Document Type

Article

Journal/Book Title/Conference

IEEE Transactions on Plasma Science

Volume

40

Issue

2

Publication Date

2-2012

First Page

305

Last Page

310

DOI

10.1109/TPS.2011.2179676

Abstract

Charging of materials by incident radiation is affected by both environmental and physical conditions. Modifying a material’s physical surface will change its reflection, transmission and absorption of the incident radiation which are integrally related to the accumulation of charge and energy deposition in the material. General arguments for incident and emitted photons, electrons and ions are considered. An optical analysis of the effects of surface modification on spacecraft charging parameters on prototypical polyimide Kapton HNTM and Cu samples is presented. Samples were roughened with abrasive compounds ranging from 0.5 to 10 μm in size, comparable to the range of incident wavelengths. They were also contaminated with thin layers of DC 704 diffusion pump oil. Using a UV/VIS/NIR light source and a diffraction grating spectrometer, measurements were performed on pristine and modified materials. The measured spectra confirmed that surface modifications induce expected changes in optical reflection, transmission, and absorption. The generally increased absorption observed results in increased photon energy deposited in the material, leading to increased charge emission through the photoelectric effect.

Comments

Published by IEEE in IEEE Transactions on Plasma Science. Author post print available for download through link above.

Research was supported by funding from the NASA James Webb Space Telescope Program through Goddard Space Flight Center and a Utah State University Eccles Research Fellowship and Undergraduate Research and Creative Opportunities grant.