The differential energy spectra of solar-flare H-1, He-3, and He-4.

Solar-flare-accelerated H-1, H-2, He-3, and He-4 isotopes are considered, and the importance of nuclear interactions during solar-flare particle acceleration is discussed. The relative abundances ratios of He-3/He-4 are determined and found to be so large as to impose limits on the production of He-3 by nuclear interactions during acceleration processes.