2. Confirmation of extended annihilation-line emission in 2005 January 20 flare: Earth occultation. DayNight

5. Evidence for hard particle spectrum in the 01/20/05 flare Hard (pion?) Component Spectrum dominated by bremsstrahlung (dots), 511 keV and n-capture (2223 keV lines and hard component. Narrow lines (solid) not clearly detected also suggesting hard spectrum.

7. Calculated gamma-ray spectra vs flare-accelerated particle power- law index. Nuclear continuum masks narrow lines for hard spectra.

8. Spectrum after hard component subtracted

9. Extended 511 keV flux comes from high-energy solar photons interacting in the spacecraft. Are these from solar pion radiation? High-energy appears to contain particles >07:15 and possibly neutrons >06:55.

10. Counts >20 MeV shows early peak coincident with sharp peak at 511 keV (likely to be high-energy solar photons causing instrumental line). Later peaks suggest neutron detection and strong particle emission (lat > 30 o ). Abrupt drop in rate at Earth occultation consistent with high-energy solar photons.

12. 511 keV line is broad early in flare and is dominated by the delayed beta- decay produced solar annihilation line. Late in the flare line is narrower, consistent with instrumental origin associated with high-energy solar photon impact on the spacecraft.

15. Spectra from three RHESSI flares revealing differing amounts of pion radiation inferred from 9-16 MeV emission. Coronas confirms pion emission in the October 28 and January 20 flares. No evidence for pion emission in November 2 flare 1/20/2005 10/28/2003 11/02/2003