Jr.: Electron and Proton Absorption Calculations for a Graphite/Epoxy Composite Model

SUMMARY The Bethe-Bloch stopping power relations for inelastic collisions have been used to determine the absorption of electron and proton energy for models of graphite, epoxy, and graphite/epoxy composites. Electron energies from 0.2 to 4.0 MeV and proton energies from 0.3 to 1.75 MeV, the energies that exist in geosynchronous Earth orbit (GEO), were used. Absorption profiles due to inelastic collisions for monoenergetic electrons were determined for cured neat epoxy resin, pure graphite, and graphite/epoxy composites. Electron energy losses due to bremsstrahlung were determined from these values. The absorption profiles due to inelastic collisions for monoenergetic protons were determined only for the cured epoxy resin. Finally, the dose-depth profiles in a cured epoxy resin were determined for an environment of distributed electron and pro-ton energies that closely approximated the energy distribution in GEO. The absorption profiles for monoenergetic particles showed that the protons did not penetrate deeper than 0.005 cm. They were absorbed at the surface o