Physics Commons^™

Electrostatic Breakdown Analysis, Sam Hansen

Senior Theses and Projects

Materials potentially suitable for spacecraft construction were exposed to electrostatic discharge in the USU Materials Physics Group lab, with hopes of identifying samples that possess greater resistance to breakdown. Breakdown shape and size may be important to determining material suitability for spacecraft construction [1]. The discharge damage sites of tested samples were examined, measured and logged into a matrix file for data analysis. Once logged, data was sorted within the matrix and compared graphically to identify trends.

Electrostatic Breakdown Analysis, Sam Hansen, Jr Dennison, Allen Andersen

Senior Theses and Projects

Materials potentially suitable for spacecraft construction were exposed to electrostatic discharge in the USU Materials Physics Group lab, with hopes of identifying samples that possess greater resistance to breakdown. Breakdown shape and size may be important to determining material suitability for spacecraft construction [1]. The discharge damage sites of tested samples were examined, measured and logged into a matrix file for data analysis. Once logged, data was sorted within the matrix and compared graphically to identify trends.

Pre-Breakdown Arcing And Electrostatic Discharge In Dielectrics Under High Dc Electric Field Stress, Allen Andersen, Jr Dennison

Journal Articles

Highly disordered insulating materials exposed to high electric fields will, over time, degrade and fail, potentially causing catastrophic damage to devices. Step-up to electrostatic discharge (ESD) tests were performed for two common polymer dielectrics, low density polyethylene and polyimide. Pre-breakdown transient current spikes or arcs were observed, using both slow and high speed detection. These pre-ESD discharge phenomena are explained in terms of breakdown modes and defect generation on a microscopic scale. The field at which pre-breakdown arcing begins was compared to the onset field for electrostatic discharge at which complete breakdown occurs for each material studied. We present evidence …

Pre-Breakdown Arcing And Electrostatic Discharge In Dielectrics Under High Dc Electric Field Stress, Allen Andersen, Jr Dennison

Conference Proceedings

Highly disordered insulating materials exposed to high electric fields will, over time, degrade and fail, potentially causing catastrophic damage to devices. Step-up electrostatic discharge (ESD) tests were performed for two common polymer dielectrics, low density polyethylene and polyimide. Prebreakdown transient current spikes or pre-arcs were observed, using both slow and high speed detection. These pre-ESD discharge phenomena are explained in terms of breakdown modes and defect generation on a microscopic scale. The field at which pre-breakdown arcing begins was compared to the onset field for electrostatic discharge at which complete breakdown begins to occur for each material. We present evidence …

Cathodolumiescence Studies Of The Density Of States Of Disordered Silicon Dioxide, Jr Dennison, Amberly Evans Jensen

Presentations

Electron bombardment measurements have shown that disordered SiO2 exhibits cathodoluminescence, with an overall intensity that varies with incident electron beam energy and current density, sample temperature, exposure time, and wavelength. A simple model based on the defect density of states—used to explain electron transport in highly disordered insulating materials—has been extended to predict the relative cathodoluminescent intensity and spectral radiance for disordered SiO 2 as a function of these variables. The spectral radiance exhibited four distinct bands, corresponding to four distinct energy distributions of defect states within the band gap; each showed different temperature dependence. These localized defect or “trap” …

Cathodoluminescence Events Coincident With Muon Detection, Kenneth Zia, Justin Dekany, Jr Dennison

Presentations

Samples of highly disordered insulating material have been irradiated with keV electron beams, resulting in three forms of electron induced light emission with differing duration: arcs (duration), “flares” (~100 s), and cathodoluminescence (as long as beam is on) [Dennison, 2013]. The arc and cathodoluminescence phenomena are well understood, while the flares’ origins are not. Flares were observed at intervals of ~2 per hr. This is within a factor of 2 for the expected muon cross section at an altitude of Logan, UT (1370 m) caused by high altitude cosmic rays; those high energy particles could have deposited sufficient energy throughout …

Discharge Breakdown Analyses, Sam Hansen, Jr Dennison, Allen Andersen

Presentations

Material breakdown due to Electrostatic discharge (ESD) is the primary cause of spacecraft damage due to environment interactions in space. This occurs when the space plasma fluxes charge a craft to high voltages where insulating craft materials then break down. This failure allows current to flow freely through the material, this can damage or destroy onboard electrical systems. My project focuses on the effects of these breakdowns on suspect materials commonly used for electrical insulation in space. The USU Material Physics Group has performed ESD tests on hundreds of samples to date. The ESD damage sites of these samples have …

Lifetimes Of Polymeric Dielectrics: A Dual-Defect Model, Allen Andersen, Jr Dennison

Presentations

Electrostatic discharge (ESD) can cause catastrophic failures in electronic devices. Estimating the lifetime of dielectrics under prolonged high field exposure is a major design concern for applications including spacecraft, high voltage DC power transmission, and semiconductor electronics. Dielectric strengths listed in engineering handbooks are primarily based on cursory measurements with poor repeatability and tend to overestimate ESD fields in real applications. Standard measurements subject test samples to ~500 V/s ramp rates until breakdown. We present the results of ESD studies in two prototypical polymer dielectrics using a ramp rate of ~20 V/4s until breakdown together with tests applying a static …

Modeling The Energy Dependent Cathodoluminescent Intensity Of A Carbon Composite Material, Justin Christensen, Kelby T. Peterson, Justin Dekany, Jr Dennison

Presentations

When highly disordered insulating materials are subjected to energetic electron bombardment they can emit photons. This process is termed “cathodoluminescence.” This occurs in the space plasma environment and is an important phenomenon to understand when designing any object to be put into space. Light emitted from spacecraft materials can affect optical detection, and can cause stray-light contamination in space-based observatories. The Materials Physics Group at Utah State University uses an ultra-high vacuum chamber equipped with electron guns and a cryostat to control the sample temperature to simulate the space environment and to observe its affects on sample materials. Previous studies …

Space Effects Survivability Testing, Lisa Montierth Phillipps, Jr Dennison, Kent Hartley, Robert H. Johnson, Justin Dekany, James S. Dyer

Presentations

A versatile test facility has been designed to study the effects of space environment fluxes and radiation damage on small scale materials samples, system components, and small satellites. Cost-effective long-duration testing for potentially environmental-induced modifications is increasingly more important as small satellite programs have longer mission lifetimes, expand to more harsh environments, make more diverse and sensitive measurements, minimize shielding to reduce mass, and utilize more compact and sensitive electronics. The facility simulates environmental components including the neutral gas atmosphere, the solar spectrum, electron plasma fluxes, and temperature. The UV/VIS/NIR solar spectrum is simulated using a class AAA Solar Simulator …

Cathodoluminescence Events Coincident With Muon Detection, Kenneth Zia

Senior Theses and Projects

No abstract provided.

Guesstimation: The Art Of Getting About The Right Answer, Jr Dennison

Presentations

No abstract provided.

Breakdown Analysis Of Electrostatic Discharge, Sam Hansen, Allen Andersen, Jr Dennison

Posters

Electrostatic discharge (ESD) and the associated material breakdown is the primary cause for spacecraft damage due to space environment interactions. This phenomenon occurs when the space plasma fluxes charge a craft to high voltages where insulating materials then break down. This failure allows current to flow freely through the material which; can damage or destroy onboard electrical systems. My work focuses on the effects of these breakdowns on suspect materials commonly used for electrical insulation in space. The USU Material Physics Group has performed ESD tests on hundreds of samples to date. The ESD damage sites of these samples have …

A Dual-Defect Model For Predicting Lifetimes For Polymeric Discharges From Accelerated Testing, Allen Andersen, Jr Dennison

Posters

Electrostatic discharge (ESD) can cause catastrophic failures in electronic devices. Estimating the lifetime of dielectrics under prolonged high field exposure is a major design concern for applications including spacecraft, high voltage DC power transmission, and semiconductor electronics. Dielectric strengths listed in engineering handbooks are primarily based on cursory measurements with poor repeatability and tend to overestimate ESD fields in real applications. Standard measurements subject test samples to ≈500 V/s ramp rates until breakdown. We present the results of ESD studies in two prototypical polymer dielectrics using a ramp rate of ≈20 V/4s until breakdown, together with tests applying a …

Cathodoluminescence Events Coincident With Muon Detection, Kenneth Zia, Justin Dekany, Jr Dennison

Posters

Samples of highly disordered insulating material were irradiated with 1 keV electron beams, resulting in three forms of light emission with differing duration: arcs (<1 s duration), flares (~100 s), and cathodoluminescence (as long as beam is on). The arc and cathodoluminescence phenomena are well understood, while the flares are not. Flares were observed at intervals of ~2 per hr. This is within a factor of 2 for the expected muon crosssection at an altitude of Logan, UT (1370 m) caused by high altitude cosmic rays. Based on this suggestive evidence, we have proposed incorporation of standard muon coincidence detection apparatus into our vacuum cathode luminescence test facility. Measurements of the muon cross-section zenith angle and angle-dependence will provide calibration of the muon detector. If muon evidence coincides with the flare events, this will provide definitive evidence of the flare origin. We will discover whether a correlation between flares of charged sample are caused by transitory muons which trigger discharge and subsequent recharging during our testing of space materials.

Cathodolumiescence Studies Of The Density Of States Of Disordered Silicon Dioxide, Jr Dennison, Amberly Evans Jensen

Presentations

Electron bombardment measurements have shown that disordered SiO2 exhibits cathodoluminescence, with an overall intensity that varies with incident electron beam energy and current density, sample temperature, exposure time, and wavelength. A simple model based on the defect density of states—used to explain electron transport in highly disordered insulating materials—has been extended to predict the relative cathodoluminescent intensity and spectral radiance for disordered SiO2 as a function of these variables. The spectral radiance exhibited four distinct bands, corresponding to four distinct energy distributions of defect states within the band gap; each showed different temperature dependence. These localized defect or “trap” states …

Investigations Of Electrical And Physical Properties Of Ceramic Materials For Spacecraft Applications, Kevin Guerch, Jr Dennison

Presentations

No abstract provided.

Dual-Defect Model Of Electrostatic Discharge In Polymeric Dielectrics, Allen Andersen, Jr Dennison

Presentations

Electrostatic discharge (ESD) is a serious concern for spacecraft, high voltage power transmission, and other applications. A parallel plate capacitor geometry under high vacuum was used to apply increasing voltages across insulating samples until ESD breakdown and to apply sub-critical fields and observe time-to-breakdown. Transient arcing was frequently observed prior to complete ESD breakdown in both cases. Results are presented for two prototypical polymeric materials, low density polyethylene (LDPE) and polyimide (PI or Kapton HN™) in terms of both statistical and physics-based models.

Many electrical aging models are described by defect creation within the material from bond stress due to …

Small Satellite Space Environments Effects Test Facility, Jr Dennison, Kent Hartley, Lisa Montierth Phillipps, Justin Dekany, James S. Dyer, Robert Johnson

Presentations

No abstract provided.

Small Satellite Space Environments Effects Test Facility, Jr Dennison, Kent Hartley, Lisa Montierth Phillipps, Justin Dekany, James S. Dyer, Robert H. Johnson

Conference Proceedings

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 …

Variations In Cathodoluminescent Intensity Of Spacecraft Materials Exposed To Energetic Electron Bombardment, Justin Dekany, Justin Christensen, Jr Dennison, Amberly Evans Jensen, Gregory Wilson, Todd Schneider, Charles W. Bowers, Robert Meloy

Presentations

Various highly insulating materials used in spacecraft construction can exhibit glow (electron-induced luminescence or cathodoluminescence) when exposed to the space plasma environment. Measurements of the absolute and relative cathodoluminescent intensity per incident electron flux of spacecraft materials are essential to predict and mitigate consequences for optical detection and for stray light contamination in space-based observatories. They also provide important information about the defect structure and electron transport properties of these materials. Previous studies have focused on how the relative spectral radiance of cathodoluminescent materials varies with changes in environmental conditions, including electron energy, current density, absorbed power density, and temperature. …

Small Satellite Space Environments Effects Test Facility, Jr Dennison, Kent Hartley, Lisa Montierth Phillipps, Robert Johnson, Justin Dekany, James Dyer

Presentations

A versatile space environments test facility has been designed and built to study the 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 missions. This is increasingly more important as small satellite programs have longer mission lifetimes, expand to more hash 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). Our vacuum chamber is particularly well suited for cost-effective, …

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

Conference Proceedings

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 …

The Dynamic Interplay Between Spacecraft Charging, Space Environment Interactions And Evolving Materials, Jr Dennison

Conference Proceedings

While the effects on spacecraft charging from varying environmental conditions and from the selection of different construction materials have been studied extensively, modification of materials properties by exposure to the space plasma environment can also have profound effects on spacecraft charging. Given the increasingly demanding nature of space missions, there is a clear need to extend our understanding of the dynamic nature of material properties that affect spacecraft charging and to expand our knowledge base of materials’ responses to specific environmental conditions so that we can more reliably predict the long term response of spacecraft to their environment. This paper …

Variations In Cathodoluminescent Intensity Of Spacecraft Materials Exposed To Energetic Electron Bombardment, Justin Dekany, Justin Christensen, Jr Dennison, Amberly Evans Jensen, Gregory Wilson, Todd Schneider, Charles W. Bowers, Robert Meloy

Conference Proceedings

Many contemporary spacecraft materials exhibit cathodoluminescence when exposed to electron flux from the space plasma environment. A quantitative, physics-based model has been developed to predict the intensity of the glow as a function of incident electron current density and energy, temperature, and intrinsic material properties. We present a comparative study of the absolute spectral radiance for several types of dielectric and composite materials based on this model which spans three orders of magnitude. Variations in intensity are contrasted for different electron environments, different sizes of samples and sample sets, different testing and analysis methods, and data acquired at different test …

Defects Density Of States Model Of Cathodoluminescent Intensity And Spectra Of Disordered Sio2, Amberly Evans Jensen, Jr Dennison

Conference Proceedings

Electron beam measurements have been made that show disordered SiO 2 exhibits luminescent behavior, and that it varies with incident beam energy and current density, sample temperature and wavelength. A simple model based on the electronic band structure and defect density of states—initially used to explain electron transport in highly disordered insulating materials—has been extended to predict the relative cathodoluminescent intensity and spectral radiance for disordered SiO 2 as a function of these variables. Insulating SiO 2 has a band gap of ~8.9 eV. Hence thermal excitation from the valence to conduction band is highly improbable; excitation is through collisions …

Electrostatic Discharge And Endurance Time Measurements Of Spacecraft Materials: A Defect-Driven Dynamic Model, Allen Andersen, Jr Dennison, Alec M. Sim, Charles Sim

Conference Proceedings

Electrostatic breakdown leads to the majority of anomalies and failures attributed to spacecraft interactions with the plasma space environment. It is therefore critical to understand how electrostatic field strength (FESD) of spacecraft materials varies due to environmental conditions such as duration of applied electric field, rate of field change, history of exposure to high fields, and temperature. We have developed a dual-defect, thermodynamic, mean-field trapping model in terms of recoverable and irrecoverable defect modes to predict probabilities of breakdown. Fits to a variety of measurements of the dependence of FESD of insulating polymers on endurance time, voltage ramp rate, and …

Synergistic Models Of Electron Emission And Transport Measurements Of Disordered Sio2, Jr Dennison, Justin Dekany, Jodie Corbridge Gillespie, Phil Lundgreen, Allen Andersen, Amberly Evans Jensen, Gregory Wilson, Alec Sim, Ryan Hoffmann

Presentations

A critical component in the prediction and mitigation of spacecraft charging issues is an accurate model of the charging, transport and electron emission properties of a broad array of materials used in the construction of spacecraft. The increased sensitivity, longer-duration missions, and ventures into more demanding environments only serve to heighten this need. One important way for the spacecraft charging community to address this issue is to expand the role of more fundamental materials physics. This includes the development of unifying theoretical models of the charge transport equations based on the creation, distribution, and occupancy of defect densities of states. …

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

Presentations

Radiation induced conductivity (RIC) occurs when incident ionizing radiation deposits energy and excites electrons into the conduction band of insulators. The increased number of charge carriers, and hence the magnitude of the enhanced conductivity, is dependent on a number of factors including temperature and the spatial and energy dependence and occupation of the material’s distribution of localized trap states within the band gap—or density of states (DOS). Expressions for RIC in terms of the filling of the DOS up to an effective Fermi level were largely developed by Rose [RCA Review, 1951], and were extended by Fowler [ …

Electrostatic Discharge And Endurance Time Measurements Of Spacecraft Materials: A Defect-Driven Dynamic Model, Allen Andersen, Jr Dennison, Alec Sim, Charles Sim

Presentations

Electrostatic discharge (ESD) is the primary cause of space environment induced failures and malfunctions. As mission lifetimes and the sensitivity and complexity of instrumentation increase, so does the need for describing the influence of the electrical aging processes on ESD. This research studies the electrostatic field strength (F_ESD) of polymeric insulators as a function of applied field and the time-to-breakdown for F < F_ESD. A dynamic physics-based model for time-to-breakdown is much more valuable than an empirical static model, since it provides the ability to predict the statistical lifetime of dielectric materials subjected to prolonged stress from …