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Charge States of Energetic Particles From Corotating Interaction Regions As Constraints On Their Source

Mazur, J. E. and Mason, G. M. and Mewaldt, R. A. (2002) Charge States of Energetic Particles From Corotating Interaction Regions As Constraints On Their Source. Astrophysical Journal, 566 (1). pp. 555-561. ISSN 0004-637X. doi:10.1086/337989.

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Since the discovery of large (factor of greater than 1000) enhancements of singly ionized helium in corotating interaction regions (CIRs), it has become clear that low charge state ions from interstellar neutrals or other heliospheric sources can be preferentially injected into the energetic particle population. The large enhancements in suprathermal and energetic He suggest that low charge state ions may likewise affect the composition of CIR-related heavy ions such as C or Ne. Therefore, a key observational test of the contribution of pickup ions to the energetic particles associated with CIRs is their ionization state. We have used instrumentation on board the low Earth orbiting SAMPEX satellite, along with the geomagnetic cutoff technique, to investigate the ionization states of CIR heavy ions in the energy range 0.5-1.0 MeV nucleon^(-1). In a sum of 14 CIR events, we find heavy-ion charge states similar to those of solar energetic particles from interplanetary shocks, with upper limits to the contribution of singly ionized particles on the order of a few percent of the total flux. We find that stripping in the interplanetary medium of singly ionized heavy ions energized in the CIR could not account for the observed high charge states. Thus, the high charge state material we observed must have originated in the bulk solar wind or its suprathermal tail.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Mason, G. M.0000-0003-2169-9618
Mewaldt, R. A.0000-0003-2178-9111
Additional Information:© 2002 The American Astronomical Society. Received 2001 May 25; accepted 2001 October 10. We thank the many members of the SAMPEX LICA instrument team who have contributed to the success of the SAMPEX mission, as well as the personnel at the Goddard Space Flight Center who constructed, launched, and operate the SAMPEX spacecraft. We appreciate discussions on ionization cross sections with A. F. Barghouty. Contract Z667103 between the University of Maryland and The Aerospace Corporation supported part of this work.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Aerospace CorporationZ667103
Subject Keywords:acceleration of particles - interplanetary medium - solar wind - Sun: particle emission
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2001-33
Issue or Number:1
Record Number:CaltechAUTHORS:20150302-163929283
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Official Citation:Charge States of Energetic Particles from Corotating Interaction Regions as Constraints on Their Source J. E. Mazur et al. 2002 ApJ 566 555
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:55440
Deposited By: Deborah Miles
Deposited On:06 Mar 2015 16:15
Last Modified:10 Nov 2021 20:45

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