Charge States of Solar Energetic Iron: Nonequilibrium Calculation with Shock-Induced Acceleration
- Creators
- Barghouty, A. F.
-
Mewaldt, R. A.
Abstract
Observed charge states of solar energetic ions by Solar, Anomalous, and Magnetospheric Particle Explorer and Advanced Composition Explorer from recent large solar events in 1992 and 1997 show an energy-dependent feature that apparently has not been seen in earlier events, e.g., in 1978–1979. The mean charge state of iron, and to a lesser extent other heavy ions, was observed to increase with energy from ∼0.5 to ∼50 MeV nucleon^(-1). We present a possible explanation for this new feature and discuss potential implications for models of particle acceleration. Our calculation suggests that this energy-dependent feature is a result of the charge-changing and energy-changing processes taking place concurrently and can be absent when the processes act over different timescales.
Additional Information
© 1999. The American Astronomical Society. Received 1999 April 30, accepted for publication 1999 June 7. Published 1999 June 28. This work is supported by NSF grant 9810653 and NASAJOVE NAG8-1208 (A. F. B.) and by NASA grants NAS5- 30704 and NAG5-6912 at Caltech. A. F. B. thanks M. Baring (Goddard Space Flight Center), G. Webb (University of Arizona), M. Popecki (University of New Hampshire), and A. Hindmarsh (Lawrence Livermore National Laboratory) for stimulating discussionsAttached Files
Published - 1999-03.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:a74345e6d4d86ad55557ae6578f81794
|
114.0 kB | Preview Download |
Additional details
- Eprint ID
- 54671
- Resolver ID
- CaltechAUTHORS:20150210-163921606
- NASA
- NAG5-6912
- NASA
- NAS5-30704
- Created
-
2015-02-20Created from EPrint's datestamp field
- Updated
-
2022-11-29Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory
- Other Numbering System Name
- Space Radiation Laboratory
- Other Numbering System Identifier
- 1999-03