HR: 16:35h
AN: SH34A-02 INVITED     [Abstracts]
TI: On the Variability of Suprathermal He⁺: new Results From STEREO and SOHO
AU: * Klecker, B
EM: berndt.klecker@mpe.mpg.de
AF: Max-Planck Institut fuer extraterrestrische Physik, Postfach 1312, Garching, 85741, Germany
AU: Galvin, A B
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: Popecki, M A
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Mouikis, C
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Farrugia, C
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Moebius, E
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Lee, M
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Ellis, L
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Simunac, K
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Singer, K
AF: EOS Space Science Center, University of New Hampshire, Durham, NH 03824, United States
AU: Blush, L M
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Bochsler, P
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Wurz, P
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Daoudi, H
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Giammanco, C
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Karrer, R
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Opitz, A
AF: Physikalisches Institut, University of Bern, Bern, 3012, Switzerland
AU: Wimmer-Schweingruber, R F
AF: Institute for Experimental and Applied Physics, University of Kiel, Kiel, 24098, Germany
AU: Koeten, M
AF: Institute for Experimental and Applied Physics, University of Kiel, Kiel, 24098, Germany
AU: Hilchenbach, M
AF: Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Strasse 2, Katlenburg- Lindau, 37191, Germany
AU: Thompson, B
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Acuna, M
AF: NASA, Goddard Space Flight Center, Greenbelt, MD 20771, United States
AU: Luhmann, J
AF: Space Sciences Laboratory, University of California, Berkeley, CA 94720, United States
AB: The two Plasma and Suprathermal Ion Composition (PLASTIC) experiments onboard STEREO-A and STEREO-B and the CELIAS experiment onboard SOHO provide measurements of velocity, mass and ionic charge of solar wind ions and of suprathermal particles up to energies of 80 keV/e (PLASTIC) and 600 keV/e (CELIAS), respectively. The observations with SOHO showed a large variability of the He⁺/He²⁺ -ratio at suprathermal energies, with He⁺/He²⁺ > 1 in many interplanetary shock related solar energetic particle (SEP) events. This variability is much larger than the observed variations in the interstellar pickup He⁺ source and suggests that the different velocity distributions of the two sources, i.e. solar wind and pickup ions of interstellar origin, play an important role for the efficiency of injection and/or acceleration of these ions. Thus PLASTIC onboard STEREO, covering the energy range from solar wind to pickup ion and suprathermal energies, has the potential for resolving some of the questions related to the large variability of the He⁺/He²⁺-ratios. In this paper we will review the SOHO measurements of pickup and suprathermal He⁺ ions at 1 AU, show first results from PLASTIC onboard STEREO and discuss the perspective to tackle some of the open questions.
DE: 2114 Energetic particles (7514)
DE: 2152 Pickup ions
DE: 7514 Energetic particles (2114)
DE: 7845 Particle acceleration
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Joint Assembly