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51.
M. I. Desai G. M. Mason R. E. Gold S. M. Krimigis C. M. S. Cohen R. A. Mewaldt J. E. Mazur J. R. Dwyer 《Space Science Reviews》2007,130(1-4):243-253
Using high-resolution mass spectrometers on board the Advanced Composition Explorer (ACE), we surveyed the event-averaged
∼0.1–60 MeV/nuc heavy ion elemental composition in 64 large solar energetic particle (LSEP) events of cycle 23. Our results
show the following: (1) The Fe/O ratio decreases with increasing energy up to ∼10 MeV/nuc in ∼92% of the events and up to
∼60 MeV/nuc in ∼64% of the events. (2) The rare isotope 3He is greatly enhanced over the corona or the solar wind values in 46% of the events. (3) The heavy ion abundances are not
systematically organized by the ion’s M/Q ratio when compared with the solar wind values. (4) Heavy ion abundances from C–Fe exhibit systematic M/Q-dependent enhancements that are remarkably similar to those seen in 3He-rich SEP events and CME-driven interplanetary (IP) shock events. Taken together, these results confirm the role of shocks
in energizing particles up to ∼60 MeV/nuc in the majority of large SEP events of cycle 23, but also show that the seed population
is not dominated by ions originating from the ambient corona or the thermal solar wind, as previously believed. Rather, it
appears that the source material for CME-associated large SEP events originates predominantly from a suprathermal population
with a heavy ion enrichment pattern that is organized according to the ion’s mass-per-charge ratio. These new results indicate
that current LSEP models must include the routine production of this dynamic suprathermal seed population as a critical pre-cursor
to the CME shock acceleration process. 相似文献
52.
G.M. Mason R. Von Steiger R.B. Decker M.I. Desai J.R. Dwyer L.A. Fisk G. Gloeckler J.T. Gosling M. Hilchenbach R. Kallenbach E. Keppler B. Klecker H. Kunow G. Mann I.G. Richardson T.R. Sanderson G.M. Simnett Y.-M. Wang R.F. Wimmer-Schweingruber M. Fränz J.E. Mazur 《Space Science Reviews》1999,89(1-2):327-367
This report emphasizes new observational aspects of CIR ions revealed by advanced instruments launched on the Ulysses, WIND,
SOHO, and ACE spacecraft, and by the unique vantage point of Ulysses which carried out the first survey of Corotating Interaction
Region (CIR) properties over a very wide range of heliolatitudes. With this more complete observational picture established,
this review is the basis to consider the status of theoretical models on origin, injection, and acceleration of CIR particles
reported by Scholer, Mann et al. (1999) in this volume.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献