HR: 11:20h
AN: SM42A-05    [Abstracts]
TI: Improved Model for Analysis of Thermal Charged-Particle Spectrograph Data for Ionospheric Research
AU: * Burchill, J K
EM: Johnathan.Burchill@nrcan.gc.ca
AF: Department of Physics University of Calgary, 2500 University Drive, N.W., Calgary, AB T2N1N4, Canada
AU: Sangalli, L
AF: Department of Physics University of Calgary, 2500 University Drive, N.W., Calgary, AB T2N1N4, Canada
AU: Knudsen, D J
AF: Department of Physics University of Calgary, 2500 University Drive, N.W., Calgary, AB T2N1N4, Canada
AB: As a source of mass for the magnetosphere, and a sink of electromagnetic energy via Joule heating, the cold, dense plasma of the ionosphere plays key roles in magnetosphere-ionosphere-thermosphere coupling. It also hosts a variety of interesting wave-particle processes that give rise to structure and acceleration. Obtaining accurate measurements of the thermal electron and ion velocity distribution functions at ionospheric altitudes has proven to be challenging, largely because the particle trajectories are disrupted by stray electric fields within and surrounding the particle analyzers. The Whalen analyzer is a compact two-dimensional energy-angle analyzer tailored towards the low-energy (<1 eV) core of ionospheric plasmas. It has flight heritage with the Freja satellite and several sounding rockets, and it will be used on several upcoming satellite missions. In this paper we present an improved model of the Whalen analyzer that takes into account abberations arising from fringing electric fields and Debye sheaths within the analyzer. We use this model to refine ion velocity and temperature estimates from the Cusp-2002 and Joule I and II rockets. We discuss implications for interpreting low-energy particle measurements from the forthcoming Canadian ePOP satellite and the ESA Swarm mission.
DE: 2407 Auroral ionosphere (2704)
DE: 2463 Plasma convection (2760)
DE: 2467 Plasma temperature and density
DE: 2494 Instruments and techniques
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting