All Physics Faculty Publications
Document Type
Article
Journal/Book Title/Conference
IEEE Transactions on Plasma Science
Volume
40
Issue
2
Publication Date
2-2012
First Page
298
Last Page
304
Abstract
Spacecraft charging codes require accurate models of electron yields as a function of accumulated charge to correctly predict the charge build up on spacecraft. The accumulated charge creates equilibrium surface potentials on spacecraft resulting from interactions with the space plasma environment. There is, however, a complex relation between these emission properties and the charge built up in spacecraft insulators.
This paper focuses on different methods appropriate to determine the fundamental electronic material property of total electron yield as the materials accumulate charge. Three methods for determining the uncharged total yield are presented:
(i) The DC Continuous Beam Method is a relatively easy and accurate method appropriate for conductors and semi- conductors with maximum total electron yield σmaxρ<1017 >Ω-cm.
(ii) The Pulse-Yield Method seeks to minimize the effects of charging and is applicable to materials with σmaxρ up to >1024 Ω-cm. (iii) The Yield Decay Method is a very difficult and time consuming technique that uses a combination of measurement and modeling to investigate the most difficult materials with σmax>4 and ρ up to >1024 Ω-cm.
Data for high purity polycrystalline Au, KaptonTM HN and CP1TM polyimides, and polycrystalline aluminum oxide ceramic are presented. These data demonstrate the relative strengths and weaknesses of each method, but more importantly show that the methods described herein are capable of reliably measuring the total electron yield of almost any spacecraft material.
Recommended Citation
RC Hoffmann and JR Dennison, “Methods to Determine Total Electron-Induced Electron Yields Over Broad Range of Conductive and Nonconductive Materials,” IEEE Trans. on Plasma Sci., 40(2), 298-304 (2012). DOI: 10.1109/TPS.2011.2178251
Comments
Published by IEEE in IEEE Transactions on Plasma Science. Author post print available for download through link above.
This study was partially funded by the NASA Solar Probe Mission through the Johns Hopkins University Applied Physics Laboratory and by the NASA Space Environments and Effects program.