Publication Date:
2013-11-14
Description:
[1] The conversion of Langmuir waves into electromagnetic radiation near the local plasma frequency ( f pe ) and twice the local plasma frequency (2 f pe ) occurs in diverse heliospheric environments including along the path of type III radio bursts, at interplanetary shocks, and in planetary foreshocks. This radiation has the potential to act as probe of remote plasma conditions, provided the conversion mechanism is well understood. One candidate conversion mechanism is the antenna radiation oflocalized Langmuir waves. Antenna radiation near 2 f pe requires the presence of nonlinear currents at 2 f pe . In this work, properties of these currents are predicted from theory and compared with STEREO/WAVES observations of Langmuir wave electric fields. It is found that the observed frequency structure, polarization, and wave number ratio are consistent with nonlinear current predictions, once electric fields near 2 f pe consistent with sheath effects are taken into account.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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