1. Plasma Heating and Particle Acceleration by Turbulence in Solar Flares Siming Liu Stanford University In collaboration with Vahé Petrosian, Yanwei Jiang, and Wei Liu Huai Rou Observatory July 9 2005

2. Outline Previous Observational Evidence Two New Aspects 3 He and heavy ion enrichment Roles of turbulence in the gradual phase Cascade and Damping of MHD Turbulence Conclusion

3. 1: Spectral Breaks (Losses vs. Acceleration) 2: LT and FP HXRs (Heating vs. Acceleration) Observational Evidence 3: Proton vs. Electron (Injections at Low Energies) 4: 3 He Enrichment (Run away Acceleration)

4. Two New Aspects The Roles of Turbulence in the Decay Phase 3 He and Heavy Ion Enrichment

5. 3 He and Heavy Ion Enrichment: Acceleration by Parallel Propagating Waves

6. 3 He and Heavy Ion Enrichment Mason et al. 2004; Reames and Ng 2004

7. n=0, v>v A >c s : Transit-time Damping Resonance Condition n>0: Cyclotron Resonances Acceleration by parallel propagating waves: n=1

8. Acceleration of 3 He and 4 He by Parallel Propagating Waves

9. Transit-Time Damping? Acceleration of 3 He and 4 He by Parallel Propagating Waves

10. Acceleration of 3 He and 4 He by Parallel Propagating Waves

11. Ion Acceleration by Parallel Propagating Waves 1.0 0.5 0.45 0.67 Q/M Q 2 /M=1

12. Heavy ion enrichment

13. The Roles of Turbulence in the Decay Phase Heating & Suppression of Conduction

14. Suppression of Conduction

15. Suppression of Conduction by Turbulence

16. Equation of Energy Conservation The turbulence can also energize the particles with the acceleration time τ ac ≈ τ sc (v/v A ) 2

17. Simple Modeling

18. Measuring the Magnetic Field? τ ac ≈ τ sc (v/v A ) 2 ; v>v A B

19. Cascade and Damping of MHD Waves Cho & Lazarian 2002 Alfv é n ~k -5/3 Slow ~k -5/3 Fast ~k -3/2 anisotropic (GS) isotropic Damping

20. Cascade vs. Damping of Turbulence Parallel (and perpendicular) waves are not damped

21. Conclusion Plasma Wave Turbulence appears to be an important channel for the release of energy during flares & Stochastic Acceleration by it can explain many of the observed flare characteristics