Abundance enhancements of silicon to iron in solar energetic particles and their implications

Rocket-borne detectors have measured differential energy spectra of elements of low abundance between silicon and iron for energetic solar particles in the August 4, 1972 event. Abundance enhancements and energy dependences were determined for the 10-40 MeV/amu interval. Four types of abundance enhancements as a function of energy are identified. The features are discussed in terms of the atomic properties of these elements and the physical conditions in the accelerating region. (R.R.)