HR: 1340h
AN: SH33A-1098    [Abstracts]
TI: Electric Field and Density Measurements with STEREO-SWaves.
AU: * Kellogg, P J
EM: kellogg@waves.space.umn.edu
AF: School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
AU: Goetz, K
EM: goetz@umn.edu
AF: School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
AU: Monson, S J
EM: monson@waves.space.umn.edu
AF: School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
AU: Bale, S D
EM: Bale@ssl.berkeley.edu
AF: Physics Dept. and Space Sciences Laboratory, University of California, Berkeley, CA 94720, United States
AU: Maksimovic, M
EM: milan.maksimovic@obspm.fr
AF: Observatoire de Paris-Meudon, Place Jules Janssen, Meudon, 92195, France
AB: The STEREO experiment SWaves has a low frequency part which is designed to make measurements of low frequency electric fields and rapid measurements of density fluctuations, using the three 6 meter stacer monopole antennas. The short antennas of STEREO respond both to density fluctuations and to electric fields. Therefore, it is desired to obtain four quantities, density and 3 components of electric field, from three measurements, the potentials on the three orthogonal antennas relative to the spacecraft, which requires some additional information. One possibility is to add a fourth equation implied by the large plasma conductivity, so large that electric field parallel to the magnetic field is zero, a condition which has often been used in electric field measurements. Under selected conditions, this seems to work. There are also conditions, for example ion acoustic waves, where the responses to density fluctuations and to electric fields are available from dispersion relations, and this provides another possible solution. A situation where it is not likely that the parallel electric field is zero is the case of solitary, intense bursts of Langmuir waves. For this case, it is expected that there is an electron density depression due to the ponderomotive pressure, and a resulting low frequency electric field from the non-neutrality which would be expected to have components parallel to the magnetic field. Examples will be discussed.
DE: 0609 Antennas
DE: 2159 Plasma waves and turbulence
DE: 2164 Solar wind plasma
DE: 7894 Instruments and techniques
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting