Ionic Charge States of Low Energy Ions in Solar Energetic Particle Events: an Overview

HR: 16:45h
AN: SH54B-03 INVITED [Abstracts]
TI: Ionic Charge States of Low Energy Ions in Solar Energetic Particle Events: an Overview
AU: * Klecker, B
EM: berndt.klecker@mpe.mpg.de
AF: Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Garching, 85748, Germany
AU: Möbius, E
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Popecki, M A
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Kistler, L M
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Hilchenbach, M
AF: Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Str. 2, Katlenburg-Lindau, 37191, Germany
AB: Measurements with advanced instrumentation on the SAMPEX, SOHO and ACE spacecraft over an extended energy range show a large variability of the energy dependence of the ionic charge of heavy ions, in particular for Fe. In this review we present an overview of ionic charge observations obtained in the energy range ~0.01- 0.50 MeV/nuc with instruments onboard the SAMPEX, SOHO, and ACE spacecraft during the time period 1992 - 2000. We compare ionic charge states as obtained in interplanetary shock related events with solar wind charge states and with charge states in 3He- and Fe-rich events. Most of the interplanetary shock related events show for iron in the energy range 0.01 - 0.25 MeV/nuc mean ionic charge states Q_Fe ~ 9 -- 11, similar to solar wind charge states, with a significant increase of Q_Fe with energy by 1-2 charge units between 0.01 and 0.5 MeV/nuc only in a few cases. In ³He-rich and Fe-rich events, on the other hand, all events show a significant increase of the mean ionic charge in this energy range, for Fe by up to 6 charge units. The implications of the energy dependence of the ionic charge states for possible sources contributing to the accelerated population, e.g. solar wind, suprathermal particles, and contributions from Fe-rich impulsive events, will be discussed.
DE: 2114 Energetic particles (7514)
DE: 7514 Energetic particles (2114)
DE: 7807 Charged particle motion and acceleration
DE: 7823 Ionization processes (2423)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting