1. Constraints on Particle Acceleration from Interplanetary Observations R. P. Lin together with L. Wang, S. Krucker at UC Berkeley, G Mason at U. Maryland, and R. Mewaldt at Caltech

2. Krucker and Lin 2002

3. Electron - 3 He-rich SEP events - ~1000s/year at solar maximum - dominated by: - electrons of ~0.1 (!) to ~100 keV energy - 3 He ~10s keV/nuc to ~MeV/nuc x10-x10 4 (!) enhancements - heavy nuclei: Fe, Mg, Si, S enhancements - high charge states - associated with: - small flares/coronal microflares - Type III radio bursts - Impulsive soft X-ray bursts (so also called Impulsive SEP events )

4. L=v(t-to) or L/v=t-to ~ 0.05 MeV/nuc - 1/v of 3 He (Mason & Mazur) ~1.5 MeV/nuc - 1/v for Electrons / Electrons 0.14–13 keV Electrons 20 – 350 keV Ions ~ 0.5 – 1 MeV

7. Electron spectrum at 1AU Typical electron spectrum can be fitted with broken power law: Break around: 30-100 keV Steeper at higher energies Oakley, Krucker, & Lin 2004

8. Comparing spectra PHOTON SPECTRA: Power law fit to HXR spectra averaged over peak ELECTRON SPECTRA: Power law fit to peak flux Assuming power spectra: THIN: d = g – 1 THICK: d = g + 1 RESULTS: 1)correlation seen 2)values are between

9. Wang, Krucker, Lin, & Gosling, 2005

10. Wang, Krucker, Lin, & Gosling 2005

13. The Sun is the most energetic particle accelerator in the solar system: - Ions up to ~ 10s of GeV - Electrons up to ~100s of MeV Acceleration to these energies occurs in transient energy releases, in two (!) processes: - Large Solar Flares, in the lower corona - Fast Coronal Mass Ejections (CMEs), in the inner heliosphere, ~2-40 solar radii

16. X-Class Flare of 2002 July 23 00:27:20–00:43:20 UT GOES X4.8 Location: S13E72 (Lin et al. 2003)

18. RHESSI Gamma-Ray Flares 2002 July 23X4.8 2003 June 17M6.9 2003 October 28X17 2003 October 29X10 2003 November 2 X8.3 2003 November 3 X3.9 2004 November 10 X2.5 2005 January 15X2.6 2005 January 17X3.8 2005 January 19X1.3 2005 January 20X7.1 Ramaty High Energy Solar Spectroscopic Imager (RHESSI)

19. Mewaldt et al 2005

20. (Mewaldt et al. 2005)

21. Oct. 28, 2003, RHESSI solar count spectrum from 11:06:20 – 11:10:04 (Smith et al. 2004, Share et al. 2004) e + - e - n-capture bremsstrahlung narrow lines broad lines

22. Murphy 2004

23. Energetic Proton Power-law Exponents 28 Oct 03 2 Nov 03 S16E08 S15W56 γ-ray lines Energy range γ-ray (SEP) γ-ray (SEP) Ne/C+O 2-20 MeV 2.0-3.2 (1.3) 1.6-3.2 (1.7) e+/C+O 10-50 MeV 2.2-3.3 (2.0) 2.3-3.3 (2.8) n-capt/C+O 10-100 MeV 2.8-3.8 (2.5) 2.8-3.8 (3.0)

25. GOES soft X-rays RHESSI 2.2 MeV line RHESSI 100-200 keV RHESSI hard X-rays WIND/WAVES radio WIND/3DP electrons

26. 20 Jan 05 Flare RHESSI Gamma-ray Spectrum - 20 Jan 05 Flare

28. In the Jan 20 Event the high energy particle-intensities reach Earth just minutes after the x-rays from the flare

29. RHESSI X-ray imaging during HXR peak: X-ray imaging Two ribbon flare with HXR footpoints (contours) with thermal loop (image)

30. Initial flare phase: GOES SXI & RHESSI enhanced SXR emission Dimming After 06:40, HXR footpoints dominate 6:40:30

31. Timing Red line (06:48UT): Solar release time derived from onsets at 1 AU assuming first arriving particles travel with the speed of light along L=1.2 AU LASCO (06:54UT): Around ~3 solar radii; lines show height assuming a constant velocity. For v=2500km/s, CME could be at ~1.5 solar radius at particle release time. Red crosses: Rising SXR loops (top of SXI emission) 2.2 MeV peaks at 06:47:30UT HXRs peak at 06:45:00UT