Bibliography



Notice:

  • Clicking on the DOI link will open a new window with the original bibliographic entry from the publisher.
  • Clicking on a single author will show all publications by the selected author.
  • Clicking on a single keyword, will show all publications by the selected keyword.




The effects of magnetic fields on photoelectron-mediated spacecraft potential fluctuations


AuthorWang, X.; Malaspina, D.; Hsu, H.-W.; Ergun, R.; M., Hor\;
Keywordschorus waves; magnetic fields; photoelectrons; spacecraft potential fluctuations; Van Allen Probes
AbstractPreviously, we have experimentally studied photoelectron-mediated spacecraft potential fluctuations associated with time-dependent external electric fields. In this paper, we investigate the effects of magnetic fields on such spacecraft potential fluctuations. A magnetic field is created above the UV-illuminated surface of a spacecraft model to alter the escape rate of photoelectrons. The packet of the observed potential oscillations becomes less positive with increasing magnetic field strength because more of the emitted photoelectrons are returned to the surface. As a result, the photoelectric charging time is increased, corresponding to a decrease in the response frequency of the photoemitting surface. The amplitude of the potential oscillations decreases when the response frequency becomes lower than the electric field oscillation frequency. A test particle simulation is validated with the laboratory experiments and applied to estimate the photoelectron escape rate from the Van Allen Probes spacecraft, showing that the photoelectron current is reduced by as much as 30\% when magnetic field strength is 1200 nT. Based on our laboratory results and computer simulations, we discuss the effects of magnetic fields on the spacecraft potential fluctuations observed by the Van Allen Probes.
Year of Publication2014
JournalJournal of Geophysical Research: Space Physics
Volume119
Number of Pages7319-7326
Section
Date Published09/2014
ISBN
URLhttp://doi.wiley.com/10.1002/jgra.v119.9
DOI10.1002/jgra.v119.910.1002/2014JA019923