HR: 0830h
AN: SP21A-08 [Abstracts]
TI: Stochastic Ion Acceleration in 3He-Rich Solar Energetic Particle Events
AU: * Liu, S
EM: liusm@stanford.edu
AF: Stanford University, Department of Physics, Stanford, CA 94305
AU: Petrosian, V
EM: vahe@astronomy.stanford.edu
AF: Stanford University, Department of Physics, Stanford, CA 94305
AU: Mason, G M
EM: gmmason@umd.edu
AF: University of Maryland, Department of Physics and IPST, College Park, MD 20742
AB:
The enhancements of heavy ions in impulsive solar energetic particle (SEP) events have long been seen as evidence for
stochastic acceleration (SA) of particles by plasma wave turbulence. However, the lack of quantitative comparison of model
predictions with observations prevents a solid conclusion about the underlying physical processes. By using the exact
dispersion relation and taking into account the effects of background α-particles, we show that SA by parallel
propagating waves can address the long standing challenge to SA models, namely the prominent enhancement and distinct
spectrum of 3He ions in some impulsive solar flares. Encouraged by this and in light of recent detections of ultra-heavy
ions in SEPs by ACE and WIND, we investigate the SA of all ions by parallel propagating waves. The observed ion
spectra and enhancements are used to constrain the turbulence spectrum and energy partition among different wave branches.
Based on this scenario, we explore the model parameter space to explain the recently discovered correlation between ion
enhancements and the iron spectral index and the correlated enhancements of heavy ions. The limitations of the model are
described and possible solutions to these difficulties are discussed.
The work at Stanford is supported by NSF grant ATM-0312344, NASA grants NAG5-12111, NAG5 11918-1, and NASA grant PC 251429
through University of Maryland (PI: G. M. Mason).
UR: http://www.stanford.edu/~liusm/post.html
DE: 2118 Energetic particles, solar
DE: 2159 Plasma waves and turbulence
DE: 2451 Particle acceleration
DE: 2483 Wave/particle interactions
DE: 7519 Flares
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly