Return to search

Experimental Investigation of Snapover: The Sudden Increase of Plasma Current Drawn to a Positively Biased Conductor When Surrounded by a Dielectric

Snapover is particularly relevant to Earth-orbiting spacecraft powered by high-voltage solar arrays. During snapover, the current collected by a positively biased conductor that is immersed in a plasma suddenly increases when two conditions are met: i) there is an immediately adjacent insulator; ii) the conductor exceeds a positive threshold voltage with respect to the plasma. The enhanced current develops as a consequence of the insulator, either through secondary electron (SE) emission or by material ionization. Experiments were performed to examine snapover onset potential and current collection dependence on conductor and insulator materials, conductor size and shape, sample history, biasing rate, and contamination and smoothness of the dielectric surface. Numerous current jumps were observed between applied voltages of 100 V and 1000 V. Both surface roughening and surface coatings were found to inhibit snapover. In general, the results did not support previous simple interpretations of the SE model.

Identiferoai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-3095
Date01 May 2001
CreatorsThomson, Clint D.
PublisherDigitalCommons@USU
Source SetsUtah State University
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceAll Graduate Theses and Dissertations
RightsCopyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact Andrew Wesolek (andrew.wesolek@usu.edu).

Page generated in 0.0016 seconds