Observational Tests of Suprathermal Particle Acceleration (Dayeh/Hill  Hill/Desai) WORKING GROUP SUMMARY

SHINE Workshop 2009 Suprathermal Ions in the Solar Wind Questions What are the major source contributors of the suprathermal population? Not the bulk SW (Everyone agree?) How common are the v -5 spectra in the heliosphere? Jury still out but lots of new data. What acceleration mechanisms are responsible for the suprathermal tail distributions? Unknown but specific, testable, differences in theories are arising. Gloeckler

SHINE Workshop /23/2008NAS - SHINE-Suprathermal Spatial Variation of Suprathermal Ions Knee from locally produced pickup ions Tail from stochastic and/or shock acceleration Schwadron Hill et al. ApJ 2009 Must look at how the suprathermals vary with position….local pickup ions vs. larger scale tail ions. Variation with distance from Sun shows much more He + and He ++ than known models. Stochastic acceleration explains compositional variation. He + He ++ He + He ++ Lines = simulatins symbols = measurements

SHINE Workshop 2009 More observations becoming available Schwadron (see also McComas et al. 2009) Lepri New Horizons/SWAP Data New at SHINE Wind/STICS at 1 AU 1-9 AU~11 AU ~3 AU Hill 2009 Gloeckler New or newly analyzed data are now joining the observations of Gloeckler et al.

SHINE Workshop 2009 Fisk Physical Picture of Fisk v -5 Theory Last SHINE Fisk transport equation was criticized as not conserving particle number! This is not so and the misunderstanding was explained: equation applies only to the tail. A physical picture was described. It requires a pumping mechanism moving particles and energy between the core to the tail. High energy tail particles diffuse out of expansion/compression regions so less energy is returned to the core => tail is accelerated. These particles diffuse These particles do not diffuse

SHINE Workshop 2009 To be separable or not? Lee agrees that Fisk’s transport equation is just Parker’s in a different form. An experimentalist agrees also, adding it took him 5 days to show. Lee also questions whether the solution is separable in space and velocity as Fisk requires? This is a critical difference between the conventional and the Fisk theory. Is it physically justifiable? Lee solves it w/o separating and does not get a power-law form. Suprathermal ion composition at 1 AU changes with solar cycle (Dayeh et al., 2009) ===> Argues that remnants from solar and interplanetary events are likely to dominate the suprathermal ion population inside Earth orbit

SHINE Workshop 2009 Is the velocity dependence separable? Lee asks whether the solution is separable as Fisk requires? This is a critical difference between the conventional and the Fisk theory. Is it physically justifiable? Lee solves it w/o separating.  Lee agrees that Fisk’s transport equation is just Parker’s in a different form. An experimentalist agrees also, adding it took him 5 days to show.