Military Jet Noise, Jazz Myres, Dr. Kent Gee

Journal of Undergraduate Research

According to the Office of Naval Research (ONR), the United States Department of Veteran Affairs spent over $1 billion dollars on military hearing loss compensation in 2010 alone1. A major cause of hearing loss is exposure to high Sound Pressure Levels, which are caused by military aircraft. These severe levels and high risks are what motivate the overarching goal of all jet noise research: to attenuate the sound impact and reduce the risk of hearing loss. My research project helps this overall purpose by characterizing jet noise and innovating more complete methods of jet noise study. The purpose of this …

Developing Microwave-Generated Hydrogen Atoms As A Reducing Agent For Tungsten Atomic Layer Deposition, Jason Kyle Anderson, Dr. David Allred

Journal of Undergraduate Research

Traditional micro fabrication processes are confined to a small subset of possible materials due to limitations on etching and are confined to low aspect ratio fabrication due to limits in both etching and stability of thicker film deposition processes.

A Bayesian Nonparametric Approach To Hyperspectral Data Analysis, Jessica Seeger, Dr. Candace Berrett

Journal of Undergraduate Research

Hyperspectral imaging (HSI) is a technology that provides a dense set of previously un- available data{o ering the opportunity for use in a variety of applications such as food safety, ecology, and non-proliferation research. HSI stores measurements across three dimen- sions (two-dimensional space and the electromagnetic spectrum), resulting in large, three- dimensional data cubes. This additional amount of information can be used to identify materials in the images remotely. However, due to the many possibilities for measurement and other errors, it is hard to distinguish between the signal (the material spectra) and these sources of noise. We combine a known …

Using Head-¬‐Mounted Displays To Teach Deaf Students In Planetariums, Holly Mumford

Journal of Undergraduate Research

During the Summer of 2012 we were able to conduct preliminary tests of HMD’s with deaf children ages 7-­‐17. Many of these were volunteers from EFY. Each subject watched a prepared video segment on the Earth, Sun and Moon, from Evans & Sutherland. They were accompanied by a translator, and ASL fluent facilitators and tech specialists. After these sessions were completed the subjects participated in a group discussion. We gained good insight and positive feedback. Once these sessions were finished I helped develop the coding system we would use in evaluating the videos, and analyzed the results.

Microelectromechanical Devices For Remote Sensing In Extreme Conditions, David Landry, Dr. David Allred

Journal of Undergraduate Research

Microelectromechanical systems (MEMS) are commonly used to build sensors for consumer products such as game console controllers1 and smart phones2. These sensors use piezoelectric materials and are wired directly into a larger electronic system. Because of their use case, these sensors are designed to operate near room temperature. The goal of this project was to help create a remotely detected MEMS accelerometer capable of operating in high temperature and high acceleration environments.

Lithium-6 Neutron Detector, Adam Wallace, Dr. Lawrence Rees

Journal of Undergraduate Research

Over the last year I have built several neutron detectors with lithium-6 glass and tested their efficiency. As stated in my proposal, this detector is being designed for use by the United States Department of Homeland Security (DHS) at portal monitors. In order to meet their requirements we had to test our detectors for neutron detection efficiency and minimize their sensitivity to gamma radiation.

High-Aspect Ratio Microaccelerometer For Extreme Environments, Adam Konneker, Dr. David Allred

Journal of Undergraduate Research

Over the course of the past year, I have had the invaluable opportunity to pursue a research project under the guidance of Dr. David Allred. I am still working on completing the project, but I have made significant progress and gained experience in designing microscale devices. The original goal of my research project was to design and build a microscale acceleration sensor, or accelerometer, capable of operating in extreme environments, which is to say in high temperatures and corrosive atmospheres. This project is one piece of a larger goal, which is to make wireless sensors for extreme environments. Thus far, …

Fabrication Of Suspended Graphene Membranes Grown By Chemical Vapor Deposition (Cvd) Using Carbon Nanotubes, Caleb Hustedt, Dr. Robert Davis, Dr. Richard Vanfleet

Journal of Undergraduate Research

Graphene is an exciting material that stands to have a large impact on the scientific community. Unfortunately, graphene cannot be fully utilized due to its small scale and time consuming production. Graphene grown by chemical vapor deposition solves these issues but comes with a cost of decreased mechanical and electrical properties due to defects. However, the exact properties of CVD graphene are not well quantified. In order to measure the qualities of CVD graphene it must be suspended. Carbon infiltrated carbon nanotube forests were fabricated with holes 2-20um in size. Imaging showed CVD graphene was suspended over up to 50 …

Time Reversal In Non-Idealistic Environments, Blaine Harker, Dr. Kent Gee, Brian Anderson

Journal of Undergraduate Research

Time reversal is a relatively new type of acoustic localization with many applications, such as lithotripsy to destroy kidney stones, and secure underwater sound communication, though in some ways time reversal is still in the development stage. To this end, we explore the efficiency and limitations of this technique due to the number of sensors used and the directivity pattern of the source to be reconstructed in the experiment.

Ultrafast/Nonlinear Optical Studies Of Cdse Nanocrystals, Kevin C. Wright, Dr. Bret C. Hess

Journal of Undergraduate Research

This research project has been much more time-consuming than I anticipated. Because the required lasers and optical elements are very sensitive and highly susceptible to accidental misalignment and damage, many parts of the multi-stage laser amplification system had to be rebuilt from the ground up several times during the course of this research. This was a great hands-on learning opportunity for me, even though it did impede the progress of my research somewhat. I have still been able to accomplish most of the objectives outlined in my proposal. Specifically, I have completed all but the final stage of the proposed …

Using Mechanical Resonance To Overcome Van Der Waals Forces In Optical Trapping Experiments, Nathan B. Terry, Dr. Justin B. Peatross

Journal of Undergraduate Research

The laser trapping of microscopic particles has many applications, especially in chemistry, biology and physics (1). It is of special interest to utilize optical trapping to levitate small objects for interferometry work. The levitation of a glass microsphere requires first that the Van der Waals forces between the sphere and the surface on which it rests (the contact surface) must be overcome. The first stage of this experiment examines overcoming these Van der Waal forces by mechanically vibrating the contact surface.

Atomic Force Microscopy Manipulation Of Cadmium Selenide Nanocrystals, Taylor D. Grow, Dr. Robert C. Davis

Journal of Undergraduate Research

Cadmium Selenide Nanocrystals are semiconducting particles that exhibit very interesting and as yet not understood quantum properties. These particles also fluoresce with very high efficiency. In order to study how the quantum state of these particles affects their flourescent properties Dr. Davis has designed an experiment where a single nanoparticle needs to be isolated between two gold electrodes. In order to do this I used a Digital Instruments Atomic Force Microscope to develop a procedure to move these particles (Fig. 1).

The Piecewise Parabolic Method In Plasma Simulation, York E. Young

Journal of Undergraduate Research

Aware of the large number of insights which may result from a better understanding of non-neutral plasmas, the Brigham Young University plasma group currently explores the electrostatic normal modes of oscillation in confined plasmas. Researchers at BYU currently perform computational studies of waves In non-neutral plasmas confined in real geometries in support of experiments both here and elsewhere.

Finding Neutron Detector Efficiency Using Monte Carlo Neutron Particle (Mcnp) Calculations, Eva Wilcox, Dr. Lawrence Rees

Journal of Undergraduate Research

A neutron detector, made by Bart Czirr, has components of plastic and a new compound called lithium gadolinium borate, with a chemical formula of LiGd(BO3)3:Ce3+.

Construction Of A Precision X-Ray Mirror, Mitchell W. Larsen

Journal of Undergraduate Research

With the expansion of x-ray technology and recent development of laser x-rays, development of a practical, high precision x-ray mirror has become more urgent. One example of a practical and current need for such a mirror is the x-ray microscope at Duke University. The above planned microscope would function by focusing x-rays on a tiny section of a cell frozen during a specific metabolic stage. The molecules in the cell would absorb these x-rays, and then radiate x-rays off. Every element would radiate a unique wavelength of x-rays, and we would thus be able to determine which elements are present …

Summary Of Dye Laser Project, Dallin S. Durfee

Journal of Undergraduate Research

In order to get a dye to lase, you have to pump it with energy. You need to get more of the lasing molecules into the higher energy excited state than the lower energy ground state. The way that I pump the dye is with a flash tube.

A Presentation Of The Mapping Of Lbn434 And Its Ramifications On The Assumption Of Clear Seeing At High Galactic Latitudes, Kristen Adams

Journal of Undergraduate Research

We recorded three to four images of each section of the nebula. Each group of images was identical in the data recorded; thus, after reduction, the individual images of each group could be combined directly to yield a higher intensity signal output. To reduce the data, I performed the following ~tandard CCD procedures: 1. Bad Pixel Corrections

2. Overscan Corrections

3. Zeroing and Trimming

4. Flat Fielding Corrections

Modeling Trapped Non-Neutral Plasmas With A Piecewise Parabolic Method, Rachel K. Berg

Journal of Undergraduate Research

The objective of my undergraduate research at Brigham young University was to adapt a numerical algorithm known as the piecewise parabolic method to solve problems of interest in the study of trapped non-neutral plasmas. The project took the better part of a year, but ultimately I was successful.

Charge Injection In Semiconductor Nanocrystals And Its Effect On Luminescence And Spin Resonance, James Owen Ostler, Dr. Bret C. Hess

Journal of Undergraduate Research

With diameters of only about 4-5 nanometers, semiconductor nanocrystals exhibit different properties than bulk semiconductors. Because of this there has been a focus in research to discover and exploit these new properties. The CdSe nanocrystal is smaller than the normal wave function of an electron in bulk semiconductors and this produces different properties in the nanocrystals than what current knowledge about semiconductors would dictate. Our experience with the different physical properties of these quantum-confined semiconductors is limited, however the possible uses for these nanocrystals are numerous. This necessitates that we research and familiarize ourselves with the properties of these nanocrystals …

A Proposed Thin Film Process For Shortening Carbon Nanotube Afm Probes, Dale S. Kitchen, Dr. Robert C. Davis

Journal of Undergraduate Research

This report describes the growth of carbon nanotubes on sharp silicon cantilevers through chemical vapor deposition (CVD) and the implementation of thin film and acid etch techniques to shorten the grown nanotubes. Silicon and silicon-nitride probes serve as the principle imaging tools for Atomic Force Microscopy (AFM). Carbon nanotubes may serve to enhance the imaging stability and resolution of AFM through their unique properties. Herein, I describe procedures, explain the presented results, and outline future work on this project.

Direct Cvd Growth Of Carbon Nanotubes On Silicon Nitride Atomic Force Microscope Probes, Matthew Housley, Dr. Robert Davis

Journal of Undergraduate Research

Atomic Force Microscopy (AFM) is currently one of the most important analytical techniques in nanoscale science and technology. Because it can image surface topography with a resolution better than 10 nm, AFM has allowed the visualization of many nanoscale structures which other microscopic techniques cannot see. Examples include individual DNA strands, extended polymer chains, monolayer steps in crystal surfaces, and carbon nanotube transistors.

Physical Vapor Deposition Of Silicon Dioxide From A Silicon Tetraacetate Precursor For Anchoring Nanotubes To Atomic Force Microscopy Probe Tips, Jed Whittaker, Dr. Robert Davis

Journal of Undergraduate Research

It has been previously shown¹ that silicon tetraacetate vapor thermally decomposes to a silicon dioxide thin film and gas phase acid anhydride at 160-170°C. Here a method is developed to anchor carbon nanotubes to atomic force microscope (AFM) tips with such a silicon dioxide thin film. Anchoring nanotubes to probe tips allows their high-resolution properties to be exploited in fluids for imaging biological samples. No tips were used as substrates in this experiment however, only silicon wafer pieces about 1 cm square. The silicon tetraacetate vapor was produced by heating it to 100-110°C, just below the melting point. This …

Stable Diode Laser Systems For Laser Cooling And Trapping, Andrew David Ludlow, Dr. Scott Bergeson

Journal of Undergraduate Research

Laser cooling and trapping has become one of the most widespread and successful research tools within atomic physics in the last twenty years. The idea is to “hit” an oncoming atom with photons of laser light, which slow the atom down. Then, using the appropriate magnetic field in conjunction with the laser light, atoms are not only slowed down to a near stop, but also become trapped and suspended in a small region of space. Since temperature is really only the measure of atoms’ speed, these slow, trapped atoms are very, very cold – near absolute zero. In the last …

X-Ray Fluorescence/X-Ray Diffraction For Forensic Analysis, Brent Kimball, Dr. Larry V. Knight

Journal of Undergraduate Research

My proposition was to determine the feasibility of using a combination x-ray fluorescence/x-ray diffraction technology (initially designed to identify strictly inorganic compounds) for the analysis of organic molecules. By modifying a mineralogical device created for NASA it is feasible to identify solid organic compounds such as drugs, harmless compounds like glucose, and some inorganic compounds that look like drugs. Emergency teams, Forensic Officers, and Police Departments and even drug manufacturers will benefit from the applications. I will provide a brief background on diffraction, clearly describe my findings, and provide proposals to further develop a working technology.

Optical Modulation Of Semiconductor Nanocrystal Transport, Brigham Russell Frandsen, Dr. Bret C. Hess

Journal of Undergraduate Research

The area of nanoelectronic devices is a rapidly growing field as new devices and techniques are continually developed. This is an important field because it is hoped that devices of this scale will replace the current larger counterparts on computer microprocessors and other components, thus greatly reducing the size, and increasing the capabilities of computers.

The Development Of An Active Noise Control System For A Small Axial Fan, Kent L. Gee, Dr. Scott D. Sommerfeldt

Journal of Undergraduate Research

Axial cooling fans used in computers, projectors, and printers often contribute significantly to background noise levels in both the workplace and classroom because of the distinct and often annoying tones they produce. These tones are principally caused by spatially unsteady flow through the fan, due to finger guards and other obstructions. Active noise control (ANC) lends itself as a viable approach to fan tonal noise reduction because of the low frequency nature of the noise, which limits the effectiveness and practicality of more traditional “passive” means of controlling noise. An ANC system cancels or attenuates unwanted noise by creating “antinoise” …

In Situ Ellipsometry Of Surfaces In An Ultrahigh Vacuum Thin Film Deposition Chamber, Joseph S. Choi, Dr. David Allred

Journal of Undergraduate Research

As current microtechnology advances toward building nanosize components for computers and aerospace devices, oxidation of thin films can have dramatic effects on the electronic and optical properties of these devices. In order to understand optical properties of thin film materials and their oxides in a high purity environment, we have been building an ultrahigh vacuum deposition chamber to achieve a base pressure under 10-9 torr. We have incorporated evaporation and sputtering capabilities to create thin films in vacuum, and an in situ ellipsometer to analyze the optical properties and oxidation of the films without exposure to atmosphere. This combined with …

Spin Current: The Contribution Of Spin To The Probability Current Of Nonrelativistic Particles With Spin, Philip Du Toit, Dr. Jean-Francois Van Huele

Journal of Undergraduate Research

Introductory quantum mechanics texts seldom treat the quantum mechanical probability current for nonrelativistic particles with spin. The procedure for calculating probability current is most often presented in relation to particles described by the Schrödinger equation, that is particles without spin.1 In later chapters, after having introduced readers to the Pauli equation and its description of particles with spin, the authors rarely return to the topic of probability current. This omission may cause readers to incorrectly infer that the calculation of the probability current for particles with spin follows the same line of argument as is used for particles without spin.

In-Doping Of Cdse Nanocrystals, Dan Allen, Dr. William Evanson

Journal of Undergraduate Research

In recent years much research has focused on the characteristics of metal and semiconductor “quantum dots” or “nanocrystals”. Cadmium selenide (CdSe) semiconductor nanocrystals of diameter less than ~10nm exhibit unique quantum mechanical properties not present in bulk materials. CdSe nanocrystals of 2-5nm in diameter photoluminesce brightly in the visible spectrum, making them attractive for applications such as photodiodes and light-emitting displays. These nanocrystals are also being researched for applications such as single electron transistors, transistors with multiple logic states, and quantum computing. Present commercial applications include single electron memory devices and luminescent tags for biological molecules.