DocumentCode :
2559028
Title :
Theory and analysis of plasma formed by hypervelocity impacts
Author :
Close, Sigrid ; Lee, Nicolas ; Fletcher, Alex ; Goel, Ashish
Author_Institution :
Dept. of Aeronaut. & Astronaut., Stanford Univ., Stanford, CA, USA
fYear :
2012
fDate :
8-13 July 2012
Abstract :
Meteoroid and space debris impacts on spacecraft are known to cause mechanical damage, but the associated electrical effects on spacecraft systems remain poorly understood. We present a theory to explain plasma production and subsequent electric fields occurring after a meteoroid strikes a spacecraft, and ionizes itself and part of the spacecraft. This plasma, with a charge separation commensurate with different species mobilities, can produce a strong electromagnetic pulse (EMP) spanning a broad frequency spectrum. Subsequent plasma oscillations can also emit significant power. We present both the theory for a dust-free plasma expansion with coherent electron oscillations, as well as results from an experiment carried out at the Max Planck Institute in Heidelberg, Germany using the Van de Graaff dust accelerator. Our experiment used a suite of sensors, including retarding potential analyzers (RPAs), a photomultiplier tube (PMT), and radiofrequency (RF) patch antennas spanning VHF through UHF. The targets included both charged and uncharged material. Our results show that RF emission occurs in conjunction with strong returns in the plasma sensors and depends strongly on the target configuration. Charged targets produced “beamed” plasma clouds, while uncharged targets produce significant return at a broader expansion angle.
Keywords :
antennas in plasma; electromagnetic pulse; ionisation; meteoroids; microstrip antennas; photomultipliers; plasma devices; plasma electromagnetic wave propagation; plasma oscillations; plasma production; sensors; space debris; space vehicles; Germany; Heidelberg; Max Planck Institute; Van de Graaff dust accelerator; broad frequency spectrum; charge separation; charged target production; coherent electron oscillations; dust-free plasma expansion; electrical effects; hypervelocity impacts; mechanical damage; meteoroid impact; photomultiplier tube; plasma formation analysis; plasma formation theory; plasma oscillations; plasma production; plasma sensors; radiofrequency emission; radiofrequency patch antennas; retarding potential analyzers; space debris impact; spacecraft systems; strong electromagnetic pulse; uncharged target production; Educational institutions; Oscillators; Plasmas; Radio frequency; Sensors; Space debris; Space vehicles;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Plasma Science (ICOPS), 2012 Abstracts IEEE International Conference on
Conference_Location :
Edinburgh
ISSN :
0730-9244
Print_ISBN :
978-1-4577-2127-4
Electronic_ISBN :
0730-9244
Type :
conf
DOI :
10.1109/PLASMA.2012.6383596
Filename :
6383596
Link To Document :
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