Condensed Matter Physics Commons^™

Enhanced Test Facility For Survivability And Characterization Of Evolving Multiscale Materials In Extreme Plasma Environments, Jr Dennison

Posters

No abstract provided.

Hemispherical Grid Retarding Field Analyzer Redesign For Secondary Electron Emission Studies, Greg Wilson, Jr Dennison

Presentations

A redesign of the Hemispherical Grid Retarding Field Analyzer is discussed in relationship to multilayer charging models. In order to accurately extend single layer charging models to dynamic multilayer scenarios, precise measurements of electron emission as well as the net surface potential must be made. By learning from the previous design and thinking of future applications, the new instrument will greatly enhance our ability to precisely measure materials undergoing energetic electron bombardment.

Of Mice And Materials: Payoffs Of Unsgc Research Infrastructure Awards, Jr Dennison, Kent Hartley, Lisa Phillipps, Justin Dekany, Robert H. Johnson, James S. Dyer

Presentations

A versatile test facility has been designed and built to study space environments effects on small satellites and system components. Testing for potentially environmental-induced modifications of small satellites is critical to avoid possible deleterious or catastrophic effects over the duration of space mission. This is increasingly more important as small satellite programs have longer mission lifetimes, expand to more harsh environments (such as polar or geosynchronous orbits), make more diverse and sensitive measurements, minimize shielding to reduce mass, and utilize more compact and sensitive electronics (often including untested off-the-shelf components). The vacuum chamber described here is particularly well suited for …

Of Mice And Materials: Payoffs Of Unsgc Research Infrastructure Awards, Jr Dennison

Presentations

No abstract provided.

Hemispherical Grid Retarding Field Analyzer Redesign For Secondary Electron Emission Studies, Greg Wilson, Jr Dennison

Conference Proceedings

A redesign of the Hemispherical Grid Retarding Field Analyzer is discussed in relationship to multilayer charging models. In order to accurately extend single layer charging models to dynamic multilayer scenarios, precise measurements of electron emission as well as the net surface potential must be made. By learning from the previous design and thinking of future applications, the new instrument will greatly enhance our ability to precisely measure materials undergoing energetic electron bombardment.

Uv Degradation Of Polycarbonate, Katie Gamaunt

Senior Theses and Projects

The decrease in visible and ultraviolet transmission spectra of polymeric and glass spacecraft materials has been measured to determine the extent of degradation due to high-energy UV radiation similar to the solar spectrum (both above and below the stratosphere, which is where most of the UV radiation is absorbed). This project looked at the effects that the atmosphere has in regards to blocking UV radiation and thus, slowing down the UV degradation process. A polycarbonate sample was exposed to radiation from a focused high intensity deuterium lamp source, which generates radiation in the UVA and UVB spectrum. A particularly severe …

Microcontroller And Memory Card Survivability In Space Conditions, Windy Olsen

Senior Theses and Projects

The Utah State University (USU) Materials Physics Group (MPG) is interested in the performance of Commercial Off the Shelf (COTS) microcontrollers in space conditions. Microcontrollers are commonly used on CubeSats, small relatively inexpensive satellites that are flown in Low Earth Orbit (LEO) at altitudes of ~160 km-2000 km. There is a large area of interest in COTS microcontrollers because they provide a more cost-effective on-board computer for CubeSats. This experiment focused on the functionality of an ATmega328 microcontroller on an Arduino Uno board inside the MPG’s Space Survivability Test (SST) Chamber. A diagnostic program was used to try to detect …

Microcontroller Survivability In Space Conditions, Windy Olsen

Senior Theses and Projects

No abstract provided.

Reduction Of Radiation Effects In Polymers, Alexandra Hughlett, Tyler Kippen, Jr Dennison

Posters

No abstract provided.

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed, Leandro Olano, Isabel Montero, María E. Dávila, A. Jacas, M. A. Rodriguez, Jr Dennison

Conference Proceedings

Secondary Emission Yield (SEY) of dielectric materials is of great importance for prediction and testing of the Multipaction discharge in RF components for space applications. An atypical behavior of the SEY of coatings composed by a mixture of conductor and dielectric microparticles was reported and modeled in [1]; in this original model, the interactions between dielectric and conductor particles were not taken into account, but an effective action of the surface voltage generated within the sample was included. The aim of the present contribution is to more accurately model the effect the electric fields between dielectric and conductor particles have …

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, María E. Dávila, Jr Dennison

Presentations

An unexpected behavior of the Secondary Emission Yield (SEY) on coatings composed by a mixture of conductor and dielectric microparticles was reported and modeled in [1]. As a follow up, we measured for a fixed primary energy the dynamic evolution of the SEY in similar samples and proposed a charging-roughness coupled model to simulate the experimental results. Two different coatings were selected: 1) TMM and Al microparticles (type 1), and 2) zeolites and gold nanoparticles (type 2). Pulsed and continuous tests were used to obtain the SEY as a function of the primary energy.

In both types of samples extremely …

Temperature Dependence Of Electrostatic Discharge In Highly Disordered Insulating Polymers, Tyler Kippen, Allen Andersen, Jr Dennison

Posters

No abstract provided.

Model For Charge Injection With Electron Beams Into Highly Disordered Insulating Materials, Jr Dennison

Presentations

The Walden-Wintle model for charge injection and transport through highly disordered insulating materials has been extended to include charge injection with a charged particle beam. The original model is applicable to charge injection into a dielectric material from a pair of electrodes in a parallel-plate geometry. It provides a versatile approach to predict the time-dependent current at a rear grounded electrode and the incident surface voltage, as the injection current density evolves over time with the development of a space charge barrier near the injection electrode. The Walden-Wintle model has been applied to many standard cases including Fowler-Nordheim injection, Schottky …

A New Physical Model For Dc Partial Discharge In Polymeric Insulators, Allen Andersen, Jr Dennison

Presentations

The physics of DC partial discharge (DCPD) continues to pose a challenge to researchers. We present a new physically-motivated model of DCPD in amorphous polymers based on our dual-defect model of dielectric breakdown. The dual-defect model is an extension of standard static mean field theories, such as the Crine model, that describe avalanche breakdown of charge carriers trapped on uniformly distributed defect sites. It assumes the presence of both high-energy chemical defects and low-energy thermally-recoverable physical defects. We present our measurements of breakdown and DCPD for several common polymeric materials in the context of this model. Improved understanding of DCPD …

Model For Charge Injection With Electron Beams Into Highly Disordered Insulating Materials, Jr Dennison

Presentations

No abstract provided.

Novel Physical Model For Dc Partial Discharge In Polymeric Insulators, Allen Andersen, Jr Dennison

Presentations

No abstract provided.

Satellite Survivability In A Harsh Space Environment: A Materials Perspective, Jr Dennison

Presentations

No abstract provided.

Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek, Tyler Kippen, Allen Andersen, Jr Dennison

Posters

Electrostatic breakdown is a leading cause of many of the anomalies and failures attributed to spacecraft interactions with the space environment. It is therefore critical to understand how the electrostatic field strength varies due to changing environmental conditions, including temperature and radiation dose. Standard step-up to electrostatic discharge (ESD) tests were performed on two polymers, low density polyethylene (LDPE) and polyetheretherketone (PEEK). Tests were done at room temperature and at other temperatures ranging from ~130 K to ~350 K. Preliminary analysis found that samples tested at a higher temperature had lower average breakdown field strength and a narrower distribution of …

Using Quantile-Quantile Plots To Compare Experimental Apples And Oranges In Physics Labs, Allen Andersen, Jr Dennison

Presentations

No abstract provided.

How The Space Environment Affects Seed Germination And Growth, Alexander Souvall, Gareema Dhiman, Andre Nguyen, Michelle Jung, Astrid Ji, Takayuki Sakai, Takahiro Shimizu, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Shaunda Wenger, Toshihiro Kameda, Jr Dennison

Posters

Understanding observed space environment effects on biological organisms such seeds are important in design of long duration space missions, such as to those planned for Mars, where appropriate storage and growth of food resources is essential. Evaluation of the effects of the real and simulated space environment on seed germination and growth in space is the purpose of this research. Preliminary tests of germination rate and growth of radish seeds in a controlled environment have identified statistically significant differences between control samples and seeds flown for 30 days in low earth orbit on the Bion M-1 launch capsule Russian research …

Microcontroller And Memory Card Survivability In Space Conditions, Windy Olsen

Senior Theses and Projects

No abstract provided.

Effects Of Space Travel On Seed Germination And Viability, Greema Dhiman, Michelle Jung, Andre Nguyen, Shaunda Wenger, Alexander Souvall, Jr Dennison, Takuyuki Sakai, Takahiro Shimizu, Yuta Takahashi, Midori Morikawa, Shusuke Okita, Akihiro Nagata, Toshihiro Kameda

Posters

No abstract provided.

Satellite Survivability In Space: A Materials Perspective, Jr Dennison

Presentations

No abstract provided.

Electron Yield Measurements Of High-Yield, Low-Conductivity Dielectric Materials, Justin Christensen

Senior Theses and Projects

No abstract provided.

Temperature Dependency Of Electrostatic Breakdown In Ldpe And Peek, Tyler Kippen, Allen Andersen, Jr Dennison

Posters

No abstract provided.

Temporal And Spatial Correlations In Electron-Induced Arcs Of Adjacent Dielectric Islands, Justin Christensen, Jr Dennison, Justin Dekany

Journal Articles

This study investigates very short duration (

Density Of State Models And Temperature Dependence Of Radiation Induced Conductivity, Jodie Corbridge Gillespie, Jr Dennison, Alec M. Sim

Journal Articles

Expressions are developed for radiation induce conductivity (RIC) over an extended temperature range, based on density of states models for highly disordered insulating materials. A general discussion of the DOS of can be given using two simple types of DOS distributions of defect states within the bandgap for disordered materials are considered, one that monotonically decreases within the bandgap and one with a distribution peak within the band gap. Three monotonically decreasing models (exponential, power law, and linear), and two peaked models (Gaussian and delta function) are considered, plus limiting cases with a uniform DOS for each type. Variations using …

Measuring And Modeling The Conductivity Of Highly Insulating Materials, David King

Senior Theses and Projects

No abstract provided.

Dynamic Secondary Electron Emission In Dielectric/Conductor Mixed Coatings, Leandro Olano, Isabel Montero, Maria E. Davila, Jr Dennison

Presentations

No abstract provided.

Reduction Of Radiation Effects In Polymers Relaxation Of Radiation Effects On The Optical Transmission Of Polymers, Alexandra Hughlett, Tyler Kippen, Jr Dennison

Presentations

No abstract provided.