Electrostatic Discharge Properties of Irradiated Nanocomposites

Author

Joshua D. McGary

Date of Award

3-9-2009

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

James C. Petrosky, PhD

Abstract

Modernization in space systems requires employment of new light-weight, high performance composite materials that reduce bulk weight and increase structural integrity. This thesis explored the behavior of one such material prior to and following a 35-year simulated space radiation life-cycle. Select electrical properties of nickel nanostrand^TM-carbon composites in seven configurations were characterized prior to electron irradiation via surface and bulk resistivity measurements and contact electrostatic discharge (ESD) measurements. Following irradiation at a fluence of 10¹⁶ e^-/cm² at an average energy of 500 keV, measurements were repeated and compared against pre-irradiation data. Configuration D is the best configuration tested for use as a satellite external surface material. All composite configurations tested in this research showed degradation in critical electrical properties when examined in the aggregate. The data showed no common trend between the electrical performance of the various composites based on location or density of the nickel nanostrands^TM in the material. Surface resistivity increased for all configurations while bulk resistivity change correlated to the type of epoxy resin used in the composite. The mechanism responsible for these changes is electron induced displacement damage within both the epoxy and carbon which reduce permittivity and, or conductivity within the bulk. ESD current waveform properties of peak current and decay time decreased in a manner sufficient to conclude that every configuration tested is subject to increased ESD frequency and intensity over a lifetime of space radiation. These materials require further engineering to better resist the changes noted in these electrical properties before used as satellite surfaces.

AFIT Designator

AFIT-GNE-ENP-09-M03

DTIC Accession Number

ADA494965

Recommended Citation

McGary, Joshua D., "Electrostatic Discharge Properties of Irradiated Nanocomposites" (2009). Theses and Dissertations. 2452.
https://scholar.afit.edu/etd/2452