HR: 0800h
AN: SH51D-0300    [Abstracts]
TI: New constraints from the inner source pickup ions on the dust population near the sun
AU: * Allegrini, F
EM: fallegrini@swri.edu
AF: Southwest Research Institute, P.O.Drawer 28510, San Antonio, TX 78228-0510 United States
AU: Schwadron, N A
EM: nschwadron@swri.edu
AF: Southwest Research Institute, P.O.Drawer 28510, San Antonio, TX 78228-0510 United States
AU: McComas, D J
EM: dmccomas@swri.edu
AF: Southwest Research Institute, P.O.Drawer 28510, San Antonio, TX 78228-0510 United States
AU: Gloeckler, G
EM: gloeckler@umdsp.umd.edu
AF: Department of Physics, University of Maryland, College Park, MD 20742 United States
AB: There are two main sources of pickup ions (PUIs) in the heliosphere: the interstellar source and the inner source, which is produced due to solar wind interaction with heliospheric grains. The inner-source PUIs are found to dominate inside 1 AU, and have a peak source rate between 10 and 30 $R_s$. The inner-source PUIs are currently thought to be generated when solar wind passes through extremely small grains. The exiting solar wind particles, mainly neutrals at solar wind energies, are then ionized and picked up by the solar wind. The IDPs in this case must be small enough, a few tens of a nm at most, to act as thin foils by allowing the solar wind ions to pass through the grains without sputtering significant mass. The inner-source PUIs have been studied thus far mainly at solar minimum. We present a comparison between three selected periods at solar minimum and solar maximum. During these periods the inner source was remarkably stable. Moreover, we show that the inner source is consistent with randomly distributed sources. These new results add two constraints to the existing constraints from the inner source on the dust population near the sun. We drew a matrix considering these constraints and evaluating the mechanisms that have been proposed.
DE: 6015 Dust
DE: 6213 Dust
DE: 2129 Interplanetary dust
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting