A Caltech Library Service

Variable fractionation of solar energetic particles according to first ionization potential

Mewaldt, R. A. and Cohen, C. M. S. and Leske, R. A. and Christian, E. R. and Cummings, A. C. and Slocum, P. L. and Stone, E. C. and von Rosenvinge, T. T. and Wiedenbeck, M. E. (2000) Variable fractionation of solar energetic particles according to first ionization potential. In: Acceleration and Transport of Energetic Particles Observed in the Heliosphere. AIP Conference Proceedings. No.528. American Institute of Physics , Melville, N.Y., pp. 123-126. ISBN 1-56396-951-3.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The average composition of solar energetic particles (SEPs), like the solar corona, is known to be depleted in elements with first ionization potential (FIP) more than ~10 eV by a factor of approximately four. We examine evidence for event to event variations in the FIP-related fractionation of SEPs, following up a 1994 study by Garrard and Stone. In a survey of 46 SEP events from 1974 to 1999 the deduced FIP-fractionation varies by a factor of ~2 from event to event, with no apparent relation to charge-to-mass dependent fractionation patterns in these same events. These results are compared to similar variations observed in the solar wind.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Mewaldt, R. A.0000-0003-2178-9111
Cohen, C. M. S.0000-0002-0978-8127
Leske, R. A.0000-0002-0156-2414
Christian, E. R.0000-0003-2134-3937
Cummings, A. C.0000-0002-3840-7696
Stone, E. C.0000-0002-2010-5462
Wiedenbeck, M. E.0000-0002-2825-3128
Additional Information:© 2000 American Institute of Physics. Issue Date: 15 September 2000. This work was supported by NASA at the California Institute of Technology (under grant NAS5- 6912), the Jet Propulsion Laboratory, and Goddard Space Flight Center.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
Goddard Space Flight CenterUNSPECIFIED
Subject Keywords:solar cosmic ray particles, cosmic ray composition, element relative abundance, ionisation potential, electric charge, solar wind
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory2000-23
Series Name:AIP Conference Proceedings
Issue or Number:528
Classification Code:PACS: 96.40.De
Record Number:CaltechAUTHORS:20111209-071511880
Persistent URL:
Official Citation:Variable fractionation of solar energetic particles according to first ionization potential R. A. Mewaldt, C. M. S. Cohen, R. A. Leske, E. R. Christian, A. C. Cummings, P. L. Slocum, E. C. Stone, T. T. von Rosenvinge, and M. E. Wiedenbeck, AIP Conf. Proc. 528, 123 (2000), DOI:10.1063/1.1324294
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:28380
Deposited By: Ruth Sustaita
Deposited On:09 Dec 2011 16:08
Last Modified:09 Nov 2021 16:56

Repository Staff Only: item control page