HR: 1340h
AN: SA33B-1321    [Abstracts]
TI: Derivation of temperature and density from Langmuir probe observations with a small surface-to-probe area ratio
AU: * Barjatya, A
EM: Aroh.Barjatya@erau.edu
AF: Embry-Riddle Aeronautical University, Physical Sciences Dept. 600 S. Clyde Morris Blvd., Daytona Beach, FL 32114, United States
AU: Swenson, C M
EM: Charles.Swenson@usu.edu
AF: Utah State University, 4120 Old Main Hill, Logan, UT 84322, United States
AU: Hysell, D L
EM: dlh37@cornell.edu
AF: Cornell University, Department of Earth and Atmospheric Sciences, Ithaca, NY 14853, United States
AB: We present the dataset from two separate payloads of the EQUIS II sounding rocket campaign. The rockets were launched into thin radar scattering layers that were observed as precursors to nighttime Equatorial Spread-F. The payloads carried an RF Plasma Impedance Probe and a fixed-bias DC Langmuir probe (DCP) on one axial boom, and an internally heated sweeping Langmuir probe (SLP) that was guarded on one side on a second axial boom. The ratio of the payload surface area to the cumulative area of the sweeping Langmuir probe instrument and its guard was only about 250. We present a charging model for the payload and instrument combination to understand the problems associated with small surface-to-probe area ratio and then correlate the instrument observations with model output. We show that on small sounding rocket payloads the DCP technique of relative electron density measurement is not accurate. The ion saturation region analysis of the SLP I-V curve produces absolute ion density that matches very well with the absolute electron density derived from the impedance probe. The derived temperatures agree reasonably well with the IRI model, but also show unusual structure at small scale. Our results suggest that even with a small surface-to-probe area ratio it is possible to derive absolute plasma density and temperature from a sweeping Langmuir probe.
DE: 2415 Equatorial ionosphere
DE: 2467 Plasma temperature and density
DE: 2494 Instruments and techniques
DE: 7853 Spacecraft/atmosphere interactions
DE: 7894 Instruments and techniques
SC: SPA-Aeronomy [SA]
MN: 2007 Fall Meeting