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Full-Text Articles in Physics
A Simple Method For Determining Shallow Charge Distributions In Dielectrics Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison
A Simple Method For Determining Shallow Charge Distributions In Dielectrics Via Pulsed Electroacoustic Measurements, Zachary Gibson, J. R. Dennison
Journal Articles
The understanding of charge dynamics in dielectric materials is paramount in mitigating electrostatic discharge events for spacecraft. The most critical spacecraft charging events are found to result from incident electrons in the energy range of 10 keV to 50 keV. The charge embedded in dielectric materials in this energy range are deposited a distance into the material on the order of a few to tens of microns. One way to measure and understand the deposited charge is via pulsed electroacoustic measurements (PEA). However, the typical PEA spatial resolution of ~ 10 μm is not sufficient to resolve or discern charge …
Perspectives On The Distributions Of Esd Breakdowns For Spacecraft Charging Applications, Allen Andersen, Krysta Moser, Jr Dennison
Perspectives On The Distributions Of Esd Breakdowns For Spacecraft Charging Applications, Allen Andersen, Krysta Moser, Jr Dennison
Journal Articles
Electrostatic discharge (ESD) continues to pose significant risks to space missions despite decades of intense study. Tabulated values of material breakdown strength used in spacecraft charging models are often based on cursory measurements that may not be fully relevant to a given mission. Materials physics offers insight into the pertinent variables that affect breakdown and how to address them experimentally for spacecraft applications. We present measured distributions of ESD data across several test configurations for three polymeric materials that, taken together, begin to provide an understanding of how to estimate the likelihood of ESD events over a spacecraft’s mission lifetime. …
Dependence Of Electrostatic Field Strength On Voltage Ramp Rate For Spacecraft Materials, Krysta Moser, Allen Andersen, Jr Dennison
Dependence Of Electrostatic Field Strength On Voltage Ramp Rate For Spacecraft Materials, Krysta Moser, Allen Andersen, Jr Dennison
Journal Articles
This work investigated the dependence of electrostatic field strength for spacecraft materials on voltage ramp rate, by applying an increasing incremental electrostatic field until electrostatic breakdown occurred. Tests on Kapton E found that at ramp rates two or three orders of magnitude lower than the maximum recommended rate, the electrostatic breakdown field, FESD was lower by a factor of two or more. This suggests that tabulated values of FESD, which have been used by the spacecraft charging community, could substantially overestimate FESD in common slowly evolving spacecraft situations. This study expanded these ramp rate tests to include a wider range …
Electrostatic Discharge And Endurance Time Measurements Of Spacecraft Materials: A Defect-Driven Dynamic Model, Allen Andersen, Jr Dennison, Alec Sim, Charles Sim
Electrostatic Discharge And Endurance Time Measurements Of Spacecraft Materials: A Defect-Driven Dynamic Model, Allen Andersen, Jr Dennison, Alec Sim, Charles Sim
Journal Articles
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 …
Dynamic Interplay Between Spacecraft Charging, Space Environment Interactions And Evolving Materials, Jr Dennison
Dynamic Interplay Between Spacecraft Charging, Space Environment Interactions And Evolving Materials, Jr Dennison
Journal Articles
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 knowledgebase 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 focuses …